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Diffstat (limited to 'src/3rdparty/libpng')
41 files changed, 54903 insertions, 0 deletions
diff --git a/src/3rdparty/libpng/ANNOUNCE b/src/3rdparty/libpng/ANNOUNCE new file mode 100644 index 0000000000..4a3b01888c --- /dev/null +++ b/src/3rdparty/libpng/ANNOUNCE @@ -0,0 +1,96 @@ + +Libpng 1.5.1 - February 3, 2011 + +This is a public release of libpng, intended for use in production codes. + +Files available for download: + +Source files with LF line endings (for Unix/Linux) and with a +"configure" script + + libpng-1.5.1.tar.xz (LZMA-compressed, recommended) + libpng-1.5.1.tar.gz + libpng-1.5.1.tar.bz2 + +Source files with CRLF line endings (for Windows), without the +"configure" script + + lpng151.7z (LZMA-compressed, recommended) + lpng151.zip + +Other information: + + libpng-1.5.1-README.txt + libpng-1.5.1-LICENSE.txt + +Changes since the last public release (1.5.0): + + Added description of png_set_crc_action() to the manual. + Added a note in the manual that the type of the iCCP profile was changed + from png_charpp to png_bytepp in png_get_iCCP(). Similarly, + it was changed from png_charpp to png_const_bytepp in png_set_iCCP(). + Ensure that png_rgb_to_gray ignores palette mapped images, if libpng + internally happens to call it with one. + Fixed the failure to handle palette mapped images correctly. + Fixed a bug in handling of interlaced images (bero at arklinux.org). + Updated CMakeLists.txt (Clifford Yapp) + Fixed typecasting of some png_debug() statements (Cosmin) + Updated documentation of png_set|get_tRNS() (Thomas Klausner). + Mentioned in the documentation that applications must #include "zlib.h" + if they need access to anything in zlib.h, and that a number of + macros such as png_memset() are no longer accessible by applications. + Corrected pngvalid gamma test "sample" function to access all of the color + samples of each pixel, instead of sampling the red channel three times. + Changed variable names index, div, exp, and gamma to char_index, divisor, + exp_b10, and gamma_val, respectively, to avoid "shadow" warnings. + Prevent png_push_crc_skip() from hanging while reading an unknown chunk + or an over-large compressed zTXt chunk with the progressive reader. + Eliminated more GCC "shadow" warnings. + Revised png_fixed() in png.c to avoid compiler warning about reaching the + end without returning anything. + In the manual, describe the png_get_IHDR() arguments in the correct order. + Added const_png_structp and const_png_infop types, and used them in + prototypes for most png_get_*() functions. + Added png_get_io_chunk_type() and deprecated png_get_io_chunk_name() + Added synopses for the IO_STATE functions and other missing synopses + to the manual. Removed the synopses from libpngpf.3 because they + were out of date and no longer useful. Better information can be + obtained by reading the prototypes and comments in pngpriv.h + Attempted to fix cpp on Solaris with S. Studio 12 cc, fix build + Added a make macro DFNCPP that is a CPP that will accept the tokens in + a .dfn file and adds configure stuff to test for such a CPP. ./configure + should fail if one is not available. + Corrected const_png_ in png.h to png_const_ to avoid polluting the namespace. + Added png_get_current_row_number and png_get_current_pass_number for the + benefit of the user transform callback. + Added png_process_data_pause and png_process_data_skip for the benefit of + progressive readers that need to stop data processing or want to optimize + skipping of unread data (e.g. if the reader marks a chunk to be skipped.) + Enhanced pngvalid, corrected an error in gray_to_rgb, corrected doc error. + pngvalid contains tests of transforms, which tests are currently disabled + because they are incompletely tested. gray_to_rgb was failing to expand + the bit depth for smaller bit depth images; this seems to be a long + standing error and resulted, apparently, in invalid output. The + documentation did not accurately describe what libpng really does when + converting RGB to gray. + Fixed incorrect examples of callback prototypes in the manual, that were + introduced in libpng-1.0.0. + In addition the order of the png_get_uint macros with respect to the + relevant function definitions has been reversed. This helps the + preprocessing of the symbol files be more robust. Furthermore, the + symbol file preprocessing now uses -DPNG_NO_USE_READ_MACROS even when + the library may actually be built with PNG_USE_READ_MACROS; this stops + the read macros interfering with the symbol file format. + Made the manual, synopses, and function prototypes use the function + argument names file_gamma, int_file_gamma, and srgb_intent consistently. + Changed PNG_UNUSED from "param=param;" to "(void)param;". + Added transform tests to pngvalid and simplified the arguments. + Added a request in the manual that applications do not use "png_" or + "PNG_" to begin any of their own symbols. + +Send comments/corrections/commendations to png-mng-implement at lists.sf.net +(subscription required; visit +https://lists.sourceforge.net/lists/listinfo/png-mng-implement +to subscribe) or to glennrp at users.sourceforge.net + +Glenn R-P diff --git a/src/3rdparty/libpng/CHANGES b/src/3rdparty/libpng/CHANGES new file mode 100644 index 0000000000..fa5f2aae79 --- /dev/null +++ b/src/3rdparty/libpng/CHANGES @@ -0,0 +1,3253 @@ +#if 0 +libpng_changes(){ /* +CHANGES - changes for libpng + +Version 0.2 + added reader into png.h + fixed small problems in stub file + +Version 0.3 + added pull reader + split up pngwrite.c to several files + added pnglib.txt + added example.c + cleaned up writer, adding a few new transformations + fixed some bugs in writer + interfaced with zlib 0.5 + added K&R support + added check for 64 KB blocks for 16 bit machines + +Version 0.4 + cleaned up code and commented code + simplified time handling into png_time + created png_color_16 and png_color_8 to handle color needs + cleaned up color type defines + fixed various bugs + made various names more consistent + interfaced with zlib 0.71 + cleaned up zTXt reader and writer (using zlib's Reset functions) + split transformations into pngrtran.c and pngwtran.c + +Version 0.5 + interfaced with zlib 0.8 + fixed many reading and writing bugs + saved using 3 spaces instead of tabs + +Version 0.6 + added png_large_malloc() and png_large_free() + added png_size_t + cleaned up some compiler warnings + added png_start_read_image() + +Version 0.7 + cleaned up lots of bugs + finished dithering and other stuff + added test program + changed name from pnglib to libpng + +Version 0.71 [June, 1995] + changed pngtest.png for zlib 0.93 + fixed error in libpng.txt and example.c + +Version 0.8 + cleaned up some bugs + added png_set_filler() + split up pngstub.c into pngmem.c, pngio.c, and pngerror.c + added #define's to remove unwanted code + moved png_info_init() to png.c + added old_size into png_realloc() + added functions to manually set filtering and compression info + changed compression parameters based on image type + optimized filter selection code + added version info + changed external functions passing floats to doubles (k&r problems?) + put all the configurable stuff in pngconf.h + enabled png_set_shift to work with paletted images on read + added png_read_update_info() - updates info structure with transformations + +Version 0.81 [August, 1995] + incorporated Tim Wegner's medium model code (thanks, Tim) + +Version 0.82 [September, 1995] + [unspecified changes] + +Version 0.85 [December, 1995] + added more medium model code (almost everything's a far) + added i/o, error, and memory callback functions + fixed some bugs (16 bit, 4 bit interlaced, etc.) + added first run progressive reader (barely tested) + +Version 0.86 [January, 1996] + fixed bugs + improved documentation + +Version 0.87 [January, 1996] + fixed medium model bugs + fixed other bugs introduced in 0.85 and 0.86 + added some minor documentation + +Version 0.88 [January, 1996] + fixed progressive bugs + replaced tabs with spaces + cleaned up documentation + added callbacks for read/write and warning/error functions + +Version 0.89 [July, 1996] + Added new initialization API to make libpng work better with shared libs + we now have png_create_read_struct(), png_create_write_struct(), + png_create_info_struct(), png_destroy_read_struct(), and + png_destroy_write_struct() instead of the separate calls to + malloc and png_read_init(), png_info_init(), and png_write_init() + Changed warning/error callback functions to fix bug - this means you + should use the new initialization API if you were using the old + png_set_message_fn() calls, and that the old API no longer exists + so that people are aware that they need to change their code + Changed filter selection API to allow selection of multiple filters + since it didn't work in previous versions of libpng anyways + Optimized filter selection code + Fixed png_set_background() to allow using an arbitrary RGB color for + paletted images + Fixed gamma and background correction for paletted images, so + png_correct_palette is not needed unless you are correcting an + external palette (you will need to #define PNG_CORRECT_PALETTE_SUPPORTED + in pngconf.h) - if nobody uses this, it may disappear in the future. + Fixed bug with Borland 64K memory allocation (Alexander Lehmann) + Fixed bug in interlace handling (Smarasderagd, I think) + Added more error checking for writing and image to reduce invalid files + Separated read and write functions so that they won't both be linked + into a binary when only reading or writing functionality is used + New pngtest image also has interlacing and zTXt + Updated documentation to reflect new API + +Version 0.90 [January, 1997] + Made CRC errors/warnings on critical and ancillary chunks configurable + libpng will use the zlib CRC routines by (compile-time) default + Changed DOS small/medium model memory support - needs zlib 1.04 (Tim Wegner) + Added external C++ wrapper statements to png.h (Gilles Dauphin) + Allow PNG file to be read when some or all of file signature has already + been read from the beginning of the stream. ****This affects the size + of info_struct and invalidates all programs that use a shared libpng**** + Fixed png_filler() declarations + Fixed? background color conversions + Fixed order of error function pointers to match documentation + Current chunk name is now available in png_struct to reduce the number + of nearly identical error messages (will simplify multi-lingual + support when available) + Try to get ready for unknown-chunk callback functions: + - previously read critical chunks are flagged, so the chunk handling + routines can determine if the chunk is in the right place + - all chunk handling routines have the same prototypes, so we will + be able to handle all chunks via a callback mechanism + Try to fix Linux "setjmp" buffer size problems + Removed png_large_malloc, png_large_free, and png_realloc functions. + +Version 0.95 [March, 1997] + Fixed bug in pngwutil.c allocating "up_row" twice and "avg_row" never + Fixed bug in PNG file signature compares when start != 0 + Changed parameter type of png_set_filler(...filler...) from png_byte + to png_uint_32 + Added test for MACOS to ensure that both math.h and fp.h are not #included + Added macros for libpng to be compiled as a Windows DLL (Andreas Kupries) + Added "packswap" transformation, which changes the endianness of + packed-pixel bytes (Kevin Bracey) + Added "strip_alpha" transformation, which removes the alpha channel of + input images without using it (not necessarily a good idea) + Added "swap_alpha" transformation, which puts the alpha channel in front + of the color bytes instead of after + Removed all implicit variable tests which assume NULL == 0 (I think) + Changed several variables to "png_size_t" to show 16/32-bit limitations + Added new pCAL chunk read/write support + Added experimental filter selection weighting (Greg Roelofs) + Removed old png_set_rgbx() and png_set_xrgb() functions that have been + obsolete for about 2 years now (use png_set_filler() instead) + Added macros to read 16- and 32-bit ints directly from buffer, to be + used only on those systems that support it (namely PowerPC and 680x0) + With some testing, this may become the default for MACOS/PPC systems. + Only calculate CRC on data if we are going to use it + Added macros for zTXt compression type PNG_zTXt_COMPRESSION_??? + Added macros for simple libpng debugging output selectable at compile time + Removed PNG_READ_END_MODE in progressive reader (Smarasderagd) + More description of info_struct in libpng.txt and png.h + More instructions in example.c + More chunk types tested in pngtest.c + Renamed pngrcb.c to pngset.c, and all png_read_<chunk> functions to be + png_set_<chunk>. We now have corresponding png_get_<chunk> + functions in pngget.c to get information in info_ptr. This isolates + the application from the internal organization of png_info_struct + (good for shared library implementations). + +Version 0.96 [May, 1997] + Fixed serious bug with < 8bpp images introduced in 0.95 + Fixed 256-color transparency bug (Greg Roelofs) + Fixed up documentation (Greg Roelofs, Laszlo Nyul) + Fixed "error" in pngconf.h for Linux setjmp() behaviour + Fixed DOS medium model support (Tim Wegner) + Fixed png_check_keyword() for case with error in static string text + Added read of CRC after IEND chunk for embedded PNGs (Laszlo Nyul) + Added typecasts to quiet compiler errors + Added more debugging info + +Version 0.97 [January, 1998] + Removed PNG_USE_OWN_CRC capability + Relocated png_set_crc_action from pngrutil.c to pngrtran.c + Fixed typecasts of "new_key", etc. (Andreas Dilger) + Added RFC 1152 [sic] date support + Fixed bug in gamma handling of 4-bit grayscale + Added 2-bit grayscale gamma handling (Glenn R-P) + Added more typecasts. 65536L becomes (png_uint_32)65536L, etc. (Glenn R-P) + Minor corrections in libpng.txt + Added simple sRGB support (Glenn R-P) + Easier conditional compiling, e.g. define PNG_READ/WRITE_NOT_FULLY_SUPPORTED; + all configurable options can be selected from command-line instead + of having to edit pngconf.h (Glenn R-P) + Fixed memory leak in pngwrite.c (free info_ptr->text) (Glenn R-P) + Added more conditions for png_do_background, to avoid changing + black pixels to background when a background is supplied and + no pixels are transparent + Repaired PNG_NO_STDIO behaviour + Tested NODIV support and made it default behaviour (Greg Roelofs) + Added "-m" option and PNGTEST_DEBUG_MEMORY to pngtest (John Bowler) + Regularized version numbering scheme and bumped shared-library major + version number to 2 to avoid problems with libpng 0.89 apps (Greg Roelofs) + +Version 0.98 [January, 1998] + Cleaned up some typos in libpng.txt and in code documentation + Fixed memory leaks in pCAL chunk processing (Glenn R-P and John Bowler) + Cosmetic change "display_gamma" to "screen_gamma" in pngrtran.c + Changed recommendation about file_gamma for PC images to .51 from .45, + in example.c and libpng.txt, added comments to distinguish between + screen_gamma, viewing_gamma, and display_gamma. + Changed all references to RFC1152 to read RFC1123 and changed the + PNG_TIME_RFC1152_SUPPORTED macro to PNG_TIME_RFC1123_SUPPORTED + Added png_invert_alpha capability (Glenn R-P -- suggestion by Jon Vincent) + Changed srgb_intent from png_byte to int to avoid compiler bugs + +Version 0.99 [January 30, 1998] + Free info_ptr->text instead of end_info_ptr->text in pngread.c (John Bowler) + Fixed a longstanding "packswap" bug in pngtrans.c + Fixed some inconsistencies in pngconf.h that prevented compiling with + PNG_READ_GAMMA_SUPPORTED and PNG_READ_hIST_SUPPORTED undefined + Fixed some typos and made other minor rearrangement of libpng.txt (Andreas) + Changed recommendation about file_gamma for PC images to .50 from .51 in + example.c and libpng.txt, and changed file_gamma for sRGB images to .45 + Added a number of functions to access information from the png structure + png_get_image_height(), etc. (Glenn R-P, suggestion by Brad Pettit) + Added TARGET_MACOS similar to zlib-1.0.8 + Define PNG_ALWAYS_EXTERN when __MWERKS__ && WIN32 are defined + Added type casting to all png_malloc() function calls + +Version 0.99a [January 31, 1998] + Added type casts and parentheses to all returns that return a value.(Tim W.) + +Version 0.99b [February 4, 1998] + Added type cast png_uint_32 on malloc function calls where needed. + Changed type of num_hist from png_uint_32 to int (same as num_palette). + Added checks for rowbytes overflow, in case png_size_t is less than 32 bits. + Renamed makefile.elf to makefile.lnx. + +Version 0.99c [February 7, 1998] + More type casting. Removed erroneous overflow test in pngmem.c. + Added png_buffered_memcpy() and png_buffered_memset(), apply them to rowbytes. + Added UNIX manual pages libpng.3 (incorporating libpng.txt) and png.5. + +Version 0.99d [February 11, 1998] + Renamed "far_to_near()" "png_far_to_near()" + Revised libpng.3 + Version 99c "buffered" operations didn't work as intended. Replaced them + with png_memcpy_check() and png_memset_check(). + Added many "if (png_ptr == NULL) return" to quell compiler warnings about + unused png_ptr, mostly in pngget.c and pngset.c. + Check for overlength tRNS chunk present when indexed-color PLTE is read. + Cleaned up spelling errors in libpng.3/libpng.txt + Corrected a problem with png_get_tRNS() which returned undefined trans array + +Version 0.99e [February 28, 1998] + Corrected png_get_tRNS() again. + Add parentheses for easier reading of pngget.c, fixed "||" should be "&&". + Touched up example.c to make more of it compileable, although the entire + file still can't be compiled (Willem van Schaik) + Fixed a bug in png_do_shift() (Bryan Tsai) + Added a space in png.h prototype for png_write_chunk_start() + Replaced pngtest.png with one created with zlib 1.1.1 + Changed pngtest to report PASS even when file size is different (Jean-loup G.) + Corrected some logic errors in png_do_invert_alpha() (Chris Patterson) + +Version 0.99f [March 5, 1998] + Corrected a bug in pngpread() introduced in version 99c (Kevin Bracey) + Moved makefiles into a "scripts" directory, and added INSTALL instruction file + Added makefile.os2 and pngos2.def (A. Zabolotny) and makefile.s2x (W. Sebok) + Added pointers to "note on libpng versions" in makefile.lnx and README + Added row callback feature when reading and writing nonprogressive rows + and added a test of this feature in pngtest.c + Added user transform callbacks, with test of the feature in pngtest.c + +Version 0.99g [March 6, 1998, morning] + Minor changes to pngtest.c to suppress compiler warnings. + Removed "beta" language from documentation. + +Version 0.99h [March 6, 1998, evening] + Minor changes to previous minor changes to pngtest.c + Changed PNG_READ_NOT_FULLY_SUPPORTED to PNG_READ_TRANSFORMS_NOT_SUPPORTED + and added PNG_PROGRESSIVE_READ_NOT_SUPPORTED macro + Added user transform capability + +Version 1.00 [March 7, 1998] + Changed several typedefs in pngrutil.c + Added makefile.wat (Pawel Mrochen), updated makefile.tc3 (Willem van Schaik) + Replaced "while(1)" with "for(;;)" + Added PNGARG() to prototypes in pngtest.c and removed some prototypes + Updated some of the makefiles (Tom Lane) + Changed some typedefs (s_start, etc.) in pngrutil.c + Fixed dimensions of "short_months" array in pngwrite.c + Replaced ansi2knr.c with the one from jpeg-v6 + +Version 1.0.0 [March 8, 1998] + Changed name from 1.00 to 1.0.0 (Adam Costello) + Added smakefile.ppc (with SCOPTIONS.ppc) for Amiga PPC (Andreas Kleinert) + +Version 1.0.0a [March 9, 1998] + Fixed three bugs in pngrtran.c to make gamma+background handling consistent + (Greg Roelofs) + Changed format of the PNG_LIBPNG_VER integer to xyyzz instead of xyz + for major, minor, and bugfix releases. This is 10001. (Adam Costello, + Tom Lane) + Make months range from 1-12 in png_convert_to_rfc1123 + +Version 1.0.0b [March 13, 1998] + Quieted compiler complaints about two empty "for" loops in pngrutil.c + Minor changes to makefile.s2x + Removed #ifdef/#endif around a png_free() in pngread.c + +Version 1.0.1 [March 14, 1998] + Changed makefile.s2x to reduce security risk of using a relative pathname + Fixed some typos in the documentation (Greg). + Fixed a problem with value of "channels" returned by png_read_update_info() + +Version 1.0.1a [April 21, 1998] + Optimized Paeth calculations by replacing abs() function calls with intrinsics + plus other loop optimizations. Improves avg decoding speed by about 20%. + Commented out i386istic "align" compiler flags in makefile.lnx. + Reduced the default warning level in some makefiles, to make them consistent. + Removed references to IJG and JPEG in the ansi2knr.c copyright statement. + Fixed a bug in png_do_strip_filler with XXRRGGBB => RRGGBB transformation. + Added grayscale and 16-bit capability to png_do_read_filler(). + Fixed a bug in pngset.c, introduced in version 0.99c, that sets rowbytes + too large when writing an image with bit_depth < 8 (Bob Dellaca). + Corrected some bugs in the experimental weighted filtering heuristics. + Moved a misplaced pngrutil code block that truncates tRNS if it has more + than num_palette entries -- test was done before num_palette was defined. + Fixed a png_convert_to_rfc1123() bug that converts day 31 to 0 (Steve Eddins). + Changed compiler flags in makefile.wat for better optimization + (Pawel Mrochen). + +Version 1.0.1b [May 2, 1998] + Relocated png_do_gray_to_rgb() within png_do_read_transformations() (Greg). + Relocated the png_composite macros from pngrtran.c to png.h (Greg). + Added makefile.sco (contributed by Mike Hopkirk). + Fixed two bugs (missing definitions of "istop") introduced in libpng-1.0.1a. + Fixed a bug in pngrtran.c that would set channels=5 under some circumstances. + More work on the Paeth-filtering, achieving imperceptible speedup + (A Kleinert). + More work on loop optimization which may help when compiled with C++ + compilers. + Added warnings when people try to use transforms they've defined out. + Collapsed 4 "i" and "c" loops into single "i" loops in pngrtran and pngwtran. + Revised paragraph about png_set_expand() in libpng.txt and libpng.3 (Greg) + +Version 1.0.1c [May 11, 1998] + Fixed a bug in pngrtran.c (introduced in libpng-1.0.1a) where the masks for + filler bytes should have been 0xff instead of 0xf. + Added max_pixel_depth=32 in pngrutil.c when using FILLER with palette images. + Moved PNG_WRITE_WEIGHTED_FILTER_SUPPORTED and PNG_WRITE_FLUSH_SUPPORTED + out of the PNG_WRITE_TRANSFORMS_NOT_SUPPORTED block of pngconf.h + Added "PNG_NO_WRITE_TRANSFORMS" etc., as alternatives for *_NOT_SUPPORTED, + for consistency, in pngconf.h + Added individual "ifndef PNG_NO_[CAPABILITY]" in pngconf.h to make it easier + to remove unwanted capabilities via the compile line + Made some corrections to grammar (which, it's) in documentation (Greg). + Corrected example.c, use of row_pointers in png_write_image(). + +Version 1.0.1d [May 24, 1998] + Corrected several statements that used side effects illegally in pngrutil.c + and pngtrans.c, that were introduced in version 1.0.1b + Revised png_read_rows() to avoid repeated if-testing for NULL (A Kleinert) + More corrections to example.c, use of row_pointers in png_write_image() + and png_read_rows(). + Added pngdll.mak and pngdef.pas to scripts directory, contributed by + Bob Dellaca, to make a png32bd.dll with Borland C++ 4.5 + Fixed error in example.c with png_set_text: num_text is 3, not 2 (Guido V.) + Changed several loops from count-down to count-up, for consistency. + +Version 1.0.1e [June 6, 1998] + Revised libpng.txt and libpng.3 description of png_set_read|write_fn(), and + added warnings when people try to set png_read_fn and png_write_fn in + the same structure. + Added a test such that png_do_gamma will be done when num_trans==0 + for truecolor images that have defined a background. This corrects an + error that was introduced in libpng-0.90 that can cause gamma processing + to be skipped. + Added tests in png.h to include "trans" and "trans_values" in structures + when PNG_READ_BACKGROUND_SUPPORTED or PNG_READ_EXPAND_SUPPORTED is defined. + Add png_free(png_ptr->time_buffer) in png_destroy_read_struct() + Moved png_convert_to_rfc_1123() from pngwrite.c to png.c + Added capability for user-provided malloc_fn() and free_fn() functions, + and revised pngtest.c to demonstrate their use, replacing the + PNGTEST_DEBUG_MEM feature. + Added makefile.w32, for Microsoft C++ 4.0 and later (Tim Wegner). + +Version 1.0.2 [June 14, 1998] + Fixed two bugs in makefile.bor . + +Version 1.0.2a [December 30, 1998] + Replaced and extended code that was removed from png_set_filler() in 1.0.1a. + Fixed a bug in png_do_filler() that made it fail to write filler bytes in + the left-most pixel of each row (Kevin Bracey). + Changed "static pngcharp tIME_string" to "static char tIME_string[30]" + in pngtest.c (Duncan Simpson). + Fixed a bug in pngtest.c that caused pngtest to try to write a tIME chunk + even when no tIME chunk was present in the source file. + Fixed a problem in pngrutil.c: gray_to_rgb didn't always work with 16-bit. + Fixed a problem in png_read_push_finish_row(), which would not skip some + passes that it should skip, for images that are less than 3 pixels high. + Interchanged the order of calls to png_do_swap() and png_do_shift() + in pngwtran.c (John Cromer). + Added #ifdef PNG_DEBUG/#endif surrounding use of PNG_DEBUG in png.h . + Changed "bad adaptive filter type" from error to warning in pngrutil.c . + Fixed a documentation error about default filtering with 8-bit indexed-color. + Separated the PNG_NO_STDIO macro into PNG_NO_STDIO and PNG_NO_CONSOLE_IO + (L. Peter Deutsch). + Added png_set_rgb_to_gray() and png_get_rgb_to_gray_status() functions. + Added png_get_copyright() and png_get_header_version() functions. + Revised comments on png_set_progressive_read_fn() in libpng.txt and example.c + Added information about debugging in libpng.txt and libpng.3 . + Changed "ln -sf" to "ln -s -f" in makefile.s2x, makefile.lnx, and + makefile.sco. + Removed lines after Dynamic Dependencies" in makefile.aco . + Revised makefile.dec to make a shared library (Jeremie Petit). + Removed trailing blanks from all files. + +Version 1.0.2a [January 6, 1999] + Removed misplaced #endif and #ifdef PNG_NO_EXTERN near the end of png.h + Added "if" tests to silence complaints about unused png_ptr in png.h and png.c + Changed "check_if_png" function in example.c to return true (nonzero) if PNG. + Changed libpng.txt to demonstrate png_sig_cmp() instead of png_check_sig() + which is obsolete. + +Version 1.0.3 [January 14, 1999] + Added makefile.hux, for Hewlett Packard HPUX 10.20 and 11.00 (Jim Rice) + Added a statement of Y2K compliance in png.h, libpng.3, and Y2KINFO. + +Version 1.0.3a [August 12, 1999] + Added check for PNG_READ_INTERLACE_SUPPORTED in pngread.c; issue a warning + if an attempt is made to read an interlaced image when it's not supported. + Added check if png_ptr->trans is defined before freeing it in pngread.c + Modified the Y2K statement to include versions back to version 0.71 + Fixed a bug in the check for valid IHDR bit_depth/color_types in pngrutil.c + Modified makefile.wat (added -zp8 flag, ".symbolic", changed some comments) + Replaced leading blanks with tab characters in makefile.hux + Changed "dworkin.wustl.edu" to "ccrc.wustl.edu" in various documents. + Changed (float)red and (float)green to (double)red, (double)green + in png_set_rgb_to_gray() to avoid "promotion" problems in AIX. + Fixed a bug in pngconf.h that omitted <stdio.h> when PNG_DEBUG==0 (K Bracey). + Reformatted libpng.3 and libpngpf.3 with proper fonts (script by J. vanZandt). + Updated documentation to refer to the PNG-1.2 specification. + Removed ansi2knr.c and left pointers to the latest source for ansi2knr.c + in makefile.knr, INSTALL, and README (L. Peter Deutsch) + Fixed bugs in calculation of the length of rowbytes when adding alpha + channels to 16-bit images, in pngrtran.c (Chris Nokleberg) + Added function png_set_user_transform_info() to store user_transform_ptr, + user_depth, and user_channels into the png_struct, and a function + png_get_user_transform_ptr() to retrieve the pointer (Chris Nokleberg) + Added function png_set_empty_plte_permitted() to make libpng useable + in MNG applications. + Corrected the typedef for png_free_ptr in png.h (Jesse Jones). + Correct gamma with srgb is 45455 instead of 45000 in pngrutil.c, to be + consistent with PNG-1.2, and allow variance of 500 before complaining. + Added assembler code contributed by Intel in file pngvcrd.c and modified + makefile.w32 to use it (Nirav Chhatrapati, INTEL Corporation, + Gilles Vollant) + Changed "ln -s -f" to "ln -f -s" in the makefiles to make Solaris happy. + Added some aliases for png_set_expand() in pngrtran.c, namely + png_set_expand_PLTE(), png_set_expand_depth(), and png_set_expand_tRNS() + (Greg Roelofs, in "PNG: The Definitive Guide"). + Added makefile.beo for BEOS on X86, contributed by Sander Stok. + +Version 1.0.3b [August 26, 1999] + Replaced 2147483647L several places with PNG_MAX_UINT macro, defined in png.h + Changed leading blanks to tabs in all makefiles. + Define PNG_USE_PNGVCRD in makefile.w32, to get MMX assembler code. + Made alternate versions of png_set_expand() in pngrtran.c, namely + png_set_gray_1_2_4_to_8, png_set_palette_to_rgb, and png_set_tRNS_to_alpha + (Greg Roelofs, in "PNG: The Definitive Guide"). Deleted the 1.0.3a aliases. + Relocated start of 'extern "C"' block in png.h so it doesn't include pngconf.h + Revised calculation of num_blocks in pngmem.c to avoid a potentially + negative shift distance, whose results are undefined in the C language. + Added a check in pngset.c to prevent writing multiple tIME chunks. + Added a check in pngwrite.c to detect invalid small window_bits sizes. + +Version 1.0.3d [September 4, 1999] + Fixed type casting of igamma in pngrutil.c + Added new png_expand functions to scripts/pngdef.pas and pngos2.def + Added a demo read_user_transform_fn that examines the row filters in pngtest.c + +Version 1.0.4 [September 24, 1999] + Define PNG_ALWAYS_EXTERN in pngconf.h if __STDC__ is defined + Delete #define PNG_INTERNAL and include "png.h" from pngasmrd.h + Made several minor corrections to pngtest.c + Renamed the makefiles with longer but more user friendly extensions. + Copied the PNG copyright and license to a separate LICENSE file. + Revised documentation, png.h, and example.c to remove reference to + "viewing_gamma" which no longer appears in the PNG specification. + Revised pngvcrd.c to use MMX code for interlacing only on the final pass. + Updated pngvcrd.c to use the faster C filter algorithms from libpng-1.0.1a + Split makefile.win32vc into two versions, makefile.vcawin32 (uses MMX + assembler code) and makefile.vcwin32 (doesn't). + Added a CPU timing report to pngtest.c (enabled by defining PNGTEST_TIMING) + Added a copy of pngnow.png to the distribution. + +Version 1.0.4a [September 25, 1999] + Increase max_pixel_depth in pngrutil.c if a user transform needs it. + Changed several division operations to right-shifts in pngvcrd.c + +Version 1.0.4b [September 30, 1999] + Added parentheses in line 3732 of pngvcrd.c + Added a comment in makefile.linux warning about buggy -O3 in pgcc 2.95.1 + +Version 1.0.4c [October 1, 1999] + Added a "png_check_version" function in png.c and pngtest.c that will generate + a helpful compiler error if an old png.h is found in the search path. + Changed type of png_user_transform_depth|channels from int to png_byte. + +Version 1.0.4d [October 6, 1999] + Changed 0.45 to 0.45455 in png_set_sRGB() + Removed unused PLTE entries from pngnow.png + Re-enabled some parts of pngvcrd.c (png_combine_row) that work properly. + +Version 1.0.4e [October 10, 1999] + Fixed sign error in pngvcrd.c (Greg Roelofs) + Replaced some instances of memcpy with simple assignments in pngvcrd (GR-P) + +Version 1.0.4f [October 15, 1999] + Surrounded example.c code with #if 0 .. #endif to prevent people from + inadvertently trying to compile it. + Changed png_get_header_version() from a function to a macro in png.h + Added type casting mostly in pngrtran.c and pngwtran.c + Removed some pointless "ptr = NULL" in pngmem.c + Added a "contrib" directory containing the source code from Greg's book. + +Version 1.0.5 [October 15, 1999] + Minor editing of the INSTALL and README files. + +Version 1.0.5a [October 23, 1999] + Added contrib/pngsuite and contrib/pngminus (Willem van Schaik) + Fixed a typo in the png_set_sRGB() function call in example.c (Jan Nijtmans) + Further optimization and bugfix of pngvcrd.c + Revised pngset.c so that it does not allocate or free memory in the user's + text_ptr structure. Instead, it makes its own copy. + Created separate write_end_info_struct in pngtest.c for a more severe test. + Added code in pngwrite.c to free info_ptr->text[i].key to stop a memory leak. + +Version 1.0.5b [November 23, 1999] + Moved PNG_FLAG_HAVE_CHUNK_HEADER, PNG_FLAG_BACKGROUND_IS_GRAY and + PNG_FLAG_WROTE_tIME from flags to mode. + Added png_write_info_before_PLTE() function. + Fixed some typecasting in contrib/gregbook/*.c + Updated scripts/makevms.com and added makevms.com to contrib/gregbook + and contrib/pngminus (Martin Zinser) + +Version 1.0.5c [November 26, 1999] + Moved png_get_header_version from png.h to png.c, to accommodate ansi2knr. + Removed all global arrays (according to PNG_NO_GLOBAL_ARRAYS macro), to + accommodate making DLL's: Moved usr_png_ver from global variable to function + png_get_header_ver() in png.c. Moved png_sig to png_sig_bytes in png.c and + eliminated use of png_sig in pngwutil.c. Moved the various png_CHNK arrays + into pngtypes.h. Eliminated use of global png_pass arrays. Declared the + png_CHNK and png_pass arrays to be "const". Made the global arrays + available to applications (although none are used in libpng itself) when + PNG_NO_GLOBAL_ARRAYS is not defined or when PNG_GLOBAL_ARRAYS is defined. + Removed some extraneous "-I" from contrib/pngminus/makefile.std + Changed the PNG_sRGB_INTENT macros in png.h to be consistent with PNG-1.2. + Change PNG_SRGB_INTENT to PNG_sRGB_INTENT in libpng.txt and libpng.3 + +Version 1.0.5d [November 29, 1999] + Add type cast (png_const_charp) two places in png.c + Eliminated pngtypes.h; use macros instead to declare PNG_CHNK arrays. + Renamed "PNG_GLOBAL_ARRAYS" to "PNG_USE_GLOBAL_ARRAYS" and made available + to applications a macro "PNG_USE_LOCAL_ARRAYS". + comment out (with #ifdef) all the new declarations when + PNG_USE_GLOBAL_ARRAYS is defined. + Added PNG_EXPORT_VAR macro to accommodate making DLL's. + +Version 1.0.5e [November 30, 1999] + Added iCCP, iTXt, and sPLT support; added "lang" member to the png_text + structure; refactored the inflate/deflate support to make adding new chunks + with trailing compressed parts easier in the future, and added new functions + png_free_iCCP, png_free_pCAL, png_free_sPLT, png_free_text, png_get_iCCP, + png_get_spalettes, png_set_iCCP, png_set_spalettes (Eric S. Raymond). + NOTE: Applications that write text chunks MUST define png_text->lang + before calling png_set_text(). It must be set to NULL if you want to + write tEXt or zTXt chunks. If you want your application to be able to + run with older versions of libpng, use + + #ifdef PNG_iTXt_SUPPORTED + png_text[i].lang = NULL; + #endif + + Changed png_get_oFFs() and png_set_oFFs() to use signed rather than unsigned + offsets (Eric S. Raymond). + Combined PNG_READ_cHNK_SUPPORTED and PNG_WRITE_cHNK_SUPPORTED macros into + PNG_cHNK_SUPPORTED and combined the three types of PNG_text_SUPPORTED + macros, leaving the separate macros also available. + Removed comments on #endifs at the end of many short, non-nested #if-blocks. + +Version 1.0.5f [December 6, 1999] + Changed makefile.solaris to issue a warning about potential problems when + the ucb "ld" is in the path ahead of the ccs "ld". + Removed "- [date]" from the "synopsis" line in libpng.3 and libpngpf.3. + Added sCAL chunk support (Eric S. Raymond). + +Version 1.0.5g [December 7, 1999] + Fixed "png_free_spallettes" typo in png.h + Added code to handle new chunks in pngpread.c + Moved PNG_CHNK string macro definitions outside of PNG_NO_EXTERN block + Added "translated_key" to png_text structure and png_write_iTXt(). + Added code in pngwrite.c to work around a newly discovered zlib bug. + +Version 1.0.5h [December 10, 1999] + NOTE: regarding the note for version 1.0.5e, the following must also + be included in your code: + png_text[i].translated_key = NULL; + Unknown chunk handling is now supported. + Option to eliminate all floating point support was added. Some new + fixed-point functions such as png_set_gAMA_fixed() were added. + Expanded tabs and removed trailing blanks in source files. + +Version 1.0.5i [December 13, 1999] + Added some type casts to silence compiler warnings. + Renamed "png_free_spalette" to "png_free_spalettes" for consistency. + Removed leading blanks from a #define in pngvcrd.c + Added some parameters to the new png_set_keep_unknown_chunks() function. + Added a test for up->location != 0 in the first instance of writing + unknown chunks in pngwrite.c + Changed "num" to "i" in png_free_spalettes() and png_free_unknowns() to + prevent recursion. + Added png_free_hIST() function. + Various patches to fix bugs in the sCAL and integer cHRM processing, + and to add some convenience macros for use with sCAL. + +Version 1.0.5j [December 21, 1999] + Changed "unit" parameter of png_write_sCAL from png_byte to int, to work + around buggy compilers. + Added new type "png_fixed_point" for integers that hold float*100000 values + Restored backward compatibility of tEXt/zTXt chunk processing: + Restored the first four members of png_text to the same order as v.1.0.5d. + Added members "lang_key" and "itxt_length" to png_text struct. Set + text_length=0 when "text" contains iTXt data. Use the "compression" + member to distinguish among tEXt/zTXt/iTXt types. Added + PNG_ITXT_COMPRESSION_NONE (1) and PNG_ITXT_COMPRESSION_zTXt(2) macros. + The "Note" above, about backward incompatibility of libpng-1.0.5e, no + longer applies. + Fixed png_read|write_iTXt() to read|write parameters in the right order, + and to write the iTXt chunk after IDAT if it appears in the end_ptr. + Added pnggccrd.c, version of pngvcrd.c Intel assembler for gcc (Greg Roelofs) + Reversed the order of trying to write floating-point and fixed-point gAMA. + +Version 1.0.5k [December 27, 1999] + Added many parentheses, e.g., "if (a && b & c)" becomes "if (a && (b & c))" + Added png_handle_as_unknown() function (Glenn) + Added png_free_chunk_list() function and chunk_list and num_chunk_list members + of png_ptr. + Eliminated erroneous warnings about multiple sPLT chunks and sPLT-after-PLTE. + Fixed a libpng-1.0.5h bug in pngrutil.c that was issuing erroneous warnings + about ignoring incorrect gAMA with sRGB (gAMA was in fact not ignored) + Added png_free_tRNS(); png_set_tRNS() now malloc's its own trans array (ESR). + Define png_get_int_32 when oFFs chunk is supported as well as when pCAL is. + Changed type of proflen from png_int_32 to png_uint_32 in png_get_iCCP(). + +Version 1.0.5l [January 1, 2000] + Added functions png_set_read_user_chunk_fn() and png_get_user_chunk_ptr() + for setting a callback function to handle unknown chunks and for + retrieving the associated user pointer (Glenn). + +Version 1.0.5m [January 7, 2000] + Added high-level functions png_read_png(), png_write_png(), png_free_pixels(). + +Version 1.0.5n [January 9, 2000] + Added png_free_PLTE() function, and modified png_set_PLTE() to malloc its + own memory for info_ptr->palette. This makes it safe for the calling + application to free its copy of the palette any time after it calls + png_set_PLTE(). + +Version 1.0.5o [January 20, 2000] + Cosmetic changes only (removed some trailing blanks and TABs) + +Version 1.0.5p [January 31, 2000] + Renamed pngdll.mak to makefile.bd32 + Cosmetic changes in pngtest.c + +Version 1.0.5q [February 5, 2000] + Relocated the makefile.solaris warning about PATH problems. + Fixed pngvcrd.c bug by pushing/popping registers in mmxsupport (Bruce Oberg) + Revised makefile.gcmmx + Added PNG_SETJMP_SUPPORTED, PNG_SETJMP_NOT_SUPPORTED, and PNG_ABORT() macros + +Version 1.0.5r [February 7, 2000] + Removed superfluous prototype for png_get_itxt from png.h + Fixed a bug in pngrtran.c that improperly expanded the background color. + Return *num_text=0 from png_get_text() when appropriate, and fix documentation + of png_get_text() in libpng.txt/libpng.3. + +Version 1.0.5s [February 18, 2000] + Added "png_jmp_env()" macro to pngconf.h, to help people migrate to the + new error handler that's planned for the next libpng release, and changed + example.c, pngtest.c, and contrib programs to use this macro. + Revised some of the DLL-export macros in pngconf.h (Greg Roelofs) + Fixed a bug in png_read_png() that caused it to fail to expand some images + that it should have expanded. + Fixed some mistakes in the unused and undocumented INCH_CONVERSIONS functions + in pngget.c + Changed the allocation of palette, history, and trans arrays back to + the version 1.0.5 method (linking instead of copying) which restores + backward compatibility with version 1.0.5. Added some remarks about + that in example.c. Added "free_me" member to info_ptr and png_ptr + and added png_free_data() function. + Updated makefile.linux and makefile.gccmmx to make directories conditionally. + Made cosmetic changes to pngasmrd.h + Added png_set_rows() and png_get_rows(), for use with png_read|write_png(). + Modified png_read_png() to allocate info_ptr->row_pointers only if it + hasn't already been allocated. + +Version 1.0.5t [March 4, 2000] + Changed png_jmp_env() migration aiding macro to png_jmpbuf(). + Fixed "interlace" typo (should be "interlaced") in contrib/gregbook/read2-x.c + Fixed bug with use of PNG_BEFORE_IHDR bit in png_ptr->mode, introduced when + PNG_FLAG_HAVE_CHUNK_HEADER was moved into png_ptr->mode in version 1.0.5b + Files in contrib/gregbook were revised to use png_jmpbuf() and to select + a 24-bit visual if one is available, and to allow abbreviated options. + Files in contrib/pngminus were revised to use the png_jmpbuf() macro. + Removed spaces in makefile.linux and makefile.gcmmx, introduced in 1.0.5s + +Version 1.0.5u [March 5, 2000] + Simplified the code that detects old png.h in png.c and pngtest.c + Renamed png_spalette (_p, _pp) to png_sPLT_t (_tp, _tpp) + Increased precision of rgb_to_gray calculations from 8 to 15 bits and + added png_set_rgb_to_gray_fixed() function. + Added makefile.bc32 (32-bit Borland C++, C mode) + +Version 1.0.5v [March 11, 2000] + Added some parentheses to the png_jmpbuf macro definition. + Updated references to the zlib home page, which has moved to freesoftware.com. + Corrected bugs in documentation regarding png_read_row() and png_write_row(). + Updated documentation of png_rgb_to_gray calculations in libpng.3/libpng.txt. + Renamed makefile.borland,turboc3 back to makefile.bor,tc3 as in version 1.0.3, + revised borland makefiles; added makefile.ibmvac3 and makefile.gcc (Cosmin) + +Version 1.0.6 [March 20, 2000] + Minor revisions of makefile.bor, libpng.txt, and gregbook/rpng2-win.c + Added makefile.sggcc (SGI IRIX with gcc) + +Version 1.0.6d [April 7, 2000] + Changed sprintf() to strcpy() in png_write_sCAL_s() to work without STDIO + Added data_length parameter to png_decompress_chunk() function + Revised documentation to remove reference to abandoned png_free_chnk functions + Fixed an error in png_rgb_to_gray_fixed() + Revised example.c, usage of png_destroy_write_struct(). + Renamed makefile.ibmvac3 to makefile.ibmc, added libpng.icc IBM project file + Added a check for info_ptr->free_me&PNG_FREE_TEXT when freeing text in png.c + Simplify png_sig_bytes() function to remove use of non-ISO-C strdup(). + +Version 1.0.6e [April 9, 2000] + Added png_data_freer() function. + In the code that checks for over-length tRNS chunks, added check of + info_ptr->num_trans as well as png_ptr->num_trans (Matthias Benckmann) + Minor revisions of libpng.txt/libpng.3. + Check for existing data and free it if the free_me flag is set, in png_set_*() + and png_handle_*(). + Only define PNG_WEIGHTED_FILTERS_SUPPORTED when PNG_FLOATING_POINT_SUPPORTED + is defined. + Changed several instances of PNG_NO_CONSOLE_ID to PNG_NO_STDIO in pngrutil.c + and mentioned the purposes of the two macros in libpng.txt/libpng.3. + +Version 1.0.6f [April 14, 2000] + Revised png_set_iCCP() and png_set_rows() to avoid prematurely freeing data. + Add checks in png_set_text() for NULL members of the input text structure. + Revised libpng.txt/libpng.3. + Removed superfluous prototype for png_set_iTXt from png.h + Removed "else" from pngread.c, after png_error(), and changed "0" to "length". + Changed several png_errors about malformed ancillary chunks to png_warnings. + +Version 1.0.6g [April 24, 2000] + Added png_pass-* arrays to pnggccrd.c when PNG_USE_LOCAL_ARRAYS is defined. + Relocated paragraph about png_set_background() in libpng.3/libpng.txt + and other revisions (Matthias Benckmann) + Relocated info_ptr->free_me, png_ptr->free_me, and other info_ptr and + png_ptr members to restore binary compatibility with libpng-1.0.5 + (breaks compatibility with libpng-1.0.6). + +Version 1.0.6h [April 24, 2000] + Changed shared library so-number pattern from 2.x.y.z to xy.z (this builds + libpng.so.10 & libpng.so.10.6h instead of libpng.so.2 & libpng.so.2.1.0.6h) + This is a temporary change for test purposes. + +Version 1.0.6i [May 2, 2000] + Rearranged some members at the end of png_info and png_struct, to put + unknown_chunks_num and free_me within the original size of the png_structs + and free_me, png_read_user_fn, and png_free_fn within the original png_info, + because some old applications allocate the structs directly instead of + using png_create_*(). + Added documentation of user memory functions in libpng.txt/libpng.3 + Modified png_read_png so that it will use user_allocated row_pointers + if present, unless free_me directs that it be freed, and added description + of the use of png_set_rows() and png_get_rows() in libpng.txt/libpng.3. + Added PNG_LEGACY_SUPPORTED macro, and #ifdef out all new (since version + 1.00) members of png_struct and png_info, to regain binary compatibility + when you define this macro. Capabilities lost in this event + are user transforms (new in version 1.0.0),the user transform pointer + (new in version 1.0.2), rgb_to_gray (new in 1.0.5), iCCP, sCAL, sPLT, + the high-level interface, and unknown chunks support (all new in 1.0.6). + This was necessary because of old applications that allocate the structs + directly as authors were instructed to do in libpng-0.88 and earlier, + instead of using png_create_*(). + Added modes PNG_CREATED_READ_STRUCT and PNG_CREATED_WRITE_STRUCT which + can be used to detect codes that directly allocate the structs, and + code to check these modes in png_read_init() and png_write_init() and + generate a libpng error if the modes aren't set and PNG_LEGACY_SUPPORTED + was not defined. + Added makefile.intel and updated makefile.watcom (Pawel Mrochen) + +Version 1.0.6j [May 3, 2000] + Overloaded png_read_init() and png_write_init() with macros that convert + calls to png_read_init_2() or png_write_init_2() that check the version + and structure sizes. + +Version 1.0.7beta11 [May 7, 2000] + Removed the new PNG_CREATED_READ_STRUCT and PNG_CREATED_WRITE_STRUCT modes + which are no longer used. + Eliminated the three new members of png_text when PNG_LEGACY_SUPPORTED is + defined or when neither PNG_READ_iTXt_SUPPORTED nor PNG_WRITE_iTXT_SUPPORTED + is defined. + Made PNG_NO_READ|WRITE_iTXt the default setting, to avoid memory + overrun when old applications fill the info_ptr->text structure directly. + Added PNGAPI macro, and added it to the definitions of all exported functions. + Relocated version macro definitions ahead of the includes of zlib.h and + pngconf.h in png.h. + +Version 1.0.7beta12 [May 12, 2000] + Revised pngset.c to avoid a problem with expanding the png_debug macro. + Deleted some extraneous defines from pngconf.h + Made PNG_NO_CONSOLE_IO the default condition when PNG_BUILD_DLL is defined. + Use MSC _RPTn debugging instead of fprintf if _MSC_VER is defined. + Added png_access_version_number() function. + Check for mask&PNG_FREE_CHNK (for TEXT, SCAL, PCAL) in png_free_data(). + Expanded libpng.3/libpng.txt information about png_data_freer(). + +Version 1.0.7beta14 [May 17, 2000] (beta13 was not published) + Changed pnggccrd.c and pngvcrd.c to handle bad adaptive filter types as + warnings instead of errors, as pngrutil.c does. + Set the PNG_INFO_IDAT valid flag in png_set_rows() so png_write_png() + will actually write IDATs. + Made the default PNG_USE_LOCAL_ARRAYS depend on PNG_DLL instead of WIN32. + Make png_free_data() ignore its final parameter except when freeing data + that can have multiple instances (text, sPLT, unknowns). + Fixed a new bug in png_set_rows(). + Removed info_ptr->valid tests from png_free_data(), as in version 1.0.5. + Added png_set_invalid() function. + Fixed incorrect illustrations of png_destroy_write_struct() in example.c. + +Version 1.0.7beta15 [May 30, 2000] + Revised the deliberately erroneous Linux setjmp code in pngconf.h to produce + fewer error messages. + Rearranged checks for Z_OK to check the most likely path first in pngpread.c + and pngwutil.c. + Added checks in pngtest.c for png_create_*() returning NULL, and mentioned + in libpng.txt/libpng.3 the need for applications to check this. + Changed names of png_default_*() functions in pngtest to pngtest_*(). + Changed return type of png_get_x|y_offset_*() from png_uint_32 to png_int_32. + Fixed some bugs in the unused PNG_INCH_CONVERSIONS functions in pngget.c + Set each pointer to NULL after freeing it in png_free_data(). + Worked around a problem in pngconf.h; AIX's strings.h defines an "index" + macro that conflicts with libpng's png_color_16.index. (Dimitri + Papadapoulos) + Added "msvc" directory with MSVC++ project files (Simon-Pierre Cadieux). + +Version 1.0.7beta16 [June 4, 2000] + Revised the workaround of AIX string.h "index" bug. + Added a check for overlength PLTE chunk in pngrutil.c. + Added PNG_NO_POINTER_INDEXING macro to use array-indexing instead of pointer + indexing in pngrutil.c and pngwutil.c to accommodate a buggy compiler. + Added a warning in png_decompress_chunk() when it runs out of data, e.g. + when it tries to read an erroneous PhotoShop iCCP chunk. + Added PNG_USE_DLL macro. + Revised the copyright/disclaimer/license notice. + Added contrib/msvctest directory + +Version 1.0.7rc1 [June 9, 2000] + Corrected the definition of PNG_TRANSFORM_INVERT_ALPHA (0x0400 not 0x0200) + Added contrib/visupng directory (Willem van Schaik) + +Version 1.0.7beta18 [June 23, 2000] + Revised PNGAPI definition, and pngvcrd.c to work with __GCC__ + and do not redefine PNGAPI if it is passed in via a compiler directive. + Revised visupng/PngFile.c to remove returns from within the Try block. + Removed leading underscores from "_PNG_H" and "_PNG_SAVE_BSD_SOURCE" macros. + Updated contrib/visupng/cexcept.h to version 1.0.0. + Fixed bugs in pngwrite.c and pngwutil.c that prevented writing iCCP chunks. + +Version 1.0.7rc2 [June 28, 2000] + Updated license to include disclaimers required by UCITA. + Fixed "DJBPP" typo in pnggccrd.c introduced in beta18. + +Version 1.0.7 [July 1, 2000] + Revised the definition of "trans_values" in libpng.3/libpng.txt + +Version 1.0.8beta1 [July 8, 2000] + Added png_free(png_ptr, key) two places in pngpread.c to stop memory leaks. + Changed PNG_NO_STDIO to PNG_NO_CONSOLE_IO, several places in pngrutil.c and + pngwutil.c. + Changed PNG_EXPORT_VAR to use PNG_IMPEXP, in pngconf.h. + Removed unused "#include <assert.h>" from png.c + Added WindowsCE support. + Revised pnggccrd.c to work with gcc-2.95.2 and in the Cygwin environment. + +Version 1.0.8beta2 [July 10, 2000] + Added project files to the wince directory and made further revisions + of pngtest.c, pngrio.c, and pngwio.c in support of WindowsCE. + +Version 1.0.8beta3 [July 11, 2000] + Only set the PNG_FLAG_FREE_TRNS or PNG_FREE_TRNS flag in png_handle_tRNS() + for indexed-color input files to avoid potential double-freeing trans array + under some unusual conditions; problem was introduced in version 1.0.6f. + Further revisions to pngtest.c and files in the wince subdirectory. + +Version 1.0.8beta4 [July 14, 2000] + Added the files pngbar.png and pngbar.jpg to the distribution. + Added makefile.cygwin, and cygwin support in pngconf.h + Added PNG_NO_ZALLOC_ZERO macro (makes png_zalloc skip zeroing memory) + +Version 1.0.8rc1 [July 16, 2000] + Revised png_debug() macros and statements to eliminate compiler warnings. + +Version 1.0.8 [July 24, 2000] + Added png_flush() in pngwrite.c, after png_write_IEND(). + Updated makefile.hpux to build a shared library. + +Version 1.0.9beta1 [November 10, 2000] + Fixed typo in scripts/makefile.hpux + Updated makevms.com in scripts and contrib/* and contrib/* (Martin Zinser) + Fixed seqence-point bug in contrib/pngminus/png2pnm (Martin Zinser) + Changed "cdrom.com" in documentation to "libpng.org" + Revised pnggccrd.c to get it all working, and updated makefile.gcmmx (Greg). + Changed type of "params" from voidp to png_voidp in png_read|write_png(). + Make sure PNGAPI and PNG_IMPEXP are defined in pngconf.h. + Revised the 3 instances of WRITEFILE in pngtest.c. + Relocated "msvc" and "wince" project subdirectories into "dll" subdirectory. + Updated png.rc in dll/msvc project + Revised makefile.dec to define and use LIBPATH and INCPATH + Increased size of global png_libpng_ver[] array from 12 to 18 chars. + Made global png_libpng_ver[], png_sig[] and png_pass_*[] arrays const. + Removed duplicate png_crc_finish() from png_handle_bKGD() function. + Added a warning when application calls png_read_update_info() multiple times. + Revised makefile.cygwin + Fixed bugs in iCCP support in pngrutil.c and pngwutil.c. + Replaced png_set_empty_plte_permitted() with png_permit_mng_features(). + +Version 1.0.9beta2 [November 19, 2000] + Renamed the "dll" subdirectory "projects". + Added borland project files to "projects" subdirectory. + Set VS_FF_PRERELEASE and VS_FF_PATCHED flags in msvc/png.rc when appropriate. + Add error message in png_set_compression_buffer_size() when malloc fails. + +Version 1.0.9beta3 [November 23, 2000] + Revised PNG_LIBPNG_BUILD_TYPE macro in png.h, used in the msvc project. + Removed the png_flush() in pngwrite.c that crashes some applications + that don't set png_output_flush_fn. + Added makefile.macosx and makefile.aix to scripts directory. + +Version 1.0.9beta4 [December 1, 2000] + Change png_chunk_warning to png_warning in png_check_keyword(). + Increased the first part of msg buffer from 16 to 18 in png_chunk_error(). + +Version 1.0.9beta5 [December 15, 2000] + Added support for filter method 64 (for PNG datastreams embedded in MNG). + +Version 1.0.9beta6 [December 18, 2000] + Revised png_set_filter() to accept filter method 64 when appropriate. + Added new PNG_HAVE_PNG_SIGNATURE bit to png_ptr->mode and use it to + help prevent applications from using MNG features in PNG datastreams. + Added png_permit_mng_features() function. + Revised libpng.3/libpng.txt. Changed "filter type" to "filter method". + +Version 1.0.9rc1 [December 23, 2000] + Revised test for PNG_HAVE_PNG_SIGNATURE in pngrutil.c + Fixed error handling of unknown compression type in png_decompress_chunk(). + In pngconf.h, define __cdecl when _MSC_VER is defined. + +Version 1.0.9beta7 [December 28, 2000] + Changed PNG_TEXT_COMPRESSION_zTXt to PNG_COMPRESSION_TYPE_BASE several places. + Revised memory management in png_set_hIST and png_handle_hIST in a backward + compatible manner. PLTE and tRNS were revised similarly. + Revised the iCCP chunk reader to ignore trailing garbage. + +Version 1.0.9beta8 [January 12, 2001] + Moved pngasmrd.h into pngconf.h. + Improved handling of out-of-spec garbage iCCP chunks generated by PhotoShop. + +Version 1.0.9beta9 [January 15, 2001] + Added png_set_invalid, png_permit_mng_features, and png_mmx_supported to + wince and msvc project module definition files. + Minor revision of makefile.cygwin. + Fixed bug with progressive reading of narrow interlaced images in pngpread.c + +Version 1.0.9beta10 [January 16, 2001] + Do not typedef png_FILE_p in pngconf.h when PNG_NO_STDIO is defined. + Fixed "png_mmx_supported" typo in project definition files. + +Version 1.0.9beta11 [January 19, 2001] + Updated makefile.sgi to make shared library. + Removed png_mmx_support() function and disabled PNG_MNG_FEATURES_SUPPORTED + by default, for the benefit of DLL forward compatibility. These will + be re-enabled in version 1.2.0. + +Version 1.0.9rc2 [January 22, 2001] + Revised cygwin support. + +Version 1.0.9 [January 31, 2001] + Added check of cygwin's ALL_STATIC in pngconf.h + Added "-nommx" parameter to contrib/gregbook/rpng2-win and rpng2-x demos. + +Version 1.0.10beta1 [March 14, 2001] + Revised makefile.dec, makefile.sgi, and makefile.sggcc; added makefile.hpgcc. + Reformatted libpng.3 to eliminate bad line breaks. + Added checks for _mmx_supported in the read_filter_row function of pnggccrd.c + Added prototype for png_mmx_support() near the top of pnggccrd.c + Moved some error checking from png_handle_IHDR to png_set_IHDR. + Added PNG_NO_READ_SUPPORTED and PNG_NO_WRITE_SUPPORTED macros. + Revised png_mmx_support() function in pnggccrd.c + Restored version 1.0.8 PNG_WRITE_EMPTY_PLTE_SUPPORTED behavior in pngwutil.c + Fixed memory leak in contrib/visupng/PngFile.c + Fixed bugs in png_combine_row() in pnggccrd.c and pngvcrd.c (C version) + Added warnings when retrieving or setting gamma=0. + Increased the first part of msg buffer from 16 to 18 in png_chunk_warning(). + +Version 1.0.10rc1 [March 23, 2001] + Changed all instances of memcpy, strcpy, and strlen to png_memcpy, png_strcpy, + and png_strlen. + Revised png_mmx_supported() function in pnggccrd.c to return proper value. + Fixed bug in progressive reading (pngpread.c) with small images (height < 8). + +Version 1.0.10 [March 30, 2001] + Deleted extraneous space (introduced in 1.0.9) from line 42 of makefile.cygwin + Added beos project files (Chris Herborth) + +Version 1.0.11beta1 [April 3, 2001] + Added type casts on several png_malloc() calls (Dimitri Papadapoulos). + Removed a no-longer needed AIX work-around from pngconf.h + Changed several "//" single-line comments to C-style in pnggccrd.c + +Version 1.0.11beta2 [April 11, 2001] + Removed PNGAPI from several functions whose prototypes did not have PNGAPI. + Updated scripts/pngos2.def + +Version 1.0.11beta3 [April 14, 2001] + Added checking the results of many instances of png_malloc() for NULL + +Version 1.0.11beta4 [April 20, 2001] + Undid the changes from version 1.0.11beta3. Added a check for NULL return + from user's malloc_fn(). + Removed some useless type casts of the NULL pointer. + Added makefile.netbsd + +Version 1.0.11 [April 27, 2001] + Revised makefile.netbsd + +Version 1.0.12beta1 [May 14, 2001] + Test for Windows platform in pngconf.h when including malloc.h (Emmanuel Blot) + Updated makefile.cygwin and handling of Cygwin's ALL_STATIC in pngconf.h + Added some never-to-be-executed code in pnggccrd.c to quiet compiler warnings. + Eliminated the png_error about apps using png_read|write_init(). Instead, + libpng will reallocate the png_struct and info_struct if they are too small. + This retains future binary compatibility for old applications written for + libpng-0.88 and earlier. + +Version 1.2.0beta1 [May 6, 2001] + Bumped DLLNUM to 2. + Re-enabled PNG_MNG_FEATURES_SUPPORTED and enabled PNG_ASSEMBLER_CODE_SUPPORTED + by default. + Added runtime selection of MMX features. + Added png_set_strip_error_numbers function and related macros. + +Version 1.2.0beta2 [May 7, 2001] + Finished merging 1.2.0beta1 with version 1.0.11 + Added a check for attempts to read or write PLTE in grayscale PNG datastreams. + +Version 1.2.0beta3 [May 17, 2001] + Enabled user memory function by default. + Modified png_create_struct so it passes user mem_ptr to user memory allocator. + Increased png_mng_features flag from png_byte to png_uint_32. + Bumped shared-library (so-number) and dll-number to 3. + +Version 1.2.0beta4 [June 23, 2001] + Check for missing profile length field in iCCP chunk and free chunk_data + in case of truncated iCCP chunk. + Bumped shared-library number to 3 in makefile.sgi and makefile.sggcc + Bumped dll-number from 2 to 3 in makefile.cygwin + Revised contrib/gregbook/rpng*-x.c to avoid a memory leak and to exit cleanly + if user attempts to run it on an 8-bit display. + Updated contrib/gregbook + Use png_malloc instead of png_zalloc to allocate palette in pngset.c + Updated makefile.ibmc + Added some typecasts to eliminate gcc 3.0 warnings. Changed prototypes + of png_write_oFFS width and height from png_uint_32 to png_int_32. + Updated example.c + Revised prototypes for png_debug_malloc and png_debug_free in pngtest.c + +Version 1.2.0beta5 [August 8, 2001] + Revised contrib/gregbook + Revised makefile.gcmmx + Revised pnggccrd.c to conditionally compile some thread-unsafe code only + when PNG_THREAD_UNSAFE_OK is defined. + Added tests to prevent pngwutil.c from writing a bKGD or tRNS chunk with + value exceeding 2^bit_depth-1 + Revised makefile.sgi and makefile.sggcc + Replaced calls to fprintf(stderr,...) with png_warning() in pnggccrd.c + Removed restriction that do_invert_mono only operate on 1-bit opaque files + +Version 1.2.0 [September 1, 2001] + Changed a png_warning() to png_debug() in pnggccrd.c + Fixed contrib/gregbook/rpng-x.c, rpng2-x.c to avoid crash with XFreeGC(). + +Version 1.2.1beta1 [October 19, 2001] + Revised makefile.std in contrib/pngminus + Include background_1 in png_struct regardless of gamma support. + Revised makefile.netbsd and makefile.macosx, added makefile.darwin. + Revised example.c to provide more details about using row_callback(). + +Version 1.2.1beta2 [October 25, 2001] + Added type cast to each NULL appearing in a function call, except for + WINCE functions. + Added makefile.so9. + +Version 1.2.1beta3 [October 27, 2001] + Removed type casts from all NULLs. + Simplified png_create_struct_2(). + +Version 1.2.1beta4 [November 7, 2001] + Revised png_create_info_struct() and png_creat_struct_2(). + Added error message if png_write_info() was omitted. + Type cast NULLs appearing in function calls when _NO_PROTO or + PNG_TYPECAST_NULL is defined. + +Version 1.2.1rc1 [November 24, 2001] + Type cast NULLs appearing in function calls except when PNG_NO_TYPECAST_NULL + is defined. + Changed typecast of "size" argument to png_size_t in pngmem.c calls to + the user malloc_fn, to agree with the prototype in png.h + Added a pop/push operation to pnggccrd.c, to preserve Eflag (Maxim Sobolev) + Updated makefile.sgi to recognize LIBPATH and INCPATH. + Updated various makefiles so "make clean" does not remove previous major + version of the shared library. + +Version 1.2.1rc2 [December 4, 2001] + Always allocate 256-entry internal palette, hist, and trans arrays, to + avoid out-of-bounds memory reference caused by invalid PNG datastreams. + Added a check for prefix_length > data_length in iCCP chunk handler. + +Version 1.2.1 [December 7, 2001] + None. + +Version 1.2.2beta1 [February 22, 2002] + Fixed a bug with reading the length of iCCP profiles (Larry Reeves). + Revised makefile.linux, makefile.gcmmx, and makefile.sgi to generate + libpng.a, libpng12.so (not libpng.so.3), and libpng12/png.h + Revised makefile.darwin to remove "-undefined suppress" option. + Added checks for gamma and chromaticity values over 21474.83, which exceed + the limit for PNG unsigned 32-bit integers when encoded. + Revised calls to png_create_read_struct() and png_create_write_struct() + for simpler debugging. + Revised png_zalloc() so zlib handles errors (uses PNG_FLAG_MALLOC_NULL_MEM_OK) + +Version 1.2.2beta2 [February 23, 2002] + Check chunk_length and idat_size for invalid (over PNG_MAX_UINT) lengths. + Check for invalid image dimensions in png_get_IHDR. + Added missing "fi;" in the install target of the SGI makefiles. + Added install-static to all makefiles that make shared libraries. + Always do gamma compensation when image is partially transparent. + +Version 1.2.2beta3 [March 7, 2002] + Compute background.gray and background_1.gray even when color_type is RGB + in case image gets reduced to gray later. + Modified shared-library makefiles to install pkgconfig/libpngNN.pc. + Export (with PNGAPI) png_zalloc, png_zfree, and png_handle_as_unknown + Removed unused png_write_destroy_info prototype from png.h + Eliminated incorrect use of width_mmx from pnggccrd.c in pixel_bytes == 8 case + Added install-shared target to all makefiles that make shared libraries. + Stopped a double free of palette, hist, and trans when not using free_me. + Added makefile.32sunu for Sun Ultra 32 and makefile.64sunu for Sun Ultra 64. + +Version 1.2.2beta4 [March 8, 2002] + Compute background.gray and background_1.gray even when color_type is RGB + in case image gets reduced to gray later (Jason Summers). + Relocated a misplaced /bin/rm in the "install-shared" makefile targets + Added PNG_1_0_X macro which can be used to build a 1.0.x-compatible library. + +Version 1.2.2beta5 [March 26, 2002] + Added missing PNGAPI to several function definitions. + Check for invalid bit_depth or color_type in png_get_IHDR(), and + check for missing PLTE or IHDR in png_push_read_chunk() (Matthias Clasen). + Revised iTXt support to accept NULL for lang and lang_key. + Compute gamma for color components of background even when color_type is gray. + Changed "()" to "{}" in scripts/libpng.pc.in. + Revised makefiles to put png.h and pngconf.h only in $prefix/include/libpngNN + Revised makefiles to make symlink to libpng.so.NN in addition to libpngNN.so + +Version 1.2.2beta6 [March 31, 2002] + +Version 1.0.13beta1 [March 31, 2002] + Prevent png_zalloc() from trying to memset memory that it failed to acquire. + Add typecasts of PNG_MAX_UINT in pngset_cHRM_fixed() (Matt Holgate). + Ensure that the right function (user or default) is used to free the + png_struct after an error in png_create_read_struct_2(). + +Version 1.2.2rc1 [April 7, 2002] + +Version 1.0.13rc1 [April 7, 2002] + Save the ebx register in pnggccrd.c (Sami Farin) + Add "mem_ptr = png_ptr->mem_ptr" in png_destroy_write_struct() (Paul Gardner). + Updated makefiles to put headers in include/libpng and remove old include/*.h. + +Version 1.2.2 [April 15, 2002] + +Version 1.0.13 [April 15, 2002] + Revised description of png_set_filter() in libpng.3/libpng.txt. + Revised makefile.netbsd and added makefile.neNNbsd and makefile.freebsd + +Version 1.0.13patch01 [April 17, 2002] + +Version 1.2.2patch01 [April 17, 2002] + Changed ${PNGMAJ}.${PNGVER} bug to ${PNGVER} in makefile.sgi and + makefile.sggcc + Fixed VER -> PNGVER typo in makefile.macosx and added install-static to + install + Added install: target to makefile.32sunu and makefile.64sunu + +Version 1.0.13patch03 [April 18, 2002] + +Version 1.2.2patch03 [April 18, 2002] + Revised 15 makefiles to link libpng.a to libpngNN.a and the include libpng + subdirectory to libpngNN subdirectory without the full pathname. + Moved generation of libpng.pc from "install" to "all" in 15 makefiles. + +Version 1.2.3rc1 [April 28, 2002] + Added install-man target to 15 makefiles (Dimitri Papadopolous-Orfanos). + Added $(DESTDIR) feature to 24 makefiles (Tim Mooney) + Fixed bug with $prefix, should be $(prefix) in makefile.hpux. + Updated cygwin-specific portion of pngconf.h and revised makefile.cygwin + Added a link from libpngNN.pc to libpng.pc in 15 makefiles. + Added links from include/libpngNN/*.h to include/*.h in 24 makefiles. + Revised makefile.darwin to make relative links without full pathname. + Added setjmp() at the end of png_create_*_struct_2() in case user forgets + to put one in their application. + Restored png_zalloc() and png_zfree() prototypes to version 1.2.1 and + removed them from module definition files. + +Version 1.2.3rc2 [May 1, 2002] + Fixed bug in reporting number of channels in pngget.c and pngset.c, + that was introduced in version 1.2.2beta5. + Exported png_zalloc(), png_zfree(), png_default_read(), png_default_write(), + png_default_flush(), and png_push_fill_buffer() and included them in + module definition files. + Added "libpng.pc" dependency to the "install-shared" target in 15 makefiles. + +Version 1.2.3rc3 [May 1, 2002] + Revised prototype for png_default_flush() + Remove old libpng.pc and libpngNN.pc before installing new ones. + +Version 1.2.3rc4 [May 2, 2002] + Typos in *.def files (png_default_read|write -> png_default_read|write_data) + In makefiles, changed rm libpng.NN.pc to rm libpngNN.pc + Added libpng-config and libpngNN-config and modified makefiles to install + them. + Changed $(MANPATH) to $(DESTDIR)$(MANPATH) in makefiles + Added "Win32 DLL VB" configuration to projects/msvc/libpng.dsp + +Version 1.2.3rc5 [May 11, 2002] + Changed "error" and "message" in prototypes to "error_message" and + "warning_message" to avoid namespace conflict. + Revised 15 makefiles to build libpng-config from libpng-config-*.in + Once more restored png_zalloc and png_zfree to regular nonexported form. + Restored png_default_read|write_data, png_default_flush, png_read_fill_buffer + to nonexported form, but with PNGAPI, and removed them from module def + files. + +Version 1.2.3rc6 [May 14, 2002] + Removed "PNGAPI" from png_zalloc() and png_zfree() in png.c + Changed "Gz" to "Gd" in projects/msvc/libpng.dsp and zlib.dsp. + Removed leftover libpng-config "sed" script from four makefiles. + Revised libpng-config creating script in 16 makefiles. + +Version 1.2.3 [May 22, 2002] + Revised libpng-config target in makefile.cygwin. + Removed description of png_set_mem_fn() from documentation. + Revised makefile.freebsd. + Minor cosmetic changes to 15 makefiles, e.g., $(DI) = $(DESTDIR)/$(INCDIR). + Revised projects/msvc/README.txt + Changed -lpng to -lpngNN in LDFLAGS in several makefiles. + +Version 1.2.4beta1 [May 24, 2002] + Added libpng.pc and libpng-config to "all:" target in 16 makefiles. + Fixed bug in 16 makefiles: $(DESTDIR)/$(LIBPATH) to $(DESTDIR)$(LIBPATH) + Added missing "\" before closing double quote in makefile.gcmmx. + Plugged various memory leaks; added png_malloc_warn() and png_set_text_2() + functions. + +Version 1.2.4beta2 [June 25, 2002] + Plugged memory leak of png_ptr->current_text (Matt Holgate). + Check for buffer overflow before reading CRC in pngpread.c (Warwick Allison) + Added -soname to the loader flags in makefile.dec, makefile.sgi, and + makefile.sggcc. + Added "test-installed" target to makefile.linux, makefile.gcmmx, + makefile.sgi, and makefile.sggcc. + +Version 1.2.4beta3 [June 28, 2002] + Plugged memory leak of row_buf in pngtest.c when there is a png_error(). + Detect buffer overflow in pngpread.c when IDAT is corrupted with extra data. + Added "test-installed" target to makefile.32sunu, makefile.64sunu, + makefile.beos, makefile.darwin, makefile.dec, makefile.macosx, + makefile.solaris, makefile.hpux, makefile.hpgcc, and makefile.so9. + +Version 1.2.4rc1 and 1.0.14rc1 [July 2, 2002] + Added "test-installed" target to makefile.cygwin and makefile.sco. + Revised pnggccrd.c to be able to back out version 1.0.x via PNG_1_0_X macro. + +Version 1.2.4 and 1.0.14 [July 8, 2002] + Changed png_warning() to png_error() when width is too large to process. + +Version 1.2.4patch01 [July 20, 2002] + Revised makefile.cygwin to use DLL number 12 instead of 13. + +Version 1.2.5beta1 [August 6, 2002] + Added code to contrib/gregbook/readpng2.c to ignore unused chunks. + Replaced toucan.png in contrib/gregbook (it has been corrupt since 1.0.11) + Removed some stray *.o files from contrib/gregbook. + Changed png_error() to png_warning() about "Too much data" in pngpread.c + and about "Extra compressed data" in pngrutil.c. + Prevent png_ptr->pass from exceeding 7 in png_push_finish_row(). + Updated makefile.hpgcc + Updated png.c and pnggccrd.c handling of return from png_mmx_support() + +Version 1.2.5beta2 [August 15, 2002] + Only issue png_warning() about "Too much data" in pngpread.c when avail_in + is nonzero. + Updated makefiles to install a separate libpng.so.3 with its own rpath. + +Version 1.2.5rc1 and 1.0.15rc1 [August 24, 2002] + Revised makefiles to not remove previous minor versions of shared libraries. + +Version 1.2.5rc2 and 1.0.15rc2 [September 16, 2002] + Revised 13 makefiles to remove "-lz" and "-L$(ZLIBLIB)", etc., from shared + library loader directive. + Added missing "$OBJSDLL" line to makefile.gcmmx. + Added missing "; fi" to makefile.32sunu. + +Version 1.2.5rc3 and 1.0.15rc3 [September 18, 2002] + Revised libpng-config script. + +Version 1.2.5 and 1.0.15 [October 3, 2002] + Revised makefile.macosx, makefile.darwin, makefile.hpgcc, and makefile.hpux, + and makefile.aix. + Relocated two misplaced PNGAPI lines in pngtest.c + +Version 1.2.6beta1 [October 22, 2002] + Commented out warning about uninitialized mmx_support in pnggccrd.c. + Changed "IBMCPP__" flag to "__IBMCPP__" in pngconf.h. + Relocated two more misplaced PNGAPI lines in pngtest.c + Fixed memory overrun bug in png_do_read_filler() with 16-bit datastreams, + introduced in version 1.0.2. + Revised makefile.macosx, makefile.dec, makefile.aix, and makefile.32sunu. + +Version 1.2.6beta2 [November 1, 2002] + Added libpng-config "--ldopts" output. + Added "AR=ar" and "ARFLAGS=rc" and changed "ar rc" to "$(AR) $(ARFLAGS)" + in makefiles. + +Version 1.2.6beta3 [July 18, 2004] + Reverted makefile changes from version 1.2.6beta2 and some of the changes + from version 1.2.6beta1; these will be postponed until version 1.2.7. + Version 1.2.6 is going to be a simple bugfix release. + Changed the one instance of "ln -sf" to "ln -f -s" in each Sun makefile. + Fixed potential overrun in pngerror.c by using strncpy instead of memcpy. + Added "#!/bin/sh" at the top of configure, for recognition of the + 'x' flag under Cygwin (Cosmin). + Optimized vacuous tests that silence compiler warnings, in png.c (Cosmin). + Added support for PNG_USER_CONFIG, in pngconf.h (Cosmin). + Fixed the special memory handler for Borland C under DOS, in pngmem.c + (Cosmin). + Removed some spurious assignments in pngrutil.c (Cosmin). + Replaced 65536 with 65536L, and 0xffff with 0xffffL, to silence warnings + on 16-bit platforms (Cosmin). + Enclosed shift op expressions in parentheses, to silence warnings (Cosmin). + Used proper type png_fixed_point, to avoid problems on 16-bit platforms, + in png_handle_sRGB() (Cosmin). + Added compression_type to png_struct, and optimized the window size + inside the deflate stream (Cosmin). + Fixed definition of isnonalpha(), in pngerror.c and pngrutil.c (Cosmin). + Fixed handling of unknown chunks that come after IDAT (Cosmin). + Allowed png_error() and png_warning() to work even if png_ptr == NULL + (Cosmin). + Replaced row_info->rowbytes with row_bytes in png_write_find_filter() + (Cosmin). + Fixed definition of PNG_LIBPNG_VER_DLLNUM (Simon-Pierre). + Used PNG_LIBPNG_VER and PNG_LIBPNG_VER_STRING instead of the hardcoded + values in png.c (Simon-Pierre, Cosmin). + Initialized png_libpng_ver[] with PNG_LIBPNG_VER_STRING (Simon-Pierre). + Replaced PNG_LIBPNG_VER_MAJOR with PNG_LIBPNG_VER_DLLNUM in png.rc + (Simon-Pierre). + Moved the definition of PNG_HEADER_VERSION_STRING near the definitions + of the other PNG_LIBPNG_VER_... symbols in png.h (Cosmin). + Relocated #ifndef PNGAPI guards in pngconf.h (Simon-Pierre, Cosmin). + Updated scripts/makefile.vc(a)win32 (Cosmin). + Updated the MSVC project (Simon-Pierre, Cosmin). + Updated the Borland C++ Builder project (Cosmin). + Avoided access to asm_flags in pngvcrd.c, if PNG_1_0_X is defined (Cosmin). + Commented out warning about uninitialized mmx_support in pngvcrd.c (Cosmin). + Removed scripts/makefile.bd32 and scripts/pngdef.pas (Cosmin). + Added extra guard around inclusion of Turbo C memory headers, in pngconf.h + (Cosmin). + Renamed projects/msvc/ to projects/visualc6/, and projects/borland/ to + projects/cbuilder5/ (Cosmin). + Moved projects/visualc6/png32ms.def to scripts/pngw32.def, + and projects/visualc6/png.rc to scripts/pngw32.rc (Cosmin). + Added projects/visualc6/pngtest.dsp; removed contrib/msvctest/ (Cosmin). + Changed line endings to DOS style in cbuilder5 and visualc6 files, even + in the tar.* distributions (Cosmin). + Updated contrib/visupng/VisualPng.dsp (Cosmin). + Updated contrib/visupng/cexcept.h to version 2.0.0 (Cosmin). + Added a separate distribution with "configure" and supporting files (Junichi). + +Version 1.2.6beta4 [July 28, 2004] + Added user ability to change png_size_t via a PNG_SIZE_T macro. + Added png_sizeof() and png_convert_size() functions. + Added PNG_SIZE_MAX (maximum value of a png_size_t variable. + Added check in png_malloc_default() for (size_t)size != (png_uint_32)size + which would indicate an overflow. + Changed sPLT failure action from png_error to png_warning and abandon chunk. + Changed sCAL and iCCP failures from png_error to png_warning and abandon. + Added png_get_uint_31(png_ptr, buf) function. + Added PNG_UINT_32_MAX macro. + Renamed PNG_MAX_UINT to PNG_UINT_31_MAX. + Made png_zalloc() issue a png_warning and return NULL on potential + overflow. + Turn on PNG_NO_ZALLOC_ZERO by default in version 1.2.x + Revised "clobber list" in pnggccrd.c so it will compile under gcc-3.4. + Revised Borland portion of png_malloc() to return NULL or issue + png_error() according to setting of PNG_FLAG_MALLOC_NULL_MEM_OK. + Added PNG_NO_SEQUENTIAL_READ_SUPPORTED macro to conditionally remove + sequential read support. + Added some "#if PNG_WRITE_SUPPORTED" blocks. + Added #ifdef to remove some redundancy in png_malloc_default(). + Use png_malloc instead of png_zalloc to allocate the pallete. + +Version 1.0.16rc1 and 1.2.6rc1 [August 4, 2004] + Fixed buffer overflow vulnerability in png_handle_tRNS() + Fixed integer arithmetic overflow vulnerability in png_read_png(). + Fixed some harmless bugs in png_handle_sBIT, etc, that would cause + duplicate chunk types to go undetected. + Fixed some timestamps in the -config version + Rearranged order of processing of color types in png_handle_tRNS(). + Added ROWBYTES macro to calculate rowbytes without integer overflow. + Updated makefile.darwin and removed makefile.macosx from scripts directory. + Imposed default one million column, one-million row limits on the image + dimensions, and added png_set_user_limits() function to override them. + Revised use of PNG_SET_USER_LIMITS_SUPPORTED macro. + Fixed wrong cast of returns from png_get_user_width|height_max(). + Changed some "keep the compiler happy" from empty statements to returns, + Revised libpng.txt to remove 1.2.x stuff from the 1.0.x distribution + +Version 1.0.16rc2 and 1.2.6rc2 [August 7, 2004] + Revised makefile.darwin and makefile.solaris. Removed makefile.macosx. + Revised pngtest's png_debug_malloc() to use png_malloc() instead of + png_malloc_default() which is not supposed to be exported. + Fixed off-by-one error in one of the conversions to PNG_ROWBYTES() in + pngpread.c. Bug was introduced in 1.2.6rc1. + Fixed bug in RGB to RGBX transformation introduced in 1.2.6rc1. + Fixed old bug in RGB to Gray transformation. + Fixed problem with 64-bit compilers by casting arguments to abs() + to png_int_32. + Changed "ln -sf" to "ln -f -s" in three makefiles (solaris, sco, so9). + Changed "HANDLE_CHUNK_*" to "PNG_HANDLE_CHUNK_*" (Cosmin) + Added "-@/bin/rm -f $(DL)/$(LIBNAME).so.$(PNGMAJ)" to 15 *NIX makefiles. + Added code to update the row_info->colortype in png_do_read_filler() (MSB). + +Version 1.0.16rc3 and 1.2.6rc3 [August 9, 2004] + Eliminated use of "abs()" in testing cHRM and gAMA values, to avoid + trouble with some 64-bit compilers. Created PNG_OUT_OF_RANGE() macro. + Revised documentation of png_set_keep_unknown_chunks(). + Check handle_as_unknown status in pngpread.c, as in pngread.c previously. + Moved "PNG_HANDLE_CHUNK_*" macros out of PNG_INTERNAL section of png.h + Added "rim" definitions for CONST4 and CONST6 in pnggccrd.c + +Version 1.0.16rc4 and 1.2.6rc4 [August 10, 2004] + Fixed mistake in pngtest.c introduced in 1.2.6rc2 (declaration of + "pinfo" was out of place). + +Version 1.0.16rc5 and 1.2.6rc5 [August 10, 2004] + Moved "PNG_HANDLE_CHUNK_*" macros out of PNG_ASSEMBLER_CODE_SUPPORTED + section of png.h where they were inadvertently placed in version rc3. + +Version 1.2.6 and 1.0.16 [August 15, 2004] + Revised pngtest so memory allocation testing is only done when PNG_DEBUG==1. + +Version 1.2.7beta1 [August 26, 2004] + Removed unused pngasmrd.h file. + Removed references to uu.net for archived files. Added references to + PNG Spec (second edition) and the PNG ISO/IEC Standard. + Added "test-dd" target in 15 makefiles, to run pngtest in DESTDIR. + Fixed bug with "optimized window size" in the IDAT datastream, that + causes libpng to write PNG files with incorrect zlib header bytes. + +Version 1.2.7beta2 [August 28, 2004] + Fixed bug with sCAL chunk and big-endian machines (David Munro). + Undid new code added in 1.2.6rc2 to update the color_type in + png_set_filler(). + Added png_set_add_alpha() that updates color type. + +Version 1.0.17rc1 and 1.2.7rc1 [September 4, 2004] + Revised png_set_strip_filler() to not remove alpha if color_type has alpha. + +Version 1.2.7 and 1.0.17 [September 12, 2004] + Added makefile.hp64 + Changed projects/msvc/png32ms.def to scripts/png32ms.def in makefile.cygwin + +Version 1.2.8beta1 [November 1, 2004] + Fixed bug in png_text_compress() that would fail to complete a large block. + Fixed bug, introduced in libpng-1.2.7, that overruns a buffer during + strip alpha operation in png_do_strip_filler(). + Added PNG_1_2_X definition in pngconf.h + Use #ifdef to comment out png_info_init in png.c and png_read_init in + pngread.c (as of 1.3.0) + +Version 1.2.8beta2 [November 2, 2004] + Reduce color_type to a nonalpha type after strip alpha operation in + png_do_strip_filler(). + +Version 1.2.8beta3 [November 3, 2004] + Revised definitions of PNG_MAX_UINT_32, PNG_MAX_SIZE, and PNG_MAXSUM + +Version 1.2.8beta4 [November 12, 2004] + Fixed (again) definition of PNG_LIBPNG_VER_DLLNUM in png.h (Cosmin). + Added PNG_LIBPNG_BUILD_PRIVATE in png.h (Cosmin). + Set png_ptr->zstream.data_type to Z_BINARY, to avoid unnecessary detection + of data type in deflate (Cosmin). + Deprecated but continue to support SPECIALBUILD and PRIVATEBUILD in favor of + PNG_LIBPNG_BUILD_SPECIAL_STRING and PNG_LIBPNG_BUILD_PRIVATE_STRING. + +Version 1.2.8beta5 [November 20, 2004] + Use png_ptr->flags instead of png_ptr->transformations to pass + PNG_STRIP_ALPHA info to png_do_strip_filler(), to preserve ABI + compatibility. + Revised handling of SPECIALBUILD, PRIVATEBUILD, + PNG_LIBPNG_BUILD_SPECIAL_STRING and PNG_LIBPNG_BUILD_PRIVATE_STRING. + +Version 1.2.8rc1 [November 24, 2004] + Moved handling of BUILD macros from pngconf.h to png.h + Added definition of PNG_LIBPNG_BASE_TYPE in png.h, inadvertently + omitted from beta5. + Revised scripts/pngw32.rc + Despammed mailing addresses by masking "@" with "at". + Inadvertently installed a supposedly faster test version of pngrutil.c + +Version 1.2.8rc2 [November 26, 2004] + Added two missing "\" in png.h + Change tests in pngread.c and pngpread.c to + if (png_ptr->transformations || (png_ptr->flags&PNG_FLAG_STRIP_ALPHA)) + png_do_read_transformations(png_ptr); + +Version 1.2.8rc3 [November 28, 2004] + Reverted pngrutil.c to version libpng-1.2.8beta5. + Added scripts/makefile.elf with supporting code in pngconf.h for symbol + versioning (John Bowler). + +Version 1.2.8rc4 [November 29, 2004] + Added projects/visualc7 (Simon-pierre). + +Version 1.2.8rc5 [November 29, 2004] + Fixed new typo in scripts/pngw32.rc + +Version 1.2.8 [December 3, 2004] + Removed projects/visualc7, added projects/visualc71. + +Version 1.2.9beta1 [February 21, 2006] + Initialized some structure members in pngwutil.c to avoid gcc-4.0.0 complaints + Revised man page and libpng.txt to make it clear that one should not call + png_read_end or png_write_end after png_read_png or png_write_png. + Updated references to png-mng-implement mailing list. + Fixed an incorrect typecast in pngrutil.c + Added PNG_NO_READ_SUPPORTED conditional for making a write-only library. + Added PNG_NO_WRITE_INTERLACING_SUPPORTED conditional. + Optimized alpha-inversion loops in pngwtran.c + Moved test for nonzero gamma outside of png_build_gamma_table() in pngrtran.c + Make sure num_trans is <= 256 before copying data in png_set_tRNS(). + Make sure num_palette is <= 256 before copying data in png_set_PLTE(). + Interchanged order of write_swap_alpha and write_invert_alpha transforms. + Added parentheses in the definition of PNG_LIBPNG_BUILD_TYPE (Cosmin). + Optimized zlib window flag (CINFO) in contrib/pngsuite/*.png (Cosmin). + Updated scripts/makefile.bc32 for Borland C++ 5.6 (Cosmin). + Exported png_get_uint_32, png_save_uint_32, png_get_uint_16, png_save_uint_16, + png_get_int_32, png_save_int_32, png_get_uint_31 (Cosmin). + Added type cast (png_byte) in png_write_sCAL() (Cosmin). + Fixed scripts/makefile.cygwin (Christian Biesinger, Cosmin). + Default iTXt support was inadvertently enabled. + +Version 1.2.9beta2 [February 21, 2006] + Check for png_rgb_to_gray and png_gray_to_rgb read transformations before + checking for png_read_dither in pngrtran.c + Revised checking of chromaticity limits to accommodate extended RGB + colorspace (John Denker). + Changed line endings in some of the project files to CRLF, even in the + "Unix" tar distributions (Cosmin). + Made png_get_int_32 and png_save_int_32 always available (Cosmin). + Updated scripts/pngos2.def, scripts/pngw32.def and projects/wince/png32ce.def + with the newly exported functions. + Eliminated distributions without the "configure" script. + Updated INSTALL instructions. + +Version 1.2.9beta3 [February 24, 2006] + Fixed CRCRLF line endings in contrib/visupng/VisualPng.dsp + Made libpng.pc respect EXEC_PREFIX (D. P. Kreil, J. Bowler) + Removed reference to pngasmrd.h from Makefile.am + Renamed CHANGES to ChangeLog. + Renamed LICENSE to COPYING. + Renamed ANNOUNCE to NEWS. + Created AUTHORS file. + +Version 1.2.9beta4 [March 3, 2006] + Changed definition of PKGCONFIG from $prefix/lib to $libdir in configure.ac + Reverted to filenames LICENSE and ANNOUNCE; removed AUTHORS and COPYING. + Removed newline from the end of some error and warning messages. + Removed test for sqrt() from configure.ac and configure. + Made swap tables in pngtrans.c PNG_CONST (Carlo Bramix). + Disabled default iTXt support that was inadvertently enabled in + libpng-1.2.9beta1. + Added "OS2" to list of systems that don't need underscores, in pnggccrd.c + Removed libpng version and date from *.c files. + +Version 1.2.9beta5 [March 4, 2006] + Removed trailing blanks from source files. + Put version and date of latest change in each source file, and changed + copyright year accordingly. + More cleanup of configure.ac, Makefile.am, and associated scripts. + Restored scripts/makefile.elf which was inadvertently deleted. + +Version 1.2.9beta6 [March 6, 2006] + Fixed typo (RELEASE) in configuration files. + +Version 1.2.9beta7 [March 7, 2006] + Removed libpng.vers and libpng.sym from libpng12_la_SOURCES in Makefile.am + Fixed inconsistent #ifdef's around png_sig_bytes() and png_set_sCAL_s() + in png.h. + Updated makefile.elf as suggested by debian. + Made cosmetic changes to some makefiles, adding LN_SF and other macros. + Made some makefiles accept "exec_prefix". + +Version 1.2.9beta8 [March 9, 2006] + Fixed some "#if defined (..." which should be "#if defined(..." + Bug introduced in libpng-1.2.8. + Fixed inconsistency in definition of png_default_read_data() + Restored blank that was lost from makefile.sggcc "clean" target in beta7. + Revised calculation of "current" and "major" for irix in ltmain.sh + Changed "mkdir" to "MKDIR_P" in some makefiles. + Separated PNG_EXPAND and PNG_EXPAND_tRNS. + Added png_set_expand_gray_1_2_4_to_8() and deprecated + png_set_gray_1_2_4_to_8() which also expands tRNS to alpha. + +Version 1.2.9beta9 [March 10, 2006] + Include "config.h" in pngconf.h when available. + Added some checks for NULL png_ptr or NULL info_ptr (timeless) + +Version 1.2.9beta10 [March 20, 2006] + Removed extra CR from contrib/visualpng/VisualPng.dsw (Cosmin) + Made pnggccrd.c PIC-compliant (Christian Aichinger). + Added makefile.mingw (Wolfgang Glas). + Revised pngconf.h MMX checking. + +Version 1.2.9beta11 [March 22, 2006] + Fixed out-of-order declaration in pngwrite.c that was introduced in beta9 + Simplified some makefiles by using LIBSO, LIBSOMAJ, and LIBSOVER macros. + +Version 1.2.9rc1 [March 31, 2006] + Defined PNG_USER_PRIVATEBUILD when including "pngusr.h" (Cosmin). + Removed nonsensical assertion check from pngtest.c (Cosmin). + +Version 1.2.9 [April 14, 2006] + Revised makefile.beos and added "none" selector in ltmain.sh + +Version 1.2.10beta1 [April 15, 2006] + Renamed "config.h" to "png_conf.h" and revised Makefile.am to add + -DPNG_BUILDING_LIBPNG to compile directive, and modified pngconf.h + to include png_conf.h only when PNG_BUILDING_LIBPNG is defined. + +Version 1.2.10beta2 [April 15, 2006] + Manually updated Makefile.in and configure. Changed png_conf.h.in + back to config.h. + +Version 1.2.10beta3 [April 15, 2006] + Change png_conf.h back to config.h in pngconf.h. + +Version 1.2.10beta4 [April 16, 2006] + Change PNG_BUILDING_LIBPNG to PNG_CONFIGURE_LIBPNG in config/Makefile*. + +Version 1.2.10beta5 [April 16, 2006] + Added a configure check for compiling assembler code in pnggccrd.c + +Version 1.2.10beta6 [April 17, 2006] + Revised the configure check for pnggccrd.c + Moved -DPNG_CONFIGURE_LIBPNG into @LIBPNG_DEFINES@ + Added @LIBPNG_DEFINES@ to arguments when building libpng.sym + +Version 1.2.10beta7 [April 18, 2006] + Change "exec_prefix=$prefix" to "exec_prefix=$(prefix)" in makefiles. + +Version 1.2.10rc1 [April 19, 2006] + Ensure pngconf.h doesn't define both PNG_USE_PNGGCCRD and PNG_USE_PNGVCRD + Fixed "LN_FS" typo in makefile.sco and makefile.solaris. + +Version 1.2.10rc2 [April 20, 2006] + Added a backslash between -DPNG_CONFIGURE_LIBPNG and -DPNG_NO_ASSEMBLER_CODE + in configure.ac and configure + Made the configure warning about versioned symbols less arrogant. + +Version 1.2.10rc3 [April 21, 2006] + Added a note in libpng.txt that png_set_sig_bytes(8) can be used when + writing an embedded PNG without the 8-byte signature. + Revised makefiles and configure to avoid making links to libpng.so.* + +Version 1.2.10 [April 23, 2006] + Reverted configure to "rc2" state. + +Version 1.2.11beta1 [May 31, 2006] + scripts/libpng.pc.in contained "configure" style version info and would + not work with makefiles. + The shared-library makefiles were linking to libpng.so.0 instead of + libpng.so.3 compatibility as the library. + +Version 1.2.11beta2 [June 2, 2006] + Increased sprintf buffer from 50 to 52 chars in pngrutil.c to avoid + buffer overflow. + Fixed bug in example.c (png_set_palette_rgb -> png_set_palette_to_rgb) + +Version 1.2.11beta3 [June 5, 2006] + Prepended "#! /bin/sh" to ltmail.sh and contrib/pngminus/*.sh (Cosmin). + Removed the accidental leftover Makefile.in~ (Cosmin). + Avoided potential buffer overflow and optimized buffer in + png_write_sCAL(), png_write_sCAL_s() (Cosmin). + Removed the include directories and libraries from CFLAGS and LDFLAGS + in scripts/makefile.gcc (Nelson A. de Oliveira, Cosmin). + +Version 1.2.11beta4 [June 6, 2006] + Allow zero-length IDAT chunks after the entire zlib datastream, but not + after another intervening chunk type. + +Version 1.0.19rc1, 1.2.11rc1 [June 13, 2006] + Deleted extraneous square brackets from [config.h] in configure.ac + +Version 1.0.19rc2, 1.2.11rc2 [June 14, 2006] + Added prototypes for PNG_INCH_CONVERSIONS functions to png.h + Revised INSTALL and autogen.sh + Fixed typo in several makefiles (-W1 should be -Wl) + Added typedef for png_int_32 and png_uint_32 on 64-bit systems. + +Version 1.0.19rc3, 1.2.11rc3 [June 15, 2006] + Removed the new typedefs for 64-bit systems (delay until version 1.4.0) + Added one zero element to png_gamma_shift[] array in pngrtran.c to avoid + reading out of bounds. + +Version 1.0.19rc4, 1.2.11rc4 [June 15, 2006] + Really removed the new typedefs for 64-bit systems. + +Version 1.0.19rc5, 1.2.11rc5 [June 22, 2006] + Removed png_sig_bytes entry from scripts/pngw32.def + +Version 1.0.19, 1.2.11 [June 26, 2006] + None. + +Version 1.0.20, 1.2.12 [June 27, 2006] + Really increased sprintf buffer from 50 to 52 chars in pngrutil.c to avoid + buffer overflow. + +Version 1.2.13beta1 [October 2, 2006] + Removed AC_FUNC_MALLOC from configure.ac + Work around Intel-Mac compiler bug by setting PNG_NO_MMX_CODE in pngconf.h + Change "logical" to "bitwise" throughout documentation. + Detect and fix attempt to write wrong iCCP profile length. + +Version 1.0.21, 1.2.13 [November 14, 2006] + Fix potential buffer overflow in sPLT chunk handler. + Fix Makefile.am to not try to link to noexistent files. + Check all exported functions for NULL png_ptr. + +Version 1.2.14beta1 [November 17, 2006] + Relocated three misplaced tests for NULL png_ptr. + Built Makefile.in with automake-1.9.6 instead of 1.9.2. + Build configure with autoconf-2.60 instead of 2.59 + +Version 1.2.14beta2 [November 17, 2006] + Added some typecasts in png_zalloc(). + +Version 1.2.14rc1 [November 20, 2006] + Changed "strtod" to "png_strtod" in pngrutil.c + +Version 1.0.22, 1.2.14 [November 27, 2006] + Added missing "$(srcdir)" in Makefile.am and Makefile.in + +Version 1.2.15beta1 [December 3, 2006] + Generated configure with autoconf-2.61 instead of 2.60 + Revised configure.ac to update libpng.pc and libpng-config. + +Version 1.2.15beta2 [December 3, 2006] + Always export MMX asm functions, just stubs if not building pnggccrd.c + +Version 1.2.15beta3 [December 4, 2006] + Add "png_bytep" typecast to profile while calculating length in pngwutil.c + +Version 1.2.15beta4 [December 7, 2006] + Added scripts/CMakeLists.txt + Changed PNG_NO_ASSEMBLER_CODE to PNG_NO_MMX_CODE in scripts, like 1.4.0beta + +Version 1.2.15beta5 [December 7, 2006] + Changed some instances of PNG_ASSEMBLER_* to PNG_MMX_* in pnggccrd.c + Revised scripts/CMakeLists.txt + +Version 1.2.15beta6 [December 13, 2006] + Revised scripts/CMakeLists.txt and configure.ac + +Version 1.2.15rc1 [December 18, 2006] + Revised scripts/CMakeLists.txt + +Version 1.2.15rc2 [December 21, 2006] + Added conditional #undef jmpbuf in pngtest.c to undo #define in AIX headers. + Added scripts/makefile.nommx + +Version 1.2.15rc3 [December 25, 2006] + Fixed shared library numbering error that was introduced in 1.2.15beta6. + +Version 1.2.15rc4 [December 27, 2006] + Fixed handling of rgb_to_gray when png_ptr->color.gray isn't set. + +Version 1.2.15rc5 [December 31, 2006] + Revised handling of rgb_to_gray. + +Version 1.2.15 [January 5, 2007] + Added some (unsigned long) typecasts in pngtest.c to avoid printing errors. + +Version 1.2.16beta1 [January 6, 2007] + Fix bugs in makefile.nommx + +Version 1.2.16beta2 [January 16, 2007] + Revised scripts/CMakeLists.txt + +Version 1.2.16 [January 31, 2007] + No changes. + +Version 1.2.17beta1 [March 6, 2007] + Revised scripts/CMakeLists.txt to install both shared and static libraries. + Deleted a redundant line from pngset.c. + +Version 1.2.17beta2 [April 26, 2007] + Relocated misplaced test for png_ptr == NULL in pngpread.c + Change "==" to "&" for testing PNG_RGB_TO_GRAY_ERR & PNG_RGB_TO_GRAY_WARN + flags. + Changed remaining instances of PNG_ASSEMBLER_* to PNG_MMX_* + Added pngerror() when write_IHDR fails in deflateInit2(). + Added "const" to some array declarations. + Mention examples of libpng usage in the libpng*.txt and libpng.3 documents. + +Version 1.2.17rc1 [May 4, 2007] + No changes. + +Version 1.2.17rc2 [May 8, 2007] + Moved several PNG_HAVE_* macros out of PNG_INTERNAL because applications + calling set_unknown_chunk_location() need them. + Changed transformation flag from PNG_EXPAND_tRNS to PNG_EXPAND in + png_set_expand_gray_1_2_4_to_8(). + Added png_ptr->unknown_chunk to hold working unknown chunk data, so it + can be free'ed in case of error. Revised unknown chunk handling in + pngrutil.c and pngpread.c to use this structure. + +Version 1.2.17rc3 [May 8, 2007] + Revised symbol-handling in configure script. + +Version 1.2.17rc4 [May 10, 2007] + Revised unknown chunk handling to avoid storing unknown critical chunks. + +Version 1.0.25 [May 15, 2007] +Version 1.2.17 [May 15, 2007] + Added "png_ptr->num_trans=0" before error return in png_handle_tRNS, + to eliminate a vulnerability (CVE-2007-2445, CERT VU#684664) + +Version 1.0.26 [May 15, 2007] +Version 1.2.18 [May 15, 2007] + Reverted the libpng-1.2.17rc3 change to symbol-handling in configure script + +Version 1.2.19beta1 [May 18, 2007] + Changed "const static" to "static PNG_CONST" everywhere, mostly undoing + change of libpng-1.2.17beta2. Changed other "const" to "PNG_CONST" + Changed some handling of unused parameters, to avoid compiler warnings. + "if (unused == NULL) return;" becomes "unused = unused". + +Version 1.2.19beta2 [May 18, 2007] + Only use the valid bits of tRNS value in png_do_expand() (Brian Cartier) + +Version 1.2.19beta3 [May 19, 2007] + Add some "png_byte" typecasts in png_check_keyword() and write new_key + instead of key in zTXt chunk (Kevin Ryde). + +Version 1.2.19beta4 [May 21, 2007] + Add png_snprintf() function and use it in place of sprint() for improved + defense against buffer overflows. + +Version 1.2.19beta5 [May 21, 2007] + Fixed png_handle_tRNS() to only use the valid bits of tRNS value. + Changed handling of more unused parameters, to avoid compiler warnings. + Removed some PNG_CONST in pngwutil.c to avoid compiler warnings. + +Version 1.2.19beta6 [May 22, 2007] + Added some #ifdef PNG_MMX_CODE_SUPPORTED where needed in pngvcrd.c + Added a special "_MSC_VER" case that defines png_snprintf to _snprintf + +Version 1.2.19beta7 [May 22, 2007] + Squelched png_squelch_warnings() in pnggccrd.c and added + an #ifdef PNG_MMX_CODE_SUPPORTED block around the declarations that caused + the warnings that png_squelch_warnings was squelching. + +Version 1.2.19beta8 [May 22, 2007] + Removed __MMX__ from test in pngconf.h. + +Version 1.2.19beta9 [May 23, 2007] + Made png_squelch_warnings() available via PNG_SQUELCH_WARNINGS macro. + Revised png_squelch_warnings() so it might work. + Updated makefile.sgcc and makefile.solaris; added makefile.solaris-x86. + +Version 1.2.19beta10 [May 24, 2007] + Resquelched png_squelch_warnings(), use "__attribute__((used))" instead. + +Version 1.4.0beta1 [April 20, 2006] + Enabled iTXt support (changes png_struct, thus requires so-number change). + Cleaned up PNG_ASSEMBLER_CODE_SUPPORTED vs PNG_MMX_CODE_SUPPORTED + Eliminated PNG_1_0_X and PNG_1_2_X macros. + Removed deprecated functions png_read_init, png_write_init, png_info_init, + png_permit_empty_plte, png_set_gray_1_2_4_to_8, png_check_sig, and + removed the deprecated macro PNG_MAX_UINT. + Moved "PNG_INTERNAL" parts of png.h and pngconf.h into pngintrn.h + Removed many WIN32_WCE #ifdefs (Cosmin). + Reduced dependency on C-runtime library when on Windows (Simon-Pierre) + Replaced sprintf() with png_sprintf() (Simon-Pierre) + +Version 1.4.0beta2 [April 20, 2006] + Revised makefiles and configure to avoid making links to libpng.so.* + Moved some leftover MMX-related defines from pngconf.h to pngintrn.h + Updated scripts/pngos2.def, pngw32.def, and projects/wince/png32ce.def + +Version 1.4.0beta3 [May 10, 2006] + Updated scripts/pngw32.def to comment out MMX functions. + Added PNG_NO_GET_INT_32 and PNG_NO_SAVE_INT_32 macros. + Scripts/libpng.pc.in contained "configure" style version info and would + not work with makefiles. + Revised pngconf.h and added pngconf.h.in, so makefiles and configure can + pass defines to libpng and applications. + +Version 1.4.0beta4 [May 11, 2006] + Revised configure.ac, Makefile.am, and many of the makefiles to write + their defines in pngconf.h. + +Version 1.4.0beta5 [May 15, 2006] + Added a missing semicolon in Makefile.am and Makefile.in + Deleted extraneous square brackets from configure.ac + +Version 1.4.0beta6 [June 2, 2006] + Increased sprintf buffer from 50 to 52 chars in pngrutil.c to avoid + buffer overflow. + Changed sonum from 0 to 1. + Removed unused prototype for png_check_sig() from png.h + +Version 1.4.0beta7 [June 16, 2006] + Exported png_write_sig (Cosmin). + Optimized buffer in png_handle_cHRM() (Cosmin). + Set pHYs = 2835 x 2835 pixels per meter, and added + sCAL = 0.352778e-3 x 0.352778e-3 meters, in pngtest.png (Cosmin). + Added png_set_benign_errors(), png_benign_error(), png_chunk_benign_error(). + Added typedef for png_int_32 and png_uint_32 on 64-bit systems. + Added "(unsigned long)" typecast on png_uint_32 variables in printf lists. + +Version 1.4.0beta8 [June 22, 2006] + Added demonstration of user chunk support in pngtest.c, to support the + public sTER chunk and a private vpAg chunk. + +Version 1.4.0beta9 [July 3, 2006] + Removed ordinals from scripts/pngw32.def and removed png_info_int and + png_set_gray_1_2_4_to_8 entries. + Inline call of png_get_uint_32() in png_get_uint_31(). + Use png_get_uint_31() to get vpAg width and height in pngtest.c + Removed WINCE and Netware projects. + Removed standalone Y2KINFO file. + +Version 1.4.0beta10 [July 12, 2006] + Eliminated automatic copy of pngconf.h to pngconf.h.in from configure and + some makefiles, because it was not working reliably. Instead, distribute + pngconf.h.in along with pngconf.h and cause configure and some of the + makefiles to update pngconf.h from pngconf.h.in. + Added pngconf.h to DEPENDENCIES in Makefile.am + +Version 1.4.0beta11 [August 19, 2006] + Removed AC_FUNC_MALLOC from configure.ac. + Added a warning when writing iCCP profile with mismatched profile length. + Patched pnggccrd.c to assemble on x86_64 platforms. + Moved chunk header reading into a separate function png_read_chunk_header() + in pngrutil.c. The chunk header (len+sig) is now serialized in a single + operation (Cosmin). + Implemented support for I/O states. Added png_ptr member io_state, and + functions png_get_io_chunk_name() and png_get_io_state() in pngget.c + (Cosmin). + Added png_get_io_chunk_name and png_get_io_state to scripts/*.def (Cosmin). + Renamed scripts/pngw32.* to scripts/pngwin.* (Cosmin). + Removed the include directories and libraries from CFLAGS and LDFLAGS + in scripts/makefile.gcc (Cosmin). + Used png_save_uint_32() to set vpAg width and height in pngtest.c (Cosmin). + Cast to proper type when getting/setting vpAg units in pngtest.c (Cosmin). + Added pngintrn.h to the Visual C++ projects (Cosmin). + Removed scripts/list (Cosmin). + Updated copyright year in scripts/pngwin.def (Cosmin). + Removed PNG_TYPECAST_NULL and used standard NULL consistently (Cosmin). + Disallowed the user to redefine png_size_t, and enforced a consistent use + of png_size_t across libpng (Cosmin). + Changed the type of png_ptr->rowbytes, PNG_ROWBYTES() and friends + to png_size_t (Cosmin). + Removed png_convert_size() and replaced png_sizeof with sizeof (Cosmin). + Removed some unnecessary type casts (Cosmin). + Changed prototype of png_get_compression_buffer_size() and + png_set_compression_buffer_size() to work with png_size_t instead of + png_uint_32 (Cosmin). + Removed png_memcpy_check() and png_memset_check() (Cosmin). + Fixed a typo (png_byte --> png_bytep) in libpng.3 and libpng.txt (Cosmin). + Clarified that png_zalloc() does not clear the allocated memory, + and png_zalloc() and png_zfree() cannot be PNGAPI (Cosmin). + Renamed png_mem_size_t to png_alloc_size_t, fixed its definition in + pngconf.h, and used it in all memory allocation functions (Cosmin). + Renamed pngintrn.h to pngpriv.h, added a comment at the top of the file + mentioning that the symbols declared in that file are private, and + updated the scripts and the Visual C++ projects accordingly (Cosmin). + Removed circular references between pngconf.h and pngconf.h.in in + scripts/makefile.vc*win32 (Cosmin). + Removing trailing '.' from the warning and error messages (Cosmin). + Added pngdefs.h that is built by makefile or configure, instead of + pngconf.h.in (Glenn). + Detect and fix attempt to write wrong iCCP profile length. + +Version 1.4.0beta12 [October 19, 2006] + Changed "logical" to "bitwise" in the documentation. + Work around Intel-Mac compiler bug by setting PNG_NO_MMX_CODE in pngconf.h + Add a typecast to stifle compiler warning in pngrutil.c + +Version 1.4.0beta13 [November 10, 2006] + Fix potential buffer overflow in sPLT chunk handler. + Fix Makefile.am to not try to link to noexistent files. + +Version 1.4.0beta14 [November 15, 2006] + Check all exported functions for NULL png_ptr. + +Version 1.4.0beta15 [November 17, 2006] + Relocated two misplaced tests for NULL png_ptr. + Built Makefile.in with automake-1.9.6 instead of 1.9.2. + Build configure with autoconf-2.60 instead of 2.59 + Add "install: all" in Makefile.am so "configure; make install" will work. + +Version 1.4.0beta16 [November 17, 2006] + Added a typecast in png_zalloc(). + +Version 1.4.0beta17 [December 4, 2006] + Changed "new_key[79] = '\0';" to "(*new_key)[79] = '\0';" in pngwutil.c + Add "png_bytep" typecast to profile while calculating length in pngwutil.c + +Version 1.4.0beta18 [December 7, 2006] + Added scripts/CMakeLists.txt + +Version 1.4.0beta19 [May 16, 2007] + Revised scripts/CMakeLists.txt + Rebuilt configure and Makefile.in with newer tools. + Added conditional #undef jmpbuf in pngtest.c to undo #define in AIX headers. + Added scripts/makefile.nommx + +Version 1.4.0beta20 [July 9, 2008] + Moved several PNG_HAVE_* macros from pngpriv.h to png.h because applications + calling set_unknown_chunk_location() need them. + Moved several macro definitions from pngpriv.h to pngconf.h + Merge with changes to the 1.2.X branch, as of 1.2.30beta04. + Deleted all use of the MMX assembler code and Intel-licensed optimizations. + Revised makefile.mingw + +Version 1.4.0beta21 [July 21, 2008] + Moved local array "chunkdata" from pngrutil.c to the png_struct, so + it will be freed by png_read_destroy() in case of a read error (Kurt + Christensen). + +Version 1.4.0beta22 [July 21, 2008] + Change "purpose" and "buffer" to png_ptr->chunkdata to avoid memory leaking. + +Version 1.4.0beta23 [July 22, 2008] + Change "chunkdata = NULL" to "png_ptr->chunkdata = NULL" several places in + png_decompress_chunk(). + +Version 1.4.0beta24 [July 25, 2008] + Change all remaining "chunkdata" to "png_ptr->chunkdata" in + png_decompress_chunk(), and remove "chunkdata" from parameter list. + Put a call to png_check_chunk_name() in png_read_chunk_header(). + Revised png_check_chunk_name() to reject a name with a lowercase 3rd byte. + Removed two calls to png_check_chunk_name() occuring later in the process. + Define PNG_NO_ERROR_NUMBERS by default in pngconf.h + +Version 1.4.0beta25 [July 30, 2008] + Added a call to png_check_chunk_name() in pngpread.c + Reverted png_check_chunk_name() to accept a name with a lowercase 3rd byte. + Added png_push_have_buffer() function to pngpread.c + Eliminated PNG_BIG_ENDIAN_SUPPORTED and associated png_get_* macros. + Made inline expansion of png_get_*() optional with PNG_USE_READ_MACROS. + Eliminated all PNG_USELESS_TESTS and PNG_CORRECT_PALETTE_SUPPORTED code. + Synced contrib directory and configure files with libpng-1.2.30beta06. + Eliminated no-longer-used pngdefs.h (but it's still built in the makefiles) + Relocated a misplaced "#endif /* PNG_NO_WRITE_FILTER */" in pngwutil.c + +Version 1.4.0beta26 [August 4, 2008] + Removed png_push_have_buffer() function in pngpread.c. It increased the + compiled library size slightly. + Changed "-Wall" to "-W -Wall" in the CFLAGS in all makefiles (Cosmin Truta) + Declared png_ptr "volatile" in pngread.c and pngwrite.c to avoid warnings. + Updated contrib/visupng/cexcept.h to version 2.0.1 + Added PNG_LITERAL_CHARACTER macros for #, [, and ]. + +Version 1.4.0beta27 [August 5, 2008] + Revised usage of PNG_LITERAL_SHARP in pngerror.c. + Moved newline character from individual png_debug messages into the + png_debug macros. + Allow user to #define their own png_debug, png_debug1, and png_debug2. + +Version 1.4.0beta28 [August 5, 2008] + Revised usage of PNG_LITERAL_SHARP in pngerror.c. + Added PNG_STRING_NEWLINE macro + +Version 1.4.0beta29 [August 9, 2008] + Revised usage of PNG_STRING_NEWLINE to work on non-ISO compilers. + Added PNG_STRING_COPYRIGHT macro. + Added non-ISO versions of png_debug macros. + +Version 1.4.0beta30 [August 14, 2008] + Added premultiplied alpha feature (Volker Wiendl). + +Version 1.4.0beta31 [August 18, 2008] + Moved png_set_premultiply_alpha from pngtrans.c to pngrtran.c + Removed extra crc check at the end of png_handle_cHRM(). Bug introduced + in libpng-1.4.0beta20. + +Version 1.4.0beta32 [August 19, 2008] + Added PNG_WRITE_FLUSH_SUPPORTED block around new png_flush() call. + Revised PNG_NO_STDIO version of png_write_flush() + +Version 1.4.0beta33 [August 20, 2008] + Added png_get|set_chunk_cache_max() to limit the total number of sPLT, + text, and unknown chunks that can be stored. + +Version 1.4.0beta34 [September 6, 2008] + Shortened tIME_string to 29 bytes in pngtest.c + Fixed off-by-one error introduced in png_push_read_zTXt() function in + libpng-1.2.30beta04/pngpread.c (Harald van Dijk) + +Version 1.4.0beta35 [October 6, 2008] + Changed "trans_values" to "trans_color". + Changed so-number from 0 to 14. Some OS do not like 0. + Revised makefile.darwin to fix shared library numbering. + Change png_set_gray_1_2_4_to_8() to png_set_expand_gray_1_2_4_to_8() + in example.c (debian bug report) + +Version 1.4.0beta36 [October 25, 2008] + Sync with tEXt vulnerability fix in libpng-1.2.33rc02. + +Version 1.4.0beta37 [November 13, 2008] + Added png_check_cHRM in png.c and moved checking from pngget.c, pngrutil.c, + and pngwrite.c + +Version 1.4.0beta38 [November 22, 2008] + Added check for zero-area RGB cHRM triangle in png_check_cHRM() and + png_check_cHRM_fixed(). + +Version 1.4.0beta39 [November 23, 2008] + Revised png_warning() to write its message on standard output by default + when warning_fn is NULL. + +Version 1.4.0beta40 [November 24, 2008] + Eliminated png_check_cHRM(). Instead, always use png_check_cHRM_fixed(). + In png_check_cHRM_fixed(), ensure white_y is > 0, and removed redundant + check for all-zero coordinates that is detected by the triangle check. + +Version 1.4.0beta41 [November 26, 2008] + Fixed string vs pointer-to-string error in png_check_keyword(). + Rearranged test expressions in png_check_cHRM_fixed() to avoid internal + overflows. + Added PNG_NO_CHECK_cHRM conditional. + +Version 1.4.0beta42, 43 [December 1, 2008] + Merge png_debug with version 1.2.34beta04. + +Version 1.4.0beta44 [December 6, 2008] + Removed redundant check for key==NULL before calling png_check_keyword() + to ensure that new_key gets initialized and removed extra warning + (Merge with version 1.2.34beta05 -- Arvan Pritchard). + +Version 1.4.0beta45 [December 9, 2008] + In png_write_png(), respect the placement of the filler bytes in an earlier + call to png_set_filler() (Jim Barry). + +Version 1.4.0beta46 [December 10, 2008] + Undid previous change and added PNG_TRANSFORM_STRIP_FILLER_BEFORE and + PNG_TRANSFORM_STRIP_FILLER_AFTER conditionals and deprecated + PNG_TRANSFORM_STRIP_FILLER (Jim Barry). + +Version 1.4.0beta47 [December 15, 2008] + Support for dithering was disabled by default, because it has never + been well tested and doesn't work very well. The code has not + been removed, however, and can be enabled by building libpng with + PNG_READ_DITHER_SUPPORTED defined. + +Version 1.4.0beta48 [February 14, 2009] + Added new exported function png_calloc(). + Combined several instances of png_malloc(); png_memset() into png_calloc(). + Removed prototype for png_freeptr() that was added in libpng-1.4.0beta24 + but was never defined. + +Version 1.4.0beta49 [February 28, 2009] + Added png_fileno() macro to pngconf.h, used in pngwio.c + Corrected order of #ifdef's in png_debug definition in png.h + Fixed bug introduced in libpng-1.4.0beta48 with the memset arguments + for pcal_params. + Fixed order of #ifdef directives in the png_debug defines in png.h + (bug introduced in libpng-1.2.34/1.4.0beta29). + Revised comments in png_set_read_fn() and png_set_write_fn(). + +Version 1.4.0beta50 [March 18, 2009] + Use png_calloc() instead of png_malloc() to allocate big_row_buf when + reading an interlaced file, to avoid a possible UMR. + Undid revision of PNG_NO_STDIO version of png_write_flush(). Users + having trouble with fflush() can build with PNG_NO_WRITE_FLUSH defined + or supply their own flush_fn() replacement. + Revised libpng*.txt and png.h documentation about use of png_write_flush() + and png_set_write_fn(). + Removed fflush() from pngtest.c. + Added "#define PNG_NO_WRITE_FLUSH" to contrib/pngminim/encoder/pngusr.h + +Version 1.4.0beta51 [March 21, 2009] + Removed new png_fileno() macro from pngconf.h . + +Version 1.4.0beta52 [March 27, 2009] + Relocated png_do_chop() ahead of building gamma tables in pngrtran.c + This avoids building 16-bit gamma tables unnecessarily. + Removed fflush() from pngtest.c. + Added "#define PNG_NO_WRITE_FLUSH" to contrib/pngminim/encoder/pngusr.h + Added a section on differences between 1.0.x and 1.2.x to libpng.3/libpng.txt + +Version 1.4.0beta53 [April 1, 2009] + Removed some remaining MMX macros from pngpriv.h + Fixed potential memory leak of "new_name" in png_write_iCCP() (Ralph Giles) + +Version 1.4.0beta54 [April 13, 2009] + Added "ifndef PNG_SKIP_SETJMP_CHECK" block in pngconf.h to allow + application code writers to bypass the check for multiple inclusion + of setjmp.h when they know that it is safe to ignore the situation. + Eliminated internal use of setjmp() in pngread.c and pngwrite.c + Reordered ancillary chunks in pngtest.png to be the same as what + pngtest now produces, and made some cosmetic changes to pngtest output. + Eliminated deprecated png_read_init_3() and png_write_init_3() functions. + +Version 1.4.0beta55 [April 15, 2009] + Simplified error handling in pngread.c and pngwrite.c by putting + the new png_read_cleanup() and png_write_cleanup() functions inline. + +Version 1.4.0beta56 [April 25, 2009] + Renamed "user_chunk_data" to "my_user_chunk_data" in pngtest.c to suppress + "shadowed declaration" warning from gcc-4.3.3. + Renamed "gamma" to "png_gamma" in pngset.c to avoid "shadowed declaration" + warning about a global "gamma" variable in math.h on some platforms. + +Version 1.4.0beta57 [May 2, 2009] + Removed prototype for png_freeptr() that was added in libpng-1.4.0beta24 + but was never defined (again). + Rebuilt configure scripts with autoconf-2.63 instead of 2.62 + Removed pngprefs.h and MMX from makefiles + +Version 1.4.0beta58 [May 14, 2009] + Changed pngw32.def to pngwin.def in makefile.mingw (typo was introduced + in beta57). + Clarified usage of sig_bit versus sig_bit_p in example.c (Vincent Torri) + +Version 1.4.0beta59 [May 15, 2009] + Reformated sources in libpng style (3-space intentation, comment format) + Fixed typo in libpng docs (PNG_FILTER_AVE should be PNG_FILTER_AVG) + Added sections about the git repository and our coding style to the + documentation + Relocated misplaced #endif in pngwrite.c, sCAL chunk handler. + +Version 1.4.0beta60 [May 19, 2009] + Conditionally compile png_read_finish_row() which is not used by + progressive readers. + Added contrib/pngminim/preader to demonstrate building minimal progressive + decoder, based on contrib/gregbook with embedded libpng and zlib. + +Version 1.4.0beta61 [May 20, 2009] + In contrib/pngminim/*, renamed "makefile.std" to "makefile", since there + is only one makefile in those directories, and revised the README files + accordingly. + More reformatting of comments, mostly to capitalize sentences. + +Version 1.4.0beta62 [June 2, 2009] + Added "#define PNG_NO_WRITE_SWAP" to contrib/pngminim/encoder/pngusr.h + and "define PNG_NO_READ_SWAP" to decoder/pngusr.h and preader/pngusr.h + Reformatted several remaining "else statement" into two lines. + Added a section to the libpng documentation about using png_get_io_ptr() + in configure scripts to detect the presence of libpng. + +Version 1.4.0beta63 [June 15, 2009] + Revised libpng*.txt and libpng.3 to mention calling png_set_IHDR() + multiple times and to specify the sample order in the tRNS chunk, + because the ISO PNG specification has a typo in the tRNS table. + Changed several PNG_UNKNOWN_CHUNK_SUPPORTED to + PNG_HANDLE_AS_UNKNOWN_SUPPORTED, to make the png_set_keep mechanism + available for ignoring known chunks even when not saving unknown chunks. + Adopted preference for consistent use of "#ifdef" and "#ifndef" versus + "#if defined()" and "if !defined()" where possible. + +Version 1.4.0beta64 [June 24, 2009] + Eliminated PNG_LEGACY_SUPPORTED code. + Moved the various unknown chunk macro definitions outside of the + PNG_READ|WRITE_ANCILLARY_CHUNK_SUPPORTED blocks. + +Version 1.4.0beta65 [June 26, 2009] + Added a reference to the libpng license in each file. + +Version 1.4.0beta66 [June 27, 2009] + Refer to the libpng license instead of the libpng license in each file. + +Version 1.4.0beta67 [July 6, 2009] + Relocated INVERT_ALPHA within png_read_png() and png_write_png(). + Added high-level API transform PNG_TRANSFORM_GRAY_TO_RGB. + Added an "xcode" project to the projects directory (Alam Arias). + +Version 1.4.0beta68 [July 19, 2009] + Avoid some tests in filter selection in pngwutil.c + +Version 1.4.0beta69 [July 25, 2009] + Simplified the new filter-selection test. This runs faster in the + common "PNG_ALL_FILTERS" and PNG_FILTER_NONE cases. + Removed extraneous declaration from the new call to png_read_gray_to_rgb() + (bug introduced in libpng-1.4.0beta67). + Fixed up xcode project (Alam Arias) + Added a prototype for png_64bit_product() in png.c + +Version 1.4.0beta70 [July 27, 2009] + Avoid a possible NULL dereference in debug build, in png_set_text_2(). + (bug introduced in libpng-0.95, discovered by Evan Rouault) + +Version 1.4.0beta71 [July 29, 2009] + Rebuilt configure scripts with autoconf-2.64. + +Version 1.4.0beta72 [August 1, 2009] + Replaced *.tar.lzma with *.tar.xz in distribution. Get the xz codec + from <http://tukaani.org/xz>. + +Version 1.4.0beta73 [August 1, 2009] + Reject attempt to write iCCP chunk with negative embedded profile length + (JD Chen) + +Version 1.4.0beta74 [August 8, 2009] + Changed png_ptr and info_ptr member "trans" to "trans_alpha". + +Version 1.4.0beta75 [August 21, 2009] + Removed an extra png_debug() recently added to png_write_find_filter(). + Fixed incorrect #ifdef in pngset.c regarding unknown chunk support. + +Version 1.4.0beta76 [August 22, 2009] + Moved an incorrectly located test in png_read_row() in pngread.c + +Version 1.4.0beta77 [August 27, 2009] + Removed lpXYZ.tar.bz2 (with CRLF), KNOWNBUG, libpng-x.y.z-KNOWNBUG.txt, + and the "noconfig" files from the distribution. + Moved CMakeLists.txt from scripts into the main libpng directory. + Various bugfixes and improvements to CMakeLists.txt (Philip Lowman) + +Version 1.4.0beta78 [August 31, 2009] + Converted all PNG_NO_* tests to PNG_*_SUPPORTED everywhere except pngconf.h + Eliminated PNG_NO_FREE_ME and PNG_FREE_ME_SUPPORTED macros. + Use png_malloc plus a loop instead of png_calloc() to initialize + row_pointers in png_read_png(). + +Version 1.4.0beta79 [September 1, 2009] + Eliminated PNG_GLOBAL_ARRAYS and PNG_LOCAL_ARRAYS; always use local arrays. + Eliminated PNG_CALLOC_SUPPORTED macro and always provide png_calloc(). + +Version 1.4.0beta80 [September 17, 2009] + Removed scripts/libpng.icc + Changed typecast of filler from png_byte to png_uint_16 in png_set_filler(). + (Dennis Gustafsson) + Fixed typo introduced in beta78 in pngtest.c ("#if def " should be "#ifdef ") + +Version 1.4.0beta81 [September 23, 2009] + Eliminated unused PNG_FLAG_FREE_* defines from pngpriv.h + Expanded TAB characters in pngrtran.c + Removed PNG_CONST from all "PNG_CONST PNG_CHNK" declarations to avoid + compiler complaints about doubly declaring things "const". + Changed all "#if [!]defined(X)" to "if[n]def X" where possible. + Eliminated unused png_ptr->row_buf_size + +Version 1.4.0beta82 [September 25, 2009] + Moved redundant IHDR checking into new png_check_IHDR() in png.c + and report all errors found in the IHDR data. + Eliminated useless call to png_check_cHRM() from pngset.c + +Version 1.4.0beta83 [September 25, 2009] + Revised png_check_IHDR() to eliminate bogus complaint about filter_type. + +Version 1.4.0beta84 [September 30, 2009] + Fixed some inconsistent indentation in pngconf.h + Revised png_check_IHDR() to add a test for width variable less than 32-bit. + +Version 1.4.0beta85 [October 1, 2009] + Revised png_check_IHDR() again, to check info_ptr members instead of + the contents of the returned parameters. + +Version 1.4.0beta86 [October 9, 2009] + Updated the "xcode" project (Alam Arias). + Eliminated a shadowed declaration of "pp" in png_handle_sPLT(). + +Version 1.4.0rc01 [October 19, 2009] + Trivial cosmetic changes. + +Version 1.4.0beta87 [October 30, 2009] + Moved version 1.4.0 back into beta. + +Version 1.4.0beta88 [October 30, 2009] + Revised libpng*.txt section about differences between 1.2.x and 1.4.0 + because most of the new features have now been ported back to 1.2.41 + +Version 1.4.0beta89 [November 1, 2009] + More bugfixes and improvements to CMakeLists.txt (Philip Lowman) + Removed a harmless extra png_set_invert_alpha() from pngwrite.c + Apply png_user_chunk_cache_max within png_decompress_chunk(). + Merged libpng-1.2.41.txt with libpng-1.4.0.txt where appropriate. + +Version 1.4.0beta90 [November 2, 2009] + Removed all remaining WIN32_WCE #ifdefs except those involving the + time.h "tm" structure + +Version 1.4.0beta91 [November 3, 2009] + Updated scripts/pngw32.def and projects/wince/png32ce.def + Copied projects/wince/png32ce.def to the scripts directory. + Added scripts/makefile.wce + Patched ltmain.sh for wince support. + Added PNG_CONVERT_tIME_SUPPORTED macro. + +Version 1.4.0beta92 [November 4, 2009] + Make inclusion of time.h in pngconf.h depend on PNG_CONVERT_tIME_SUPPORTED + Make #define PNG_CONVERT_tIME_SUPPORTED depend on PNG_WRITE_tIME_SUPPORTED + Revised libpng*.txt to describe differences from 1.2.40 to 1.4.0 (instead + of differences from 1.2.41 to 1.4.0) + +Version 1.4.0beta93 [November 7, 2009] + Added PNG_DEPSTRUCT, PNG_DEPRECATED, PNG_USE_RESULT, PNG_NORETURN, and + PNG_ALLOCATED macros to detect deprecated direct access to the + png_struct or info_struct members and other deprecated usage in + applications (John Bowler). + Updated scripts/makefile* to add "-DPNG_CONFIGURE_LIBPNG" to CFLAGS, + to prevent warnings about direct access to png structs by libpng + functions while building libpng. They need to be tested, especially + those using compilers other than gcc. + Updated projects/visualc6 and visualc71 with "/d PNG_CONFIGURE_LIBPNG". + They should work but still need to be updated to remove + references to pnggccrd.c or pngvcrd.c and ASM building. + Added README.txt to the beos, cbuilder5, netware, and xcode projects warning + that they need to be updated, to remove references to pnggccrd.c and + pngvcrd.c and to depend on pngpriv.h + Removed three direct references to read_info_ptr members in pngtest.c + that were detected by the new PNG_DEPSTRUCT macro. + Moved the png_debug macro definitions and the png_read_destroy(), + png_write_destroy() and png_far_to_near() prototypes from png.h + to pngpriv.h (John Bowler) + Moved the synopsis lines for png_read_destroy(), png_write_destroy() + png_debug(), png_debug1(), and png_debug2() from libpng.3 to libpngpf.3. + +Version 1.4.0beta94 [November 9, 2009] + Removed the obsolete, unused pnggccrd.c and pngvcrd.c files. + Updated CMakeLists.txt to add "-DPNG_CONFIGURE_LIBPNG" to the definitions. + Removed dependency of pngtest.o on pngpriv.h in the makefiles. + Only #define PNG_DEPSTRUCT, etc. in pngconf.h if not already defined. + +Version 1.4.0beta95 [November 10, 2009] + Changed png_check_sig() to !png_sig_cmp() in contrib programs. + Added -DPNG_CONFIGURE_LIBPNG to contrib/pngminm/*/makefile + Changed png_check_sig() to !png_sig_cmp() in contrib programs. + Corrected the png_get_IHDR() call in contrib/gregbook/readpng2.c + Changed pngminim/*/gather.sh to stop trying to remove pnggccrd.c and pngvcrd.c + Added dependency on pngpriv.h in contrib/pngminim/*/makefile + +Version 1.4.0beta96 [November 12, 2009] + Renamed scripts/makefile.wce to scripts/makefile.cegcc + Revised Makefile.am to use libpng.sys while building libpng.so + so that only PNG_EXPORT functions are exported. + Removed the deprecated png_check_sig() function/macro. + Removed recently removed function names from scripts/*.def + Revised pngtest.png to put chunks in the same order written by pngtest + (evidently the same change made in libpng-1.0beta54 was lost). + Added PNG_PRIVATE macro definition in pngconf.h for possible future use. + +Version 1.4.0beta97 [November 13, 2009] + Restored pngtest.png to the libpng-1.4.0beta7 version. + Removed projects/beos and netware.txt; no one seems to be supporting them. + Revised Makefile.in + +Version 1.4.0beta98 [November 13, 2009] + Added the "xcode" project to zip distributions, + Fixed a typo in scripts/pngwin.def introduced in beta97. + +Version 1.4.0beta99 [November 14, 2009] + Moved libpng-config.in and libpng.pc-configure.in out of the scripts + directory, to libpng-config.in and libpng-pc.in, respectively, and + modified Makefile.am and configure.ac accordingly. Now "configure" + needs nothing from the "scripts" directory. + Avoid redefining PNG_CONST in pngconf.h + +Version 1.4.0beta100 [November 14, 2009] + Removed ASM builds from projects/visualc6 and projects/visualc71 + Removed scripts/makefile.nommx and makefile.vcawin32 + Revised CMakeLists.txt to account for new location of libpng-config.in + and libpng-pc.in + Updated INSTALL to reflect removal and relocation of files. + +Version 1.4.0beta101 [November 14, 2009] + Restored the binary files (*.jpg, *.png, some project files) that were + accidentally deleted from the zip and 7z distributions when the xcode + project was added. + +Version 1.4.0beta102 [November 18, 2009] + Added libpng-config.in and libpng-pc.in to the zip and 7z distributions. + Fixed a typo in projects/visualc6/pngtest.dsp, introduced in beta100. + Moved descriptions of makefiles and other scripts out of INSTALL into + scripts/README.txt + Updated the copyright year in scripts/pngwin.rc from 2006 to 2009. + +Version 1.4.0beta103 [November 21, 2009] + Removed obsolete comments about ASM from projects/visualc71/README_zlib.txt + Align row_buf on 16-byte boundary in memory. + Restored the PNG_WRITE_FLUSH_AFTER_IEND_SUPPORTED guard around the call + to png_flush() after png_write_IEND(). See 1.4.0beta32, 1.4.0beta50 + changes above and 1.2.30, 1.2.30rc01 and rc03 in 1.2.41 CHANGES. Someone + needs this feature. + Make the 'png_jmpbuf' macro expand to a call that records the correct + longjmp function as well as returning a pointer to the setjmp + jmp_buf buffer, and marked direct access to jmpbuf 'deprecated'. + (John Bowler) + +Version 1.4.0beta104 [November 22, 2009] + Removed png_longjmp_ptr from scripts/*.def and libpng.3 + Rebuilt configure scripts with autoconf-2.65 + +Version 1.4.0beta105 [November 25, 2009] + Use fast integer PNG_DIVIDE_BY_255() or PNG_DIVIDE_BY_65535() + to accomplish alpha premultiplication when + PNG_READ_COMPOSITE_NODIV_SUPPORTED is defined. + Changed "/255" to "/255.0" in background calculations to make it clear + that the 255 is used as a double. + +Version 1.4.0beta106 [November 27, 2009] + Removed premultiplied alpha feature. + +Version 1.4.0beta107 [December 4, 2009] + Updated README + Added "#define PNG_NO_PEDANTIC_WARNINGS" in the libpng source files. + Removed "-DPNG_CONFIGURE_LIBPNG" from the makefiles and projects. + Revised scripts/makefile.netbsd, makefile.openbsd, and makefile.sco + to put png.h and pngconf.h in $prefix/include, like the other scripts, + instead of in $prefix/include/libpng. Also revised makefile.sco + to put them in $prefix/include/libpng15 instead of in + $prefix/include/libpng/libpng15. + +Version 1.4.0beta108 [December 11, 2009] + Removed leftover "-DPNG_CONFIGURE_LIBPNG" from contrib/pngminim/*/makefile + Relocated png_do_chop() to its original position in pngrtran.c; the + change in version 1.2.41beta08 caused transparency to be handled wrong + in some 16-bit datastreams (Yusaku Sugai). + +Version 1.4.0beta109 [December 13, 2009] + Added "bit_depth" parameter to the private png_build_gamma_table() function. + Pass bit_depth=8 to png_build_gamma_table() when bit_depth is 16 but the + PNG_16_TO_8 transform has been set, to avoid unnecessary build of 16-bit + tables. + +Version 1.4.0rc02 [December 20, 2009] + Declared png_cleanup_needed "volatile" in pngread.c and pngwrite.c + +Version 1.4.0rc03 [December 22, 2009] + Renamed libpng-pc.in back to libpng.pc.in and revised CMakeLists.txt + (revising the change in 1.4.0beta99) + +Version 1.4.0rc04 [December 25, 2009] + Swapped PNG_UNKNOWN_CHUNKS_SUPPORTED and PNG_HANDLE_AS_UNKNOWN_SUPPORTED + in pngset.c to be consistent with other changes in version 1.2.38. + +Version 1.4.0rc05 [December 25, 2009] + Changed "libpng-pc.in" to "libpng.pc.in" in configure.ac, configure, and + Makefile.in to be consistent with changes in libpng-1.4.0rc03 + +Version 1.4.0rc06 [December 29, 2009] + Reverted the gamma_table changes from libpng-1.4.0beta109. + Fixed some indentation errors. + +Version 1.4.0rc07 [January 1, 2010] + Revised libpng*.txt and libpng.3 about 1.2.x->1.4.x differences. + Use png_calloc() instead of png_malloc(); png_memset() in pngrutil.c + Update copyright year to 2010. + +Version 1.4.0rc08 [January 2, 2010] + Avoid deprecated references to png_ptr-io_ptr and png_ptr->error_ptr + in pngtest.c + +Version 1.4.0 [January 3, 2010] + No changes. + +Version 1.4.1beta01 [January 8, 2010] + Updated CMakeLists.txt for consistent indentation and to avoid an + unclosed if-statement warning (Philip Lowman). + Revised Makefile.am and Makefile.in to remove references to Y2KINFO, + KNOWNBUG, and libpng.la (Robert Schwebel). + Revised the makefiles to install the same files and symbolic + links as configure, except for libpng.la and libpng14.la. + Make png_set|get_compression_buffer_size() available even when + PNG_WRITE_SUPPORTED is not enabled. + Revised Makefile.am and Makefile.in to simplify their maintenance. + Revised scripts/makefile.linux to install a link to libpng14.so.14.1 + +Version 1.4.1beta02 [January 9, 2010] + Revised the rest of the makefiles to install a link to libpng14.so.14.1 + +Version 1.4.1beta03 [January 10, 2010] + Removed png_set_premultiply_alpha() from scripts/*.def + +Version 1.4.1rc01 [January 16, 2010] + No changes. + +Version 1.4.1beta04 [January 23, 2010] + Revised png_decompress_chunk() to improve speed and memory usage when + decoding large chunks. + Added png_set|get_chunk_malloc_max() functions. + +Version 1.4.1beta05 [January 26, 2010] + Relocated "int k" declaration in pngtest.c to minimize its scope. + +Version 1.4.1beta06 [January 28, 2010] + Revised png_decompress_chunk() to use a two-pass method suggested by + John Bowler. + +Version 1.4.1beta07 [February 6, 2010] + Folded some long lines in the source files. + Added defineable PNG_USER_CHUNK_CACHE_MAX, PNG_USER_CHUNK_MALLOC_MAX, + and a PNG_USER_LIMITS_SUPPORTED flag. + Eliminated use of png_ptr->irowbytes and reused the slot in png_ptr as + png_ptr->png_user_chunk_malloc_max. + Revised png_push_save_buffer() to do fewer but larger png_malloc() calls. + +Version 1.4.1beta08 [February 6, 2010] + Minor cleanup and updating of dates and copyright year. + +Version 1.5.0beta01 [February 7, 2010] + Moved declaration of png_struct into private pngstruct.h and png_info + into pnginfo.h + +Version 1.4.1beta09 and 1.5.0beta02 [February 7, 2010] + Reverted to original png_push_save_buffer() code. + +Version 1.4.1beta10 and 1.5.0beta03 [February 8, 2010] + Return allocated "old_buffer" in png_push_save_buffer() before + calling png_error(), to avoid a potential memory leak. + Updated configure script to use SO number 15. + +Version 1.5.0beta04 [February 9, 2010] + Removed malformed "incomplete struct declaration" of png_info from png.h + +Version 1.5.0beta05 [February 12, 2010] + Removed PNG_DEPSTRUCT markup in pngstruct.h and pnginfo.h, and undid the + linewrapping that it entailed. + Revised comments in pngstruct.h and pnginfo.h and added pointers to + the libpng license. + Changed PNG_INTERNAL to PNG_EXPOSE_INTERNAL_STRUCTURES + Removed the cbuilder5 project, which has not been updated to 1.4.0. + +Version 1.4.1beta12 and 1.5.0beta06 [February 14, 2010] + Fixed type declaration of png_get_chunk_malloc_max() in pngget.c (Daisuke + Nishikawa) + +Version 1.5.0beta07 [omitted] + +Version 1.5.0beta08 [February 19, 2010] + Changed #ifdef PNG_NO_STDIO_SUPPORTED to #ifdef PNG_NO_CONSOLE_IO_SUPPORTED + wherever png_snprintf() is used to construct error and warning messages. + Noted in scripts/makefile.mingw that it expects to be run under MSYS. + Removed obsolete unused MMX-querying support from contrib/gregbook + Added exported png_longjmp() function. + Removed the AIX redefinition of jmpbuf in png.h + Added -D_ALLSOURCE in configure.ac, makefile.aix, and CMakeLists.txt + when building on AIX. + +Version 1.5.0beta09 [February 19, 2010] + Removed -D_ALLSOURCE from configure.ac, makefile.aix, and CMakeLists.txt. + Changed the name of png_ptr->jmpbuf to png_ptr->png_jmpbuf in pngstruct.h + +Version 1.5.0beta10 [February 25, 2010] + Removed unused gzio.c from contrib/pngminim gather and makefile scripts + Removed replacement error handlers from contrib/gregbook. Because of + the new png_longjmp() function they are no longer needed. + +Version 1.5.0beta11 [March 6, 2010] + Removed checking for already-included setjmp.h from pngconf.h + Fixed inconsistent indentations and made numerous cosmetic changes. + Revised the "SEE ALSO" style of libpng.3, libpngpf.3, and png.5 + +Version 1.5.0beta12 [March 9, 2010] + Moved "#include png.h" inside pngpriv.h and removed "#include png.h" from + the source files, along with "#define PNG_EXPOSE_INTERNAL_STRUCTURES" + and "#define PNG_NO_PEDANTIC_WARNINGS" (John Bowler). + Created new pngdebug.h and moved debug definitions there. + +Version 1.5.0beta13 [March 10, 2010] + Protect pngstruct.h, pnginfo.h, and pngdebug.h from being included twice. + Revise the "#ifdef" blocks in png_inflate() so it will compile when neither + PNG_USER_CHUNK_MALLOC_MAX nor PNG_SET_CHUNK_MALLOC_LIMIT_SUPPORTED + is defined. + Removed unused png_measure_compressed_chunk() from pngpriv.h and libpngpf.3 + Moved the 'config.h' support from pngconf.h to pngpriv.h + Removed PNGAPI from the png_longjmp_ptr typedef. + Eliminated dependence of pngtest.c on the private pngdebug.h file. + Make all png_debug macros into *unterminated* statements or + expressions (i.e. a trailing ';' must always be added) and correct + the format statements in various png_debug messages. + +Version 1.5.0beta14 [March 14, 2010] + Removed direct access to png_ptr->io_ptr from the Windows code in pngtest.c + Revised Makefile.am to account for recent additions and replacements. + Corrected CE and OS/2 DEF files (scripts/png*def) for symbols removed and + added ordinal numbers to the Windows DEF file and corrected the duplicated + ordinal numbers on CE symbols that are commented out. + Added back in export symbols that can be present in the Windows build but + are disabled by default. + PNG_EXPORT changed to include an 'ordinal' field for DEF file generation. + PNG_CALLBACK added to make callback definitions uniform. PNGAPI split + into PNGCAPI (base C form), PNGAPI (exports) and PNGCBAPI (callbacks), + and appropriate changes made to all files. Cygwin builds re-hinged to + allow procedure call standard changes and to remove the need for the DEF + file (fixes build on Cygwin). + Enabled 'attribute' warnings that are relevant to library APIs and callbacks. + Changed rules for generation of the various symbol files and added a new + rule for a DEF file (which is also added to the distribution). + Updated the symbol file generation to stop it adding spurious spaces + to EOL (coming from preprocessor macro expansion). Added a facility + to join tokens in the output and rewrite *.dfn to use this. + Eliminated scripts/*.def in favor of libpng.def; updated projects/visualc71 + and removed scripts/makefile.cygwin. + Made PNG_BUILD_DLL safe: it can be set whenever a DLL is being built. + Removed the include of sys/types.h - apparently unnecessary now on the + platforms on which it happened (all but Mac OS and RISC OS). + Moved the Mac OS test into pngpriv.h (the only place it is used.) + +Version 1.5.0beta15 [March 17, 2010] + Added symbols.chk target to Makefile.am to validate the symbols in png.h + against the new DEF file scripts/symbols.def. + Changed the default DEF file back to pngwin.def. + Removed makefile.mingw. + Eliminated PNG_NO_EXTERN and PNG_ALL_EXTERN + +Version 1.5.0beta16 [April 1, 2010] + Make png_text_struct independent of PNG_iTXt_SUPPORTED, so that + fields are initialized in all configurations. The READ/WRITE + macros (PNG_(READ|WRITE)_iTXt_SUPPORTED) still function as + before to disable code to actually read or write iTXt chunks + and iTXt_SUPPORTED can be used to detect presence of either + read or write support (but it is probably better to check for + the one actually required - read or write.) + Combined multiple png_warning() calls for a single error. + Restored the macro definition of png_check_sig(). + +Version 1.5.0beta17 [April 17, 2010] + Added some "(long)" typecasts to printf calls in png_handle_cHRM(). + Documented the fact that png_set_dither() was disabled since libpng-1.4.0. + Reenabled png_set_dither() but renamed it to png_set_quantize() to reflect + more accurately what it actually does. At the same time, renamed + the PNG_DITHER_[RED,GREEN_BLUE]_BITS macros to + PNG_QUANTIZE_[RED,GREEN,BLUE]_BITS. + Added some "(long)" typecasts to printf calls in png_handle_cHRM(). + Freeze build-time only configuration in the build. + In all prior versions of libpng most configuration options + controlled by compiler #defines had to be repeated by the + application code that used libpng. This patch changes this + so that compilation options that can only be changed at build + time are frozen in the build. Options that are compiler + dependent (and those that are system dependent) are evaluated + each time - pngconf.h holds these. Options that can be changed + per-file in the application are in png.h. Frozen options are + in the new installed header file pnglibconf.h (John Bowler) + Removed the xcode project because it has not been updated to work + with libpng-1.5.0. + Removed the ability to include optional pngusr.h + +Version 1.5.0beta18 [April 17, 2010] + Restored the ability to include optional pngusr.h + Moved replacements for png_error() and png_warning() from the + contrib/pngminim project to pngerror.c, for use when warnings or + errors are disabled via PNG_NO_WARN or PNG_NO_ERROR_TEXT, to avoid + storing unneeded error/warning text. + Updated contrib/pngminim project to work with the new pnglibconf.h + Added some PNG_NO_* defines to contrib/pngminim/*/pngusr.h to save space. + +Version 1.5.0beta19 [April 24, 2010] + Added PNG_{READ,WRITE}_INT_FUNCTIONS_SUPPORTED. This allows the functions + to read and write ints to be disabled independently of PNG_USE_READ_MACROS, + which allows libpng to be built with the functions even though the default + is to use the macros - this allows applications to choose at app build + time whether or not to use macros (previously impossible because the + functions weren't in the default build.) + Changed Windows calling convention back to __cdecl for API functions. + For Windows/x86 platforms only: + __stdcall is no longer needed for Visual Basic, so libpng-1.5.0 uses + __cdecl throughout (both API functions and callbacks) on Windows/x86 + platforms. + Replaced visualc6 and visualc71 projects with new vstudio project + Relaxed the overly-restrictive permissions of some files. + +Version 1.5.0beta20 [April 24, 2010] + Relaxed more overly-restrictive permissions of some files. + +Version 1.5.0beta21 [April 27, 2010] + Removed some unwanted binary bytes and changed CRLF to NEWLINE in the new + vstudio project files, and some trivial editing of some files in the + scripts directory. + Set PNG_NO_READ_BGR, PNG_NO_IO_STATE, and PNG_NO_TIME_RFC1123 in + contrib/pngminim/decoder/pngusr.h to make a smaller decoder application. + +Version 1.5.0beta22 [April 28, 2010] + Fixed dependencies of GET_INT_32 - it does not require READ_INT_FUNCTIONS + because it has a macro equivalent. + Improved the options.awk script; added an "everything off" option. + Revised contrib/pngminim to use the "everything off" option in pngusr.dfa. + +Version 1.5.0beta23 [April 29, 2010] + Corrected PNG_REMOVED macro to take five arguments. + The macro was documented with two arguments (name,ordinal), however + the symbol checking .dfn files assumed five arguments. The five + argument form seems more useful so it is changed to that. + Corrected PNG_UNKNOWN_CHUNKS_SUPPORTED to PNG_HANDLE_AS_UNKNOWN_SUPPORTED + in gregbook/readpng2.c + Corrected protection of png_get_user_transform_ptr. The API declaration in + png.h is removed if both READ and WRITE USER_TRANSFORM are turned off + but was left defined in pngtrans.c + Added logunsupported=1 to cause pnglibconf.h to document disabled options. + This makes the installed pnglibconf.h more readable but causes no + other change. The intention is that users of libpng will find it + easier to understand if an API they need is missing. + Include png_reset_zstream() in png.c only when PNG_READ_SUPPORTED is defined. + Removed dummy_inflate.c from contrib/pngminim/encoder + Removed contrib/pngminim/*/gather.sh; gathering is now done in the makefile. + +Version 1.5.0beta24 [May 7, 2010] + Use bitwise "&" instead of arithmetic mod in pngrutil.c calculation of the + offset of the png_ptr->rowbuf pointer into png_ptr->big_row_buf. + Added more blank lines for readability. + +Version 1.5.0beta25 [June 18, 2010] + In pngpread.c: png_push_have_row() add check for new_row > height + Removed the now-redundant check for out-of-bounds new_row from example.c + +Version 1.5.0beta26 [June 18, 2010] + In pngpread.c: png_push_process_row() add check for too many rows. + +Version 1.5.0beta27 [June 18, 2010] + Removed the check added in beta25 as it is now redundant. + +Version 1.5.0beta28 [June 20, 2010] + Rewrote png_process_IDAT_data to consistently treat extra data as warnings + and handle end conditions more cleanly. + Removed the new (beta26) check in png_push_process_row(). + +Version 1.5.0beta29 [June 21, 2010] + Revised scripts/options.awk to work on Sunos (but still doesn't work) + Added comment to options.awk and contrib/pngminim/*/makefile to try nawk. + +Version 1.5.0beta30 [June 22, 2010] + Stop memory leak when reading a malformed sCAL chunk. + +Version 1.5.0beta31 [June 26, 2010] + Revised pngpread.c patch of beta28 to avoid an endless loop. + Removed some trailing blanks. + +Version 1.5.0beta32 [June 26, 2010] + Removed leftover scripts/options.patch and scripts/options.rej + +Version 1.5.0beta33 [July 6, 3010] + Made FIXED and FLOATING options consistent in the APIs they enable and + disable. Corrected scripts/options.awk to handle both command line + options and options specified in the .dfa files. + Changed char *msg to PNG_CONST char *msg in pngrutil.c + Make png_set_sRGB_gAMA_and_cHRM set values using either the fixed or + floating point APIs, but not both. + Reversed patch to remove error handler when the jmp_buf is stored in the + main program structure, not the png_struct. + The error handler is needed because the default handler in libpng will + always use the jmp_buf in the library control structure; this is never + set. The gregbook code is a useful example because, even though it + uses setjmp/longjmp, it shows how error handling can be implemented + using control mechanisms not directly supported by libpng. The + technique will work correctly with mechanisms such as Microsoft + Structure Exceptions or C++ exceptions (compiler willing - note that gcc + does not by default support interworking of C and C++ error handling.) + Reverted changes to call png_longjmp in contrib/gregbook where it is not + appropriate. If mainprog->jmpbuf is used by setjmp, then png_longjmp + cannot be used. + Changed "extern PNG_EXPORT" to "PNG_EXPORT" in png.h (Jan Nijtmans) + Changed "extern" to "PNG_EXTERN" in pngpriv.h (except for the 'extern "C" {') + +Version 1.5.0beta34 [July 12, 2010] + Put #ifndef PNG_EXTERN, #endif around the define PNG_EXTERN in pngpriv.h + +Version 1.5.0beta35 [July 24, 2010] + Removed some newly-added TAB characters. + Added -DNO_PNG_SNPRINTF to CFLAGS in scripts/makefile.dj2 + Moved the definition of png_snprintf() outside of the enclosing + #ifdef blocks in pngconf.h + +Version 1.5.0beta36 [July 29, 2010] + Patches by John Bowler: + Fixed point APIs are now supported throughout (no missing APIs). + Internal fixed point arithmetic support exists for all internal floating + point operations. + sCAL validates the floating point strings it is passed. + Safe, albeit rudimentary, Watcom support is provided by PNG_API_RULE==2 + Two new APIs exist to get the number of passes without turning on the + PNG_INTERLACE transform and to get the number of rows in the current + pass. + A new test program, pngvalid.c, validates the gamma code. + Errors in the 16 bit gamma correction (overflows) have been corrected. + cHRM chunk testing is done consistently (previously the floating point + API bypassed it, because the test really didn't work on FP, now the test + is performed on the actual values to be stored in the PNG file so it + works in the FP case too.) + Most floating point APIs now simply call the fixed point APIs after + converting the values to the fixed point form used in the PNG file. + The standard headers no longer include zlib.h, which is currently only + required for pngstruct.h and can therefore be internal. + Revised png_get_int_32 to undo the PNG two's complement representation of + negative numbers. + +Version 1.5.0beta37 [July 30, 2010] + Added a typecast in png_get_int_32() in png.h and pngrutil.h to avoid + a compiler warning. + Replaced oFFs 0,0 with oFFs -10,20 in pngtest.png + +Version 1.5.0beta38 [July 31, 2010] + Implemented remaining "_fixed" functions. + Corrected a number of recently introduced warnings mostly resulting from + safe but uncast assignments to shorter integers. Also added a zlib + VStudio release library project because the latest zlib Official Windows + build does not include such a thing. + Revised png_get_int_16() to be similar to png_get_int_32(). + Restored projects/visualc71. + +Version 1.5.0beta39 [August 2, 2010] + VisualC/GCC warning fixes, VisualC build fixes + The changes include support for function attributes in VC in addition to + those already present in GCC - necessary because without these some + warnings are unavoidable. Fixes include signed/unsigned fixes in + pngvalid and checks with gcc -Wall -Wextra -Wunused. + VC requires function attributes on function definitions as well as + declarations, PNG_FUNCTION has been added to enable this and the + relevant function definitions changed. + +Version 1.5.0beta40 [August 6, 2010] + Correct use of _WINDOWS_ in pngconf.h + Removed png_mem_ #defines; they are no longer used. + Added the sRGB chunk to pngtest.png + +Version 1.5.0beta41 [August 11, 2010] + Added the cHRM chunk to pngtest.png + Don't try to use version-script with cygwin/mingw. + Revised contrib/gregbook to work under cygwin/mingw. + +Version 1.5.0beta42 [August 18, 2010] + Add .dll.a to the list of extensions to be symlinked by Makefile.am (Yaakov) + Made all API functions that have const arguments and constant string + literal pointers declare them (John Bowler). + +Version 1.5.0beta43 [August 20, 2010] + Removed spurious tabs, shorten long lines (no source change) + Also added scripts/chkfmt to validate the format of all the files that can + reasonably be validated (it is suggested to run "make distclean" before + checking, because some machine generated files have long lines.) + Reformatted the CHANGES file to be more consistent throughout. + Made changes to address various issues identified by GCC, mostly + signed/unsigned and shortening problems on assignment but also a few + difficult to optimize (for GCC) loops. + Fixed non-GCC fixed point builds. In png.c a declaration was misplaced + in an earlier update. Fixed to declare the auto variables at the head. + Use cexcept.h in pngvalid.c. + +Version 1.5.0beta44 [August 24, 2010] + Updated CMakeLists.txt to use CMAKE_INSTALL_LIBDIR variable; useful for + installing libpng in /usr/lib64 (Funda Wang). + Revised CMakeLists.txt to put the man pages in share/man/man* not man/man* + Revised CMakeLists.txt to make symlinks instead of copies when installing. + Changed PNG_LIB_NAME from pngNN to libpngNN in CMakeLists.txt (Philip Lowman) + Implemented memory checks within pngvalid + Reformatted/rearranged pngvalid.c to assist use of progressive reader. + Check interlaced images in pngvalid + Clarified pngusr.h comments in pnglibconf.dfa + Simplified the pngvalid error-handling code now that cexcept.h is in place. + Implemented progressive reader in pngvalid.c for standard tests + Implemented progressive read in pngvalid.c gamma tests + Turn on progressive reader in pngvalid.c by default and tidy code. + +Version 1.5.0beta45 [August 26, 2010] + Added an explicit make step to projects/vstudio for pnglibconf.h + Also corrected zlib.vcxproj into which Visual Studio had introduced + what it calls an "authoring error". The change to make pnglibconf.h + simply copies the file; in the future it may actually generate the + file from scripts/pnglibconf.dfa as the other build systems do. + Changed pngvalid to work when floating point APIs are disabled + Renamed the prebuilt scripts/pnglibconf.h to scripts/pnglibconf.h.prebuilt + Supply default values for PNG_USER_PRIVATEBUILD and PNG_USER_DLLFNAME_POSTFIX + in pngpriv.h in case the user neglected to define them in their pngusr.h + +Version 1.5.0beta46 [August 28, 2010] + Added new private header files to libpng_sources in CMakeLists.txt + Added PNG_READ_16BIT, PNG_WRITE_16BIT, and PNG_16BIT options. + Added reference to scripts/pnglibconf.h.prebuilt in the visualc71 project. + +Version 1.5.0beta47 [September 11, 2010] + Fixed a number of problems with 64-bit compilation reported by Visual + Studio 2010 (John Bowler). + +Version 1.5.0beta48 [October 4, 2010] + Updated CMakeLists.txt (Philip Lowman). + Revised autogen.sh to recognize and use $AUTOCONF, $AUTOMAKE, $AUTOHEADER, + $AUTOPOINT, $ACLOCAL and $LIBTOOLIZE + Fixed problem with symbols creation in Makefile.am which was assuming that + all versions of ccp write to standard output by default (Martin Banky). The + bug was introduced in libpng-1.2.9beta5. + Removed unused mkinstalldirs. + +Version 1.5.0beta49 [October 8, 2010] + Undid Makefile.am revision of 1.5.0beta48. + +Version 1.5.0beta50 [October 14, 2010] + Revised Makefile.in to account for mkinstalldirs being removed. + Added some "(unsigned long)" typecasts in printf statements in pngvalid.c. + Suppressed a compiler warning in png_handle_sPLT(). + Check for out-of-range text compression mode in png_set_text(). + +Version 1.5.0beta51 [October 15, 2010] + Changed embedded dates to "(PENDING RELEASE) in beta releases (and future + rc releases) to minimize the difference between releases. + +Version 1.5.0beta52 [October 16, 2010] + Restored some of the embedded dates (in png.h, png.c, documentation, etc.) + +Version 1.5.0beta53 [October 18, 2010] + Updated INSTALL to mention using "make maintainer-clean" and to remove + obsolete statement about a custom ltmain.sh + Disabled "color-tests" by default in Makefile.am so it will work with + automake versions earlier than 1.11.1 + Use document name "libpng-manual.txt" instead of "libpng-<version>.txt" + to simplify version differences. + Removed obsolete remarks about setjmp handling from INSTALL. + Revised and renamed the typedef in png.h and png.c that was designed + to catch library and header mismatch. + +Version 1.5.0beta54 [November 10, 2010] + Require 48 bytes, not 64 bytes, for big_row_buf in overflow checks. + Used a consistent structure for the pngget.c functions. + +Version 1.5.0beta55 [November 21, 2010] + Revised png_get_uint_32, png_get_int_32, png_get_uint_16 (Cosmin) + Moved reading of file signature into png_read_sig (Cosmin) + Fixed atomicity of chunk header serialization (Cosmin) + Added test for io_state in pngtest.c (Cosmin) + Added "#!/bin/sh" at the top of contrib/pngminim/*/gather.sh scripts. + Changes to remove gcc warnings (John Bowler) + Certain optional gcc warning flags resulted in warnings in libpng code. + With these changes only -Wconversion and -Wcast-qual cannot be turned on. + Changes are trivial rearrangements of code. -Wconversion is not possible + for pngrutil.c (because of the widespread use of += et al on variables + smaller than (int) or (unsigned int)) and -Wcast-qual is not possible + with pngwio.c and pngwutil.c because the 'write' callback and zlib + compression both fail to declare their input buffers with 'const'. + +Version 1.5.0beta56 [December 7, 2010] + Added the private PNG_UNUSED() macro definition in pngpriv.h. + Added some commentary about PNG_EXPORT in png.h and pngconf.h + Revised PNG_EXPORT() macro and added PNG_EXPORTA() macro, with the + objective of simplifying and improving the cosmetic appearance of png.h. + Fixed some incorrect "=" macro names in pnglibconf.dfa + Included documentation of changes in 1.5.0 from 1.4.x in libpng-manual.txt + +Version 1.5.0beta57 [December 9, 2010] + Documented the pngvalid gamma error summary with additional comments and + print statements. + Improved missing symbol handling in checksym.awk; symbols missing in both + the old and new files can now be optionally ignored, treated as errors + or warnings. + Removed references to pngvcrd.c and pnggccrd.c from the vstudio project. + Updated "libpng14" to "libpng15" in the visualc71 project. + Enabled the strip16 tests in pngvalid.` + Don't display test results (except PASS/FAIL) when running "make test". + Instead put them in pngtest-log.txt + Added "--with-zprefix=<string>" to configure.ac + Updated the prebuilt configuration files to autoconf version 2.68 + +Version 1.5.0beta58 [December 19, 2010] + Fixed interlace image handling and add test cases (John Bowler) + Fixed the clean rule in Makefile.am to remove pngtest-log.txt + Made minor changes to work around warnings in gcc 3.4 + +Version 1.5.0rc01 [December 27, 2010] + No changes. + +Version 1.5.0rc02 [December 27, 2010] + Eliminated references to the scripts/*.def files in project/visualc71. + +Version 1.5.0rc03 [December 28, 2010] + Eliminated scripts/*.def and revised Makefile.am accordingly + +Version 1.5.0rc04 [December 29, 2010] + Fixed bug in background transformation handling in pngrtran.c (it was + looking for the flag in png_ptr->transformations instead of in + png_ptr->flags) (David Raymond). + +Version 1.5.0rc05 [December 31, 2010] + Fixed typo in a comment in CMakeLists.txt (libpng14 => libpng15) (Cosmin) + +Version 1.5.0rc06 [January 4, 2011] + Changed the new configure option "zprefix=string" to "zlib-prefix=string" + +Version 1.5.0rc07 [January 4, 2011] + Updated copyright year. + +Version 1.5.0 [January 6, 2011] + No changes. + +version 1.5.1beta01 [January 8, 2011] + Added description of png_set_crc_action() to the manual. + Added a note in the manual that the type of the iCCP profile was changed + from png_charpp to png_bytepp in png_get_iCCP(). This change happened + in version 1.5.0beta36 but is not noted in the CHANGES. Similarly, + it was changed from png_charpp to png_const_bytepp in png_set_iCCP(). + Ensure that png_rgb_to_gray ignores palette mapped images, if libpng + internally happens to call it with one. + Fixed a failure to handle palette mapped images correctly. + +Version 1.5.1beta02 [January 14, 2011] + Fixed a bug in handling of interlaced images (bero at arklinux.org). + Updated CMakeLists.txt (Clifford Yapp) + +Version 1.5.1beta03 [January 14, 2011] + Fixed typecasting of some png_debug() statements (Cosmin) + +Version 1.5.1beta04 [January 16, 2011] + Updated documentation of png_set|get_tRNS() (Thomas Klausner). + Mentioned in the documentation that applications must #include "zlib.h" + if they need access to anything in zlib.h, and that a number of + macros such as png_memset() are no longer accessible by applications. + Corrected pngvalid gamma test "sample" function to access all of the color + samples of each pixel, instead of sampling the red channel three times. + Prefixed variable names index, div, exp, gamma with "png_" to avoid "shadow" + warnings, and (mistakenly) changed png_exp() to exp(). + +Version 1.5.1beta05 [January 16, 2011] + Changed variable names png_index, png_div, png_exp, and png_gamma to + char_index, divisor, exp_b10, and gamma_val, respectively, and + changed exp() back to png_exp(). + +Version 1.5.1beta06 [January 20, 2011] + Prevent png_push_crc_skip() from hanging while reading an unknown chunk + or an over-large compressed zTXt chunk with the progressive reader. + Eliminated more GCC "shadow" warnings. + Revised png_fixed() in png.c to avoid compiler warning about reaching the + end without returning anything. + +Version 1.5.1beta07 [January 22, 2011] + In the manual, describe the png_get_IHDR() arguments in the correct order. + Added const_png_structp and const_png_infop types, and used them in + prototypes for most png_get_*() functions. + +Version 1.5.1beta08 [January 23, 2011] + Added png_get_io_chunk_type() and deprecated png_get_io_chunk_name() + Added synopses for the IO_STATE functions and other missing synopses + to the manual. Removed the synopses from libpngpf.3 because they + were out of date and no longer useful. Better information can be + obtained by reading the prototypes and comments in pngpriv.h + Attempted to fix cpp on Solaris with S. Studio 12 cc, fix build + Added a make macro DFNCPP that is a CPP that will accept the tokens in + a .dfn file and adds configure stuff to test for such a CPP. ./configure + should fail if one is not available. + Corrected const_png_ in png.h to png_const_ to avoid polluting the namespace. + Added png_get_current_row_number and png_get_current_pass_number for the + benefit of the user transform callback. + Added png_process_data_pause and png_process_data_skip for the benefit of + progressive readers that need to stop data processing or want to optimize + skipping of unread data (e.g., if the reader marks a chunk to be skipped.) + +Version 1.5.1beta09 [January 24, 2011] + Enhanced pngvalid, corrected an error in gray_to_rgb, corrected doc error. + pngvalid contains tests of transforms, which tests are currently disabled + because they are incompletely tested. gray_to_rgb was failing to expand + the bit depth for smaller bit depth images; this seems to be a long + standing error and resulted, apparently, in invalid output. The + documentation did not accurately describe what libpng really does when + converting RGB to gray. + +Version 1.5.1beta10 [January 27, 2010] + Fixed incorrect examples of callback prototypes in the manual, that were + introduced in libpng-1.0.0. + In addition the order of the png_get_uint macros with respect to the + relevant function definitions has been reversed. This helps the + preprocessing of the symbol files be more robust. Furthermore, the + symbol file preprocessing now uses -DPNG_NO_USE_READ_MACROS even when + the library may actually be built with PNG_USE_READ_MACROS; this stops + the read macros interfering with the symbol file format. + Made the manual, synopses, and function prototypes use the function + argument names file_gamma, int_file_gamma, and srgb_intent consistently. + +Version 1.5.1beta11 [January 28, 2011] + Changed PNG_UNUSED from "param=param;" to "{if(param){}}". + Corrected local variable type in new API png_process_data_skip() + The type was self-evidently incorrect but only causes problems on 64 bit + architectures. + Added transform tests to pngvalid and simplified the arguments. + +Version 1.5.1rc01 [January 29, 2011] + No changes. + +Version 1.5.1rc02 [January 31, 2011] + Added a request in the manual that applications do not use "png_" or + "PNG_" to begin any of their own symbols. + Changed PNG_UNUSED to "(void)param;" and updated the commentary in pngpriv.h + +Version 1.5.1 [February 3, 2011] + No changes. + +Send comments/corrections/commendations to png-mng-implement at lists.sf.net +(subscription required; visit +https://lists.sourceforge.net/lists/listinfo/png-mng-implement +to subscribe) +or to glennrp at users.sourceforge.net + +Glenn R-P +*/ } +#endif diff --git a/src/3rdparty/libpng/CMakeLists.txt b/src/3rdparty/libpng/CMakeLists.txt new file mode 100644 index 0000000000..2ee5bf3384 --- /dev/null +++ b/src/3rdparty/libpng/CMakeLists.txt @@ -0,0 +1,406 @@ +cmake_minimum_required(VERSION 2.4.4) +set(CMAKE_ALLOW_LOOSE_LOOP_CONSTRUCTS true) + +if(UNIX AND NOT DEFINED CMAKE_BUILD_TYPE) + if(CMAKE_MAJOR_VERSION EQUAL 2 AND CMAKE_MINOR_VERSION EQUAL 4) + # workaround CMake 2.4.x bug + set(CMAKE_BUILD_TYPE "RelWithDebInfo" CACHE STRING + "Choose the type of build, options are: + None(CMAKE_CXX_FLAGS or CMAKE_C_FLAGS used) + Debug + Release + RelWithDebInfo + MinSizeRel.") + else() + set(CMAKE_BUILD_TYPE "RelWithDebInfo" CACHE STRING + "Choose the type of build, options are: + None(CMAKE_CXX_FLAGS or CMAKE_C_FLAGS used) + Debug + Release + RelWithDebInfo + MinSizeRel.") + endif() +endif() + +project(libpng C) +enable_testing() + +# Copyright (C) 2007-2011 Glenn Randers-Pehrson + +# This code is released under the libpng license. +# For conditions of distribution and use, see the disclaimer +# and license in png.h + +set(PNGLIB_MAJOR 1) +set(PNGLIB_MINOR 5) +set(PNGLIB_RELEASE 1) +set(PNGLIB_NAME libpng${PNGLIB_MAJOR}${PNGLIB_MINOR}) +set(PNGLIB_VERSION ${PNGLIB_MAJOR}.${PNGLIB_MINOR}.${PNGLIB_RELEASE}) + +# needed packages +find_package(ZLIB REQUIRED) +include_directories(${ZLIB_INCLUDE_DIR}) + +if(NOT WIN32) + find_library(M_LIBRARY + NAMES m + PATHS /usr/lib /usr/local/lib + ) + if(NOT M_LIBRARY) + message(STATUS + "math library 'libm' not found - floating point support disabled") + endif() +else() + # not needed on windows + set(M_LIBRARY "") +endif() + +# COMMAND LINE OPTIONS +if(DEFINED PNG_SHARED) + option(PNG_SHARED "Build shared lib" ${PNG_SHARED}) +else() + option(PNG_SHARED "Build shared lib" ON) +endif() +if(DEFINED PNG_STATIC) + option(PNG_STATIC "Build static lib" ${PNG_STATIC}) +else() + option(PNG_STATIC "Build static lib" ON) +endif() + +if(MINGW) + option(PNG_TESTS "Build pngtest" NO) +else() + option(PNG_TESTS "Build pngtest" YES) +endif() + +option(PNG_NO_CONSOLE_IO "FIXME" YES) +option(PNG_NO_STDIO "FIXME" YES) +option(PNG_DEBUG "Build with debug output" NO) +option(PNGARG "FIXME" YES) +#TODO: +# PNG_CONSOLE_IO_SUPPORTED + +# maybe needs improving, but currently I don't know when we can enable what :) +set(png_asm_tmp "OFF") +if(NOT WIN32) + find_program(uname_executable NAMES uname PATHS /bin /usr/bin /usr/local/bin) + if(uname_executable) + exec_program(${uname_executable} + ARGS --machine OUTPUT_VARIABLE uname_output) + if("uname_output" MATCHES "^.*i[1-9]86.*$") + set(png_asm_tmp "ON") + else("uname_output" MATCHES "^.*i[1-9]86.*$") + set(png_asm_tmp "OFF") + endif("uname_output" MATCHES "^.*i[1-9]86.*$") + endif(uname_executable) +else() + # this env var is normally only set on win64 + set(TEXT "ProgramFiles(x86)") + if("$ENV{${TEXT}}" STREQUAL "") + set(png_asm_tmp "ON") + endif("$ENV{${TEXT}}" STREQUAL "") +endif() + +# SET LIBNAME +set(PNG_LIB_NAME png${PNGLIB_MAJOR}${PNGLIB_MINOR}) + +# to distinguish between debug and release lib +set(CMAKE_DEBUG_POSTFIX "d") + +# Use the prebuilt pnglibconf.h file from the scripts folder +configure_file(${CMAKE_CURRENT_SOURCE_DIR}/scripts/pnglibconf.h.prebuilt + ${CMAKE_CURRENT_BINARY_DIR}/pnglibconf.h) +include_directories(${CMAKE_CURRENT_BINARY_DIR}) + +# OUR SOURCES +set(libpng_public_hdrs + png.h + pngconf.h + ${CMAKE_CURRENT_BINARY_DIR}/pnglibconf.h +) +set(libpng_sources + ${libpng_public_hdrs} + pngdebug.h + pnginfo.h + pngpriv.h + pngstruct.h + png.c + pngerror.c + pngget.c + pngmem.c + pngpread.c + pngread.c + pngrio.c + pngrtran.c + pngrutil.c + pngset.c + pngtrans.c + pngwio.c + pngwrite.c + pngwtran.c + pngwutil.c +) +set(pngtest_sources + pngtest.c +) +# SOME NEEDED DEFINITIONS + +add_definitions(-DPNG_CONFIGURE_LIBPNG) + +if(_AIX) + add_definitions(-D_ALL_SOURCE) +endif(_AIX) + +if(MSVC) + add_definitions(-DPNG_NO_MODULEDEF -D_CRT_SECURE_NO_DEPRECATE) +endif(MSVC) + +if(PNG_SHARED OR NOT MSVC) + #if building msvc static this has NOT to be defined + add_definitions(-DZLIB_DLL) +endif() + + +if(PNG_CONSOLE_IO_SUPPORTED) + add_definitions(-DPNG_CONSOLE_IO_SUPPORTED) +endif() + +if(PNG_NO_CONSOLE_IO) + add_definitions(-DPNG_NO_CONSOLE_IO) +endif() + +if(PNG_NO_STDIO) + add_definitions(-DPNG_NO_STDIO) +endif() + +if(PNG_DEBUG) + add_definitions(-DPNG_DEBUG) +endif() + +if(NOT M_LIBRARY AND NOT WIN32) + add_definitions(-DPNG_NO_FLOATING_POINT_SUPPORTED) +endif() + +# NOW BUILD OUR TARGET +include_directories(${CMAKE_CURRENT_SOURCE_DIR} ${ZLIB_INCLUDE_DIR}) + +if(PNG_SHARED) + add_library(${PNG_LIB_NAME} SHARED ${libpng_sources}) + if(MSVC) + # msvc does not append 'lib' - do it here to have consistent name + set_target_properties(${PNG_LIB_NAME} PROPERTIES PREFIX "lib") + set_target_properties(${PNG_LIB_NAME} PROPERTIES IMPORT_PREFIX "lib") + endif() + target_link_libraries(${PNG_LIB_NAME} ${ZLIB_LIBRARY} ${M_LIBRARY}) +endif() + +if(PNG_STATIC) +# does not work without changing name + set(PNG_LIB_NAME_STATIC ${PNG_LIB_NAME}_static) + add_library(${PNG_LIB_NAME_STATIC} STATIC ${libpng_sources}) + if(MSVC) + # msvc does not append 'lib' - do it here to have consistent name + set_target_properties(${PNG_LIB_NAME_STATIC} PROPERTIES PREFIX "lib") + endif() + target_link_libraries(${PNG_LIB_NAME_STATIC} ${ZLIB_LIBRARY} ${M_LIBRARY}) +endif() + + +if(PNG_SHARED AND WIN32) + set_target_properties(${PNG_LIB_NAME} PROPERTIES DEFINE_SYMBOL PNG_BUILD_DLL) +endif() + +if(PNG_TESTS AND PNG_SHARED) + # does not work with msvc due to png_lib_ver issue + add_executable(pngtest ${pngtest_sources}) + target_link_libraries(pngtest ${PNG_LIB_NAME}) + add_test(pngtest ./pngtest ${CMAKE_CURRENT_SOURCE_DIR}/pngtest.png) +endif() + +# +# Set a variable with CMake code which: +# Creates a symlink from src to dest (if possible) or alternatively +# copies if different. +macro(_png_generate_symlink_code CODE SRC DEST) + if(WIN32 AND NOT CYGWIN) + set(_png_gsc_message "Copying ${SRC} to ${DEST} if needed") + set(_png_gsc_operation "copy_if_different") + else() + set(_png_gsc_message "Symlinking ${SRC} to ${DEST}") + set(_png_gsc_operation "create_symlink") + endif() + + set(${CODE} " + message(STATUS \"${_png_gsc_message}\") + execute_process(COMMAND \${CMAKE_COMMAND} -E ${_png_gsc_operation} + \"${SRC}\" \"${DEST}\") + ") +endmacro() + +# CREATE PKGCONFIG FILES +# we use the same files like ./configure, so we have to set its vars +if(NOT DEFINED CMAKE_INSTALL_LIBDIR) + set(CMAKE_INSTALL_LIBDIR lib) +endif(NOT DEFINED CMAKE_INSTALL_LIBDIR) +set(prefix ${CMAKE_INSTALL_PREFIX}) +set(exec_prefix ${CMAKE_INSTALL_PREFIX}) +set(libdir ${CMAKE_INSTALL_PREFIX}/${CMAKE_INSTALL_LIBDIR}) +set(includedir ${CMAKE_INSTALL_PREFIX}/include) +set(LIBS "-lz -lm") +configure_file(${CMAKE_CURRENT_SOURCE_DIR}/libpng.pc.in + ${CMAKE_CURRENT_BINARY_DIR}/${PNGLIB_NAME}.pc @ONLY) +_png_generate_symlink_code(PNG_PC_INSTALL_CODE + ${CMAKE_CURRENT_BINARY_DIR}/${PNGLIB_NAME}.pc + ${CMAKE_CURRENT_BINARY_DIR}/libpng.pc) +install(CODE ${PNG_PC_INSTALL_CODE}) + +configure_file(${CMAKE_CURRENT_SOURCE_DIR}/libpng-config.in + ${CMAKE_CURRENT_BINARY_DIR}/${PNGLIB_NAME}-config @ONLY) +_png_generate_symlink_code(PNG_CONFIG_INSTALL_CODE + ${CMAKE_CURRENT_BINARY_DIR}/${PNGLIB_NAME}-config + ${CMAKE_CURRENT_BINARY_DIR}/libpng-config) +install(CODE ${PNG_CONFIG_INSTALL_CODE}) + +# SET UP LINKS +if(PNG_SHARED) + set_target_properties(${PNG_LIB_NAME} PROPERTIES +# VERSION 15.${PNGLIB_RELEASE}.1.5.1 + VERSION 15.${PNGLIB_RELEASE}.0 + SOVERSION 15 + CLEAN_DIRECT_OUTPUT 1) +endif() +if(PNG_STATIC) + # MSVC doesn't use a different file extension for shared vs. static + # libs. We are able to change OUTPUT_NAME to remove the _static + # for all other platforms. + if(NOT MSVC) + set_target_properties(${PNG_LIB_NAME_STATIC} PROPERTIES + OUTPUT_NAME ${PNG_LIB_NAME} + CLEAN_DIRECT_OUTPUT 1) + endif() +endif() + +# If CMake > 2.4.x, we set a variable used below to export +# targets to an export file. +# TODO: Use VERSION_GREATER after our cmake_minimum_required >= 2.6.2 +if(CMAKE_MAJOR_VERSION GREATER 1 AND CMAKE_MINOR_VERSION GREATER 4) + set(PNG_EXPORT_RULE EXPORT libpng) +elseif(CMAKE_MAJOR_VERSION GREATER 2) # future proof + set(PNG_EXPORT_RULE EXPORT libpng) +endif() + +# INSTALL +if(NOT SKIP_INSTALL_LIBRARIES AND NOT SKIP_INSTALL_ALL ) + if(PNG_SHARED) + install(TARGETS ${PNG_LIB_NAME} + ${PNG_EXPORT_RULE} + RUNTIME DESTINATION bin + LIBRARY DESTINATION ${CMAKE_INSTALL_LIBDIR} + ARCHIVE DESTINATION ${CMAKE_INSTALL_LIBDIR}) + + # Create a symlink for libpng.dll.a => libpng15.dll.a on Cygwin + if(CYGWIN) + _png_generate_symlink_code(PNG_SHARED_IMPLIB_INSTALL_CODE + ${PNGLIB_NAME}${CMAKE_IMPORT_LIBRARY_SUFFIX} + libpng${CMAKE_IMPORT_LIBRARY_SUFFIX}) + install(CODE ${PNG_SHARED_IMPLIB_INSTALL_CODE}) + install(FILES + ${CMAKE_CURRENT_BINARY_DIR}/libpng${CMAKE_IMPORT_LIBRARY_SUFFIX} + DESTINATION ${CMAKE_INSTALL_LIBDIR}) + endif() + + if(NOT WIN32) + IF(CMAKE_LIBRARY_OUTPUT_DIRECTORY) + _png_generate_symlink_code(PNG_SHARED_INSTALL_CODE + ${CMAKE_LIBRARY_OUTPUT_DIRECTORY}/${PNGLIB_NAME}${CMAKE_SHARED_LIBRARY_SUFFIX} + ${CMAKE_LIBRARY_OUTPUT_DIRECTORY}/libpng${CMAKE_SHARED_LIBRARY_SUFFIX}) + install(CODE ${PNG_SHARED_INSTALL_CODE}) + install(FILES + ${CMAKE_LIBRARY_OUTPUT_DIRECTORY}/libpng${CMAKE_SHARED_LIBRARY_SUFFIX} + DESTINATION ${CMAKE_INSTALL_LIBDIR}) + ELSE(CMAKE_LIBRARY_OUTPUT_DIRECTORY) + _png_generate_symlink_code(PNG_SHARED_INSTALL_CODE + ${PNGLIB_NAME}${CMAKE_SHARED_LIBRARY_SUFFIX} + libpng${CMAKE_SHARED_LIBRARY_SUFFIX}) + install(CODE ${PNG_SHARED_INSTALL_CODE}) + install(FILES + ${CMAKE_CURRENT_BINARY_DIR}/libpng${CMAKE_SHARED_LIBRARY_SUFFIX} + DESTINATION ${CMAKE_INSTALL_LIBDIR}) + ENDIF(CMAKE_LIBRARY_OUTPUT_DIRECTORY) + endif() + endif() + + if(PNG_STATIC) + install(TARGETS ${PNG_LIB_NAME_STATIC} + ${PNG_EXPORT_RULE} + LIBRARY DESTINATION ${CMAKE_INSTALL_LIBDIR} + ARCHIVE DESTINATION ${CMAKE_INSTALL_LIBDIR}) + if(NOT WIN32 OR CYGWIN) + IF(CMAKE_ARCHIVE_OUTPUT_DIRECTORY) + _png_generate_symlink_code(PNG_STATIC_INSTALL_CODE +${CMAKE_ARCHIVE_OUTPUT_DIRECTORY}/${PNGLIB_NAME}${CMAKE_STATIC_LIBRARY_SUFFIX} + ${CMAKE_ARCHIVE_OUTPUT_DIRECTORY}/libpng${CMAKE_STATIC_LIBRARY_SUFFIX}) + install(CODE ${PNG_STATIC_INSTALL_CODE}) + install(FILES + ${CMAKE_ARCHIVE_OUTPUT_DIRECTORY}/libpng${CMAKE_STATIC_LIBRARY_SUFFIX} + DESTINATION ${CMAKE_INSTALL_LIBDIR}) + ELSE(CMAKE_ARCHIVE_OUTPUT_DIRECTORY) + _png_generate_symlink_code(PNG_STATIC_INSTALL_CODE + ${PNGLIB_NAME}${CMAKE_STATIC_LIBRARY_SUFFIX} + libpng${CMAKE_STATIC_LIBRARY_SUFFIX}) + install(CODE ${PNG_STATIC_INSTALL_CODE}) + install(FILES + ${CMAKE_CURRENT_BINARY_DIR}/libpng${CMAKE_STATIC_LIBRARY_SUFFIX} + DESTINATION ${CMAKE_INSTALL_LIBDIR}) + ENDIF(CMAKE_ARCHIVE_OUTPUT_DIRECTORY) + endif() + endif() +endif() + +if(NOT SKIP_INSTALL_HEADERS AND NOT SKIP_INSTALL_ALL ) + install(FILES ${libpng_public_hdrs} DESTINATION include) + install(FILES ${libpng_public_hdrs} DESTINATION include/${PNGLIB_NAME}) +endif() +if(NOT SKIP_INSTALL_EXECUTABLES AND NOT SKIP_INSTALL_ALL ) + install(PROGRAMS ${CMAKE_CURRENT_BINARY_DIR}/libpng-config DESTINATION bin) + install(PROGRAMS ${CMAKE_CURRENT_BINARY_DIR}/${PNGLIB_NAME}-config + DESTINATION bin) +endif() +if(NOT SKIP_INSTALL_FILES AND NOT SKIP_INSTALL_ALL ) + # Install man pages + if(NOT PNG_MAN_DIR) + set(PNG_MAN_DIR "share/man") + endif() + install(FILES libpng.3 libpngpf.3 DESTINATION ${PNG_MAN_DIR}/man3) + install(FILES png.5 DESTINATION ${PNG_MAN_DIR}/man5) + # Install pkg-config files + install(FILES ${CMAKE_CURRENT_BINARY_DIR}/libpng.pc + DESTINATION ${CMAKE_INSTALL_LIBDIR}/pkgconfig) + install(PROGRAMS ${CMAKE_CURRENT_BINARY_DIR}/libpng-config + DESTINATION bin) + install(FILES ${CMAKE_CURRENT_BINARY_DIR}/${PNGLIB_NAME}.pc + DESTINATION ${CMAKE_INSTALL_LIBDIR}/pkgconfig) + install(PROGRAMS ${CMAKE_CURRENT_BINARY_DIR}/${PNGLIB_NAME}-config + DESTINATION bin) +endif() + +# On versions of CMake that support it, create an export file CMake +# users can include() to import our targets +if(PNG_EXPORT_RULE AND NOT SKIP_INSTALL_EXPORT AND NOT SKIP_INSTALL_ALL ) + install(EXPORT libpng DESTINATION lib/libpng FILE lib${PNG_LIB_NAME}.cmake) +endif() + +# what's with libpng-$VER%.txt and all the extra files? + + +# UNINSTALL +# do we need this? + + +# DIST +# do we need this? + +# to create msvc import lib for mingw compiled shared lib +# pexports libpng.dll > libpng.def +# lib /def:libpng.def /machine:x86 + diff --git a/src/3rdparty/libpng/INSTALL b/src/3rdparty/libpng/INSTALL new file mode 100644 index 0000000000..353bfff326 --- /dev/null +++ b/src/3rdparty/libpng/INSTALL @@ -0,0 +1,135 @@ + +Installing libpng + +On Unix/Linux and similar systems, you can simply type + + ./configure [--prefix=/path] + make check + make install + +and ignore the rest of this document. + +If configure does not work on your system and you have a reasonably +up-to-date set of tools, running ./autogen.sh before running ./configure +may fix the problem. You can also run the individual commands in +autogen.sh with the --force option, if supported by your version of +the tools. To be really sure that you aren't using any of the included +pre-built scripts, you can do this: + + ./configure --enable-maintainer-mode + make maintainer-clean + ./autogen.sh + ./configure [--prefix=/path] [other options] + make + make install + make check + +Instead, you can use one of the custom-built makefiles in the +"scripts" directory + + cp scripts/makefile.system makefile + make test + make install + +The files that are presently available in the scripts directory +are listed and described in scripts/README.txt. + +Or you can use one of the "projects" in the "projects" directory. + +Before installing libpng, you must first install zlib, if it +is not already on your system. zlib can usually be found +wherever you got libpng. zlib can be placed in another directory, +at the same level as libpng. + +If you want to use "cmake" (see www.cmake.org), type + + cmake . -DCMAKE_INSTALL_PREFIX=/path + make + make install + +If your system already has a preinstalled zlib you will still need +to have access to the zlib.h and zconf.h include files that +correspond to the version of zlib that's installed. + +You can rename the directories that you downloaded (they +might be called "libpng-x.y.z" or "libpngNN" and "zlib-1.2.5" +or "zlib125") so that you have directories called "zlib" and "libpng". + +Your directory structure should look like this: + + .. (the parent directory) + libpng (this directory) + INSTALL (this file) + README + *.h + *.c + CMakeLists.txt => "cmake" script + configuration files: + configure.ac, configure, Makefile.am, Makefile.in, + autogen.sh, config.guess, ltmain.sh, missing, libpng.pc.in, + libpng-config.in, aclocal.m4, config.h.in, config.sub, + depcomp, install-sh, mkinstalldirs, test-pngtest.sh + contrib + gregbook + pngminim + pngminus + pngsuite + visupng + projects + visualc71 + vstudio + scripts + makefile.* + *.def (module definition files) + etc. + pngtest.png + etc. + zlib + README + *.h + *.c + contrib + etc. + +If the line endings in the files look funny, you may wish to get the other +distribution of libpng. It is available in both tar.gz (UNIX style line +endings) and zip (DOS style line endings) formats. + +If you are building libpng with MSVC, you can enter the +libpng projects\visualc6 or visualc71 directory and follow the instructions +in README.txt. + +Otherwise enter the zlib directory and follow the instructions in zlib/README, +then come back here and run "configure" or choose the appropriate +makefile.sys in the scripts directory. + +Copy the file (or files) that you need from the +scripts directory into this directory, for example + + MSDOS example: copy scripts\makefile.msc makefile + UNIX example: cp scripts/makefile.std makefile + +Read the makefile to see if you need to change any source or +target directories to match your preferences. + +Then read pnglibconf.dfa to see if you want to make any configuration +changes. + +Then just run "make" which will create the libpng library in +this directory and "make test" which will run a quick test that reads +the "pngtest.png" file and writes a "pngout.png" file that should be +identical to it. Look for "9782 zero samples" in the output of the +test. For more confidence, you can run another test by typing +"pngtest pngnow.png" and looking for "289 zero samples" in the output. +Also, you can run "pngtest -m contrib/pngsuite/*.png" and compare +your output with the result shown in contrib/pngsuite/README. + +Most of the makefiles will allow you to run "make install" to +put the library in its final resting place (if you want to +do that, run "make install" in the zlib directory first if necessary). +Some also allow you to run "make test-installed" after you have +run "make install". + +Further information can be found in the README and libpng-manual.txt +files, in the individual makefiles, in png.h, and the manual pages +libpng.3 and png.5. diff --git a/src/3rdparty/libpng/LICENSE b/src/3rdparty/libpng/LICENSE new file mode 100644 index 0000000000..b28f15c74f --- /dev/null +++ b/src/3rdparty/libpng/LICENSE @@ -0,0 +1,111 @@ + +This copy of the libpng notices is provided for your convenience. In case of +any discrepancy between this copy and the notices in the file png.h that is +included in the libpng distribution, the latter shall prevail. + +COPYRIGHT NOTICE, DISCLAIMER, and LICENSE: + +If you modify libpng you may insert additional notices immediately following +this sentence. + +This code is released under the libpng license. + +libpng versions 1.2.6, August 15, 2004, through 1.5.1, February 3, 2011, are +Copyright (c) 2004, 2006-2011 Glenn Randers-Pehrson, and are +distributed according to the same disclaimer and license as libpng-1.2.5 +with the following individual added to the list of Contributing Authors + + Cosmin Truta + +libpng versions 1.0.7, July 1, 2000, through 1.2.5 - October 3, 2002, are +Copyright (c) 2000-2002 Glenn Randers-Pehrson, and are +distributed according to the same disclaimer and license as libpng-1.0.6 +with the following individuals added to the list of Contributing Authors + + Simon-Pierre Cadieux + Eric S. Raymond + Gilles Vollant + +and with the following additions to the disclaimer: + + There is no warranty against interference with your enjoyment of the + library or against infringement. There is no warranty that our + efforts or the library will fulfill any of your particular purposes + or needs. This library is provided with all faults, and the entire + risk of satisfactory quality, performance, accuracy, and effort is with + the user. + +libpng versions 0.97, January 1998, through 1.0.6, March 20, 2000, are +Copyright (c) 1998, 1999 Glenn Randers-Pehrson, and are +distributed according to the same disclaimer and license as libpng-0.96, +with the following individuals added to the list of Contributing Authors: + + Tom Lane + Glenn Randers-Pehrson + Willem van Schaik + +libpng versions 0.89, June 1996, through 0.96, May 1997, are +Copyright (c) 1996, 1997 Andreas Dilger +Distributed according to the same disclaimer and license as libpng-0.88, +with the following individuals added to the list of Contributing Authors: + + John Bowler + Kevin Bracey + Sam Bushell + Magnus Holmgren + Greg Roelofs + Tom Tanner + +libpng versions 0.5, May 1995, through 0.88, January 1996, are +Copyright (c) 1995, 1996 Guy Eric Schalnat, Group 42, Inc. + +For the purposes of this copyright and license, "Contributing Authors" +is defined as the following set of individuals: + + Andreas Dilger + Dave Martindale + Guy Eric Schalnat + Paul Schmidt + Tim Wegner + +The PNG Reference Library is supplied "AS IS". The Contributing Authors +and Group 42, Inc. disclaim all warranties, expressed or implied, +including, without limitation, the warranties of merchantability and of +fitness for any purpose. The Contributing Authors and Group 42, Inc. +assume no liability for direct, indirect, incidental, special, exemplary, +or consequential damages, which may result from the use of the PNG +Reference Library, even if advised of the possibility of such damage. + +Permission is hereby granted to use, copy, modify, and distribute this +source code, or portions hereof, for any purpose, without fee, subject +to the following restrictions: + +1. The origin of this source code must not be misrepresented. + +2. Altered versions must be plainly marked as such and must not + be misrepresented as being the original source. + +3. This Copyright notice may not be removed or altered from any + source or altered source distribution. + +The Contributing Authors and Group 42, Inc. specifically permit, without +fee, and encourage the use of this source code as a component to +supporting the PNG file format in commercial products. If you use this +source code in a product, acknowledgment is not required but would be +appreciated. + + +A "png_get_copyright" function is available, for convenient use in "about" +boxes and the like: + + printf("%s",png_get_copyright(NULL)); + +Also, the PNG logo (in PNG format, of course) is supplied in the +files "pngbar.png" and "pngbar.jpg (88x31) and "pngnow.png" (98x31). + +Libpng is OSI Certified Open Source Software. OSI Certified Open Source is a +certification mark of the Open Source Initiative. + +Glenn Randers-Pehrson +glennrp at users.sourceforge.net +February 3, 2011 diff --git a/src/3rdparty/libpng/README b/src/3rdparty/libpng/README new file mode 100644 index 0000000000..9dd6745f0a --- /dev/null +++ b/src/3rdparty/libpng/README @@ -0,0 +1,205 @@ +README for libpng version 1.5.1 - February 3, 2011 (shared library 15.0) +See the note about version numbers near the top of png.h + +See INSTALL for instructions on how to install libpng. + +Libpng comes in several distribution formats. Get libpng-*.tar.gz, +libpng-*.tar.xz or libpng-*.tar.bz2 if you want UNIX-style line endings +in the text files, or lpng*.zip if you want DOS-style line endings. + +Version 0.89 was the first official release of libpng. Don't let the +fact that it's the first release fool you. The libpng library has been in +extensive use and testing since mid-1995. By late 1997 it had +finally gotten to the stage where there hadn't been significant +changes to the API in some time, and people have a bad feeling about +libraries with versions < 1.0. Version 1.0.0 was released in +March 1998. + +**** +Note that some of the changes to the png_info structure render this +version of the library binary incompatible with libpng-0.89 or +earlier versions if you are using a shared library. The type of the +"filler" parameter for png_set_filler() has changed from png_byte to +png_uint_32, which will affect shared-library applications that use +this function. + +To avoid problems with changes to the internals of png_info_struct, +new APIs have been made available in 0.95 to avoid direct application +access to info_ptr. These functions are the png_set_<chunk> and +png_get_<chunk> functions. These functions should be used when +accessing/storing the info_struct data, rather than manipulating it +directly, to avoid such problems in the future. + +It is important to note that the APIs do not make current programs +that access the info struct directly incompatible with the new +library. However, it is strongly suggested that new programs use +the new APIs (as shown in example.c and pngtest.c), and older programs +be converted to the new format, to facilitate upgrades in the future. +**** + +Additions since 0.90 include the ability to compile libpng as a +Windows DLL, and new APIs for accessing data in the info struct. +Experimental functions include the ability to set weighting and cost +factors for row filter selection, direct reads of integers from buffers +on big-endian processors that support misaligned data access, faster +methods of doing alpha composition, and more accurate 16->8 bit color +conversion. + +The additions since 0.89 include the ability to read from a PNG stream +which has had some (or all) of the signature bytes read by the calling +application. This also allows the reading of embedded PNG streams that +do not have the PNG file signature. As well, it is now possible to set +the library action on the detection of chunk CRC errors. It is possible +to set different actions based on whether the CRC error occurred in a +critical or an ancillary chunk. + +The changes made to the library, and bugs fixed are based on discussions +on the PNG-implement mailing list and not on material submitted +privately to Guy, Andreas, or Glenn. They will forward any good +suggestions to the list. + +For a detailed description on using libpng, read libpng-manual.txt. For +examples of libpng in a program, see example.c and pngtest.c. For usage +information and restrictions (what little they are) on libpng, see +png.h. For a description on using zlib (the compression library used by +libpng) and zlib's restrictions, see zlib.h + +I have included a general makefile, as well as several machine and +compiler specific ones, but you may have to modify one for your own needs. + +You should use zlib 1.0.4 or later to run this, but it MAY work with +versions as old as zlib 0.95. Even so, there are bugs in older zlib +versions which can cause the output of invalid compression streams for +some images. You will definitely need zlib 1.0.4 or later if you are +taking advantage of the MS-DOS "far" structure allocation for the small +and medium memory models. You should also note that zlib is a +compression library that is useful for more things than just PNG files. +You can use zlib as a drop-in replacement for fread() and fwrite() if +you are so inclined. + +zlib should be available at the same place that libpng is, or at. +ftp://ftp.info-zip.org/pub/infozip/zlib + +You may also want a copy of the PNG specification. It is available +as an RFC, a W3C Recommendation, and an ISO/IEC Standard. You can find +these at http://www.libpng.org/pub/png/documents/ + +This code is currently being archived at libpng.sf.net in the +[DOWNLOAD] area, and on CompuServe, Lib 20 (PNG SUPPORT) +at GO GRAPHSUP. If you can't find it in any of those places, +e-mail me, and I'll help you find it. + +If you have any code changes, requests, problems, etc., please e-mail +them to me. Also, I'd appreciate any make files or project files, +and any modifications you needed to make to get libpng to compile, +along with a #define variable to tell what compiler/system you are on. +If you needed to add transformations to libpng, or wish libpng would +provide the image in a different way, drop me a note (and code, if +possible), so I can consider supporting the transformation. +Finally, if you get any warning messages when compiling libpng +(note: not zlib), and they are easy to fix, I'd appreciate the +fix. Please mention "libpng" somewhere in the subject line. Thanks. + +This release was created and will be supported by myself (of course +based in a large way on Guy's and Andreas' earlier work), and the PNG +development group. + +Send comments/corrections/commendations to png-mng-implement at +lists.sourceforge.net (subscription required; visit +https://lists.sourceforge.net/lists/listinfo/png-mng-implement +to subscribe) or to glennrp at users.sourceforge.net + +You can't reach Guy, the original libpng author, at the addresses +given in previous versions of this document. He and Andreas will +read mail addressed to the png-implement list, however. + +Please do not send general questions about PNG. Send them to +the (png-list at ccrc.wustl.edu, subscription required, write to +majordomo at ccrc.wustl.edu with "subscribe png-list" in your message). +On the other hand, +please do not send libpng questions to that address, send them to me +or to the png-implement list. I'll +get them in the end anyway. If you have a question about something +in the PNG specification that is related to using libpng, send it +to me. Send me any questions that start with "I was using libpng, +and ...". If in doubt, send questions to me. I'll bounce them +to others, if necessary. + +Please do not send suggestions on how to change PNG. We have +been discussing PNG for nine years now, and it is official and +finished. If you have suggestions for libpng, however, I'll +gladly listen. Even if your suggestion is not used immediately, +it may be used later. + +Files in this distribution: + + ANNOUNCE => Announcement of this version, with recent changes + CHANGES => Description of changes between libpng versions + KNOWNBUG => List of known bugs and deficiencies + LICENSE => License to use and redistribute libpng + README => This file + TODO => Things not implemented in the current library + Y2KINFO => Statement of Y2K compliance + example.c => Example code for using libpng functions + libpng.3 => manual page for libpng (includes libpng-manual.txt) + libpng-manual.txt => Description of libpng and its functions + libpngpf.3 => manual page for libpng's private functions + png.5 => manual page for the PNG format + png.c => Basic interface functions common to library + png.h => Library function and interface declarations (public) + pngpriv.h => Library function and interface declarations (private) + pngconf.h => System specific library configuration (public) + pngstruct.h => png_struct declaration (private) + pnginfo.h => png_info struct declaration (private) + pngdebug.h => debugging macros (private) + pngerror.c => Error/warning message I/O functions + pngget.c => Functions for retrieving info from struct + pngmem.c => Memory handling functions + pngbar.png => PNG logo, 88x31 + pngnow.png => PNG logo, 98x31 + pngpread.c => Progressive reading functions + pngread.c => Read data/helper high-level functions + pngrio.c => Lowest-level data read I/O functions + pngrtran.c => Read data transformation functions + pngrutil.c => Read data utility functions + pngset.c => Functions for storing data into the info_struct + pngtest.c => Library test program + pngtest.png => Library test sample image + pngtrans.c => Common data transformation functions + pngwio.c => Lowest-level write I/O functions + pngwrite.c => High-level write functions + pngwtran.c => Write data transformations + pngwutil.c => Write utility functions + contrib => Contributions + gregbook => source code for PNG reading and writing, from + Greg Roelofs' "PNG: The Definitive Guide", + O'Reilly, 1999 + msvctest => Builds and runs pngtest using a MSVC workspace + pngminus => Simple pnm2png and png2pnm programs + pngsuite => Test images + visupng => Contains a MSVC workspace for VisualPng + projects => Contains project files and workspaces for + building a DLL + cbuilder5 => Contains a Borland workspace for building + libpng and zlib + visualc6 => Contains a Microsoft Visual C++ (MSVC) + workspace for building libpng and zlib + visualc71 => Contains a Microsoft Visual C++ (MSVC) + workspace for building libpng and zlib + xcode => Contains an Apple xcode + workspace for building libpng and zlib + scripts => Directory containing scripts for building libpng: + (see scripts/README.txt for the list of scripts) + +Good luck, and happy coding. + +-Glenn Randers-Pehrson (current maintainer, since 1998) + Internet: glennrp at users.sourceforge.net + +-Andreas Eric Dilger (former maintainer, 1996-1997) + Internet: adilger at enel.ucalgary.ca + Web: http://www-mddsp.enel.ucalgary.ca/People/adilger/ + +-Guy Eric Schalnat (original author and former maintainer, 1995-1996) + (formerly of Group 42, Inc) + Internet: gschal at infinet.com diff --git a/src/3rdparty/libpng/TODO b/src/3rdparty/libpng/TODO new file mode 100644 index 0000000000..6e1f028bd7 --- /dev/null +++ b/src/3rdparty/libpng/TODO @@ -0,0 +1,27 @@ +/* +TODO - list of things to do for libpng: + +Final bug fixes. +Better C++ wrapper/full C++ implementation? +Fix problem with C++ and EXTERN "C". +cHRM transformation. +Remove setjmp/longjmp usage in favor of returning error codes. +Add "grayscale->palette" transformation and "palette->grayscale" detection. +Improved dithering. +Multi-lingual error and warning message support. +Complete sRGB transformation (presently it simply uses gamma=0.45455). +Man pages for function calls. +Better documentation. +Better filter selection + (counting huffman bits/precompression? filter inertia? filter costs?). +Histogram creation. +Text conversion between different code pages (Latin-1 -> Mac and DOS). +Avoid building gamma tables whenever possible. +Use greater precision when changing to linear gamma for compositing against + background and doing rgb-to-gray transformation. +Investigate pre-incremented loop counters and other loop constructions. +Add interpolated method of handling interlacing. +Switch to the simpler zlib (zlib/libpng) license if legally possible. +Extend pngvalid.c to validate more of the libpng transformations. + +*/ diff --git a/src/3rdparty/libpng/config.guess b/src/3rdparty/libpng/config.guess new file mode 100644 index 0000000000..dc84c68ef7 --- /dev/null +++ b/src/3rdparty/libpng/config.guess @@ -0,0 +1,1501 @@ +#! /bin/sh +# Attempt to guess a canonical system name. +# Copyright (C) 1992, 1993, 1994, 1995, 1996, 1997, 1998, 1999, +# 2000, 2001, 2002, 2003, 2004, 2005, 2006, 2007, 2008, 2009 +# Free Software Foundation, Inc. + +timestamp='2009-11-20' + +# This file is free software; you can redistribute it and/or modify it +# under the terms of the GNU General Public License as published by +# the Free Software Foundation; either version 2 of the License, or +# (at your option) any later version. +# +# This program is distributed in the hope that it will be useful, but +# WITHOUT ANY WARRANTY; without even the implied warranty of +# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU +# General Public License for more details. +# +# You should have received a copy of the GNU General Public License +# along with this program; if not, write to the Free Software +# Foundation, Inc., 51 Franklin Street - Fifth Floor, Boston, MA +# 02110-1301, USA. +# +# As a special exception to the GNU General Public License, if you +# distribute this file as part of a program that contains a +# configuration script generated by Autoconf, you may include it under +# the same distribution terms that you use for the rest of that program. + + +# Originally written by Per Bothner. Please send patches (context +# diff format) to <config-patches@gnu.org> and include a ChangeLog +# entry. +# +# This script attempts to guess a canonical system name similar to +# config.sub. If it succeeds, it prints the system name on stdout, and +# exits with 0. Otherwise, it exits with 1. +# +# You can get the latest version of this script from: +# http://git.savannah.gnu.org/gitweb/?p=config.git;a=blob_plain;f=config.guess;hb=HEAD + +me=`echo "$0" | sed -e 's,.*/,,'` + +usage="\ +Usage: $0 [OPTION] + +Output the configuration name of the system \`$me' is run on. + +Operation modes: + -h, --help print this help, then exit + -t, --time-stamp print date of last modification, then exit + -v, --version print version number, then exit + +Report bugs and patches to <config-patches@gnu.org>." + +version="\ +GNU config.guess ($timestamp) + +Originally written by Per Bothner. +Copyright (C) 1992, 1993, 1994, 1995, 1996, 1997, 1998, 1999, 2000, 2001, +2002, 2003, 2004, 2005, 2006, 2007, 2008 Free Software Foundation, Inc. + +This is free software; see the source for copying conditions. There is NO +warranty; not even for MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE." + +help=" +Try \`$me --help' for more information." + +# Parse command line +while test $# -gt 0 ; do + case $1 in + --time-stamp | --time* | -t ) + echo "$timestamp" ; exit ;; + --version | -v ) + echo "$version" ; exit ;; + --help | --h* | -h ) + echo "$usage"; exit ;; + -- ) # Stop option processing + shift; break ;; + - ) # Use stdin as input. + break ;; + -* ) + echo "$me: invalid option $1$help" >&2 + exit 1 ;; + * ) + break ;; + esac +done + +if test $# != 0; then + echo "$me: too many arguments$help" >&2 + exit 1 +fi + +trap 'exit 1' 1 2 15 + +# CC_FOR_BUILD -- compiler used by this script. Note that the use of a +# compiler to aid in system detection is discouraged as it requires +# temporary files to be created and, as you can see below, it is a +# headache to deal with in a portable fashion. + +# Historically, `CC_FOR_BUILD' used to be named `HOST_CC'. We still +# use `HOST_CC' if defined, but it is deprecated. + +# Portable tmp directory creation inspired by the Autoconf team. + +set_cc_for_build=' +trap "exitcode=\$?; (rm -f \$tmpfiles 2>/dev/null; rmdir \$tmp 2>/dev/null) && exit \$exitcode" 0 ; +trap "rm -f \$tmpfiles 2>/dev/null; rmdir \$tmp 2>/dev/null; exit 1" 1 2 13 15 ; +: ${TMPDIR=/tmp} ; + { tmp=`(umask 077 && mktemp -d "$TMPDIR/cgXXXXXX") 2>/dev/null` && test -n "$tmp" && test -d "$tmp" ; } || + { test -n "$RANDOM" && tmp=$TMPDIR/cg$$-$RANDOM && (umask 077 && mkdir $tmp) ; } || + { tmp=$TMPDIR/cg-$$ && (umask 077 && mkdir $tmp) && echo "Warning: creating insecure temp directory" >&2 ; } || + { echo "$me: cannot create a temporary directory in $TMPDIR" >&2 ; exit 1 ; } ; +dummy=$tmp/dummy ; +tmpfiles="$dummy.c $dummy.o $dummy.rel $dummy" ; +case $CC_FOR_BUILD,$HOST_CC,$CC in + ,,) echo "int x;" > $dummy.c ; + for c in cc gcc c89 c99 ; do + if ($c -c -o $dummy.o $dummy.c) >/dev/null 2>&1 ; then + CC_FOR_BUILD="$c"; break ; + fi ; + done ; + if test x"$CC_FOR_BUILD" = x ; then + CC_FOR_BUILD=no_compiler_found ; + fi + ;; + ,,*) CC_FOR_BUILD=$CC ;; + ,*,*) CC_FOR_BUILD=$HOST_CC ;; +esac ; set_cc_for_build= ;' + +# This is needed to find uname on a Pyramid OSx when run in the BSD universe. +# (ghazi@noc.rutgers.edu 1994-08-24) +if (test -f /.attbin/uname) >/dev/null 2>&1 ; then + PATH=$PATH:/.attbin ; export PATH +fi + +UNAME_MACHINE=`(uname -m) 2>/dev/null` || UNAME_MACHINE=unknown +UNAME_RELEASE=`(uname -r) 2>/dev/null` || UNAME_RELEASE=unknown +UNAME_SYSTEM=`(uname -s) 2>/dev/null` || UNAME_SYSTEM=unknown +UNAME_VERSION=`(uname -v) 2>/dev/null` || UNAME_VERSION=unknown + +# Note: order is significant - the case branches are not exclusive. + +case "${UNAME_MACHINE}:${UNAME_SYSTEM}:${UNAME_RELEASE}:${UNAME_VERSION}" in + *:NetBSD:*:*) + # NetBSD (nbsd) targets should (where applicable) match one or + # more of the tupples: *-*-netbsdelf*, *-*-netbsdaout*, + # *-*-netbsdecoff* and *-*-netbsd*. For targets that recently + # switched to ELF, *-*-netbsd* would select the old + # object file format. This provides both forward + # compatibility and a consistent mechanism for selecting the + # object file format. + # + # Note: NetBSD doesn't particularly care about the vendor + # portion of the name. We always set it to "unknown". + sysctl="sysctl -n hw.machine_arch" + UNAME_MACHINE_ARCH=`(/sbin/$sysctl 2>/dev/null || \ + /usr/sbin/$sysctl 2>/dev/null || echo unknown)` + case "${UNAME_MACHINE_ARCH}" in + armeb) machine=armeb-unknown ;; + arm*) machine=arm-unknown ;; + sh3el) machine=shl-unknown ;; + sh3eb) machine=sh-unknown ;; + sh5el) machine=sh5le-unknown ;; + *) machine=${UNAME_MACHINE_ARCH}-unknown ;; + esac + # The Operating System including object format, if it has switched + # to ELF recently, or will in the future. + case "${UNAME_MACHINE_ARCH}" in + arm*|i386|m68k|ns32k|sh3*|sparc|vax) + eval $set_cc_for_build + if echo __ELF__ | $CC_FOR_BUILD -E - 2>/dev/null \ + | grep -q __ELF__ + then + # Once all utilities can be ECOFF (netbsdecoff) or a.out (netbsdaout). + # Return netbsd for either. FIX? + os=netbsd + else + os=netbsdelf + fi + ;; + *) + os=netbsd + ;; + esac + # The OS release + # Debian GNU/NetBSD machines have a different userland, and + # thus, need a distinct triplet. However, they do not need + # kernel version information, so it can be replaced with a + # suitable tag, in the style of linux-gnu. + case "${UNAME_VERSION}" in + Debian*) + release='-gnu' + ;; + *) + release=`echo ${UNAME_RELEASE}|sed -e 's/[-_].*/\./'` + ;; + esac + # Since CPU_TYPE-MANUFACTURER-KERNEL-OPERATING_SYSTEM: + # contains redundant information, the shorter form: + # CPU_TYPE-MANUFACTURER-OPERATING_SYSTEM is used. + echo "${machine}-${os}${release}" + exit ;; + *:OpenBSD:*:*) + UNAME_MACHINE_ARCH=`arch | sed 's/OpenBSD.//'` + echo ${UNAME_MACHINE_ARCH}-unknown-openbsd${UNAME_RELEASE} + exit ;; + *:ekkoBSD:*:*) + echo ${UNAME_MACHINE}-unknown-ekkobsd${UNAME_RELEASE} + exit ;; + *:SolidBSD:*:*) + echo ${UNAME_MACHINE}-unknown-solidbsd${UNAME_RELEASE} + exit ;; + macppc:MirBSD:*:*) + echo powerpc-unknown-mirbsd${UNAME_RELEASE} + exit ;; + *:MirBSD:*:*) + echo ${UNAME_MACHINE}-unknown-mirbsd${UNAME_RELEASE} + exit ;; + alpha:OSF1:*:*) + case $UNAME_RELEASE in + *4.0) + UNAME_RELEASE=`/usr/sbin/sizer -v | awk '{print $3}'` + ;; + *5.*) + UNAME_RELEASE=`/usr/sbin/sizer -v | awk '{print $4}'` + ;; + esac + # According to Compaq, /usr/sbin/psrinfo has been available on + # OSF/1 and Tru64 systems produced since 1995. I hope that + # covers most systems running today. This code pipes the CPU + # types through head -n 1, so we only detect the type of CPU 0. + ALPHA_CPU_TYPE=`/usr/sbin/psrinfo -v | sed -n -e 's/^ The alpha \(.*\) processor.*$/\1/p' | head -n 1` + case "$ALPHA_CPU_TYPE" in + "EV4 (21064)") + UNAME_MACHINE="alpha" ;; + "EV4.5 (21064)") + UNAME_MACHINE="alpha" ;; + "LCA4 (21066/21068)") + UNAME_MACHINE="alpha" ;; + "EV5 (21164)") + UNAME_MACHINE="alphaev5" ;; + "EV5.6 (21164A)") + UNAME_MACHINE="alphaev56" ;; + "EV5.6 (21164PC)") + UNAME_MACHINE="alphapca56" ;; + "EV5.7 (21164PC)") + UNAME_MACHINE="alphapca57" ;; + "EV6 (21264)") + UNAME_MACHINE="alphaev6" ;; + "EV6.7 (21264A)") + UNAME_MACHINE="alphaev67" ;; + "EV6.8CB (21264C)") + UNAME_MACHINE="alphaev68" ;; + "EV6.8AL (21264B)") + UNAME_MACHINE="alphaev68" ;; + "EV6.8CX (21264D)") + UNAME_MACHINE="alphaev68" ;; + "EV6.9A (21264/EV69A)") + UNAME_MACHINE="alphaev69" ;; + "EV7 (21364)") + UNAME_MACHINE="alphaev7" ;; + "EV7.9 (21364A)") + UNAME_MACHINE="alphaev79" ;; + esac + # A Pn.n version is a patched version. + # A Vn.n version is a released version. + # A Tn.n version is a released field test version. + # A Xn.n version is an unreleased experimental baselevel. + # 1.2 uses "1.2" for uname -r. + echo ${UNAME_MACHINE}-dec-osf`echo ${UNAME_RELEASE} | sed -e 's/^[PVTX]//' | tr 'ABCDEFGHIJKLMNOPQRSTUVWXYZ' 'abcdefghijklmnopqrstuvwxyz'` + exit ;; + Alpha\ *:Windows_NT*:*) + # How do we know it's Interix rather than the generic POSIX subsystem? + # Should we change UNAME_MACHINE based on the output of uname instead + # of the specific Alpha model? + echo alpha-pc-interix + exit ;; + 21064:Windows_NT:50:3) + echo alpha-dec-winnt3.5 + exit ;; + Amiga*:UNIX_System_V:4.0:*) + echo m68k-unknown-sysv4 + exit ;; + *:[Aa]miga[Oo][Ss]:*:*) + echo ${UNAME_MACHINE}-unknown-amigaos + exit ;; + *:[Mm]orph[Oo][Ss]:*:*) + echo ${UNAME_MACHINE}-unknown-morphos + exit ;; + *:OS/390:*:*) + echo i370-ibm-openedition + exit ;; + *:z/VM:*:*) + echo s390-ibm-zvmoe + exit ;; + *:OS400:*:*) + echo powerpc-ibm-os400 + exit ;; + arm:RISC*:1.[012]*:*|arm:riscix:1.[012]*:*) + echo arm-acorn-riscix${UNAME_RELEASE} + exit ;; + arm:riscos:*:*|arm:RISCOS:*:*) + echo arm-unknown-riscos + exit ;; + SR2?01:HI-UX/MPP:*:* | SR8000:HI-UX/MPP:*:*) + echo hppa1.1-hitachi-hiuxmpp + exit ;; + Pyramid*:OSx*:*:* | MIS*:OSx*:*:* | MIS*:SMP_DC-OSx*:*:*) + # akee@wpdis03.wpafb.af.mil (Earle F. Ake) contributed MIS and NILE. + if test "`(/bin/universe) 2>/dev/null`" = att ; then + echo pyramid-pyramid-sysv3 + else + echo pyramid-pyramid-bsd + fi + exit ;; + NILE*:*:*:dcosx) + echo pyramid-pyramid-svr4 + exit ;; + DRS?6000:unix:4.0:6*) + echo sparc-icl-nx6 + exit ;; + DRS?6000:UNIX_SV:4.2*:7* | DRS?6000:isis:4.2*:7*) + case `/usr/bin/uname -p` in + sparc) echo sparc-icl-nx7; exit ;; + esac ;; + s390x:SunOS:*:*) + echo ${UNAME_MACHINE}-ibm-solaris2`echo ${UNAME_RELEASE}|sed -e 's/[^.]*//'` + exit ;; + sun4H:SunOS:5.*:*) + echo sparc-hal-solaris2`echo ${UNAME_RELEASE}|sed -e 's/[^.]*//'` + exit ;; + sun4*:SunOS:5.*:* | tadpole*:SunOS:5.*:*) + echo sparc-sun-solaris2`echo ${UNAME_RELEASE}|sed -e 's/[^.]*//'` + exit ;; + i86pc:AuroraUX:5.*:* | i86xen:AuroraUX:5.*:*) + echo i386-pc-auroraux${UNAME_RELEASE} + exit ;; + i86pc:SunOS:5.*:* | i86xen:SunOS:5.*:*) + eval $set_cc_for_build + SUN_ARCH="i386" + # If there is a compiler, see if it is configured for 64-bit objects. + # Note that the Sun cc does not turn __LP64__ into 1 like gcc does. + # This test works for both compilers. + if [ "$CC_FOR_BUILD" != 'no_compiler_found' ]; then + if (echo '#ifdef __amd64'; echo IS_64BIT_ARCH; echo '#endif') | \ + (CCOPTS= $CC_FOR_BUILD -E - 2>/dev/null) | \ + grep IS_64BIT_ARCH >/dev/null + then + SUN_ARCH="x86_64" + fi + fi + echo ${SUN_ARCH}-pc-solaris2`echo ${UNAME_RELEASE}|sed -e 's/[^.]*//'` + exit ;; + sun4*:SunOS:6*:*) + # According to config.sub, this is the proper way to canonicalize + # SunOS6. Hard to guess exactly what SunOS6 will be like, but + # it's likely to be more like Solaris than SunOS4. + echo sparc-sun-solaris3`echo ${UNAME_RELEASE}|sed -e 's/[^.]*//'` + exit ;; + sun4*:SunOS:*:*) + case "`/usr/bin/arch -k`" in + Series*|S4*) + UNAME_RELEASE=`uname -v` + ;; + esac + # Japanese Language versions have a version number like `4.1.3-JL'. + echo sparc-sun-sunos`echo ${UNAME_RELEASE}|sed -e 's/-/_/'` + exit ;; + sun3*:SunOS:*:*) + echo m68k-sun-sunos${UNAME_RELEASE} + exit ;; + sun*:*:4.2BSD:*) + UNAME_RELEASE=`(sed 1q /etc/motd | awk '{print substr($5,1,3)}') 2>/dev/null` + test "x${UNAME_RELEASE}" = "x" && UNAME_RELEASE=3 + case "`/bin/arch`" in + sun3) + echo m68k-sun-sunos${UNAME_RELEASE} + ;; + sun4) + echo sparc-sun-sunos${UNAME_RELEASE} + ;; + esac + exit ;; + aushp:SunOS:*:*) + echo sparc-auspex-sunos${UNAME_RELEASE} + exit ;; + # The situation for MiNT is a little confusing. The machine name + # can be virtually everything (everything which is not + # "atarist" or "atariste" at least should have a processor + # > m68000). The system name ranges from "MiNT" over "FreeMiNT" + # to the lowercase version "mint" (or "freemint"). Finally + # the system name "TOS" denotes a system which is actually not + # MiNT. But MiNT is downward compatible to TOS, so this should + # be no problem. + atarist[e]:*MiNT:*:* | atarist[e]:*mint:*:* | atarist[e]:*TOS:*:*) + echo m68k-atari-mint${UNAME_RELEASE} + exit ;; + atari*:*MiNT:*:* | atari*:*mint:*:* | atarist[e]:*TOS:*:*) + echo m68k-atari-mint${UNAME_RELEASE} + exit ;; + *falcon*:*MiNT:*:* | *falcon*:*mint:*:* | *falcon*:*TOS:*:*) + echo m68k-atari-mint${UNAME_RELEASE} + exit ;; + milan*:*MiNT:*:* | milan*:*mint:*:* | *milan*:*TOS:*:*) + echo m68k-milan-mint${UNAME_RELEASE} + exit ;; + hades*:*MiNT:*:* | hades*:*mint:*:* | *hades*:*TOS:*:*) + echo m68k-hades-mint${UNAME_RELEASE} + exit ;; + *:*MiNT:*:* | *:*mint:*:* | *:*TOS:*:*) + echo m68k-unknown-mint${UNAME_RELEASE} + exit ;; + m68k:machten:*:*) + echo m68k-apple-machten${UNAME_RELEASE} + exit ;; + powerpc:machten:*:*) + echo powerpc-apple-machten${UNAME_RELEASE} + exit ;; + RISC*:Mach:*:*) + echo mips-dec-mach_bsd4.3 + exit ;; + RISC*:ULTRIX:*:*) + echo mips-dec-ultrix${UNAME_RELEASE} + exit ;; + VAX*:ULTRIX*:*:*) + echo vax-dec-ultrix${UNAME_RELEASE} + exit ;; + 2020:CLIX:*:* | 2430:CLIX:*:*) + echo clipper-intergraph-clix${UNAME_RELEASE} + exit ;; + mips:*:*:UMIPS | mips:*:*:RISCos) + eval $set_cc_for_build + sed 's/^ //' << EOF >$dummy.c +#ifdef __cplusplus +#include <stdio.h> /* for printf() prototype */ + int main (int argc, char *argv[]) { +#else + int main (argc, argv) int argc; char *argv[]; { +#endif + #if defined (host_mips) && defined (MIPSEB) + #if defined (SYSTYPE_SYSV) + printf ("mips-mips-riscos%ssysv\n", argv[1]); exit (0); + #endif + #if defined (SYSTYPE_SVR4) + printf ("mips-mips-riscos%ssvr4\n", argv[1]); exit (0); + #endif + #if defined (SYSTYPE_BSD43) || defined(SYSTYPE_BSD) + printf ("mips-mips-riscos%sbsd\n", argv[1]); exit (0); + #endif + #endif + exit (-1); + } +EOF + $CC_FOR_BUILD -o $dummy $dummy.c && + dummyarg=`echo "${UNAME_RELEASE}" | sed -n 's/\([0-9]*\).*/\1/p'` && + SYSTEM_NAME=`$dummy $dummyarg` && + { echo "$SYSTEM_NAME"; exit; } + echo mips-mips-riscos${UNAME_RELEASE} + exit ;; + Motorola:PowerMAX_OS:*:*) + echo powerpc-motorola-powermax + exit ;; + Motorola:*:4.3:PL8-*) + echo powerpc-harris-powermax + exit ;; + Night_Hawk:*:*:PowerMAX_OS | Synergy:PowerMAX_OS:*:*) + echo powerpc-harris-powermax + exit ;; + Night_Hawk:Power_UNIX:*:*) + echo powerpc-harris-powerunix + exit ;; + m88k:CX/UX:7*:*) + echo m88k-harris-cxux7 + exit ;; + m88k:*:4*:R4*) + echo m88k-motorola-sysv4 + exit ;; + m88k:*:3*:R3*) + echo m88k-motorola-sysv3 + exit ;; + AViiON:dgux:*:*) + # DG/UX returns AViiON for all architectures + UNAME_PROCESSOR=`/usr/bin/uname -p` + if [ $UNAME_PROCESSOR = mc88100 ] || [ $UNAME_PROCESSOR = mc88110 ] + then + if [ ${TARGET_BINARY_INTERFACE}x = m88kdguxelfx ] || \ + [ ${TARGET_BINARY_INTERFACE}x = x ] + then + echo m88k-dg-dgux${UNAME_RELEASE} + else + echo m88k-dg-dguxbcs${UNAME_RELEASE} + fi + else + echo i586-dg-dgux${UNAME_RELEASE} + fi + exit ;; + M88*:DolphinOS:*:*) # DolphinOS (SVR3) + echo m88k-dolphin-sysv3 + exit ;; + M88*:*:R3*:*) + # Delta 88k system running SVR3 + echo m88k-motorola-sysv3 + exit ;; + XD88*:*:*:*) # Tektronix XD88 system running UTekV (SVR3) + echo m88k-tektronix-sysv3 + exit ;; + Tek43[0-9][0-9]:UTek:*:*) # Tektronix 4300 system running UTek (BSD) + echo m68k-tektronix-bsd + exit ;; + *:IRIX*:*:*) + echo mips-sgi-irix`echo ${UNAME_RELEASE}|sed -e 's/-/_/g'` + exit ;; + ????????:AIX?:[12].1:2) # AIX 2.2.1 or AIX 2.1.1 is RT/PC AIX. + echo romp-ibm-aix # uname -m gives an 8 hex-code CPU id + exit ;; # Note that: echo "'`uname -s`'" gives 'AIX ' + i*86:AIX:*:*) + echo i386-ibm-aix + exit ;; + ia64:AIX:*:*) + if [ -x /usr/bin/oslevel ] ; then + IBM_REV=`/usr/bin/oslevel` + else + IBM_REV=${UNAME_VERSION}.${UNAME_RELEASE} + fi + echo ${UNAME_MACHINE}-ibm-aix${IBM_REV} + exit ;; + *:AIX:2:3) + if grep bos325 /usr/include/stdio.h >/dev/null 2>&1; then + eval $set_cc_for_build + sed 's/^ //' << EOF >$dummy.c + #include <sys/systemcfg.h> + + main() + { + if (!__power_pc()) + exit(1); + puts("powerpc-ibm-aix3.2.5"); + exit(0); + } +EOF + if $CC_FOR_BUILD -o $dummy $dummy.c && SYSTEM_NAME=`$dummy` + then + echo "$SYSTEM_NAME" + else + echo rs6000-ibm-aix3.2.5 + fi + elif grep bos324 /usr/include/stdio.h >/dev/null 2>&1; then + echo rs6000-ibm-aix3.2.4 + else + echo rs6000-ibm-aix3.2 + fi + exit ;; + *:AIX:*:[456]) + IBM_CPU_ID=`/usr/sbin/lsdev -C -c processor -S available | sed 1q | awk '{ print $1 }'` + if /usr/sbin/lsattr -El ${IBM_CPU_ID} | grep ' POWER' >/dev/null 2>&1; then + IBM_ARCH=rs6000 + else + IBM_ARCH=powerpc + fi + if [ -x /usr/bin/oslevel ] ; then + IBM_REV=`/usr/bin/oslevel` + else + IBM_REV=${UNAME_VERSION}.${UNAME_RELEASE} + fi + echo ${IBM_ARCH}-ibm-aix${IBM_REV} + exit ;; + *:AIX:*:*) + echo rs6000-ibm-aix + exit ;; + ibmrt:4.4BSD:*|romp-ibm:BSD:*) + echo romp-ibm-bsd4.4 + exit ;; + ibmrt:*BSD:*|romp-ibm:BSD:*) # covers RT/PC BSD and + echo romp-ibm-bsd${UNAME_RELEASE} # 4.3 with uname added to + exit ;; # report: romp-ibm BSD 4.3 + *:BOSX:*:*) + echo rs6000-bull-bosx + exit ;; + DPX/2?00:B.O.S.:*:*) + echo m68k-bull-sysv3 + exit ;; + 9000/[34]??:4.3bsd:1.*:*) + echo m68k-hp-bsd + exit ;; + hp300:4.4BSD:*:* | 9000/[34]??:4.3bsd:2.*:*) + echo m68k-hp-bsd4.4 + exit ;; + 9000/[34678]??:HP-UX:*:*) + HPUX_REV=`echo ${UNAME_RELEASE}|sed -e 's/[^.]*.[0B]*//'` + case "${UNAME_MACHINE}" in + 9000/31? ) HP_ARCH=m68000 ;; + 9000/[34]?? ) HP_ARCH=m68k ;; + 9000/[678][0-9][0-9]) + if [ -x /usr/bin/getconf ]; then + sc_cpu_version=`/usr/bin/getconf SC_CPU_VERSION 2>/dev/null` + sc_kernel_bits=`/usr/bin/getconf SC_KERNEL_BITS 2>/dev/null` + case "${sc_cpu_version}" in + 523) HP_ARCH="hppa1.0" ;; # CPU_PA_RISC1_0 + 528) HP_ARCH="hppa1.1" ;; # CPU_PA_RISC1_1 + 532) # CPU_PA_RISC2_0 + case "${sc_kernel_bits}" in + 32) HP_ARCH="hppa2.0n" ;; + 64) HP_ARCH="hppa2.0w" ;; + '') HP_ARCH="hppa2.0" ;; # HP-UX 10.20 + esac ;; + esac + fi + if [ "${HP_ARCH}" = "" ]; then + eval $set_cc_for_build + sed 's/^ //' << EOF >$dummy.c + + #define _HPUX_SOURCE + #include <stdlib.h> + #include <unistd.h> + + int main () + { + #if defined(_SC_KERNEL_BITS) + long bits = sysconf(_SC_KERNEL_BITS); + #endif + long cpu = sysconf (_SC_CPU_VERSION); + + switch (cpu) + { + case CPU_PA_RISC1_0: puts ("hppa1.0"); break; + case CPU_PA_RISC1_1: puts ("hppa1.1"); break; + case CPU_PA_RISC2_0: + #if defined(_SC_KERNEL_BITS) + switch (bits) + { + case 64: puts ("hppa2.0w"); break; + case 32: puts ("hppa2.0n"); break; + default: puts ("hppa2.0"); break; + } break; + #else /* !defined(_SC_KERNEL_BITS) */ + puts ("hppa2.0"); break; + #endif + default: puts ("hppa1.0"); break; + } + exit (0); + } +EOF + (CCOPTS= $CC_FOR_BUILD -o $dummy $dummy.c 2>/dev/null) && HP_ARCH=`$dummy` + test -z "$HP_ARCH" && HP_ARCH=hppa + fi ;; + esac + if [ ${HP_ARCH} = "hppa2.0w" ] + then + eval $set_cc_for_build + + # hppa2.0w-hp-hpux* has a 64-bit kernel and a compiler generating + # 32-bit code. hppa64-hp-hpux* has the same kernel and a compiler + # generating 64-bit code. GNU and HP use different nomenclature: + # + # $ CC_FOR_BUILD=cc ./config.guess + # => hppa2.0w-hp-hpux11.23 + # $ CC_FOR_BUILD="cc +DA2.0w" ./config.guess + # => hppa64-hp-hpux11.23 + + if echo __LP64__ | (CCOPTS= $CC_FOR_BUILD -E - 2>/dev/null) | + grep -q __LP64__ + then + HP_ARCH="hppa2.0w" + else + HP_ARCH="hppa64" + fi + fi + echo ${HP_ARCH}-hp-hpux${HPUX_REV} + exit ;; + ia64:HP-UX:*:*) + HPUX_REV=`echo ${UNAME_RELEASE}|sed -e 's/[^.]*.[0B]*//'` + echo ia64-hp-hpux${HPUX_REV} + exit ;; + 3050*:HI-UX:*:*) + eval $set_cc_for_build + sed 's/^ //' << EOF >$dummy.c + #include <unistd.h> + int + main () + { + long cpu = sysconf (_SC_CPU_VERSION); + /* The order matters, because CPU_IS_HP_MC68K erroneously returns + true for CPU_PA_RISC1_0. CPU_IS_PA_RISC returns correct + results, however. */ + if (CPU_IS_PA_RISC (cpu)) + { + switch (cpu) + { + case CPU_PA_RISC1_0: puts ("hppa1.0-hitachi-hiuxwe2"); break; + case CPU_PA_RISC1_1: puts ("hppa1.1-hitachi-hiuxwe2"); break; + case CPU_PA_RISC2_0: puts ("hppa2.0-hitachi-hiuxwe2"); break; + default: puts ("hppa-hitachi-hiuxwe2"); break; + } + } + else if (CPU_IS_HP_MC68K (cpu)) + puts ("m68k-hitachi-hiuxwe2"); + else puts ("unknown-hitachi-hiuxwe2"); + exit (0); + } +EOF + $CC_FOR_BUILD -o $dummy $dummy.c && SYSTEM_NAME=`$dummy` && + { echo "$SYSTEM_NAME"; exit; } + echo unknown-hitachi-hiuxwe2 + exit ;; + 9000/7??:4.3bsd:*:* | 9000/8?[79]:4.3bsd:*:* ) + echo hppa1.1-hp-bsd + exit ;; + 9000/8??:4.3bsd:*:*) + echo hppa1.0-hp-bsd + exit ;; + *9??*:MPE/iX:*:* | *3000*:MPE/iX:*:*) + echo hppa1.0-hp-mpeix + exit ;; + hp7??:OSF1:*:* | hp8?[79]:OSF1:*:* ) + echo hppa1.1-hp-osf + exit ;; + hp8??:OSF1:*:*) + echo hppa1.0-hp-osf + exit ;; + i*86:OSF1:*:*) + if [ -x /usr/sbin/sysversion ] ; then + echo ${UNAME_MACHINE}-unknown-osf1mk + else + echo ${UNAME_MACHINE}-unknown-osf1 + fi + exit ;; + parisc*:Lites*:*:*) + echo hppa1.1-hp-lites + exit ;; + C1*:ConvexOS:*:* | convex:ConvexOS:C1*:*) + echo c1-convex-bsd + exit ;; + C2*:ConvexOS:*:* | convex:ConvexOS:C2*:*) + if getsysinfo -f scalar_acc + then echo c32-convex-bsd + else echo c2-convex-bsd + fi + exit ;; + C34*:ConvexOS:*:* | convex:ConvexOS:C34*:*) + echo c34-convex-bsd + exit ;; + C38*:ConvexOS:*:* | convex:ConvexOS:C38*:*) + echo c38-convex-bsd + exit ;; + C4*:ConvexOS:*:* | convex:ConvexOS:C4*:*) + echo c4-convex-bsd + exit ;; + CRAY*Y-MP:*:*:*) + echo ymp-cray-unicos${UNAME_RELEASE} | sed -e 's/\.[^.]*$/.X/' + exit ;; + CRAY*[A-Z]90:*:*:*) + echo ${UNAME_MACHINE}-cray-unicos${UNAME_RELEASE} \ + | sed -e 's/CRAY.*\([A-Z]90\)/\1/' \ + -e y/ABCDEFGHIJKLMNOPQRSTUVWXYZ/abcdefghijklmnopqrstuvwxyz/ \ + -e 's/\.[^.]*$/.X/' + exit ;; + CRAY*TS:*:*:*) + echo t90-cray-unicos${UNAME_RELEASE} | sed -e 's/\.[^.]*$/.X/' + exit ;; + CRAY*T3E:*:*:*) + echo alphaev5-cray-unicosmk${UNAME_RELEASE} | sed -e 's/\.[^.]*$/.X/' + exit ;; + CRAY*SV1:*:*:*) + echo sv1-cray-unicos${UNAME_RELEASE} | sed -e 's/\.[^.]*$/.X/' + exit ;; + *:UNICOS/mp:*:*) + echo craynv-cray-unicosmp${UNAME_RELEASE} | sed -e 's/\.[^.]*$/.X/' + exit ;; + F30[01]:UNIX_System_V:*:* | F700:UNIX_System_V:*:*) + FUJITSU_PROC=`uname -m | tr 'ABCDEFGHIJKLMNOPQRSTUVWXYZ' 'abcdefghijklmnopqrstuvwxyz'` + FUJITSU_SYS=`uname -p | tr 'ABCDEFGHIJKLMNOPQRSTUVWXYZ' 'abcdefghijklmnopqrstuvwxyz' | sed -e 's/\///'` + FUJITSU_REL=`echo ${UNAME_RELEASE} | sed -e 's/ /_/'` + echo "${FUJITSU_PROC}-fujitsu-${FUJITSU_SYS}${FUJITSU_REL}" + exit ;; + 5000:UNIX_System_V:4.*:*) + FUJITSU_SYS=`uname -p | tr 'ABCDEFGHIJKLMNOPQRSTUVWXYZ' 'abcdefghijklmnopqrstuvwxyz' | sed -e 's/\///'` + FUJITSU_REL=`echo ${UNAME_RELEASE} | tr 'ABCDEFGHIJKLMNOPQRSTUVWXYZ' 'abcdefghijklmnopqrstuvwxyz' | sed -e 's/ /_/'` + echo "sparc-fujitsu-${FUJITSU_SYS}${FUJITSU_REL}" + exit ;; + i*86:BSD/386:*:* | i*86:BSD/OS:*:* | *:Ascend\ Embedded/OS:*:*) + echo ${UNAME_MACHINE}-pc-bsdi${UNAME_RELEASE} + exit ;; + sparc*:BSD/OS:*:*) + echo sparc-unknown-bsdi${UNAME_RELEASE} + exit ;; + *:BSD/OS:*:*) + echo ${UNAME_MACHINE}-unknown-bsdi${UNAME_RELEASE} + exit ;; + *:FreeBSD:*:*) + case ${UNAME_MACHINE} in + pc98) + echo i386-unknown-freebsd`echo ${UNAME_RELEASE}|sed -e 's/[-(].*//'` ;; + amd64) + echo x86_64-unknown-freebsd`echo ${UNAME_RELEASE}|sed -e 's/[-(].*//'` ;; + *) + echo ${UNAME_MACHINE}-unknown-freebsd`echo ${UNAME_RELEASE}|sed -e 's/[-(].*//'` ;; + esac + exit ;; + i*:CYGWIN*:*) + echo ${UNAME_MACHINE}-pc-cygwin + exit ;; + *:MINGW*:*) + echo ${UNAME_MACHINE}-pc-mingw32 + exit ;; + i*:windows32*:*) + # uname -m includes "-pc" on this system. + echo ${UNAME_MACHINE}-mingw32 + exit ;; + i*:PW*:*) + echo ${UNAME_MACHINE}-pc-pw32 + exit ;; + *:Interix*:*) + case ${UNAME_MACHINE} in + x86) + echo i586-pc-interix${UNAME_RELEASE} + exit ;; + authenticamd | genuineintel | EM64T) + echo x86_64-unknown-interix${UNAME_RELEASE} + exit ;; + IA64) + echo ia64-unknown-interix${UNAME_RELEASE} + exit ;; + esac ;; + [345]86:Windows_95:* | [345]86:Windows_98:* | [345]86:Windows_NT:*) + echo i${UNAME_MACHINE}-pc-mks + exit ;; + 8664:Windows_NT:*) + echo x86_64-pc-mks + exit ;; + i*:Windows_NT*:* | Pentium*:Windows_NT*:*) + # How do we know it's Interix rather than the generic POSIX subsystem? + # It also conflicts with pre-2.0 versions of AT&T UWIN. Should we + # UNAME_MACHINE based on the output of uname instead of i386? + echo i586-pc-interix + exit ;; + i*:UWIN*:*) + echo ${UNAME_MACHINE}-pc-uwin + exit ;; + amd64:CYGWIN*:*:* | x86_64:CYGWIN*:*:*) + echo x86_64-unknown-cygwin + exit ;; + p*:CYGWIN*:*) + echo powerpcle-unknown-cygwin + exit ;; + prep*:SunOS:5.*:*) + echo powerpcle-unknown-solaris2`echo ${UNAME_RELEASE}|sed -e 's/[^.]*//'` + exit ;; + *:GNU:*:*) + # the GNU system + echo `echo ${UNAME_MACHINE}|sed -e 's,[-/].*$,,'`-unknown-gnu`echo ${UNAME_RELEASE}|sed -e 's,/.*$,,'` + exit ;; + *:GNU/*:*:*) + # other systems with GNU libc and userland + echo ${UNAME_MACHINE}-unknown-`echo ${UNAME_SYSTEM} | sed 's,^[^/]*/,,' | tr '[A-Z]' '[a-z]'``echo ${UNAME_RELEASE}|sed -e 's/[-(].*//'`-gnu + exit ;; + i*86:Minix:*:*) + echo ${UNAME_MACHINE}-pc-minix + exit ;; + alpha:Linux:*:*) + case `sed -n '/^cpu model/s/^.*: \(.*\)/\1/p' < /proc/cpuinfo` in + EV5) UNAME_MACHINE=alphaev5 ;; + EV56) UNAME_MACHINE=alphaev56 ;; + PCA56) UNAME_MACHINE=alphapca56 ;; + PCA57) UNAME_MACHINE=alphapca56 ;; + EV6) UNAME_MACHINE=alphaev6 ;; + EV67) UNAME_MACHINE=alphaev67 ;; + EV68*) UNAME_MACHINE=alphaev68 ;; + esac + objdump --private-headers /bin/sh | grep -q ld.so.1 + if test "$?" = 0 ; then LIBC="libc1" ; else LIBC="" ; fi + echo ${UNAME_MACHINE}-unknown-linux-gnu${LIBC} + exit ;; + arm*:Linux:*:*) + eval $set_cc_for_build + if echo __ARM_EABI__ | $CC_FOR_BUILD -E - 2>/dev/null \ + | grep -q __ARM_EABI__ + then + echo ${UNAME_MACHINE}-unknown-linux-gnu + else + echo ${UNAME_MACHINE}-unknown-linux-gnueabi + fi + exit ;; + avr32*:Linux:*:*) + echo ${UNAME_MACHINE}-unknown-linux-gnu + exit ;; + cris:Linux:*:*) + echo cris-axis-linux-gnu + exit ;; + crisv32:Linux:*:*) + echo crisv32-axis-linux-gnu + exit ;; + frv:Linux:*:*) + echo frv-unknown-linux-gnu + exit ;; + i*86:Linux:*:*) + LIBC=gnu + eval $set_cc_for_build + sed 's/^ //' << EOF >$dummy.c + #ifdef __dietlibc__ + LIBC=dietlibc + #endif +EOF + eval `$CC_FOR_BUILD -E $dummy.c 2>/dev/null | grep '^LIBC'` + echo "${UNAME_MACHINE}-pc-linux-${LIBC}" + exit ;; + ia64:Linux:*:*) + echo ${UNAME_MACHINE}-unknown-linux-gnu + exit ;; + m32r*:Linux:*:*) + echo ${UNAME_MACHINE}-unknown-linux-gnu + exit ;; + m68*:Linux:*:*) + echo ${UNAME_MACHINE}-unknown-linux-gnu + exit ;; + mips:Linux:*:* | mips64:Linux:*:*) + eval $set_cc_for_build + sed 's/^ //' << EOF >$dummy.c + #undef CPU + #undef ${UNAME_MACHINE} + #undef ${UNAME_MACHINE}el + #if defined(__MIPSEL__) || defined(__MIPSEL) || defined(_MIPSEL) || defined(MIPSEL) + CPU=${UNAME_MACHINE}el + #else + #if defined(__MIPSEB__) || defined(__MIPSEB) || defined(_MIPSEB) || defined(MIPSEB) + CPU=${UNAME_MACHINE} + #else + CPU= + #endif + #endif +EOF + eval `$CC_FOR_BUILD -E $dummy.c 2>/dev/null | grep '^CPU'` + test x"${CPU}" != x && { echo "${CPU}-unknown-linux-gnu"; exit; } + ;; + or32:Linux:*:*) + echo or32-unknown-linux-gnu + exit ;; + padre:Linux:*:*) + echo sparc-unknown-linux-gnu + exit ;; + parisc64:Linux:*:* | hppa64:Linux:*:*) + echo hppa64-unknown-linux-gnu + exit ;; + parisc:Linux:*:* | hppa:Linux:*:*) + # Look for CPU level + case `grep '^cpu[^a-z]*:' /proc/cpuinfo 2>/dev/null | cut -d' ' -f2` in + PA7*) echo hppa1.1-unknown-linux-gnu ;; + PA8*) echo hppa2.0-unknown-linux-gnu ;; + *) echo hppa-unknown-linux-gnu ;; + esac + exit ;; + ppc64:Linux:*:*) + echo powerpc64-unknown-linux-gnu + exit ;; + ppc:Linux:*:*) + echo powerpc-unknown-linux-gnu + exit ;; + s390:Linux:*:* | s390x:Linux:*:*) + echo ${UNAME_MACHINE}-ibm-linux + exit ;; + sh64*:Linux:*:*) + echo ${UNAME_MACHINE}-unknown-linux-gnu + exit ;; + sh*:Linux:*:*) + echo ${UNAME_MACHINE}-unknown-linux-gnu + exit ;; + sparc:Linux:*:* | sparc64:Linux:*:*) + echo ${UNAME_MACHINE}-unknown-linux-gnu + exit ;; + vax:Linux:*:*) + echo ${UNAME_MACHINE}-dec-linux-gnu + exit ;; + x86_64:Linux:*:*) + echo x86_64-unknown-linux-gnu + exit ;; + xtensa*:Linux:*:*) + echo ${UNAME_MACHINE}-unknown-linux-gnu + exit ;; + i*86:DYNIX/ptx:4*:*) + # ptx 4.0 does uname -s correctly, with DYNIX/ptx in there. + # earlier versions are messed up and put the nodename in both + # sysname and nodename. + echo i386-sequent-sysv4 + exit ;; + i*86:UNIX_SV:4.2MP:2.*) + # Unixware is an offshoot of SVR4, but it has its own version + # number series starting with 2... + # I am not positive that other SVR4 systems won't match this, + # I just have to hope. -- rms. + # Use sysv4.2uw... so that sysv4* matches it. + echo ${UNAME_MACHINE}-pc-sysv4.2uw${UNAME_VERSION} + exit ;; + i*86:OS/2:*:*) + # If we were able to find `uname', then EMX Unix compatibility + # is probably installed. + echo ${UNAME_MACHINE}-pc-os2-emx + exit ;; + i*86:XTS-300:*:STOP) + echo ${UNAME_MACHINE}-unknown-stop + exit ;; + i*86:atheos:*:*) + echo ${UNAME_MACHINE}-unknown-atheos + exit ;; + i*86:syllable:*:*) + echo ${UNAME_MACHINE}-pc-syllable + exit ;; + i*86:LynxOS:2.*:* | i*86:LynxOS:3.[01]*:* | i*86:LynxOS:4.[02]*:*) + echo i386-unknown-lynxos${UNAME_RELEASE} + exit ;; + i*86:*DOS:*:*) + echo ${UNAME_MACHINE}-pc-msdosdjgpp + exit ;; + i*86:*:4.*:* | i*86:SYSTEM_V:4.*:*) + UNAME_REL=`echo ${UNAME_RELEASE} | sed 's/\/MP$//'` + if grep Novell /usr/include/link.h >/dev/null 2>/dev/null; then + echo ${UNAME_MACHINE}-univel-sysv${UNAME_REL} + else + echo ${UNAME_MACHINE}-pc-sysv${UNAME_REL} + fi + exit ;; + i*86:*:5:[678]*) + # UnixWare 7.x, OpenUNIX and OpenServer 6. + case `/bin/uname -X | grep "^Machine"` in + *486*) UNAME_MACHINE=i486 ;; + *Pentium) UNAME_MACHINE=i586 ;; + *Pent*|*Celeron) UNAME_MACHINE=i686 ;; + esac + echo ${UNAME_MACHINE}-unknown-sysv${UNAME_RELEASE}${UNAME_SYSTEM}${UNAME_VERSION} + exit ;; + i*86:*:3.2:*) + if test -f /usr/options/cb.name; then + UNAME_REL=`sed -n 's/.*Version //p' </usr/options/cb.name` + echo ${UNAME_MACHINE}-pc-isc$UNAME_REL + elif /bin/uname -X 2>/dev/null >/dev/null ; then + UNAME_REL=`(/bin/uname -X|grep Release|sed -e 's/.*= //')` + (/bin/uname -X|grep i80486 >/dev/null) && UNAME_MACHINE=i486 + (/bin/uname -X|grep '^Machine.*Pentium' >/dev/null) \ + && UNAME_MACHINE=i586 + (/bin/uname -X|grep '^Machine.*Pent *II' >/dev/null) \ + && UNAME_MACHINE=i686 + (/bin/uname -X|grep '^Machine.*Pentium Pro' >/dev/null) \ + && UNAME_MACHINE=i686 + echo ${UNAME_MACHINE}-pc-sco$UNAME_REL + else + echo ${UNAME_MACHINE}-pc-sysv32 + fi + exit ;; + pc:*:*:*) + # Left here for compatibility: + # uname -m prints for DJGPP always 'pc', but it prints nothing about + # the processor, so we play safe by assuming i586. + # Note: whatever this is, it MUST be the same as what config.sub + # prints for the "djgpp" host, or else GDB configury will decide that + # this is a cross-build. + echo i586-pc-msdosdjgpp + exit ;; + Intel:Mach:3*:*) + echo i386-pc-mach3 + exit ;; + paragon:*:*:*) + echo i860-intel-osf1 + exit ;; + i860:*:4.*:*) # i860-SVR4 + if grep Stardent /usr/include/sys/uadmin.h >/dev/null 2>&1 ; then + echo i860-stardent-sysv${UNAME_RELEASE} # Stardent Vistra i860-SVR4 + else # Add other i860-SVR4 vendors below as they are discovered. + echo i860-unknown-sysv${UNAME_RELEASE} # Unknown i860-SVR4 + fi + exit ;; + mini*:CTIX:SYS*5:*) + # "miniframe" + echo m68010-convergent-sysv + exit ;; + mc68k:UNIX:SYSTEM5:3.51m) + echo m68k-convergent-sysv + exit ;; + M680?0:D-NIX:5.3:*) + echo m68k-diab-dnix + exit ;; + M68*:*:R3V[5678]*:*) + test -r /sysV68 && { echo 'm68k-motorola-sysv'; exit; } ;; + 3[345]??:*:4.0:3.0 | 3[34]??A:*:4.0:3.0 | 3[34]??,*:*:4.0:3.0 | 3[34]??/*:*:4.0:3.0 | 4400:*:4.0:3.0 | 4850:*:4.0:3.0 | SKA40:*:4.0:3.0 | SDS2:*:4.0:3.0 | SHG2:*:4.0:3.0 | S7501*:*:4.0:3.0) + OS_REL='' + test -r /etc/.relid \ + && OS_REL=.`sed -n 's/[^ ]* [^ ]* \([0-9][0-9]\).*/\1/p' < /etc/.relid` + /bin/uname -p 2>/dev/null | grep 86 >/dev/null \ + && { echo i486-ncr-sysv4.3${OS_REL}; exit; } + /bin/uname -p 2>/dev/null | /bin/grep entium >/dev/null \ + && { echo i586-ncr-sysv4.3${OS_REL}; exit; } ;; + 3[34]??:*:4.0:* | 3[34]??,*:*:4.0:*) + /bin/uname -p 2>/dev/null | grep 86 >/dev/null \ + && { echo i486-ncr-sysv4; exit; } ;; + NCR*:*:4.2:* | MPRAS*:*:4.2:*) + OS_REL='.3' + test -r /etc/.relid \ + && OS_REL=.`sed -n 's/[^ ]* [^ ]* \([0-9][0-9]\).*/\1/p' < /etc/.relid` + /bin/uname -p 2>/dev/null | grep 86 >/dev/null \ + && { echo i486-ncr-sysv4.3${OS_REL}; exit; } + /bin/uname -p 2>/dev/null | /bin/grep entium >/dev/null \ + && { echo i586-ncr-sysv4.3${OS_REL}; exit; } + /bin/uname -p 2>/dev/null | /bin/grep pteron >/dev/null \ + && { echo i586-ncr-sysv4.3${OS_REL}; exit; } ;; + m68*:LynxOS:2.*:* | m68*:LynxOS:3.0*:*) + echo m68k-unknown-lynxos${UNAME_RELEASE} + exit ;; + mc68030:UNIX_System_V:4.*:*) + echo m68k-atari-sysv4 + exit ;; + TSUNAMI:LynxOS:2.*:*) + echo sparc-unknown-lynxos${UNAME_RELEASE} + exit ;; + rs6000:LynxOS:2.*:*) + echo rs6000-unknown-lynxos${UNAME_RELEASE} + exit ;; + PowerPC:LynxOS:2.*:* | PowerPC:LynxOS:3.[01]*:* | PowerPC:LynxOS:4.[02]*:*) + echo powerpc-unknown-lynxos${UNAME_RELEASE} + exit ;; + SM[BE]S:UNIX_SV:*:*) + echo mips-dde-sysv${UNAME_RELEASE} + exit ;; + RM*:ReliantUNIX-*:*:*) + echo mips-sni-sysv4 + exit ;; + RM*:SINIX-*:*:*) + echo mips-sni-sysv4 + exit ;; + *:SINIX-*:*:*) + if uname -p 2>/dev/null >/dev/null ; then + UNAME_MACHINE=`(uname -p) 2>/dev/null` + echo ${UNAME_MACHINE}-sni-sysv4 + else + echo ns32k-sni-sysv + fi + exit ;; + PENTIUM:*:4.0*:*) # Unisys `ClearPath HMP IX 4000' SVR4/MP effort + # says <Richard.M.Bartel@ccMail.Census.GOV> + echo i586-unisys-sysv4 + exit ;; + *:UNIX_System_V:4*:FTX*) + # From Gerald Hewes <hewes@openmarket.com>. + # How about differentiating between stratus architectures? -djm + echo hppa1.1-stratus-sysv4 + exit ;; + *:*:*:FTX*) + # From seanf@swdc.stratus.com. + echo i860-stratus-sysv4 + exit ;; + i*86:VOS:*:*) + # From Paul.Green@stratus.com. + echo ${UNAME_MACHINE}-stratus-vos + exit ;; + *:VOS:*:*) + # From Paul.Green@stratus.com. + echo hppa1.1-stratus-vos + exit ;; + mc68*:A/UX:*:*) + echo m68k-apple-aux${UNAME_RELEASE} + exit ;; + news*:NEWS-OS:6*:*) + echo mips-sony-newsos6 + exit ;; + R[34]000:*System_V*:*:* | R4000:UNIX_SYSV:*:* | R*000:UNIX_SV:*:*) + if [ -d /usr/nec ]; then + echo mips-nec-sysv${UNAME_RELEASE} + else + echo mips-unknown-sysv${UNAME_RELEASE} + fi + exit ;; + BeBox:BeOS:*:*) # BeOS running on hardware made by Be, PPC only. + echo powerpc-be-beos + exit ;; + BeMac:BeOS:*:*) # BeOS running on Mac or Mac clone, PPC only. + echo powerpc-apple-beos + exit ;; + BePC:BeOS:*:*) # BeOS running on Intel PC compatible. + echo i586-pc-beos + exit ;; + BePC:Haiku:*:*) # Haiku running on Intel PC compatible. + echo i586-pc-haiku + exit ;; + SX-4:SUPER-UX:*:*) + echo sx4-nec-superux${UNAME_RELEASE} + exit ;; + SX-5:SUPER-UX:*:*) + echo sx5-nec-superux${UNAME_RELEASE} + exit ;; + SX-6:SUPER-UX:*:*) + echo sx6-nec-superux${UNAME_RELEASE} + exit ;; + SX-7:SUPER-UX:*:*) + echo sx7-nec-superux${UNAME_RELEASE} + exit ;; + SX-8:SUPER-UX:*:*) + echo sx8-nec-superux${UNAME_RELEASE} + exit ;; + SX-8R:SUPER-UX:*:*) + echo sx8r-nec-superux${UNAME_RELEASE} + exit ;; + Power*:Rhapsody:*:*) + echo powerpc-apple-rhapsody${UNAME_RELEASE} + exit ;; + *:Rhapsody:*:*) + echo ${UNAME_MACHINE}-apple-rhapsody${UNAME_RELEASE} + exit ;; + *:Darwin:*:*) + UNAME_PROCESSOR=`uname -p` || UNAME_PROCESSOR=unknown + case $UNAME_PROCESSOR in + i386) + eval $set_cc_for_build + if [ "$CC_FOR_BUILD" != 'no_compiler_found' ]; then + if (echo '#ifdef __LP64__'; echo IS_64BIT_ARCH; echo '#endif') | \ + (CCOPTS= $CC_FOR_BUILD -E - 2>/dev/null) | \ + grep IS_64BIT_ARCH >/dev/null + then + UNAME_PROCESSOR="x86_64" + fi + fi ;; + unknown) UNAME_PROCESSOR=powerpc ;; + esac + echo ${UNAME_PROCESSOR}-apple-darwin${UNAME_RELEASE} + exit ;; + *:procnto*:*:* | *:QNX:[0123456789]*:*) + UNAME_PROCESSOR=`uname -p` + if test "$UNAME_PROCESSOR" = "x86"; then + UNAME_PROCESSOR=i386 + UNAME_MACHINE=pc + fi + echo ${UNAME_PROCESSOR}-${UNAME_MACHINE}-nto-qnx${UNAME_RELEASE} + exit ;; + *:QNX:*:4*) + echo i386-pc-qnx + exit ;; + NSE-?:NONSTOP_KERNEL:*:*) + echo nse-tandem-nsk${UNAME_RELEASE} + exit ;; + NSR-?:NONSTOP_KERNEL:*:*) + echo nsr-tandem-nsk${UNAME_RELEASE} + exit ;; + *:NonStop-UX:*:*) + echo mips-compaq-nonstopux + exit ;; + BS2000:POSIX*:*:*) + echo bs2000-siemens-sysv + exit ;; + DS/*:UNIX_System_V:*:*) + echo ${UNAME_MACHINE}-${UNAME_SYSTEM}-${UNAME_RELEASE} + exit ;; + *:Plan9:*:*) + # "uname -m" is not consistent, so use $cputype instead. 386 + # is converted to i386 for consistency with other x86 + # operating systems. + if test "$cputype" = "386"; then + UNAME_MACHINE=i386 + else + UNAME_MACHINE="$cputype" + fi + echo ${UNAME_MACHINE}-unknown-plan9 + exit ;; + *:TOPS-10:*:*) + echo pdp10-unknown-tops10 + exit ;; + *:TENEX:*:*) + echo pdp10-unknown-tenex + exit ;; + KS10:TOPS-20:*:* | KL10:TOPS-20:*:* | TYPE4:TOPS-20:*:*) + echo pdp10-dec-tops20 + exit ;; + XKL-1:TOPS-20:*:* | TYPE5:TOPS-20:*:*) + echo pdp10-xkl-tops20 + exit ;; + *:TOPS-20:*:*) + echo pdp10-unknown-tops20 + exit ;; + *:ITS:*:*) + echo pdp10-unknown-its + exit ;; + SEI:*:*:SEIUX) + echo mips-sei-seiux${UNAME_RELEASE} + exit ;; + *:DragonFly:*:*) + echo ${UNAME_MACHINE}-unknown-dragonfly`echo ${UNAME_RELEASE}|sed -e 's/[-(].*//'` + exit ;; + *:*VMS:*:*) + UNAME_MACHINE=`(uname -p) 2>/dev/null` + case "${UNAME_MACHINE}" in + A*) echo alpha-dec-vms ; exit ;; + I*) echo ia64-dec-vms ; exit ;; + V*) echo vax-dec-vms ; exit ;; + esac ;; + *:XENIX:*:SysV) + echo i386-pc-xenix + exit ;; + i*86:skyos:*:*) + echo ${UNAME_MACHINE}-pc-skyos`echo ${UNAME_RELEASE}` | sed -e 's/ .*$//' + exit ;; + i*86:rdos:*:*) + echo ${UNAME_MACHINE}-pc-rdos + exit ;; + i*86:AROS:*:*) + echo ${UNAME_MACHINE}-pc-aros + exit ;; +esac + +#echo '(No uname command or uname output not recognized.)' 1>&2 +#echo "${UNAME_MACHINE}:${UNAME_SYSTEM}:${UNAME_RELEASE}:${UNAME_VERSION}" 1>&2 + +eval $set_cc_for_build +cat >$dummy.c <<EOF +#ifdef _SEQUENT_ +# include <sys/types.h> +# include <sys/utsname.h> +#endif +main () +{ +#if defined (sony) +#if defined (MIPSEB) + /* BFD wants "bsd" instead of "newsos". Perhaps BFD should be changed, + I don't know.... */ + printf ("mips-sony-bsd\n"); exit (0); +#else +#include <sys/param.h> + printf ("m68k-sony-newsos%s\n", +#ifdef NEWSOS4 + "4" +#else + "" +#endif + ); exit (0); +#endif +#endif + +#if defined (__arm) && defined (__acorn) && defined (__unix) + printf ("arm-acorn-riscix\n"); exit (0); +#endif + +#if defined (hp300) && !defined (hpux) + printf ("m68k-hp-bsd\n"); exit (0); +#endif + +#if defined (NeXT) +#if !defined (__ARCHITECTURE__) +#define __ARCHITECTURE__ "m68k" +#endif + int version; + version=`(hostinfo | sed -n 's/.*NeXT Mach \([0-9]*\).*/\1/p') 2>/dev/null`; + if (version < 4) + printf ("%s-next-nextstep%d\n", __ARCHITECTURE__, version); + else + printf ("%s-next-openstep%d\n", __ARCHITECTURE__, version); + exit (0); +#endif + +#if defined (MULTIMAX) || defined (n16) +#if defined (UMAXV) + printf ("ns32k-encore-sysv\n"); exit (0); +#else +#if defined (CMU) + printf ("ns32k-encore-mach\n"); exit (0); +#else + printf ("ns32k-encore-bsd\n"); exit (0); +#endif +#endif +#endif + +#if defined (__386BSD__) + printf ("i386-pc-bsd\n"); exit (0); +#endif + +#if defined (sequent) +#if defined (i386) + printf ("i386-sequent-dynix\n"); exit (0); +#endif +#if defined (ns32000) + printf ("ns32k-sequent-dynix\n"); exit (0); +#endif +#endif + +#if defined (_SEQUENT_) + struct utsname un; + + uname(&un); + + if (strncmp(un.version, "V2", 2) == 0) { + printf ("i386-sequent-ptx2\n"); exit (0); + } + if (strncmp(un.version, "V1", 2) == 0) { /* XXX is V1 correct? */ + printf ("i386-sequent-ptx1\n"); exit (0); + } + printf ("i386-sequent-ptx\n"); exit (0); + +#endif + +#if defined (vax) +# if !defined (ultrix) +# include <sys/param.h> +# if defined (BSD) +# if BSD == 43 + printf ("vax-dec-bsd4.3\n"); exit (0); +# else +# if BSD == 199006 + printf ("vax-dec-bsd4.3reno\n"); exit (0); +# else + printf ("vax-dec-bsd\n"); exit (0); +# endif +# endif +# else + printf ("vax-dec-bsd\n"); exit (0); +# endif +# else + printf ("vax-dec-ultrix\n"); exit (0); +# endif +#endif + +#if defined (alliant) && defined (i860) + printf ("i860-alliant-bsd\n"); exit (0); +#endif + + exit (1); +} +EOF + +$CC_FOR_BUILD -o $dummy $dummy.c 2>/dev/null && SYSTEM_NAME=`$dummy` && + { echo "$SYSTEM_NAME"; exit; } + +# Apollos put the system type in the environment. + +test -d /usr/apollo && { echo ${ISP}-apollo-${SYSTYPE}; exit; } + +# Convex versions that predate uname can use getsysinfo(1) + +if [ -x /usr/convex/getsysinfo ] +then + case `getsysinfo -f cpu_type` in + c1*) + echo c1-convex-bsd + exit ;; + c2*) + if getsysinfo -f scalar_acc + then echo c32-convex-bsd + else echo c2-convex-bsd + fi + exit ;; + c34*) + echo c34-convex-bsd + exit ;; + c38*) + echo c38-convex-bsd + exit ;; + c4*) + echo c4-convex-bsd + exit ;; + esac +fi + +cat >&2 <<EOF +$0: unable to guess system type + +This script, last modified $timestamp, has failed to recognize +the operating system you are using. It is advised that you +download the most up to date version of the config scripts from + + http://git.savannah.gnu.org/gitweb/?p=config.git;a=blob_plain;f=config.guess;hb=HEAD +and + http://git.savannah.gnu.org/gitweb/?p=config.git;a=blob_plain;f=config.sub;hb=HEAD + +If the version you run ($0) is already up to date, please +send the following data and any information you think might be +pertinent to <config-patches@gnu.org> in order to provide the needed +information to handle your system. + +config.guess timestamp = $timestamp + +uname -m = `(uname -m) 2>/dev/null || echo unknown` +uname -r = `(uname -r) 2>/dev/null || echo unknown` +uname -s = `(uname -s) 2>/dev/null || echo unknown` +uname -v = `(uname -v) 2>/dev/null || echo unknown` + +/usr/bin/uname -p = `(/usr/bin/uname -p) 2>/dev/null` +/bin/uname -X = `(/bin/uname -X) 2>/dev/null` + +hostinfo = `(hostinfo) 2>/dev/null` +/bin/universe = `(/bin/universe) 2>/dev/null` +/usr/bin/arch -k = `(/usr/bin/arch -k) 2>/dev/null` +/bin/arch = `(/bin/arch) 2>/dev/null` +/usr/bin/oslevel = `(/usr/bin/oslevel) 2>/dev/null` +/usr/convex/getsysinfo = `(/usr/convex/getsysinfo) 2>/dev/null` + +UNAME_MACHINE = ${UNAME_MACHINE} +UNAME_RELEASE = ${UNAME_RELEASE} +UNAME_SYSTEM = ${UNAME_SYSTEM} +UNAME_VERSION = ${UNAME_VERSION} +EOF + +exit 1 + +# Local variables: +# eval: (add-hook 'write-file-hooks 'time-stamp) +# time-stamp-start: "timestamp='" +# time-stamp-format: "%:y-%02m-%02d" +# time-stamp-end: "'" +# End: diff --git a/src/3rdparty/libpng/config.h.in b/src/3rdparty/libpng/config.h.in new file mode 100644 index 0000000000..fb2349568c --- /dev/null +++ b/src/3rdparty/libpng/config.h.in @@ -0,0 +1,86 @@ +/* config.h.in. Generated from configure.ac by autoheader. */ + +/* Define to 1 if you have the <dlfcn.h> header file. */ +#undef HAVE_DLFCN_H + +/* Define to 1 if you have the <inttypes.h> header file. */ +#undef HAVE_INTTYPES_H + +/* Define to 1 if you have the `m' library (-lm). */ +#undef HAVE_LIBM + +/* Define to 1 if you have the `z' library (-lz). */ +#undef HAVE_LIBZ + +/* Define to 1 if you have the <malloc.h> header file. */ +#undef HAVE_MALLOC_H + +/* Define to 1 if you have the <memory.h> header file. */ +#undef HAVE_MEMORY_H + +/* Define to 1 if you have the `memset' function. */ +#undef HAVE_MEMSET + +/* Define to 1 if you have the `pow' function. */ +#undef HAVE_POW + +/* Define to 1 if you have the <stdint.h> header file. */ +#undef HAVE_STDINT_H + +/* Define to 1 if you have the <stdlib.h> header file. */ +#undef HAVE_STDLIB_H + +/* Define to 1 if you have the <strings.h> header file. */ +#undef HAVE_STRINGS_H + +/* Define to 1 if you have the <string.h> header file. */ +#undef HAVE_STRING_H + +/* Define to 1 if you have the <sys/stat.h> header file. */ +#undef HAVE_SYS_STAT_H + +/* Define to 1 if you have the <sys/types.h> header file. */ +#undef HAVE_SYS_TYPES_H + +/* Define to 1 if you have the <unistd.h> header file. */ +#undef HAVE_UNISTD_H + +/* Define to the sub-directory in which libtool stores uninstalled libraries. + */ +#undef LT_OBJDIR + +/* Name of package */ +#undef PACKAGE + +/* Define to the address where bug reports for this package should be sent. */ +#undef PACKAGE_BUGREPORT + +/* Define to the full name of this package. */ +#undef PACKAGE_NAME + +/* Define to the full name and version of this package. */ +#undef PACKAGE_STRING + +/* Define to the one symbol short name of this package. */ +#undef PACKAGE_TARNAME + +/* Define to the home page for this package. */ +#undef PACKAGE_URL + +/* Define to the version of this package. */ +#undef PACKAGE_VERSION + +/* Define to 1 if you have the ANSI C header files. */ +#undef STDC_HEADERS + +/* Define to 1 if your <sys/time.h> declares `struct tm'. */ +#undef TM_IN_SYS_TIME + +/* Version number of package */ +#undef VERSION + +/* Define to empty if `const' does not conform to ANSI C. */ +#undef const + +/* Define to `unsigned int' if <sys/types.h> does not define. */ +#undef size_t diff --git a/src/3rdparty/libpng/config.sub b/src/3rdparty/libpng/config.sub new file mode 100644 index 0000000000..2a55a50751 --- /dev/null +++ b/src/3rdparty/libpng/config.sub @@ -0,0 +1,1705 @@ +#! /bin/sh +# Configuration validation subroutine script. +# Copyright (C) 1992, 1993, 1994, 1995, 1996, 1997, 1998, 1999, +# 2000, 2001, 2002, 2003, 2004, 2005, 2006, 2007, 2008, 2009 +# Free Software Foundation, Inc. + +timestamp='2009-11-20' + +# This file is (in principle) common to ALL GNU software. +# The presence of a machine in this file suggests that SOME GNU software +# can handle that machine. It does not imply ALL GNU software can. +# +# This file is free software; you can redistribute it and/or modify +# it under the terms of the GNU General Public License as published by +# the Free Software Foundation; either version 2 of the License, or +# (at your option) any later version. +# +# This program is distributed in the hope that it will be useful, +# but WITHOUT ANY WARRANTY; without even the implied warranty of +# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the +# GNU General Public License for more details. +# +# You should have received a copy of the GNU General Public License +# along with this program; if not, write to the Free Software +# Foundation, Inc., 51 Franklin Street - Fifth Floor, Boston, MA +# 02110-1301, USA. +# +# As a special exception to the GNU General Public License, if you +# distribute this file as part of a program that contains a +# configuration script generated by Autoconf, you may include it under +# the same distribution terms that you use for the rest of that program. + + +# Please send patches to <config-patches@gnu.org>. Submit a context +# diff and a properly formatted GNU ChangeLog entry. +# +# Configuration subroutine to validate and canonicalize a configuration type. +# Supply the specified configuration type as an argument. +# If it is invalid, we print an error message on stderr and exit with code 1. +# Otherwise, we print the canonical config type on stdout and succeed. + +# You can get the latest version of this script from: +# http://git.savannah.gnu.org/gitweb/?p=config.git;a=blob_plain;f=config.sub;hb=HEAD + +# This file is supposed to be the same for all GNU packages +# and recognize all the CPU types, system types and aliases +# that are meaningful with *any* GNU software. +# Each package is responsible for reporting which valid configurations +# it does not support. The user should be able to distinguish +# a failure to support a valid configuration from a meaningless +# configuration. + +# The goal of this file is to map all the various variations of a given +# machine specification into a single specification in the form: +# CPU_TYPE-MANUFACTURER-OPERATING_SYSTEM +# or in some cases, the newer four-part form: +# CPU_TYPE-MANUFACTURER-KERNEL-OPERATING_SYSTEM +# It is wrong to echo any other type of specification. + +me=`echo "$0" | sed -e 's,.*/,,'` + +usage="\ +Usage: $0 [OPTION] CPU-MFR-OPSYS + $0 [OPTION] ALIAS + +Canonicalize a configuration name. + +Operation modes: + -h, --help print this help, then exit + -t, --time-stamp print date of last modification, then exit + -v, --version print version number, then exit + +Report bugs and patches to <config-patches@gnu.org>." + +version="\ +GNU config.sub ($timestamp) + +Copyright (C) 1992, 1993, 1994, 1995, 1996, 1997, 1998, 1999, 2000, 2001, +2002, 2003, 2004, 2005, 2006, 2007, 2008 Free Software Foundation, Inc. + +This is free software; see the source for copying conditions. There is NO +warranty; not even for MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE." + +help=" +Try \`$me --help' for more information." + +# Parse command line +while test $# -gt 0 ; do + case $1 in + --time-stamp | --time* | -t ) + echo "$timestamp" ; exit ;; + --version | -v ) + echo "$version" ; exit ;; + --help | --h* | -h ) + echo "$usage"; exit ;; + -- ) # Stop option processing + shift; break ;; + - ) # Use stdin as input. + break ;; + -* ) + echo "$me: invalid option $1$help" + exit 1 ;; + + *local*) + # First pass through any local machine types. + echo $1 + exit ;; + + * ) + break ;; + esac +done + +case $# in + 0) echo "$me: missing argument$help" >&2 + exit 1;; + 1) ;; + *) echo "$me: too many arguments$help" >&2 + exit 1;; +esac + +# Separate what the user gave into CPU-COMPANY and OS or KERNEL-OS (if any). +# Here we must recognize all the valid KERNEL-OS combinations. +maybe_os=`echo $1 | sed 's/^\(.*\)-\([^-]*-[^-]*\)$/\2/'` +case $maybe_os in + nto-qnx* | linux-gnu* | linux-dietlibc | linux-newlib* | linux-uclibc* | \ + uclinux-uclibc* | uclinux-gnu* | kfreebsd*-gnu* | knetbsd*-gnu* | netbsd*-gnu* | \ + kopensolaris*-gnu* | \ + storm-chaos* | os2-emx* | rtmk-nova*) + os=-$maybe_os + basic_machine=`echo $1 | sed 's/^\(.*\)-\([^-]*-[^-]*\)$/\1/'` + ;; + *) + basic_machine=`echo $1 | sed 's/-[^-]*$//'` + if [ $basic_machine != $1 ] + then os=`echo $1 | sed 's/.*-/-/'` + else os=; fi + ;; +esac + +### Let's recognize common machines as not being operating systems so +### that things like config.sub decstation-3100 work. We also +### recognize some manufacturers as not being operating systems, so we +### can provide default operating systems below. +case $os in + -sun*os*) + # Prevent following clause from handling this invalid input. + ;; + -dec* | -mips* | -sequent* | -encore* | -pc532* | -sgi* | -sony* | \ + -att* | -7300* | -3300* | -delta* | -motorola* | -sun[234]* | \ + -unicom* | -ibm* | -next | -hp | -isi* | -apollo | -altos* | \ + -convergent* | -ncr* | -news | -32* | -3600* | -3100* | -hitachi* |\ + -c[123]* | -convex* | -sun | -crds | -omron* | -dg | -ultra | -tti* | \ + -harris | -dolphin | -highlevel | -gould | -cbm | -ns | -masscomp | \ + -apple | -axis | -knuth | -cray | -microblaze) + os= + basic_machine=$1 + ;; + -bluegene*) + os=-cnk + ;; + -sim | -cisco | -oki | -wec | -winbond) + os= + basic_machine=$1 + ;; + -scout) + ;; + -wrs) + os=-vxworks + basic_machine=$1 + ;; + -chorusos*) + os=-chorusos + basic_machine=$1 + ;; + -chorusrdb) + os=-chorusrdb + basic_machine=$1 + ;; + -hiux*) + os=-hiuxwe2 + ;; + -sco6) + os=-sco5v6 + basic_machine=`echo $1 | sed -e 's/86-.*/86-pc/'` + ;; + -sco5) + os=-sco3.2v5 + basic_machine=`echo $1 | sed -e 's/86-.*/86-pc/'` + ;; + -sco4) + os=-sco3.2v4 + basic_machine=`echo $1 | sed -e 's/86-.*/86-pc/'` + ;; + -sco3.2.[4-9]*) + os=`echo $os | sed -e 's/sco3.2./sco3.2v/'` + basic_machine=`echo $1 | sed -e 's/86-.*/86-pc/'` + ;; + -sco3.2v[4-9]*) + # Don't forget version if it is 3.2v4 or newer. + basic_machine=`echo $1 | sed -e 's/86-.*/86-pc/'` + ;; + -sco5v6*) + # Don't forget version if it is 3.2v4 or newer. + basic_machine=`echo $1 | sed -e 's/86-.*/86-pc/'` + ;; + -sco*) + os=-sco3.2v2 + basic_machine=`echo $1 | sed -e 's/86-.*/86-pc/'` + ;; + -udk*) + basic_machine=`echo $1 | sed -e 's/86-.*/86-pc/'` + ;; + -isc) + os=-isc2.2 + basic_machine=`echo $1 | sed -e 's/86-.*/86-pc/'` + ;; + -clix*) + basic_machine=clipper-intergraph + ;; + -isc*) + basic_machine=`echo $1 | sed -e 's/86-.*/86-pc/'` + ;; + -lynx*) + os=-lynxos + ;; + -ptx*) + basic_machine=`echo $1 | sed -e 's/86-.*/86-sequent/'` + ;; + -windowsnt*) + os=`echo $os | sed -e 's/windowsnt/winnt/'` + ;; + -psos*) + os=-psos + ;; + -mint | -mint[0-9]*) + basic_machine=m68k-atari + os=-mint + ;; +esac + +# Decode aliases for certain CPU-COMPANY combinations. +case $basic_machine in + # Recognize the basic CPU types without company name. + # Some are omitted here because they have special meanings below. + 1750a | 580 \ + | a29k \ + | alpha | alphaev[4-8] | alphaev56 | alphaev6[78] | alphapca5[67] \ + | alpha64 | alpha64ev[4-8] | alpha64ev56 | alpha64ev6[78] | alpha64pca5[67] \ + | am33_2.0 \ + | arc | arm | arm[bl]e | arme[lb] | armv[2345] | armv[345][lb] | avr | avr32 \ + | bfin \ + | c4x | clipper \ + | d10v | d30v | dlx | dsp16xx \ + | fido | fr30 | frv \ + | h8300 | h8500 | hppa | hppa1.[01] | hppa2.0 | hppa2.0[nw] | hppa64 \ + | i370 | i860 | i960 | ia64 \ + | ip2k | iq2000 \ + | lm32 \ + | m32c | m32r | m32rle | m68000 | m68k | m88k \ + | maxq | mb | microblaze | mcore | mep | metag \ + | mips | mipsbe | mipseb | mipsel | mipsle \ + | mips16 \ + | mips64 | mips64el \ + | mips64octeon | mips64octeonel \ + | mips64orion | mips64orionel \ + | mips64r5900 | mips64r5900el \ + | mips64vr | mips64vrel \ + | mips64vr4100 | mips64vr4100el \ + | mips64vr4300 | mips64vr4300el \ + | mips64vr5000 | mips64vr5000el \ + | mips64vr5900 | mips64vr5900el \ + | mipsisa32 | mipsisa32el \ + | mipsisa32r2 | mipsisa32r2el \ + | mipsisa64 | mipsisa64el \ + | mipsisa64r2 | mipsisa64r2el \ + | mipsisa64sb1 | mipsisa64sb1el \ + | mipsisa64sr71k | mipsisa64sr71kel \ + | mipstx39 | mipstx39el \ + | mn10200 | mn10300 \ + | moxie \ + | mt \ + | msp430 \ + | nios | nios2 \ + | ns16k | ns32k \ + | or32 \ + | pdp10 | pdp11 | pj | pjl \ + | powerpc | powerpc64 | powerpc64le | powerpcle | ppcbe \ + | pyramid \ + | rx \ + | score \ + | sh | sh[1234] | sh[24]a | sh[24]aeb | sh[23]e | sh[34]eb | sheb | shbe | shle | sh[1234]le | sh3ele \ + | sh64 | sh64le \ + | sparc | sparc64 | sparc64b | sparc64v | sparc86x | sparclet | sparclite \ + | sparcv8 | sparcv9 | sparcv9b | sparcv9v \ + | spu | strongarm \ + | tahoe | thumb | tic4x | tic80 | tron \ + | ubicom32 \ + | v850 | v850e \ + | we32k \ + | x86 | xc16x | xscale | xscalee[bl] | xstormy16 | xtensa \ + | z8k | z80) + basic_machine=$basic_machine-unknown + ;; + m6811 | m68hc11 | m6812 | m68hc12 | picochip) + # Motorola 68HC11/12. + basic_machine=$basic_machine-unknown + os=-none + ;; + m88110 | m680[12346]0 | m683?2 | m68360 | m5200 | v70 | w65 | z8k) + ;; + ms1) + basic_machine=mt-unknown + ;; + + # We use `pc' rather than `unknown' + # because (1) that's what they normally are, and + # (2) the word "unknown" tends to confuse beginning users. + i*86 | x86_64) + basic_machine=$basic_machine-pc + ;; + # Object if more than one company name word. + *-*-*) + echo Invalid configuration \`$1\': machine \`$basic_machine\' not recognized 1>&2 + exit 1 + ;; + # Recognize the basic CPU types with company name. + 580-* \ + | a29k-* \ + | alpha-* | alphaev[4-8]-* | alphaev56-* | alphaev6[78]-* \ + | alpha64-* | alpha64ev[4-8]-* | alpha64ev56-* | alpha64ev6[78]-* \ + | alphapca5[67]-* | alpha64pca5[67]-* | arc-* \ + | arm-* | armbe-* | armle-* | armeb-* | armv*-* \ + | avr-* | avr32-* \ + | bfin-* | bs2000-* \ + | c[123]* | c30-* | [cjt]90-* | c4x-* | c54x-* | c55x-* | c6x-* \ + | clipper-* | craynv-* | cydra-* \ + | d10v-* | d30v-* | dlx-* \ + | elxsi-* \ + | f30[01]-* | f700-* | fido-* | fr30-* | frv-* | fx80-* \ + | h8300-* | h8500-* \ + | hppa-* | hppa1.[01]-* | hppa2.0-* | hppa2.0[nw]-* | hppa64-* \ + | i*86-* | i860-* | i960-* | ia64-* \ + | ip2k-* | iq2000-* \ + | lm32-* \ + | m32c-* | m32r-* | m32rle-* \ + | m68000-* | m680[012346]0-* | m68360-* | m683?2-* | m68k-* \ + | m88110-* | m88k-* | maxq-* | mcore-* | metag-* | microblaze-* \ + | mips-* | mipsbe-* | mipseb-* | mipsel-* | mipsle-* \ + | mips16-* \ + | mips64-* | mips64el-* \ + | mips64octeon-* | mips64octeonel-* \ + | mips64orion-* | mips64orionel-* \ + | mips64r5900-* | mips64r5900el-* \ + | mips64vr-* | mips64vrel-* \ + | mips64vr4100-* | mips64vr4100el-* \ + | mips64vr4300-* | mips64vr4300el-* \ + | mips64vr5000-* | mips64vr5000el-* \ + | mips64vr5900-* | mips64vr5900el-* \ + | mipsisa32-* | mipsisa32el-* \ + | mipsisa32r2-* | mipsisa32r2el-* \ + | mipsisa64-* | mipsisa64el-* \ + | mipsisa64r2-* | mipsisa64r2el-* \ + | mipsisa64sb1-* | mipsisa64sb1el-* \ + | mipsisa64sr71k-* | mipsisa64sr71kel-* \ + | mipstx39-* | mipstx39el-* \ + | mmix-* \ + | mt-* \ + | msp430-* \ + | nios-* | nios2-* \ + | none-* | np1-* | ns16k-* | ns32k-* \ + | orion-* \ + | pdp10-* | pdp11-* | pj-* | pjl-* | pn-* | power-* \ + | powerpc-* | powerpc64-* | powerpc64le-* | powerpcle-* | ppcbe-* \ + | pyramid-* \ + | romp-* | rs6000-* | rx-* \ + | sh-* | sh[1234]-* | sh[24]a-* | sh[24]aeb-* | sh[23]e-* | sh[34]eb-* | sheb-* | shbe-* \ + | shle-* | sh[1234]le-* | sh3ele-* | sh64-* | sh64le-* \ + | sparc-* | sparc64-* | sparc64b-* | sparc64v-* | sparc86x-* | sparclet-* \ + | sparclite-* \ + | sparcv8-* | sparcv9-* | sparcv9b-* | sparcv9v-* | strongarm-* | sv1-* | sx?-* \ + | tahoe-* | thumb-* \ + | tic30-* | tic4x-* | tic54x-* | tic55x-* | tic6x-* | tic80-* | tile-* \ + | tron-* \ + | ubicom32-* \ + | v850-* | v850e-* | vax-* \ + | we32k-* \ + | x86-* | x86_64-* | xc16x-* | xps100-* | xscale-* | xscalee[bl]-* \ + | xstormy16-* | xtensa*-* \ + | ymp-* \ + | z8k-* | z80-*) + ;; + # Recognize the basic CPU types without company name, with glob match. + xtensa*) + basic_machine=$basic_machine-unknown + ;; + # Recognize the various machine names and aliases which stand + # for a CPU type and a company and sometimes even an OS. + 386bsd) + basic_machine=i386-unknown + os=-bsd + ;; + 3b1 | 7300 | 7300-att | att-7300 | pc7300 | safari | unixpc) + basic_machine=m68000-att + ;; + 3b*) + basic_machine=we32k-att + ;; + a29khif) + basic_machine=a29k-amd + os=-udi + ;; + abacus) + basic_machine=abacus-unknown + ;; + adobe68k) + basic_machine=m68010-adobe + os=-scout + ;; + alliant | fx80) + basic_machine=fx80-alliant + ;; + altos | altos3068) + basic_machine=m68k-altos + ;; + am29k) + basic_machine=a29k-none + os=-bsd + ;; + amd64) + basic_machine=x86_64-pc + ;; + amd64-*) + basic_machine=x86_64-`echo $basic_machine | sed 's/^[^-]*-//'` + ;; + amdahl) + basic_machine=580-amdahl + os=-sysv + ;; + amiga | amiga-*) + basic_machine=m68k-unknown + ;; + amigaos | amigados) + basic_machine=m68k-unknown + os=-amigaos + ;; + amigaunix | amix) + basic_machine=m68k-unknown + os=-sysv4 + ;; + apollo68) + basic_machine=m68k-apollo + os=-sysv + ;; + apollo68bsd) + basic_machine=m68k-apollo + os=-bsd + ;; + aros) + basic_machine=i386-pc + os=-aros + ;; + aux) + basic_machine=m68k-apple + os=-aux + ;; + balance) + basic_machine=ns32k-sequent + os=-dynix + ;; + blackfin) + basic_machine=bfin-unknown + os=-linux + ;; + blackfin-*) + basic_machine=bfin-`echo $basic_machine | sed 's/^[^-]*-//'` + os=-linux + ;; + bluegene*) + basic_machine=powerpc-ibm + os=-cnk + ;; + c90) + basic_machine=c90-cray + os=-unicos + ;; + cegcc) + basic_machine=arm-unknown + os=-cegcc + ;; + convex-c1) + basic_machine=c1-convex + os=-bsd + ;; + convex-c2) + basic_machine=c2-convex + os=-bsd + ;; + convex-c32) + basic_machine=c32-convex + os=-bsd + ;; + convex-c34) + basic_machine=c34-convex + os=-bsd + ;; + convex-c38) + basic_machine=c38-convex + os=-bsd + ;; + cray | j90) + basic_machine=j90-cray + os=-unicos + ;; + craynv) + basic_machine=craynv-cray + os=-unicosmp + ;; + cr16) + basic_machine=cr16-unknown + os=-elf + ;; + crds | unos) + basic_machine=m68k-crds + ;; + crisv32 | crisv32-* | etraxfs*) + basic_machine=crisv32-axis + ;; + cris | cris-* | etrax*) + basic_machine=cris-axis + ;; + crx) + basic_machine=crx-unknown + os=-elf + ;; + da30 | da30-*) + basic_machine=m68k-da30 + ;; + decstation | decstation-3100 | pmax | pmax-* | pmin | dec3100 | decstatn) + basic_machine=mips-dec + ;; + decsystem10* | dec10*) + basic_machine=pdp10-dec + os=-tops10 + ;; + decsystem20* | dec20*) + basic_machine=pdp10-dec + os=-tops20 + ;; + delta | 3300 | motorola-3300 | motorola-delta \ + | 3300-motorola | delta-motorola) + basic_machine=m68k-motorola + ;; + delta88) + basic_machine=m88k-motorola + os=-sysv3 + ;; + dicos) + basic_machine=i686-pc + os=-dicos + ;; + djgpp) + basic_machine=i586-pc + os=-msdosdjgpp + ;; + dpx20 | dpx20-*) + basic_machine=rs6000-bull + os=-bosx + ;; + dpx2* | dpx2*-bull) + basic_machine=m68k-bull + os=-sysv3 + ;; + ebmon29k) + basic_machine=a29k-amd + os=-ebmon + ;; + elxsi) + basic_machine=elxsi-elxsi + os=-bsd + ;; + encore | umax | mmax) + basic_machine=ns32k-encore + ;; + es1800 | OSE68k | ose68k | ose | OSE) + basic_machine=m68k-ericsson + os=-ose + ;; + fx2800) + basic_machine=i860-alliant + ;; + genix) + basic_machine=ns32k-ns + ;; + gmicro) + basic_machine=tron-gmicro + os=-sysv + ;; + go32) + basic_machine=i386-pc + os=-go32 + ;; + h3050r* | hiux*) + basic_machine=hppa1.1-hitachi + os=-hiuxwe2 + ;; + h8300hms) + basic_machine=h8300-hitachi + os=-hms + ;; + h8300xray) + basic_machine=h8300-hitachi + os=-xray + ;; + h8500hms) + basic_machine=h8500-hitachi + os=-hms + ;; + harris) + basic_machine=m88k-harris + os=-sysv3 + ;; + hp300-*) + basic_machine=m68k-hp + ;; + hp300bsd) + basic_machine=m68k-hp + os=-bsd + ;; + hp300hpux) + basic_machine=m68k-hp + os=-hpux + ;; + hp3k9[0-9][0-9] | hp9[0-9][0-9]) + basic_machine=hppa1.0-hp + ;; + hp9k2[0-9][0-9] | hp9k31[0-9]) + basic_machine=m68000-hp + ;; + hp9k3[2-9][0-9]) + basic_machine=m68k-hp + ;; + hp9k6[0-9][0-9] | hp6[0-9][0-9]) + basic_machine=hppa1.0-hp + ;; + hp9k7[0-79][0-9] | hp7[0-79][0-9]) + basic_machine=hppa1.1-hp + ;; + hp9k78[0-9] | hp78[0-9]) + # FIXME: really hppa2.0-hp + basic_machine=hppa1.1-hp + ;; + hp9k8[67]1 | hp8[67]1 | hp9k80[24] | hp80[24] | hp9k8[78]9 | hp8[78]9 | hp9k893 | hp893) + # FIXME: really hppa2.0-hp + basic_machine=hppa1.1-hp + ;; + hp9k8[0-9][13679] | hp8[0-9][13679]) + basic_machine=hppa1.1-hp + ;; + hp9k8[0-9][0-9] | hp8[0-9][0-9]) + basic_machine=hppa1.0-hp + ;; + hppa-next) + os=-nextstep3 + ;; + hppaosf) + basic_machine=hppa1.1-hp + os=-osf + ;; + hppro) + basic_machine=hppa1.1-hp + os=-proelf + ;; + i370-ibm* | ibm*) + basic_machine=i370-ibm + ;; +# I'm not sure what "Sysv32" means. Should this be sysv3.2? + i*86v32) + basic_machine=`echo $1 | sed -e 's/86.*/86-pc/'` + os=-sysv32 + ;; + i*86v4*) + basic_machine=`echo $1 | sed -e 's/86.*/86-pc/'` + os=-sysv4 + ;; + i*86v) + basic_machine=`echo $1 | sed -e 's/86.*/86-pc/'` + os=-sysv + ;; + i*86sol2) + basic_machine=`echo $1 | sed -e 's/86.*/86-pc/'` + os=-solaris2 + ;; + i386mach) + basic_machine=i386-mach + os=-mach + ;; + i386-vsta | vsta) + basic_machine=i386-unknown + os=-vsta + ;; + iris | iris4d) + basic_machine=mips-sgi + case $os in + -irix*) + ;; + *) + os=-irix4 + ;; + esac + ;; + isi68 | isi) + basic_machine=m68k-isi + os=-sysv + ;; + m68knommu) + basic_machine=m68k-unknown + os=-linux + ;; + m68knommu-*) + basic_machine=m68k-`echo $basic_machine | sed 's/^[^-]*-//'` + os=-linux + ;; + m88k-omron*) + basic_machine=m88k-omron + ;; + magnum | m3230) + basic_machine=mips-mips + os=-sysv + ;; + merlin) + basic_machine=ns32k-utek + os=-sysv + ;; + microblaze) + basic_machine=microblaze-xilinx + ;; + mingw32) + basic_machine=i386-pc + os=-mingw32 + ;; + mingw32ce) + basic_machine=arm-unknown + os=-mingw32ce + ;; + miniframe) + basic_machine=m68000-convergent + ;; + *mint | -mint[0-9]* | *MiNT | *MiNT[0-9]*) + basic_machine=m68k-atari + os=-mint + ;; + mips3*-*) + basic_machine=`echo $basic_machine | sed -e 's/mips3/mips64/'` + ;; + mips3*) + basic_machine=`echo $basic_machine | sed -e 's/mips3/mips64/'`-unknown + ;; + monitor) + basic_machine=m68k-rom68k + os=-coff + ;; + morphos) + basic_machine=powerpc-unknown + os=-morphos + ;; + msdos) + basic_machine=i386-pc + os=-msdos + ;; + ms1-*) + basic_machine=`echo $basic_machine | sed -e 's/ms1-/mt-/'` + ;; + mvs) + basic_machine=i370-ibm + os=-mvs + ;; + ncr3000) + basic_machine=i486-ncr + os=-sysv4 + ;; + netbsd386) + basic_machine=i386-unknown + os=-netbsd + ;; + netwinder) + basic_machine=armv4l-rebel + os=-linux + ;; + news | news700 | news800 | news900) + basic_machine=m68k-sony + os=-newsos + ;; + news1000) + basic_machine=m68030-sony + os=-newsos + ;; + news-3600 | risc-news) + basic_machine=mips-sony + os=-newsos + ;; + necv70) + basic_machine=v70-nec + os=-sysv + ;; + next | m*-next ) + basic_machine=m68k-next + case $os in + -nextstep* ) + ;; + -ns2*) + os=-nextstep2 + ;; + *) + os=-nextstep3 + ;; + esac + ;; + nh3000) + basic_machine=m68k-harris + os=-cxux + ;; + nh[45]000) + basic_machine=m88k-harris + os=-cxux + ;; + nindy960) + basic_machine=i960-intel + os=-nindy + ;; + mon960) + basic_machine=i960-intel + os=-mon960 + ;; + nonstopux) + basic_machine=mips-compaq + os=-nonstopux + ;; + np1) + basic_machine=np1-gould + ;; + nsr-tandem) + basic_machine=nsr-tandem + ;; + op50n-* | op60c-*) + basic_machine=hppa1.1-oki + os=-proelf + ;; + openrisc | openrisc-*) + basic_machine=or32-unknown + ;; + os400) + basic_machine=powerpc-ibm + os=-os400 + ;; + OSE68000 | ose68000) + basic_machine=m68000-ericsson + os=-ose + ;; + os68k) + basic_machine=m68k-none + os=-os68k + ;; + pa-hitachi) + basic_machine=hppa1.1-hitachi + os=-hiuxwe2 + ;; + paragon) + basic_machine=i860-intel + os=-osf + ;; + parisc) + basic_machine=hppa-unknown + os=-linux + ;; + parisc-*) + basic_machine=hppa-`echo $basic_machine | sed 's/^[^-]*-//'` + os=-linux + ;; + pbd) + basic_machine=sparc-tti + ;; + pbb) + basic_machine=m68k-tti + ;; + pc532 | pc532-*) + basic_machine=ns32k-pc532 + ;; + pc98) + basic_machine=i386-pc + ;; + pc98-*) + basic_machine=i386-`echo $basic_machine | sed 's/^[^-]*-//'` + ;; + pentium | p5 | k5 | k6 | nexgen | viac3) + basic_machine=i586-pc + ;; + pentiumpro | p6 | 6x86 | athlon | athlon_*) + basic_machine=i686-pc + ;; + pentiumii | pentium2 | pentiumiii | pentium3) + basic_machine=i686-pc + ;; + pentium4) + basic_machine=i786-pc + ;; + pentium-* | p5-* | k5-* | k6-* | nexgen-* | viac3-*) + basic_machine=i586-`echo $basic_machine | sed 's/^[^-]*-//'` + ;; + pentiumpro-* | p6-* | 6x86-* | athlon-*) + basic_machine=i686-`echo $basic_machine | sed 's/^[^-]*-//'` + ;; + pentiumii-* | pentium2-* | pentiumiii-* | pentium3-*) + basic_machine=i686-`echo $basic_machine | sed 's/^[^-]*-//'` + ;; + pentium4-*) + basic_machine=i786-`echo $basic_machine | sed 's/^[^-]*-//'` + ;; + pn) + basic_machine=pn-gould + ;; + power) basic_machine=power-ibm + ;; + ppc) basic_machine=powerpc-unknown + ;; + ppc-*) basic_machine=powerpc-`echo $basic_machine | sed 's/^[^-]*-//'` + ;; + ppcle | powerpclittle | ppc-le | powerpc-little) + basic_machine=powerpcle-unknown + ;; + ppcle-* | powerpclittle-*) + basic_machine=powerpcle-`echo $basic_machine | sed 's/^[^-]*-//'` + ;; + ppc64) basic_machine=powerpc64-unknown + ;; + ppc64-*) basic_machine=powerpc64-`echo $basic_machine | sed 's/^[^-]*-//'` + ;; + ppc64le | powerpc64little | ppc64-le | powerpc64-little) + basic_machine=powerpc64le-unknown + ;; + ppc64le-* | powerpc64little-*) + basic_machine=powerpc64le-`echo $basic_machine | sed 's/^[^-]*-//'` + ;; + ps2) + basic_machine=i386-ibm + ;; + pw32) + basic_machine=i586-unknown + os=-pw32 + ;; + rdos) + basic_machine=i386-pc + os=-rdos + ;; + rom68k) + basic_machine=m68k-rom68k + os=-coff + ;; + rm[46]00) + basic_machine=mips-siemens + ;; + rtpc | rtpc-*) + basic_machine=romp-ibm + ;; + s390 | s390-*) + basic_machine=s390-ibm + ;; + s390x | s390x-*) + basic_machine=s390x-ibm + ;; + sa29200) + basic_machine=a29k-amd + os=-udi + ;; + sb1) + basic_machine=mipsisa64sb1-unknown + ;; + sb1el) + basic_machine=mipsisa64sb1el-unknown + ;; + sde) + basic_machine=mipsisa32-sde + os=-elf + ;; + sei) + basic_machine=mips-sei + os=-seiux + ;; + sequent) + basic_machine=i386-sequent + ;; + sh) + basic_machine=sh-hitachi + os=-hms + ;; + sh5el) + basic_machine=sh5le-unknown + ;; + sh64) + basic_machine=sh64-unknown + ;; + sparclite-wrs | simso-wrs) + basic_machine=sparclite-wrs + os=-vxworks + ;; + sps7) + basic_machine=m68k-bull + os=-sysv2 + ;; + spur) + basic_machine=spur-unknown + ;; + st2000) + basic_machine=m68k-tandem + ;; + stratus) + basic_machine=i860-stratus + os=-sysv4 + ;; + sun2) + basic_machine=m68000-sun + ;; + sun2os3) + basic_machine=m68000-sun + os=-sunos3 + ;; + sun2os4) + basic_machine=m68000-sun + os=-sunos4 + ;; + sun3os3) + basic_machine=m68k-sun + os=-sunos3 + ;; + sun3os4) + basic_machine=m68k-sun + os=-sunos4 + ;; + sun4os3) + basic_machine=sparc-sun + os=-sunos3 + ;; + sun4os4) + basic_machine=sparc-sun + os=-sunos4 + ;; + sun4sol2) + basic_machine=sparc-sun + os=-solaris2 + ;; + sun3 | sun3-*) + basic_machine=m68k-sun + ;; + sun4) + basic_machine=sparc-sun + ;; + sun386 | sun386i | roadrunner) + basic_machine=i386-sun + ;; + sv1) + basic_machine=sv1-cray + os=-unicos + ;; + symmetry) + basic_machine=i386-sequent + os=-dynix + ;; + t3e) + basic_machine=alphaev5-cray + os=-unicos + ;; + t90) + basic_machine=t90-cray + os=-unicos + ;; + tic54x | c54x*) + basic_machine=tic54x-unknown + os=-coff + ;; + tic55x | c55x*) + basic_machine=tic55x-unknown + os=-coff + ;; + tic6x | c6x*) + basic_machine=tic6x-unknown + os=-coff + ;; + tile*) + basic_machine=tile-unknown + os=-linux-gnu + ;; + tx39) + basic_machine=mipstx39-unknown + ;; + tx39el) + basic_machine=mipstx39el-unknown + ;; + toad1) + basic_machine=pdp10-xkl + os=-tops20 + ;; + tower | tower-32) + basic_machine=m68k-ncr + ;; + tpf) + basic_machine=s390x-ibm + os=-tpf + ;; + udi29k) + basic_machine=a29k-amd + os=-udi + ;; + ultra3) + basic_machine=a29k-nyu + os=-sym1 + ;; + v810 | necv810) + basic_machine=v810-nec + os=-none + ;; + vaxv) + basic_machine=vax-dec + os=-sysv + ;; + vms) + basic_machine=vax-dec + os=-vms + ;; + vpp*|vx|vx-*) + basic_machine=f301-fujitsu + ;; + vxworks960) + basic_machine=i960-wrs + os=-vxworks + ;; + vxworks68) + basic_machine=m68k-wrs + os=-vxworks + ;; + vxworks29k) + basic_machine=a29k-wrs + os=-vxworks + ;; + w65*) + basic_machine=w65-wdc + os=-none + ;; + w89k-*) + basic_machine=hppa1.1-winbond + os=-proelf + ;; + xbox) + basic_machine=i686-pc + os=-mingw32 + ;; + xps | xps100) + basic_machine=xps100-honeywell + ;; + ymp) + basic_machine=ymp-cray + os=-unicos + ;; + z8k-*-coff) + basic_machine=z8k-unknown + os=-sim + ;; + z80-*-coff) + basic_machine=z80-unknown + os=-sim + ;; + none) + basic_machine=none-none + os=-none + ;; + +# Here we handle the default manufacturer of certain CPU types. It is in +# some cases the only manufacturer, in others, it is the most popular. + w89k) + basic_machine=hppa1.1-winbond + ;; + op50n) + basic_machine=hppa1.1-oki + ;; + op60c) + basic_machine=hppa1.1-oki + ;; + romp) + basic_machine=romp-ibm + ;; + mmix) + basic_machine=mmix-knuth + ;; + rs6000) + basic_machine=rs6000-ibm + ;; + vax) + basic_machine=vax-dec + ;; + pdp10) + # there are many clones, so DEC is not a safe bet + basic_machine=pdp10-unknown + ;; + pdp11) + basic_machine=pdp11-dec + ;; + we32k) + basic_machine=we32k-att + ;; + sh[1234] | sh[24]a | sh[24]aeb | sh[34]eb | sh[1234]le | sh[23]ele) + basic_machine=sh-unknown + ;; + sparc | sparcv8 | sparcv9 | sparcv9b | sparcv9v) + basic_machine=sparc-sun + ;; + cydra) + basic_machine=cydra-cydrome + ;; + orion) + basic_machine=orion-highlevel + ;; + orion105) + basic_machine=clipper-highlevel + ;; + mac | mpw | mac-mpw) + basic_machine=m68k-apple + ;; + pmac | pmac-mpw) + basic_machine=powerpc-apple + ;; + *-unknown) + # Make sure to match an already-canonicalized machine name. + ;; + *) + echo Invalid configuration \`$1\': machine \`$basic_machine\' not recognized 1>&2 + exit 1 + ;; +esac + +# Here we canonicalize certain aliases for manufacturers. +case $basic_machine in + *-digital*) + basic_machine=`echo $basic_machine | sed 's/digital.*/dec/'` + ;; + *-commodore*) + basic_machine=`echo $basic_machine | sed 's/commodore.*/cbm/'` + ;; + *) + ;; +esac + +# Decode manufacturer-specific aliases for certain operating systems. + +if [ x"$os" != x"" ] +then +case $os in + # First match some system type aliases + # that might get confused with valid system types. + # -solaris* is a basic system type, with this one exception. + -auroraux) + os=-auroraux + ;; + -solaris1 | -solaris1.*) + os=`echo $os | sed -e 's|solaris1|sunos4|'` + ;; + -solaris) + os=-solaris2 + ;; + -svr4*) + os=-sysv4 + ;; + -unixware*) + os=-sysv4.2uw + ;; + -gnu/linux*) + os=`echo $os | sed -e 's|gnu/linux|linux-gnu|'` + ;; + # First accept the basic system types. + # The portable systems comes first. + # Each alternative MUST END IN A *, to match a version number. + # -sysv* is not here because it comes later, after sysvr4. + -gnu* | -bsd* | -mach* | -minix* | -genix* | -ultrix* | -irix* \ + | -*vms* | -sco* | -esix* | -isc* | -aix* | -cnk* | -sunos | -sunos[34]*\ + | -hpux* | -unos* | -osf* | -luna* | -dgux* | -auroraux* | -solaris* \ + | -sym* | -kopensolaris* \ + | -amigaos* | -amigados* | -msdos* | -newsos* | -unicos* | -aof* \ + | -aos* | -aros* \ + | -nindy* | -vxsim* | -vxworks* | -ebmon* | -hms* | -mvs* \ + | -clix* | -riscos* | -uniplus* | -iris* | -rtu* | -xenix* \ + | -hiux* | -386bsd* | -knetbsd* | -mirbsd* | -netbsd* \ + | -openbsd* | -solidbsd* \ + | -ekkobsd* | -kfreebsd* | -freebsd* | -riscix* | -lynxos* \ + | -bosx* | -nextstep* | -cxux* | -aout* | -elf* | -oabi* \ + | -ptx* | -coff* | -ecoff* | -winnt* | -domain* | -vsta* \ + | -udi* | -eabi* | -lites* | -ieee* | -go32* | -aux* \ + | -chorusos* | -chorusrdb* | -cegcc* \ + | -cygwin* | -pe* | -psos* | -moss* | -proelf* | -rtems* \ + | -mingw32* | -linux-gnu* | -linux-newlib* | -linux-uclibc* \ + | -uxpv* | -beos* | -mpeix* | -udk* \ + | -interix* | -uwin* | -mks* | -rhapsody* | -darwin* | -opened* \ + | -openstep* | -oskit* | -conix* | -pw32* | -nonstopux* \ + | -storm-chaos* | -tops10* | -tenex* | -tops20* | -its* \ + | -os2* | -vos* | -palmos* | -uclinux* | -nucleus* \ + | -morphos* | -superux* | -rtmk* | -rtmk-nova* | -windiss* \ + | -powermax* | -dnix* | -nx6 | -nx7 | -sei* | -dragonfly* \ + | -skyos* | -haiku* | -rdos* | -toppers* | -drops* | -es*) + # Remember, each alternative MUST END IN *, to match a version number. + ;; + -qnx*) + case $basic_machine in + x86-* | i*86-*) + ;; + *) + os=-nto$os + ;; + esac + ;; + -nto-qnx*) + ;; + -nto*) + os=`echo $os | sed -e 's|nto|nto-qnx|'` + ;; + -sim | -es1800* | -hms* | -xray | -os68k* | -none* | -v88r* \ + | -windows* | -osx | -abug | -netware* | -os9* | -beos* | -haiku* \ + | -macos* | -mpw* | -magic* | -mmixware* | -mon960* | -lnews*) + ;; + -mac*) + os=`echo $os | sed -e 's|mac|macos|'` + ;; + -linux-dietlibc) + os=-linux-dietlibc + ;; + -linux*) + os=`echo $os | sed -e 's|linux|linux-gnu|'` + ;; + -sunos5*) + os=`echo $os | sed -e 's|sunos5|solaris2|'` + ;; + -sunos6*) + os=`echo $os | sed -e 's|sunos6|solaris3|'` + ;; + -opened*) + os=-openedition + ;; + -os400*) + os=-os400 + ;; + -wince*) + os=-wince + ;; + -osfrose*) + os=-osfrose + ;; + -osf*) + os=-osf + ;; + -utek*) + os=-bsd + ;; + -dynix*) + os=-bsd + ;; + -acis*) + os=-aos + ;; + -atheos*) + os=-atheos + ;; + -syllable*) + os=-syllable + ;; + -386bsd) + os=-bsd + ;; + -ctix* | -uts*) + os=-sysv + ;; + -nova*) + os=-rtmk-nova + ;; + -ns2 ) + os=-nextstep2 + ;; + -nsk*) + os=-nsk + ;; + # Preserve the version number of sinix5. + -sinix5.*) + os=`echo $os | sed -e 's|sinix|sysv|'` + ;; + -sinix*) + os=-sysv4 + ;; + -tpf*) + os=-tpf + ;; + -triton*) + os=-sysv3 + ;; + -oss*) + os=-sysv3 + ;; + -svr4) + os=-sysv4 + ;; + -svr3) + os=-sysv3 + ;; + -sysvr4) + os=-sysv4 + ;; + # This must come after -sysvr4. + -sysv*) + ;; + -ose*) + os=-ose + ;; + -es1800*) + os=-ose + ;; + -xenix) + os=-xenix + ;; + -*mint | -mint[0-9]* | -*MiNT | -MiNT[0-9]*) + os=-mint + ;; + -aros*) + os=-aros + ;; + -kaos*) + os=-kaos + ;; + -zvmoe) + os=-zvmoe + ;; + -dicos*) + os=-dicos + ;; + -none) + ;; + *) + # Get rid of the `-' at the beginning of $os. + os=`echo $os | sed 's/[^-]*-//'` + echo Invalid configuration \`$1\': system \`$os\' not recognized 1>&2 + exit 1 + ;; +esac +else + +# Here we handle the default operating systems that come with various machines. +# The value should be what the vendor currently ships out the door with their +# machine or put another way, the most popular os provided with the machine. + +# Note that if you're going to try to match "-MANUFACTURER" here (say, +# "-sun"), then you have to tell the case statement up towards the top +# that MANUFACTURER isn't an operating system. Otherwise, code above +# will signal an error saying that MANUFACTURER isn't an operating +# system, and we'll never get to this point. + +case $basic_machine in + score-*) + os=-elf + ;; + spu-*) + os=-elf + ;; + *-acorn) + os=-riscix1.2 + ;; + arm*-rebel) + os=-linux + ;; + arm*-semi) + os=-aout + ;; + c4x-* | tic4x-*) + os=-coff + ;; + # This must come before the *-dec entry. + pdp10-*) + os=-tops20 + ;; + pdp11-*) + os=-none + ;; + *-dec | vax-*) + os=-ultrix4.2 + ;; + m68*-apollo) + os=-domain + ;; + i386-sun) + os=-sunos4.0.2 + ;; + m68000-sun) + os=-sunos3 + # This also exists in the configure program, but was not the + # default. + # os=-sunos4 + ;; + m68*-cisco) + os=-aout + ;; + mep-*) + os=-elf + ;; + mips*-cisco) + os=-elf + ;; + mips*-*) + os=-elf + ;; + or32-*) + os=-coff + ;; + *-tti) # must be before sparc entry or we get the wrong os. + os=-sysv3 + ;; + sparc-* | *-sun) + os=-sunos4.1.1 + ;; + *-be) + os=-beos + ;; + *-haiku) + os=-haiku + ;; + *-ibm) + os=-aix + ;; + *-knuth) + os=-mmixware + ;; + *-wec) + os=-proelf + ;; + *-winbond) + os=-proelf + ;; + *-oki) + os=-proelf + ;; + *-hp) + os=-hpux + ;; + *-hitachi) + os=-hiux + ;; + i860-* | *-att | *-ncr | *-altos | *-motorola | *-convergent) + os=-sysv + ;; + *-cbm) + os=-amigaos + ;; + *-dg) + os=-dgux + ;; + *-dolphin) + os=-sysv3 + ;; + m68k-ccur) + os=-rtu + ;; + m88k-omron*) + os=-luna + ;; + *-next ) + os=-nextstep + ;; + *-sequent) + os=-ptx + ;; + *-crds) + os=-unos + ;; + *-ns) + os=-genix + ;; + i370-*) + os=-mvs + ;; + *-next) + os=-nextstep3 + ;; + *-gould) + os=-sysv + ;; + *-highlevel) + os=-bsd + ;; + *-encore) + os=-bsd + ;; + *-sgi) + os=-irix + ;; + *-siemens) + os=-sysv4 + ;; + *-masscomp) + os=-rtu + ;; + f30[01]-fujitsu | f700-fujitsu) + os=-uxpv + ;; + *-rom68k) + os=-coff + ;; + *-*bug) + os=-coff + ;; + *-apple) + os=-macos + ;; + *-atari*) + os=-mint + ;; + *) + os=-none + ;; +esac +fi + +# Here we handle the case where we know the os, and the CPU type, but not the +# manufacturer. We pick the logical manufacturer. +vendor=unknown +case $basic_machine in + *-unknown) + case $os in + -riscix*) + vendor=acorn + ;; + -sunos*) + vendor=sun + ;; + -cnk*|-aix*) + vendor=ibm + ;; + -beos*) + vendor=be + ;; + -hpux*) + vendor=hp + ;; + -mpeix*) + vendor=hp + ;; + -hiux*) + vendor=hitachi + ;; + -unos*) + vendor=crds + ;; + -dgux*) + vendor=dg + ;; + -luna*) + vendor=omron + ;; + -genix*) + vendor=ns + ;; + -mvs* | -opened*) + vendor=ibm + ;; + -os400*) + vendor=ibm + ;; + -ptx*) + vendor=sequent + ;; + -tpf*) + vendor=ibm + ;; + -vxsim* | -vxworks* | -windiss*) + vendor=wrs + ;; + -aux*) + vendor=apple + ;; + -hms*) + vendor=hitachi + ;; + -mpw* | -macos*) + vendor=apple + ;; + -*mint | -mint[0-9]* | -*MiNT | -MiNT[0-9]*) + vendor=atari + ;; + -vos*) + vendor=stratus + ;; + esac + basic_machine=`echo $basic_machine | sed "s/unknown/$vendor/"` + ;; +esac + +echo $basic_machine$os +exit + +# Local variables: +# eval: (add-hook 'write-file-hooks 'time-stamp) +# time-stamp-start: "timestamp='" +# time-stamp-format: "%:y-%02m-%02d" +# time-stamp-end: "'" +# End: diff --git a/src/3rdparty/libpng/configure.ac b/src/3rdparty/libpng/configure.ac new file mode 100644 index 0000000000..ff277a4d66 --- /dev/null +++ b/src/3rdparty/libpng/configure.ac @@ -0,0 +1,167 @@ +# configure.ac + +dnl Process this file with autoconf to produce a configure script. +dnl +dnl Minor upgrades (compatible ABI): increment the package version +dnl (third field in two places below) and set the PNGLIB_RELEASE +dnl variable. +dnl +dnl Major upgrades (incompatible ABI): increment the package major +dnl version (second field, or first if desired), set the minor +dnl to 0, set PNGLIB_MAJOR below *and* follow the instructions in +dnl Makefile.am to upgrade the package name. + +dnl This is here to prevent earlier autoconf from being used, it +dnl should not be necessary to regenerate configure if the time +dnl stamps are correct +AC_PREREQ(2.59) + +dnl Version number stuff here: + +AC_INIT([libpng], [1.5.1], [png-mng-implement@lists.sourceforge.net]) +AM_INIT_AUTOMAKE +dnl stop configure from automagically running automake +AM_MAINTAINER_MODE + +PNGLIB_VERSION=1.5.1 +PNGLIB_MAJOR=1 +PNGLIB_MINOR=5 +PNGLIB_RELEASE=1 + +dnl End of version number stuff + +AC_CONFIG_SRCDIR([pngget.c]) +AM_CONFIG_HEADER(config.h) + +# Checks for programs. +AC_LANG([C]) +AC_PROG_CC +AC_PROG_LD +AC_PROG_CPP +AC_CHECK_TOOL(SED, sed, :) +AC_CHECK_TOOL(AWK, awk, :) +AC_PROG_INSTALL +AC_PROG_LN_S +AC_PROG_MAKE_SET +LT_INIT([win32-dll]) + +# On Solaris 10 and 12 CPP gets set to cc -E, however this still +# does some input parsing. We need strict ANSI-C style tokenization, +# check this: +AC_REQUIRE_CPP +AC_MSG_CHECKING([for a C preprocessor that does not parse its input]) +AC_TRY_CPP([1.5.0 16BIT], + [DFNCPP="$CPP"], + [DFNCPP="" + sav_CPP="$CPP" + for CPP in "${CC-cc} -E" "${CC-cc} -E -traditional-cpp" "/lib/cpp" "cpp"; do + AC_TRY_CPP([1.5.0 16BIT], + [DFNCPP="$CPP"] + [break],,) + done + CPP="$sav_CPP"]) +if test -n "$DFNCPP"; then + AC_MSG_RESULT([$DFNCPP]) + AC_SUBST(DFNCPP) +else + AC_MSG_FAILURE([not found], 1) +fi + +# Checks for header files. +AC_HEADER_STDC +AC_CHECK_HEADERS([malloc.h stdlib.h string.h strings.h]) + +# Checks for typedefs, structures, and compiler characteristics. +AC_C_CONST +AC_TYPE_SIZE_T +AC_STRUCT_TM + +# Checks for library functions. +AC_FUNC_STRTOD +AC_CHECK_FUNCS([memset], , AC_ERROR([memset not found in libc])) +AC_CHECK_FUNCS([pow], , AC_CHECK_LIB(m, pow, , AC_ERROR([cannot find pow])) ) +AC_ARG_WITH(zlib-prefix, + AC_HELP_STRING([--with-zlib-prefix], + [prefix that may have been used in installed zlib]), + [ZPREFIX=${withval}], + [ZPREFIX='z_']) +AC_CHECK_LIB(z, zlibVersion, , + AC_CHECK_LIB(z, ${ZPREFIX}zlibVersion, , + AC_ERROR([zlib not installed]))) + + +LIBPNG_DEFINES=-DPNG_CONFIGURE_LIBPNG +LIBPNG_DEFINES=$LIBPNG_DEFINES +AC_SUBST(LIBPNG_DEFINES) + +AC_MSG_CHECKING([if libraries can be versioned]) +# Special case for PE/COFF platforms: ld reports +# support for version-script, but doesn't actually +# DO anything with it. +case $host in +*cygwin* | *mingw32* | *interix* ) + have_ld_version_script=no + AC_MSG_RESULT(no) +;; +* ) +GLD=`$LD --help < /dev/null 2>/dev/null | grep version-script` +if test "$GLD"; then + have_ld_version_script=yes + AC_MSG_RESULT(yes) +else + have_ld_version_script=no + AC_MSG_RESULT(no) + AC_MSG_WARN(*** You have not enabled versioned symbols.) +fi +;; +esac + +AM_CONDITIONAL(HAVE_LD_VERSION_SCRIPT, test "$have_ld_version_script" = "yes") + +if test "$have_ld_version_script" = "yes"; then + AC_MSG_CHECKING([for symbol prefix]) + SYMBOL_PREFIX=`echo "PREFIX=__USER_LABEL_PREFIX__" \ + | ${CPP-${CC-gcc} -E} - 2>&1 \ + | ${EGREP-grep} "^PREFIX=" \ + | ${SED-sed} "s:^PREFIX=::"` + AC_SUBST(SYMBOL_PREFIX) + AC_MSG_RESULT($SYMBOL_PREFIX) +fi + +# Substitutions for .in files +AC_SUBST(PNGLIB_VERSION) +AC_SUBST(PNGLIB_MAJOR) +AC_SUBST(PNGLIB_MINOR) +AC_SUBST(PNGLIB_RELEASE) + +# Additional arguments (and substitutions) +# Allow the pkg-config directory to be set +AC_ARG_WITH(pkgconfigdir, + AC_HELP_STRING([--with-pkgconfigdir], + [Use the specified pkgconfig dir (default is libdir/pkgconfig)]), + [pkgconfigdir=${withval}], + [pkgconfigdir='${libdir}/pkgconfig']) + +AC_SUBST([pkgconfigdir]) +AC_MSG_NOTICE([pkgconfig directory is ${pkgconfigdir}]) + +# Make the *-config binary config scripts optional +AC_ARG_WITH(binconfigs, + AC_HELP_STRING([--with-binconfigs], + [Generate shell libpng-config scripts as well as pkg-config data] + [@<:@default=yes@:>@]), + [if test "${withval}" = no; then + binconfigs= + AC_MSG_NOTICE([libpng-config scripts will not be built]) + else + binconfigs='${binconfigs}' + fi], + [binconfigs='${binconfigs}']) +AC_SUBST([binconfigs]) + +# Config files, substituting as above +AC_CONFIG_FILES([Makefile libpng.pc:libpng.pc.in]) +AC_CONFIG_FILES([libpng-config:libpng-config.in], + [chmod +x libpng-config]) + +AC_OUTPUT diff --git a/src/3rdparty/libpng/example.c b/src/3rdparty/libpng/example.c new file mode 100644 index 0000000000..cd3682f014 --- /dev/null +++ b/src/3rdparty/libpng/example.c @@ -0,0 +1,843 @@ + +#if 0 /* in case someone actually tries to compile this */ + +/* example.c - an example of using libpng + * Last changed in libpng 1.5.0 [January 6, 2011] + * This file has been placed in the public domain by the authors. + * Maintained 1998-2011 Glenn Randers-Pehrson + * Maintained 1996, 1997 Andreas Dilger) + * Written 1995, 1996 Guy Eric Schalnat, Group 42, Inc.) + */ + +/* This is an example of how to use libpng to read and write PNG files. + * The file libpng-manual.txt is much more verbose then this. If you have not + * read it, do so first. This was designed to be a starting point of an + * implementation. This is not officially part of libpng, is hereby placed + * in the public domain, and therefore does not require a copyright notice. + * + * This file does not currently compile, because it is missing certain + * parts, like allocating memory to hold an image. You will have to + * supply these parts to get it to compile. For an example of a minimal + * working PNG reader/writer, see pngtest.c, included in this distribution; + * see also the programs in the contrib directory. + */ + +#include "png.h" + + /* The png_jmpbuf() macro, used in error handling, became available in + * libpng version 1.0.6. If you want to be able to run your code with older + * versions of libpng, you must define the macro yourself (but only if it + * is not already defined by libpng!). + */ + +#ifndef png_jmpbuf +# define png_jmpbuf(png_ptr) ((png_ptr)->png_jmpbuf) +#endif + +/* Check to see if a file is a PNG file using png_sig_cmp(). png_sig_cmp() + * returns zero if the image is a PNG and nonzero if it isn't a PNG. + * + * The function check_if_png() shown here, but not used, returns nonzero (true) + * if the file can be opened and is a PNG, 0 (false) otherwise. + * + * If this call is successful, and you are going to keep the file open, + * you should call png_set_sig_bytes(png_ptr, PNG_BYTES_TO_CHECK); once + * you have created the png_ptr, so that libpng knows your application + * has read that many bytes from the start of the file. Make sure you + * don't call png_set_sig_bytes() with more than 8 bytes read or give it + * an incorrect number of bytes read, or you will either have read too + * many bytes (your fault), or you are telling libpng to read the wrong + * number of magic bytes (also your fault). + * + * Many applications already read the first 2 or 4 bytes from the start + * of the image to determine the file type, so it would be easiest just + * to pass the bytes to png_sig_cmp() or even skip that if you know + * you have a PNG file, and call png_set_sig_bytes(). + */ +#define PNG_BYTES_TO_CHECK 4 +int check_if_png(char *file_name, FILE **fp) +{ + char buf[PNG_BYTES_TO_CHECK]; + + /* Open the prospective PNG file. */ + if ((*fp = fopen(file_name, "rb")) == NULL) + return 0; + + /* Read in some of the signature bytes */ + if (fread(buf, 1, PNG_BYTES_TO_CHECK, *fp) != PNG_BYTES_TO_CHECK) + return 0; + + /* Compare the first PNG_BYTES_TO_CHECK bytes of the signature. + Return nonzero (true) if they match */ + + return(!png_sig_cmp(buf, (png_size_t)0, PNG_BYTES_TO_CHECK)); +} + +/* Read a PNG file. You may want to return an error code if the read + * fails (depending upon the failure). There are two "prototypes" given + * here - one where we are given the filename, and we need to open the + * file, and the other where we are given an open file (possibly with + * some or all of the magic bytes read - see comments above). + */ +#ifdef open_file /* prototype 1 */ +void read_png(char *file_name) /* We need to open the file */ +{ + png_structp png_ptr; + png_infop info_ptr; + unsigned int sig_read = 0; + png_uint_32 width, height; + int bit_depth, color_type, interlace_type; + FILE *fp; + + if ((fp = fopen(file_name, "rb")) == NULL) + return (ERROR); + +#else no_open_file /* prototype 2 */ +void read_png(FILE *fp, unsigned int sig_read) /* File is already open */ +{ + png_structp png_ptr; + png_infop info_ptr; + png_uint_32 width, height; + int bit_depth, color_type, interlace_type; +#endif no_open_file /* Only use one prototype! */ + + /* Create and initialize the png_struct with the desired error handler + * functions. If you want to use the default stderr and longjump method, + * you can supply NULL for the last three parameters. We also supply the + * the compiler header file version, so that we know if the application + * was compiled with a compatible version of the library. REQUIRED + */ + png_ptr = png_create_read_struct(PNG_LIBPNG_VER_STRING, + png_voidp user_error_ptr, user_error_fn, user_warning_fn); + + if (png_ptr == NULL) + { + fclose(fp); + return (ERROR); + } + + /* Allocate/initialize the memory for image information. REQUIRED. */ + info_ptr = png_create_info_struct(png_ptr); + if (info_ptr == NULL) + { + fclose(fp); + png_destroy_read_struct(&png_ptr, NULL, NULL); + return (ERROR); + } + + /* Set error handling if you are using the setjmp/longjmp method (this is + * the normal method of doing things with libpng). REQUIRED unless you + * set up your own error handlers in the png_create_read_struct() earlier. + */ + + if (setjmp(png_jmpbuf(png_ptr))) + { + /* Free all of the memory associated with the png_ptr and info_ptr */ + png_destroy_read_struct(&png_ptr, &info_ptr, NULL); + fclose(fp); + /* If we get here, we had a problem reading the file */ + return (ERROR); + } + + /* One of the following I/O initialization methods is REQUIRED */ +#ifdef streams /* PNG file I/O method 1 */ + /* Set up the input control if you are using standard C streams */ + png_init_io(png_ptr, fp); + +#else no_streams /* PNG file I/O method 2 */ + /* If you are using replacement read functions, instead of calling + * png_init_io() here you would call: + */ + png_set_read_fn(png_ptr, (void *)user_io_ptr, user_read_fn); + /* where user_io_ptr is a structure you want available to the callbacks */ +#endif no_streams /* Use only one I/O method! */ + + /* If we have already read some of the signature */ + png_set_sig_bytes(png_ptr, sig_read); + +#ifdef hilevel + /* + * If you have enough memory to read in the entire image at once, + * and you need to specify only transforms that can be controlled + * with one of the PNG_TRANSFORM_* bits (this presently excludes + * quantizing, filling, setting background, and doing gamma + * adjustment), then you can read the entire image (including + * pixels) into the info structure with this call: + */ + png_read_png(png_ptr, info_ptr, png_transforms, NULL); + +#else + /* OK, you're doing it the hard way, with the lower-level functions */ + + /* The call to png_read_info() gives us all of the information from the + * PNG file before the first IDAT (image data chunk). REQUIRED + */ + png_read_info(png_ptr, info_ptr); + + png_get_IHDR(png_ptr, info_ptr, &width, &height, &bit_depth, &color_type, + &interlace_type, NULL, NULL); + + /* Set up the data transformations you want. Note that these are all + * optional. Only call them if you want/need them. Many of the + * transformations only work on specific types of images, and many + * are mutually exclusive. + */ + + /* Tell libpng to strip 16 bit/color files down to 8 bits/color */ + png_set_strip_16(png_ptr); + + /* Strip alpha bytes from the input data without combining with the + * background (not recommended). + */ + png_set_strip_alpha(png_ptr); + + /* Extract multiple pixels with bit depths of 1, 2, and 4 from a single + * byte into separate bytes (useful for paletted and grayscale images). + */ + png_set_packing(png_ptr); + + /* Change the order of packed pixels to least significant bit first + * (not useful if you are using png_set_packing). */ + png_set_packswap(png_ptr); + + /* Expand paletted colors into true RGB triplets */ + if (color_type == PNG_COLOR_TYPE_PALETTE) + png_set_palette_to_rgb(png_ptr); + + /* Expand grayscale images to the full 8 bits from 1, 2, or 4 bits/pixel */ + if (color_type == PNG_COLOR_TYPE_GRAY && bit_depth < 8) + png_set_expand_gray_1_2_4_to_8(png_ptr); + + /* Expand paletted or RGB images with transparency to full alpha channels + * so the data will be available as RGBA quartets. + */ + if (png_get_valid(png_ptr, info_ptr, PNG_INFO_tRNS)) + png_set_tRNS_to_alpha(png_ptr); + + /* Set the background color to draw transparent and alpha images over. + * It is possible to set the red, green, and blue components directly + * for paletted images instead of supplying a palette index. Note that + * even if the PNG file supplies a background, you are not required to + * use it - you should use the (solid) application background if it has one. + */ + + png_color_16 my_background, *image_background; + + if (png_get_bKGD(png_ptr, info_ptr, &image_background)) + png_set_background(png_ptr, image_background, + PNG_BACKGROUND_GAMMA_FILE, 1, 1.0); + else + png_set_background(png_ptr, &my_background, + PNG_BACKGROUND_GAMMA_SCREEN, 0, 1.0); + + /* Some suggestions as to how to get a screen gamma value + * + * Note that screen gamma is the display_exponent, which includes + * the CRT_exponent and any correction for viewing conditions + */ + if (/* We have a user-defined screen gamma value */) + { + screen_gamma = user-defined screen_gamma; + } + /* This is one way that applications share the same screen gamma value */ + else if ((gamma_str = getenv("SCREEN_GAMMA")) != NULL) + { + screen_gamma = atof(gamma_str); + } + /* If we don't have another value */ + else + { + screen_gamma = 2.2; /* A good guess for a PC monitor in a dimly + lit room */ + screen_gamma = 1.7 or 1.0; /* A good guess for Mac systems */ + } + + /* Tell libpng to handle the gamma conversion for you. The final call + * is a good guess for PC generated images, but it should be configurable + * by the user at run time by the user. It is strongly suggested that + * your application support gamma correction. + */ + + int intent; + + if (png_get_sRGB(png_ptr, info_ptr, &intent)) + png_set_gamma(png_ptr, screen_gamma, 0.45455); + else + { + double image_gamma; + if (png_get_gAMA(png_ptr, info_ptr, &image_gamma)) + png_set_gamma(png_ptr, screen_gamma, image_gamma); + else + png_set_gamma(png_ptr, screen_gamma, 0.45455); + } + +#ifdef PNG_READ_QUANTIZE_SUPPORTED + /* Quantize RGB files down to 8 bit palette or reduce palettes + * to the number of colors available on your screen. + */ + if (color_type & PNG_COLOR_MASK_COLOR) + { + int num_palette; + png_colorp palette; + + /* This reduces the image to the application supplied palette */ + if (/* We have our own palette */) + { + /* An array of colors to which the image should be quantized */ + png_color std_color_cube[MAX_SCREEN_COLORS]; + + png_set_quantize(png_ptr, std_color_cube, MAX_SCREEN_COLORS, + MAX_SCREEN_COLORS, NULL, 0); + } + /* This reduces the image to the palette supplied in the file */ + else if (png_get_PLTE(png_ptr, info_ptr, &palette, &num_palette)) + { + png_uint_16p histogram = NULL; + + png_get_hIST(png_ptr, info_ptr, &histogram); + + png_set_quantize(png_ptr, palette, num_palette, + max_screen_colors, histogram, 0); + } + } +#endif /* PNG_READ_QUANTIZE_SUPPORTED */ + + /* Invert monochrome files to have 0 as white and 1 as black */ + png_set_invert_mono(png_ptr); + + /* If you want to shift the pixel values from the range [0,255] or + * [0,65535] to the original [0,7] or [0,31], or whatever range the + * colors were originally in: + */ + if (png_get_valid(png_ptr, info_ptr, PNG_INFO_sBIT)) + { + png_color_8p sig_bit_p; + + png_get_sBIT(png_ptr, info_ptr, &sig_bit_p); + png_set_shift(png_ptr, sig_bit_p); + } + + /* Flip the RGB pixels to BGR (or RGBA to BGRA) */ + if (color_type & PNG_COLOR_MASK_COLOR) + png_set_bgr(png_ptr); + + /* Swap the RGBA or GA data to ARGB or AG (or BGRA to ABGR) */ + png_set_swap_alpha(png_ptr); + + /* Swap bytes of 16 bit files to least significant byte first */ + png_set_swap(png_ptr); + + /* Add filler (or alpha) byte (before/after each RGB triplet) */ + png_set_filler(png_ptr, 0xff, PNG_FILLER_AFTER); + + /* Turn on interlace handling. REQUIRED if you are not using + * png_read_image(). To see how to handle interlacing passes, + * see the png_read_row() method below: + */ + number_passes = png_set_interlace_handling(png_ptr); + + /* Optional call to gamma correct and add the background to the palette + * and update info structure. REQUIRED if you are expecting libpng to + * update the palette for you (ie you selected such a transform above). + */ + png_read_update_info(png_ptr, info_ptr); + + /* Allocate the memory to hold the image using the fields of info_ptr. */ + + /* The easiest way to read the image: */ + png_bytep row_pointers[height]; + + /* Clear the pointer array */ + for (row = 0; row < height; row++) + row_pointers[row] = NULL; + + for (row = 0; row < height; row++) + row_pointers[row] = png_malloc(png_ptr, png_get_rowbytes(png_ptr, + info_ptr)); + + /* Now it's time to read the image. One of these methods is REQUIRED */ +#ifdef entire /* Read the entire image in one go */ + png_read_image(png_ptr, row_pointers); + +#else no_entire /* Read the image one or more scanlines at a time */ + /* The other way to read images - deal with interlacing: */ + + for (pass = 0; pass < number_passes; pass++) + { +#ifdef single /* Read the image a single row at a time */ + for (y = 0; y < height; y++) + { + png_read_rows(png_ptr, &row_pointers[y], NULL, 1); + } + +#else no_single /* Read the image several rows at a time */ + for (y = 0; y < height; y += number_of_rows) + { +#ifdef sparkle /* Read the image using the "sparkle" effect. */ + png_read_rows(png_ptr, &row_pointers[y], NULL, + number_of_rows); +#else no_sparkle /* Read the image using the "rectangle" effect */ + png_read_rows(png_ptr, NULL, &row_pointers[y], + number_of_rows); +#endif no_sparkle /* Use only one of these two methods */ + } + + /* If you want to display the image after every pass, do so here */ +#endif no_single /* Use only one of these two methods */ + } +#endif no_entire /* Use only one of these two methods */ + + /* Read rest of file, and get additional chunks in info_ptr - REQUIRED */ + png_read_end(png_ptr, info_ptr); +#endif hilevel + + /* At this point you have read the entire image */ + + /* Clean up after the read, and free any memory allocated - REQUIRED */ + png_destroy_read_struct(&png_ptr, &info_ptr, NULL); + + /* Close the file */ + fclose(fp); + + /* That's it */ + return (OK); +} + +/* Progressively read a file */ + +int +initialize_png_reader(png_structp *png_ptr, png_infop *info_ptr) +{ + /* Create and initialize the png_struct with the desired error handler + * functions. If you want to use the default stderr and longjump method, + * you can supply NULL for the last three parameters. We also check that + * the library version is compatible in case we are using dynamically + * linked libraries. + */ + *png_ptr = png_create_read_struct(PNG_LIBPNG_VER_STRING, + png_voidp user_error_ptr, user_error_fn, user_warning_fn); + + if (*png_ptr == NULL) + { + *info_ptr = NULL; + return (ERROR); + } + + *info_ptr = png_create_info_struct(png_ptr); + + if (*info_ptr == NULL) + { + png_destroy_read_struct(png_ptr, info_ptr, NULL); + return (ERROR); + } + + if (setjmp(png_jmpbuf((*png_ptr)))) + { + png_destroy_read_struct(png_ptr, info_ptr, NULL); + return (ERROR); + } + + /* This one's new. You will need to provide all three + * function callbacks, even if you aren't using them all. + * If you aren't using all functions, you can specify NULL + * parameters. Even when all three functions are NULL, + * you need to call png_set_progressive_read_fn(). + * These functions shouldn't be dependent on global or + * static variables if you are decoding several images + * simultaneously. You should store stream specific data + * in a separate struct, given as the second parameter, + * and retrieve the pointer from inside the callbacks using + * the function png_get_progressive_ptr(png_ptr). + */ + png_set_progressive_read_fn(*png_ptr, (void *)stream_data, + info_callback, row_callback, end_callback); + + return (OK); +} + +int +process_data(png_structp *png_ptr, png_infop *info_ptr, + png_bytep buffer, png_uint_32 length) +{ + if (setjmp(png_jmpbuf((*png_ptr)))) + { + /* Free the png_ptr and info_ptr memory on error */ + png_destroy_read_struct(png_ptr, info_ptr, NULL); + return (ERROR); + } + + /* This one's new also. Simply give it chunks of data as + * they arrive from the data stream (in order, of course). + * On segmented machines, don't give it any more than 64K. + * The library seems to run fine with sizes of 4K, although + * you can give it much less if necessary (I assume you can + * give it chunks of 1 byte, but I haven't tried with less + * than 256 bytes yet). When this function returns, you may + * want to display any rows that were generated in the row + * callback, if you aren't already displaying them there. + */ + png_process_data(*png_ptr, *info_ptr, buffer, length); + return (OK); +} + +info_callback(png_structp png_ptr, png_infop info) +{ + /* Do any setup here, including setting any of the transformations + * mentioned in the Reading PNG files section. For now, you _must_ + * call either png_start_read_image() or png_read_update_info() + * after all the transformations are set (even if you don't set + * any). You may start getting rows before png_process_data() + * returns, so this is your last chance to prepare for that. + */ +} + +row_callback(png_structp png_ptr, png_bytep new_row, + png_uint_32 row_num, int pass) +{ + /* + * This function is called for every row in the image. If the + * image is interlaced, and you turned on the interlace handler, + * this function will be called for every row in every pass. + * + * In this function you will receive a pointer to new row data from + * libpng called new_row that is to replace a corresponding row (of + * the same data format) in a buffer allocated by your application. + * + * The new row data pointer "new_row" may be NULL, indicating there is + * no new data to be replaced (in cases of interlace loading). + * + * If new_row is not NULL then you need to call + * png_progressive_combine_row() to replace the corresponding row as + * shown below: + */ + + /* Get pointer to corresponding row in our + * PNG read buffer. + */ + png_bytep old_row = ((png_bytep *)our_data)[row_num]; + + /* If both rows are allocated then copy the new row + * data to the corresponding row data. + */ + if ((old_row != NULL) && (new_row != NULL)) + png_progressive_combine_row(png_ptr, old_row, new_row); + + /* + * The rows and passes are called in order, so you don't really + * need the row_num and pass, but I'm supplying them because it + * may make your life easier. + * + * For the non-NULL rows of interlaced images, you must call + * png_progressive_combine_row() passing in the new row and the + * old row, as demonstrated above. You can call this function for + * NULL rows (it will just return) and for non-interlaced images + * (it just does the png_memcpy for you) if it will make the code + * easier. Thus, you can just do this for all cases: + */ + + png_progressive_combine_row(png_ptr, old_row, new_row); + + /* where old_row is what was displayed for previous rows. Note + * that the first pass (pass == 0 really) will completely cover + * the old row, so the rows do not have to be initialized. After + * the first pass (and only for interlaced images), you will have + * to pass the current row as new_row, and the function will combine + * the old row and the new row. + */ +} + +end_callback(png_structp png_ptr, png_infop info) +{ + /* This function is called when the whole image has been read, + * including any chunks after the image (up to and including + * the IEND). You will usually have the same info chunk as you + * had in the header, although some data may have been added + * to the comments and time fields. + * + * Most people won't do much here, perhaps setting a flag that + * marks the image as finished. + */ +} + +/* Write a png file */ +void write_png(char *file_name /* , ... other image information ... */) +{ + FILE *fp; + png_structp png_ptr; + png_infop info_ptr; + png_colorp palette; + + /* Open the file */ + fp = fopen(file_name, "wb"); + if (fp == NULL) + return (ERROR); + + /* Create and initialize the png_struct with the desired error handler + * functions. If you want to use the default stderr and longjump method, + * you can supply NULL for the last three parameters. We also check that + * the library version is compatible with the one used at compile time, + * in case we are using dynamically linked libraries. REQUIRED. + */ + png_ptr = png_create_write_struct(PNG_LIBPNG_VER_STRING, + png_voidp user_error_ptr, user_error_fn, user_warning_fn); + + if (png_ptr == NULL) + { + fclose(fp); + return (ERROR); + } + + /* Allocate/initialize the image information data. REQUIRED */ + info_ptr = png_create_info_struct(png_ptr); + if (info_ptr == NULL) + { + fclose(fp); + png_destroy_write_struct(&png_ptr, NULL); + return (ERROR); + } + + /* Set error handling. REQUIRED if you aren't supplying your own + * error handling functions in the png_create_write_struct() call. + */ + if (setjmp(png_jmpbuf(png_ptr))) + { + /* If we get here, we had a problem writing the file */ + fclose(fp); + png_destroy_write_struct(&png_ptr, &info_ptr); + return (ERROR); + } + + /* One of the following I/O initialization functions is REQUIRED */ + +#ifdef streams /* I/O initialization method 1 */ + /* Set up the output control if you are using standard C streams */ + png_init_io(png_ptr, fp); + +#else no_streams /* I/O initialization method 2 */ + /* If you are using replacement write functions, instead of calling + * png_init_io() here you would call + */ + png_set_write_fn(png_ptr, (void *)user_io_ptr, user_write_fn, + user_IO_flush_function); + /* where user_io_ptr is a structure you want available to the callbacks */ +#endif no_streams /* Only use one initialization method */ + +#ifdef hilevel + /* This is the easy way. Use it if you already have all the + * image info living in the structure. You could "|" many + * PNG_TRANSFORM flags into the png_transforms integer here. + */ + png_write_png(png_ptr, info_ptr, png_transforms, NULL); + +#else + /* This is the hard way */ + + /* Set the image information here. Width and height are up to 2^31, + * bit_depth is one of 1, 2, 4, 8, or 16, but valid values also depend on + * the color_type selected. color_type is one of PNG_COLOR_TYPE_GRAY, + * PNG_COLOR_TYPE_GRAY_ALPHA, PNG_COLOR_TYPE_PALETTE, PNG_COLOR_TYPE_RGB, + * or PNG_COLOR_TYPE_RGB_ALPHA. interlace is either PNG_INTERLACE_NONE or + * PNG_INTERLACE_ADAM7, and the compression_type and filter_type MUST + * currently be PNG_COMPRESSION_TYPE_BASE and PNG_FILTER_TYPE_BASE. REQUIRED + */ + png_set_IHDR(png_ptr, info_ptr, width, height, bit_depth, PNG_COLOR_TYPE_???, + PNG_INTERLACE_????, PNG_COMPRESSION_TYPE_BASE, PNG_FILTER_TYPE_BASE); + + /* Set the palette if there is one. REQUIRED for indexed-color images */ + palette = (png_colorp)png_malloc(png_ptr, PNG_MAX_PALETTE_LENGTH + * png_sizeof(png_color)); + /* ... Set palette colors ... */ + png_set_PLTE(png_ptr, info_ptr, palette, PNG_MAX_PALETTE_LENGTH); + /* You must not free palette here, because png_set_PLTE only makes a link to + * the palette that you malloced. Wait until you are about to destroy + * the png structure. + */ + + /* Optional significant bit (sBIT) chunk */ + png_color_8 sig_bit; + + /* If we are dealing with a grayscale image then */ + sig_bit.gray = true_bit_depth; + + /* Otherwise, if we are dealing with a color image then */ + sig_bit.red = true_red_bit_depth; + sig_bit.green = true_green_bit_depth; + sig_bit.blue = true_blue_bit_depth; + + /* If the image has an alpha channel then */ + sig_bit.alpha = true_alpha_bit_depth; + + png_set_sBIT(png_ptr, info_ptr, &sig_bit); + + + /* Optional gamma chunk is strongly suggested if you have any guess + * as to the correct gamma of the image. + */ + png_set_gAMA(png_ptr, info_ptr, gamma); + + /* Optionally write comments into the image */ + text_ptr[0].key = "Title"; + text_ptr[0].text = "Mona Lisa"; + text_ptr[0].compression = PNG_TEXT_COMPRESSION_NONE; + text_ptr[0].itxt_length = 0; + text_ptr[0].lang = NULL; + text_ptr[0].lang_key = NULL; + text_ptr[1].key = "Author"; + text_ptr[1].text = "Leonardo DaVinci"; + text_ptr[1].compression = PNG_TEXT_COMPRESSION_NONE; + text_ptr[1].itxt_length = 0; + text_ptr[1].lang = NULL; + text_ptr[1].lang_key = NULL; + text_ptr[2].key = "Description"; + text_ptr[2].text = "<long text>"; + text_ptr[2].compression = PNG_TEXT_COMPRESSION_zTXt; + text_ptr[2].itxt_length = 0; + text_ptr[2].lang = NULL; + text_ptr[2].lang_key = NULL; + png_set_text(png_ptr, info_ptr, text_ptr, 3); + + /* Other optional chunks like cHRM, bKGD, tRNS, tIME, oFFs, pHYs */ + + /* Note that if sRGB is present the gAMA and cHRM chunks must be ignored + * on read and, if your application chooses to write them, they must + * be written in accordance with the sRGB profile + */ + + /* Write the file header information. REQUIRED */ + png_write_info(png_ptr, info_ptr); + + /* If you want, you can write the info in two steps, in case you need to + * write your private chunk ahead of PLTE: + * + * png_write_info_before_PLTE(write_ptr, write_info_ptr); + * write_my_chunk(); + * png_write_info(png_ptr, info_ptr); + * + * However, given the level of known- and unknown-chunk support in 1.2.0 + * and up, this should no longer be necessary. + */ + + /* Once we write out the header, the compression type on the text + * chunks gets changed to PNG_TEXT_COMPRESSION_NONE_WR or + * PNG_TEXT_COMPRESSION_zTXt_WR, so it doesn't get written out again + * at the end. + */ + + /* Set up the transformations you want. Note that these are + * all optional. Only call them if you want them. + */ + + /* Invert monochrome pixels */ + png_set_invert_mono(png_ptr); + + /* Shift the pixels up to a legal bit depth and fill in + * as appropriate to correctly scale the image. + */ + png_set_shift(png_ptr, &sig_bit); + + /* Pack pixels into bytes */ + png_set_packing(png_ptr); + + /* Swap location of alpha bytes from ARGB to RGBA */ + png_set_swap_alpha(png_ptr); + + /* Get rid of filler (OR ALPHA) bytes, pack XRGB/RGBX/ARGB/RGBA into + * RGB (4 channels -> 3 channels). The second parameter is not used. + */ + png_set_filler(png_ptr, 0, PNG_FILLER_BEFORE); + + /* Flip BGR pixels to RGB */ + png_set_bgr(png_ptr); + + /* Swap bytes of 16-bit files to most significant byte first */ + png_set_swap(png_ptr); + + /* Swap bits of 1, 2, 4 bit packed pixel formats */ + png_set_packswap(png_ptr); + + /* Turn on interlace handling if you are not using png_write_image() */ + if (interlacing) + number_passes = png_set_interlace_handling(png_ptr); + + else + number_passes = 1; + + /* The easiest way to write the image (you may have a different memory + * layout, however, so choose what fits your needs best). You need to + * use the first method if you aren't handling interlacing yourself. + */ + png_uint_32 k, height, width; + png_byte image[height][width*bytes_per_pixel]; + png_bytep row_pointers[height]; + + if (height > PNG_UINT_32_MAX/png_sizeof(png_bytep)) + png_error (png_ptr, "Image is too tall to process in memory"); + + for (k = 0; k < height; k++) + row_pointers[k] = image + k*width*bytes_per_pixel; + + /* One of the following output methods is REQUIRED */ + +#ifdef entire /* Write out the entire image data in one call */ + png_write_image(png_ptr, row_pointers); + + /* The other way to write the image - deal with interlacing */ + +#else no_entire /* Write out the image data by one or more scanlines */ + + /* The number of passes is either 1 for non-interlaced images, + * or 7 for interlaced images. + */ + for (pass = 0; pass < number_passes; pass++) + { + /* Write a few rows at a time. */ + png_write_rows(png_ptr, &row_pointers[first_row], number_of_rows); + + /* If you are only writing one row at a time, this works */ + for (y = 0; y < height; y++) + png_write_rows(png_ptr, &row_pointers[y], 1); + } +#endif no_entire /* Use only one output method */ + + /* You can write optional chunks like tEXt, zTXt, and tIME at the end + * as well. Shouldn't be necessary in 1.2.0 and up as all the public + * chunks are supported and you can use png_set_unknown_chunks() to + * register unknown chunks into the info structure to be written out. + */ + + /* It is REQUIRED to call this to finish writing the rest of the file */ + png_write_end(png_ptr, info_ptr); +#endif hilevel + + /* If you png_malloced a palette, free it here (don't free info_ptr->palette, + * as recommended in versions 1.0.5m and earlier of this example; if + * libpng mallocs info_ptr->palette, libpng will free it). If you + * allocated it with malloc() instead of png_malloc(), use free() instead + * of png_free(). + */ + png_free(png_ptr, palette); + palette = NULL; + + /* Similarly, if you png_malloced any data that you passed in with + * png_set_something(), such as a hist or trans array, free it here, + * when you can be sure that libpng is through with it. + */ + png_free(png_ptr, trans); + trans = NULL; + /* Whenever you use png_free() it is a good idea to set the pointer to + * NULL in case your application inadvertently tries to png_free() it + * again. When png_free() sees a NULL it returns without action, thus + * avoiding the double-free security problem. + */ + + /* Clean up after the write, and free any memory allocated */ + png_destroy_write_struct(&png_ptr, &info_ptr); + + /* Close the file */ + fclose(fp); + + /* That's it */ + return (OK); +} + +#endif /* if 0 */ diff --git a/src/3rdparty/libpng/libpng-manual.txt b/src/3rdparty/libpng/libpng-manual.txt new file mode 100644 index 0000000000..77adf7aec8 --- /dev/null +++ b/src/3rdparty/libpng/libpng-manual.txt @@ -0,0 +1,4136 @@ +libpng-manual.txt - A description on how to use and modify libpng + + libpng version 1.5.1 - February 3, 2011 + Updated and distributed by Glenn Randers-Pehrson + <glennrp at users.sourceforge.net> + Copyright (c) 1998-2011 Glenn Randers-Pehrson + + This document is released under the libpng license. + For conditions of distribution and use, see the disclaimer + and license in png.h + + Based on: + + libpng versions 0.97, January 1998, through 1.5.1 - February 3, 2011 + Updated and distributed by Glenn Randers-Pehrson + Copyright (c) 1998-2011 Glenn Randers-Pehrson + + libpng 1.0 beta 6 version 0.96 May 28, 1997 + Updated and distributed by Andreas Dilger + Copyright (c) 1996, 1997 Andreas Dilger + + libpng 1.0 beta 2 - version 0.88 January 26, 1996 + For conditions of distribution and use, see copyright + notice in png.h. Copyright (c) 1995, 1996 Guy Eric + Schalnat, Group 42, Inc. + + Updated/rewritten per request in the libpng FAQ + Copyright (c) 1995, 1996 Frank J. T. Wojcik + December 18, 1995 & January 20, 1996 + +I. Introduction + +This file describes how to use and modify the PNG reference library +(known as libpng) for your own use. There are five sections to this +file: introduction, structures, reading, writing, and modification and +configuration notes for various special platforms. In addition to this +file, example.c is a good starting point for using the library, as +it is heavily commented and should include everything most people +will need. We assume that libpng is already installed; see the +INSTALL file for instructions on how to install libpng. + +For examples of libpng usage, see the files "example.c", "pngtest.c", +and the files in the "contrib" directory, all of which are included in +the libpng distribution. + +Libpng was written as a companion to the PNG specification, as a way +of reducing the amount of time and effort it takes to support the PNG +file format in application programs. + +The PNG specification (second edition), November 2003, is available as +a W3C Recommendation and as an ISO Standard (ISO/IEC 15948:2003 (E)) at +<http://www.w3.org/TR/2003/REC-PNG-20031110/ +The W3C and ISO documents have identical technical content. + +The PNG-1.2 specification is available at +<http://www.libpng.org/pub/png/documents/>. It is technically equivalent +to the PNG specification (second edition) but has some additional material. + +The PNG-1.0 specification is available +as RFC 2083 <http://www.libpng.org/pub/png/documents/> and as a +W3C Recommendation <http://www.w3.org/TR/REC.png.html>. + +Some additional chunks are described in the special-purpose public chunks +documents at <http://www.libpng.org/pub/png/documents/>. + +Other information +about PNG, and the latest version of libpng, can be found at the PNG home +page, <http://www.libpng.org/pub/png/>. + +Most users will not have to modify the library significantly; advanced +users may want to modify it more. All attempts were made to make it as +complete as possible, while keeping the code easy to understand. +Currently, this library only supports C. Support for other languages +is being considered. + +Libpng has been designed to handle multiple sessions at one time, +to be easily modifiable, to be portable to the vast majority of +machines (ANSI, K&R, 16-, 32-, and 64-bit) available, and to be easy +to use. The ultimate goal of libpng is to promote the acceptance of +the PNG file format in whatever way possible. While there is still +work to be done (see the TODO file), libpng should cover the +majority of the needs of its users. + +Libpng uses zlib for its compression and decompression of PNG files. +Further information about zlib, and the latest version of zlib, can +be found at the zlib home page, <http://www.info-zip.org/pub/infozip/zlib/>. +The zlib compression utility is a general purpose utility that is +useful for more than PNG files, and can be used without libpng. +See the documentation delivered with zlib for more details. +You can usually find the source files for the zlib utility wherever you +find the libpng source files. + +Libpng is thread safe, provided the threads are using different +instances of the structures. Each thread should have its own +png_struct and png_info instances, and thus its own image. +Libpng does not protect itself against two threads using the +same instance of a structure. + +II. Structures + +There are two main structures that are important to libpng, png_struct +and png_info. Both are internal structures that are no longer exposed +in the libpng interface (as of libpng 1.5.0). + +The png_info structure is designed to provide information about the +PNG file. At one time, the fields of png_info were intended to be +directly accessible to the user. However, this tended to cause problems +with applications using dynamically loaded libraries, and as a result +a set of interface functions for png_info (the png_get_*() and png_set_*() +functions) was developed. + +The png_struct structure is the object used by the library to decode a +single image. As of 1.5.0 this structure is also not exposed. + +Almost all libpng APIs require a pointer to a png_struct as the first argument. +Many (in particular the png_set and png_get APIs) also require a pointer +to png_info as the second argument. Some application visible macros +defined in png.h designed for basic data access (reading and writing +integers in the PNG format) break this rule, but it's almost always safe +to assume that a (png_struct*) has to be passed to call an API function. + +The png.h header file is an invaluable reference for programming with libpng. +And while I'm on the topic, make sure you include the libpng header file: + +#include <png.h> + +Types + +The png.h header file defines a number of integral types used by the +APIs. Most of these are fairly obvious; for example types corresponding +to integers of particular sizes and types for passing color values. + +One exception is how non-integral numbers are handled. For application +convenience most APIs that take such numbers have C (double) arguments, +however internally PNG, and libpng, use 32 bit signed integers and encode +the value by multiplying by 100,000. As of libpng 1.5.0 a convenience +macro PNG_FP_1 is defined in png.h along with a type (png_fixed_point) +which is simply (png_int_32). + +All APIs that take (double) arguments also have an matching API that +takes the corresponding fixed point integer arguments. The fixed point +API has the same name as the floating point one with _fixed appended. +The actual range of values permitted in the APIs is frequently less than +the full range of (png_fixed_point) (-21474 to +21474). When APIs require +a non-negative argument the type is recorded as png_uint_32 above. Consult +the header file and the text below for more information. + +Special care must be take with sCAL chunk handling because the chunk itself +uses non-integral values encoded as strings containing decimal floating point +numbers. See the comments in the header file. + +Configuration + +The main header file function declarations are frequently protected by C +preprocessing directives of the form: + + #ifdef PNG_feature_SUPPORTED + declare-function + #endif + +The library can be built without support for these APIs, although a +standard build will have all implemented APIs. Application programs +should check the feature macros before using an API for maximum +portability. From libpng 1.5.0 the feature macros set during the build +of libpng are recorded in the header file "pnglibconf.h" and this file +is always included by png.h. + +If you don't need to change the library configuration from the default skip to +the next section ("Reading"). + +Notice that some of the makefiles in the 'scripts' directory and (in 1.5.0) all +of the build project files in the 'projects' directory simply copy +scripts/pnglibconf.h.prebuilt to pnglibconf.h. This means that these build +systems do not permit easy auto-configuration of the library - they only +support the default configuration. + +The easiest way to make minor changes to the libpng configuration when +auto-configuration is supported is to add definitions to the command line +using (typically) CPPFLAGS. For example: + +CPPFLAGS=-DPNG_NO_FLOATING_ARITHMETIC + +will change the internal libpng math implementation for gamma correction and +other arithmetic calculations to fixed point, avoiding the need for fast +floating point support. The result can be seen in the generated pnglibconf.h - +make sure it contains the changed feature macro setting. + +If you need to make more extensive configuration changes - more than one or two +feature macro settings - you can either add -DPNG_USER_CONFIG to the build +command line and put a list of feature macro settings in pngusr.h or you can set +DFA_XTRA (a makefile variable) to a file containing the same information in the +form of 'option' settings. + +A. Changing pnglibconf.h + +A variety of methods exist to build libpng. Not all of these support +reconfiguration of pnglibconf.h. To reconfigure pnglibconf.h it must either be +rebuilt from scripts/pnglibconf.dfa using awk or it must be edited by hand. + +Hand editing is achieved by copying scripts/pnglibconf.h.prebuilt and changing +the lines defining the supported features, paying very close attention to the +'option' information in scripts/pnglibconf.dfa that describes those features and +their requirements. This is easy to get wrong. + +B. Configuration using DFA_XTRA + +Rebuilding from pnglibconf.dfa is easy if a functioning 'awk', or a later +variant such as 'nawk' or 'gawk', is available. The configure build will +automatically find an appropriate awk and build pnglibconf.h. +scripts/pnglibconf.mak contains a set of make rules for doing the same thing if +configure is not used, and many of the makefiles in the scripts directory use +this approach. + +When rebuilding simply write new file containing changed options and set +DFA_XTRA to the name of this file. This causes the build to append the new file +to the end of scripts/pnglibconf.dfa. pngusr.dfa should contain lines of the +following forms: + +everything = off + +This turns all optional features off. Include it at the start of pngusr.dfa to +make it easier to build a minimal configuration. You will need to turn at least +some features on afterward to enable either reading or writing code, or both. + +option feature on +option feature off + +Enable or disable a single feature. This will automatically enable other +features required by a feature that is turned on or disable other features that +require a feature which is turned off. Conflicting settings will cause an error +message to be emitted by awk. + +setting feature default value + +Changes the default value of setting 'feature' to 'value'. There are a small +number of settings listed at the top of pnglibconf.h, they are documented in the +source code. Most of these values have performance implications for the library +but most of them have no visible effect on the API. Some can also be overridden +from the API. + +C. Configuration using PNG_USR_CONFIG + +If -DPNG_USR_CONFIG is added to the CFLAGS when pnglibconf.h is built the file +pngusr.h will automatically be included before the options in +scripts/pnglibconf.dfa are processed. pngusr.h should contain only macro +definitions turning features on or off or setting settings. + +Apart from the global setting "everything = off" all the options listed above +can be set using macros in pngusr.h: + +#define PNG_feature_SUPPORTED + +is equivalent to: + +option feature on + +#define PNG_NO_feature + +is equivalent to: + +option feature off + +#define PNG_feature value + +is equivalent to: + +setting feature default value + +Notice that in both cases, pngusr.dfa and pngusr.h, the contents of the +pngusr file you supply override the contents of scripts/pnglibconf.dfa + +If confusing or incomprehensible behavior results it is possible to +examine the intermediate file pnglibconf.dfn to find the full set of +dependency information for each setting and option. Simply locate the +feature in the file and read the C comments that precede it. + +III. Reading + +We'll now walk you through the possible functions to call when reading +in a PNG file sequentially, briefly explaining the syntax and purpose +of each one. See example.c and png.h for more detail. While +progressive reading is covered in the next section, you will still +need some of the functions discussed in this section to read a PNG +file. + +Setup + +You will want to do the I/O initialization(*) before you get into libpng, +so if it doesn't work, you don't have much to undo. Of course, you +will also want to insure that you are, in fact, dealing with a PNG +file. Libpng provides a simple check to see if a file is a PNG file. +To use it, pass in the first 1 to 8 bytes of the file to the function +png_sig_cmp(), and it will return 0 (false) if the bytes match the +corresponding bytes of the PNG signature, or nonzero (true) otherwise. +Of course, the more bytes you pass in, the greater the accuracy of the +prediction. + +If you are intending to keep the file pointer open for use in libpng, +you must ensure you don't read more than 8 bytes from the beginning +of the file, and you also have to make a call to png_set_sig_bytes_read() +with the number of bytes you read from the beginning. Libpng will +then only check the bytes (if any) that your program didn't read. + +(*): If you are not using the standard I/O functions, you will need +to replace them with custom functions. See the discussion under +Customizing libpng. + + + FILE *fp = fopen(file_name, "rb"); + if (!fp) + { + return (ERROR); + } + + fread(header, 1, number, fp); + is_png = !png_sig_cmp(header, 0, number); + + if (!is_png) + { + return (NOT_PNG); + } + + +Next, png_struct and png_info need to be allocated and initialized. In +order to ensure that the size of these structures is correct even with a +dynamically linked libpng, there are functions to initialize and +allocate the structures. We also pass the library version, optional +pointers to error handling functions, and a pointer to a data struct for +use by the error functions, if necessary (the pointer and functions can +be NULL if the default error handlers are to be used). See the section +on Changes to Libpng below regarding the old initialization functions. +The structure allocation functions quietly return NULL if they fail to +create the structure, so your application should check for that. + + png_structp png_ptr = png_create_read_struct + (PNG_LIBPNG_VER_STRING, (png_voidp)user_error_ptr, + user_error_fn, user_warning_fn); + + if (!png_ptr) + return (ERROR); + + png_infop info_ptr = png_create_info_struct(png_ptr); + + if (!info_ptr) + { + png_destroy_read_struct(&png_ptr, + (png_infopp)NULL, (png_infopp)NULL); + return (ERROR); + } + + png_infop end_info = png_create_info_struct(png_ptr); + + if (!end_info) + { + png_destroy_read_struct(&png_ptr, &info_ptr, + (png_infopp)NULL); + return (ERROR); + } + +If you want to use your own memory allocation routines, +use a libpng that was built with PNG_USER_MEM_SUPPORTED defined, and use +png_create_read_struct_2() instead of png_create_read_struct(): + + png_structp png_ptr = png_create_read_struct_2 + (PNG_LIBPNG_VER_STRING, (png_voidp)user_error_ptr, + user_error_fn, user_warning_fn, (png_voidp) + user_mem_ptr, user_malloc_fn, user_free_fn); + +The error handling routines passed to png_create_read_struct() +and the memory alloc/free routines passed to png_create_struct_2() +are only necessary if you are not using the libpng supplied error +handling and memory alloc/free functions. + +When libpng encounters an error, it expects to longjmp back +to your routine. Therefore, you will need to call setjmp and pass +your png_jmpbuf(png_ptr). If you read the file from different +routines, you will need to update the jmpbuf field every time you enter +a new routine that will call a png_*() function. + +See your documentation of setjmp/longjmp for your compiler for more +information on setjmp/longjmp. See the discussion on libpng error +handling in the Customizing Libpng section below for more information +on the libpng error handling. If an error occurs, and libpng longjmp's +back to your setjmp, you will want to call png_destroy_read_struct() to +free any memory. + + if (setjmp(png_jmpbuf(png_ptr))) + { + png_destroy_read_struct(&png_ptr, &info_ptr, + &end_info); + fclose(fp); + return (ERROR); + } + +If you would rather avoid the complexity of setjmp/longjmp issues, +you can compile libpng with PNG_NO_SETJMP, in which case +errors will result in a call to PNG_ABORT() which defaults to abort(). + +You can #define PNG_ABORT() to a function that does something +more useful than abort(), as long as your function does not +return. + +Now you need to set up the input code. The default for libpng is to +use the C function fread(). If you use this, you will need to pass a +valid FILE * in the function png_init_io(). Be sure that the file is +opened in binary mode. If you wish to handle reading data in another +way, you need not call the png_init_io() function, but you must then +implement the libpng I/O methods discussed in the Customizing Libpng +section below. + + png_init_io(png_ptr, fp); + +If you had previously opened the file and read any of the signature from +the beginning in order to see if this was a PNG file, you need to let +libpng know that there are some bytes missing from the start of the file. + + png_set_sig_bytes(png_ptr, number); + +You can change the zlib compression buffer size to be used while +reading compressed data with + + png_set_compression_buffer_size(png_ptr, buffer_size); + +where the default size is 8192 bytes. Note that the buffer size +is changed immediately and the buffer is reallocated immediately, +instead of setting a flag to be acted upon later. + +If you want CRC errors to be handled in a different manner than +the default, use + + png_set_crc_action(png_ptr, crit_action, ancil_action); + +The values for png_set_crc_action() say how libpng is to handle CRC errors in +ancillary and critical chunks, and whether to use the data contained +therein. Note that it is impossible to "discard" data in a critical +chunk. + +Choices for (int) crit_action are + PNG_CRC_DEFAULT 0 error/quit + PNG_CRC_ERROR_QUIT 1 error/quit + PNG_CRC_WARN_USE 3 warn/use data + PNG_CRC_QUIET_USE 4 quiet/use data + PNG_CRC_NO_CHANGE 5 use the current value + +Choices for (int) ancil_action are + PNG_CRC_DEFAULT 0 error/quit + PNG_CRC_ERROR_QUIT 1 error/quit + PNG_CRC_WARN_DISCARD 2 warn/discard data + PNG_CRC_WARN_USE 3 warn/use data + PNG_CRC_QUIET_USE 4 quiet/use data + PNG_CRC_NO_CHANGE 5 use the current value + +Setting up callback code + +You can set up a callback function to handle any unknown chunks in the +input stream. You must supply the function + + read_chunk_callback(png_structp png_ptr, + png_unknown_chunkp chunk); + { + /* The unknown chunk structure contains your + chunk data, along with similar data for any other + unknown chunks: */ + + png_byte name[5]; + png_byte *data; + png_size_t size; + + /* Note that libpng has already taken care of + the CRC handling */ + + /* put your code here. Search for your chunk in the + unknown chunk structure, process it, and return one + of the following: */ + + return (-n); /* chunk had an error */ + return (0); /* did not recognize */ + return (n); /* success */ + } + +(You can give your function another name that you like instead of +"read_chunk_callback") + +To inform libpng about your function, use + + png_set_read_user_chunk_fn(png_ptr, user_chunk_ptr, + read_chunk_callback); + +This names not only the callback function, but also a user pointer that +you can retrieve with + + png_get_user_chunk_ptr(png_ptr); + +If you call the png_set_read_user_chunk_fn() function, then all unknown +chunks will be saved when read, in case your callback function will need +one or more of them. This behavior can be changed with the +png_set_keep_unknown_chunks() function, described below. + +At this point, you can set up a callback function that will be +called after each row has been read, which you can use to control +a progress meter or the like. It's demonstrated in pngtest.c. +You must supply a function + + void read_row_callback(png_structp png_ptr, + png_uint_32 row, int pass); + { + /* put your code here */ + } + +(You can give it another name that you like instead of "read_row_callback") + +To inform libpng about your function, use + + png_set_read_status_fn(png_ptr, read_row_callback); + +Unknown-chunk handling + +Now you get to set the way the library processes unknown chunks in the +input PNG stream. Both known and unknown chunks will be read. Normal +behavior is that known chunks will be parsed into information in +various info_ptr members while unknown chunks will be discarded. This +behavior can be wasteful if your application will never use some known +chunk types. To change this, you can call: + + png_set_keep_unknown_chunks(png_ptr, keep, + chunk_list, num_chunks); + keep - 0: default unknown chunk handling + 1: ignore; do not keep + 2: keep only if safe-to-copy + 3: keep even if unsafe-to-copy + + You can use these definitions: + PNG_HANDLE_CHUNK_AS_DEFAULT 0 + PNG_HANDLE_CHUNK_NEVER 1 + PNG_HANDLE_CHUNK_IF_SAFE 2 + PNG_HANDLE_CHUNK_ALWAYS 3 + + chunk_list - list of chunks affected (a byte string, + five bytes per chunk, NULL or '\0' if + num_chunks is 0) + + num_chunks - number of chunks affected; if 0, all + unknown chunks are affected. If nonzero, + only the chunks in the list are affected + +Unknown chunks declared in this way will be saved as raw data onto a +list of png_unknown_chunk structures. If a chunk that is normally +known to libpng is named in the list, it will be handled as unknown, +according to the "keep" directive. If a chunk is named in successive +instances of png_set_keep_unknown_chunks(), the final instance will +take precedence. The IHDR and IEND chunks should not be named in +chunk_list; if they are, libpng will process them normally anyway. + +Here is an example of the usage of png_set_keep_unknown_chunks(), +where the private "vpAg" chunk will later be processed by a user chunk +callback function: + + png_byte vpAg[5]={118, 112, 65, 103, (png_byte) '\0'}; + + #if defined(PNG_UNKNOWN_CHUNKS_SUPPORTED) + png_byte unused_chunks[]= + { + 104, 73, 83, 84, (png_byte) '\0', /* hIST */ + 105, 84, 88, 116, (png_byte) '\0', /* iTXt */ + 112, 67, 65, 76, (png_byte) '\0', /* pCAL */ + 115, 67, 65, 76, (png_byte) '\0', /* sCAL */ + 115, 80, 76, 84, (png_byte) '\0', /* sPLT */ + 116, 73, 77, 69, (png_byte) '\0', /* tIME */ + }; + #endif + + ... + + #if defined(PNG_UNKNOWN_CHUNKS_SUPPORTED) + /* ignore all unknown chunks: */ + png_set_keep_unknown_chunks(read_ptr, 1, NULL, 0); + + /* except for vpAg: */ + png_set_keep_unknown_chunks(read_ptr, 2, vpAg, 1); + + /* also ignore unused known chunks: */ + png_set_keep_unknown_chunks(read_ptr, 1, unused_chunks, + (int)sizeof(unused_chunks)/5); + #endif + +User limits + +The PNG specification allows the width and height of an image to be as +large as 2^31-1 (0x7fffffff), or about 2.147 billion rows and columns. +Since very few applications really need to process such large images, +we have imposed an arbitrary 1-million limit on rows and columns. +Larger images will be rejected immediately with a png_error() call. If +you wish to override this limit, you can use + + png_set_user_limits(png_ptr, width_max, height_max); + +to set your own limits, or use width_max = height_max = 0x7fffffffL +to allow all valid dimensions (libpng may reject some very large images +anyway because of potential buffer overflow conditions). + +You should put this statement after you create the PNG structure and +before calling png_read_info(), png_read_png(), or png_process_data(). +If you need to retrieve the limits that are being applied, use + + width_max = png_get_user_width_max(png_ptr); + height_max = png_get_user_height_max(png_ptr); + +The PNG specification sets no limit on the number of ancillary chunks +allowed in a PNG datastream. You can impose a limit on the total number +of sPLT, tEXt, iTXt, zTXt, and unknown chunks that will be stored, with + + png_set_chunk_cache_max(png_ptr, user_chunk_cache_max); + +where 0x7fffffffL means unlimited. You can retrieve this limit with + + chunk_cache_max = png_get_chunk_cache_max(png_ptr); + +This limit also applies to the number of buffers that can be allocated +by png_decompress_chunk() while decompressing iTXt, zTXt, and iCCP chunks. + +You can also set a limit on the amount of memory that a compressed chunk +other than IDAT can occupy, with + + png_set_chunk_malloc_max(png_ptr, user_chunk_malloc_max); + +and you can retrieve the limit with + + chunk_malloc_max = png_get_chunk_malloc_max(png_ptr); + +Any chunks that would cause either of these limits to be exceeded will +be ignored. + +The high-level read interface + +At this point there are two ways to proceed; through the high-level +read interface, or through a sequence of low-level read operations. +You can use the high-level interface if (a) you are willing to read +the entire image into memory, and (b) the input transformations +you want to do are limited to the following set: + + PNG_TRANSFORM_IDENTITY No transformation + PNG_TRANSFORM_STRIP_16 Strip 16-bit samples to + 8 bits + PNG_TRANSFORM_STRIP_ALPHA Discard the alpha channel + PNG_TRANSFORM_PACKING Expand 1, 2 and 4-bit + samples to bytes + PNG_TRANSFORM_PACKSWAP Change order of packed + pixels to LSB first + PNG_TRANSFORM_EXPAND Perform set_expand() + PNG_TRANSFORM_INVERT_MONO Invert monochrome images + PNG_TRANSFORM_SHIFT Normalize pixels to the + sBIT depth + PNG_TRANSFORM_BGR Flip RGB to BGR, RGBA + to BGRA + PNG_TRANSFORM_SWAP_ALPHA Flip RGBA to ARGB or GA + to AG + PNG_TRANSFORM_INVERT_ALPHA Change alpha from opacity + to transparency + PNG_TRANSFORM_SWAP_ENDIAN Byte-swap 16-bit samples + PNG_TRANSFORM_GRAY_TO_RGB Expand grayscale samples + to RGB (or GA to RGBA) + +(This excludes setting a background color, doing gamma transformation, +quantizing, and setting filler.) If this is the case, simply do this: + + png_read_png(png_ptr, info_ptr, png_transforms, NULL) + +where png_transforms is an integer containing the bitwise OR of some +set of transformation flags. This call is equivalent to png_read_info(), +followed the set of transformations indicated by the transform mask, +then png_read_image(), and finally png_read_end(). + +(The final parameter of this call is not yet used. Someday it might point +to transformation parameters required by some future input transform.) + +You must use png_transforms and not call any png_set_transform() functions +when you use png_read_png(). + +After you have called png_read_png(), you can retrieve the image data +with + + row_pointers = png_get_rows(png_ptr, info_ptr); + +where row_pointers is an array of pointers to the pixel data for each row: + + png_bytep row_pointers[height]; + +If you know your image size and pixel size ahead of time, you can allocate +row_pointers prior to calling png_read_png() with + + if (height > PNG_UINT_32_MAX/png_sizeof(png_byte)) + png_error (png_ptr, + "Image is too tall to process in memory"); + + if (width > PNG_UINT_32_MAX/pixel_size) + png_error (png_ptr, + "Image is too wide to process in memory"); + + row_pointers = png_malloc(png_ptr, + height*png_sizeof(png_bytep)); + + for (int i=0; i<height, i++) + row_pointers[i]=NULL; /* security precaution */ + + for (int i=0; i<height, i++) + row_pointers[i]=png_malloc(png_ptr, + width*pixel_size); + + png_set_rows(png_ptr, info_ptr, &row_pointers); + +Alternatively you could allocate your image in one big block and define +row_pointers[i] to point into the proper places in your block. + +If you use png_set_rows(), the application is responsible for freeing +row_pointers (and row_pointers[i], if they were separately allocated). + +If you don't allocate row_pointers ahead of time, png_read_png() will +do it, and it'll be free'ed by libpng when you call png_destroy_*(). + +The low-level read interface + +If you are going the low-level route, you are now ready to read all +the file information up to the actual image data. You do this with a +call to png_read_info(). + + png_read_info(png_ptr, info_ptr); + +This will process all chunks up to but not including the image data. + +Querying the info structure + +Functions are used to get the information from the info_ptr once it +has been read. Note that these fields may not be completely filled +in until png_read_end() has read the chunk data following the image. + + png_get_IHDR(png_ptr, info_ptr, &width, &height, + &bit_depth, &color_type, &interlace_type, + &compression_type, &filter_method); + + width - holds the width of the image + in pixels (up to 2^31). + + height - holds the height of the image + in pixels (up to 2^31). + + bit_depth - holds the bit depth of one of the + image channels. (valid values are + 1, 2, 4, 8, 16 and depend also on + the color_type. See also + significant bits (sBIT) below). + + color_type - describes which color/alpha channels + are present. + PNG_COLOR_TYPE_GRAY + (bit depths 1, 2, 4, 8, 16) + PNG_COLOR_TYPE_GRAY_ALPHA + (bit depths 8, 16) + PNG_COLOR_TYPE_PALETTE + (bit depths 1, 2, 4, 8) + PNG_COLOR_TYPE_RGB + (bit_depths 8, 16) + PNG_COLOR_TYPE_RGB_ALPHA + (bit_depths 8, 16) + + PNG_COLOR_MASK_PALETTE + PNG_COLOR_MASK_COLOR + PNG_COLOR_MASK_ALPHA + + interlace_type - (PNG_INTERLACE_NONE or + PNG_INTERLACE_ADAM7) + + compression_type - (must be PNG_COMPRESSION_TYPE_BASE + for PNG 1.0) + + filter_method - (must be PNG_FILTER_TYPE_BASE + for PNG 1.0, and can also be + PNG_INTRAPIXEL_DIFFERENCING if + the PNG datastream is embedded in + a MNG-1.0 datastream) + + Any or all of interlace_type, compression_type, or + filter_method can be NULL if you are + not interested in their values. + + Note that png_get_IHDR() returns 32-bit data into + the application's width and height variables. + This is an unsafe situation if these are 16-bit + variables. In such situations, the + png_get_image_width() and png_get_image_height() + functions described below are safer. + + width = png_get_image_width(png_ptr, + info_ptr); + + height = png_get_image_height(png_ptr, + info_ptr); + + bit_depth = png_get_bit_depth(png_ptr, + info_ptr); + + color_type = png_get_color_type(png_ptr, + info_ptr); + + interlace_type = png_get_interlace_type(png_ptr, + info_ptr); + + compression_type = png_get_compression_type(png_ptr, + info_ptr); + + filter_method = png_get_filter_type(png_ptr, + info_ptr); + + channels = png_get_channels(png_ptr, info_ptr); + + channels - number of channels of info for the + color type (valid values are 1 (GRAY, + PALETTE), 2 (GRAY_ALPHA), 3 (RGB), + 4 (RGB_ALPHA or RGB + filler byte)) + + rowbytes = png_get_rowbytes(png_ptr, info_ptr); + + rowbytes - number of bytes needed to hold a row + + signature = png_get_signature(png_ptr, info_ptr); + + signature - holds the signature read from the + file (if any). The data is kept in + the same offset it would be if the + whole signature were read (i.e. if an + application had already read in 4 + bytes of signature before starting + libpng, the remaining 4 bytes would + be in signature[4] through signature[7] + (see png_set_sig_bytes())). + +These are also important, but their validity depends on whether the chunk +has been read. The png_get_valid(png_ptr, info_ptr, PNG_INFO_<chunk>) and +png_get_<chunk>(png_ptr, info_ptr, ...) functions return non-zero if the +data has been read, or zero if it is missing. The parameters to the +png_get_<chunk> are set directly if they are simple data types, or a +pointer into the info_ptr is returned for any complex types. + + png_get_PLTE(png_ptr, info_ptr, &palette, + &num_palette); + + palette - the palette for the file + (array of png_color) + + num_palette - number of entries in the palette + + png_get_gAMA(png_ptr, info_ptr, &file_gamma); + png_get_gAMA_fixed(png_ptr, info_ptr, &int_file_gamma); + + file_gamma - the gamma at which the file is + written (PNG_INFO_gAMA) + + int_file_gamma - 100,000 times the gamma at which the + file is written + + png_get_sRGB(png_ptr, info_ptr, &srgb_intent); + + file_srgb_intent - the rendering intent (PNG_INFO_sRGB) + The presence of the sRGB chunk + means that the pixel data is in the + sRGB color space. This chunk also + implies specific values of gAMA and + cHRM. + + png_get_iCCP(png_ptr, info_ptr, &name, + &compression_type, &profile, &proflen); + + name - The profile name. + + compression_type - The compression type; always + PNG_COMPRESSION_TYPE_BASE for PNG 1.0. + You may give NULL to this argument to + ignore it. + + profile - International Color Consortium color + profile data. May contain NULs. + + proflen - length of profile data in bytes. + + png_get_sBIT(png_ptr, info_ptr, &sig_bit); + + sig_bit - the number of significant bits for + (PNG_INFO_sBIT) each of the gray, + red, green, and blue channels, + whichever are appropriate for the + given color type (png_color_16) + + png_get_tRNS(png_ptr, info_ptr, &trans_alpha, + &num_trans, &trans_color); + + trans_alpha - array of alpha (transparency) + entries for palette (PNG_INFO_tRNS) + + num_trans - number of transparent entries + (PNG_INFO_tRNS) + + trans_color - graylevel or color sample values of + the single transparent color for + non-paletted images (PNG_INFO_tRNS) + + png_get_hIST(png_ptr, info_ptr, &hist); + (PNG_INFO_hIST) + + hist - histogram of palette (array of + png_uint_16) + + png_get_tIME(png_ptr, info_ptr, &mod_time); + + mod_time - time image was last modified + (PNG_VALID_tIME) + + png_get_bKGD(png_ptr, info_ptr, &background); + + background - background color (PNG_VALID_bKGD) + valid 16-bit red, green and blue + values, regardless of color_type + + num_comments = png_get_text(png_ptr, info_ptr, + &text_ptr, &num_text); + + num_comments - number of comments + + text_ptr - array of png_text holding image + comments + + text_ptr[i].compression - type of compression used + on "text" PNG_TEXT_COMPRESSION_NONE + PNG_TEXT_COMPRESSION_zTXt + PNG_ITXT_COMPRESSION_NONE + PNG_ITXT_COMPRESSION_zTXt + + text_ptr[i].key - keyword for comment. Must contain + 1-79 characters. + + text_ptr[i].text - text comments for current + keyword. Can be empty. + + text_ptr[i].text_length - length of text string, + after decompression, 0 for iTXt + + text_ptr[i].itxt_length - length of itxt string, + after decompression, 0 for tEXt/zTXt + + text_ptr[i].lang - language of comment (empty + string for unknown). + + text_ptr[i].lang_key - keyword in UTF-8 + (empty string for unknown). + + Note that the itxt_length, lang, and lang_key + members of the text_ptr structure only exist + when the library is built with iTXt chunk support. + + num_text - number of comments (same as + num_comments; you can put NULL here + to avoid the duplication) + + Note while png_set_text() will accept text, language, + and translated keywords that can be NULL pointers, the + structure returned by png_get_text will always contain + regular zero-terminated C strings. They might be + empty strings but they will never be NULL pointers. + + num_spalettes = png_get_sPLT(png_ptr, info_ptr, + &palette_ptr); + + num_spalettes - number of sPLT chunks read. + + palette_ptr - array of palette structures holding + contents of one or more sPLT chunks + read. + + png_get_oFFs(png_ptr, info_ptr, &offset_x, &offset_y, + &unit_type); + + offset_x - positive offset from the left edge + of the screen + + offset_y - positive offset from the top edge + of the screen + + unit_type - PNG_OFFSET_PIXEL, PNG_OFFSET_MICROMETER + + png_get_pHYs(png_ptr, info_ptr, &res_x, &res_y, + &unit_type); + + res_x - pixels/unit physical resolution in + x direction + + res_y - pixels/unit physical resolution in + x direction + + unit_type - PNG_RESOLUTION_UNKNOWN, + PNG_RESOLUTION_METER + + png_get_sCAL(png_ptr, info_ptr, &unit, &width, + &height) + + unit - physical scale units (an integer) + + width - width of a pixel in physical scale units + + height - height of a pixel in physical scale units + (width and height are doubles) + + png_get_sCAL_s(png_ptr, info_ptr, &unit, &width, + &height) + + unit - physical scale units (an integer) + + width - width of a pixel in physical scale units + + height - height of a pixel in physical scale units + (width and height are strings like "2.54") + + num_unknown_chunks = png_get_unknown_chunks(png_ptr, + info_ptr, &unknowns) + + unknowns - array of png_unknown_chunk + structures holding unknown chunks + + unknowns[i].name - name of unknown chunk + + unknowns[i].data - data of unknown chunk + + unknowns[i].size - size of unknown chunk's data + + unknowns[i].location - position of chunk in file + + The value of "i" corresponds to the order in which the + chunks were read from the PNG file or inserted with the + png_set_unknown_chunks() function. + +The data from the pHYs chunk can be retrieved in several convenient +forms: + + res_x = png_get_x_pixels_per_meter(png_ptr, + info_ptr) + + res_y = png_get_y_pixels_per_meter(png_ptr, + info_ptr) + + res_x_and_y = png_get_pixels_per_meter(png_ptr, + info_ptr) + + res_x = png_get_x_pixels_per_inch(png_ptr, + info_ptr) + + res_y = png_get_y_pixels_per_inch(png_ptr, + info_ptr) + + res_x_and_y = png_get_pixels_per_inch(png_ptr, + info_ptr) + + aspect_ratio = png_get_pixel_aspect_ratio(png_ptr, + info_ptr) + + Each of these returns 0 [signifying "unknown"] if + the data is not present or if res_x is 0; + res_x_and_y is 0 if res_x != res_y + + Note that because of the way the resolutions are + stored internally, the inch conversions won't + come out to exactly even number. For example, + 72 dpi is stored as 0.28346 pixels/meter, and + when this is retrieved it is 71.9988 dpi, so + be sure to round the returned value appropriately + if you want to display a reasonable-looking result. + +The data from the oFFs chunk can be retrieved in several convenient +forms: + + x_offset = png_get_x_offset_microns(png_ptr, info_ptr); + + y_offset = png_get_y_offset_microns(png_ptr, info_ptr); + + x_offset = png_get_x_offset_inches(png_ptr, info_ptr); + + y_offset = png_get_y_offset_inches(png_ptr, info_ptr); + + Each of these returns 0 [signifying "unknown" if both + x and y are 0] if the data is not present or if the + chunk is present but the unit is the pixel. The + remark about inexact inch conversions applies here + as well, because a value in inches can't always be + converted to microns and back without some loss + of precision. + +For more information, see the png_info definition in png.h and the +PNG specification for chunk contents. Be careful with trusting +rowbytes, as some of the transformations could increase the space +needed to hold a row (expand, filler, gray_to_rgb, etc.). +See png_read_update_info(), below. + +A quick word about text_ptr and num_text. PNG stores comments in +keyword/text pairs, one pair per chunk, with no limit on the number +of text chunks, and a 2^31 byte limit on their size. While there are +suggested keywords, there is no requirement to restrict the use to these +strings. It is strongly suggested that keywords and text be sensible +to humans (that's the point), so don't use abbreviations. Non-printing +symbols are not allowed. See the PNG specification for more details. +There is also no requirement to have text after the keyword. + +Keywords should be limited to 79 Latin-1 characters without leading or +trailing spaces, but non-consecutive spaces are allowed within the +keyword. It is possible to have the same keyword any number of times. +The text_ptr is an array of png_text structures, each holding a +pointer to a language string, a pointer to a keyword and a pointer to +a text string. The text string, language code, and translated +keyword may be empty or NULL pointers. The keyword/text +pairs are put into the array in the order that they are received. +However, some or all of the text chunks may be after the image, so, to +make sure you have read all the text chunks, don't mess with these +until after you read the stuff after the image. This will be +mentioned again below in the discussion that goes with png_read_end(). + +Input transformations + +After you've read the header information, you can set up the library +to handle any special transformations of the image data. The various +ways to transform the data will be described in the order that they +should occur. This is important, as some of these change the color +type and/or bit depth of the data, and some others only work on +certain color types and bit depths. Even though each transformation +checks to see if it has data that it can do something with, you should +make sure to only enable a transformation if it will be valid for the +data. For example, don't swap red and blue on grayscale data. + +The colors used for the background and transparency values should be +supplied in the same format/depth as the current image data. They +are stored in the same format/depth as the image data in a bKGD or tRNS +chunk, so this is what libpng expects for this data. The colors are +transformed to keep in sync with the image data when an application +calls the png_read_update_info() routine (see below). + +Data will be decoded into the supplied row buffers packed into bytes +unless the library has been told to transform it into another format. +For example, 4 bit/pixel paletted or grayscale data will be returned +2 pixels/byte with the leftmost pixel in the high-order bits of the +byte, unless png_set_packing() is called. 8-bit RGB data will be stored +in RGB RGB RGB format unless png_set_filler() or png_set_add_alpha() +is called to insert filler bytes, either before or after each RGB triplet. +16-bit RGB data will be returned RRGGBB RRGGBB, with the most significant +byte of the color value first, unless png_set_strip_16() is called to +transform it to regular RGB RGB triplets, or png_set_filler() or +png_set_add alpha() is called to insert filler bytes, either before or +after each RRGGBB triplet. Similarly, 8-bit or 16-bit grayscale data can +be modified with +png_set_filler(), png_set_add_alpha(), or png_set_strip_16(). + +The following code transforms grayscale images of less than 8 to 8 bits, +changes paletted images to RGB, and adds a full alpha channel if there is +transparency information in a tRNS chunk. This is most useful on +grayscale images with bit depths of 2 or 4 or if there is a multiple-image +viewing application that wishes to treat all images in the same way. + + if (color_type == PNG_COLOR_TYPE_PALETTE) + png_set_palette_to_rgb(png_ptr); + + if (color_type == PNG_COLOR_TYPE_GRAY && + bit_depth < 8) png_set_expand_gray_1_2_4_to_8(png_ptr); + + if (png_get_valid(png_ptr, info_ptr, + PNG_INFO_tRNS)) png_set_tRNS_to_alpha(png_ptr); + +These three functions are actually aliases for png_set_expand(), added +in libpng version 1.0.4, with the function names expanded to improve code +readability. In some future version they may actually do different +things. + +As of libpng version 1.2.9, png_set_expand_gray_1_2_4_to_8() was +added. It expands the sample depth without changing tRNS to alpha. + +As of libpng version 1.5.1, not all possible expansions are supported. + +In the following table, the 01 means grayscale with depth<8, 31 means +indexed with depth<8, other numerals represent the color type, "T" means +the tRNS chunk is present, A means an alpha channel is present, and O +means tRNS or alpha is present but all pixels in the image are opaque. + + FROM 01 31 0 0T 0O 2 2T 2O 3 3T 3O 4A 4O 6A 6O + TO + 01 - + 31 - + 0 1 - + 0T - + 0O - + 2 GX - + 2T - + 2O - + 3 1 - + 3T - + 3O - + 4A T - + 4O - + 6A GX TX TX - + 6O GX TX - + +Within the matrix, + "-" means the transformation is not supported. + "X" means the transformation is obtained by png_set_expand(). + "1" means the transformation is obtained by + png_set_expand_gray_1_2_4_to_8 + "G" means the transformation is obtained by + png_set_gray_to_rgb(). + "P" means the transformation is obtained by + png_set_expand_palette_to_rgb(). + "T" means the transformation is obtained by + png_set_tRNS_to_alpha(). + +PNG can have files with 16 bits per channel. If you only can handle +8 bits per channel, this will strip the pixels down to 8 bit. + + if (bit_depth == 16) + png_set_strip_16(png_ptr); + +If, for some reason, you don't need the alpha channel on an image, +and you want to remove it rather than combining it with the background +(but the image author certainly had in mind that you *would* combine +it with the background, so that's what you should probably do): + + if (color_type & PNG_COLOR_MASK_ALPHA) + png_set_strip_alpha(png_ptr); + +In PNG files, the alpha channel in an image +is the level of opacity. If you need the alpha channel in an image to +be the level of transparency instead of opacity, you can invert the +alpha channel (or the tRNS chunk data) after it's read, so that 0 is +fully opaque and 255 (in 8-bit or paletted images) or 65535 (in 16-bit +images) is fully transparent, with + + png_set_invert_alpha(png_ptr); + +PNG files pack pixels of bit depths 1, 2, and 4 into bytes as small as +they can, resulting in, for example, 8 pixels per byte for 1 bit +files. This code expands to 1 pixel per byte without changing the +values of the pixels: + + if (bit_depth < 8) + png_set_packing(png_ptr); + +PNG files have possible bit depths of 1, 2, 4, 8, and 16. All pixels +stored in a PNG image have been "scaled" or "shifted" up to the next +higher possible bit depth (e.g. from 5 bits/sample in the range [0,31] +to 8 bits/sample in the range [0, 255]). However, it is also possible +to convert the PNG pixel data back to the original bit depth of the +image. This call reduces the pixels back down to the original bit depth: + + png_color_8p sig_bit; + + if (png_get_sBIT(png_ptr, info_ptr, &sig_bit)) + png_set_shift(png_ptr, sig_bit); + +PNG files store 3-color pixels in red, green, blue order. This code +changes the storage of the pixels to blue, green, red: + + if (color_type == PNG_COLOR_TYPE_RGB || + color_type == PNG_COLOR_TYPE_RGB_ALPHA) + png_set_bgr(png_ptr); + +PNG files store RGB pixels packed into 3 or 6 bytes. This code expands them +into 4 or 8 bytes for windowing systems that need them in this format: + + if (color_type == PNG_COLOR_TYPE_RGB) + png_set_filler(png_ptr, filler, PNG_FILLER_BEFORE); + +where "filler" is the 8 or 16-bit number to fill with, and the location is +either PNG_FILLER_BEFORE or PNG_FILLER_AFTER, depending upon whether +you want the filler before the RGB or after. This transformation +does not affect images that already have full alpha channels. To add an +opaque alpha channel, use filler=0xff or 0xffff and PNG_FILLER_AFTER which +will generate RGBA pixels. + +Note that png_set_filler() does not change the color type. If you want +to do that, you can add a true alpha channel with + + if (color_type == PNG_COLOR_TYPE_RGB || + color_type == PNG_COLOR_TYPE_GRAY) + png_set_add_alpha(png_ptr, filler, PNG_FILLER_AFTER); + +where "filler" contains the alpha value to assign to each pixel. +This function was added in libpng-1.2.7. + +If you are reading an image with an alpha channel, and you need the +data as ARGB instead of the normal PNG format RGBA: + + if (color_type == PNG_COLOR_TYPE_RGB_ALPHA) + png_set_swap_alpha(png_ptr); + +For some uses, you may want a grayscale image to be represented as +RGB. This code will do that conversion: + + if (color_type == PNG_COLOR_TYPE_GRAY || + color_type == PNG_COLOR_TYPE_GRAY_ALPHA) + png_set_gray_to_rgb(png_ptr); + +Conversely, you can convert an RGB or RGBA image to grayscale or grayscale +with alpha. + + if (color_type == PNG_COLOR_TYPE_RGB || + color_type == PNG_COLOR_TYPE_RGB_ALPHA) + png_set_rgb_to_gray_fixed(png_ptr, error_action, + int red_weight, int green_weight); + + error_action = 1: silently do the conversion + + error_action = 2: issue a warning if the original + image has any pixel where + red != green or red != blue + + error_action = 3: issue an error and abort the + conversion if the original + image has any pixel where + red != green or red != blue + + red_weight: weight of red component times 100000 + + green_weight: weight of green component times 100000 + If either weight is negative, default + weights (21268, 71514) are used. + +If you have set error_action = 1 or 2, you can +later check whether the image really was gray, after processing +the image rows, with the png_get_rgb_to_gray_status(png_ptr) function. +It will return a png_byte that is zero if the image was gray or +1 if there were any non-gray pixels. bKGD and sBIT data +will be silently converted to grayscale, using the green channel +data, regardless of the error_action setting. + +With red_weight+green_weight<=100000, +the normalized graylevel is computed: + + int rw = red_weight * 65536; + int gw = green_weight * 65536; + int bw = 65536 - (rw + gw); + gray = (rw*red + gw*green + bw*blue)/65536; + +The default values approximate those recommended in the Charles +Poynton's Color FAQ, <http://www.inforamp.net/~poynton/> +Copyright (c) 1998-01-04 Charles Poynton <poynton at inforamp.net> + + Y = 0.212671 * R + 0.715160 * G + 0.072169 * B + +Libpng approximates this with integers scaled by 32768: + + Y = (6968 * R + 23434 * G + 2366 * B)/32768 + +The calculation is done in a linear colorspace, if the image gamma +can be determined. + +If you have a grayscale and you are using png_set_expand_depth(), +png_set_expand(), or png_set_gray_to_rgb to change to truecolor or to +a higher bit-depth, you must either supply the background color as a gray +value at the original file bit-depth (need_expand = 1) or else supply the +background color as an RGB triplet at the final, expanded bit depth +(need_expand = 0). Similarly, if you are reading a paletted image, you +must either supply the background color as a palette index (need_expand = 1) +or as an RGB triplet that may or may not be in the palette (need_expand = 0). + + png_color_16 my_background; + png_color_16p image_background; + + if (png_get_bKGD(png_ptr, info_ptr, &image_background)) + png_set_background(png_ptr, image_background, + PNG_BACKGROUND_GAMMA_FILE, 1, 1.0); + else + png_set_background(png_ptr, &my_background, + PNG_BACKGROUND_GAMMA_SCREEN, 0, 1.0); + +The png_set_background() function tells libpng to composite images +with alpha or simple transparency against the supplied background +color. If the PNG file contains a bKGD chunk (PNG_INFO_bKGD valid), +you may use this color, or supply another color more suitable for +the current display (e.g., the background color from a web page). You +need to tell libpng whether the color is in the gamma space of the +display (PNG_BACKGROUND_GAMMA_SCREEN for colors you supply), the file +(PNG_BACKGROUND_GAMMA_FILE for colors from the bKGD chunk), or one +that is neither of these gammas (PNG_BACKGROUND_GAMMA_UNIQUE - I don't +know why anyone would use this, but it's here). + +To properly display PNG images on any kind of system, the application needs +to know what the display gamma is. Ideally, the user will know this, and +the application will allow them to set it. One method of allowing the user +to set the display gamma separately for each system is to check for a +SCREEN_GAMMA or DISPLAY_GAMMA environment variable, which will hopefully be +correctly set. + +Note that display_gamma is the overall gamma correction required to produce +pleasing results, which depends on the lighting conditions in the surrounding +environment. In a dim or brightly lit room, no compensation other than +the physical gamma exponent of the monitor is needed, while in a dark room +a slightly smaller exponent is better. + + double gamma, screen_gamma; + + if (/* We have a user-defined screen + gamma value */) + { + screen_gamma = user_defined_screen_gamma; + } + + /* One way that applications can share the same + screen gamma value */ + else if ((gamma_str = getenv("SCREEN_GAMMA")) + != NULL) + { + screen_gamma = (double)atof(gamma_str); + } + + /* If we don't have another value */ + else + { + screen_gamma = 2.2; /* A good guess for a + PC monitor in a bright office or a dim room */ + + screen_gamma = 2.0; /* A good guess for a + PC monitor in a dark room */ + + screen_gamma = 1.7 or 1.0; /* A good + guess for Mac systems */ + } + +The functions png_set_gamma() and its fixed point equivalent +png_set_gamma_fixed() handle gamma transformations of the data. +Pass both the file gamma and the current screen_gamma. If the file does +not have a gamma value, you can pass one anyway if you have an idea what +it is (usually 0.45455 is a good guess for GIF images on PCs). Note +that file gammas are inverted from screen gammas. See the discussions +on gamma in the PNG specification for an excellent description of what +gamma is, and why all applications should support it. It is strongly +recommended that PNG viewers support gamma correction. + + if (png_get_gAMA(png_ptr, info_ptr, &file_gamma)) + png_set_gamma(png_ptr, screen_gamma, file_gamma); + + else + png_set_gamma(png_ptr, screen_gamma, 0.45455); + +If you need to reduce an RGB file to a paletted file, or if a paletted +file has more entries then will fit on your screen, png_set_quantize() +will do that. Note that this is a simple match quantization that merely +finds the closest color available. This should work fairly well with +optimized palettes, but fairly badly with linear color cubes. If you +pass a palette that is larger then maximum_colors, the file will +reduce the number of colors in the palette so it will fit into +maximum_colors. If there is a histogram, it will use it to make +more intelligent choices when reducing the palette. If there is no +histogram, it may not do as good a job. + + if (color_type & PNG_COLOR_MASK_COLOR) + { + if (png_get_valid(png_ptr, info_ptr, + PNG_INFO_PLTE)) + { + png_uint_16p histogram = NULL; + + png_get_hIST(png_ptr, info_ptr, + &histogram); + png_set_quantize(png_ptr, palette, num_palette, + max_screen_colors, histogram, 1); + } + + else + { + png_color std_color_cube[MAX_SCREEN_COLORS] = + { ... colors ... }; + + png_set_quantize(png_ptr, std_color_cube, + MAX_SCREEN_COLORS, MAX_SCREEN_COLORS, + NULL,0); + } + } + +PNG files describe monochrome as black being zero and white being one. +The following code will reverse this (make black be one and white be +zero): + + if (bit_depth == 1 && color_type == PNG_COLOR_TYPE_GRAY) + png_set_invert_mono(png_ptr); + +This function can also be used to invert grayscale and gray-alpha images: + + if (color_type == PNG_COLOR_TYPE_GRAY || + color_type == PNG_COLOR_TYPE_GRAY_ALPHA) + png_set_invert_mono(png_ptr); + +PNG files store 16 bit pixels in network byte order (big-endian, +ie. most significant bits first). This code changes the storage to the +other way (little-endian, i.e. least significant bits first, the +way PCs store them): + + if (bit_depth == 16) + png_set_swap(png_ptr); + +If you are using packed-pixel images (1, 2, or 4 bits/pixel), and you +need to change the order the pixels are packed into bytes, you can use: + + if (bit_depth < 8) + png_set_packswap(png_ptr); + +Finally, you can write your own transformation function if none of +the existing ones meets your needs. This is done by setting a callback +with + + png_set_read_user_transform_fn(png_ptr, + read_transform_fn); + +You must supply the function + + void read_transform_fn(png_structp png_ptr, row_info_ptr + row_info, png_bytep data) + +See pngtest.c for a working example. Your function will be called +after all of the other transformations have been processed. Take care with +interlaced images if you do the interlace yourself - the width of the row is the +width in 'row_info', not the overall image width. + +If supported libpng provides two information routines that you can use to find +where you are in processing the image: + + png_get_current_pass_number(png_structp png_ptr); + png_get_current_row_number(png_structp png_ptr); + +Don't try using these outside a transform callback - firstly they are only +supported if user transforms are supported, secondly they may well return +unexpected results unless the row is actually being processed at the moment they +are called. + +You can also set up a pointer to a user structure for use by your +callback function, and you can inform libpng that your transform +function will change the number of channels or bit depth with the +function + + png_set_user_transform_info(png_ptr, user_ptr, + user_depth, user_channels); + +The user's application, not libpng, is responsible for allocating and +freeing any memory required for the user structure. + +You can retrieve the pointer via the function +png_get_user_transform_ptr(). For example: + + voidp read_user_transform_ptr = + png_get_user_transform_ptr(png_ptr); + +The last thing to handle is interlacing; this is covered in detail below, +but you must call the function here if you want libpng to handle expansion +of the interlaced image. + + number_of_passes = png_set_interlace_handling(png_ptr); + +After setting the transformations, libpng can update your png_info +structure to reflect any transformations you've requested with this +call. This is most useful to update the info structure's rowbytes +field so you can use it to allocate your image memory. This function +will also update your palette with the correct screen_gamma and +background if these have been given with the calls above. + + png_read_update_info(png_ptr, info_ptr); + +After you call png_read_update_info(), you can allocate any +memory you need to hold the image. The row data is simply +raw byte data for all forms of images. As the actual allocation +varies among applications, no example will be given. If you +are allocating one large chunk, you will need to build an +array of pointers to each row, as it will be needed for some +of the functions below. + +Remember: Before you call png_read_update_info(), the png_get_ +functions return the values corresponding to the original PNG image. +After you call png_read_update_info the values refer to the image +that libpng will output. Consequently you must call all the png_set_ +functions before you call png_read_update_info(). This is particularly +important for png_set_interlace_handling() - if you are going to call +png_read_update_info() you must call png_set_interlace_handling() before +it unless you want to receive interlaced output. + +Reading image data + +After you've allocated memory, you can read the image data. +The simplest way to do this is in one function call. If you are +allocating enough memory to hold the whole image, you can just +call png_read_image() and libpng will read in all the image data +and put it in the memory area supplied. You will need to pass in +an array of pointers to each row. + +This function automatically handles interlacing, so you don't +need to call png_set_interlace_handling() (unless you call +png_read_update_info()) or call this function multiple times, or any +of that other stuff necessary with png_read_rows(). + + png_read_image(png_ptr, row_pointers); + +where row_pointers is: + + png_bytep row_pointers[height]; + +You can point to void or char or whatever you use for pixels. + +If you don't want to read in the whole image at once, you can +use png_read_rows() instead. If there is no interlacing (check +interlace_type == PNG_INTERLACE_NONE), this is simple: + + png_read_rows(png_ptr, row_pointers, NULL, + number_of_rows); + +where row_pointers is the same as in the png_read_image() call. + +If you are doing this just one row at a time, you can do this with +a single row_pointer instead of an array of row_pointers: + + png_bytep row_pointer = row; + png_read_row(png_ptr, row_pointer, NULL); + +If the file is interlaced (interlace_type != 0 in the IHDR chunk), things +get somewhat harder. The only current (PNG Specification version 1.2) +interlacing type for PNG is (interlace_type == PNG_INTERLACE_ADAM7); +a somewhat complicated 2D interlace scheme, known as Adam7, that +breaks down an image into seven smaller images of varying size, based +on an 8x8 grid. This number is defined (from libpng 1.5) as +PNG_INTERLACE_ADAM7_PASSES in png.h + +libpng can fill out those images or it can give them to you "as is". +It is almost always better to have libpng handle the interlacing for you. +If you want the images filled out, there are two ways to do that. The one +mentioned in the PNG specification is to expand each pixel to cover +those pixels that have not been read yet (the "rectangle" method). +This results in a blocky image for the first pass, which gradually +smooths out as more pixels are read. The other method is the "sparkle" +method, where pixels are drawn only in their final locations, with the +rest of the image remaining whatever colors they were initialized to +before the start of the read. The first method usually looks better, +but tends to be slower, as there are more pixels to put in the rows. + +If, as is likely, you want libpng to expand the images, call this before +calling png_start_read_image() or png_read_update_info(): + + if (interlace_type == PNG_INTERLACE_ADAM7) + number_of_passes + = png_set_interlace_handling(png_ptr); + +This will return the number of passes needed. Currently, this is seven, +but may change if another interlace type is added. This function can be +called even if the file is not interlaced, where it will return one pass. +You then need to read the whole image 'number_of_passes' times. Each time +will distribute the pixels from the current pass to the correct place in +the output image, so you need to supply the same rows to png_read_rows in +each pass. + +If you are not going to display the image after each pass, but are +going to wait until the entire image is read in, use the sparkle +effect. This effect is faster and the end result of either method +is exactly the same. If you are planning on displaying the image +after each pass, the "rectangle" effect is generally considered the +better looking one. + +If you only want the "sparkle" effect, just call png_read_rows() as +normal, with the third parameter NULL. Make sure you make pass over +the image number_of_passes times, and you don't change the data in the +rows between calls. You can change the locations of the data, just +not the data. Each pass only writes the pixels appropriate for that +pass, and assumes the data from previous passes is still valid. + + png_read_rows(png_ptr, row_pointers, NULL, + number_of_rows); + +If you only want the first effect (the rectangles), do the same as +before except pass the row buffer in the third parameter, and leave +the second parameter NULL. + + png_read_rows(png_ptr, NULL, row_pointers, + number_of_rows); + +If you don't want libpng to handle the interlacing details, just call +png_read_rows() PNG_INTERLACE_ADAM7_PASSES times to read in all the images. +Each of the images is a valid image by itself, however you will almost +certainly need to distribute the pixels from each sub-image to the +correct place. This is where everything gets very tricky. + +If you want to retrieve the separate images you must pass the correct +number of rows to each successive call of png_read_rows(). The calculation +gets pretty complicated for small images, where some sub-images may +not even exist because either their width or height ends up zero. +libpng provides two macros to help you in 1.5 and later versions: + + png_uint_32 width = PNG_PASS_COLS(image_width, pass_number); + png_uint_32 height = PNG_PASS_ROWS(image_height, pass_number); + +Respectively these tell you the width and height of the sub-image +corresponding to the numbered pass. 'pass' is in in the range 0 to 6 - +this can be confusing because the specification refers to the same passes +as 1 to 7! Be careful, you must check both the width and height before +calling png_read_rows() and not call it for that pass if either is zero. + +You can, of course, read each sub-image row by row. If you want to +produce optimal code to make a pixel-by-pixel transformation of an +interlaced image this is the best approach; read each row of each pass, +transform it, and write it out to a new interlaced image. + +If you want to de-interlace the image yourself libpng provides further +macros to help that tell you where to place the pixels in the output image. +Because the interlacing scheme is rectangular - sub-image pixels are always +arranged on a rectangular grid - all you need to know for each pass is the +starting column and row in the output image of the first pixel plus the +spacing between each pixel. As of libpng 1.5 there are four macros to +retrieve this information: + + png_uint_32 x = PNG_PASS_START_COL(pass); + png_uint_32 y = PNG_PASS_START_ROW(pass); + png_uint_32 xStep = 1U << PNG_PASS_COL_SHIFT(pass); + png_uint_32 yStep = 1U << PNG_PASS_ROW_SHIFT(pass); + +These allow you to write the obvious loop: + + png_uint_32 input_y = 0; + png_uint_32 output_y = PNG_PASS_START_ROW(pass); + + while (output_y < output_image_height) + { + png_uint_32 input_x = 0; + png_uint_32 output_x = PNG_PASS_START_COL(pass); + + while (output_x < output_image_width) + { + image[output_y][output_x] = + subimage[pass][input_y][input_x++]; + + output_x += xStep; + } + + ++input_y; + output_y += yStep; + } + +Notice that the steps between successive output rows and columns are +returned as shifts. This is possible because the pixels in the subimages +are always a power of 2 apart - 1, 2, 4 or 8 pixels - in the original +image. In practice you may need to directly calculate the output coordinate +given an input coordinate. libpng provides two further macros for this +purpose: + + png_uint_32 output_x = PNG_COL_FROM_PASS_COL(input_x, pass); + png_uint_32 output_y = PNG_ROW_FROM_PASS_ROW(input_y, pass); + +Finally a pair of macros are provided to tell you if a particular image +row or column appears in a given pass: + + int col_in_pass = PNG_COL_IN_INTERLACE_PASS(output_x, pass); + int row_in_pass = PNG_ROW_IN_INTERLACE_PASS(output_y, pass); + +Bear in mind that you will probably also need to check the width and height +of the pass in addition to the above to be sure the pass even exists! + +With any luck you are convinced by now that you don't want to do your own +interlace handling. In reality normally the only good reason for doing this +is if you are processing PNG files on a pixel-by-pixel basis and don't want +to load the whole file into memory when it is interlaced. + +libpng includes a test program, pngvalid, that illustrates reading and +writing of interlaced images. If you can't get interlacing to work in your +code and don't want to leave it to libpng (the recommended approach) see +how pngvalid.c does it. + +Finishing a sequential read + +After you are finished reading the image through the +low-level interface, you can finish reading the file. If you are +interested in comments or time, which may be stored either before or +after the image data, you should pass the separate png_info struct if +you want to keep the comments from before and after the image +separate. If you are not interested, you can pass NULL. + + png_read_end(png_ptr, end_info); + +When you are done, you can free all memory allocated by libpng like this: + + png_destroy_read_struct(&png_ptr, &info_ptr, + &end_info); + +It is also possible to individually free the info_ptr members that +point to libpng-allocated storage with the following function: + + png_free_data(png_ptr, info_ptr, mask, seq) + + mask - identifies data to be freed, a mask + containing the bitwise OR of one or + more of + PNG_FREE_PLTE, PNG_FREE_TRNS, + PNG_FREE_HIST, PNG_FREE_ICCP, + PNG_FREE_PCAL, PNG_FREE_ROWS, + PNG_FREE_SCAL, PNG_FREE_SPLT, + PNG_FREE_TEXT, PNG_FREE_UNKN, + or simply PNG_FREE_ALL + + seq - sequence number of item to be freed + (-1 for all items) + +This function may be safely called when the relevant storage has +already been freed, or has not yet been allocated, or was allocated +by the user and not by libpng, and will in those cases do nothing. +The "seq" parameter is ignored if only one item of the selected data +type, such as PLTE, is allowed. If "seq" is not -1, and multiple items +are allowed for the data type identified in the mask, such as text or +sPLT, only the n'th item in the structure is freed, where n is "seq". + +The default behavior is only to free data that was allocated internally +by libpng. This can be changed, so that libpng will not free the data, +or so that it will free data that was allocated by the user with png_malloc() +or png_zalloc() and passed in via a png_set_*() function, with + + png_data_freer(png_ptr, info_ptr, freer, mask) + + freer - one of + PNG_DESTROY_WILL_FREE_DATA + PNG_SET_WILL_FREE_DATA + PNG_USER_WILL_FREE_DATA + + mask - which data elements are affected + same choices as in png_free_data() + +This function only affects data that has already been allocated. +You can call this function after reading the PNG data but before calling +any png_set_*() functions, to control whether the user or the png_set_*() +function is responsible for freeing any existing data that might be present, +and again after the png_set_*() functions to control whether the user +or png_destroy_*() is supposed to free the data. When the user assumes +responsibility for libpng-allocated data, the application must use +png_free() to free it, and when the user transfers responsibility to libpng +for data that the user has allocated, the user must have used png_malloc() +or png_zalloc() to allocate it. + +If you allocated your row_pointers in a single block, as suggested above in +the description of the high level read interface, you must not transfer +responsibility for freeing it to the png_set_rows or png_read_destroy function, +because they would also try to free the individual row_pointers[i]. + +If you allocated text_ptr.text, text_ptr.lang, and text_ptr.translated_keyword +separately, do not transfer responsibility for freeing text_ptr to libpng, +because when libpng fills a png_text structure it combines these members with +the key member, and png_free_data() will free only text_ptr.key. Similarly, +if you transfer responsibility for free'ing text_ptr from libpng to your +application, your application must not separately free those members. + +The png_free_data() function will turn off the "valid" flag for anything +it frees. If you need to turn the flag off for a chunk that was freed by +your application instead of by libpng, you can use + + png_set_invalid(png_ptr, info_ptr, mask); + + mask - identifies the chunks to be made invalid, + containing the bitwise OR of one or + more of + PNG_INFO_gAMA, PNG_INFO_sBIT, + PNG_INFO_cHRM, PNG_INFO_PLTE, + PNG_INFO_tRNS, PNG_INFO_bKGD, + PNG_INFO_hIST, PNG_INFO_pHYs, + PNG_INFO_oFFs, PNG_INFO_tIME, + PNG_INFO_pCAL, PNG_INFO_sRGB, + PNG_INFO_iCCP, PNG_INFO_sPLT, + PNG_INFO_sCAL, PNG_INFO_IDAT + +For a more compact example of reading a PNG image, see the file example.c. + +Reading PNG files progressively + +The progressive reader is slightly different then the non-progressive +reader. Instead of calling png_read_info(), png_read_rows(), and +png_read_end(), you make one call to png_process_data(), which calls +callbacks when it has the info, a row, or the end of the image. You +set up these callbacks with png_set_progressive_read_fn(). You don't +have to worry about the input/output functions of libpng, as you are +giving the library the data directly in png_process_data(). I will +assume that you have read the section on reading PNG files above, +so I will only highlight the differences (although I will show +all of the code). + +png_structp png_ptr; +png_infop info_ptr; + + /* An example code fragment of how you would + initialize the progressive reader in your + application. */ + int + initialize_png_reader() + { + png_ptr = png_create_read_struct + (PNG_LIBPNG_VER_STRING, (png_voidp)user_error_ptr, + user_error_fn, user_warning_fn); + + if (!png_ptr) + return (ERROR); + + info_ptr = png_create_info_struct(png_ptr); + + if (!info_ptr) + { + png_destroy_read_struct(&png_ptr, + (png_infopp)NULL, (png_infopp)NULL); + return (ERROR); + } + + if (setjmp(png_jmpbuf(png_ptr))) + { + png_destroy_read_struct(&png_ptr, &info_ptr, + (png_infopp)NULL); + return (ERROR); + } + + /* This one's new. You can provide functions + to be called when the header info is valid, + when each row is completed, and when the image + is finished. If you aren't using all functions, + you can specify NULL parameters. Even when all + three functions are NULL, you need to call + png_set_progressive_read_fn(). You can use + any struct as the user_ptr (cast to a void pointer + for the function call), and retrieve the pointer + from inside the callbacks using the function + + png_get_progressive_ptr(png_ptr); + + which will return a void pointer, which you have + to cast appropriately. + */ + png_set_progressive_read_fn(png_ptr, (void *)user_ptr, + info_callback, row_callback, end_callback); + + return 0; + } + + /* A code fragment that you call as you receive blocks + of data */ + int + process_data(png_bytep buffer, png_uint_32 length) + { + if (setjmp(png_jmpbuf(png_ptr))) + { + png_destroy_read_struct(&png_ptr, &info_ptr, + (png_infopp)NULL); + return (ERROR); + } + + /* This one's new also. Simply give it a chunk + of data from the file stream (in order, of + course). On machines with segmented memory + models machines, don't give it any more than + 64K. The library seems to run fine with sizes + of 4K. Although you can give it much less if + necessary (I assume you can give it chunks of + 1 byte, I haven't tried less then 256 bytes + yet). When this function returns, you may + want to display any rows that were generated + in the row callback if you don't already do + so there. + */ + png_process_data(png_ptr, info_ptr, buffer, length); + + /* At this point you can call png_process_data_skip if + you want to handle data the library will skip yourself; + it simply returns the number of bytes to skip (and stops + libpng skipping that number of bytes on the next + png_process_data call). + return 0; + } + + /* This function is called (as set by + png_set_progressive_read_fn() above) when enough data + has been supplied so all of the header has been + read. + */ + void + info_callback(png_structp png_ptr, png_infop info) + { + /* Do any setup here, including setting any of + the transformations mentioned in the Reading + PNG files section. For now, you _must_ call + either png_start_read_image() or + png_read_update_info() after all the + transformations are set (even if you don't set + any). You may start getting rows before + png_process_data() returns, so this is your + last chance to prepare for that. + + This is where you turn on interlace handling, + assuming you don't want to do it yourself. + + If you need to you can stop the processing of + your original input data at this point by calling + png_process_data_pause. This returns the number + of unprocessed bytes from the last png_process_data + call - it is up to you to ensure that the next call + sees these bytes again. If you don't want to bother + with this you can get libpng to cache the unread + bytes by setting the 'save' parameter (see png.h) but + then libpng will have to copy the data internally. + */ + } + + /* This function is called when each row of image + data is complete */ + void + row_callback(png_structp png_ptr, png_bytep new_row, + png_uint_32 row_num, int pass) + { + /* If the image is interlaced, and you turned + on the interlace handler, this function will + be called for every row in every pass. Some + of these rows will not be changed from the + previous pass. When the row is not changed, + the new_row variable will be NULL. The rows + and passes are called in order, so you don't + really need the row_num and pass, but I'm + supplying them because it may make your life + easier. + + If you did not turn on interlace handling then + the callback is called for each row of each + sub-image when the image is interlaced. In this + case 'row_num' is the row in the sub-image, not + the row in the output image as it is in all other + cases. + + For the non-NULL rows of interlaced images when + you have switched on libpng interlace handling, + you must call png_progressive_combine_row() + passing in the row and the old row. You can + call this function for NULL rows (it will just + return) and for non-interlaced images (it just + does the memcpy for you) if it will make the + code easier. Thus, you can just do this for + all cases if you switch on interlace handling; + */ + + png_progressive_combine_row(png_ptr, old_row, + new_row); + + /* where old_row is what was displayed for + previously for the row. Note that the first + pass (pass == 0, really) will completely cover + the old row, so the rows do not have to be + initialized. After the first pass (and only + for interlaced images), you will have to pass + the current row, and the function will combine + the old row and the new row. + + You can also call png_process_data_pause in this + callback - see above. + */ + } + + void + end_callback(png_structp png_ptr, png_infop info) + { + /* This function is called after the whole image + has been read, including any chunks after the + image (up to and including the IEND). You + will usually have the same info chunk as you + had in the header, although some data may have + been added to the comments and time fields. + + Most people won't do much here, perhaps setting + a flag that marks the image as finished. + */ + } + + + +IV. Writing + +Much of this is very similar to reading. However, everything of +importance is repeated here, so you won't have to constantly look +back up in the reading section to understand writing. + +Setup + +You will want to do the I/O initialization before you get into libpng, +so if it doesn't work, you don't have anything to undo. If you are not +using the standard I/O functions, you will need to replace them with +custom writing functions. See the discussion under Customizing libpng. + + FILE *fp = fopen(file_name, "wb"); + + if (!fp) + return (ERROR); + +Next, png_struct and png_info need to be allocated and initialized. +As these can be both relatively large, you may not want to store these +on the stack, unless you have stack space to spare. Of course, you +will want to check if they return NULL. If you are also reading, +you won't want to name your read structure and your write structure +both "png_ptr"; you can call them anything you like, such as +"read_ptr" and "write_ptr". Look at pngtest.c, for example. + + png_structp png_ptr = png_create_write_struct + (PNG_LIBPNG_VER_STRING, (png_voidp)user_error_ptr, + user_error_fn, user_warning_fn); + + if (!png_ptr) + return (ERROR); + + png_infop info_ptr = png_create_info_struct(png_ptr); + if (!info_ptr) + { + png_destroy_write_struct(&png_ptr, + (png_infopp)NULL); + return (ERROR); + } + +If you want to use your own memory allocation routines, +define PNG_USER_MEM_SUPPORTED and use +png_create_write_struct_2() instead of png_create_write_struct(): + + png_structp png_ptr = png_create_write_struct_2 + (PNG_LIBPNG_VER_STRING, (png_voidp)user_error_ptr, + user_error_fn, user_warning_fn, (png_voidp) + user_mem_ptr, user_malloc_fn, user_free_fn); + +After you have these structures, you will need to set up the +error handling. When libpng encounters an error, it expects to +longjmp() back to your routine. Therefore, you will need to call +setjmp() and pass the png_jmpbuf(png_ptr). If you +write the file from different routines, you will need to update +the png_jmpbuf(png_ptr) every time you enter a new routine that will +call a png_*() function. See your documentation of setjmp/longjmp +for your compiler for more information on setjmp/longjmp. See +the discussion on libpng error handling in the Customizing Libpng +section below for more information on the libpng error handling. + + if (setjmp(png_jmpbuf(png_ptr))) + { + png_destroy_write_struct(&png_ptr, &info_ptr); + fclose(fp); + return (ERROR); + } + ... + return; + +If you would rather avoid the complexity of setjmp/longjmp issues, +you can compile libpng with PNG_NO_SETJMP, in which case +errors will result in a call to PNG_ABORT() which defaults to abort(). + +You can #define PNG_ABORT() to a function that does something +more useful than abort(), as long as your function does not +return. + +Now you need to set up the output code. The default for libpng is to +use the C function fwrite(). If you use this, you will need to pass a +valid FILE * in the function png_init_io(). Be sure that the file is +opened in binary mode. Again, if you wish to handle writing data in +another way, see the discussion on libpng I/O handling in the Customizing +Libpng section below. + + png_init_io(png_ptr, fp); + +If you are embedding your PNG into a datastream such as MNG, and don't +want libpng to write the 8-byte signature, or if you have already +written the signature in your application, use + + png_set_sig_bytes(png_ptr, 8); + +to inform libpng that it should not write a signature. + +Write callbacks + +At this point, you can set up a callback function that will be +called after each row has been written, which you can use to control +a progress meter or the like. It's demonstrated in pngtest.c. +You must supply a function + + void write_row_callback(png_structp png_ptr, png_uint_32 row, + int pass); + { + /* put your code here */ + } + +(You can give it another name that you like instead of "write_row_callback") + +To inform libpng about your function, use + + png_set_write_status_fn(png_ptr, write_row_callback); + +You now have the option of modifying how the compression library will +run. The following functions are mainly for testing, but may be useful +in some cases, like if you need to write PNG files extremely fast and +are willing to give up some compression, or if you want to get the +maximum possible compression at the expense of slower writing. If you +have no special needs in this area, let the library do what it wants by +not calling this function at all, as it has been tuned to deliver a good +speed/compression ratio. The second parameter to png_set_filter() is +the filter method, for which the only valid values are 0 (as of the +July 1999 PNG specification, version 1.2) or 64 (if you are writing +a PNG datastream that is to be embedded in a MNG datastream). The third +parameter is a flag that indicates which filter type(s) are to be tested +for each scanline. See the PNG specification for details on the specific +filter types. + + + /* turn on or off filtering, and/or choose + specific filters. You can use either a single + PNG_FILTER_VALUE_NAME or the bitwise OR of one + or more PNG_FILTER_NAME masks. + */ + png_set_filter(png_ptr, 0, + PNG_FILTER_NONE | PNG_FILTER_VALUE_NONE | + PNG_FILTER_SUB | PNG_FILTER_VALUE_SUB | + PNG_FILTER_UP | PNG_FILTER_VALUE_UP | + PNG_FILTER_AVG | PNG_FILTER_VALUE_AVG | + PNG_FILTER_PAETH | PNG_FILTER_VALUE_PAETH| + PNG_ALL_FILTERS); + +If an application wants to start and stop using particular filters during +compression, it should start out with all of the filters (to ensure that +the previous row of pixels will be stored in case it's needed later), +and then add and remove them after the start of compression. + +If you are writing a PNG datastream that is to be embedded in a MNG +datastream, the second parameter can be either 0 or 64. + +The png_set_compression_*() functions interface to the zlib compression +library, and should mostly be ignored unless you really know what you are +doing. The only generally useful call is png_set_compression_level() +which changes how much time zlib spends on trying to compress the image +data. See the Compression Library (zlib.h and algorithm.txt, distributed +with zlib) for details on the compression levels. + + /* set the zlib compression level */ + png_set_compression_level(png_ptr, + Z_BEST_COMPRESSION); + + /* set other zlib parameters */ + png_set_compression_mem_level(png_ptr, 8); + png_set_compression_strategy(png_ptr, + Z_DEFAULT_STRATEGY); + png_set_compression_window_bits(png_ptr, 15); + png_set_compression_method(png_ptr, 8); + png_set_compression_buffer_size(png_ptr, 8192) + +extern PNG_EXPORT(void,png_set_zbuf_size) + +Setting the contents of info for output + +You now need to fill in the png_info structure with all the data you +wish to write before the actual image. Note that the only thing you +are allowed to write after the image is the text chunks and the time +chunk (as of PNG Specification 1.2, anyway). See png_write_end() and +the latest PNG specification for more information on that. If you +wish to write them before the image, fill them in now, and flag that +data as being valid. If you want to wait until after the data, don't +fill them until png_write_end(). For all the fields in png_info and +their data types, see png.h. For explanations of what the fields +contain, see the PNG specification. + +Some of the more important parts of the png_info are: + + png_set_IHDR(png_ptr, info_ptr, width, height, + bit_depth, color_type, interlace_type, + compression_type, filter_method) + + width - holds the width of the image + in pixels (up to 2^31). + + height - holds the height of the image + in pixels (up to 2^31). + + bit_depth - holds the bit depth of one of the + image channels. + (valid values are 1, 2, 4, 8, 16 + and depend also on the + color_type. See also significant + bits (sBIT) below). + + color_type - describes which color/alpha + channels are present. + PNG_COLOR_TYPE_GRAY + (bit depths 1, 2, 4, 8, 16) + PNG_COLOR_TYPE_GRAY_ALPHA + (bit depths 8, 16) + PNG_COLOR_TYPE_PALETTE + (bit depths 1, 2, 4, 8) + PNG_COLOR_TYPE_RGB + (bit_depths 8, 16) + PNG_COLOR_TYPE_RGB_ALPHA + (bit_depths 8, 16) + + PNG_COLOR_MASK_PALETTE + PNG_COLOR_MASK_COLOR + PNG_COLOR_MASK_ALPHA + + interlace_type - PNG_INTERLACE_NONE or + PNG_INTERLACE_ADAM7 + + compression_type - (must be + PNG_COMPRESSION_TYPE_DEFAULT) + + filter_method - (must be PNG_FILTER_TYPE_DEFAULT + or, if you are writing a PNG to + be embedded in a MNG datastream, + can also be + PNG_INTRAPIXEL_DIFFERENCING) + +If you call png_set_IHDR(), the call must appear before any of the +other png_set_*() functions, because they might require access to some of +the IHDR settings. The remaining png_set_*() functions can be called +in any order. + +If you wish, you can reset the compression_type, interlace_type, or +filter_method later by calling png_set_IHDR() again; if you do this, the +width, height, bit_depth, and color_type must be the same in each call. + + png_set_PLTE(png_ptr, info_ptr, palette, + num_palette); + + palette - the palette for the file + (array of png_color) + num_palette - number of entries in the palette + + png_set_gAMA(png_ptr, info_ptr, file_gamma); + png_set_gAMA_fixed(png_ptr, info_ptr, int_file_gamma); + + file_gamma - the gamma at which the image was + created (PNG_INFO_gAMA) + + int_file_gamma - 100,000 times the gamma at which + the image was created + + png_set_sRGB(png_ptr, info_ptr, srgb_intent); + + srgb_intent - the rendering intent + (PNG_INFO_sRGB) The presence of + the sRGB chunk means that the pixel + data is in the sRGB color space. + This chunk also implies specific + values of gAMA and cHRM. Rendering + intent is the CSS-1 property that + has been defined by the International + Color Consortium + (http://www.color.org). + It can be one of + PNG_sRGB_INTENT_SATURATION, + PNG_sRGB_INTENT_PERCEPTUAL, + PNG_sRGB_INTENT_ABSOLUTE, or + PNG_sRGB_INTENT_RELATIVE. + + + png_set_sRGB_gAMA_and_cHRM(png_ptr, info_ptr, + srgb_intent); + + srgb_intent - the rendering intent + (PNG_INFO_sRGB) The presence of the + sRGB chunk means that the pixel + data is in the sRGB color space. + This function also causes gAMA and + cHRM chunks with the specific values + that are consistent with sRGB to be + written. + + png_set_iCCP(png_ptr, info_ptr, name, compression_type, + profile, proflen); + + name - The profile name. + + compression_type - The compression type; always + PNG_COMPRESSION_TYPE_BASE for PNG 1.0. + You may give NULL to this argument to + ignore it. + + profile - International Color Consortium color + profile data. May contain NULs. + + proflen - length of profile data in bytes. + + png_set_sBIT(png_ptr, info_ptr, sig_bit); + + sig_bit - the number of significant bits for + (PNG_INFO_sBIT) each of the gray, red, + green, and blue channels, whichever are + appropriate for the given color type + (png_color_16) + + png_set_tRNS(png_ptr, info_ptr, trans_alpha, + num_trans, trans_color); + + trans_alpha - array of alpha (transparency) + entries for palette (PNG_INFO_tRNS) + + trans_color - graylevel or color sample values + (in order red, green, blue) of the + single transparent color for + non-paletted images (PNG_INFO_tRNS) + + num_trans - number of transparent entries + (PNG_INFO_tRNS) + + png_set_hIST(png_ptr, info_ptr, hist); + + hist - histogram of palette (array of + png_uint_16) (PNG_INFO_hIST) + + png_set_tIME(png_ptr, info_ptr, mod_time); + + mod_time - time image was last modified + (PNG_VALID_tIME) + + png_set_bKGD(png_ptr, info_ptr, background); + + background - background color (PNG_VALID_bKGD) + + png_set_text(png_ptr, info_ptr, text_ptr, num_text); + + text_ptr - array of png_text holding image + comments + + text_ptr[i].compression - type of compression used + on "text" PNG_TEXT_COMPRESSION_NONE + PNG_TEXT_COMPRESSION_zTXt + PNG_ITXT_COMPRESSION_NONE + PNG_ITXT_COMPRESSION_zTXt + text_ptr[i].key - keyword for comment. Must contain + 1-79 characters. + text_ptr[i].text - text comments for current + keyword. Can be NULL or empty. + text_ptr[i].text_length - length of text string, + after decompression, 0 for iTXt + text_ptr[i].itxt_length - length of itxt string, + after decompression, 0 for tEXt/zTXt + text_ptr[i].lang - language of comment (NULL or + empty for unknown). + text_ptr[i].translated_keyword - keyword in UTF-8 (NULL + or empty for unknown). + Note that the itxt_length, lang, and lang_key + members of the text_ptr structure only exist + when the library is built with iTXt chunk support. + + num_text - number of comments + + png_set_sPLT(png_ptr, info_ptr, &palette_ptr, + num_spalettes); + + palette_ptr - array of png_sPLT_struct structures + to be added to the list of palettes + in the info structure. + num_spalettes - number of palette structures to be + added. + + png_set_oFFs(png_ptr, info_ptr, offset_x, offset_y, + unit_type); + + offset_x - positive offset from the left + edge of the screen + + offset_y - positive offset from the top + edge of the screen + + unit_type - PNG_OFFSET_PIXEL, PNG_OFFSET_MICROMETER + + png_set_pHYs(png_ptr, info_ptr, res_x, res_y, + unit_type); + + res_x - pixels/unit physical resolution + in x direction + + res_y - pixels/unit physical resolution + in y direction + + unit_type - PNG_RESOLUTION_UNKNOWN, + PNG_RESOLUTION_METER + + png_set_sCAL(png_ptr, info_ptr, unit, width, height) + + unit - physical scale units (an integer) + + width - width of a pixel in physical scale units + + height - height of a pixel in physical scale units + (width and height are doubles) + + png_set_sCAL_s(png_ptr, info_ptr, unit, width, height) + + unit - physical scale units (an integer) + + width - width of a pixel in physical scale units + + height - height of a pixel in physical scale units + (width and height are strings like "2.54") + + png_set_unknown_chunks(png_ptr, info_ptr, &unknowns, + num_unknowns) + + unknowns - array of png_unknown_chunk + structures holding unknown chunks + unknowns[i].name - name of unknown chunk + unknowns[i].data - data of unknown chunk + unknowns[i].size - size of unknown chunk's data + unknowns[i].location - position to write chunk in file + 0: do not write chunk + PNG_HAVE_IHDR: before PLTE + PNG_HAVE_PLTE: before IDAT + PNG_AFTER_IDAT: after IDAT + +The "location" member is set automatically according to +what part of the output file has already been written. +You can change its value after calling png_set_unknown_chunks() +as demonstrated in pngtest.c. Within each of the "locations", +the chunks are sequenced according to their position in the +structure (that is, the value of "i", which is the order in which +the chunk was either read from the input file or defined with +png_set_unknown_chunks). + +A quick word about text and num_text. text is an array of png_text +structures. num_text is the number of valid structures in the array. +Each png_text structure holds a language code, a keyword, a text value, +and a compression type. + +The compression types have the same valid numbers as the compression +types of the image data. Currently, the only valid number is zero. +However, you can store text either compressed or uncompressed, unlike +images, which always have to be compressed. So if you don't want the +text compressed, set the compression type to PNG_TEXT_COMPRESSION_NONE. +Because tEXt and zTXt chunks don't have a language field, if you +specify PNG_TEXT_COMPRESSION_NONE or PNG_TEXT_COMPRESSION_zTXt +any language code or translated keyword will not be written out. + +Until text gets around 1000 bytes, it is not worth compressing it. +After the text has been written out to the file, the compression type +is set to PNG_TEXT_COMPRESSION_NONE_WR or PNG_TEXT_COMPRESSION_zTXt_WR, +so that it isn't written out again at the end (in case you are calling +png_write_end() with the same struct). + +The keywords that are given in the PNG Specification are: + + Title Short (one line) title or + caption for image + + Author Name of image's creator + + Description Description of image (possibly long) + + Copyright Copyright notice + + Creation Time Time of original image creation + (usually RFC 1123 format, see below) + + Software Software used to create the image + + Disclaimer Legal disclaimer + + Warning Warning of nature of content + + Source Device used to create the image + + Comment Miscellaneous comment; conversion + from other image format + +The keyword-text pairs work like this. Keywords should be short +simple descriptions of what the comment is about. Some typical +keywords are found in the PNG specification, as is some recommendations +on keywords. You can repeat keywords in a file. You can even write +some text before the image and some after. For example, you may want +to put a description of the image before the image, but leave the +disclaimer until after, so viewers working over modem connections +don't have to wait for the disclaimer to go over the modem before +they start seeing the image. Finally, keywords should be full +words, not abbreviations. Keywords and text are in the ISO 8859-1 +(Latin-1) character set (a superset of regular ASCII) and can not +contain NUL characters, and should not contain control or other +unprintable characters. To make the comments widely readable, stick +with basic ASCII, and avoid machine specific character set extensions +like the IBM-PC character set. The keyword must be present, but +you can leave off the text string on non-compressed pairs. +Compressed pairs must have a text string, as only the text string +is compressed anyway, so the compression would be meaningless. + +PNG supports modification time via the png_time structure. Two +conversion routines are provided, png_convert_from_time_t() for +time_t and png_convert_from_struct_tm() for struct tm. The +time_t routine uses gmtime(). You don't have to use either of +these, but if you wish to fill in the png_time structure directly, +you should provide the time in universal time (GMT) if possible +instead of your local time. Note that the year number is the full +year (e.g. 1998, rather than 98 - PNG is year 2000 compliant!), and +that months start with 1. + +If you want to store the time of the original image creation, you should +use a plain tEXt chunk with the "Creation Time" keyword. This is +necessary because the "creation time" of a PNG image is somewhat vague, +depending on whether you mean the PNG file, the time the image was +created in a non-PNG format, a still photo from which the image was +scanned, or possibly the subject matter itself. In order to facilitate +machine-readable dates, it is recommended that the "Creation Time" +tEXt chunk use RFC 1123 format dates (e.g. "22 May 1997 18:07:10 GMT"), +although this isn't a requirement. Unlike the tIME chunk, the +"Creation Time" tEXt chunk is not expected to be automatically changed +by the software. To facilitate the use of RFC 1123 dates, a function +png_convert_to_rfc1123(png_timep) is provided to convert from PNG +time to an RFC 1123 format string. + +Writing unknown chunks + +You can use the png_set_unknown_chunks function to queue up chunks +for writing. You give it a chunk name, raw data, and a size; that's +all there is to it. The chunks will be written by the next following +png_write_info_before_PLTE, png_write_info, or png_write_end function. +Any chunks previously read into the info structure's unknown-chunk +list will also be written out in a sequence that satisfies the PNG +specification's ordering rules. + +The high-level write interface + +At this point there are two ways to proceed; through the high-level +write interface, or through a sequence of low-level write operations. +You can use the high-level interface if your image data is present +in the info structure. All defined output +transformations are permitted, enabled by the following masks. + + PNG_TRANSFORM_IDENTITY No transformation + PNG_TRANSFORM_PACKING Pack 1, 2 and 4-bit samples + PNG_TRANSFORM_PACKSWAP Change order of packed + pixels to LSB first + PNG_TRANSFORM_INVERT_MONO Invert monochrome images + PNG_TRANSFORM_SHIFT Normalize pixels to the + sBIT depth + PNG_TRANSFORM_BGR Flip RGB to BGR, RGBA + to BGRA + PNG_TRANSFORM_SWAP_ALPHA Flip RGBA to ARGB or GA + to AG + PNG_TRANSFORM_INVERT_ALPHA Change alpha from opacity + to transparency + PNG_TRANSFORM_SWAP_ENDIAN Byte-swap 16-bit samples + PNG_TRANSFORM_STRIP_FILLER Strip out filler + bytes (deprecated). + PNG_TRANSFORM_STRIP_FILLER_BEFORE Strip out leading + filler bytes + PNG_TRANSFORM_STRIP_FILLER_AFTER Strip out trailing + filler bytes + +If you have valid image data in the info structure (you can use +png_set_rows() to put image data in the info structure), simply do this: + + png_write_png(png_ptr, info_ptr, png_transforms, NULL) + +where png_transforms is an integer containing the bitwise OR of some set of +transformation flags. This call is equivalent to png_write_info(), +followed the set of transformations indicated by the transform mask, +then png_write_image(), and finally png_write_end(). + +(The final parameter of this call is not yet used. Someday it might point +to transformation parameters required by some future output transform.) + +You must use png_transforms and not call any png_set_transform() functions +when you use png_write_png(). + +The low-level write interface + +If you are going the low-level route instead, you are now ready to +write all the file information up to the actual image data. You do +this with a call to png_write_info(). + + png_write_info(png_ptr, info_ptr); + +Note that there is one transformation you may need to do before +png_write_info(). In PNG files, the alpha channel in an image is the +level of opacity. If your data is supplied as a level of transparency, +you can invert the alpha channel before you write it, so that 0 is +fully transparent and 255 (in 8-bit or paletted images) or 65535 +(in 16-bit images) is fully opaque, with + + png_set_invert_alpha(png_ptr); + +This must appear before png_write_info() instead of later with the +other transformations because in the case of paletted images the tRNS +chunk data has to be inverted before the tRNS chunk is written. If +your image is not a paletted image, the tRNS data (which in such cases +represents a single color to be rendered as transparent) won't need to +be changed, and you can safely do this transformation after your +png_write_info() call. + +If you need to write a private chunk that you want to appear before +the PLTE chunk when PLTE is present, you can write the PNG info in +two steps, and insert code to write your own chunk between them: + + png_write_info_before_PLTE(png_ptr, info_ptr); + png_set_unknown_chunks(png_ptr, info_ptr, ...); + png_write_info(png_ptr, info_ptr); + +After you've written the file information, you can set up the library +to handle any special transformations of the image data. The various +ways to transform the data will be described in the order that they +should occur. This is important, as some of these change the color +type and/or bit depth of the data, and some others only work on +certain color types and bit depths. Even though each transformation +checks to see if it has data that it can do something with, you should +make sure to only enable a transformation if it will be valid for the +data. For example, don't swap red and blue on grayscale data. + +PNG files store RGB pixels packed into 3 or 6 bytes. This code tells +the library to strip input data that has 4 or 8 bytes per pixel down +to 3 or 6 bytes (or strip 2 or 4-byte grayscale+filler data to 1 or 2 +bytes per pixel). + + png_set_filler(png_ptr, 0, PNG_FILLER_BEFORE); + +where the 0 is unused, and the location is either PNG_FILLER_BEFORE or +PNG_FILLER_AFTER, depending upon whether the filler byte in the pixel +is stored XRGB or RGBX. + +PNG files pack pixels of bit depths 1, 2, and 4 into bytes as small as +they can, resulting in, for example, 8 pixels per byte for 1 bit files. +If the data is supplied at 1 pixel per byte, use this code, which will +correctly pack the pixels into a single byte: + + png_set_packing(png_ptr); + +PNG files reduce possible bit depths to 1, 2, 4, 8, and 16. If your +data is of another bit depth, you can write an sBIT chunk into the +file so that decoders can recover the original data if desired. + + /* Set the true bit depth of the image data */ + if (color_type & PNG_COLOR_MASK_COLOR) + { + sig_bit.red = true_bit_depth; + sig_bit.green = true_bit_depth; + sig_bit.blue = true_bit_depth; + } + + else + { + sig_bit.gray = true_bit_depth; + } + + if (color_type & PNG_COLOR_MASK_ALPHA) + { + sig_bit.alpha = true_bit_depth; + } + + png_set_sBIT(png_ptr, info_ptr, &sig_bit); + +If the data is stored in the row buffer in a bit depth other than +one supported by PNG (e.g. 3 bit data in the range 0-7 for a 4-bit PNG), +this will scale the values to appear to be the correct bit depth as +is required by PNG. + + png_set_shift(png_ptr, &sig_bit); + +PNG files store 16 bit pixels in network byte order (big-endian, +ie. most significant bits first). This code would be used if they are +supplied the other way (little-endian, i.e. least significant bits +first, the way PCs store them): + + if (bit_depth > 8) + png_set_swap(png_ptr); + +If you are using packed-pixel images (1, 2, or 4 bits/pixel), and you +need to change the order the pixels are packed into bytes, you can use: + + if (bit_depth < 8) + png_set_packswap(png_ptr); + +PNG files store 3 color pixels in red, green, blue order. This code +would be used if they are supplied as blue, green, red: + + png_set_bgr(png_ptr); + +PNG files describe monochrome as black being zero and white being +one. This code would be used if the pixels are supplied with this reversed +(black being one and white being zero): + + png_set_invert_mono(png_ptr); + +Finally, you can write your own transformation function if none of +the existing ones meets your needs. This is done by setting a callback +with + + png_set_write_user_transform_fn(png_ptr, + write_transform_fn); + +You must supply the function + + void write_transform_fn(png_structp png_ptr ptr, + row_info_ptr row_info, png_bytep data) + +See pngtest.c for a working example. Your function will be called +before any of the other transformations are processed. If supported +libpng also supplies an information routine that may be called from +your callback: + + png_get_current_row_number(png_ptr); + +This returns the current row passed to the transform. Even with interlaced +images the value returned is the row in the final output image. + +You can also set up a pointer to a user structure for use by your +callback function. + + png_set_user_transform_info(png_ptr, user_ptr, 0, 0); + +The user_channels and user_depth parameters of this function are ignored +when writing; you can set them to zero as shown. + +You can retrieve the pointer via the function png_get_user_transform_ptr(). +For example: + + voidp write_user_transform_ptr = + png_get_user_transform_ptr(png_ptr); + +It is possible to have libpng flush any pending output, either manually, +or automatically after a certain number of lines have been written. To +flush the output stream a single time call: + + png_write_flush(png_ptr); + +and to have libpng flush the output stream periodically after a certain +number of scanlines have been written, call: + + png_set_flush(png_ptr, nrows); + +Note that the distance between rows is from the last time png_write_flush() +was called, or the first row of the image if it has never been called. +So if you write 50 lines, and then png_set_flush 25, it will flush the +output on the next scanline, and every 25 lines thereafter, unless +png_write_flush() is called before 25 more lines have been written. +If nrows is too small (less than about 10 lines for a 640 pixel wide +RGB image) the image compression may decrease noticeably (although this +may be acceptable for real-time applications). Infrequent flushing will +only degrade the compression performance by a few percent over images +that do not use flushing. + +Writing the image data + +That's it for the transformations. Now you can write the image data. +The simplest way to do this is in one function call. If you have the +whole image in memory, you can just call png_write_image() and libpng +will write the image. You will need to pass in an array of pointers to +each row. This function automatically handles interlacing, so you don't +need to call png_set_interlace_handling() or call this function multiple +times, or any of that other stuff necessary with png_write_rows(). + + png_write_image(png_ptr, row_pointers); + +where row_pointers is: + + png_byte *row_pointers[height]; + +You can point to void or char or whatever you use for pixels. + +If you don't want to write the whole image at once, you can +use png_write_rows() instead. If the file is not interlaced, +this is simple: + + png_write_rows(png_ptr, row_pointers, + number_of_rows); + +row_pointers is the same as in the png_write_image() call. + +If you are just writing one row at a time, you can do this with +a single row_pointer instead of an array of row_pointers: + + png_bytep row_pointer = row; + + png_write_row(png_ptr, row_pointer); + +When the file is interlaced, things can get a good deal more complicated. +The only currently (as of the PNG Specification version 1.2, dated July +1999) defined interlacing scheme for PNG files is the "Adam7" interlace +scheme, that breaks down an image into seven smaller images of varying +size. libpng will build these images for you, or you can do them +yourself. If you want to build them yourself, see the PNG specification +for details of which pixels to write when. + +If you don't want libpng to handle the interlacing details, just +use png_set_interlace_handling() and call png_write_rows() the +correct number of times to write all the sub-images +(png_set_interlace_handling() returns the number of sub-images.) + +If you want libpng to build the sub-images, call this before you start +writing any rows: + + number_of_passes = png_set_interlace_handling(png_ptr); + +This will return the number of passes needed. Currently, this is seven, +but may change if another interlace type is added. + +Then write the complete image number_of_passes times. + + png_write_rows(png_ptr, row_pointers, number_of_rows); + +Think carefully before you write an interlaced image. Typically code that +reads such images reads all the image data into memory, uncompressed, before +doing any processing. Only code that can display an image on the fly can +take advantage of the interlacing and even then the image has to be exactly +the correct size for the output device, because scaling an image requires +adjacent pixels and these are not available until all the passes have been +read. + +If you do write an interlaced image you will hardly ever need to handle +the interlacing yourself. Call png_set_interlace_handling() and use the +approach described above. + +The only time it is conceivable that you will really need to write an +interlaced image pass-by-pass is when you have read one pass by pass and +made some pixel-by-pixel transformation to it, as described in the read +code above. In this case use the PNG_PASS_ROWS and PNG_PASS_COLS macros +to determine the size of each sub-image in turn and simply write the rows +you obtained from the read code. + +Finishing a sequential write + +After you are finished writing the image, you should finish writing +the file. If you are interested in writing comments or time, you should +pass an appropriately filled png_info pointer. If you are not interested, +you can pass NULL. + + png_write_end(png_ptr, info_ptr); + +When you are done, you can free all memory used by libpng like this: + + png_destroy_write_struct(&png_ptr, &info_ptr); + +It is also possible to individually free the info_ptr members that +point to libpng-allocated storage with the following function: + + png_free_data(png_ptr, info_ptr, mask, seq) + + mask - identifies data to be freed, a mask + containing the bitwise OR of one or + more of + PNG_FREE_PLTE, PNG_FREE_TRNS, + PNG_FREE_HIST, PNG_FREE_ICCP, + PNG_FREE_PCAL, PNG_FREE_ROWS, + PNG_FREE_SCAL, PNG_FREE_SPLT, + PNG_FREE_TEXT, PNG_FREE_UNKN, + or simply PNG_FREE_ALL + + seq - sequence number of item to be freed + (-1 for all items) + +This function may be safely called when the relevant storage has +already been freed, or has not yet been allocated, or was allocated +by the user and not by libpng, and will in those cases do nothing. +The "seq" parameter is ignored if only one item of the selected data +type, such as PLTE, is allowed. If "seq" is not -1, and multiple items +are allowed for the data type identified in the mask, such as text or +sPLT, only the n'th item in the structure is freed, where n is "seq". + +If you allocated data such as a palette that you passed in to libpng +with png_set_*, you must not free it until just before the call to +png_destroy_write_struct(). + +The default behavior is only to free data that was allocated internally +by libpng. This can be changed, so that libpng will not free the data, +or so that it will free data that was allocated by the user with png_malloc() +or png_zalloc() and passed in via a png_set_*() function, with + + png_data_freer(png_ptr, info_ptr, freer, mask) + + freer - one of + PNG_DESTROY_WILL_FREE_DATA + PNG_SET_WILL_FREE_DATA + PNG_USER_WILL_FREE_DATA + + mask - which data elements are affected + same choices as in png_free_data() + +For example, to transfer responsibility for some data from a read structure +to a write structure, you could use + + png_data_freer(read_ptr, read_info_ptr, + PNG_USER_WILL_FREE_DATA, + PNG_FREE_PLTE|PNG_FREE_tRNS|PNG_FREE_hIST) + + png_data_freer(write_ptr, write_info_ptr, + PNG_DESTROY_WILL_FREE_DATA, + PNG_FREE_PLTE|PNG_FREE_tRNS|PNG_FREE_hIST) + +thereby briefly reassigning responsibility for freeing to the user but +immediately afterwards reassigning it once more to the write_destroy +function. Having done this, it would then be safe to destroy the read +structure and continue to use the PLTE, tRNS, and hIST data in the write +structure. + +This function only affects data that has already been allocated. +You can call this function before calling after the png_set_*() functions +to control whether the user or png_destroy_*() is supposed to free the data. +When the user assumes responsibility for libpng-allocated data, the +application must use +png_free() to free it, and when the user transfers responsibility to libpng +for data that the user has allocated, the user must have used png_malloc() +or png_zalloc() to allocate it. + +If you allocated text_ptr.text, text_ptr.lang, and text_ptr.translated_keyword +separately, do not transfer responsibility for freeing text_ptr to libpng, +because when libpng fills a png_text structure it combines these members with +the key member, and png_free_data() will free only text_ptr.key. Similarly, +if you transfer responsibility for free'ing text_ptr from libpng to your +application, your application must not separately free those members. +For a more compact example of writing a PNG image, see the file example.c. + +V. Modifying/Customizing libpng: + +There are two issues here. The first is changing how libpng does +standard things like memory allocation, input/output, and error handling. +The second deals with more complicated things like adding new chunks, +adding new transformations, and generally changing how libpng works. +Both of those are compile-time issues; that is, they are generally +determined at the time the code is written, and there is rarely a need +to provide the user with a means of changing them. + +Memory allocation, input/output, and error handling + +All of the memory allocation, input/output, and error handling in libpng +goes through callbacks that are user-settable. The default routines are +in pngmem.c, pngrio.c, pngwio.c, and pngerror.c, respectively. To change +these functions, call the appropriate png_set_*_fn() function. + +Memory allocation is done through the functions png_malloc(), png_calloc(), +and png_free(). These currently just call the standard C functions. +png_calloc() calls png_malloc() and then clears the newly +allocated memory to zero. There is limited support for certain systems +with segmented memory architectures and the types of pointers declared by +png.h match this; you will have to use appropriate pointers in your +application. Since it is +unlikely that the method of handling memory allocation on a platform +will change between applications, these functions must be modified in +the library at compile time. If you prefer to use a different method +of allocating and freeing data, you can use png_create_read_struct_2() or +png_create_write_struct_2() to register your own functions as described +above. These functions also provide a void pointer that can be retrieved +via + + mem_ptr=png_get_mem_ptr(png_ptr); + +Your replacement memory functions must have prototypes as follows: + + png_voidp malloc_fn(png_structp png_ptr, + png_alloc_size_t size); + + void free_fn(png_structp png_ptr, png_voidp ptr); + +Your malloc_fn() must return NULL in case of failure. The png_malloc() +function will normally call png_error() if it receives a NULL from the +system memory allocator or from your replacement malloc_fn(). + +Your free_fn() will never be called with a NULL ptr, since libpng's +png_free() checks for NULL before calling free_fn(). + +Input/Output in libpng is done through png_read() and png_write(), +which currently just call fread() and fwrite(). The FILE * is stored in +png_struct and is initialized via png_init_io(). If you wish to change +the method of I/O, the library supplies callbacks that you can set +through the function png_set_read_fn() and png_set_write_fn() at run +time, instead of calling the png_init_io() function. These functions +also provide a void pointer that can be retrieved via the function +png_get_io_ptr(). For example: + + png_set_read_fn(png_structp read_ptr, + voidp read_io_ptr, png_rw_ptr read_data_fn) + + png_set_write_fn(png_structp write_ptr, + voidp write_io_ptr, png_rw_ptr write_data_fn, + png_flush_ptr output_flush_fn); + + voidp read_io_ptr = png_get_io_ptr(read_ptr); + voidp write_io_ptr = png_get_io_ptr(write_ptr); + +The replacement I/O functions must have prototypes as follows: + + void user_read_data(png_structp png_ptr, + png_bytep data, png_size_t length); + + void user_write_data(png_structp png_ptr, + png_bytep data, png_size_t length); + + void user_flush_data(png_structp png_ptr); + +The user_read_data() function is responsible for detecting and +handling end-of-data errors. + +Supplying NULL for the read, write, or flush functions sets them back +to using the default C stream functions, which expect the io_ptr to +point to a standard *FILE structure. It is probably a mistake +to use NULL for one of write_data_fn and output_flush_fn but not both +of them, unless you have built libpng with PNG_NO_WRITE_FLUSH defined. +It is an error to read from a write stream, and vice versa. + +Error handling in libpng is done through png_error() and png_warning(). +Errors handled through png_error() are fatal, meaning that png_error() +should never return to its caller. Currently, this is handled via +setjmp() and longjmp() (unless you have compiled libpng with +PNG_NO_SETJMP, in which case it is handled via PNG_ABORT()), +but you could change this to do things like exit() if you should wish, +as long as your function does not return. + +On non-fatal errors, png_warning() is called +to print a warning message, and then control returns to the calling code. +By default png_error() and png_warning() print a message on stderr via +fprintf() unless the library is compiled with PNG_NO_CONSOLE_IO defined +(because you don't want the messages) or PNG_NO_STDIO defined (because +fprintf() isn't available). If you wish to change the behavior of the error +functions, you will need to set up your own message callbacks. These +functions are normally supplied at the time that the png_struct is created. +It is also possible to redirect errors and warnings to your own replacement +functions after png_create_*_struct() has been called by calling: + + png_set_error_fn(png_structp png_ptr, + png_voidp error_ptr, png_error_ptr error_fn, + png_error_ptr warning_fn); + + png_voidp error_ptr = png_get_error_ptr(png_ptr); + +If NULL is supplied for either error_fn or warning_fn, then the libpng +default function will be used, calling fprintf() and/or longjmp() if a +problem is encountered. The replacement error functions should have +parameters as follows: + + void user_error_fn(png_structp png_ptr, + png_const_charp error_msg); + + void user_warning_fn(png_structp png_ptr, + png_const_charp warning_msg); + +The motivation behind using setjmp() and longjmp() is the C++ throw and +catch exception handling methods. This makes the code much easier to write, +as there is no need to check every return code of every function call. +However, there are some uncertainties about the status of local variables +after a longjmp, so the user may want to be careful about doing anything +after setjmp returns non-zero besides returning itself. Consult your +compiler documentation for more details. For an alternative approach, you +may wish to use the "cexcept" facility (see http://cexcept.sourceforge.net). + +Custom chunks + +If you need to read or write custom chunks, you may need to get deeper +into the libpng code. The library now has mechanisms for storing +and writing chunks of unknown type; you can even declare callbacks +for custom chunks. However, this may not be good enough if the +library code itself needs to know about interactions between your +chunk and existing `intrinsic' chunks. + +If you need to write a new intrinsic chunk, first read the PNG +specification. Acquire a first level of understanding of how it works. +Pay particular attention to the sections that describe chunk names, +and look at how other chunks were designed, so you can do things +similarly. Second, check out the sections of libpng that read and +write chunks. Try to find a chunk that is similar to yours and use +it as a template. More details can be found in the comments inside +the code. It is best to handle unknown chunks in a generic method, +via callback functions, instead of by modifying libpng functions. + +If you wish to write your own transformation for the data, look through +the part of the code that does the transformations, and check out some of +the simpler ones to get an idea of how they work. Try to find a similar +transformation to the one you want to add and copy off of it. More details +can be found in the comments inside the code itself. + +Configuring for 16 bit platforms + +You will want to look into zconf.h to tell zlib (and thus libpng) that +it cannot allocate more then 64K at a time. Even if you can, the memory +won't be accessible. So limit zlib and libpng to 64K by defining MAXSEG_64K. + +Configuring for DOS + +For DOS users who only have access to the lower 640K, you will +have to limit zlib's memory usage via a png_set_compression_mem_level() +call. See zlib.h or zconf.h in the zlib library for more information. + +Configuring for Medium Model + +Libpng's support for medium model has been tested on most of the popular +compilers. Make sure MAXSEG_64K gets defined, USE_FAR_KEYWORD gets +defined, and FAR gets defined to far in pngconf.h, and you should be +all set. Everything in the library (except for zlib's structure) is +expecting far data. You must use the typedefs with the p or pp on +the end for pointers (or at least look at them and be careful). Make +note that the rows of data are defined as png_bytepp, which is an +unsigned char far * far *. + +Configuring for gui/windowing platforms: + +You will need to write new error and warning functions that use the GUI +interface, as described previously, and set them to be the error and +warning functions at the time that png_create_*_struct() is called, +in order to have them available during the structure initialization. +They can be changed later via png_set_error_fn(). On some compilers, +you may also have to change the memory allocators (png_malloc, etc.). + +Configuring for compiler xxx: + +All includes for libpng are in pngconf.h. If you need to add, change +or delete an include, this is the place to do it. +The includes that are not needed outside libpng are placed in pngpriv.h, +which is only used by the routines inside libpng itself. +The files in libpng proper only include pngpriv.h and png.h, which +in turn includes pngconf.h. + +Configuring zlib: + +There are special functions to configure the compression. Perhaps the +most useful one changes the compression level, which currently uses +input compression values in the range 0 - 9. The library normally +uses the default compression level (Z_DEFAULT_COMPRESSION = 6). Tests +have shown that for a large majority of images, compression values in +the range 3-6 compress nearly as well as higher levels, and do so much +faster. For online applications it may be desirable to have maximum speed +(Z_BEST_SPEED = 1). With versions of zlib after v0.99, you can also +specify no compression (Z_NO_COMPRESSION = 0), but this would create +files larger than just storing the raw bitmap. You can specify the +compression level by calling: + + png_set_compression_level(png_ptr, level); + +Another useful one is to reduce the memory level used by the library. +The memory level defaults to 8, but it can be lowered if you are +short on memory (running DOS, for example, where you only have 640K). +Note that the memory level does have an effect on compression; among +other things, lower levels will result in sections of incompressible +data being emitted in smaller stored blocks, with a correspondingly +larger relative overhead of up to 15% in the worst case. + + png_set_compression_mem_level(png_ptr, level); + +The other functions are for configuring zlib. They are not recommended +for normal use and may result in writing an invalid PNG file. See +zlib.h for more information on what these mean. + + png_set_compression_strategy(png_ptr, + strategy); + + png_set_compression_window_bits(png_ptr, + window_bits); + + png_set_compression_method(png_ptr, method); + png_set_compression_buffer_size(png_ptr, size); + +Controlling row filtering + +If you want to control whether libpng uses filtering or not, which +filters are used, and how it goes about picking row filters, you +can call one of these functions. The selection and configuration +of row filters can have a significant impact on the size and +encoding speed and a somewhat lesser impact on the decoding speed +of an image. Filtering is enabled by default for RGB and grayscale +images (with and without alpha), but not for paletted images nor +for any images with bit depths less than 8 bits/pixel. + +The 'method' parameter sets the main filtering method, which is +currently only '0' in the PNG 1.2 specification. The 'filters' +parameter sets which filter(s), if any, should be used for each +scanline. Possible values are PNG_ALL_FILTERS and PNG_NO_FILTERS +to turn filtering on and off, respectively. + +Individual filter types are PNG_FILTER_NONE, PNG_FILTER_SUB, +PNG_FILTER_UP, PNG_FILTER_AVG, PNG_FILTER_PAETH, which can be bitwise +ORed together with '|' to specify one or more filters to use. +These filters are described in more detail in the PNG specification. +If you intend to change the filter type during the course of writing +the image, you should start with flags set for all of the filters +you intend to use so that libpng can initialize its internal +structures appropriately for all of the filter types. (Note that this +means the first row must always be adaptively filtered, because libpng +currently does not allocate the filter buffers until png_write_row() +is called for the first time.) + + filters = PNG_FILTER_NONE | PNG_FILTER_SUB + PNG_FILTER_UP | PNG_FILTER_AVG | + PNG_FILTER_PAETH | PNG_ALL_FILTERS; + + png_set_filter(png_ptr, PNG_FILTER_TYPE_BASE, + filters); + The second parameter can also be + PNG_INTRAPIXEL_DIFFERENCING if you are + writing a PNG to be embedded in a MNG + datastream. This parameter must be the + same as the value of filter_method used + in png_set_IHDR(). + +It is also possible to influence how libpng chooses from among the +available filters. This is done in one or both of two ways - by +telling it how important it is to keep the same filter for successive +rows, and by telling it the relative computational costs of the filters. + + double weights[3] = {1.5, 1.3, 1.1}, + costs[PNG_FILTER_VALUE_LAST] = + {1.0, 1.3, 1.3, 1.5, 1.7}; + + png_set_filter_heuristics(png_ptr, + PNG_FILTER_HEURISTIC_WEIGHTED, 3, + weights, costs); + +The weights are multiplying factors that indicate to libpng that the +row filter should be the same for successive rows unless another row filter +is that many times better than the previous filter. In the above example, +if the previous 3 filters were SUB, SUB, NONE, the SUB filter could have a +"sum of absolute differences" 1.5 x 1.3 times higher than other filters +and still be chosen, while the NONE filter could have a sum 1.1 times +higher than other filters and still be chosen. Unspecified weights are +taken to be 1.0, and the specified weights should probably be declining +like those above in order to emphasize recent filters over older filters. + +The filter costs specify for each filter type a relative decoding cost +to be considered when selecting row filters. This means that filters +with higher costs are less likely to be chosen over filters with lower +costs, unless their "sum of absolute differences" is that much smaller. +The costs do not necessarily reflect the exact computational speeds of +the various filters, since this would unduly influence the final image +size. + +Note that the numbers above were invented purely for this example and +are given only to help explain the function usage. Little testing has +been done to find optimum values for either the costs or the weights. + +Removing unwanted object code + +There are a bunch of #define's in pngconf.h that control what parts of +libpng are compiled. All the defines end in _SUPPORTED. If you are +never going to use a capability, you can change the #define to #undef +before recompiling libpng and save yourself code and data space, or +you can turn off individual capabilities with defines that begin with +PNG_NO_. + +In libpng-1.5.0 and later, the #define's are in pnglibconf.h instead. + +You can also turn all of the transforms and ancillary chunk capabilities +off en masse with compiler directives that define +PNG_NO_READ[or WRITE]_TRANSFORMS, or PNG_NO_READ[or WRITE]_ANCILLARY_CHUNKS, +or all four, +along with directives to turn on any of the capabilities that you do +want. The PNG_NO_READ[or WRITE]_TRANSFORMS directives disable the extra +transformations but still leave the library fully capable of reading +and writing PNG files with all known public chunks. Use of the +PNG_NO_READ[or WRITE]_ANCILLARY_CHUNKS directive produces a library +that is incapable of reading or writing ancillary chunks. If you are +not using the progressive reading capability, you can turn that off +with PNG_NO_PROGRESSIVE_READ (don't confuse this with the INTERLACING +capability, which you'll still have). + +All the reading and writing specific code are in separate files, so the +linker should only grab the files it needs. However, if you want to +make sure, or if you are building a stand alone library, all the +reading files start with pngr and all the writing files start with +pngw. The files that don't match either (like png.c, pngtrans.c, etc.) +are used for both reading and writing, and always need to be included. +The progressive reader is in pngpread.c + +If you are creating or distributing a dynamically linked library (a .so +or DLL file), you should not remove or disable any parts of the library, +as this will cause applications linked with different versions of the +library to fail if they call functions not available in your library. +The size of the library itself should not be an issue, because only +those sections that are actually used will be loaded into memory. + +Requesting debug printout + +The macro definition PNG_DEBUG can be used to request debugging +printout. Set it to an integer value in the range 0 to 3. Higher +numbers result in increasing amounts of debugging information. The +information is printed to the "stderr" file, unless another file +name is specified in the PNG_DEBUG_FILE macro definition. + +When PNG_DEBUG > 0, the following functions (macros) become available: + + png_debug(level, message) + png_debug1(level, message, p1) + png_debug2(level, message, p1, p2) + +in which "level" is compared to PNG_DEBUG to decide whether to print +the message, "message" is the formatted string to be printed, +and p1 and p2 are parameters that are to be embedded in the string +according to printf-style formatting directives. For example, + + png_debug1(2, "foo=%d\n", foo); + +is expanded to + + if (PNG_DEBUG > 2) + fprintf(PNG_DEBUG_FILE, "foo=%d\n", foo); + +When PNG_DEBUG is defined but is zero, the macros aren't defined, but you +can still use PNG_DEBUG to control your own debugging: + + #ifdef PNG_DEBUG + fprintf(stderr, ... + #endif + +When PNG_DEBUG = 1, the macros are defined, but only png_debug statements +having level = 0 will be printed. There aren't any such statements in +this version of libpng, but if you insert some they will be printed. + +VI. MNG support + +The MNG specification (available at http://www.libpng.org/pub/mng) allows +certain extensions to PNG for PNG images that are embedded in MNG datastreams. +Libpng can support some of these extensions. To enable them, use the +png_permit_mng_features() function: + + feature_set = png_permit_mng_features(png_ptr, mask) + + mask is a png_uint_32 containing the bitwise OR of the + features you want to enable. These include + PNG_FLAG_MNG_EMPTY_PLTE + PNG_FLAG_MNG_FILTER_64 + PNG_ALL_MNG_FEATURES + + feature_set is a png_uint_32 that is the bitwise AND of + your mask with the set of MNG features that is + supported by the version of libpng that you are using. + +It is an error to use this function when reading or writing a standalone +PNG file with the PNG 8-byte signature. The PNG datastream must be wrapped +in a MNG datastream. As a minimum, it must have the MNG 8-byte signature +and the MHDR and MEND chunks. Libpng does not provide support for these +or any other MNG chunks; your application must provide its own support for +them. You may wish to consider using libmng (available at +http://www.libmng.com) instead. + +VII. Changes to Libpng from version 0.88 + +It should be noted that versions of libpng later than 0.96 are not +distributed by the original libpng author, Guy Schalnat, nor by +Andreas Dilger, who had taken over from Guy during 1996 and 1997, and +distributed versions 0.89 through 0.96, but rather by another member +of the original PNG Group, Glenn Randers-Pehrson. Guy and Andreas are +still alive and well, but they have moved on to other things. + +The old libpng functions png_read_init(), png_write_init(), +png_info_init(), png_read_destroy(), and png_write_destroy() have been +moved to PNG_INTERNAL in version 0.95 to discourage their use. These +functions will be removed from libpng version 1.4.0. + +The preferred method of creating and initializing the libpng structures is +via the png_create_read_struct(), png_create_write_struct(), and +png_create_info_struct() because they isolate the size of the structures +from the application, allow version error checking, and also allow the +use of custom error handling routines during the initialization, which +the old functions do not. The functions png_read_destroy() and +png_write_destroy() do not actually free the memory that libpng +allocated for these structs, but just reset the data structures, so they +can be used instead of png_destroy_read_struct() and +png_destroy_write_struct() if you feel there is too much system overhead +allocating and freeing the png_struct for each image read. + +Setting the error callbacks via png_set_message_fn() before +png_read_init() as was suggested in libpng-0.88 is no longer supported +because this caused applications that do not use custom error functions +to fail if the png_ptr was not initialized to zero. It is still possible +to set the error callbacks AFTER png_read_init(), or to change them with +png_set_error_fn(), which is essentially the same function, but with a new +name to force compilation errors with applications that try to use the old +method. + +Starting with version 1.0.7, you can find out which version of the library +you are using at run-time: + + png_uint_32 libpng_vn = png_access_version_number(); + +The number libpng_vn is constructed from the major version, minor +version with leading zero, and release number with leading zero, +(e.g., libpng_vn for version 1.0.7 is 10007). + +You can also check which version of png.h you used when compiling your +application: + + png_uint_32 application_vn = PNG_LIBPNG_VER; + +VIII. Changes to Libpng from version 1.0.x to 1.2.x + +Support for user memory management was enabled by default. To +accomplish this, the functions png_create_read_struct_2(), +png_create_write_struct_2(), png_set_mem_fn(), png_get_mem_ptr(), +png_malloc_default(), and png_free_default() were added. + +Support for the iTXt chunk has been enabled by default as of +version 1.2.41. + +Support for certain MNG features was enabled. + +Support for numbered error messages was added. However, we never got +around to actually numbering the error messages. The function +png_set_strip_error_numbers() was added (Note: the prototype for this +function was inadvertently removed from png.h in PNG_NO_ASSEMBLER_CODE +builds of libpng-1.2.15. It was restored in libpng-1.2.36). + +The png_malloc_warn() function was added at libpng-1.2.3. This issues +a png_warning and returns NULL instead of aborting when it fails to +acquire the requested memory allocation. + +Support for setting user limits on image width and height was enabled +by default. The functions png_set_user_limits(), png_get_user_width_max(), +and png_get_user_height_max() were added at libpng-1.2.6. + +The png_set_add_alpha() function was added at libpng-1.2.7. + +The function png_set_expand_gray_1_2_4_to_8() was added at libpng-1.2.9. +Unlike png_set_gray_1_2_4_to_8(), the new function does not expand the +tRNS chunk to alpha. The png_set_gray_1_2_4_to_8() function is +deprecated. + +A number of macro definitions in support of runtime selection of +assembler code features (especially Intel MMX code support) were +added at libpng-1.2.0: + + PNG_ASM_FLAG_MMX_SUPPORT_COMPILED + PNG_ASM_FLAG_MMX_SUPPORT_IN_CPU + PNG_ASM_FLAG_MMX_READ_COMBINE_ROW + PNG_ASM_FLAG_MMX_READ_INTERLACE + PNG_ASM_FLAG_MMX_READ_FILTER_SUB + PNG_ASM_FLAG_MMX_READ_FILTER_UP + PNG_ASM_FLAG_MMX_READ_FILTER_AVG + PNG_ASM_FLAG_MMX_READ_FILTER_PAETH + PNG_ASM_FLAGS_INITIALIZED + PNG_MMX_READ_FLAGS + PNG_MMX_FLAGS + PNG_MMX_WRITE_FLAGS + PNG_MMX_FLAGS + +We added the following functions in support of runtime +selection of assembler code features: + + png_get_mmx_flagmask() + png_set_mmx_thresholds() + png_get_asm_flags() + png_get_mmx_bitdepth_threshold() + png_get_mmx_rowbytes_threshold() + png_set_asm_flags() + +We replaced all of these functions with simple stubs in libpng-1.2.20, +when the Intel assembler code was removed due to a licensing issue. + +These macros are deprecated: + + PNG_READ_TRANSFORMS_NOT_SUPPORTED + PNG_PROGRESSIVE_READ_NOT_SUPPORTED + PNG_NO_SEQUENTIAL_READ_SUPPORTED + PNG_WRITE_TRANSFORMS_NOT_SUPPORTED + PNG_READ_ANCILLARY_CHUNKS_NOT_SUPPORTED + PNG_WRITE_ANCILLARY_CHUNKS_NOT_SUPPORTED + +They have been replaced, respectively, by: + + PNG_NO_READ_TRANSFORMS + PNG_NO_PROGRESSIVE_READ + PNG_NO_SEQUENTIAL_READ + PNG_NO_WRITE_TRANSFORMS + PNG_NO_READ_ANCILLARY_CHUNKS + PNG_NO_WRITE_ANCILLARY_CHUNKS + +PNG_MAX_UINT was replaced with PNG_UINT_31_MAX. It has been +deprecated since libpng-1.0.16 and libpng-1.2.6. + +The function + png_check_sig(sig, num) +was replaced with + !png_sig_cmp(sig, 0, num) +It has been deprecated since libpng-0.90. + +The function + png_set_gray_1_2_4_to_8() +which also expands tRNS to alpha was replaced with + png_set_expand_gray_1_2_4_to_8() +which does not. It has been deprecated since libpng-1.0.18 and 1.2.9. + +IX. Changes to Libpng from version 1.0.x/1.2.x to 1.4.x + +Private libpng prototypes and macro definitions were moved from +png.h and pngconf.h into a new pngpriv.h header file. + +Functions png_set_benign_errors(), png_benign_error(), and +png_chunk_benign_error() were added. + +Support for setting the maximum amount of memory that the application +will allocate for reading chunks was added, as a security measure. +The functions png_set_chunk_cache_max() and png_get_chunk_cache_max() +were added to the library. + +We implemented support for I/O states by adding png_ptr member io_state +and functions png_get_io_chunk_name() and png_get_io_state() in pngget.c + +We added PNG_TRANSFORM_GRAY_TO_RGB to the available high-level +input transforms. + +Checking for and reporting of errors in the IHDR chunk is more thorough. + +Support for global arrays was removed, to improve thread safety. + +Some obsolete/deprecated macros and functions have been removed. + +Typecasted NULL definitions such as + #define png_voidp_NULL (png_voidp)NULL +were eliminated. If you used these in your application, just use +NULL instead. + +The png_struct and info_struct members "trans" and "trans_values" were +changed to "trans_alpha" and "trans_color", respectively. + +The obsolete, unused pnggccrd.c and pngvcrd.c files and related makefiles +were removed. + +The PNG_1_0_X and PNG_1_2_X macros were eliminated. + +The PNG_LEGACY_SUPPORTED macro was eliminated. + +Many WIN32_WCE #ifdefs were removed. + +The functions png_read_init(info_ptr), png_write_init(info_ptr), +png_info_init(info_ptr), png_read_destroy(), and png_write_destroy() +have been removed. They have been deprecated since libpng-0.95. + +The png_permit_empty_plte() was removed. It has been deprecated +since libpng-1.0.9. Use png_permit_mng_features() instead. + +We removed the obsolete stub functions png_get_mmx_flagmask(), +png_set_mmx_thresholds(), png_get_asm_flags(), +png_get_mmx_bitdepth_threshold(), png_get_mmx_rowbytes_threshold(), +png_set_asm_flags(), and png_mmx_supported() + +We removed the obsolete png_check_sig(), png_memcpy_check(), and +png_memset_check() functions. Instead use !png_sig_cmp(), memcpy(), +and memset(), respectively. + +The function png_set_gray_1_2_4_to_8() was removed. It has been +deprecated since libpng-1.0.18 and 1.2.9, when it was replaced with +png_set_expand_gray_1_2_4_to_8() because the former function also +expanded palette images. + +Macros for png_get_uint_16, png_get_uint_32, and png_get_int_32 +were added and are used by default instead of the corresponding +functions. Unfortunately, +from libpng-1.4.0 until 1.4.4, the png_get_uint_16 macro (but not the +function) incorrectly returned a value of type png_uint_32. + +We changed the prototype for png_malloc() from + png_malloc(png_structp png_ptr, png_uint_32 size) +to + png_malloc(png_structp png_ptr, png_alloc_size_t size) + +This also applies to the prototype for the user replacement malloc_fn(). + +The png_calloc() function was added and is used in place of +of "png_malloc(); memset();" except in the case in png_read_png() +where the array consists of pointers; in this case a "for" loop is used +after the png_malloc() to set the pointers to NULL, to give robust. +behavior in case the application runs out of memory part-way through +the process. + +We changed the prototypes of png_get_compression_buffer_size() and +png_set_compression_buffer_size() to work with png_size_t instead of +png_uint_32. + +Support for numbered error messages was removed by default, since we +never got around to actually numbering the error messages. The function +png_set_strip_error_numbers() was removed from the library by default. + +The png_zalloc() and png_zfree() functions are no longer exported. +The png_zalloc() function no longer zeroes out the memory that it +allocates. + +Support for dithering was disabled by default in libpng-1.4.0, because +been well tested and doesn't actually "dither". The code was not +removed, however, and could be enabled by building libpng with +PNG_READ_DITHER_SUPPORTED defined. In libpng-1.4.2, this support +was reenabled, but the function was renamed png_set_quantize() to +reflect more accurately what it actually does. At the same time, +the PNG_DITHER_[RED,GREEN_BLUE]_BITS macros were also renamed to +PNG_QUANTIZE_[RED,GREEN,BLUE]_BITS, and PNG_READ_DITHER_SUPPORTED +was renamed to PNG_READ_QUANTIZE_SUPPORTED. + +We removed the trailing '.' from the warning and error messages. + +X. Changes to Libpng from version 1.4.x to 1.5.x + +From libpng-1.4.0 until 1.4.4, the png_get_uint_16 macro (but not the +function) incorrectly returned a value of type png_uint_32. + +A. Changes that affect users of libpng + +There are no substantial API changes between the non-deprecated parts of +the 1.4.5 API and the 1.5.0 API, however the ability to directly access +the main libpng control structures, png_struct and png_info, deprecated +in earlier versions of libpng, has been completely removed from +libpng 1.5. + +We no longer include zlib.h in png.h. Applications that need access +to information in zlib.h will need to add the '#include "zlib.h"' +directive. It does not matter whether it is placed prior to or after +the '"#include png.h"' directive. + +We moved the png_strcpy(), png_strncpy(), png_strlen(), png_memcpy(), +png_memcmp(), png_sprintf, and png_memcpy() macros into a private +header file (pngpriv.h) that is not accessible to applications. + +In png_get_iCCP, the type of "profile" was changed from png_charpp +to png_bytepp, and in png_set_iCCP, from png_charp to png_const_bytep. + +There are changes of form in png.h, including new and changed macros to +declare +parts of the API. Some API functions with arguments that are pointers to +data not modified within the function have been corrected to declare +these arguments with PNG_CONST. + +Much of the internal use of C macros to control the library build has also +changed and some of this is visible in the exported header files, in +particular the use of macros to control data and API elements visible +during application compilation may require significant revision to +application code. (It is extremely rare for an application to do this.) + +Any program that compiled against libpng 1.4 and did not use deprecated +features or access internal library structures should compile and work +against libpng 1.5. + +libpng 1.5.0 adds PNG_ PASS macros to help in the reading and writing of +interlaced images. The macros return the number of rows and columns in +each pass and information that can be used to de-interlace and (if +absolutely necessary) interlace an image. + +libpng 1.5.0 adds an API png_longjmp(png_ptr, value). This API calls +the application provided png_longjmp_ptr on the internal, but application +initialized, jmpbuf. It is provided as a convenience to avoid the need +to use the png_jmpbuf macro, which had the unnecessary side effect of +resetting the internal png_longjmp_ptr value. + +libpng 1.5.0 includes a complete fixed point API. By default this is +present along with the corresponding floating point API. In general the +fixed point API is faster and smaller than the floating point one because +the PNG file format used fixed point, not floating point. This applies +even if the library uses floating point in internal calculations. A new +macro, PNG_FLOATING_ARITHMETIC_SUPPORTED, reveals whether the library +uses floating point arithmetic (the default) or fixed point arithmetic +internally for performance critical calculations such as gamma correction. +In some cases, the gamma calculations may produce slightly different +results. This has changed the results in png_rgb_to_gray and in alpha +composition (png_set_background for example). This applies even if the +original image was already linear (gamma == 1.0) and, therefore, it is +not necessary to linearize the image. This is because libpng has *not* +been changed to optimize that case correctly, yet. + +Fixed point support for the sCAL chunk comes with an important caveat; +the sCAL specification uses a decimal encoding of floating point values +and the accuracy of PNG fixed point values is insufficient for +representation of these values. Consequently a "string" API +(png_get_sCAL_s and png_set_sCAL_s) is the only reliable way of reading +arbitrary sCAL chunks in the absence of either the floating point API or +internal floating point calculations. + +Applications no longer need to include the optional distribution header +file pngusr.h or define the corresponding macros during application +build in order to see the correct variant of the libpng API. From 1.5.0 +application code can check for the corresponding _SUPPORTED macro: + +#ifdef PNG_INCH_CONVERSIONS_SUPPORTED + /* code that uses the inch conversion APIs. */ +#endif + +This macro will only be defined if the inch conversion functions have been +compiled into libpng. The full set of macros, and whether or not support +has been compiled in, are available in the header file pnglibconf.h. +This header file is specific to the libpng build. Notice that prior to +1.5.0 the _SUPPORTED macros would always have the default definition unless +reset by pngusr.h or by explicit settings on the compiler command line. +These settings may produce compiler warnings or errors in 1.5.0 because +of macro redefinition. + +From libpng-1.4.0 until 1.4.4, the png_get_uint_16 macro (but not the +function) incorrectly returned a value of type png_uint_32. libpng 1.5.0 +is consistent with the implementation in 1.4.5 and 1.2.x (where the macro +did not exist.) + +Applications can now choose whether to use these macros or to call the +corresponding function by defining PNG_USE_READ_MACROS or +PNG_NO_USE_READ_MACROS before including png.h. Notice that this is +only supported from 1.5.0 -defining PNG_NO_USE_READ_MACROS prior to 1.5.0 + will lead to a link failure. + +B. Changes to the build and configuration of libpng + +Details of internal changes to the library code can be found in the CHANGES +file. These will be of no concern to the vast majority of library users or +builders, however the few who configure libpng to a non-default feature +set may need to change how this is done. + +There should be no need for library builders to alter build scripts if +these use the distributed build support - configure or the makefiles - +however users of the makefiles may care to update their build scripts +to build pnglibconf.h where the corresponding makefile does not do so. + +Building libpng with a non-default configuration has changed completely. +The old method using pngusr.h should still work correctly even though the +way pngusr.h is used in the build has been changed, however library +builders will probably want to examine the changes to take advantage of +new capabilities and to simplify their build system. + +B.1 Specific changes to library configuration capabilities + +The library now supports a complete fixed point implementation and can +thus be used on systems which have no floating point support or very +limited or slow support. Previously gamma correction, an essential part +of complete PNG support, required reasonably fast floating point. + +As part of this the choice of internal implementation has been made +independent of the choice of fixed versus floating point APIs and all the +missing fixed point APIs have been implemented. + +The exact mechanism used to control attributes of API functions has +changed. A single set of operating system independent macro definitions +is used and operating system specific directives are defined in +pnglibconf.h + +As part of this the mechanism used to choose procedure call standards on +those systems that allow a choice has been changed. At present this only +affects certain Microsoft (DOS, Windows) and IBM (OS/2) operating systems +running on Intel processors. As before PNGAPI is defined where required +to control the exported API functions; however, two new macros, PNGCBAPI +and PNGCAPI, are used instead for callback functions (PNGCBAPI) and +(PNGCAPI) for functions that must match a C library prototype (currently +only png_longjmp_ptr, which must match the C longjmp function.) The new +approach is documented in pngconf.h + +Despite these changes libpng 1.5.0 only supports the native C function +calling standard on those platforms tested so far (__cdecl on Microsoft +Windows). This is because the support requirements for alternative +calling conventions seem to no longer exist. Developers who find it +necessary to set PNG_API_RULE to 1 should advise the mailing list +(png-mng-implement) of this and library builders who use Openwatcom and +therefore set PNG_API_RULE to 2 should also contact the mailing list. + +A new test program, pngvalid, is provided in addition to pngtest. +pngvalid validates the arithmetic accuracy of the gamma correction +calculations and includes a number of validations of the file format. +A subset of the full range of tests is run when "make check" is done +(in the 'configure' build.) pngvalid also allows total allocated memory +usage to be evaluated and performs additional memory overwrite validation. + +Many changes to individual feature macros have been made. The following +are the changes most likely to be noticed by library builders who +configure libpng: + +1) All feature macros now have consistent naming: + +#define PNG_NO_feature turns the feature off +#define PNG_feature_SUPPORTED turns the feature on + +pnglibconf.h contains one line for each feature macro which is either: + +#define PNG_feature_SUPPORTED + +if the feature is supported or: + +/*#undef PNG_feature_SUPPORTED*/ + +if it is not. Library code consistently checks for the 'SUPPORTED' macro. +It does not, and should not, check for the 'NO' macro which will not +normally be defined even if the feature is not supported. + +Compatibility with the old names is provided as follows: + +PNG_INCH_CONVERSIONS turns on PNG_INCH_CONVERSIONS_SUPPORTED + +And the following definitions disable the corresponding feature: + +PNG_SETJMP_NOT_SUPPORTED disables SETJMP +PNG_READ_TRANSFORMS_NOT_SUPPORTED disables READ_TRANSFORMS +PNG_NO_READ_COMPOSITED_NODIV disables READ_COMPOSITE_NODIV +PNG_WRITE_TRANSFORMS_NOT_SUPPORTED disables WRITE_TRANSFORMS +PNG_READ_ANCILLARY_CHUNKS_NOT_SUPPORTED disables READ_ANCILLARY_CHUNKS +PNG_WRITE_ANCILLARY_CHUNKS_NOT_SUPPORTED disables WRITE_ANCILLARY_CHUNKS + +Library builders should remove use of the above, inconsistent, names. + +2) Warning and error message formatting was previously conditional on +the STDIO feature. The library has been changed to use the +CONSOLE_IO feature instead. This means that if CONSOLE_IO is disabled +the library no longer uses the printf(3) functions, even though the +default read/write implementations use (FILE) style stdio.h functions. + +3) Three feature macros now control the fixed/floating point decisions: + +PNG_FLOATING_POINT_SUPPORTED enables the floating point APIs + +PNG_FIXED_POINT_SUPPORTED enables the fixed point APIs; however, in +practice these are normally required internally anyway (because the PNG +file format is fixed point), therefore in most cases PNG_NO_FIXED_POINT +merely stops the function from being exported. + +PNG_FLOATING_ARITHMETIC_SUPPORTED chooses between the internal floating +point implementation or the fixed point one. Typically the fixed point +implementation is larger and slower than the floating point implementation +on a system that supports floating point, however it may be faster on a +system which lacks floating point hardware and therefore uses a software +emulation. + +4) Added PNG_{READ,WRITE}_INT_FUNCTIONS_SUPPORTED. This allows the +functions to read and write ints to be disabled independently of +PNG_USE_READ_MACROS, which allows libpng to be built with the functions +even though the default is to use the macros - this allows applications +to choose at app buildtime whether or not to use macros (previously +impossible because the functions weren't in the default build.) + +B.2 Changes to the configuration mechanism + +Prior to libpng-1.5.0 library builders who needed to configure libpng +had either to modify the exported pngconf.h header file to add system +specific configuration or had to write feature selection macros into +pngusr.h and cause this to be included into pngconf.h by defining +PNG_USER_CONFIG. The latter mechanism had the disadvantage that an +application built without PNG_USER_CONFIG defined would see the +unmodified, default, libpng API and thus would probably fail to link. + +These mechanisms still work in the configure build and in any makefile +build that builds pnglibconf.h although the feature selection macros +have changed somewhat as described above. In 1.5.0, however, pngusr.h is +processed only once, when the exported header file pnglibconf.h is built. +pngconf.h no longer includes pngusr.h, therefore it is ignored after the +build of pnglibconf.h and it is never included in an application build. + +The rarely used alternative of adding a list of feature macros to the +CFLAGS setting in the build also still works, however the macros will be +copied to pnglibconf.h and this may produce macro redefinition warnings +when the individual C files are compiled. + +All configuration now only works if pnglibconf.h is built from +scripts/pnglibconf.dfa. This requires the program awk. Brian Kernighan +(the original author of awk) maintains C source code of that awk and this +and all known later implementations (often called by subtly different +names - nawk and gawk for example) are adequate to build pnglibconf.h. +The Sun Microsystems (now Oracle) program 'awk' is an earlier version +and does not work, this may also apply to other systems that have a +functioning awk called 'nawk'. + +Configuration options are now documented in scripts/pnglibconf.dfa. This +file also includes dependency information that ensures a configuration is +consistent; that is, if a feature is switched off dependent features are +also removed. As a recommended alternative to using feature macros in +pngusr.h a system builder may also define equivalent options in pngusr.dfa +(or, indeed, any file) and add that to the configuration by setting +DFA_XTRA to the file name. The makefiles in contrib/pngminim illustrate +how to do this, and a case where pngusr.h is still required. + +XI. Detecting libpng + +The png_get_io_ptr() function has been present since libpng-0.88, has never +changed, and is unaffected by conditional compilation macros. It is the +best choice for use in configure scripts for detecting the presence of any +libpng version since 0.88. In an autoconf "configure.in" you could use + + AC_CHECK_LIB(png, png_get_io_ptr, ... + +XII. Source code repository + +Since about February 2009, version 1.2.34, libpng has been under "git" source +control. The git repository was built from old libpng-x.y.z.tar.gz files +going back to version 0.70. You can access the git repository (read only) +at + + git://libpng.git.sourceforge.net/gitroot/libpng + +or you can browse it via "gitweb" at + + http://libpng.git.sourceforge.net/git/gitweb.cgi?p=libpng + +Patches can be sent to glennrp at users.sourceforge.net or to +png-mng-implement at lists.sourceforge.net or you can upload them to +the libpng bug tracker at + + http://libpng.sourceforge.net + +We also accept patches built from the tar or zip distributions, and +simple verbal discriptions of bug fixes, reported either to the +SourceForge bug tracker or to the png-mng-implement at lists.sf.net +mailing list. + +XIII. Coding style + +Our coding style is similar to the "Allman" style, with curly +braces on separate lines: + + if (condition) + { + action; + } + + else if (another condition) + { + another action; + } + +The braces can be omitted from simple one-line actions: + + if (condition) + return (0); + +We use 3-space indentation, except for continued statements which +are usually indented the same as the first line of the statement +plus four more spaces. + +For macro definitions we use 2-space indentation, always leaving the "#" +in the first column. + + #ifndef PNG_NO_FEATURE + # ifndef PNG_FEATURE_SUPPORTED + # define PNG_FEATURE_SUPPORTED + # endif + #endif + +Comments appear with the leading "/*" at the same indentation as +the statement that follows the comment: + + /* Single-line comment */ + statement; + + /* This is a multiple-line + * comment. + */ + statement; + +Very short comments can be placed after the end of the statement +to which they pertain: + + statement; /* comment */ + +We don't use C++ style ("//") comments. We have, however, +used them in the past in some now-abandoned MMX assembler +code. + +Functions and their curly braces are not indented, and +exported functions are marked with PNGAPI: + + /* This is a public function that is visible to + * application programmers. It does thus-and-so. + */ + void PNGAPI + png_exported_function(png_ptr, png_info, foo) + { + body; + } + +The prototypes for all exported functions appear in png.h, +above the comment that says + + /* Maintainer: Put new public prototypes here ... */ + +We mark all non-exported functions with "/* PRIVATE */"": + + void /* PRIVATE */ + png_non_exported_function(png_ptr, png_info, foo) + { + body; + } + +The prototypes for non-exported functions (except for those in +pngtest) appear in +pngpriv.h +above the comment that says + + /* Maintainer: Put new private prototypes here ^ and in libpngpf.3 */ + +To avoid polluting the global namespace, the names of all exported +functions and variables begin with "png_", and all publicly visible C +preprocessor macros begin with "PNG_". We request that applications that +use libpng *not* begin any of their own symbols with either of these strings. + +We put a space after each comma and after each semicolon +in "for" statements, and we put spaces before and after each +C binary operator and after "for" or "while", and before +"?". We don't put a space between a typecast and the expression +being cast, nor do we put one between a function name and the +left parenthesis that follows it: + + for (i = 2; i > 0; --i) + y[i] = a(x) + (int)b; + +We prefer #ifdef and #ifndef to #if defined() and if !defined() +when there is only one macro being tested. + +We do not use the TAB character for indentation in the C sources. + +Lines do not exceed 80 characters. + +Other rules can be inferred by inspecting the libpng source. + +XIV. Y2K Compliance in libpng + +February 3, 2011 + +Since the PNG Development group is an ad-hoc body, we can't make +an official declaration. + +This is your unofficial assurance that libpng from version 0.71 and +upward through 1.5.1 are Y2K compliant. It is my belief that earlier +versions were also Y2K compliant. + +Libpng only has three year fields. One is a 2-byte unsigned integer that +will hold years up to 65535. The other two hold the date in text +format, and will hold years up to 9999. + +The integer is + "png_uint_16 year" in png_time_struct. + +The strings are + "png_charp time_buffer" in png_struct and + "near_time_buffer", which is a local character string in png.c. + +There are seven time-related functions: + + png_convert_to_rfc_1123() in png.c + (formerly png_convert_to_rfc_1152() in error) + png_convert_from_struct_tm() in pngwrite.c, called + in pngwrite.c + png_convert_from_time_t() in pngwrite.c + png_get_tIME() in pngget.c + png_handle_tIME() in pngrutil.c, called in pngread.c + png_set_tIME() in pngset.c + png_write_tIME() in pngwutil.c, called in pngwrite.c + +All appear to handle dates properly in a Y2K environment. The +png_convert_from_time_t() function calls gmtime() to convert from system +clock time, which returns (year - 1900), which we properly convert to +the full 4-digit year. There is a possibility that applications using +libpng are not passing 4-digit years into the png_convert_to_rfc_1123() +function, or that they are incorrectly passing only a 2-digit year +instead of "year - 1900" into the png_convert_from_struct_tm() function, +but this is not under our control. The libpng documentation has always +stated that it works with 4-digit years, and the APIs have been +documented as such. + +The tIME chunk itself is also Y2K compliant. It uses a 2-byte unsigned +integer to hold the year, and can hold years as large as 65535. + +zlib, upon which libpng depends, is also Y2K compliant. It contains +no date-related code. + + + Glenn Randers-Pehrson + libpng maintainer + PNG Development Group diff --git a/src/3rdparty/libpng/libpng.3 b/src/3rdparty/libpng/libpng.3 new file mode 100644 index 0000000000..ecc42777bf --- /dev/null +++ b/src/3rdparty/libpng/libpng.3 @@ -0,0 +1,5376 @@ +.TH LIBPNG 3 "February 3, 2011" +.SH NAME +libpng \- Portable Network Graphics (PNG) Reference Library 1.5.1 +.SH SYNOPSIS +\fI\fB + +\fB#include <png.h>\fP + +\fI\fB + +\fBpng_uint_32 png_access_version_number \fI(void\fP\fB);\fP + +\fI\fB + +\fBvoid png_benign_error (png_structp \fP\fIpng_ptr\fP\fB, png_const_charp \fIerror\fP\fB);\fP + +\fI\fB + +\fBvoid png_build_grayscale_palette (int \fP\fIbit_depth\fP\fB, png_colorp \fIpalette\fP\fB);\fP + +\fI\fB + +\fBpng_voidp png_calloc (png_structp \fP\fIpng_ptr\fP\fB, png_alloc_size_t \fIsize\fP\fB);\fP + +\fI\fB + +\fBvoid png_chunk_benign_error (png_structp \fP\fIpng_ptr\fP\fB, png_const_charp \fIerror\fP\fB);\fP + +\fI\fB + +\fBvoid png_chunk_error (png_structp \fP\fIpng_ptr\fP\fB, png_const_charp \fIerror\fP\fB);\fP + +\fI\fB + +\fBvoid png_chunk_warning (png_structp \fP\fIpng_ptr\fP\fB, png_const_charp \fImessage\fP\fB);\fP + +\fI\fB + +\fBvoid png_convert_from_struct_tm (png_timep \fP\fIptime\fP\fB, struct tm FAR * \fIttime\fP\fB);\fP + +\fI\fB + +\fBvoid png_convert_from_time_t (png_timep \fP\fIptime\fP\fB, time_t \fIttime\fP\fB);\fP + +\fI\fB + +\fBpng_charp png_convert_to_rfc1123 (png_structp \fP\fIpng_ptr\fP\fB, png_timep \fIptime\fP\fB);\fP + +\fI\fB + +\fBpng_infop png_create_info_struct (png_structp \fIpng_ptr\fP\fB);\fP + +\fI\fB + +\fBpng_structp png_create_read_struct (png_const_charp \fP\fIuser_png_ver\fP\fB, png_voidp \fP\fIerror_ptr\fP\fB, png_error_ptr \fP\fIerror_fn\fP\fB, png_error_ptr \fIwarn_fn\fP\fB);\fP + +\fI\fB + +\fBpng_structp png_create_read_struct_2 (png_const_charp \fP\fIuser_png_ver\fP\fB, png_voidp \fP\fIerror_ptr\fP\fB, png_error_ptr \fP\fIerror_fn\fP\fB, png_error_ptr \fP\fIwarn_fn\fP\fB, png_voidp \fP\fImem_ptr\fP\fB, png_malloc_ptr \fP\fImalloc_fn\fP\fB, png_free_ptr \fIfree_fn\fP\fB);\fP + +\fI\fB + +\fBpng_structp png_create_write_struct (png_const_charp \fP\fIuser_png_ver\fP\fB, png_voidp \fP\fIerror_ptr\fP\fB, png_error_ptr \fP\fIerror_fn\fP\fB, png_error_ptr \fIwarn_fn\fP\fB);\fP + +\fI\fB + +\fBpng_structp png_create_write_struct_2 (png_const_charp \fP\fIuser_png_ver\fP\fB, png_voidp \fP\fIerror_ptr\fP\fB, png_error_ptr \fP\fIerror_fn\fP\fB, png_error_ptr \fP\fIwarn_fn\fP\fB, png_voidp \fP\fImem_ptr\fP\fB, png_malloc_ptr \fP\fImalloc_fn\fP\fB, png_free_ptr \fIfree_fn\fP\fB);\fP + +\fI\fB + +\fBvoid png_data_freer (png_structp \fP\fIpng_ptr\fP\fB, png_infop \fP\fIinfo_ptr\fP\fB, int \fP\fIfreer\fP\fB, png_uint_32 \fImask)\fP\fB);\fP + +\fI\fB + +\fBvoid png_destroy_info_struct (png_structp \fP\fIpng_ptr\fP\fB, png_infopp \fIinfo_ptr_ptr\fP\fB);\fP + +\fI\fB + +\fBvoid png_destroy_read_struct (png_structpp \fP\fIpng_ptr_ptr\fP\fB, png_infopp \fP\fIinfo_ptr_ptr\fP\fB, png_infopp \fIend_info_ptr_ptr\fP\fB);\fP + +\fI\fB + +\fBvoid png_destroy_write_struct (png_structpp \fP\fIpng_ptr_ptr\fP\fB, png_infopp \fIinfo_ptr_ptr\fP\fB);\fP + +\fI\fB + +\fBvoid png_err (png_structp \fIpng_ptr\fP\fB);\fP + +\fI\fB + +\fBvoid png_error (png_structp \fP\fIpng_ptr\fP\fB, png_const_charp \fIerror\fP\fB);\fP + +\fI\fB + +\fBvoid png_free (png_structp \fP\fIpng_ptr\fP\fB, png_voidp \fIptr\fP\fB);\fP + +\fI\fB + +\fBvoid png_free_chunk_list (png_structp \fIpng_ptr\fP\fB);\fP + +\fI\fB + +\fBvoid png_free_default (png_structp \fP\fIpng_ptr\fP\fB, png_voidp \fIptr\fP\fB);\fP + +\fI\fB + +\fBvoid png_free_data (png_structp \fP\fIpng_ptr\fP\fB, png_infop \fP\fIinfo_ptr\fP\fB, int \fInum\fP\fB);\fP + +\fI\fB + +\fBpng_byte png_get_bit_depth (png_const_structp \fP\fIpng_ptr\fP\fB, png_const_infop \fIinfo_ptr\fP\fB);\fP + +\fI\fB + +\fBpng_uint_32 png_get_bKGD (png_const_structp \fP\fIpng_ptr\fP\fB, png_infop \fP\fIinfo_ptr\fP\fB, png_color_16p \fI*background\fP\fB);\fP + +\fI\fB + +\fBpng_byte png_get_channels (png_const_structp \fP\fIpng_ptr\fP\fB, png_const_infop \fIinfo_ptr\fP\fB);\fP + +\fI\fB + +\fBpng_uint_32 png_get_cHRM (png_const_structp \fP\fIpng_ptr\fP\fB, png_const_infop \fP\fIinfo_ptr\fP\fB, double \fP\fI*white_x\fP\fB, double \fP\fI*white_y\fP\fB, double \fP\fI*red_x\fP\fB, double \fP\fI*red_y\fP\fB, double \fP\fI*green_x\fP\fB, double \fP\fI*green_y\fP\fB, double \fP\fI*blue_x\fP\fB, double \fI*blue_y\fP\fB);\fP + +\fI\fB + +\fBpng_uint_32 png_get_cHRM_fixed (png_const_structp \fP\fIpng_ptr\fP\fB, png_const_infop \fP\fIinfo_ptr\fP\fB, png_uint_32 \fP\fI*white_x\fP\fB, png_uint_32 \fP\fI*white_y\fP\fB, png_uint_32 \fP\fI*red_x\fP\fB, png_uint_32 \fP\fI*red_y\fP\fB, png_uint_32 \fP\fI*green_x\fP\fB, png_uint_32 \fP\fI*green_y\fP\fB, png_uint_32 \fP\fI*blue_x\fP\fB, png_uint_32 \fI*blue_y\fP\fB);\fP + +\fI\fB + +\fBpng_uint_32 png_get_chunk_cache_max (png_const_structp \fIpng_ptr\fP\fB);\fP + +\fI\fB + +\fI\fB + +\fBpng_alloc_size_t png_get_chunk_malloc_max (png_const_structp \fIpng_ptr\fP\fB);\fP + +\fI\fB + +\fBpng_byte png_get_color_type (png_const_structp \fP\fIpng_ptr\fP\fB, png_const_infop \fIinfo_ptr\fP\fB);\fP + +\fI\fB + +\fBpng_uint_32 png_get_compression_buffer_size (png_const_structp \fIpng_ptr\fP\fB);\fP + +\fI\fB + +\fBpng_byte png_get_compression_type (png_const_structp \fP\fIpng_ptr\fP\fB, png_const_infop \fIinfo_ptr\fP\fB);\fP + +\fI\fB + +\fBpng_byte png_get_copyright (png_const_structp \fIpng_ptr\fP\fB);\fP + +\fI\fB + +\fBpng_uint_32 png_get_current_row_number \fI(png_const_structp\fP\fB);\fP + +\fI\fB + +\fBpng_byte png_get_current_pass_number \fI(png_const_structp\fP\fB);\fP + +\fI\fB + +\fBpng_voidp png_get_error_ptr (png_const_structp \fIpng_ptr\fP\fB);\fP + +\fI\fB + +\fBpng_byte png_get_filter_type (png_const_structp \fP\fIpng_ptr\fP\fB, png_const_infop \fIinfo_ptr\fP\fB);\fP + +\fI\fB + +\fBpng_uint_32 png_get_gAMA (png_const_structp \fP\fIpng_ptr\fP\fB, png_const_infop \fP\fIinfo_ptr\fP\fB, double \fI*file_gamma\fP\fB);\fP + +\fI\fB + +\fBpng_uint_32 png_get_gAMA_fixed (png_const_structp \fP\fIpng_ptr\fP\fB, png_const_infop \fP\fIinfo_ptr\fP\fB, png_uint_32 \fI*int_file_gamma\fP\fB);\fP + +\fI\fB + +\fBpng_byte png_get_header_ver (png_const_structp \fIpng_ptr\fP\fB);\fP + +\fI\fB + +\fBpng_byte png_get_header_version (png_const_structp \fIpng_ptr\fP\fB);\fP + +\fI\fB + +\fBpng_uint_32 png_get_hIST (png_const_structp \fP\fIpng_ptr\fP\fB, png_const_infop \fP\fIinfo_ptr\fP\fB, png_uint_16p \fI*hist\fP\fB);\fP + +\fI\fB + +\fBpng_uint_32 png_get_iCCP (png_const_structp \fP\fIpng_ptr\fP\fB, png_const_infop \fP\fIinfo_ptr\fP\fB, png_charpp \fP\fIname\fP\fB, int \fP\fI*compression_type\fP\fB, png_bytepp \fP\fIprofile\fP\fB, png_uint_32 \fI*proflen\fP\fB);\fP + +\fI\fB + +\fBpng_uint_32 png_get_IHDR (png_structp \fP\fIpng_ptr\fP\fB, png_infop \fP\fIinfo_ptr\fP\fB, png_uint_32 \fP\fI*width\fP\fB, png_uint_32 \fP\fI*height\fP\fB, int \fP\fI*bit_depth\fP\fB, int \fP\fI*color_type\fP\fB, int \fP\fI*interlace_type\fP\fB, int \fP\fI*compression_type\fP\fB, int \fI*filter_type\fP\fB);\fP + +\fI\fB + +\fBpng_uint_32 png_get_image_height (png_const_structp \fP\fIpng_ptr\fP\fB, png_const_infop \fIinfo_ptr\fP\fB);\fP + +\fI\fB + +\fBpng_uint_32 png_get_image_width (png_const_structp \fP\fIpng_ptr\fP\fB, png_const_infop \fIinfo_ptr\fP\fB);\fP + +\fI\fB + +\fBpng_int_32 png_get_int_32 (png_bytep \fIbuf\fP\fB);\fP + +\fI\fB + +\fBpng_byte png_get_interlace_type (png_const_structp \fP\fIpng_ptr\fP\fB, png_const_infop \fIinfo_ptr\fP\fB);\fP + +\fI\fB + +\fBpng_const_bytep png_get_io_chunk_name (png_structp \fIpng_ptr\fP\fB);\fP + +\fI\fB + +\fBpng_uint_32 png_get_io_chunk_type (png_const_structp \fIpng_ptr\fP\fB);\fP + +\fI\fB + +\fBpng_voidp png_get_io_ptr (png_structp \fIpng_ptr\fP\fB);\fP + +\fI\fB + +\fBpng_uint_32 png_get_io_state (png_structp \fIpng_ptr\fP\fB);\fP + +\fI\fB + +\fBpng_byte png_get_libpng_ver (png_const_structp \fIpng_ptr\fP\fB);\fP + +\fI\fB + +\fBpng_voidp png_get_mem_ptr (png_const_structp \fIpng_ptr\fP\fB);\fP + +\fI\fB + +\fBpng_uint_32 png_get_oFFs (png_const_structp \fP\fIpng_ptr\fP\fB, png_const_infop \fP\fIinfo_ptr\fP\fB, png_uint_32 \fP\fI*offset_x\fP\fB, png_uint_32 \fP\fI*offset_y\fP\fB, int \fI*unit_type\fP\fB);\fP + +\fI\fB + +\fBpng_uint_32 png_get_pCAL (png_const_structp \fP\fIpng_ptr\fP\fB, png_const_infop \fP\fIinfo_ptr\fP\fB, png_charp \fP\fI*purpose\fP\fB, png_int_32 \fP\fI*X0\fP\fB, png_int_32 \fP\fI*X1\fP\fB, int \fP\fI*type\fP\fB, int \fP\fI*nparams\fP\fB, png_charp \fP\fI*units\fP\fB, png_charpp \fI*params\fP\fB);\fP + +\fI\fB + +\fBpng_uint_32 png_get_pHYs (png_const_structp \fP\fIpng_ptr\fP\fB, png_const_infop \fP\fIinfo_ptr\fP\fB, png_uint_32 \fP\fI*res_x\fP\fB, png_uint_32 \fP\fI*res_y\fP\fB, int \fI*unit_type\fP\fB);\fP + +\fI\fB + +\fBfloat png_get_pixel_aspect_ratio (png_const_structp \fP\fIpng_ptr\fP\fB, png_const_infop \fIinfo_ptr\fP\fB);\fP + +\fI\fB + +\fBpng_uint_32 png_get_pHYs_dpi (png_const_structp \fP\fIpng_ptr\fP\fB, png_const_infop \fP\fIinfo_ptr\fP\fB, png_uint_32 \fP\fI*res_x\fP\fB, png_uint_32 \fP\fI*res_y\fP\fB, int \fI*unit_type\fP\fB);\fP + +\fI\fB + +\fBpng_fixed_point png_get_pixel_aspect_ratio_fixed (png_const_structp \fP\fIpng_ptr\fP\fB, png_const_infop \fIinfo_ptr\fP\fB);\fP + +\fI\fB + +\fBpng_uint_32 png_get_pixels_per_inch (png_const_structp \fP\fIpng_ptr\fP\fB, png_const_infop \fIinfo_ptr\fP\fB);\fP + +\fI\fB + +\fBpng_uint_32 png_get_pixels_per_meter (png_const_structp \fP\fIpng_ptr\fP\fB, png_const_infop \fIinfo_ptr\fP\fB);\fP + +\fI\fB + +\fBpng_voidp png_get_progressive_ptr (png_const_structp \fIpng_ptr\fP\fB);\fP + +\fI\fB + +\fBpng_uint_32 png_get_PLTE (png_const_structp \fP\fIpng_ptr\fP\fB, png_const_infop \fP\fIinfo_ptr\fP\fB, png_colorp \fP\fI*palette\fP\fB, int \fI*num_palette\fP\fB);\fP + +\fI\fB + +\fBpng_byte png_get_rgb_to_gray_status (png_const_structp \fIpng_ptr) + +\fBpng_uint_32 png_get_rowbytes (png_const_structp \fP\fIpng_ptr\fP\fB, png_const_infop \fIinfo_ptr\fP\fB);\fP + +\fI\fB + +\fBpng_bytepp png_get_rows (png_const_structp \fP\fIpng_ptr\fP\fB, png_const_infop \fIinfo_ptr\fP\fB);\fP + +\fI\fB + +\fBpng_uint_32 png_get_sBIT (png_const_structp \fP\fIpng_ptr\fP\fB, png_infop \fP\fIinfo_ptr\fP\fB, png_color_8p \fI*sig_bit\fP\fB);\fP + +\fI\fB + +\fBvoid png_get_sCAL (png_const_structp \fP\fIpng_ptr\fP\fB, png_const_infop \fP\fIinfo_ptr\fP\fB, int* \fP\fIunit\fP\fB, double* \fP\fIwidth\fP\fB, double* \fIheight\fP\fB);\fP + +\fI\fB + +\fBvoid png_get_sCAL_fixed (png_const_structp \fP\fIpng_ptr\fP\fB, png_const_infop \fP\fIinfo_ptr\fP\fB, int* \fP\fIunit\fP\fB, png_fixed_pointp \fP\fIwidth\fP\fB, png_fixed_pointp \fIheight\fP\fB);\fP + +\fI\fB + +\fBvoid png_get_sCAL_s (png_const_structp \fP\fIpng_ptr\fP\fB, png_const_infop \fP\fIinfo_ptr\fP\fB, int* \fP\fIunit\fP\fB, png_charpp \fP\fIwidth\fP\fB, png_charpp \fIheight\fP\fB);\fP + +\fI\fB + +\fBpng_bytep png_get_signature (png_const_structp \fP\fIpng_ptr\fP\fB, png_infop \fIinfo_ptr\fP\fB);\fP + +\fI\fB + +\fBpng_uint_32 png_get_sPLT (png_const_structp \fP\fIpng_ptr\fP\fB, png_const_infop \fP\fIinfo_ptr\fP\fB, png_spalette_p \fI*splt_ptr\fP\fB);\fP + +\fI\fB + +\fBpng_uint_32 png_get_sRGB (png_const_structp \fP\fIpng_ptr\fP\fB, png_const_infop \fP\fIinfo_ptr\fP\fB, int \fI*file_srgb_intent\fP\fB);\fP + +\fI\fB + +\fBpng_uint_32 png_get_text (png_const_structp \fP\fIpng_ptr\fP\fB, png_const_infop \fP\fIinfo_ptr\fP\fB, png_textp \fP\fI*text_ptr\fP\fB, int \fI*num_text\fP\fB);\fP + +\fI\fB + +\fBpng_uint_32 png_get_tIME (png_const_structp \fP\fIpng_ptr\fP\fB, png_infop \fP\fIinfo_ptr\fP\fB, png_timep \fI*mod_time\fP\fB);\fP + +\fI\fB + +\fBpng_uint_32 png_get_tRNS (png_const_structp \fP\fIpng_ptr\fP\fB, png_infop \fP\fIinfo_ptr\fP\fB, png_bytep \fP\fI*trans_alpha\fP\fB, int \fP\fI*num_trans\fP\fB, png_color_16p \fI*trans_color\fP\fB);\fP + +\fI\fB + +\fB/* This function is really an inline macro. \fI*/ + +\fBpng_uint_16 png_get_uint_16 (png_bytep \fIbuf\fP\fB);\fP + +\fI\fB + +\fBpng_uint_32 png_get_uint_31 (png_structp \fP\fIpng_ptr\fP\fB, png_bytep \fIbuf\fP\fB);\fP + +\fI\fB + +\fB/* This function is really an inline macro. \fI*/ + +\fBpng_uint_32 png_get_uint_32 (png_bytep \fIbuf\fP\fB);\fP + +\fI\fB + +\fBpng_uint_32 png_get_unknown_chunks (png_const_structp \fP\fIpng_ptr\fP\fB, png_const_infop \fP\fIinfo_ptr\fP\fB, png_unknown_chunkpp \fIunknowns\fP\fB);\fP + +\fI\fB + +\fBpng_voidp png_get_user_chunk_ptr (png_const_structp \fIpng_ptr\fP\fB);\fP + +\fI\fB + +\fBpng_uint_32 png_get_user_height_max (png_const_structp \fIpng_ptr\fP\fB);\fP + +\fI\fB + +\fBpng_voidp png_get_user_transform_ptr (png_const_structp \fIpng_ptr\fP\fB);\fP + +\fI\fB + +\fBpng_uint_32 png_get_user_width_max (png_const_structp \fIpng_ptr\fP\fB);\fP + +\fI\fB + +\fBpng_uint_32 png_get_valid (png_const_structp \fP\fIpng_ptr\fP\fB, png_const_infop \fP\fIinfo_ptr\fP\fB, png_uint_32 \fIflag\fP\fB);\fP + +\fI\fB + +\fBfloat png_get_x_offset_inches (png_const_structp \fP\fIpng_ptr\fP\fB, png_const_infop \fIinfo_ptr\fP\fB);\fP + +\fI\fB + +\fBpng_fixed_point png_get_x_offset_inches_fixed (png_structp \fP\fIpng_ptr\fP\fB, png_const_infop \fIinfo_ptr\fP\fB);\fP + +\fI\fB + +\fBpng_int_32 png_get_x_offset_microns (png_const_structp \fP\fIpng_ptr\fP\fB, png_const_infop \fIinfo_ptr\fP\fB);\fP + +\fI\fB + +\fBpng_int_32 png_get_x_offset_pixels (png_const_structp \fP\fIpng_ptr\fP\fB, png_const_infop \fIinfo_ptr\fP\fB);\fP + +\fI\fB + +\fBpng_uint_32 png_get_x_pixels_per_inch (png_const_structp \fP\fIpng_ptr\fP\fB, png_const_infop \fIinfo_ptr\fP\fB);\fP + +\fI\fB + +\fBpng_uint_32 png_get_x_pixels_per_meter (png_const_structp \fP\fIpng_ptr\fP\fB, png_const_infop \fIinfo_ptr\fP\fB);\fP + +\fI\fB + +\fBfloat png_get_y_offset_inches (png_const_structp \fP\fIpng_ptr\fP\fB, png_const_infop \fIinfo_ptr\fP\fB);\fP + +\fI\fB + +\fBpng_fixed_point png_get_y_offset_inches_fixed (png_structp \fP\fIpng_ptr\fP\fB, png_const_infop \fIinfo_ptr\fP\fB);\fP + +\fI\fB + +\fBpng_int_32 png_get_y_offset_microns (png_const_structp \fP\fIpng_ptr\fP\fB, png_const_infop \fIinfo_ptr\fP\fB);\fP + +\fI\fB + +\fBpng_int_32 png_get_y_offset_pixels (png_const_structp \fP\fIpng_ptr\fP\fB, png_const_infop \fIinfo_ptr\fP\fB);\fP + +\fI\fB + +\fBpng_uint_32 png_get_y_pixels_per_inch (png_const_structp \fP\fIpng_ptr\fP\fB, png_const_infop \fIinfo_ptr\fP\fB);\fP + +\fI\fB + +\fBpng_uint_32 png_get_y_pixels_per_meter (png_const_structp \fP\fIpng_ptr\fP\fB, png_const_infop \fIinfo_ptr\fP\fB);\fP + +\fI\fB + +\fBint png_handle_as_unknown (png_structp \fP\fIpng_ptr\fP\fB, png_bytep \fIchunk_name\fP\fB);\fP + +\fI\fB + +\fBvoid png_info_init_3 (png_infopp \fP\fIinfo_ptr\fP\fB, png_size_t \fIpng_info_struct_size\fP\fB);\fP + +\fI\fB + +\fBvoid png_init_io (png_structp \fP\fIpng_ptr\fP\fB, FILE \fI*fp\fP\fB);\fP + +\fI\fB + +\fBvoid png_longjmp (png_structp \fP\fIpng_ptr\fP\fB, int \fIval\fP\fB);\fP + +\fI\fB + +\fBpng_voidp png_malloc (png_structp \fP\fIpng_ptr\fP\fB, png_alloc_size_t \fIsize\fP\fB);\fP + +\fI\fB + +\fBpng_voidp png_malloc_default (png_structp \fP\fIpng_ptr\fP\fB, png_alloc_size_t \fIsize\fP\fB);\fP + +\fI\fB + +\fBpng_voidp png_malloc_warn (png_structp \fP\fIpng_ptr\fP\fB, png_alloc_size_t \fIsize\fP\fB);\fP + +\fI\fB + +\fBpng_uint_32 png_permit_mng_features (png_structp \fP\fIpng_ptr\fP\fB, png_uint_32 \fImng_features_permitted\fP\fB);\fP + +\fI\fB + +\fBvoid png_process_data (png_structp \fP\fIpng_ptr\fP\fB, png_infop \fP\fIinfo_ptr\fP\fB, png_bytep \fP\fIbuffer\fP\fB, png_size_t \fIbuffer_size\fP\fB);\fP + +\fI\fB + +\fBpng_size_t png_process_data_pause \fP\fI(png_structp\fP\fB, int \fIsave\fP\fB);\fP + +\fI\fB + +\fBpng_uint_32 png_process_data_skip \fI(png_structp\fP\fB);\fP + +\fI\fB + +\fBvoid png_progressive_combine_row (png_structp \fP\fIpng_ptr\fP\fB, png_bytep \fP\fIold_row\fP\fB, png_bytep \fInew_row\fP\fB);\fP + +\fI\fB + +\fBvoid png_read_end (png_structp \fP\fIpng_ptr\fP\fB, png_infop \fIinfo_ptr\fP\fB);\fP + +\fI\fB + +\fBvoid png_read_image (png_structp \fP\fIpng_ptr\fP\fB, png_bytepp \fIimage\fP\fB);\fP + +\fI\fB + +\fBvoid png_read_info (png_structp \fP\fIpng_ptr\fP\fB, png_infop \fIinfo_ptr\fP\fB);\fP + +\fI\fB + +\fBvoid png_read_png (png_structp \fP\fIpng_ptr\fP\fB, png_infop \fP\fIinfo_ptr\fP\fB, int \fP\fItransforms\fP\fB, png_voidp \fIparams\fP\fB);\fP + +\fI\fB + +\fBvoid png_read_row (png_structp \fP\fIpng_ptr\fP\fB, png_bytep \fP\fIrow\fP\fB, png_bytep \fIdisplay_row\fP\fB);\fP + +\fI\fB + +\fBvoid png_read_rows (png_structp \fP\fIpng_ptr\fP\fB, png_bytepp \fP\fIrow\fP\fB, png_bytepp \fP\fIdisplay_row\fP\fB, png_uint_32 \fInum_rows\fP\fB);\fP + +\fI\fB + +\fBvoid png_read_update_info (png_structp \fP\fIpng_ptr\fP\fB, png_infop \fIinfo_ptr\fP\fB);\fP + +\fI\fB + +\fBint png_reset_zstream (png_structp \fIpng_ptr\fP\fB);\fP + +\fI\fB + +\fBvoid png_save_int_32 (png_bytep \fP\fIbuf\fP\fB, png_int_32 \fIi\fP\fB);\fP + +\fI\fB + +\fBvoid png_save_uint_16 (png_bytep \fP\fIbuf\fP\fB, unsigned int \fIi\fP\fB);\fP + +\fI\fB + +\fBvoid png_save_uint_32 (png_bytep \fP\fIbuf\fP\fB, png_uint_32 \fIi\fP\fB);\fP + +\fI\fB + +\fBvoid png_set_add_alpha (png_structp \fP\fIpng_ptr\fP\fB, png_uint_32 \fP\fIfiller\fP\fB, int \fIflags\fP\fB);\fP + +\fI\fB + +\fBvoid png_set_background (png_structp \fP\fIpng_ptr\fP\fB, png_color_16p \fP\fIbackground_color\fP\fB, int \fP\fIbackground_gamma_code\fP\fB, int \fP\fIneed_expand\fP\fB, double \fIbackground_gamma\fP\fB);\fP + +\fI\fB + +\fBvoid png_set_background_fixed (png_structp \fP\fIpng_ptr\fP\fB, png_color_16p \fP\fIbackground_color\fP\fB, int \fP\fIbackground_gamma_code\fP\fB, int \fP\fIneed_expand\fP\fB, png_uint_32 \fIbackground_gamma\fP\fB);\fP + +\fI\fB + +\fBvoid png_set_benign_errors (png_structp \fP\fIpng_ptr\fP\fB, int \fIallowed\fP\fB);\fP + +\fI\fB + +\fBvoid png_set_bgr (png_structp \fIpng_ptr\fP\fB);\fP + +\fI\fB + +\fBvoid png_set_bKGD (png_structp \fP\fIpng_ptr\fP\fB, png_infop \fP\fIinfo_ptr\fP\fB, png_color_16p \fIbackground\fP\fB);\fP + +\fI\fB + +\fBvoid png_set_cHRM (png_structp \fP\fIpng_ptr\fP\fB, png_infop \fP\fIinfo_ptr\fP\fB, double \fP\fIwhite_x\fP\fB, double \fP\fIwhite_y\fP\fB, double \fP\fIred_x\fP\fB, double \fP\fIred_y\fP\fB, double \fP\fIgreen_x\fP\fB, double \fP\fIgreen_y\fP\fB, double \fP\fIblue_x\fP\fB, double \fIblue_y\fP\fB);\fP + +\fI\fB + +\fBvoid png_set_cHRM_fixed (png_structp \fP\fIpng_ptr\fP\fB, png_infop \fP\fIinfo_ptr\fP\fB, png_uint_32 \fP\fIwhite_x\fP\fB, png_uint_32 \fP\fIwhite_y\fP\fB, png_uint_32 \fP\fIred_x\fP\fB, png_uint_32 \fP\fIred_y\fP\fB, png_uint_32 \fP\fIgreen_x\fP\fB, png_uint_32 \fP\fIgreen_y\fP\fB, png_uint_32 \fP\fIblue_x\fP\fB, png_uint_32 \fIblue_y\fP\fB);\fP + +\fI\fB + +\fBvoid png_set_chunk_cache_max (png_structp \fP\fIpng_ptr\fP\fB, png_uint_32 \fIuser_chunk_cache_max\fP\fB);\fP + +\fI\fB + +\fBvoid png_set_compression_level (png_structp \fP\fIpng_ptr\fP\fB, int \fIlevel\fP\fB);\fP + +\fI\fB + +\fBvoid png_set_compression_mem_level (png_structp \fP\fIpng_ptr\fP\fB, int \fImem_level\fP\fB);\fP + +\fI\fB + +\fBvoid png_set_compression_method (png_structp \fP\fIpng_ptr\fP\fB, int \fImethod\fP\fB);\fP + +\fI\fB + +\fBvoid png_set_compression_strategy (png_structp \fP\fIpng_ptr\fP\fB, int \fIstrategy\fP\fB);\fP + +\fI\fB + +\fBvoid png_set_compression_window_bits (png_structp \fP\fIpng_ptr\fP\fB, int \fIwindow_bits\fP\fB);\fP + +\fI\fB + +\fBvoid png_set_crc_action (png_structp \fP\fIpng_ptr\fP\fB, int \fP\fIcrit_action\fP\fB, int \fIancil_action\fP\fB);\fP + +\fI\fB + +\fBvoid png_set_error_fn (png_structp \fP\fIpng_ptr\fP\fB, png_voidp \fP\fIerror_ptr\fP\fB, png_error_ptr \fP\fIerror_fn\fP\fB, png_error_ptr \fIwarning_fn\fP\fB);\fP + +\fI\fB + +\fBvoid png_set_expand (png_structp \fIpng_ptr\fP\fB);\fP + +\fI\fB + +\fBvoid png_set_expand_gray_1_2_4_to_8 (png_structp \fIpng_ptr\fP\fB);\fP + +\fI\fB + +\fBvoid png_set_filler (png_structp \fP\fIpng_ptr\fP\fB, png_uint_32 \fP\fIfiller\fP\fB, int \fIflags\fP\fB);\fP + +\fI\fB + +\fBvoid png_set_filter (png_structp \fP\fIpng_ptr\fP\fB, int \fP\fImethod\fP\fB, int \fIfilters\fP\fB);\fP + +\fI\fB + +\fBvoid png_set_filter_heuristics (png_structp \fP\fIpng_ptr\fP\fB, int \fP\fIheuristic_method\fP\fB, int \fP\fInum_weights\fP\fB, png_doublep \fP\fIfilter_weights\fP\fB, png_doublep \fIfilter_costs\fP\fB);\fP + +\fI\fB + +\fBvoid png_set_filter_heuristics_fixed (png_structp \fP\fIpng_ptr\fP\fB, int \fP\fIheuristic_method\fP\fB, int \fP\fInum_weights\fP\fB, png_fixed_point_p \fP\fIfilter_weights\fP\fB, png_fixed_point_p \fIfilter_costs\fP\fB);\fP + +\fI\fB + +\fBvoid png_set_flush (png_structp \fP\fIpng_ptr\fP\fB, int \fInrows\fP\fB);\fP + +\fI\fB + +\fBvoid png_set_gamma (png_structp \fP\fIpng_ptr\fP\fB, double \fP\fIscreen_gamma\fP\fB, double \fIdefault_file_gamma\fP\fB);\fP + +\fI\fB + +\fBvoid png_set_gamma_fixed (png_structp \fP\fIpng_ptr\fP\fB, png_uint_32 \fP\fIscreen_gamma\fP\fB, png_uint_32 \fIdefault_file_gamma\fP\fB);\fP + +\fI\fB + +\fBvoid png_set_gAMA (png_structp \fP\fIpng_ptr\fP\fB, png_infop \fP\fIinfo_ptr\fP\fB, double \fIfile_gamma\fP\fB);\fP + +\fI\fB + +\fBvoid png_set_gAMA_fixed (png_structp \fP\fIpng_ptr\fP\fB, png_infop \fP\fIinfo_ptr\fP\fB, png_uint_32 \fIfile_gamma\fP\fB);\fP + +\fI\fB + +\fBvoid png_set_gray_1_2_4_to_8 (png_structp \fIpng_ptr\fP\fB);\fP + +\fI\fB + +\fBvoid png_set_gray_to_rgb (png_structp \fIpng_ptr\fP\fB);\fP + +\fI\fB + +\fBvoid png_set_hIST (png_structp \fP\fIpng_ptr\fP\fB, png_infop \fP\fIinfo_ptr\fP\fB, png_uint_16p \fIhist\fP\fB);\fP + +\fI\fB + +\fBvoid png_set_iCCP (png_structp \fP\fIpng_ptr\fP\fB, png_infop \fP\fIinfo_ptr\fP\fB, png_const_charp \fP\fIname\fP\fB, int \fP\fIcompression_type\fP\fB, png_const_bytep \fP\fIprofile\fP\fB, png_uint_32 \fIproflen\fP\fB);\fP + +\fI\fB + +\fBint png_set_interlace_handling (png_structp \fIpng_ptr\fP\fB);\fP + +\fI\fB + +\fBvoid png_set_invalid (png_structp \fP\fIpng_ptr\fP\fB, png_infop \fP\fIinfo_ptr\fP\fB, int \fImask\fP\fB);\fP + +\fI\fB + +\fBvoid png_set_invert_alpha (png_structp \fIpng_ptr\fP\fB);\fP + +\fI\fB + +\fBvoid png_set_invert_mono (png_structp \fIpng_ptr\fP\fB);\fP + +\fI\fB + +\fBvoid png_set_IHDR (png_structp \fP\fIpng_ptr\fP\fB, png_infop \fP\fIinfo_ptr\fP\fB, png_uint_32 \fP\fIwidth\fP\fB, png_uint_32 \fP\fIheight\fP\fB, int \fP\fIbit_depth\fP\fB, int \fP\fIcolor_type\fP\fB, int \fP\fIinterlace_type\fP\fB, int \fP\fIcompression_type\fP\fB, int \fIfilter_type\fP\fB);\fP + +\fI\fB + +\fBvoid png_set_keep_unknown_chunks (png_structp \fP\fIpng_ptr\fP\fB, int \fP\fIkeep\fP\fB, png_bytep \fP\fIchunk_list\fP\fB, int \fInum_chunks\fP\fB);\fP + +\fI\fB + +\fBjmp_buf* png_set_longjmp_fn (png_structp \fP\fIpng_ptr\fP\fB, png_longjmp_ptr \fP\fIlongjmp_fn\fP\fB, size_t \fIjmp_buf_size\fP\fB);\fP + +\fI\fB + +\fBvoid png_set_chunk_malloc_max (png_structp \fP\fIpng_ptr\fP\fB, png_alloc_size_t \fIuser_chunk_cache_max\fP\fB);\fP + +\fI\fB + +\fBvoid png_set_compression_buffer_size (png_structp \fP\fIpng_ptr\fP\fB, png_uint_32 \fIsize\fP\fB);\fP + +\fI\fB + +\fBvoid png_set_mem_fn (png_structp \fP\fIpng_ptr\fP\fB, png_voidp \fP\fImem_ptr\fP\fB, png_malloc_ptr \fP\fImalloc_fn\fP\fB, png_free_ptr \fIfree_fn\fP\fB);\fP + +\fI\fB + +\fBvoid png_set_oFFs (png_structp \fP\fIpng_ptr\fP\fB, png_infop \fP\fIinfo_ptr\fP\fB, png_uint_32 \fP\fIoffset_x\fP\fB, png_uint_32 \fP\fIoffset_y\fP\fB, int \fIunit_type\fP\fB);\fP + +\fI\fB + +\fBvoid png_set_packing (png_structp \fIpng_ptr\fP\fB);\fP + +\fI\fB + +\fBvoid png_set_packswap (png_structp \fIpng_ptr\fP\fB);\fP + +\fI\fB + +\fBvoid png_set_palette_to_rgb (png_structp \fIpng_ptr\fP\fB);\fP + +\fI\fB + +\fBvoid png_set_pCAL (png_structp \fP\fIpng_ptr\fP\fB, png_infop \fP\fIinfo_ptr\fP\fB, png_charp \fP\fIpurpose\fP\fB, png_int_32 \fP\fIX0\fP\fB, png_int_32 \fP\fIX1\fP\fB, int \fP\fItype\fP\fB, int \fP\fInparams\fP\fB, png_charp \fP\fIunits\fP\fB, png_charpp \fIparams\fP\fB);\fP + +\fI\fB + +\fBvoid png_set_pHYs (png_structp \fP\fIpng_ptr\fP\fB, png_infop \fP\fIinfo_ptr\fP\fB, png_uint_32 \fP\fIres_x\fP\fB, png_uint_32 \fP\fIres_y\fP\fB, int \fIunit_type\fP\fB);\fP + +\fI\fB + +\fBvoid png_set_progressive_read_fn (png_structp \fP\fIpng_ptr\fP\fB, png_voidp \fP\fIprogressive_ptr\fP\fB, png_progressive_info_ptr \fP\fIinfo_fn\fP\fB, png_progressive_row_ptr \fP\fIrow_fn\fP\fB, png_progressive_end_ptr \fIend_fn\fP\fB);\fP + +\fI\fB + +\fBvoid png_set_PLTE (png_structp \fP\fIpng_ptr\fP\fB, png_infop \fP\fIinfo_ptr\fP\fB, png_colorp \fP\fIpalette\fP\fB, int \fInum_palette\fP\fB);\fP + +\fI\fB + +\fBvoid png_set_quantize (png_structp \fP\fIpng_ptr\fP\fB, png_colorp \fP\fIpalette\fP\fB, int \fP\fInum_palette\fP\fB, int \fP\fImaximum_colors\fP\fB, png_uint_16p \fP\fIhistogram\fP\fB, int \fIfull_quantize\fP\fB);\fP + +\fI\fB + +\fBvoid png_set_read_fn (png_structp \fP\fIpng_ptr\fP\fB, png_voidp \fP\fIio_ptr\fP\fB, png_rw_ptr \fIread_data_fn\fP\fB);\fP + +\fI\fB + +\fBvoid png_set_read_status_fn (png_structp \fP\fIpng_ptr\fP\fB, png_read_status_ptr \fIread_row_fn\fP\fB);\fP + +\fI\fB + +\fBvoid png_set_read_user_chunk_fn (png_structp \fP\fIpng_ptr\fP\fB, png_voidp \fP\fIuser_chunk_ptr\fP\fB, png_user_chunk_ptr \fIread_user_chunk_fn\fP\fB);\fP + +\fI\fB + +\fBvoid png_set_read_user_transform_fn (png_structp \fP\fIpng_ptr\fP\fB, png_user_transform_ptr \fIread_user_transform_fn\fP\fB);\fP + +\fI\fB + +\fBvoid png_set_rgb_to_gray (png_structp \fP\fIpng_ptr\fP\fB, int \fP\fIerror_action\fP\fB, double \fP\fIred\fP\fB, double \fIgreen\fP\fB);\fP + +\fI\fB + +\fBvoid png_set_rgb_to_gray_fixed (png_structp \fP\fIpng_ptr\fP\fB, int error_action png_uint_32 \fP\fIred\fP\fB, png_uint_32 \fIgreen\fP\fB);\fP + +\fI\fB + +\fBvoid png_set_rows (png_structp \fP\fIpng_ptr\fP\fB, png_infop \fP\fIinfo_ptr\fP\fB, png_bytepp \fIrow_pointers\fP\fB);\fP + +\fI\fB + +\fBvoid png_set_sBIT (png_structp \fP\fIpng_ptr\fP\fB, png_infop \fP\fIinfo_ptr\fP\fB, png_color_8p \fIsig_bit\fP\fB);\fP + +\fI\fB + +\fBvoid png_set_sCAL (png_structp \fP\fIpng_ptr\fP\fB, png_infop \fP\fIinfo_ptr\fP\fB, int \fP\fIunit\fP\fB, double \fP\fIwidth\fP\fB, double \fIheight\fP\fB);\fP + +\fI\fB + +\fBvoid png_set_sCAL_fixed (png_structp \fP\fIpng_ptr\fP\fB, png_infop \fP\fIinfo_ptr\fP\fB, int \fP\fIunit\fP\fB, png_fixed_point \fP\fIwidth\fP\fB, png_fixed_point \fIheight\fP\fB);\fP + +\fI\fB + +\fBvoid png_set_sCAL_s (png_structp \fP\fIpng_ptr\fP\fB, png_infop \fP\fIinfo_ptr\fP\fB, int \fP\fIunit\fP\fB, png_charp \fP\fIwidth\fP\fB, png_charp \fIheight\fP\fB);\fP + +\fI\fB + +\fBvoid png_set_shift (png_structp \fP\fIpng_ptr\fP\fB, png_color_8p \fItrue_bits\fP\fB);\fP + +\fI\fB + +\fBvoid png_set_sig_bytes (png_structp \fP\fIpng_ptr\fP\fB, int \fInum_bytes\fP\fB);\fP + +\fI\fB + +\fBvoid png_set_sPLT (png_structp \fP\fIpng_ptr\fP\fB, png_infop \fP\fIinfo_ptr\fP\fB, png_spalette_p \fP\fIsplt_ptr\fP\fB, int \fInum_spalettes\fP\fB);\fP + +\fI\fB + +\fBvoid png_set_sRGB (png_structp \fP\fIpng_ptr\fP\fB, png_infop \fP\fIinfo_ptr\fP\fB, int \fIsrgb_intent\fP\fB);\fP + +\fI\fB + +\fBvoid png_set_sRGB_gAMA_and_cHRM (png_structp \fP\fIpng_ptr\fP\fB, png_infop \fP\fIinfo_ptr\fP\fB, int \fIsrgb_intent\fP\fB);\fP + +\fI\fB + +\fBvoid png_set_strip_16 (png_structp \fIpng_ptr\fP\fB);\fP + +\fI\fB + +\fBvoid png_set_strip_alpha (png_structp \fIpng_ptr\fP\fB);\fP + +\fI\fB + +\fBvoid png_set_strip_error_numbers (png_structp \fP\fIpng_ptr\fP\fB, png_uint_32 \fIstrip_mode\fP\fB);\fP + +\fI\fB + +\fBvoid png_set_swap (png_structp \fIpng_ptr\fP\fB);\fP + +\fI\fB + +\fBvoid png_set_swap_alpha (png_structp \fIpng_ptr\fP\fB);\fP + +\fI\fB + +\fBvoid png_set_text (png_structp \fP\fIpng_ptr\fP\fB, png_infop \fP\fIinfo_ptr\fP\fB, png_textp \fP\fItext_ptr\fP\fB, int \fInum_text\fP\fB);\fP + +\fI\fB + +\fBvoid png_set_tIME (png_structp \fP\fIpng_ptr\fP\fB, png_infop \fP\fIinfo_ptr\fP\fB, png_timep \fImod_time\fP\fB);\fP + +\fI\fB + +\fBvoid png_set_tRNS (png_structp \fP\fIpng_ptr\fP\fB, png_infop \fP\fIinfo_ptr\fP\fB, png_bytep \fP\fItrans_alpha\fP\fB, int \fP\fInum_trans\fP\fB, png_color_16p \fItrans_color\fP\fB);\fP + +\fI\fB + +\fBvoid png_set_tRNS_to_alpha (png_structp \fIpng_ptr\fP\fB);\fP + +\fI\fB + +\fBpng_uint_32 png_set_unknown_chunks (png_structp \fP\fIpng_ptr\fP\fB, png_infop \fP\fIinfo_ptr\fP\fB, png_unknown_chunkp \fP\fIunknowns\fP\fB, int \fP\fInum\fP\fB, int \fIlocation\fP\fB);\fP + +\fI\fB + +\fBvoid png_set_unknown_chunk_location (png_structp \fP\fIpng_ptr\fP\fB, png_infop \fP\fIinfo_ptr\fP\fB, int \fP\fIchunk\fP\fB, int \fIlocation\fP\fB);\fP + +\fI\fB + +\fBvoid png_set_user_limits (png_structp \fP\fIpng_ptr\fP\fB, png_uint_32 \fP\fIuser_width_max\fP\fB, png_uint_32 \fIuser_height_max\fP\fB);\fP + +\fI\fB + +\fBvoid png_set_user_transform_info (png_structp \fP\fIpng_ptr\fP\fB, png_voidp \fP\fIuser_transform_ptr\fP\fB, int \fP\fIuser_transform_depth\fP\fB, int \fIuser_transform_channels\fP\fB);\fP + +\fI\fB + +\fBvoid png_set_write_fn (png_structp \fP\fIpng_ptr\fP\fB, png_voidp \fP\fIio_ptr\fP\fB, png_rw_ptr \fP\fIwrite_data_fn\fP\fB, png_flush_ptr \fIoutput_flush_fn\fP\fB);\fP + +\fI\fB + +\fBvoid png_set_write_status_fn (png_structp \fP\fIpng_ptr\fP\fB, png_write_status_ptr \fIwrite_row_fn\fP\fB);\fP + +\fI\fB + +\fBvoid png_set_write_user_transform_fn (png_structp \fP\fIpng_ptr\fP\fB, png_user_transform_ptr \fIwrite_user_transform_fn\fP\fB);\fP + +\fI\fB + +\fBint png_sig_cmp (png_bytep \fP\fIsig\fP\fB, png_size_t \fP\fIstart\fP\fB, png_size_t \fInum_to_check\fP\fB);\fP + +\fI\fB + +\fBvoid png_start_read_image (png_structp \fIpng_ptr\fP\fB);\fP + +\fI\fB + +\fBvoid png_warning (png_structp \fP\fIpng_ptr\fP\fB, png_const_charp \fImessage\fP\fB);\fP + +\fI\fB + +\fBvoid png_write_chunk (png_structp \fP\fIpng_ptr\fP\fB, png_bytep \fP\fIchunk_name\fP\fB, png_bytep \fP\fIdata\fP\fB, png_size_t \fIlength\fP\fB);\fP + +\fI\fB + +\fBvoid png_write_chunk_data (png_structp \fP\fIpng_ptr\fP\fB, png_bytep \fP\fIdata\fP\fB, png_size_t \fIlength\fP\fB);\fP + +\fI\fB + +\fBvoid png_write_chunk_end (png_structp \fIpng_ptr\fP\fB);\fP + +\fI\fB + +\fBvoid png_write_chunk_start (png_structp \fP\fIpng_ptr\fP\fB, png_bytep \fP\fIchunk_name\fP\fB, png_uint_32 \fIlength\fP\fB);\fP + +\fI\fB + +\fBvoid png_write_end (png_structp \fP\fIpng_ptr\fP\fB, png_infop \fIinfo_ptr\fP\fB);\fP + +\fI\fB + +\fBvoid png_write_flush (png_structp \fIpng_ptr\fP\fB);\fP + +\fI\fB + +\fBvoid png_write_image (png_structp \fP\fIpng_ptr\fP\fB, png_bytepp \fIimage\fP\fB);\fP + +\fI\fB + +\fBvoid png_write_info (png_structp \fP\fIpng_ptr\fP\fB, png_infop \fIinfo_ptr\fP\fB);\fP + +\fI\fB + +\fBvoid png_write_info_before_PLTE (png_structp \fP\fIpng_ptr\fP\fB, png_infop \fIinfo_ptr\fP\fB);\fP + +\fI\fB + +\fBvoid png_write_png (png_structp \fP\fIpng_ptr\fP\fB, png_infop \fP\fIinfo_ptr\fP\fB, int \fP\fItransforms\fP\fB, png_voidp \fIparams\fP\fB);\fP + +\fI\fB + +\fBvoid png_write_row (png_structp \fP\fIpng_ptr\fP\fB, png_bytep \fIrow\fP\fB);\fP + +\fI\fB + +\fBvoid png_write_rows (png_structp \fP\fIpng_ptr\fP\fB, png_bytepp \fP\fIrow\fP\fB, png_uint_32 \fInum_rows\fP\fB);\fP + +\fI\fB + +\fBvoid png_write_sig (png_structp \fIpng_ptr\fP\fB);\fP + +\fI\fB + +\fBvoidpf png_zalloc (voidpf \fP\fIpng_ptr\fP\fB, uInt \fP\fIitems\fP\fB, uInt \fIsize\fP\fB);\fP + +\fI\fB + +\fBvoid png_zfree (voidpf \fP\fIpng_ptr\fP\fB, voidpf \fIptr\fP\fB);\fP + +\fI\fB + +.SH DESCRIPTION +The +.I libpng +library supports encoding, decoding, and various manipulations of +the Portable Network Graphics (PNG) format image files. It uses the +.IR zlib(3) +compression library. +Following is a copy of the libpng-manual.txt file that accompanies libpng. +.SH LIBPNG.TXT +libpng-manual.txt - A description on how to use and modify libpng + + libpng version 1.5.1 - February 3, 2011 + Updated and distributed by Glenn Randers-Pehrson + <glennrp at users.sourceforge.net> + Copyright (c) 1998-2011 Glenn Randers-Pehrson + + This document is released under the libpng license. + For conditions of distribution and use, see the disclaimer + and license in png.h + + Based on: + + libpng versions 0.97, January 1998, through 1.5.1 - February 3, 2011 + Updated and distributed by Glenn Randers-Pehrson + Copyright (c) 1998-2011 Glenn Randers-Pehrson + + libpng 1.0 beta 6 version 0.96 May 28, 1997 + Updated and distributed by Andreas Dilger + Copyright (c) 1996, 1997 Andreas Dilger + + libpng 1.0 beta 2 - version 0.88 January 26, 1996 + For conditions of distribution and use, see copyright + notice in png.h. Copyright (c) 1995, 1996 Guy Eric + Schalnat, Group 42, Inc. + + Updated/rewritten per request in the libpng FAQ + Copyright (c) 1995, 1996 Frank J. T. Wojcik + December 18, 1995 & January 20, 1996 + +.SH I. Introduction + +This file describes how to use and modify the PNG reference library +(known as libpng) for your own use. There are five sections to this +file: introduction, structures, reading, writing, and modification and +configuration notes for various special platforms. In addition to this +file, example.c is a good starting point for using the library, as +it is heavily commented and should include everything most people +will need. We assume that libpng is already installed; see the +INSTALL file for instructions on how to install libpng. + +For examples of libpng usage, see the files "example.c", "pngtest.c", +and the files in the "contrib" directory, all of which are included in +the libpng distribution. + +Libpng was written as a companion to the PNG specification, as a way +of reducing the amount of time and effort it takes to support the PNG +file format in application programs. + +The PNG specification (second edition), November 2003, is available as +a W3C Recommendation and as an ISO Standard (ISO/IEC 15948:2003 (E)) at +<http://www.w3.org/TR/2003/REC-PNG-20031110/ +The W3C and ISO documents have identical technical content. + +The PNG-1.2 specification is available at +<http://www.libpng.org/pub/png/documents/>. It is technically equivalent +to the PNG specification (second edition) but has some additional material. + +The PNG-1.0 specification is available +as RFC 2083 <http://www.libpng.org/pub/png/documents/> and as a +W3C Recommendation <http://www.w3.org/TR/REC.png.html>. + +Some additional chunks are described in the special-purpose public chunks +documents at <http://www.libpng.org/pub/png/documents/>. + +Other information +about PNG, and the latest version of libpng, can be found at the PNG home +page, <http://www.libpng.org/pub/png/>. + +Most users will not have to modify the library significantly; advanced +users may want to modify it more. All attempts were made to make it as +complete as possible, while keeping the code easy to understand. +Currently, this library only supports C. Support for other languages +is being considered. + +Libpng has been designed to handle multiple sessions at one time, +to be easily modifiable, to be portable to the vast majority of +machines (ANSI, K&R, 16-, 32-, and 64-bit) available, and to be easy +to use. The ultimate goal of libpng is to promote the acceptance of +the PNG file format in whatever way possible. While there is still +work to be done (see the TODO file), libpng should cover the +majority of the needs of its users. + +Libpng uses zlib for its compression and decompression of PNG files. +Further information about zlib, and the latest version of zlib, can +be found at the zlib home page, <http://www.info-zip.org/pub/infozip/zlib/>. +The zlib compression utility is a general purpose utility that is +useful for more than PNG files, and can be used without libpng. +See the documentation delivered with zlib for more details. +You can usually find the source files for the zlib utility wherever you +find the libpng source files. + +Libpng is thread safe, provided the threads are using different +instances of the structures. Each thread should have its own +png_struct and png_info instances, and thus its own image. +Libpng does not protect itself against two threads using the +same instance of a structure. + +.SH II. Structures + +There are two main structures that are important to libpng, png_struct +and png_info. Both are internal structures that are no longer exposed +in the libpng interface (as of libpng 1.5.0). + +The png_info structure is designed to provide information about the +PNG file. At one time, the fields of png_info were intended to be +directly accessible to the user. However, this tended to cause problems +with applications using dynamically loaded libraries, and as a result +a set of interface functions for png_info (the png_get_*() and png_set_*() +functions) was developed. + +The png_struct structure is the object used by the library to decode a +single image. As of 1.5.0 this structure is also not exposed. + +Almost all libpng APIs require a pointer to a png_struct as the first argument. +Many (in particular the png_set and png_get APIs) also require a pointer +to png_info as the second argument. Some application visible macros +defined in png.h designed for basic data access (reading and writing +integers in the PNG format) break this rule, but it's almost always safe +to assume that a (png_struct*) has to be passed to call an API function. + +The png.h header file is an invaluable reference for programming with libpng. +And while I'm on the topic, make sure you include the libpng header file: + +#include <png.h> + +.SS Types + +The png.h header file defines a number of integral types used by the +APIs. Most of these are fairly obvious; for example types corresponding +to integers of particular sizes and types for passing color values. + +One exception is how non-integral numbers are handled. For application +convenience most APIs that take such numbers have C (double) arguments, +however internally PNG, and libpng, use 32 bit signed integers and encode +the value by multiplying by 100,000. As of libpng 1.5.0 a convenience +macro PNG_FP_1 is defined in png.h along with a type (png_fixed_point) +which is simply (png_int_32). + +All APIs that take (double) arguments also have an matching API that +takes the corresponding fixed point integer arguments. The fixed point +API has the same name as the floating point one with _fixed appended. +The actual range of values permitted in the APIs is frequently less than +the full range of (png_fixed_point) (-21474 to +21474). When APIs require +a non-negative argument the type is recorded as png_uint_32 above. Consult +the header file and the text below for more information. + +Special care must be take with sCAL chunk handling because the chunk itself +uses non-integral values encoded as strings containing decimal floating point +numbers. See the comments in the header file. + +.SS Configuration + +The main header file function declarations are frequently protected by C +preprocessing directives of the form: + + #ifdef PNG_feature_SUPPORTED + declare-function + #endif + +The library can be built without support for these APIs, although a +standard build will have all implemented APIs. Application programs +should check the feature macros before using an API for maximum +portability. From libpng 1.5.0 the feature macros set during the build +of libpng are recorded in the header file "pnglibconf.h" and this file +is always included by png.h. + +If you don't need to change the library configuration from the default skip to +the next section ("Reading"). + +Notice that some of the makefiles in the 'scripts' directory and (in 1.5.0) all +of the build project files in the 'projects' directory simply copy +scripts/pnglibconf.h.prebuilt to pnglibconf.h. This means that these build +systems do not permit easy auto-configuration of the library - they only +support the default configuration. + +The easiest way to make minor changes to the libpng configuration when +auto-configuration is supported is to add definitions to the command line +using (typically) CPPFLAGS. For example: + +CPPFLAGS=-DPNG_NO_FLOATING_ARITHMETIC + +will change the internal libpng math implementation for gamma correction and +other arithmetic calculations to fixed point, avoiding the need for fast +floating point support. The result can be seen in the generated pnglibconf.h - +make sure it contains the changed feature macro setting. + +If you need to make more extensive configuration changes - more than one or two +feature macro settings - you can either add -DPNG_USER_CONFIG to the build +command line and put a list of feature macro settings in pngusr.h or you can set +DFA_XTRA (a makefile variable) to a file containing the same information in the +form of 'option' settings. + +A. Changing pnglibconf.h + +A variety of methods exist to build libpng. Not all of these support +reconfiguration of pnglibconf.h. To reconfigure pnglibconf.h it must either be +rebuilt from scripts/pnglibconf.dfa using awk or it must be edited by hand. + +Hand editing is achieved by copying scripts/pnglibconf.h.prebuilt and changing +the lines defining the supported features, paying very close attention to the +'option' information in scripts/pnglibconf.dfa that describes those features and +their requirements. This is easy to get wrong. + +B. Configuration using DFA_XTRA + +Rebuilding from pnglibconf.dfa is easy if a functioning 'awk', or a later +variant such as 'nawk' or 'gawk', is available. The configure build will +automatically find an appropriate awk and build pnglibconf.h. +scripts/pnglibconf.mak contains a set of make rules for doing the same thing if +configure is not used, and many of the makefiles in the scripts directory use +this approach. + +When rebuilding simply write new file containing changed options and set +DFA_XTRA to the name of this file. This causes the build to append the new file +to the end of scripts/pnglibconf.dfa. pngusr.dfa should contain lines of the +following forms: + +everything = off + +This turns all optional features off. Include it at the start of pngusr.dfa to +make it easier to build a minimal configuration. You will need to turn at least +some features on afterward to enable either reading or writing code, or both. + +option feature on +option feature off + +Enable or disable a single feature. This will automatically enable other +features required by a feature that is turned on or disable other features that +require a feature which is turned off. Conflicting settings will cause an error +message to be emitted by awk. + +setting feature default value + +Changes the default value of setting 'feature' to 'value'. There are a small +number of settings listed at the top of pnglibconf.h, they are documented in the +source code. Most of these values have performance implications for the library +but most of them have no visible effect on the API. Some can also be overridden +from the API. + +C. Configuration using PNG_USR_CONFIG + +If -DPNG_USR_CONFIG is added to the CFLAGS when pnglibconf.h is built the file +pngusr.h will automatically be included before the options in +scripts/pnglibconf.dfa are processed. pngusr.h should contain only macro +definitions turning features on or off or setting settings. + +Apart from the global setting "everything = off" all the options listed above +can be set using macros in pngusr.h: + +#define PNG_feature_SUPPORTED + +is equivalent to: + +option feature on + +#define PNG_NO_feature + +is equivalent to: + +option feature off + +#define PNG_feature value + +is equivalent to: + +setting feature default value + +Notice that in both cases, pngusr.dfa and pngusr.h, the contents of the +pngusr file you supply override the contents of scripts/pnglibconf.dfa + +If confusing or incomprehensible behavior results it is possible to +examine the intermediate file pnglibconf.dfn to find the full set of +dependency information for each setting and option. Simply locate the +feature in the file and read the C comments that precede it. + +.SH III. Reading + +We'll now walk you through the possible functions to call when reading +in a PNG file sequentially, briefly explaining the syntax and purpose +of each one. See example.c and png.h for more detail. While +progressive reading is covered in the next section, you will still +need some of the functions discussed in this section to read a PNG +file. + +.SS Setup + +You will want to do the I/O initialization(*) before you get into libpng, +so if it doesn't work, you don't have much to undo. Of course, you +will also want to insure that you are, in fact, dealing with a PNG +file. Libpng provides a simple check to see if a file is a PNG file. +To use it, pass in the first 1 to 8 bytes of the file to the function +png_sig_cmp(), and it will return 0 (false) if the bytes match the +corresponding bytes of the PNG signature, or nonzero (true) otherwise. +Of course, the more bytes you pass in, the greater the accuracy of the +prediction. + +If you are intending to keep the file pointer open for use in libpng, +you must ensure you don't read more than 8 bytes from the beginning +of the file, and you also have to make a call to png_set_sig_bytes_read() +with the number of bytes you read from the beginning. Libpng will +then only check the bytes (if any) that your program didn't read. + +(*): If you are not using the standard I/O functions, you will need +to replace them with custom functions. See the discussion under +Customizing libpng. + + + FILE *fp = fopen(file_name, "rb"); + if (!fp) + { + return (ERROR); + } + + fread(header, 1, number, fp); + is_png = !png_sig_cmp(header, 0, number); + + if (!is_png) + { + return (NOT_PNG); + } + + +Next, png_struct and png_info need to be allocated and initialized. In +order to ensure that the size of these structures is correct even with a +dynamically linked libpng, there are functions to initialize and +allocate the structures. We also pass the library version, optional +pointers to error handling functions, and a pointer to a data struct for +use by the error functions, if necessary (the pointer and functions can +be NULL if the default error handlers are to be used). See the section +on Changes to Libpng below regarding the old initialization functions. +The structure allocation functions quietly return NULL if they fail to +create the structure, so your application should check for that. + + png_structp png_ptr = png_create_read_struct + (PNG_LIBPNG_VER_STRING, (png_voidp)user_error_ptr, + user_error_fn, user_warning_fn); + + if (!png_ptr) + return (ERROR); + + png_infop info_ptr = png_create_info_struct(png_ptr); + + if (!info_ptr) + { + png_destroy_read_struct(&png_ptr, + (png_infopp)NULL, (png_infopp)NULL); + return (ERROR); + } + + png_infop end_info = png_create_info_struct(png_ptr); + + if (!end_info) + { + png_destroy_read_struct(&png_ptr, &info_ptr, + (png_infopp)NULL); + return (ERROR); + } + +If you want to use your own memory allocation routines, +use a libpng that was built with PNG_USER_MEM_SUPPORTED defined, and use +png_create_read_struct_2() instead of png_create_read_struct(): + + png_structp png_ptr = png_create_read_struct_2 + (PNG_LIBPNG_VER_STRING, (png_voidp)user_error_ptr, + user_error_fn, user_warning_fn, (png_voidp) + user_mem_ptr, user_malloc_fn, user_free_fn); + +The error handling routines passed to png_create_read_struct() +and the memory alloc/free routines passed to png_create_struct_2() +are only necessary if you are not using the libpng supplied error +handling and memory alloc/free functions. + +When libpng encounters an error, it expects to longjmp back +to your routine. Therefore, you will need to call setjmp and pass +your png_jmpbuf(png_ptr). If you read the file from different +routines, you will need to update the jmpbuf field every time you enter +a new routine that will call a png_*() function. + +See your documentation of setjmp/longjmp for your compiler for more +information on setjmp/longjmp. See the discussion on libpng error +handling in the Customizing Libpng section below for more information +on the libpng error handling. If an error occurs, and libpng longjmp's +back to your setjmp, you will want to call png_destroy_read_struct() to +free any memory. + + if (setjmp(png_jmpbuf(png_ptr))) + { + png_destroy_read_struct(&png_ptr, &info_ptr, + &end_info); + fclose(fp); + return (ERROR); + } + +If you would rather avoid the complexity of setjmp/longjmp issues, +you can compile libpng with PNG_NO_SETJMP, in which case +errors will result in a call to PNG_ABORT() which defaults to abort(). + +You can #define PNG_ABORT() to a function that does something +more useful than abort(), as long as your function does not +return. + +Now you need to set up the input code. The default for libpng is to +use the C function fread(). If you use this, you will need to pass a +valid FILE * in the function png_init_io(). Be sure that the file is +opened in binary mode. If you wish to handle reading data in another +way, you need not call the png_init_io() function, but you must then +implement the libpng I/O methods discussed in the Customizing Libpng +section below. + + png_init_io(png_ptr, fp); + +If you had previously opened the file and read any of the signature from +the beginning in order to see if this was a PNG file, you need to let +libpng know that there are some bytes missing from the start of the file. + + png_set_sig_bytes(png_ptr, number); + +You can change the zlib compression buffer size to be used while +reading compressed data with + + png_set_compression_buffer_size(png_ptr, buffer_size); + +where the default size is 8192 bytes. Note that the buffer size +is changed immediately and the buffer is reallocated immediately, +instead of setting a flag to be acted upon later. + +If you want CRC errors to be handled in a different manner than +the default, use + + png_set_crc_action(png_ptr, crit_action, ancil_action); + +The values for png_set_crc_action() say how libpng is to handle CRC errors in +ancillary and critical chunks, and whether to use the data contained +therein. Note that it is impossible to "discard" data in a critical +chunk. + +Choices for (int) crit_action are + PNG_CRC_DEFAULT 0 error/quit + PNG_CRC_ERROR_QUIT 1 error/quit + PNG_CRC_WARN_USE 3 warn/use data + PNG_CRC_QUIET_USE 4 quiet/use data + PNG_CRC_NO_CHANGE 5 use the current value + +Choices for (int) ancil_action are + PNG_CRC_DEFAULT 0 error/quit + PNG_CRC_ERROR_QUIT 1 error/quit + PNG_CRC_WARN_DISCARD 2 warn/discard data + PNG_CRC_WARN_USE 3 warn/use data + PNG_CRC_QUIET_USE 4 quiet/use data + PNG_CRC_NO_CHANGE 5 use the current value + +.SS Setting up callback code + +You can set up a callback function to handle any unknown chunks in the +input stream. You must supply the function + + read_chunk_callback(png_structp png_ptr, + png_unknown_chunkp chunk); + { + /* The unknown chunk structure contains your + chunk data, along with similar data for any other + unknown chunks: */ + + png_byte name[5]; + png_byte *data; + png_size_t size; + + /* Note that libpng has already taken care of + the CRC handling */ + + /* put your code here. Search for your chunk in the + unknown chunk structure, process it, and return one + of the following: */ + + return (-n); /* chunk had an error */ + return (0); /* did not recognize */ + return (n); /* success */ + } + +(You can give your function another name that you like instead of +"read_chunk_callback") + +To inform libpng about your function, use + + png_set_read_user_chunk_fn(png_ptr, user_chunk_ptr, + read_chunk_callback); + +This names not only the callback function, but also a user pointer that +you can retrieve with + + png_get_user_chunk_ptr(png_ptr); + +If you call the png_set_read_user_chunk_fn() function, then all unknown +chunks will be saved when read, in case your callback function will need +one or more of them. This behavior can be changed with the +png_set_keep_unknown_chunks() function, described below. + +At this point, you can set up a callback function that will be +called after each row has been read, which you can use to control +a progress meter or the like. It's demonstrated in pngtest.c. +You must supply a function + + void read_row_callback(png_structp png_ptr, + png_uint_32 row, int pass); + { + /* put your code here */ + } + +(You can give it another name that you like instead of "read_row_callback") + +To inform libpng about your function, use + + png_set_read_status_fn(png_ptr, read_row_callback); + +.SS Unknown-chunk handling + +Now you get to set the way the library processes unknown chunks in the +input PNG stream. Both known and unknown chunks will be read. Normal +behavior is that known chunks will be parsed into information in +various info_ptr members while unknown chunks will be discarded. This +behavior can be wasteful if your application will never use some known +chunk types. To change this, you can call: + + png_set_keep_unknown_chunks(png_ptr, keep, + chunk_list, num_chunks); + keep - 0: default unknown chunk handling + 1: ignore; do not keep + 2: keep only if safe-to-copy + 3: keep even if unsafe-to-copy + + You can use these definitions: + PNG_HANDLE_CHUNK_AS_DEFAULT 0 + PNG_HANDLE_CHUNK_NEVER 1 + PNG_HANDLE_CHUNK_IF_SAFE 2 + PNG_HANDLE_CHUNK_ALWAYS 3 + + chunk_list - list of chunks affected (a byte string, + five bytes per chunk, NULL or '\0' if + num_chunks is 0) + + num_chunks - number of chunks affected; if 0, all + unknown chunks are affected. If nonzero, + only the chunks in the list are affected + +Unknown chunks declared in this way will be saved as raw data onto a +list of png_unknown_chunk structures. If a chunk that is normally +known to libpng is named in the list, it will be handled as unknown, +according to the "keep" directive. If a chunk is named in successive +instances of png_set_keep_unknown_chunks(), the final instance will +take precedence. The IHDR and IEND chunks should not be named in +chunk_list; if they are, libpng will process them normally anyway. + +Here is an example of the usage of png_set_keep_unknown_chunks(), +where the private "vpAg" chunk will later be processed by a user chunk +callback function: + + png_byte vpAg[5]={118, 112, 65, 103, (png_byte) '\0'}; + + #if defined(PNG_UNKNOWN_CHUNKS_SUPPORTED) + png_byte unused_chunks[]= + { + 104, 73, 83, 84, (png_byte) '\0', /* hIST */ + 105, 84, 88, 116, (png_byte) '\0', /* iTXt */ + 112, 67, 65, 76, (png_byte) '\0', /* pCAL */ + 115, 67, 65, 76, (png_byte) '\0', /* sCAL */ + 115, 80, 76, 84, (png_byte) '\0', /* sPLT */ + 116, 73, 77, 69, (png_byte) '\0', /* tIME */ + }; + #endif + + ... + + #if defined(PNG_UNKNOWN_CHUNKS_SUPPORTED) + /* ignore all unknown chunks: */ + png_set_keep_unknown_chunks(read_ptr, 1, NULL, 0); + + /* except for vpAg: */ + png_set_keep_unknown_chunks(read_ptr, 2, vpAg, 1); + + /* also ignore unused known chunks: */ + png_set_keep_unknown_chunks(read_ptr, 1, unused_chunks, + (int)sizeof(unused_chunks)/5); + #endif + +.SS User limits + +The PNG specification allows the width and height of an image to be as +large as 2^31-1 (0x7fffffff), or about 2.147 billion rows and columns. +Since very few applications really need to process such large images, +we have imposed an arbitrary 1-million limit on rows and columns. +Larger images will be rejected immediately with a png_error() call. If +you wish to override this limit, you can use + + png_set_user_limits(png_ptr, width_max, height_max); + +to set your own limits, or use width_max = height_max = 0x7fffffffL +to allow all valid dimensions (libpng may reject some very large images +anyway because of potential buffer overflow conditions). + +You should put this statement after you create the PNG structure and +before calling png_read_info(), png_read_png(), or png_process_data(). +If you need to retrieve the limits that are being applied, use + + width_max = png_get_user_width_max(png_ptr); + height_max = png_get_user_height_max(png_ptr); + +The PNG specification sets no limit on the number of ancillary chunks +allowed in a PNG datastream. You can impose a limit on the total number +of sPLT, tEXt, iTXt, zTXt, and unknown chunks that will be stored, with + + png_set_chunk_cache_max(png_ptr, user_chunk_cache_max); + +where 0x7fffffffL means unlimited. You can retrieve this limit with + + chunk_cache_max = png_get_chunk_cache_max(png_ptr); + +This limit also applies to the number of buffers that can be allocated +by png_decompress_chunk() while decompressing iTXt, zTXt, and iCCP chunks. + +You can also set a limit on the amount of memory that a compressed chunk +other than IDAT can occupy, with + + png_set_chunk_malloc_max(png_ptr, user_chunk_malloc_max); + +and you can retrieve the limit with + + chunk_malloc_max = png_get_chunk_malloc_max(png_ptr); + +Any chunks that would cause either of these limits to be exceeded will +be ignored. + +.SS The high-level read interface + +At this point there are two ways to proceed; through the high-level +read interface, or through a sequence of low-level read operations. +You can use the high-level interface if (a) you are willing to read +the entire image into memory, and (b) the input transformations +you want to do are limited to the following set: + + PNG_TRANSFORM_IDENTITY No transformation + PNG_TRANSFORM_STRIP_16 Strip 16-bit samples to + 8 bits + PNG_TRANSFORM_STRIP_ALPHA Discard the alpha channel + PNG_TRANSFORM_PACKING Expand 1, 2 and 4-bit + samples to bytes + PNG_TRANSFORM_PACKSWAP Change order of packed + pixels to LSB first + PNG_TRANSFORM_EXPAND Perform set_expand() + PNG_TRANSFORM_INVERT_MONO Invert monochrome images + PNG_TRANSFORM_SHIFT Normalize pixels to the + sBIT depth + PNG_TRANSFORM_BGR Flip RGB to BGR, RGBA + to BGRA + PNG_TRANSFORM_SWAP_ALPHA Flip RGBA to ARGB or GA + to AG + PNG_TRANSFORM_INVERT_ALPHA Change alpha from opacity + to transparency + PNG_TRANSFORM_SWAP_ENDIAN Byte-swap 16-bit samples + PNG_TRANSFORM_GRAY_TO_RGB Expand grayscale samples + to RGB (or GA to RGBA) + +(This excludes setting a background color, doing gamma transformation, +quantizing, and setting filler.) If this is the case, simply do this: + + png_read_png(png_ptr, info_ptr, png_transforms, NULL) + +where png_transforms is an integer containing the bitwise OR of some +set of transformation flags. This call is equivalent to png_read_info(), +followed the set of transformations indicated by the transform mask, +then png_read_image(), and finally png_read_end(). + +(The final parameter of this call is not yet used. Someday it might point +to transformation parameters required by some future input transform.) + +You must use png_transforms and not call any png_set_transform() functions +when you use png_read_png(). + +After you have called png_read_png(), you can retrieve the image data +with + + row_pointers = png_get_rows(png_ptr, info_ptr); + +where row_pointers is an array of pointers to the pixel data for each row: + + png_bytep row_pointers[height]; + +If you know your image size and pixel size ahead of time, you can allocate +row_pointers prior to calling png_read_png() with + + if (height > PNG_UINT_32_MAX/png_sizeof(png_byte)) + png_error (png_ptr, + "Image is too tall to process in memory"); + + if (width > PNG_UINT_32_MAX/pixel_size) + png_error (png_ptr, + "Image is too wide to process in memory"); + + row_pointers = png_malloc(png_ptr, + height*png_sizeof(png_bytep)); + + for (int i=0; i<height, i++) + row_pointers[i]=NULL; /* security precaution */ + + for (int i=0; i<height, i++) + row_pointers[i]=png_malloc(png_ptr, + width*pixel_size); + + png_set_rows(png_ptr, info_ptr, &row_pointers); + +Alternatively you could allocate your image in one big block and define +row_pointers[i] to point into the proper places in your block. + +If you use png_set_rows(), the application is responsible for freeing +row_pointers (and row_pointers[i], if they were separately allocated). + +If you don't allocate row_pointers ahead of time, png_read_png() will +do it, and it'll be free'ed by libpng when you call png_destroy_*(). + +.SS The low-level read interface + +If you are going the low-level route, you are now ready to read all +the file information up to the actual image data. You do this with a +call to png_read_info(). + + png_read_info(png_ptr, info_ptr); + +This will process all chunks up to but not including the image data. + +.SS Querying the info structure + +Functions are used to get the information from the info_ptr once it +has been read. Note that these fields may not be completely filled +in until png_read_end() has read the chunk data following the image. + + png_get_IHDR(png_ptr, info_ptr, &width, &height, + &bit_depth, &color_type, &interlace_type, + &compression_type, &filter_method); + + width - holds the width of the image + in pixels (up to 2^31). + + height - holds the height of the image + in pixels (up to 2^31). + + bit_depth - holds the bit depth of one of the + image channels. (valid values are + 1, 2, 4, 8, 16 and depend also on + the color_type. See also + significant bits (sBIT) below). + + color_type - describes which color/alpha channels + are present. + PNG_COLOR_TYPE_GRAY + (bit depths 1, 2, 4, 8, 16) + PNG_COLOR_TYPE_GRAY_ALPHA + (bit depths 8, 16) + PNG_COLOR_TYPE_PALETTE + (bit depths 1, 2, 4, 8) + PNG_COLOR_TYPE_RGB + (bit_depths 8, 16) + PNG_COLOR_TYPE_RGB_ALPHA + (bit_depths 8, 16) + + PNG_COLOR_MASK_PALETTE + PNG_COLOR_MASK_COLOR + PNG_COLOR_MASK_ALPHA + + interlace_type - (PNG_INTERLACE_NONE or + PNG_INTERLACE_ADAM7) + + compression_type - (must be PNG_COMPRESSION_TYPE_BASE + for PNG 1.0) + + filter_method - (must be PNG_FILTER_TYPE_BASE + for PNG 1.0, and can also be + PNG_INTRAPIXEL_DIFFERENCING if + the PNG datastream is embedded in + a MNG-1.0 datastream) + + Any or all of interlace_type, compression_type, or + filter_method can be NULL if you are + not interested in their values. + + Note that png_get_IHDR() returns 32-bit data into + the application's width and height variables. + This is an unsafe situation if these are 16-bit + variables. In such situations, the + png_get_image_width() and png_get_image_height() + functions described below are safer. + + width = png_get_image_width(png_ptr, + info_ptr); + + height = png_get_image_height(png_ptr, + info_ptr); + + bit_depth = png_get_bit_depth(png_ptr, + info_ptr); + + color_type = png_get_color_type(png_ptr, + info_ptr); + + interlace_type = png_get_interlace_type(png_ptr, + info_ptr); + + compression_type = png_get_compression_type(png_ptr, + info_ptr); + + filter_method = png_get_filter_type(png_ptr, + info_ptr); + + channels = png_get_channels(png_ptr, info_ptr); + + channels - number of channels of info for the + color type (valid values are 1 (GRAY, + PALETTE), 2 (GRAY_ALPHA), 3 (RGB), + 4 (RGB_ALPHA or RGB + filler byte)) + + rowbytes = png_get_rowbytes(png_ptr, info_ptr); + + rowbytes - number of bytes needed to hold a row + + signature = png_get_signature(png_ptr, info_ptr); + + signature - holds the signature read from the + file (if any). The data is kept in + the same offset it would be if the + whole signature were read (i.e. if an + application had already read in 4 + bytes of signature before starting + libpng, the remaining 4 bytes would + be in signature[4] through signature[7] + (see png_set_sig_bytes())). + +These are also important, but their validity depends on whether the chunk +has been read. The png_get_valid(png_ptr, info_ptr, PNG_INFO_<chunk>) and +png_get_<chunk>(png_ptr, info_ptr, ...) functions return non-zero if the +data has been read, or zero if it is missing. The parameters to the +png_get_<chunk> are set directly if they are simple data types, or a +pointer into the info_ptr is returned for any complex types. + + png_get_PLTE(png_ptr, info_ptr, &palette, + &num_palette); + + palette - the palette for the file + (array of png_color) + + num_palette - number of entries in the palette + + png_get_gAMA(png_ptr, info_ptr, &file_gamma); + png_get_gAMA_fixed(png_ptr, info_ptr, &int_file_gamma); + + file_gamma - the gamma at which the file is + written (PNG_INFO_gAMA) + + int_file_gamma - 100,000 times the gamma at which the + file is written + + png_get_sRGB(png_ptr, info_ptr, &srgb_intent); + + file_srgb_intent - the rendering intent (PNG_INFO_sRGB) + The presence of the sRGB chunk + means that the pixel data is in the + sRGB color space. This chunk also + implies specific values of gAMA and + cHRM. + + png_get_iCCP(png_ptr, info_ptr, &name, + &compression_type, &profile, &proflen); + + name - The profile name. + + compression_type - The compression type; always + PNG_COMPRESSION_TYPE_BASE for PNG 1.0. + You may give NULL to this argument to + ignore it. + + profile - International Color Consortium color + profile data. May contain NULs. + + proflen - length of profile data in bytes. + + png_get_sBIT(png_ptr, info_ptr, &sig_bit); + + sig_bit - the number of significant bits for + (PNG_INFO_sBIT) each of the gray, + red, green, and blue channels, + whichever are appropriate for the + given color type (png_color_16) + + png_get_tRNS(png_ptr, info_ptr, &trans_alpha, + &num_trans, &trans_color); + + trans_alpha - array of alpha (transparency) + entries for palette (PNG_INFO_tRNS) + + num_trans - number of transparent entries + (PNG_INFO_tRNS) + + trans_color - graylevel or color sample values of + the single transparent color for + non-paletted images (PNG_INFO_tRNS) + + png_get_hIST(png_ptr, info_ptr, &hist); + (PNG_INFO_hIST) + + hist - histogram of palette (array of + png_uint_16) + + png_get_tIME(png_ptr, info_ptr, &mod_time); + + mod_time - time image was last modified + (PNG_VALID_tIME) + + png_get_bKGD(png_ptr, info_ptr, &background); + + background - background color (PNG_VALID_bKGD) + valid 16-bit red, green and blue + values, regardless of color_type + + num_comments = png_get_text(png_ptr, info_ptr, + &text_ptr, &num_text); + + num_comments - number of comments + + text_ptr - array of png_text holding image + comments + + text_ptr[i].compression - type of compression used + on "text" PNG_TEXT_COMPRESSION_NONE + PNG_TEXT_COMPRESSION_zTXt + PNG_ITXT_COMPRESSION_NONE + PNG_ITXT_COMPRESSION_zTXt + + text_ptr[i].key - keyword for comment. Must contain + 1-79 characters. + + text_ptr[i].text - text comments for current + keyword. Can be empty. + + text_ptr[i].text_length - length of text string, + after decompression, 0 for iTXt + + text_ptr[i].itxt_length - length of itxt string, + after decompression, 0 for tEXt/zTXt + + text_ptr[i].lang - language of comment (empty + string for unknown). + + text_ptr[i].lang_key - keyword in UTF-8 + (empty string for unknown). + + Note that the itxt_length, lang, and lang_key + members of the text_ptr structure only exist + when the library is built with iTXt chunk support. + + num_text - number of comments (same as + num_comments; you can put NULL here + to avoid the duplication) + + Note while png_set_text() will accept text, language, + and translated keywords that can be NULL pointers, the + structure returned by png_get_text will always contain + regular zero-terminated C strings. They might be + empty strings but they will never be NULL pointers. + + num_spalettes = png_get_sPLT(png_ptr, info_ptr, + &palette_ptr); + + num_spalettes - number of sPLT chunks read. + + palette_ptr - array of palette structures holding + contents of one or more sPLT chunks + read. + + png_get_oFFs(png_ptr, info_ptr, &offset_x, &offset_y, + &unit_type); + + offset_x - positive offset from the left edge + of the screen + + offset_y - positive offset from the top edge + of the screen + + unit_type - PNG_OFFSET_PIXEL, PNG_OFFSET_MICROMETER + + png_get_pHYs(png_ptr, info_ptr, &res_x, &res_y, + &unit_type); + + res_x - pixels/unit physical resolution in + x direction + + res_y - pixels/unit physical resolution in + x direction + + unit_type - PNG_RESOLUTION_UNKNOWN, + PNG_RESOLUTION_METER + + png_get_sCAL(png_ptr, info_ptr, &unit, &width, + &height) + + unit - physical scale units (an integer) + + width - width of a pixel in physical scale units + + height - height of a pixel in physical scale units + (width and height are doubles) + + png_get_sCAL_s(png_ptr, info_ptr, &unit, &width, + &height) + + unit - physical scale units (an integer) + + width - width of a pixel in physical scale units + + height - height of a pixel in physical scale units + (width and height are strings like "2.54") + + num_unknown_chunks = png_get_unknown_chunks(png_ptr, + info_ptr, &unknowns) + + unknowns - array of png_unknown_chunk + structures holding unknown chunks + + unknowns[i].name - name of unknown chunk + + unknowns[i].data - data of unknown chunk + + unknowns[i].size - size of unknown chunk's data + + unknowns[i].location - position of chunk in file + + The value of "i" corresponds to the order in which the + chunks were read from the PNG file or inserted with the + png_set_unknown_chunks() function. + +The data from the pHYs chunk can be retrieved in several convenient +forms: + + res_x = png_get_x_pixels_per_meter(png_ptr, + info_ptr) + + res_y = png_get_y_pixels_per_meter(png_ptr, + info_ptr) + + res_x_and_y = png_get_pixels_per_meter(png_ptr, + info_ptr) + + res_x = png_get_x_pixels_per_inch(png_ptr, + info_ptr) + + res_y = png_get_y_pixels_per_inch(png_ptr, + info_ptr) + + res_x_and_y = png_get_pixels_per_inch(png_ptr, + info_ptr) + + aspect_ratio = png_get_pixel_aspect_ratio(png_ptr, + info_ptr) + + Each of these returns 0 [signifying "unknown"] if + the data is not present or if res_x is 0; + res_x_and_y is 0 if res_x != res_y + + Note that because of the way the resolutions are + stored internally, the inch conversions won't + come out to exactly even number. For example, + 72 dpi is stored as 0.28346 pixels/meter, and + when this is retrieved it is 71.9988 dpi, so + be sure to round the returned value appropriately + if you want to display a reasonable-looking result. + +The data from the oFFs chunk can be retrieved in several convenient +forms: + + x_offset = png_get_x_offset_microns(png_ptr, info_ptr); + + y_offset = png_get_y_offset_microns(png_ptr, info_ptr); + + x_offset = png_get_x_offset_inches(png_ptr, info_ptr); + + y_offset = png_get_y_offset_inches(png_ptr, info_ptr); + + Each of these returns 0 [signifying "unknown" if both + x and y are 0] if the data is not present or if the + chunk is present but the unit is the pixel. The + remark about inexact inch conversions applies here + as well, because a value in inches can't always be + converted to microns and back without some loss + of precision. + +For more information, see the png_info definition in png.h and the +PNG specification for chunk contents. Be careful with trusting +rowbytes, as some of the transformations could increase the space +needed to hold a row (expand, filler, gray_to_rgb, etc.). +See png_read_update_info(), below. + +A quick word about text_ptr and num_text. PNG stores comments in +keyword/text pairs, one pair per chunk, with no limit on the number +of text chunks, and a 2^31 byte limit on their size. While there are +suggested keywords, there is no requirement to restrict the use to these +strings. It is strongly suggested that keywords and text be sensible +to humans (that's the point), so don't use abbreviations. Non-printing +symbols are not allowed. See the PNG specification for more details. +There is also no requirement to have text after the keyword. + +Keywords should be limited to 79 Latin-1 characters without leading or +trailing spaces, but non-consecutive spaces are allowed within the +keyword. It is possible to have the same keyword any number of times. +The text_ptr is an array of png_text structures, each holding a +pointer to a language string, a pointer to a keyword and a pointer to +a text string. The text string, language code, and translated +keyword may be empty or NULL pointers. The keyword/text +pairs are put into the array in the order that they are received. +However, some or all of the text chunks may be after the image, so, to +make sure you have read all the text chunks, don't mess with these +until after you read the stuff after the image. This will be +mentioned again below in the discussion that goes with png_read_end(). + +.SS Input transformations + +After you've read the header information, you can set up the library +to handle any special transformations of the image data. The various +ways to transform the data will be described in the order that they +should occur. This is important, as some of these change the color +type and/or bit depth of the data, and some others only work on +certain color types and bit depths. Even though each transformation +checks to see if it has data that it can do something with, you should +make sure to only enable a transformation if it will be valid for the +data. For example, don't swap red and blue on grayscale data. + +The colors used for the background and transparency values should be +supplied in the same format/depth as the current image data. They +are stored in the same format/depth as the image data in a bKGD or tRNS +chunk, so this is what libpng expects for this data. The colors are +transformed to keep in sync with the image data when an application +calls the png_read_update_info() routine (see below). + +Data will be decoded into the supplied row buffers packed into bytes +unless the library has been told to transform it into another format. +For example, 4 bit/pixel paletted or grayscale data will be returned +2 pixels/byte with the leftmost pixel in the high-order bits of the +byte, unless png_set_packing() is called. 8-bit RGB data will be stored +in RGB RGB RGB format unless png_set_filler() or png_set_add_alpha() +is called to insert filler bytes, either before or after each RGB triplet. +16-bit RGB data will be returned RRGGBB RRGGBB, with the most significant +byte of the color value first, unless png_set_strip_16() is called to +transform it to regular RGB RGB triplets, or png_set_filler() or +png_set_add alpha() is called to insert filler bytes, either before or +after each RRGGBB triplet. Similarly, 8-bit or 16-bit grayscale data can +be modified with +png_set_filler(), png_set_add_alpha(), or png_set_strip_16(). + +The following code transforms grayscale images of less than 8 to 8 bits, +changes paletted images to RGB, and adds a full alpha channel if there is +transparency information in a tRNS chunk. This is most useful on +grayscale images with bit depths of 2 or 4 or if there is a multiple-image +viewing application that wishes to treat all images in the same way. + + if (color_type == PNG_COLOR_TYPE_PALETTE) + png_set_palette_to_rgb(png_ptr); + + if (color_type == PNG_COLOR_TYPE_GRAY && + bit_depth < 8) png_set_expand_gray_1_2_4_to_8(png_ptr); + + if (png_get_valid(png_ptr, info_ptr, + PNG_INFO_tRNS)) png_set_tRNS_to_alpha(png_ptr); + +These three functions are actually aliases for png_set_expand(), added +in libpng version 1.0.4, with the function names expanded to improve code +readability. In some future version they may actually do different +things. + +As of libpng version 1.2.9, png_set_expand_gray_1_2_4_to_8() was +added. It expands the sample depth without changing tRNS to alpha. + +As of libpng version 1.5.1, not all possible expansions are supported. + +In the following table, the 01 means grayscale with depth<8, 31 means +indexed with depth<8, other numerals represent the color type, "T" means +the tRNS chunk is present, A means an alpha channel is present, and O +means tRNS or alpha is present but all pixels in the image are opaque. + + FROM 01 31 0 0T 0O 2 2T 2O 3 3T 3O 4A 4O 6A 6O + TO + 01 - + 31 - + 0 1 - + 0T - + 0O - + 2 GX - + 2T - + 2O - + 3 1 - + 3T - + 3O - + 4A T - + 4O - + 6A GX TX TX - + 6O GX TX - + +Within the matrix, + "-" means the transformation is not supported. + "X" means the transformation is obtained by png_set_expand(). + "1" means the transformation is obtained by + png_set_expand_gray_1_2_4_to_8 + "G" means the transformation is obtained by + png_set_gray_to_rgb(). + "P" means the transformation is obtained by + png_set_expand_palette_to_rgb(). + "T" means the transformation is obtained by + png_set_tRNS_to_alpha(). + +PNG can have files with 16 bits per channel. If you only can handle +8 bits per channel, this will strip the pixels down to 8 bit. + + if (bit_depth == 16) + png_set_strip_16(png_ptr); + +If, for some reason, you don't need the alpha channel on an image, +and you want to remove it rather than combining it with the background +(but the image author certainly had in mind that you *would* combine +it with the background, so that's what you should probably do): + + if (color_type & PNG_COLOR_MASK_ALPHA) + png_set_strip_alpha(png_ptr); + +In PNG files, the alpha channel in an image +is the level of opacity. If you need the alpha channel in an image to +be the level of transparency instead of opacity, you can invert the +alpha channel (or the tRNS chunk data) after it's read, so that 0 is +fully opaque and 255 (in 8-bit or paletted images) or 65535 (in 16-bit +images) is fully transparent, with + + png_set_invert_alpha(png_ptr); + +PNG files pack pixels of bit depths 1, 2, and 4 into bytes as small as +they can, resulting in, for example, 8 pixels per byte for 1 bit +files. This code expands to 1 pixel per byte without changing the +values of the pixels: + + if (bit_depth < 8) + png_set_packing(png_ptr); + +PNG files have possible bit depths of 1, 2, 4, 8, and 16. All pixels +stored in a PNG image have been "scaled" or "shifted" up to the next +higher possible bit depth (e.g. from 5 bits/sample in the range [0,31] +to 8 bits/sample in the range [0, 255]). However, it is also possible +to convert the PNG pixel data back to the original bit depth of the +image. This call reduces the pixels back down to the original bit depth: + + png_color_8p sig_bit; + + if (png_get_sBIT(png_ptr, info_ptr, &sig_bit)) + png_set_shift(png_ptr, sig_bit); + +PNG files store 3-color pixels in red, green, blue order. This code +changes the storage of the pixels to blue, green, red: + + if (color_type == PNG_COLOR_TYPE_RGB || + color_type == PNG_COLOR_TYPE_RGB_ALPHA) + png_set_bgr(png_ptr); + +PNG files store RGB pixels packed into 3 or 6 bytes. This code expands them +into 4 or 8 bytes for windowing systems that need them in this format: + + if (color_type == PNG_COLOR_TYPE_RGB) + png_set_filler(png_ptr, filler, PNG_FILLER_BEFORE); + +where "filler" is the 8 or 16-bit number to fill with, and the location is +either PNG_FILLER_BEFORE or PNG_FILLER_AFTER, depending upon whether +you want the filler before the RGB or after. This transformation +does not affect images that already have full alpha channels. To add an +opaque alpha channel, use filler=0xff or 0xffff and PNG_FILLER_AFTER which +will generate RGBA pixels. + +Note that png_set_filler() does not change the color type. If you want +to do that, you can add a true alpha channel with + + if (color_type == PNG_COLOR_TYPE_RGB || + color_type == PNG_COLOR_TYPE_GRAY) + png_set_add_alpha(png_ptr, filler, PNG_FILLER_AFTER); + +where "filler" contains the alpha value to assign to each pixel. +This function was added in libpng-1.2.7. + +If you are reading an image with an alpha channel, and you need the +data as ARGB instead of the normal PNG format RGBA: + + if (color_type == PNG_COLOR_TYPE_RGB_ALPHA) + png_set_swap_alpha(png_ptr); + +For some uses, you may want a grayscale image to be represented as +RGB. This code will do that conversion: + + if (color_type == PNG_COLOR_TYPE_GRAY || + color_type == PNG_COLOR_TYPE_GRAY_ALPHA) + png_set_gray_to_rgb(png_ptr); + +Conversely, you can convert an RGB or RGBA image to grayscale or grayscale +with alpha. + + if (color_type == PNG_COLOR_TYPE_RGB || + color_type == PNG_COLOR_TYPE_RGB_ALPHA) + png_set_rgb_to_gray_fixed(png_ptr, error_action, + int red_weight, int green_weight); + + error_action = 1: silently do the conversion + + error_action = 2: issue a warning if the original + image has any pixel where + red != green or red != blue + + error_action = 3: issue an error and abort the + conversion if the original + image has any pixel where + red != green or red != blue + + red_weight: weight of red component times 100000 + + green_weight: weight of green component times 100000 + If either weight is negative, default + weights (21268, 71514) are used. + +If you have set error_action = 1 or 2, you can +later check whether the image really was gray, after processing +the image rows, with the png_get_rgb_to_gray_status(png_ptr) function. +It will return a png_byte that is zero if the image was gray or +1 if there were any non-gray pixels. bKGD and sBIT data +will be silently converted to grayscale, using the green channel +data, regardless of the error_action setting. + +With red_weight+green_weight<=100000, +the normalized graylevel is computed: + + int rw = red_weight * 65536; + int gw = green_weight * 65536; + int bw = 65536 - (rw + gw); + gray = (rw*red + gw*green + bw*blue)/65536; + +The default values approximate those recommended in the Charles +Poynton's Color FAQ, <http://www.inforamp.net/~poynton/> +Copyright (c) 1998-01-04 Charles Poynton <poynton at inforamp.net> + + Y = 0.212671 * R + 0.715160 * G + 0.072169 * B + +Libpng approximates this with integers scaled by 32768: + + Y = (6968 * R + 23434 * G + 2366 * B)/32768 + +The calculation is done in a linear colorspace, if the image gamma +can be determined. + +If you have a grayscale and you are using png_set_expand_depth(), +png_set_expand(), or png_set_gray_to_rgb to change to truecolor or to +a higher bit-depth, you must either supply the background color as a gray +value at the original file bit-depth (need_expand = 1) or else supply the +background color as an RGB triplet at the final, expanded bit depth +(need_expand = 0). Similarly, if you are reading a paletted image, you +must either supply the background color as a palette index (need_expand = 1) +or as an RGB triplet that may or may not be in the palette (need_expand = 0). + + png_color_16 my_background; + png_color_16p image_background; + + if (png_get_bKGD(png_ptr, info_ptr, &image_background)) + png_set_background(png_ptr, image_background, + PNG_BACKGROUND_GAMMA_FILE, 1, 1.0); + else + png_set_background(png_ptr, &my_background, + PNG_BACKGROUND_GAMMA_SCREEN, 0, 1.0); + +The png_set_background() function tells libpng to composite images +with alpha or simple transparency against the supplied background +color. If the PNG file contains a bKGD chunk (PNG_INFO_bKGD valid), +you may use this color, or supply another color more suitable for +the current display (e.g., the background color from a web page). You +need to tell libpng whether the color is in the gamma space of the +display (PNG_BACKGROUND_GAMMA_SCREEN for colors you supply), the file +(PNG_BACKGROUND_GAMMA_FILE for colors from the bKGD chunk), or one +that is neither of these gammas (PNG_BACKGROUND_GAMMA_UNIQUE - I don't +know why anyone would use this, but it's here). + +To properly display PNG images on any kind of system, the application needs +to know what the display gamma is. Ideally, the user will know this, and +the application will allow them to set it. One method of allowing the user +to set the display gamma separately for each system is to check for a +SCREEN_GAMMA or DISPLAY_GAMMA environment variable, which will hopefully be +correctly set. + +Note that display_gamma is the overall gamma correction required to produce +pleasing results, which depends on the lighting conditions in the surrounding +environment. In a dim or brightly lit room, no compensation other than +the physical gamma exponent of the monitor is needed, while in a dark room +a slightly smaller exponent is better. + + double gamma, screen_gamma; + + if (/* We have a user-defined screen + gamma value */) + { + screen_gamma = user_defined_screen_gamma; + } + + /* One way that applications can share the same + screen gamma value */ + else if ((gamma_str = getenv("SCREEN_GAMMA")) + != NULL) + { + screen_gamma = (double)atof(gamma_str); + } + + /* If we don't have another value */ + else + { + screen_gamma = 2.2; /* A good guess for a + PC monitor in a bright office or a dim room */ + + screen_gamma = 2.0; /* A good guess for a + PC monitor in a dark room */ + + screen_gamma = 1.7 or 1.0; /* A good + guess for Mac systems */ + } + +The functions png_set_gamma() and its fixed point equivalent +png_set_gamma_fixed() handle gamma transformations of the data. +Pass both the file gamma and the current screen_gamma. If the file does +not have a gamma value, you can pass one anyway if you have an idea what +it is (usually 0.45455 is a good guess for GIF images on PCs). Note +that file gammas are inverted from screen gammas. See the discussions +on gamma in the PNG specification for an excellent description of what +gamma is, and why all applications should support it. It is strongly +recommended that PNG viewers support gamma correction. + + if (png_get_gAMA(png_ptr, info_ptr, &file_gamma)) + png_set_gamma(png_ptr, screen_gamma, file_gamma); + + else + png_set_gamma(png_ptr, screen_gamma, 0.45455); + +If you need to reduce an RGB file to a paletted file, or if a paletted +file has more entries then will fit on your screen, png_set_quantize() +will do that. Note that this is a simple match quantization that merely +finds the closest color available. This should work fairly well with +optimized palettes, but fairly badly with linear color cubes. If you +pass a palette that is larger then maximum_colors, the file will +reduce the number of colors in the palette so it will fit into +maximum_colors. If there is a histogram, it will use it to make +more intelligent choices when reducing the palette. If there is no +histogram, it may not do as good a job. + + if (color_type & PNG_COLOR_MASK_COLOR) + { + if (png_get_valid(png_ptr, info_ptr, + PNG_INFO_PLTE)) + { + png_uint_16p histogram = NULL; + + png_get_hIST(png_ptr, info_ptr, + &histogram); + png_set_quantize(png_ptr, palette, num_palette, + max_screen_colors, histogram, 1); + } + + else + { + png_color std_color_cube[MAX_SCREEN_COLORS] = + { ... colors ... }; + + png_set_quantize(png_ptr, std_color_cube, + MAX_SCREEN_COLORS, MAX_SCREEN_COLORS, + NULL,0); + } + } + +PNG files describe monochrome as black being zero and white being one. +The following code will reverse this (make black be one and white be +zero): + + if (bit_depth == 1 && color_type == PNG_COLOR_TYPE_GRAY) + png_set_invert_mono(png_ptr); + +This function can also be used to invert grayscale and gray-alpha images: + + if (color_type == PNG_COLOR_TYPE_GRAY || + color_type == PNG_COLOR_TYPE_GRAY_ALPHA) + png_set_invert_mono(png_ptr); + +PNG files store 16 bit pixels in network byte order (big-endian, +ie. most significant bits first). This code changes the storage to the +other way (little-endian, i.e. least significant bits first, the +way PCs store them): + + if (bit_depth == 16) + png_set_swap(png_ptr); + +If you are using packed-pixel images (1, 2, or 4 bits/pixel), and you +need to change the order the pixels are packed into bytes, you can use: + + if (bit_depth < 8) + png_set_packswap(png_ptr); + +Finally, you can write your own transformation function if none of +the existing ones meets your needs. This is done by setting a callback +with + + png_set_read_user_transform_fn(png_ptr, + read_transform_fn); + +You must supply the function + + void read_transform_fn(png_structp png_ptr, row_info_ptr + row_info, png_bytep data) + +See pngtest.c for a working example. Your function will be called +after all of the other transformations have been processed. Take care with +interlaced images if you do the interlace yourself - the width of the row is the +width in 'row_info', not the overall image width. + +If supported libpng provides two information routines that you can use to find +where you are in processing the image: + + png_get_current_pass_number(png_structp png_ptr); + png_get_current_row_number(png_structp png_ptr); + +Don't try using these outside a transform callback - firstly they are only +supported if user transforms are supported, secondly they may well return +unexpected results unless the row is actually being processed at the moment they +are called. + +You can also set up a pointer to a user structure for use by your +callback function, and you can inform libpng that your transform +function will change the number of channels or bit depth with the +function + + png_set_user_transform_info(png_ptr, user_ptr, + user_depth, user_channels); + +The user's application, not libpng, is responsible for allocating and +freeing any memory required for the user structure. + +You can retrieve the pointer via the function +png_get_user_transform_ptr(). For example: + + voidp read_user_transform_ptr = + png_get_user_transform_ptr(png_ptr); + +The last thing to handle is interlacing; this is covered in detail below, +but you must call the function here if you want libpng to handle expansion +of the interlaced image. + + number_of_passes = png_set_interlace_handling(png_ptr); + +After setting the transformations, libpng can update your png_info +structure to reflect any transformations you've requested with this +call. This is most useful to update the info structure's rowbytes +field so you can use it to allocate your image memory. This function +will also update your palette with the correct screen_gamma and +background if these have been given with the calls above. + + png_read_update_info(png_ptr, info_ptr); + +After you call png_read_update_info(), you can allocate any +memory you need to hold the image. The row data is simply +raw byte data for all forms of images. As the actual allocation +varies among applications, no example will be given. If you +are allocating one large chunk, you will need to build an +array of pointers to each row, as it will be needed for some +of the functions below. + +Remember: Before you call png_read_update_info(), the png_get_ +functions return the values corresponding to the original PNG image. +After you call png_read_update_info the values refer to the image +that libpng will output. Consequently you must call all the png_set_ +functions before you call png_read_update_info(). This is particularly +important for png_set_interlace_handling() - if you are going to call +png_read_update_info() you must call png_set_interlace_handling() before +it unless you want to receive interlaced output. + +.SS Reading image data + +After you've allocated memory, you can read the image data. +The simplest way to do this is in one function call. If you are +allocating enough memory to hold the whole image, you can just +call png_read_image() and libpng will read in all the image data +and put it in the memory area supplied. You will need to pass in +an array of pointers to each row. + +This function automatically handles interlacing, so you don't +need to call png_set_interlace_handling() (unless you call +png_read_update_info()) or call this function multiple times, or any +of that other stuff necessary with png_read_rows(). + + png_read_image(png_ptr, row_pointers); + +where row_pointers is: + + png_bytep row_pointers[height]; + +You can point to void or char or whatever you use for pixels. + +If you don't want to read in the whole image at once, you can +use png_read_rows() instead. If there is no interlacing (check +interlace_type == PNG_INTERLACE_NONE), this is simple: + + png_read_rows(png_ptr, row_pointers, NULL, + number_of_rows); + +where row_pointers is the same as in the png_read_image() call. + +If you are doing this just one row at a time, you can do this with +a single row_pointer instead of an array of row_pointers: + + png_bytep row_pointer = row; + png_read_row(png_ptr, row_pointer, NULL); + +If the file is interlaced (interlace_type != 0 in the IHDR chunk), things +get somewhat harder. The only current (PNG Specification version 1.2) +interlacing type for PNG is (interlace_type == PNG_INTERLACE_ADAM7); +a somewhat complicated 2D interlace scheme, known as Adam7, that +breaks down an image into seven smaller images of varying size, based +on an 8x8 grid. This number is defined (from libpng 1.5) as +PNG_INTERLACE_ADAM7_PASSES in png.h + +libpng can fill out those images or it can give them to you "as is". +It is almost always better to have libpng handle the interlacing for you. +If you want the images filled out, there are two ways to do that. The one +mentioned in the PNG specification is to expand each pixel to cover +those pixels that have not been read yet (the "rectangle" method). +This results in a blocky image for the first pass, which gradually +smooths out as more pixels are read. The other method is the "sparkle" +method, where pixels are drawn only in their final locations, with the +rest of the image remaining whatever colors they were initialized to +before the start of the read. The first method usually looks better, +but tends to be slower, as there are more pixels to put in the rows. + +If, as is likely, you want libpng to expand the images, call this before +calling png_start_read_image() or png_read_update_info(): + + if (interlace_type == PNG_INTERLACE_ADAM7) + number_of_passes + = png_set_interlace_handling(png_ptr); + +This will return the number of passes needed. Currently, this is seven, +but may change if another interlace type is added. This function can be +called even if the file is not interlaced, where it will return one pass. +You then need to read the whole image 'number_of_passes' times. Each time +will distribute the pixels from the current pass to the correct place in +the output image, so you need to supply the same rows to png_read_rows in +each pass. + +If you are not going to display the image after each pass, but are +going to wait until the entire image is read in, use the sparkle +effect. This effect is faster and the end result of either method +is exactly the same. If you are planning on displaying the image +after each pass, the "rectangle" effect is generally considered the +better looking one. + +If you only want the "sparkle" effect, just call png_read_rows() as +normal, with the third parameter NULL. Make sure you make pass over +the image number_of_passes times, and you don't change the data in the +rows between calls. You can change the locations of the data, just +not the data. Each pass only writes the pixels appropriate for that +pass, and assumes the data from previous passes is still valid. + + png_read_rows(png_ptr, row_pointers, NULL, + number_of_rows); + +If you only want the first effect (the rectangles), do the same as +before except pass the row buffer in the third parameter, and leave +the second parameter NULL. + + png_read_rows(png_ptr, NULL, row_pointers, + number_of_rows); + +If you don't want libpng to handle the interlacing details, just call +png_read_rows() PNG_INTERLACE_ADAM7_PASSES times to read in all the images. +Each of the images is a valid image by itself, however you will almost +certainly need to distribute the pixels from each sub-image to the +correct place. This is where everything gets very tricky. + +If you want to retrieve the separate images you must pass the correct +number of rows to each successive call of png_read_rows(). The calculation +gets pretty complicated for small images, where some sub-images may +not even exist because either their width or height ends up zero. +libpng provides two macros to help you in 1.5 and later versions: + + png_uint_32 width = PNG_PASS_COLS(image_width, pass_number); + png_uint_32 height = PNG_PASS_ROWS(image_height, pass_number); + +Respectively these tell you the width and height of the sub-image +corresponding to the numbered pass. 'pass' is in in the range 0 to 6 - +this can be confusing because the specification refers to the same passes +as 1 to 7! Be careful, you must check both the width and height before +calling png_read_rows() and not call it for that pass if either is zero. + +You can, of course, read each sub-image row by row. If you want to +produce optimal code to make a pixel-by-pixel transformation of an +interlaced image this is the best approach; read each row of each pass, +transform it, and write it out to a new interlaced image. + +If you want to de-interlace the image yourself libpng provides further +macros to help that tell you where to place the pixels in the output image. +Because the interlacing scheme is rectangular - sub-image pixels are always +arranged on a rectangular grid - all you need to know for each pass is the +starting column and row in the output image of the first pixel plus the +spacing between each pixel. As of libpng 1.5 there are four macros to +retrieve this information: + + png_uint_32 x = PNG_PASS_START_COL(pass); + png_uint_32 y = PNG_PASS_START_ROW(pass); + png_uint_32 xStep = 1U << PNG_PASS_COL_SHIFT(pass); + png_uint_32 yStep = 1U << PNG_PASS_ROW_SHIFT(pass); + +These allow you to write the obvious loop: + + png_uint_32 input_y = 0; + png_uint_32 output_y = PNG_PASS_START_ROW(pass); + + while (output_y < output_image_height) + { + png_uint_32 input_x = 0; + png_uint_32 output_x = PNG_PASS_START_COL(pass); + + while (output_x < output_image_width) + { + image[output_y][output_x] = + subimage[pass][input_y][input_x++]; + + output_x += xStep; + } + + ++input_y; + output_y += yStep; + } + +Notice that the steps between successive output rows and columns are +returned as shifts. This is possible because the pixels in the subimages +are always a power of 2 apart - 1, 2, 4 or 8 pixels - in the original +image. In practice you may need to directly calculate the output coordinate +given an input coordinate. libpng provides two further macros for this +purpose: + + png_uint_32 output_x = PNG_COL_FROM_PASS_COL(input_x, pass); + png_uint_32 output_y = PNG_ROW_FROM_PASS_ROW(input_y, pass); + +Finally a pair of macros are provided to tell you if a particular image +row or column appears in a given pass: + + int col_in_pass = PNG_COL_IN_INTERLACE_PASS(output_x, pass); + int row_in_pass = PNG_ROW_IN_INTERLACE_PASS(output_y, pass); + +Bear in mind that you will probably also need to check the width and height +of the pass in addition to the above to be sure the pass even exists! + +With any luck you are convinced by now that you don't want to do your own +interlace handling. In reality normally the only good reason for doing this +is if you are processing PNG files on a pixel-by-pixel basis and don't want +to load the whole file into memory when it is interlaced. + +libpng includes a test program, pngvalid, that illustrates reading and +writing of interlaced images. If you can't get interlacing to work in your +code and don't want to leave it to libpng (the recommended approach) see +how pngvalid.c does it. + +.SS Finishing a sequential read + +After you are finished reading the image through the +low-level interface, you can finish reading the file. If you are +interested in comments or time, which may be stored either before or +after the image data, you should pass the separate png_info struct if +you want to keep the comments from before and after the image +separate. If you are not interested, you can pass NULL. + + png_read_end(png_ptr, end_info); + +When you are done, you can free all memory allocated by libpng like this: + + png_destroy_read_struct(&png_ptr, &info_ptr, + &end_info); + +It is also possible to individually free the info_ptr members that +point to libpng-allocated storage with the following function: + + png_free_data(png_ptr, info_ptr, mask, seq) + + mask - identifies data to be freed, a mask + containing the bitwise OR of one or + more of + PNG_FREE_PLTE, PNG_FREE_TRNS, + PNG_FREE_HIST, PNG_FREE_ICCP, + PNG_FREE_PCAL, PNG_FREE_ROWS, + PNG_FREE_SCAL, PNG_FREE_SPLT, + PNG_FREE_TEXT, PNG_FREE_UNKN, + or simply PNG_FREE_ALL + + seq - sequence number of item to be freed + (-1 for all items) + +This function may be safely called when the relevant storage has +already been freed, or has not yet been allocated, or was allocated +by the user and not by libpng, and will in those cases do nothing. +The "seq" parameter is ignored if only one item of the selected data +type, such as PLTE, is allowed. If "seq" is not -1, and multiple items +are allowed for the data type identified in the mask, such as text or +sPLT, only the n'th item in the structure is freed, where n is "seq". + +The default behavior is only to free data that was allocated internally +by libpng. This can be changed, so that libpng will not free the data, +or so that it will free data that was allocated by the user with png_malloc() +or png_zalloc() and passed in via a png_set_*() function, with + + png_data_freer(png_ptr, info_ptr, freer, mask) + + freer - one of + PNG_DESTROY_WILL_FREE_DATA + PNG_SET_WILL_FREE_DATA + PNG_USER_WILL_FREE_DATA + + mask - which data elements are affected + same choices as in png_free_data() + +This function only affects data that has already been allocated. +You can call this function after reading the PNG data but before calling +any png_set_*() functions, to control whether the user or the png_set_*() +function is responsible for freeing any existing data that might be present, +and again after the png_set_*() functions to control whether the user +or png_destroy_*() is supposed to free the data. When the user assumes +responsibility for libpng-allocated data, the application must use +png_free() to free it, and when the user transfers responsibility to libpng +for data that the user has allocated, the user must have used png_malloc() +or png_zalloc() to allocate it. + +If you allocated your row_pointers in a single block, as suggested above in +the description of the high level read interface, you must not transfer +responsibility for freeing it to the png_set_rows or png_read_destroy function, +because they would also try to free the individual row_pointers[i]. + +If you allocated text_ptr.text, text_ptr.lang, and text_ptr.translated_keyword +separately, do not transfer responsibility for freeing text_ptr to libpng, +because when libpng fills a png_text structure it combines these members with +the key member, and png_free_data() will free only text_ptr.key. Similarly, +if you transfer responsibility for free'ing text_ptr from libpng to your +application, your application must not separately free those members. + +The png_free_data() function will turn off the "valid" flag for anything +it frees. If you need to turn the flag off for a chunk that was freed by +your application instead of by libpng, you can use + + png_set_invalid(png_ptr, info_ptr, mask); + + mask - identifies the chunks to be made invalid, + containing the bitwise OR of one or + more of + PNG_INFO_gAMA, PNG_INFO_sBIT, + PNG_INFO_cHRM, PNG_INFO_PLTE, + PNG_INFO_tRNS, PNG_INFO_bKGD, + PNG_INFO_hIST, PNG_INFO_pHYs, + PNG_INFO_oFFs, PNG_INFO_tIME, + PNG_INFO_pCAL, PNG_INFO_sRGB, + PNG_INFO_iCCP, PNG_INFO_sPLT, + PNG_INFO_sCAL, PNG_INFO_IDAT + +For a more compact example of reading a PNG image, see the file example.c. + +.SS Reading PNG files progressively + +The progressive reader is slightly different then the non-progressive +reader. Instead of calling png_read_info(), png_read_rows(), and +png_read_end(), you make one call to png_process_data(), which calls +callbacks when it has the info, a row, or the end of the image. You +set up these callbacks with png_set_progressive_read_fn(). You don't +have to worry about the input/output functions of libpng, as you are +giving the library the data directly in png_process_data(). I will +assume that you have read the section on reading PNG files above, +so I will only highlight the differences (although I will show +all of the code). + +png_structp png_ptr; +png_infop info_ptr; + + /* An example code fragment of how you would + initialize the progressive reader in your + application. */ + int + initialize_png_reader() + { + png_ptr = png_create_read_struct + (PNG_LIBPNG_VER_STRING, (png_voidp)user_error_ptr, + user_error_fn, user_warning_fn); + + if (!png_ptr) + return (ERROR); + + info_ptr = png_create_info_struct(png_ptr); + + if (!info_ptr) + { + png_destroy_read_struct(&png_ptr, + (png_infopp)NULL, (png_infopp)NULL); + return (ERROR); + } + + if (setjmp(png_jmpbuf(png_ptr))) + { + png_destroy_read_struct(&png_ptr, &info_ptr, + (png_infopp)NULL); + return (ERROR); + } + + /* This one's new. You can provide functions + to be called when the header info is valid, + when each row is completed, and when the image + is finished. If you aren't using all functions, + you can specify NULL parameters. Even when all + three functions are NULL, you need to call + png_set_progressive_read_fn(). You can use + any struct as the user_ptr (cast to a void pointer + for the function call), and retrieve the pointer + from inside the callbacks using the function + + png_get_progressive_ptr(png_ptr); + + which will return a void pointer, which you have + to cast appropriately. + */ + png_set_progressive_read_fn(png_ptr, (void *)user_ptr, + info_callback, row_callback, end_callback); + + return 0; + } + + /* A code fragment that you call as you receive blocks + of data */ + int + process_data(png_bytep buffer, png_uint_32 length) + { + if (setjmp(png_jmpbuf(png_ptr))) + { + png_destroy_read_struct(&png_ptr, &info_ptr, + (png_infopp)NULL); + return (ERROR); + } + + /* This one's new also. Simply give it a chunk + of data from the file stream (in order, of + course). On machines with segmented memory + models machines, don't give it any more than + 64K. The library seems to run fine with sizes + of 4K. Although you can give it much less if + necessary (I assume you can give it chunks of + 1 byte, I haven't tried less then 256 bytes + yet). When this function returns, you may + want to display any rows that were generated + in the row callback if you don't already do + so there. + */ + png_process_data(png_ptr, info_ptr, buffer, length); + + /* At this point you can call png_process_data_skip if + you want to handle data the library will skip yourself; + it simply returns the number of bytes to skip (and stops + libpng skipping that number of bytes on the next + png_process_data call). + return 0; + } + + /* This function is called (as set by + png_set_progressive_read_fn() above) when enough data + has been supplied so all of the header has been + read. + */ + void + info_callback(png_structp png_ptr, png_infop info) + { + /* Do any setup here, including setting any of + the transformations mentioned in the Reading + PNG files section. For now, you _must_ call + either png_start_read_image() or + png_read_update_info() after all the + transformations are set (even if you don't set + any). You may start getting rows before + png_process_data() returns, so this is your + last chance to prepare for that. + + This is where you turn on interlace handling, + assuming you don't want to do it yourself. + + If you need to you can stop the processing of + your original input data at this point by calling + png_process_data_pause. This returns the number + of unprocessed bytes from the last png_process_data + call - it is up to you to ensure that the next call + sees these bytes again. If you don't want to bother + with this you can get libpng to cache the unread + bytes by setting the 'save' parameter (see png.h) but + then libpng will have to copy the data internally. + */ + } + + /* This function is called when each row of image + data is complete */ + void + row_callback(png_structp png_ptr, png_bytep new_row, + png_uint_32 row_num, int pass) + { + /* If the image is interlaced, and you turned + on the interlace handler, this function will + be called for every row in every pass. Some + of these rows will not be changed from the + previous pass. When the row is not changed, + the new_row variable will be NULL. The rows + and passes are called in order, so you don't + really need the row_num and pass, but I'm + supplying them because it may make your life + easier. + + If you did not turn on interlace handling then + the callback is called for each row of each + sub-image when the image is interlaced. In this + case 'row_num' is the row in the sub-image, not + the row in the output image as it is in all other + cases. + + For the non-NULL rows of interlaced images when + you have switched on libpng interlace handling, + you must call png_progressive_combine_row() + passing in the row and the old row. You can + call this function for NULL rows (it will just + return) and for non-interlaced images (it just + does the memcpy for you) if it will make the + code easier. Thus, you can just do this for + all cases if you switch on interlace handling; + */ + + png_progressive_combine_row(png_ptr, old_row, + new_row); + + /* where old_row is what was displayed for + previously for the row. Note that the first + pass (pass == 0, really) will completely cover + the old row, so the rows do not have to be + initialized. After the first pass (and only + for interlaced images), you will have to pass + the current row, and the function will combine + the old row and the new row. + + You can also call png_process_data_pause in this + callback - see above. + */ + } + + void + end_callback(png_structp png_ptr, png_infop info) + { + /* This function is called after the whole image + has been read, including any chunks after the + image (up to and including the IEND). You + will usually have the same info chunk as you + had in the header, although some data may have + been added to the comments and time fields. + + Most people won't do much here, perhaps setting + a flag that marks the image as finished. + */ + } + + + +.SH IV. Writing + +Much of this is very similar to reading. However, everything of +importance is repeated here, so you won't have to constantly look +back up in the reading section to understand writing. + +.SS Setup + +You will want to do the I/O initialization before you get into libpng, +so if it doesn't work, you don't have anything to undo. If you are not +using the standard I/O functions, you will need to replace them with +custom writing functions. See the discussion under Customizing libpng. + + FILE *fp = fopen(file_name, "wb"); + + if (!fp) + return (ERROR); + +Next, png_struct and png_info need to be allocated and initialized. +As these can be both relatively large, you may not want to store these +on the stack, unless you have stack space to spare. Of course, you +will want to check if they return NULL. If you are also reading, +you won't want to name your read structure and your write structure +both "png_ptr"; you can call them anything you like, such as +"read_ptr" and "write_ptr". Look at pngtest.c, for example. + + png_structp png_ptr = png_create_write_struct + (PNG_LIBPNG_VER_STRING, (png_voidp)user_error_ptr, + user_error_fn, user_warning_fn); + + if (!png_ptr) + return (ERROR); + + png_infop info_ptr = png_create_info_struct(png_ptr); + if (!info_ptr) + { + png_destroy_write_struct(&png_ptr, + (png_infopp)NULL); + return (ERROR); + } + +If you want to use your own memory allocation routines, +define PNG_USER_MEM_SUPPORTED and use +png_create_write_struct_2() instead of png_create_write_struct(): + + png_structp png_ptr = png_create_write_struct_2 + (PNG_LIBPNG_VER_STRING, (png_voidp)user_error_ptr, + user_error_fn, user_warning_fn, (png_voidp) + user_mem_ptr, user_malloc_fn, user_free_fn); + +After you have these structures, you will need to set up the +error handling. When libpng encounters an error, it expects to +longjmp() back to your routine. Therefore, you will need to call +setjmp() and pass the png_jmpbuf(png_ptr). If you +write the file from different routines, you will need to update +the png_jmpbuf(png_ptr) every time you enter a new routine that will +call a png_*() function. See your documentation of setjmp/longjmp +for your compiler for more information on setjmp/longjmp. See +the discussion on libpng error handling in the Customizing Libpng +section below for more information on the libpng error handling. + + if (setjmp(png_jmpbuf(png_ptr))) + { + png_destroy_write_struct(&png_ptr, &info_ptr); + fclose(fp); + return (ERROR); + } + ... + return; + +If you would rather avoid the complexity of setjmp/longjmp issues, +you can compile libpng with PNG_NO_SETJMP, in which case +errors will result in a call to PNG_ABORT() which defaults to abort(). + +You can #define PNG_ABORT() to a function that does something +more useful than abort(), as long as your function does not +return. + +Now you need to set up the output code. The default for libpng is to +use the C function fwrite(). If you use this, you will need to pass a +valid FILE * in the function png_init_io(). Be sure that the file is +opened in binary mode. Again, if you wish to handle writing data in +another way, see the discussion on libpng I/O handling in the Customizing +Libpng section below. + + png_init_io(png_ptr, fp); + +If you are embedding your PNG into a datastream such as MNG, and don't +want libpng to write the 8-byte signature, or if you have already +written the signature in your application, use + + png_set_sig_bytes(png_ptr, 8); + +to inform libpng that it should not write a signature. + +.SS Write callbacks + +At this point, you can set up a callback function that will be +called after each row has been written, which you can use to control +a progress meter or the like. It's demonstrated in pngtest.c. +You must supply a function + + void write_row_callback(png_structp png_ptr, png_uint_32 row, + int pass); + { + /* put your code here */ + } + +(You can give it another name that you like instead of "write_row_callback") + +To inform libpng about your function, use + + png_set_write_status_fn(png_ptr, write_row_callback); + +You now have the option of modifying how the compression library will +run. The following functions are mainly for testing, but may be useful +in some cases, like if you need to write PNG files extremely fast and +are willing to give up some compression, or if you want to get the +maximum possible compression at the expense of slower writing. If you +have no special needs in this area, let the library do what it wants by +not calling this function at all, as it has been tuned to deliver a good +speed/compression ratio. The second parameter to png_set_filter() is +the filter method, for which the only valid values are 0 (as of the +July 1999 PNG specification, version 1.2) or 64 (if you are writing +a PNG datastream that is to be embedded in a MNG datastream). The third +parameter is a flag that indicates which filter type(s) are to be tested +for each scanline. See the PNG specification for details on the specific +filter types. + + + /* turn on or off filtering, and/or choose + specific filters. You can use either a single + PNG_FILTER_VALUE_NAME or the bitwise OR of one + or more PNG_FILTER_NAME masks. + */ + png_set_filter(png_ptr, 0, + PNG_FILTER_NONE | PNG_FILTER_VALUE_NONE | + PNG_FILTER_SUB | PNG_FILTER_VALUE_SUB | + PNG_FILTER_UP | PNG_FILTER_VALUE_UP | + PNG_FILTER_AVG | PNG_FILTER_VALUE_AVG | + PNG_FILTER_PAETH | PNG_FILTER_VALUE_PAETH| + PNG_ALL_FILTERS); + +If an application wants to start and stop using particular filters during +compression, it should start out with all of the filters (to ensure that +the previous row of pixels will be stored in case it's needed later), +and then add and remove them after the start of compression. + +If you are writing a PNG datastream that is to be embedded in a MNG +datastream, the second parameter can be either 0 or 64. + +The png_set_compression_*() functions interface to the zlib compression +library, and should mostly be ignored unless you really know what you are +doing. The only generally useful call is png_set_compression_level() +which changes how much time zlib spends on trying to compress the image +data. See the Compression Library (zlib.h and algorithm.txt, distributed +with zlib) for details on the compression levels. + + /* set the zlib compression level */ + png_set_compression_level(png_ptr, + Z_BEST_COMPRESSION); + + /* set other zlib parameters */ + png_set_compression_mem_level(png_ptr, 8); + png_set_compression_strategy(png_ptr, + Z_DEFAULT_STRATEGY); + png_set_compression_window_bits(png_ptr, 15); + png_set_compression_method(png_ptr, 8); + png_set_compression_buffer_size(png_ptr, 8192) + +extern PNG_EXPORT(void,png_set_zbuf_size) + +.SS Setting the contents of info for output + +You now need to fill in the png_info structure with all the data you +wish to write before the actual image. Note that the only thing you +are allowed to write after the image is the text chunks and the time +chunk (as of PNG Specification 1.2, anyway). See png_write_end() and +the latest PNG specification for more information on that. If you +wish to write them before the image, fill them in now, and flag that +data as being valid. If you want to wait until after the data, don't +fill them until png_write_end(). For all the fields in png_info and +their data types, see png.h. For explanations of what the fields +contain, see the PNG specification. + +Some of the more important parts of the png_info are: + + png_set_IHDR(png_ptr, info_ptr, width, height, + bit_depth, color_type, interlace_type, + compression_type, filter_method) + + width - holds the width of the image + in pixels (up to 2^31). + + height - holds the height of the image + in pixels (up to 2^31). + + bit_depth - holds the bit depth of one of the + image channels. + (valid values are 1, 2, 4, 8, 16 + and depend also on the + color_type. See also significant + bits (sBIT) below). + + color_type - describes which color/alpha + channels are present. + PNG_COLOR_TYPE_GRAY + (bit depths 1, 2, 4, 8, 16) + PNG_COLOR_TYPE_GRAY_ALPHA + (bit depths 8, 16) + PNG_COLOR_TYPE_PALETTE + (bit depths 1, 2, 4, 8) + PNG_COLOR_TYPE_RGB + (bit_depths 8, 16) + PNG_COLOR_TYPE_RGB_ALPHA + (bit_depths 8, 16) + + PNG_COLOR_MASK_PALETTE + PNG_COLOR_MASK_COLOR + PNG_COLOR_MASK_ALPHA + + interlace_type - PNG_INTERLACE_NONE or + PNG_INTERLACE_ADAM7 + + compression_type - (must be + PNG_COMPRESSION_TYPE_DEFAULT) + + filter_method - (must be PNG_FILTER_TYPE_DEFAULT + or, if you are writing a PNG to + be embedded in a MNG datastream, + can also be + PNG_INTRAPIXEL_DIFFERENCING) + +If you call png_set_IHDR(), the call must appear before any of the +other png_set_*() functions, because they might require access to some of +the IHDR settings. The remaining png_set_*() functions can be called +in any order. + +If you wish, you can reset the compression_type, interlace_type, or +filter_method later by calling png_set_IHDR() again; if you do this, the +width, height, bit_depth, and color_type must be the same in each call. + + png_set_PLTE(png_ptr, info_ptr, palette, + num_palette); + + palette - the palette for the file + (array of png_color) + num_palette - number of entries in the palette + + png_set_gAMA(png_ptr, info_ptr, file_gamma); + png_set_gAMA_fixed(png_ptr, info_ptr, int_file_gamma); + + file_gamma - the gamma at which the image was + created (PNG_INFO_gAMA) + + int_file_gamma - 100,000 times the gamma at which + the image was created + + png_set_sRGB(png_ptr, info_ptr, srgb_intent); + + srgb_intent - the rendering intent + (PNG_INFO_sRGB) The presence of + the sRGB chunk means that the pixel + data is in the sRGB color space. + This chunk also implies specific + values of gAMA and cHRM. Rendering + intent is the CSS-1 property that + has been defined by the International + Color Consortium + (http://www.color.org). + It can be one of + PNG_sRGB_INTENT_SATURATION, + PNG_sRGB_INTENT_PERCEPTUAL, + PNG_sRGB_INTENT_ABSOLUTE, or + PNG_sRGB_INTENT_RELATIVE. + + + png_set_sRGB_gAMA_and_cHRM(png_ptr, info_ptr, + srgb_intent); + + srgb_intent - the rendering intent + (PNG_INFO_sRGB) The presence of the + sRGB chunk means that the pixel + data is in the sRGB color space. + This function also causes gAMA and + cHRM chunks with the specific values + that are consistent with sRGB to be + written. + + png_set_iCCP(png_ptr, info_ptr, name, compression_type, + profile, proflen); + + name - The profile name. + + compression_type - The compression type; always + PNG_COMPRESSION_TYPE_BASE for PNG 1.0. + You may give NULL to this argument to + ignore it. + + profile - International Color Consortium color + profile data. May contain NULs. + + proflen - length of profile data in bytes. + + png_set_sBIT(png_ptr, info_ptr, sig_bit); + + sig_bit - the number of significant bits for + (PNG_INFO_sBIT) each of the gray, red, + green, and blue channels, whichever are + appropriate for the given color type + (png_color_16) + + png_set_tRNS(png_ptr, info_ptr, trans_alpha, + num_trans, trans_color); + + trans_alpha - array of alpha (transparency) + entries for palette (PNG_INFO_tRNS) + + trans_color - graylevel or color sample values + (in order red, green, blue) of the + single transparent color for + non-paletted images (PNG_INFO_tRNS) + + num_trans - number of transparent entries + (PNG_INFO_tRNS) + + png_set_hIST(png_ptr, info_ptr, hist); + + hist - histogram of palette (array of + png_uint_16) (PNG_INFO_hIST) + + png_set_tIME(png_ptr, info_ptr, mod_time); + + mod_time - time image was last modified + (PNG_VALID_tIME) + + png_set_bKGD(png_ptr, info_ptr, background); + + background - background color (PNG_VALID_bKGD) + + png_set_text(png_ptr, info_ptr, text_ptr, num_text); + + text_ptr - array of png_text holding image + comments + + text_ptr[i].compression - type of compression used + on "text" PNG_TEXT_COMPRESSION_NONE + PNG_TEXT_COMPRESSION_zTXt + PNG_ITXT_COMPRESSION_NONE + PNG_ITXT_COMPRESSION_zTXt + text_ptr[i].key - keyword for comment. Must contain + 1-79 characters. + text_ptr[i].text - text comments for current + keyword. Can be NULL or empty. + text_ptr[i].text_length - length of text string, + after decompression, 0 for iTXt + text_ptr[i].itxt_length - length of itxt string, + after decompression, 0 for tEXt/zTXt + text_ptr[i].lang - language of comment (NULL or + empty for unknown). + text_ptr[i].translated_keyword - keyword in UTF-8 (NULL + or empty for unknown). + Note that the itxt_length, lang, and lang_key + members of the text_ptr structure only exist + when the library is built with iTXt chunk support. + + num_text - number of comments + + png_set_sPLT(png_ptr, info_ptr, &palette_ptr, + num_spalettes); + + palette_ptr - array of png_sPLT_struct structures + to be added to the list of palettes + in the info structure. + num_spalettes - number of palette structures to be + added. + + png_set_oFFs(png_ptr, info_ptr, offset_x, offset_y, + unit_type); + + offset_x - positive offset from the left + edge of the screen + + offset_y - positive offset from the top + edge of the screen + + unit_type - PNG_OFFSET_PIXEL, PNG_OFFSET_MICROMETER + + png_set_pHYs(png_ptr, info_ptr, res_x, res_y, + unit_type); + + res_x - pixels/unit physical resolution + in x direction + + res_y - pixels/unit physical resolution + in y direction + + unit_type - PNG_RESOLUTION_UNKNOWN, + PNG_RESOLUTION_METER + + png_set_sCAL(png_ptr, info_ptr, unit, width, height) + + unit - physical scale units (an integer) + + width - width of a pixel in physical scale units + + height - height of a pixel in physical scale units + (width and height are doubles) + + png_set_sCAL_s(png_ptr, info_ptr, unit, width, height) + + unit - physical scale units (an integer) + + width - width of a pixel in physical scale units + + height - height of a pixel in physical scale units + (width and height are strings like "2.54") + + png_set_unknown_chunks(png_ptr, info_ptr, &unknowns, + num_unknowns) + + unknowns - array of png_unknown_chunk + structures holding unknown chunks + unknowns[i].name - name of unknown chunk + unknowns[i].data - data of unknown chunk + unknowns[i].size - size of unknown chunk's data + unknowns[i].location - position to write chunk in file + 0: do not write chunk + PNG_HAVE_IHDR: before PLTE + PNG_HAVE_PLTE: before IDAT + PNG_AFTER_IDAT: after IDAT + +The "location" member is set automatically according to +what part of the output file has already been written. +You can change its value after calling png_set_unknown_chunks() +as demonstrated in pngtest.c. Within each of the "locations", +the chunks are sequenced according to their position in the +structure (that is, the value of "i", which is the order in which +the chunk was either read from the input file or defined with +png_set_unknown_chunks). + +A quick word about text and num_text. text is an array of png_text +structures. num_text is the number of valid structures in the array. +Each png_text structure holds a language code, a keyword, a text value, +and a compression type. + +The compression types have the same valid numbers as the compression +types of the image data. Currently, the only valid number is zero. +However, you can store text either compressed or uncompressed, unlike +images, which always have to be compressed. So if you don't want the +text compressed, set the compression type to PNG_TEXT_COMPRESSION_NONE. +Because tEXt and zTXt chunks don't have a language field, if you +specify PNG_TEXT_COMPRESSION_NONE or PNG_TEXT_COMPRESSION_zTXt +any language code or translated keyword will not be written out. + +Until text gets around 1000 bytes, it is not worth compressing it. +After the text has been written out to the file, the compression type +is set to PNG_TEXT_COMPRESSION_NONE_WR or PNG_TEXT_COMPRESSION_zTXt_WR, +so that it isn't written out again at the end (in case you are calling +png_write_end() with the same struct). + +The keywords that are given in the PNG Specification are: + + Title Short (one line) title or + caption for image + + Author Name of image's creator + + Description Description of image (possibly long) + + Copyright Copyright notice + + Creation Time Time of original image creation + (usually RFC 1123 format, see below) + + Software Software used to create the image + + Disclaimer Legal disclaimer + + Warning Warning of nature of content + + Source Device used to create the image + + Comment Miscellaneous comment; conversion + from other image format + +The keyword-text pairs work like this. Keywords should be short +simple descriptions of what the comment is about. Some typical +keywords are found in the PNG specification, as is some recommendations +on keywords. You can repeat keywords in a file. You can even write +some text before the image and some after. For example, you may want +to put a description of the image before the image, but leave the +disclaimer until after, so viewers working over modem connections +don't have to wait for the disclaimer to go over the modem before +they start seeing the image. Finally, keywords should be full +words, not abbreviations. Keywords and text are in the ISO 8859-1 +(Latin-1) character set (a superset of regular ASCII) and can not +contain NUL characters, and should not contain control or other +unprintable characters. To make the comments widely readable, stick +with basic ASCII, and avoid machine specific character set extensions +like the IBM-PC character set. The keyword must be present, but +you can leave off the text string on non-compressed pairs. +Compressed pairs must have a text string, as only the text string +is compressed anyway, so the compression would be meaningless. + +PNG supports modification time via the png_time structure. Two +conversion routines are provided, png_convert_from_time_t() for +time_t and png_convert_from_struct_tm() for struct tm. The +time_t routine uses gmtime(). You don't have to use either of +these, but if you wish to fill in the png_time structure directly, +you should provide the time in universal time (GMT) if possible +instead of your local time. Note that the year number is the full +year (e.g. 1998, rather than 98 - PNG is year 2000 compliant!), and +that months start with 1. + +If you want to store the time of the original image creation, you should +use a plain tEXt chunk with the "Creation Time" keyword. This is +necessary because the "creation time" of a PNG image is somewhat vague, +depending on whether you mean the PNG file, the time the image was +created in a non-PNG format, a still photo from which the image was +scanned, or possibly the subject matter itself. In order to facilitate +machine-readable dates, it is recommended that the "Creation Time" +tEXt chunk use RFC 1123 format dates (e.g. "22 May 1997 18:07:10 GMT"), +although this isn't a requirement. Unlike the tIME chunk, the +"Creation Time" tEXt chunk is not expected to be automatically changed +by the software. To facilitate the use of RFC 1123 dates, a function +png_convert_to_rfc1123(png_timep) is provided to convert from PNG +time to an RFC 1123 format string. + +.SS Writing unknown chunks + +You can use the png_set_unknown_chunks function to queue up chunks +for writing. You give it a chunk name, raw data, and a size; that's +all there is to it. The chunks will be written by the next following +png_write_info_before_PLTE, png_write_info, or png_write_end function. +Any chunks previously read into the info structure's unknown-chunk +list will also be written out in a sequence that satisfies the PNG +specification's ordering rules. + +.SS The high-level write interface + +At this point there are two ways to proceed; through the high-level +write interface, or through a sequence of low-level write operations. +You can use the high-level interface if your image data is present +in the info structure. All defined output +transformations are permitted, enabled by the following masks. + + PNG_TRANSFORM_IDENTITY No transformation + PNG_TRANSFORM_PACKING Pack 1, 2 and 4-bit samples + PNG_TRANSFORM_PACKSWAP Change order of packed + pixels to LSB first + PNG_TRANSFORM_INVERT_MONO Invert monochrome images + PNG_TRANSFORM_SHIFT Normalize pixels to the + sBIT depth + PNG_TRANSFORM_BGR Flip RGB to BGR, RGBA + to BGRA + PNG_TRANSFORM_SWAP_ALPHA Flip RGBA to ARGB or GA + to AG + PNG_TRANSFORM_INVERT_ALPHA Change alpha from opacity + to transparency + PNG_TRANSFORM_SWAP_ENDIAN Byte-swap 16-bit samples + PNG_TRANSFORM_STRIP_FILLER Strip out filler + bytes (deprecated). + PNG_TRANSFORM_STRIP_FILLER_BEFORE Strip out leading + filler bytes + PNG_TRANSFORM_STRIP_FILLER_AFTER Strip out trailing + filler bytes + +If you have valid image data in the info structure (you can use +png_set_rows() to put image data in the info structure), simply do this: + + png_write_png(png_ptr, info_ptr, png_transforms, NULL) + +where png_transforms is an integer containing the bitwise OR of some set of +transformation flags. This call is equivalent to png_write_info(), +followed the set of transformations indicated by the transform mask, +then png_write_image(), and finally png_write_end(). + +(The final parameter of this call is not yet used. Someday it might point +to transformation parameters required by some future output transform.) + +You must use png_transforms and not call any png_set_transform() functions +when you use png_write_png(). + +.SS The low-level write interface + +If you are going the low-level route instead, you are now ready to +write all the file information up to the actual image data. You do +this with a call to png_write_info(). + + png_write_info(png_ptr, info_ptr); + +Note that there is one transformation you may need to do before +png_write_info(). In PNG files, the alpha channel in an image is the +level of opacity. If your data is supplied as a level of transparency, +you can invert the alpha channel before you write it, so that 0 is +fully transparent and 255 (in 8-bit or paletted images) or 65535 +(in 16-bit images) is fully opaque, with + + png_set_invert_alpha(png_ptr); + +This must appear before png_write_info() instead of later with the +other transformations because in the case of paletted images the tRNS +chunk data has to be inverted before the tRNS chunk is written. If +your image is not a paletted image, the tRNS data (which in such cases +represents a single color to be rendered as transparent) won't need to +be changed, and you can safely do this transformation after your +png_write_info() call. + +If you need to write a private chunk that you want to appear before +the PLTE chunk when PLTE is present, you can write the PNG info in +two steps, and insert code to write your own chunk between them: + + png_write_info_before_PLTE(png_ptr, info_ptr); + png_set_unknown_chunks(png_ptr, info_ptr, ...); + png_write_info(png_ptr, info_ptr); + +After you've written the file information, you can set up the library +to handle any special transformations of the image data. The various +ways to transform the data will be described in the order that they +should occur. This is important, as some of these change the color +type and/or bit depth of the data, and some others only work on +certain color types and bit depths. Even though each transformation +checks to see if it has data that it can do something with, you should +make sure to only enable a transformation if it will be valid for the +data. For example, don't swap red and blue on grayscale data. + +PNG files store RGB pixels packed into 3 or 6 bytes. This code tells +the library to strip input data that has 4 or 8 bytes per pixel down +to 3 or 6 bytes (or strip 2 or 4-byte grayscale+filler data to 1 or 2 +bytes per pixel). + + png_set_filler(png_ptr, 0, PNG_FILLER_BEFORE); + +where the 0 is unused, and the location is either PNG_FILLER_BEFORE or +PNG_FILLER_AFTER, depending upon whether the filler byte in the pixel +is stored XRGB or RGBX. + +PNG files pack pixels of bit depths 1, 2, and 4 into bytes as small as +they can, resulting in, for example, 8 pixels per byte for 1 bit files. +If the data is supplied at 1 pixel per byte, use this code, which will +correctly pack the pixels into a single byte: + + png_set_packing(png_ptr); + +PNG files reduce possible bit depths to 1, 2, 4, 8, and 16. If your +data is of another bit depth, you can write an sBIT chunk into the +file so that decoders can recover the original data if desired. + + /* Set the true bit depth of the image data */ + if (color_type & PNG_COLOR_MASK_COLOR) + { + sig_bit.red = true_bit_depth; + sig_bit.green = true_bit_depth; + sig_bit.blue = true_bit_depth; + } + + else + { + sig_bit.gray = true_bit_depth; + } + + if (color_type & PNG_COLOR_MASK_ALPHA) + { + sig_bit.alpha = true_bit_depth; + } + + png_set_sBIT(png_ptr, info_ptr, &sig_bit); + +If the data is stored in the row buffer in a bit depth other than +one supported by PNG (e.g. 3 bit data in the range 0-7 for a 4-bit PNG), +this will scale the values to appear to be the correct bit depth as +is required by PNG. + + png_set_shift(png_ptr, &sig_bit); + +PNG files store 16 bit pixels in network byte order (big-endian, +ie. most significant bits first). This code would be used if they are +supplied the other way (little-endian, i.e. least significant bits +first, the way PCs store them): + + if (bit_depth > 8) + png_set_swap(png_ptr); + +If you are using packed-pixel images (1, 2, or 4 bits/pixel), and you +need to change the order the pixels are packed into bytes, you can use: + + if (bit_depth < 8) + png_set_packswap(png_ptr); + +PNG files store 3 color pixels in red, green, blue order. This code +would be used if they are supplied as blue, green, red: + + png_set_bgr(png_ptr); + +PNG files describe monochrome as black being zero and white being +one. This code would be used if the pixels are supplied with this reversed +(black being one and white being zero): + + png_set_invert_mono(png_ptr); + +Finally, you can write your own transformation function if none of +the existing ones meets your needs. This is done by setting a callback +with + + png_set_write_user_transform_fn(png_ptr, + write_transform_fn); + +You must supply the function + + void write_transform_fn(png_structp png_ptr ptr, + row_info_ptr row_info, png_bytep data) + +See pngtest.c for a working example. Your function will be called +before any of the other transformations are processed. If supported +libpng also supplies an information routine that may be called from +your callback: + + png_get_current_row_number(png_ptr); + +This returns the current row passed to the transform. Even with interlaced +images the value returned is the row in the final output image. + +You can also set up a pointer to a user structure for use by your +callback function. + + png_set_user_transform_info(png_ptr, user_ptr, 0, 0); + +The user_channels and user_depth parameters of this function are ignored +when writing; you can set them to zero as shown. + +You can retrieve the pointer via the function png_get_user_transform_ptr(). +For example: + + voidp write_user_transform_ptr = + png_get_user_transform_ptr(png_ptr); + +It is possible to have libpng flush any pending output, either manually, +or automatically after a certain number of lines have been written. To +flush the output stream a single time call: + + png_write_flush(png_ptr); + +and to have libpng flush the output stream periodically after a certain +number of scanlines have been written, call: + + png_set_flush(png_ptr, nrows); + +Note that the distance between rows is from the last time png_write_flush() +was called, or the first row of the image if it has never been called. +So if you write 50 lines, and then png_set_flush 25, it will flush the +output on the next scanline, and every 25 lines thereafter, unless +png_write_flush() is called before 25 more lines have been written. +If nrows is too small (less than about 10 lines for a 640 pixel wide +RGB image) the image compression may decrease noticeably (although this +may be acceptable for real-time applications). Infrequent flushing will +only degrade the compression performance by a few percent over images +that do not use flushing. + +.SS Writing the image data + +That's it for the transformations. Now you can write the image data. +The simplest way to do this is in one function call. If you have the +whole image in memory, you can just call png_write_image() and libpng +will write the image. You will need to pass in an array of pointers to +each row. This function automatically handles interlacing, so you don't +need to call png_set_interlace_handling() or call this function multiple +times, or any of that other stuff necessary with png_write_rows(). + + png_write_image(png_ptr, row_pointers); + +where row_pointers is: + + png_byte *row_pointers[height]; + +You can point to void or char or whatever you use for pixels. + +If you don't want to write the whole image at once, you can +use png_write_rows() instead. If the file is not interlaced, +this is simple: + + png_write_rows(png_ptr, row_pointers, + number_of_rows); + +row_pointers is the same as in the png_write_image() call. + +If you are just writing one row at a time, you can do this with +a single row_pointer instead of an array of row_pointers: + + png_bytep row_pointer = row; + + png_write_row(png_ptr, row_pointer); + +When the file is interlaced, things can get a good deal more complicated. +The only currently (as of the PNG Specification version 1.2, dated July +1999) defined interlacing scheme for PNG files is the "Adam7" interlace +scheme, that breaks down an image into seven smaller images of varying +size. libpng will build these images for you, or you can do them +yourself. If you want to build them yourself, see the PNG specification +for details of which pixels to write when. + +If you don't want libpng to handle the interlacing details, just +use png_set_interlace_handling() and call png_write_rows() the +correct number of times to write all the sub-images +(png_set_interlace_handling() returns the number of sub-images.) + +If you want libpng to build the sub-images, call this before you start +writing any rows: + + number_of_passes = png_set_interlace_handling(png_ptr); + +This will return the number of passes needed. Currently, this is seven, +but may change if another interlace type is added. + +Then write the complete image number_of_passes times. + + png_write_rows(png_ptr, row_pointers, number_of_rows); + +Think carefully before you write an interlaced image. Typically code that +reads such images reads all the image data into memory, uncompressed, before +doing any processing. Only code that can display an image on the fly can +take advantage of the interlacing and even then the image has to be exactly +the correct size for the output device, because scaling an image requires +adjacent pixels and these are not available until all the passes have been +read. + +If you do write an interlaced image you will hardly ever need to handle +the interlacing yourself. Call png_set_interlace_handling() and use the +approach described above. + +The only time it is conceivable that you will really need to write an +interlaced image pass-by-pass is when you have read one pass by pass and +made some pixel-by-pixel transformation to it, as described in the read +code above. In this case use the PNG_PASS_ROWS and PNG_PASS_COLS macros +to determine the size of each sub-image in turn and simply write the rows +you obtained from the read code. + +.SS Finishing a sequential write + +After you are finished writing the image, you should finish writing +the file. If you are interested in writing comments or time, you should +pass an appropriately filled png_info pointer. If you are not interested, +you can pass NULL. + + png_write_end(png_ptr, info_ptr); + +When you are done, you can free all memory used by libpng like this: + + png_destroy_write_struct(&png_ptr, &info_ptr); + +It is also possible to individually free the info_ptr members that +point to libpng-allocated storage with the following function: + + png_free_data(png_ptr, info_ptr, mask, seq) + + mask - identifies data to be freed, a mask + containing the bitwise OR of one or + more of + PNG_FREE_PLTE, PNG_FREE_TRNS, + PNG_FREE_HIST, PNG_FREE_ICCP, + PNG_FREE_PCAL, PNG_FREE_ROWS, + PNG_FREE_SCAL, PNG_FREE_SPLT, + PNG_FREE_TEXT, PNG_FREE_UNKN, + or simply PNG_FREE_ALL + + seq - sequence number of item to be freed + (-1 for all items) + +This function may be safely called when the relevant storage has +already been freed, or has not yet been allocated, or was allocated +by the user and not by libpng, and will in those cases do nothing. +The "seq" parameter is ignored if only one item of the selected data +type, such as PLTE, is allowed. If "seq" is not -1, and multiple items +are allowed for the data type identified in the mask, such as text or +sPLT, only the n'th item in the structure is freed, where n is "seq". + +If you allocated data such as a palette that you passed in to libpng +with png_set_*, you must not free it until just before the call to +png_destroy_write_struct(). + +The default behavior is only to free data that was allocated internally +by libpng. This can be changed, so that libpng will not free the data, +or so that it will free data that was allocated by the user with png_malloc() +or png_zalloc() and passed in via a png_set_*() function, with + + png_data_freer(png_ptr, info_ptr, freer, mask) + + freer - one of + PNG_DESTROY_WILL_FREE_DATA + PNG_SET_WILL_FREE_DATA + PNG_USER_WILL_FREE_DATA + + mask - which data elements are affected + same choices as in png_free_data() + +For example, to transfer responsibility for some data from a read structure +to a write structure, you could use + + png_data_freer(read_ptr, read_info_ptr, + PNG_USER_WILL_FREE_DATA, + PNG_FREE_PLTE|PNG_FREE_tRNS|PNG_FREE_hIST) + + png_data_freer(write_ptr, write_info_ptr, + PNG_DESTROY_WILL_FREE_DATA, + PNG_FREE_PLTE|PNG_FREE_tRNS|PNG_FREE_hIST) + +thereby briefly reassigning responsibility for freeing to the user but +immediately afterwards reassigning it once more to the write_destroy +function. Having done this, it would then be safe to destroy the read +structure and continue to use the PLTE, tRNS, and hIST data in the write +structure. + +This function only affects data that has already been allocated. +You can call this function before calling after the png_set_*() functions +to control whether the user or png_destroy_*() is supposed to free the data. +When the user assumes responsibility for libpng-allocated data, the +application must use +png_free() to free it, and when the user transfers responsibility to libpng +for data that the user has allocated, the user must have used png_malloc() +or png_zalloc() to allocate it. + +If you allocated text_ptr.text, text_ptr.lang, and text_ptr.translated_keyword +separately, do not transfer responsibility for freeing text_ptr to libpng, +because when libpng fills a png_text structure it combines these members with +the key member, and png_free_data() will free only text_ptr.key. Similarly, +if you transfer responsibility for free'ing text_ptr from libpng to your +application, your application must not separately free those members. +For a more compact example of writing a PNG image, see the file example.c. + +.SH V. Modifying/Customizing libpng: + +There are two issues here. The first is changing how libpng does +standard things like memory allocation, input/output, and error handling. +The second deals with more complicated things like adding new chunks, +adding new transformations, and generally changing how libpng works. +Both of those are compile-time issues; that is, they are generally +determined at the time the code is written, and there is rarely a need +to provide the user with a means of changing them. + +Memory allocation, input/output, and error handling + +All of the memory allocation, input/output, and error handling in libpng +goes through callbacks that are user-settable. The default routines are +in pngmem.c, pngrio.c, pngwio.c, and pngerror.c, respectively. To change +these functions, call the appropriate png_set_*_fn() function. + +Memory allocation is done through the functions png_malloc(), png_calloc(), +and png_free(). These currently just call the standard C functions. +png_calloc() calls png_malloc() and then clears the newly +allocated memory to zero. There is limited support for certain systems +with segmented memory architectures and the types of pointers declared by +png.h match this; you will have to use appropriate pointers in your +application. Since it is +unlikely that the method of handling memory allocation on a platform +will change between applications, these functions must be modified in +the library at compile time. If you prefer to use a different method +of allocating and freeing data, you can use png_create_read_struct_2() or +png_create_write_struct_2() to register your own functions as described +above. These functions also provide a void pointer that can be retrieved +via + + mem_ptr=png_get_mem_ptr(png_ptr); + +Your replacement memory functions must have prototypes as follows: + + png_voidp malloc_fn(png_structp png_ptr, + png_alloc_size_t size); + + void free_fn(png_structp png_ptr, png_voidp ptr); + +Your malloc_fn() must return NULL in case of failure. The png_malloc() +function will normally call png_error() if it receives a NULL from the +system memory allocator or from your replacement malloc_fn(). + +Your free_fn() will never be called with a NULL ptr, since libpng's +png_free() checks for NULL before calling free_fn(). + +Input/Output in libpng is done through png_read() and png_write(), +which currently just call fread() and fwrite(). The FILE * is stored in +png_struct and is initialized via png_init_io(). If you wish to change +the method of I/O, the library supplies callbacks that you can set +through the function png_set_read_fn() and png_set_write_fn() at run +time, instead of calling the png_init_io() function. These functions +also provide a void pointer that can be retrieved via the function +png_get_io_ptr(). For example: + + png_set_read_fn(png_structp read_ptr, + voidp read_io_ptr, png_rw_ptr read_data_fn) + + png_set_write_fn(png_structp write_ptr, + voidp write_io_ptr, png_rw_ptr write_data_fn, + png_flush_ptr output_flush_fn); + + voidp read_io_ptr = png_get_io_ptr(read_ptr); + voidp write_io_ptr = png_get_io_ptr(write_ptr); + +The replacement I/O functions must have prototypes as follows: + + void user_read_data(png_structp png_ptr, + png_bytep data, png_size_t length); + + void user_write_data(png_structp png_ptr, + png_bytep data, png_size_t length); + + void user_flush_data(png_structp png_ptr); + +The user_read_data() function is responsible for detecting and +handling end-of-data errors. + +Supplying NULL for the read, write, or flush functions sets them back +to using the default C stream functions, which expect the io_ptr to +point to a standard *FILE structure. It is probably a mistake +to use NULL for one of write_data_fn and output_flush_fn but not both +of them, unless you have built libpng with PNG_NO_WRITE_FLUSH defined. +It is an error to read from a write stream, and vice versa. + +Error handling in libpng is done through png_error() and png_warning(). +Errors handled through png_error() are fatal, meaning that png_error() +should never return to its caller. Currently, this is handled via +setjmp() and longjmp() (unless you have compiled libpng with +PNG_NO_SETJMP, in which case it is handled via PNG_ABORT()), +but you could change this to do things like exit() if you should wish, +as long as your function does not return. + +On non-fatal errors, png_warning() is called +to print a warning message, and then control returns to the calling code. +By default png_error() and png_warning() print a message on stderr via +fprintf() unless the library is compiled with PNG_NO_CONSOLE_IO defined +(because you don't want the messages) or PNG_NO_STDIO defined (because +fprintf() isn't available). If you wish to change the behavior of the error +functions, you will need to set up your own message callbacks. These +functions are normally supplied at the time that the png_struct is created. +It is also possible to redirect errors and warnings to your own replacement +functions after png_create_*_struct() has been called by calling: + + png_set_error_fn(png_structp png_ptr, + png_voidp error_ptr, png_error_ptr error_fn, + png_error_ptr warning_fn); + + png_voidp error_ptr = png_get_error_ptr(png_ptr); + +If NULL is supplied for either error_fn or warning_fn, then the libpng +default function will be used, calling fprintf() and/or longjmp() if a +problem is encountered. The replacement error functions should have +parameters as follows: + + void user_error_fn(png_structp png_ptr, + png_const_charp error_msg); + + void user_warning_fn(png_structp png_ptr, + png_const_charp warning_msg); + +The motivation behind using setjmp() and longjmp() is the C++ throw and +catch exception handling methods. This makes the code much easier to write, +as there is no need to check every return code of every function call. +However, there are some uncertainties about the status of local variables +after a longjmp, so the user may want to be careful about doing anything +after setjmp returns non-zero besides returning itself. Consult your +compiler documentation for more details. For an alternative approach, you +may wish to use the "cexcept" facility (see http://cexcept.sourceforge.net). + +.SS Custom chunks + +If you need to read or write custom chunks, you may need to get deeper +into the libpng code. The library now has mechanisms for storing +and writing chunks of unknown type; you can even declare callbacks +for custom chunks. However, this may not be good enough if the +library code itself needs to know about interactions between your +chunk and existing `intrinsic' chunks. + +If you need to write a new intrinsic chunk, first read the PNG +specification. Acquire a first level of understanding of how it works. +Pay particular attention to the sections that describe chunk names, +and look at how other chunks were designed, so you can do things +similarly. Second, check out the sections of libpng that read and +write chunks. Try to find a chunk that is similar to yours and use +it as a template. More details can be found in the comments inside +the code. It is best to handle unknown chunks in a generic method, +via callback functions, instead of by modifying libpng functions. + +If you wish to write your own transformation for the data, look through +the part of the code that does the transformations, and check out some of +the simpler ones to get an idea of how they work. Try to find a similar +transformation to the one you want to add and copy off of it. More details +can be found in the comments inside the code itself. + +.SS Configuring for 16 bit platforms + +You will want to look into zconf.h to tell zlib (and thus libpng) that +it cannot allocate more then 64K at a time. Even if you can, the memory +won't be accessible. So limit zlib and libpng to 64K by defining MAXSEG_64K. + +.SS Configuring for DOS + +For DOS users who only have access to the lower 640K, you will +have to limit zlib's memory usage via a png_set_compression_mem_level() +call. See zlib.h or zconf.h in the zlib library for more information. + +.SS Configuring for Medium Model + +Libpng's support for medium model has been tested on most of the popular +compilers. Make sure MAXSEG_64K gets defined, USE_FAR_KEYWORD gets +defined, and FAR gets defined to far in pngconf.h, and you should be +all set. Everything in the library (except for zlib's structure) is +expecting far data. You must use the typedefs with the p or pp on +the end for pointers (or at least look at them and be careful). Make +note that the rows of data are defined as png_bytepp, which is an +unsigned char far * far *. + +.SS Configuring for gui/windowing platforms: + +You will need to write new error and warning functions that use the GUI +interface, as described previously, and set them to be the error and +warning functions at the time that png_create_*_struct() is called, +in order to have them available during the structure initialization. +They can be changed later via png_set_error_fn(). On some compilers, +you may also have to change the memory allocators (png_malloc, etc.). + +.SS Configuring for compiler xxx: + +All includes for libpng are in pngconf.h. If you need to add, change +or delete an include, this is the place to do it. +The includes that are not needed outside libpng are placed in pngpriv.h, +which is only used by the routines inside libpng itself. +The files in libpng proper only include pngpriv.h and png.h, which +in turn includes pngconf.h. + +.SS Configuring zlib: + +There are special functions to configure the compression. Perhaps the +most useful one changes the compression level, which currently uses +input compression values in the range 0 - 9. The library normally +uses the default compression level (Z_DEFAULT_COMPRESSION = 6). Tests +have shown that for a large majority of images, compression values in +the range 3-6 compress nearly as well as higher levels, and do so much +faster. For online applications it may be desirable to have maximum speed +(Z_BEST_SPEED = 1). With versions of zlib after v0.99, you can also +specify no compression (Z_NO_COMPRESSION = 0), but this would create +files larger than just storing the raw bitmap. You can specify the +compression level by calling: + + png_set_compression_level(png_ptr, level); + +Another useful one is to reduce the memory level used by the library. +The memory level defaults to 8, but it can be lowered if you are +short on memory (running DOS, for example, where you only have 640K). +Note that the memory level does have an effect on compression; among +other things, lower levels will result in sections of incompressible +data being emitted in smaller stored blocks, with a correspondingly +larger relative overhead of up to 15% in the worst case. + + png_set_compression_mem_level(png_ptr, level); + +The other functions are for configuring zlib. They are not recommended +for normal use and may result in writing an invalid PNG file. See +zlib.h for more information on what these mean. + + png_set_compression_strategy(png_ptr, + strategy); + + png_set_compression_window_bits(png_ptr, + window_bits); + + png_set_compression_method(png_ptr, method); + png_set_compression_buffer_size(png_ptr, size); + +.SS Controlling row filtering + +If you want to control whether libpng uses filtering or not, which +filters are used, and how it goes about picking row filters, you +can call one of these functions. The selection and configuration +of row filters can have a significant impact on the size and +encoding speed and a somewhat lesser impact on the decoding speed +of an image. Filtering is enabled by default for RGB and grayscale +images (with and without alpha), but not for paletted images nor +for any images with bit depths less than 8 bits/pixel. + +The 'method' parameter sets the main filtering method, which is +currently only '0' in the PNG 1.2 specification. The 'filters' +parameter sets which filter(s), if any, should be used for each +scanline. Possible values are PNG_ALL_FILTERS and PNG_NO_FILTERS +to turn filtering on and off, respectively. + +Individual filter types are PNG_FILTER_NONE, PNG_FILTER_SUB, +PNG_FILTER_UP, PNG_FILTER_AVG, PNG_FILTER_PAETH, which can be bitwise +ORed together with '|' to specify one or more filters to use. +These filters are described in more detail in the PNG specification. +If you intend to change the filter type during the course of writing +the image, you should start with flags set for all of the filters +you intend to use so that libpng can initialize its internal +structures appropriately for all of the filter types. (Note that this +means the first row must always be adaptively filtered, because libpng +currently does not allocate the filter buffers until png_write_row() +is called for the first time.) + + filters = PNG_FILTER_NONE | PNG_FILTER_SUB + PNG_FILTER_UP | PNG_FILTER_AVG | + PNG_FILTER_PAETH | PNG_ALL_FILTERS; + + png_set_filter(png_ptr, PNG_FILTER_TYPE_BASE, + filters); + The second parameter can also be + PNG_INTRAPIXEL_DIFFERENCING if you are + writing a PNG to be embedded in a MNG + datastream. This parameter must be the + same as the value of filter_method used + in png_set_IHDR(). + +It is also possible to influence how libpng chooses from among the +available filters. This is done in one or both of two ways - by +telling it how important it is to keep the same filter for successive +rows, and by telling it the relative computational costs of the filters. + + double weights[3] = {1.5, 1.3, 1.1}, + costs[PNG_FILTER_VALUE_LAST] = + {1.0, 1.3, 1.3, 1.5, 1.7}; + + png_set_filter_heuristics(png_ptr, + PNG_FILTER_HEURISTIC_WEIGHTED, 3, + weights, costs); + +The weights are multiplying factors that indicate to libpng that the +row filter should be the same for successive rows unless another row filter +is that many times better than the previous filter. In the above example, +if the previous 3 filters were SUB, SUB, NONE, the SUB filter could have a +"sum of absolute differences" 1.5 x 1.3 times higher than other filters +and still be chosen, while the NONE filter could have a sum 1.1 times +higher than other filters and still be chosen. Unspecified weights are +taken to be 1.0, and the specified weights should probably be declining +like those above in order to emphasize recent filters over older filters. + +The filter costs specify for each filter type a relative decoding cost +to be considered when selecting row filters. This means that filters +with higher costs are less likely to be chosen over filters with lower +costs, unless their "sum of absolute differences" is that much smaller. +The costs do not necessarily reflect the exact computational speeds of +the various filters, since this would unduly influence the final image +size. + +Note that the numbers above were invented purely for this example and +are given only to help explain the function usage. Little testing has +been done to find optimum values for either the costs or the weights. + +.SS Removing unwanted object code + +There are a bunch of #define's in pngconf.h that control what parts of +libpng are compiled. All the defines end in _SUPPORTED. If you are +never going to use a capability, you can change the #define to #undef +before recompiling libpng and save yourself code and data space, or +you can turn off individual capabilities with defines that begin with +PNG_NO_. + +In libpng-1.5.0 and later, the #define's are in pnglibconf.h instead. + +You can also turn all of the transforms and ancillary chunk capabilities +off en masse with compiler directives that define +PNG_NO_READ[or WRITE]_TRANSFORMS, or PNG_NO_READ[or WRITE]_ANCILLARY_CHUNKS, +or all four, +along with directives to turn on any of the capabilities that you do +want. The PNG_NO_READ[or WRITE]_TRANSFORMS directives disable the extra +transformations but still leave the library fully capable of reading +and writing PNG files with all known public chunks. Use of the +PNG_NO_READ[or WRITE]_ANCILLARY_CHUNKS directive produces a library +that is incapable of reading or writing ancillary chunks. If you are +not using the progressive reading capability, you can turn that off +with PNG_NO_PROGRESSIVE_READ (don't confuse this with the INTERLACING +capability, which you'll still have). + +All the reading and writing specific code are in separate files, so the +linker should only grab the files it needs. However, if you want to +make sure, or if you are building a stand alone library, all the +reading files start with pngr and all the writing files start with +pngw. The files that don't match either (like png.c, pngtrans.c, etc.) +are used for both reading and writing, and always need to be included. +The progressive reader is in pngpread.c + +If you are creating or distributing a dynamically linked library (a .so +or DLL file), you should not remove or disable any parts of the library, +as this will cause applications linked with different versions of the +library to fail if they call functions not available in your library. +The size of the library itself should not be an issue, because only +those sections that are actually used will be loaded into memory. + +.SS Requesting debug printout + +The macro definition PNG_DEBUG can be used to request debugging +printout. Set it to an integer value in the range 0 to 3. Higher +numbers result in increasing amounts of debugging information. The +information is printed to the "stderr" file, unless another file +name is specified in the PNG_DEBUG_FILE macro definition. + +When PNG_DEBUG > 0, the following functions (macros) become available: + + png_debug(level, message) + png_debug1(level, message, p1) + png_debug2(level, message, p1, p2) + +in which "level" is compared to PNG_DEBUG to decide whether to print +the message, "message" is the formatted string to be printed, +and p1 and p2 are parameters that are to be embedded in the string +according to printf-style formatting directives. For example, + + png_debug1(2, "foo=%d\n", foo); + +is expanded to + + if (PNG_DEBUG > 2) + fprintf(PNG_DEBUG_FILE, "foo=%d\n", foo); + +When PNG_DEBUG is defined but is zero, the macros aren't defined, but you +can still use PNG_DEBUG to control your own debugging: + + #ifdef PNG_DEBUG + fprintf(stderr, ... + #endif + +When PNG_DEBUG = 1, the macros are defined, but only png_debug statements +having level = 0 will be printed. There aren't any such statements in +this version of libpng, but if you insert some they will be printed. + +.SH VI. MNG support + +The MNG specification (available at http://www.libpng.org/pub/mng) allows +certain extensions to PNG for PNG images that are embedded in MNG datastreams. +Libpng can support some of these extensions. To enable them, use the +png_permit_mng_features() function: + + feature_set = png_permit_mng_features(png_ptr, mask) + + mask is a png_uint_32 containing the bitwise OR of the + features you want to enable. These include + PNG_FLAG_MNG_EMPTY_PLTE + PNG_FLAG_MNG_FILTER_64 + PNG_ALL_MNG_FEATURES + + feature_set is a png_uint_32 that is the bitwise AND of + your mask with the set of MNG features that is + supported by the version of libpng that you are using. + +It is an error to use this function when reading or writing a standalone +PNG file with the PNG 8-byte signature. The PNG datastream must be wrapped +in a MNG datastream. As a minimum, it must have the MNG 8-byte signature +and the MHDR and MEND chunks. Libpng does not provide support for these +or any other MNG chunks; your application must provide its own support for +them. You may wish to consider using libmng (available at +http://www.libmng.com) instead. + +.SH VII. Changes to Libpng from version 0.88 + +It should be noted that versions of libpng later than 0.96 are not +distributed by the original libpng author, Guy Schalnat, nor by +Andreas Dilger, who had taken over from Guy during 1996 and 1997, and +distributed versions 0.89 through 0.96, but rather by another member +of the original PNG Group, Glenn Randers-Pehrson. Guy and Andreas are +still alive and well, but they have moved on to other things. + +The old libpng functions png_read_init(), png_write_init(), +png_info_init(), png_read_destroy(), and png_write_destroy() have been +moved to PNG_INTERNAL in version 0.95 to discourage their use. These +functions will be removed from libpng version 1.4.0. + +The preferred method of creating and initializing the libpng structures is +via the png_create_read_struct(), png_create_write_struct(), and +png_create_info_struct() because they isolate the size of the structures +from the application, allow version error checking, and also allow the +use of custom error handling routines during the initialization, which +the old functions do not. The functions png_read_destroy() and +png_write_destroy() do not actually free the memory that libpng +allocated for these structs, but just reset the data structures, so they +can be used instead of png_destroy_read_struct() and +png_destroy_write_struct() if you feel there is too much system overhead +allocating and freeing the png_struct for each image read. + +Setting the error callbacks via png_set_message_fn() before +png_read_init() as was suggested in libpng-0.88 is no longer supported +because this caused applications that do not use custom error functions +to fail if the png_ptr was not initialized to zero. It is still possible +to set the error callbacks AFTER png_read_init(), or to change them with +png_set_error_fn(), which is essentially the same function, but with a new +name to force compilation errors with applications that try to use the old +method. + +Starting with version 1.0.7, you can find out which version of the library +you are using at run-time: + + png_uint_32 libpng_vn = png_access_version_number(); + +The number libpng_vn is constructed from the major version, minor +version with leading zero, and release number with leading zero, +(e.g., libpng_vn for version 1.0.7 is 10007). + +You can also check which version of png.h you used when compiling your +application: + + png_uint_32 application_vn = PNG_LIBPNG_VER; + +.SH VIII. Changes to Libpng from version 1.0.x to 1.2.x + +Support for user memory management was enabled by default. To +accomplish this, the functions png_create_read_struct_2(), +png_create_write_struct_2(), png_set_mem_fn(), png_get_mem_ptr(), +png_malloc_default(), and png_free_default() were added. + +Support for the iTXt chunk has been enabled by default as of +version 1.2.41. + +Support for certain MNG features was enabled. + +Support for numbered error messages was added. However, we never got +around to actually numbering the error messages. The function +png_set_strip_error_numbers() was added (Note: the prototype for this +function was inadvertently removed from png.h in PNG_NO_ASSEMBLER_CODE +builds of libpng-1.2.15. It was restored in libpng-1.2.36). + +The png_malloc_warn() function was added at libpng-1.2.3. This issues +a png_warning and returns NULL instead of aborting when it fails to +acquire the requested memory allocation. + +Support for setting user limits on image width and height was enabled +by default. The functions png_set_user_limits(), png_get_user_width_max(), +and png_get_user_height_max() were added at libpng-1.2.6. + +The png_set_add_alpha() function was added at libpng-1.2.7. + +The function png_set_expand_gray_1_2_4_to_8() was added at libpng-1.2.9. +Unlike png_set_gray_1_2_4_to_8(), the new function does not expand the +tRNS chunk to alpha. The png_set_gray_1_2_4_to_8() function is +deprecated. + +A number of macro definitions in support of runtime selection of +assembler code features (especially Intel MMX code support) were +added at libpng-1.2.0: + + PNG_ASM_FLAG_MMX_SUPPORT_COMPILED + PNG_ASM_FLAG_MMX_SUPPORT_IN_CPU + PNG_ASM_FLAG_MMX_READ_COMBINE_ROW + PNG_ASM_FLAG_MMX_READ_INTERLACE + PNG_ASM_FLAG_MMX_READ_FILTER_SUB + PNG_ASM_FLAG_MMX_READ_FILTER_UP + PNG_ASM_FLAG_MMX_READ_FILTER_AVG + PNG_ASM_FLAG_MMX_READ_FILTER_PAETH + PNG_ASM_FLAGS_INITIALIZED + PNG_MMX_READ_FLAGS + PNG_MMX_FLAGS + PNG_MMX_WRITE_FLAGS + PNG_MMX_FLAGS + +We added the following functions in support of runtime +selection of assembler code features: + + png_get_mmx_flagmask() + png_set_mmx_thresholds() + png_get_asm_flags() + png_get_mmx_bitdepth_threshold() + png_get_mmx_rowbytes_threshold() + png_set_asm_flags() + +We replaced all of these functions with simple stubs in libpng-1.2.20, +when the Intel assembler code was removed due to a licensing issue. + +These macros are deprecated: + + PNG_READ_TRANSFORMS_NOT_SUPPORTED + PNG_PROGRESSIVE_READ_NOT_SUPPORTED + PNG_NO_SEQUENTIAL_READ_SUPPORTED + PNG_WRITE_TRANSFORMS_NOT_SUPPORTED + PNG_READ_ANCILLARY_CHUNKS_NOT_SUPPORTED + PNG_WRITE_ANCILLARY_CHUNKS_NOT_SUPPORTED + +They have been replaced, respectively, by: + + PNG_NO_READ_TRANSFORMS + PNG_NO_PROGRESSIVE_READ + PNG_NO_SEQUENTIAL_READ + PNG_NO_WRITE_TRANSFORMS + PNG_NO_READ_ANCILLARY_CHUNKS + PNG_NO_WRITE_ANCILLARY_CHUNKS + +PNG_MAX_UINT was replaced with PNG_UINT_31_MAX. It has been +deprecated since libpng-1.0.16 and libpng-1.2.6. + +The function + png_check_sig(sig, num) +was replaced with + !png_sig_cmp(sig, 0, num) +It has been deprecated since libpng-0.90. + +The function + png_set_gray_1_2_4_to_8() +which also expands tRNS to alpha was replaced with + png_set_expand_gray_1_2_4_to_8() +which does not. It has been deprecated since libpng-1.0.18 and 1.2.9. + +.SH IX. Changes to Libpng from version 1.0.x/1.2.x to 1.4.x + +Private libpng prototypes and macro definitions were moved from +png.h and pngconf.h into a new pngpriv.h header file. + +Functions png_set_benign_errors(), png_benign_error(), and +png_chunk_benign_error() were added. + +Support for setting the maximum amount of memory that the application +will allocate for reading chunks was added, as a security measure. +The functions png_set_chunk_cache_max() and png_get_chunk_cache_max() +were added to the library. + +We implemented support for I/O states by adding png_ptr member io_state +and functions png_get_io_chunk_name() and png_get_io_state() in pngget.c + +We added PNG_TRANSFORM_GRAY_TO_RGB to the available high-level +input transforms. + +Checking for and reporting of errors in the IHDR chunk is more thorough. + +Support for global arrays was removed, to improve thread safety. + +Some obsolete/deprecated macros and functions have been removed. + +Typecasted NULL definitions such as + #define png_voidp_NULL (png_voidp)NULL +were eliminated. If you used these in your application, just use +NULL instead. + +The png_struct and info_struct members "trans" and "trans_values" were +changed to "trans_alpha" and "trans_color", respectively. + +The obsolete, unused pnggccrd.c and pngvcrd.c files and related makefiles +were removed. + +The PNG_1_0_X and PNG_1_2_X macros were eliminated. + +The PNG_LEGACY_SUPPORTED macro was eliminated. + +Many WIN32_WCE #ifdefs were removed. + +The functions png_read_init(info_ptr), png_write_init(info_ptr), +png_info_init(info_ptr), png_read_destroy(), and png_write_destroy() +have been removed. They have been deprecated since libpng-0.95. + +The png_permit_empty_plte() was removed. It has been deprecated +since libpng-1.0.9. Use png_permit_mng_features() instead. + +We removed the obsolete stub functions png_get_mmx_flagmask(), +png_set_mmx_thresholds(), png_get_asm_flags(), +png_get_mmx_bitdepth_threshold(), png_get_mmx_rowbytes_threshold(), +png_set_asm_flags(), and png_mmx_supported() + +We removed the obsolete png_check_sig(), png_memcpy_check(), and +png_memset_check() functions. Instead use !png_sig_cmp(), memcpy(), +and memset(), respectively. + +The function png_set_gray_1_2_4_to_8() was removed. It has been +deprecated since libpng-1.0.18 and 1.2.9, when it was replaced with +png_set_expand_gray_1_2_4_to_8() because the former function also +expanded palette images. + +Macros for png_get_uint_16, png_get_uint_32, and png_get_int_32 +were added and are used by default instead of the corresponding +functions. Unfortunately, +from libpng-1.4.0 until 1.4.4, the png_get_uint_16 macro (but not the +function) incorrectly returned a value of type png_uint_32. + +We changed the prototype for png_malloc() from + png_malloc(png_structp png_ptr, png_uint_32 size) +to + png_malloc(png_structp png_ptr, png_alloc_size_t size) + +This also applies to the prototype for the user replacement malloc_fn(). + +The png_calloc() function was added and is used in place of +of "png_malloc(); memset();" except in the case in png_read_png() +where the array consists of pointers; in this case a "for" loop is used +after the png_malloc() to set the pointers to NULL, to give robust. +behavior in case the application runs out of memory part-way through +the process. + +We changed the prototypes of png_get_compression_buffer_size() and +png_set_compression_buffer_size() to work with png_size_t instead of +png_uint_32. + +Support for numbered error messages was removed by default, since we +never got around to actually numbering the error messages. The function +png_set_strip_error_numbers() was removed from the library by default. + +The png_zalloc() and png_zfree() functions are no longer exported. +The png_zalloc() function no longer zeroes out the memory that it +allocates. + +Support for dithering was disabled by default in libpng-1.4.0, because +been well tested and doesn't actually "dither". The code was not +removed, however, and could be enabled by building libpng with +PNG_READ_DITHER_SUPPORTED defined. In libpng-1.4.2, this support +was reenabled, but the function was renamed png_set_quantize() to +reflect more accurately what it actually does. At the same time, +the PNG_DITHER_[RED,GREEN_BLUE]_BITS macros were also renamed to +PNG_QUANTIZE_[RED,GREEN,BLUE]_BITS, and PNG_READ_DITHER_SUPPORTED +was renamed to PNG_READ_QUANTIZE_SUPPORTED. + +We removed the trailing '.' from the warning and error messages. + +.SH X. Changes to Libpng from version 1.4.x to 1.5.x + +From libpng-1.4.0 until 1.4.4, the png_get_uint_16 macro (but not the +function) incorrectly returned a value of type png_uint_32. + +A. Changes that affect users of libpng + +There are no substantial API changes between the non-deprecated parts of +the 1.4.5 API and the 1.5.0 API, however the ability to directly access +the main libpng control structures, png_struct and png_info, deprecated +in earlier versions of libpng, has been completely removed from +libpng 1.5. + +We no longer include zlib.h in png.h. Applications that need access +to information in zlib.h will need to add the '#include "zlib.h"' +directive. It does not matter whether it is placed prior to or after +the '"#include png.h"' directive. + +We moved the png_strcpy(), png_strncpy(), png_strlen(), png_memcpy(), +png_memcmp(), png_sprintf, and png_memcpy() macros into a private +header file (pngpriv.h) that is not accessible to applications. + +In png_get_iCCP, the type of "profile" was changed from png_charpp +to png_bytepp, and in png_set_iCCP, from png_charp to png_const_bytep. + +There are changes of form in png.h, including new and changed macros to +declare +parts of the API. Some API functions with arguments that are pointers to +data not modified within the function have been corrected to declare +these arguments with PNG_CONST. + +Much of the internal use of C macros to control the library build has also +changed and some of this is visible in the exported header files, in +particular the use of macros to control data and API elements visible +during application compilation may require significant revision to +application code. (It is extremely rare for an application to do this.) + +Any program that compiled against libpng 1.4 and did not use deprecated +features or access internal library structures should compile and work +against libpng 1.5. + +libpng 1.5.0 adds PNG_ PASS macros to help in the reading and writing of +interlaced images. The macros return the number of rows and columns in +each pass and information that can be used to de-interlace and (if +absolutely necessary) interlace an image. + +libpng 1.5.0 adds an API png_longjmp(png_ptr, value). This API calls +the application provided png_longjmp_ptr on the internal, but application +initialized, jmpbuf. It is provided as a convenience to avoid the need +to use the png_jmpbuf macro, which had the unnecessary side effect of +resetting the internal png_longjmp_ptr value. + +libpng 1.5.0 includes a complete fixed point API. By default this is +present along with the corresponding floating point API. In general the +fixed point API is faster and smaller than the floating point one because +the PNG file format used fixed point, not floating point. This applies +even if the library uses floating point in internal calculations. A new +macro, PNG_FLOATING_ARITHMETIC_SUPPORTED, reveals whether the library +uses floating point arithmetic (the default) or fixed point arithmetic +internally for performance critical calculations such as gamma correction. +In some cases, the gamma calculations may produce slightly different +results. This has changed the results in png_rgb_to_gray and in alpha +composition (png_set_background for example). This applies even if the +original image was already linear (gamma == 1.0) and, therefore, it is +not necessary to linearize the image. This is because libpng has *not* +been changed to optimize that case correctly, yet. + +Fixed point support for the sCAL chunk comes with an important caveat; +the sCAL specification uses a decimal encoding of floating point values +and the accuracy of PNG fixed point values is insufficient for +representation of these values. Consequently a "string" API +(png_get_sCAL_s and png_set_sCAL_s) is the only reliable way of reading +arbitrary sCAL chunks in the absence of either the floating point API or +internal floating point calculations. + +Applications no longer need to include the optional distribution header +file pngusr.h or define the corresponding macros during application +build in order to see the correct variant of the libpng API. From 1.5.0 +application code can check for the corresponding _SUPPORTED macro: + +#ifdef PNG_INCH_CONVERSIONS_SUPPORTED + /* code that uses the inch conversion APIs. */ +#endif + +This macro will only be defined if the inch conversion functions have been +compiled into libpng. The full set of macros, and whether or not support +has been compiled in, are available in the header file pnglibconf.h. +This header file is specific to the libpng build. Notice that prior to +1.5.0 the _SUPPORTED macros would always have the default definition unless +reset by pngusr.h or by explicit settings on the compiler command line. +These settings may produce compiler warnings or errors in 1.5.0 because +of macro redefinition. + +From libpng-1.4.0 until 1.4.4, the png_get_uint_16 macro (but not the +function) incorrectly returned a value of type png_uint_32. libpng 1.5.0 +is consistent with the implementation in 1.4.5 and 1.2.x (where the macro +did not exist.) + +Applications can now choose whether to use these macros or to call the +corresponding function by defining PNG_USE_READ_MACROS or +PNG_NO_USE_READ_MACROS before including png.h. Notice that this is +only supported from 1.5.0 -defining PNG_NO_USE_READ_MACROS prior to 1.5.0 + will lead to a link failure. + +B. Changes to the build and configuration of libpng + +Details of internal changes to the library code can be found in the CHANGES +file. These will be of no concern to the vast majority of library users or +builders, however the few who configure libpng to a non-default feature +set may need to change how this is done. + +There should be no need for library builders to alter build scripts if +these use the distributed build support - configure or the makefiles - +however users of the makefiles may care to update their build scripts +to build pnglibconf.h where the corresponding makefile does not do so. + +Building libpng with a non-default configuration has changed completely. +The old method using pngusr.h should still work correctly even though the +way pngusr.h is used in the build has been changed, however library +builders will probably want to examine the changes to take advantage of +new capabilities and to simplify their build system. + +B.1 Specific changes to library configuration capabilities + +The library now supports a complete fixed point implementation and can +thus be used on systems which have no floating point support or very +limited or slow support. Previously gamma correction, an essential part +of complete PNG support, required reasonably fast floating point. + +As part of this the choice of internal implementation has been made +independent of the choice of fixed versus floating point APIs and all the +missing fixed point APIs have been implemented. + +The exact mechanism used to control attributes of API functions has +changed. A single set of operating system independent macro definitions +is used and operating system specific directives are defined in +pnglibconf.h + +As part of this the mechanism used to choose procedure call standards on +those systems that allow a choice has been changed. At present this only +affects certain Microsoft (DOS, Windows) and IBM (OS/2) operating systems +running on Intel processors. As before PNGAPI is defined where required +to control the exported API functions; however, two new macros, PNGCBAPI +and PNGCAPI, are used instead for callback functions (PNGCBAPI) and +(PNGCAPI) for functions that must match a C library prototype (currently +only png_longjmp_ptr, which must match the C longjmp function.) The new +approach is documented in pngconf.h + +Despite these changes libpng 1.5.0 only supports the native C function +calling standard on those platforms tested so far (__cdecl on Microsoft +Windows). This is because the support requirements for alternative +calling conventions seem to no longer exist. Developers who find it +necessary to set PNG_API_RULE to 1 should advise the mailing list +(png-mng-implement) of this and library builders who use Openwatcom and +therefore set PNG_API_RULE to 2 should also contact the mailing list. + +A new test program, pngvalid, is provided in addition to pngtest. +pngvalid validates the arithmetic accuracy of the gamma correction +calculations and includes a number of validations of the file format. +A subset of the full range of tests is run when "make check" is done +(in the 'configure' build.) pngvalid also allows total allocated memory +usage to be evaluated and performs additional memory overwrite validation. + +Many changes to individual feature macros have been made. The following +are the changes most likely to be noticed by library builders who +configure libpng: + +1) All feature macros now have consistent naming: + +#define PNG_NO_feature turns the feature off +#define PNG_feature_SUPPORTED turns the feature on + +pnglibconf.h contains one line for each feature macro which is either: + +#define PNG_feature_SUPPORTED + +if the feature is supported or: + +/*#undef PNG_feature_SUPPORTED*/ + +if it is not. Library code consistently checks for the 'SUPPORTED' macro. +It does not, and should not, check for the 'NO' macro which will not +normally be defined even if the feature is not supported. + +Compatibility with the old names is provided as follows: + +PNG_INCH_CONVERSIONS turns on PNG_INCH_CONVERSIONS_SUPPORTED + +And the following definitions disable the corresponding feature: + +PNG_SETJMP_NOT_SUPPORTED disables SETJMP +PNG_READ_TRANSFORMS_NOT_SUPPORTED disables READ_TRANSFORMS +PNG_NO_READ_COMPOSITED_NODIV disables READ_COMPOSITE_NODIV +PNG_WRITE_TRANSFORMS_NOT_SUPPORTED disables WRITE_TRANSFORMS +PNG_READ_ANCILLARY_CHUNKS_NOT_SUPPORTED disables READ_ANCILLARY_CHUNKS +PNG_WRITE_ANCILLARY_CHUNKS_NOT_SUPPORTED disables WRITE_ANCILLARY_CHUNKS + +Library builders should remove use of the above, inconsistent, names. + +2) Warning and error message formatting was previously conditional on +the STDIO feature. The library has been changed to use the +CONSOLE_IO feature instead. This means that if CONSOLE_IO is disabled +the library no longer uses the printf(3) functions, even though the +default read/write implementations use (FILE) style stdio.h functions. + +3) Three feature macros now control the fixed/floating point decisions: + +PNG_FLOATING_POINT_SUPPORTED enables the floating point APIs + +PNG_FIXED_POINT_SUPPORTED enables the fixed point APIs; however, in +practice these are normally required internally anyway (because the PNG +file format is fixed point), therefore in most cases PNG_NO_FIXED_POINT +merely stops the function from being exported. + +PNG_FLOATING_ARITHMETIC_SUPPORTED chooses between the internal floating +point implementation or the fixed point one. Typically the fixed point +implementation is larger and slower than the floating point implementation +on a system that supports floating point, however it may be faster on a +system which lacks floating point hardware and therefore uses a software +emulation. + +4) Added PNG_{READ,WRITE}_INT_FUNCTIONS_SUPPORTED. This allows the +functions to read and write ints to be disabled independently of +PNG_USE_READ_MACROS, which allows libpng to be built with the functions +even though the default is to use the macros - this allows applications +to choose at app buildtime whether or not to use macros (previously +impossible because the functions weren't in the default build.) + +B.2 Changes to the configuration mechanism + +Prior to libpng-1.5.0 library builders who needed to configure libpng +had either to modify the exported pngconf.h header file to add system +specific configuration or had to write feature selection macros into +pngusr.h and cause this to be included into pngconf.h by defining +PNG_USER_CONFIG. The latter mechanism had the disadvantage that an +application built without PNG_USER_CONFIG defined would see the +unmodified, default, libpng API and thus would probably fail to link. + +These mechanisms still work in the configure build and in any makefile +build that builds pnglibconf.h although the feature selection macros +have changed somewhat as described above. In 1.5.0, however, pngusr.h is +processed only once, when the exported header file pnglibconf.h is built. +pngconf.h no longer includes pngusr.h, therefore it is ignored after the +build of pnglibconf.h and it is never included in an application build. + +The rarely used alternative of adding a list of feature macros to the +CFLAGS setting in the build also still works, however the macros will be +copied to pnglibconf.h and this may produce macro redefinition warnings +when the individual C files are compiled. + +All configuration now only works if pnglibconf.h is built from +scripts/pnglibconf.dfa. This requires the program awk. Brian Kernighan +(the original author of awk) maintains C source code of that awk and this +and all known later implementations (often called by subtly different +names - nawk and gawk for example) are adequate to build pnglibconf.h. +The Sun Microsystems (now Oracle) program 'awk' is an earlier version +and does not work, this may also apply to other systems that have a +functioning awk called 'nawk'. + +Configuration options are now documented in scripts/pnglibconf.dfa. This +file also includes dependency information that ensures a configuration is +consistent; that is, if a feature is switched off dependent features are +also removed. As a recommended alternative to using feature macros in +pngusr.h a system builder may also define equivalent options in pngusr.dfa +(or, indeed, any file) and add that to the configuration by setting +DFA_XTRA to the file name. The makefiles in contrib/pngminim illustrate +how to do this, and a case where pngusr.h is still required. + +.SH XI. Detecting libpng + +The png_get_io_ptr() function has been present since libpng-0.88, has never +changed, and is unaffected by conditional compilation macros. It is the +best choice for use in configure scripts for detecting the presence of any +libpng version since 0.88. In an autoconf "configure.in" you could use + + AC_CHECK_LIB(png, png_get_io_ptr, ... + +.SH XII. Source code repository + +Since about February 2009, version 1.2.34, libpng has been under "git" source +control. The git repository was built from old libpng-x.y.z.tar.gz files +going back to version 0.70. You can access the git repository (read only) +at + + git://libpng.git.sourceforge.net/gitroot/libpng + +or you can browse it via "gitweb" at + + http://libpng.git.sourceforge.net/git/gitweb.cgi?p=libpng + +Patches can be sent to glennrp at users.sourceforge.net or to +png-mng-implement at lists.sourceforge.net or you can upload them to +the libpng bug tracker at + + http://libpng.sourceforge.net + +We also accept patches built from the tar or zip distributions, and +simple verbal discriptions of bug fixes, reported either to the +SourceForge bug tracker or to the png-mng-implement at lists.sf.net +mailing list. + +.SH XIII. Coding style + +Our coding style is similar to the "Allman" style, with curly +braces on separate lines: + + if (condition) + { + action; + } + + else if (another condition) + { + another action; + } + +The braces can be omitted from simple one-line actions: + + if (condition) + return (0); + +We use 3-space indentation, except for continued statements which +are usually indented the same as the first line of the statement +plus four more spaces. + +For macro definitions we use 2-space indentation, always leaving the "#" +in the first column. + + #ifndef PNG_NO_FEATURE + # ifndef PNG_FEATURE_SUPPORTED + # define PNG_FEATURE_SUPPORTED + # endif + #endif + +Comments appear with the leading "/*" at the same indentation as +the statement that follows the comment: + + /* Single-line comment */ + statement; + + /* This is a multiple-line + * comment. + */ + statement; + +Very short comments can be placed after the end of the statement +to which they pertain: + + statement; /* comment */ + +We don't use C++ style ("//") comments. We have, however, +used them in the past in some now-abandoned MMX assembler +code. + +Functions and their curly braces are not indented, and +exported functions are marked with PNGAPI: + + /* This is a public function that is visible to + * application programmers. It does thus-and-so. + */ + void PNGAPI + png_exported_function(png_ptr, png_info, foo) + { + body; + } + +The prototypes for all exported functions appear in png.h, +above the comment that says + + /* Maintainer: Put new public prototypes here ... */ + +We mark all non-exported functions with "/* PRIVATE */"": + + void /* PRIVATE */ + png_non_exported_function(png_ptr, png_info, foo) + { + body; + } + +The prototypes for non-exported functions (except for those in +pngtest) appear in +pngpriv.h +above the comment that says + + /* Maintainer: Put new private prototypes here ^ and in libpngpf.3 */ + +To avoid polluting the global namespace, the names of all exported +functions and variables begin with "png_", and all publicly visible C +preprocessor macros begin with "PNG_". We request that applications that +use libpng *not* begin any of their own symbols with either of these strings. + +We put a space after each comma and after each semicolon +in "for" statements, and we put spaces before and after each +C binary operator and after "for" or "while", and before +"?". We don't put a space between a typecast and the expression +being cast, nor do we put one between a function name and the +left parenthesis that follows it: + + for (i = 2; i > 0; --i) + y[i] = a(x) + (int)b; + +We prefer #ifdef and #ifndef to #if defined() and if !defined() +when there is only one macro being tested. + +We do not use the TAB character for indentation in the C sources. + +Lines do not exceed 80 characters. + +Other rules can be inferred by inspecting the libpng source. + +.SH XIV. Y2K Compliance in libpng + +February 3, 2011 + +Since the PNG Development group is an ad-hoc body, we can't make +an official declaration. + +This is your unofficial assurance that libpng from version 0.71 and +upward through 1.5.1 are Y2K compliant. It is my belief that earlier +versions were also Y2K compliant. + +Libpng only has three year fields. One is a 2-byte unsigned integer that +will hold years up to 65535. The other two hold the date in text +format, and will hold years up to 9999. + +The integer is + "png_uint_16 year" in png_time_struct. + +The strings are + "png_charp time_buffer" in png_struct and + "near_time_buffer", which is a local character string in png.c. + +There are seven time-related functions: + + png_convert_to_rfc_1123() in png.c + (formerly png_convert_to_rfc_1152() in error) + png_convert_from_struct_tm() in pngwrite.c, called + in pngwrite.c + png_convert_from_time_t() in pngwrite.c + png_get_tIME() in pngget.c + png_handle_tIME() in pngrutil.c, called in pngread.c + png_set_tIME() in pngset.c + png_write_tIME() in pngwutil.c, called in pngwrite.c + +All appear to handle dates properly in a Y2K environment. The +png_convert_from_time_t() function calls gmtime() to convert from system +clock time, which returns (year - 1900), which we properly convert to +the full 4-digit year. There is a possibility that applications using +libpng are not passing 4-digit years into the png_convert_to_rfc_1123() +function, or that they are incorrectly passing only a 2-digit year +instead of "year - 1900" into the png_convert_from_struct_tm() function, +but this is not under our control. The libpng documentation has always +stated that it works with 4-digit years, and the APIs have been +documented as such. + +The tIME chunk itself is also Y2K compliant. It uses a 2-byte unsigned +integer to hold the year, and can hold years as large as 65535. + +zlib, upon which libpng depends, is also Y2K compliant. It contains +no date-related code. + + + Glenn Randers-Pehrson + libpng maintainer + PNG Development Group + +.SH NOTE + +Note about libpng version numbers: + +Due to various miscommunications, unforeseen code incompatibilities +and occasional factors outside the authors' control, version numbering +on the library has not always been consistent and straightforward. +The following table summarizes matters since version 0.89c, which was +the first widely used release: + + source png.h png.h shared-lib + version string int version + ------- ------ ----- ---------- + 0.89c ("beta 3") 0.89 89 1.0.89 + 0.90 ("beta 4") 0.90 90 0.90 + 0.95 ("beta 5") 0.95 95 0.95 + 0.96 ("beta 6") 0.96 96 0.96 + 0.97b ("beta 7") 1.00.97 97 1.0.1 + 0.97c 0.97 97 2.0.97 + 0.98 0.98 98 2.0.98 + 0.99 0.99 98 2.0.99 + 0.99a-m 0.99 99 2.0.99 + 1.00 1.00 100 2.1.0 + 1.0.0 1.0.0 100 2.1.0 + 1.0.0 (from here on, the 100 2.1.0 + 1.0.1 png.h string is 10001 2.1.0 + 1.0.1a-e identical to the 10002 from here on, the + 1.0.2 source version) 10002 shared library is 2.V + 1.0.2a-b 10003 where V is the source + 1.0.1 10001 code version except as + 1.0.1a-e 10002 2.1.0.1a-e noted. + 1.0.2 10002 2.1.0.2 + 1.0.2a-b 10003 2.1.0.2a-b + 1.0.3 10003 2.1.0.3 + 1.0.3a-d 10004 2.1.0.3a-d + 1.0.4 10004 2.1.0.4 + 1.0.4a-f 10005 2.1.0.4a-f + 1.0.5 (+ 2 patches) 10005 2.1.0.5 + 1.0.5a-d 10006 2.1.0.5a-d + 1.0.5e-r 10100 2.1.0.5e-r + 1.0.5s-v 10006 2.1.0.5s-v + 1.0.6 (+ 3 patches) 10006 2.1.0.6 + 1.0.6d-g 10007 2.1.0.6d-g + 1.0.6h 10007 10.6h + 1.0.6i 10007 10.6i + 1.0.6j 10007 2.1.0.6j + 1.0.7beta11-14 DLLNUM 10007 2.1.0.7beta11-14 + 1.0.7beta15-18 1 10007 2.1.0.7beta15-18 + 1.0.7rc1-2 1 10007 2.1.0.7rc1-2 + 1.0.7 1 10007 2.1.0.7 + 1.0.8beta1-4 1 10008 2.1.0.8beta1-4 + 1.0.8rc1 1 10008 2.1.0.8rc1 + 1.0.8 1 10008 2.1.0.8 + 1.0.9beta1-6 1 10009 2.1.0.9beta1-6 + 1.0.9rc1 1 10009 2.1.0.9rc1 + 1.0.9beta7-10 1 10009 2.1.0.9beta7-10 + 1.0.9rc2 1 10009 2.1.0.9rc2 + 1.0.9 1 10009 2.1.0.9 + 1.0.10beta1 1 10010 2.1.0.10beta1 + 1.0.10rc1 1 10010 2.1.0.10rc1 + 1.0.10 1 10010 2.1.0.10 + 1.0.11beta1-3 1 10011 2.1.0.11beta1-3 + 1.0.11rc1 1 10011 2.1.0.11rc1 + 1.0.11 1 10011 2.1.0.11 + 1.0.12beta1-2 2 10012 2.1.0.12beta1-2 + 1.0.12rc1 2 10012 2.1.0.12rc1 + 1.0.12 2 10012 2.1.0.12 + 1.1.0a-f - 10100 2.1.1.0a-f abandoned + 1.2.0beta1-2 2 10200 2.1.2.0beta1-2 + 1.2.0beta3-5 3 10200 3.1.2.0beta3-5 + 1.2.0rc1 3 10200 3.1.2.0rc1 + 1.2.0 3 10200 3.1.2.0 + 1.2.1beta-4 3 10201 3.1.2.1beta1-4 + 1.2.1rc1-2 3 10201 3.1.2.1rc1-2 + 1.2.1 3 10201 3.1.2.1 + 1.2.2beta1-6 12 10202 12.so.0.1.2.2beta1-6 + 1.0.13beta1 10 10013 10.so.0.1.0.13beta1 + 1.0.13rc1 10 10013 10.so.0.1.0.13rc1 + 1.2.2rc1 12 10202 12.so.0.1.2.2rc1 + 1.0.13 10 10013 10.so.0.1.0.13 + 1.2.2 12 10202 12.so.0.1.2.2 + 1.2.3rc1-6 12 10203 12.so.0.1.2.3rc1-6 + 1.2.3 12 10203 12.so.0.1.2.3 + 1.2.4beta1-3 13 10204 12.so.0.1.2.4beta1-3 + 1.2.4rc1 13 10204 12.so.0.1.2.4rc1 + 1.0.14 10 10014 10.so.0.1.0.14 + 1.2.4 13 10204 12.so.0.1.2.4 + 1.2.5beta1-2 13 10205 12.so.0.1.2.5beta1-2 + 1.0.15rc1 10 10015 10.so.0.1.0.15rc1 + 1.0.15 10 10015 10.so.0.1.0.15 + 1.2.5 13 10205 12.so.0.1.2.5 + 1.2.6beta1-4 13 10206 12.so.0.1.2.6beta1-4 + 1.2.6rc1-5 13 10206 12.so.0.1.2.6rc1-5 + 1.0.16 10 10016 10.so.0.1.0.16 + 1.2.6 13 10206 12.so.0.1.2.6 + 1.2.7beta1-2 13 10207 12.so.0.1.2.7beta1-2 + 1.0.17rc1 10 10017 12.so.0.1.0.17rc1 + 1.2.7rc1 13 10207 12.so.0.1.2.7rc1 + 1.0.17 10 10017 12.so.0.1.0.17 + 1.2.7 13 10207 12.so.0.1.2.7 + 1.2.8beta1-5 13 10208 12.so.0.1.2.8beta1-5 + 1.0.18rc1-5 10 10018 12.so.0.1.0.18rc1-5 + 1.2.8rc1-5 13 10208 12.so.0.1.2.8rc1-5 + 1.0.18 10 10018 12.so.0.1.0.18 + 1.2.8 13 10208 12.so.0.1.2.8 + 1.2.9beta1-3 13 10209 12.so.0.1.2.9beta1-3 + 1.2.9beta4-11 13 10209 12.so.0.9[.0] + 1.2.9rc1 13 10209 12.so.0.9[.0] + 1.2.9 13 10209 12.so.0.9[.0] + 1.2.10beta1-7 13 10210 12.so.0.10[.0] + 1.2.10rc1-2 13 10210 12.so.0.10[.0] + 1.2.10 13 10210 12.so.0.10[.0] + 1.4.0beta1-6 14 10400 14.so.0.0[.0] + 1.2.11beta1-4 13 10210 12.so.0.11[.0] + 1.4.0beta7-8 14 10400 14.so.0.0[.0] + 1.2.11 13 10211 12.so.0.11[.0] + 1.2.12 13 10212 12.so.0.12[.0] + 1.4.0beta9-14 14 10400 14.so.0.0[.0] + 1.2.13 13 10213 12.so.0.13[.0] + 1.4.0beta15-36 14 10400 14.so.0.0[.0] + 1.4.0beta37-87 14 10400 14.so.14.0[.0] + 1.4.0rc01 14 10400 14.so.14.0[.0] + 1.4.0beta88-109 14 10400 14.so.14.0[.0] + 1.4.0rc02-08 14 10400 14.so.14.0[.0] + 1.4.0 14 10400 14.so.14.0[.0] + 1.4.1beta01-03 14 10401 14.so.14.1[.0] + 1.4.1rc01 14 10401 14.so.14.1[.0] + 1.4.1beta04-12 14 10401 14.so.14.1[.0] + 1.4.1 14 10401 14.so.14.1[.0] + 1.4.2 14 10402 14.so.14.2[.0] + 1.4.3 14 10403 14.so.14.3[.0] + 1.4.4 14 10404 14.so.14.4[.0] + 1.5.0beta01-58 15 10500 15.so.15.0[.0] + 1.5.0rc01-07 15 10500 15.so.15.0[.0] + 1.5.0 15 10500 15.so.15.0[.0] + 1.5.1beta01-11 15 10501 15.so.15.1[.0] + 1.5.1rc01-02 15 10501 15.so.15.1[.0] + 1.5.1 15 10501 15.so.15.1[.0] + +Henceforth the source version will match the shared-library minor +and patch numbers; the shared-library major version number will be +used for changes in backward compatibility, as it is intended. The +PNG_PNGLIB_VER macro, which is not used within libpng but is available +for applications, is an unsigned integer of the form xyyzz corresponding +to the source version x.y.z (leading zeros in y and z). Beta versions +were given the previous public release number plus a letter, until +version 1.0.6j; from then on they were given the upcoming public +release number plus "betaNN" or "rcN". + +.SH "SEE ALSO" +.BR "png"(5), " libpngpf"(3), " zlib"(3), " deflate"(5), " " and " zlib"(5) + +.LP +.IR libpng : +.IP +http://libpng.sourceforge.net (follow the [DOWNLOAD] link) +http://www.libpng.org/pub/png + +.LP +.IR zlib : +.IP +(generally) at the same location as +.I libpng +or at +.br +ftp://ftp.info-zip.org/pub/infozip/zlib + +.LP +.IR PNG specification: RFC 2083 +.IP +(generally) at the same location as +.I libpng +or at +.br +ftp://ds.internic.net/rfc/rfc2083.txt +.br +or (as a W3C Recommendation) at +.br +http://www.w3.org/TR/REC-png.html + +.LP +In the case of any inconsistency between the PNG specification +and this library, the specification takes precedence. + +.SH AUTHORS +This man page: Glenn Randers-Pehrson +<glennrp at users.sourceforge.net> + +The contributing authors would like to thank all those who helped +with testing, bug fixes, and patience. This wouldn't have been +possible without all of you. + +Thanks to Frank J. T. Wojcik for helping with the documentation. + +Libpng version 1.5.1 - February 3, 2011: +Initially created in 1995 by Guy Eric Schalnat, then of Group 42, Inc. +Currently maintained by Glenn Randers-Pehrson (glennrp at users.sourceforge.net). + +Supported by the PNG development group +.br +png-mng-implement at lists.sf.net +(subscription required; visit +png-mng-implement at lists.sourceforge.net (subscription required; visit +https://lists.sourceforge.net/lists/listinfo/png-mng-implement +to subscribe). + +.SH COPYRIGHT NOTICE, DISCLAIMER, and LICENSE: + +(This copy of the libpng notices is provided for your convenience. In case of +any discrepancy between this copy and the notices in the file png.h that is +included in the libpng distribution, the latter shall prevail.) + +If you modify libpng you may insert additional notices immediately following +this sentence. + +This code is released under the libpng license. + +libpng versions 1.2.6, August 15, 2004, through 1.5.1, February 3, 2011, are +Copyright (c) 2004,2006-2007 Glenn Randers-Pehrson, and are +distributed according to the same disclaimer and license as libpng-1.2.5 +with the following individual added to the list of Contributing Authors + + Cosmin Truta + +libpng versions 1.0.7, July 1, 2000, through 1.2.5 - October 3, 2002, are +Copyright (c) 2000-2002 Glenn Randers-Pehrson, and are +distributed according to the same disclaimer and license as libpng-1.0.6 +with the following individuals added to the list of Contributing Authors + + Simon-Pierre Cadieux + Eric S. Raymond + Gilles Vollant + +and with the following additions to the disclaimer: + + There is no warranty against interference with your + enjoyment of the library or against infringement. + There is no warranty that our efforts or the library + will fulfill any of your particular purposes or needs. + This library is provided with all faults, and the entire + risk of satisfactory quality, performance, accuracy, and + effort is with the user. + +libpng versions 0.97, January 1998, through 1.0.6, March 20, 2000, are +Copyright (c) 1998, 1999 Glenn Randers-Pehrson +Distributed according to the same disclaimer and license as libpng-0.96, +with the following individuals added to the list of Contributing Authors: + + Tom Lane + Glenn Randers-Pehrson + Willem van Schaik + +libpng versions 0.89, June 1996, through 0.96, May 1997, are +Copyright (c) 1996, 1997 Andreas Dilger +Distributed according to the same disclaimer and license as libpng-0.88, +with the following individuals added to the list of Contributing Authors: + + John Bowler + Kevin Bracey + Sam Bushell + Magnus Holmgren + Greg Roelofs + Tom Tanner + +libpng versions 0.5, May 1995, through 0.88, January 1996, are +Copyright (c) 1995, 1996 Guy Eric Schalnat, Group 42, Inc. + +For the purposes of this copyright and license, "Contributing Authors" +is defined as the following set of individuals: + + Andreas Dilger + Dave Martindale + Guy Eric Schalnat + Paul Schmidt + Tim Wegner + +The PNG Reference Library is supplied "AS IS". The Contributing Authors +and Group 42, Inc. disclaim all warranties, expressed or implied, +including, without limitation, the warranties of merchantability and of +fitness for any purpose. The Contributing Authors and Group 42, Inc. +assume no liability for direct, indirect, incidental, special, exemplary, +or consequential damages, which may result from the use of the PNG +Reference Library, even if advised of the possibility of such damage. + +Permission is hereby granted to use, copy, modify, and distribute this +source code, or portions hereof, for any purpose, without fee, subject +to the following restrictions: + +1. The origin of this source code must not be misrepresented. + +2. Altered versions must be plainly marked as such and + must not be misrepresented as being the original source. + +3. This Copyright notice may not be removed or altered from + any source or altered source distribution. + +The Contributing Authors and Group 42, Inc. specifically permit, without +fee, and encourage the use of this source code as a component to +supporting the PNG file format in commercial products. If you use this +source code in a product, acknowledgment is not required but would be +appreciated. + + +A "png_get_copyright" function is available, for convenient use in "about" +boxes and the like: + + printf("%s",png_get_copyright(NULL)); + +Also, the PNG logo (in PNG format, of course) is supplied in the +files "pngbar.png" and "pngbar.jpg (88x31) and "pngnow.png" (98x31). + +Libpng is OSI Certified Open Source Software. OSI Certified Open Source is a +certification mark of the Open Source Initiative. + +Glenn Randers-Pehrson +glennrp at users.sourceforge.net +February 3, 2011 + +.\" end of man page + diff --git a/src/3rdparty/libpng/libpng.pc.in b/src/3rdparty/libpng/libpng.pc.in new file mode 100644 index 0000000000..3e7e2c58a7 --- /dev/null +++ b/src/3rdparty/libpng/libpng.pc.in @@ -0,0 +1,11 @@ +prefix=@prefix@ +exec_prefix=@exec_prefix@ +libdir=@libdir@ +includedir=@includedir@/libpng@PNGLIB_MAJOR@@PNGLIB_MINOR@ + +Name: libpng +Description: Loads and saves PNG files +Version: @PNGLIB_VERSION@ +Libs: -L${libdir} -lpng@PNGLIB_MAJOR@@PNGLIB_MINOR@ +Libs.private: @LIBS@ +Cflags: -I${includedir} diff --git a/src/3rdparty/libpng/libpngpf.3 b/src/3rdparty/libpng/libpngpf.3 new file mode 100644 index 0000000000..ff6e1641ea --- /dev/null +++ b/src/3rdparty/libpng/libpngpf.3 @@ -0,0 +1,30 @@ +.TH LIBPNGPF 3 "February 3, 2011" +.SH NAME +libpng \- Portable Network Graphics (PNG) Reference Library 1.5.1 +(private functions) +.SH SYNOPSIS +\fB#include \fI"pngpriv.h" + +\fI\fB + +\fBAs of libpng version \fP\fI1.5.1\fP\fB, this section is no longer \fP\fImaintained\fP\fB, now \fIthat + +\fBthe private function prototypes are hidden in pngpriv.h and not \fIaccessible + +\fBto applications. Look in pngpriv.h for the prototypes and a short \fIdescription + +\fBof each \fIfunction. + +\fI\fB + +.SH DESCRIPTION +The functions previously listed here are used privately by libpng +and are not recommended for use by applications. They are +not "exported" to applications using shared libraries. They +are listed alphabetically here as an aid to libpng maintainers. +See pngpriv.h for more information on these functions. + +.SH SEE ALSO +.BR "png"(5), " libpng"(3), " zlib"(3), " deflate"(5), " " and " zlib"(5) +.SH AUTHOR +Glenn Randers-Pehrson diff --git a/src/3rdparty/libpng/png.5 b/src/3rdparty/libpng/png.5 new file mode 100644 index 0000000000..9c5f8d3366 --- /dev/null +++ b/src/3rdparty/libpng/png.5 @@ -0,0 +1,74 @@ +.TH PNG 5 "February 3, 2011" +.SH NAME +png \- Portable Network Graphics (PNG) format +.SH DESCRIPTION +PNG (Portable Network Graphics) is an extensible file format for the +lossless, portable, well-compressed storage of raster images. PNG provides +a patent-free replacement for GIF and can also replace many +common uses of TIFF. Indexed-color, grayscale, and truecolor images are +supported, plus an optional alpha channel. Sample depths range from +1 to 16 bits. +.br + +PNG is designed to work well in online viewing applications, such as the +World Wide Web, so it is fully streamable with a progressive display +option. PNG is robust, providing both full file integrity checking and +fast, simple detection of common transmission errors. Also, PNG can store +gamma and chromaticity data for improved color matching on heterogeneous +platforms. + +.SH "SEE ALSO" +.BR "libpng"(3), " libpngpf"(3), " zlib"(3), " deflate"(5), " " and " zlib"(5) +.LP +PNG specification (second edition), November 2003: +.IP +.br + <http://www.w3.org/TR/2003/REC-PNG-20031110/ +PNG 1.2 specification, July 1999: +.IP +.br +http://www.libpng.org/pub/png +.LP +PNG 1.0 specification, October 1996: +.IP +.br +RFC 2083 +.IP +.br +ftp://ds.internic.net/rfc/rfc2083.txt +.br +or (as a W3C Recommendation) at +.br +http://www.w3.org/TR/REC-png.html +.SH AUTHORS +This man page: Glenn Randers-Pehrson +.LP +Portable Network Graphics (PNG) Specification (Second Edition) +Information technology - Computer graphics and image processing - +Portable Network Graphics (PNG): Functional specification. +ISO/IEC 15948:2003 (E) (November 10, 2003): David Duce and others. +.LP +Portable Network Graphics (PNG) Specification Version 1.2 (July 8, 1999): +Glenn Randers-Pehrson and others (png-list). +.LP +Portable Network Graphics (PNG) Specification Version 1.0 (October 1, 1996): +Thomas Boutell and others (png-list). +.LP + + +.SH COPYRIGHT NOTICE +.LP +This man page is Copyright (c) 1998-2006 Glenn Randers-Pehrson. See png.h +for conditions of use and distribution. +.LP +The PNG Specification (Second Edition) is +Copyright (c) 2003 W3C. (MIT, ERCIM, Keio), All Rights Reserved. +.LP +The PNG-1.2 specification is copyright (c) 1999 Glenn Randers-Pehrson. +See the specification for conditions of use and distribution. +.LP +The PNG-1.0 specification is copyright (c) 1996 Massachusetts Institute of +Technology. See the specification for conditions of use and distribution. +.LP +.\" end of man page + diff --git a/src/3rdparty/libpng/png.c b/src/3rdparty/libpng/png.c new file mode 100644 index 0000000000..764f47c20c --- /dev/null +++ b/src/3rdparty/libpng/png.c @@ -0,0 +1,2362 @@ + +/* png.c - location for general purpose libpng functions + * + * Last changed in libpng 1.5.1 [February 3, 2011] + * Copyright (c) 1998-2011 Glenn Randers-Pehrson + * (Version 0.96 Copyright (c) 1996, 1997 Andreas Dilger) + * (Version 0.88 Copyright (c) 1995, 1996 Guy Eric Schalnat, Group 42, Inc.) + * + * This code is released under the libpng license. + * For conditions of distribution and use, see the disclaimer + * and license in png.h + */ + +#include "pngpriv.h" + +/* Generate a compiler error if there is an old png.h in the search path. */ +typedef png_libpng_version_1_5_1 Your_png_h_is_not_version_1_5_1; + +/* Tells libpng that we have already handled the first "num_bytes" bytes + * of the PNG file signature. If the PNG data is embedded into another + * stream we can set num_bytes = 8 so that libpng will not attempt to read + * or write any of the magic bytes before it starts on the IHDR. + */ + +#ifdef PNG_READ_SUPPORTED +void PNGAPI +png_set_sig_bytes(png_structp png_ptr, int num_bytes) +{ + png_debug(1, "in png_set_sig_bytes"); + + if (png_ptr == NULL) + return; + + if (num_bytes > 8) + png_error(png_ptr, "Too many bytes for PNG signature"); + + png_ptr->sig_bytes = (png_byte)(num_bytes < 0 ? 0 : num_bytes); +} + +/* Checks whether the supplied bytes match the PNG signature. We allow + * checking less than the full 8-byte signature so that those apps that + * already read the first few bytes of a file to determine the file type + * can simply check the remaining bytes for extra assurance. Returns + * an integer less than, equal to, or greater than zero if sig is found, + * respectively, to be less than, to match, or be greater than the correct + * PNG signature (this is the same behaviour as strcmp, memcmp, etc). + */ +int PNGAPI +png_sig_cmp(png_const_bytep sig, png_size_t start, png_size_t num_to_check) +{ + png_byte png_signature[8] = {137, 80, 78, 71, 13, 10, 26, 10}; + + if (num_to_check > 8) + num_to_check = 8; + + else if (num_to_check < 1) + return (-1); + + if (start > 7) + return (-1); + + if (start + num_to_check > 8) + num_to_check = 8 - start; + + return ((int)(png_memcmp(&sig[start], &png_signature[start], num_to_check))); +} + +#endif /* PNG_READ_SUPPORTED */ + +#if defined(PNG_READ_SUPPORTED) || defined(PNG_WRITE_SUPPORTED) +/* Function to allocate memory for zlib */ +PNG_FUNCTION(voidpf /* PRIVATE */, +png_zalloc,(voidpf png_ptr, uInt items, uInt size),PNG_ALLOCATED) +{ + png_voidp ptr; + png_structp p=(png_structp)png_ptr; + png_uint_32 save_flags=p->flags; + png_alloc_size_t num_bytes; + + if (png_ptr == NULL) + return (NULL); + + if (items > PNG_UINT_32_MAX/size) + { + png_warning (p, "Potential overflow in png_zalloc()"); + return (NULL); + } + num_bytes = (png_alloc_size_t)items * size; + + p->flags|=PNG_FLAG_MALLOC_NULL_MEM_OK; + ptr = (png_voidp)png_malloc((png_structp)png_ptr, num_bytes); + p->flags=save_flags; + + return ((voidpf)ptr); +} + +/* Function to free memory for zlib */ +void /* PRIVATE */ +png_zfree(voidpf png_ptr, voidpf ptr) +{ + png_free((png_structp)png_ptr, (png_voidp)ptr); +} + +/* Reset the CRC variable to 32 bits of 1's. Care must be taken + * in case CRC is > 32 bits to leave the top bits 0. + */ +void /* PRIVATE */ +png_reset_crc(png_structp png_ptr) +{ + png_ptr->crc = crc32(0, Z_NULL, 0); +} + +/* Calculate the CRC over a section of data. We can only pass as + * much data to this routine as the largest single buffer size. We + * also check that this data will actually be used before going to the + * trouble of calculating it. + */ +void /* PRIVATE */ +png_calculate_crc(png_structp png_ptr, png_const_bytep ptr, png_size_t length) +{ + int need_crc = 1; + + if (png_ptr->chunk_name[0] & 0x20) /* ancillary */ + { + if ((png_ptr->flags & PNG_FLAG_CRC_ANCILLARY_MASK) == + (PNG_FLAG_CRC_ANCILLARY_USE | PNG_FLAG_CRC_ANCILLARY_NOWARN)) + need_crc = 0; + } + + else /* critical */ + { + if (png_ptr->flags & PNG_FLAG_CRC_CRITICAL_IGNORE) + need_crc = 0; + } + + if (need_crc) + png_ptr->crc = crc32(png_ptr->crc, ptr, (uInt)length); +} + +/* Allocate the memory for an info_struct for the application. We don't + * really need the png_ptr, but it could potentially be useful in the + * future. This should be used in favour of malloc(png_sizeof(png_info)) + * and png_info_init() so that applications that want to use a shared + * libpng don't have to be recompiled if png_info changes size. + */ +PNG_FUNCTION(png_infop,PNGAPI +png_create_info_struct,(png_structp png_ptr),PNG_ALLOCATED) +{ + png_infop info_ptr; + + png_debug(1, "in png_create_info_struct"); + + if (png_ptr == NULL) + return (NULL); + +#ifdef PNG_USER_MEM_SUPPORTED + info_ptr = (png_infop)png_create_struct_2(PNG_STRUCT_INFO, + png_ptr->malloc_fn, png_ptr->mem_ptr); +#else + info_ptr = (png_infop)png_create_struct(PNG_STRUCT_INFO); +#endif + if (info_ptr != NULL) + png_info_init_3(&info_ptr, png_sizeof(png_info)); + + return (info_ptr); +} + +/* This function frees the memory associated with a single info struct. + * Normally, one would use either png_destroy_read_struct() or + * png_destroy_write_struct() to free an info struct, but this may be + * useful for some applications. + */ +void PNGAPI +png_destroy_info_struct(png_structp png_ptr, png_infopp info_ptr_ptr) +{ + png_infop info_ptr = NULL; + + png_debug(1, "in png_destroy_info_struct"); + + if (png_ptr == NULL) + return; + + if (info_ptr_ptr != NULL) + info_ptr = *info_ptr_ptr; + + if (info_ptr != NULL) + { + png_info_destroy(png_ptr, info_ptr); + +#ifdef PNG_USER_MEM_SUPPORTED + png_destroy_struct_2((png_voidp)info_ptr, png_ptr->free_fn, + png_ptr->mem_ptr); +#else + png_destroy_struct((png_voidp)info_ptr); +#endif + *info_ptr_ptr = NULL; + } +} + +/* Initialize the info structure. This is now an internal function (0.89) + * and applications using it are urged to use png_create_info_struct() + * instead. + */ + +void PNGAPI +png_info_init_3(png_infopp ptr_ptr, png_size_t png_info_struct_size) +{ + png_infop info_ptr = *ptr_ptr; + + png_debug(1, "in png_info_init_3"); + + if (info_ptr == NULL) + return; + + if (png_sizeof(png_info) > png_info_struct_size) + { + png_destroy_struct(info_ptr); + info_ptr = (png_infop)png_create_struct(PNG_STRUCT_INFO); + *ptr_ptr = info_ptr; + } + + /* Set everything to 0 */ + png_memset(info_ptr, 0, png_sizeof(png_info)); +} + +void PNGAPI +png_data_freer(png_structp png_ptr, png_infop info_ptr, + int freer, png_uint_32 mask) +{ + png_debug(1, "in png_data_freer"); + + if (png_ptr == NULL || info_ptr == NULL) + return; + + if (freer == PNG_DESTROY_WILL_FREE_DATA) + info_ptr->free_me |= mask; + + else if (freer == PNG_USER_WILL_FREE_DATA) + info_ptr->free_me &= ~mask; + + else + png_warning(png_ptr, + "Unknown freer parameter in png_data_freer"); +} + +void PNGAPI +png_free_data(png_structp png_ptr, png_infop info_ptr, png_uint_32 mask, + int num) +{ + png_debug(1, "in png_free_data"); + + if (png_ptr == NULL || info_ptr == NULL) + return; + +#ifdef PNG_TEXT_SUPPORTED + /* Free text item num or (if num == -1) all text items */ + if ((mask & PNG_FREE_TEXT) & info_ptr->free_me) + { + if (num != -1) + { + if (info_ptr->text && info_ptr->text[num].key) + { + png_free(png_ptr, info_ptr->text[num].key); + info_ptr->text[num].key = NULL; + } + } + + else + { + int i; + for (i = 0; i < info_ptr->num_text; i++) + png_free_data(png_ptr, info_ptr, PNG_FREE_TEXT, i); + png_free(png_ptr, info_ptr->text); + info_ptr->text = NULL; + info_ptr->num_text=0; + } + } +#endif + +#ifdef PNG_tRNS_SUPPORTED + /* Free any tRNS entry */ + if ((mask & PNG_FREE_TRNS) & info_ptr->free_me) + { + png_free(png_ptr, info_ptr->trans_alpha); + info_ptr->trans_alpha = NULL; + info_ptr->valid &= ~PNG_INFO_tRNS; + } +#endif + +#ifdef PNG_sCAL_SUPPORTED + /* Free any sCAL entry */ + if ((mask & PNG_FREE_SCAL) & info_ptr->free_me) + { +#if defined(PNG_FIXED_POINT_SUPPORTED) && !defined(PNG_FLOATING_POINT_SUPPORTED) + png_free(png_ptr, info_ptr->scal_s_width); + png_free(png_ptr, info_ptr->scal_s_height); + info_ptr->scal_s_width = NULL; + info_ptr->scal_s_height = NULL; +#endif + info_ptr->valid &= ~PNG_INFO_sCAL; + } +#endif + +#ifdef PNG_pCAL_SUPPORTED + /* Free any pCAL entry */ + if ((mask & PNG_FREE_PCAL) & info_ptr->free_me) + { + png_free(png_ptr, info_ptr->pcal_purpose); + png_free(png_ptr, info_ptr->pcal_units); + info_ptr->pcal_purpose = NULL; + info_ptr->pcal_units = NULL; + if (info_ptr->pcal_params != NULL) + { + int i; + for (i = 0; i < (int)info_ptr->pcal_nparams; i++) + { + png_free(png_ptr, info_ptr->pcal_params[i]); + info_ptr->pcal_params[i] = NULL; + } + png_free(png_ptr, info_ptr->pcal_params); + info_ptr->pcal_params = NULL; + } + info_ptr->valid &= ~PNG_INFO_pCAL; + } +#endif + +#ifdef PNG_iCCP_SUPPORTED + /* Free any iCCP entry */ + if ((mask & PNG_FREE_ICCP) & info_ptr->free_me) + { + png_free(png_ptr, info_ptr->iccp_name); + png_free(png_ptr, info_ptr->iccp_profile); + info_ptr->iccp_name = NULL; + info_ptr->iccp_profile = NULL; + info_ptr->valid &= ~PNG_INFO_iCCP; + } +#endif + +#ifdef PNG_sPLT_SUPPORTED + /* Free a given sPLT entry, or (if num == -1) all sPLT entries */ + if ((mask & PNG_FREE_SPLT) & info_ptr->free_me) + { + if (num != -1) + { + if (info_ptr->splt_palettes) + { + png_free(png_ptr, info_ptr->splt_palettes[num].name); + png_free(png_ptr, info_ptr->splt_palettes[num].entries); + info_ptr->splt_palettes[num].name = NULL; + info_ptr->splt_palettes[num].entries = NULL; + } + } + + else + { + if (info_ptr->splt_palettes_num) + { + int i; + for (i = 0; i < (int)info_ptr->splt_palettes_num; i++) + png_free_data(png_ptr, info_ptr, PNG_FREE_SPLT, i); + + png_free(png_ptr, info_ptr->splt_palettes); + info_ptr->splt_palettes = NULL; + info_ptr->splt_palettes_num = 0; + } + info_ptr->valid &= ~PNG_INFO_sPLT; + } + } +#endif + +#ifdef PNG_UNKNOWN_CHUNKS_SUPPORTED + if (png_ptr->unknown_chunk.data) + { + png_free(png_ptr, png_ptr->unknown_chunk.data); + png_ptr->unknown_chunk.data = NULL; + } + + if ((mask & PNG_FREE_UNKN) & info_ptr->free_me) + { + if (num != -1) + { + if (info_ptr->unknown_chunks) + { + png_free(png_ptr, info_ptr->unknown_chunks[num].data); + info_ptr->unknown_chunks[num].data = NULL; + } + } + + else + { + int i; + + if (info_ptr->unknown_chunks_num) + { + for (i = 0; i < info_ptr->unknown_chunks_num; i++) + png_free_data(png_ptr, info_ptr, PNG_FREE_UNKN, i); + + png_free(png_ptr, info_ptr->unknown_chunks); + info_ptr->unknown_chunks = NULL; + info_ptr->unknown_chunks_num = 0; + } + } + } +#endif + +#ifdef PNG_hIST_SUPPORTED + /* Free any hIST entry */ + if ((mask & PNG_FREE_HIST) & info_ptr->free_me) + { + png_free(png_ptr, info_ptr->hist); + info_ptr->hist = NULL; + info_ptr->valid &= ~PNG_INFO_hIST; + } +#endif + + /* Free any PLTE entry that was internally allocated */ + if ((mask & PNG_FREE_PLTE) & info_ptr->free_me) + { + png_zfree(png_ptr, info_ptr->palette); + info_ptr->palette = NULL; + info_ptr->valid &= ~PNG_INFO_PLTE; + info_ptr->num_palette = 0; + } + +#ifdef PNG_INFO_IMAGE_SUPPORTED + /* Free any image bits attached to the info structure */ + if ((mask & PNG_FREE_ROWS) & info_ptr->free_me) + { + if (info_ptr->row_pointers) + { + int row; + for (row = 0; row < (int)info_ptr->height; row++) + { + png_free(png_ptr, info_ptr->row_pointers[row]); + info_ptr->row_pointers[row] = NULL; + } + png_free(png_ptr, info_ptr->row_pointers); + info_ptr->row_pointers = NULL; + } + info_ptr->valid &= ~PNG_INFO_IDAT; + } +#endif + + if (num != -1) + mask &= ~PNG_FREE_MUL; + + info_ptr->free_me &= ~mask; +} + +/* This is an internal routine to free any memory that the info struct is + * pointing to before re-using it or freeing the struct itself. Recall + * that png_free() checks for NULL pointers for us. + */ +void /* PRIVATE */ +png_info_destroy(png_structp png_ptr, png_infop info_ptr) +{ + png_debug(1, "in png_info_destroy"); + + png_free_data(png_ptr, info_ptr, PNG_FREE_ALL, -1); + +#ifdef PNG_HANDLE_AS_UNKNOWN_SUPPORTED + if (png_ptr->num_chunk_list) + { + png_free(png_ptr, png_ptr->chunk_list); + png_ptr->chunk_list = NULL; + png_ptr->num_chunk_list = 0; + } +#endif + + png_info_init_3(&info_ptr, png_sizeof(png_info)); +} +#endif /* defined(PNG_READ_SUPPORTED) || defined(PNG_WRITE_SUPPORTED) */ + +/* This function returns a pointer to the io_ptr associated with the user + * functions. The application should free any memory associated with this + * pointer before png_write_destroy() or png_read_destroy() are called. + */ +png_voidp PNGAPI +png_get_io_ptr(png_structp png_ptr) +{ + if (png_ptr == NULL) + return (NULL); + + return (png_ptr->io_ptr); +} + +#if defined(PNG_READ_SUPPORTED) || defined(PNG_WRITE_SUPPORTED) +# ifdef PNG_STDIO_SUPPORTED +/* Initialize the default input/output functions for the PNG file. If you + * use your own read or write routines, you can call either png_set_read_fn() + * or png_set_write_fn() instead of png_init_io(). If you have defined + * PNG_NO_STDIO, you must use a function of your own because "FILE *" isn't + * necessarily available. + */ +void PNGAPI +png_init_io(png_structp png_ptr, png_FILE_p fp) +{ + png_debug(1, "in png_init_io"); + + if (png_ptr == NULL) + return; + + png_ptr->io_ptr = (png_voidp)fp; +} +# endif + +# ifdef PNG_TIME_RFC1123_SUPPORTED +/* Convert the supplied time into an RFC 1123 string suitable for use in + * a "Creation Time" or other text-based time string. + */ +png_const_charp PNGAPI +png_convert_to_rfc1123(png_structp png_ptr, png_const_timep ptime) +{ + static PNG_CONST char short_months[12][4] = + {"Jan", "Feb", "Mar", "Apr", "May", "Jun", + "Jul", "Aug", "Sep", "Oct", "Nov", "Dec"}; + + if (png_ptr == NULL) + return (NULL); + + if (png_ptr->time_buffer == NULL) + { + png_ptr->time_buffer = (png_charp)png_malloc(png_ptr, (png_uint_32)(29* + png_sizeof(char))); + } + +# ifdef USE_FAR_KEYWORD + { + char near_time_buf[29]; + png_snprintf6(near_time_buf, 29, "%d %s %d %02d:%02d:%02d +0000", + ptime->day % 32, short_months[(ptime->month - 1) % 12], + ptime->year, ptime->hour % 24, ptime->minute % 60, + ptime->second % 61); + png_memcpy(png_ptr->time_buffer, near_time_buf, + 29*png_sizeof(char)); + } +# else + png_snprintf6(png_ptr->time_buffer, 29, "%d %s %d %02d:%02d:%02d +0000", + ptime->day % 32, short_months[(ptime->month - 1) % 12], + ptime->year, ptime->hour % 24, ptime->minute % 60, + ptime->second % 61); +# endif + return png_ptr->time_buffer; +} +# endif /* PNG_TIME_RFC1123_SUPPORTED */ + +#endif /* defined(PNG_READ_SUPPORTED) || defined(PNG_WRITE_SUPPORTED) */ + +png_const_charp PNGAPI +png_get_copyright(png_const_structp png_ptr) +{ + PNG_UNUSED(png_ptr) /* Silence compiler warning about unused png_ptr */ +#ifdef PNG_STRING_COPYRIGHT + return PNG_STRING_COPYRIGHT +#else +# ifdef __STDC__ + return PNG_STRING_NEWLINE \ + "libpng version 1.5.1 - February 3, 2011" PNG_STRING_NEWLINE \ + "Copyright (c) 1998-2011 Glenn Randers-Pehrson" PNG_STRING_NEWLINE \ + "Copyright (c) 1996-1997 Andreas Dilger" PNG_STRING_NEWLINE \ + "Copyright (c) 1995-1996 Guy Eric Schalnat, Group 42, Inc." \ + PNG_STRING_NEWLINE; +# else + return "libpng version 1.5.1 - February 3, 2011\ + Copyright (c) 1998-2011 Glenn Randers-Pehrson\ + Copyright (c) 1996-1997 Andreas Dilger\ + Copyright (c) 1995-1996 Guy Eric Schalnat, Group 42, Inc."; +# endif +#endif +} + +/* The following return the library version as a short string in the + * format 1.0.0 through 99.99.99zz. To get the version of *.h files + * used with your application, print out PNG_LIBPNG_VER_STRING, which + * is defined in png.h. + * Note: now there is no difference between png_get_libpng_ver() and + * png_get_header_ver(). Due to the version_nn_nn_nn typedef guard, + * it is guaranteed that png.c uses the correct version of png.h. + */ +png_const_charp PNGAPI +png_get_libpng_ver(png_const_structp png_ptr) +{ + /* Version of *.c files used when building libpng */ + return png_get_header_ver(png_ptr); +} + +png_const_charp PNGAPI +png_get_header_ver(png_const_structp png_ptr) +{ + /* Version of *.h files used when building libpng */ + PNG_UNUSED(png_ptr) /* Silence compiler warning about unused png_ptr */ + return PNG_LIBPNG_VER_STRING; +} + +png_const_charp PNGAPI +png_get_header_version(png_const_structp png_ptr) +{ + /* Returns longer string containing both version and date */ + PNG_UNUSED(png_ptr) /* Silence compiler warning about unused png_ptr */ +#ifdef __STDC__ + return PNG_HEADER_VERSION_STRING +# ifndef PNG_READ_SUPPORTED + " (NO READ SUPPORT)" +# endif + PNG_STRING_NEWLINE; +#else + return PNG_HEADER_VERSION_STRING; +#endif +} + +#if defined(PNG_READ_SUPPORTED) || defined(PNG_WRITE_SUPPORTED) +# ifdef PNG_HANDLE_AS_UNKNOWN_SUPPORTED +int PNGAPI +png_handle_as_unknown(png_structp png_ptr, png_const_bytep chunk_name) +{ + /* Check chunk_name and return "keep" value if it's on the list, else 0 */ + int i; + png_bytep p; + if (png_ptr == NULL || chunk_name == NULL || png_ptr->num_chunk_list<=0) + return 0; + + p = png_ptr->chunk_list + png_ptr->num_chunk_list*5 - 5; + for (i = png_ptr->num_chunk_list; i; i--, p -= 5) + if (!png_memcmp(chunk_name, p, 4)) + return ((int)*(p + 4)); + return 0; +} +# endif +#endif /* defined(PNG_READ_SUPPORTED) || defined(PNG_WRITE_SUPPORTED) */ + +#ifdef PNG_READ_SUPPORTED +/* This function, added to libpng-1.0.6g, is untested. */ +int PNGAPI +png_reset_zstream(png_structp png_ptr) +{ + if (png_ptr == NULL) + return Z_STREAM_ERROR; + + return (inflateReset(&png_ptr->zstream)); +} +#endif /* PNG_READ_SUPPORTED */ + +/* This function was added to libpng-1.0.7 */ +png_uint_32 PNGAPI +png_access_version_number(void) +{ + /* Version of *.c files used when building libpng */ + return((png_uint_32)PNG_LIBPNG_VER); +} + + + +#if defined(PNG_READ_SUPPORTED) || defined(PNG_WRITE_SUPPORTED) +# ifdef PNG_SIZE_T +/* Added at libpng version 1.2.6 */ + PNG_EXTERN png_size_t PNGAPI png_convert_size PNGARG((size_t size)); +png_size_t PNGAPI +png_convert_size(size_t size) +{ + if (size > (png_size_t)-1) + PNG_ABORT(); /* We haven't got access to png_ptr, so no png_error() */ + + return ((png_size_t)size); +} +# endif /* PNG_SIZE_T */ + +/* Added at libpng version 1.2.34 and 1.4.0 (moved from pngset.c) */ +# ifdef PNG_CHECK_cHRM_SUPPORTED + +int /* PRIVATE */ +png_check_cHRM_fixed(png_structp png_ptr, + png_fixed_point white_x, png_fixed_point white_y, png_fixed_point red_x, + png_fixed_point red_y, png_fixed_point green_x, png_fixed_point green_y, + png_fixed_point blue_x, png_fixed_point blue_y) +{ + int ret = 1; + unsigned long xy_hi,xy_lo,yx_hi,yx_lo; + + png_debug(1, "in function png_check_cHRM_fixed"); + + if (png_ptr == NULL) + return 0; + + if (white_x < 0 || white_y <= 0 || + red_x < 0 || red_y < 0 || + green_x < 0 || green_y < 0 || + blue_x < 0 || blue_y < 0) + { + png_warning(png_ptr, + "Ignoring attempt to set negative chromaticity value"); + ret = 0; + } + if (white_x > (png_fixed_point)PNG_UINT_31_MAX || + white_y > (png_fixed_point)PNG_UINT_31_MAX || + red_x > (png_fixed_point)PNG_UINT_31_MAX || + red_y > (png_fixed_point)PNG_UINT_31_MAX || + green_x > (png_fixed_point)PNG_UINT_31_MAX || + green_y > (png_fixed_point)PNG_UINT_31_MAX || + blue_x > (png_fixed_point)PNG_UINT_31_MAX || + blue_y > (png_fixed_point)PNG_UINT_31_MAX ) + { + png_warning(png_ptr, + "Ignoring attempt to set chromaticity value exceeding 21474.83"); + ret = 0; + } + if (white_x > 100000L - white_y) + { + png_warning(png_ptr, "Invalid cHRM white point"); + ret = 0; + } + + if (red_x > 100000L - red_y) + { + png_warning(png_ptr, "Invalid cHRM red point"); + ret = 0; + } + + if (green_x > 100000L - green_y) + { + png_warning(png_ptr, "Invalid cHRM green point"); + ret = 0; + } + + if (blue_x > 100000L - blue_y) + { + png_warning(png_ptr, "Invalid cHRM blue point"); + ret = 0; + } + + png_64bit_product(green_x - red_x, blue_y - red_y, &xy_hi, &xy_lo); + png_64bit_product(green_y - red_y, blue_x - red_x, &yx_hi, &yx_lo); + + if (xy_hi == yx_hi && xy_lo == yx_lo) + { + png_warning(png_ptr, + "Ignoring attempt to set cHRM RGB triangle with zero area"); + ret = 0; + } + + return ret; +} +# endif /* PNG_CHECK_cHRM_SUPPORTED */ + +void /* PRIVATE */ +png_check_IHDR(png_structp png_ptr, + png_uint_32 width, png_uint_32 height, int bit_depth, + int color_type, int interlace_type, int compression_type, + int filter_type) +{ + int error = 0; + + /* Check for width and height valid values */ + if (width == 0) + { + png_warning(png_ptr, "Image width is zero in IHDR"); + error = 1; + } + + if (height == 0) + { + png_warning(png_ptr, "Image height is zero in IHDR"); + error = 1; + } + +# ifdef PNG_SET_USER_LIMITS_SUPPORTED + if (width > png_ptr->user_width_max || width > PNG_USER_WIDTH_MAX) + +# else + if (width > PNG_USER_WIDTH_MAX) +# endif + { + png_warning(png_ptr, "Image width exceeds user limit in IHDR"); + error = 1; + } + +# ifdef PNG_SET_USER_LIMITS_SUPPORTED + if (height > png_ptr->user_height_max || height > PNG_USER_HEIGHT_MAX) +# else + if (height > PNG_USER_HEIGHT_MAX) +# endif + { + png_warning(png_ptr, "Image height exceeds user limit in IHDR"); + error = 1; + } + + if (width > PNG_UINT_31_MAX) + { + png_warning(png_ptr, "Invalid image width in IHDR"); + error = 1; + } + + if (height > PNG_UINT_31_MAX) + { + png_warning(png_ptr, "Invalid image height in IHDR"); + error = 1; + } + + if (width > (PNG_UINT_32_MAX + >> 3) /* 8-byte RGBA pixels */ + - 48 /* bigrowbuf hack */ + - 1 /* filter byte */ + - 7*8 /* rounding of width to multiple of 8 pixels */ + - 8) /* extra max_pixel_depth pad */ + png_warning(png_ptr, "Width is too large for libpng to process pixels"); + + /* Check other values */ + if (bit_depth != 1 && bit_depth != 2 && bit_depth != 4 && + bit_depth != 8 && bit_depth != 16) + { + png_warning(png_ptr, "Invalid bit depth in IHDR"); + error = 1; + } + + if (color_type < 0 || color_type == 1 || + color_type == 5 || color_type > 6) + { + png_warning(png_ptr, "Invalid color type in IHDR"); + error = 1; + } + + if (((color_type == PNG_COLOR_TYPE_PALETTE) && bit_depth > 8) || + ((color_type == PNG_COLOR_TYPE_RGB || + color_type == PNG_COLOR_TYPE_GRAY_ALPHA || + color_type == PNG_COLOR_TYPE_RGB_ALPHA) && bit_depth < 8)) + { + png_warning(png_ptr, "Invalid color type/bit depth combination in IHDR"); + error = 1; + } + + if (interlace_type >= PNG_INTERLACE_LAST) + { + png_warning(png_ptr, "Unknown interlace method in IHDR"); + error = 1; + } + + if (compression_type != PNG_COMPRESSION_TYPE_BASE) + { + png_warning(png_ptr, "Unknown compression method in IHDR"); + error = 1; + } + +# ifdef PNG_MNG_FEATURES_SUPPORTED + /* Accept filter_method 64 (intrapixel differencing) only if + * 1. Libpng was compiled with PNG_MNG_FEATURES_SUPPORTED and + * 2. Libpng did not read a PNG signature (this filter_method is only + * used in PNG datastreams that are embedded in MNG datastreams) and + * 3. The application called png_permit_mng_features with a mask that + * included PNG_FLAG_MNG_FILTER_64 and + * 4. The filter_method is 64 and + * 5. The color_type is RGB or RGBA + */ + if ((png_ptr->mode & PNG_HAVE_PNG_SIGNATURE) && + png_ptr->mng_features_permitted) + png_warning(png_ptr, "MNG features are not allowed in a PNG datastream"); + + if (filter_type != PNG_FILTER_TYPE_BASE) + { + if (!((png_ptr->mng_features_permitted & PNG_FLAG_MNG_FILTER_64) && + (filter_type == PNG_INTRAPIXEL_DIFFERENCING) && + ((png_ptr->mode & PNG_HAVE_PNG_SIGNATURE) == 0) && + (color_type == PNG_COLOR_TYPE_RGB || + color_type == PNG_COLOR_TYPE_RGB_ALPHA))) + { + png_warning(png_ptr, "Unknown filter method in IHDR"); + error = 1; + } + + if (png_ptr->mode & PNG_HAVE_PNG_SIGNATURE) + { + png_warning(png_ptr, "Invalid filter method in IHDR"); + error = 1; + } + } + +# else + if (filter_type != PNG_FILTER_TYPE_BASE) + { + png_warning(png_ptr, "Unknown filter method in IHDR"); + error = 1; + } +# endif + + if (error == 1) + png_error(png_ptr, "Invalid IHDR data"); +} + +#if defined(PNG_sCAL_SUPPORTED) || defined(PNG_pCAL_SUPPORTED) +/* ASCII to fp functions */ +/* Check an ASCII formated floating point value, see the more detailed + * comments in pngpriv.h + */ +/* The following is used internally to preserve the 'valid' flag */ +#define png_fp_add(state, flags) ((state) |= (flags)) +#define png_fp_set(state, value)\ + ((state) = (value) | ((state) & PNG_FP_WAS_VALID)) + +/* Internal type codes: bits above the base state! */ +#define PNG_FP_SIGN 0 /* [+-] */ +#define PNG_FP_DOT 4 /* . */ +#define PNG_FP_DIGIT 8 /* [0123456789] */ +#define PNG_FP_E 12 /* [Ee] */ + +int /* PRIVATE */ +png_check_fp_number(png_const_charp string, png_size_t size, int *statep, + png_size_tp whereami) +{ + int state = *statep; + png_size_t i = *whereami; + + while (i < size) + { + int type; + /* First find the type of the next character */ + { + char ch = string[i]; + + if (ch >= 48 && ch <= 57) + type = PNG_FP_DIGIT; + + else switch (ch) + { + case 43: case 45: type = PNG_FP_SIGN; break; + case 46: type = PNG_FP_DOT; break; + case 69: case 101: type = PNG_FP_E; break; + default: goto PNG_FP_End; + } + } + + /* Now deal with this type according to the current + * state, the type is arranged to not overlap the + * bits of the PNG_FP_STATE. + */ + switch ((state & PNG_FP_STATE) + type) + { + case PNG_FP_INTEGER + PNG_FP_SIGN: + if (state & PNG_FP_SAW_ANY) + goto PNG_FP_End; /* not a part of the number */ + + png_fp_add(state, PNG_FP_SAW_SIGN); + break; + + case PNG_FP_INTEGER + PNG_FP_DOT: + /* Ok as trailer, ok as lead of fraction. */ + if (state & PNG_FP_SAW_DOT) /* two dots */ + goto PNG_FP_End; + + else if (state & PNG_FP_SAW_DIGIT) /* trailing dot? */ + png_fp_add(state, PNG_FP_SAW_DOT); + + else + png_fp_set(state, PNG_FP_FRACTION | PNG_FP_SAW_DOT); + + break; + + case PNG_FP_INTEGER + PNG_FP_DIGIT: + if (state & PNG_FP_SAW_DOT) /* delayed fraction */ + png_fp_set(state, PNG_FP_FRACTION | PNG_FP_SAW_DOT); + + png_fp_add(state, PNG_FP_SAW_DIGIT + PNG_FP_WAS_VALID); + + break; + case PNG_FP_INTEGER + PNG_FP_E: + if ((state & PNG_FP_SAW_DIGIT) == 0) + goto PNG_FP_End; + + png_fp_set(state, PNG_FP_EXPONENT); + + break; + + /* case PNG_FP_FRACTION + PNG_FP_SIGN: + goto PNG_FP_End; ** no sign in exponent */ + + /* case PNG_FP_FRACTION + PNG_FP_DOT: + goto PNG_FP_End; ** Because SAW_DOT is always set */ + + case PNG_FP_FRACTION + PNG_FP_DIGIT: + png_fp_add(state, PNG_FP_SAW_DIGIT + PNG_FP_WAS_VALID); + break; + + case PNG_FP_FRACTION + PNG_FP_E: + /* This is correct because the trailing '.' on an + * integer is handled above - so we can only get here + * with the sequence ".E" (with no preceding digits). + */ + if ((state & PNG_FP_SAW_DIGIT) == 0) + goto PNG_FP_End; + + png_fp_set(state, PNG_FP_EXPONENT); + + break; + + case PNG_FP_EXPONENT + PNG_FP_SIGN: + if (state & PNG_FP_SAW_ANY) + goto PNG_FP_End; /* not a part of the number */ + + png_fp_add(state, PNG_FP_SAW_SIGN); + + break; + + /* case PNG_FP_EXPONENT + PNG_FP_DOT: + goto PNG_FP_End; */ + + case PNG_FP_EXPONENT + PNG_FP_DIGIT: + png_fp_add(state, PNG_FP_SAW_DIGIT + PNG_FP_WAS_VALID); + + break; + + /* case PNG_FP_EXPONEXT + PNG_FP_E: + goto PNG_FP_End; */ + + default: goto PNG_FP_End; /* I.e. break 2 */ + } + + /* The character seems ok, continue. */ + ++i; + } + +PNG_FP_End: + /* Here at the end, update the state and return the correct + * return code. + */ + *statep = state; + *whereami = i; + + return (state & PNG_FP_SAW_DIGIT) != 0; +} + + +/* The same but for a complete string. */ +int +png_check_fp_string(png_const_charp string, png_size_t size) +{ + int state=0; + png_size_t char_index=0; + + return png_check_fp_number(string, size, &state, &char_index) && + (char_index == size || string[char_index] == 0); +} +#endif /* pCAL or sCAL */ + +#ifdef PNG_READ_sCAL_SUPPORTED +# ifdef PNG_FLOATING_POINT_SUPPORTED +/* Utility used below - a simple accurate power of ten from an integral + * exponent. + */ +static double +png_pow10(int power) +{ + int recip = 0; + double d = 1; + + /* Handle negative exponent with a reciprocal at the end because + * 10 is exact whereas .1 is inexact in base 2 + */ + if (power < 0) + { + if (power < DBL_MIN_10_EXP) return 0; + recip = 1, power = -power; + } + + if (power > 0) + { + /* Decompose power bitwise. */ + double mult = 10; + do + { + if (power & 1) d *= mult; + mult *= mult; + power >>= 1; + } + while (power > 0); + + if (recip) d = 1/d; + } + /* else power is 0 and d is 1 */ + + return d; +} + +/* Function to format a floating point value in ASCII with a given + * precision. + */ +void /* PRIVATE */ +png_ascii_from_fp(png_structp png_ptr, png_charp ascii, png_size_t size, + double fp, unsigned int precision) +{ + /* We use standard functions from math.h, but not printf because + * that would require stdio. The caller must supply a buffer of + * sufficient size or we will png_error. The tests on size and + * the space in ascii[] consumed are indicated below. + */ + if (precision < 1) + precision = DBL_DIG; + + /* Enforce the limit of the implementation precision too. */ + if (precision > DBL_DIG+1) + precision = DBL_DIG+1; + + /* Basic sanity checks */ + if (size >= precision+5) /* See the requirements below. */ + { + if (fp < 0) + { + fp = -fp; + *ascii++ = 45; /* '-' PLUS 1 TOTAL 1*/ + --size; + } + + if (fp >= DBL_MIN && fp <= DBL_MAX) + { + int exp_b10; /* A base 10 exponent */ + double base; /* 10^exp_b10 */ + + /* First extract a base 10 exponent of the number, + * the calculation below rounds down when converting + * from base 2 to base 10 (multiply by log10(2) - + * 0.3010, but 77/256 is 0.3008, so exp_b10 needs to + * be increased. Note that the arithmetic shift + * performs a floor() unlike C arithmetic - using a + * C multiply would break the following for negative + * exponents. + */ + (void)frexp(fp, &exp_b10); /* exponent to base 2 */ + + exp_b10 = (exp_b10 * 77) >> 8; /* <= exponent to base 10 */ + + /* Avoid underflow here. */ + base = png_pow10(exp_b10); /* May underflow */ + + while (base < DBL_MIN || base < fp) + { + /* And this may overflow. */ + double test = png_pow10(exp_b10+1); + + if (test <= DBL_MAX) + ++exp_b10, base = test; + + else + break; + } + + /* Normalize fp and correct exp_b10, after this fp is in the + * range [.1,1) and exp_b10 is both the exponent and the digit + * *before* which the decimal point should be inserted + * (starting with 0 for the first digit). Note that this + * works even if 10^exp_b10 is out of range because of the + * test on DBL_MAX above. + */ + fp /= base; + while (fp >= 1) fp /= 10, ++exp_b10; + + /* Because of the code above fp may, at this point, be + * less than .1, this is ok because the code below can + * handle the leading zeros this generates, so no attempt + * is made to correct that here. + */ + + { + int czero, clead, cdigits; + char exponent[10]; + + /* Allow up to two leading zeros - this will not lengthen + * the number compared to using E-n. + */ + if (exp_b10 < 0 && exp_b10 > -3) /* PLUS 3 TOTAL 4 */ + { + czero = -exp_b10; /* PLUS 2 digits: TOTAL 3 */ + exp_b10 = 0; /* Dot added below before first output. */ + } + else + czero = 0; /* No zeros to add */ + + /* Generate the digit list, stripping trailing zeros and + * inserting a '.' before a digit if the exponent is 0. + */ + clead = czero; /* Count of leading zeros */ + cdigits = 0; /* Count of digits in list. */ + + do + { + double d; + + fp *= 10; + /* Use modf here, not floor and subtract, so that + * the separation is done in one step. At the end + * of the loop don't break the number into parts so + * that the final digit is rounded. + */ + if (cdigits+czero-clead+1 < (int)precision) + fp = modf(fp, &d); + + else + { + d = floor(fp + .5); + + if (d > 9) + { + /* Rounding up to 10, handle that here. */ + if (czero > 0) + { + --czero, d = 1; + if (cdigits == 0) --clead; + } + else + { + while (cdigits > 0 && d > 9) + { + int ch = *--ascii; + + if (exp_b10 != (-1)) + ++exp_b10; + + else if (ch == 46) + { + ch = *--ascii, ++size; + /* Advance exp_b10 to '1', so that the + * decimal point happens after the + * previous digit. + */ + exp_b10 = 1; + } + + --cdigits; + d = ch - 47; /* I.e. 1+(ch-48) */ + } + + /* Did we reach the beginning? If so adjust the + * exponent but take into account the leading + * decimal point. + */ + if (d > 9) /* cdigits == 0 */ + { + if (exp_b10 == (-1)) + { + /* Leading decimal point (plus zeros?), if + * we lose the decimal point here it must + * be reentered below. + */ + int ch = *--ascii; + + if (ch == 46) + ++size, exp_b10 = 1; + + /* Else lost a leading zero, so 'exp_b10' is + * still ok at (-1) + */ + } + else + ++exp_b10; + + /* In all cases we output a '1' */ + d = 1; + } + } + } + fp = 0; /* Guarantees termination below. */ + } + + if (d == 0) + { + ++czero; + if (cdigits == 0) ++clead; + } + else + { + /* Included embedded zeros in the digit count. */ + cdigits += czero - clead; + clead = 0; + + while (czero > 0) + { + /* exp_b10 == (-1) means we just output the decimal + * place - after the DP don't adjust 'exp_b10' any + * more! + */ + if (exp_b10 != (-1)) + { + if (exp_b10 == 0) *ascii++ = 46, --size; + /* PLUS 1: TOTAL 4 */ + --exp_b10; + } + *ascii++ = 48, --czero; + } + + if (exp_b10 != (-1)) + { + if (exp_b10 == 0) *ascii++ = 46, --size; /* counted + above */ + --exp_b10; + } + *ascii++ = (char)(48 + (int)d), ++cdigits; + } + } + while (cdigits+czero-clead < (int)precision && fp > DBL_MIN); + + /* The total output count (max) is now 4+precision */ + + /* Check for an exponent, if we don't need one we are + * done and just need to terminate the string. At + * this point exp_b10==(-1) is effectively if flag - it got + * to '-1' because of the decrement after outputing + * the decimal point above (the exponent required is + * *not* -1!) + */ + if (exp_b10 >= (-1) && exp_b10 <= 2) + { + /* The following only happens if we didn't output the + * leading zeros above for negative exponent, so this + * doest add to the digit requirement. Note that the + * two zeros here can only be output if the two leading + * zeros were *not* output, so this doesn't increase + * the output count. + */ + while (--exp_b10 >= 0) *ascii++ = 48; + + *ascii = 0; + + /* Total buffer requirement (including the '\0') is + * 5+precision - see check at the start. + */ + return; + } + + /* Here if an exponent is required, adjust size for + * the digits we output but did not count. The total + * digit output here so far is at most 1+precision - no + * decimal point and no leading or trailing zeros have + * been output. + */ + size -= cdigits; + + *ascii++ = 69, --size; /* 'E': PLUS 1 TOTAL 2+precision*/ + if (exp_b10 < 0) + { + *ascii++ = 45, --size; /* '-': PLUS 1 TOTAL 3+precision */ + exp_b10 = -exp_b10; + } + + cdigits = 0; + + while (exp_b10 > 0) + { + exponent[cdigits++] = (char)(48 + exp_b10 % 10); + exp_b10 /= 10; + } + + /* Need another size check here for the exponent digits, so + * this need not be considered above. + */ + if ((int)size > cdigits) + { + while (cdigits > 0) *ascii++ = exponent[--cdigits]; + + *ascii = 0; + + return; + } + } + } + else if (!(fp >= DBL_MIN)) + { + *ascii++ = 48; /* '0' */ + *ascii = 0; + return; + } + else + { + *ascii++ = 105; /* 'i' */ + *ascii++ = 110; /* 'n' */ + *ascii++ = 102; /* 'f' */ + *ascii = 0; + return; + } + } + + /* Here on buffer too small. */ + png_error(png_ptr, "ASCII conversion buffer too small"); +} + +# endif /* FLOATING_POINT */ + +# ifdef PNG_FIXED_POINT_SUPPORTED +/* Function to format a fixed point value in ASCII. + */ +void /* PRIVATE */ +png_ascii_from_fixed(png_structp png_ptr, png_charp ascii, png_size_t size, + png_fixed_point fp) +{ + /* Require space for 10 decimal digits, a decimal point, a minus sign and a + * trailing \0, 13 characters: + */ + if (size > 12) + { + png_uint_32 num; + + /* Avoid overflow here on the minimum integer. */ + if (fp < 0) + *ascii++ = 45, --size, num = -fp; + else + num = fp; + + if (num <= 0x80000000U) /* else overflowed */ + { + unsigned int ndigits = 0, first = 16/*flag value*/; + char digits[10]; + + while (num) + { + /* Split the low digit off num: */ + unsigned int tmp = num/10; + num -= tmp*10; + digits[ndigits++] = (char)(48 + num); + /* Record the first non-zero digit, note that this is a number + * starting at 1, it's not actually the array index. + */ + if (first == 16 && num > 0) + first = ndigits; + num = tmp; + } + + if (ndigits > 0) + { + while (ndigits > 5) *ascii++ = digits[--ndigits]; + /* The remaining digits are fractional digits, ndigits is '5' or + * smaller at this point. It is certainly not zero. Check for a + * non-zero fractional digit: + */ + if (first <= 5) + { + unsigned int i; + *ascii++ = 46; /* decimal point */ + /* ndigits may be <5 for small numbers, output leading zeros + * then ndigits digits to first: + */ + i = 5; + while (ndigits < i) *ascii++ = 48, --i; + while (ndigits >= first) *ascii++ = digits[--ndigits]; + /* Don't output the trailing zeros! */ + } + } + else + *ascii++ = 48; + + /* And null terminate the string: */ + *ascii = 0; + return; + } + } + + /* Here on buffer too small. */ + png_error(png_ptr, "ASCII conversion buffer too small"); +} +# endif /* FIXED_POINT */ +#endif /* READ_SCAL */ + +#if defined(PNG_FLOATING_POINT_SUPPORTED) && \ + !defined(PNG_FIXED_POINT_MACRO_SUPPORTED) +png_fixed_point +png_fixed(png_structp png_ptr, double fp, png_const_charp text) +{ + double r = floor(100000 * fp + .5); + + if (r > 2147483647. || r < -2147483648.) + png_fixed_error(png_ptr, text); + + return (png_fixed_point)r; +} +#endif + +#if defined(PNG_READ_GAMMA_SUPPORTED) || \ + defined(PNG_INCH_CONVERSIONS_SUPPORTED) || defined(PNG__READ_pHYs_SUPPORTED) +/* muldiv functions */ +/* This API takes signed arguments and rounds the result to the nearest + * integer (or, for a fixed point number - the standard argument - to + * the nearest .00001). Overflow and divide by zero are signalled in + * the result, a boolean - true on success, false on overflow. + */ +int +png_muldiv(png_fixed_point_p res, png_fixed_point a, png_int_32 times, + png_int_32 divisor) +{ + /* Return a * times / divisor, rounded. */ + if (divisor != 0) + { + if (a == 0 || times == 0) + { + *res = 0; + return 1; + } + else + { +#ifdef PNG_FLOATING_ARITHMETIC_SUPPORTED + double r = a; + r *= times; + r /= divisor; + r = floor(r+.5); + + /* A png_fixed_point is a 32 bit integer. */ + if (r <= 2147483647. && r >= -2147483648.) + { + *res = (png_fixed_point)r; + return 1; + } +#else + int negative = 0; + png_uint_32 A, T, D; + png_uint_32 s16, s32, s00; + + if (a < 0) + negative = 1, A = -a; + else + A = a; + + if (times < 0) + negative = !negative, T = -times; + else + T = times; + + if (divisor < 0) + negative = !negative, D = -divisor; + else + D = divisor; + + /* Following can't overflow because the arguments only + * have 31 bits each, however the result may be 32 bits. + */ + s16 = (A >> 16) * (T & 0xffff) + + (A & 0xffff) * (T >> 16); + /* Can't overflow because the a*times bit is only 30 + * bits at most. + */ + s32 = (A >> 16) * (T >> 16) + (s16 >> 16); + s00 = (A & 0xffff) * (T & 0xffff); + + s16 = (s16 & 0xffff) << 16; + s00 += s16; + + if (s00 < s16) + ++s32; /* carry */ + + if (s32 < D) /* else overflow */ + { + /* s32.s00 is now the 64 bit product, do a standard + * division, we know that s32 < D, so the maximum + * required shift is 31. + */ + int bitshift = 32; + png_fixed_point result = 0; /* NOTE: signed */ + + while (--bitshift >= 0) + { + png_uint_32 d32, d00; + + if (bitshift > 0) + d32 = D >> (32-bitshift), d00 = D << bitshift; + + else + d32 = 0, d00 = D; + + if (s32 > d32) + { + if (s00 < d00) --s32; /* carry */ + s32 -= d32, s00 -= d00, result += 1<<bitshift; + } + + else + if (s32 == d32 && s00 >= d00) + s32 = 0, s00 -= d00, result += 1<<bitshift; + } + + /* Handle the rounding. */ + if (s00 >= (D >> 1)) + ++result; + + if (negative) + result = -result; + + /* Check for overflow. */ + if ((negative && result <= 0) || (!negative && result >= 0)) + { + *res = result; + return 1; + } + } +#endif + } + } + + return 0; +} +#endif /* READ_GAMMA || INCH_CONVERSIONS */ + +#if defined(PNG_READ_GAMMA_SUPPORTED) || defined(PNG_INCH_CONVERSIONS_SUPPORTED) +/* The following is for when the caller doesn't much care about the + * result. + */ +png_fixed_point +png_muldiv_warn(png_structp png_ptr, png_fixed_point a, png_int_32 times, + png_int_32 divisor) +{ + png_fixed_point result; + + if (png_muldiv(&result, a, times, divisor)) + return result; + + png_warning(png_ptr, "fixed point overflow ignored"); + return 0; +} +#endif + +#ifdef PNG_READ_GAMMA_SUPPORTED /* more fixed point functions for gammma */ +/* Calculate a reciprocal, return 0 on div-by-zero or overflow. */ +png_fixed_point +png_reciprocal(png_fixed_point a) +{ +#ifdef PNG_FLOATING_ARITHMETIC_SUPPORTED + double r = floor(1E10/a+.5); + + if (r <= 2147483647. && r >= -2147483648.) + return (png_fixed_point)r; +#else + png_fixed_point res; + + if (png_muldiv(&res, 100000, 100000, a)) + return res; +#endif + + return 0; /* error/overflow */ +} + +/* A local convenience routine. */ +static png_fixed_point +png_product2(png_fixed_point a, png_fixed_point b) +{ + /* The required result is 1/a * 1/b; the following preserves accuracy. */ +#ifdef PNG_FLOATING_ARITHMETIC_SUPPORTED + double r = a * 1E-5; + r *= b; + r = floor(r+.5); + + if (r <= 2147483647. && r >= -2147483648.) + return (png_fixed_point)r; +#else + png_fixed_point res; + + if (png_muldiv(&res, a, b, 100000)) + return res; +#endif + + return 0; /* overflow */ +} + +/* The inverse of the above. */ +png_fixed_point +png_reciprocal2(png_fixed_point a, png_fixed_point b) +{ + /* The required result is 1/a * 1/b; the following preserves accuracy. */ +#ifdef PNG_FLOATING_ARITHMETIC_SUPPORTED + double r = 1E15/a; + r /= b; + r = floor(r+.5); + + if (r <= 2147483647. && r >= -2147483648.) + return (png_fixed_point)r; +#else + /* This may overflow because the range of png_fixed_point isn't symmetric, + * but this API is only used for the product of file and screen gamma so it + * doesn't matter that the smallest number it can produce is 1/21474, not + * 1/100000 + */ + png_fixed_point res = png_product2(a, b); + + if (res != 0) + return png_reciprocal(res); +#endif + + return 0; /* overflow */ +} +#endif /* READ_GAMMA */ + +#ifdef PNG_CHECK_cHRM_SUPPORTED +/* Added at libpng version 1.2.34 (Dec 8, 2008) and 1.4.0 (Jan 2, + * 2010: moved from pngset.c) */ +/* + * Multiply two 32-bit numbers, V1 and V2, using 32-bit + * arithmetic, to produce a 64 bit result in the HI/LO words. + * + * A B + * x C D + * ------ + * AD || BD + * AC || CB || 0 + * + * where A and B are the high and low 16-bit words of V1, + * C and D are the 16-bit words of V2, AD is the product of + * A and D, and X || Y is (X << 16) + Y. +*/ + +void /* PRIVATE */ +png_64bit_product (long v1, long v2, unsigned long *hi_product, + unsigned long *lo_product) +{ + int a, b, c, d; + long lo, hi, x, y; + + a = (v1 >> 16) & 0xffff; + b = v1 & 0xffff; + c = (v2 >> 16) & 0xffff; + d = v2 & 0xffff; + + lo = b * d; /* BD */ + x = a * d + c * b; /* AD + CB */ + y = ((lo >> 16) & 0xffff) + x; + + lo = (lo & 0xffff) | ((y & 0xffff) << 16); + hi = (y >> 16) & 0xffff; + + hi += a * c; /* AC */ + + *hi_product = (unsigned long)hi; + *lo_product = (unsigned long)lo; +} +#endif /* CHECK_cHRM */ + +#ifdef PNG_READ_GAMMA_SUPPORTED /* gamma table code */ +#ifndef PNG_FLOATING_ARITHMETIC_SUPPORTED +/* Fixed point gamma. + * + * To calculate gamma this code implements fast log() and exp() calls using only + * fixed point arithmetic. This code has sufficient precision for either 8 or + * 16 bit sample values. + * + * The tables used here were calculated using simple 'bc' programs, but C double + * precision floating point arithmetic would work fine. The programs are given + * at the head of each table. + * + * 8 bit log table + * This is a table of -log(value/255)/log(2) for 'value' in the range 128 to + * 255, so it's the base 2 logarithm of a normalized 8 bit floating point + * mantissa. The numbers are 32 bit fractions. + */ +static png_uint_32 +png_8bit_l2[128] = +{ +# if PNG_DO_BC + for (i=128;i<256;++i) { .5 - l(i/255)/l(2)*65536*65536; } +# endif + 4270715492U, 4222494797U, 4174646467U, 4127164793U, 4080044201U, 4033279239U, + 3986864580U, 3940795015U, 3895065449U, 3849670902U, 3804606499U, 3759867474U, + 3715449162U, 3671346997U, 3627556511U, 3584073329U, 3540893168U, 3498011834U, + 3455425220U, 3413129301U, 3371120137U, 3329393864U, 3287946700U, 3246774933U, + 3205874930U, 3165243125U, 3124876025U, 3084770202U, 3044922296U, 3005329011U, + 2965987113U, 2926893432U, 2888044853U, 2849438323U, 2811070844U, 2772939474U, + 2735041326U, 2697373562U, 2659933400U, 2622718104U, 2585724991U, 2548951424U, + 2512394810U, 2476052606U, 2439922311U, 2404001468U, 2368287663U, 2332778523U, + 2297471715U, 2262364947U, 2227455964U, 2192742551U, 2158222529U, 2123893754U, + 2089754119U, 2055801552U, 2022034013U, 1988449497U, 1955046031U, 1921821672U, + 1888774511U, 1855902668U, 1823204291U, 1790677560U, 1758320682U, 1726131893U, + 1694109454U, 1662251657U, 1630556815U, 1599023271U, 1567649391U, 1536433567U, + 1505374214U, 1474469770U, 1443718700U, 1413119487U, 1382670639U, 1352370686U, + 1322218179U, 1292211689U, 1262349810U, 1232631153U, 1203054352U, 1173618059U, + 1144320946U, 1115161701U, 1086139034U, 1057251672U, 1028498358U, 999877854U, + 971388940U, 943030410U, 914801076U, 886699767U, 858725327U, 830876614U, + 803152505U, 775551890U, 748073672U, 720716771U, 693480120U, 666362667U, + 639363374U, 612481215U, 585715177U, 559064263U, 532527486U, 506103872U, + 479792461U, 453592303U, 427502463U, 401522014U, 375650043U, 349885648U, + 324227938U, 298676034U, 273229066U, 247886176U, 222646516U, 197509248U, + 172473545U, 147538590U, 122703574U, 97967701U, 73330182U, 48790236U, + 24347096U, 0U +#if 0 + /* The following are the values for 16 bit tables - these work fine for the 8 + * bit conversions but produce very slightly larger errors in the 16 bit log + * (about 1.2 as opposed to 0.7 absolute error in the final value). To use + * these all the shifts below must be adjusted appropriately. + */ + 65166, 64430, 63700, 62976, 62257, 61543, 60835, 60132, 59434, 58741, 58054, + 57371, 56693, 56020, 55352, 54689, 54030, 53375, 52726, 52080, 51439, 50803, + 50170, 49542, 48918, 48298, 47682, 47070, 46462, 45858, 45257, 44661, 44068, + 43479, 42894, 42312, 41733, 41159, 40587, 40020, 39455, 38894, 38336, 37782, + 37230, 36682, 36137, 35595, 35057, 34521, 33988, 33459, 32932, 32408, 31887, + 31369, 30854, 30341, 29832, 29325, 28820, 28319, 27820, 27324, 26830, 26339, + 25850, 25364, 24880, 24399, 23920, 23444, 22970, 22499, 22029, 21562, 21098, + 20636, 20175, 19718, 19262, 18808, 18357, 17908, 17461, 17016, 16573, 16132, + 15694, 15257, 14822, 14390, 13959, 13530, 13103, 12678, 12255, 11834, 11415, + 10997, 10582, 10168, 9756, 9346, 8937, 8531, 8126, 7723, 7321, 6921, 6523, + 6127, 5732, 5339, 4947, 4557, 4169, 3782, 3397, 3014, 2632, 2251, 1872, 1495, + 1119, 744, 372 +#endif +}; + +static png_int_32 +png_log8bit(unsigned int x) +{ + unsigned int lg2 = 0; + /* Each time 'x' is multiplied by 2, 1 must be subtracted off the final log, + * because the log is actually negate that means adding 1. The final + * returned value thus has the range 0 (for 255 input) to 7.994 (for 1 + * input), return 7.99998 for the overflow (log 0) case - so the result is + * always at most 19 bits. + */ + if ((x &= 0xff) == 0) + return 0xffffffff; + + if ((x & 0xf0) == 0) + lg2 = 4, x <<= 4; + + if ((x & 0xc0) == 0) + lg2 += 2, x <<= 2; + + if ((x & 0x80) == 0) + lg2 += 1, x <<= 1; + + /* result is at most 19 bits, so this cast is safe: */ + return (png_int_32)((lg2 << 16) + ((png_8bit_l2[x-128]+32768)>>16)); +} + +/* The above gives exact (to 16 binary places) log2 values for 8 bit images, + * for 16 bit images we use the most significant 8 bits of the 16 bit value to + * get an approximation then multiply the approximation by a correction factor + * determined by the remaining up to 8 bits. This requires an additional step + * in the 16 bit case. + * + * We want log2(value/65535), we have log2(v'/255), where: + * + * value = v' * 256 + v'' + * = v' * f + * + * So f is value/v', which is equal to (256+v''/v') since v' is in the range 128 + * to 255 and v'' is in the range 0 to 255 f will be in the range 256 to less + * than 258. The final factor also needs to correct for the fact that our 8 bit + * value is scaled by 255, whereas the 16 bit values must be scaled by 65535. + * + * This gives a final formula using a calculated value 'x' which is value/v' and + * scaling by 65536 to match the above table: + * + * log2(x/257) * 65536 + * + * Since these numbers are so close to '1' we can use simple linear + * interpolation between the two end values 256/257 (result -368.61) and 258/257 + * (result 367.179). The values used below are scaled by a further 64 to give + * 16 bit precision in the interpolation: + * + * Start (256): -23591 + * Zero (257): 0 + * End (258): 23499 + */ +static png_int_32 +png_log16bit(png_uint_32 x) +{ + unsigned int lg2 = 0; + + /* As above, but now the input has 16 bits. */ + if ((x &= 0xffff) == 0) + return 0xffffffff; + + if ((x & 0xff00) == 0) + lg2 = 8, x <<= 8; + + if ((x & 0xf000) == 0) + lg2 += 4, x <<= 4; + + if ((x & 0xc000) == 0) + lg2 += 2, x <<= 2; + + if ((x & 0x8000) == 0) + lg2 += 1, x <<= 1; + + /* Calculate the base logarithm from the top 8 bits as a 28 bit fractional + * value. + */ + lg2 <<= 28; + lg2 += (png_8bit_l2[(x>>8)-128]+8) >> 4; + + /* Now we need to interpolate the factor, this requires a division by the top + * 8 bits. Do this with maximum precision. + */ + x = ((x << 16) + (x >> 9)) / (x >> 8); + + /* Since we divided by the top 8 bits of 'x' there will be a '1' at 1<<24, + * the value at 1<<16 (ignoring this) will be 0 or 1; this gives us exactly + * 16 bits to interpolate to get the low bits of the result. Round the + * answer. Note that the end point values are scaled by 64 to retain overall + * precision and that 'lg2' is current scaled by an extra 12 bits, so adjust + * the overall scaling by 6-12. Round at every step. + */ + x -= 1U << 24; + + if (x <= 65536U) /* <= '257' */ + lg2 += ((23591U * (65536U-x)) + (1U << (16+6-12-1))) >> (16+6-12); + + else + lg2 -= ((23499U * (x-65536U)) + (1U << (16+6-12-1))) >> (16+6-12); + + /* Safe, because the result can't have more than 20 bits: */ + return (png_int_32)((lg2 + 2048) >> 12); +} + +/* The 'exp()' case must invert the above, taking a 20 bit fixed point + * logarithmic value and returning a 16 or 8 bit number as appropriate. In + * each case only the low 16 bits are relevant - the fraction - since the + * integer bits (the top 4) simply determine a shift. + * + * The worst case is the 16 bit distinction between 65535 and 65534, this + * requires perhaps spurious accuracty in the decoding of the logarithm to + * distinguish log2(65535/65534.5) - 10^-5 or 17 bits. There is little chance + * of getting this accuracy in practice. + * + * To deal with this the following exp() function works out the exponent of the + * frational part of the logarithm by using an accurate 32 bit value from the + * top four fractional bits then multiplying in the remaining bits. + */ +static png_uint_32 +png_32bit_exp[16] = +{ +# if PNG_DO_BC + for (i=0;i<16;++i) { .5 + e(-i/16*l(2))*2^32; } +# endif + /* NOTE: the first entry is deliberately set to the maximum 32 bit value. */ + 4294967295U, 4112874773U, 3938502376U, 3771522796U, 3611622603U, 3458501653U, + 3311872529U, 3171459999U, 3037000500U, 2908241642U, 2784941738U, 2666869345U, + 2553802834U, 2445529972U, 2341847524U, 2242560872U +}; + +/* Adjustment table; provided to explain the numbers in the code below. */ +#if PNG_DO_BC +for (i=11;i>=0;--i){ print i, " ", (1 - e(-(2^i)/65536*l(2))) * 2^(32-i), "\n"} + 11 44937.64284865548751208448 + 10 45180.98734845585101160448 + 9 45303.31936980687359311872 + 8 45364.65110595323018870784 + 7 45395.35850361789624614912 + 6 45410.72259715102037508096 + 5 45418.40724413220722311168 + 4 45422.25021786898173001728 + 3 45424.17186732298419044352 + 2 45425.13273269940811464704 + 1 45425.61317555035558641664 + 0 45425.85339951654943850496 +#endif + +static png_uint_32 +png_exp(png_fixed_point x) +{ + if (x > 0 && x <= 0xfffff) /* Else overflow or zero (underflow) */ + { + /* Obtain a 4 bit approximation */ + png_uint_32 e = png_32bit_exp[(x >> 12) & 0xf]; + + /* Incorporate the low 12 bits - these decrease the returned value by + * multiplying by a number less than 1 if the bit is set. The multiplier + * is determined by the above table and the shift. Notice that the values + * converge on 45426 and this is used to allow linear interpolation of the + * low bits. + */ + if (x & 0x800) + e -= (((e >> 16) * 44938U) + 16U) >> 5; + + if (x & 0x400) + e -= (((e >> 16) * 45181U) + 32U) >> 6; + + if (x & 0x200) + e -= (((e >> 16) * 45303U) + 64U) >> 7; + + if (x & 0x100) + e -= (((e >> 16) * 45365U) + 128U) >> 8; + + if (x & 0x080) + e -= (((e >> 16) * 45395U) + 256U) >> 9; + + if (x & 0x040) + e -= (((e >> 16) * 45410U) + 512U) >> 10; + + /* And handle the low 6 bits in a single block. */ + e -= (((e >> 16) * 355U * (x & 0x3fU)) + 256U) >> 9; + + /* Handle the upper bits of x. */ + e >>= x >> 16; + return e; + } + + /* Check for overflow */ + if (x <= 0) + return png_32bit_exp[0]; + + /* Else underflow */ + return 0; +} + +static png_byte +png_exp8bit(png_fixed_point lg2) +{ + /* Get a 32 bit value: */ + png_uint_32 x = png_exp(lg2); + + /* Convert the 32 bit value to 0..255 by multiplying by 256-1, note that the + * second, rounding, step can't overflow because of the first, subtraction, + * step. + */ + x -= x >> 8; + return (png_byte)((x + 0x7fffffU) >> 24); +} + +static png_uint_16 +png_exp16bit(png_fixed_point lg2) +{ + /* Get a 32 bit value: */ + png_uint_32 x = png_exp(lg2); + + /* Convert the 32 bit value to 0..65535 by multiplying by 65536-1: */ + x -= x >> 16; + return (png_uint_16)((x + 32767U) >> 16); +} +#endif /* FLOATING_ARITHMETIC */ + +png_byte +png_gamma_8bit_correct(unsigned int value, png_fixed_point gamma_val) +{ + if (value > 0 && value < 255) + { +# ifdef PNG_FLOATING_ARITHMETIC_SUPPORTED + double r = floor(255*pow(value/255.,gamma_val*.00001)+.5); + return (png_byte)r; +# else + png_int_32 lg2 = png_log8bit(value); + png_fixed_point res; + + if (png_muldiv(&res, gamma_val, lg2, PNG_FP_1)) + return png_exp8bit(res); + + /* Overflow. */ + value = 0; +# endif + } + + return (png_byte)value; +} + +png_uint_16 +png_gamma_16bit_correct(unsigned int value, png_fixed_point gamma_val) +{ + if (value > 0 && value < 65535) + { +# ifdef PNG_FLOATING_ARITHMETIC_SUPPORTED + double r = floor(65535*pow(value/65535.,gamma_val*.00001)+.5); + return (png_uint_16)r; +# else + png_int_32 lg2 = png_log16bit(value); + png_fixed_point res; + + if (png_muldiv(&res, gamma_val, lg2, PNG_FP_1)) + return png_exp16bit(res); + + /* Overflow. */ + value = 0; +# endif + } + + return (png_uint_16)value; +} + +/* This does the right thing based on the bit_depth field of the + * png_struct, interpreting values as 8 or 16 bit. While the result + * is nominally a 16 bit value if bit depth is 8 then the result is + * 8 bit (as are the arguments.) + */ +png_uint_16 /* PRIVATE */ +png_gamma_correct(png_structp png_ptr, unsigned int value, + png_fixed_point gamma_val) +{ + if (png_ptr->bit_depth == 8) + return png_gamma_8bit_correct(value, gamma_val); + + else + return png_gamma_16bit_correct(value, gamma_val); +} + +/* This is the shared test on whether a gamma value is 'significant' - whether + * it is worth doing gamma correction. + */ +int /* PRIVATE */ +png_gamma_significant(png_fixed_point gamma_val) +{ + return gamma_val < PNG_FP_1 - PNG_GAMMA_THRESHOLD_FIXED || + gamma_val > PNG_FP_1 + PNG_GAMMA_THRESHOLD_FIXED; +} + +/* Internal function to build a single 16 bit table - the table consists of + * 'num' 256 entry subtables, where 'num' is determined by 'shift' - the amount + * to shift the input values right (or 16-number_of_signifiant_bits). + * + * The caller is responsible for ensuring that the table gets cleaned up on + * png_error (i.e. if one of the mallocs below fails) - i.e. the *table argument + * should be somewhere that will be cleaned. + */ +static void +png_build_16bit_table(png_structp png_ptr, png_uint_16pp *ptable, + PNG_CONST unsigned int shift, PNG_CONST png_fixed_point gamma_val) +{ + /* Various values derived from 'shift': */ + PNG_CONST unsigned int num = 1U << (8U - shift); + PNG_CONST unsigned int max = (1U << (16U - shift))-1U; + PNG_CONST unsigned int max_by_2 = 1U << (15U-shift); + unsigned int i; + + png_uint_16pp table = *ptable = + (png_uint_16pp)png_calloc(png_ptr, num * png_sizeof(png_uint_16p)); + + for (i = 0; i < num; i++) + { + png_uint_16p sub_table = table[i] = + (png_uint_16p)png_malloc(png_ptr, 256 * png_sizeof(png_uint_16)); + + /* The 'threshold' test is repeated here because it can arise for one of + * the 16 bit tables even if the others don't hit it. + */ + if (png_gamma_significant(gamma_val)) + { + /* The old code would overflow at the end and this would cause the + * 'pow' function to return a result >1, resulting in an + * arithmetic error. This code follows the spec exactly; ig is + * the recovered input sample, it always has 8-16 bits. + * + * We want input * 65535/max, rounded, the arithmetic fits in 32 + * bits (unsigned) so long as max <= 32767. + */ + unsigned int j; + for (j = 0; j < 256; j++) + { + png_uint_32 ig = (j << (8-shift)) + i; +# ifdef PNG_FLOATING_ARITHMETIC_SUPPORTED + /* Inline the 'max' scaling operation: */ + double d = floor(65535*pow(ig/(double)max, gamma_val*.00001)+.5); + sub_table[j] = (png_uint_16)d; +# else + if (shift) + ig = (ig * 65535U + max_by_2)/max; + + sub_table[j] = png_gamma_16bit_correct(ig, gamma_val); +# endif + } + } + else + { + /* We must still build a table, but do it the fast way. */ + unsigned int j; + + for (j = 0; j < 256; j++) + { + png_uint_32 ig = (j << (8-shift)) + i; + + if (shift) + ig = (ig * 65535U + max_by_2)/max; + + sub_table[j] = (png_uint_16)ig; + } + } + } +} + +/* NOTE: this function expects the *inverse* of the overall gamma transformation + * required. + */ +static void +png_build_16to8_table(png_structp png_ptr, png_uint_16pp *ptable, + PNG_CONST unsigned int shift, PNG_CONST png_fixed_point gamma_val) +{ + PNG_CONST unsigned int num = 1U << (8U - shift); + PNG_CONST unsigned int max = (1U << (16U - shift))-1U; + unsigned int i; + png_uint_32 last; + + png_uint_16pp table = *ptable = + (png_uint_16pp)png_calloc(png_ptr, num * png_sizeof(png_uint_16p)); + + /* 'num' is the number of tables and also the number of low bits of low + * bits of the input 16 bit value used to select a table. Each table is + * itself index by the high 8 bits of the value. + */ + for (i = 0; i < num; i++) + table[i] = (png_uint_16p)png_malloc(png_ptr, + 256 * png_sizeof(png_uint_16)); + + /* 'gamma_val' is set to the reciprocal of the value calculated above, so + * pow(out,g) is an *input* value. 'last' is the last input value set. + * + * In the loop 'i' is used to find output values. Since the output is 8 + * bit there are only 256 possible values. The tables are set up to + * select the closest possible output value for each input by finding + * the input value at the boundary between each pair of output values + * and filling the table up to that boundary with the lower output + * value. + * + * The boundary values are 0.5,1.5..253.5,254.5. Since these are 9 bit + * values the code below uses a 16 bit value in i; the values start at + * 128.5 (for 0.5) and step by 257, for a total of 254 values (the last + * entries are filled with 255). Start i at 128 and fill all 'last' + * table entries <= 'max' + */ + last = 0; + for (i = 0; i < 255; ++i) /* 8 bit output value */ + { + /* Find the corresponding maximum input value */ + png_uint_16 out = (png_uint_16)(i * 257U); /* 16 bit output value */ + + /* Find the boundary value in 16 bits: */ + png_uint_32 bound = png_gamma_16bit_correct(out+128U, gamma_val); + + /* Adjust (round) to (16-shift) bits: */ + bound = (bound * max + 32768U)/65535U + 1U; + + while (last < bound) + { + table[last & (0xffU >> shift)][last >> (8U - shift)] = out; + last++; + } + } + + /* And fill in the final entries. */ + while (last < (num << 8)) + { + table[last & (0xff >> shift)][last >> (8U - shift)] = 65535U; + last++; + } +} + +/* Build a single 8 bit table: same as the 16 bit case but much simpler (and + * typically much faster). Note that libpng currently does no sBIT processing + * (apparently contrary to the spec) so a 256 entry table is always generated. + */ +static void +png_build_8bit_table(png_structp png_ptr, png_bytepp ptable, + PNG_CONST png_fixed_point gamma_val) +{ + unsigned int i; + png_bytep table = *ptable = (png_bytep)png_malloc(png_ptr, 256); + + if (png_gamma_significant(gamma_val)) for (i=0; i<256; i++) + table[i] = png_gamma_8bit_correct(i, gamma_val); + + else for (i=0; i<256; ++i) + table[i] = (png_byte)i; +} + +/* We build the 8- or 16-bit gamma tables here. Note that for 16-bit + * tables, we don't make a full table if we are reducing to 8-bit in + * the future. Note also how the gamma_16 tables are segmented so that + * we don't need to allocate > 64K chunks for a full 16-bit table. + */ +void /* PRIVATE */ +png_build_gamma_table(png_structp png_ptr, int bit_depth) +{ + png_debug(1, "in png_build_gamma_table"); + + if (bit_depth <= 8) + { + png_build_8bit_table(png_ptr, &png_ptr->gamma_table, + png_ptr->screen_gamma > 0 ? png_reciprocal2(png_ptr->gamma, + png_ptr->screen_gamma) : PNG_FP_1); + +#if defined(PNG_READ_BACKGROUND_SUPPORTED) || \ + defined(PNG_READ_RGB_TO_GRAY_SUPPORTED) + if (png_ptr->transformations & ((PNG_BACKGROUND) | PNG_RGB_TO_GRAY)) + { + png_build_8bit_table(png_ptr, &png_ptr->gamma_to_1, + png_reciprocal(png_ptr->gamma)); + + png_build_8bit_table(png_ptr, &png_ptr->gamma_from_1, + png_ptr->screen_gamma > 0 ? png_reciprocal(png_ptr->screen_gamma) : + png_ptr->gamma/* Probably doing rgb_to_gray */); + } +#endif /* PNG_READ_BACKGROUND_SUPPORTED || PNG_RGB_TO_GRAY_SUPPORTED */ + } + else + { + png_byte shift, sig_bit; + + if (png_ptr->color_type & PNG_COLOR_MASK_COLOR) + { + sig_bit = png_ptr->sig_bit.red; + + if (png_ptr->sig_bit.green > sig_bit) + sig_bit = png_ptr->sig_bit.green; + + if (png_ptr->sig_bit.blue > sig_bit) + sig_bit = png_ptr->sig_bit.blue; + } + else + sig_bit = png_ptr->sig_bit.gray; + + /* 16 bit gamma code uses this equation: + * + * ov = table[(iv & 0xff) >> gamma_shift][iv >> 8] + * + * Where 'iv' is the input color value and 'ov' is the output value - + * pow(iv, gamma). + * + * Thus the gamma table consists of up to 256 256 entry tables. The table + * is selected by the (8-gamma_shift) most significant of the low 8 bits of + * the color value then indexed by the upper 8 bits: + * + * table[low bits][high 8 bits] + * + * So the table 'n' corresponds to all those 'iv' of: + * + * <all high 8 bit values><n << gamma_shift>..<(n+1 << gamma_shift)-1> + * + */ + if (sig_bit > 0 && sig_bit < 16U) + shift = (png_byte)(16U - sig_bit); /* shift == insignificant bits */ + + else + shift = 0; /* keep all 16 bits */ + + if (png_ptr->transformations & PNG_16_TO_8) + { + /* PNG_MAX_GAMMA_8 is the number of bits to keep - effectively + * the significant bits in the *input* when the output will + * eventually be 8 bits. By default it is 11. + */ + if (shift < (16U - PNG_MAX_GAMMA_8)) + shift = (16U - PNG_MAX_GAMMA_8); + } + + if (shift > 8U) + shift = 8U; /* Guarantees at least one table! */ + + png_ptr->gamma_shift = shift; + +#ifdef PNG_16BIT_SUPPORTED + if (png_ptr->transformations & (PNG_16_TO_8 | PNG_BACKGROUND)) +#endif + png_build_16to8_table(png_ptr, &png_ptr->gamma_16_table, shift, + png_ptr->screen_gamma > 0 ? png_product2(png_ptr->gamma, + png_ptr->screen_gamma) : PNG_FP_1); + +#ifdef PNG_16BIT_SUPPORTED + else + png_build_16bit_table(png_ptr, &png_ptr->gamma_16_table, shift, + png_ptr->screen_gamma > 0 ? png_reciprocal2(png_ptr->gamma, + png_ptr->screen_gamma) : PNG_FP_1); +#endif + +#if defined(PNG_READ_BACKGROUND_SUPPORTED) || \ + defined(PNG_READ_RGB_TO_GRAY_SUPPORTED) + if (png_ptr->transformations & (PNG_BACKGROUND | PNG_RGB_TO_GRAY)) + { + png_build_16bit_table(png_ptr, &png_ptr->gamma_16_to_1, shift, + png_reciprocal(png_ptr->gamma)); + + /* Notice that the '16 from 1' table should be full precision, however + * the lookup on this table still uses gamma_shift, so it can't be. + * TODO: fix this. + */ + png_build_16bit_table(png_ptr, &png_ptr->gamma_16_from_1, shift, + png_ptr->screen_gamma > 0 ? png_reciprocal(png_ptr->screen_gamma) : + png_ptr->gamma/* Probably doing rgb_to_gray */); + } +#endif /* PNG_READ_BACKGROUND_SUPPORTED || PNG_RGB_TO_GRAY_SUPPORTED */ + } +} +#endif /* READ_GAMMA */ +#endif /* defined(PNG_READ_SUPPORTED) || defined(PNG_WRITE_SUPPORTED) */ diff --git a/src/3rdparty/libpng/png.h b/src/3rdparty/libpng/png.h new file mode 100644 index 0000000000..100f56dba2 --- /dev/null +++ b/src/3rdparty/libpng/png.h @@ -0,0 +1,2280 @@ + +/* png.h - header file for PNG reference library + * + * libpng version 1.5.1 - February 3, 2011 + * Copyright (c) 1998-2011 Glenn Randers-Pehrson + * (Version 0.96 Copyright (c) 1996, 1997 Andreas Dilger) + * (Version 0.88 Copyright (c) 1995, 1996 Guy Eric Schalnat, Group 42, Inc.) + * + * This code is released under the libpng license (See LICENSE, below) + * + * Authors and maintainers: + * libpng versions 0.71, May 1995, through 0.88, January 1996: Guy Schalnat + * libpng versions 0.89c, June 1996, through 0.96, May 1997: Andreas Dilger + * libpng versions 0.97, January 1998, through 1.5.1 - February 3, 2011: Glenn + * See also "Contributing Authors", below. + * + * Note about libpng version numbers: + * + * Due to various miscommunications, unforeseen code incompatibilities + * and occasional factors outside the authors' control, version numbering + * on the library has not always been consistent and straightforward. + * The following table summarizes matters since version 0.89c, which was + * the first widely used release: + * + * source png.h png.h shared-lib + * version string int version + * ------- ------ ----- ---------- + * 0.89c "1.0 beta 3" 0.89 89 1.0.89 + * 0.90 "1.0 beta 4" 0.90 90 0.90 [should have been 2.0.90] + * 0.95 "1.0 beta 5" 0.95 95 0.95 [should have been 2.0.95] + * 0.96 "1.0 beta 6" 0.96 96 0.96 [should have been 2.0.96] + * 0.97b "1.00.97 beta 7" 1.00.97 97 1.0.1 [should have been 2.0.97] + * 0.97c 0.97 97 2.0.97 + * 0.98 0.98 98 2.0.98 + * 0.99 0.99 98 2.0.99 + * 0.99a-m 0.99 99 2.0.99 + * 1.00 1.00 100 2.1.0 [100 should be 10000] + * 1.0.0 (from here on, the 100 2.1.0 [100 should be 10000] + * 1.0.1 png.h string is 10001 2.1.0 + * 1.0.1a-e identical to the 10002 from here on, the shared library + * 1.0.2 source version) 10002 is 2.V where V is the source code + * 1.0.2a-b 10003 version, except as noted. + * 1.0.3 10003 + * 1.0.3a-d 10004 + * 1.0.4 10004 + * 1.0.4a-f 10005 + * 1.0.5 (+ 2 patches) 10005 + * 1.0.5a-d 10006 + * 1.0.5e-r 10100 (not source compatible) + * 1.0.5s-v 10006 (not binary compatible) + * 1.0.6 (+ 3 patches) 10006 (still binary incompatible) + * 1.0.6d-f 10007 (still binary incompatible) + * 1.0.6g 10007 + * 1.0.6h 10007 10.6h (testing xy.z so-numbering) + * 1.0.6i 10007 10.6i + * 1.0.6j 10007 2.1.0.6j (incompatible with 1.0.0) + * 1.0.7beta11-14 DLLNUM 10007 2.1.0.7beta11-14 (binary compatible) + * 1.0.7beta15-18 1 10007 2.1.0.7beta15-18 (binary compatible) + * 1.0.7rc1-2 1 10007 2.1.0.7rc1-2 (binary compatible) + * 1.0.7 1 10007 (still compatible) + * 1.0.8beta1-4 1 10008 2.1.0.8beta1-4 + * 1.0.8rc1 1 10008 2.1.0.8rc1 + * 1.0.8 1 10008 2.1.0.8 + * 1.0.9beta1-6 1 10009 2.1.0.9beta1-6 + * 1.0.9rc1 1 10009 2.1.0.9rc1 + * 1.0.9beta7-10 1 10009 2.1.0.9beta7-10 + * 1.0.9rc2 1 10009 2.1.0.9rc2 + * 1.0.9 1 10009 2.1.0.9 + * 1.0.10beta1 1 10010 2.1.0.10beta1 + * 1.0.10rc1 1 10010 2.1.0.10rc1 + * 1.0.10 1 10010 2.1.0.10 + * 1.0.11beta1-3 1 10011 2.1.0.11beta1-3 + * 1.0.11rc1 1 10011 2.1.0.11rc1 + * 1.0.11 1 10011 2.1.0.11 + * 1.0.12beta1-2 2 10012 2.1.0.12beta1-2 + * 1.0.12rc1 2 10012 2.1.0.12rc1 + * 1.0.12 2 10012 2.1.0.12 + * 1.1.0a-f - 10100 2.1.1.0a-f (branch abandoned) + * 1.2.0beta1-2 2 10200 2.1.2.0beta1-2 + * 1.2.0beta3-5 3 10200 3.1.2.0beta3-5 + * 1.2.0rc1 3 10200 3.1.2.0rc1 + * 1.2.0 3 10200 3.1.2.0 + * 1.2.1beta1-4 3 10201 3.1.2.1beta1-4 + * 1.2.1rc1-2 3 10201 3.1.2.1rc1-2 + * 1.2.1 3 10201 3.1.2.1 + * 1.2.2beta1-6 12 10202 12.so.0.1.2.2beta1-6 + * 1.0.13beta1 10 10013 10.so.0.1.0.13beta1 + * 1.0.13rc1 10 10013 10.so.0.1.0.13rc1 + * 1.2.2rc1 12 10202 12.so.0.1.2.2rc1 + * 1.0.13 10 10013 10.so.0.1.0.13 + * 1.2.2 12 10202 12.so.0.1.2.2 + * 1.2.3rc1-6 12 10203 12.so.0.1.2.3rc1-6 + * 1.2.3 12 10203 12.so.0.1.2.3 + * 1.2.4beta1-3 13 10204 12.so.0.1.2.4beta1-3 + * 1.0.14rc1 13 10014 10.so.0.1.0.14rc1 + * 1.2.4rc1 13 10204 12.so.0.1.2.4rc1 + * 1.0.14 10 10014 10.so.0.1.0.14 + * 1.2.4 13 10204 12.so.0.1.2.4 + * 1.2.5beta1-2 13 10205 12.so.0.1.2.5beta1-2 + * 1.0.15rc1-3 10 10015 10.so.0.1.0.15rc1-3 + * 1.2.5rc1-3 13 10205 12.so.0.1.2.5rc1-3 + * 1.0.15 10 10015 10.so.0.1.0.15 + * 1.2.5 13 10205 12.so.0.1.2.5 + * 1.2.6beta1-4 13 10206 12.so.0.1.2.6beta1-4 + * 1.0.16 10 10016 10.so.0.1.0.16 + * 1.2.6 13 10206 12.so.0.1.2.6 + * 1.2.7beta1-2 13 10207 12.so.0.1.2.7beta1-2 + * 1.0.17rc1 10 10017 12.so.0.1.0.17rc1 + * 1.2.7rc1 13 10207 12.so.0.1.2.7rc1 + * 1.0.17 10 10017 12.so.0.1.0.17 + * 1.2.7 13 10207 12.so.0.1.2.7 + * 1.2.8beta1-5 13 10208 12.so.0.1.2.8beta1-5 + * 1.0.18rc1-5 10 10018 12.so.0.1.0.18rc1-5 + * 1.2.8rc1-5 13 10208 12.so.0.1.2.8rc1-5 + * 1.0.18 10 10018 12.so.0.1.0.18 + * 1.2.8 13 10208 12.so.0.1.2.8 + * 1.2.9beta1-3 13 10209 12.so.0.1.2.9beta1-3 + * 1.2.9beta4-11 13 10209 12.so.0.9[.0] + * 1.2.9rc1 13 10209 12.so.0.9[.0] + * 1.2.9 13 10209 12.so.0.9[.0] + * 1.2.10beta1-7 13 10210 12.so.0.10[.0] + * 1.2.10rc1-2 13 10210 12.so.0.10[.0] + * 1.2.10 13 10210 12.so.0.10[.0] + * 1.4.0beta1-5 14 10400 14.so.0.0[.0] + * 1.2.11beta1-4 13 10211 12.so.0.11[.0] + * 1.4.0beta7-8 14 10400 14.so.0.0[.0] + * 1.2.11 13 10211 12.so.0.11[.0] + * 1.2.12 13 10212 12.so.0.12[.0] + * 1.4.0beta9-14 14 10400 14.so.0.0[.0] + * 1.2.13 13 10213 12.so.0.13[.0] + * 1.4.0beta15-36 14 10400 14.so.0.0[.0] + * 1.4.0beta37-87 14 10400 14.so.14.0[.0] + * 1.4.0rc01 14 10400 14.so.14.0[.0] + * 1.4.0beta88-109 14 10400 14.so.14.0[.0] + * 1.4.0rc02-08 14 10400 14.so.14.0[.0] + * 1.4.0 14 10400 14.so.14.0[.0] + * 1.4.1beta01-03 14 10401 14.so.14.1[.0] + * 1.4.1rc01 14 10401 14.so.14.1[.0] + * 1.4.1beta04-12 14 10401 14.so.14.1[.0] + * 1.4.1 14 10401 14.so.14.1[.0] + * 1.4.2 14 10402 14.so.14.2[.0] + * 1.4.3 14 10403 14.so.14.3[.0] + * 1.4.4 14 10404 14.so.14.4[.0] + * 1.5.0beta01-58 15 10500 15.so.15.0[.0] + * 1.5.0rc01-07 15 10500 15.so.15.0[.0] + * 1.5.0 15 10500 15.so.15.0[.0] + * 1.5.1beta01-11 15 10501 15.so.15.1[.0] + * 1.5.1rc01-02 15 10501 15.so.15.1[.0] + * 1.5.1 15 10501 15.so.15.1[.0] + * + * Henceforth the source version will match the shared-library major + * and minor numbers; the shared-library major version number will be + * used for changes in backward compatibility, as it is intended. The + * PNG_LIBPNG_VER macro, which is not used within libpng but is available + * for applications, is an unsigned integer of the form xyyzz corresponding + * to the source version x.y.z (leading zeros in y and z). Beta versions + * were given the previous public release number plus a letter, until + * version 1.0.6j; from then on they were given the upcoming public + * release number plus "betaNN" or "rcN". + * + * Binary incompatibility exists only when applications make direct access + * to the info_ptr or png_ptr members through png.h, and the compiled + * application is loaded with a different version of the library. + * + * DLLNUM will change each time there are forward or backward changes + * in binary compatibility (e.g., when a new feature is added). + * + * See libpng-manual.txt or libpng.3 for more information. The PNG + * specification is available as a W3C Recommendation and as an ISO + * Specification, <http://www.w3.org/TR/2003/REC-PNG-20031110/ + */ + +/* + * COPYRIGHT NOTICE, DISCLAIMER, and LICENSE: + * + * If you modify libpng you may insert additional notices immediately following + * this sentence. + * + * This code is released under the libpng license. + * + * libpng versions 1.2.6, August 15, 2004, through 1.5.1, February 3, 2011, are + * Copyright (c) 2004, 2006-2011 Glenn Randers-Pehrson, and are + * distributed according to the same disclaimer and license as libpng-1.2.5 + * with the following individual added to the list of Contributing Authors: + * + * Cosmin Truta + * + * libpng versions 1.0.7, July 1, 2000, through 1.2.5, October 3, 2002, are + * Copyright (c) 2000-2002 Glenn Randers-Pehrson, and are + * distributed according to the same disclaimer and license as libpng-1.0.6 + * with the following individuals added to the list of Contributing Authors: + * + * Simon-Pierre Cadieux + * Eric S. Raymond + * Gilles Vollant + * + * and with the following additions to the disclaimer: + * + * There is no warranty against interference with your enjoyment of the + * library or against infringement. There is no warranty that our + * efforts or the library will fulfill any of your particular purposes + * or needs. This library is provided with all faults, and the entire + * risk of satisfactory quality, performance, accuracy, and effort is with + * the user. + * + * libpng versions 0.97, January 1998, through 1.0.6, March 20, 2000, are + * Copyright (c) 1998, 1999, 2000 Glenn Randers-Pehrson, and are + * distributed according to the same disclaimer and license as libpng-0.96, + * with the following individuals added to the list of Contributing Authors: + * + * Tom Lane + * Glenn Randers-Pehrson + * Willem van Schaik + * + * libpng versions 0.89, June 1996, through 0.96, May 1997, are + * Copyright (c) 1996, 1997 Andreas Dilger + * Distributed according to the same disclaimer and license as libpng-0.88, + * with the following individuals added to the list of Contributing Authors: + * + * John Bowler + * Kevin Bracey + * Sam Bushell + * Magnus Holmgren + * Greg Roelofs + * Tom Tanner + * + * libpng versions 0.5, May 1995, through 0.88, January 1996, are + * Copyright (c) 1995, 1996 Guy Eric Schalnat, Group 42, Inc. + * + * For the purposes of this copyright and license, "Contributing Authors" + * is defined as the following set of individuals: + * + * Andreas Dilger + * Dave Martindale + * Guy Eric Schalnat + * Paul Schmidt + * Tim Wegner + * + * The PNG Reference Library is supplied "AS IS". The Contributing Authors + * and Group 42, Inc. disclaim all warranties, expressed or implied, + * including, without limitation, the warranties of merchantability and of + * fitness for any purpose. The Contributing Authors and Group 42, Inc. + * assume no liability for direct, indirect, incidental, special, exemplary, + * or consequential damages, which may result from the use of the PNG + * Reference Library, even if advised of the possibility of such damage. + * + * Permission is hereby granted to use, copy, modify, and distribute this + * source code, or portions hereof, for any purpose, without fee, subject + * to the following restrictions: + * + * 1. The origin of this source code must not be misrepresented. + * + * 2. Altered versions must be plainly marked as such and must not + * be misrepresented as being the original source. + * + * 3. This Copyright notice may not be removed or altered from + * any source or altered source distribution. + * + * The Contributing Authors and Group 42, Inc. specifically permit, without + * fee, and encourage the use of this source code as a component to + * supporting the PNG file format in commercial products. If you use this + * source code in a product, acknowledgment is not required but would be + * appreciated. + */ + +/* + * A "png_get_copyright" function is available, for convenient use in "about" + * boxes and the like: + * + * printf("%s", png_get_copyright(NULL)); + * + * Also, the PNG logo (in PNG format, of course) is supplied in the + * files "pngbar.png" and "pngbar.jpg (88x31) and "pngnow.png" (98x31). + */ + +/* + * Libpng is OSI Certified Open Source Software. OSI Certified is a + * certification mark of the Open Source Initiative. + */ + +/* + * The contributing authors would like to thank all those who helped + * with testing, bug fixes, and patience. This wouldn't have been + * possible without all of you. + * + * Thanks to Frank J. T. Wojcik for helping with the documentation. + */ + +/* + * Y2K compliance in libpng: + * ========================= + * + * February 3, 2011 + * + * Since the PNG Development group is an ad-hoc body, we can't make + * an official declaration. + * + * This is your unofficial assurance that libpng from version 0.71 and + * upward through 1.5.1 are Y2K compliant. It is my belief that + * earlier versions were also Y2K compliant. + * + * Libpng only has three year fields. One is a 2-byte unsigned integer + * that will hold years up to 65535. The other two hold the date in text + * format, and will hold years up to 9999. + * + * The integer is + * "png_uint_16 year" in png_time_struct. + * + * The strings are + * "png_charp time_buffer" in png_struct and + * "near_time_buffer", which is a local character string in png.c. + * + * There are seven time-related functions: + * png.c: png_convert_to_rfc_1123() in png.c + * (formerly png_convert_to_rfc_1152() in error) + * png_convert_from_struct_tm() in pngwrite.c, called in pngwrite.c + * png_convert_from_time_t() in pngwrite.c + * png_get_tIME() in pngget.c + * png_handle_tIME() in pngrutil.c, called in pngread.c + * png_set_tIME() in pngset.c + * png_write_tIME() in pngwutil.c, called in pngwrite.c + * + * All handle dates properly in a Y2K environment. The + * png_convert_from_time_t() function calls gmtime() to convert from system + * clock time, which returns (year - 1900), which we properly convert to + * the full 4-digit year. There is a possibility that applications using + * libpng are not passing 4-digit years into the png_convert_to_rfc_1123() + * function, or that they are incorrectly passing only a 2-digit year + * instead of "year - 1900" into the png_convert_from_struct_tm() function, + * but this is not under our control. The libpng documentation has always + * stated that it works with 4-digit years, and the APIs have been + * documented as such. + * + * The tIME chunk itself is also Y2K compliant. It uses a 2-byte unsigned + * integer to hold the year, and can hold years as large as 65535. + * + * zlib, upon which libpng depends, is also Y2K compliant. It contains + * no date-related code. + * + * Glenn Randers-Pehrson + * libpng maintainer + * PNG Development Group + */ + +#ifndef PNG_H +#define PNG_H + +/* This is not the place to learn how to use libpng. The file libpng-manual.txt + * describes how to use libpng, and the file example.c summarizes it + * with some code on which to build. This file is useful for looking + * at the actual function definitions and structure components. + */ + +/* Version information for png.h - this should match the version in png.c */ +#define PNG_LIBPNG_VER_STRING "1.5.1" +#define PNG_HEADER_VERSION_STRING \ + " libpng version 1.5.1 - February 3, 2011\n" + +#define PNG_LIBPNG_VER_SONUM 15 +#define PNG_LIBPNG_VER_DLLNUM 15 + +/* These should match the first 3 components of PNG_LIBPNG_VER_STRING: */ +#define PNG_LIBPNG_VER_MAJOR 1 +#define PNG_LIBPNG_VER_MINOR 5 +#define PNG_LIBPNG_VER_RELEASE 1 +/* This should match the numeric part of the final component of + * PNG_LIBPNG_VER_STRING, omitting any leading zero: + */ + +#define PNG_LIBPNG_VER_BUILD 0 + +/* Release Status */ +#define PNG_LIBPNG_BUILD_ALPHA 1 +#define PNG_LIBPNG_BUILD_BETA 2 +#define PNG_LIBPNG_BUILD_RC 3 +#define PNG_LIBPNG_BUILD_STABLE 4 +#define PNG_LIBPNG_BUILD_RELEASE_STATUS_MASK 7 + +/* Release-Specific Flags */ +#define PNG_LIBPNG_BUILD_PATCH 8 /* Can be OR'ed with + PNG_LIBPNG_BUILD_STABLE only */ +#define PNG_LIBPNG_BUILD_PRIVATE 16 /* Cannot be OR'ed with + PNG_LIBPNG_BUILD_SPECIAL */ +#define PNG_LIBPNG_BUILD_SPECIAL 32 /* Cannot be OR'ed with + PNG_LIBPNG_BUILD_PRIVATE */ + +#define PNG_LIBPNG_BUILD_BASE_TYPE PNG_LIBPNG_BUILD_BETA + +/* Careful here. At one time, Guy wanted to use 082, but that would be octal. + * We must not include leading zeros. + * Versions 0.7 through 1.0.0 were in the range 0 to 100 here (only + * version 1.0.0 was mis-numbered 100 instead of 10000). From + * version 1.0.1 it's xxyyzz, where x=major, y=minor, z=release + */ +#define PNG_LIBPNG_VER 10501 /* 1.5.1 */ + +/* Library configuration: these options cannot be changed after + * the library has been built. + */ +#ifndef PNGLCONF_H + /* If pnglibconf.h is missing, you can + * copy scripts/pnglibconf.h.prebuilt to pnglibconf.h + */ +# include "pnglibconf.h" +#endif + +#ifndef PNG_VERSION_INFO_ONLY +/* Standard header files (not needed for the version info) */ +# ifdef PNG_SETJMP_SUPPORTED +# include <setjmp.h> +# endif + +/* Need the time information for converting tIME chunks, it + * defines struct tm: + */ +#ifdef PNG_CONVERT_tIME_SUPPORTED + /* "time.h" functions are not supported on all operating systems */ +# include <time.h> +#endif + +/* Machine specific configuration. */ +# include "pngconf.h" +#endif + +/* + * Added at libpng-1.2.8 + * + * Ref MSDN: Private as priority over Special + * VS_FF_PRIVATEBUILD File *was not* built using standard release + * procedures. If this value is given, the StringFileInfo block must + * contain a PrivateBuild string. + * + * VS_FF_SPECIALBUILD File *was* built by the original company using + * standard release procedures but is a variation of the standard + * file of the same version number. If this value is given, the + * StringFileInfo block must contain a SpecialBuild string. + */ + +#ifdef PNG_USER_PRIVATEBUILD /* From pnglibconf.h */ +# define PNG_LIBPNG_BUILD_TYPE \ + (PNG_LIBPNG_BUILD_BASE_TYPE | PNG_LIBPNG_BUILD_PRIVATE) +#else +# ifdef PNG_LIBPNG_SPECIALBUILD +# define PNG_LIBPNG_BUILD_TYPE \ + (PNG_LIBPNG_BUILD_BASE_TYPE | PNG_LIBPNG_BUILD_SPECIAL) +# else +# define PNG_LIBPNG_BUILD_TYPE (PNG_LIBPNG_BUILD_BASE_TYPE) +# endif +#endif + +#ifndef PNG_VERSION_INFO_ONLY + +/* Inhibit C++ name-mangling for libpng functions but not for system calls. */ +#ifdef __cplusplus +extern "C" { +#endif /* __cplusplus */ + +/* Version information for C files, stored in png.c. This had better match + * the version above. + */ +#define png_libpng_ver png_get_header_ver(NULL) + +/* This file is arranged in several sections: + * + * 1. Any configuration options that can be specified by for the application + * code when it is built. (Build time configuration is in pnglibconf.h) + * 2. Type definitions (base types are defined in pngconf.h), structure + * definitions. + * 3. Exported library functions. + * + * The library source code has additional files (principally pngpriv.h) that + * allow configuration of the library. + */ +/* Section 1: run time configuration + * See pnglibconf.h for build time configuration + * + * Run time configuration allows the application to choose between + * implementations of certain arithmetic APIs. The default is set + * at build time and recorded in pnglibconf.h, but it is safe to + * override these (and only these) settings. Note that this won't + * change what the library does, only application code, and the + * settings can (and probably should) be made on a per-file basis + * by setting the #defines before including png.h + * + * Use macros to read integers from PNG data or use the exported + * functions? + * PNG_USE_READ_MACROS: use the macros (see below) Note that + * the macros evaluate their argument multiple times. + * PNG_NO_USE_READ_MACROS: call the relevant library function. + * + * Use the alternative algorithm for compositing alpha samples that + * does not use division? + * PNG_READ_COMPOSITE_NODIV_SUPPORTED: use the 'no division' + * algorithm. + * PNG_NO_READ_COMPOSITE_NODIV: use the 'division' algorithm. + * + * How to handle benign errors if PNG_ALLOW_BENIGN_ERRORS is + * false? + * PNG_ALLOW_BENIGN_ERRORS: map calls to the benign error + * APIs to png_warning. + * Otherwise the calls are mapped to png_error. + */ + +/* Section 2: type definitions, including structures and compile time + * constants. + * See pngconf.h for base types that vary by machine/system + */ + +/* This triggers a compiler error in png.c, if png.c and png.h + * do not agree upon the version number. + */ +typedef char* png_libpng_version_1_5_1; + +/* Three color definitions. The order of the red, green, and blue, (and the + * exact size) is not important, although the size of the fields need to + * be png_byte or png_uint_16 (as defined below). + */ +typedef struct png_color_struct +{ + png_byte red; + png_byte green; + png_byte blue; +} png_color; +typedef png_color FAR * png_colorp; +typedef PNG_CONST png_color FAR * png_const_colorp; +typedef png_color FAR * FAR * png_colorpp; + +typedef struct png_color_16_struct +{ + png_byte index; /* used for palette files */ + png_uint_16 red; /* for use in red green blue files */ + png_uint_16 green; + png_uint_16 blue; + png_uint_16 gray; /* for use in grayscale files */ +} png_color_16; +typedef png_color_16 FAR * png_color_16p; +typedef PNG_CONST png_color_16 FAR * png_const_color_16p; +typedef png_color_16 FAR * FAR * png_color_16pp; + +typedef struct png_color_8_struct +{ + png_byte red; /* for use in red green blue files */ + png_byte green; + png_byte blue; + png_byte gray; /* for use in grayscale files */ + png_byte alpha; /* for alpha channel files */ +} png_color_8; +typedef png_color_8 FAR * png_color_8p; +typedef PNG_CONST png_color_8 FAR * png_const_color_8p; +typedef png_color_8 FAR * FAR * png_color_8pp; + +/* + * The following two structures are used for the in-core representation + * of sPLT chunks. + */ +typedef struct png_sPLT_entry_struct +{ + png_uint_16 red; + png_uint_16 green; + png_uint_16 blue; + png_uint_16 alpha; + png_uint_16 frequency; +} png_sPLT_entry; +typedef png_sPLT_entry FAR * png_sPLT_entryp; +typedef PNG_CONST png_sPLT_entry FAR * png_const_sPLT_entryp; +typedef png_sPLT_entry FAR * FAR * png_sPLT_entrypp; + +/* When the depth of the sPLT palette is 8 bits, the color and alpha samples + * occupy the LSB of their respective members, and the MSB of each member + * is zero-filled. The frequency member always occupies the full 16 bits. + */ + +typedef struct png_sPLT_struct +{ + png_charp name; /* palette name */ + png_byte depth; /* depth of palette samples */ + png_sPLT_entryp entries; /* palette entries */ + png_int_32 nentries; /* number of palette entries */ +} png_sPLT_t; +typedef png_sPLT_t FAR * png_sPLT_tp; +typedef PNG_CONST png_sPLT_t FAR * png_const_sPLT_tp; +typedef png_sPLT_t FAR * FAR * png_sPLT_tpp; + +#ifdef PNG_TEXT_SUPPORTED +/* png_text holds the contents of a text/ztxt/itxt chunk in a PNG file, + * and whether that contents is compressed or not. The "key" field + * points to a regular zero-terminated C string. The "text", "lang", and + * "lang_key" fields can be regular C strings, empty strings, or NULL pointers. + * However, the * structure returned by png_get_text() will always contain + * regular zero-terminated C strings (possibly empty), never NULL pointers, + * so they can be safely used in printf() and other string-handling functions. + */ +typedef struct png_text_struct +{ + int compression; /* compression value: + -1: tEXt, none + 0: zTXt, deflate + 1: iTXt, none + 2: iTXt, deflate */ + png_charp key; /* keyword, 1-79 character description of "text" */ + png_charp text; /* comment, may be an empty string (ie "") + or a NULL pointer */ + png_size_t text_length; /* length of the text string */ + png_size_t itxt_length; /* length of the itxt string */ + png_charp lang; /* language code, 0-79 characters + or a NULL pointer */ + png_charp lang_key; /* keyword translated UTF-8 string, 0 or more + chars or a NULL pointer */ +} png_text; +typedef png_text FAR * png_textp; +typedef PNG_CONST png_text FAR * png_const_textp; +typedef png_text FAR * FAR * png_textpp; +#endif + +/* Supported compression types for text in PNG files (tEXt, and zTXt). + * The values of the PNG_TEXT_COMPRESSION_ defines should NOT be changed. */ +#define PNG_TEXT_COMPRESSION_NONE_WR -3 +#define PNG_TEXT_COMPRESSION_zTXt_WR -2 +#define PNG_TEXT_COMPRESSION_NONE -1 +#define PNG_TEXT_COMPRESSION_zTXt 0 +#define PNG_ITXT_COMPRESSION_NONE 1 +#define PNG_ITXT_COMPRESSION_zTXt 2 +#define PNG_TEXT_COMPRESSION_LAST 3 /* Not a valid value */ + +/* png_time is a way to hold the time in an machine independent way. + * Two conversions are provided, both from time_t and struct tm. There + * is no portable way to convert to either of these structures, as far + * as I know. If you know of a portable way, send it to me. As a side + * note - PNG has always been Year 2000 compliant! + */ +typedef struct png_time_struct +{ + png_uint_16 year; /* full year, as in, 1995 */ + png_byte month; /* month of year, 1 - 12 */ + png_byte day; /* day of month, 1 - 31 */ + png_byte hour; /* hour of day, 0 - 23 */ + png_byte minute; /* minute of hour, 0 - 59 */ + png_byte second; /* second of minute, 0 - 60 (for leap seconds) */ +} png_time; +typedef png_time FAR * png_timep; +typedef PNG_CONST png_time FAR * png_const_timep; +typedef png_time FAR * FAR * png_timepp; + +#if defined(PNG_UNKNOWN_CHUNKS_SUPPORTED) || \ + defined(PNG_HANDLE_AS_UNKNOWN_SUPPORTED) +/* png_unknown_chunk is a structure to hold queued chunks for which there is + * no specific support. The idea is that we can use this to queue + * up private chunks for output even though the library doesn't actually + * know about their semantics. + */ +typedef struct png_unknown_chunk_t +{ + png_byte name[5]; + png_byte *data; + png_size_t size; + + /* libpng-using applications should NOT directly modify this byte. */ + png_byte location; /* mode of operation at read time */ +} +png_unknown_chunk; +typedef png_unknown_chunk FAR * png_unknown_chunkp; +typedef PNG_CONST png_unknown_chunk FAR * png_const_unknown_chunkp; +typedef png_unknown_chunk FAR * FAR * png_unknown_chunkpp; +#endif + +typedef struct png_info_def png_info; +typedef png_info FAR * png_infop; +typedef PNG_CONST png_info FAR * png_const_infop; +typedef png_info FAR * FAR * png_infopp; + +/* Maximum positive integer used in PNG is (2^31)-1 */ +#define PNG_UINT_31_MAX ((png_uint_32)0x7fffffffL) +#define PNG_UINT_32_MAX ((png_uint_32)(-1)) +#define PNG_SIZE_MAX ((png_size_t)(-1)) + +/* These are constants for fixed point values encoded in the + * PNG specification manner (x100000) + */ +#define PNG_FP_1 100000 +#define PNG_FP_HALF 50000 + +/* These describe the color_type field in png_info. */ +/* color type masks */ +#define PNG_COLOR_MASK_PALETTE 1 +#define PNG_COLOR_MASK_COLOR 2 +#define PNG_COLOR_MASK_ALPHA 4 + +/* color types. Note that not all combinations are legal */ +#define PNG_COLOR_TYPE_GRAY 0 +#define PNG_COLOR_TYPE_PALETTE (PNG_COLOR_MASK_COLOR | PNG_COLOR_MASK_PALETTE) +#define PNG_COLOR_TYPE_RGB (PNG_COLOR_MASK_COLOR) +#define PNG_COLOR_TYPE_RGB_ALPHA (PNG_COLOR_MASK_COLOR | PNG_COLOR_MASK_ALPHA) +#define PNG_COLOR_TYPE_GRAY_ALPHA (PNG_COLOR_MASK_ALPHA) +/* aliases */ +#define PNG_COLOR_TYPE_RGBA PNG_COLOR_TYPE_RGB_ALPHA +#define PNG_COLOR_TYPE_GA PNG_COLOR_TYPE_GRAY_ALPHA + +/* This is for compression type. PNG 1.0-1.2 only define the single type. */ +#define PNG_COMPRESSION_TYPE_BASE 0 /* Deflate method 8, 32K window */ +#define PNG_COMPRESSION_TYPE_DEFAULT PNG_COMPRESSION_TYPE_BASE + +/* This is for filter type. PNG 1.0-1.2 only define the single type. */ +#define PNG_FILTER_TYPE_BASE 0 /* Single row per-byte filtering */ +#define PNG_INTRAPIXEL_DIFFERENCING 64 /* Used only in MNG datastreams */ +#define PNG_FILTER_TYPE_DEFAULT PNG_FILTER_TYPE_BASE + +/* These are for the interlacing type. These values should NOT be changed. */ +#define PNG_INTERLACE_NONE 0 /* Non-interlaced image */ +#define PNG_INTERLACE_ADAM7 1 /* Adam7 interlacing */ +#define PNG_INTERLACE_LAST 2 /* Not a valid value */ + +/* These are for the oFFs chunk. These values should NOT be changed. */ +#define PNG_OFFSET_PIXEL 0 /* Offset in pixels */ +#define PNG_OFFSET_MICROMETER 1 /* Offset in micrometers (1/10^6 meter) */ +#define PNG_OFFSET_LAST 2 /* Not a valid value */ + +/* These are for the pCAL chunk. These values should NOT be changed. */ +#define PNG_EQUATION_LINEAR 0 /* Linear transformation */ +#define PNG_EQUATION_BASE_E 1 /* Exponential base e transform */ +#define PNG_EQUATION_ARBITRARY 2 /* Arbitrary base exponential transform */ +#define PNG_EQUATION_HYPERBOLIC 3 /* Hyperbolic sine transformation */ +#define PNG_EQUATION_LAST 4 /* Not a valid value */ + +/* These are for the sCAL chunk. These values should NOT be changed. */ +#define PNG_SCALE_UNKNOWN 0 /* unknown unit (image scale) */ +#define PNG_SCALE_METER 1 /* meters per pixel */ +#define PNG_SCALE_RADIAN 2 /* radians per pixel */ +#define PNG_SCALE_LAST 3 /* Not a valid value */ + +/* These are for the pHYs chunk. These values should NOT be changed. */ +#define PNG_RESOLUTION_UNKNOWN 0 /* pixels/unknown unit (aspect ratio) */ +#define PNG_RESOLUTION_METER 1 /* pixels/meter */ +#define PNG_RESOLUTION_LAST 2 /* Not a valid value */ + +/* These are for the sRGB chunk. These values should NOT be changed. */ +#define PNG_sRGB_INTENT_PERCEPTUAL 0 +#define PNG_sRGB_INTENT_RELATIVE 1 +#define PNG_sRGB_INTENT_SATURATION 2 +#define PNG_sRGB_INTENT_ABSOLUTE 3 +#define PNG_sRGB_INTENT_LAST 4 /* Not a valid value */ + +/* This is for text chunks */ +#define PNG_KEYWORD_MAX_LENGTH 79 + +/* Maximum number of entries in PLTE/sPLT/tRNS arrays */ +#define PNG_MAX_PALETTE_LENGTH 256 + +/* These determine if an ancillary chunk's data has been successfully read + * from the PNG header, or if the application has filled in the corresponding + * data in the info_struct to be written into the output file. The values + * of the PNG_INFO_<chunk> defines should NOT be changed. + */ +#define PNG_INFO_gAMA 0x0001 +#define PNG_INFO_sBIT 0x0002 +#define PNG_INFO_cHRM 0x0004 +#define PNG_INFO_PLTE 0x0008 +#define PNG_INFO_tRNS 0x0010 +#define PNG_INFO_bKGD 0x0020 +#define PNG_INFO_hIST 0x0040 +#define PNG_INFO_pHYs 0x0080 +#define PNG_INFO_oFFs 0x0100 +#define PNG_INFO_tIME 0x0200 +#define PNG_INFO_pCAL 0x0400 +#define PNG_INFO_sRGB 0x0800 /* GR-P, 0.96a */ +#define PNG_INFO_iCCP 0x1000 /* ESR, 1.0.6 */ +#define PNG_INFO_sPLT 0x2000 /* ESR, 1.0.6 */ +#define PNG_INFO_sCAL 0x4000 /* ESR, 1.0.6 */ +#define PNG_INFO_IDAT 0x8000L /* ESR, 1.0.6 */ + +/* This is used for the transformation routines, as some of them + * change these values for the row. It also should enable using + * the routines for other purposes. + */ +typedef struct png_row_info_struct +{ + png_uint_32 width; /* width of row */ + png_size_t rowbytes; /* number of bytes in row */ + png_byte color_type; /* color type of row */ + png_byte bit_depth; /* bit depth of row */ + png_byte channels; /* number of channels (1, 2, 3, or 4) */ + png_byte pixel_depth; /* bits per pixel (depth * channels) */ +} png_row_info; + +typedef png_row_info FAR * png_row_infop; +typedef png_row_info FAR * FAR * png_row_infopp; + +/* These are the function types for the I/O functions and for the functions + * that allow the user to override the default I/O functions with his or her + * own. The png_error_ptr type should match that of user-supplied warning + * and error functions, while the png_rw_ptr type should match that of the + * user read/write data functions. Note that the 'write' function must not + * modify the buffer it is passed. The 'read' function, on the other hand, is + * expected to return the read data in the buffer. + */ +typedef struct png_struct_def png_struct; +typedef PNG_CONST png_struct FAR * png_const_structp; +typedef png_struct FAR * png_structp; + +typedef PNG_CALLBACK(void, *png_error_ptr, (png_structp, png_const_charp), ); +typedef PNG_CALLBACK(void, *png_rw_ptr, (png_structp, png_bytep, png_size_t), ); +typedef PNG_CALLBACK(void, *png_flush_ptr, (png_structp), ); +typedef PNG_CALLBACK(void, *png_read_status_ptr, (png_structp, png_uint_32, + int), ); +typedef PNG_CALLBACK(void, *png_write_status_ptr, (png_structp, png_uint_32, + int), ); + +#ifdef PNG_PROGRESSIVE_READ_SUPPORTED +typedef PNG_CALLBACK(void, *png_progressive_info_ptr, + (png_structp, png_infop), ); +typedef PNG_CALLBACK(void, *png_progressive_end_ptr, + (png_structp, png_infop), ); +typedef PNG_CALLBACK(void, *png_progressive_row_ptr, + (png_structp, png_bytep, png_uint_32, int), ); +#endif + +#if defined(PNG_READ_USER_TRANSFORM_SUPPORTED) || \ + defined(PNG_WRITE_USER_TRANSFORM_SUPPORTED) +typedef PNG_CALLBACK(void, *png_user_transform_ptr, + (png_structp, png_row_infop, png_bytep), ); +#endif + +#ifdef PNG_USER_CHUNKS_SUPPORTED +typedef PNG_CALLBACK(int, *png_user_chunk_ptr, (png_structp, + png_unknown_chunkp), ); +#endif +#ifdef PNG_UNKNOWN_CHUNKS_SUPPORTED +typedef PNG_CALLBACK(void, *png_unknown_chunk_ptr, (png_structp), ); +#endif + +#ifdef PNG_SETJMP_SUPPORTED +/* This must match the function definition in <setjmp.h>, and the + * application must include this before png.h to obtain the definition + * of jmp_buf. The function is required to be PNG_NORETURN. (Note that + * PNG_PTR_NORETURN is used here because current versions of the Microsoft + * C compiler do not support the PNG_NORETURN attribute on a pointer.) + * + * If you get a type warning from the compiler when linking against this line + * then your compiler has 'longjmp' that does not match the requirements of the + * compiler that built libpng. You will have to write a wrapper function for + * your compiler's longjmp and call png_set_longjmp_fn directly (not via the + * png_jmpbuf macro.) + * + * If you get a warning here while building the library you will need to make + * changes to ensure that pnglibconf.h records the calling convention used by + * your compiler. This may be very difficult - try using a different compiler + * to build the library! + */ +typedef PNG_FUNCTION(void, (PNGCAPI *png_longjmp_ptr), PNGARG((jmp_buf, int)), + PNG_PTR_NORETURN); +#endif + +/* Transform masks for the high-level interface */ +#define PNG_TRANSFORM_IDENTITY 0x0000 /* read and write */ +#define PNG_TRANSFORM_STRIP_16 0x0001 /* read only */ +#define PNG_TRANSFORM_STRIP_ALPHA 0x0002 /* read only */ +#define PNG_TRANSFORM_PACKING 0x0004 /* read and write */ +#define PNG_TRANSFORM_PACKSWAP 0x0008 /* read and write */ +#define PNG_TRANSFORM_EXPAND 0x0010 /* read only */ +#define PNG_TRANSFORM_INVERT_MONO 0x0020 /* read and write */ +#define PNG_TRANSFORM_SHIFT 0x0040 /* read and write */ +#define PNG_TRANSFORM_BGR 0x0080 /* read and write */ +#define PNG_TRANSFORM_SWAP_ALPHA 0x0100 /* read and write */ +#define PNG_TRANSFORM_SWAP_ENDIAN 0x0200 /* read and write */ +#define PNG_TRANSFORM_INVERT_ALPHA 0x0400 /* read and write */ +#define PNG_TRANSFORM_STRIP_FILLER 0x0800 /* write only */ +/* Added to libpng-1.2.34 */ +#define PNG_TRANSFORM_STRIP_FILLER_BEFORE PNG_TRANSFORM_STRIP_FILLER +#define PNG_TRANSFORM_STRIP_FILLER_AFTER 0x1000 /* write only */ +/* Added to libpng-1.4.0 */ +#define PNG_TRANSFORM_GRAY_TO_RGB 0x2000 /* read only */ + +/* Flags for MNG supported features */ +#define PNG_FLAG_MNG_EMPTY_PLTE 0x01 +#define PNG_FLAG_MNG_FILTER_64 0x04 +#define PNG_ALL_MNG_FEATURES 0x05 + +/* NOTE: prior to 1.5 these functions had no 'API' style declaration, + * this allowed the zlib default functions to be used on Windows + * platforms. In 1.5 the zlib default malloc (which just calls malloc and + * ignores the first argument) should be completely compatible with the + * following. + */ +typedef PNG_CALLBACK(png_voidp, *png_malloc_ptr, (png_structp, + png_alloc_size_t), ); +typedef PNG_CALLBACK(void, *png_free_ptr, (png_structp, png_voidp), ); + +typedef png_struct FAR * FAR * png_structpp; + +/* Section 3: exported functions + * Here are the function definitions most commonly used. This is not + * the place to find out how to use libpng. See libpng-manual.txt for the + * full explanation, see example.c for the summary. This just provides + * a simple one line description of the use of each function. + * + * The PNG_EXPORT() and PNG_EXPORTA() macros used below are defined in + * pngconf.h and in the *.dfn files in the scripts directory. + * + * PNG_EXPORT(ordinal, type, name, (args)); + * + * ordinal: ordinal that is used while building + * *.def files. The ordinal value is only + * relevant when preprocessing png.h with + * the *.dfn files for building symbol table + * entries, and are removed by pngconf.h. + * type: return type of the function + * name: function name + * args: function arguments, with types + * + * When we wish to append attributes to a function prototype we use + * the PNG_EXPORTA() macro instead. + * + * PNG_EXPORTA(ordinal, type, name, (args), attributes); + * + * ordinal, type, name, and args: same as in PNG_EXPORT(). + * attributes: function attributes + */ + +/* Returns the version number of the library */ +PNG_EXPORT(1, png_uint_32, png_access_version_number, (void)); + +/* Tell lib we have already handled the first <num_bytes> magic bytes. + * Handling more than 8 bytes from the beginning of the file is an error. + */ +PNG_EXPORT(2, void, png_set_sig_bytes, (png_structp png_ptr, int num_bytes)); + +/* Check sig[start] through sig[start + num_to_check - 1] to see if it's a + * PNG file. Returns zero if the supplied bytes match the 8-byte PNG + * signature, and non-zero otherwise. Having num_to_check == 0 or + * start > 7 will always fail (ie return non-zero). + */ +PNG_EXPORT(3, int, png_sig_cmp, (png_const_bytep sig, png_size_t start, + png_size_t num_to_check)); + +/* Simple signature checking function. This is the same as calling + * png_check_sig(sig, n) := !png_sig_cmp(sig, 0, n). + */ +#define png_check_sig(sig, n) !png_sig_cmp((sig), 0, (n)) + +/* Allocate and initialize png_ptr struct for reading, and any other memory. */ +PNG_EXPORTA(4, png_structp, png_create_read_struct, + (png_const_charp user_png_ver, png_voidp error_ptr, + png_error_ptr error_fn, png_error_ptr warn_fn), + PNG_ALLOCATED); + +/* Allocate and initialize png_ptr struct for writing, and any other memory */ +PNG_EXPORTA(5, png_structp, png_create_write_struct, + (png_const_charp user_png_ver, png_voidp error_ptr, png_error_ptr error_fn, + png_error_ptr warn_fn), + PNG_ALLOCATED); + +PNG_EXPORT(6, png_size_t, png_get_compression_buffer_size, + (png_const_structp png_ptr)); + +PNG_EXPORT(7, void, png_set_compression_buffer_size, (png_structp png_ptr, + png_size_t size)); + +/* Moved from pngconf.h in 1.4.0 and modified to ensure setjmp/longjmp + * match up. + */ +#ifdef PNG_SETJMP_SUPPORTED +/* This function returns the jmp_buf built in to *png_ptr. It must be + * supplied with an appropriate 'longjmp' function to use on that jmp_buf + * unless the default error function is overridden in which case NULL is + * acceptable. The size of the jmp_buf is checked against the actual size + * allocated by the library - the call will return NULL on a mismatch + * indicating an ABI mismatch. + */ +PNG_EXPORT(8, jmp_buf*, png_set_longjmp_fn, (png_structp png_ptr, + png_longjmp_ptr longjmp_fn, size_t jmp_buf_size)); +# define png_jmpbuf(png_ptr) \ + (*png_set_longjmp_fn((png_ptr), longjmp, sizeof (jmp_buf))) +#else +# define png_jmpbuf(png_ptr) \ + (LIBPNG_WAS_COMPILED_WITH__PNG_NO_SETJMP) +#endif +/* This function should be used by libpng applications in place of + * longjmp(png_ptr->jmpbuf, val). If longjmp_fn() has been set, it + * will use it; otherwise it will call PNG_ABORT(). This function was + * added in libpng-1.5.0. + */ +PNG_EXPORTA(9, void, png_longjmp, (png_structp png_ptr, int val), + PNG_NORETURN); + +#ifdef PNG_READ_SUPPORTED +/* Reset the compression stream */ +PNG_EXPORT(10, int, png_reset_zstream, (png_structp png_ptr)); +#endif + +/* New functions added in libpng-1.0.2 (not enabled by default until 1.2.0) */ +#ifdef PNG_USER_MEM_SUPPORTED +PNG_EXPORTA(11, png_structp, png_create_read_struct_2, + (png_const_charp user_png_ver, png_voidp error_ptr, png_error_ptr error_fn, + png_error_ptr warn_fn, + png_voidp mem_ptr, png_malloc_ptr malloc_fn, png_free_ptr free_fn), + PNG_ALLOCATED); +PNG_EXPORTA(12, png_structp, png_create_write_struct_2, + (png_const_charp user_png_ver, png_voidp error_ptr, png_error_ptr error_fn, + png_error_ptr warn_fn, + png_voidp mem_ptr, png_malloc_ptr malloc_fn, png_free_ptr free_fn), + PNG_ALLOCATED); +#endif + +/* Write the PNG file signature. */ +PNG_EXPORT(13, void, png_write_sig, (png_structp png_ptr)); + +/* Write a PNG chunk - size, type, (optional) data, CRC. */ +PNG_EXPORT(14, void, png_write_chunk, (png_structp png_ptr, png_const_bytep + chunk_name, png_const_bytep data, png_size_t length)); + +/* Write the start of a PNG chunk - length and chunk name. */ +PNG_EXPORT(15, void, png_write_chunk_start, (png_structp png_ptr, + png_const_bytep chunk_name, png_uint_32 length)); + +/* Write the data of a PNG chunk started with png_write_chunk_start(). */ +PNG_EXPORT(16, void, png_write_chunk_data, (png_structp png_ptr, + png_const_bytep data, png_size_t length)); + +/* Finish a chunk started with png_write_chunk_start() (includes CRC). */ +PNG_EXPORT(17, void, png_write_chunk_end, (png_structp png_ptr)); + +/* Allocate and initialize the info structure */ +PNG_EXPORTA(18, png_infop, png_create_info_struct, (png_structp png_ptr), + PNG_ALLOCATED); + +PNG_EXPORT(19, void, png_info_init_3, (png_infopp info_ptr, + png_size_t png_info_struct_size)); + +/* Writes all the PNG information before the image. */ +PNG_EXPORT(20, void, png_write_info_before_PLTE, + (png_structp png_ptr, png_infop info_ptr)); +PNG_EXPORT(21, void, png_write_info, + (png_structp png_ptr, png_infop info_ptr)); + +#ifdef PNG_SEQUENTIAL_READ_SUPPORTED +/* Read the information before the actual image data. */ +PNG_EXPORT(22, void, png_read_info, + (png_structp png_ptr, png_infop info_ptr)); +#endif + +#ifdef PNG_TIME_RFC1123_SUPPORTED +PNG_EXPORT(23, png_const_charp, png_convert_to_rfc1123, + (png_structp png_ptr, + png_const_timep ptime)); +#endif + +#ifdef PNG_CONVERT_tIME_SUPPORTED +/* Convert from a struct tm to png_time */ +PNG_EXPORT(24, void, png_convert_from_struct_tm, (png_timep ptime, + PNG_CONST struct tm FAR * ttime)); + +/* Convert from time_t to png_time. Uses gmtime() */ +PNG_EXPORT(25, void, png_convert_from_time_t, + (png_timep ptime, time_t ttime)); +#endif /* PNG_CONVERT_tIME_SUPPORTED */ + +#ifdef PNG_READ_EXPAND_SUPPORTED +/* Expand data to 24-bit RGB, or 8-bit grayscale, with alpha if available. */ +PNG_EXPORT(26, void, png_set_expand, (png_structp png_ptr)); +PNG_EXPORT(27, void, png_set_expand_gray_1_2_4_to_8, (png_structp png_ptr)); +PNG_EXPORT(28, void, png_set_palette_to_rgb, (png_structp png_ptr)); +PNG_EXPORT(29, void, png_set_tRNS_to_alpha, (png_structp png_ptr)); +#endif + +#if defined(PNG_READ_BGR_SUPPORTED) || defined(PNG_WRITE_BGR_SUPPORTED) +/* Use blue, green, red order for pixels. */ +PNG_EXPORT(30, void, png_set_bgr, (png_structp png_ptr)); +#endif + +#ifdef PNG_READ_GRAY_TO_RGB_SUPPORTED +/* Expand the grayscale to 24-bit RGB if necessary. */ +PNG_EXPORT(31, void, png_set_gray_to_rgb, (png_structp png_ptr)); +#endif + +#ifdef PNG_READ_RGB_TO_GRAY_SUPPORTED +/* Reduce RGB to grayscale. */ +PNG_FP_EXPORT(32, void, png_set_rgb_to_gray, (png_structp png_ptr, + int error_action, double red, double green)); +PNG_FIXED_EXPORT(33, void, png_set_rgb_to_gray_fixed, (png_structp png_ptr, + int error_action, png_fixed_point red, png_fixed_point green)); + +PNG_EXPORT(34, png_byte, png_get_rgb_to_gray_status, (png_const_structp + png_ptr)); +#endif + +PNG_EXPORT(35, void, png_build_grayscale_palette, (int bit_depth, + png_colorp palette)); + +#ifdef PNG_READ_STRIP_ALPHA_SUPPORTED +PNG_EXPORT(36, void, png_set_strip_alpha, (png_structp png_ptr)); +#endif + +#if defined(PNG_READ_SWAP_ALPHA_SUPPORTED) || \ + defined(PNG_WRITE_SWAP_ALPHA_SUPPORTED) +PNG_EXPORT(37, void, png_set_swap_alpha, (png_structp png_ptr)); +#endif + +#if defined(PNG_READ_INVERT_ALPHA_SUPPORTED) || \ + defined(PNG_WRITE_INVERT_ALPHA_SUPPORTED) +PNG_EXPORT(38, void, png_set_invert_alpha, (png_structp png_ptr)); +#endif + +#if defined(PNG_READ_FILLER_SUPPORTED) || defined(PNG_WRITE_FILLER_SUPPORTED) +/* Add a filler byte to 8-bit Gray or 24-bit RGB images. */ +PNG_EXPORT(39, void, png_set_filler, (png_structp png_ptr, png_uint_32 filler, + int flags)); +/* The values of the PNG_FILLER_ defines should NOT be changed */ +# define PNG_FILLER_BEFORE 0 +# define PNG_FILLER_AFTER 1 +/* Add an alpha byte to 8-bit Gray or 24-bit RGB images. */ +PNG_EXPORT(40, void, png_set_add_alpha, + (png_structp png_ptr, png_uint_32 filler, + int flags)); +#endif /* PNG_READ_FILLER_SUPPORTED || PNG_WRITE_FILLER_SUPPORTED */ + +#if defined(PNG_READ_SWAP_SUPPORTED) || defined(PNG_WRITE_SWAP_SUPPORTED) +/* Swap bytes in 16-bit depth files. */ +PNG_EXPORT(41, void, png_set_swap, (png_structp png_ptr)); +#endif + +#if defined(PNG_READ_PACK_SUPPORTED) || defined(PNG_WRITE_PACK_SUPPORTED) +/* Use 1 byte per pixel in 1, 2, or 4-bit depth files. */ +PNG_EXPORT(42, void, png_set_packing, (png_structp png_ptr)); +#endif + +#if defined(PNG_READ_PACKSWAP_SUPPORTED) || \ + defined(PNG_WRITE_PACKSWAP_SUPPORTED) +/* Swap packing order of pixels in bytes. */ +PNG_EXPORT(43, void, png_set_packswap, (png_structp png_ptr)); +#endif + +#if defined(PNG_READ_SHIFT_SUPPORTED) || defined(PNG_WRITE_SHIFT_SUPPORTED) +/* Converts files to legal bit depths. */ +PNG_EXPORT(44, void, png_set_shift, (png_structp png_ptr, png_const_color_8p + true_bits)); +#endif + +#if defined(PNG_READ_INTERLACING_SUPPORTED) || \ + defined(PNG_WRITE_INTERLACING_SUPPORTED) +/* Have the code handle the interlacing. Returns the number of passes. + * MUST be called before png_read_update_info or png_start_read_image, + * otherwise it will not have the desired effect. Note that it is still + * necessary to call png_read_row or png_read_rows png_get_image_height + * times for each pass. +*/ +PNG_EXPORT(45, int, png_set_interlace_handling, (png_structp png_ptr)); +#endif + +#if defined(PNG_READ_INVERT_SUPPORTED) || defined(PNG_WRITE_INVERT_SUPPORTED) +/* Invert monochrome files */ +PNG_EXPORT(46, void, png_set_invert_mono, (png_structp png_ptr)); +#endif + +#ifdef PNG_READ_BACKGROUND_SUPPORTED +/* Handle alpha and tRNS by replacing with a background color. */ +PNG_FP_EXPORT(47, void, png_set_background, (png_structp png_ptr, + png_const_color_16p background_color, int background_gamma_code, + int need_expand, double background_gamma)); +PNG_FIXED_EXPORT(215, void, png_set_background_fixed, (png_structp png_ptr, + png_const_color_16p background_color, int background_gamma_code, + int need_expand, png_fixed_point background_gamma)); +#endif +#ifdef PNG_READ_BACKGROUND_SUPPORTED +# define PNG_BACKGROUND_GAMMA_UNKNOWN 0 +# define PNG_BACKGROUND_GAMMA_SCREEN 1 +# define PNG_BACKGROUND_GAMMA_FILE 2 +# define PNG_BACKGROUND_GAMMA_UNIQUE 3 +#endif + +#ifdef PNG_READ_16_TO_8_SUPPORTED +/* Strip the second byte of information from a 16-bit depth file. */ +PNG_EXPORT(48, void, png_set_strip_16, (png_structp png_ptr)); +#endif + +#ifdef PNG_READ_QUANTIZE_SUPPORTED +/* Turn on quantizing, and reduce the palette to the number of colors + * available. + */ +PNG_EXPORT(49, void, png_set_quantize, + (png_structp png_ptr, png_colorp palette, + int num_palette, int maximum_colors, png_const_uint_16p histogram, + int full_quantize)); +#endif + +#ifdef PNG_READ_GAMMA_SUPPORTED +/* The threshold on gamma processing is configurable but hard-wired into the + * library. The following is the floating point variant. + */ +#define PNG_GAMMA_THRESHOLD (PNG_GAMMA_THRESHOLD_FIXED*.00001) + +/* Handle gamma correction. Screen_gamma=(display_exponent) */ +PNG_FP_EXPORT(50, void, png_set_gamma, + (png_structp png_ptr, double screen_gamma, + double default_file_gamma)); +PNG_FIXED_EXPORT(208, void, png_set_gamma_fixed, (png_structp png_ptr, + png_fixed_point screen_gamma, png_fixed_point default_file_gamma)); +#endif + +#ifdef PNG_WRITE_FLUSH_SUPPORTED +/* Set how many lines between output flushes - 0 for no flushing */ +PNG_EXPORT(51, void, png_set_flush, (png_structp png_ptr, int nrows)); +/* Flush the current PNG output buffer */ +PNG_EXPORT(52, void, png_write_flush, (png_structp png_ptr)); +#endif + +/* Optional update palette with requested transformations */ +PNG_EXPORT(53, void, png_start_read_image, (png_structp png_ptr)); + +/* Optional call to update the users info structure */ +PNG_EXPORT(54, void, png_read_update_info, + (png_structp png_ptr, png_infop info_ptr)); + +#ifdef PNG_SEQUENTIAL_READ_SUPPORTED +/* Read one or more rows of image data. */ +PNG_EXPORT(55, void, png_read_rows, (png_structp png_ptr, png_bytepp row, + png_bytepp display_row, png_uint_32 num_rows)); +#endif + +#ifdef PNG_SEQUENTIAL_READ_SUPPORTED +/* Read a row of data. */ +PNG_EXPORT(56, void, png_read_row, (png_structp png_ptr, png_bytep row, + png_bytep display_row)); +#endif + +#ifdef PNG_SEQUENTIAL_READ_SUPPORTED +/* Read the whole image into memory at once. */ +PNG_EXPORT(57, void, png_read_image, (png_structp png_ptr, png_bytepp image)); +#endif + +/* Write a row of image data */ +PNG_EXPORT(58, void, png_write_row, + (png_structp png_ptr, png_const_bytep row)); + +/* Write a few rows of image data: (*row) is not written; however, the type + * is declared as writeable to maintain compatibility with previous versions + * of libpng and to allow the 'display_row' array from read_rows to be passed + * unchanged to write_rows. + */ +PNG_EXPORT(59, void, png_write_rows, (png_structp png_ptr, png_bytepp row, + png_uint_32 num_rows)); + +/* Write the image data */ +PNG_EXPORT(60, void, png_write_image, + (png_structp png_ptr, png_bytepp image)); + +/* Write the end of the PNG file. */ +PNG_EXPORT(61, void, png_write_end, + (png_structp png_ptr, png_infop info_ptr)); + +#ifdef PNG_SEQUENTIAL_READ_SUPPORTED +/* Read the end of the PNG file. */ +PNG_EXPORT(62, void, png_read_end, (png_structp png_ptr, png_infop info_ptr)); +#endif + +/* Free any memory associated with the png_info_struct */ +PNG_EXPORT(63, void, png_destroy_info_struct, (png_structp png_ptr, + png_infopp info_ptr_ptr)); + +/* Free any memory associated with the png_struct and the png_info_structs */ +PNG_EXPORT(64, void, png_destroy_read_struct, (png_structpp png_ptr_ptr, + png_infopp info_ptr_ptr, png_infopp end_info_ptr_ptr)); + +/* Free any memory associated with the png_struct and the png_info_structs */ +PNG_EXPORT(65, void, png_destroy_write_struct, (png_structpp png_ptr_ptr, + png_infopp info_ptr_ptr)); + +/* Set the libpng method of handling chunk CRC errors */ +PNG_EXPORT(66, void, png_set_crc_action, + (png_structp png_ptr, int crit_action, int ancil_action)); + +/* Values for png_set_crc_action() say how to handle CRC errors in + * ancillary and critical chunks, and whether to use the data contained + * therein. Note that it is impossible to "discard" data in a critical + * chunk. For versions prior to 0.90, the action was always error/quit, + * whereas in version 0.90 and later, the action for CRC errors in ancillary + * chunks is warn/discard. These values should NOT be changed. + * + * value action:critical action:ancillary + */ +#define PNG_CRC_DEFAULT 0 /* error/quit warn/discard data */ +#define PNG_CRC_ERROR_QUIT 1 /* error/quit error/quit */ +#define PNG_CRC_WARN_DISCARD 2 /* (INVALID) warn/discard data */ +#define PNG_CRC_WARN_USE 3 /* warn/use data warn/use data */ +#define PNG_CRC_QUIET_USE 4 /* quiet/use data quiet/use data */ +#define PNG_CRC_NO_CHANGE 5 /* use current value use current value */ + +/* These functions give the user control over the scan-line filtering in + * libpng and the compression methods used by zlib. These functions are + * mainly useful for testing, as the defaults should work with most users. + * Those users who are tight on memory or want faster performance at the + * expense of compression can modify them. See the compression library + * header file (zlib.h) for an explination of the compression functions. + */ + +/* Set the filtering method(s) used by libpng. Currently, the only valid + * value for "method" is 0. + */ +PNG_EXPORT(67, void, png_set_filter, + (png_structp png_ptr, int method, int filters)); + +/* Flags for png_set_filter() to say which filters to use. The flags + * are chosen so that they don't conflict with real filter types + * below, in case they are supplied instead of the #defined constants. + * These values should NOT be changed. + */ +#define PNG_NO_FILTERS 0x00 +#define PNG_FILTER_NONE 0x08 +#define PNG_FILTER_SUB 0x10 +#define PNG_FILTER_UP 0x20 +#define PNG_FILTER_AVG 0x40 +#define PNG_FILTER_PAETH 0x80 +#define PNG_ALL_FILTERS (PNG_FILTER_NONE | PNG_FILTER_SUB | PNG_FILTER_UP | \ + PNG_FILTER_AVG | PNG_FILTER_PAETH) + +/* Filter values (not flags) - used in pngwrite.c, pngwutil.c for now. + * These defines should NOT be changed. + */ +#define PNG_FILTER_VALUE_NONE 0 +#define PNG_FILTER_VALUE_SUB 1 +#define PNG_FILTER_VALUE_UP 2 +#define PNG_FILTER_VALUE_AVG 3 +#define PNG_FILTER_VALUE_PAETH 4 +#define PNG_FILTER_VALUE_LAST 5 + +#ifdef PNG_WRITE_WEIGHTED_FILTER_SUPPORTED /* EXPERIMENTAL */ +/* The "heuristic_method" is given by one of the PNG_FILTER_HEURISTIC_ + * defines, either the default (minimum-sum-of-absolute-differences), or + * the experimental method (weighted-minimum-sum-of-absolute-differences). + * + * Weights are factors >= 1.0, indicating how important it is to keep the + * filter type consistent between rows. Larger numbers mean the current + * filter is that many times as likely to be the same as the "num_weights" + * previous filters. This is cumulative for each previous row with a weight. + * There needs to be "num_weights" values in "filter_weights", or it can be + * NULL if the weights aren't being specified. Weights have no influence on + * the selection of the first row filter. Well chosen weights can (in theory) + * improve the compression for a given image. + * + * Costs are factors >= 1.0 indicating the relative decoding costs of a + * filter type. Higher costs indicate more decoding expense, and are + * therefore less likely to be selected over a filter with lower computational + * costs. There needs to be a value in "filter_costs" for each valid filter + * type (given by PNG_FILTER_VALUE_LAST), or it can be NULL if you aren't + * setting the costs. Costs try to improve the speed of decompression without + * unduly increasing the compressed image size. + * + * A negative weight or cost indicates the default value is to be used, and + * values in the range [0.0, 1.0) indicate the value is to remain unchanged. + * The default values for both weights and costs are currently 1.0, but may + * change if good general weighting/cost heuristics can be found. If both + * the weights and costs are set to 1.0, this degenerates the WEIGHTED method + * to the UNWEIGHTED method, but with added encoding time/computation. + */ +PNG_FP_EXPORT(68, void, png_set_filter_heuristics, (png_structp png_ptr, + int heuristic_method, int num_weights, png_const_doublep filter_weights, + png_const_doublep filter_costs)); +PNG_FIXED_EXPORT(209, void, png_set_filter_heuristics_fixed, + (png_structp png_ptr, + int heuristic_method, int num_weights, png_const_fixed_point_p + filter_weights, png_const_fixed_point_p filter_costs)); +#endif /* PNG_WRITE_WEIGHTED_FILTER_SUPPORTED */ + +/* Heuristic used for row filter selection. These defines should NOT be + * changed. + */ +#define PNG_FILTER_HEURISTIC_DEFAULT 0 /* Currently "UNWEIGHTED" */ +#define PNG_FILTER_HEURISTIC_UNWEIGHTED 1 /* Used by libpng < 0.95 */ +#define PNG_FILTER_HEURISTIC_WEIGHTED 2 /* Experimental feature */ +#define PNG_FILTER_HEURISTIC_LAST 3 /* Not a valid value */ + +/* Set the library compression level. Currently, valid values range from + * 0 - 9, corresponding directly to the zlib compression levels 0 - 9 + * (0 - no compression, 9 - "maximal" compression). Note that tests have + * shown that zlib compression levels 3-6 usually perform as well as level 9 + * for PNG images, and do considerably fewer caclulations. In the future, + * these values may not correspond directly to the zlib compression levels. + */ +PNG_EXPORT(69, void, png_set_compression_level, + (png_structp png_ptr, int level)); + +PNG_EXPORT(70, void, png_set_compression_mem_level, (png_structp png_ptr, + int mem_level)); + +PNG_EXPORT(71, void, png_set_compression_strategy, (png_structp png_ptr, + int strategy)); + +PNG_EXPORT(72, void, png_set_compression_window_bits, (png_structp png_ptr, + int window_bits)); + +PNG_EXPORT(73, void, png_set_compression_method, (png_structp png_ptr, + int method)); + +/* These next functions are called for input/output, memory, and error + * handling. They are in the file pngrio.c, pngwio.c, and pngerror.c, + * and call standard C I/O routines such as fread(), fwrite(), and + * fprintf(). These functions can be made to use other I/O routines + * at run time for those applications that need to handle I/O in a + * different manner by calling png_set_???_fn(). See libpng-manual.txt for + * more information. + */ + +#ifdef PNG_STDIO_SUPPORTED +/* Initialize the input/output for the PNG file to the default functions. */ +PNG_EXPORT(74, void, png_init_io, (png_structp png_ptr, png_FILE_p fp)); +#endif + +/* Replace the (error and abort), and warning functions with user + * supplied functions. If no messages are to be printed you must still + * write and use replacement functions. The replacement error_fn should + * still do a longjmp to the last setjmp location if you are using this + * method of error handling. If error_fn or warning_fn is NULL, the + * default function will be used. + */ + +PNG_EXPORT(75, void, png_set_error_fn, + (png_structp png_ptr, png_voidp error_ptr, + png_error_ptr error_fn, png_error_ptr warning_fn)); + +/* Return the user pointer associated with the error functions */ +PNG_EXPORT(76, png_voidp, png_get_error_ptr, (png_const_structp png_ptr)); + +/* Replace the default data output functions with a user supplied one(s). + * If buffered output is not used, then output_flush_fn can be set to NULL. + * If PNG_WRITE_FLUSH_SUPPORTED is not defined at libpng compile time + * output_flush_fn will be ignored (and thus can be NULL). + * It is probably a mistake to use NULL for output_flush_fn if + * write_data_fn is not also NULL unless you have built libpng with + * PNG_WRITE_FLUSH_SUPPORTED undefined, because in this case libpng's + * default flush function, which uses the standard *FILE structure, will + * be used. + */ +PNG_EXPORT(77, void, png_set_write_fn, (png_structp png_ptr, png_voidp io_ptr, + png_rw_ptr write_data_fn, png_flush_ptr output_flush_fn)); + +/* Replace the default data input function with a user supplied one. */ +PNG_EXPORT(78, void, png_set_read_fn, (png_structp png_ptr, png_voidp io_ptr, + png_rw_ptr read_data_fn)); + +/* Return the user pointer associated with the I/O functions */ +PNG_EXPORT(79, png_voidp, png_get_io_ptr, (png_structp png_ptr)); + +PNG_EXPORT(80, void, png_set_read_status_fn, (png_structp png_ptr, + png_read_status_ptr read_row_fn)); + +PNG_EXPORT(81, void, png_set_write_status_fn, (png_structp png_ptr, + png_write_status_ptr write_row_fn)); + +#ifdef PNG_USER_MEM_SUPPORTED +/* Replace the default memory allocation functions with user supplied one(s). */ +PNG_EXPORT(82, void, png_set_mem_fn, (png_structp png_ptr, png_voidp mem_ptr, + png_malloc_ptr malloc_fn, png_free_ptr free_fn)); +/* Return the user pointer associated with the memory functions */ +PNG_EXPORT(83, png_voidp, png_get_mem_ptr, (png_const_structp png_ptr)); +#endif + +#ifdef PNG_READ_USER_TRANSFORM_SUPPORTED +PNG_EXPORT(84, void, png_set_read_user_transform_fn, (png_structp png_ptr, + png_user_transform_ptr read_user_transform_fn)); +#endif + +#ifdef PNG_WRITE_USER_TRANSFORM_SUPPORTED +PNG_EXPORT(85, void, png_set_write_user_transform_fn, (png_structp png_ptr, + png_user_transform_ptr write_user_transform_fn)); +#endif + +#ifdef PNG_USER_TRANSFORM_PTR_SUPPORTED +PNG_EXPORT(86, void, png_set_user_transform_info, (png_structp png_ptr, + png_voidp user_transform_ptr, int user_transform_depth, + int user_transform_channels)); +/* Return the user pointer associated with the user transform functions */ +PNG_EXPORT(87, png_voidp, png_get_user_transform_ptr, + (png_const_structp png_ptr)); +#endif + +#ifdef PNG_USER_TRANSFORM_INFO_SUPPORTED +/* Return information about the row currently being processed. Note that these + * APIs do not fail but will return unexpected results if called outside a user + * transform callback. Also note that when transforming an interlaced image the + * row number is still the row in the final, de-interlaced, image but the row + * only contains the data of the current pass - consult png_row_info for the + * actual width of the row! + */ +PNG_EXPORT(217, png_uint_32, png_get_current_row_number, (png_const_structp)); +PNG_EXPORT(218, png_byte, png_get_current_pass_number, (png_const_structp)); +#endif + +#ifdef PNG_USER_CHUNKS_SUPPORTED +PNG_EXPORT(88, void, png_set_read_user_chunk_fn, (png_structp png_ptr, + png_voidp user_chunk_ptr, png_user_chunk_ptr read_user_chunk_fn)); +PNG_EXPORT(89, png_voidp, png_get_user_chunk_ptr, (png_const_structp png_ptr)); +#endif + +#ifdef PNG_PROGRESSIVE_READ_SUPPORTED +/* Sets the function callbacks for the push reader, and a pointer to a + * user-defined structure available to the callback functions. + */ +PNG_EXPORT(90, void, png_set_progressive_read_fn, (png_structp png_ptr, + png_voidp progressive_ptr, png_progressive_info_ptr info_fn, + png_progressive_row_ptr row_fn, png_progressive_end_ptr end_fn)); + +/* Returns the user pointer associated with the push read functions */ +PNG_EXPORT(91, png_voidp, png_get_progressive_ptr, (png_const_structp png_ptr)); + +/* Function to be called when data becomes available */ +PNG_EXPORT(92, void, png_process_data, + (png_structp png_ptr, png_infop info_ptr, + png_bytep buffer, png_size_t buffer_size)); + +/* A function which may be called *only* within png_process_data to stop the + * processing of any more data. The function returns the number of bytes + * remaining, excluding any that libpng has cached internally. A subsequent + * call to png_process_data must supply these bytes again. If the argument + * 'save' is set to true the routine will first save all the pending data and + * will always return 0. + */ +PNG_EXPORT(219, png_size_t, png_process_data_pause, (png_structp, int save)); + +/* A function which may be called *only* outside (after) a call to + * png_process_data. It returns the number of bytes of data to skip in the + * input. Normally it will return 0, but if it returns a non-zero value the + * application must skip than number of bytes of input data and pass the + * following data to the next call to png_process_data. + */ +PNG_EXPORT(220, png_uint_32, png_process_data_skip, (png_structp)); + +/* Function that combines rows. 'new_row' is a flag that should come from + * the callback and be non-NULL if anything needs to be done; the library + * stores its own version of the new data internally and ignores the passed + * in value. + */ +PNG_EXPORT(93, void, png_progressive_combine_row, (png_structp png_ptr, + png_bytep old_row, png_const_bytep new_row)); +#endif /* PNG_PROGRESSIVE_READ_SUPPORTED */ + +PNG_EXPORTA(94, png_voidp, png_malloc, + (png_structp png_ptr, png_alloc_size_t size), + PNG_ALLOCATED); +/* Added at libpng version 1.4.0 */ +PNG_EXPORTA(95, png_voidp, png_calloc, + (png_structp png_ptr, png_alloc_size_t size), + PNG_ALLOCATED); + +/* Added at libpng version 1.2.4 */ +PNG_EXPORTA(96, png_voidp, png_malloc_warn, (png_structp png_ptr, + png_alloc_size_t size), PNG_ALLOCATED); + +/* Frees a pointer allocated by png_malloc() */ +PNG_EXPORT(97, void, png_free, (png_structp png_ptr, png_voidp ptr)); + +/* Free data that was allocated internally */ +PNG_EXPORT(98, void, png_free_data, + (png_structp png_ptr, png_infop info_ptr, png_uint_32 free_me, int num)); + +/* Reassign responsibility for freeing existing data, whether allocated + * by libpng or by the application */ +PNG_EXPORT(99, void, png_data_freer, + (png_structp png_ptr, png_infop info_ptr, int freer, png_uint_32 mask)); + +/* Assignments for png_data_freer */ +#define PNG_DESTROY_WILL_FREE_DATA 1 +#define PNG_SET_WILL_FREE_DATA 1 +#define PNG_USER_WILL_FREE_DATA 2 +/* Flags for png_ptr->free_me and info_ptr->free_me */ +#define PNG_FREE_HIST 0x0008 +#define PNG_FREE_ICCP 0x0010 +#define PNG_FREE_SPLT 0x0020 +#define PNG_FREE_ROWS 0x0040 +#define PNG_FREE_PCAL 0x0080 +#define PNG_FREE_SCAL 0x0100 +#define PNG_FREE_UNKN 0x0200 +#define PNG_FREE_LIST 0x0400 +#define PNG_FREE_PLTE 0x1000 +#define PNG_FREE_TRNS 0x2000 +#define PNG_FREE_TEXT 0x4000 +#define PNG_FREE_ALL 0x7fff +#define PNG_FREE_MUL 0x4220 /* PNG_FREE_SPLT|PNG_FREE_TEXT|PNG_FREE_UNKN */ + +#ifdef PNG_USER_MEM_SUPPORTED +PNG_EXPORTA(100, png_voidp, png_malloc_default, (png_structp png_ptr, + png_alloc_size_t size), PNG_ALLOCATED); +PNG_EXPORT(101, void, png_free_default, (png_structp png_ptr, png_voidp ptr)); +#endif + +#ifdef PNG_ERROR_TEXT_SUPPORTED +/* Fatal error in PNG image of libpng - can't continue */ +PNG_EXPORTA(102, void, png_error, + (png_structp png_ptr, png_const_charp error_message), + PNG_NORETURN); + +/* The same, but the chunk name is prepended to the error string. */ +PNG_EXPORTA(103, void, png_chunk_error, (png_structp png_ptr, + png_const_charp error_message), PNG_NORETURN); + +#else +/* Fatal error in PNG image of libpng - can't continue */ +PNG_EXPORTA(104, void, png_err, (png_structp png_ptr), PNG_NORETURN); +#endif + +/* Non-fatal error in libpng. Can continue, but may have a problem. */ +PNG_EXPORT(105, void, png_warning, (png_structp png_ptr, + png_const_charp warning_message)); + +/* Non-fatal error in libpng, chunk name is prepended to message. */ +PNG_EXPORT(106, void, png_chunk_warning, (png_structp png_ptr, + png_const_charp warning_message)); + +#ifdef PNG_BENIGN_ERRORS_SUPPORTED +/* Benign error in libpng. Can continue, but may have a problem. + * User can choose whether to handle as a fatal error or as a warning. */ +# undef png_benign_error +PNG_EXPORT(107, void, png_benign_error, (png_structp png_ptr, + png_const_charp warning_message)); + +/* Same, chunk name is prepended to message. */ +# undef png_chunk_benign_error +PNG_EXPORT(108, void, png_chunk_benign_error, (png_structp png_ptr, + png_const_charp warning_message)); + +PNG_EXPORT(109, void, png_set_benign_errors, + (png_structp png_ptr, int allowed)); +#else +# ifdef PNG_ALLOW_BENIGN_ERRORS +# define png_benign_error png_warning +# define png_chunk_benign_error png_chunk_warning +# else +# define png_benign_error png_error +# define png_chunk_benign_error png_chunk_error +# endif +#endif + +/* The png_set_<chunk> functions are for storing values in the png_info_struct. + * Similarly, the png_get_<chunk> calls are used to read values from the + * png_info_struct, either storing the parameters in the passed variables, or + * setting pointers into the png_info_struct where the data is stored. The + * png_get_<chunk> functions return a non-zero value if the data was available + * in info_ptr, or return zero and do not change any of the parameters if the + * data was not available. + * + * These functions should be used instead of directly accessing png_info + * to avoid problems with future changes in the size and internal layout of + * png_info_struct. + */ +/* Returns "flag" if chunk data is valid in info_ptr. */ +PNG_EXPORT(110, png_uint_32, png_get_valid, + (png_const_structp png_ptr, png_const_infop info_ptr, + png_uint_32 flag)); + +/* Returns number of bytes needed to hold a transformed row. */ +PNG_EXPORT(111, png_size_t, png_get_rowbytes, (png_const_structp png_ptr, + png_const_infop info_ptr)); + +#ifdef PNG_INFO_IMAGE_SUPPORTED +/* Returns row_pointers, which is an array of pointers to scanlines that was + * returned from png_read_png(). + */ +PNG_EXPORT(112, png_bytepp, png_get_rows, + (png_const_structp png_ptr, png_const_infop info_ptr)); +/* Set row_pointers, which is an array of pointers to scanlines for use + * by png_write_png(). + */ +PNG_EXPORT(113, void, png_set_rows, (png_structp png_ptr, + png_infop info_ptr, png_bytepp row_pointers)); +#endif + +/* Returns number of color channels in image. */ +PNG_EXPORT(114, png_byte, png_get_channels, + (png_const_structp png_ptr, png_const_infop info_ptr)); + +#ifdef PNG_EASY_ACCESS_SUPPORTED +/* Returns image width in pixels. */ +PNG_EXPORT(115, png_uint_32, png_get_image_width, (png_const_structp png_ptr, + png_const_infop info_ptr)); + +/* Returns image height in pixels. */ +PNG_EXPORT(116, png_uint_32, png_get_image_height, (png_const_structp png_ptr, + png_const_infop info_ptr)); + +/* Returns image bit_depth. */ +PNG_EXPORT(117, png_byte, png_get_bit_depth, + (png_const_structp png_ptr, png_const_infop info_ptr)); + +/* Returns image color_type. */ +PNG_EXPORT(118, png_byte, png_get_color_type, (png_const_structp png_ptr, + png_const_infop info_ptr)); + +/* Returns image filter_type. */ +PNG_EXPORT(119, png_byte, png_get_filter_type, (png_const_structp png_ptr, + png_const_infop info_ptr)); + +/* Returns image interlace_type. */ +PNG_EXPORT(120, png_byte, png_get_interlace_type, (png_const_structp png_ptr, + png_const_infop info_ptr)); + +/* Returns image compression_type. */ +PNG_EXPORT(121, png_byte, png_get_compression_type, (png_const_structp png_ptr, + png_const_infop info_ptr)); + +/* Returns image resolution in pixels per meter, from pHYs chunk data. */ +PNG_EXPORT(122, png_uint_32, png_get_pixels_per_meter, + (png_const_structp png_ptr, png_const_infop info_ptr)); +PNG_EXPORT(123, png_uint_32, png_get_x_pixels_per_meter, + (png_const_structp png_ptr, png_const_infop info_ptr)); +PNG_EXPORT(124, png_uint_32, png_get_y_pixels_per_meter, + (png_const_structp png_ptr, png_const_infop info_ptr)); + +/* Returns pixel aspect ratio, computed from pHYs chunk data. */ +PNG_FP_EXPORT(125, float, png_get_pixel_aspect_ratio, + (png_const_structp png_ptr, png_const_infop info_ptr)); +PNG_FIXED_EXPORT(210, png_fixed_point, png_get_pixel_aspect_ratio_fixed, + (png_const_structp png_ptr, png_const_infop info_ptr)); + +/* Returns image x, y offset in pixels or microns, from oFFs chunk data. */ +PNG_EXPORT(126, png_int_32, png_get_x_offset_pixels, + (png_const_structp png_ptr, png_const_infop info_ptr)); +PNG_EXPORT(127, png_int_32, png_get_y_offset_pixels, + (png_const_structp png_ptr, png_const_infop info_ptr)); +PNG_EXPORT(128, png_int_32, png_get_x_offset_microns, + (png_const_structp png_ptr, png_const_infop info_ptr)); +PNG_EXPORT(129, png_int_32, png_get_y_offset_microns, + (png_const_structp png_ptr, png_const_infop info_ptr)); + +#endif /* PNG_EASY_ACCESS_SUPPORTED */ + +/* Returns pointer to signature string read from PNG header */ +PNG_EXPORT(130, png_const_bytep, png_get_signature, + (png_const_structp png_ptr, png_infop info_ptr)); + +#ifdef PNG_bKGD_SUPPORTED +PNG_EXPORT(131, png_uint_32, png_get_bKGD, + (png_const_structp png_ptr, png_infop info_ptr, + png_color_16p *background)); +#endif + +#ifdef PNG_bKGD_SUPPORTED +PNG_EXPORT(132, void, png_set_bKGD, (png_structp png_ptr, png_infop info_ptr, + png_const_color_16p background)); +#endif + +#ifdef PNG_cHRM_SUPPORTED +PNG_FP_EXPORT(133, png_uint_32, png_get_cHRM, (png_const_structp png_ptr, + png_const_infop info_ptr, double *white_x, double *white_y, double *red_x, + double *red_y, double *green_x, double *green_y, double *blue_x, + double *blue_y)); +#ifdef PNG_FIXED_POINT_SUPPORTED /* Otherwise not implemented */ +PNG_FIXED_EXPORT(134, png_uint_32, png_get_cHRM_fixed, + (png_const_structp png_ptr, + png_const_infop info_ptr, png_fixed_point *int_white_x, + png_fixed_point *int_white_y, png_fixed_point *int_red_x, + png_fixed_point *int_red_y, png_fixed_point *int_green_x, + png_fixed_point *int_green_y, png_fixed_point *int_blue_x, + png_fixed_point *int_blue_y)); +#endif +#endif + +#ifdef PNG_cHRM_SUPPORTED +PNG_FP_EXPORT(135, void, png_set_cHRM, + (png_structp png_ptr, png_infop info_ptr, + double white_x, double white_y, double red_x, double red_y, double green_x, + double green_y, double blue_x, double blue_y)); +PNG_FIXED_EXPORT(136, void, png_set_cHRM_fixed, (png_structp png_ptr, + png_infop info_ptr, png_fixed_point int_white_x, + png_fixed_point int_white_y, png_fixed_point int_red_x, + png_fixed_point int_red_y, png_fixed_point int_green_x, + png_fixed_point int_green_y, png_fixed_point int_blue_x, + png_fixed_point int_blue_y)); +#endif + +#ifdef PNG_gAMA_SUPPORTED +PNG_FP_EXPORT(137, png_uint_32, png_get_gAMA, + (png_const_structp png_ptr, png_const_infop info_ptr, + double *file_gamma)); +PNG_FIXED_EXPORT(138, png_uint_32, png_get_gAMA_fixed, + (png_const_structp png_ptr, png_const_infop info_ptr, + png_fixed_point *int_file_gamma)); +#endif + +#ifdef PNG_gAMA_SUPPORTED +PNG_FP_EXPORT(139, void, png_set_gAMA, (png_structp png_ptr, + png_infop info_ptr, double file_gamma)); +PNG_FIXED_EXPORT(140, void, png_set_gAMA_fixed, (png_structp png_ptr, + png_infop info_ptr, png_fixed_point int_file_gamma)); +#endif + +#ifdef PNG_hIST_SUPPORTED +PNG_EXPORT(141, png_uint_32, png_get_hIST, + (png_const_structp png_ptr, png_const_infop info_ptr, + png_uint_16p *hist)); +#endif + +#ifdef PNG_hIST_SUPPORTED +PNG_EXPORT(142, void, png_set_hIST, (png_structp png_ptr, + png_infop info_ptr, png_const_uint_16p hist)); +#endif + +PNG_EXPORT(143, png_uint_32, png_get_IHDR, + (png_structp png_ptr, png_infop info_ptr, + png_uint_32 *width, png_uint_32 *height, int *bit_depth, int *color_type, + int *interlace_method, int *compression_method, int *filter_method)); + +PNG_EXPORT(144, void, png_set_IHDR, + (png_structp png_ptr, png_infop info_ptr, + png_uint_32 width, png_uint_32 height, int bit_depth, int color_type, + int interlace_method, int compression_method, int filter_method)); + +#ifdef PNG_oFFs_SUPPORTED +PNG_EXPORT(145, png_uint_32, png_get_oFFs, + (png_const_structp png_ptr, png_const_infop info_ptr, + png_int_32 *offset_x, png_int_32 *offset_y, int *unit_type)); +#endif + +#ifdef PNG_oFFs_SUPPORTED +PNG_EXPORT(146, void, png_set_oFFs, + (png_structp png_ptr, png_infop info_ptr, + png_int_32 offset_x, png_int_32 offset_y, int unit_type)); +#endif + +#ifdef PNG_pCAL_SUPPORTED +PNG_EXPORT(147, png_uint_32, png_get_pCAL, + (png_const_structp png_ptr, png_const_infop info_ptr, + png_charp *purpose, png_int_32 *X0, png_int_32 *X1, int *type, + int *nparams, + png_charp *units, png_charpp *params)); +#endif + +#ifdef PNG_pCAL_SUPPORTED +PNG_EXPORT(148, void, png_set_pCAL, (png_structp png_ptr, + png_infop info_ptr, + png_const_charp purpose, png_int_32 X0, png_int_32 X1, int type, + int nparams, png_const_charp units, png_charpp params)); +#endif + +#ifdef PNG_pHYs_SUPPORTED +PNG_EXPORT(149, png_uint_32, png_get_pHYs, + (png_const_structp png_ptr, png_const_infop info_ptr, + png_uint_32 *res_x, png_uint_32 *res_y, int *unit_type)); +#endif + +#ifdef PNG_pHYs_SUPPORTED +PNG_EXPORT(150, void, png_set_pHYs, + (png_structp png_ptr, png_infop info_ptr, + png_uint_32 res_x, png_uint_32 res_y, int unit_type)); +#endif + +PNG_EXPORT(151, png_uint_32, png_get_PLTE, + (png_const_structp png_ptr, png_const_infop info_ptr, + png_colorp *palette, int *num_palette)); + +PNG_EXPORT(152, void, png_set_PLTE, + (png_structp png_ptr, png_infop info_ptr, + png_const_colorp palette, int num_palette)); + +#ifdef PNG_sBIT_SUPPORTED +PNG_EXPORT(153, png_uint_32, png_get_sBIT, + (png_const_structp png_ptr, png_infop info_ptr, + png_color_8p *sig_bit)); +#endif + +#ifdef PNG_sBIT_SUPPORTED +PNG_EXPORT(154, void, png_set_sBIT, + (png_structp png_ptr, png_infop info_ptr, png_const_color_8p sig_bit)); +#endif + +#ifdef PNG_sRGB_SUPPORTED +PNG_EXPORT(155, png_uint_32, png_get_sRGB, (png_const_structp png_ptr, + png_const_infop info_ptr, int *file_srgb_intent)); +#endif + +#ifdef PNG_sRGB_SUPPORTED +PNG_EXPORT(156, void, png_set_sRGB, + (png_structp png_ptr, png_infop info_ptr, int srgb_intent)); +PNG_EXPORT(157, void, png_set_sRGB_gAMA_and_cHRM, (png_structp png_ptr, + png_infop info_ptr, int srgb_intent)); +#endif + +#ifdef PNG_iCCP_SUPPORTED +PNG_EXPORT(158, png_uint_32, png_get_iCCP, + (png_const_structp png_ptr, png_const_infop info_ptr, + png_charpp name, int *compression_type, png_bytepp profile, + png_uint_32 *proflen)); +#endif + +#ifdef PNG_iCCP_SUPPORTED +PNG_EXPORT(159, void, png_set_iCCP, + (png_structp png_ptr, png_infop info_ptr, + png_const_charp name, int compression_type, png_const_bytep profile, + png_uint_32 proflen)); +#endif + +#ifdef PNG_sPLT_SUPPORTED +PNG_EXPORT(160, png_uint_32, png_get_sPLT, + (png_const_structp png_ptr, png_const_infop info_ptr, + png_sPLT_tpp entries)); +#endif + +#ifdef PNG_sPLT_SUPPORTED +PNG_EXPORT(161, void, png_set_sPLT, + (png_structp png_ptr, png_infop info_ptr, + png_const_sPLT_tp entries, int nentries)); +#endif + +#ifdef PNG_TEXT_SUPPORTED +/* png_get_text also returns the number of text chunks in *num_text */ +PNG_EXPORT(162, png_uint_32, png_get_text, + (png_const_structp png_ptr, png_const_infop info_ptr, + png_textp *text_ptr, int *num_text)); +#endif + +/* Note while png_set_text() will accept a structure whose text, + * language, and translated keywords are NULL pointers, the structure + * returned by png_get_text will always contain regular + * zero-terminated C strings. They might be empty strings but + * they will never be NULL pointers. + */ + +#ifdef PNG_TEXT_SUPPORTED +PNG_EXPORT(163, void, png_set_text, + (png_structp png_ptr, png_infop info_ptr, + png_const_textp text_ptr, int num_text)); +#endif + +#ifdef PNG_tIME_SUPPORTED +PNG_EXPORT(164, png_uint_32, png_get_tIME, + (png_const_structp png_ptr, png_infop info_ptr, png_timep *mod_time)); +#endif + +#ifdef PNG_tIME_SUPPORTED +PNG_EXPORT(165, void, png_set_tIME, + (png_structp png_ptr, png_infop info_ptr, png_const_timep mod_time)); +#endif + +#ifdef PNG_tRNS_SUPPORTED +PNG_EXPORT(166, png_uint_32, png_get_tRNS, + (png_const_structp png_ptr, png_infop info_ptr, + png_bytep *trans_alpha, int *num_trans, png_color_16p *trans_color)); +#endif + +#ifdef PNG_tRNS_SUPPORTED +PNG_EXPORT(167, void, png_set_tRNS, + (png_structp png_ptr, png_infop info_ptr, + png_const_bytep trans_alpha, int num_trans, + png_const_color_16p trans_color)); +#endif + +#ifdef PNG_sCAL_SUPPORTED +PNG_FP_EXPORT(168, png_uint_32, png_get_sCAL, + (png_const_structp png_ptr, png_const_infop info_ptr, + int *unit, double *width, double *height)); +#ifdef PNG_FLOATING_ARITHMETIC_SUPPORTED +/* NOTE: this API is currently implemented using floating point arithmetic, + * consequently it can only be used on systems with floating point support. + * In any case the range of values supported by png_fixed_point is small and it + * is highly recommended that png_get_sCAL_s be used instead. + */ +PNG_FIXED_EXPORT(214, png_uint_32, png_get_sCAL_fixed, + (png_structp png_ptr, png_const_infop info_ptr, int *unit, + png_fixed_point *width, + png_fixed_point *height)); +#endif +PNG_EXPORT(169, png_uint_32, png_get_sCAL_s, + (png_const_structp png_ptr, png_const_infop info_ptr, + int *unit, png_charpp swidth, png_charpp sheight)); + +PNG_FP_EXPORT(170, void, png_set_sCAL, + (png_structp png_ptr, png_infop info_ptr, + int unit, double width, double height)); +PNG_FIXED_EXPORT(213, void, png_set_sCAL_fixed, (png_structp png_ptr, + png_infop info_ptr, int unit, png_fixed_point width, + png_fixed_point height)); +PNG_EXPORT(171, void, png_set_sCAL_s, + (png_structp png_ptr, png_infop info_ptr, + int unit, png_const_charp swidth, png_const_charp sheight)); +#endif /* PNG_sCAL_SUPPORTED */ + +#ifdef PNG_HANDLE_AS_UNKNOWN_SUPPORTED +/* Provide a list of chunks and how they are to be handled, if the built-in + handling or default unknown chunk handling is not desired. Any chunks not + listed will be handled in the default manner. The IHDR and IEND chunks + must not be listed. + keep = 0: follow default behaviour + = 1: do not keep + = 2: keep only if safe-to-copy + = 3: keep even if unsafe-to-copy +*/ +PNG_EXPORT(172, void, png_set_keep_unknown_chunks, + (png_structp png_ptr, int keep, + png_const_bytep chunk_list, int num_chunks)); +PNG_EXPORT(173, int, png_handle_as_unknown, (png_structp png_ptr, + png_const_bytep chunk_name)); +#endif +#ifdef PNG_UNKNOWN_CHUNKS_SUPPORTED +PNG_EXPORT(174, void, png_set_unknown_chunks, (png_structp png_ptr, + png_infop info_ptr, png_const_unknown_chunkp unknowns, + int num_unknowns)); +PNG_EXPORT(175, void, png_set_unknown_chunk_location, + (png_structp png_ptr, png_infop info_ptr, int chunk, int location)); +PNG_EXPORT(176, int, png_get_unknown_chunks, (png_const_structp png_ptr, + png_const_infop info_ptr, png_unknown_chunkpp entries)); +#endif + +/* Png_free_data() will turn off the "valid" flag for anything it frees. + * If you need to turn it off for a chunk that your application has freed, + * you can use png_set_invalid(png_ptr, info_ptr, PNG_INFO_CHNK); + */ +PNG_EXPORT(177, void, png_set_invalid, + (png_structp png_ptr, png_infop info_ptr, int mask)); + +#ifdef PNG_INFO_IMAGE_SUPPORTED +/* The "params" pointer is currently not used and is for future expansion. */ +PNG_EXPORT(178, void, png_read_png, (png_structp png_ptr, png_infop info_ptr, + int transforms, png_voidp params)); +PNG_EXPORT(179, void, png_write_png, (png_structp png_ptr, png_infop info_ptr, + int transforms, png_voidp params)); +#endif + +PNG_EXPORT(180, png_const_charp, png_get_copyright, + (png_const_structp png_ptr)); +PNG_EXPORT(181, png_const_charp, png_get_header_ver, + (png_const_structp png_ptr)); +PNG_EXPORT(182, png_const_charp, png_get_header_version, + (png_const_structp png_ptr)); +PNG_EXPORT(183, png_const_charp, png_get_libpng_ver, + (png_const_structp png_ptr)); + +#ifdef PNG_MNG_FEATURES_SUPPORTED +PNG_EXPORT(184, png_uint_32, png_permit_mng_features, (png_structp png_ptr, + png_uint_32 mng_features_permitted)); +#endif + +/* For use in png_set_keep_unknown, added to version 1.2.6 */ +#define PNG_HANDLE_CHUNK_AS_DEFAULT 0 +#define PNG_HANDLE_CHUNK_NEVER 1 +#define PNG_HANDLE_CHUNK_IF_SAFE 2 +#define PNG_HANDLE_CHUNK_ALWAYS 3 + +/* Strip the prepended error numbers ("#nnn ") from error and warning + * messages before passing them to the error or warning handler. + */ +#ifdef PNG_ERROR_NUMBERS_SUPPORTED +PNG_EXPORT(185, void, png_set_strip_error_numbers, + (png_structp png_ptr, + png_uint_32 strip_mode)); +#endif + +/* Added in libpng-1.2.6 */ +#ifdef PNG_SET_USER_LIMITS_SUPPORTED +PNG_EXPORT(186, void, png_set_user_limits, (png_structp png_ptr, + png_uint_32 user_width_max, png_uint_32 user_height_max)); +PNG_EXPORT(187, png_uint_32, png_get_user_width_max, + (png_const_structp png_ptr)); +PNG_EXPORT(188, png_uint_32, png_get_user_height_max, + (png_const_structp png_ptr)); +/* Added in libpng-1.4.0 */ +PNG_EXPORT(189, void, png_set_chunk_cache_max, (png_structp png_ptr, + png_uint_32 user_chunk_cache_max)); +PNG_EXPORT(190, png_uint_32, png_get_chunk_cache_max, + (png_const_structp png_ptr)); +/* Added in libpng-1.4.1 */ +PNG_EXPORT(191, void, png_set_chunk_malloc_max, (png_structp png_ptr, + png_alloc_size_t user_chunk_cache_max)); +PNG_EXPORT(192, png_alloc_size_t, png_get_chunk_malloc_max, + (png_const_structp png_ptr)); +#endif + +#if defined(PNG_INCH_CONVERSIONS_SUPPORTED) +PNG_EXPORT(193, png_uint_32, png_get_pixels_per_inch, + (png_const_structp png_ptr, png_const_infop info_ptr)); + +PNG_EXPORT(194, png_uint_32, png_get_x_pixels_per_inch, + (png_const_structp png_ptr, png_const_infop info_ptr)); + +PNG_EXPORT(195, png_uint_32, png_get_y_pixels_per_inch, + (png_const_structp png_ptr, png_const_infop info_ptr)); + +PNG_FP_EXPORT(196, float, png_get_x_offset_inches, + (png_const_structp png_ptr, png_const_infop info_ptr)); +#ifdef PNG_FIXED_POINT_SUPPORTED /* otherwise not implemented. */ +PNG_FIXED_EXPORT(211, png_fixed_point, png_get_x_offset_inches_fixed, + (png_structp png_ptr, png_const_infop info_ptr)); +#endif + +PNG_FP_EXPORT(197, float, png_get_y_offset_inches, (png_const_structp png_ptr, + png_const_infop info_ptr)); +#ifdef PNG_FIXED_POINT_SUPPORTED /* otherwise not implemented. */ +PNG_FIXED_EXPORT(212, png_fixed_point, png_get_y_offset_inches_fixed, + (png_structp png_ptr, png_const_infop info_ptr)); +#endif + +# ifdef PNG_pHYs_SUPPORTED +PNG_EXPORT(198, png_uint_32, png_get_pHYs_dpi, (png_const_structp png_ptr, + png_const_infop info_ptr, png_uint_32 *res_x, png_uint_32 *res_y, + int *unit_type)); +# endif /* PNG_pHYs_SUPPORTED */ +#endif /* PNG_INCH_CONVERSIONS_SUPPORTED */ + +/* Added in libpng-1.4.0 */ +#ifdef PNG_IO_STATE_SUPPORTED +PNG_EXPORT(199, png_uint_32, png_get_io_state, (png_structp png_ptr)); + +PNG_EXPORTA(200, png_const_bytep, png_get_io_chunk_name, + (png_structp png_ptr), PNG_DEPRECATED); +PNG_EXPORT(216, png_uint_32, png_get_io_chunk_type, + (png_const_structp png_ptr)); + +/* The flags returned by png_get_io_state() are the following: */ +# define PNG_IO_NONE 0x0000 /* no I/O at this moment */ +# define PNG_IO_READING 0x0001 /* currently reading */ +# define PNG_IO_WRITING 0x0002 /* currently writing */ +# define PNG_IO_SIGNATURE 0x0010 /* currently at the file signature */ +# define PNG_IO_CHUNK_HDR 0x0020 /* currently at the chunk header */ +# define PNG_IO_CHUNK_DATA 0x0040 /* currently at the chunk data */ +# define PNG_IO_CHUNK_CRC 0x0080 /* currently at the chunk crc */ +# define PNG_IO_MASK_OP 0x000f /* current operation: reading/writing */ +# define PNG_IO_MASK_LOC 0x00f0 /* current location: sig/hdr/data/crc */ +#endif /* ?PNG_IO_STATE_SUPPORTED */ + +/* Interlace support. The following macros are always defined so that if + * libpng interlace handling is turned off the macros may be used to handle + * interlaced images within the application. + */ +#define PNG_INTERLACE_ADAM7_PASSES 7 + +/* Two macros to return the first row and first column of the original, + * full, image which appears in a given pass. 'pass' is in the range 0 + * to 6 and the result is in the range 0 to 7. + */ +#define PNG_PASS_START_ROW(pass) (((1U&~(pass))<<(3-((pass)>>1)))&7) +#define PNG_PASS_START_COL(pass) (((1U& (pass))<<(3-(((pass)+1)>>1)))&7) + +/* Two macros to help evaluate the number of rows or columns in each + * pass. This is expressed as a shift - effectively log2 of the number or + * rows or columns in each 8x8 tile of the original image. + */ +#define PNG_PASS_ROW_SHIFT(pass) ((pass)>2?(8-(pass))>>1:3) +#define PNG_PASS_COL_SHIFT(pass) ((pass)>1?(7-(pass))>>1:3) + +/* Hence two macros to determine the number of rows or columns in a given + * pass of an image given its height or width. In fact these macros may + * return non-zero even though the sub-image is empty, because the other + * dimension may be empty for a small image. + */ +#define PNG_PASS_ROWS(height, pass) (((height)+(((1<<PNG_PASS_ROW_SHIFT(pass))\ + -1)-PNG_PASS_START_ROW(pass)))>>PNG_PASS_ROW_SHIFT(pass)) +#define PNG_PASS_COLS(width, pass) (((width)+(((1<<PNG_PASS_COL_SHIFT(pass))\ + -1)-PNG_PASS_START_COL(pass)))>>PNG_PASS_COL_SHIFT(pass)) + +/* For the progressive reader it is necessary to find the row in the output + * image given a row in an interlaced image, so two more macros: + */ +#define PNG_ROW_FROM_PASS_ROW(yIn, pass) \ + (((yIn)<<PNG_PASS_ROW_SHIFT(pass))+PNG_PASS_START_ROW(pass)) +#define PNG_COL_FROM_PASS_COL(xIn, pass) \ + (((xIn)<<PNG_PASS_COL_SHIFT(pass))+PNG_PASS_START_COL(pass)) + +/* Two macros which return a boolean (0 or 1) saying whether the given row + * or column is in a particular pass. These use a common utility macro that + * returns a mask for a given pass - the offset 'off' selects the row or + * column version. The mask has the appropriate bit set for each column in + * the tile. + */ +#define PNG_PASS_MASK(pass,off) ( \ + ((0x110145AFU>>(((7-(off))-(pass))<<2)) & 0xFU) | \ + ((0x01145AF0U>>(((7-(off))-(pass))<<2)) & 0xF0U)) + +#define PNG_ROW_IN_INTERLACE_PASS(y, pass) \ + ((PNG_PASS_MASK(pass,0) >> ((y)&7)) & 1) +#define PNG_COL_IN_INTERLACE_PASS(x, pass) \ + ((PNG_PASS_MASK(pass,1) >> ((x)&7)) & 1) + +#ifdef PNG_READ_COMPOSITE_NODIV_SUPPORTED +/* With these routines we avoid an integer divide, which will be slower on + * most machines. However, it does take more operations than the corresponding + * divide method, so it may be slower on a few RISC systems. There are two + * shifts (by 8 or 16 bits) and an addition, versus a single integer divide. + * + * Note that the rounding factors are NOT supposed to be the same! 128 and + * 32768 are correct for the NODIV code; 127 and 32767 are correct for the + * standard method. + * + * [Optimized code by Greg Roelofs and Mark Adler...blame us for bugs. :-) ] + */ + + /* fg and bg should be in `gamma 1.0' space; alpha is the opacity */ + +# define png_composite(composite, fg, alpha, bg) \ + { png_uint_16 temp = (png_uint_16)((png_uint_16)(fg) \ + * (png_uint_16)(alpha) \ + + (png_uint_16)(bg)*(png_uint_16)(255 \ + - (png_uint_16)(alpha)) + (png_uint_16)128); \ + (composite) = (png_byte)((temp + (temp >> 8)) >> 8); } + +# define png_composite_16(composite, fg, alpha, bg) \ + { png_uint_32 temp = (png_uint_32)((png_uint_32)(fg) \ + * (png_uint_32)(alpha) \ + + (png_uint_32)(bg)*(png_uint_32)(65535L \ + - (png_uint_32)(alpha)) + (png_uint_32)32768L); \ + (composite) = (png_uint_16)((temp + (temp >> 16)) >> 16); } + +#else /* Standard method using integer division */ + +# define png_composite(composite, fg, alpha, bg) \ + (composite) = (png_byte)(((png_uint_16)(fg) * (png_uint_16)(alpha) + \ + (png_uint_16)(bg) * (png_uint_16)(255 - (png_uint_16)(alpha)) + \ + (png_uint_16)127) / 255) + +# define png_composite_16(composite, fg, alpha, bg) \ + (composite) = (png_uint_16)(((png_uint_32)(fg) * (png_uint_32)(alpha) + \ + (png_uint_32)(bg)*(png_uint_32)(65535L - (png_uint_32)(alpha)) + \ + (png_uint_32)32767) / (png_uint_32)65535L) +#endif /* PNG_READ_COMPOSITE_NODIV_SUPPORTED */ + +#ifdef PNG_READ_INT_FUNCTIONS_SUPPORTED +PNG_EXPORT(201, png_uint_32, png_get_uint_32, (png_const_bytep buf)); +PNG_EXPORT(202, png_uint_16, png_get_uint_16, (png_const_bytep buf)); +PNG_EXPORT(203, png_int_32, png_get_int_32, (png_const_bytep buf)); +#endif + +PNG_EXPORT(204, png_uint_32, png_get_uint_31, (png_structp png_ptr, + png_const_bytep buf)); +/* No png_get_int_16 -- may be added if there's a real need for it. */ + +/* Place a 32-bit number into a buffer in PNG byte order (big-endian). */ +#ifdef PNG_WRITE_INT_FUNCTIONS_SUPPORTED +PNG_EXPORT(205, void, png_save_uint_32, (png_bytep buf, png_uint_32 i)); +#endif +#ifdef PNG_SAVE_INT_32_SUPPORTED +PNG_EXPORT(206, void, png_save_int_32, (png_bytep buf, png_int_32 i)); +#endif + +/* Place a 16-bit number into a buffer in PNG byte order. + * The parameter is declared unsigned int, not png_uint_16, + * just to avoid potential problems on pre-ANSI C compilers. + */ +#ifdef PNG_WRITE_INT_FUNCTIONS_SUPPORTED +PNG_EXPORT(207, void, png_save_uint_16, (png_bytep buf, unsigned int i)); +/* No png_save_int_16 -- may be added if there's a real need for it. */ +#endif + +#ifdef PNG_USE_READ_MACROS +/* Inline macros to do direct reads of bytes from the input buffer. + * The png_get_int_32() routine assumes we are using two's complement + * format for negative values, which is almost certainly true. + */ +# define png_get_uint_32(buf) \ + (((png_uint_32)(*(buf)) << 24) + \ + ((png_uint_32)(*((buf) + 1)) << 16) + \ + ((png_uint_32)(*((buf) + 2)) << 8) + \ + ((png_uint_32)(*((buf) + 3)))) + + /* From libpng-1.4.0 until 1.4.4, the png_get_uint_16 macro (but not the + * function) incorrectly returned a value of type png_uint_32. + */ +# define png_get_uint_16(buf) \ + ((png_uint_16) \ + (((unsigned int)(*(buf)) << 8) + \ + ((unsigned int)(*((buf) + 1))))) + +# define png_get_int_32(buf) \ + ((png_int_32)((*(buf) & 0x80) \ + ? -((png_int_32)((png_get_uint_32(buf) ^ 0xffffffffL) + 1)) \ + : (png_int_32)png_get_uint_32(buf))) +#endif + +/* Maintainer: Put new public prototypes here ^, in libpng.3, and project + * defs + */ + +/* The last ordinal number (this is the *last* one already used; the next + * one to use is one more than this.) Maintainer, remember to add an entry to + * scripts/symbols.def as well. + */ +#ifdef PNG_EXPORT_LAST_ORDINAL + PNG_EXPORT_LAST_ORDINAL(220); +#endif + +#ifdef __cplusplus +} +#endif + +#endif /* PNG_VERSION_INFO_ONLY */ +/* Do not put anything past this line */ +#endif /* PNG_H */ diff --git a/src/3rdparty/libpng/pngconf.h b/src/3rdparty/libpng/pngconf.h new file mode 100644 index 0000000000..d0b34549cb --- /dev/null +++ b/src/3rdparty/libpng/pngconf.h @@ -0,0 +1,639 @@ + +/* pngconf.h - machine configurable file for libpng + * + * libpng version 1.5.1 - February 3, 2011 + * + * Copyright (c) 1998-2011 Glenn Randers-Pehrson + * (Version 0.96 Copyright (c) 1996, 1997 Andreas Dilger) + * (Version 0.88 Copyright (c) 1995, 1996 Guy Eric Schalnat, Group 42, Inc.) + * + * This code is released under the libpng license. + * For conditions of distribution and use, see the disclaimer + * and license in png.h + * + */ + +/* Any machine specific code is near the front of this file, so if you + * are configuring libpng for a machine, you may want to read the section + * starting here down to where it starts to typedef png_color, png_text, + * and png_info. + */ + +#ifndef PNGCONF_H +#define PNGCONF_H + +/* PNG_NO_LIMITS_H may be used to turn off the use of the standard C + * definition file for machine specific limits, this may impact the + * correctness of the definitons below (see uses of INT_MAX). + */ +#ifndef PNG_NO_LIMITS_H +# include <limits.h> +#endif + +/* For the memory copy APIs (i.e. the standard definitions of these), + * because this file defines png_memcpy and so on the base APIs must + * be defined here. + */ +#if defined(BSD) && !defined(VXWORKS) +# include <strings.h> +#else +# include <string.h> +#endif + +/* For png_FILE_p - this provides the standard definition of a + * FILE + */ +#ifdef PNG_STDIO_SUPPORTED +# include <stdio.h> +#endif + +/* This controls optimization of the reading of 16 and 32 bit values + * from PNG files. It can be set on a per-app-file basis - it + * just changes whether a macro is used to the function is called. + * The library builder sets the default, if read functions are not + * built into the library the macro implementation is forced on. + */ +#ifndef PNG_READ_INT_FUNCTIONS_SUPPORTED +# define PNG_USE_READ_MACROS +#endif +#if !defined(PNG_NO_USE_READ_MACROS) && !defined(PNG_USE_READ_MACROS) +# if PNG_DEFAULT_READ_MACROS +# define PNG_USE_READ_MACROS +# endif +#endif + +/* COMPILER SPECIFIC OPTIONS. + * + * These options are provided so that a variety of difficult compilers + * can be used. Some are fixed at build time (e.g. PNG_API_RULE + * below) but still have compiler specific implementations, others + * may be changed on a per-file basis when compiling against libpng. + */ + +/* The PNGARG macro protects us against machines that don't have function + * prototypes (ie K&R style headers). If your compiler does not handle + * function prototypes, define this macro and use the included ansi2knr. + * I've always been able to use _NO_PROTO as the indicator, but you may + * need to drag the empty declaration out in front of here, or change the + * ifdef to suit your own needs. + */ +#ifndef PNGARG + +# ifdef OF /* zlib prototype munger */ +# define PNGARG(arglist) OF(arglist) +# else + +# ifdef _NO_PROTO +# define PNGARG(arglist) () +# else +# define PNGARG(arglist) arglist +# endif /* _NO_PROTO */ + +# endif /* OF */ + +#endif /* PNGARG */ + +/* Function calling conventions. + * ============================= + * Normally it is not necessary to specify to the compiler how to call + * a function - it just does it - however on x86 systems derived from + * Microsoft and Borland C compilers ('IBM PC', 'DOS', 'Windows' systems + * and some others) there are multiple ways to call a function and the + * default can be changed on the compiler command line. For this reason + * libpng specifies the calling convention of every exported function and + * every function called via a user supplied function pointer. This is + * done in this file by defining the following macros: + * + * PNGAPI Calling convention for exported functions. + * PNGCBAPI Calling convention for user provided (callback) functions. + * PNGCAPI Calling convention used by the ANSI-C library (required + * for longjmp callbacks and sometimes used internally to + * specify the calling convention for zlib). + * + * These macros should never be overridden. If it is necessary to + * change calling convention in a private build this can be done + * by setting PNG_API_RULE (which defaults to 0) to one of the values + * below to select the correct 'API' variants. + * + * PNG_API_RULE=0 Use PNGCAPI - the 'C' calling convention - throughout. + * This is correct in every known environment. + * PNG_API_RULE=1 Use the operating system convention for PNGAPI and + * the 'C' calling convention (from PNGCAPI) for + * callbacks (PNGCBAPI). This is no longer required + * in any known environment - if it has to be used + * please post an explanation of the problem to the + * libpng mailing list. + * + * These cases only differ if the operating system does not use the C + * calling convention, at present this just means the above cases + * (x86 DOS/Windows sytems) and, even then, this does not apply to + * Cygwin running on those systems. + * + * Note that the value must be defined in pnglibconf.h so that what + * the application uses to call the library matches the conventions + * set when building the library. + */ + +/* Symbol export + * ============= + * When building a shared library it is almost always necessary to tell + * the compiler which symbols to export. The png.h macro 'PNG_EXPORT' + * is used to mark the symbols. On some systems these symbols can be + * extracted at link time and need no special processing by the compiler, + * on other systems the symbols are flagged by the compiler and just + * the declaration requires a special tag applied (unfortunately) in a + * compiler dependent way. Some systems can do either. + * + * A small number of older systems also require a symbol from a DLL to + * be flagged to the program that calls it. This is a problem because + * we do not know in the header file included by application code that + * the symbol will come from a shared library, as opposed to a statically + * linked one. For this reason the application must tell us by setting + * the magic flag PNG_USE_DLL to turn on the special processing before + * it includes png.h. + * + * Four additional macros are used to make this happen: + * + * PNG_IMPEXP The magic (if any) to cause a symbol to be exported from + * the build or imported if PNG_USE_DLL is set - compiler + * and system specific. + * + * PNG_EXPORT_TYPE(type) A macro that pre or appends PNG_IMPEXP to + * 'type', compiler specific. + * + * PNG_DLL_EXPORT Set to the magic to use during a libpng build to + * make a symbol exported from the DLL. + * + * PNG_DLL_IMPORT Set to the magic to force the libpng symbols to come + * from a DLL - used to define PNG_IMPEXP when + * PNG_USE_DLL is set. + */ + +/* System specific discovery. + * ========================== + * This code is used at build time to find PNG_IMPEXP, the API settings + * and PNG_EXPORT_TYPE(), it may also set a macro to indicate the DLL + * import processing is possible. On Windows/x86 systems it also sets + * compiler-specific macros to the values required to change the calling + * conventions of the various functions. + */ +#if ( defined(_Windows) || defined(_WINDOWS) || defined(WIN32) ||\ + defined(_WIN32) || defined(__WIN32__) || defined(__CYGWIN__) ) &&\ + ( defined(_X86_) || defined(_X64_) || defined(_M_IX86) ||\ + defined(_M_X64) || defined(_M_IA64) ) + /* Windows system (DOS doesn't support DLLs) running on x86/x64. Includes + * builds under Cygwin or MinGW. Also includes Watcom builds but these need + * special treatment because they are not compatible with GCC or Visual C + * because of different calling conventions. + */ +# if PNG_API_RULE == 2 + /* If this line results in an error, either because __watcall is not + * understood or because of a redefine just below you cannot use *this* + * build of the library with the compiler you are using. *This* build was + * build using Watcom and applications must also be built using Watcom! + */ +# define PNGCAPI __watcall +# endif + +# if defined(__GNUC__) || (defined (_MSC_VER) && (_MSC_VER >= 800)) || defined(__WINSCW__) +# define PNGCAPI __cdecl +# if PNG_API_RULE == 1 +# define PNGAPI __stdcall +# endif +# else + /* An older compiler, or one not detected (erroneously) above, + * if necessary override on the command line to get the correct + * variants for the compiler. + */ +# ifndef PNGCAPI +# define PNGCAPI _cdecl +# endif +# if PNG_API_RULE == 1 && !defined(PNGAPI) +# define PNGAPI _stdcall +# endif +# endif /* compiler/api */ + /* NOTE: PNGCBAPI always defaults to PNGCAPI. */ + +# if defined(PNGAPI) && !defined(PNG_USER_PRIVATEBUILD) + ERROR: PNG_USER_PRIVATEBUILD must be defined if PNGAPI is changed +# endif + +# if (defined(_MSC_VER) && _MSC_VER < 800) ||\ + (defined(__BORLANDC__) && __BORLANDC__ < 0x500) + /* older Borland and MSC + * compilers used '__export' and required this to be after + * the type. + */ +# ifndef PNG_EXPORT_TYPE +# define PNG_EXPORT_TYPE(type) type PNG_IMPEXP +# endif +# define PNG_DLL_EXPORT __export +# else /* newer compiler */ +# define PNG_DLL_EXPORT __declspec(dllexport) +# ifndef PNG_DLL_IMPORT +# define PNG_DLL_IMPORT __declspec(dllimport) +# endif +# endif /* compiler */ + +#else /* !Windows/x86 */ +# if (defined(__IBMC__) || defined(__IBMCPP__)) && defined(__OS2__) +# define PNGAPI _System +# else /* !Windows/x86 && !OS/2 */ + /* Use the defaults, or define PNG*API on the command line (but + * this will have to be done for every compile!) + */ +# endif /* other system, !OS/2 */ +#endif /* !Windows/x86 */ + +/* Now do all the defaulting . */ +#ifndef PNGCAPI +# define PNGCAPI +#endif +#ifndef PNGCBAPI +# define PNGCBAPI PNGCAPI +#endif +#ifndef PNGAPI +# define PNGAPI PNGCAPI +#endif + +/* The default for PNG_IMPEXP depends on whether the library is + * being built or used. + */ +#ifndef PNG_IMPEXP +# ifdef PNGLIB_BUILD + /* Building the library */ +# if (defined(DLL_EXPORT)/*from libtool*/ ||\ + defined(_WINDLL) || defined(_DLL) || defined(__DLL__) ||\ + defined(_USRDLL) ||\ + defined(PNG_BUILD_DLL)) && defined(PNG_DLL_EXPORT) + /* Building a DLL. */ +# define PNG_IMPEXP PNG_DLL_EXPORT +# endif /* DLL */ +# else + /* Using the library */ +# if defined(PNG_USE_DLL) && defined(PNG_DLL_IMPORT) + /* This forces use of a DLL, disallowing static linking */ +# define PNG_IMPEXP PNG_DLL_IMPORT +# endif +# endif + +# if !defined(PNG_IMPEXP) +# include <qconfig.h> +# if defined(QT_VISIBILITY_AVAILABLE) +# define PNG_IMPEXP __attribute__((visibility("default"))) +# endif +# endif + +# ifndef PNG_IMPEXP +# define PNG_IMPEXP +# endif +#endif + +/* THe following complexity is concerned with getting the 'attributes' of the + * declared function in the correct place. This potentially requires a separate + * PNG_EXPORT function for every compiler. + */ +#ifndef PNG_FUNCTION +# ifdef __GNUC__ +# define PNG_FUNCTION(type, name, args, attributes)\ + attributes type name args +# else /* !GNUC */ +# ifdef _MSC_VER +# define PNG_FUNCTION(type, name, args, attributes)\ + attributes type name args +# else /* !MSC */ +# define PNG_FUNCTION(type, name, args, attributes)\ + type name args +# endif +# endif +#endif + +#ifndef PNG_EXPORT_TYPE +# define PNG_EXPORT_TYPE(type) PNG_IMPEXP type +#endif + + /* The ordinal value is only relevant when preprocessing png.h for symbol + * table entries, so we discard it here. See the .dfn files in the + * scripts directory. + */ +#ifndef PNG_EXPORTA +# define PNG_EXPORTA(ordinal, type, name, args, attributes)\ + extern PNG_FUNCTION(PNG_EXPORT_TYPE(type),(PNGAPI name),PNGARG(args),\ + attributes) +#endif + +#define PNG_EXPORT(ordinal, type, name, args)\ + PNG_EXPORTA(ordinal, type, name, args, ) + +/* Use PNG_REMOVED to comment out a removed interface. */ +#ifndef PNG_REMOVED +# define PNG_REMOVED(ordinal, type, name, args, attributes) +#endif + +#ifndef PNG_CALLBACK +# define PNG_CALLBACK(type, name, args, attributes)\ + type (PNGCBAPI name) PNGARG(args) attributes +#endif + +/* Support for compiler specific function attributes. These are used + * so that where compiler support is available incorrect use of API + * functions in png.h will generate compiler warnings. + * + * Added at libpng-1.2.41. + */ + +#ifndef PNG_NO_PEDANTIC_WARNINGS +# ifndef PNG_PEDANTIC_WARNINGS_SUPPORTED +# define PNG_PEDANTIC_WARNINGS_SUPPORTED +# endif +#endif + +#ifdef PNG_PEDANTIC_WARNINGS_SUPPORTED + /* Support for compiler specific function attributes. These are used + * so that where compiler support is available incorrect use of API + * functions in png.h will generate compiler warnings. Added at libpng + * version 1.2.41. + */ +# ifdef __GNUC__ +# ifndef PNG_USE_RESULT +# define PNG_USE_RESULT __attribute__((__warn_unused_result__)) +# endif +# ifndef PNG_NORETURN +# define PNG_NORETURN __attribute__((__noreturn__)) +# endif +# ifndef PNG_PTR_NORETURN +# define PNG_PTR_NORETURN __attribute__((__noreturn__)) +# endif +# ifndef PNG_ALLOCATED +# define PNG_ALLOCATED __attribute__((__malloc__)) +# endif + + /* This specifically protects structure members that should only be + * accessed from within the library, therefore should be empty during + * a library build. + */ +# ifndef PNGLIB_BUILD +# ifndef PNG_DEPRECATED +# define PNG_DEPRECATED __attribute__((__deprecated__)) +# endif +# ifndef PNG_DEPSTRUCT +# define PNG_DEPSTRUCT __attribute__((__deprecated__)) +# endif +# ifndef PNG_PRIVATE +# if 0 /* Doesn't work so we use deprecated instead*/ +# define PNG_PRIVATE \ + __attribute__((warning("This function is not exported by libpng."))) +# else +# define PNG_PRIVATE \ + __attribute__((__deprecated__)) +# endif +# endif /* PNG_PRIVATE */ +# endif /* PNGLIB_BUILD */ +# endif /* __GNUC__ */ +# ifdef _MSC_VER /* may need to check value */ +# ifndef PNG_USE_RESULT +# define PNG_USE_RESULT /*not supported*/ +# endif +# ifndef PNG_NORETURN +# define PNG_NORETURN __declspec(noreturn) +# endif +# ifndef PNG_PTR_NORETURN +# define PNG_PTR_NORETURN /*not supported*/ +# endif +# ifndef PNG_ALLOCATED +# define PNG_ALLOCATED __declspec(restrict) +# endif + + /* This specifically protects structure members that should only be + * accessed from within the library, therefore should be empty during + * a library build. + */ +# ifndef PNGLIB_BUILD +# ifndef PNG_DEPRECATED +# define PNG_DEPRECATED __declspec(deprecated) +# endif +# ifndef PNG_DEPSTRUCT +# define PNG_DEPSTRUCT __declspec(deprecated) +# endif +# ifndef PNG_PRIVATE +# define PNG_PRIVATE __declspec(deprecated) +# endif /* PNG_PRIVATE */ +# endif /* PNGLIB_BUILD */ +# endif /* __GNUC__ */ +#endif /* PNG_PEDANTIC_WARNINGS */ + +#ifndef PNG_DEPRECATED +# define PNG_DEPRECATED /* Use of this function is deprecated */ +#endif +#ifndef PNG_USE_RESULT +# define PNG_USE_RESULT /* The result of this function must be checked */ +#endif +#ifndef PNG_NORETURN +# define PNG_NORETURN /* This function does not return */ +#endif +#ifndef PNG_ALLOCATED +# define PNG_ALLOCATED /* The result of the function is new memory */ +#endif +#ifndef PNG_DEPSTRUCT +# define PNG_DEPSTRUCT /* Access to this struct member is deprecated */ +#endif +#ifndef PNG_PRIVATE +# define PNG_PRIVATE /* This is a private libpng function */ +#endif +#ifndef PNG_FP_EXPORT /* A floating point API. */ +# ifdef PNG_FLOATING_POINT_SUPPORTED +# define PNG_FP_EXPORT(ordinal, type, name, args)\ + PNG_EXPORT(ordinal, type, name, args) +# else /* No floating point APIs */ +# define PNG_FP_EXPORT(ordinal, type, name, args) +# endif +#endif +#ifndef PNG_FIXED_EXPORT /* A fixed point API. */ +# ifdef PNG_FIXED_POINT_SUPPORTED +# define PNG_FIXED_EXPORT(ordinal, type, name, args)\ + PNG_EXPORT(ordinal, type, name, args) +# else /* No fixed point APIs */ +# define PNG_FIXED_EXPORT(ordinal, type, name, args) +# endif +#endif + +/* The following uses const char * instead of char * for error + * and warning message functions, so some compilers won't complain. + * If you do not want to use const, define PNG_NO_CONST here. + * + * This should not change how the APIs are called, so it can be done + * on a per-file basis in the application. + */ +#ifndef PNG_CONST +# ifndef PNG_NO_CONST +# define PNG_CONST const +# else +# define PNG_CONST +# endif +#endif + +/* Some typedefs to get us started. These should be safe on most of the + * common platforms. The typedefs should be at least as large as the + * numbers suggest (a png_uint_32 must be at least 32 bits long), but they + * don't have to be exactly that size. Some compilers dislike passing + * unsigned shorts as function parameters, so you may be better off using + * unsigned int for png_uint_16. + */ + +#if defined(INT_MAX) && (INT_MAX > 0x7ffffffeL) +typedef unsigned int png_uint_32; +typedef int png_int_32; +#else +typedef unsigned long png_uint_32; +typedef long png_int_32; +#endif +typedef unsigned short png_uint_16; +typedef short png_int_16; +typedef unsigned char png_byte; + +#ifdef PNG_NO_SIZE_T +typedef unsigned int png_size_t; +#else +typedef size_t png_size_t; +#endif +#define png_sizeof(x) (sizeof (x)) + +/* The following is needed for medium model support. It cannot be in the + * pngpriv.h header. Needs modification for other compilers besides + * MSC. Model independent support declares all arrays and pointers to be + * large using the far keyword. The zlib version used must also support + * model independent data. As of version zlib 1.0.4, the necessary changes + * have been made in zlib. The USE_FAR_KEYWORD define triggers other + * changes that are needed. (Tim Wegner) + */ + +/* Separate compiler dependencies (problem here is that zlib.h always + * defines FAR. (SJT) + */ +#ifdef __BORLANDC__ +# if defined(__LARGE__) || defined(__HUGE__) || defined(__COMPACT__) +# define LDATA 1 +# else +# define LDATA 0 +# endif + /* GRR: why is Cygwin in here? Cygwin is not Borland C... */ +# if !defined(__WIN32__) && !defined(__FLAT__) && !defined(__CYGWIN__) +# define PNG_MAX_MALLOC_64K /* only used in build */ +# if (LDATA != 1) +# ifndef FAR +# define FAR __far +# endif +# define USE_FAR_KEYWORD +# endif /* LDATA != 1 */ + /* Possibly useful for moving data out of default segment. + * Uncomment it if you want. Could also define FARDATA as + * const if your compiler supports it. (SJT) +# define FARDATA FAR + */ +# endif /* __WIN32__, __FLAT__, __CYGWIN__ */ +#endif /* __BORLANDC__ */ + + +/* Suggest testing for specific compiler first before testing for + * FAR. The Watcom compiler defines both __MEDIUM__ and M_I86MM, + * making reliance oncertain keywords suspect. (SJT) + */ + +/* MSC Medium model */ +#ifdef FAR +# ifdef M_I86MM +# define USE_FAR_KEYWORD +# define FARDATA FAR +# include <dos.h> +# endif +#endif + +/* SJT: default case */ +#ifndef FAR +# define FAR +#endif + +/* At this point FAR is always defined */ +#ifndef FARDATA +# define FARDATA +#endif + +/* Typedef for floating-point numbers that are converted + * to fixed-point with a multiple of 100,000, e.g., gamma + */ +typedef png_int_32 png_fixed_point; + +/* Add typedefs for pointers */ +typedef void FAR * png_voidp; +typedef PNG_CONST void FAR * png_const_voidp; +typedef png_byte FAR * png_bytep; +typedef PNG_CONST png_byte FAR * png_const_bytep; +typedef png_uint_32 FAR * png_uint_32p; +typedef PNG_CONST png_uint_32 FAR * png_const_uint_32p; +typedef png_int_32 FAR * png_int_32p; +typedef PNG_CONST png_int_32 FAR * png_const_int_32p; +typedef png_uint_16 FAR * png_uint_16p; +typedef PNG_CONST png_uint_16 FAR * png_const_uint_16p; +typedef png_int_16 FAR * png_int_16p; +typedef PNG_CONST png_int_16 FAR * png_const_int_16p; +typedef char FAR * png_charp; +typedef PNG_CONST char FAR * png_const_charp; +typedef png_fixed_point FAR * png_fixed_point_p; +typedef PNG_CONST png_fixed_point FAR * png_const_fixed_point_p; +typedef png_size_t FAR * png_size_tp; +typedef PNG_CONST png_size_t FAR * png_const_size_tp; + +#ifdef PNG_STDIO_SUPPORTED +typedef FILE * png_FILE_p; +#endif + +#ifdef PNG_FLOATING_POINT_SUPPORTED +typedef double FAR * png_doublep; +typedef PNG_CONST double FAR * png_const_doublep; +#endif + +/* Pointers to pointers; i.e. arrays */ +typedef png_byte FAR * FAR * png_bytepp; +typedef png_uint_32 FAR * FAR * png_uint_32pp; +typedef png_int_32 FAR * FAR * png_int_32pp; +typedef png_uint_16 FAR * FAR * png_uint_16pp; +typedef png_int_16 FAR * FAR * png_int_16pp; +typedef PNG_CONST char FAR * FAR * png_const_charpp; +typedef char FAR * FAR * png_charpp; +typedef png_fixed_point FAR * FAR * png_fixed_point_pp; +#ifdef PNG_FLOATING_POINT_SUPPORTED +typedef double FAR * FAR * png_doublepp; +#endif + +/* Pointers to pointers to pointers; i.e., pointer to array */ +typedef char FAR * FAR * FAR * png_charppp; + +/* png_alloc_size_t is guaranteed to be no smaller than png_size_t, + * and no smaller than png_uint_32. Casts from png_size_t or png_uint_32 + * to png_alloc_size_t are not necessary; in fact, it is recommended + * not to use them at all so that the compiler can complain when something + * turns out to be problematic. + * Casts in the other direction (from png_alloc_size_t to png_size_t or + * png_uint_32) should be explicitly applied; however, we do not expect + * to encounter practical situations that require such conversions. + */ +#if defined(__TURBOC__) && !defined(__FLAT__) + typedef unsigned long png_alloc_size_t; +#else +# if defined(_MSC_VER) && defined(MAXSEG_64K) + typedef unsigned long png_alloc_size_t; +# else + /* This is an attempt to detect an old Windows system where (int) is + * actually 16 bits, in that case png_malloc must have an argument with a + * bigger size to accomodate the requirements of the library. + */ +# if (defined(_Windows) || defined(_WINDOWS) || defined(_WINDOWS_)) && \ + (!defined(INT_MAX) || INT_MAX <= 0x7ffffffeL) + typedef DWORD png_alloc_size_t; +# else + typedef png_size_t png_alloc_size_t; +# endif +# endif +#endif + +#endif /* PNGCONF_H */ diff --git a/src/3rdparty/libpng/pngdebug.h b/src/3rdparty/libpng/pngdebug.h new file mode 100644 index 0000000000..16f81fdd14 --- /dev/null +++ b/src/3rdparty/libpng/pngdebug.h @@ -0,0 +1,157 @@ + +/* pngdebug.h - Debugging macros for libpng, also used in pngtest.c + * + * Copyright (c) 1998-2011 Glenn Randers-Pehrson + * (Version 0.96 Copyright (c) 1996, 1997 Andreas Dilger) + * (Version 0.88 Copyright (c) 1995, 1996 Guy Eric Schalnat, Group 42, Inc.) + * + * Last changed in libpng 1.5.0 [January 6, 2011] + * + * This code is released under the libpng license. + * For conditions of distribution and use, see the disclaimer + * and license in png.h + */ + +/* Define PNG_DEBUG at compile time for debugging information. Higher + * numbers for PNG_DEBUG mean more debugging information. This has + * only been added since version 0.95 so it is not implemented throughout + * libpng yet, but more support will be added as needed. + * + * png_debug[1-2]?(level, message ,arg{0-2}) + * Expands to a statement (either a simple expression or a compound + * do..while(0) statement) that outputs a message with parameter + * substitution if PNG_DEBUG is defined to 2 or more. If PNG_DEBUG + * is undefined, 0 or 1 every png_debug expands to a simple expression + * (actually ((void)0)). + * + * level: level of detail of message, starting at 0. A level 'n' + * message is preceded by 'n' tab characters (not implemented + * on Microsoft compilers unless PNG_DEBUG_FILE is also + * defined, to allow debug DLL compilation with no standard IO). + * message: a printf(3) style text string. A trailing '\n' is added + * to the message. + * arg: 0 to 2 arguments for printf(3) style substitution in message. + */ +#ifndef PNGDEBUG_H +#define PNGDEBUG_H +/* These settings control the formatting of messages in png.c and pngerror.c */ +/* Moved to pngdebug.h at 1.5.0 */ +# ifndef PNG_LITERAL_SHARP +# define PNG_LITERAL_SHARP 0x23 +# endif +# ifndef PNG_LITERAL_LEFT_SQUARE_BRACKET +# define PNG_LITERAL_LEFT_SQUARE_BRACKET 0x5b +# endif +# ifndef PNG_LITERAL_RIGHT_SQUARE_BRACKET +# define PNG_LITERAL_RIGHT_SQUARE_BRACKET 0x5d +# endif +# ifndef PNG_STRING_NEWLINE +# define PNG_STRING_NEWLINE "\n" +# endif + +#ifdef PNG_DEBUG +# if (PNG_DEBUG > 0) +# if !defined(PNG_DEBUG_FILE) && defined(_MSC_VER) +# include <crtdbg.h> +# if (PNG_DEBUG > 1) +# ifndef _DEBUG +# define _DEBUG +# endif +# ifndef png_debug +# define png_debug(l,m) _RPT0(_CRT_WARN,m PNG_STRING_NEWLINE) +# endif +# ifndef png_debug1 +# define png_debug1(l,m,p1) _RPT1(_CRT_WARN,m PNG_STRING_NEWLINE,p1) +# endif +# ifndef png_debug2 +# define png_debug2(l,m,p1,p2) \ + _RPT2(_CRT_WARN,m PNG_STRING_NEWLINE,p1,p2) +# endif +# endif +# else /* PNG_DEBUG_FILE || !_MSC_VER */ +# ifndef PNG_STDIO_SUPPORTED +# include <stdio.h> /* not included yet */ +# endif +# ifndef PNG_DEBUG_FILE +# define PNG_DEBUG_FILE stderr +# endif /* PNG_DEBUG_FILE */ + +# if (PNG_DEBUG > 1) +/* Note: ["%s"m PNG_STRING_NEWLINE] probably does not work on + * non-ISO compilers + */ +# ifdef __STDC__ +# ifndef png_debug +# define png_debug(l,m) \ + do { \ + int num_tabs=l; \ + fprintf(PNG_DEBUG_FILE,"%s"m PNG_STRING_NEWLINE,(num_tabs==1 ? "\t" : \ + (num_tabs==2 ? "\t\t":(num_tabs>2 ? "\t\t\t":"")))); \ + } while (0) +# endif +# ifndef png_debug1 +# define png_debug1(l,m,p1) \ + do { \ + int num_tabs=l; \ + fprintf(PNG_DEBUG_FILE,"%s"m PNG_STRING_NEWLINE,(num_tabs==1 ? "\t" : \ + (num_tabs==2 ? "\t\t":(num_tabs>2 ? "\t\t\t":""))),p1); \ + } while (0) +# endif +# ifndef png_debug2 +# define png_debug2(l,m,p1,p2) \ + do { \ + int num_tabs=l; \ + fprintf(PNG_DEBUG_FILE,"%s"m PNG_STRING_NEWLINE,(num_tabs==1 ? "\t" : \ + (num_tabs==2 ? "\t\t":(num_tabs>2 ? "\t\t\t":""))),p1,p2); \ + } while (0) +# endif +# else /* __STDC __ */ +# ifndef png_debug +# define png_debug(l,m) \ + do { \ + int num_tabs=l; \ + char format[256]; \ + snprintf(format,256,"%s%s%s",(num_tabs==1 ? "\t" : \ + (num_tabs==2 ? "\t\t":(num_tabs>2 ? "\t\t\t":""))), \ + m,PNG_STRING_NEWLINE); \ + fprintf(PNG_DEBUG_FILE,format); \ + } while (0) +# endif +# ifndef png_debug1 +# define png_debug1(l,m,p1) \ + do { \ + int num_tabs=l; \ + char format[256]; \ + snprintf(format,256,"%s%s%s",(num_tabs==1 ? "\t" : \ + (num_tabs==2 ? "\t\t":(num_tabs>2 ? "\t\t\t":""))), \ + m,PNG_STRING_NEWLINE); \ + fprintf(PNG_DEBUG_FILE,format,p1); \ + } while (0) +# endif +# ifndef png_debug2 +# define png_debug2(l,m,p1,p2) \ + do { \ + int num_tabs=l; \ + char format[256]; \ + snprintf(format,256,"%s%s%s",(num_tabs==1 ? "\t" : \ + (num_tabs==2 ? "\t\t":(num_tabs>2 ? "\t\t\t":""))), \ + m,PNG_STRING_NEWLINE); \ + fprintf(PNG_DEBUG_FILE,format,p1,p2); \ + } while (0) +# endif +# endif /* __STDC __ */ +# endif /* (PNG_DEBUG > 1) */ + +# endif /* _MSC_VER */ +# endif /* (PNG_DEBUG > 0) */ +#endif /* PNG_DEBUG */ +#ifndef png_debug +# define png_debug(l, m) ((void)0) +#endif +#ifndef png_debug1 +# define png_debug1(l, m, p1) ((void)0) +#endif +#ifndef png_debug2 +# define png_debug2(l, m, p1, p2) ((void)0) +#endif +#endif /* PNGDEBUG_H */ diff --git a/src/3rdparty/libpng/pngerror.c b/src/3rdparty/libpng/pngerror.c new file mode 100644 index 0000000000..8290bb4106 --- /dev/null +++ b/src/3rdparty/libpng/pngerror.c @@ -0,0 +1,447 @@ + +/* pngerror.c - stub functions for i/o and memory allocation + * + * Last changed in libpng 1.5.1 [February 3, 2011] + * Copyright (c) 1998-2011 Glenn Randers-Pehrson + * (Version 0.96 Copyright (c) 1996, 1997 Andreas Dilger) + * (Version 0.88 Copyright (c) 1995, 1996 Guy Eric Schalnat, Group 42, Inc.) + * + * This code is released under the libpng license. + * For conditions of distribution and use, see the disclaimer + * and license in png.h + * + * This file provides a location for all error handling. Users who + * need special error handling are expected to write replacement functions + * and use png_set_error_fn() to use those functions. See the instructions + * at each function. + */ + +#include "pngpriv.h" + +#if defined(PNG_READ_SUPPORTED) || defined(PNG_WRITE_SUPPORTED) + +static PNG_FUNCTION(void, png_default_error,PNGARG((png_structp png_ptr, + png_const_charp error_message)),PNG_NORETURN); + +#ifdef PNG_WARNINGS_SUPPORTED +static void /* PRIVATE */ +png_default_warning PNGARG((png_structp png_ptr, + png_const_charp warning_message)); +#endif /* PNG_WARNINGS_SUPPORTED */ + +/* This function is called whenever there is a fatal error. This function + * should not be changed. If there is a need to handle errors differently, + * you should supply a replacement error function and use png_set_error_fn() + * to replace the error function at run-time. + */ +#ifdef PNG_ERROR_TEXT_SUPPORTED +PNG_FUNCTION(void,PNGAPI +png_error,(png_structp png_ptr, png_const_charp error_message),PNG_NORETURN) +{ +#ifdef PNG_ERROR_NUMBERS_SUPPORTED + char msg[16]; + if (png_ptr != NULL) + { + if (png_ptr->flags& + (PNG_FLAG_STRIP_ERROR_NUMBERS|PNG_FLAG_STRIP_ERROR_TEXT)) + { + if (*error_message == PNG_LITERAL_SHARP) + { + /* Strip "#nnnn " from beginning of error message. */ + int offset; + for (offset = 1; offset<15; offset++) + if (error_message[offset] == ' ') + break; + + if (png_ptr->flags&PNG_FLAG_STRIP_ERROR_TEXT) + { + int i; + for (i = 0; i < offset - 1; i++) + msg[i] = error_message[i + 1]; + msg[i - 1] = '\0'; + error_message = msg; + } + + else + error_message += offset; + } + + else + { + if (png_ptr->flags&PNG_FLAG_STRIP_ERROR_TEXT) + { + msg[0] = '0'; + msg[1] = '\0'; + error_message = msg; + } + } + } + } +#endif + if (png_ptr != NULL && png_ptr->error_fn != NULL) + (*(png_ptr->error_fn))(png_ptr, error_message); + + /* If the custom handler doesn't exist, or if it returns, + use the default handler, which will not return. */ + png_default_error(png_ptr, error_message); +} +#else +PNG_FUNCTION(void,PNGAPI +png_err,(png_structp png_ptr),PNG_NORETURN) +{ + if (png_ptr != NULL && png_ptr->error_fn != NULL) + (*(png_ptr->error_fn))(png_ptr, '\0'); + + /* If the custom handler doesn't exist, or if it returns, + use the default handler, which will not return. */ + png_default_error(png_ptr, '\0'); +} +#endif /* PNG_ERROR_TEXT_SUPPORTED */ + +#ifdef PNG_WARNINGS_SUPPORTED +/* This function is called whenever there is a non-fatal error. This function + * should not be changed. If there is a need to handle warnings differently, + * you should supply a replacement warning function and use + * png_set_error_fn() to replace the warning function at run-time. + */ +void PNGAPI +png_warning(png_structp png_ptr, png_const_charp warning_message) +{ + int offset = 0; + if (png_ptr != NULL) + { +#ifdef PNG_ERROR_NUMBERS_SUPPORTED + if (png_ptr->flags& + (PNG_FLAG_STRIP_ERROR_NUMBERS|PNG_FLAG_STRIP_ERROR_TEXT)) +#endif + { + if (*warning_message == PNG_LITERAL_SHARP) + { + for (offset = 1; offset < 15; offset++) + if (warning_message[offset] == ' ') + break; + } + } + } + if (png_ptr != NULL && png_ptr->warning_fn != NULL) + (*(png_ptr->warning_fn))(png_ptr, warning_message + offset); + else + png_default_warning(png_ptr, warning_message + offset); +} +#endif /* PNG_WARNINGS_SUPPORTED */ + +#ifdef PNG_BENIGN_ERRORS_SUPPORTED +void PNGAPI +png_benign_error(png_structp png_ptr, png_const_charp error_message) +{ + if (png_ptr->flags & PNG_FLAG_BENIGN_ERRORS_WARN) + png_warning(png_ptr, error_message); + else + png_error(png_ptr, error_message); +} +#endif + +/* These utilities are used internally to build an error message that relates + * to the current chunk. The chunk name comes from png_ptr->chunk_name, + * this is used to prefix the message. The message is limited in length + * to 63 bytes, the name characters are output as hex digits wrapped in [] + * if the character is invalid. + */ +#define isnonalpha(c) ((c) < 65 || (c) > 122 || ((c) > 90 && (c) < 97)) +static PNG_CONST char png_digit[16] = { + '0', '1', '2', '3', '4', '5', '6', '7', '8', '9', + 'A', 'B', 'C', 'D', 'E', 'F' +}; + +#define PNG_MAX_ERROR_TEXT 64 +#if defined(PNG_WARNINGS_SUPPORTED) || defined(PNG_ERROR_TEXT_SUPPORTED) +static void /* PRIVATE */ +png_format_buffer(png_structp png_ptr, png_charp buffer, png_const_charp + error_message) +{ + int iout = 0, iin = 0; + + while (iin < 4) + { + int c = png_ptr->chunk_name[iin++]; + if (isnonalpha(c)) + { + buffer[iout++] = PNG_LITERAL_LEFT_SQUARE_BRACKET; + buffer[iout++] = png_digit[(c & 0xf0) >> 4]; + buffer[iout++] = png_digit[c & 0x0f]; + buffer[iout++] = PNG_LITERAL_RIGHT_SQUARE_BRACKET; + } + + else + { + buffer[iout++] = (png_byte)c; + } + } + + if (error_message == NULL) + buffer[iout] = '\0'; + + else + { + buffer[iout++] = ':'; + buffer[iout++] = ' '; + png_memcpy(buffer + iout, error_message, PNG_MAX_ERROR_TEXT); + buffer[iout + PNG_MAX_ERROR_TEXT - 1] = '\0'; + } +} +#endif /* PNG_WARNINGS_SUPPORTED || PNG_ERROR_TEXT_SUPPORTED */ + +#if defined(PNG_READ_SUPPORTED) && defined(PNG_ERROR_TEXT_SUPPORTED) +PNG_FUNCTION(void,PNGAPI +png_chunk_error,(png_structp png_ptr, png_const_charp error_message), + PNG_NORETURN) +{ + char msg[18+PNG_MAX_ERROR_TEXT]; + if (png_ptr == NULL) + png_error(png_ptr, error_message); + + else + { + png_format_buffer(png_ptr, msg, error_message); + png_error(png_ptr, msg); + } +} +#endif /* PNG_READ_SUPPORTED && PNG_ERROR_TEXT_SUPPORTED */ + +#ifdef PNG_WARNINGS_SUPPORTED +void PNGAPI +png_chunk_warning(png_structp png_ptr, png_const_charp warning_message) +{ + char msg[18+PNG_MAX_ERROR_TEXT]; + if (png_ptr == NULL) + png_warning(png_ptr, warning_message); + + else + { + png_format_buffer(png_ptr, msg, warning_message); + png_warning(png_ptr, msg); + } +} +#endif /* PNG_WARNINGS_SUPPORTED */ + +#ifdef PNG_READ_SUPPORTED +#ifdef PNG_BENIGN_ERRORS_SUPPORTED +void PNGAPI +png_chunk_benign_error(png_structp png_ptr, png_const_charp error_message) +{ + if (png_ptr->flags & PNG_FLAG_BENIGN_ERRORS_WARN) + png_chunk_warning(png_ptr, error_message); + + else + png_chunk_error(png_ptr, error_message); +} +#endif +#endif /* PNG_READ_SUPPORTED */ + +#ifdef PNG_ERROR_TEXT_SUPPORTED +#ifdef PNG_FLOATING_POINT_SUPPORTED +PNG_FUNCTION(void, +png_fixed_error,(png_structp png_ptr, png_const_charp name),PNG_NORETURN) +{ +# define fixed_message "fixed point overflow in " +# define fixed_message_ln ((sizeof fixed_message)-1) + int iin; + char msg[fixed_message_ln+PNG_MAX_ERROR_TEXT]; + png_memcpy(msg, fixed_message, fixed_message_ln); + iin = 0; + if (name != NULL) while (iin < (PNG_MAX_ERROR_TEXT-1) && name[iin] != 0) + { + msg[fixed_message_ln + iin] = name[iin]; + ++iin; + } + msg[fixed_message_ln + iin] = 0; + png_error(png_ptr, msg); +} +#endif +#endif + +#ifdef PNG_SETJMP_SUPPORTED +/* This API only exists if ANSI-C style error handling is used, + * otherwise it is necessary for png_default_error to be overridden. + */ +jmp_buf* PNGAPI +png_set_longjmp_fn(png_structp png_ptr, png_longjmp_ptr longjmp_fn, + size_t jmp_buf_size) +{ + if (png_ptr == NULL || jmp_buf_size != png_sizeof(jmp_buf)) + return NULL; + + png_ptr->longjmp_fn = longjmp_fn; + return &png_ptr->png_jmpbuf; +} +#endif + +/* This is the default error handling function. Note that replacements for + * this function MUST NOT RETURN, or the program will likely crash. This + * function is used by default, or if the program supplies NULL for the + * error function pointer in png_set_error_fn(). + */ +static PNG_FUNCTION(void /* PRIVATE */, +png_default_error,(png_structp png_ptr, png_const_charp error_message), + PNG_NORETURN) +{ +#ifdef PNG_CONSOLE_IO_SUPPORTED +#ifdef PNG_ERROR_NUMBERS_SUPPORTED + if (*error_message == PNG_LITERAL_SHARP) + { + /* Strip "#nnnn " from beginning of error message. */ + int offset; + char error_number[16]; + for (offset = 0; offset<15; offset++) + { + error_number[offset] = error_message[offset + 1]; + if (error_message[offset] == ' ') + break; + } + + if ((offset > 1) && (offset < 15)) + { + error_number[offset - 1] = '\0'; + fprintf(stderr, "libpng error no. %s: %s", + error_number, error_message + offset + 1); + fprintf(stderr, PNG_STRING_NEWLINE); + } + + else + { + fprintf(stderr, "libpng error: %s, offset=%d", + error_message, offset); + fprintf(stderr, PNG_STRING_NEWLINE); + } + } + else +#endif + { + fprintf(stderr, "libpng error: %s", error_message); + fprintf(stderr, PNG_STRING_NEWLINE); + } +#endif +#ifndef PNG_CONSOLE_IO_SUPPORTED + PNG_UNUSED(error_message) /* Make compiler happy */ +#endif + png_longjmp(png_ptr, 1); +} + +PNG_FUNCTION(void,PNGAPI +png_longjmp,(png_structp png_ptr, int val),PNG_NORETURN) +{ +#ifdef PNG_SETJMP_SUPPORTED + if (png_ptr && png_ptr->longjmp_fn) + { +# ifdef USE_FAR_KEYWORD + { + jmp_buf png_jmpbuf; + png_memcpy(png_jmpbuf, png_ptr->png_jmpbuf, png_sizeof(jmp_buf)); + png_ptr->longjmp_fn(png_jmpbuf, val); + } + +# else + png_ptr->longjmp_fn(png_ptr->png_jmpbuf, val); +# endif + } +#endif + /* Here if not setjmp support or if png_ptr is null. */ + PNG_ABORT(); +} + +#ifdef PNG_WARNINGS_SUPPORTED +/* This function is called when there is a warning, but the library thinks + * it can continue anyway. Replacement functions don't have to do anything + * here if you don't want them to. In the default configuration, png_ptr is + * not used, but it is passed in case it may be useful. + */ +static void /* PRIVATE */ +png_default_warning(png_structp png_ptr, png_const_charp warning_message) +{ +#ifdef PNG_CONSOLE_IO_SUPPORTED +# ifdef PNG_ERROR_NUMBERS_SUPPORTED + if (*warning_message == PNG_LITERAL_SHARP) + { + int offset; + char warning_number[16]; + for (offset = 0; offset < 15; offset++) + { + warning_number[offset] = warning_message[offset + 1]; + if (warning_message[offset] == ' ') + break; + } + + if ((offset > 1) && (offset < 15)) + { + warning_number[offset + 1] = '\0'; + fprintf(stderr, "libpng warning no. %s: %s", + warning_number, warning_message + offset); + fprintf(stderr, PNG_STRING_NEWLINE); + } + + else + { + fprintf(stderr, "libpng warning: %s", + warning_message); + fprintf(stderr, PNG_STRING_NEWLINE); + } + } + else +# endif + + { + fprintf(stderr, "libpng warning: %s", warning_message); + fprintf(stderr, PNG_STRING_NEWLINE); + } +#else + PNG_UNUSED(warning_message) /* Make compiler happy */ +#endif + PNG_UNUSED(png_ptr) /* Make compiler happy */ +} +#endif /* PNG_WARNINGS_SUPPORTED */ + +/* This function is called when the application wants to use another method + * of handling errors and warnings. Note that the error function MUST NOT + * return to the calling routine or serious problems will occur. The return + * method used in the default routine calls longjmp(png_ptr->png_jmpbuf, 1) + */ +void PNGAPI +png_set_error_fn(png_structp png_ptr, png_voidp error_ptr, + png_error_ptr error_fn, png_error_ptr warning_fn) +{ + if (png_ptr == NULL) + return; + + png_ptr->error_ptr = error_ptr; + png_ptr->error_fn = error_fn; + png_ptr->warning_fn = warning_fn; +} + + +/* This function returns a pointer to the error_ptr associated with the user + * functions. The application should free any memory associated with this + * pointer before png_write_destroy and png_read_destroy are called. + */ +png_voidp PNGAPI +png_get_error_ptr(png_const_structp png_ptr) +{ + if (png_ptr == NULL) + return NULL; + + return ((png_voidp)png_ptr->error_ptr); +} + + +#ifdef PNG_ERROR_NUMBERS_SUPPORTED +void PNGAPI +png_set_strip_error_numbers(png_structp png_ptr, png_uint_32 strip_mode) +{ + if (png_ptr != NULL) + { + png_ptr->flags &= + ((~(PNG_FLAG_STRIP_ERROR_NUMBERS | + PNG_FLAG_STRIP_ERROR_TEXT))&strip_mode); + } +} +#endif +#endif /* PNG_READ_SUPPORTED || PNG_WRITE_SUPPORTED */ diff --git a/src/3rdparty/libpng/pngget.c b/src/3rdparty/libpng/pngget.c new file mode 100644 index 0000000000..b5e5798c02 --- /dev/null +++ b/src/3rdparty/libpng/pngget.c @@ -0,0 +1,1032 @@ + +/* pngget.c - retrieval of values from info struct + * + * Last changed in libpng 1.5.1 [February 3, 2011] + * Copyright (c) 1998-2011 Glenn Randers-Pehrson + * (Version 0.96 Copyright (c) 1996, 1997 Andreas Dilger) + * (Version 0.88 Copyright (c) 1995, 1996 Guy Eric Schalnat, Group 42, Inc.) + * + * This code is released under the libpng license. + * For conditions of distribution and use, see the disclaimer + * and license in png.h + * + */ + +#include "pngpriv.h" + +#if defined(PNG_READ_SUPPORTED) || defined(PNG_WRITE_SUPPORTED) + +png_uint_32 PNGAPI +png_get_valid(png_const_structp png_ptr, png_const_infop info_ptr, + png_uint_32 flag) +{ + if (png_ptr != NULL && info_ptr != NULL) + return(info_ptr->valid & flag); + + return(0); +} + +png_size_t PNGAPI +png_get_rowbytes(png_const_structp png_ptr, png_const_infop info_ptr) +{ + if (png_ptr != NULL && info_ptr != NULL) + return(info_ptr->rowbytes); + + return(0); +} + +#ifdef PNG_INFO_IMAGE_SUPPORTED +png_bytepp PNGAPI +png_get_rows(png_const_structp png_ptr, png_const_infop info_ptr) +{ + if (png_ptr != NULL && info_ptr != NULL) + return(info_ptr->row_pointers); + + return(0); +} +#endif + +#ifdef PNG_EASY_ACCESS_SUPPORTED +/* Easy access to info, added in libpng-0.99 */ +png_uint_32 PNGAPI +png_get_image_width(png_const_structp png_ptr, png_const_infop info_ptr) +{ + if (png_ptr != NULL && info_ptr != NULL) + return info_ptr->width; + + return (0); +} + +png_uint_32 PNGAPI +png_get_image_height(png_const_structp png_ptr, png_const_infop info_ptr) +{ + if (png_ptr != NULL && info_ptr != NULL) + return info_ptr->height; + + return (0); +} + +png_byte PNGAPI +png_get_bit_depth(png_const_structp png_ptr, png_const_infop info_ptr) +{ + if (png_ptr != NULL && info_ptr != NULL) + return info_ptr->bit_depth; + + return (0); +} + +png_byte PNGAPI +png_get_color_type(png_const_structp png_ptr, png_const_infop info_ptr) +{ + if (png_ptr != NULL && info_ptr != NULL) + return info_ptr->color_type; + + return (0); +} + +png_byte PNGAPI +png_get_filter_type(png_const_structp png_ptr, png_const_infop info_ptr) +{ + if (png_ptr != NULL && info_ptr != NULL) + return info_ptr->filter_type; + + return (0); +} + +png_byte PNGAPI +png_get_interlace_type(png_const_structp png_ptr, png_const_infop info_ptr) +{ + if (png_ptr != NULL && info_ptr != NULL) + return info_ptr->interlace_type; + + return (0); +} + +png_byte PNGAPI +png_get_compression_type(png_const_structp png_ptr, png_const_infop info_ptr) +{ + if (png_ptr != NULL && info_ptr != NULL) + return info_ptr->compression_type; + + return (0); +} + +png_uint_32 PNGAPI +png_get_x_pixels_per_meter(png_const_structp png_ptr, png_const_infop info_ptr) +{ +#ifdef PNG_pHYs_SUPPORTED + if (png_ptr != NULL && info_ptr != NULL && (info_ptr->valid & PNG_INFO_pHYs)) + { + png_debug1(1, "in %s retrieval function", + "png_get_x_pixels_per_meter"); + + if (info_ptr->phys_unit_type == PNG_RESOLUTION_METER) + return (info_ptr->x_pixels_per_unit); + } +#endif + + return (0); +} + +png_uint_32 PNGAPI +png_get_y_pixels_per_meter(png_const_structp png_ptr, png_const_infop info_ptr) +{ +#ifdef PNG_pHYs_SUPPORTED + if (png_ptr != NULL && info_ptr != NULL && (info_ptr->valid & PNG_INFO_pHYs)) + { + png_debug1(1, "in %s retrieval function", + "png_get_y_pixels_per_meter"); + + if (info_ptr->phys_unit_type == PNG_RESOLUTION_METER) + return (info_ptr->y_pixels_per_unit); + } +#endif + + return (0); +} + +png_uint_32 PNGAPI +png_get_pixels_per_meter(png_const_structp png_ptr, png_const_infop info_ptr) +{ +#ifdef PNG_pHYs_SUPPORTED + if (png_ptr != NULL && info_ptr != NULL && (info_ptr->valid & PNG_INFO_pHYs)) + { + png_debug1(1, "in %s retrieval function", "png_get_pixels_per_meter"); + + if (info_ptr->phys_unit_type == PNG_RESOLUTION_METER && + info_ptr->x_pixels_per_unit == info_ptr->y_pixels_per_unit) + return (info_ptr->x_pixels_per_unit); + } +#endif + + return (0); +} + +#ifdef PNG_FLOATING_POINT_SUPPORTED +float PNGAPI +png_get_pixel_aspect_ratio(png_const_structp png_ptr, png_const_infop info_ptr) +{ +#ifdef PNG_READ_pHYs_SUPPORTED + if (png_ptr != NULL && info_ptr != NULL && (info_ptr->valid & PNG_INFO_pHYs)) + { + png_debug1(1, "in %s retrieval function", "png_get_aspect_ratio"); + + if (info_ptr->x_pixels_per_unit != 0) + return ((float)((float)info_ptr->y_pixels_per_unit + /(float)info_ptr->x_pixels_per_unit)); + } +#endif + + return ((float)0.0); +} +#endif + +#ifdef PNG_FIXED_POINT_SUPPORTED +png_fixed_point PNGAPI +png_get_pixel_aspect_ratio_fixed(png_const_structp png_ptr, + png_const_infop info_ptr) +{ +#ifdef PNG_READ_pHYs_SUPPORTED + if (png_ptr != NULL && info_ptr != NULL && (info_ptr->valid & PNG_INFO_pHYs) + && info_ptr->x_pixels_per_unit > 0 && info_ptr->y_pixels_per_unit > 0 + && info_ptr->x_pixels_per_unit <= PNG_UINT_31_MAX + && info_ptr->y_pixels_per_unit <= PNG_UINT_31_MAX) + { + png_fixed_point res; + + png_debug1(1, "in %s retrieval function", "png_get_aspect_ratio_fixed"); + + /* The following casts work because a PNG 4 byte integer only has a valid + * range of 0..2^31-1; otherwise the cast might overflow. + */ + if (png_muldiv(&res, (png_int_32)info_ptr->y_pixels_per_unit, PNG_FP_1, + (png_int_32)info_ptr->x_pixels_per_unit)) + return res; + } +#endif + + return 0; +} +#endif + +png_int_32 PNGAPI +png_get_x_offset_microns(png_const_structp png_ptr, png_const_infop info_ptr) +{ +#ifdef PNG_oFFs_SUPPORTED + if (png_ptr != NULL && info_ptr != NULL && (info_ptr->valid & PNG_INFO_oFFs)) + { + png_debug1(1, "in %s retrieval function", "png_get_x_offset_microns"); + + if (info_ptr->offset_unit_type == PNG_OFFSET_MICROMETER) + return (info_ptr->x_offset); + } +#endif + + return (0); +} + +png_int_32 PNGAPI +png_get_y_offset_microns(png_const_structp png_ptr, png_const_infop info_ptr) +{ +#ifdef PNG_oFFs_SUPPORTED + if (png_ptr != NULL && info_ptr != NULL && (info_ptr->valid & PNG_INFO_oFFs)) + { + png_debug1(1, "in %s retrieval function", "png_get_y_offset_microns"); + + if (info_ptr->offset_unit_type == PNG_OFFSET_MICROMETER) + return (info_ptr->y_offset); + } +#endif + + return (0); +} + +png_int_32 PNGAPI +png_get_x_offset_pixels(png_const_structp png_ptr, png_const_infop info_ptr) +{ +#ifdef PNG_oFFs_SUPPORTED + if (png_ptr != NULL && info_ptr != NULL && (info_ptr->valid & PNG_INFO_oFFs)) + { + png_debug1(1, "in %s retrieval function", "png_get_x_offset_pixels"); + + if (info_ptr->offset_unit_type == PNG_OFFSET_PIXEL) + return (info_ptr->x_offset); + } +#endif + + return (0); +} + +png_int_32 PNGAPI +png_get_y_offset_pixels(png_const_structp png_ptr, png_const_infop info_ptr) +{ +#ifdef PNG_oFFs_SUPPORTED + if (png_ptr != NULL && info_ptr != NULL && (info_ptr->valid & PNG_INFO_oFFs)) + { + png_debug1(1, "in %s retrieval function", "png_get_y_offset_pixels"); + + if (info_ptr->offset_unit_type == PNG_OFFSET_PIXEL) + return (info_ptr->y_offset); + } +#endif + + return (0); +} + +#ifdef PNG_INCH_CONVERSIONS_SUPPORTED +static png_uint_32 +ppi_from_ppm(png_uint_32 ppm) +{ +#if 0 + /* The conversion is *(2.54/100), in binary (32 digits): + * .00000110100000001001110101001001 + */ + png_uint_32 t1001, t1101; + ppm >>= 1; /* .1 */ + t1001 = ppm + (ppm >> 3); /* .1001 */ + t1101 = t1001 + (ppm >> 1); /* .1101 */ + ppm >>= 20; /* .000000000000000000001 */ + t1101 += t1101 >> 15; /* .1101000000000001101 */ + t1001 >>= 11; /* .000000000001001 */ + t1001 += t1001 >> 12; /* .000000000001001000000001001 */ + ppm += t1001; /* .000000000001001000001001001 */ + ppm += t1101; /* .110100000001001110101001001 */ + return (ppm + 16) >> 5;/* .00000110100000001001110101001001 */ +#else + /* The argument is a PNG unsigned integer, so it is not permitted + * to be bigger than 2^31. + */ + png_fixed_point result; + if (ppm <= PNG_UINT_31_MAX && png_muldiv(&result, (png_int_32)ppm, 127, + 5000)) + return result; + + /* Overflow. */ + return 0; +#endif +} + +png_uint_32 PNGAPI +png_get_pixels_per_inch(png_const_structp png_ptr, png_const_infop info_ptr) +{ + return ppi_from_ppm(png_get_pixels_per_meter(png_ptr, info_ptr)); +} + +png_uint_32 PNGAPI +png_get_x_pixels_per_inch(png_const_structp png_ptr, png_const_infop info_ptr) +{ + return ppi_from_ppm(png_get_x_pixels_per_meter(png_ptr, info_ptr)); +} + +png_uint_32 PNGAPI +png_get_y_pixels_per_inch(png_const_structp png_ptr, png_const_infop info_ptr) +{ + return ppi_from_ppm(png_get_y_pixels_per_meter(png_ptr, info_ptr)); +} + +#ifdef PNG_FIXED_POINT_SUPPORTED +static png_fixed_point +png_fixed_inches_from_microns(png_structp png_ptr, png_int_32 microns) +{ + /* Convert from metres * 1,000,000 to inches * 100,000, meters to + * inches is simply *(100/2.54), so we want *(10/2.54) == 500/127. + * Notice that this can overflow - a warning is output and 0 is + * returned. + */ + return png_muldiv_warn(png_ptr, microns, 500, 127); +} + +png_fixed_point PNGAPI +png_get_x_offset_inches_fixed(png_structp png_ptr, + png_const_infop info_ptr) +{ + return png_fixed_inches_from_microns(png_ptr, + png_get_x_offset_microns(png_ptr, info_ptr)); +} +#endif + +#ifdef PNG_FIXED_POINT_SUPPORTED +png_fixed_point PNGAPI +png_get_y_offset_inches_fixed(png_structp png_ptr, + png_const_infop info_ptr) +{ + return png_fixed_inches_from_microns(png_ptr, + png_get_y_offset_microns(png_ptr, info_ptr)); +} +#endif + +#ifdef PNG_FLOATING_POINT_SUPPORTED +float PNGAPI +png_get_x_offset_inches(png_const_structp png_ptr, png_const_infop info_ptr) +{ + /* To avoid the overflow do the conversion directly in floating + * point. + */ + return (float)(png_get_x_offset_microns(png_ptr, info_ptr) * .00003937); +} +#endif + +#ifdef PNG_FLOATING_POINT_SUPPORTED +float PNGAPI +png_get_y_offset_inches(png_const_structp png_ptr, png_const_infop info_ptr) +{ + /* To avoid the overflow do the conversion directly in floating + * point. + */ + return (float)(png_get_y_offset_microns(png_ptr, info_ptr) * .00003937); +} +#endif + +#ifdef PNG_pHYs_SUPPORTED +png_uint_32 PNGAPI +png_get_pHYs_dpi(png_const_structp png_ptr, png_const_infop info_ptr, + png_uint_32 *res_x, png_uint_32 *res_y, int *unit_type) +{ + png_uint_32 retval = 0; + + if (png_ptr != NULL && info_ptr != NULL && (info_ptr->valid & PNG_INFO_pHYs)) + { + png_debug1(1, "in %s retrieval function", "pHYs"); + + if (res_x != NULL) + { + *res_x = info_ptr->x_pixels_per_unit; + retval |= PNG_INFO_pHYs; + } + + if (res_y != NULL) + { + *res_y = info_ptr->y_pixels_per_unit; + retval |= PNG_INFO_pHYs; + } + + if (unit_type != NULL) + { + *unit_type = (int)info_ptr->phys_unit_type; + retval |= PNG_INFO_pHYs; + + if (*unit_type == 1) + { + if (res_x != NULL) *res_x = (png_uint_32)(*res_x * .0254 + .50); + if (res_y != NULL) *res_y = (png_uint_32)(*res_y * .0254 + .50); + } + } + } + + return (retval); +} +#endif /* PNG_pHYs_SUPPORTED */ +#endif /* PNG_INCH_CONVERSIONS_SUPPORTED */ + +/* png_get_channels really belongs in here, too, but it's been around longer */ + +#endif /* PNG_EASY_ACCESS_SUPPORTED */ + +png_byte PNGAPI +png_get_channels(png_const_structp png_ptr, png_const_infop info_ptr) +{ + if (png_ptr != NULL && info_ptr != NULL) + return(info_ptr->channels); + + return (0); +} + +png_const_bytep PNGAPI +png_get_signature(png_const_structp png_ptr, png_infop info_ptr) +{ + if (png_ptr != NULL && info_ptr != NULL) + return(info_ptr->signature); + + return (NULL); +} + +#ifdef PNG_bKGD_SUPPORTED +png_uint_32 PNGAPI +png_get_bKGD(png_const_structp png_ptr, png_infop info_ptr, + png_color_16p *background) +{ + if (png_ptr != NULL && info_ptr != NULL && (info_ptr->valid & PNG_INFO_bKGD) + && background != NULL) + { + png_debug1(1, "in %s retrieval function", "bKGD"); + + *background = &(info_ptr->background); + return (PNG_INFO_bKGD); + } + + return (0); +} +#endif + +#ifdef PNG_cHRM_SUPPORTED +# ifdef PNG_FLOATING_POINT_SUPPORTED +png_uint_32 PNGAPI +png_get_cHRM(png_const_structp png_ptr, png_const_infop info_ptr, + double *white_x, double *white_y, double *red_x, double *red_y, + double *green_x, double *green_y, double *blue_x, double *blue_y) +{ + if (png_ptr != NULL && info_ptr != NULL && (info_ptr->valid & PNG_INFO_cHRM)) + { + png_debug1(1, "in %s retrieval function", "cHRM"); + + if (white_x != NULL) + *white_x = png_float(png_ptr, info_ptr->x_white, "cHRM white X"); + if (white_y != NULL) + *white_y = png_float(png_ptr, info_ptr->y_white, "cHRM white Y"); + if (red_x != NULL) + *red_x = png_float(png_ptr, info_ptr->x_red, "cHRM red X"); + if (red_y != NULL) + *red_y = png_float(png_ptr, info_ptr->y_red, "cHRM red Y"); + if (green_x != NULL) + *green_x = png_float(png_ptr, info_ptr->x_green, "cHRM green X"); + if (green_y != NULL) + *green_y = png_float(png_ptr, info_ptr->y_green, "cHRM green Y"); + if (blue_x != NULL) + *blue_x = png_float(png_ptr, info_ptr->x_blue, "cHRM blue X"); + if (blue_y != NULL) + *blue_y = png_float(png_ptr, info_ptr->y_blue, "cHRM blue Y"); + return (PNG_INFO_cHRM); + } + + return (0); +} +# endif + +# ifdef PNG_FIXED_POINT_SUPPORTED +png_uint_32 PNGAPI +png_get_cHRM_fixed(png_const_structp png_ptr, png_const_infop info_ptr, + png_fixed_point *white_x, png_fixed_point *white_y, png_fixed_point *red_x, + png_fixed_point *red_y, png_fixed_point *green_x, png_fixed_point *green_y, + png_fixed_point *blue_x, png_fixed_point *blue_y) +{ + png_debug1(1, "in %s retrieval function", "cHRM"); + + if (png_ptr != NULL && info_ptr != NULL && (info_ptr->valid & PNG_INFO_cHRM)) + { + if (white_x != NULL) + *white_x = info_ptr->x_white; + if (white_y != NULL) + *white_y = info_ptr->y_white; + if (red_x != NULL) + *red_x = info_ptr->x_red; + if (red_y != NULL) + *red_y = info_ptr->y_red; + if (green_x != NULL) + *green_x = info_ptr->x_green; + if (green_y != NULL) + *green_y = info_ptr->y_green; + if (blue_x != NULL) + *blue_x = info_ptr->x_blue; + if (blue_y != NULL) + *blue_y = info_ptr->y_blue; + return (PNG_INFO_cHRM); + } + + return (0); +} +# endif +#endif + +#ifdef PNG_gAMA_SUPPORTED +png_uint_32 PNGFAPI +png_get_gAMA_fixed(png_const_structp png_ptr, png_const_infop info_ptr, + png_fixed_point *file_gamma) +{ + png_debug1(1, "in %s retrieval function", "gAMA"); + + if (png_ptr != NULL && info_ptr != NULL && (info_ptr->valid & PNG_INFO_gAMA) + && file_gamma != NULL) + { + *file_gamma = info_ptr->gamma; + return (PNG_INFO_gAMA); + } + + return (0); +} +# ifdef PNG_FLOATING_POINT_SUPPORTED +png_uint_32 PNGAPI +png_get_gAMA(png_const_structp png_ptr, png_const_infop info_ptr, + double *file_gamma) +{ + png_fixed_point igamma; + png_uint_32 ok = png_get_gAMA_fixed(png_ptr, info_ptr, &igamma); + + if (ok) + *file_gamma = png_float(png_ptr, igamma, "png_get_gAMA"); + + return ok; +} + +# endif +#endif + +#ifdef PNG_sRGB_SUPPORTED +png_uint_32 PNGAPI +png_get_sRGB(png_const_structp png_ptr, png_const_infop info_ptr, + int *file_srgb_intent) +{ + png_debug1(1, "in %s retrieval function", "sRGB"); + + if (png_ptr != NULL && info_ptr != NULL && (info_ptr->valid & PNG_INFO_sRGB) + && file_srgb_intent != NULL) + { + *file_srgb_intent = (int)info_ptr->srgb_intent; + return (PNG_INFO_sRGB); + } + + return (0); +} +#endif + +#ifdef PNG_iCCP_SUPPORTED +png_uint_32 PNGAPI +png_get_iCCP(png_const_structp png_ptr, png_const_infop info_ptr, + png_charpp name, int *compression_type, + png_bytepp profile, png_uint_32 *proflen) +{ + png_debug1(1, "in %s retrieval function", "iCCP"); + + if (png_ptr != NULL && info_ptr != NULL && (info_ptr->valid & PNG_INFO_iCCP) + && name != NULL && profile != NULL && proflen != NULL) + { + *name = info_ptr->iccp_name; + *profile = info_ptr->iccp_profile; + /* Compression_type is a dummy so the API won't have to change + * if we introduce multiple compression types later. + */ + *proflen = (int)info_ptr->iccp_proflen; + *compression_type = (int)info_ptr->iccp_compression; + return (PNG_INFO_iCCP); + } + + return (0); +} +#endif + +#ifdef PNG_sPLT_SUPPORTED +png_uint_32 PNGAPI +png_get_sPLT(png_const_structp png_ptr, png_const_infop info_ptr, + png_sPLT_tpp spalettes) +{ + if (png_ptr != NULL && info_ptr != NULL && spalettes != NULL) + { + *spalettes = info_ptr->splt_palettes; + return ((png_uint_32)info_ptr->splt_palettes_num); + } + + return (0); +} +#endif + +#ifdef PNG_hIST_SUPPORTED +png_uint_32 PNGAPI +png_get_hIST(png_const_structp png_ptr, png_const_infop info_ptr, + png_uint_16p *hist) +{ + png_debug1(1, "in %s retrieval function", "hIST"); + + if (png_ptr != NULL && info_ptr != NULL && (info_ptr->valid & PNG_INFO_hIST) + && hist != NULL) + { + *hist = info_ptr->hist; + return (PNG_INFO_hIST); + } + + return (0); +} +#endif + +png_uint_32 PNGAPI +png_get_IHDR(png_structp png_ptr, png_infop info_ptr, + png_uint_32 *width, png_uint_32 *height, int *bit_depth, + int *color_type, int *interlace_type, int *compression_type, + int *filter_type) + +{ + png_debug1(1, "in %s retrieval function", "IHDR"); + + if (png_ptr == NULL || info_ptr == NULL || width == NULL || + height == NULL || bit_depth == NULL || color_type == NULL) + return (0); + + *width = info_ptr->width; + *height = info_ptr->height; + *bit_depth = info_ptr->bit_depth; + *color_type = info_ptr->color_type; + + if (compression_type != NULL) + *compression_type = info_ptr->compression_type; + + if (filter_type != NULL) + *filter_type = info_ptr->filter_type; + + if (interlace_type != NULL) + *interlace_type = info_ptr->interlace_type; + + /* This is redundant if we can be sure that the info_ptr values were all + * assigned in png_set_IHDR(). We do the check anyhow in case an + * application has ignored our advice not to mess with the members + * of info_ptr directly. + */ + png_check_IHDR (png_ptr, info_ptr->width, info_ptr->height, + info_ptr->bit_depth, info_ptr->color_type, info_ptr->interlace_type, + info_ptr->compression_type, info_ptr->filter_type); + + return (1); +} + +#ifdef PNG_oFFs_SUPPORTED +png_uint_32 PNGAPI +png_get_oFFs(png_const_structp png_ptr, png_const_infop info_ptr, + png_int_32 *offset_x, png_int_32 *offset_y, int *unit_type) +{ + png_debug1(1, "in %s retrieval function", "oFFs"); + + if (png_ptr != NULL && info_ptr != NULL && (info_ptr->valid & PNG_INFO_oFFs) + && offset_x != NULL && offset_y != NULL && unit_type != NULL) + { + *offset_x = info_ptr->x_offset; + *offset_y = info_ptr->y_offset; + *unit_type = (int)info_ptr->offset_unit_type; + return (PNG_INFO_oFFs); + } + + return (0); +} +#endif + +#ifdef PNG_pCAL_SUPPORTED +png_uint_32 PNGAPI +png_get_pCAL(png_const_structp png_ptr, png_const_infop info_ptr, + png_charp *purpose, png_int_32 *X0, png_int_32 *X1, int *type, int *nparams, + png_charp *units, png_charpp *params) +{ + png_debug1(1, "in %s retrieval function", "pCAL"); + + if (png_ptr != NULL && info_ptr != NULL && (info_ptr->valid & PNG_INFO_pCAL) + && purpose != NULL && X0 != NULL && X1 != NULL && type != NULL && + nparams != NULL && units != NULL && params != NULL) + { + *purpose = info_ptr->pcal_purpose; + *X0 = info_ptr->pcal_X0; + *X1 = info_ptr->pcal_X1; + *type = (int)info_ptr->pcal_type; + *nparams = (int)info_ptr->pcal_nparams; + *units = info_ptr->pcal_units; + *params = info_ptr->pcal_params; + return (PNG_INFO_pCAL); + } + + return (0); +} +#endif + +#ifdef PNG_sCAL_SUPPORTED +# ifdef PNG_FIXED_POINT_SUPPORTED +# ifdef PNG_FLOATING_ARITHMETIC_SUPPORTED +png_uint_32 PNGAPI +png_get_sCAL_fixed(png_structp png_ptr, png_const_infop info_ptr, + int *unit, png_fixed_point *width, png_fixed_point *height) +{ + if (png_ptr != NULL && info_ptr != NULL && + (info_ptr->valid & PNG_INFO_sCAL)) + { + *unit = info_ptr->scal_unit; + /*TODO: make this work without FP support */ + *width = png_fixed(png_ptr, atof(info_ptr->scal_s_width), "sCAL width"); + *height = png_fixed(png_ptr, atof(info_ptr->scal_s_height), + "sCAL height"); + return (PNG_INFO_sCAL); + } + + return(0); +} +# endif /* FLOATING_ARITHMETIC */ +# endif /* FIXED_POINT */ +# ifdef PNG_FLOATING_POINT_SUPPORTED +png_uint_32 PNGAPI +png_get_sCAL(png_const_structp png_ptr, png_const_infop info_ptr, + int *unit, double *width, double *height) +{ + if (png_ptr != NULL && info_ptr != NULL && + (info_ptr->valid & PNG_INFO_sCAL)) + { + *unit = info_ptr->scal_unit; + *width = atof(info_ptr->scal_s_width); + *height = atof(info_ptr->scal_s_height); + return (PNG_INFO_sCAL); + } + + return(0); +} +# endif /* FLOATING POINT */ +png_uint_32 PNGAPI +png_get_sCAL_s(png_const_structp png_ptr, png_const_infop info_ptr, + int *unit, png_charpp width, png_charpp height) +{ + if (png_ptr != NULL && info_ptr != NULL && + (info_ptr->valid & PNG_INFO_sCAL)) + { + *unit = info_ptr->scal_unit; + *width = info_ptr->scal_s_width; + *height = info_ptr->scal_s_height; + return (PNG_INFO_sCAL); + } + + return(0); +} +#endif /* sCAL */ + +#ifdef PNG_pHYs_SUPPORTED +png_uint_32 PNGAPI +png_get_pHYs(png_const_structp png_ptr, png_const_infop info_ptr, + png_uint_32 *res_x, png_uint_32 *res_y, int *unit_type) +{ + png_uint_32 retval = 0; + + png_debug1(1, "in %s retrieval function", "pHYs"); + + if (png_ptr != NULL && info_ptr != NULL && + (info_ptr->valid & PNG_INFO_pHYs)) + { + if (res_x != NULL) + { + *res_x = info_ptr->x_pixels_per_unit; + retval |= PNG_INFO_pHYs; + } + + if (res_y != NULL) + { + *res_y = info_ptr->y_pixels_per_unit; + retval |= PNG_INFO_pHYs; + } + + if (unit_type != NULL) + { + *unit_type = (int)info_ptr->phys_unit_type; + retval |= PNG_INFO_pHYs; + } + } + + return (retval); +} +#endif /* pHYs */ + +png_uint_32 PNGAPI +png_get_PLTE(png_const_structp png_ptr, png_const_infop info_ptr, + png_colorp *palette, int *num_palette) +{ + png_debug1(1, "in %s retrieval function", "PLTE"); + + if (png_ptr != NULL && info_ptr != NULL && (info_ptr->valid & PNG_INFO_PLTE) + && palette != NULL) + { + *palette = info_ptr->palette; + *num_palette = info_ptr->num_palette; + png_debug1(3, "num_palette = %d", *num_palette); + return (PNG_INFO_PLTE); + } + + return (0); +} + +#ifdef PNG_sBIT_SUPPORTED +png_uint_32 PNGAPI +png_get_sBIT(png_const_structp png_ptr, png_infop info_ptr, + png_color_8p *sig_bit) +{ + png_debug1(1, "in %s retrieval function", "sBIT"); + + if (png_ptr != NULL && info_ptr != NULL && (info_ptr->valid & PNG_INFO_sBIT) + && sig_bit != NULL) + { + *sig_bit = &(info_ptr->sig_bit); + return (PNG_INFO_sBIT); + } + + return (0); +} +#endif + +#ifdef PNG_TEXT_SUPPORTED +png_uint_32 PNGAPI +png_get_text(png_const_structp png_ptr, png_const_infop info_ptr, + png_textp *text_ptr, int *num_text) +{ + if (png_ptr != NULL && info_ptr != NULL && info_ptr->num_text > 0) + { + png_debug1(1, "in %s retrieval function", + (png_ptr->chunk_name[0] == '\0' ? "text" : + (png_const_charp)png_ptr->chunk_name)); + + if (text_ptr != NULL) + *text_ptr = info_ptr->text; + + if (num_text != NULL) + *num_text = info_ptr->num_text; + + return ((png_uint_32)info_ptr->num_text); + } + + if (num_text != NULL) + *num_text = 0; + + return(0); +} +#endif + +#ifdef PNG_tIME_SUPPORTED +png_uint_32 PNGAPI +png_get_tIME(png_const_structp png_ptr, png_infop info_ptr, png_timep *mod_time) +{ + png_debug1(1, "in %s retrieval function", "tIME"); + + if (png_ptr != NULL && info_ptr != NULL && (info_ptr->valid & PNG_INFO_tIME) + && mod_time != NULL) + { + *mod_time = &(info_ptr->mod_time); + return (PNG_INFO_tIME); + } + + return (0); +} +#endif + +#ifdef PNG_tRNS_SUPPORTED +png_uint_32 PNGAPI +png_get_tRNS(png_const_structp png_ptr, png_infop info_ptr, + png_bytep *trans_alpha, int *num_trans, png_color_16p *trans_color) +{ + png_uint_32 retval = 0; + if (png_ptr != NULL && info_ptr != NULL && (info_ptr->valid & PNG_INFO_tRNS)) + { + png_debug1(1, "in %s retrieval function", "tRNS"); + + if (info_ptr->color_type == PNG_COLOR_TYPE_PALETTE) + { + if (trans_alpha != NULL) + { + *trans_alpha = info_ptr->trans_alpha; + retval |= PNG_INFO_tRNS; + } + + if (trans_color != NULL) + *trans_color = &(info_ptr->trans_color); + } + + else /* if (info_ptr->color_type != PNG_COLOR_TYPE_PALETTE) */ + { + if (trans_color != NULL) + { + *trans_color = &(info_ptr->trans_color); + retval |= PNG_INFO_tRNS; + } + + if (trans_alpha != NULL) + *trans_alpha = NULL; + } + + if (num_trans != NULL) + { + *num_trans = info_ptr->num_trans; + retval |= PNG_INFO_tRNS; + } + } + + return (retval); +} +#endif + +#ifdef PNG_UNKNOWN_CHUNKS_SUPPORTED +int PNGAPI +png_get_unknown_chunks(png_const_structp png_ptr, png_const_infop info_ptr, + png_unknown_chunkpp unknowns) +{ + if (png_ptr != NULL && info_ptr != NULL && unknowns != NULL) + { + *unknowns = info_ptr->unknown_chunks; + return info_ptr->unknown_chunks_num; + } + + return (0); +} +#endif + +#ifdef PNG_READ_RGB_TO_GRAY_SUPPORTED +png_byte PNGAPI +png_get_rgb_to_gray_status (png_const_structp png_ptr) +{ + return (png_byte)(png_ptr ? png_ptr->rgb_to_gray_status : 0); +} +#endif + +#ifdef PNG_USER_CHUNKS_SUPPORTED +png_voidp PNGAPI +png_get_user_chunk_ptr(png_const_structp png_ptr) +{ + return (png_ptr ? png_ptr->user_chunk_ptr : NULL); +} +#endif + +png_size_t PNGAPI +png_get_compression_buffer_size(png_const_structp png_ptr) +{ + return (png_ptr ? png_ptr->zbuf_size : 0L); +} + + +#ifdef PNG_SET_USER_LIMITS_SUPPORTED +/* These functions were added to libpng 1.2.6 and were enabled + * by default in libpng-1.4.0 */ +png_uint_32 PNGAPI +png_get_user_width_max (png_const_structp png_ptr) +{ + return (png_ptr ? png_ptr->user_width_max : 0); +} + +png_uint_32 PNGAPI +png_get_user_height_max (png_const_structp png_ptr) +{ + return (png_ptr ? png_ptr->user_height_max : 0); +} + +/* This function was added to libpng 1.4.0 */ +png_uint_32 PNGAPI +png_get_chunk_cache_max (png_const_structp png_ptr) +{ + return (png_ptr ? png_ptr->user_chunk_cache_max : 0); +} + +/* This function was added to libpng 1.4.1 */ +png_alloc_size_t PNGAPI +png_get_chunk_malloc_max (png_const_structp png_ptr) +{ + return (png_ptr ? png_ptr->user_chunk_malloc_max : 0); +} +#endif /* ?PNG_SET_USER_LIMITS_SUPPORTED */ + +/* These functions were added to libpng 1.4.0 */ +#ifdef PNG_IO_STATE_SUPPORTED +png_uint_32 PNGAPI +png_get_io_state (png_structp png_ptr) +{ + return png_ptr->io_state; +} + +png_uint_32 PNGAPI +png_get_io_chunk_type (png_const_structp png_ptr) +{ + return ((png_ptr->chunk_name[0] << 24) + + (png_ptr->chunk_name[1] << 16) + + (png_ptr->chunk_name[2] << 8) + + (png_ptr->chunk_name[3])); +} + +png_const_bytep PNGAPI +png_get_io_chunk_name (png_structp png_ptr) +{ + return png_ptr->chunk_name; +} +#endif /* ?PNG_IO_STATE_SUPPORTED */ + +#endif /* PNG_READ_SUPPORTED || PNG_WRITE_SUPPORTED */ diff --git a/src/3rdparty/libpng/pnginfo.h b/src/3rdparty/libpng/pnginfo.h new file mode 100644 index 0000000000..fa19f85e72 --- /dev/null +++ b/src/3rdparty/libpng/pnginfo.h @@ -0,0 +1,270 @@ + +/* pnginfo.h - header file for PNG reference library + * + * Copyright (c) 1998-2011 Glenn Randers-Pehrson + * (Version 0.96 Copyright (c) 1996, 1997 Andreas Dilger) + * (Version 0.88 Copyright (c) 1995, 1996 Guy Eric Schalnat, Group 42, Inc.) + * + * Last changed in libpng 1.5.0 [January 6, 2011] + * + * This code is released under the libpng license. + * For conditions of distribution and use, see the disclaimer + * and license in png.h + */ + + /* png_info is a structure that holds the information in a PNG file so + * that the application can find out the characteristics of the image. + * If you are reading the file, this structure will tell you what is + * in the PNG file. If you are writing the file, fill in the information + * you want to put into the PNG file, using png_set_*() functions, then + * call png_write_info(). + * + * The names chosen should be very close to the PNG specification, so + * consult that document for information about the meaning of each field. + * + * With libpng < 0.95, it was only possible to directly set and read the + * the values in the png_info_struct, which meant that the contents and + * order of the values had to remain fixed. With libpng 0.95 and later, + * however, there are now functions that abstract the contents of + * png_info_struct from the application, so this makes it easier to use + * libpng with dynamic libraries, and even makes it possible to use + * libraries that don't have all of the libpng ancillary chunk-handing + * functionality. In libpng-1.5.0 this was moved into a separate private + * file that is not visible to applications. + * + * The following members may have allocated storage attached that should be + * cleaned up before the structure is discarded: palette, trans, text, + * pcal_purpose, pcal_units, pcal_params, hist, iccp_name, iccp_profile, + * splt_palettes, scal_unit, row_pointers, and unknowns. By default, these + * are automatically freed when the info structure is deallocated, if they were + * allocated internally by libpng. This behavior can be changed by means + * of the png_data_freer() function. + * + * More allocation details: all the chunk-reading functions that + * change these members go through the corresponding png_set_* + * functions. A function to clear these members is available: see + * png_free_data(). The png_set_* functions do not depend on being + * able to point info structure members to any of the storage they are + * passed (they make their own copies), EXCEPT that the png_set_text + * functions use the same storage passed to them in the text_ptr or + * itxt_ptr structure argument, and the png_set_rows and png_set_unknowns + * functions do not make their own copies. + */ +#ifndef PNGINFO_H +#define PNGINFO_H + +struct png_info_def +{ + /* the following are necessary for every PNG file */ + png_uint_32 width; /* width of image in pixels (from IHDR) */ + png_uint_32 height; /* height of image in pixels (from IHDR) */ + png_uint_32 valid; /* valid chunk data (see PNG_INFO_ below) */ + png_size_t rowbytes; /* bytes needed to hold an untransformed row */ + png_colorp palette; /* array of color values (valid & PNG_INFO_PLTE) */ + png_uint_16 num_palette; /* number of color entries in "palette" (PLTE) */ + png_uint_16 num_trans; /* number of transparent palette color (tRNS) */ + png_byte bit_depth; /* 1, 2, 4, 8, or 16 bits/channel (from IHDR) */ + png_byte color_type; /* see PNG_COLOR_TYPE_ below (from IHDR) */ + /* The following three should have been named *_method not *_type */ + png_byte compression_type; /* must be PNG_COMPRESSION_TYPE_BASE (IHDR) */ + png_byte filter_type; /* must be PNG_FILTER_TYPE_BASE (from IHDR) */ + png_byte interlace_type; /* One of PNG_INTERLACE_NONE, PNG_INTERLACE_ADAM7 */ + + /* The following is informational only on read, and not used on writes. */ + png_byte channels; /* number of data channels per pixel (1, 2, 3, 4) */ + png_byte pixel_depth; /* number of bits per pixel */ + png_byte spare_byte; /* to align the data, and for future use */ + png_byte signature[8]; /* magic bytes read by libpng from start of file */ + + /* The rest of the data is optional. If you are reading, check the + * valid field to see if the information in these are valid. If you + * are writing, set the valid field to those chunks you want written, + * and initialize the appropriate fields below. + */ + +#if defined(PNG_gAMA_SUPPORTED) + /* The gAMA chunk describes the gamma characteristics of the system + * on which the image was created, normally in the range [1.0, 2.5]. + * Data is valid if (valid & PNG_INFO_gAMA) is non-zero. + */ + png_fixed_point gamma; +#endif + +#ifdef PNG_sRGB_SUPPORTED + /* GR-P, 0.96a */ + /* Data valid if (valid & PNG_INFO_sRGB) non-zero. */ + png_byte srgb_intent; /* sRGB rendering intent [0, 1, 2, or 3] */ +#endif + +#ifdef PNG_TEXT_SUPPORTED + /* The tEXt, and zTXt chunks contain human-readable textual data in + * uncompressed, compressed, and optionally compressed forms, respectively. + * The data in "text" is an array of pointers to uncompressed, + * null-terminated C strings. Each chunk has a keyword that describes the + * textual data contained in that chunk. Keywords are not required to be + * unique, and the text string may be empty. Any number of text chunks may + * be in an image. + */ + int num_text; /* number of comments read or comments to write */ + int max_text; /* current size of text array */ + png_textp text; /* array of comments read or comments to write */ +#endif /* PNG_TEXT_SUPPORTED */ + +#ifdef PNG_tIME_SUPPORTED + /* The tIME chunk holds the last time the displayed image data was + * modified. See the png_time struct for the contents of this struct. + */ + png_time mod_time; +#endif + +#ifdef PNG_sBIT_SUPPORTED + /* The sBIT chunk specifies the number of significant high-order bits + * in the pixel data. Values are in the range [1, bit_depth], and are + * only specified for the channels in the pixel data. The contents of + * the low-order bits is not specified. Data is valid if + * (valid & PNG_INFO_sBIT) is non-zero. + */ + png_color_8 sig_bit; /* significant bits in color channels */ +#endif + +#if defined(PNG_tRNS_SUPPORTED) || defined(PNG_READ_EXPAND_SUPPORTED) || \ +defined(PNG_READ_BACKGROUND_SUPPORTED) + /* The tRNS chunk supplies transparency data for paletted images and + * other image types that don't need a full alpha channel. There are + * "num_trans" transparency values for a paletted image, stored in the + * same order as the palette colors, starting from index 0. Values + * for the data are in the range [0, 255], ranging from fully transparent + * to fully opaque, respectively. For non-paletted images, there is a + * single color specified that should be treated as fully transparent. + * Data is valid if (valid & PNG_INFO_tRNS) is non-zero. + */ + png_bytep trans; /* alpha values for paletted image */ + png_bytep trans_alpha; /* alpha values for paletted image */ + png_color_16 trans_color; /* transparent color for non-palette image */ +#endif + +#if defined(PNG_bKGD_SUPPORTED) || defined(PNG_READ_BACKGROUND_SUPPORTED) + /* The bKGD chunk gives the suggested image background color if the + * display program does not have its own background color and the image + * is needs to composited onto a background before display. The colors + * in "background" are normally in the same color space/depth as the + * pixel data. Data is valid if (valid & PNG_INFO_bKGD) is non-zero. + */ + png_color_16 background; +#endif + +#ifdef PNG_oFFs_SUPPORTED + /* The oFFs chunk gives the offset in "offset_unit_type" units rightwards + * and downwards from the top-left corner of the display, page, or other + * application-specific co-ordinate space. See the PNG_OFFSET_ defines + * below for the unit types. Valid if (valid & PNG_INFO_oFFs) non-zero. + */ + png_int_32 x_offset; /* x offset on page */ + png_int_32 y_offset; /* y offset on page */ + png_byte offset_unit_type; /* offset units type */ +#endif + +#ifdef PNG_pHYs_SUPPORTED + /* The pHYs chunk gives the physical pixel density of the image for + * display or printing in "phys_unit_type" units (see PNG_RESOLUTION_ + * defines below). Data is valid if (valid & PNG_INFO_pHYs) is non-zero. + */ + png_uint_32 x_pixels_per_unit; /* horizontal pixel density */ + png_uint_32 y_pixels_per_unit; /* vertical pixel density */ + png_byte phys_unit_type; /* resolution type (see PNG_RESOLUTION_ below) */ +#endif + +#ifdef PNG_hIST_SUPPORTED + /* The hIST chunk contains the relative frequency or importance of the + * various palette entries, so that a viewer can intelligently select a + * reduced-color palette, if required. Data is an array of "num_palette" + * values in the range [0,65535]. Data valid if (valid & PNG_INFO_hIST) + * is non-zero. + */ + png_uint_16p hist; +#endif + +#ifdef PNG_cHRM_SUPPORTED + /* The cHRM chunk describes the CIE color characteristics of the monitor + * on which the PNG was created. This data allows the viewer to do gamut + * mapping of the input image to ensure that the viewer sees the same + * colors in the image as the creator. Values are in the range + * [0.0, 0.8]. Data valid if (valid & PNG_INFO_cHRM) non-zero. + */ + png_fixed_point x_white; + png_fixed_point y_white; + png_fixed_point x_red; + png_fixed_point y_red; + png_fixed_point x_green; + png_fixed_point y_green; + png_fixed_point x_blue; + png_fixed_point y_blue; +#endif + +#ifdef PNG_pCAL_SUPPORTED + /* The pCAL chunk describes a transformation between the stored pixel + * values and original physical data values used to create the image. + * The integer range [0, 2^bit_depth - 1] maps to the floating-point + * range given by [pcal_X0, pcal_X1], and are further transformed by a + * (possibly non-linear) transformation function given by "pcal_type" + * and "pcal_params" into "pcal_units". Please see the PNG_EQUATION_ + * defines below, and the PNG-Group's PNG extensions document for a + * complete description of the transformations and how they should be + * implemented, and for a description of the ASCII parameter strings. + * Data values are valid if (valid & PNG_INFO_pCAL) non-zero. + */ + png_charp pcal_purpose; /* pCAL chunk description string */ + png_int_32 pcal_X0; /* minimum value */ + png_int_32 pcal_X1; /* maximum value */ + png_charp pcal_units; /* Latin-1 string giving physical units */ + png_charpp pcal_params; /* ASCII strings containing parameter values */ + png_byte pcal_type; /* equation type (see PNG_EQUATION_ below) */ + png_byte pcal_nparams; /* number of parameters given in pcal_params */ +#endif + +/* New members added in libpng-1.0.6 */ + png_uint_32 free_me; /* flags items libpng is responsible for freeing */ + +#if defined(PNG_UNKNOWN_CHUNKS_SUPPORTED) || \ + defined(PNG_HANDLE_AS_UNKNOWN_SUPPORTED) + /* Storage for unknown chunks that the library doesn't recognize. */ + png_unknown_chunkp unknown_chunks; + int unknown_chunks_num; +#endif + +#ifdef PNG_iCCP_SUPPORTED + /* iCCP chunk data. */ + png_charp iccp_name; /* profile name */ + png_bytep iccp_profile; /* International Color Consortium profile data */ + png_uint_32 iccp_proflen; /* ICC profile data length */ + png_byte iccp_compression; /* Always zero */ +#endif + +#ifdef PNG_sPLT_SUPPORTED + /* Data on sPLT chunks (there may be more than one). */ + png_sPLT_tp splt_palettes; + png_uint_32 splt_palettes_num; +#endif + +#ifdef PNG_sCAL_SUPPORTED + /* The sCAL chunk describes the actual physical dimensions of the + * subject matter of the graphic. The chunk contains a unit specification + * a byte value, and two ASCII strings representing floating-point + * values. The values are width and height corresponsing to one pixel + * in the image. Data values are valid if (valid & PNG_INFO_sCAL) is + * non-zero. + */ + png_byte scal_unit; /* unit of physical scale */ + png_charp scal_s_width; /* string containing height */ + png_charp scal_s_height; /* string containing width */ +#endif + +#ifdef PNG_INFO_IMAGE_SUPPORTED + /* Memory has been allocated if (valid & PNG_ALLOCATED_INFO_ROWS) + non-zero */ + /* Data valid if (valid & PNG_INFO_IDAT) non-zero */ + png_bytepp row_pointers; /* the image bits */ +#endif + +}; +#endif /* PNGINFO_H */ diff --git a/src/3rdparty/libpng/pnglibconf.h b/src/3rdparty/libpng/pnglibconf.h new file mode 100644 index 0000000000..b1d2169105 --- /dev/null +++ b/src/3rdparty/libpng/pnglibconf.h @@ -0,0 +1,176 @@ + +/* libpng STANDARD API DEFINITION */ + +/* pnglibconf.h - library build configuration */ + +/* libpng version 1.5.0 - last changed on January 6, 2011 */ + +/* Copyright (c) 1998-2011 Glenn Randers-Pehrson */ + +/* This code is released under the libpng license. */ +/* For conditions of distribution and use, see the disclaimer */ +/* and license in png.h */ + +/* pnglibconf.h */ +/* Machine generated file: DO NOT EDIT */ +/* Derived from: scripts/pnglibconf.dfa */ +#ifndef PNGLCONF_H +#define PNGLCONF_H +/* settings */ +#define PNG_MAX_GAMMA_8 11 +#define PNG_CALLOC_SUPPORTED +#define PNG_QUANTIZE_RED_BITS 5 +#define PNG_USER_WIDTH_MAX 1000000L +#define PNG_QUANTIZE_GREEN_BITS 5 +#define PNG_API_RULE 0 +#define PNG_QUANTIZE_BLUE_BITS 5 +#define PNG_USER_CHUNK_CACHE_MAX 0 +#define PNG_USER_HEIGHT_MAX 1000000L +#define PNG_sCAL_PRECISION 5 +#define PNG_COST_SHIFT 3 +#define PNG_WEIGHT_SHIFT 8 +#define PNG_USER_CHUNK_MALLOC_MAX 0 +#define PNG_DEFAULT_READ_MACROS 1 +#define PNG_ZBUF_SIZE 8192 +#define PNG_GAMMA_THRESHOLD_FIXED 5000 +/* end of settings */ +/* options */ +#define PNG_INFO_IMAGE_SUPPORTED +#define PNG_HANDLE_AS_UNKNOWN_SUPPORTED +#define PNG_POINTER_INDEXING_SUPPORTED +#define PNG_WARNINGS_SUPPORTED +#define PNG_FLOATING_ARITHMETIC_SUPPORTED +#define PNG_WRITE_SUPPORTED +#define PNG_WRITE_INTERLACING_SUPPORTED +#define PNG_WRITE_16BIT_SUPPORTED +#define PNG_EASY_ACCESS_SUPPORTED +#define PNG_ALIGN_MEMORY_SUPPORTED +#define PNG_WRITE_WEIGHTED_FILTER_SUPPORTED +#define PNG_WRITE_UNKNOWN_CHUNKS_SUPPORTED +#define PNG_USER_LIMITS_SUPPORTED +#define PNG_FIXED_POINT_SUPPORTED +/*#undef PNG_ERROR_NUMBERS_SUPPORTED*/ +#define PNG_ERROR_TEXT_SUPPORTED +#define PNG_READ_SUPPORTED +/*#undef PNG_READ_16_TO_8_ACCURATE_SCALE_SUPPORTED*/ +#define PNG_BENIGN_ERRORS_SUPPORTED +#define PNG_SETJMP_SUPPORTED +#define PNG_WRITE_FLUSH_SUPPORTED +#define PNG_MNG_FEATURES_SUPPORTED +#define PNG_FLOATING_POINT_SUPPORTED +#define PNG_INCH_CONVERSIONS_SUPPORTED +#define PNG_STDIO_SUPPORTED +#define PNG_READ_UNKNOWN_CHUNKS_SUPPORTED +#define PNG_USER_MEM_SUPPORTED +#define PNG_IO_STATE_SUPPORTED +#define PNG_SET_USER_LIMITS_SUPPORTED +#define PNG_READ_ANCILLARY_CHUNKS_SUPPORTED +#define PNG_WRITE_INT_FUNCTIONS_SUPPORTED +#define PNG_WRITE_ANCILLARY_CHUNKS_SUPPORTED +#define PNG_WRITE_FILTER_SUPPORTED +#define PNG_SET_CHUNK_CACHE_LIMIT_SUPPORTED +#define PNG_WRITE_iCCP_SUPPORTED +#define PNG_READ_TRANSFORMS_SUPPORTED +#define PNG_READ_GAMMA_SUPPORTED +#define PNG_READ_bKGD_SUPPORTED +#define PNG_UNKNOWN_CHUNKS_SUPPORTED +#define PNG_READ_sCAL_SUPPORTED +#define PNG_WRITE_hIST_SUPPORTED +#define PNG_READ_OPT_PLTE_SUPPORTED +#define PNG_SET_CHUNK_MALLOC_LIMIT_SUPPORTED +#define PNG_WRITE_gAMA_SUPPORTED +#define PNG_READ_GRAY_TO_RGB_SUPPORTED +#define PNG_WRITE_pCAL_SUPPORTED +#define PNG_READ_INVERT_ALPHA_SUPPORTED +#define PNG_WRITE_TRANSFORMS_SUPPORTED +#define PNG_READ_sBIT_SUPPORTED +#define PNG_READ_PACK_SUPPORTED +#define PNG_WRITE_SWAP_SUPPORTED +#define PNG_READ_cHRM_SUPPORTED +#define PNG_WRITE_tIME_SUPPORTED +#define PNG_READ_INTERLACING_SUPPORTED +#define PNG_READ_tRNS_SUPPORTED +#define PNG_WRITE_pHYs_SUPPORTED +#define PNG_WRITE_INVERT_SUPPORTED +#define PNG_READ_RGB_TO_GRAY_SUPPORTED +#define PNG_WRITE_sRGB_SUPPORTED +#define PNG_READ_oFFs_SUPPORTED +#define PNG_WRITE_FILLER_SUPPORTED +#define PNG_WRITE_TEXT_SUPPORTED +#define PNG_WRITE_SHIFT_SUPPORTED +#define PNG_PROGRESSIVE_READ_SUPPORTED +#define PNG_READ_SHIFT_SUPPORTED +#define PNG_CONVERT_tIME_SUPPORTED +#define PNG_READ_USER_TRANSFORM_SUPPORTED +#define PNG_READ_INT_FUNCTIONS_SUPPORTED +#define PNG_READ_USER_CHUNKS_SUPPORTED +#define PNG_READ_hIST_SUPPORTED +#define PNG_READ_16BIT_SUPPORTED +#define PNG_READ_SWAP_ALPHA_SUPPORTED +#define PNG_READ_COMPOSITE_NODIV_SUPPORTED +#define PNG_SEQUENTIAL_READ_SUPPORTED +#define PNG_READ_BACKGROUND_SUPPORTED +#define PNG_READ_QUANTIZE_SUPPORTED +#define PNG_READ_iCCP_SUPPORTED +#define PNG_READ_STRIP_ALPHA_SUPPORTED +#define PNG_READ_PACKSWAP_SUPPORTED +#define PNG_READ_sRGB_SUPPORTED +#define PNG_WRITE_tEXt_SUPPORTED +#define PNG_READ_gAMA_SUPPORTED +#define PNG_READ_pCAL_SUPPORTED +#define PNG_READ_EXPAND_SUPPORTED +#define PNG_WRITE_sPLT_SUPPORTED +#define PNG_READ_SWAP_SUPPORTED +#define PNG_READ_tIME_SUPPORTED +#define PNG_READ_pHYs_SUPPORTED +#define PNG_WRITE_SWAP_ALPHA_SUPPORTED +#define PNG_TIME_RFC1123_SUPPORTED +#define PNG_READ_TEXT_SUPPORTED +#define PNG_WRITE_BGR_SUPPORTED +#define PNG_USER_CHUNKS_SUPPORTED +#define PNG_CONSOLE_IO_SUPPORTED +#define PNG_WRITE_PACK_SUPPORTED +#define PNG_READ_FILLER_SUPPORTED +#define PNG_WRITE_bKGD_SUPPORTED +#define PNG_WRITE_tRNS_SUPPORTED +#define PNG_READ_sPLT_SUPPORTED +#define PNG_WRITE_sCAL_SUPPORTED +#define PNG_WRITE_oFFs_SUPPORTED +#define PNG_READ_tEXt_SUPPORTED +#define PNG_WRITE_sBIT_SUPPORTED +#define PNG_READ_INVERT_SUPPORTED +#define PNG_READ_16_TO_8_SUPPORTED +#define PNG_WRITE_cHRM_SUPPORTED +#define PNG_16BIT_SUPPORTED +#define PNG_WRITE_USER_TRANSFORM_SUPPORTED +#define PNG_READ_BGR_SUPPORTED +#define PNG_WRITE_PACKSWAP_SUPPORTED +#define PNG_WRITE_INVERT_ALPHA_SUPPORTED +#define PNG_sCAL_SUPPORTED +#define PNG_WRITE_zTXt_SUPPORTED +#define PNG_sBIT_SUPPORTED +#define PNG_cHRM_SUPPORTED +#define PNG_bKGD_SUPPORTED +#define PNG_tRNS_SUPPORTED +#define PNG_WRITE_iTXt_SUPPORTED +#define PNG_oFFs_SUPPORTED +#define PNG_USER_TRANSFORM_PTR_SUPPORTED +#define PNG_USER_TRANSFORM_INFO_SUPPORTED +#define PNG_hIST_SUPPORTED +#define PNG_iCCP_SUPPORTED +#define PNG_sRGB_SUPPORTED +#define PNG_READ_zTXt_SUPPORTED +#define PNG_gAMA_SUPPORTED +#define PNG_pCAL_SUPPORTED +#define PNG_CHECK_cHRM_SUPPORTED +#define PNG_tIME_SUPPORTED +#define PNG_pHYs_SUPPORTED +#define PNG_READ_iTXt_SUPPORTED +#define PNG_TEXT_SUPPORTED +#define PNG_SAVE_INT_32_SUPPORTED +#define PNG_sPLT_SUPPORTED +#define PNG_tEXt_SUPPORTED +#define PNG_zTXt_SUPPORTED +#define PNG_iTXt_SUPPORTED +/* end of options */ +#endif /* PNGLCONF_H */ diff --git a/src/3rdparty/libpng/pngmem.c b/src/3rdparty/libpng/pngmem.c new file mode 100644 index 0000000000..a15d8b0859 --- /dev/null +++ b/src/3rdparty/libpng/pngmem.c @@ -0,0 +1,658 @@ + +/* pngmem.c - stub functions for memory allocation + * + * Last changed in libpng 1.5.1 [February 3, 2011] + * Copyright (c) 1998-2011 Glenn Randers-Pehrson + * (Version 0.96 Copyright (c) 1996, 1997 Andreas Dilger) + * (Version 0.88 Copyright (c) 1995, 1996 Guy Eric Schalnat, Group 42, Inc.) + * + * This code is released under the libpng license. + * For conditions of distribution and use, see the disclaimer + * and license in png.h + * + * This file provides a location for all memory allocation. Users who + * need special memory handling are expected to supply replacement + * functions for png_malloc() and png_free(), and to use + * png_create_read_struct_2() and png_create_write_struct_2() to + * identify the replacement functions. + */ + +#include "pngpriv.h" + +#if defined(PNG_READ_SUPPORTED) || defined(PNG_WRITE_SUPPORTED) + +/* Borland DOS special memory handler */ +#if defined(__TURBOC__) && !defined(_Windows) && !defined(__FLAT__) +/* If you change this, be sure to change the one in png.h also */ + +/* Allocate memory for a png_struct. The malloc and memset can be replaced + by a single call to calloc() if this is thought to improve performance. */ +PNG_FUNCTION(png_voidp /* PRIVATE */, +png_create_struct,(int type),PNG_ALLOCATED) +{ +# ifdef PNG_USER_MEM_SUPPORTED + return (png_create_struct_2(type, NULL, NULL)); +} + +/* Alternate version of png_create_struct, for use with user-defined malloc. */ +PNG_FUNCTION(png_voidp /* PRIVATE */, +png_create_struct_2,(int type, png_malloc_ptr malloc_fn, png_voidp mem_ptr), + PNG_ALLOCATED) +{ +# endif /* PNG_USER_MEM_SUPPORTED */ + png_size_t size; + png_voidp struct_ptr; + + if (type == PNG_STRUCT_INFO) + size = png_sizeof(png_info); + + else if (type == PNG_STRUCT_PNG) + size = png_sizeof(png_struct); + + else + return (png_get_copyright(NULL)); + +# ifdef PNG_USER_MEM_SUPPORTED + if (malloc_fn != NULL) + { + png_struct dummy_struct; + png_structp png_ptr = &dummy_struct; + png_ptr->mem_ptr=mem_ptr; + struct_ptr = (*(malloc_fn))(png_ptr, (png_uint_32)size); + } + + else +# endif /* PNG_USER_MEM_SUPPORTED */ + struct_ptr = (png_voidp)farmalloc(size); + if (struct_ptr != NULL) + png_memset(struct_ptr, 0, size); + + return (struct_ptr); +} + +/* Free memory allocated by a png_create_struct() call */ +void /* PRIVATE */ +png_destroy_struct(png_voidp struct_ptr) +{ +# ifdef PNG_USER_MEM_SUPPORTED + png_destroy_struct_2(struct_ptr, NULL, NULL); +} + +/* Free memory allocated by a png_create_struct() call */ +void /* PRIVATE */ +png_destroy_struct_2(png_voidp struct_ptr, png_free_ptr free_fn, + png_voidp mem_ptr) +{ +# endif + if (struct_ptr != NULL) + { +# ifdef PNG_USER_MEM_SUPPORTED + if (free_fn != NULL) + { + png_struct dummy_struct; + png_structp png_ptr = &dummy_struct; + png_ptr->mem_ptr=mem_ptr; + (*(free_fn))(png_ptr, struct_ptr); + return; + } + +# endif /* PNG_USER_MEM_SUPPORTED */ + farfree (struct_ptr); + } +} + +/* Allocate memory. For reasonable files, size should never exceed + * 64K. However, zlib may allocate more then 64K if you don't tell + * it not to. See zconf.h and png.h for more information. zlib does + * need to allocate exactly 64K, so whatever you call here must + * have the ability to do that. + * + * Borland seems to have a problem in DOS mode for exactly 64K. + * It gives you a segment with an offset of 8 (perhaps to store its + * memory stuff). zlib doesn't like this at all, so we have to + * detect and deal with it. This code should not be needed in + * Windows or OS/2 modes, and only in 16 bit mode. This code has + * been updated by Alexander Lehmann for version 0.89 to waste less + * memory. + * + * Note that we can't use png_size_t for the "size" declaration, + * since on some systems a png_size_t is a 16-bit quantity, and as a + * result, we would be truncating potentially larger memory requests + * (which should cause a fatal error) and introducing major problems. + */ +PNG_FUNCTION(png_voidp,PNGAPI +png_calloc,(png_structp png_ptr, png_alloc_size_t size),PNG_ALLOCATED) +{ + png_voidp ret; + + ret = (png_malloc(png_ptr, size)); + + if (ret != NULL) + png_memset(ret,0,(png_size_t)size); + + return (ret); +} + +PNG_FUNCTION(png_voidp,PNGAPI +png_malloc,(png_structp png_ptr, png_alloc_size_t size),PNG_ALLOCATED) +{ + png_voidp ret; + + if (png_ptr == NULL || size == 0) + return (NULL); + +# ifdef PNG_USER_MEM_SUPPORTED + if (png_ptr->malloc_fn != NULL) + ret = ((png_voidp)(*(png_ptr->malloc_fn))(png_ptr, (png_size_t)size)); + + else + ret = (png_malloc_default(png_ptr, size)); + + if (ret == NULL && (png_ptr->flags&PNG_FLAG_MALLOC_NULL_MEM_OK) == 0) + png_error(png_ptr, "Out of memory"); + + return (ret); +} + +PNG_FUNCTION(png_voidp,PNGAPI +png_malloc_default,(png_structp png_ptr, png_alloc_size_t size),PNG_ALLOCATED) +{ + png_voidp ret; +# endif /* PNG_USER_MEM_SUPPORTED */ + + if (png_ptr == NULL || size == 0) + return (NULL); + +# ifdef PNG_MAX_MALLOC_64K + if (size > (png_uint_32)65536L) + { + png_warning(png_ptr, "Cannot Allocate > 64K"); + ret = NULL; + } + + else +# endif + + if (size != (size_t)size) + ret = NULL; + + else if (size == (png_uint_32)65536L) + { + if (png_ptr->offset_table == NULL) + { + /* Try to see if we need to do any of this fancy stuff */ + ret = farmalloc(size); + if (ret == NULL || ((png_size_t)ret & 0xffff)) + { + int num_blocks; + png_uint_32 total_size; + png_bytep table; + int i; + png_byte huge * hptr; + + if (ret != NULL) + { + farfree(ret); + ret = NULL; + } + + if (png_ptr->zlib_window_bits > 14) + num_blocks = (int)(1 << (png_ptr->zlib_window_bits - 14)); + + else + num_blocks = 1; + + if (png_ptr->zlib_mem_level >= 7) + num_blocks += (int)(1 << (png_ptr->zlib_mem_level - 7)); + + else + num_blocks++; + + total_size = ((png_uint_32)65536L) * (png_uint_32)num_blocks+16; + + table = farmalloc(total_size); + + if (table == NULL) + { +# ifndef PNG_USER_MEM_SUPPORTED + if ((png_ptr->flags&PNG_FLAG_MALLOC_NULL_MEM_OK) == 0) + png_error(png_ptr, "Out Of Memory"); /* Note "O", "M" */ + + else + png_warning(png_ptr, "Out Of Memory"); +# endif + return (NULL); + } + + if ((png_size_t)table & 0xfff0) + { +# ifndef PNG_USER_MEM_SUPPORTED + if ((png_ptr->flags&PNG_FLAG_MALLOC_NULL_MEM_OK) == 0) + png_error(png_ptr, + "Farmalloc didn't return normalized pointer"); + + else + png_warning(png_ptr, + "Farmalloc didn't return normalized pointer"); +# endif + return (NULL); + } + + png_ptr->offset_table = table; + png_ptr->offset_table_ptr = farmalloc(num_blocks * + png_sizeof(png_bytep)); + + if (png_ptr->offset_table_ptr == NULL) + { +# ifndef PNG_USER_MEM_SUPPORTED + if ((png_ptr->flags&PNG_FLAG_MALLOC_NULL_MEM_OK) == 0) + png_error(png_ptr, "Out Of memory"); /* Note "O", "m" */ + + else + png_warning(png_ptr, "Out Of memory"); +# endif + return (NULL); + } + + hptr = (png_byte huge *)table; + if ((png_size_t)hptr & 0xf) + { + hptr = (png_byte huge *)((long)(hptr) & 0xfffffff0L); + hptr = hptr + 16L; /* "hptr += 16L" fails on Turbo C++ 3.0 */ + } + + for (i = 0; i < num_blocks; i++) + { + png_ptr->offset_table_ptr[i] = (png_bytep)hptr; + hptr = hptr + (png_uint_32)65536L; /* "+=" fails on TC++3.0 */ + } + + png_ptr->offset_table_number = num_blocks; + png_ptr->offset_table_count = 0; + png_ptr->offset_table_count_free = 0; + } + } + + if (png_ptr->offset_table_count >= png_ptr->offset_table_number) + { +# ifndef PNG_USER_MEM_SUPPORTED + if ((png_ptr->flags&PNG_FLAG_MALLOC_NULL_MEM_OK) == 0) + png_error(png_ptr, "Out of Memory"); /* Note "o" and "M" */ + + else + png_warning(png_ptr, "Out of Memory"); +# endif + return (NULL); + } + + ret = png_ptr->offset_table_ptr[png_ptr->offset_table_count++]; + } + + else + ret = farmalloc(size); + +# ifndef PNG_USER_MEM_SUPPORTED + if (ret == NULL) + { + if ((png_ptr->flags&PNG_FLAG_MALLOC_NULL_MEM_OK) == 0) + png_error(png_ptr, "Out of memory"); /* Note "o" and "m" */ + + else + png_warning(png_ptr, "Out of memory"); /* Note "o" and "m" */ + } +# endif + + return (ret); +} + +/* Free a pointer allocated by png_malloc(). In the default + * configuration, png_ptr is not used, but is passed in case it + * is needed. If ptr is NULL, return without taking any action. + */ +void PNGAPI +png_free(png_structp png_ptr, png_voidp ptr) +{ + if (png_ptr == NULL || ptr == NULL) + return; + +# ifdef PNG_USER_MEM_SUPPORTED + if (png_ptr->free_fn != NULL) + { + (*(png_ptr->free_fn))(png_ptr, ptr); + return; + } + + else + png_free_default(png_ptr, ptr); +} + +void PNGAPI +png_free_default(png_structp png_ptr, png_voidp ptr) +{ +# endif /* PNG_USER_MEM_SUPPORTED */ + + if (png_ptr == NULL || ptr == NULL) + return; + + if (png_ptr->offset_table != NULL) + { + int i; + + for (i = 0; i < png_ptr->offset_table_count; i++) + { + if (ptr == png_ptr->offset_table_ptr[i]) + { + ptr = NULL; + png_ptr->offset_table_count_free++; + break; + } + } + if (png_ptr->offset_table_count_free == png_ptr->offset_table_count) + { + farfree(png_ptr->offset_table); + farfree(png_ptr->offset_table_ptr); + png_ptr->offset_table = NULL; + png_ptr->offset_table_ptr = NULL; + } + } + + if (ptr != NULL) + farfree(ptr); +} + +#else /* Not the Borland DOS special memory handler */ + +/* Allocate memory for a png_struct or a png_info. The malloc and + memset can be replaced by a single call to calloc() if this is thought + to improve performance noticably. */ +PNG_FUNCTION(png_voidp /* PRIVATE */, +png_create_struct,(int type),PNG_ALLOCATED) +{ +# ifdef PNG_USER_MEM_SUPPORTED + return (png_create_struct_2(type, NULL, NULL)); +} + +/* Allocate memory for a png_struct or a png_info. The malloc and + memset can be replaced by a single call to calloc() if this is thought + to improve performance noticably. */ +PNG_FUNCTION(png_voidp /* PRIVATE */, +png_create_struct_2,(int type, png_malloc_ptr malloc_fn, png_voidp mem_ptr), + PNG_ALLOCATED) +{ +# endif /* PNG_USER_MEM_SUPPORTED */ + png_size_t size; + png_voidp struct_ptr; + + if (type == PNG_STRUCT_INFO) + size = png_sizeof(png_info); + + else if (type == PNG_STRUCT_PNG) + size = png_sizeof(png_struct); + + else + return (NULL); + +# ifdef PNG_USER_MEM_SUPPORTED + if (malloc_fn != NULL) + { + png_struct dummy_struct; + png_structp png_ptr = &dummy_struct; + png_ptr->mem_ptr=mem_ptr; + struct_ptr = (*(malloc_fn))(png_ptr, size); + + if (struct_ptr != NULL) + png_memset(struct_ptr, 0, size); + + return (struct_ptr); + } +# endif /* PNG_USER_MEM_SUPPORTED */ + +# if defined(__TURBOC__) && !defined(__FLAT__) + struct_ptr = (png_voidp)farmalloc(size); +# else +# if defined(_MSC_VER) && defined(MAXSEG_64K) + struct_ptr = (png_voidp)halloc(size, 1); +# else + struct_ptr = (png_voidp)malloc(size); +# endif +# endif + + if (struct_ptr != NULL) + png_memset(struct_ptr, 0, size); + + return (struct_ptr); +} + + +/* Free memory allocated by a png_create_struct() call */ +void /* PRIVATE */ +png_destroy_struct(png_voidp struct_ptr) +{ +# ifdef PNG_USER_MEM_SUPPORTED + png_destroy_struct_2(struct_ptr, NULL, NULL); +} + +/* Free memory allocated by a png_create_struct() call */ +void /* PRIVATE */ +png_destroy_struct_2(png_voidp struct_ptr, png_free_ptr free_fn, + png_voidp mem_ptr) +{ +# endif /* PNG_USER_MEM_SUPPORTED */ + if (struct_ptr != NULL) + { +# ifdef PNG_USER_MEM_SUPPORTED + if (free_fn != NULL) + { + png_struct dummy_struct; + png_structp png_ptr = &dummy_struct; + png_ptr->mem_ptr=mem_ptr; + (*(free_fn))(png_ptr, struct_ptr); + return; + } +# endif /* PNG_USER_MEM_SUPPORTED */ +# if defined(__TURBOC__) && !defined(__FLAT__) + farfree(struct_ptr); + +# else +# if defined(_MSC_VER) && defined(MAXSEG_64K) + hfree(struct_ptr); + +# else + free(struct_ptr); + +# endif +# endif + } +} + +/* Allocate memory. For reasonable files, size should never exceed + * 64K. However, zlib may allocate more then 64K if you don't tell + * it not to. See zconf.h and png.h for more information. zlib does + * need to allocate exactly 64K, so whatever you call here must + * have the ability to do that. + */ + +PNG_FUNCTION(png_voidp,PNGAPI +png_calloc,(png_structp png_ptr, png_alloc_size_t size),PNG_ALLOCATED) +{ + png_voidp ret; + + ret = (png_malloc(png_ptr, size)); + + if (ret != NULL) + png_memset(ret,0,(png_size_t)size); + + return (ret); +} + +PNG_FUNCTION(png_voidp,PNGAPI +png_malloc,(png_structp png_ptr, png_alloc_size_t size),PNG_ALLOCATED) +{ + png_voidp ret; + +# ifdef PNG_USER_MEM_SUPPORTED + if (png_ptr == NULL || size == 0) + return (NULL); + + if (png_ptr->malloc_fn != NULL) + ret = ((png_voidp)(*(png_ptr->malloc_fn))(png_ptr, (png_size_t)size)); + + else + ret = (png_malloc_default(png_ptr, size)); + + if (ret == NULL && (png_ptr->flags&PNG_FLAG_MALLOC_NULL_MEM_OK) == 0) + png_error(png_ptr, "Out of Memory"); + + return (ret); +} + +PNG_FUNCTION(png_voidp,PNGAPI +png_malloc_default,(png_structp png_ptr, png_alloc_size_t size),PNG_ALLOCATED) +{ + png_voidp ret; +# endif /* PNG_USER_MEM_SUPPORTED */ + + if (png_ptr == NULL || size == 0) + return (NULL); + +# ifdef PNG_MAX_MALLOC_64K + if (size > (png_uint_32)65536L) + { +# ifndef PNG_USER_MEM_SUPPORTED + if ((png_ptr->flags&PNG_FLAG_MALLOC_NULL_MEM_OK) == 0) + png_error(png_ptr, "Cannot Allocate > 64K"); + + else +# endif + return NULL; + } +# endif + + /* Check for overflow */ +# if defined(__TURBOC__) && !defined(__FLAT__) + + if (size != (unsigned long)size) + ret = NULL; + + else + ret = farmalloc(size); + +# else +# if defined(_MSC_VER) && defined(MAXSEG_64K) + if (size != (unsigned long)size) + ret = NULL; + + else + ret = halloc(size, 1); + +# else + if (size != (size_t)size) + ret = NULL; + + else + ret = malloc((size_t)size); +# endif +# endif + +# ifndef PNG_USER_MEM_SUPPORTED + if (ret == NULL && (png_ptr->flags&PNG_FLAG_MALLOC_NULL_MEM_OK) == 0) + png_error(png_ptr, "Out of Memory"); +# endif + + return (ret); +} + +/* Free a pointer allocated by png_malloc(). If ptr is NULL, return + * without taking any action. + */ +void PNGAPI +png_free(png_structp png_ptr, png_voidp ptr) +{ + if (png_ptr == NULL || ptr == NULL) + return; + +# ifdef PNG_USER_MEM_SUPPORTED + if (png_ptr->free_fn != NULL) + { + (*(png_ptr->free_fn))(png_ptr, ptr); + return; + } + + else + png_free_default(png_ptr, ptr); +} + +void PNGAPI +png_free_default(png_structp png_ptr, png_voidp ptr) +{ + if (png_ptr == NULL || ptr == NULL) + return; + +# endif /* PNG_USER_MEM_SUPPORTED */ + +# if defined(__TURBOC__) && !defined(__FLAT__) + farfree(ptr); + +# else +# if defined(_MSC_VER) && defined(MAXSEG_64K) + hfree(ptr); + +# else + free(ptr); + +# endif +# endif +} +#endif /* Not Borland DOS special memory handler */ + +/* This function was added at libpng version 1.2.3. The png_malloc_warn() + * function will set up png_malloc() to issue a png_warning and return NULL + * instead of issuing a png_error, if it fails to allocate the requested + * memory. + */ +PNG_FUNCTION(png_voidp,PNGAPI +png_malloc_warn,(png_structp png_ptr, png_alloc_size_t size),PNG_ALLOCATED) +{ + png_voidp ptr; + png_uint_32 save_flags; + if (png_ptr == NULL) + return (NULL); + + save_flags = png_ptr->flags; + png_ptr->flags|=PNG_FLAG_MALLOC_NULL_MEM_OK; + ptr = (png_voidp)png_malloc((png_structp)png_ptr, size); + png_ptr->flags=save_flags; + return(ptr); +} + + +#ifdef PNG_USER_MEM_SUPPORTED +/* This function is called when the application wants to use another method + * of allocating and freeing memory. + */ +void PNGAPI +png_set_mem_fn(png_structp png_ptr, png_voidp mem_ptr, png_malloc_ptr + malloc_fn, png_free_ptr free_fn) +{ + if (png_ptr != NULL) + { + png_ptr->mem_ptr = mem_ptr; + png_ptr->malloc_fn = malloc_fn; + png_ptr->free_fn = free_fn; + } +} + +/* This function returns a pointer to the mem_ptr associated with the user + * functions. The application should free any memory associated with this + * pointer before png_write_destroy and png_read_destroy are called. + */ +png_voidp PNGAPI +png_get_mem_ptr(png_const_structp png_ptr) +{ + if (png_ptr == NULL) + return (NULL); + + return ((png_voidp)png_ptr->mem_ptr); +} +#endif /* PNG_USER_MEM_SUPPORTED */ +#endif /* PNG_READ_SUPPORTED || PNG_WRITE_SUPPORTED */ diff --git a/src/3rdparty/libpng/pngpread.c b/src/3rdparty/libpng/pngpread.c new file mode 100644 index 0000000000..7b1149bab1 --- /dev/null +++ b/src/3rdparty/libpng/pngpread.c @@ -0,0 +1,1854 @@ + +/* pngpread.c - read a png file in push mode + * + * Last changed in libpng 1.5.1 [February 3, 2011] + * Copyright (c) 1998-2011 Glenn Randers-Pehrson + * (Version 0.96 Copyright (c) 1996, 1997 Andreas Dilger) + * (Version 0.88 Copyright (c) 1995, 1996 Guy Eric Schalnat, Group 42, Inc.) + * + * This code is released under the libpng license. + * For conditions of distribution and use, see the disclaimer + * and license in png.h + */ + +#include "pngpriv.h" + +#ifdef PNG_PROGRESSIVE_READ_SUPPORTED + +/* Push model modes */ +#define PNG_READ_SIG_MODE 0 +#define PNG_READ_CHUNK_MODE 1 +#define PNG_READ_IDAT_MODE 2 +#define PNG_SKIP_MODE 3 +#define PNG_READ_tEXt_MODE 4 +#define PNG_READ_zTXt_MODE 5 +#define PNG_READ_DONE_MODE 6 +#define PNG_READ_iTXt_MODE 7 +#define PNG_ERROR_MODE 8 + +void PNGAPI +png_process_data(png_structp png_ptr, png_infop info_ptr, + png_bytep buffer, png_size_t buffer_size) +{ + if (png_ptr == NULL || info_ptr == NULL) + return; + + png_push_restore_buffer(png_ptr, buffer, buffer_size); + + while (png_ptr->buffer_size) + { + png_process_some_data(png_ptr, info_ptr); + } +} + +png_size_t PNGAPI +png_process_data_pause(png_structp png_ptr, int save) +{ + if (png_ptr != NULL) + { + /* It's easiest for the caller if we do the save, then the caller doesn't + * have to supply the same data again: + */ + if (save) + png_push_save_buffer(png_ptr); + else + { + /* This includes any pending saved bytes: */ + png_size_t remaining = png_ptr->buffer_size; + png_ptr->buffer_size = 0; + + /* So subtract the saved buffer size, unless all the data + * is actually 'saved', in which case we just return 0 + */ + if (png_ptr->save_buffer_size < remaining) + return remaining - png_ptr->save_buffer_size; + } + } + + return 0; +} + +png_uint_32 PNGAPI +png_process_data_skip(png_structp png_ptr) +{ + png_uint_32 remaining = 0; + + if (png_ptr != NULL && png_ptr->process_mode == PNG_SKIP_MODE && + png_ptr->skip_length > 0) + { + /* At the end of png_process_data the buffer size must be 0 (see the loop + * above) so we can detect a broken call here: + */ + if (png_ptr->buffer_size != 0) + png_error(png_ptr, + "png_process_data_skip called inside png_process_data"); + + /* If is impossible for there to be a saved buffer at this point - + * otherwise we could not be in SKIP mode. This will also happen if + * png_process_skip is called inside png_process_data (but only very + * rarely.) + */ + if (png_ptr->save_buffer_size != 0) + png_error(png_ptr, "png_process_data_skip called with saved data"); + + remaining = png_ptr->skip_length; + png_ptr->skip_length = 0; + png_ptr->process_mode = PNG_READ_CHUNK_MODE; + } + + return remaining; +} + +/* What we do with the incoming data depends on what we were previously + * doing before we ran out of data... + */ +void /* PRIVATE */ +png_process_some_data(png_structp png_ptr, png_infop info_ptr) +{ + if (png_ptr == NULL) + return; + + switch (png_ptr->process_mode) + { + case PNG_READ_SIG_MODE: + { + png_push_read_sig(png_ptr, info_ptr); + break; + } + + case PNG_READ_CHUNK_MODE: + { + png_push_read_chunk(png_ptr, info_ptr); + break; + } + + case PNG_READ_IDAT_MODE: + { + png_push_read_IDAT(png_ptr); + break; + } + +#ifdef PNG_READ_tEXt_SUPPORTED + case PNG_READ_tEXt_MODE: + { + png_push_read_tEXt(png_ptr, info_ptr); + break; + } + +#endif +#ifdef PNG_READ_zTXt_SUPPORTED + case PNG_READ_zTXt_MODE: + { + png_push_read_zTXt(png_ptr, info_ptr); + break; + } + +#endif +#ifdef PNG_READ_iTXt_SUPPORTED + case PNG_READ_iTXt_MODE: + { + png_push_read_iTXt(png_ptr, info_ptr); + break; + } + +#endif + case PNG_SKIP_MODE: + { + png_push_crc_finish(png_ptr); + break; + } + + default: + { + png_ptr->buffer_size = 0; + break; + } + } +} + +/* Read any remaining signature bytes from the stream and compare them with + * the correct PNG signature. It is possible that this routine is called + * with bytes already read from the signature, either because they have been + * checked by the calling application, or because of multiple calls to this + * routine. + */ +void /* PRIVATE */ +png_push_read_sig(png_structp png_ptr, png_infop info_ptr) +{ + png_size_t num_checked = png_ptr->sig_bytes, + num_to_check = 8 - num_checked; + + if (png_ptr->buffer_size < num_to_check) + { + num_to_check = png_ptr->buffer_size; + } + + png_push_fill_buffer(png_ptr, &(info_ptr->signature[num_checked]), + num_to_check); + png_ptr->sig_bytes = (png_byte)(png_ptr->sig_bytes + num_to_check); + + if (png_sig_cmp(info_ptr->signature, num_checked, num_to_check)) + { + if (num_checked < 4 && + png_sig_cmp(info_ptr->signature, num_checked, num_to_check - 4)) + png_error(png_ptr, "Not a PNG file"); + + else + png_error(png_ptr, "PNG file corrupted by ASCII conversion"); + } + else + { + if (png_ptr->sig_bytes >= 8) + { + png_ptr->process_mode = PNG_READ_CHUNK_MODE; + } + } +} + +void /* PRIVATE */ +png_push_read_chunk(png_structp png_ptr, png_infop info_ptr) +{ + PNG_IHDR; + PNG_IDAT; + PNG_IEND; + PNG_PLTE; +#ifdef PNG_READ_bKGD_SUPPORTED + PNG_bKGD; +#endif +#ifdef PNG_READ_cHRM_SUPPORTED + PNG_cHRM; +#endif +#ifdef PNG_READ_gAMA_SUPPORTED + PNG_gAMA; +#endif +#ifdef PNG_READ_hIST_SUPPORTED + PNG_hIST; +#endif +#ifdef PNG_READ_iCCP_SUPPORTED + PNG_iCCP; +#endif +#ifdef PNG_READ_iTXt_SUPPORTED + PNG_iTXt; +#endif +#ifdef PNG_READ_oFFs_SUPPORTED + PNG_oFFs; +#endif +#ifdef PNG_READ_pCAL_SUPPORTED + PNG_pCAL; +#endif +#ifdef PNG_READ_pHYs_SUPPORTED + PNG_pHYs; +#endif +#ifdef PNG_READ_sBIT_SUPPORTED + PNG_sBIT; +#endif +#ifdef PNG_READ_sCAL_SUPPORTED + PNG_sCAL; +#endif +#ifdef PNG_READ_sRGB_SUPPORTED + PNG_sRGB; +#endif +#ifdef PNG_READ_sPLT_SUPPORTED + PNG_sPLT; +#endif +#ifdef PNG_READ_tEXt_SUPPORTED + PNG_tEXt; +#endif +#ifdef PNG_READ_tIME_SUPPORTED + PNG_tIME; +#endif +#ifdef PNG_READ_tRNS_SUPPORTED + PNG_tRNS; +#endif +#ifdef PNG_READ_zTXt_SUPPORTED + PNG_zTXt; +#endif + + /* First we make sure we have enough data for the 4 byte chunk name + * and the 4 byte chunk length before proceeding with decoding the + * chunk data. To fully decode each of these chunks, we also make + * sure we have enough data in the buffer for the 4 byte CRC at the + * end of every chunk (except IDAT, which is handled separately). + */ + if (!(png_ptr->mode & PNG_HAVE_CHUNK_HEADER)) + { + png_byte chunk_length[4]; + + if (png_ptr->buffer_size < 8) + { + png_push_save_buffer(png_ptr); + return; + } + + png_push_fill_buffer(png_ptr, chunk_length, 4); + png_ptr->push_length = png_get_uint_31(png_ptr, chunk_length); + png_reset_crc(png_ptr); + png_crc_read(png_ptr, png_ptr->chunk_name, 4); + png_check_chunk_name(png_ptr, png_ptr->chunk_name); + png_ptr->mode |= PNG_HAVE_CHUNK_HEADER; + } + + if (!png_memcmp(png_ptr->chunk_name, png_IDAT, 4)) + if (png_ptr->mode & PNG_AFTER_IDAT) + png_ptr->mode |= PNG_HAVE_CHUNK_AFTER_IDAT; + + if (!png_memcmp(png_ptr->chunk_name, png_IHDR, 4)) + { + if (png_ptr->push_length != 13) + png_error(png_ptr, "Invalid IHDR length"); + + if (png_ptr->push_length + 4 > png_ptr->buffer_size) + { + png_push_save_buffer(png_ptr); + return; + } + + png_handle_IHDR(png_ptr, info_ptr, png_ptr->push_length); + } + + else if (!png_memcmp(png_ptr->chunk_name, png_IEND, 4)) + { + if (png_ptr->push_length + 4 > png_ptr->buffer_size) + { + png_push_save_buffer(png_ptr); + return; + } + + png_handle_IEND(png_ptr, info_ptr, png_ptr->push_length); + + png_ptr->process_mode = PNG_READ_DONE_MODE; + png_push_have_end(png_ptr, info_ptr); + } + +#ifdef PNG_HANDLE_AS_UNKNOWN_SUPPORTED + else if (png_handle_as_unknown(png_ptr, png_ptr->chunk_name)) + { + if (png_ptr->push_length + 4 > png_ptr->buffer_size) + { + png_push_save_buffer(png_ptr); + return; + } + + if (!png_memcmp(png_ptr->chunk_name, png_IDAT, 4)) + png_ptr->mode |= PNG_HAVE_IDAT; + + png_handle_unknown(png_ptr, info_ptr, png_ptr->push_length); + + if (!png_memcmp(png_ptr->chunk_name, png_PLTE, 4)) + png_ptr->mode |= PNG_HAVE_PLTE; + + else if (!png_memcmp(png_ptr->chunk_name, png_IDAT, 4)) + { + if (!(png_ptr->mode & PNG_HAVE_IHDR)) + png_error(png_ptr, "Missing IHDR before IDAT"); + + else if (png_ptr->color_type == PNG_COLOR_TYPE_PALETTE && + !(png_ptr->mode & PNG_HAVE_PLTE)) + png_error(png_ptr, "Missing PLTE before IDAT"); + } + } + +#endif + else if (!png_memcmp(png_ptr->chunk_name, png_PLTE, 4)) + { + if (png_ptr->push_length + 4 > png_ptr->buffer_size) + { + png_push_save_buffer(png_ptr); + return; + } + png_handle_PLTE(png_ptr, info_ptr, png_ptr->push_length); + } + + else if (!png_memcmp(png_ptr->chunk_name, png_IDAT, 4)) + { + /* If we reach an IDAT chunk, this means we have read all of the + * header chunks, and we can start reading the image (or if this + * is called after the image has been read - we have an error). + */ + + if (!(png_ptr->mode & PNG_HAVE_IHDR)) + png_error(png_ptr, "Missing IHDR before IDAT"); + + else if (png_ptr->color_type == PNG_COLOR_TYPE_PALETTE && + !(png_ptr->mode & PNG_HAVE_PLTE)) + png_error(png_ptr, "Missing PLTE before IDAT"); + + if (png_ptr->mode & PNG_HAVE_IDAT) + { + if (!(png_ptr->mode & PNG_HAVE_CHUNK_AFTER_IDAT)) + if (png_ptr->push_length == 0) + return; + + if (png_ptr->mode & PNG_AFTER_IDAT) + png_benign_error(png_ptr, "Too many IDATs found"); + } + + png_ptr->idat_size = png_ptr->push_length; + png_ptr->mode |= PNG_HAVE_IDAT; + png_ptr->process_mode = PNG_READ_IDAT_MODE; + png_push_have_info(png_ptr, info_ptr); + png_ptr->zstream.avail_out = + (uInt) PNG_ROWBYTES(png_ptr->pixel_depth, + png_ptr->iwidth) + 1; + png_ptr->zstream.next_out = png_ptr->row_buf; + return; + } + +#ifdef PNG_READ_gAMA_SUPPORTED + else if (!png_memcmp(png_ptr->chunk_name, png_gAMA, 4)) + { + if (png_ptr->push_length + 4 > png_ptr->buffer_size) + { + png_push_save_buffer(png_ptr); + return; + } + + png_handle_gAMA(png_ptr, info_ptr, png_ptr->push_length); + } + +#endif +#ifdef PNG_READ_sBIT_SUPPORTED + else if (!png_memcmp(png_ptr->chunk_name, png_sBIT, 4)) + { + if (png_ptr->push_length + 4 > png_ptr->buffer_size) + { + png_push_save_buffer(png_ptr); + return; + } + + png_handle_sBIT(png_ptr, info_ptr, png_ptr->push_length); + } + +#endif +#ifdef PNG_READ_cHRM_SUPPORTED + else if (!png_memcmp(png_ptr->chunk_name, png_cHRM, 4)) + { + if (png_ptr->push_length + 4 > png_ptr->buffer_size) + { + png_push_save_buffer(png_ptr); + return; + } + + png_handle_cHRM(png_ptr, info_ptr, png_ptr->push_length); + } + +#endif +#ifdef PNG_READ_sRGB_SUPPORTED + else if (!png_memcmp(png_ptr->chunk_name, png_sRGB, 4)) + { + if (png_ptr->push_length + 4 > png_ptr->buffer_size) + { + png_push_save_buffer(png_ptr); + return; + } + + png_handle_sRGB(png_ptr, info_ptr, png_ptr->push_length); + } + +#endif +#ifdef PNG_READ_iCCP_SUPPORTED + else if (!png_memcmp(png_ptr->chunk_name, png_iCCP, 4)) + { + if (png_ptr->push_length + 4 > png_ptr->buffer_size) + { + png_push_save_buffer(png_ptr); + return; + } + + png_handle_iCCP(png_ptr, info_ptr, png_ptr->push_length); + } + +#endif +#ifdef PNG_READ_sPLT_SUPPORTED + else if (!png_memcmp(png_ptr->chunk_name, png_sPLT, 4)) + { + if (png_ptr->push_length + 4 > png_ptr->buffer_size) + { + png_push_save_buffer(png_ptr); + return; + } + + png_handle_sPLT(png_ptr, info_ptr, png_ptr->push_length); + } + +#endif +#ifdef PNG_READ_tRNS_SUPPORTED + else if (!png_memcmp(png_ptr->chunk_name, png_tRNS, 4)) + { + if (png_ptr->push_length + 4 > png_ptr->buffer_size) + { + png_push_save_buffer(png_ptr); + return; + } + + png_handle_tRNS(png_ptr, info_ptr, png_ptr->push_length); + } + +#endif +#ifdef PNG_READ_bKGD_SUPPORTED + else if (!png_memcmp(png_ptr->chunk_name, png_bKGD, 4)) + { + if (png_ptr->push_length + 4 > png_ptr->buffer_size) + { + png_push_save_buffer(png_ptr); + return; + } + + png_handle_bKGD(png_ptr, info_ptr, png_ptr->push_length); + } + +#endif +#ifdef PNG_READ_hIST_SUPPORTED + else if (!png_memcmp(png_ptr->chunk_name, png_hIST, 4)) + { + if (png_ptr->push_length + 4 > png_ptr->buffer_size) + { + png_push_save_buffer(png_ptr); + return; + } + + png_handle_hIST(png_ptr, info_ptr, png_ptr->push_length); + } + +#endif +#ifdef PNG_READ_pHYs_SUPPORTED + else if (!png_memcmp(png_ptr->chunk_name, png_pHYs, 4)) + { + if (png_ptr->push_length + 4 > png_ptr->buffer_size) + { + png_push_save_buffer(png_ptr); + return; + } + + png_handle_pHYs(png_ptr, info_ptr, png_ptr->push_length); + } + +#endif +#ifdef PNG_READ_oFFs_SUPPORTED + else if (!png_memcmp(png_ptr->chunk_name, png_oFFs, 4)) + { + if (png_ptr->push_length + 4 > png_ptr->buffer_size) + { + png_push_save_buffer(png_ptr); + return; + } + + png_handle_oFFs(png_ptr, info_ptr, png_ptr->push_length); + } +#endif + +#ifdef PNG_READ_pCAL_SUPPORTED + else if (!png_memcmp(png_ptr->chunk_name, png_pCAL, 4)) + { + if (png_ptr->push_length + 4 > png_ptr->buffer_size) + { + png_push_save_buffer(png_ptr); + return; + } + + png_handle_pCAL(png_ptr, info_ptr, png_ptr->push_length); + } + +#endif +#ifdef PNG_READ_sCAL_SUPPORTED + else if (!png_memcmp(png_ptr->chunk_name, png_sCAL, 4)) + { + if (png_ptr->push_length + 4 > png_ptr->buffer_size) + { + png_push_save_buffer(png_ptr); + return; + } + + png_handle_sCAL(png_ptr, info_ptr, png_ptr->push_length); + } + +#endif +#ifdef PNG_READ_tIME_SUPPORTED + else if (!png_memcmp(png_ptr->chunk_name, png_tIME, 4)) + { + if (png_ptr->push_length + 4 > png_ptr->buffer_size) + { + png_push_save_buffer(png_ptr); + return; + } + + png_handle_tIME(png_ptr, info_ptr, png_ptr->push_length); + } + +#endif +#ifdef PNG_READ_tEXt_SUPPORTED + else if (!png_memcmp(png_ptr->chunk_name, png_tEXt, 4)) + { + if (png_ptr->push_length + 4 > png_ptr->buffer_size) + { + png_push_save_buffer(png_ptr); + return; + } + + png_push_handle_tEXt(png_ptr, info_ptr, png_ptr->push_length); + } + +#endif +#ifdef PNG_READ_zTXt_SUPPORTED + else if (!png_memcmp(png_ptr->chunk_name, png_zTXt, 4)) + { + if (png_ptr->push_length + 4 > png_ptr->buffer_size) + { + png_push_save_buffer(png_ptr); + return; + } + + png_push_handle_zTXt(png_ptr, info_ptr, png_ptr->push_length); + } + +#endif +#ifdef PNG_READ_iTXt_SUPPORTED + else if (!png_memcmp(png_ptr->chunk_name, png_iTXt, 4)) + { + if (png_ptr->push_length + 4 > png_ptr->buffer_size) + { + png_push_save_buffer(png_ptr); + return; + } + + png_push_handle_iTXt(png_ptr, info_ptr, png_ptr->push_length); + } + +#endif + else + { + if (png_ptr->push_length + 4 > png_ptr->buffer_size) + { + png_push_save_buffer(png_ptr); + return; + } + png_push_handle_unknown(png_ptr, info_ptr, png_ptr->push_length); + } + + png_ptr->mode &= ~PNG_HAVE_CHUNK_HEADER; +} + +void /* PRIVATE */ +png_push_crc_skip(png_structp png_ptr, png_uint_32 skip) +{ + png_ptr->process_mode = PNG_SKIP_MODE; + png_ptr->skip_length = skip; +} + +void /* PRIVATE */ +png_push_crc_finish(png_structp png_ptr) +{ + if (png_ptr->skip_length && png_ptr->save_buffer_size) + { + png_size_t save_size = png_ptr->save_buffer_size; + png_uint_32 skip_length = png_ptr->skip_length; + + /* We want the smaller of 'skip_length' and 'save_buffer_size', but + * they are of different types and we don't know which variable has the + * fewest bits. Carefully select the smaller and cast it to the type of + * the larger - this cannot overflow. Do not cast in the following test + * - it will break on either 16 or 64 bit platforms. + */ + if (skip_length < save_size) + save_size = (png_size_t)skip_length; + + else + skip_length = (png_uint_32)save_size; + + png_calculate_crc(png_ptr, png_ptr->save_buffer_ptr, save_size); + + png_ptr->skip_length -= skip_length; + png_ptr->buffer_size -= save_size; + png_ptr->save_buffer_size -= save_size; + png_ptr->save_buffer_ptr += save_size; + } + if (png_ptr->skip_length && png_ptr->current_buffer_size) + { + png_size_t save_size = png_ptr->current_buffer_size; + png_uint_32 skip_length = png_ptr->skip_length; + + /* We want the smaller of 'skip_length' and 'current_buffer_size', here, + * the same problem exists as above and the same solution. + */ + if (skip_length < save_size) + save_size = (png_size_t)skip_length; + + else + skip_length = (png_uint_32)save_size; + + png_calculate_crc(png_ptr, png_ptr->current_buffer_ptr, save_size); + + png_ptr->skip_length -= skip_length; + png_ptr->buffer_size -= save_size; + png_ptr->current_buffer_size -= save_size; + png_ptr->current_buffer_ptr += save_size; + } + if (!png_ptr->skip_length) + { + if (png_ptr->buffer_size < 4) + { + png_push_save_buffer(png_ptr); + return; + } + + png_crc_finish(png_ptr, 0); + png_ptr->process_mode = PNG_READ_CHUNK_MODE; + } +} + +void PNGCBAPI +png_push_fill_buffer(png_structp png_ptr, png_bytep buffer, png_size_t length) +{ + png_bytep ptr; + + if (png_ptr == NULL) + return; + + ptr = buffer; + if (png_ptr->save_buffer_size) + { + png_size_t save_size; + + if (length < png_ptr->save_buffer_size) + save_size = length; + + else + save_size = png_ptr->save_buffer_size; + + png_memcpy(ptr, png_ptr->save_buffer_ptr, save_size); + length -= save_size; + ptr += save_size; + png_ptr->buffer_size -= save_size; + png_ptr->save_buffer_size -= save_size; + png_ptr->save_buffer_ptr += save_size; + } + if (length && png_ptr->current_buffer_size) + { + png_size_t save_size; + + if (length < png_ptr->current_buffer_size) + save_size = length; + + else + save_size = png_ptr->current_buffer_size; + + png_memcpy(ptr, png_ptr->current_buffer_ptr, save_size); + png_ptr->buffer_size -= save_size; + png_ptr->current_buffer_size -= save_size; + png_ptr->current_buffer_ptr += save_size; + } +} + +void /* PRIVATE */ +png_push_save_buffer(png_structp png_ptr) +{ + if (png_ptr->save_buffer_size) + { + if (png_ptr->save_buffer_ptr != png_ptr->save_buffer) + { + png_size_t i, istop; + png_bytep sp; + png_bytep dp; + + istop = png_ptr->save_buffer_size; + for (i = 0, sp = png_ptr->save_buffer_ptr, dp = png_ptr->save_buffer; + i < istop; i++, sp++, dp++) + { + *dp = *sp; + } + } + } + if (png_ptr->save_buffer_size + png_ptr->current_buffer_size > + png_ptr->save_buffer_max) + { + png_size_t new_max; + png_bytep old_buffer; + + if (png_ptr->save_buffer_size > PNG_SIZE_MAX - + (png_ptr->current_buffer_size + 256)) + { + png_error(png_ptr, "Potential overflow of save_buffer"); + } + + new_max = png_ptr->save_buffer_size + png_ptr->current_buffer_size + 256; + old_buffer = png_ptr->save_buffer; + png_ptr->save_buffer = (png_bytep)png_malloc_warn(png_ptr, + (png_size_t)new_max); + + if (png_ptr->save_buffer == NULL) + { + png_free(png_ptr, old_buffer); + png_error(png_ptr, "Insufficient memory for save_buffer"); + } + + png_memcpy(png_ptr->save_buffer, old_buffer, png_ptr->save_buffer_size); + png_free(png_ptr, old_buffer); + png_ptr->save_buffer_max = new_max; + } + if (png_ptr->current_buffer_size) + { + png_memcpy(png_ptr->save_buffer + png_ptr->save_buffer_size, + png_ptr->current_buffer_ptr, png_ptr->current_buffer_size); + png_ptr->save_buffer_size += png_ptr->current_buffer_size; + png_ptr->current_buffer_size = 0; + } + png_ptr->save_buffer_ptr = png_ptr->save_buffer; + png_ptr->buffer_size = 0; +} + +void /* PRIVATE */ +png_push_restore_buffer(png_structp png_ptr, png_bytep buffer, + png_size_t buffer_length) +{ + png_ptr->current_buffer = buffer; + png_ptr->current_buffer_size = buffer_length; + png_ptr->buffer_size = buffer_length + png_ptr->save_buffer_size; + png_ptr->current_buffer_ptr = png_ptr->current_buffer; +} + +void /* PRIVATE */ +png_push_read_IDAT(png_structp png_ptr) +{ + PNG_IDAT; + if (!(png_ptr->mode & PNG_HAVE_CHUNK_HEADER)) + { + png_byte chunk_length[4]; + + if (png_ptr->buffer_size < 8) + { + png_push_save_buffer(png_ptr); + return; + } + + png_push_fill_buffer(png_ptr, chunk_length, 4); + png_ptr->push_length = png_get_uint_31(png_ptr, chunk_length); + png_reset_crc(png_ptr); + png_crc_read(png_ptr, png_ptr->chunk_name, 4); + png_ptr->mode |= PNG_HAVE_CHUNK_HEADER; + + if (png_memcmp(png_ptr->chunk_name, png_IDAT, 4)) + { + png_ptr->process_mode = PNG_READ_CHUNK_MODE; + + if (!(png_ptr->flags & PNG_FLAG_ZLIB_FINISHED)) + png_error(png_ptr, "Not enough compressed data"); + + return; + } + + png_ptr->idat_size = png_ptr->push_length; + } + if (png_ptr->idat_size && png_ptr->save_buffer_size) + { + png_size_t save_size = png_ptr->save_buffer_size; + png_uint_32 idat_size = png_ptr->idat_size; + + /* We want the smaller of 'idat_size' and 'current_buffer_size', but they + * are of different types and we don't know which variable has the fewest + * bits. Carefully select the smaller and cast it to the type of the + * larger - this cannot overflow. Do not cast in the following test - it + * will break on either 16 or 64 bit platforms. + */ + if (idat_size < save_size) + save_size = (png_size_t)idat_size; + + else + idat_size = (png_uint_32)save_size; + + png_calculate_crc(png_ptr, png_ptr->save_buffer_ptr, save_size); + + png_process_IDAT_data(png_ptr, png_ptr->save_buffer_ptr, save_size); + + png_ptr->idat_size -= idat_size; + png_ptr->buffer_size -= save_size; + png_ptr->save_buffer_size -= save_size; + png_ptr->save_buffer_ptr += save_size; + } + + if (png_ptr->idat_size && png_ptr->current_buffer_size) + { + png_size_t save_size = png_ptr->current_buffer_size; + png_uint_32 idat_size = png_ptr->idat_size; + + /* We want the smaller of 'idat_size' and 'current_buffer_size', but they + * are of different types and we don't know which variable has the fewest + * bits. Carefully select the smaller and cast it to the type of the + * larger - this cannot overflow. + */ + if (idat_size < save_size) + save_size = (png_size_t)idat_size; + + else + idat_size = (png_uint_32)save_size; + + png_calculate_crc(png_ptr, png_ptr->current_buffer_ptr, save_size); + + png_process_IDAT_data(png_ptr, png_ptr->current_buffer_ptr, save_size); + + png_ptr->idat_size -= idat_size; + png_ptr->buffer_size -= save_size; + png_ptr->current_buffer_size -= save_size; + png_ptr->current_buffer_ptr += save_size; + } + if (!png_ptr->idat_size) + { + if (png_ptr->buffer_size < 4) + { + png_push_save_buffer(png_ptr); + return; + } + + png_crc_finish(png_ptr, 0); + png_ptr->mode &= ~PNG_HAVE_CHUNK_HEADER; + png_ptr->mode |= PNG_AFTER_IDAT; + } +} + +void /* PRIVATE */ +png_process_IDAT_data(png_structp png_ptr, png_bytep buffer, + png_size_t buffer_length) +{ + /* The caller checks for a non-zero buffer length. */ + if (!(buffer_length > 0) || buffer == NULL) + png_error(png_ptr, "No IDAT data (internal error)"); + + /* This routine must process all the data it has been given + * before returning, calling the row callback as required to + * handle the uncompressed results. + */ + png_ptr->zstream.next_in = buffer; + png_ptr->zstream.avail_in = (uInt)buffer_length; + + /* Keep going until the decompressed data is all processed + * or the stream marked as finished. + */ + while (png_ptr->zstream.avail_in > 0 && + !(png_ptr->flags & PNG_FLAG_ZLIB_FINISHED)) + { + int ret; + + /* We have data for zlib, but we must check that zlib + * has someplace to put the results. It doesn't matter + * if we don't expect any results -- it may be the input + * data is just the LZ end code. + */ + if (!(png_ptr->zstream.avail_out > 0)) + { + png_ptr->zstream.avail_out = + (uInt) PNG_ROWBYTES(png_ptr->pixel_depth, + png_ptr->iwidth) + 1; + + png_ptr->zstream.next_out = png_ptr->row_buf; + } + + /* Using Z_SYNC_FLUSH here means that an unterminated + * LZ stream (a stream with a missing end code) can still + * be handled, otherwise (Z_NO_FLUSH) a future zlib + * implementation might defer output and therefore + * change the current behavior (see comments in inflate.c + * for why this doesn't happen at present with zlib 1.2.5). + */ + ret = inflate(&png_ptr->zstream, Z_SYNC_FLUSH); + + /* Check for any failure before proceeding. */ + if (ret != Z_OK && ret != Z_STREAM_END) + { + /* Terminate the decompression. */ + png_ptr->flags |= PNG_FLAG_ZLIB_FINISHED; + + /* This may be a truncated stream (missing or + * damaged end code). Treat that as a warning. + */ + if (png_ptr->row_number >= png_ptr->num_rows || + png_ptr->pass > 6) + png_warning(png_ptr, "Truncated compressed data in IDAT"); + + else + png_error(png_ptr, "Decompression error in IDAT"); + + /* Skip the check on unprocessed input */ + return; + } + + /* Did inflate output any data? */ + if (png_ptr->zstream.next_out != png_ptr->row_buf) + { + /* Is this unexpected data after the last row? + * If it is, artificially terminate the LZ output + * here. + */ + if (png_ptr->row_number >= png_ptr->num_rows || + png_ptr->pass > 6) + { + /* Extra data. */ + png_warning(png_ptr, "Extra compressed data in IDAT"); + png_ptr->flags |= PNG_FLAG_ZLIB_FINISHED; + + /* Do no more processing; skip the unprocessed + * input check below. + */ + return; + } + + /* Do we have a complete row? */ + if (png_ptr->zstream.avail_out == 0) + png_push_process_row(png_ptr); + } + + /* And check for the end of the stream. */ + if (ret == Z_STREAM_END) + png_ptr->flags |= PNG_FLAG_ZLIB_FINISHED; + } + + /* All the data should have been processed, if anything + * is left at this point we have bytes of IDAT data + * after the zlib end code. + */ + if (png_ptr->zstream.avail_in > 0) + png_warning(png_ptr, "Extra compression data in IDAT"); +} + +void /* PRIVATE */ +png_push_process_row(png_structp png_ptr) +{ + png_ptr->row_info.color_type = png_ptr->color_type; + png_ptr->row_info.width = png_ptr->iwidth; + png_ptr->row_info.channels = png_ptr->channels; + png_ptr->row_info.bit_depth = png_ptr->bit_depth; + png_ptr->row_info.pixel_depth = png_ptr->pixel_depth; + + png_ptr->row_info.rowbytes = PNG_ROWBYTES(png_ptr->row_info.pixel_depth, + png_ptr->row_info.width); + + png_read_filter_row(png_ptr, &(png_ptr->row_info), + png_ptr->row_buf + 1, png_ptr->prev_row + 1, + (int)(png_ptr->row_buf[0])); + + png_memcpy(png_ptr->prev_row, png_ptr->row_buf, png_ptr->rowbytes + 1); + + if (png_ptr->transformations || (png_ptr->flags&PNG_FLAG_STRIP_ALPHA)) + png_do_read_transformations(png_ptr); + +#ifdef PNG_READ_INTERLACING_SUPPORTED + /* Blow up interlaced rows to full size */ + if (png_ptr->interlaced && (png_ptr->transformations & PNG_INTERLACE)) + { + if (png_ptr->pass < 6) +/* old interface (pre-1.0.9): + png_do_read_interlace(&(png_ptr->row_info), + png_ptr->row_buf + 1, png_ptr->pass, png_ptr->transformations); + */ + png_do_read_interlace(png_ptr); + + switch (png_ptr->pass) + { + case 0: + { + int i; + for (i = 0; i < 8 && png_ptr->pass == 0; i++) + { + png_push_have_row(png_ptr, png_ptr->row_buf + 1); + png_read_push_finish_row(png_ptr); /* Updates png_ptr->pass */ + } + + if (png_ptr->pass == 2) /* Pass 1 might be empty */ + { + for (i = 0; i < 4 && png_ptr->pass == 2; i++) + { + png_push_have_row(png_ptr, NULL); + png_read_push_finish_row(png_ptr); + } + } + + if (png_ptr->pass == 4 && png_ptr->height <= 4) + { + for (i = 0; i < 2 && png_ptr->pass == 4; i++) + { + png_push_have_row(png_ptr, NULL); + png_read_push_finish_row(png_ptr); + } + } + + if (png_ptr->pass == 6 && png_ptr->height <= 4) + { + png_push_have_row(png_ptr, NULL); + png_read_push_finish_row(png_ptr); + } + + break; + } + + case 1: + { + int i; + for (i = 0; i < 8 && png_ptr->pass == 1; i++) + { + png_push_have_row(png_ptr, png_ptr->row_buf + 1); + png_read_push_finish_row(png_ptr); + } + + if (png_ptr->pass == 2) /* Skip top 4 generated rows */ + { + for (i = 0; i < 4 && png_ptr->pass == 2; i++) + { + png_push_have_row(png_ptr, NULL); + png_read_push_finish_row(png_ptr); + } + } + + break; + } + + case 2: + { + int i; + + for (i = 0; i < 4 && png_ptr->pass == 2; i++) + { + png_push_have_row(png_ptr, png_ptr->row_buf + 1); + png_read_push_finish_row(png_ptr); + } + + for (i = 0; i < 4 && png_ptr->pass == 2; i++) + { + png_push_have_row(png_ptr, NULL); + png_read_push_finish_row(png_ptr); + } + + if (png_ptr->pass == 4) /* Pass 3 might be empty */ + { + for (i = 0; i < 2 && png_ptr->pass == 4; i++) + { + png_push_have_row(png_ptr, NULL); + png_read_push_finish_row(png_ptr); + } + } + + break; + } + + case 3: + { + int i; + + for (i = 0; i < 4 && png_ptr->pass == 3; i++) + { + png_push_have_row(png_ptr, png_ptr->row_buf + 1); + png_read_push_finish_row(png_ptr); + } + + if (png_ptr->pass == 4) /* Skip top two generated rows */ + { + for (i = 0; i < 2 && png_ptr->pass == 4; i++) + { + png_push_have_row(png_ptr, NULL); + png_read_push_finish_row(png_ptr); + } + } + + break; + } + + case 4: + { + int i; + + for (i = 0; i < 2 && png_ptr->pass == 4; i++) + { + png_push_have_row(png_ptr, png_ptr->row_buf + 1); + png_read_push_finish_row(png_ptr); + } + + for (i = 0; i < 2 && png_ptr->pass == 4; i++) + { + png_push_have_row(png_ptr, NULL); + png_read_push_finish_row(png_ptr); + } + + if (png_ptr->pass == 6) /* Pass 5 might be empty */ + { + png_push_have_row(png_ptr, NULL); + png_read_push_finish_row(png_ptr); + } + + break; + } + + case 5: + { + int i; + + for (i = 0; i < 2 && png_ptr->pass == 5; i++) + { + png_push_have_row(png_ptr, png_ptr->row_buf + 1); + png_read_push_finish_row(png_ptr); + } + + if (png_ptr->pass == 6) /* Skip top generated row */ + { + png_push_have_row(png_ptr, NULL); + png_read_push_finish_row(png_ptr); + } + + break; + } + + default: + case 6: + { + png_push_have_row(png_ptr, png_ptr->row_buf + 1); + png_read_push_finish_row(png_ptr); + + if (png_ptr->pass != 6) + break; + + png_push_have_row(png_ptr, NULL); + png_read_push_finish_row(png_ptr); + } + } + } + else +#endif + { + png_push_have_row(png_ptr, png_ptr->row_buf + 1); + png_read_push_finish_row(png_ptr); + } +} + +void /* PRIVATE */ +png_read_push_finish_row(png_structp png_ptr) +{ + /* Arrays to facilitate easy interlacing - use pass (0 - 6) as index */ + + /* Start of interlace block */ + PNG_CONST int FARDATA png_pass_start[] = {0, 4, 0, 2, 0, 1, 0}; + + /* Offset to next interlace block */ + PNG_CONST int FARDATA png_pass_inc[] = {8, 8, 4, 4, 2, 2, 1}; + + /* Start of interlace block in the y direction */ + PNG_CONST int FARDATA png_pass_ystart[] = {0, 0, 4, 0, 2, 0, 1}; + + /* Offset to next interlace block in the y direction */ + PNG_CONST int FARDATA png_pass_yinc[] = {8, 8, 8, 4, 4, 2, 2}; + + /* Height of interlace block. This is not currently used - if you need + * it, uncomment it here and in png.h + PNG_CONST int FARDATA png_pass_height[] = {8, 8, 4, 4, 2, 2, 1}; + */ + + png_ptr->row_number++; + if (png_ptr->row_number < png_ptr->num_rows) + return; + +#ifdef PNG_READ_INTERLACING_SUPPORTED + if (png_ptr->interlaced) + { + png_ptr->row_number = 0; + png_memset(png_ptr->prev_row, 0, png_ptr->rowbytes + 1); + + do + { + png_ptr->pass++; + if ((png_ptr->pass == 1 && png_ptr->width < 5) || + (png_ptr->pass == 3 && png_ptr->width < 3) || + (png_ptr->pass == 5 && png_ptr->width < 2)) + png_ptr->pass++; + + if (png_ptr->pass > 7) + png_ptr->pass--; + + if (png_ptr->pass >= 7) + break; + + png_ptr->iwidth = (png_ptr->width + + png_pass_inc[png_ptr->pass] - 1 - + png_pass_start[png_ptr->pass]) / + png_pass_inc[png_ptr->pass]; + + if (png_ptr->transformations & PNG_INTERLACE) + break; + + png_ptr->num_rows = (png_ptr->height + + png_pass_yinc[png_ptr->pass] - 1 - + png_pass_ystart[png_ptr->pass]) / + png_pass_yinc[png_ptr->pass]; + + } while (png_ptr->iwidth == 0 || png_ptr->num_rows == 0); + } +#endif /* PNG_READ_INTERLACING_SUPPORTED */ +} + +#ifdef PNG_READ_tEXt_SUPPORTED +void /* PRIVATE */ +png_push_handle_tEXt(png_structp png_ptr, png_infop info_ptr, png_uint_32 + length) +{ + if (!(png_ptr->mode & PNG_HAVE_IHDR) || (png_ptr->mode & PNG_HAVE_IEND)) + { + PNG_UNUSED(info_ptr) /* To quiet some compiler warnings */ + png_error(png_ptr, "Out of place tEXt"); + /*NOT REACHED*/ + } + +#ifdef PNG_MAX_MALLOC_64K + png_ptr->skip_length = 0; /* This may not be necessary */ + + if (length > (png_uint_32)65535L) /* Can't hold entire string in memory */ + { + png_warning(png_ptr, "tEXt chunk too large to fit in memory"); + png_ptr->skip_length = length - (png_uint_32)65535L; + length = (png_uint_32)65535L; + } +#endif + + png_ptr->current_text = (png_charp)png_malloc(png_ptr, + (png_size_t)(length + 1)); + png_ptr->current_text[length] = '\0'; + png_ptr->current_text_ptr = png_ptr->current_text; + png_ptr->current_text_size = (png_size_t)length; + png_ptr->current_text_left = (png_size_t)length; + png_ptr->process_mode = PNG_READ_tEXt_MODE; +} + +void /* PRIVATE */ +png_push_read_tEXt(png_structp png_ptr, png_infop info_ptr) +{ + if (png_ptr->buffer_size && png_ptr->current_text_left) + { + png_size_t text_size; + + if (png_ptr->buffer_size < png_ptr->current_text_left) + text_size = png_ptr->buffer_size; + + else + text_size = png_ptr->current_text_left; + + png_crc_read(png_ptr, (png_bytep)png_ptr->current_text_ptr, text_size); + png_ptr->current_text_left -= text_size; + png_ptr->current_text_ptr += text_size; + } + if (!(png_ptr->current_text_left)) + { + png_textp text_ptr; + png_charp text; + png_charp key; + int ret; + + if (png_ptr->buffer_size < 4) + { + png_push_save_buffer(png_ptr); + return; + } + + png_push_crc_finish(png_ptr); + +#ifdef PNG_MAX_MALLOC_64K + if (png_ptr->skip_length) + return; +#endif + + key = png_ptr->current_text; + + for (text = key; *text; text++) + /* Empty loop */ ; + + if (text < key + png_ptr->current_text_size) + text++; + + text_ptr = (png_textp)png_malloc(png_ptr, png_sizeof(png_text)); + text_ptr->compression = PNG_TEXT_COMPRESSION_NONE; + text_ptr->key = key; + text_ptr->itxt_length = 0; + text_ptr->lang = NULL; + text_ptr->lang_key = NULL; + text_ptr->text = text; + + ret = png_set_text_2(png_ptr, info_ptr, text_ptr, 1); + + png_free(png_ptr, key); + png_free(png_ptr, text_ptr); + png_ptr->current_text = NULL; + + if (ret) + png_warning(png_ptr, "Insufficient memory to store text chunk"); + } +} +#endif + +#ifdef PNG_READ_zTXt_SUPPORTED +void /* PRIVATE */ +png_push_handle_zTXt(png_structp png_ptr, png_infop info_ptr, png_uint_32 + length) +{ + if (!(png_ptr->mode & PNG_HAVE_IHDR) || (png_ptr->mode & PNG_HAVE_IEND)) + { + PNG_UNUSED(info_ptr) /* To quiet some compiler warnings */ + png_error(png_ptr, "Out of place zTXt"); + /*NOT REACHED*/ + } + +#ifdef PNG_MAX_MALLOC_64K + /* We can't handle zTXt chunks > 64K, since we don't have enough space + * to be able to store the uncompressed data. Actually, the threshold + * is probably around 32K, but it isn't as definite as 64K is. + */ + if (length > (png_uint_32)65535L) + { + png_warning(png_ptr, "zTXt chunk too large to fit in memory"); + png_push_crc_skip(png_ptr, length); + return; + } +#endif + + png_ptr->current_text = (png_charp)png_malloc(png_ptr, + (png_size_t)(length + 1)); + png_ptr->current_text[length] = '\0'; + png_ptr->current_text_ptr = png_ptr->current_text; + png_ptr->current_text_size = (png_size_t)length; + png_ptr->current_text_left = (png_size_t)length; + png_ptr->process_mode = PNG_READ_zTXt_MODE; +} + +void /* PRIVATE */ +png_push_read_zTXt(png_structp png_ptr, png_infop info_ptr) +{ + if (png_ptr->buffer_size && png_ptr->current_text_left) + { + png_size_t text_size; + + if (png_ptr->buffer_size < (png_uint_32)png_ptr->current_text_left) + text_size = png_ptr->buffer_size; + + else + text_size = png_ptr->current_text_left; + + png_crc_read(png_ptr, (png_bytep)png_ptr->current_text_ptr, text_size); + png_ptr->current_text_left -= text_size; + png_ptr->current_text_ptr += text_size; + } + if (!(png_ptr->current_text_left)) + { + png_textp text_ptr; + png_charp text; + png_charp key; + int ret; + png_size_t text_size, key_size; + + if (png_ptr->buffer_size < 4) + { + png_push_save_buffer(png_ptr); + return; + } + + png_push_crc_finish(png_ptr); + + key = png_ptr->current_text; + + for (text = key; *text; text++) + /* Empty loop */ ; + + /* zTXt can't have zero text */ + if (text >= key + png_ptr->current_text_size) + { + png_ptr->current_text = NULL; + png_free(png_ptr, key); + return; + } + + text++; + + if (*text != PNG_TEXT_COMPRESSION_zTXt) /* Check compression byte */ + { + png_ptr->current_text = NULL; + png_free(png_ptr, key); + return; + } + + text++; + + png_ptr->zstream.next_in = (png_bytep)text; + png_ptr->zstream.avail_in = (uInt)(png_ptr->current_text_size - + (text - key)); + png_ptr->zstream.next_out = png_ptr->zbuf; + png_ptr->zstream.avail_out = (uInt)png_ptr->zbuf_size; + + key_size = text - key; + text_size = 0; + text = NULL; + ret = Z_STREAM_END; + + while (png_ptr->zstream.avail_in) + { + ret = inflate(&png_ptr->zstream, Z_PARTIAL_FLUSH); + if (ret != Z_OK && ret != Z_STREAM_END) + { + inflateReset(&png_ptr->zstream); + png_ptr->zstream.avail_in = 0; + png_ptr->current_text = NULL; + png_free(png_ptr, key); + png_free(png_ptr, text); + return; + } + + if (!(png_ptr->zstream.avail_out) || ret == Z_STREAM_END) + { + if (text == NULL) + { + text = (png_charp)png_malloc(png_ptr, + (png_ptr->zbuf_size + - png_ptr->zstream.avail_out + key_size + 1)); + + png_memcpy(text + key_size, png_ptr->zbuf, + png_ptr->zbuf_size - png_ptr->zstream.avail_out); + + png_memcpy(text, key, key_size); + + text_size = key_size + png_ptr->zbuf_size - + png_ptr->zstream.avail_out; + + *(text + text_size) = '\0'; + } + + else + { + png_charp tmp; + + tmp = text; + text = (png_charp)png_malloc(png_ptr, text_size + + (png_ptr->zbuf_size + - png_ptr->zstream.avail_out + 1)); + + png_memcpy(text, tmp, text_size); + png_free(png_ptr, tmp); + + png_memcpy(text + text_size, png_ptr->zbuf, + png_ptr->zbuf_size - png_ptr->zstream.avail_out); + + text_size += png_ptr->zbuf_size - png_ptr->zstream.avail_out; + *(text + text_size) = '\0'; + } + + if (ret != Z_STREAM_END) + { + png_ptr->zstream.next_out = png_ptr->zbuf; + png_ptr->zstream.avail_out = (uInt)png_ptr->zbuf_size; + } + } + else + { + break; + } + + if (ret == Z_STREAM_END) + break; + } + + inflateReset(&png_ptr->zstream); + png_ptr->zstream.avail_in = 0; + + if (ret != Z_STREAM_END) + { + png_ptr->current_text = NULL; + png_free(png_ptr, key); + png_free(png_ptr, text); + return; + } + + png_ptr->current_text = NULL; + png_free(png_ptr, key); + key = text; + text += key_size; + + text_ptr = (png_textp)png_malloc(png_ptr, + png_sizeof(png_text)); + text_ptr->compression = PNG_TEXT_COMPRESSION_zTXt; + text_ptr->key = key; + text_ptr->itxt_length = 0; + text_ptr->lang = NULL; + text_ptr->lang_key = NULL; + text_ptr->text = text; + + ret = png_set_text_2(png_ptr, info_ptr, text_ptr, 1); + + png_free(png_ptr, key); + png_free(png_ptr, text_ptr); + + if (ret) + png_warning(png_ptr, "Insufficient memory to store text chunk"); + } +} +#endif + +#ifdef PNG_READ_iTXt_SUPPORTED +void /* PRIVATE */ +png_push_handle_iTXt(png_structp png_ptr, png_infop info_ptr, png_uint_32 + length) +{ + if (!(png_ptr->mode & PNG_HAVE_IHDR) || (png_ptr->mode & PNG_HAVE_IEND)) + { + PNG_UNUSED(info_ptr) /* To quiet some compiler warnings */ + png_error(png_ptr, "Out of place iTXt"); + /*NOT REACHED*/ + } + +#ifdef PNG_MAX_MALLOC_64K + png_ptr->skip_length = 0; /* This may not be necessary */ + + if (length > (png_uint_32)65535L) /* Can't hold entire string in memory */ + { + png_warning(png_ptr, "iTXt chunk too large to fit in memory"); + png_ptr->skip_length = length - (png_uint_32)65535L; + length = (png_uint_32)65535L; + } +#endif + + png_ptr->current_text = (png_charp)png_malloc(png_ptr, + (png_size_t)(length + 1)); + png_ptr->current_text[length] = '\0'; + png_ptr->current_text_ptr = png_ptr->current_text; + png_ptr->current_text_size = (png_size_t)length; + png_ptr->current_text_left = (png_size_t)length; + png_ptr->process_mode = PNG_READ_iTXt_MODE; +} + +void /* PRIVATE */ +png_push_read_iTXt(png_structp png_ptr, png_infop info_ptr) +{ + + if (png_ptr->buffer_size && png_ptr->current_text_left) + { + png_size_t text_size; + + if (png_ptr->buffer_size < png_ptr->current_text_left) + text_size = png_ptr->buffer_size; + + else + text_size = png_ptr->current_text_left; + + png_crc_read(png_ptr, (png_bytep)png_ptr->current_text_ptr, text_size); + png_ptr->current_text_left -= text_size; + png_ptr->current_text_ptr += text_size; + } + + if (!(png_ptr->current_text_left)) + { + png_textp text_ptr; + png_charp key; + int comp_flag; + png_charp lang; + png_charp lang_key; + png_charp text; + int ret; + + if (png_ptr->buffer_size < 4) + { + png_push_save_buffer(png_ptr); + return; + } + + png_push_crc_finish(png_ptr); + +#ifdef PNG_MAX_MALLOC_64K + if (png_ptr->skip_length) + return; +#endif + + key = png_ptr->current_text; + + for (lang = key; *lang; lang++) + /* Empty loop */ ; + + if (lang < key + png_ptr->current_text_size - 3) + lang++; + + comp_flag = *lang++; + lang++; /* Skip comp_type, always zero */ + + for (lang_key = lang; *lang_key; lang_key++) + /* Empty loop */ ; + + lang_key++; /* Skip NUL separator */ + + text=lang_key; + + if (lang_key < key + png_ptr->current_text_size - 1) + { + for (; *text; text++) + /* Empty loop */ ; + } + + if (text < key + png_ptr->current_text_size) + text++; + + text_ptr = (png_textp)png_malloc(png_ptr, + png_sizeof(png_text)); + + text_ptr->compression = comp_flag + 2; + text_ptr->key = key; + text_ptr->lang = lang; + text_ptr->lang_key = lang_key; + text_ptr->text = text; + text_ptr->text_length = 0; + text_ptr->itxt_length = png_strlen(text); + + ret = png_set_text_2(png_ptr, info_ptr, text_ptr, 1); + + png_ptr->current_text = NULL; + + png_free(png_ptr, text_ptr); + if (ret) + png_warning(png_ptr, "Insufficient memory to store iTXt chunk"); + } +} +#endif + +/* This function is called when we haven't found a handler for this + * chunk. If there isn't a problem with the chunk itself (ie a bad chunk + * name or a critical chunk), the chunk is (currently) silently ignored. + */ +void /* PRIVATE */ +png_push_handle_unknown(png_structp png_ptr, png_infop info_ptr, png_uint_32 + length) +{ + png_uint_32 skip = 0; + + if (!(png_ptr->chunk_name[0] & 0x20)) + { +#ifdef PNG_READ_UNKNOWN_CHUNKS_SUPPORTED + if (png_handle_as_unknown(png_ptr, png_ptr->chunk_name) != + PNG_HANDLE_CHUNK_ALWAYS +#ifdef PNG_READ_USER_CHUNKS_SUPPORTED + && png_ptr->read_user_chunk_fn == NULL +#endif + ) +#endif + png_chunk_error(png_ptr, "unknown critical chunk"); + + PNG_UNUSED(info_ptr) /* To quiet some compiler warnings */ + } + +#ifdef PNG_READ_UNKNOWN_CHUNKS_SUPPORTED + if (png_ptr->flags & PNG_FLAG_KEEP_UNKNOWN_CHUNKS) + { +#ifdef PNG_MAX_MALLOC_64K + if (length > (png_uint_32)65535L) + { + png_warning(png_ptr, "unknown chunk too large to fit in memory"); + skip = length - (png_uint_32)65535L; + length = (png_uint_32)65535L; + } +#endif + png_memcpy((png_charp)png_ptr->unknown_chunk.name, + (png_charp)png_ptr->chunk_name, + png_sizeof(png_ptr->unknown_chunk.name)); + png_ptr->unknown_chunk.name[png_sizeof(png_ptr->unknown_chunk.name) - 1] + = '\0'; + + png_ptr->unknown_chunk.size = (png_size_t)length; + + if (length == 0) + png_ptr->unknown_chunk.data = NULL; + + else + { + png_ptr->unknown_chunk.data = (png_bytep)png_malloc(png_ptr, + (png_size_t)length); + png_crc_read(png_ptr, (png_bytep)png_ptr->unknown_chunk.data, length); + } + +#ifdef PNG_READ_USER_CHUNKS_SUPPORTED + if (png_ptr->read_user_chunk_fn != NULL) + { + /* Callback to user unknown chunk handler */ + int ret; + ret = (*(png_ptr->read_user_chunk_fn)) + (png_ptr, &png_ptr->unknown_chunk); + + if (ret < 0) + png_chunk_error(png_ptr, "error in user chunk"); + + if (ret == 0) + { + if (!(png_ptr->chunk_name[0] & 0x20)) + if (png_handle_as_unknown(png_ptr, png_ptr->chunk_name) != + PNG_HANDLE_CHUNK_ALWAYS) + png_chunk_error(png_ptr, "unknown critical chunk"); + png_set_unknown_chunks(png_ptr, info_ptr, + &png_ptr->unknown_chunk, 1); + } + } + + else +#endif + png_set_unknown_chunks(png_ptr, info_ptr, &png_ptr->unknown_chunk, 1); + png_free(png_ptr, png_ptr->unknown_chunk.data); + png_ptr->unknown_chunk.data = NULL; + } + + else +#endif + skip=length; + png_push_crc_skip(png_ptr, skip); +} + +void /* PRIVATE */ +png_push_have_info(png_structp png_ptr, png_infop info_ptr) +{ + if (png_ptr->info_fn != NULL) + (*(png_ptr->info_fn))(png_ptr, info_ptr); +} + +void /* PRIVATE */ +png_push_have_end(png_structp png_ptr, png_infop info_ptr) +{ + if (png_ptr->end_fn != NULL) + (*(png_ptr->end_fn))(png_ptr, info_ptr); +} + +void /* PRIVATE */ +png_push_have_row(png_structp png_ptr, png_bytep row) +{ + if (png_ptr->row_fn != NULL) + (*(png_ptr->row_fn))(png_ptr, row, png_ptr->row_number, + (int)png_ptr->pass); +} + +void PNGAPI +png_progressive_combine_row (png_structp png_ptr, png_bytep old_row, + png_const_bytep new_row) +{ + PNG_CONST int FARDATA png_pass_dsp_mask[7] = + {0xff, 0x0f, 0xff, 0x33, 0xff, 0x55, 0xff}; + + if (png_ptr == NULL) + return; + + if (new_row != NULL) /* new_row must == png_ptr->row_buf here. */ + png_combine_row(png_ptr, old_row, png_pass_dsp_mask[png_ptr->pass]); +} + +void PNGAPI +png_set_progressive_read_fn(png_structp png_ptr, png_voidp progressive_ptr, + png_progressive_info_ptr info_fn, png_progressive_row_ptr row_fn, + png_progressive_end_ptr end_fn) +{ + if (png_ptr == NULL) + return; + + png_ptr->info_fn = info_fn; + png_ptr->row_fn = row_fn; + png_ptr->end_fn = end_fn; + + png_set_read_fn(png_ptr, progressive_ptr, png_push_fill_buffer); +} + +png_voidp PNGAPI +png_get_progressive_ptr(png_const_structp png_ptr) +{ + if (png_ptr == NULL) + return (NULL); + + return png_ptr->io_ptr; +} +#endif /* PNG_PROGRESSIVE_READ_SUPPORTED */ diff --git a/src/3rdparty/libpng/pngpriv.h b/src/3rdparty/libpng/pngpriv.h new file mode 100644 index 0000000000..9b90f26801 --- /dev/null +++ b/src/3rdparty/libpng/pngpriv.h @@ -0,0 +1,1245 @@ + +/* pngpriv.h - private declarations for use inside libpng + * + * For conditions of distribution and use, see copyright notice in png.h + * Copyright (c) 1998-2011 Glenn Randers-Pehrson + * (Version 0.96 Copyright (c) 1996, 1997 Andreas Dilger) + * (Version 0.88 Copyright (c) 1995, 1996 Guy Eric Schalnat, Group 42, Inc.) + * + * Last changed in libpng 1.5.0 [January 6, 2011] + * + * This code is released under the libpng license. + * For conditions of distribution and use, see the disclaimer + * and license in png.h + */ + +/* The symbols declared in this file (including the functions declared + * as PNG_EXTERN) are PRIVATE. They are not part of the libpng public + * interface, and are not recommended for use by regular applications. + * Some of them may become public in the future; others may stay private, + * change in an incompatible way, or even disappear. + * Although the libpng users are not forbidden to include this header, + * they should be well aware of the issues that may arise from doing so. + */ + +#ifndef PNGPRIV_H +#define PNGPRIV_H + +#ifdef _MSC_VER +# define _CRT_SECURE_NO_DEPRECATE +#endif + +/* This is required for the definition of abort(), used as a last ditch + * error handler when all else fails. + */ +#include <stdlib.h> + +#define PNGLIB_BUILD +#ifdef PNG_USER_CONFIG +# include "pngusr.h" + /* These should have been defined in pngusr.h */ +# ifndef PNG_USER_PRIVATEBUILD +# define PNG_USER_PRIVATEBUILD "Custom libpng build" +# endif +# ifndef PNG_USER_DLLFNAME_POSTFIX +# define PNG_USER_DLLFNAME_POSTFIX "Cb" +# endif +#endif +#include "png.h" +#include "pnginfo.h" +#include "pngstruct.h" + +/* This is used for 16 bit gamma tables - only the top level pointers are const, + * this could be changed: + */ +typedef PNG_CONST png_uint_16p FAR * png_const_uint_16pp; + +/* Added at libpng-1.2.9 */ +/* Moved to pngpriv.h at libpng-1.5.0 */ + +/* config.h is created by and PNG_CONFIGURE_LIBPNG is set by the "configure" + * script. We may need it here to get the correct configuration on things + * like limits. + */ +#ifdef PNG_CONFIGURE_LIBPNG +# ifdef HAVE_CONFIG_H +# include "config.h" +# endif +#endif + +/* Moved to pngpriv.h at libpng-1.5.0 */ +/* NOTE: some of these may have been used in external applications as + * these definitions were exposed in pngconf.h prior to 1.5. + */ + +/* If you are running on a machine where you cannot allocate more + * than 64K of memory at once, uncomment this. While libpng will not + * normally need that much memory in a chunk (unless you load up a very + * large file), zlib needs to know how big of a chunk it can use, and + * libpng thus makes sure to check any memory allocation to verify it + * will fit into memory. + * + * zlib provides 'MAXSEG_64K' which, if defined, indicates the + * same limit and pngconf.h (already included) sets the limit + * if certain operating systems are detected. + */ +#if defined(MAXSEG_64K) && !defined(PNG_MAX_MALLOC_64K) +# define PNG_MAX_MALLOC_64K +#endif + +/* Unused formal parameter warnings are silenced using the following macro + * which is expected to have no bad effects on performance (optimizing + * compilers will probably remove it entirely). Note that if you replace + * it with something other than whitespace, you must include the terminating + * semicolon. + */ +#define PNG_UNUSED(param) (void)param; + +/* Just a little check that someone hasn't tried to define something + * contradictory. + */ +#if (PNG_ZBUF_SIZE > 65536L) && defined(PNG_MAX_MALLOC_64K) +# undef PNG_ZBUF_SIZE +# define PNG_ZBUF_SIZE 65536L +#endif + +/* If warnings or errors are turned off the code is disabled + * or redirected here. + */ +#ifndef PNG_WARNINGS_SUPPORTED +# define png_warning(s1,s2) ((void)0) +# define png_chunk_warning(s1,s2) ((void)0) +#endif +#ifndef PNG_ERROR_TEXT_SUPPORTED +# define png_error(s1,s2) png_err(s1) +# define png_chunk_error(s1,s2) png_err(s1) +# define png_fixed_error(s1,s2) png_err(s1) +#endif + +#ifndef PNG_EXTERN +/* The functions exported by PNG_EXTERN are internal functions, which + * aren't usually used outside the library (as far as I know), so it is + * debatable if they should be exported at all. In the future, when it + * is possible to have run-time registry of chunk-handling functions, + * some of these might be made available again. +# define PNG_EXTERN extern + */ +# define PNG_EXTERN +#endif + +/* Some fixed point APIs are still required even if not exported because + * they get used by the corresponding floating point APIs. This magic + * deals with this: + */ +#ifdef PNG_FIXED_POINT_SUPPORTED +# define PNGFAPI PNGAPI +#else +# define PNGFAPI /* PRIVATE */ +#endif + +/* Other defines specific to compilers can go here. Try to keep + * them inside an appropriate ifdef/endif pair for portability. + */ +#if defined(PNG_FLOATING_POINT_SUPPORTED) ||\ + defined(PNG_FLOATING_ARITHMETIC_SUPPORTED) + /* png.c requires the following ANSI-C constants if the conversion of + * floating point to ASCII is implemented therein: + * + * DBL_DIG Maximum number of decimal digits (can be set to any constant) + * DBL_MIN Smallest normalized fp number (can be set to an arbitrary value) + * DBL_MAX Maximum floating point number (can be set to an arbitrary value) + */ +# include <float.h> + +# if (defined(__MWERKS__) && defined(macintosh)) || defined(applec) || \ + defined(THINK_C) || defined(__SC__) || defined(TARGET_OS_MAC) + /* We need to check that <math.h> hasn't already been included earlier + * as it seems it doesn't agree with <fp.h>, yet we should really use + * <fp.h> if possible. + */ +# if !defined(__MATH_H__) && !defined(__MATH_H) && !defined(__cmath__) +# include <fp.h> +# endif +# else +# include <math.h> +# endif +# if defined(_AMIGA) && defined(__SASC) && defined(_M68881) + /* Amiga SAS/C: We must include builtin FPU functions when compiling using + * MATH=68881 + */ +# include <m68881.h> +# endif +#endif + +/* This provides the non-ANSI (far) memory allocation routines. */ +#if defined(__TURBOC__) && defined(__MSDOS__) +# include <mem.h> +# include <alloc.h> +#endif + +#if defined(WIN32) || defined(_Windows) || defined(_WINDOWS) || \ + defined(_WIN32) || defined(__WIN32__) +# if !defined(__SYMBIAN32__) +# include <windows.h> /* defines _WINDOWS_ macro */ +# endif +#endif + +/* Moved here around 1.5.0beta36 from pngconf.h */ +/* Users may want to use these so they are not private. Any library + * functions that are passed far data must be model-independent. + */ + +/* Memory model/platform independent fns */ +#ifndef PNG_ABORT +# if defined(_WINDOWS_) || defined(_WIN32_WCE) +# define PNG_ABORT() ExitProcess(0) +# else +# define PNG_ABORT() abort() +# endif +#endif + +#ifdef USE_FAR_KEYWORD +/* Use this to make far-to-near assignments */ +# define CHECK 1 +# define NOCHECK 0 +# define CVT_PTR(ptr) (png_far_to_near(png_ptr,ptr,CHECK)) +# define CVT_PTR_NOCHECK(ptr) (png_far_to_near(png_ptr,ptr,NOCHECK)) +# define png_strcpy _fstrcpy +# define png_strncpy _fstrncpy /* Added to v 1.2.6 */ +# define png_strlen _fstrlen +# define png_memcmp _fmemcmp /* SJT: added */ +# define png_memcpy _fmemcpy +# define png_memset _fmemset +# define png_sprintf sprintf +#else +# ifdef _WINDOWS_ /* Favor Windows over C runtime fns */ +# define CVT_PTR(ptr) (ptr) +# define CVT_PTR_NOCHECK(ptr) (ptr) +# define png_strcpy lstrcpyA +# define png_strncpy lstrcpynA +# define png_strlen lstrlenA +# define png_memcmp memcmp +# define png_memcpy CopyMemory +# define png_memset memset +# define png_sprintf wsprintfA +# else +# define CVT_PTR(ptr) (ptr) +# define CVT_PTR_NOCHECK(ptr) (ptr) +# define png_strcpy strcpy +# define png_strncpy strncpy /* Added to v 1.2.6 */ +# define png_strlen strlen +# define png_memcmp memcmp /* SJT: added */ +# define png_memcpy memcpy +# define png_memset memset +# define png_sprintf sprintf +# endif +#endif +/* End of memory model/platform independent support */ + +#ifndef PNG_NO_SNPRINTF +# ifdef _MSC_VER +# define png_snprintf _snprintf /* Added to v 1.2.19 */ +# define png_snprintf2 _snprintf +# define png_snprintf6 _snprintf +# else +# define png_snprintf snprintf /* Added to v 1.2.19 */ +# define png_snprintf2 snprintf +# define png_snprintf6 snprintf +# endif +#else + /* You don't have or don't want to use snprintf(). Caution: Using + * sprintf instead of snprintf exposes your application to accidental + * or malevolent buffer overflows. If you don't have snprintf() + * as a general rule you should provide one (you can get one from + * Portable OpenSSH). + */ +# define png_snprintf(s1,n,fmt,x1) png_sprintf(s1,fmt,x1) +# define png_snprintf2(s1,n,fmt,x1,x2) png_sprintf(s1,fmt,x1,x2) +# define png_snprintf6(s1,n,fmt,x1,x2,x3,x4,x5,x6) \ + png_sprintf(s1,fmt,x1,x2,x3,x4,x5,x6) +#endif +/* End of 1.5.0beta36 move from pngconf.h */ + +/* CONSTANTS and UTILITY MACROS + * These are used internally by libpng and not exposed in the API + */ + +/* Various modes of operation. Note that after an init, mode is set to + * zero automatically when the structure is created. + */ +#define PNG_HAVE_IHDR 0x01 +#define PNG_HAVE_PLTE 0x02 +#define PNG_HAVE_IDAT 0x04 +#define PNG_AFTER_IDAT 0x08 /* Have complete zlib datastream */ +#define PNG_HAVE_IEND 0x10 +#define PNG_HAVE_gAMA 0x20 +#define PNG_HAVE_cHRM 0x40 +#define PNG_HAVE_sRGB 0x80 +#define PNG_HAVE_CHUNK_HEADER 0x100 +#define PNG_WROTE_tIME 0x200 +#define PNG_WROTE_INFO_BEFORE_PLTE 0x400 +#define PNG_BACKGROUND_IS_GRAY 0x800 +#define PNG_HAVE_PNG_SIGNATURE 0x1000 +#define PNG_HAVE_CHUNK_AFTER_IDAT 0x2000 /* Have another chunk after IDAT */ + +/* Flags for the transformations the PNG library does on the image data */ +#define PNG_BGR 0x0001 +#define PNG_INTERLACE 0x0002 +#define PNG_PACK 0x0004 +#define PNG_SHIFT 0x0008 +#define PNG_SWAP_BYTES 0x0010 +#define PNG_INVERT_MONO 0x0020 +#define PNG_QUANTIZE 0x0040 +#define PNG_BACKGROUND 0x0080 +#define PNG_BACKGROUND_EXPAND 0x0100 + /* 0x0200 unused */ +#define PNG_16_TO_8 0x0400 +#define PNG_RGBA 0x0800 +#define PNG_EXPAND 0x1000 +#define PNG_GAMMA 0x2000 +#define PNG_GRAY_TO_RGB 0x4000 +#define PNG_FILLER 0x8000L +#define PNG_PACKSWAP 0x10000L +#define PNG_SWAP_ALPHA 0x20000L +#define PNG_STRIP_ALPHA 0x40000L +#define PNG_INVERT_ALPHA 0x80000L +#define PNG_USER_TRANSFORM 0x100000L +#define PNG_RGB_TO_GRAY_ERR 0x200000L +#define PNG_RGB_TO_GRAY_WARN 0x400000L +#define PNG_RGB_TO_GRAY 0x600000L /* two bits, RGB_TO_GRAY_ERR|WARN */ + /* 0x800000L Unused */ +#define PNG_ADD_ALPHA 0x1000000L /* Added to libpng-1.2.7 */ +#define PNG_EXPAND_tRNS 0x2000000L /* Added to libpng-1.2.9 */ + /* 0x4000000L unused */ + /* 0x8000000L unused */ + /* 0x10000000L unused */ + /* 0x20000000L unused */ + /* 0x40000000L unused */ + +/* Flags for png_create_struct */ +#define PNG_STRUCT_PNG 0x0001 +#define PNG_STRUCT_INFO 0x0002 + +/* Scaling factor for filter heuristic weighting calculations */ +#define PNG_WEIGHT_FACTOR (1<<(PNG_WEIGHT_SHIFT)) +#define PNG_COST_FACTOR (1<<(PNG_COST_SHIFT)) + +/* Flags for the png_ptr->flags rather than declaring a byte for each one */ +#define PNG_FLAG_ZLIB_CUSTOM_STRATEGY 0x0001 +#define PNG_FLAG_ZLIB_CUSTOM_LEVEL 0x0002 +#define PNG_FLAG_ZLIB_CUSTOM_MEM_LEVEL 0x0004 +#define PNG_FLAG_ZLIB_CUSTOM_WINDOW_BITS 0x0008 +#define PNG_FLAG_ZLIB_CUSTOM_METHOD 0x0010 +#define PNG_FLAG_ZLIB_FINISHED 0x0020 +#define PNG_FLAG_ROW_INIT 0x0040 +#define PNG_FLAG_FILLER_AFTER 0x0080 +#define PNG_FLAG_CRC_ANCILLARY_USE 0x0100 +#define PNG_FLAG_CRC_ANCILLARY_NOWARN 0x0200 +#define PNG_FLAG_CRC_CRITICAL_USE 0x0400 +#define PNG_FLAG_CRC_CRITICAL_IGNORE 0x0800 + /* 0x1000 unused */ + /* 0x2000 unused */ + /* 0x4000 unused */ +#define PNG_FLAG_KEEP_UNKNOWN_CHUNKS 0x8000L +#define PNG_FLAG_KEEP_UNSAFE_CHUNKS 0x10000L +#define PNG_FLAG_LIBRARY_MISMATCH 0x20000L +#define PNG_FLAG_STRIP_ERROR_NUMBERS 0x40000L +#define PNG_FLAG_STRIP_ERROR_TEXT 0x80000L +#define PNG_FLAG_MALLOC_NULL_MEM_OK 0x100000L +#define PNG_FLAG_ADD_ALPHA 0x200000L /* Added to libpng-1.2.8 */ +#define PNG_FLAG_STRIP_ALPHA 0x400000L /* Added to libpng-1.2.8 */ +#define PNG_FLAG_BENIGN_ERRORS_WARN 0x800000L /* Added to libpng-1.4.0 */ + /* 0x1000000L unused */ + /* 0x2000000L unused */ + /* 0x4000000L unused */ + /* 0x8000000L unused */ + /* 0x10000000L unused */ + /* 0x20000000L unused */ + /* 0x40000000L unused */ + +#define PNG_FLAG_CRC_ANCILLARY_MASK (PNG_FLAG_CRC_ANCILLARY_USE | \ + PNG_FLAG_CRC_ANCILLARY_NOWARN) + +#define PNG_FLAG_CRC_CRITICAL_MASK (PNG_FLAG_CRC_CRITICAL_USE | \ + PNG_FLAG_CRC_CRITICAL_IGNORE) + +#define PNG_FLAG_CRC_MASK (PNG_FLAG_CRC_ANCILLARY_MASK | \ + PNG_FLAG_CRC_CRITICAL_MASK) + +/* zlib.h declares a magic type 'uInt' that limits the amount of data that zlib + * can handle at once. This type need be no larger than 16 bits (so maximum of + * 65535), this define allows us to discover how big it is, but limited by the + * maximuum for png_size_t. The value can be overriden in a library build + * (pngusr.h, or set it in CPPFLAGS) and it works to set it to a considerably + * lower value (e.g. 255 works). A lower value may help memory usage (slightly) + * and may even improve performance on some systems (and degrade it on others.) + */ +#ifndef ZLIB_IO_MAX +# define ZLIB_IO_MAX ((uInt)-1) +#endif + +/* Save typing and make code easier to understand */ + +#define PNG_COLOR_DIST(c1, c2) (abs((int)((c1).red) - (int)((c2).red)) + \ + abs((int)((c1).green) - (int)((c2).green)) + \ + abs((int)((c1).blue) - (int)((c2).blue))) + +/* Added to libpng-1.2.6 JB */ +#define PNG_ROWBYTES(pixel_bits, width) \ + ((pixel_bits) >= 8 ? \ + ((png_size_t)(width) * (((png_size_t)(pixel_bits)) >> 3)) : \ + (( ((png_size_t)(width) * ((png_size_t)(pixel_bits))) + 7) >> 3) ) + +/* PNG_OUT_OF_RANGE returns true if value is outside the range + * ideal-delta..ideal+delta. Each argument is evaluated twice. + * "ideal" and "delta" should be constants, normally simple + * integers, "value" a variable. Added to libpng-1.2.6 JB + */ +#define PNG_OUT_OF_RANGE(value, ideal, delta) \ + ( (value) < (ideal)-(delta) || (value) > (ideal)+(delta) ) + +/* Conversions between fixed and floating point, only defined if + * required (to make sure the code doesn't accidentally use float + * when it is supposedly disabled.) + */ +#ifdef PNG_FLOATING_POINT_SUPPORTED +/* The floating point conversion can't overflow, though it can and + * does lose accuracy relative to the original fixed point value. + * In practice this doesn't matter because png_fixed_point only + * stores numbers with very low precision. The png_ptr and s + * arguments are unused by default but are there in case error + * checking becomes a requirement. + */ +#define png_float(png_ptr, fixed, s) (.00001 * (fixed)) + +/* The fixed point conversion performs range checking and evaluates + * its argument multiple times, so must be used with care. The + * range checking uses the PNG specification values for a signed + * 32 bit fixed point value except that the values are deliberately + * rounded-to-zero to an integral value - 21474 (21474.83 is roughly + * (2^31-1) * 100000). 's' is a string that describes the value being + * converted. + * + * NOTE: this macro will raise a png_error if the range check fails, + * therefore it is normally only appropriate to use this on values + * that come from API calls or other sources where an out of range + * error indicates a programming error, not a data error! + * + * NOTE: by default this is off - the macro is not used - because the + * function call saves a lot of code. + */ +#ifdef PNG_FIXED_POINT_MACRO_SUPPORTED +#define png_fixed(png_ptr, fp, s) ((fp) <= 21474 && (fp) >= -21474 ?\ + ((png_fixed_point)(100000 * (fp))) : (png_fixed_error(png_ptr, s),0)) +#else +PNG_EXTERN png_fixed_point png_fixed PNGARG((png_structp png_ptr, double fp, + png_const_charp text)); +#endif +#endif + +/* Constant strings for known chunk types. If you need to add a chunk, + * define the name here, and add an invocation of the macro wherever it's + * needed. + */ +#define PNG_IHDR PNG_CONST png_byte png_IHDR[5] = { 73, 72, 68, 82, '\0'} +#define PNG_IDAT PNG_CONST png_byte png_IDAT[5] = { 73, 68, 65, 84, '\0'} +#define PNG_IEND PNG_CONST png_byte png_IEND[5] = { 73, 69, 78, 68, '\0'} +#define PNG_PLTE PNG_CONST png_byte png_PLTE[5] = { 80, 76, 84, 69, '\0'} +#define PNG_bKGD PNG_CONST png_byte png_bKGD[5] = { 98, 75, 71, 68, '\0'} +#define PNG_cHRM PNG_CONST png_byte png_cHRM[5] = { 99, 72, 82, 77, '\0'} +#define PNG_gAMA PNG_CONST png_byte png_gAMA[5] = {103, 65, 77, 65, '\0'} +#define PNG_hIST PNG_CONST png_byte png_hIST[5] = {104, 73, 83, 84, '\0'} +#define PNG_iCCP PNG_CONST png_byte png_iCCP[5] = {105, 67, 67, 80, '\0'} +#define PNG_iTXt PNG_CONST png_byte png_iTXt[5] = {105, 84, 88, 116, '\0'} +#define PNG_oFFs PNG_CONST png_byte png_oFFs[5] = {111, 70, 70, 115, '\0'} +#define PNG_pCAL PNG_CONST png_byte png_pCAL[5] = {112, 67, 65, 76, '\0'} +#define PNG_sCAL PNG_CONST png_byte png_sCAL[5] = {115, 67, 65, 76, '\0'} +#define PNG_pHYs PNG_CONST png_byte png_pHYs[5] = {112, 72, 89, 115, '\0'} +#define PNG_sBIT PNG_CONST png_byte png_sBIT[5] = {115, 66, 73, 84, '\0'} +#define PNG_sPLT PNG_CONST png_byte png_sPLT[5] = {115, 80, 76, 84, '\0'} +#define PNG_sRGB PNG_CONST png_byte png_sRGB[5] = {115, 82, 71, 66, '\0'} +#define PNG_sTER PNG_CONST png_byte png_sTER[5] = {115, 84, 69, 82, '\0'} +#define PNG_tEXt PNG_CONST png_byte png_tEXt[5] = {116, 69, 88, 116, '\0'} +#define PNG_tIME PNG_CONST png_byte png_tIME[5] = {116, 73, 77, 69, '\0'} +#define PNG_tRNS PNG_CONST png_byte png_tRNS[5] = {116, 82, 78, 83, '\0'} +#define PNG_zTXt PNG_CONST png_byte png_zTXt[5] = {122, 84, 88, 116, '\0'} + + +/* Inhibit C++ name-mangling for libpng functions but not for system calls. */ +#ifdef __cplusplus +extern "C" { +#endif /* __cplusplus */ + +/* These functions are used internally in the code. They generally + * shouldn't be used unless you are writing code to add or replace some + * functionality in libpng. More information about most functions can + * be found in the files where the functions are located. + */ + +/* Allocate memory for an internal libpng struct */ +PNG_EXTERN PNG_FUNCTION(png_voidp,png_create_struct,PNGARG((int type)), + PNG_ALLOCATED); + +/* Free memory from internal libpng struct */ +PNG_EXTERN void png_destroy_struct PNGARG((png_voidp struct_ptr)); + +PNG_EXTERN PNG_FUNCTION(png_voidp,png_create_struct_2, + PNGARG((int type, png_malloc_ptr malloc_fn, png_voidp mem_ptr)), + PNG_ALLOCATED); +PNG_EXTERN void png_destroy_struct_2 PNGARG((png_voidp struct_ptr, + png_free_ptr free_fn, png_voidp mem_ptr)); + +/* Free any memory that info_ptr points to and reset struct. */ +PNG_EXTERN void png_info_destroy PNGARG((png_structp png_ptr, + png_infop info_ptr)); + +/* Function to allocate memory for zlib. PNGAPI is disallowed. */ +PNG_EXTERN PNG_FUNCTION(voidpf,png_zalloc,PNGARG((voidpf png_ptr, uInt items, + uInt size)),PNG_ALLOCATED); + +/* Function to free memory for zlib. PNGAPI is disallowed. */ +PNG_EXTERN void png_zfree PNGARG((voidpf png_ptr, voidpf ptr)); + +/* Next four functions are used internally as callbacks. PNGCBAPI is required + * but not PNG_EXPORT. PNGAPI added at libpng version 1.2.3, changed to + * PNGCBAPI at 1.5.0 + */ + +PNG_EXTERN void PNGCBAPI png_default_read_data PNGARG((png_structp png_ptr, + png_bytep data, png_size_t length)); + +#ifdef PNG_PROGRESSIVE_READ_SUPPORTED +PNG_EXTERN void PNGCBAPI png_push_fill_buffer PNGARG((png_structp png_ptr, + png_bytep buffer, png_size_t length)); +#endif + +PNG_EXTERN void PNGCBAPI png_default_write_data PNGARG((png_structp png_ptr, + png_bytep data, png_size_t length)); + +#ifdef PNG_WRITE_FLUSH_SUPPORTED +# ifdef PNG_STDIO_SUPPORTED +PNG_EXTERN void PNGCBAPI png_default_flush PNGARG((png_structp png_ptr)); +# endif +#endif + +/* Reset the CRC variable */ +PNG_EXTERN void png_reset_crc PNGARG((png_structp png_ptr)); + +/* Write the "data" buffer to whatever output you are using */ +PNG_EXTERN void png_write_data PNGARG((png_structp png_ptr, + png_const_bytep data, png_size_t length)); + +/* Read and check the PNG file signature */ +PNG_EXTERN void png_read_sig PNGARG((png_structp png_ptr, png_infop info_ptr)); + +/* Read the chunk header (length + type name) */ +PNG_EXTERN png_uint_32 png_read_chunk_header PNGARG((png_structp png_ptr)); + +/* Read data from whatever input you are using into the "data" buffer */ +PNG_EXTERN void png_read_data PNGARG((png_structp png_ptr, png_bytep data, + png_size_t length)); + +/* Read bytes into buf, and update png_ptr->crc */ +PNG_EXTERN void png_crc_read PNGARG((png_structp png_ptr, png_bytep buf, + png_size_t length)); + +/* Decompress data in a chunk that uses compression */ +#if defined(PNG_zTXt_SUPPORTED) || defined(PNG_iTXt_SUPPORTED) || \ + defined(PNG_iCCP_SUPPORTED) || defined(PNG_sPLT_SUPPORTED) +PNG_EXTERN void png_decompress_chunk PNGARG((png_structp png_ptr, + int comp_type, png_size_t chunklength, png_size_t prefix_length, + png_size_t *data_length)); +#endif + +/* Read "skip" bytes, read the file crc, and (optionally) verify png_ptr->crc */ +PNG_EXTERN int png_crc_finish PNGARG((png_structp png_ptr, png_uint_32 skip)); + +/* Read the CRC from the file and compare it to the libpng calculated CRC */ +PNG_EXTERN int png_crc_error PNGARG((png_structp png_ptr)); + +/* Calculate the CRC over a section of data. Note that we are only + * passing a maximum of 64K on systems that have this as a memory limit, + * since this is the maximum buffer size we can specify. + */ +PNG_EXTERN void png_calculate_crc PNGARG((png_structp png_ptr, + png_const_bytep ptr, png_size_t length)); + +#ifdef PNG_WRITE_FLUSH_SUPPORTED +PNG_EXTERN void png_flush PNGARG((png_structp png_ptr)); +#endif + +/* Write various chunks */ + +/* Write the IHDR chunk, and update the png_struct with the necessary + * information. + */ +PNG_EXTERN void png_write_IHDR PNGARG((png_structp png_ptr, png_uint_32 width, + png_uint_32 height, + int bit_depth, int color_type, int compression_method, int filter_method, + int interlace_method)); + +PNG_EXTERN void png_write_PLTE PNGARG((png_structp png_ptr, + png_const_colorp palette, png_uint_32 num_pal)); + +PNG_EXTERN void png_write_IDAT PNGARG((png_structp png_ptr, png_bytep data, + png_size_t length)); + +PNG_EXTERN void png_write_IEND PNGARG((png_structp png_ptr)); + +#ifdef PNG_WRITE_gAMA_SUPPORTED +# ifdef PNG_FLOATING_POINT_SUPPORTED +PNG_EXTERN void png_write_gAMA PNGARG((png_structp png_ptr, double file_gamma)); +# endif +# ifdef PNG_FIXED_POINT_SUPPORTED +PNG_EXTERN void png_write_gAMA_fixed PNGARG((png_structp png_ptr, + png_fixed_point file_gamma)); +# endif +#endif + +#ifdef PNG_WRITE_sBIT_SUPPORTED +PNG_EXTERN void png_write_sBIT PNGARG((png_structp png_ptr, + png_const_color_8p sbit, int color_type)); +#endif + +#ifdef PNG_WRITE_cHRM_SUPPORTED +# ifdef PNG_FLOATING_POINT_SUPPORTED +PNG_EXTERN void png_write_cHRM PNGARG((png_structp png_ptr, + double white_x, double white_y, + double red_x, double red_y, double green_x, double green_y, + double blue_x, double blue_y)); +# endif +PNG_EXTERN void png_write_cHRM_fixed PNGARG((png_structp png_ptr, + png_fixed_point int_white_x, png_fixed_point int_white_y, + png_fixed_point int_red_x, png_fixed_point int_red_y, png_fixed_point + int_green_x, png_fixed_point int_green_y, png_fixed_point int_blue_x, + png_fixed_point int_blue_y)); +#endif + +#ifdef PNG_WRITE_sRGB_SUPPORTED +PNG_EXTERN void png_write_sRGB PNGARG((png_structp png_ptr, + int intent)); +#endif + +#ifdef PNG_WRITE_iCCP_SUPPORTED +PNG_EXTERN void png_write_iCCP PNGARG((png_structp png_ptr, + png_const_charp name, int compression_type, + png_const_charp profile, int proflen)); + /* Note to maintainer: profile should be png_bytep */ +#endif + +#ifdef PNG_WRITE_sPLT_SUPPORTED +PNG_EXTERN void png_write_sPLT PNGARG((png_structp png_ptr, + png_const_sPLT_tp palette)); +#endif + +#ifdef PNG_WRITE_tRNS_SUPPORTED +PNG_EXTERN void png_write_tRNS PNGARG((png_structp png_ptr, + png_const_bytep trans, png_const_color_16p values, int number, + int color_type)); +#endif + +#ifdef PNG_WRITE_bKGD_SUPPORTED +PNG_EXTERN void png_write_bKGD PNGARG((png_structp png_ptr, + png_const_color_16p values, int color_type)); +#endif + +#ifdef PNG_WRITE_hIST_SUPPORTED +PNG_EXTERN void png_write_hIST PNGARG((png_structp png_ptr, + png_const_uint_16p hist, int num_hist)); +#endif + +#if defined(PNG_WRITE_TEXT_SUPPORTED) || defined(PNG_WRITE_pCAL_SUPPORTED) || \ + defined(PNG_WRITE_iCCP_SUPPORTED) || defined(PNG_WRITE_sPLT_SUPPORTED) +PNG_EXTERN png_size_t png_check_keyword PNGARG((png_structp png_ptr, + png_const_charp key, png_charpp new_key)); +#endif + +#ifdef PNG_WRITE_tEXt_SUPPORTED +PNG_EXTERN void png_write_tEXt PNGARG((png_structp png_ptr, png_const_charp key, + png_const_charp text, png_size_t text_len)); +#endif + +#ifdef PNG_WRITE_zTXt_SUPPORTED +PNG_EXTERN void png_write_zTXt PNGARG((png_structp png_ptr, png_const_charp key, + png_const_charp text, png_size_t text_len, int compression)); +#endif + +#ifdef PNG_WRITE_iTXt_SUPPORTED +PNG_EXTERN void png_write_iTXt PNGARG((png_structp png_ptr, + int compression, png_const_charp key, png_const_charp lang, + png_const_charp lang_key, png_const_charp text)); +#endif + +#ifdef PNG_TEXT_SUPPORTED /* Added at version 1.0.14 and 1.2.4 */ +PNG_EXTERN int png_set_text_2 PNGARG((png_structp png_ptr, + png_infop info_ptr, png_const_textp text_ptr, int num_text)); +#endif + +#ifdef PNG_WRITE_oFFs_SUPPORTED +PNG_EXTERN void png_write_oFFs PNGARG((png_structp png_ptr, + png_int_32 x_offset, png_int_32 y_offset, int unit_type)); +#endif + +#ifdef PNG_WRITE_pCAL_SUPPORTED +PNG_EXTERN void png_write_pCAL PNGARG((png_structp png_ptr, png_charp purpose, + png_int_32 X0, png_int_32 X1, int type, int nparams, + png_const_charp units, png_charpp params)); +#endif + +#ifdef PNG_WRITE_pHYs_SUPPORTED +PNG_EXTERN void png_write_pHYs PNGARG((png_structp png_ptr, + png_uint_32 x_pixels_per_unit, png_uint_32 y_pixels_per_unit, + int unit_type)); +#endif + +#ifdef PNG_WRITE_tIME_SUPPORTED +PNG_EXTERN void png_write_tIME PNGARG((png_structp png_ptr, + png_const_timep mod_time)); +#endif + +#ifdef PNG_WRITE_sCAL_SUPPORTED +PNG_EXTERN void png_write_sCAL_s PNGARG((png_structp png_ptr, + int unit, png_const_charp width, png_const_charp height)); +#endif + +/* Called when finished processing a row of data */ +PNG_EXTERN void png_write_finish_row PNGARG((png_structp png_ptr)); + +/* Internal use only. Called before first row of data */ +PNG_EXTERN void png_write_start_row PNGARG((png_structp png_ptr)); + +/* Combine a row of data, dealing with alpha, etc. if requested */ +PNG_EXTERN void png_combine_row PNGARG((png_structp png_ptr, png_bytep row, + int mask)); + +#ifdef PNG_READ_INTERLACING_SUPPORTED +/* Expand an interlaced row */ +/* OLD pre-1.0.9 interface: +PNG_EXTERN void png_do_read_interlace PNGARG((png_row_infop row_info, + png_bytep row, int pass, png_uint_32 transformations)); + */ +PNG_EXTERN void png_do_read_interlace PNGARG((png_structp png_ptr)); +#endif + +/* GRR TO DO (2.0 or whenever): simplify other internal calling interfaces */ + +#ifdef PNG_WRITE_INTERLACING_SUPPORTED +/* Grab pixels out of a row for an interlaced pass */ +PNG_EXTERN void png_do_write_interlace PNGARG((png_row_infop row_info, + png_bytep row, int pass)); +#endif + +/* Unfilter a row */ +PNG_EXTERN void png_read_filter_row PNGARG((png_structp png_ptr, + png_row_infop row_info, png_bytep row, png_const_bytep prev_row, + int filter)); + +/* Choose the best filter to use and filter the row data */ +PNG_EXTERN void png_write_find_filter PNGARG((png_structp png_ptr, + png_row_infop row_info)); + +/* Write out the filtered row. */ +PNG_EXTERN void png_write_filtered_row PNGARG((png_structp png_ptr, + png_bytep filtered_row)); +/* Finish a row while reading, dealing with interlacing passes, etc. */ +PNG_EXTERN void png_read_finish_row PNGARG((png_structp png_ptr)); + +/* Initialize the row buffers, etc. */ +PNG_EXTERN void png_read_start_row PNGARG((png_structp png_ptr)); +/* Optional call to update the users info structure */ +PNG_EXTERN void png_read_transform_info PNGARG((png_structp png_ptr, + png_infop info_ptr)); + +/* These are the functions that do the transformations */ +#ifdef PNG_READ_FILLER_SUPPORTED +PNG_EXTERN void png_do_read_filler PNGARG((png_row_infop row_info, + png_bytep row, png_uint_32 filler, png_uint_32 flags)); +#endif + +#ifdef PNG_READ_SWAP_ALPHA_SUPPORTED +PNG_EXTERN void png_do_read_swap_alpha PNGARG((png_row_infop row_info, + png_bytep row)); +#endif + +#ifdef PNG_WRITE_SWAP_ALPHA_SUPPORTED +PNG_EXTERN void png_do_write_swap_alpha PNGARG((png_row_infop row_info, + png_bytep row)); +#endif + +#ifdef PNG_READ_INVERT_ALPHA_SUPPORTED +PNG_EXTERN void png_do_read_invert_alpha PNGARG((png_row_infop row_info, + png_bytep row)); +#endif + +#ifdef PNG_WRITE_INVERT_ALPHA_SUPPORTED +PNG_EXTERN void png_do_write_invert_alpha PNGARG((png_row_infop row_info, + png_bytep row)); +#endif + +#if defined(PNG_WRITE_FILLER_SUPPORTED) || \ + defined(PNG_READ_STRIP_ALPHA_SUPPORTED) +PNG_EXTERN void png_do_strip_filler PNGARG((png_row_infop row_info, + png_bytep row, png_uint_32 flags)); +#endif + +#ifdef PNG_16BIT_SUPPORTED +#if defined(PNG_READ_SWAP_SUPPORTED) || defined(PNG_WRITE_SWAP_SUPPORTED) +PNG_EXTERN void png_do_swap PNGARG((png_row_infop row_info, + png_bytep row)); +#endif +#endif + +#if defined(PNG_READ_PACKSWAP_SUPPORTED) || \ + defined(PNG_WRITE_PACKSWAP_SUPPORTED) +PNG_EXTERN void png_do_packswap PNGARG((png_row_infop row_info, + png_bytep row)); +#endif + +#ifdef PNG_READ_RGB_TO_GRAY_SUPPORTED +PNG_EXTERN int png_do_rgb_to_gray PNGARG((png_structp png_ptr, + png_row_infop row_info, png_bytep row)); +#endif + +#ifdef PNG_READ_GRAY_TO_RGB_SUPPORTED +PNG_EXTERN void png_do_gray_to_rgb PNGARG((png_row_infop row_info, + png_bytep row)); +#endif + +#ifdef PNG_READ_PACK_SUPPORTED +PNG_EXTERN void png_do_unpack PNGARG((png_row_infop row_info, + png_bytep row)); +#endif + +#ifdef PNG_READ_SHIFT_SUPPORTED +PNG_EXTERN void png_do_unshift PNGARG((png_row_infop row_info, + png_bytep row, png_const_color_8p sig_bits)); +#endif + +#if defined(PNG_READ_INVERT_SUPPORTED) || defined(PNG_WRITE_INVERT_SUPPORTED) +PNG_EXTERN void png_do_invert PNGARG((png_row_infop row_info, + png_bytep row)); +#endif + +#ifdef PNG_READ_16_TO_8_SUPPORTED +PNG_EXTERN void png_do_chop PNGARG((png_row_infop row_info, + png_bytep row)); +#endif + +#ifdef PNG_READ_QUANTIZE_SUPPORTED +PNG_EXTERN void png_do_quantize PNGARG((png_row_infop row_info, + png_bytep row, png_const_bytep palette_lookup, + png_const_bytep quantize_lookup)); + +# ifdef PNG_CORRECT_PALETTE_SUPPORTED +PNG_EXTERN void png_correct_palette PNGARG((png_structp png_ptr, + png_colorp palette, int num_palette)); +# endif +#endif + +#if defined(PNG_READ_BGR_SUPPORTED) || defined(PNG_WRITE_BGR_SUPPORTED) +PNG_EXTERN void png_do_bgr PNGARG((png_row_infop row_info, + png_bytep row)); +#endif + +#ifdef PNG_WRITE_PACK_SUPPORTED +PNG_EXTERN void png_do_pack PNGARG((png_row_infop row_info, + png_bytep row, png_uint_32 bit_depth)); +#endif + +#ifdef PNG_WRITE_SHIFT_SUPPORTED +PNG_EXTERN void png_do_shift PNGARG((png_row_infop row_info, + png_bytep row, png_const_color_8p bit_depth)); +#endif + +#ifdef PNG_READ_BACKGROUND_SUPPORTED +# ifdef PNG_READ_GAMMA_SUPPORTED +PNG_EXTERN void png_do_background PNGARG((png_row_infop row_info, + png_bytep row, png_const_color_16p trans_color, + png_const_color_16p background, png_const_color_16p background_1, + png_const_bytep gamma_table, png_const_bytep gamma_from_1, + png_const_bytep gamma_to_1, png_const_uint_16pp gamma_16, + png_const_uint_16pp gamma_16_from_1, png_const_uint_16pp gamma_16_to_1, + int gamma_shift)); +# else +PNG_EXTERN void png_do_background PNGARG((png_row_infop row_info, + png_bytep row, png_const_color_16p trans_color, + png_const_color_16p background)); +# endif +#endif + +#ifdef PNG_READ_GAMMA_SUPPORTED +PNG_EXTERN void png_do_gamma PNGARG((png_row_infop row_info, + png_bytep row, png_const_bytep gamma_table, + png_const_uint_16pp gamma_16_table, int gamma_shift)); +#endif + +#ifdef PNG_READ_EXPAND_SUPPORTED +PNG_EXTERN void png_do_expand_palette PNGARG((png_row_infop row_info, + png_bytep row, png_const_colorp palette, png_const_bytep trans, + int num_trans)); +PNG_EXTERN void png_do_expand PNGARG((png_row_infop row_info, + png_bytep row, png_const_color_16p trans_color)); +#endif + +/* The following decodes the appropriate chunks, and does error correction, + * then calls the appropriate callback for the chunk if it is valid. + */ + +/* Decode the IHDR chunk */ +PNG_EXTERN void png_handle_IHDR PNGARG((png_structp png_ptr, png_infop info_ptr, + png_uint_32 length)); +PNG_EXTERN void png_handle_PLTE PNGARG((png_structp png_ptr, png_infop info_ptr, + png_uint_32 length)); +PNG_EXTERN void png_handle_IEND PNGARG((png_structp png_ptr, png_infop info_ptr, + png_uint_32 length)); + +#ifdef PNG_READ_bKGD_SUPPORTED +PNG_EXTERN void png_handle_bKGD PNGARG((png_structp png_ptr, png_infop info_ptr, + png_uint_32 length)); +#endif + +#ifdef PNG_READ_cHRM_SUPPORTED +PNG_EXTERN void png_handle_cHRM PNGARG((png_structp png_ptr, png_infop info_ptr, + png_uint_32 length)); +#endif + +#ifdef PNG_READ_gAMA_SUPPORTED +PNG_EXTERN void png_handle_gAMA PNGARG((png_structp png_ptr, png_infop info_ptr, + png_uint_32 length)); +#endif + +#ifdef PNG_READ_hIST_SUPPORTED +PNG_EXTERN void png_handle_hIST PNGARG((png_structp png_ptr, png_infop info_ptr, + png_uint_32 length)); +#endif + +#ifdef PNG_READ_iCCP_SUPPORTED +PNG_EXTERN void png_handle_iCCP PNGARG((png_structp png_ptr, png_infop info_ptr, + png_uint_32 length)); +#endif /* PNG_READ_iCCP_SUPPORTED */ + +#ifdef PNG_READ_iTXt_SUPPORTED +PNG_EXTERN void png_handle_iTXt PNGARG((png_structp png_ptr, png_infop info_ptr, + png_uint_32 length)); +#endif + +#ifdef PNG_READ_oFFs_SUPPORTED +PNG_EXTERN void png_handle_oFFs PNGARG((png_structp png_ptr, png_infop info_ptr, + png_uint_32 length)); +#endif + +#ifdef PNG_READ_pCAL_SUPPORTED +PNG_EXTERN void png_handle_pCAL PNGARG((png_structp png_ptr, png_infop info_ptr, + png_uint_32 length)); +#endif + +#ifdef PNG_READ_pHYs_SUPPORTED +PNG_EXTERN void png_handle_pHYs PNGARG((png_structp png_ptr, png_infop info_ptr, + png_uint_32 length)); +#endif + +#ifdef PNG_READ_sBIT_SUPPORTED +PNG_EXTERN void png_handle_sBIT PNGARG((png_structp png_ptr, png_infop info_ptr, + png_uint_32 length)); +#endif + +#ifdef PNG_READ_sCAL_SUPPORTED +PNG_EXTERN void png_handle_sCAL PNGARG((png_structp png_ptr, png_infop info_ptr, + png_uint_32 length)); +#endif + +#ifdef PNG_READ_sPLT_SUPPORTED +PNG_EXTERN void png_handle_sPLT PNGARG((png_structp png_ptr, png_infop info_ptr, + png_uint_32 length)); +#endif /* PNG_READ_sPLT_SUPPORTED */ + +#ifdef PNG_READ_sRGB_SUPPORTED +PNG_EXTERN void png_handle_sRGB PNGARG((png_structp png_ptr, png_infop info_ptr, + png_uint_32 length)); +#endif + +#ifdef PNG_READ_tEXt_SUPPORTED +PNG_EXTERN void png_handle_tEXt PNGARG((png_structp png_ptr, png_infop info_ptr, + png_uint_32 length)); +#endif + +#ifdef PNG_READ_tIME_SUPPORTED +PNG_EXTERN void png_handle_tIME PNGARG((png_structp png_ptr, png_infop info_ptr, + png_uint_32 length)); +#endif + +#ifdef PNG_READ_tRNS_SUPPORTED +PNG_EXTERN void png_handle_tRNS PNGARG((png_structp png_ptr, png_infop info_ptr, + png_uint_32 length)); +#endif + +#ifdef PNG_READ_zTXt_SUPPORTED +PNG_EXTERN void png_handle_zTXt PNGARG((png_structp png_ptr, png_infop info_ptr, + png_uint_32 length)); +#endif + +PNG_EXTERN void png_handle_unknown PNGARG((png_structp png_ptr, + png_infop info_ptr, png_uint_32 length)); + +PNG_EXTERN void png_check_chunk_name PNGARG((png_structp png_ptr, + png_const_bytep chunk_name)); + +/* Handle the transformations for reading and writing */ +PNG_EXTERN void png_do_read_transformations PNGARG((png_structp png_ptr)); +PNG_EXTERN void png_do_write_transformations PNGARG((png_structp png_ptr)); + +PNG_EXTERN void png_init_read_transformations PNGARG((png_structp png_ptr)); + +#ifdef PNG_PROGRESSIVE_READ_SUPPORTED +PNG_EXTERN void png_push_read_chunk PNGARG((png_structp png_ptr, + png_infop info_ptr)); +PNG_EXTERN void png_push_read_sig PNGARG((png_structp png_ptr, + png_infop info_ptr)); +PNG_EXTERN void png_push_check_crc PNGARG((png_structp png_ptr)); +PNG_EXTERN void png_push_crc_skip PNGARG((png_structp png_ptr, + png_uint_32 length)); +PNG_EXTERN void png_push_crc_finish PNGARG((png_structp png_ptr)); +PNG_EXTERN void png_push_save_buffer PNGARG((png_structp png_ptr)); +PNG_EXTERN void png_push_restore_buffer PNGARG((png_structp png_ptr, + png_bytep buffer, png_size_t buffer_length)); +PNG_EXTERN void png_push_read_IDAT PNGARG((png_structp png_ptr)); +PNG_EXTERN void png_process_IDAT_data PNGARG((png_structp png_ptr, + png_bytep buffer, png_size_t buffer_length)); +PNG_EXTERN void png_push_process_row PNGARG((png_structp png_ptr)); +PNG_EXTERN void png_push_handle_unknown PNGARG((png_structp png_ptr, + png_infop info_ptr, png_uint_32 length)); +PNG_EXTERN void png_push_have_info PNGARG((png_structp png_ptr, + png_infop info_ptr)); +PNG_EXTERN void png_push_have_end PNGARG((png_structp png_ptr, + png_infop info_ptr)); +PNG_EXTERN void png_push_have_row PNGARG((png_structp png_ptr, png_bytep row)); +PNG_EXTERN void png_push_read_end PNGARG((png_structp png_ptr, + png_infop info_ptr)); +PNG_EXTERN void png_process_some_data PNGARG((png_structp png_ptr, + png_infop info_ptr)); +PNG_EXTERN void png_read_push_finish_row PNGARG((png_structp png_ptr)); +# ifdef PNG_READ_tEXt_SUPPORTED +PNG_EXTERN void png_push_handle_tEXt PNGARG((png_structp png_ptr, + png_infop info_ptr, png_uint_32 length)); +PNG_EXTERN void png_push_read_tEXt PNGARG((png_structp png_ptr, + png_infop info_ptr)); +# endif +# ifdef PNG_READ_zTXt_SUPPORTED +PNG_EXTERN void png_push_handle_zTXt PNGARG((png_structp png_ptr, + png_infop info_ptr, png_uint_32 length)); +PNG_EXTERN void png_push_read_zTXt PNGARG((png_structp png_ptr, + png_infop info_ptr)); +# endif +# ifdef PNG_READ_iTXt_SUPPORTED +PNG_EXTERN void png_push_handle_iTXt PNGARG((png_structp png_ptr, + png_infop info_ptr, png_uint_32 length)); +PNG_EXTERN void png_push_read_iTXt PNGARG((png_structp png_ptr, + png_infop info_ptr)); +# endif + +#endif /* PNG_PROGRESSIVE_READ_SUPPORTED */ + +#ifdef PNG_MNG_FEATURES_SUPPORTED +PNG_EXTERN void png_do_read_intrapixel PNGARG((png_row_infop row_info, + png_bytep row)); +PNG_EXTERN void png_do_write_intrapixel PNGARG((png_row_infop row_info, + png_bytep row)); +#endif + +/* Added at libpng version 1.4.0 */ +#ifdef PNG_CHECK_cHRM_SUPPORTED +PNG_EXTERN int png_check_cHRM_fixed PNGARG((png_structp png_ptr, + png_fixed_point int_white_x, png_fixed_point int_white_y, + png_fixed_point int_red_x, png_fixed_point int_red_y, png_fixed_point + int_green_x, png_fixed_point int_green_y, png_fixed_point int_blue_x, + png_fixed_point int_blue_y)); +#endif + +#ifdef PNG_CHECK_cHRM_SUPPORTED +/* Added at libpng version 1.2.34 and 1.4.0 */ +/* Currently only used by png_check_cHRM_fixed */ +PNG_EXTERN void png_64bit_product PNGARG((long v1, long v2, + unsigned long *hi_product, unsigned long *lo_product)); +#endif + +/* Added at libpng version 1.4.0 */ +PNG_EXTERN void png_check_IHDR PNGARG((png_structp png_ptr, + png_uint_32 width, png_uint_32 height, int bit_depth, + int color_type, int interlace_type, int compression_type, + int filter_type)); + +/* Free all memory used by the read (old method - NOT DLL EXPORTED) */ +PNG_EXTERN void png_read_destroy PNGARG((png_structp png_ptr, + png_infop info_ptr, png_infop end_info_ptr)); + +/* Free any memory used in png_ptr struct (old method - NOT DLL EXPORTED) */ +PNG_EXTERN void png_write_destroy PNGARG((png_structp png_ptr)); + +#ifdef USE_FAR_KEYWORD /* memory model conversion function */ +PNG_EXTERN void *png_far_to_near PNGARG((png_structp png_ptr, png_voidp ptr, + int check)); +#endif /* USE_FAR_KEYWORD */ + +#if defined(PNG_FLOATING_POINT_SUPPORTED) && defined(PNG_ERROR_TEXT_SUPPORTED) +PNG_EXTERN PNG_FUNCTION(void, png_fixed_error, (png_structp png_ptr, + png_const_charp name),PNG_NORETURN); +#endif + +/* ASCII to FP interfaces, currently only implemented if sCAL + * support is required. + */ +#if defined(PNG_READ_sCAL_SUPPORTED) +/* MAX_DIGITS is actually the maximum number of characters in an sCAL + * width or height, derived from the precision (number of significant + * digits - a build time settable option) and assumpitions about the + * maximum ridiculous exponent. + */ +#define PNG_sCAL_MAX_DIGITS (PNG_sCAL_PRECISION+1/*.*/+1/*E*/+10/*exponent*/) + +#ifdef PNG_FLOATING_POINT_SUPPORTED +PNG_EXTERN void png_ascii_from_fp PNGARG((png_structp png_ptr, png_charp ascii, + png_size_t size, double fp, unsigned int precision)); +#endif /* FLOATING_POINT */ + +#ifdef PNG_FIXED_POINT_SUPPORTED +PNG_EXTERN void png_ascii_from_fixed PNGARG((png_structp png_ptr, + png_charp ascii, png_size_t size, png_fixed_point fp)); +#endif /* FIXED_POINT */ +#endif /* READ_sCAL */ + +#if defined(PNG_sCAL_SUPPORTED) || defined(PNG_pCAL_SUPPORTED) +/* An internal API to validate the format of a floating point number. + * The result is the index of the next character. If the number is + * not valid it will be the index of a character in the supposed number. + * + * The format of a number is defined in the PNG extensions specification + * and this API is strictly conformant to that spec, not anyone elses! + * + * The format as a regular expression is: + * + * [+-]?[0-9]+.?([Ee][+-]?[0-9]+)? + * + * or: + * + * [+-]?.[0-9]+(.[0-9]+)?([Ee][+-]?[0-9]+)? + * + * The complexity is that either integer or fraction must be present and the + * fraction is permitted to have no digits only if the integer is present. + * + * NOTE: The dangling E problem. + * There is a PNG valid floating point number in the following: + * + * PNG floating point numb1.ers are not greedy. + * + * Working this out requires *TWO* character lookahead (because of the + * sign), the parser does not do this - it will fail at the 'r' - this + * doesn't matter for PNG sCAL chunk values, but it requires more care + * if the value were ever to be embedded in something more complex. Use + * ANSI-C strtod if you need the lookahead. + */ +/* State table for the parser. */ +#define PNG_FP_INTEGER 0 /* before or in integer */ +#define PNG_FP_FRACTION 1 /* before or in fraction */ +#define PNG_FP_EXPONENT 2 /* before or in exponent */ +#define PNG_FP_STATE 3 /* mask for the above */ +#define PNG_FP_SAW_SIGN 4 /* Saw +/- in current state */ +#define PNG_FP_SAW_DIGIT 8 /* Saw a digit in current state */ +#define PNG_FP_SAW_DOT 16 /* Saw a dot in current state */ +#define PNG_FP_SAW_E 32 /* Saw an E (or e) in current state */ +#define PNG_FP_SAW_ANY 60 /* Saw any of the above 4 */ +#define PNG_FP_WAS_VALID 64 /* Preceding substring is a valid fp number */ +#define PNG_FP_INVALID 128 /* Available for callers as a distinct value */ + +/* Result codes for the parser (boolean - true meants ok, false means + * not ok yet.) + */ +#define PNG_FP_MAYBE 0 /* The number may be valid in the future */ +#define PNG_FP_OK 1 /* The number is valid */ + +/* The actual parser. This can be called repeatedly, it updates + * the index into the string and the state variable (which must + * be initialzed to 0). It returns a result code, as above. There + * is no point calling the parser any more if it fails to advance to + * the end of the string - it is stuck on an invalid character (or + * terminated by '\0'). + * + * Note that the pointer will consume an E or even an E+ then leave + * a 'maybe' state even though a preceding integer.fraction is valid. + * The PNG_FP_WAS_VALID flag indicates that a preceding substring was + * a valid number. It's possible to recover from this by calling + * the parser again (from the start, with state 0) but with a string + * that omits the last character (i.e. set the size to the index of + * the problem character.) This has not been tested within libpng. + */ +PNG_EXTERN int png_check_fp_number PNGARG((png_const_charp string, + png_size_t size, int *statep, png_size_tp whereami)); + +/* This is the same but it checks a complete string and returns true + * only if it just contains a floating point number. + */ +PNG_EXTERN int png_check_fp_string PNGARG((png_const_charp string, + png_size_t size)); +#endif /* pCAL || sCAL */ + +#if defined(PNG_READ_GAMMA_SUPPORTED) ||\ + defined(PNG_INCH_CONVERSIONS_SUPPORTED) || defined(PNG_READ_pHYs_SUPPORTED) +/* Added at libpng version 1.5.0 */ +/* This is a utility to provide a*times/div (rounded) and indicate + * if there is an overflow. The result is a boolean - false (0) + * for overflow, true (1) if no overflow, in which case *res + * holds the result. + */ +PNG_EXTERN int png_muldiv PNGARG((png_fixed_point_p res, png_fixed_point a, + png_int_32 times, png_int_32 div)); +#endif + +#if defined(PNG_READ_GAMMA_SUPPORTED) || defined(PNG_INCH_CONVERSIONS_SUPPORTED) +/* Same deal, but issue a warning on overflow and return 0. */ +PNG_EXTERN png_fixed_point png_muldiv_warn PNGARG((png_structp png_ptr, + png_fixed_point a, png_int_32 times, png_int_32 div)); +#endif + +#ifdef PNG_READ_GAMMA_SUPPORTED +/* Calculate a reciprocal - used for gamma values. This returns + * 0 if the argument is 0 in order to maintain an undefined value, + * there are no warnings. + */ +PNG_EXTERN png_fixed_point png_reciprocal PNGARG((png_fixed_point a)); + +/* The same but gives a reciprocal of the product of two fixed point + * values. Accuracy is suitable for gamma calculations but this is + * not exact - use png_muldiv for that. + */ +PNG_EXTERN png_fixed_point png_reciprocal2 PNGARG((png_fixed_point a, + png_fixed_point b)); +#endif + +#ifdef PNG_READ_GAMMA_SUPPORTED +/* Internal fixed point gamma correction. These APIs are called as + * required to convert single values - they don't need to be fast, + * they are not used when processing image pixel values. + * + * While the input is an 'unsigned' value it must actually be the + * correct bit value - 0..255 or 0..65535 as required. + */ +PNG_EXTERN png_uint_16 png_gamma_correct PNGARG((png_structp png_ptr, + unsigned int value, png_fixed_point gamma)); +PNG_EXTERN int png_gamma_significant PNGARG((png_fixed_point gamma)); +PNG_EXTERN png_uint_16 png_gamma_16bit_correct PNGARG((unsigned int value, + png_fixed_point gamma)); +PNG_EXTERN png_byte png_gamma_8bit_correct PNGARG((unsigned int value, + png_fixed_point gamma)); +PNG_EXTERN void png_build_gamma_table PNGARG((png_structp png_ptr, + int bit_depth)); +#endif + +/* Maintainer: Put new private prototypes here ^ and in libpngpf.3 */ + + +#include "pngdebug.h" + +#ifdef __cplusplus +} +#endif + +#endif /* PNGPRIV_H */ diff --git a/src/3rdparty/libpng/pngread.c b/src/3rdparty/libpng/pngread.c new file mode 100644 index 0000000000..2c8f2cd687 --- /dev/null +++ b/src/3rdparty/libpng/pngread.c @@ -0,0 +1,1466 @@ + +/* pngread.c - read a PNG file + * + * Last changed in libpng 1.5.1 [$RDATE%] + * Copyright (c) 1998-2011 Glenn Randers-Pehrson + * (Version 0.96 Copyright (c) 1996, 1997 Andreas Dilger) + * (Version 0.88 Copyright (c) 1995, 1996 Guy Eric Schalnat, Group 42, Inc.) + * + * This code is released under the libpng license. + * For conditions of distribution and use, see the disclaimer + * and license in png.h + * + * This file contains routines that an application calls directly to + * read a PNG file or stream. + */ + +#include "pngpriv.h" + +#ifdef PNG_READ_SUPPORTED + +/* Create a PNG structure for reading, and allocate any memory needed. */ +PNG_FUNCTION(png_structp,PNGAPI +png_create_read_struct,(png_const_charp user_png_ver, png_voidp error_ptr, + png_error_ptr error_fn, png_error_ptr warn_fn),PNG_ALLOCATED) +{ + +#ifdef PNG_USER_MEM_SUPPORTED + return (png_create_read_struct_2(user_png_ver, error_ptr, error_fn, + warn_fn, NULL, NULL, NULL)); +} + +/* Alternate create PNG structure for reading, and allocate any memory + * needed. + */ +PNG_FUNCTION(png_structp,PNGAPI +png_create_read_struct_2,(png_const_charp user_png_ver, png_voidp error_ptr, + png_error_ptr error_fn, png_error_ptr warn_fn, png_voidp mem_ptr, + png_malloc_ptr malloc_fn, png_free_ptr free_fn),PNG_ALLOCATED) +{ +#endif /* PNG_USER_MEM_SUPPORTED */ + +#ifdef PNG_SETJMP_SUPPORTED + volatile +#endif + png_structp png_ptr; + volatile int png_cleanup_needed = 0; + +#ifdef PNG_SETJMP_SUPPORTED +#ifdef USE_FAR_KEYWORD + jmp_buf png_jmpbuf; +#endif +#endif + + int i; + + png_debug(1, "in png_create_read_struct"); + +#ifdef PNG_USER_MEM_SUPPORTED + png_ptr = (png_structp)png_create_struct_2(PNG_STRUCT_PNG, + malloc_fn, mem_ptr); +#else + png_ptr = (png_structp)png_create_struct(PNG_STRUCT_PNG); +#endif + if (png_ptr == NULL) + return (NULL); + + /* Added at libpng-1.2.6 */ +#ifdef PNG_USER_LIMITS_SUPPORTED + png_ptr->user_width_max = PNG_USER_WIDTH_MAX; + png_ptr->user_height_max = PNG_USER_HEIGHT_MAX; + +# ifdef PNG_USER_CHUNK_CACHE_MAX + /* Added at libpng-1.2.43 and 1.4.0 */ + png_ptr->user_chunk_cache_max = PNG_USER_CHUNK_CACHE_MAX; +# endif + +# ifdef PNG_SET_USER_CHUNK_MALLOC_MAX + /* Added at libpng-1.2.43 and 1.4.1 */ + png_ptr->user_chunk_malloc_max = PNG_USER_CHUNK_MALLOC_MAX; +# endif +#endif + +#ifdef PNG_SETJMP_SUPPORTED +/* Applications that neglect to set up their own setjmp() and then + encounter a png_error() will longjmp here. Since the jmpbuf is + then meaningless we abort instead of returning. */ +#ifdef USE_FAR_KEYWORD + if (setjmp(png_jmpbuf)) +#else + if (setjmp(png_jmpbuf(png_ptr))) /* Sets longjmp to match setjmp */ +#endif + PNG_ABORT(); +#ifdef USE_FAR_KEYWORD + png_memcpy(png_jmpbuf(png_ptr), png_jmpbuf, png_sizeof(jmp_buf)); +#endif +#endif /* PNG_SETJMP_SUPPORTED */ + +#ifdef PNG_USER_MEM_SUPPORTED + png_set_mem_fn(png_ptr, mem_ptr, malloc_fn, free_fn); +#endif + + png_set_error_fn(png_ptr, error_ptr, error_fn, warn_fn); + + if (user_png_ver) + { + i = 0; + + do + { + if (user_png_ver[i] != png_libpng_ver[i]) + png_ptr->flags |= PNG_FLAG_LIBRARY_MISMATCH; + } while (png_libpng_ver[i++]); + } + + else + png_ptr->flags |= PNG_FLAG_LIBRARY_MISMATCH; + + + if (png_ptr->flags & PNG_FLAG_LIBRARY_MISMATCH) + { + /* Libpng 0.90 and later are binary incompatible with libpng 0.89, so + * we must recompile any applications that use any older library version. + * For versions after libpng 1.0, we will be compatible, so we need + * only check the first digit. + */ + if (user_png_ver == NULL || user_png_ver[0] != png_libpng_ver[0] || + (user_png_ver[0] == '1' && user_png_ver[2] != png_libpng_ver[2]) || + (user_png_ver[0] == '0' && user_png_ver[2] < '9')) + { +#ifdef PNG_CONSOLE_IO_SUPPORTED + char msg[80]; + if (user_png_ver) + { + png_snprintf2(msg, 80, + "Application built with libpng-%.20s" + " but running with %.20s", + user_png_ver, + png_libpng_ver); + png_warning(png_ptr, msg); + } +#else + png_warning(png_ptr, + "Incompatible libpng version in application and library"); +#endif +#ifdef PNG_ERROR_NUMBERS_SUPPORTED + png_ptr->flags = 0; +#endif + + png_cleanup_needed = 1; + } + } + + if (!png_cleanup_needed) + { + /* Initialize zbuf - compression buffer */ + png_ptr->zbuf_size = PNG_ZBUF_SIZE; + png_ptr->zbuf = (png_bytep)png_malloc_warn(png_ptr, png_ptr->zbuf_size); + + if (png_ptr->zbuf == NULL) + png_cleanup_needed = 1; + } + + png_ptr->zstream.zalloc = png_zalloc; + png_ptr->zstream.zfree = png_zfree; + png_ptr->zstream.opaque = (voidpf)png_ptr; + + if (!png_cleanup_needed) + { + switch (inflateInit(&png_ptr->zstream)) + { + case Z_OK: + break; /* Do nothing */ + + case Z_MEM_ERROR: + png_warning(png_ptr, "zlib memory error"); + png_cleanup_needed = 1; + break; + + case Z_STREAM_ERROR: + png_warning(png_ptr, "zlib stream error"); + png_cleanup_needed = 1; + break; + + case Z_VERSION_ERROR: + png_warning(png_ptr, "zlib version error"); + png_cleanup_needed = 1; + break; + + default: png_warning(png_ptr, "Unknown zlib error"); + png_cleanup_needed = 1; + } + } + + if (png_cleanup_needed) + { + /* Clean up PNG structure and deallocate any memory. */ + png_free(png_ptr, png_ptr->zbuf); + png_ptr->zbuf = NULL; +#ifdef PNG_USER_MEM_SUPPORTED + png_destroy_struct_2((png_voidp)png_ptr, + (png_free_ptr)free_fn, (png_voidp)mem_ptr); +#else + png_destroy_struct((png_voidp)png_ptr); +#endif + return (NULL); + } + + png_ptr->zstream.next_out = png_ptr->zbuf; + png_ptr->zstream.avail_out = (uInt)png_ptr->zbuf_size; + + png_set_read_fn(png_ptr, NULL, NULL); + + + return (png_ptr); +} + + +#ifdef PNG_SEQUENTIAL_READ_SUPPORTED +/* Read the information before the actual image data. This has been + * changed in v0.90 to allow reading a file that already has the magic + * bytes read from the stream. You can tell libpng how many bytes have + * been read from the beginning of the stream (up to the maximum of 8) + * via png_set_sig_bytes(), and we will only check the remaining bytes + * here. The application can then have access to the signature bytes we + * read if it is determined that this isn't a valid PNG file. + */ +void PNGAPI +png_read_info(png_structp png_ptr, png_infop info_ptr) +{ + png_debug(1, "in png_read_info"); + + if (png_ptr == NULL || info_ptr == NULL) + return; + + /* Read and check the PNG file signature. */ + png_read_sig(png_ptr, info_ptr); + + for (;;) + { + PNG_IHDR; + PNG_IDAT; + PNG_IEND; + PNG_PLTE; +#ifdef PNG_READ_bKGD_SUPPORTED + PNG_bKGD; +#endif +#ifdef PNG_READ_cHRM_SUPPORTED + PNG_cHRM; +#endif +#ifdef PNG_READ_gAMA_SUPPORTED + PNG_gAMA; +#endif +#ifdef PNG_READ_hIST_SUPPORTED + PNG_hIST; +#endif +#ifdef PNG_READ_iCCP_SUPPORTED + PNG_iCCP; +#endif +#ifdef PNG_READ_iTXt_SUPPORTED + PNG_iTXt; +#endif +#ifdef PNG_READ_oFFs_SUPPORTED + PNG_oFFs; +#endif +#ifdef PNG_READ_pCAL_SUPPORTED + PNG_pCAL; +#endif +#ifdef PNG_READ_pHYs_SUPPORTED + PNG_pHYs; +#endif +#ifdef PNG_READ_sBIT_SUPPORTED + PNG_sBIT; +#endif +#ifdef PNG_READ_sCAL_SUPPORTED + PNG_sCAL; +#endif +#ifdef PNG_READ_sPLT_SUPPORTED + PNG_sPLT; +#endif +#ifdef PNG_READ_sRGB_SUPPORTED + PNG_sRGB; +#endif +#ifdef PNG_READ_tEXt_SUPPORTED + PNG_tEXt; +#endif +#ifdef PNG_READ_tIME_SUPPORTED + PNG_tIME; +#endif +#ifdef PNG_READ_tRNS_SUPPORTED + PNG_tRNS; +#endif +#ifdef PNG_READ_zTXt_SUPPORTED + PNG_zTXt; +#endif + png_uint_32 length = png_read_chunk_header(png_ptr); + PNG_CONST png_bytep chunk_name = png_ptr->chunk_name; + + /* This should be a binary subdivision search or a hash for + * matching the chunk name rather than a linear search. + */ + if (!png_memcmp(chunk_name, png_IDAT, 4)) + if (png_ptr->mode & PNG_AFTER_IDAT) + png_ptr->mode |= PNG_HAVE_CHUNK_AFTER_IDAT; + + if (!png_memcmp(chunk_name, png_IHDR, 4)) + png_handle_IHDR(png_ptr, info_ptr, length); + + else if (!png_memcmp(chunk_name, png_IEND, 4)) + png_handle_IEND(png_ptr, info_ptr, length); + +#ifdef PNG_HANDLE_AS_UNKNOWN_SUPPORTED + else if (png_handle_as_unknown(png_ptr, chunk_name)) + { + if (!png_memcmp(chunk_name, png_IDAT, 4)) + png_ptr->mode |= PNG_HAVE_IDAT; + + png_handle_unknown(png_ptr, info_ptr, length); + + if (!png_memcmp(chunk_name, png_PLTE, 4)) + png_ptr->mode |= PNG_HAVE_PLTE; + + else if (!png_memcmp(chunk_name, png_IDAT, 4)) + { + if (!(png_ptr->mode & PNG_HAVE_IHDR)) + png_error(png_ptr, "Missing IHDR before IDAT"); + + else if (png_ptr->color_type == PNG_COLOR_TYPE_PALETTE && + !(png_ptr->mode & PNG_HAVE_PLTE)) + png_error(png_ptr, "Missing PLTE before IDAT"); + + break; + } + } +#endif + else if (!png_memcmp(chunk_name, png_PLTE, 4)) + png_handle_PLTE(png_ptr, info_ptr, length); + + else if (!png_memcmp(chunk_name, png_IDAT, 4)) + { + if (!(png_ptr->mode & PNG_HAVE_IHDR)) + png_error(png_ptr, "Missing IHDR before IDAT"); + + else if (png_ptr->color_type == PNG_COLOR_TYPE_PALETTE && + !(png_ptr->mode & PNG_HAVE_PLTE)) + png_error(png_ptr, "Missing PLTE before IDAT"); + + png_ptr->idat_size = length; + png_ptr->mode |= PNG_HAVE_IDAT; + break; + } + +#ifdef PNG_READ_bKGD_SUPPORTED + else if (!png_memcmp(chunk_name, png_bKGD, 4)) + png_handle_bKGD(png_ptr, info_ptr, length); +#endif + +#ifdef PNG_READ_cHRM_SUPPORTED + else if (!png_memcmp(chunk_name, png_cHRM, 4)) + png_handle_cHRM(png_ptr, info_ptr, length); +#endif + +#ifdef PNG_READ_gAMA_SUPPORTED + else if (!png_memcmp(chunk_name, png_gAMA, 4)) + png_handle_gAMA(png_ptr, info_ptr, length); +#endif + +#ifdef PNG_READ_hIST_SUPPORTED + else if (!png_memcmp(chunk_name, png_hIST, 4)) + png_handle_hIST(png_ptr, info_ptr, length); +#endif + +#ifdef PNG_READ_oFFs_SUPPORTED + else if (!png_memcmp(chunk_name, png_oFFs, 4)) + png_handle_oFFs(png_ptr, info_ptr, length); +#endif + +#ifdef PNG_READ_pCAL_SUPPORTED + else if (!png_memcmp(chunk_name, png_pCAL, 4)) + png_handle_pCAL(png_ptr, info_ptr, length); +#endif + +#ifdef PNG_READ_sCAL_SUPPORTED + else if (!png_memcmp(chunk_name, png_sCAL, 4)) + png_handle_sCAL(png_ptr, info_ptr, length); +#endif + +#ifdef PNG_READ_pHYs_SUPPORTED + else if (!png_memcmp(chunk_name, png_pHYs, 4)) + png_handle_pHYs(png_ptr, info_ptr, length); +#endif + +#ifdef PNG_READ_sBIT_SUPPORTED + else if (!png_memcmp(chunk_name, png_sBIT, 4)) + png_handle_sBIT(png_ptr, info_ptr, length); +#endif + +#ifdef PNG_READ_sRGB_SUPPORTED + else if (!png_memcmp(chunk_name, png_sRGB, 4)) + png_handle_sRGB(png_ptr, info_ptr, length); +#endif + +#ifdef PNG_READ_iCCP_SUPPORTED + else if (!png_memcmp(chunk_name, png_iCCP, 4)) + png_handle_iCCP(png_ptr, info_ptr, length); +#endif + +#ifdef PNG_READ_sPLT_SUPPORTED + else if (!png_memcmp(chunk_name, png_sPLT, 4)) + png_handle_sPLT(png_ptr, info_ptr, length); +#endif + +#ifdef PNG_READ_tEXt_SUPPORTED + else if (!png_memcmp(chunk_name, png_tEXt, 4)) + png_handle_tEXt(png_ptr, info_ptr, length); +#endif + +#ifdef PNG_READ_tIME_SUPPORTED + else if (!png_memcmp(chunk_name, png_tIME, 4)) + png_handle_tIME(png_ptr, info_ptr, length); +#endif + +#ifdef PNG_READ_tRNS_SUPPORTED + else if (!png_memcmp(chunk_name, png_tRNS, 4)) + png_handle_tRNS(png_ptr, info_ptr, length); +#endif + +#ifdef PNG_READ_zTXt_SUPPORTED + else if (!png_memcmp(chunk_name, png_zTXt, 4)) + png_handle_zTXt(png_ptr, info_ptr, length); +#endif + +#ifdef PNG_READ_iTXt_SUPPORTED + else if (!png_memcmp(chunk_name, png_iTXt, 4)) + png_handle_iTXt(png_ptr, info_ptr, length); +#endif + + else + png_handle_unknown(png_ptr, info_ptr, length); + } +} +#endif /* PNG_SEQUENTIAL_READ_SUPPORTED */ + +/* Optional call to update the users info_ptr structure */ +void PNGAPI +png_read_update_info(png_structp png_ptr, png_infop info_ptr) +{ + png_debug(1, "in png_read_update_info"); + + if (png_ptr == NULL) + return; + + if (!(png_ptr->flags & PNG_FLAG_ROW_INIT)) + png_read_start_row(png_ptr); + + else + png_warning(png_ptr, + "Ignoring extra png_read_update_info() call;" + " row buffer not reallocated"); + + png_read_transform_info(png_ptr, info_ptr); +} + +#ifdef PNG_SEQUENTIAL_READ_SUPPORTED +/* Initialize palette, background, etc, after transformations + * are set, but before any reading takes place. This allows + * the user to obtain a gamma-corrected palette, for example. + * If the user doesn't call this, we will do it ourselves. + */ +void PNGAPI +png_start_read_image(png_structp png_ptr) +{ + png_debug(1, "in png_start_read_image"); + + if (png_ptr == NULL) + return; + + if (!(png_ptr->flags & PNG_FLAG_ROW_INIT)) + png_read_start_row(png_ptr); + else + png_warning(png_ptr, + "Ignoring extra png_start_read_image() call;" + " row buffer not reallocated"); +} +#endif /* PNG_SEQUENTIAL_READ_SUPPORTED */ + +#ifdef PNG_SEQUENTIAL_READ_SUPPORTED +void PNGAPI +png_read_row(png_structp png_ptr, png_bytep row, png_bytep dsp_row) +{ + PNG_IDAT; + PNG_CONST int png_pass_dsp_mask[7] = {0xff, 0x0f, 0xff, 0x33, 0xff, 0x55, + 0xff}; + PNG_CONST int png_pass_mask[7] = {0x80, 0x08, 0x88, 0x22, 0xaa, 0x55, 0xff}; + int ret; + + if (png_ptr == NULL) + return; + + png_debug2(1, "in png_read_row (row %lu, pass %d)", + (unsigned long)png_ptr->row_number, png_ptr->pass); + + if (!(png_ptr->flags & PNG_FLAG_ROW_INIT)) + png_read_start_row(png_ptr); + + if (png_ptr->row_number == 0 && png_ptr->pass == 0) + { + /* Check for transforms that have been set but were defined out */ +#if defined(PNG_WRITE_INVERT_SUPPORTED) && !defined(PNG_READ_INVERT_SUPPORTED) + if (png_ptr->transformations & PNG_INVERT_MONO) + png_warning(png_ptr, "PNG_READ_INVERT_SUPPORTED is not defined"); +#endif + +#if defined(PNG_WRITE_FILLER_SUPPORTED) && !defined(PNG_READ_FILLER_SUPPORTED) + if (png_ptr->transformations & PNG_FILLER) + png_warning(png_ptr, "PNG_READ_FILLER_SUPPORTED is not defined"); +#endif + +#if defined(PNG_WRITE_PACKSWAP_SUPPORTED) && \ + !defined(PNG_READ_PACKSWAP_SUPPORTED) + if (png_ptr->transformations & PNG_PACKSWAP) + png_warning(png_ptr, "PNG_READ_PACKSWAP_SUPPORTED is not defined"); +#endif + +#if defined(PNG_WRITE_PACK_SUPPORTED) && !defined(PNG_READ_PACK_SUPPORTED) + if (png_ptr->transformations & PNG_PACK) + png_warning(png_ptr, "PNG_READ_PACK_SUPPORTED is not defined"); +#endif + +#if defined(PNG_WRITE_SHIFT_SUPPORTED) && !defined(PNG_READ_SHIFT_SUPPORTED) + if (png_ptr->transformations & PNG_SHIFT) + png_warning(png_ptr, "PNG_READ_SHIFT_SUPPORTED is not defined"); +#endif + +#if defined(PNG_WRITE_BGR_SUPPORTED) && !defined(PNG_READ_BGR_SUPPORTED) + if (png_ptr->transformations & PNG_BGR) + png_warning(png_ptr, "PNG_READ_BGR_SUPPORTED is not defined"); +#endif + +#if defined(PNG_WRITE_SWAP_SUPPORTED) && !defined(PNG_READ_SWAP_SUPPORTED) + if (png_ptr->transformations & PNG_SWAP_BYTES) + png_warning(png_ptr, "PNG_READ_SWAP_SUPPORTED is not defined"); +#endif + } + +#ifdef PNG_READ_INTERLACING_SUPPORTED + /* If interlaced and we do not need a new row, combine row and return */ + if (png_ptr->interlaced && (png_ptr->transformations & PNG_INTERLACE)) + { + switch (png_ptr->pass) + { + case 0: + if (png_ptr->row_number & 0x07) + { + if (dsp_row != NULL) + png_combine_row(png_ptr, dsp_row, + png_pass_dsp_mask[png_ptr->pass]); + png_read_finish_row(png_ptr); + return; + } + break; + + case 1: + if ((png_ptr->row_number & 0x07) || png_ptr->width < 5) + { + if (dsp_row != NULL) + png_combine_row(png_ptr, dsp_row, + png_pass_dsp_mask[png_ptr->pass]); + + png_read_finish_row(png_ptr); + return; + } + break; + + case 2: + if ((png_ptr->row_number & 0x07) != 4) + { + if (dsp_row != NULL && (png_ptr->row_number & 4)) + png_combine_row(png_ptr, dsp_row, + png_pass_dsp_mask[png_ptr->pass]); + + png_read_finish_row(png_ptr); + return; + } + break; + + case 3: + if ((png_ptr->row_number & 3) || png_ptr->width < 3) + { + if (dsp_row != NULL) + png_combine_row(png_ptr, dsp_row, + png_pass_dsp_mask[png_ptr->pass]); + + png_read_finish_row(png_ptr); + return; + } + break; + + case 4: + if ((png_ptr->row_number & 3) != 2) + { + if (dsp_row != NULL && (png_ptr->row_number & 2)) + png_combine_row(png_ptr, dsp_row, + png_pass_dsp_mask[png_ptr->pass]); + + png_read_finish_row(png_ptr); + return; + } + break; + case 5: + if ((png_ptr->row_number & 1) || png_ptr->width < 2) + { + if (dsp_row != NULL) + png_combine_row(png_ptr, dsp_row, + png_pass_dsp_mask[png_ptr->pass]); + + png_read_finish_row(png_ptr); + return; + } + break; + + default: + case 6: + if (!(png_ptr->row_number & 1)) + { + png_read_finish_row(png_ptr); + return; + } + break; + } + } +#endif + + if (!(png_ptr->mode & PNG_HAVE_IDAT)) + png_error(png_ptr, "Invalid attempt to read row data"); + + png_ptr->zstream.next_out = png_ptr->row_buf; + png_ptr->zstream.avail_out = + (uInt)(PNG_ROWBYTES(png_ptr->pixel_depth, + png_ptr->iwidth) + 1); + + do + { + if (!(png_ptr->zstream.avail_in)) + { + while (!png_ptr->idat_size) + { + png_crc_finish(png_ptr, 0); + + png_ptr->idat_size = png_read_chunk_header(png_ptr); + if (png_memcmp(png_ptr->chunk_name, png_IDAT, 4)) + png_error(png_ptr, "Not enough image data"); + } + png_ptr->zstream.avail_in = (uInt)png_ptr->zbuf_size; + png_ptr->zstream.next_in = png_ptr->zbuf; + if (png_ptr->zbuf_size > png_ptr->idat_size) + png_ptr->zstream.avail_in = (uInt)png_ptr->idat_size; + png_crc_read(png_ptr, png_ptr->zbuf, + (png_size_t)png_ptr->zstream.avail_in); + png_ptr->idat_size -= png_ptr->zstream.avail_in; + } + + ret = inflate(&png_ptr->zstream, Z_PARTIAL_FLUSH); + + if (ret == Z_STREAM_END) + { + if (png_ptr->zstream.avail_out || png_ptr->zstream.avail_in || + png_ptr->idat_size) + png_benign_error(png_ptr, "Extra compressed data"); + png_ptr->mode |= PNG_AFTER_IDAT; + png_ptr->flags |= PNG_FLAG_ZLIB_FINISHED; + break; + } + + if (ret != Z_OK) + png_error(png_ptr, png_ptr->zstream.msg ? png_ptr->zstream.msg : + "Decompression error"); + + } while (png_ptr->zstream.avail_out); + + png_ptr->row_info.color_type = png_ptr->color_type; + png_ptr->row_info.width = png_ptr->iwidth; + png_ptr->row_info.channels = png_ptr->channels; + png_ptr->row_info.bit_depth = png_ptr->bit_depth; + png_ptr->row_info.pixel_depth = png_ptr->pixel_depth; + png_ptr->row_info.rowbytes = PNG_ROWBYTES(png_ptr->row_info.pixel_depth, + png_ptr->row_info.width); + + if (png_ptr->row_buf[0]) + png_read_filter_row(png_ptr, &(png_ptr->row_info), + png_ptr->row_buf + 1, png_ptr->prev_row + 1, + (int)(png_ptr->row_buf[0])); + + png_memcpy(png_ptr->prev_row, png_ptr->row_buf, png_ptr->rowbytes + 1); + +#ifdef PNG_MNG_FEATURES_SUPPORTED + if ((png_ptr->mng_features_permitted & PNG_FLAG_MNG_FILTER_64) && + (png_ptr->filter_type == PNG_INTRAPIXEL_DIFFERENCING)) + { + /* Intrapixel differencing */ + png_do_read_intrapixel(&(png_ptr->row_info), png_ptr->row_buf + 1); + } +#endif + + + if (png_ptr->transformations || (png_ptr->flags&PNG_FLAG_STRIP_ALPHA)) + png_do_read_transformations(png_ptr); + +#ifdef PNG_READ_INTERLACING_SUPPORTED + /* Blow up interlaced rows to full size */ + if (png_ptr->interlaced && + (png_ptr->transformations & PNG_INTERLACE)) + { + if (png_ptr->pass < 6) + /* Old interface (pre-1.0.9): + * png_do_read_interlace(&(png_ptr->row_info), + * png_ptr->row_buf + 1, png_ptr->pass, png_ptr->transformations); + */ + png_do_read_interlace(png_ptr); + + if (dsp_row != NULL) + png_combine_row(png_ptr, dsp_row, png_pass_dsp_mask[png_ptr->pass]); + + if (row != NULL) + png_combine_row(png_ptr, row, png_pass_mask[png_ptr->pass]); + } + + else +#endif + { + if (row != NULL) + png_combine_row(png_ptr, row, 0xff); + + if (dsp_row != NULL) + png_combine_row(png_ptr, dsp_row, 0xff); + } + png_read_finish_row(png_ptr); + + if (png_ptr->read_row_fn != NULL) + (*(png_ptr->read_row_fn))(png_ptr, png_ptr->row_number, png_ptr->pass); +} +#endif /* PNG_SEQUENTIAL_READ_SUPPORTED */ + +#ifdef PNG_SEQUENTIAL_READ_SUPPORTED +/* Read one or more rows of image data. If the image is interlaced, + * and png_set_interlace_handling() has been called, the rows need to + * contain the contents of the rows from the previous pass. If the + * image has alpha or transparency, and png_handle_alpha()[*] has been + * called, the rows contents must be initialized to the contents of the + * screen. + * + * "row" holds the actual image, and pixels are placed in it + * as they arrive. If the image is displayed after each pass, it will + * appear to "sparkle" in. "display_row" can be used to display a + * "chunky" progressive image, with finer detail added as it becomes + * available. If you do not want this "chunky" display, you may pass + * NULL for display_row. If you do not want the sparkle display, and + * you have not called png_handle_alpha(), you may pass NULL for rows. + * If you have called png_handle_alpha(), and the image has either an + * alpha channel or a transparency chunk, you must provide a buffer for + * rows. In this case, you do not have to provide a display_row buffer + * also, but you may. If the image is not interlaced, or if you have + * not called png_set_interlace_handling(), the display_row buffer will + * be ignored, so pass NULL to it. + * + * [*] png_handle_alpha() does not exist yet, as of this version of libpng + */ + +void PNGAPI +png_read_rows(png_structp png_ptr, png_bytepp row, + png_bytepp display_row, png_uint_32 num_rows) +{ + png_uint_32 i; + png_bytepp rp; + png_bytepp dp; + + png_debug(1, "in png_read_rows"); + + if (png_ptr == NULL) + return; + + rp = row; + dp = display_row; + if (rp != NULL && dp != NULL) + for (i = 0; i < num_rows; i++) + { + png_bytep rptr = *rp++; + png_bytep dptr = *dp++; + + png_read_row(png_ptr, rptr, dptr); + } + + else if (rp != NULL) + for (i = 0; i < num_rows; i++) + { + png_bytep rptr = *rp; + png_read_row(png_ptr, rptr, NULL); + rp++; + } + + else if (dp != NULL) + for (i = 0; i < num_rows; i++) + { + png_bytep dptr = *dp; + png_read_row(png_ptr, NULL, dptr); + dp++; + } +} +#endif /* PNG_SEQUENTIAL_READ_SUPPORTED */ + +#ifdef PNG_SEQUENTIAL_READ_SUPPORTED +/* Read the entire image. If the image has an alpha channel or a tRNS + * chunk, and you have called png_handle_alpha()[*], you will need to + * initialize the image to the current image that PNG will be overlaying. + * We set the num_rows again here, in case it was incorrectly set in + * png_read_start_row() by a call to png_read_update_info() or + * png_start_read_image() if png_set_interlace_handling() wasn't called + * prior to either of these functions like it should have been. You can + * only call this function once. If you desire to have an image for + * each pass of a interlaced image, use png_read_rows() instead. + * + * [*] png_handle_alpha() does not exist yet, as of this version of libpng + */ +void PNGAPI +png_read_image(png_structp png_ptr, png_bytepp image) +{ + png_uint_32 i, image_height; + int pass, j; + png_bytepp rp; + + png_debug(1, "in png_read_image"); + + if (png_ptr == NULL) + return; + +#ifdef PNG_READ_INTERLACING_SUPPORTED + if (!(png_ptr->flags & PNG_FLAG_ROW_INIT)) + { + pass = png_set_interlace_handling(png_ptr); + /* And make sure transforms are initialized. */ + png_start_read_image(png_ptr); + } + else + { + if (png_ptr->interlaced && !(png_ptr->transformations & PNG_INTERLACE)) + { + /* Caller called png_start_read_image or png_read_update_info without + * first turning on the PNG_INTERLACE transform. We can fix this here, + * but the caller should do it! + */ + png_warning(png_ptr, "Interlace handling should be turned on when " + "using png_read_image"); + /* Make sure this is set correctly */ + png_ptr->num_rows = png_ptr->height; + } + + /* Obtain the pass number, which also turns on the PNG_INTERLACE flag in + * the above error case. + */ + pass = png_set_interlace_handling(png_ptr); + } +#else + if (png_ptr->interlaced) + png_error(png_ptr, + "Cannot read interlaced image -- interlace handler disabled"); + + pass = 1; +#endif + + image_height=png_ptr->height; + + for (j = 0; j < pass; j++) + { + rp = image; + for (i = 0; i < image_height; i++) + { + png_read_row(png_ptr, *rp, NULL); + rp++; + } + } +} +#endif /* PNG_SEQUENTIAL_READ_SUPPORTED */ + +#ifdef PNG_SEQUENTIAL_READ_SUPPORTED +/* Read the end of the PNG file. Will not read past the end of the + * file, will verify the end is accurate, and will read any comments + * or time information at the end of the file, if info is not NULL. + */ +void PNGAPI +png_read_end(png_structp png_ptr, png_infop info_ptr) +{ + png_debug(1, "in png_read_end"); + + if (png_ptr == NULL) + return; + + png_crc_finish(png_ptr, 0); /* Finish off CRC from last IDAT chunk */ + + do + { + PNG_IHDR; + PNG_IDAT; + PNG_IEND; + PNG_PLTE; +#ifdef PNG_READ_bKGD_SUPPORTED + PNG_bKGD; +#endif +#ifdef PNG_READ_cHRM_SUPPORTED + PNG_cHRM; +#endif +#ifdef PNG_READ_gAMA_SUPPORTED + PNG_gAMA; +#endif +#ifdef PNG_READ_hIST_SUPPORTED + PNG_hIST; +#endif +#ifdef PNG_READ_iCCP_SUPPORTED + PNG_iCCP; +#endif +#ifdef PNG_READ_iTXt_SUPPORTED + PNG_iTXt; +#endif +#ifdef PNG_READ_oFFs_SUPPORTED + PNG_oFFs; +#endif +#ifdef PNG_READ_pCAL_SUPPORTED + PNG_pCAL; +#endif +#ifdef PNG_READ_pHYs_SUPPORTED + PNG_pHYs; +#endif +#ifdef PNG_READ_sBIT_SUPPORTED + PNG_sBIT; +#endif +#ifdef PNG_READ_sCAL_SUPPORTED + PNG_sCAL; +#endif +#ifdef PNG_READ_sPLT_SUPPORTED + PNG_sPLT; +#endif +#ifdef PNG_READ_sRGB_SUPPORTED + PNG_sRGB; +#endif +#ifdef PNG_READ_tEXt_SUPPORTED + PNG_tEXt; +#endif +#ifdef PNG_READ_tIME_SUPPORTED + PNG_tIME; +#endif +#ifdef PNG_READ_tRNS_SUPPORTED + PNG_tRNS; +#endif +#ifdef PNG_READ_zTXt_SUPPORTED + PNG_zTXt; +#endif + png_uint_32 length = png_read_chunk_header(png_ptr); + PNG_CONST png_bytep chunk_name = png_ptr->chunk_name; + + if (!png_memcmp(chunk_name, png_IHDR, 4)) + png_handle_IHDR(png_ptr, info_ptr, length); + + else if (!png_memcmp(chunk_name, png_IEND, 4)) + png_handle_IEND(png_ptr, info_ptr, length); + +#ifdef PNG_HANDLE_AS_UNKNOWN_SUPPORTED + else if (png_handle_as_unknown(png_ptr, chunk_name)) + { + if (!png_memcmp(chunk_name, png_IDAT, 4)) + { + if ((length > 0) || (png_ptr->mode & PNG_HAVE_CHUNK_AFTER_IDAT)) + png_benign_error(png_ptr, "Too many IDATs found"); + } + png_handle_unknown(png_ptr, info_ptr, length); + if (!png_memcmp(chunk_name, png_PLTE, 4)) + png_ptr->mode |= PNG_HAVE_PLTE; + } +#endif + + else if (!png_memcmp(chunk_name, png_IDAT, 4)) + { + /* Zero length IDATs are legal after the last IDAT has been + * read, but not after other chunks have been read. + */ + if ((length > 0) || (png_ptr->mode & PNG_HAVE_CHUNK_AFTER_IDAT)) + png_benign_error(png_ptr, "Too many IDATs found"); + + png_crc_finish(png_ptr, length); + } + else if (!png_memcmp(chunk_name, png_PLTE, 4)) + png_handle_PLTE(png_ptr, info_ptr, length); + +#ifdef PNG_READ_bKGD_SUPPORTED + else if (!png_memcmp(chunk_name, png_bKGD, 4)) + png_handle_bKGD(png_ptr, info_ptr, length); +#endif + +#ifdef PNG_READ_cHRM_SUPPORTED + else if (!png_memcmp(chunk_name, png_cHRM, 4)) + png_handle_cHRM(png_ptr, info_ptr, length); +#endif + +#ifdef PNG_READ_gAMA_SUPPORTED + else if (!png_memcmp(chunk_name, png_gAMA, 4)) + png_handle_gAMA(png_ptr, info_ptr, length); +#endif + +#ifdef PNG_READ_hIST_SUPPORTED + else if (!png_memcmp(chunk_name, png_hIST, 4)) + png_handle_hIST(png_ptr, info_ptr, length); +#endif + +#ifdef PNG_READ_oFFs_SUPPORTED + else if (!png_memcmp(chunk_name, png_oFFs, 4)) + png_handle_oFFs(png_ptr, info_ptr, length); +#endif + +#ifdef PNG_READ_pCAL_SUPPORTED + else if (!png_memcmp(chunk_name, png_pCAL, 4)) + png_handle_pCAL(png_ptr, info_ptr, length); +#endif + +#ifdef PNG_READ_sCAL_SUPPORTED + else if (!png_memcmp(chunk_name, png_sCAL, 4)) + png_handle_sCAL(png_ptr, info_ptr, length); +#endif + +#ifdef PNG_READ_pHYs_SUPPORTED + else if (!png_memcmp(chunk_name, png_pHYs, 4)) + png_handle_pHYs(png_ptr, info_ptr, length); +#endif + +#ifdef PNG_READ_sBIT_SUPPORTED + else if (!png_memcmp(chunk_name, png_sBIT, 4)) + png_handle_sBIT(png_ptr, info_ptr, length); +#endif + +#ifdef PNG_READ_sRGB_SUPPORTED + else if (!png_memcmp(chunk_name, png_sRGB, 4)) + png_handle_sRGB(png_ptr, info_ptr, length); +#endif + +#ifdef PNG_READ_iCCP_SUPPORTED + else if (!png_memcmp(chunk_name, png_iCCP, 4)) + png_handle_iCCP(png_ptr, info_ptr, length); +#endif + +#ifdef PNG_READ_sPLT_SUPPORTED + else if (!png_memcmp(chunk_name, png_sPLT, 4)) + png_handle_sPLT(png_ptr, info_ptr, length); +#endif + +#ifdef PNG_READ_tEXt_SUPPORTED + else if (!png_memcmp(chunk_name, png_tEXt, 4)) + png_handle_tEXt(png_ptr, info_ptr, length); +#endif + +#ifdef PNG_READ_tIME_SUPPORTED + else if (!png_memcmp(chunk_name, png_tIME, 4)) + png_handle_tIME(png_ptr, info_ptr, length); +#endif + +#ifdef PNG_READ_tRNS_SUPPORTED + else if (!png_memcmp(chunk_name, png_tRNS, 4)) + png_handle_tRNS(png_ptr, info_ptr, length); +#endif + +#ifdef PNG_READ_zTXt_SUPPORTED + else if (!png_memcmp(chunk_name, png_zTXt, 4)) + png_handle_zTXt(png_ptr, info_ptr, length); +#endif + +#ifdef PNG_READ_iTXt_SUPPORTED + else if (!png_memcmp(chunk_name, png_iTXt, 4)) + png_handle_iTXt(png_ptr, info_ptr, length); +#endif + + else + png_handle_unknown(png_ptr, info_ptr, length); + } while (!(png_ptr->mode & PNG_HAVE_IEND)); +} +#endif /* PNG_SEQUENTIAL_READ_SUPPORTED */ + +/* Free all memory used by the read */ +void PNGAPI +png_destroy_read_struct(png_structpp png_ptr_ptr, png_infopp info_ptr_ptr, + png_infopp end_info_ptr_ptr) +{ + png_structp png_ptr = NULL; + png_infop info_ptr = NULL, end_info_ptr = NULL; +#ifdef PNG_USER_MEM_SUPPORTED + png_free_ptr free_fn = NULL; + png_voidp mem_ptr = NULL; +#endif + + png_debug(1, "in png_destroy_read_struct"); + + if (png_ptr_ptr != NULL) + png_ptr = *png_ptr_ptr; + if (png_ptr == NULL) + return; + +#ifdef PNG_USER_MEM_SUPPORTED + free_fn = png_ptr->free_fn; + mem_ptr = png_ptr->mem_ptr; +#endif + + if (info_ptr_ptr != NULL) + info_ptr = *info_ptr_ptr; + + if (end_info_ptr_ptr != NULL) + end_info_ptr = *end_info_ptr_ptr; + + png_read_destroy(png_ptr, info_ptr, end_info_ptr); + + if (info_ptr != NULL) + { +#ifdef PNG_TEXT_SUPPORTED + png_free_data(png_ptr, info_ptr, PNG_FREE_TEXT, -1); +#endif + +#ifdef PNG_USER_MEM_SUPPORTED + png_destroy_struct_2((png_voidp)info_ptr, (png_free_ptr)free_fn, + (png_voidp)mem_ptr); +#else + png_destroy_struct((png_voidp)info_ptr); +#endif + *info_ptr_ptr = NULL; + } + + if (end_info_ptr != NULL) + { +#ifdef PNG_READ_TEXT_SUPPORTED + png_free_data(png_ptr, end_info_ptr, PNG_FREE_TEXT, -1); +#endif +#ifdef PNG_USER_MEM_SUPPORTED + png_destroy_struct_2((png_voidp)end_info_ptr, (png_free_ptr)free_fn, + (png_voidp)mem_ptr); +#else + png_destroy_struct((png_voidp)end_info_ptr); +#endif + *end_info_ptr_ptr = NULL; + } + + if (png_ptr != NULL) + { +#ifdef PNG_USER_MEM_SUPPORTED + png_destroy_struct_2((png_voidp)png_ptr, (png_free_ptr)free_fn, + (png_voidp)mem_ptr); +#else + png_destroy_struct((png_voidp)png_ptr); +#endif + *png_ptr_ptr = NULL; + } +} + +/* Free all memory used by the read (old method) */ +void /* PRIVATE */ +png_read_destroy(png_structp png_ptr, png_infop info_ptr, + png_infop end_info_ptr) +{ +#ifdef PNG_SETJMP_SUPPORTED + jmp_buf tmp_jmp; +#endif + png_error_ptr error_fn; + png_error_ptr warning_fn; + png_voidp error_ptr; +#ifdef PNG_USER_MEM_SUPPORTED + png_free_ptr free_fn; +#endif + + png_debug(1, "in png_read_destroy"); + + if (info_ptr != NULL) + png_info_destroy(png_ptr, info_ptr); + + if (end_info_ptr != NULL) + png_info_destroy(png_ptr, end_info_ptr); + + png_free(png_ptr, png_ptr->zbuf); + png_free(png_ptr, png_ptr->big_row_buf); + png_free(png_ptr, png_ptr->prev_row); + png_free(png_ptr, png_ptr->chunkdata); + +#ifdef PNG_READ_QUANTIZE_SUPPORTED + png_free(png_ptr, png_ptr->palette_lookup); + png_free(png_ptr, png_ptr->quantize_index); +#endif + +#ifdef PNG_READ_GAMMA_SUPPORTED + png_free(png_ptr, png_ptr->gamma_table); +#endif + +#ifdef PNG_READ_BACKGROUND_SUPPORTED + png_free(png_ptr, png_ptr->gamma_from_1); + png_free(png_ptr, png_ptr->gamma_to_1); +#endif + + if (png_ptr->free_me & PNG_FREE_PLTE) + png_zfree(png_ptr, png_ptr->palette); + png_ptr->free_me &= ~PNG_FREE_PLTE; + +#if defined(PNG_tRNS_SUPPORTED) || \ + defined(PNG_READ_EXPAND_SUPPORTED) || defined(PNG_READ_BACKGROUND_SUPPORTED) + if (png_ptr->free_me & PNG_FREE_TRNS) + png_free(png_ptr, png_ptr->trans_alpha); + png_ptr->free_me &= ~PNG_FREE_TRNS; +#endif + +#ifdef PNG_READ_hIST_SUPPORTED + if (png_ptr->free_me & PNG_FREE_HIST) + png_free(png_ptr, png_ptr->hist); + png_ptr->free_me &= ~PNG_FREE_HIST; +#endif + +#ifdef PNG_READ_GAMMA_SUPPORTED + if (png_ptr->gamma_16_table != NULL) + { + int i; + int istop = (1 << (8 - png_ptr->gamma_shift)); + for (i = 0; i < istop; i++) + { + png_free(png_ptr, png_ptr->gamma_16_table[i]); + } + png_free(png_ptr, png_ptr->gamma_16_table); + } + +#ifdef PNG_READ_BACKGROUND_SUPPORTED + if (png_ptr->gamma_16_from_1 != NULL) + { + int i; + int istop = (1 << (8 - png_ptr->gamma_shift)); + for (i = 0; i < istop; i++) + { + png_free(png_ptr, png_ptr->gamma_16_from_1[i]); + } + png_free(png_ptr, png_ptr->gamma_16_from_1); + } + if (png_ptr->gamma_16_to_1 != NULL) + { + int i; + int istop = (1 << (8 - png_ptr->gamma_shift)); + for (i = 0; i < istop; i++) + { + png_free(png_ptr, png_ptr->gamma_16_to_1[i]); + } + png_free(png_ptr, png_ptr->gamma_16_to_1); + } +#endif +#endif + +#ifdef PNG_TIME_RFC1123_SUPPORTED + png_free(png_ptr, png_ptr->time_buffer); +#endif + + inflateEnd(&png_ptr->zstream); + +#ifdef PNG_PROGRESSIVE_READ_SUPPORTED + png_free(png_ptr, png_ptr->save_buffer); +#endif + +#ifdef PNG_PROGRESSIVE_READ_SUPPORTED +#ifdef PNG_TEXT_SUPPORTED + png_free(png_ptr, png_ptr->current_text); +#endif /* PNG_TEXT_SUPPORTED */ +#endif /* PNG_PROGRESSIVE_READ_SUPPORTED */ + + /* Save the important info out of the png_struct, in case it is + * being used again. + */ +#ifdef PNG_SETJMP_SUPPORTED + png_memcpy(tmp_jmp, png_ptr->png_jmpbuf, png_sizeof(jmp_buf)); +#endif + + error_fn = png_ptr->error_fn; + warning_fn = png_ptr->warning_fn; + error_ptr = png_ptr->error_ptr; +#ifdef PNG_USER_MEM_SUPPORTED + free_fn = png_ptr->free_fn; +#endif + + png_memset(png_ptr, 0, png_sizeof(png_struct)); + + png_ptr->error_fn = error_fn; + png_ptr->warning_fn = warning_fn; + png_ptr->error_ptr = error_ptr; +#ifdef PNG_USER_MEM_SUPPORTED + png_ptr->free_fn = free_fn; +#endif + +#ifdef PNG_SETJMP_SUPPORTED + png_memcpy(png_ptr->png_jmpbuf, tmp_jmp, png_sizeof(jmp_buf)); +#endif + +} + +void PNGAPI +png_set_read_status_fn(png_structp png_ptr, png_read_status_ptr read_row_fn) +{ + if (png_ptr == NULL) + return; + + png_ptr->read_row_fn = read_row_fn; +} + + +#ifdef PNG_SEQUENTIAL_READ_SUPPORTED +#ifdef PNG_INFO_IMAGE_SUPPORTED +void PNGAPI +png_read_png(png_structp png_ptr, png_infop info_ptr, + int transforms, + voidp params) +{ + int row; + + if (png_ptr == NULL) + return; + + /* png_read_info() gives us all of the information from the + * PNG file before the first IDAT (image data chunk). + */ + png_read_info(png_ptr, info_ptr); + if (info_ptr->height > PNG_UINT_32_MAX/png_sizeof(png_bytep)) + png_error(png_ptr, "Image is too high to process with png_read_png()"); + + /* -------------- image transformations start here ------------------- */ + +#ifdef PNG_READ_16_TO_8_SUPPORTED + /* Tell libpng to strip 16 bit/color files down to 8 bits per color. + */ + if (transforms & PNG_TRANSFORM_STRIP_16) + png_set_strip_16(png_ptr); +#endif + +#ifdef PNG_READ_STRIP_ALPHA_SUPPORTED + /* Strip alpha bytes from the input data without combining with + * the background (not recommended). + */ + if (transforms & PNG_TRANSFORM_STRIP_ALPHA) + png_set_strip_alpha(png_ptr); +#endif + +#if defined(PNG_READ_PACK_SUPPORTED) && !defined(PNG_READ_EXPAND_SUPPORTED) + /* Extract multiple pixels with bit depths of 1, 2, or 4 from a single + * byte into separate bytes (useful for paletted and grayscale images). + */ + if (transforms & PNG_TRANSFORM_PACKING) + png_set_packing(png_ptr); +#endif + +#ifdef PNG_READ_PACKSWAP_SUPPORTED + /* Change the order of packed pixels to least significant bit first + * (not useful if you are using png_set_packing). + */ + if (transforms & PNG_TRANSFORM_PACKSWAP) + png_set_packswap(png_ptr); +#endif + +#ifdef PNG_READ_EXPAND_SUPPORTED + /* Expand paletted colors into true RGB triplets + * Expand grayscale images to full 8 bits from 1, 2, or 4 bits/pixel + * Expand paletted or RGB images with transparency to full alpha + * channels so the data will be available as RGBA quartets. + */ + if (transforms & PNG_TRANSFORM_EXPAND) + if ((png_ptr->bit_depth < 8) || + (png_ptr->color_type == PNG_COLOR_TYPE_PALETTE) || + (png_get_valid(png_ptr, info_ptr, PNG_INFO_tRNS))) + png_set_expand(png_ptr); +#endif + + /* We don't handle background color or gamma transformation or quantizing. + */ + +#ifdef PNG_READ_INVERT_SUPPORTED + /* Invert monochrome files to have 0 as white and 1 as black + */ + if (transforms & PNG_TRANSFORM_INVERT_MONO) + png_set_invert_mono(png_ptr); +#endif + +#ifdef PNG_READ_SHIFT_SUPPORTED + /* If you want to shift the pixel values from the range [0,255] or + * [0,65535] to the original [0,7] or [0,31], or whatever range the + * colors were originally in: + */ + if ((transforms & PNG_TRANSFORM_SHIFT) + && png_get_valid(png_ptr, info_ptr, PNG_INFO_sBIT)) + { + png_color_8p sig_bit; + + png_get_sBIT(png_ptr, info_ptr, &sig_bit); + png_set_shift(png_ptr, sig_bit); + } +#endif + +#ifdef PNG_READ_BGR_SUPPORTED + /* Flip the RGB pixels to BGR (or RGBA to BGRA) */ + if (transforms & PNG_TRANSFORM_BGR) + png_set_bgr(png_ptr); +#endif + +#ifdef PNG_READ_SWAP_ALPHA_SUPPORTED + /* Swap the RGBA or GA data to ARGB or AG (or BGRA to ABGR) */ + if (transforms & PNG_TRANSFORM_SWAP_ALPHA) + png_set_swap_alpha(png_ptr); +#endif + +#ifdef PNG_READ_SWAP_SUPPORTED + /* Swap bytes of 16 bit files to least significant byte first */ + if (transforms & PNG_TRANSFORM_SWAP_ENDIAN) + png_set_swap(png_ptr); +#endif + +/* Added at libpng-1.2.41 */ +#ifdef PNG_READ_INVERT_ALPHA_SUPPORTED + /* Invert the alpha channel from opacity to transparency */ + if (transforms & PNG_TRANSFORM_INVERT_ALPHA) + png_set_invert_alpha(png_ptr); +#endif + +/* Added at libpng-1.2.41 */ +#ifdef PNG_READ_GRAY_TO_RGB_SUPPORTED + /* Expand grayscale image to RGB */ + if (transforms & PNG_TRANSFORM_GRAY_TO_RGB) + png_set_gray_to_rgb(png_ptr); +#endif + + /* We don't handle adding filler bytes */ + + /* Optional call to gamma correct and add the background to the palette + * and update info structure. REQUIRED if you are expecting libpng to + * update the palette for you (i.e., you selected such a transform above). + */ + png_read_update_info(png_ptr, info_ptr); + + /* -------------- image transformations end here ------------------- */ + + png_free_data(png_ptr, info_ptr, PNG_FREE_ROWS, 0); + if (info_ptr->row_pointers == NULL) + { + png_uint_32 iptr; + + info_ptr->row_pointers = (png_bytepp)png_malloc(png_ptr, + info_ptr->height * png_sizeof(png_bytep)); + for (iptr=0; iptr<info_ptr->height; iptr++) + info_ptr->row_pointers[iptr] = NULL; + + info_ptr->free_me |= PNG_FREE_ROWS; + + for (row = 0; row < (int)info_ptr->height; row++) + info_ptr->row_pointers[row] = (png_bytep)png_malloc(png_ptr, + png_get_rowbytes(png_ptr, info_ptr)); + } + + png_read_image(png_ptr, info_ptr->row_pointers); + info_ptr->valid |= PNG_INFO_IDAT; + + /* Read rest of file, and get additional chunks in info_ptr - REQUIRED */ + png_read_end(png_ptr, info_ptr); + + PNG_UNUSED(transforms) /* Quiet compiler warnings */ + PNG_UNUSED(params) + +} +#endif /* PNG_INFO_IMAGE_SUPPORTED */ +#endif /* PNG_SEQUENTIAL_READ_SUPPORTED */ +#endif /* PNG_READ_SUPPORTED */ diff --git a/src/3rdparty/libpng/pngrio.c b/src/3rdparty/libpng/pngrio.c new file mode 100644 index 0000000000..e9c381c5ba --- /dev/null +++ b/src/3rdparty/libpng/pngrio.c @@ -0,0 +1,176 @@ + +/* pngrio.c - functions for data input + * + * Last changed in libpng 1.5.0 [January 6, 2011] + * Copyright (c) 1998-2011 Glenn Randers-Pehrson + * (Version 0.96 Copyright (c) 1996, 1997 Andreas Dilger) + * (Version 0.88 Copyright (c) 1995, 1996 Guy Eric Schalnat, Group 42, Inc.) + * + * This code is released under the libpng license. + * For conditions of distribution and use, see the disclaimer + * and license in png.h + * + * This file provides a location for all input. Users who need + * special handling are expected to write a function that has the same + * arguments as this and performs a similar function, but that possibly + * has a different input method. Note that you shouldn't change this + * function, but rather write a replacement function and then make + * libpng use it at run time with png_set_read_fn(...). + */ + +#include "pngpriv.h" + +#ifdef PNG_READ_SUPPORTED + +/* Read the data from whatever input you are using. The default routine + * reads from a file pointer. Note that this routine sometimes gets called + * with very small lengths, so you should implement some kind of simple + * buffering if you are using unbuffered reads. This should never be asked + * to read more then 64K on a 16 bit machine. + */ +void /* PRIVATE */ +png_read_data(png_structp png_ptr, png_bytep data, png_size_t length) +{ + png_debug1(4, "reading %d bytes", (int)length); + + if (png_ptr->read_data_fn != NULL) + (*(png_ptr->read_data_fn))(png_ptr, data, length); + + else + png_error(png_ptr, "Call to NULL read function"); +} + +#ifdef PNG_STDIO_SUPPORTED +/* This is the function that does the actual reading of data. If you are + * not reading from a standard C stream, you should create a replacement + * read_data function and use it at run time with png_set_read_fn(), rather + * than changing the library. + */ +# ifndef USE_FAR_KEYWORD +void PNGCBAPI +png_default_read_data(png_structp png_ptr, png_bytep data, png_size_t length) +{ + png_size_t check; + + if (png_ptr == NULL) + return; + + /* fread() returns 0 on error, so it is OK to store this in a png_size_t + * instead of an int, which is what fread() actually returns. + */ + check = fread(data, 1, length, (png_FILE_p)png_ptr->io_ptr); + + if (check != length) + png_error(png_ptr, "Read Error"); +} +# else +/* This is the model-independent version. Since the standard I/O library + can't handle far buffers in the medium and small models, we have to copy + the data. +*/ + +#define NEAR_BUF_SIZE 1024 +#define MIN(a,b) (a <= b ? a : b) + +static void PNGCBAPI +png_default_read_data(png_structp png_ptr, png_bytep data, png_size_t length) +{ + png_size_t check; + png_byte *n_data; + png_FILE_p io_ptr; + + if (png_ptr == NULL) + return; + + /* Check if data really is near. If so, use usual code. */ + n_data = (png_byte *)CVT_PTR_NOCHECK(data); + io_ptr = (png_FILE_p)CVT_PTR(png_ptr->io_ptr); + + if ((png_bytep)n_data == data) + { + check = fread(n_data, 1, length, io_ptr); + } + + else + { + png_byte buf[NEAR_BUF_SIZE]; + png_size_t read, remaining, err; + check = 0; + remaining = length; + + do + { + read = MIN(NEAR_BUF_SIZE, remaining); + err = fread(buf, 1, read, io_ptr); + png_memcpy(data, buf, read); /* copy far buffer to near buffer */ + + if (err != read) + break; + + else + check += err; + + data += read; + remaining -= read; + } + while (remaining != 0); + } + + if ((png_uint_32)check != (png_uint_32)length) + png_error(png_ptr, "read Error"); +} +# endif +#endif + +/* This function allows the application to supply a new input function + * for libpng if standard C streams aren't being used. + * + * This function takes as its arguments: + * + * png_ptr - pointer to a png input data structure + * + * io_ptr - pointer to user supplied structure containing info about + * the input functions. May be NULL. + * + * read_data_fn - pointer to a new input function that takes as its + * arguments a pointer to a png_struct, a pointer to + * a location where input data can be stored, and a 32-bit + * unsigned int that is the number of bytes to be read. + * To exit and output any fatal error messages the new write + * function should call png_error(png_ptr, "Error msg"). + * May be NULL, in which case libpng's default function will + * be used. + */ +void PNGAPI +png_set_read_fn(png_structp png_ptr, png_voidp io_ptr, + png_rw_ptr read_data_fn) +{ + if (png_ptr == NULL) + return; + + png_ptr->io_ptr = io_ptr; + +#ifdef PNG_STDIO_SUPPORTED + if (read_data_fn != NULL) + png_ptr->read_data_fn = read_data_fn; + + else + png_ptr->read_data_fn = png_default_read_data; +#else + png_ptr->read_data_fn = read_data_fn; +#endif + + /* It is an error to write to a read device */ + if (png_ptr->write_data_fn != NULL) + { + png_ptr->write_data_fn = NULL; + png_warning(png_ptr, + "Can't set both read_data_fn and write_data_fn in the" + " same structure"); + } + +#ifdef PNG_WRITE_FLUSH_SUPPORTED + png_ptr->output_flush_fn = NULL; +#endif +} +#endif /* PNG_READ_SUPPORTED */ diff --git a/src/3rdparty/libpng/pngrtran.c b/src/3rdparty/libpng/pngrtran.c new file mode 100644 index 0000000000..e6e0c46b4d --- /dev/null +++ b/src/3rdparty/libpng/pngrtran.c @@ -0,0 +1,4224 @@ + +/* pngrtran.c - transforms the data in a row for PNG readers + * + * Last changed in libpng 1.5.1 [February 3, 2011] + * Copyright (c) 1998-2011 Glenn Randers-Pehrson + * (Version 0.96 Copyright (c) 1996, 1997 Andreas Dilger) + * (Version 0.88 Copyright (c) 1995, 1996 Guy Eric Schalnat, Group 42, Inc.) + * + * This code is released under the libpng license. + * For conditions of distribution and use, see the disclaimer + * and license in png.h + * + * This file contains functions optionally called by an application + * in order to tell libpng how to handle data when reading a PNG. + * Transformations that are used in both reading and writing are + * in pngtrans.c. + */ + +#include "pngpriv.h" + +#ifdef PNG_READ_SUPPORTED + +/* Set the action on getting a CRC error for an ancillary or critical chunk. */ +void PNGAPI +png_set_crc_action(png_structp png_ptr, int crit_action, int ancil_action) +{ + png_debug(1, "in png_set_crc_action"); + + if (png_ptr == NULL) + return; + + /* Tell libpng how we react to CRC errors in critical chunks */ + switch (crit_action) + { + case PNG_CRC_NO_CHANGE: /* Leave setting as is */ + break; + + case PNG_CRC_WARN_USE: /* Warn/use data */ + png_ptr->flags &= ~PNG_FLAG_CRC_CRITICAL_MASK; + png_ptr->flags |= PNG_FLAG_CRC_CRITICAL_USE; + break; + + case PNG_CRC_QUIET_USE: /* Quiet/use data */ + png_ptr->flags &= ~PNG_FLAG_CRC_CRITICAL_MASK; + png_ptr->flags |= PNG_FLAG_CRC_CRITICAL_USE | + PNG_FLAG_CRC_CRITICAL_IGNORE; + break; + + case PNG_CRC_WARN_DISCARD: /* Not a valid action for critical data */ + png_warning(png_ptr, + "Can't discard critical data on CRC error"); + case PNG_CRC_ERROR_QUIT: /* Error/quit */ + + case PNG_CRC_DEFAULT: + default: + png_ptr->flags &= ~PNG_FLAG_CRC_CRITICAL_MASK; + break; + } + + /* Tell libpng how we react to CRC errors in ancillary chunks */ + switch (ancil_action) + { + case PNG_CRC_NO_CHANGE: /* Leave setting as is */ + break; + + case PNG_CRC_WARN_USE: /* Warn/use data */ + png_ptr->flags &= ~PNG_FLAG_CRC_ANCILLARY_MASK; + png_ptr->flags |= PNG_FLAG_CRC_ANCILLARY_USE; + break; + + case PNG_CRC_QUIET_USE: /* Quiet/use data */ + png_ptr->flags &= ~PNG_FLAG_CRC_ANCILLARY_MASK; + png_ptr->flags |= PNG_FLAG_CRC_ANCILLARY_USE | + PNG_FLAG_CRC_ANCILLARY_NOWARN; + break; + + case PNG_CRC_ERROR_QUIT: /* Error/quit */ + png_ptr->flags &= ~PNG_FLAG_CRC_ANCILLARY_MASK; + png_ptr->flags |= PNG_FLAG_CRC_ANCILLARY_NOWARN; + break; + + case PNG_CRC_WARN_DISCARD: /* Warn/discard data */ + + case PNG_CRC_DEFAULT: + default: + png_ptr->flags &= ~PNG_FLAG_CRC_ANCILLARY_MASK; + break; + } +} + +#ifdef PNG_READ_BACKGROUND_SUPPORTED +/* Handle alpha and tRNS via a background color */ +void PNGFAPI +png_set_background_fixed(png_structp png_ptr, + png_const_color_16p background_color, int background_gamma_code, + int need_expand, png_fixed_point background_gamma) +{ + png_debug(1, "in png_set_background_fixed"); + + if (png_ptr == NULL) + return; + + if (background_gamma_code == PNG_BACKGROUND_GAMMA_UNKNOWN) + { + png_warning(png_ptr, "Application must supply a known background gamma"); + return; + } + + png_ptr->transformations |= PNG_BACKGROUND; + png_memcpy(&(png_ptr->background), background_color, + png_sizeof(png_color_16)); + png_ptr->background_gamma = background_gamma; + png_ptr->background_gamma_type = (png_byte)(background_gamma_code); + png_ptr->transformations |= (need_expand ? PNG_BACKGROUND_EXPAND : 0); +} + +# ifdef PNG_FLOATING_POINT_SUPPORTED +void PNGAPI +png_set_background(png_structp png_ptr, + png_const_color_16p background_color, int background_gamma_code, + int need_expand, double background_gamma) +{ + png_set_background_fixed(png_ptr, background_color, background_gamma_code, + need_expand, png_fixed(png_ptr, background_gamma, "png_set_background")); +} +# endif /* FLOATING_POINT */ +#endif /* READ_BACKGROUND */ + +#ifdef PNG_READ_16_TO_8_SUPPORTED +/* Strip 16 bit depth files to 8 bit depth */ +void PNGAPI +png_set_strip_16(png_structp png_ptr) +{ + png_debug(1, "in png_set_strip_16"); + + if (png_ptr == NULL) + return; + + png_ptr->transformations |= PNG_16_TO_8; +} +#endif + +#ifdef PNG_READ_STRIP_ALPHA_SUPPORTED +void PNGAPI +png_set_strip_alpha(png_structp png_ptr) +{ + png_debug(1, "in png_set_strip_alpha"); + + if (png_ptr == NULL) + return; + + png_ptr->flags |= PNG_FLAG_STRIP_ALPHA; +} +#endif + +#ifdef PNG_READ_QUANTIZE_SUPPORTED +/* Dither file to 8 bit. Supply a palette, the current number + * of elements in the palette, the maximum number of elements + * allowed, and a histogram if possible. If the current number + * of colors is greater then the maximum number, the palette will be + * modified to fit in the maximum number. "full_quantize" indicates + * whether we need a quantizing cube set up for RGB images, or if we + * simply are reducing the number of colors in a paletted image. + */ + +typedef struct png_dsort_struct +{ + struct png_dsort_struct FAR * next; + png_byte left; + png_byte right; +} png_dsort; +typedef png_dsort FAR * png_dsortp; +typedef png_dsort FAR * FAR * png_dsortpp; + +void PNGAPI +png_set_quantize(png_structp png_ptr, png_colorp palette, + int num_palette, int maximum_colors, png_const_uint_16p histogram, + int full_quantize) +{ + png_debug(1, "in png_set_quantize"); + + if (png_ptr == NULL) + return; + + png_ptr->transformations |= PNG_QUANTIZE; + + if (!full_quantize) + { + int i; + + png_ptr->quantize_index = (png_bytep)png_malloc(png_ptr, + (png_uint_32)(num_palette * png_sizeof(png_byte))); + for (i = 0; i < num_palette; i++) + png_ptr->quantize_index[i] = (png_byte)i; + } + + if (num_palette > maximum_colors) + { + if (histogram != NULL) + { + /* This is easy enough, just throw out the least used colors. + * Perhaps not the best solution, but good enough. + */ + + int i; + + /* Initialize an array to sort colors */ + png_ptr->quantize_sort = (png_bytep)png_malloc(png_ptr, + (png_uint_32)(num_palette * png_sizeof(png_byte))); + + /* Initialize the quantize_sort array */ + for (i = 0; i < num_palette; i++) + png_ptr->quantize_sort[i] = (png_byte)i; + + /* Find the least used palette entries by starting a + * bubble sort, and running it until we have sorted + * out enough colors. Note that we don't care about + * sorting all the colors, just finding which are + * least used. + */ + + for (i = num_palette - 1; i >= maximum_colors; i--) + { + int done; /* To stop early if the list is pre-sorted */ + int j; + + done = 1; + for (j = 0; j < i; j++) + { + if (histogram[png_ptr->quantize_sort[j]] + < histogram[png_ptr->quantize_sort[j + 1]]) + { + png_byte t; + + t = png_ptr->quantize_sort[j]; + png_ptr->quantize_sort[j] = png_ptr->quantize_sort[j + 1]; + png_ptr->quantize_sort[j + 1] = t; + done = 0; + } + } + + if (done) + break; + } + + /* Swap the palette around, and set up a table, if necessary */ + if (full_quantize) + { + int j = num_palette; + + /* Put all the useful colors within the max, but don't + * move the others. + */ + for (i = 0; i < maximum_colors; i++) + { + if ((int)png_ptr->quantize_sort[i] >= maximum_colors) + { + do + j--; + while ((int)png_ptr->quantize_sort[j] >= maximum_colors); + + palette[i] = palette[j]; + } + } + } + else + { + int j = num_palette; + + /* Move all the used colors inside the max limit, and + * develop a translation table. + */ + for (i = 0; i < maximum_colors; i++) + { + /* Only move the colors we need to */ + if ((int)png_ptr->quantize_sort[i] >= maximum_colors) + { + png_color tmp_color; + + do + j--; + while ((int)png_ptr->quantize_sort[j] >= maximum_colors); + + tmp_color = palette[j]; + palette[j] = palette[i]; + palette[i] = tmp_color; + /* Indicate where the color went */ + png_ptr->quantize_index[j] = (png_byte)i; + png_ptr->quantize_index[i] = (png_byte)j; + } + } + + /* Find closest color for those colors we are not using */ + for (i = 0; i < num_palette; i++) + { + if ((int)png_ptr->quantize_index[i] >= maximum_colors) + { + int min_d, k, min_k, d_index; + + /* Find the closest color to one we threw out */ + d_index = png_ptr->quantize_index[i]; + min_d = PNG_COLOR_DIST(palette[d_index], palette[0]); + for (k = 1, min_k = 0; k < maximum_colors; k++) + { + int d; + + d = PNG_COLOR_DIST(palette[d_index], palette[k]); + + if (d < min_d) + { + min_d = d; + min_k = k; + } + } + /* Point to closest color */ + png_ptr->quantize_index[i] = (png_byte)min_k; + } + } + } + png_free(png_ptr, png_ptr->quantize_sort); + png_ptr->quantize_sort = NULL; + } + else + { + /* This is much harder to do simply (and quickly). Perhaps + * we need to go through a median cut routine, but those + * don't always behave themselves with only a few colors + * as input. So we will just find the closest two colors, + * and throw out one of them (chosen somewhat randomly). + * [We don't understand this at all, so if someone wants to + * work on improving it, be our guest - AED, GRP] + */ + int i; + int max_d; + int num_new_palette; + png_dsortp t; + png_dsortpp hash; + + t = NULL; + + /* Initialize palette index arrays */ + png_ptr->index_to_palette = (png_bytep)png_malloc(png_ptr, + (png_uint_32)(num_palette * png_sizeof(png_byte))); + png_ptr->palette_to_index = (png_bytep)png_malloc(png_ptr, + (png_uint_32)(num_palette * png_sizeof(png_byte))); + + /* Initialize the sort array */ + for (i = 0; i < num_palette; i++) + { + png_ptr->index_to_palette[i] = (png_byte)i; + png_ptr->palette_to_index[i] = (png_byte)i; + } + + hash = (png_dsortpp)png_calloc(png_ptr, (png_uint_32)(769 * + png_sizeof(png_dsortp))); + + num_new_palette = num_palette; + + /* Initial wild guess at how far apart the farthest pixel + * pair we will be eliminating will be. Larger + * numbers mean more areas will be allocated, Smaller + * numbers run the risk of not saving enough data, and + * having to do this all over again. + * + * I have not done extensive checking on this number. + */ + max_d = 96; + + while (num_new_palette > maximum_colors) + { + for (i = 0; i < num_new_palette - 1; i++) + { + int j; + + for (j = i + 1; j < num_new_palette; j++) + { + int d; + + d = PNG_COLOR_DIST(palette[i], palette[j]); + + if (d <= max_d) + { + + t = (png_dsortp)png_malloc_warn(png_ptr, + (png_uint_32)(png_sizeof(png_dsort))); + + if (t == NULL) + break; + + t->next = hash[d]; + t->left = (png_byte)i; + t->right = (png_byte)j; + hash[d] = t; + } + } + if (t == NULL) + break; + } + + if (t != NULL) + for (i = 0; i <= max_d; i++) + { + if (hash[i] != NULL) + { + png_dsortp p; + + for (p = hash[i]; p; p = p->next) + { + if ((int)png_ptr->index_to_palette[p->left] + < num_new_palette && + (int)png_ptr->index_to_palette[p->right] + < num_new_palette) + { + int j, next_j; + + if (num_new_palette & 0x01) + { + j = p->left; + next_j = p->right; + } + else + { + j = p->right; + next_j = p->left; + } + + num_new_palette--; + palette[png_ptr->index_to_palette[j]] + = palette[num_new_palette]; + if (!full_quantize) + { + int k; + + for (k = 0; k < num_palette; k++) + { + if (png_ptr->quantize_index[k] == + png_ptr->index_to_palette[j]) + png_ptr->quantize_index[k] = + png_ptr->index_to_palette[next_j]; + + if ((int)png_ptr->quantize_index[k] == + num_new_palette) + png_ptr->quantize_index[k] = + png_ptr->index_to_palette[j]; + } + } + + png_ptr->index_to_palette[png_ptr->palette_to_index + [num_new_palette]] = png_ptr->index_to_palette[j]; + + png_ptr->palette_to_index[png_ptr->index_to_palette[j]] + = png_ptr->palette_to_index[num_new_palette]; + + png_ptr->index_to_palette[j] = + (png_byte)num_new_palette; + + png_ptr->palette_to_index[num_new_palette] = + (png_byte)j; + } + if (num_new_palette <= maximum_colors) + break; + } + if (num_new_palette <= maximum_colors) + break; + } + } + + for (i = 0; i < 769; i++) + { + if (hash[i] != NULL) + { + png_dsortp p = hash[i]; + while (p) + { + t = p->next; + png_free(png_ptr, p); + p = t; + } + } + hash[i] = 0; + } + max_d += 96; + } + png_free(png_ptr, hash); + png_free(png_ptr, png_ptr->palette_to_index); + png_free(png_ptr, png_ptr->index_to_palette); + png_ptr->palette_to_index = NULL; + png_ptr->index_to_palette = NULL; + } + num_palette = maximum_colors; + } + if (png_ptr->palette == NULL) + { + png_ptr->palette = palette; + } + png_ptr->num_palette = (png_uint_16)num_palette; + + if (full_quantize) + { + int i; + png_bytep distance; + int total_bits = PNG_QUANTIZE_RED_BITS + PNG_QUANTIZE_GREEN_BITS + + PNG_QUANTIZE_BLUE_BITS; + int num_red = (1 << PNG_QUANTIZE_RED_BITS); + int num_green = (1 << PNG_QUANTIZE_GREEN_BITS); + int num_blue = (1 << PNG_QUANTIZE_BLUE_BITS); + png_size_t num_entries = ((png_size_t)1 << total_bits); + + png_ptr->palette_lookup = (png_bytep)png_calloc(png_ptr, + (png_uint_32)(num_entries * png_sizeof(png_byte))); + + distance = (png_bytep)png_malloc(png_ptr, (png_uint_32)(num_entries * + png_sizeof(png_byte))); + + png_memset(distance, 0xff, num_entries * png_sizeof(png_byte)); + + for (i = 0; i < num_palette; i++) + { + int ir, ig, ib; + int r = (palette[i].red >> (8 - PNG_QUANTIZE_RED_BITS)); + int g = (palette[i].green >> (8 - PNG_QUANTIZE_GREEN_BITS)); + int b = (palette[i].blue >> (8 - PNG_QUANTIZE_BLUE_BITS)); + + for (ir = 0; ir < num_red; ir++) + { + /* int dr = abs(ir - r); */ + int dr = ((ir > r) ? ir - r : r - ir); + int index_r = (ir << (PNG_QUANTIZE_BLUE_BITS + + PNG_QUANTIZE_GREEN_BITS)); + + for (ig = 0; ig < num_green; ig++) + { + /* int dg = abs(ig - g); */ + int dg = ((ig > g) ? ig - g : g - ig); + int dt = dr + dg; + int dm = ((dr > dg) ? dr : dg); + int index_g = index_r | (ig << PNG_QUANTIZE_BLUE_BITS); + + for (ib = 0; ib < num_blue; ib++) + { + int d_index = index_g | ib; + /* int db = abs(ib - b); */ + int db = ((ib > b) ? ib - b : b - ib); + int dmax = ((dm > db) ? dm : db); + int d = dmax + dt + db; + + if (d < (int)distance[d_index]) + { + distance[d_index] = (png_byte)d; + png_ptr->palette_lookup[d_index] = (png_byte)i; + } + } + } + } + } + + png_free(png_ptr, distance); + } +} +#endif /* PNG_READ_QUANTIZE_SUPPORTED */ + +#ifdef PNG_READ_GAMMA_SUPPORTED +/* Transform the image from the file_gamma to the screen_gamma. We + * only do transformations on images where the file_gamma and screen_gamma + * are not close reciprocals, otherwise it slows things down slightly, and + * also needlessly introduces small errors. + * + * We will turn off gamma transformation later if no semitransparent entries + * are present in the tRNS array for palette images. We can't do it here + * because we don't necessarily have the tRNS chunk yet. + */ +static int /* PRIVATE */ +png_gamma_threshold(png_fixed_point scrn_gamma, png_fixed_point file_gamma) +{ + /* PNG_GAMMA_THRESHOLD is the threshold for performing gamma + * correction as a difference of the overall transform from 1.0 + * + * We want to compare the threshold with s*f - 1, if we get + * overflow here it is because of wacky gamma values so we + * turn on processing anyway. + */ + png_fixed_point gtest; + return !png_muldiv(>est, scrn_gamma, file_gamma, PNG_FP_1) || + png_gamma_significant(gtest); +} + +void PNGFAPI +png_set_gamma_fixed(png_structp png_ptr, png_fixed_point scrn_gamma, + png_fixed_point file_gamma) +{ + png_debug(1, "in png_set_gamma_fixed"); + + if (png_ptr == NULL) + return; + + if ((png_ptr->color_type & PNG_COLOR_MASK_ALPHA) || + (png_ptr->color_type == PNG_COLOR_TYPE_PALETTE) || + png_gamma_threshold(scrn_gamma, file_gamma)) + png_ptr->transformations |= PNG_GAMMA; + png_ptr->gamma = file_gamma; + png_ptr->screen_gamma = scrn_gamma; +} + +# ifdef PNG_FLOATING_POINT_SUPPORTED +void PNGAPI +png_set_gamma(png_structp png_ptr, double scrn_gamma, double file_gamma) +{ + png_set_gamma_fixed(png_ptr, + png_fixed(png_ptr, scrn_gamma, "png_set_gamma screen gamma"), + png_fixed(png_ptr, file_gamma, "png_set_gamma file gamma")); +} +# endif /* FLOATING_POINT_SUPPORTED */ +#endif /* READ_GAMMA */ + +#ifdef PNG_READ_EXPAND_SUPPORTED +/* Expand paletted images to RGB, expand grayscale images of + * less than 8-bit depth to 8-bit depth, and expand tRNS chunks + * to alpha channels. + */ +void PNGAPI +png_set_expand(png_structp png_ptr) +{ + png_debug(1, "in png_set_expand"); + + if (png_ptr == NULL) + return; + + png_ptr->transformations |= (PNG_EXPAND | PNG_EXPAND_tRNS); + png_ptr->flags &= ~PNG_FLAG_ROW_INIT; +} + +/* GRR 19990627: the following three functions currently are identical + * to png_set_expand(). However, it is entirely reasonable that someone + * might wish to expand an indexed image to RGB but *not* expand a single, + * fully transparent palette entry to a full alpha channel--perhaps instead + * convert tRNS to the grayscale/RGB format (16-bit RGB value), or replace + * the transparent color with a particular RGB value, or drop tRNS entirely. + * IOW, a future version of the library may make the transformations flag + * a bit more fine-grained, with separate bits for each of these three + * functions. + * + * More to the point, these functions make it obvious what libpng will be + * doing, whereas "expand" can (and does) mean any number of things. + * + * GRP 20060307: In libpng-1.2.9, png_set_gray_1_2_4_to_8() was modified + * to expand only the sample depth but not to expand the tRNS to alpha + * and its name was changed to png_set_expand_gray_1_2_4_to_8(). + */ + +/* Expand paletted images to RGB. */ +void PNGAPI +png_set_palette_to_rgb(png_structp png_ptr) +{ + png_debug(1, "in png_set_palette_to_rgb"); + + if (png_ptr == NULL) + return; + + png_ptr->transformations |= (PNG_EXPAND | PNG_EXPAND_tRNS); + png_ptr->flags &= ~PNG_FLAG_ROW_INIT; +} + +/* Expand grayscale images of less than 8-bit depth to 8 bits. */ +void PNGAPI +png_set_expand_gray_1_2_4_to_8(png_structp png_ptr) +{ + png_debug(1, "in png_set_expand_gray_1_2_4_to_8"); + + if (png_ptr == NULL) + return; + + png_ptr->transformations |= PNG_EXPAND; + png_ptr->flags &= ~PNG_FLAG_ROW_INIT; +} + + + +/* Expand tRNS chunks to alpha channels. */ +void PNGAPI +png_set_tRNS_to_alpha(png_structp png_ptr) +{ + png_debug(1, "in png_set_tRNS_to_alpha"); + + png_ptr->transformations |= (PNG_EXPAND | PNG_EXPAND_tRNS); + png_ptr->flags &= ~PNG_FLAG_ROW_INIT; +} +#endif /* defined(PNG_READ_EXPAND_SUPPORTED) */ + +#ifdef PNG_READ_GRAY_TO_RGB_SUPPORTED +void PNGAPI +png_set_gray_to_rgb(png_structp png_ptr) +{ + png_debug(1, "in png_set_gray_to_rgb"); + + if (png_ptr != NULL) + { + /* Because rgb must be 8 bits or more: */ + png_set_expand_gray_1_2_4_to_8(png_ptr); + png_ptr->transformations |= PNG_GRAY_TO_RGB; + png_ptr->flags &= ~PNG_FLAG_ROW_INIT; + } +} +#endif + +#ifdef PNG_READ_RGB_TO_GRAY_SUPPORTED +void PNGFAPI +png_set_rgb_to_gray_fixed(png_structp png_ptr, int error_action, + png_fixed_point red, png_fixed_point green) +{ + png_debug(1, "in png_set_rgb_to_gray"); + + if (png_ptr == NULL) + return; + + switch(error_action) + { + case 1: + png_ptr->transformations |= PNG_RGB_TO_GRAY; + break; + + case 2: + png_ptr->transformations |= PNG_RGB_TO_GRAY_WARN; + break; + + case 3: + png_ptr->transformations |= PNG_RGB_TO_GRAY_ERR; + break; + + default: + png_error(png_ptr, "invalid error action to rgb_to_gray"); + break; + } + if (png_ptr->color_type == PNG_COLOR_TYPE_PALETTE) +#ifdef PNG_READ_EXPAND_SUPPORTED + png_ptr->transformations |= PNG_EXPAND; +#else + { + png_warning(png_ptr, + "Cannot do RGB_TO_GRAY without EXPAND_SUPPORTED"); + + png_ptr->transformations &= ~PNG_RGB_TO_GRAY; + } +#endif + { + png_uint_16 red_int, green_int; + if (red < 0 || green < 0) + { + red_int = 6968; /* .212671 * 32768 + .5 */ + green_int = 23434; /* .715160 * 32768 + .5 */ + } + + else if (red + green < 100000L) + { + red_int = (png_uint_16)(((png_uint_32)red*32768L)/100000L); + green_int = (png_uint_16)(((png_uint_32)green*32768L)/100000L); + } + + else + { + png_warning(png_ptr, "ignoring out of range rgb_to_gray coefficients"); + red_int = 6968; + green_int = 23434; + } + + png_ptr->rgb_to_gray_red_coeff = red_int; + png_ptr->rgb_to_gray_green_coeff = green_int; + png_ptr->rgb_to_gray_blue_coeff = + (png_uint_16)(32768 - red_int - green_int); + } +} + +#ifdef PNG_FLOATING_POINT_SUPPORTED +/* Convert a RGB image to a grayscale of the same width. This allows us, + * for example, to convert a 24 bpp RGB image into an 8 bpp grayscale image. + */ + +void PNGAPI +png_set_rgb_to_gray(png_structp png_ptr, int error_action, double red, + double green) +{ + if (png_ptr == NULL) + return; + + png_set_rgb_to_gray_fixed(png_ptr, error_action, + png_fixed(png_ptr, red, "rgb to gray red coefficient"), + png_fixed(png_ptr, green, "rgb to gray green coefficient")); +} +#endif /* FLOATING POINT */ + +#endif + +#if defined(PNG_READ_USER_TRANSFORM_SUPPORTED) || \ + defined(PNG_WRITE_USER_TRANSFORM_SUPPORTED) +void PNGAPI +png_set_read_user_transform_fn(png_structp png_ptr, png_user_transform_ptr + read_user_transform_fn) +{ + png_debug(1, "in png_set_read_user_transform_fn"); + + if (png_ptr == NULL) + return; + +#ifdef PNG_READ_USER_TRANSFORM_SUPPORTED + png_ptr->transformations |= PNG_USER_TRANSFORM; + png_ptr->read_user_transform_fn = read_user_transform_fn; +#endif +} +#endif + +/* Initialize everything needed for the read. This includes modifying + * the palette. + */ +void /* PRIVATE */ +png_init_read_transformations(png_structp png_ptr) +{ + png_debug(1, "in png_init_read_transformations"); + + { +#if defined(PNG_READ_BACKGROUND_SUPPORTED) || \ + defined(PNG_READ_SHIFT_SUPPORTED) || \ + defined(PNG_READ_GAMMA_SUPPORTED) + int color_type = png_ptr->color_type; +#endif + +#if defined(PNG_READ_EXPAND_SUPPORTED) && defined(PNG_READ_BACKGROUND_SUPPORTED) + +#ifdef PNG_READ_GRAY_TO_RGB_SUPPORTED + /* Detect gray background and attempt to enable optimization + * for gray --> RGB case + * + * Note: if PNG_BACKGROUND_EXPAND is set and color_type is either RGB or + * RGB_ALPHA (in which case need_expand is superfluous anyway), the + * background color might actually be gray yet not be flagged as such. + * This is not a problem for the current code, which uses + * PNG_BACKGROUND_IS_GRAY only to decide when to do the + * png_do_gray_to_rgb() transformation. + */ + if ((png_ptr->transformations & PNG_BACKGROUND_EXPAND) && + !(color_type & PNG_COLOR_MASK_COLOR)) + { + png_ptr->mode |= PNG_BACKGROUND_IS_GRAY; + } + + else if ((png_ptr->transformations & PNG_BACKGROUND) && + !(png_ptr->transformations & PNG_BACKGROUND_EXPAND) && + (png_ptr->transformations & PNG_GRAY_TO_RGB) && + png_ptr->background.red == png_ptr->background.green && + png_ptr->background.red == png_ptr->background.blue) + { + png_ptr->mode |= PNG_BACKGROUND_IS_GRAY; + png_ptr->background.gray = png_ptr->background.red; + } +#endif + + if ((png_ptr->transformations & PNG_BACKGROUND_EXPAND) && + (png_ptr->transformations & PNG_EXPAND)) + { + if (!(color_type & PNG_COLOR_MASK_COLOR)) /* i.e., GRAY or GRAY_ALPHA */ + { + /* Expand background and tRNS chunks */ + switch (png_ptr->bit_depth) + { + case 1: + png_ptr->background.gray *= (png_uint_16)0xff; + png_ptr->background.red = png_ptr->background.green + = png_ptr->background.blue = png_ptr->background.gray; + if (!(png_ptr->transformations & PNG_EXPAND_tRNS)) + { + png_ptr->trans_color.gray *= (png_uint_16)0xff; + png_ptr->trans_color.red = png_ptr->trans_color.green + = png_ptr->trans_color.blue = png_ptr->trans_color.gray; + } + break; + + case 2: + png_ptr->background.gray *= (png_uint_16)0x55; + png_ptr->background.red = png_ptr->background.green + = png_ptr->background.blue = png_ptr->background.gray; + if (!(png_ptr->transformations & PNG_EXPAND_tRNS)) + { + png_ptr->trans_color.gray *= (png_uint_16)0x55; + png_ptr->trans_color.red = png_ptr->trans_color.green + = png_ptr->trans_color.blue = png_ptr->trans_color.gray; + } + break; + + case 4: + png_ptr->background.gray *= (png_uint_16)0x11; + png_ptr->background.red = png_ptr->background.green + = png_ptr->background.blue = png_ptr->background.gray; + if (!(png_ptr->transformations & PNG_EXPAND_tRNS)) + { + png_ptr->trans_color.gray *= (png_uint_16)0x11; + png_ptr->trans_color.red = png_ptr->trans_color.green + = png_ptr->trans_color.blue = png_ptr->trans_color.gray; + } + break; + + default: + + case 8: + + case 16: + png_ptr->background.red = png_ptr->background.green + = png_ptr->background.blue = png_ptr->background.gray; + break; + } + } + else if (color_type == PNG_COLOR_TYPE_PALETTE) + { + png_ptr->background.red = + png_ptr->palette[png_ptr->background.index].red; + png_ptr->background.green = + png_ptr->palette[png_ptr->background.index].green; + png_ptr->background.blue = + png_ptr->palette[png_ptr->background.index].blue; + +#ifdef PNG_READ_INVERT_ALPHA_SUPPORTED + if (png_ptr->transformations & PNG_INVERT_ALPHA) + { +#ifdef PNG_READ_EXPAND_SUPPORTED + if (!(png_ptr->transformations & PNG_EXPAND_tRNS)) +#endif + { + /* Invert the alpha channel (in tRNS) unless the pixels are + * going to be expanded, in which case leave it for later + */ + int i, istop; + istop=(int)png_ptr->num_trans; + for (i=0; i<istop; i++) + png_ptr->trans_alpha[i] = (png_byte)(255 - + png_ptr->trans_alpha[i]); + } + } +#endif + + } + } +#endif + +#if defined(PNG_READ_BACKGROUND_SUPPORTED) && defined(PNG_READ_GAMMA_SUPPORTED) + png_ptr->background_1 = png_ptr->background; +#endif +#ifdef PNG_READ_GAMMA_SUPPORTED + + if ((color_type == PNG_COLOR_TYPE_PALETTE && png_ptr->num_trans != 0) + && png_gamma_threshold(png_ptr->screen_gamma, png_ptr->gamma)) + { + int i, k; + k=0; + for (i=0; i<png_ptr->num_trans; i++) + { + if (png_ptr->trans_alpha[i] != 0 && png_ptr->trans_alpha[i] != 0xff) + k=1; /* Partial transparency is present */ + } + if (k == 0) + png_ptr->transformations &= ~PNG_GAMMA; + } + + if ((png_ptr->transformations & (PNG_GAMMA | PNG_RGB_TO_GRAY)) && + png_ptr->gamma != 0) + { + png_build_gamma_table(png_ptr, png_ptr->bit_depth); + +#ifdef PNG_READ_BACKGROUND_SUPPORTED + if (png_ptr->transformations & PNG_BACKGROUND) + { + if (color_type == PNG_COLOR_TYPE_PALETTE) + { + /* Could skip if no transparency */ + png_color back, back_1; + png_colorp palette = png_ptr->palette; + int num_palette = png_ptr->num_palette; + int i; + if (png_ptr->background_gamma_type == PNG_BACKGROUND_GAMMA_FILE) + { + + back.red = png_ptr->gamma_table[png_ptr->background.red]; + back.green = png_ptr->gamma_table[png_ptr->background.green]; + back.blue = png_ptr->gamma_table[png_ptr->background.blue]; + + back_1.red = png_ptr->gamma_to_1[png_ptr->background.red]; + back_1.green = png_ptr->gamma_to_1[png_ptr->background.green]; + back_1.blue = png_ptr->gamma_to_1[png_ptr->background.blue]; + } + else + { + png_fixed_point g, gs; + + switch (png_ptr->background_gamma_type) + { + case PNG_BACKGROUND_GAMMA_SCREEN: + g = (png_ptr->screen_gamma); + gs = PNG_FP_1; + break; + + case PNG_BACKGROUND_GAMMA_FILE: + g = png_reciprocal(png_ptr->gamma); + gs = png_reciprocal2(png_ptr->gamma, + png_ptr->screen_gamma); + break; + + case PNG_BACKGROUND_GAMMA_UNIQUE: + g = png_reciprocal(png_ptr->background_gamma); + gs = png_reciprocal2(png_ptr->background_gamma, + png_ptr->screen_gamma); + break; + default: + g = PNG_FP_1; /* back_1 */ + gs = PNG_FP_1; /* back */ + break; + } + + if (png_gamma_significant(gs)) + { + back.red = (png_byte)png_ptr->background.red; + back.green = (png_byte)png_ptr->background.green; + back.blue = (png_byte)png_ptr->background.blue; + } + + else + { + back.red = png_gamma_8bit_correct(png_ptr->background.red, + gs); + back.green = png_gamma_8bit_correct(png_ptr->background.green, + gs); + back.blue = png_gamma_8bit_correct(png_ptr->background.blue, + gs); + } + back_1.red = png_gamma_8bit_correct(png_ptr->background.red, g); + back_1.green = png_gamma_8bit_correct(png_ptr->background.green, + g); + back_1.blue = png_gamma_8bit_correct(png_ptr->background.blue, + g); + } + for (i = 0; i < num_palette; i++) + { + if (i < (int)png_ptr->num_trans && + png_ptr->trans_alpha[i] != 0xff) + { + if (png_ptr->trans_alpha[i] == 0) + { + palette[i] = back; + } + else /* if (png_ptr->trans_alpha[i] != 0xff) */ + { + png_byte v, w; + + v = png_ptr->gamma_to_1[palette[i].red]; + png_composite(w, v, png_ptr->trans_alpha[i], back_1.red); + palette[i].red = png_ptr->gamma_from_1[w]; + + v = png_ptr->gamma_to_1[palette[i].green]; + png_composite(w, v, png_ptr->trans_alpha[i], back_1.green); + palette[i].green = png_ptr->gamma_from_1[w]; + + v = png_ptr->gamma_to_1[palette[i].blue]; + png_composite(w, v, png_ptr->trans_alpha[i], back_1.blue); + palette[i].blue = png_ptr->gamma_from_1[w]; + } + } + else + { + palette[i].red = png_ptr->gamma_table[palette[i].red]; + palette[i].green = png_ptr->gamma_table[palette[i].green]; + palette[i].blue = png_ptr->gamma_table[palette[i].blue]; + } + } + /* Prevent the transformations being done again, and make sure + * that the now spurious alpha channel is stripped - the code + * has just reduced background composition and gamma correction + * to a simple alpha channel strip. + */ + png_ptr->transformations &= ~PNG_BACKGROUND; + png_ptr->transformations &= ~PNG_GAMMA; + png_ptr->flags |= PNG_FLAG_STRIP_ALPHA; + } + + /* if (png_ptr->background_gamma_type!=PNG_BACKGROUND_GAMMA_UNKNOWN) */ + else + /* color_type != PNG_COLOR_TYPE_PALETTE */ + { + png_fixed_point g = PNG_FP_1; + png_fixed_point gs = PNG_FP_1; + + switch (png_ptr->background_gamma_type) + { + case PNG_BACKGROUND_GAMMA_SCREEN: + g = png_ptr->screen_gamma; + /* gs = PNG_FP_1; */ + break; + + case PNG_BACKGROUND_GAMMA_FILE: + g = png_reciprocal(png_ptr->gamma); + gs = png_reciprocal2(png_ptr->gamma, png_ptr->screen_gamma); + break; + + case PNG_BACKGROUND_GAMMA_UNIQUE: + g = png_reciprocal(png_ptr->background_gamma); + gs = png_reciprocal2(png_ptr->background_gamma, + png_ptr->screen_gamma); + break; + + default: + png_error(png_ptr, "invalid background gamma type"); + } + + png_ptr->background_1.gray = png_gamma_correct(png_ptr, + png_ptr->background.gray, g); + + png_ptr->background.gray = png_gamma_correct(png_ptr, + png_ptr->background.gray, gs); + + if ((png_ptr->background.red != png_ptr->background.green) || + (png_ptr->background.red != png_ptr->background.blue) || + (png_ptr->background.red != png_ptr->background.gray)) + { + /* RGB or RGBA with color background */ + png_ptr->background_1.red = png_gamma_correct(png_ptr, + png_ptr->background.red, g); + + png_ptr->background_1.green = png_gamma_correct(png_ptr, + png_ptr->background.green, g); + + png_ptr->background_1.blue = png_gamma_correct(png_ptr, + png_ptr->background.blue, g); + + png_ptr->background.red = png_gamma_correct(png_ptr, + png_ptr->background.red, gs); + + png_ptr->background.green = png_gamma_correct(png_ptr, + png_ptr->background.green, gs); + + png_ptr->background.blue = png_gamma_correct(png_ptr, + png_ptr->background.blue, gs); + } + + else + { + /* GRAY, GRAY ALPHA, RGB, or RGBA with gray background */ + png_ptr->background_1.red = png_ptr->background_1.green + = png_ptr->background_1.blue = png_ptr->background_1.gray; + + png_ptr->background.red = png_ptr->background.green + = png_ptr->background.blue = png_ptr->background.gray; + } + } + } + else + /* Transformation does not include PNG_BACKGROUND */ +#endif /* PNG_READ_BACKGROUND_SUPPORTED */ + if (color_type == PNG_COLOR_TYPE_PALETTE) + { + png_colorp palette = png_ptr->palette; + int num_palette = png_ptr->num_palette; + int i; + + for (i = 0; i < num_palette; i++) + { + palette[i].red = png_ptr->gamma_table[palette[i].red]; + palette[i].green = png_ptr->gamma_table[palette[i].green]; + palette[i].blue = png_ptr->gamma_table[palette[i].blue]; + } + + /* Done the gamma correction. */ + png_ptr->transformations &= ~PNG_GAMMA; + } + } +#ifdef PNG_READ_BACKGROUND_SUPPORTED + else +#endif +#endif /* PNG_READ_GAMMA_SUPPORTED */ +#ifdef PNG_READ_BACKGROUND_SUPPORTED + /* No GAMMA transformation */ + if ((png_ptr->transformations & PNG_BACKGROUND) && + (color_type == PNG_COLOR_TYPE_PALETTE)) + { + int i; + int istop = (int)png_ptr->num_trans; + png_color back; + png_colorp palette = png_ptr->palette; + + back.red = (png_byte)png_ptr->background.red; + back.green = (png_byte)png_ptr->background.green; + back.blue = (png_byte)png_ptr->background.blue; + + for (i = 0; i < istop; i++) + { + if (png_ptr->trans_alpha[i] == 0) + { + palette[i] = back; + } + + else if (png_ptr->trans_alpha[i] != 0xff) + { + /* The png_composite() macro is defined in png.h */ + png_composite(palette[i].red, palette[i].red, + png_ptr->trans_alpha[i], back.red); + + png_composite(palette[i].green, palette[i].green, + png_ptr->trans_alpha[i], back.green); + + png_composite(palette[i].blue, palette[i].blue, + png_ptr->trans_alpha[i], back.blue); + } + } + + /* Handled alpha, still need to strip the channel. */ + png_ptr->transformations &= ~PNG_BACKGROUND; + png_ptr->flags |= PNG_FLAG_STRIP_ALPHA; + } +#endif /* PNG_READ_BACKGROUND_SUPPORTED */ + +#ifdef PNG_READ_SHIFT_SUPPORTED + if ((png_ptr->transformations & PNG_SHIFT) && + (color_type == PNG_COLOR_TYPE_PALETTE)) + { + png_uint_16 i; + png_uint_16 istop = png_ptr->num_palette; + int sr = 8 - png_ptr->sig_bit.red; + int sg = 8 - png_ptr->sig_bit.green; + int sb = 8 - png_ptr->sig_bit.blue; + + if (sr < 0 || sr > 8) + sr = 0; + + if (sg < 0 || sg > 8) + sg = 0; + + if (sb < 0 || sb > 8) + sb = 0; + + for (i = 0; i < istop; i++) + { + png_ptr->palette[i].red >>= sr; + png_ptr->palette[i].green >>= sg; + png_ptr->palette[i].blue >>= sb; + } + } +#endif /* PNG_READ_SHIFT_SUPPORTED */ + } +#if !defined(PNG_READ_GAMMA_SUPPORTED) && !defined(PNG_READ_SHIFT_SUPPORTED) \ + && !defined(PNG_READ_BACKGROUND_SUPPORTED) + if (png_ptr) + return; +#endif +} + +/* Modify the info structure to reflect the transformations. The + * info should be updated so a PNG file could be written with it, + * assuming the transformations result in valid PNG data. + */ +void /* PRIVATE */ +png_read_transform_info(png_structp png_ptr, png_infop info_ptr) +{ + png_debug(1, "in png_read_transform_info"); + +#ifdef PNG_READ_EXPAND_SUPPORTED + if (png_ptr->transformations & PNG_EXPAND) + { + if (info_ptr->color_type == PNG_COLOR_TYPE_PALETTE) + { + if (png_ptr->num_trans && + (png_ptr->transformations & PNG_EXPAND_tRNS)) + info_ptr->color_type = PNG_COLOR_TYPE_RGB_ALPHA; + + else + info_ptr->color_type = PNG_COLOR_TYPE_RGB; + + info_ptr->bit_depth = 8; + info_ptr->num_trans = 0; + } + else + { + if (png_ptr->num_trans) + { + if (png_ptr->transformations & PNG_EXPAND_tRNS) + info_ptr->color_type |= PNG_COLOR_MASK_ALPHA; + } + if (info_ptr->bit_depth < 8) + info_ptr->bit_depth = 8; + + info_ptr->num_trans = 0; + } + } +#endif + +#ifdef PNG_READ_BACKGROUND_SUPPORTED + if (png_ptr->transformations & PNG_BACKGROUND) + { + info_ptr->color_type = (png_byte)(info_ptr->color_type & + ~PNG_COLOR_MASK_ALPHA); + info_ptr->num_trans = 0; + info_ptr->background = png_ptr->background; + } +#endif + +#ifdef PNG_READ_GAMMA_SUPPORTED + if (png_ptr->transformations & PNG_GAMMA) + { + info_ptr->gamma = png_ptr->gamma; + } +#endif + +#ifdef PNG_READ_16_TO_8_SUPPORTED +#ifdef PNG_READ_16BIT_SUPPORTED + if ((png_ptr->transformations & PNG_16_TO_8) && (info_ptr->bit_depth == 16)) + info_ptr->bit_depth = 8; +#else + /* Force chopping 16-bit input down to 8 */ + if (info_ptr->bit_depth == 16) + { + png_ptr->transformations |=PNG_16_TO_8; + info_ptr->bit_depth = 8; + } +#endif +#endif + +#ifdef PNG_READ_GRAY_TO_RGB_SUPPORTED + if (png_ptr->transformations & PNG_GRAY_TO_RGB) + info_ptr->color_type |= PNG_COLOR_MASK_COLOR; +#endif + +#ifdef PNG_READ_RGB_TO_GRAY_SUPPORTED + if (png_ptr->transformations & PNG_RGB_TO_GRAY) + info_ptr->color_type &= ~PNG_COLOR_MASK_COLOR; +#endif + +#ifdef PNG_READ_QUANTIZE_SUPPORTED + if (png_ptr->transformations & PNG_QUANTIZE) + { + if (((info_ptr->color_type == PNG_COLOR_TYPE_RGB) || + (info_ptr->color_type == PNG_COLOR_TYPE_RGB_ALPHA)) && + png_ptr->palette_lookup && info_ptr->bit_depth == 8) + { + info_ptr->color_type = PNG_COLOR_TYPE_PALETTE; + } + } +#endif + +#ifdef PNG_READ_PACK_SUPPORTED + if ((png_ptr->transformations & PNG_PACK) && (info_ptr->bit_depth < 8)) + info_ptr->bit_depth = 8; +#endif + + if (info_ptr->color_type == PNG_COLOR_TYPE_PALETTE) + info_ptr->channels = 1; + + else if (info_ptr->color_type & PNG_COLOR_MASK_COLOR) + info_ptr->channels = 3; + + else + info_ptr->channels = 1; + +#ifdef PNG_READ_STRIP_ALPHA_SUPPORTED + if (png_ptr->flags & PNG_FLAG_STRIP_ALPHA) + info_ptr->color_type &= ~PNG_COLOR_MASK_ALPHA; +#endif + + if (info_ptr->color_type & PNG_COLOR_MASK_ALPHA) + info_ptr->channels++; + +#ifdef PNG_READ_FILLER_SUPPORTED + /* STRIP_ALPHA and FILLER allowed: MASK_ALPHA bit stripped above */ + if ((png_ptr->transformations & PNG_FILLER) && + ((info_ptr->color_type == PNG_COLOR_TYPE_RGB) || + (info_ptr->color_type == PNG_COLOR_TYPE_GRAY))) + { + info_ptr->channels++; + /* If adding a true alpha channel not just filler */ + if (png_ptr->transformations & PNG_ADD_ALPHA) + info_ptr->color_type |= PNG_COLOR_MASK_ALPHA; + } +#endif + +#if defined(PNG_USER_TRANSFORM_PTR_SUPPORTED) && \ +defined(PNG_READ_USER_TRANSFORM_SUPPORTED) + if (png_ptr->transformations & PNG_USER_TRANSFORM) + { + if (info_ptr->bit_depth < png_ptr->user_transform_depth) + info_ptr->bit_depth = png_ptr->user_transform_depth; + + if (info_ptr->channels < png_ptr->user_transform_channels) + info_ptr->channels = png_ptr->user_transform_channels; + } +#endif + + info_ptr->pixel_depth = (png_byte)(info_ptr->channels * + info_ptr->bit_depth); + + info_ptr->rowbytes = PNG_ROWBYTES(info_ptr->pixel_depth, info_ptr->width); + +#ifndef PNG_READ_EXPAND_SUPPORTED + if (png_ptr) + return; +#endif +} + +/* Transform the row. The order of transformations is significant, + * and is very touchy. If you add a transformation, take care to + * decide how it fits in with the other transformations here. + */ +void /* PRIVATE */ +png_do_read_transformations(png_structp png_ptr) +{ + png_debug(1, "in png_do_read_transformations"); + + if (png_ptr->row_buf == NULL) + { +#ifdef PNG_CONSOLE_IO_SUPPORTED + char msg[50]; + + png_snprintf2(msg, 50, + "NULL row buffer for row %ld, pass %d", (long)png_ptr->row_number, + png_ptr->pass); + png_error(png_ptr, msg); +#else + png_error(png_ptr, "NULL row buffer"); +#endif + } +#ifdef PNG_WARN_UNINITIALIZED_ROW + if (!(png_ptr->flags & PNG_FLAG_ROW_INIT)) + /* Application has failed to call either png_read_start_image() + * or png_read_update_info() after setting transforms that expand + * pixels. This check added to libpng-1.2.19 + */ +#if (PNG_WARN_UNINITIALIZED_ROW==1) + png_error(png_ptr, "Uninitialized row"); +#else + png_warning(png_ptr, "Uninitialized row"); +#endif +#endif + +#ifdef PNG_READ_EXPAND_SUPPORTED + if (png_ptr->transformations & PNG_EXPAND) + { + if (png_ptr->row_info.color_type == PNG_COLOR_TYPE_PALETTE) + { + png_do_expand_palette(&(png_ptr->row_info), png_ptr->row_buf + 1, + png_ptr->palette, png_ptr->trans_alpha, png_ptr->num_trans); + } + else + { + if (png_ptr->num_trans && + (png_ptr->transformations & PNG_EXPAND_tRNS)) + png_do_expand(&(png_ptr->row_info), png_ptr->row_buf + 1, + &(png_ptr->trans_color)); + else + + png_do_expand(&(png_ptr->row_info), png_ptr->row_buf + 1, + NULL); + } + } +#endif + +#ifdef PNG_READ_STRIP_ALPHA_SUPPORTED + if (png_ptr->flags & PNG_FLAG_STRIP_ALPHA) + png_do_strip_filler(&(png_ptr->row_info), png_ptr->row_buf + 1, + PNG_FLAG_FILLER_AFTER | (png_ptr->flags & PNG_FLAG_STRIP_ALPHA)); +#endif + +#ifdef PNG_READ_RGB_TO_GRAY_SUPPORTED + if (png_ptr->transformations & PNG_RGB_TO_GRAY) + { + int rgb_error = + png_do_rgb_to_gray(png_ptr, &(png_ptr->row_info), + png_ptr->row_buf + 1); + + if (rgb_error) + { + png_ptr->rgb_to_gray_status=1; + if ((png_ptr->transformations & PNG_RGB_TO_GRAY) == + PNG_RGB_TO_GRAY_WARN) + png_warning(png_ptr, "png_do_rgb_to_gray found nongray pixel"); + + if ((png_ptr->transformations & PNG_RGB_TO_GRAY) == + PNG_RGB_TO_GRAY_ERR) + png_error(png_ptr, "png_do_rgb_to_gray found nongray pixel"); + } + } +#endif + +/* From Andreas Dilger e-mail to png-implement, 26 March 1998: + * + * In most cases, the "simple transparency" should be done prior to doing + * gray-to-RGB, or you will have to test 3x as many bytes to check if a + * pixel is transparent. You would also need to make sure that the + * transparency information is upgraded to RGB. + * + * To summarize, the current flow is: + * - Gray + simple transparency -> compare 1 or 2 gray bytes and composite + * with background "in place" if transparent, + * convert to RGB if necessary + * - Gray + alpha -> composite with gray background and remove alpha bytes, + * convert to RGB if necessary + * + * To support RGB backgrounds for gray images we need: + * - Gray + simple transparency -> convert to RGB + simple transparency, + * compare 3 or 6 bytes and composite with + * background "in place" if transparent + * (3x compare/pixel compared to doing + * composite with gray bkgrnd) + * - Gray + alpha -> convert to RGB + alpha, composite with background and + * remove alpha bytes (3x float + * operations/pixel compared with composite + * on gray background) + * + * Greg's change will do this. The reason it wasn't done before is for + * performance, as this increases the per-pixel operations. If we would check + * in advance if the background was gray or RGB, and position the gray-to-RGB + * transform appropriately, then it would save a lot of work/time. + */ + +#ifdef PNG_READ_GRAY_TO_RGB_SUPPORTED + /* If gray -> RGB, do so now only if background is non-gray; else do later + * for performance reasons + */ + if ((png_ptr->transformations & PNG_GRAY_TO_RGB) && + !(png_ptr->mode & PNG_BACKGROUND_IS_GRAY)) + png_do_gray_to_rgb(&(png_ptr->row_info), png_ptr->row_buf + 1); +#endif + +#ifdef PNG_READ_BACKGROUND_SUPPORTED + if ((png_ptr->transformations & PNG_BACKGROUND) && + ((png_ptr->num_trans != 0) || + (png_ptr->color_type & PNG_COLOR_MASK_ALPHA))) + png_do_background(&(png_ptr->row_info), png_ptr->row_buf + 1, + &(png_ptr->trans_color), &(png_ptr->background) +#ifdef PNG_READ_GAMMA_SUPPORTED + , &(png_ptr->background_1), + png_ptr->gamma_table, png_ptr->gamma_from_1, + png_ptr->gamma_to_1, png_ptr->gamma_16_table, + png_ptr->gamma_16_from_1, png_ptr->gamma_16_to_1, + png_ptr->gamma_shift +#endif + ); +#endif + +#ifdef PNG_READ_GAMMA_SUPPORTED + if ((png_ptr->transformations & PNG_GAMMA) && +#ifdef PNG_READ_BACKGROUND_SUPPORTED + !((png_ptr->transformations & PNG_BACKGROUND) && + ((png_ptr->num_trans != 0) || + (png_ptr->color_type & PNG_COLOR_MASK_ALPHA))) && +#endif + (png_ptr->color_type != PNG_COLOR_TYPE_PALETTE)) + png_do_gamma(&(png_ptr->row_info), png_ptr->row_buf + 1, + png_ptr->gamma_table, png_ptr->gamma_16_table, + png_ptr->gamma_shift); +#endif + +#ifdef PNG_READ_16_TO_8_SUPPORTED + if (png_ptr->transformations & PNG_16_TO_8) + png_do_chop(&(png_ptr->row_info), png_ptr->row_buf + 1); +#endif + +#ifdef PNG_READ_QUANTIZE_SUPPORTED + if (png_ptr->transformations & PNG_QUANTIZE) + { + png_do_quantize(&(png_ptr->row_info), png_ptr->row_buf + 1, + png_ptr->palette_lookup, png_ptr->quantize_index); + + if (png_ptr->row_info.rowbytes == 0) + png_error(png_ptr, "png_do_quantize returned rowbytes=0"); + } +#endif /* PNG_READ_QUANTIZE_SUPPORTED */ + +#ifdef PNG_READ_INVERT_SUPPORTED + if (png_ptr->transformations & PNG_INVERT_MONO) + png_do_invert(&(png_ptr->row_info), png_ptr->row_buf + 1); +#endif + +#ifdef PNG_READ_SHIFT_SUPPORTED + if (png_ptr->transformations & PNG_SHIFT) + png_do_unshift(&(png_ptr->row_info), png_ptr->row_buf + 1, + &(png_ptr->shift)); +#endif + +#ifdef PNG_READ_PACK_SUPPORTED + if (png_ptr->transformations & PNG_PACK) + png_do_unpack(&(png_ptr->row_info), png_ptr->row_buf + 1); +#endif + +#ifdef PNG_READ_BGR_SUPPORTED + if (png_ptr->transformations & PNG_BGR) + png_do_bgr(&(png_ptr->row_info), png_ptr->row_buf + 1); +#endif + +#ifdef PNG_READ_PACKSWAP_SUPPORTED + if (png_ptr->transformations & PNG_PACKSWAP) + png_do_packswap(&(png_ptr->row_info), png_ptr->row_buf + 1); +#endif + +#ifdef PNG_READ_GRAY_TO_RGB_SUPPORTED + /* If gray -> RGB, do so now only if we did not do so above */ + if ((png_ptr->transformations & PNG_GRAY_TO_RGB) && + (png_ptr->mode & PNG_BACKGROUND_IS_GRAY)) + png_do_gray_to_rgb(&(png_ptr->row_info), png_ptr->row_buf + 1); +#endif + +#ifdef PNG_READ_FILLER_SUPPORTED + if (png_ptr->transformations & PNG_FILLER) + png_do_read_filler(&(png_ptr->row_info), png_ptr->row_buf + 1, + (png_uint_32)png_ptr->filler, png_ptr->flags); +#endif + +#ifdef PNG_READ_INVERT_ALPHA_SUPPORTED + if (png_ptr->transformations & PNG_INVERT_ALPHA) + png_do_read_invert_alpha(&(png_ptr->row_info), png_ptr->row_buf + 1); +#endif + +#ifdef PNG_READ_SWAP_ALPHA_SUPPORTED + if (png_ptr->transformations & PNG_SWAP_ALPHA) + png_do_read_swap_alpha(&(png_ptr->row_info), png_ptr->row_buf + 1); +#endif + +#ifdef PNG_READ_16BIT_SUPPORTED +#ifdef PNG_READ_SWAP_SUPPORTED + if (png_ptr->transformations & PNG_SWAP_BYTES) + png_do_swap(&(png_ptr->row_info), png_ptr->row_buf + 1); +#endif +#endif + +#ifdef PNG_READ_USER_TRANSFORM_SUPPORTED + if (png_ptr->transformations & PNG_USER_TRANSFORM) + { + if (png_ptr->read_user_transform_fn != NULL) + (*(png_ptr->read_user_transform_fn)) /* User read transform function */ + (png_ptr, /* png_ptr */ + &(png_ptr->row_info), /* row_info: */ + /* png_uint_32 width; width of row */ + /* png_size_t rowbytes; number of bytes in row */ + /* png_byte color_type; color type of pixels */ + /* png_byte bit_depth; bit depth of samples */ + /* png_byte channels; number of channels (1-4) */ + /* png_byte pixel_depth; bits per pixel (depth*channels) */ + png_ptr->row_buf + 1); /* start of pixel data for row */ +#ifdef PNG_USER_TRANSFORM_PTR_SUPPORTED + if (png_ptr->user_transform_depth) + png_ptr->row_info.bit_depth = png_ptr->user_transform_depth; + + if (png_ptr->user_transform_channels) + png_ptr->row_info.channels = png_ptr->user_transform_channels; +#endif + png_ptr->row_info.pixel_depth = (png_byte)(png_ptr->row_info.bit_depth * + png_ptr->row_info.channels); + + png_ptr->row_info.rowbytes = PNG_ROWBYTES(png_ptr->row_info.pixel_depth, + png_ptr->row_info.width); + } +#endif + +} + +#ifdef PNG_READ_PACK_SUPPORTED +/* Unpack pixels of 1, 2, or 4 bits per pixel into 1 byte per pixel, + * without changing the actual values. Thus, if you had a row with + * a bit depth of 1, you would end up with bytes that only contained + * the numbers 0 or 1. If you would rather they contain 0 and 255, use + * png_do_shift() after this. + */ +void /* PRIVATE */ +png_do_unpack(png_row_infop row_info, png_bytep row) +{ + png_debug(1, "in png_do_unpack"); + + if (row_info->bit_depth < 8) + { + png_uint_32 i; + png_uint_32 row_width=row_info->width; + + switch (row_info->bit_depth) + { + case 1: + { + png_bytep sp = row + (png_size_t)((row_width - 1) >> 3); + png_bytep dp = row + (png_size_t)row_width - 1; + png_uint_32 shift = 7 - (int)((row_width + 7) & 0x07); + for (i = 0; i < row_width; i++) + { + *dp = (png_byte)((*sp >> shift) & 0x01); + + if (shift == 7) + { + shift = 0; + sp--; + } + + else + shift++; + + dp--; + } + break; + } + + case 2: + { + + png_bytep sp = row + (png_size_t)((row_width - 1) >> 2); + png_bytep dp = row + (png_size_t)row_width - 1; + png_uint_32 shift = (int)((3 - ((row_width + 3) & 0x03)) << 1); + for (i = 0; i < row_width; i++) + { + *dp = (png_byte)((*sp >> shift) & 0x03); + + if (shift == 6) + { + shift = 0; + sp--; + } + + else + shift += 2; + + dp--; + } + break; + } + + case 4: + { + png_bytep sp = row + (png_size_t)((row_width - 1) >> 1); + png_bytep dp = row + (png_size_t)row_width - 1; + png_uint_32 shift = (int)((1 - ((row_width + 1) & 0x01)) << 2); + for (i = 0; i < row_width; i++) + { + *dp = (png_byte)((*sp >> shift) & 0x0f); + + if (shift == 4) + { + shift = 0; + sp--; + } + + else + shift = 4; + + dp--; + } + break; + } + + default: + break; + } + row_info->bit_depth = 8; + row_info->pixel_depth = (png_byte)(8 * row_info->channels); + row_info->rowbytes = row_width * row_info->channels; + } +} +#endif + +#ifdef PNG_READ_SHIFT_SUPPORTED +/* Reverse the effects of png_do_shift. This routine merely shifts the + * pixels back to their significant bits values. Thus, if you have + * a row of bit depth 8, but only 5 are significant, this will shift + * the values back to 0 through 31. + */ +void /* PRIVATE */ +png_do_unshift(png_row_infop row_info, png_bytep row, + png_const_color_8p sig_bits) +{ + png_debug(1, "in png_do_unshift"); + + if ( + row_info->color_type != PNG_COLOR_TYPE_PALETTE) + { + int shift[4]; + int channels = 0; + int c; + png_uint_16 value = 0; + png_uint_32 row_width = row_info->width; + + if (row_info->color_type & PNG_COLOR_MASK_COLOR) + { + shift[channels++] = row_info->bit_depth - sig_bits->red; + shift[channels++] = row_info->bit_depth - sig_bits->green; + shift[channels++] = row_info->bit_depth - sig_bits->blue; + } + + else + { + shift[channels++] = row_info->bit_depth - sig_bits->gray; + } + + if (row_info->color_type & PNG_COLOR_MASK_ALPHA) + { + shift[channels++] = row_info->bit_depth - sig_bits->alpha; + } + + for (c = 0; c < channels; c++) + { + if (shift[c] <= 0) + shift[c] = 0; + + else + value = 1; + } + + if (!value) + return; + + switch (row_info->bit_depth) + { + default: + break; + + case 2: + { + png_bytep bp; + png_size_t i; + png_size_t istop = row_info->rowbytes; + + for (bp = row, i = 0; i < istop; i++) + { + *bp >>= 1; + *bp++ &= 0x55; + } + break; + } + + case 4: + { + png_bytep bp = row; + png_size_t i; + png_size_t istop = row_info->rowbytes; + png_byte mask = (png_byte)((((int)0xf0 >> shift[0]) & (int)0xf0) | + (png_byte)((int)0xf >> shift[0])); + + for (i = 0; i < istop; i++) + { + *bp >>= shift[0]; + *bp++ &= mask; + } + break; + } + + case 8: + { + png_bytep bp = row; + png_uint_32 i; + png_uint_32 istop = row_width * channels; + + for (i = 0; i < istop; i++) + { + *bp++ >>= shift[i%channels]; + } + break; + } + +#ifdef PNG_READ_16BIT_SUPPORTED + case 16: + { + png_bytep bp = row; + png_uint_32 i; + png_uint_32 istop = channels * row_width; + + for (i = 0; i < istop; i++) + { + value = (png_uint_16)((*bp << 8) + *(bp + 1)); + value >>= shift[i%channels]; + *bp++ = (png_byte)(value >> 8); + *bp++ = (png_byte)(value & 0xff); + } + break; + } +#endif + } + } +} +#endif + +#ifdef PNG_READ_16_TO_8_SUPPORTED +/* Chop rows of bit depth 16 down to 8 */ +void /* PRIVATE */ +png_do_chop(png_row_infop row_info, png_bytep row) +{ + png_debug(1, "in png_do_chop"); + + if (row_info->bit_depth == 16) + { + png_bytep sp = row; + png_bytep dp = row; + png_uint_32 i; + png_uint_32 istop = row_info->width * row_info->channels; + + for (i = 0; i<istop; i++, sp += 2, dp++) + { +#ifdef PNG_READ_16_TO_8_ACCURATE_SCALE_SUPPORTED + /* This does a more accurate scaling of the 16-bit color + * value, rather than a simple low-byte truncation. + * + * What the ideal calculation should be: + * *dp = (((((png_uint_32)(*sp) << 8) | + * (png_uint_32)(*(sp + 1))) * 255 + 127) + * / (png_uint_32)65535L; + * + * GRR: no, I think this is what it really should be: + * *dp = (((((png_uint_32)(*sp) << 8) | + * (png_uint_32)(*(sp + 1))) + 128L) + * / (png_uint_32)257L; + * + * GRR: here's the exact calculation with shifts: + * temp = (((png_uint_32)(*sp) << 8) | + * (png_uint_32)(*(sp + 1))) + 128L; + * *dp = (temp - (temp >> 8)) >> 8; + * + * Approximate calculation with shift/add instead of multiply/divide: + * *dp = ((((png_uint_32)(*sp) << 8) | + * (png_uint_32)((int)(*(sp + 1)) - *sp)) + 128) >> 8; + * + * What we actually do to avoid extra shifting and conversion: + */ + + *dp = *sp + ((((int)(*(sp + 1)) - *sp) > 128) ? 1 : 0); +#else + /* Simply discard the low order byte */ + *dp = *sp; +#endif + } + row_info->bit_depth = 8; + row_info->pixel_depth = (png_byte)(8 * row_info->channels); + row_info->rowbytes = row_info->width * row_info->channels; + } +} +#endif + +#ifdef PNG_READ_SWAP_ALPHA_SUPPORTED +void /* PRIVATE */ +png_do_read_swap_alpha(png_row_infop row_info, png_bytep row) +{ + png_debug(1, "in png_do_read_swap_alpha"); + + { + png_uint_32 row_width = row_info->width; + if (row_info->color_type == PNG_COLOR_TYPE_RGB_ALPHA) + { + /* This converts from RGBA to ARGB */ + if (row_info->bit_depth == 8) + { + png_bytep sp = row + row_info->rowbytes; + png_bytep dp = sp; + png_byte save; + png_uint_32 i; + + for (i = 0; i < row_width; i++) + { + save = *(--sp); + *(--dp) = *(--sp); + *(--dp) = *(--sp); + *(--dp) = *(--sp); + *(--dp) = save; + } + } + +#ifdef PNG_READ_16BIT_SUPPORTED + /* This converts from RRGGBBAA to AARRGGBB */ + else + { + png_bytep sp = row + row_info->rowbytes; + png_bytep dp = sp; + png_byte save[2]; + png_uint_32 i; + + for (i = 0; i < row_width; i++) + { + save[0] = *(--sp); + save[1] = *(--sp); + *(--dp) = *(--sp); + *(--dp) = *(--sp); + *(--dp) = *(--sp); + *(--dp) = *(--sp); + *(--dp) = *(--sp); + *(--dp) = *(--sp); + *(--dp) = save[0]; + *(--dp) = save[1]; + } + } +#endif + } + + else if (row_info->color_type == PNG_COLOR_TYPE_GRAY_ALPHA) + { + /* This converts from GA to AG */ + if (row_info->bit_depth == 8) + { + png_bytep sp = row + row_info->rowbytes; + png_bytep dp = sp; + png_byte save; + png_uint_32 i; + + for (i = 0; i < row_width; i++) + { + save = *(--sp); + *(--dp) = *(--sp); + *(--dp) = save; + } + } + +#ifdef PNG_READ_16BIT_SUPPORTED + /* This converts from GGAA to AAGG */ + else + { + png_bytep sp = row + row_info->rowbytes; + png_bytep dp = sp; + png_byte save[2]; + png_uint_32 i; + + for (i = 0; i < row_width; i++) + { + save[0] = *(--sp); + save[1] = *(--sp); + *(--dp) = *(--sp); + *(--dp) = *(--sp); + *(--dp) = save[0]; + *(--dp) = save[1]; + } + } +#endif + } + } +} +#endif + +#ifdef PNG_READ_INVERT_ALPHA_SUPPORTED +void /* PRIVATE */ +png_do_read_invert_alpha(png_row_infop row_info, png_bytep row) +{ + png_uint_32 row_width; + png_debug(1, "in png_do_read_invert_alpha"); + + row_width = row_info->width; + if (row_info->color_type == PNG_COLOR_TYPE_RGB_ALPHA) + { + if (row_info->bit_depth == 8) + { + /* This inverts the alpha channel in RGBA */ + png_bytep sp = row + row_info->rowbytes; + png_bytep dp = sp; + png_uint_32 i; + + for (i = 0; i < row_width; i++) + { + *(--dp) = (png_byte)(255 - *(--sp)); + +/* This does nothing: + *(--dp) = *(--sp); + *(--dp) = *(--sp); + *(--dp) = *(--sp); + We can replace it with: +*/ + sp-=3; + dp=sp; + } + } + +#ifdef PNG_READ_16BIT_SUPPORTED + /* This inverts the alpha channel in RRGGBBAA */ + else + { + png_bytep sp = row + row_info->rowbytes; + png_bytep dp = sp; + png_uint_32 i; + + for (i = 0; i < row_width; i++) + { + *(--dp) = (png_byte)(255 - *(--sp)); + *(--dp) = (png_byte)(255 - *(--sp)); + +/* This does nothing: + *(--dp) = *(--sp); + *(--dp) = *(--sp); + *(--dp) = *(--sp); + *(--dp) = *(--sp); + *(--dp) = *(--sp); + *(--dp) = *(--sp); + We can replace it with: +*/ + sp-=6; + dp=sp; + } + } +#endif + } + else if (row_info->color_type == PNG_COLOR_TYPE_GRAY_ALPHA) + { + if (row_info->bit_depth == 8) + { + /* This inverts the alpha channel in GA */ + png_bytep sp = row + row_info->rowbytes; + png_bytep dp = sp; + png_uint_32 i; + + for (i = 0; i < row_width; i++) + { + *(--dp) = (png_byte)(255 - *(--sp)); + *(--dp) = *(--sp); + } + } + +#ifdef PNG_READ_16BIT_SUPPORTED + else + { + /* This inverts the alpha channel in GGAA */ + png_bytep sp = row + row_info->rowbytes; + png_bytep dp = sp; + png_uint_32 i; + + for (i = 0; i < row_width; i++) + { + *(--dp) = (png_byte)(255 - *(--sp)); + *(--dp) = (png_byte)(255 - *(--sp)); +/* + *(--dp) = *(--sp); + *(--dp) = *(--sp); +*/ + sp-=2; + dp=sp; + } + } +#endif + } +} +#endif + +#ifdef PNG_READ_FILLER_SUPPORTED +/* Add filler channel if we have RGB color */ +void /* PRIVATE */ +png_do_read_filler(png_row_infop row_info, png_bytep row, + png_uint_32 filler, png_uint_32 flags) +{ + png_uint_32 i; + png_uint_32 row_width = row_info->width; + +#ifdef PNG_READ_16BIT_SUPPORTED + png_byte hi_filler = (png_byte)((filler>>8) & 0xff); +#endif + png_byte lo_filler = (png_byte)(filler & 0xff); + + png_debug(1, "in png_do_read_filler"); + + if ( + row_info->color_type == PNG_COLOR_TYPE_GRAY) + { + if (row_info->bit_depth == 8) + { + if (flags & PNG_FLAG_FILLER_AFTER) + { + /* This changes the data from G to GX */ + png_bytep sp = row + (png_size_t)row_width; + png_bytep dp = sp + (png_size_t)row_width; + for (i = 1; i < row_width; i++) + { + *(--dp) = lo_filler; + *(--dp) = *(--sp); + } + *(--dp) = lo_filler; + row_info->channels = 2; + row_info->pixel_depth = 16; + row_info->rowbytes = row_width * 2; + } + + else + { + /* This changes the data from G to XG */ + png_bytep sp = row + (png_size_t)row_width; + png_bytep dp = sp + (png_size_t)row_width; + for (i = 0; i < row_width; i++) + { + *(--dp) = *(--sp); + *(--dp) = lo_filler; + } + row_info->channels = 2; + row_info->pixel_depth = 16; + row_info->rowbytes = row_width * 2; + } + } + +#ifdef PNG_READ_16BIT_SUPPORTED + else if (row_info->bit_depth == 16) + { + if (flags & PNG_FLAG_FILLER_AFTER) + { + /* This changes the data from GG to GGXX */ + png_bytep sp = row + (png_size_t)row_width * 2; + png_bytep dp = sp + (png_size_t)row_width * 2; + for (i = 1; i < row_width; i++) + { + *(--dp) = hi_filler; + *(--dp) = lo_filler; + *(--dp) = *(--sp); + *(--dp) = *(--sp); + } + *(--dp) = hi_filler; + *(--dp) = lo_filler; + row_info->channels = 2; + row_info->pixel_depth = 32; + row_info->rowbytes = row_width * 4; + } + + else + { + /* This changes the data from GG to XXGG */ + png_bytep sp = row + (png_size_t)row_width * 2; + png_bytep dp = sp + (png_size_t)row_width * 2; + for (i = 0; i < row_width; i++) + { + *(--dp) = *(--sp); + *(--dp) = *(--sp); + *(--dp) = hi_filler; + *(--dp) = lo_filler; + } + row_info->channels = 2; + row_info->pixel_depth = 32; + row_info->rowbytes = row_width * 4; + } + } +#endif + } /* COLOR_TYPE == GRAY */ + else if (row_info->color_type == PNG_COLOR_TYPE_RGB) + { + if (row_info->bit_depth == 8) + { + if (flags & PNG_FLAG_FILLER_AFTER) + { + /* This changes the data from RGB to RGBX */ + png_bytep sp = row + (png_size_t)row_width * 3; + png_bytep dp = sp + (png_size_t)row_width; + for (i = 1; i < row_width; i++) + { + *(--dp) = lo_filler; + *(--dp) = *(--sp); + *(--dp) = *(--sp); + *(--dp) = *(--sp); + } + *(--dp) = lo_filler; + row_info->channels = 4; + row_info->pixel_depth = 32; + row_info->rowbytes = row_width * 4; + } + + else + { + /* This changes the data from RGB to XRGB */ + png_bytep sp = row + (png_size_t)row_width * 3; + png_bytep dp = sp + (png_size_t)row_width; + for (i = 0; i < row_width; i++) + { + *(--dp) = *(--sp); + *(--dp) = *(--sp); + *(--dp) = *(--sp); + *(--dp) = lo_filler; + } + row_info->channels = 4; + row_info->pixel_depth = 32; + row_info->rowbytes = row_width * 4; + } + } + +#ifdef PNG_READ_16BIT_SUPPORTED + else if (row_info->bit_depth == 16) + { + if (flags & PNG_FLAG_FILLER_AFTER) + { + /* This changes the data from RRGGBB to RRGGBBXX */ + png_bytep sp = row + (png_size_t)row_width * 6; + png_bytep dp = sp + (png_size_t)row_width * 2; + for (i = 1; i < row_width; i++) + { + *(--dp) = hi_filler; + *(--dp) = lo_filler; + *(--dp) = *(--sp); + *(--dp) = *(--sp); + *(--dp) = *(--sp); + *(--dp) = *(--sp); + *(--dp) = *(--sp); + *(--dp) = *(--sp); + } + *(--dp) = hi_filler; + *(--dp) = lo_filler; + row_info->channels = 4; + row_info->pixel_depth = 64; + row_info->rowbytes = row_width * 8; + } + + else + { + /* This changes the data from RRGGBB to XXRRGGBB */ + png_bytep sp = row + (png_size_t)row_width * 6; + png_bytep dp = sp + (png_size_t)row_width * 2; + for (i = 0; i < row_width; i++) + { + *(--dp) = *(--sp); + *(--dp) = *(--sp); + *(--dp) = *(--sp); + *(--dp) = *(--sp); + *(--dp) = *(--sp); + *(--dp) = *(--sp); + *(--dp) = hi_filler; + *(--dp) = lo_filler; + } + + row_info->channels = 4; + row_info->pixel_depth = 64; + row_info->rowbytes = row_width * 8; + } + } +#endif + } /* COLOR_TYPE == RGB */ +} +#endif + +#ifdef PNG_READ_GRAY_TO_RGB_SUPPORTED +/* Expand grayscale files to RGB, with or without alpha */ +void /* PRIVATE */ +png_do_gray_to_rgb(png_row_infop row_info, png_bytep row) +{ + png_uint_32 i; + png_uint_32 row_width = row_info->width; + + png_debug(1, "in png_do_gray_to_rgb"); + + if (row_info->bit_depth >= 8 && + !(row_info->color_type & PNG_COLOR_MASK_COLOR)) + { + if (row_info->color_type == PNG_COLOR_TYPE_GRAY) + { + if (row_info->bit_depth == 8) + { + /* This changes G to RGB */ + png_bytep sp = row + (png_size_t)row_width - 1; + png_bytep dp = sp + (png_size_t)row_width * 2; + for (i = 0; i < row_width; i++) + { + *(dp--) = *sp; + *(dp--) = *sp; + *(dp--) = *(sp--); + } + } + + else + { + /* This changes GG to RRGGBB */ + png_bytep sp = row + (png_size_t)row_width * 2 - 1; + png_bytep dp = sp + (png_size_t)row_width * 4; + for (i = 0; i < row_width; i++) + { + *(dp--) = *sp; + *(dp--) = *(sp - 1); + *(dp--) = *sp; + *(dp--) = *(sp - 1); + *(dp--) = *(sp--); + *(dp--) = *(sp--); + } + } + } + + else if (row_info->color_type == PNG_COLOR_TYPE_GRAY_ALPHA) + { + if (row_info->bit_depth == 8) + { + /* This changes GA to RGBA */ + png_bytep sp = row + (png_size_t)row_width * 2 - 1; + png_bytep dp = sp + (png_size_t)row_width * 2; + for (i = 0; i < row_width; i++) + { + *(dp--) = *(sp--); + *(dp--) = *sp; + *(dp--) = *sp; + *(dp--) = *(sp--); + } + } + + else + { + /* This changes GGAA to RRGGBBAA */ + png_bytep sp = row + (png_size_t)row_width * 4 - 1; + png_bytep dp = sp + (png_size_t)row_width * 4; + for (i = 0; i < row_width; i++) + { + *(dp--) = *(sp--); + *(dp--) = *(sp--); + *(dp--) = *sp; + *(dp--) = *(sp - 1); + *(dp--) = *sp; + *(dp--) = *(sp - 1); + *(dp--) = *(sp--); + *(dp--) = *(sp--); + } + } + } + row_info->channels += (png_byte)2; + row_info->color_type |= PNG_COLOR_MASK_COLOR; + row_info->pixel_depth = (png_byte)(row_info->channels * + row_info->bit_depth); + row_info->rowbytes = PNG_ROWBYTES(row_info->pixel_depth, row_width); + } +} +#endif + +#ifdef PNG_READ_RGB_TO_GRAY_SUPPORTED +/* Reduce RGB files to grayscale, with or without alpha + * using the equation given in Poynton's ColorFAQ at + * <http://www.inforamp.net/~poynton/> (THIS LINK IS DEAD June 2008) + * New link: + * <http://www.poynton.com/notes/colour_and_gamma/> + * Charles Poynton poynton at poynton.com + * + * Y = 0.212671 * R + 0.715160 * G + 0.072169 * B + * + * We approximate this with + * + * Y = 0.21268 * R + 0.7151 * G + 0.07217 * B + * + * which can be expressed with integers as + * + * Y = (6969 * R + 23434 * G + 2365 * B)/32768 + * + * The calculation is to be done in a linear colorspace. + * + * Other integer coefficents can be used via png_set_rgb_to_gray(). + */ +int /* PRIVATE */ +png_do_rgb_to_gray(png_structp png_ptr, png_row_infop row_info, png_bytep row) + +{ + png_uint_32 i; + + png_uint_32 row_width = row_info->width; + int rgb_error = 0; + + png_debug(1, "in png_do_rgb_to_gray"); + + if (!(row_info->color_type & PNG_COLOR_MASK_PALETTE) && + (row_info->color_type & PNG_COLOR_MASK_COLOR)) + { + png_uint_32 rc = png_ptr->rgb_to_gray_red_coeff; + png_uint_32 gc = png_ptr->rgb_to_gray_green_coeff; + png_uint_32 bc = png_ptr->rgb_to_gray_blue_coeff; + + if (row_info->color_type == PNG_COLOR_TYPE_RGB) + { + if (row_info->bit_depth == 8) + { +#if defined(PNG_READ_GAMMA_SUPPORTED) || defined(PNG_READ_BACKGROUND_SUPPORTED) + if (png_ptr->gamma_from_1 != NULL && png_ptr->gamma_to_1 != NULL) + { + png_bytep sp = row; + png_bytep dp = row; + + for (i = 0; i < row_width; i++) + { + png_byte red = png_ptr->gamma_to_1[*(sp++)]; + png_byte green = png_ptr->gamma_to_1[*(sp++)]; + png_byte blue = png_ptr->gamma_to_1[*(sp++)]; + + if (red != green || red != blue) + { + rgb_error |= 1; + *(dp++) = png_ptr->gamma_from_1[ + (rc*red + gc*green + bc*blue)>>15]; + } + + else + *(dp++) = *(sp - 1); + } + } + else +#endif + { + png_bytep sp = row; + png_bytep dp = row; + for (i = 0; i < row_width; i++) + { + png_byte red = *(sp++); + png_byte green = *(sp++); + png_byte blue = *(sp++); + + if (red != green || red != blue) + { + rgb_error |= 1; + *(dp++) = (png_byte)((rc*red + gc*green + bc*blue)>>15); + } + + else + *(dp++) = *(sp - 1); + } + } + } + + else /* RGB bit_depth == 16 */ + { +#if defined(PNG_READ_GAMMA_SUPPORTED) || defined(PNG_READ_BACKGROUND_SUPPORTED) + if (png_ptr->gamma_16_to_1 != NULL && + png_ptr->gamma_16_from_1 != NULL) + { + png_bytep sp = row; + png_bytep dp = row; + for (i = 0; i < row_width; i++) + { + png_uint_16 red, green, blue, w; + + red = (png_uint_16)(((*(sp))<<8) | *(sp + 1)); sp += 2; + green = (png_uint_16)(((*(sp))<<8) | *(sp + 1)); sp += 2; + blue = (png_uint_16)(((*(sp))<<8) | *(sp + 1)); sp += 2; + + if (red == green && red == blue) + w = red; + + else + { + png_uint_16 red_1 = png_ptr->gamma_16_to_1[(red&0xff) + >> png_ptr->gamma_shift][red>>8]; + png_uint_16 green_1 = + png_ptr->gamma_16_to_1[(green&0xff) >> + png_ptr->gamma_shift][green>>8]; + png_uint_16 blue_1 = png_ptr->gamma_16_to_1[(blue&0xff) + >> png_ptr->gamma_shift][blue>>8]; + png_uint_16 gray16 = (png_uint_16)((rc*red_1 + gc*green_1 + + bc*blue_1)>>15); + w = png_ptr->gamma_16_from_1[(gray16&0xff) >> + png_ptr->gamma_shift][gray16 >> 8]; + rgb_error |= 1; + } + + *(dp++) = (png_byte)((w>>8) & 0xff); + *(dp++) = (png_byte)(w & 0xff); + } + } + else +#endif + { + png_bytep sp = row; + png_bytep dp = row; + for (i = 0; i < row_width; i++) + { + png_uint_16 red, green, blue, gray16; + + red = (png_uint_16)(((*(sp))<<8) | *(sp + 1)); sp += 2; + green = (png_uint_16)(((*(sp))<<8) | *(sp + 1)); sp += 2; + blue = (png_uint_16)(((*(sp))<<8) | *(sp + 1)); sp += 2; + + if (red != green || red != blue) + rgb_error |= 1; + + gray16 = (png_uint_16)((rc*red + gc*green + bc*blue)>>15); + *(dp++) = (png_byte)((gray16>>8) & 0xff); + *(dp++) = (png_byte)(gray16 & 0xff); + } + } + } + } + if (row_info->color_type == PNG_COLOR_TYPE_RGB_ALPHA) + { + if (row_info->bit_depth == 8) + { +#if defined(PNG_READ_GAMMA_SUPPORTED) || defined(PNG_READ_BACKGROUND_SUPPORTED) + if (png_ptr->gamma_from_1 != NULL && png_ptr->gamma_to_1 != NULL) + { + png_bytep sp = row; + png_bytep dp = row; + for (i = 0; i < row_width; i++) + { + png_byte red = png_ptr->gamma_to_1[*(sp++)]; + png_byte green = png_ptr->gamma_to_1[*(sp++)]; + png_byte blue = png_ptr->gamma_to_1[*(sp++)]; + + if (red != green || red != blue) + rgb_error |= 1; + + *(dp++) = png_ptr->gamma_from_1 + [(rc*red + gc*green + bc*blue)>>15]; + + *(dp++) = *(sp++); /* alpha */ + } + } + else +#endif + { + png_bytep sp = row; + png_bytep dp = row; + for (i = 0; i < row_width; i++) + { + png_byte red = *(sp++); + png_byte green = *(sp++); + png_byte blue = *(sp++); + if (red != green || red != blue) + rgb_error |= 1; + + *(dp++) = (png_byte)((rc*red + gc*green + bc*blue)>>15); + *(dp++) = *(sp++); /* alpha */ + } + } + } + else /* RGBA bit_depth == 16 */ + { +#if defined(PNG_READ_GAMMA_SUPPORTED) || defined(PNG_READ_BACKGROUND_SUPPORTED) + if (png_ptr->gamma_16_to_1 != NULL && + png_ptr->gamma_16_from_1 != NULL) + { + png_bytep sp = row; + png_bytep dp = row; + for (i = 0; i < row_width; i++) + { + png_uint_16 red, green, blue, w; + + red = (png_uint_16)(((*(sp))<<8) | *(sp + 1)); sp += 2; + green = (png_uint_16)(((*(sp))<<8) | *(sp + 1)); sp += 2; + blue = (png_uint_16)(((*(sp))<<8) | *(sp + 1)); sp += 2; + + if (red == green && red == blue) + w = red; + + else + { + png_uint_16 red_1 = png_ptr->gamma_16_to_1[(red&0xff) >> + png_ptr->gamma_shift][red>>8]; + + png_uint_16 green_1 = + png_ptr->gamma_16_to_1[(green&0xff) >> + png_ptr->gamma_shift][green>>8]; + + png_uint_16 blue_1 = png_ptr->gamma_16_to_1[(blue&0xff) >> + png_ptr->gamma_shift][blue>>8]; + + png_uint_16 gray16 = (png_uint_16)((rc * red_1 + + gc * green_1 + bc * blue_1)>>15); + + w = png_ptr->gamma_16_from_1[(gray16&0xff) >> + png_ptr->gamma_shift][gray16 >> 8]; + + rgb_error |= 1; + } + + *(dp++) = (png_byte)((w>>8) & 0xff); + *(dp++) = (png_byte)(w & 0xff); + *(dp++) = *(sp++); /* alpha */ + *(dp++) = *(sp++); + } + } + else +#endif + { + png_bytep sp = row; + png_bytep dp = row; + for (i = 0; i < row_width; i++) + { + png_uint_16 red, green, blue, gray16; + red = (png_uint_16)((*(sp)<<8) | *(sp + 1)); sp += 2; + green = (png_uint_16)((*(sp)<<8) | *(sp + 1)); sp += 2; + blue = (png_uint_16)((*(sp)<<8) | *(sp + 1)); sp += 2; + + if (red != green || red != blue) + rgb_error |= 1; + + gray16 = (png_uint_16)((rc*red + gc*green + bc*blue)>>15); + *(dp++) = (png_byte)((gray16>>8) & 0xff); + *(dp++) = (png_byte)(gray16 & 0xff); + *(dp++) = *(sp++); /* alpha */ + *(dp++) = *(sp++); + } + } + } + } + row_info->channels -= 2; + row_info->color_type = (png_byte)(row_info->color_type & + ~PNG_COLOR_MASK_COLOR); + row_info->pixel_depth = (png_byte)(row_info->channels * + row_info->bit_depth); + row_info->rowbytes = PNG_ROWBYTES(row_info->pixel_depth, row_width); + } + return rgb_error; +} +#endif + +/* Build a grayscale palette. Palette is assumed to be 1 << bit_depth + * large of png_color. This lets grayscale images be treated as + * paletted. Most useful for gamma correction and simplification + * of code. + */ +void PNGAPI +png_build_grayscale_palette(int bit_depth, png_colorp palette) +{ + int num_palette; + int color_inc; + int i; + int v; + + png_debug(1, "in png_do_build_grayscale_palette"); + + if (palette == NULL) + return; + + switch (bit_depth) + { + case 1: + num_palette = 2; + color_inc = 0xff; + break; + + case 2: + num_palette = 4; + color_inc = 0x55; + break; + + case 4: + num_palette = 16; + color_inc = 0x11; + break; + + case 8: + num_palette = 256; + color_inc = 1; + break; + + default: + num_palette = 0; + color_inc = 0; + break; + } + + for (i = 0, v = 0; i < num_palette; i++, v += color_inc) + { + palette[i].red = (png_byte)v; + palette[i].green = (png_byte)v; + palette[i].blue = (png_byte)v; + } +} + + +#ifdef PNG_READ_BACKGROUND_SUPPORTED +/* Replace any alpha or transparency with the supplied background color. + * "background" is already in the screen gamma, while "background_1" is + * at a gamma of 1.0. Paletted files have already been taken care of. + */ +void /* PRIVATE */ +png_do_background(png_row_infop row_info, png_bytep row, + png_const_color_16p trans_color, png_const_color_16p background +#ifdef PNG_READ_GAMMA_SUPPORTED + , png_const_color_16p background_1, png_const_bytep gamma_table, + png_const_bytep gamma_from_1, png_const_bytep gamma_to_1, + png_const_uint_16pp gamma_16, png_const_uint_16pp gamma_16_from_1, + png_const_uint_16pp gamma_16_to_1, int gamma_shift +#endif + ) +{ + png_bytep sp, dp; + png_uint_32 i; + png_uint_32 row_width = row_info->width; + int shift; + + png_debug(1, "in png_do_background"); + + if (background != NULL && + (!(row_info->color_type & PNG_COLOR_MASK_ALPHA) || + (row_info->color_type != PNG_COLOR_TYPE_PALETTE && trans_color))) + { + switch (row_info->color_type) + { + case PNG_COLOR_TYPE_GRAY: + { + switch (row_info->bit_depth) + { + case 1: + { + sp = row; + shift = 7; + for (i = 0; i < row_width; i++) + { + if ((png_uint_16)((*sp >> shift) & 0x01) + == trans_color->gray) + { + *sp &= (png_byte)((0x7f7f >> (7 - shift)) & 0xff); + *sp |= (png_byte)(background->gray << shift); + } + + if (!shift) + { + shift = 7; + sp++; + } + + else + shift--; + } + break; + } + + case 2: + { +#ifdef PNG_READ_GAMMA_SUPPORTED + if (gamma_table != NULL) + { + sp = row; + shift = 6; + for (i = 0; i < row_width; i++) + { + if ((png_uint_16)((*sp >> shift) & 0x03) + == trans_color->gray) + { + *sp &= (png_byte)((0x3f3f >> (6 - shift)) & 0xff); + *sp |= (png_byte)(background->gray << shift); + } + + else + { + png_byte p = (png_byte)((*sp >> shift) & 0x03); + png_byte g = (png_byte)((gamma_table [p | (p << 2) | + (p << 4) | (p << 6)] >> 6) & 0x03); + *sp &= (png_byte)((0x3f3f >> (6 - shift)) & 0xff); + *sp |= (png_byte)(g << shift); + } + + if (!shift) + { + shift = 6; + sp++; + } + + else + shift -= 2; + } + } + + else +#endif + { + sp = row; + shift = 6; + for (i = 0; i < row_width; i++) + { + if ((png_uint_16)((*sp >> shift) & 0x03) + == trans_color->gray) + { + *sp &= (png_byte)((0x3f3f >> (6 - shift)) & 0xff); + *sp |= (png_byte)(background->gray << shift); + } + + if (!shift) + { + shift = 6; + sp++; + } + + else + shift -= 2; + } + } + break; + } + + case 4: + { +#ifdef PNG_READ_GAMMA_SUPPORTED + if (gamma_table != NULL) + { + sp = row; + shift = 4; + for (i = 0; i < row_width; i++) + { + if ((png_uint_16)((*sp >> shift) & 0x0f) + == trans_color->gray) + { + *sp &= (png_byte)((0xf0f >> (4 - shift)) & 0xff); + *sp |= (png_byte)(background->gray << shift); + } + + else + { + png_byte p = (png_byte)((*sp >> shift) & 0x0f); + png_byte g = (png_byte)((gamma_table[p | + (p << 4)] >> 4) & 0x0f); + *sp &= (png_byte)((0xf0f >> (4 - shift)) & 0xff); + *sp |= (png_byte)(g << shift); + } + + if (!shift) + { + shift = 4; + sp++; + } + + else + shift -= 4; + } + } + + else +#endif + { + sp = row; + shift = 4; + for (i = 0; i < row_width; i++) + { + if ((png_uint_16)((*sp >> shift) & 0x0f) + == trans_color->gray) + { + *sp &= (png_byte)((0xf0f >> (4 - shift)) & 0xff); + *sp |= (png_byte)(background->gray << shift); + } + + if (!shift) + { + shift = 4; + sp++; + } + + else + shift -= 4; + } + } + break; + } + + case 8: + { +#ifdef PNG_READ_GAMMA_SUPPORTED + if (gamma_table != NULL) + { + sp = row; + for (i = 0; i < row_width; i++, sp++) + { + if (*sp == trans_color->gray) + *sp = (png_byte)background->gray; + + else + *sp = gamma_table[*sp]; + } + } + else +#endif + { + sp = row; + for (i = 0; i < row_width; i++, sp++) + { + if (*sp == trans_color->gray) + *sp = (png_byte)background->gray; + } + } + break; + } + + case 16: + { +#ifdef PNG_READ_GAMMA_SUPPORTED + if (gamma_16 != NULL) + { + sp = row; + for (i = 0; i < row_width; i++, sp += 2) + { + png_uint_16 v; + + v = (png_uint_16)(((*sp) << 8) + *(sp + 1)); + + if (v == trans_color->gray) + { + /* Background is already in screen gamma */ + *sp = (png_byte)((background->gray >> 8) & 0xff); + *(sp + 1) = (png_byte)(background->gray & 0xff); + } + + else + { + v = gamma_16[*(sp + 1) >> gamma_shift][*sp]; + *sp = (png_byte)((v >> 8) & 0xff); + *(sp + 1) = (png_byte)(v & 0xff); + } + } + } + else +#endif + { + sp = row; + for (i = 0; i < row_width; i++, sp += 2) + { + png_uint_16 v; + + v = (png_uint_16)(((*sp) << 8) + *(sp + 1)); + + if (v == trans_color->gray) + { + *sp = (png_byte)((background->gray >> 8) & 0xff); + *(sp + 1) = (png_byte)(background->gray & 0xff); + } + } + } + break; + } + + default: + break; + } + break; + } + + case PNG_COLOR_TYPE_RGB: + { + if (row_info->bit_depth == 8) + { +#ifdef PNG_READ_GAMMA_SUPPORTED + if (gamma_table != NULL) + { + sp = row; + for (i = 0; i < row_width; i++, sp += 3) + { + if (*sp == trans_color->red && + *(sp + 1) == trans_color->green && + *(sp + 2) == trans_color->blue) + { + *sp = (png_byte)background->red; + *(sp + 1) = (png_byte)background->green; + *(sp + 2) = (png_byte)background->blue; + } + + else + { + *sp = gamma_table[*sp]; + *(sp + 1) = gamma_table[*(sp + 1)]; + *(sp + 2) = gamma_table[*(sp + 2)]; + } + } + } + else +#endif + { + sp = row; + for (i = 0; i < row_width; i++, sp += 3) + { + if (*sp == trans_color->red && + *(sp + 1) == trans_color->green && + *(sp + 2) == trans_color->blue) + { + *sp = (png_byte)background->red; + *(sp + 1) = (png_byte)background->green; + *(sp + 2) = (png_byte)background->blue; + } + } + } + } + else /* if (row_info->bit_depth == 16) */ + { +#ifdef PNG_READ_GAMMA_SUPPORTED + if (gamma_16 != NULL) + { + sp = row; + for (i = 0; i < row_width; i++, sp += 6) + { + png_uint_16 r = (png_uint_16)(((*sp) << 8) + *(sp + 1)); + + png_uint_16 g = (png_uint_16)(((*(sp + 2)) << 8) + + *(sp + 3)); + + png_uint_16 b = (png_uint_16)(((*(sp + 4)) << 8) + + *(sp + 5)); + + if (r == trans_color->red && g == trans_color->green && + b == trans_color->blue) + { + /* Background is already in screen gamma */ + *sp = (png_byte)((background->red >> 8) & 0xff); + *(sp + 1) = (png_byte)(background->red & 0xff); + *(sp + 2) = (png_byte)((background->green >> 8) & 0xff); + *(sp + 3) = (png_byte)(background->green & 0xff); + *(sp + 4) = (png_byte)((background->blue >> 8) & 0xff); + *(sp + 5) = (png_byte)(background->blue & 0xff); + } + + else + { + png_uint_16 v = gamma_16[*(sp + 1) >> gamma_shift][*sp]; + *sp = (png_byte)((v >> 8) & 0xff); + *(sp + 1) = (png_byte)(v & 0xff); + + v = gamma_16[*(sp + 3) >> gamma_shift][*(sp + 2)]; + *(sp + 2) = (png_byte)((v >> 8) & 0xff); + *(sp + 3) = (png_byte)(v & 0xff); + + v = gamma_16[*(sp + 5) >> gamma_shift][*(sp + 4)]; + *(sp + 4) = (png_byte)((v >> 8) & 0xff); + *(sp + 5) = (png_byte)(v & 0xff); + } + } + } + + else +#endif + { + sp = row; + for (i = 0; i < row_width; i++, sp += 6) + { + png_uint_16 r = (png_uint_16)(((*sp) << 8) + *(sp + 1)); + + png_uint_16 g = (png_uint_16)(((*(sp + 2)) << 8) + + *(sp + 3)); + + png_uint_16 b = (png_uint_16)(((*(sp + 4)) << 8) + + *(sp + 5)); + + if (r == trans_color->red && g == trans_color->green && + b == trans_color->blue) + { + *sp = (png_byte)((background->red >> 8) & 0xff); + *(sp + 1) = (png_byte)(background->red & 0xff); + *(sp + 2) = (png_byte)((background->green >> 8) & 0xff); + *(sp + 3) = (png_byte)(background->green & 0xff); + *(sp + 4) = (png_byte)((background->blue >> 8) & 0xff); + *(sp + 5) = (png_byte)(background->blue & 0xff); + } + } + } + } + break; + } + + case PNG_COLOR_TYPE_GRAY_ALPHA: + { + if (row_info->bit_depth == 8) + { +#ifdef PNG_READ_GAMMA_SUPPORTED + if (gamma_to_1 != NULL && gamma_from_1 != NULL && + gamma_table != NULL) + { + sp = row; + dp = row; + for (i = 0; i < row_width; i++, sp += 2, dp++) + { + png_uint_16 a = *(sp + 1); + + if (a == 0xff) + *dp = gamma_table[*sp]; + + else if (a == 0) + { + /* Background is already in screen gamma */ + *dp = (png_byte)background->gray; + } + + else + { + png_byte v, w; + + v = gamma_to_1[*sp]; + png_composite(w, v, a, background_1->gray); + *dp = gamma_from_1[w]; + } + } + } + else +#endif + { + sp = row; + dp = row; + for (i = 0; i < row_width; i++, sp += 2, dp++) + { + png_byte a = *(sp + 1); + + if (a == 0xff) + *dp = *sp; + +#ifdef PNG_READ_GAMMA_SUPPORTED + else if (a == 0) + *dp = (png_byte)background->gray; + + else + png_composite(*dp, *sp, a, background_1->gray); + +#else + *dp = (png_byte)background->gray; +#endif + } + } + } + else /* if (png_ptr->bit_depth == 16) */ + { +#ifdef PNG_READ_GAMMA_SUPPORTED + if (gamma_16 != NULL && gamma_16_from_1 != NULL && + gamma_16_to_1 != NULL) + { + sp = row; + dp = row; + for (i = 0; i < row_width; i++, sp += 4, dp += 2) + { + png_uint_16 a = (png_uint_16)(((*(sp + 2)) << 8) + + *(sp + 3)); + + if (a == (png_uint_16)0xffff) + { + png_uint_16 v; + + v = gamma_16[*(sp + 1) >> gamma_shift][*sp]; + *dp = (png_byte)((v >> 8) & 0xff); + *(dp + 1) = (png_byte)(v & 0xff); + } + +#ifdef PNG_READ_GAMMA_SUPPORTED + else if (a == 0) +#else + else +#endif + { + /* Background is already in screen gamma */ + *dp = (png_byte)((background->gray >> 8) & 0xff); + *(dp + 1) = (png_byte)(background->gray & 0xff); + } + +#ifdef PNG_READ_GAMMA_SUPPORTED + else + { + png_uint_16 g, v, w; + + g = gamma_16_to_1[*(sp + 1) >> gamma_shift][*sp]; + png_composite_16(v, g, a, background_1->gray); + w = gamma_16_from_1[(v&0xff) >> gamma_shift][v >> 8]; + *dp = (png_byte)((w >> 8) & 0xff); + *(dp + 1) = (png_byte)(w & 0xff); + } +#endif + } + } + else +#endif + { + sp = row; + dp = row; + for (i = 0; i < row_width; i++, sp += 4, dp += 2) + { + png_uint_16 a = (png_uint_16)(((*(sp + 2)) << 8) + + *(sp + 3)); + + if (a == (png_uint_16)0xffff) + png_memcpy(dp, sp, 2); + +#ifdef PNG_READ_GAMMA_SUPPORTED + else if (a == 0) +#else + else +#endif + { + *dp = (png_byte)((background->gray >> 8) & 0xff); + *(dp + 1) = (png_byte)(background->gray & 0xff); + } + +#ifdef PNG_READ_GAMMA_SUPPORTED + else + { + png_uint_16 g, v; + + g = (png_uint_16)(((*sp) << 8) + *(sp + 1)); + png_composite_16(v, g, a, background_1->gray); + *dp = (png_byte)((v >> 8) & 0xff); + *(dp + 1) = (png_byte)(v & 0xff); + } +#endif + } + } + } + break; + } + + case PNG_COLOR_TYPE_RGB_ALPHA: + { + if (row_info->bit_depth == 8) + { +#ifdef PNG_READ_GAMMA_SUPPORTED + if (gamma_to_1 != NULL && gamma_from_1 != NULL && + gamma_table != NULL) + { + sp = row; + dp = row; + for (i = 0; i < row_width; i++, sp += 4, dp += 3) + { + png_byte a = *(sp + 3); + + if (a == 0xff) + { + *dp = gamma_table[*sp]; + *(dp + 1) = gamma_table[*(sp + 1)]; + *(dp + 2) = gamma_table[*(sp + 2)]; + } + + else if (a == 0) + { + /* Background is already in screen gamma */ + *dp = (png_byte)background->red; + *(dp + 1) = (png_byte)background->green; + *(dp + 2) = (png_byte)background->blue; + } + + else + { + png_byte v, w; + + v = gamma_to_1[*sp]; + png_composite(w, v, a, background_1->red); + *dp = gamma_from_1[w]; + + v = gamma_to_1[*(sp + 1)]; + png_composite(w, v, a, background_1->green); + *(dp + 1) = gamma_from_1[w]; + + v = gamma_to_1[*(sp + 2)]; + png_composite(w, v, a, background_1->blue); + *(dp + 2) = gamma_from_1[w]; + } + } + } + else +#endif + { + sp = row; + dp = row; + for (i = 0; i < row_width; i++, sp += 4, dp += 3) + { + png_byte a = *(sp + 3); + + if (a == 0xff) + { + *dp = *sp; + *(dp + 1) = *(sp + 1); + *(dp + 2) = *(sp + 2); + } + + else if (a == 0) + { + *dp = (png_byte)background->red; + *(dp + 1) = (png_byte)background->green; + *(dp + 2) = (png_byte)background->blue; + } + + else + { + png_composite(*dp, *sp, a, background->red); + + png_composite(*(dp + 1), *(sp + 1), a, + background->green); + + png_composite(*(dp + 2), *(sp + 2), a, + background->blue); + } + } + } + } + else /* if (row_info->bit_depth == 16) */ + { +#ifdef PNG_READ_GAMMA_SUPPORTED + if (gamma_16 != NULL && gamma_16_from_1 != NULL && + gamma_16_to_1 != NULL) + { + sp = row; + dp = row; + for (i = 0; i < row_width; i++, sp += 8, dp += 6) + { + png_uint_16 a = (png_uint_16)(((png_uint_16)(*(sp + 6)) + << 8) + (png_uint_16)(*(sp + 7))); + + if (a == (png_uint_16)0xffff) + { + png_uint_16 v; + + v = gamma_16[*(sp + 1) >> gamma_shift][*sp]; + *dp = (png_byte)((v >> 8) & 0xff); + *(dp + 1) = (png_byte)(v & 0xff); + + v = gamma_16[*(sp + 3) >> gamma_shift][*(sp + 2)]; + *(dp + 2) = (png_byte)((v >> 8) & 0xff); + *(dp + 3) = (png_byte)(v & 0xff); + + v = gamma_16[*(sp + 5) >> gamma_shift][*(sp + 4)]; + *(dp + 4) = (png_byte)((v >> 8) & 0xff); + *(dp + 5) = (png_byte)(v & 0xff); + } + + else if (a == 0) + { + /* Background is already in screen gamma */ + *dp = (png_byte)((background->red >> 8) & 0xff); + *(dp + 1) = (png_byte)(background->red & 0xff); + *(dp + 2) = (png_byte)((background->green >> 8) & 0xff); + *(dp + 3) = (png_byte)(background->green & 0xff); + *(dp + 4) = (png_byte)((background->blue >> 8) & 0xff); + *(dp + 5) = (png_byte)(background->blue & 0xff); + } + + else + { + png_uint_16 v, w, x; + + v = gamma_16_to_1[*(sp + 1) >> gamma_shift][*sp]; + png_composite_16(w, v, a, background_1->red); + + x = gamma_16_from_1[((w&0xff) >> gamma_shift)][w >> 8]; + *dp = (png_byte)((x >> 8) & 0xff); + *(dp + 1) = (png_byte)(x & 0xff); + + v = gamma_16_to_1[*(sp + 3) >> gamma_shift][*(sp + 2)]; + png_composite_16(w, v, a, background_1->green); + + x = gamma_16_from_1[((w&0xff) >> gamma_shift)][w >> 8]; + *(dp + 2) = (png_byte)((x >> 8) & 0xff); + *(dp + 3) = (png_byte)(x & 0xff); + + v = gamma_16_to_1[*(sp + 5) >> gamma_shift][*(sp + 4)]; + png_composite_16(w, v, a, background_1->blue); + + x = gamma_16_from_1[(w & 0xff) >> gamma_shift][w >> 8]; + *(dp + 4) = (png_byte)((x >> 8) & 0xff); + *(dp + 5) = (png_byte)(x & 0xff); + } + } + } + + else +#endif + { + sp = row; + dp = row; + for (i = 0; i < row_width; i++, sp += 8, dp += 6) + { + png_uint_16 a = (png_uint_16)(((png_uint_16)(*(sp + 6)) + << 8) + (png_uint_16)(*(sp + 7))); + + if (a == (png_uint_16)0xffff) + { + png_memcpy(dp, sp, 6); + } + + else if (a == 0) + { + *dp = (png_byte)((background->red >> 8) & 0xff); + *(dp + 1) = (png_byte)(background->red & 0xff); + *(dp + 2) = (png_byte)((background->green >> 8) & 0xff); + *(dp + 3) = (png_byte)(background->green & 0xff); + *(dp + 4) = (png_byte)((background->blue >> 8) & 0xff); + *(dp + 5) = (png_byte)(background->blue & 0xff); + } + + else + { + png_uint_16 v; + + png_uint_16 r = (png_uint_16)(((*sp) << 8) + *(sp + 1)); + png_uint_16 g = (png_uint_16)(((*(sp + 2)) << 8) + + *(sp + 3)); + png_uint_16 b = (png_uint_16)(((*(sp + 4)) << 8) + + *(sp + 5)); + + png_composite_16(v, r, a, background->red); + *dp = (png_byte)((v >> 8) & 0xff); + *(dp + 1) = (png_byte)(v & 0xff); + + png_composite_16(v, g, a, background->green); + *(dp + 2) = (png_byte)((v >> 8) & 0xff); + *(dp + 3) = (png_byte)(v & 0xff); + + png_composite_16(v, b, a, background->blue); + *(dp + 4) = (png_byte)((v >> 8) & 0xff); + *(dp + 5) = (png_byte)(v & 0xff); + } + } + } + } + break; + } + + default: + break; + } + + if (row_info->color_type & PNG_COLOR_MASK_ALPHA) + { + row_info->color_type = (png_byte)(row_info->color_type & + ~PNG_COLOR_MASK_ALPHA); + row_info->channels--; + row_info->pixel_depth = (png_byte)(row_info->channels * + row_info->bit_depth); + row_info->rowbytes = PNG_ROWBYTES(row_info->pixel_depth, row_width); + } + } +} +#endif + +#ifdef PNG_READ_GAMMA_SUPPORTED +/* Gamma correct the image, avoiding the alpha channel. Make sure + * you do this after you deal with the transparency issue on grayscale + * or RGB images. If your bit depth is 8, use gamma_table, if it + * is 16, use gamma_16_table and gamma_shift. Build these with + * build_gamma_table(). + */ +void /* PRIVATE */ +png_do_gamma(png_row_infop row_info, png_bytep row, + png_const_bytep gamma_table, png_const_uint_16pp gamma_16_table, + int gamma_shift) +{ + png_bytep sp; + png_uint_32 i; + png_uint_32 row_width=row_info->width; + + png_debug(1, "in png_do_gamma"); + + if (((row_info->bit_depth <= 8 && gamma_table != NULL) || + (row_info->bit_depth == 16 && gamma_16_table != NULL))) + { + switch (row_info->color_type) + { + case PNG_COLOR_TYPE_RGB: + { + if (row_info->bit_depth == 8) + { + sp = row; + for (i = 0; i < row_width; i++) + { + *sp = gamma_table[*sp]; + sp++; + *sp = gamma_table[*sp]; + sp++; + *sp = gamma_table[*sp]; + sp++; + } + } + + else /* if (row_info->bit_depth == 16) */ + { + sp = row; + for (i = 0; i < row_width; i++) + { + png_uint_16 v; + + v = gamma_16_table[*(sp + 1) >> gamma_shift][*sp]; + *sp = (png_byte)((v >> 8) & 0xff); + *(sp + 1) = (png_byte)(v & 0xff); + sp += 2; + + v = gamma_16_table[*(sp + 1) >> gamma_shift][*sp]; + *sp = (png_byte)((v >> 8) & 0xff); + *(sp + 1) = (png_byte)(v & 0xff); + sp += 2; + + v = gamma_16_table[*(sp + 1) >> gamma_shift][*sp]; + *sp = (png_byte)((v >> 8) & 0xff); + *(sp + 1) = (png_byte)(v & 0xff); + sp += 2; + } + } + break; + } + + case PNG_COLOR_TYPE_RGB_ALPHA: + { + if (row_info->bit_depth == 8) + { + sp = row; + for (i = 0; i < row_width; i++) + { + *sp = gamma_table[*sp]; + sp++; + + *sp = gamma_table[*sp]; + sp++; + + *sp = gamma_table[*sp]; + sp++; + + sp++; + } + } + + else /* if (row_info->bit_depth == 16) */ + { + sp = row; + for (i = 0; i < row_width; i++) + { + png_uint_16 v = gamma_16_table[*(sp + 1) >> gamma_shift][*sp]; + *sp = (png_byte)((v >> 8) & 0xff); + *(sp + 1) = (png_byte)(v & 0xff); + sp += 2; + + v = gamma_16_table[*(sp + 1) >> gamma_shift][*sp]; + *sp = (png_byte)((v >> 8) & 0xff); + *(sp + 1) = (png_byte)(v & 0xff); + sp += 2; + + v = gamma_16_table[*(sp + 1) >> gamma_shift][*sp]; + *sp = (png_byte)((v >> 8) & 0xff); + *(sp + 1) = (png_byte)(v & 0xff); + sp += 4; + } + } + break; + } + + case PNG_COLOR_TYPE_GRAY_ALPHA: + { + if (row_info->bit_depth == 8) + { + sp = row; + for (i = 0; i < row_width; i++) + { + *sp = gamma_table[*sp]; + sp += 2; + } + } + + else /* if (row_info->bit_depth == 16) */ + { + sp = row; + for (i = 0; i < row_width; i++) + { + png_uint_16 v = gamma_16_table[*(sp + 1) >> gamma_shift][*sp]; + *sp = (png_byte)((v >> 8) & 0xff); + *(sp + 1) = (png_byte)(v & 0xff); + sp += 4; + } + } + break; + } + + case PNG_COLOR_TYPE_GRAY: + { + if (row_info->bit_depth == 2) + { + sp = row; + for (i = 0; i < row_width; i += 4) + { + int a = *sp & 0xc0; + int b = *sp & 0x30; + int c = *sp & 0x0c; + int d = *sp & 0x03; + + *sp = (png_byte)( + ((((int)gamma_table[a|(a>>2)|(a>>4)|(a>>6)]) ) & 0xc0)| + ((((int)gamma_table[(b<<2)|b|(b>>2)|(b>>4)])>>2) & 0x30)| + ((((int)gamma_table[(c<<4)|(c<<2)|c|(c>>2)])>>4) & 0x0c)| + ((((int)gamma_table[(d<<6)|(d<<4)|(d<<2)|d])>>6) )); + sp++; + } + } + + if (row_info->bit_depth == 4) + { + sp = row; + for (i = 0; i < row_width; i += 2) + { + int msb = *sp & 0xf0; + int lsb = *sp & 0x0f; + + *sp = (png_byte)((((int)gamma_table[msb | (msb >> 4)]) & 0xf0) + | (((int)gamma_table[(lsb << 4) | lsb]) >> 4)); + sp++; + } + } + + else if (row_info->bit_depth == 8) + { + sp = row; + for (i = 0; i < row_width; i++) + { + *sp = gamma_table[*sp]; + sp++; + } + } + + else if (row_info->bit_depth == 16) + { + sp = row; + for (i = 0; i < row_width; i++) + { + png_uint_16 v = gamma_16_table[*(sp + 1) >> gamma_shift][*sp]; + *sp = (png_byte)((v >> 8) & 0xff); + *(sp + 1) = (png_byte)(v & 0xff); + sp += 2; + } + } + break; + } + + default: + break; + } + } +} +#endif + +#ifdef PNG_READ_EXPAND_SUPPORTED +/* Expands a palette row to an RGB or RGBA row depending + * upon whether you supply trans and num_trans. + */ +void /* PRIVATE */ +png_do_expand_palette(png_row_infop row_info, png_bytep row, + png_const_colorp palette, png_const_bytep trans_alpha, int num_trans) +{ + int shift, value; + png_bytep sp, dp; + png_uint_32 i; + png_uint_32 row_width=row_info->width; + + png_debug(1, "in png_do_expand_palette"); + + if (row_info->color_type == PNG_COLOR_TYPE_PALETTE) + { + if (row_info->bit_depth < 8) + { + switch (row_info->bit_depth) + { + case 1: + { + sp = row + (png_size_t)((row_width - 1) >> 3); + dp = row + (png_size_t)row_width - 1; + shift = 7 - (int)((row_width + 7) & 0x07); + for (i = 0; i < row_width; i++) + { + if ((*sp >> shift) & 0x01) + *dp = 1; + + else + *dp = 0; + + if (shift == 7) + { + shift = 0; + sp--; + } + + else + shift++; + + dp--; + } + break; + } + + case 2: + { + sp = row + (png_size_t)((row_width - 1) >> 2); + dp = row + (png_size_t)row_width - 1; + shift = (int)((3 - ((row_width + 3) & 0x03)) << 1); + for (i = 0; i < row_width; i++) + { + value = (*sp >> shift) & 0x03; + *dp = (png_byte)value; + if (shift == 6) + { + shift = 0; + sp--; + } + + else + shift += 2; + + dp--; + } + break; + } + + case 4: + { + sp = row + (png_size_t)((row_width - 1) >> 1); + dp = row + (png_size_t)row_width - 1; + shift = (int)((row_width & 0x01) << 2); + for (i = 0; i < row_width; i++) + { + value = (*sp >> shift) & 0x0f; + *dp = (png_byte)value; + if (shift == 4) + { + shift = 0; + sp--; + } + + else + shift += 4; + + dp--; + } + break; + } + + default: + break; + } + row_info->bit_depth = 8; + row_info->pixel_depth = 8; + row_info->rowbytes = row_width; + } + + if (row_info->bit_depth == 8) + { + { + if (trans_alpha != NULL) + { + sp = row + (png_size_t)row_width - 1; + dp = row + (png_size_t)(row_width << 2) - 1; + + for (i = 0; i < row_width; i++) + { + if ((int)(*sp) >= num_trans) + *dp-- = 0xff; + + else + *dp-- = trans_alpha[*sp]; + + *dp-- = palette[*sp].blue; + *dp-- = palette[*sp].green; + *dp-- = palette[*sp].red; + sp--; + } + row_info->bit_depth = 8; + row_info->pixel_depth = 32; + row_info->rowbytes = row_width * 4; + row_info->color_type = 6; + row_info->channels = 4; + } + + else + { + sp = row + (png_size_t)row_width - 1; + dp = row + (png_size_t)(row_width * 3) - 1; + + for (i = 0; i < row_width; i++) + { + *dp-- = palette[*sp].blue; + *dp-- = palette[*sp].green; + *dp-- = palette[*sp].red; + sp--; + } + + row_info->bit_depth = 8; + row_info->pixel_depth = 24; + row_info->rowbytes = row_width * 3; + row_info->color_type = 2; + row_info->channels = 3; + } + } + } + } +} + +/* If the bit depth < 8, it is expanded to 8. Also, if the already + * expanded transparency value is supplied, an alpha channel is built. + */ +void /* PRIVATE */ +png_do_expand(png_row_infop row_info, png_bytep row, + png_const_color_16p trans_value) +{ + int shift, value; + png_bytep sp, dp; + png_uint_32 i; + png_uint_32 row_width=row_info->width; + + png_debug(1, "in png_do_expand"); + + { + if (row_info->color_type == PNG_COLOR_TYPE_GRAY) + { + png_uint_16 gray = (png_uint_16)(trans_value ? trans_value->gray : 0); + + if (row_info->bit_depth < 8) + { + switch (row_info->bit_depth) + { + case 1: + { + gray = (png_uint_16)((gray & 0x01) * 0xff); + sp = row + (png_size_t)((row_width - 1) >> 3); + dp = row + (png_size_t)row_width - 1; + shift = 7 - (int)((row_width + 7) & 0x07); + for (i = 0; i < row_width; i++) + { + if ((*sp >> shift) & 0x01) + *dp = 0xff; + + else + *dp = 0; + + if (shift == 7) + { + shift = 0; + sp--; + } + + else + shift++; + + dp--; + } + break; + } + + case 2: + { + gray = (png_uint_16)((gray & 0x03) * 0x55); + sp = row + (png_size_t)((row_width - 1) >> 2); + dp = row + (png_size_t)row_width - 1; + shift = (int)((3 - ((row_width + 3) & 0x03)) << 1); + for (i = 0; i < row_width; i++) + { + value = (*sp >> shift) & 0x03; + *dp = (png_byte)(value | (value << 2) | (value << 4) | + (value << 6)); + if (shift == 6) + { + shift = 0; + sp--; + } + + else + shift += 2; + + dp--; + } + break; + } + + case 4: + { + gray = (png_uint_16)((gray & 0x0f) * 0x11); + sp = row + (png_size_t)((row_width - 1) >> 1); + dp = row + (png_size_t)row_width - 1; + shift = (int)((1 - ((row_width + 1) & 0x01)) << 2); + for (i = 0; i < row_width; i++) + { + value = (*sp >> shift) & 0x0f; + *dp = (png_byte)(value | (value << 4)); + if (shift == 4) + { + shift = 0; + sp--; + } + + else + shift = 4; + + dp--; + } + break; + } + + default: + break; + } + + row_info->bit_depth = 8; + row_info->pixel_depth = 8; + row_info->rowbytes = row_width; + } + + if (trans_value != NULL) + { + if (row_info->bit_depth == 8) + { + gray = gray & 0xff; + sp = row + (png_size_t)row_width - 1; + dp = row + (png_size_t)(row_width << 1) - 1; + + for (i = 0; i < row_width; i++) + { + if (*sp == gray) + *dp-- = 0; + + else + *dp-- = 0xff; + + *dp-- = *sp--; + } + } + + else if (row_info->bit_depth == 16) + { + png_byte gray_high = (png_byte)((gray >> 8) & 0xff); + png_byte gray_low = (png_byte)(gray & 0xff); + sp = row + row_info->rowbytes - 1; + dp = row + (row_info->rowbytes << 1) - 1; + for (i = 0; i < row_width; i++) + { + if (*(sp - 1) == gray_high && *(sp) == gray_low) + { + *dp-- = 0; + *dp-- = 0; + } + + else + { + *dp-- = 0xff; + *dp-- = 0xff; + } + + *dp-- = *sp--; + *dp-- = *sp--; + } + } + + row_info->color_type = PNG_COLOR_TYPE_GRAY_ALPHA; + row_info->channels = 2; + row_info->pixel_depth = (png_byte)(row_info->bit_depth << 1); + row_info->rowbytes = PNG_ROWBYTES(row_info->pixel_depth, + row_width); + } + } + else if (row_info->color_type == PNG_COLOR_TYPE_RGB && trans_value) + { + if (row_info->bit_depth == 8) + { + png_byte red = (png_byte)(trans_value->red & 0xff); + png_byte green = (png_byte)(trans_value->green & 0xff); + png_byte blue = (png_byte)(trans_value->blue & 0xff); + sp = row + (png_size_t)row_info->rowbytes - 1; + dp = row + (png_size_t)(row_width << 2) - 1; + for (i = 0; i < row_width; i++) + { + if (*(sp - 2) == red && *(sp - 1) == green && *(sp) == blue) + *dp-- = 0; + + else + *dp-- = 0xff; + + *dp-- = *sp--; + *dp-- = *sp--; + *dp-- = *sp--; + } + } + else if (row_info->bit_depth == 16) + { + png_byte red_high = (png_byte)((trans_value->red >> 8) & 0xff); + png_byte green_high = (png_byte)((trans_value->green >> 8) & 0xff); + png_byte blue_high = (png_byte)((trans_value->blue >> 8) & 0xff); + png_byte red_low = (png_byte)(trans_value->red & 0xff); + png_byte green_low = (png_byte)(trans_value->green & 0xff); + png_byte blue_low = (png_byte)(trans_value->blue & 0xff); + sp = row + row_info->rowbytes - 1; + dp = row + (png_size_t)(row_width << 3) - 1; + for (i = 0; i < row_width; i++) + { + if (*(sp - 5) == red_high && + *(sp - 4) == red_low && + *(sp - 3) == green_high && + *(sp - 2) == green_low && + *(sp - 1) == blue_high && + *(sp ) == blue_low) + { + *dp-- = 0; + *dp-- = 0; + } + + else + { + *dp-- = 0xff; + *dp-- = 0xff; + } + + *dp-- = *sp--; + *dp-- = *sp--; + *dp-- = *sp--; + *dp-- = *sp--; + *dp-- = *sp--; + *dp-- = *sp--; + } + } + row_info->color_type = PNG_COLOR_TYPE_RGB_ALPHA; + row_info->channels = 4; + row_info->pixel_depth = (png_byte)(row_info->bit_depth << 2); + row_info->rowbytes = PNG_ROWBYTES(row_info->pixel_depth, row_width); + } + } +} +#endif + +#ifdef PNG_READ_QUANTIZE_SUPPORTED +void /* PRIVATE */ +png_do_quantize(png_row_infop row_info, png_bytep row, + png_const_bytep palette_lookup, png_const_bytep quantize_lookup) +{ + png_bytep sp, dp; + png_uint_32 i; + png_uint_32 row_width=row_info->width; + + png_debug(1, "in png_do_quantize"); + + if (row_info->bit_depth == 8) + { + if (row_info->color_type == PNG_COLOR_TYPE_RGB && palette_lookup) + { + int r, g, b, p; + sp = row; + dp = row; + for (i = 0; i < row_width; i++) + { + r = *sp++; + g = *sp++; + b = *sp++; + + /* This looks real messy, but the compiler will reduce + * it down to a reasonable formula. For example, with + * 5 bits per color, we get: + * p = (((r >> 3) & 0x1f) << 10) | + * (((g >> 3) & 0x1f) << 5) | + * ((b >> 3) & 0x1f); + */ + p = (((r >> (8 - PNG_QUANTIZE_RED_BITS)) & + ((1 << PNG_QUANTIZE_RED_BITS) - 1)) << + (PNG_QUANTIZE_GREEN_BITS + PNG_QUANTIZE_BLUE_BITS)) | + (((g >> (8 - PNG_QUANTIZE_GREEN_BITS)) & + ((1 << PNG_QUANTIZE_GREEN_BITS) - 1)) << + (PNG_QUANTIZE_BLUE_BITS)) | + ((b >> (8 - PNG_QUANTIZE_BLUE_BITS)) & + ((1 << PNG_QUANTIZE_BLUE_BITS) - 1)); + + *dp++ = palette_lookup[p]; + } + + row_info->color_type = PNG_COLOR_TYPE_PALETTE; + row_info->channels = 1; + row_info->pixel_depth = row_info->bit_depth; + row_info->rowbytes = PNG_ROWBYTES(row_info->pixel_depth, row_width); + } + + else if (row_info->color_type == PNG_COLOR_TYPE_RGB_ALPHA && + palette_lookup != NULL) + { + int r, g, b, p; + sp = row; + dp = row; + for (i = 0; i < row_width; i++) + { + r = *sp++; + g = *sp++; + b = *sp++; + sp++; + + p = (((r >> (8 - PNG_QUANTIZE_RED_BITS)) & + ((1 << PNG_QUANTIZE_RED_BITS) - 1)) << + (PNG_QUANTIZE_GREEN_BITS + PNG_QUANTIZE_BLUE_BITS)) | + (((g >> (8 - PNG_QUANTIZE_GREEN_BITS)) & + ((1 << PNG_QUANTIZE_GREEN_BITS) - 1)) << + (PNG_QUANTIZE_BLUE_BITS)) | + ((b >> (8 - PNG_QUANTIZE_BLUE_BITS)) & + ((1 << PNG_QUANTIZE_BLUE_BITS) - 1)); + + *dp++ = palette_lookup[p]; + } + + row_info->color_type = PNG_COLOR_TYPE_PALETTE; + row_info->channels = 1; + row_info->pixel_depth = row_info->bit_depth; + row_info->rowbytes = PNG_ROWBYTES(row_info->pixel_depth, row_width); + } + + else if (row_info->color_type == PNG_COLOR_TYPE_PALETTE && + quantize_lookup) + { + sp = row; + + for (i = 0; i < row_width; i++, sp++) + { + *sp = quantize_lookup[*sp]; + } + } + } +} +#endif /* PNG_READ_QUANTIZE_SUPPORTED */ + +#ifdef PNG_MNG_FEATURES_SUPPORTED +/* Undoes intrapixel differencing */ +void /* PRIVATE */ +png_do_read_intrapixel(png_row_infop row_info, png_bytep row) +{ + png_debug(1, "in png_do_read_intrapixel"); + + if ( + (row_info->color_type & PNG_COLOR_MASK_COLOR)) + { + int bytes_per_pixel; + png_uint_32 row_width = row_info->width; + + if (row_info->bit_depth == 8) + { + png_bytep rp; + png_uint_32 i; + + if (row_info->color_type == PNG_COLOR_TYPE_RGB) + bytes_per_pixel = 3; + + else if (row_info->color_type == PNG_COLOR_TYPE_RGB_ALPHA) + bytes_per_pixel = 4; + + else + return; + + for (i = 0, rp = row; i < row_width; i++, rp += bytes_per_pixel) + { + *(rp) = (png_byte)((256 + *rp + *(rp + 1)) & 0xff); + *(rp+2) = (png_byte)((256 + *(rp + 2) + *(rp + 1)) & 0xff); + } + } + else if (row_info->bit_depth == 16) + { + png_bytep rp; + png_uint_32 i; + + if (row_info->color_type == PNG_COLOR_TYPE_RGB) + bytes_per_pixel = 6; + + else if (row_info->color_type == PNG_COLOR_TYPE_RGB_ALPHA) + bytes_per_pixel = 8; + + else + return; + + for (i = 0, rp = row; i < row_width; i++, rp += bytes_per_pixel) + { + png_uint_32 s0 = (*(rp ) << 8) | *(rp + 1); + png_uint_32 s1 = (*(rp + 2) << 8) | *(rp + 3); + png_uint_32 s2 = (*(rp + 4) << 8) | *(rp + 5); + png_uint_32 red = (png_uint_32)((s0 + s1 + 65536L) & 0xffffL); + png_uint_32 blue = (png_uint_32)((s2 + s1 + 65536L) & 0xffffL); + *(rp ) = (png_byte)((red >> 8) & 0xff); + *(rp + 1) = (png_byte)(red & 0xff); + *(rp + 4) = (png_byte)((blue >> 8) & 0xff); + *(rp + 5) = (png_byte)(blue & 0xff); + } + } + } +} +#endif /* PNG_MNG_FEATURES_SUPPORTED */ +#endif /* PNG_READ_SUPPORTED */ diff --git a/src/3rdparty/libpng/pngrutil.c b/src/3rdparty/libpng/pngrutil.c new file mode 100644 index 0000000000..4c3cd53813 --- /dev/null +++ b/src/3rdparty/libpng/pngrutil.c @@ -0,0 +1,3616 @@ + +/* pngrutil.c - utilities to read a PNG file + * + * Last changed in libpng 1.5.1 [February 3, 2011] + * Copyright (c) 1998-2011 Glenn Randers-Pehrson + * (Version 0.96 Copyright (c) 1996, 1997 Andreas Dilger) + * (Version 0.88 Copyright (c) 1995, 1996 Guy Eric Schalnat, Group 42, Inc.) + * + * This code is released under the libpng license. + * For conditions of distribution and use, see the disclaimer + * and license in png.h + * + * This file contains routines that are only called from within + * libpng itself during the course of reading an image. + */ + +#include "pngpriv.h" + +#ifdef PNG_READ_SUPPORTED + +#define png_strtod(p,a,b) strtod(a,b) + +png_uint_32 PNGAPI +png_get_uint_31(png_structp png_ptr, png_const_bytep buf) +{ + png_uint_32 uval = png_get_uint_32(buf); + + if (uval > PNG_UINT_31_MAX) + png_error(png_ptr, "PNG unsigned integer out of range"); + + return (uval); +} + +#if defined(PNG_READ_gAMA_SUPPORTED) || defined(PNG_READ_cHRM_SUPPORTED) +/* The following is a variation on the above for use with the fixed + * point values used for gAMA and cHRM. Instead of png_error it + * issues a warning and returns (-1) - an invalid value because both + * gAMA and cHRM use *unsigned* integers for fixed point values. + */ +#define PNG_FIXED_ERROR (-1) + +static png_fixed_point /* PRIVATE */ +png_get_fixed_point(png_structp png_ptr, png_const_bytep buf) +{ + png_uint_32 uval = png_get_uint_32(buf); + + if (uval <= PNG_UINT_31_MAX) + return (png_fixed_point)uval; /* known to be in range */ + + /* The caller can turn off the warning by passing NULL. */ + if (png_ptr != NULL) + png_warning(png_ptr, "PNG fixed point integer out of range"); + + return PNG_FIXED_ERROR; +} +#endif + +#ifdef PNG_READ_INT_FUNCTIONS_SUPPORTED +/* NOTE: the read macros will obscure these definitions, so that if + * PNG_USE_READ_MACROS is set the library will not use them internally, + * but the APIs will still be available externally. + * + * The parentheses around "PNGAPI function_name" in the following three + * functions are necessary because they allow the macros to co-exist with + * these (unused but exported) functions. + */ + +/* Grab an unsigned 32-bit integer from a buffer in big-endian format. */ +png_uint_32 (PNGAPI +png_get_uint_32)(png_const_bytep buf) +{ + png_uint_32 uval = + ((png_uint_32)(*(buf )) << 24) + + ((png_uint_32)(*(buf + 1)) << 16) + + ((png_uint_32)(*(buf + 2)) << 8) + + ((png_uint_32)(*(buf + 3)) ) ; + + return uval; +} + +/* Grab a signed 32-bit integer from a buffer in big-endian format. The + * data is stored in the PNG file in two's complement format and there + * is no guarantee that a 'png_int_32' is exactly 32 bits, therefore + * the following code does a two's complement to native conversion. + */ +png_int_32 (PNGAPI +png_get_int_32)(png_const_bytep buf) +{ + png_uint_32 uval = png_get_uint_32(buf); + if ((uval & 0x80000000L) == 0) /* non-negative */ + return uval; + + uval = (uval ^ 0xffffffffL) + 1; /* 2's complement: -x = ~x+1 */ + return -(png_int_32)uval; +} + +/* Grab an unsigned 16-bit integer from a buffer in big-endian format. */ +png_uint_16 (PNGAPI +png_get_uint_16)(png_const_bytep buf) +{ + /* ANSI-C requires an int value to accomodate at least 16 bits so this + * works and allows the compiler not to worry about possible narrowing + * on 32 bit systems. (Pre-ANSI systems did not make integers smaller + * than 16 bits either.) + */ + unsigned int val = + ((unsigned int)(*buf) << 8) + + ((unsigned int)(*(buf + 1))); + + return (png_uint_16)val; +} + +#endif /* PNG_READ_INT_FUNCTIONS_SUPPORTED */ + +/* Read and check the PNG file signature */ +void /* PRIVATE */ +png_read_sig(png_structp png_ptr, png_infop info_ptr) +{ + png_size_t num_checked, num_to_check; + + /* Exit if the user application does not expect a signature. */ + if (png_ptr->sig_bytes >= 8) + return; + + num_checked = png_ptr->sig_bytes; + num_to_check = 8 - num_checked; + +#ifdef PNG_IO_STATE_SUPPORTED + png_ptr->io_state = PNG_IO_READING | PNG_IO_SIGNATURE; +#endif + + /* The signature must be serialized in a single I/O call. */ + png_read_data(png_ptr, &(info_ptr->signature[num_checked]), num_to_check); + png_ptr->sig_bytes = 8; + + if (png_sig_cmp(info_ptr->signature, num_checked, num_to_check)) + { + if (num_checked < 4 && + png_sig_cmp(info_ptr->signature, num_checked, num_to_check - 4)) + png_error(png_ptr, "Not a PNG file"); + else + png_error(png_ptr, "PNG file corrupted by ASCII conversion"); + } + if (num_checked < 3) + png_ptr->mode |= PNG_HAVE_PNG_SIGNATURE; +} + +/* Read the chunk header (length + type name). + * Put the type name into png_ptr->chunk_name, and return the length. + */ +png_uint_32 /* PRIVATE */ +png_read_chunk_header(png_structp png_ptr) +{ + png_byte buf[8]; + png_uint_32 length; + +#ifdef PNG_IO_STATE_SUPPORTED + png_ptr->io_state = PNG_IO_READING | PNG_IO_CHUNK_HDR; +#endif + + /* Read the length and the chunk name. + * This must be performed in a single I/O call. + */ + png_read_data(png_ptr, buf, 8); + length = png_get_uint_31(png_ptr, buf); + + /* Put the chunk name into png_ptr->chunk_name. */ + png_memcpy(png_ptr->chunk_name, buf + 4, 4); + + png_debug2(0, "Reading %s chunk, length = %u", + png_ptr->chunk_name, length); + + /* Reset the crc and run it over the chunk name. */ + png_reset_crc(png_ptr); + png_calculate_crc(png_ptr, png_ptr->chunk_name, 4); + + /* Check to see if chunk name is valid. */ + png_check_chunk_name(png_ptr, png_ptr->chunk_name); + +#ifdef PNG_IO_STATE_SUPPORTED + png_ptr->io_state = PNG_IO_READING | PNG_IO_CHUNK_DATA; +#endif + + return length; +} + +/* Read data, and (optionally) run it through the CRC. */ +void /* PRIVATE */ +png_crc_read(png_structp png_ptr, png_bytep buf, png_size_t length) +{ + if (png_ptr == NULL) + return; + + png_read_data(png_ptr, buf, length); + png_calculate_crc(png_ptr, buf, length); +} + +/* Optionally skip data and then check the CRC. Depending on whether we + * are reading a ancillary or critical chunk, and how the program has set + * things up, we may calculate the CRC on the data and print a message. + * Returns '1' if there was a CRC error, '0' otherwise. + */ +int /* PRIVATE */ +png_crc_finish(png_structp png_ptr, png_uint_32 skip) +{ + png_size_t i; + png_size_t istop = png_ptr->zbuf_size; + + for (i = (png_size_t)skip; i > istop; i -= istop) + { + png_crc_read(png_ptr, png_ptr->zbuf, png_ptr->zbuf_size); + } + + if (i) + { + png_crc_read(png_ptr, png_ptr->zbuf, i); + } + + if (png_crc_error(png_ptr)) + { + if (((png_ptr->chunk_name[0] & 0x20) && /* Ancillary */ + !(png_ptr->flags & PNG_FLAG_CRC_ANCILLARY_NOWARN)) || + (!(png_ptr->chunk_name[0] & 0x20) && /* Critical */ + (png_ptr->flags & PNG_FLAG_CRC_CRITICAL_USE))) + { + png_chunk_warning(png_ptr, "CRC error"); + } + + else + { + png_chunk_benign_error(png_ptr, "CRC error"); + return (0); + } + + return (1); + } + + return (0); +} + +/* Compare the CRC stored in the PNG file with that calculated by libpng from + * the data it has read thus far. + */ +int /* PRIVATE */ +png_crc_error(png_structp png_ptr) +{ + png_byte crc_bytes[4]; + png_uint_32 crc; + int need_crc = 1; + + if (png_ptr->chunk_name[0] & 0x20) /* ancillary */ + { + if ((png_ptr->flags & PNG_FLAG_CRC_ANCILLARY_MASK) == + (PNG_FLAG_CRC_ANCILLARY_USE | PNG_FLAG_CRC_ANCILLARY_NOWARN)) + need_crc = 0; + } + + else /* critical */ + { + if (png_ptr->flags & PNG_FLAG_CRC_CRITICAL_IGNORE) + need_crc = 0; + } + +#ifdef PNG_IO_STATE_SUPPORTED + png_ptr->io_state = PNG_IO_READING | PNG_IO_CHUNK_CRC; +#endif + + /* The chunk CRC must be serialized in a single I/O call. */ + png_read_data(png_ptr, crc_bytes, 4); + + if (need_crc) + { + crc = png_get_uint_32(crc_bytes); + return ((int)(crc != png_ptr->crc)); + } + + else + return (0); +} + +#if defined(PNG_READ_zTXt_SUPPORTED) || defined(PNG_READ_iTXt_SUPPORTED) || \ + defined(PNG_READ_iCCP_SUPPORTED) +static png_size_t +png_inflate(png_structp png_ptr, png_bytep data, png_size_t size, + png_bytep output, png_size_t output_size) +{ + png_size_t count = 0; + + /* zlib can't necessarily handle more than 65535 bytes at once (i.e. it can't + * even necessarily handle 65536 bytes) because the type uInt is "16 bits or + * more". Consequently it is necessary to chunk the input to zlib. This + * code uses ZLIB_IO_MAX, from pngpriv.h, as the maximum (the maximum value + * that can be stored in a uInt.) It is possible to set ZLIB_IO_MAX to a + * lower value in pngpriv.h and this may sometimes have a performance + * advantage, because it forces access of the input data to be separated from + * at least some of the use by some period of time. + */ + png_ptr->zstream.next_in = data; + /* avail_in is set below from 'size' */ + png_ptr->zstream.avail_in = 0; + + while (1) + { + int ret, avail; + + /* The setting of 'avail_in' used to be outside the loop, by setting it + * inside it is possible to chunk the input to zlib and simply rely on + * zlib to advance the 'next_in' pointer. This allows arbitrary amounts o + * data to be passed through zlib at the unavoidable cost of requiring a + * window save (memcpy of up to 32768 output bytes) every ZLIB_IO_MAX + * input bytes. + */ + if (png_ptr->zstream.avail_in == 0 && size > 0) + { + if (size <= ZLIB_IO_MAX) + { + /* The value is less than ZLIB_IO_MAX so the cast is safe: */ + png_ptr->zstream.avail_in = (uInt)size; + size = 0; + } + + else + { + png_ptr->zstream.avail_in = ZLIB_IO_MAX; + size -= ZLIB_IO_MAX; + } + } + + /* Reset the output buffer each time round - we empty it + * after every inflate call. + */ + png_ptr->zstream.next_out = png_ptr->zbuf; + png_ptr->zstream.avail_out = png_ptr->zbuf_size; + + ret = inflate(&png_ptr->zstream, Z_NO_FLUSH); + avail = png_ptr->zbuf_size - png_ptr->zstream.avail_out; + + /* First copy/count any new output - but only if we didn't + * get an error code. + */ + if ((ret == Z_OK || ret == Z_STREAM_END) && avail > 0) + { + png_size_t space = avail; /* > 0, see above */ + + if (output != 0 && output_size > count) + { + png_size_t copy = output_size - count; + + if (space < copy) + copy = space; + + png_memcpy(output + count, png_ptr->zbuf, copy); + } + count += space; + } + + if (ret == Z_OK) + continue; + + /* Termination conditions - always reset the zstream, it + * must be left in inflateInit state. + */ + png_ptr->zstream.avail_in = 0; + inflateReset(&png_ptr->zstream); + + if (ret == Z_STREAM_END) + return count; /* NOTE: may be zero. */ + + /* Now handle the error codes - the API always returns 0 + * and the error message is dumped into the uncompressed + * buffer if available. + */ + { + PNG_CONST char *msg; +#ifdef PNG_CONSOLE_IO_SUPPORTED + char umsg[52]; +#endif + if (png_ptr->zstream.msg != 0) + msg = png_ptr->zstream.msg; + + else + { +#ifdef PNG_CONSOLE_IO_SUPPORTED + switch (ret) + { + case Z_BUF_ERROR: + msg = "Buffer error in compressed datastream in %s chunk"; + break; + + case Z_DATA_ERROR: + msg = "Data error in compressed datastream in %s chunk"; + break; + + default: + msg = "Incomplete compressed datastream in %s chunk"; + break; + } + + png_snprintf(umsg, sizeof umsg, msg, png_ptr->chunk_name); + msg = umsg; +#else + msg = "Damaged compressed datastream in chunk other than IDAT"; +#endif + } + + png_warning(png_ptr, msg); + } + + /* 0 means an error - notice that this code simply ignores + * zero length compressed chunks as a result. + */ + return 0; + } +} + +/* + * Decompress trailing data in a chunk. The assumption is that chunkdata + * points at an allocated area holding the contents of a chunk with a + * trailing compressed part. What we get back is an allocated area + * holding the original prefix part and an uncompressed version of the + * trailing part (the malloc area passed in is freed). + */ +void /* PRIVATE */ +png_decompress_chunk(png_structp png_ptr, int comp_type, + png_size_t chunklength, + png_size_t prefix_size, png_size_t *newlength) +{ + /* The caller should guarantee this */ + if (prefix_size > chunklength) + { + /* The recovery is to delete the chunk. */ + png_warning(png_ptr, "invalid chunklength"); + prefix_size = 0; /* To delete everything */ + } + + else if (comp_type == PNG_COMPRESSION_TYPE_BASE) + { + png_size_t expanded_size = png_inflate(png_ptr, + (png_bytep)(png_ptr->chunkdata + prefix_size), + chunklength - prefix_size, + 0, /*output*/ + 0); /*output size*/ + + /* Now check the limits on this chunk - if the limit fails the + * compressed data will be removed, the prefix will remain. + */ +#ifdef PNG_SET_CHUNK_MALLOC_LIMIT_SUPPORTED + if (png_ptr->user_chunk_malloc_max && + (prefix_size + expanded_size >= png_ptr->user_chunk_malloc_max - 1)) +#else +# ifdef PNG_USER_CHUNK_MALLOC_MAX + if ((PNG_USER_CHUNK_MALLOC_MAX > 0) && + prefix_size + expanded_size >= PNG_USER_CHUNK_MALLOC_MAX - 1) +# endif +#endif + png_warning(png_ptr, "Exceeded size limit while expanding chunk"); + + /* If the size is zero either there was an error and a message + * has already been output (warning) or the size really is zero + * and we have nothing to do - the code will exit through the + * error case below. + */ +#if defined(PNG_SET_CHUNK_MALLOC_LIMIT_SUPPORTED) || \ + defined(PNG_USER_CHUNK_MALLOC_MAX) + else if (expanded_size > 0) +#else + if (expanded_size > 0) +#endif + { + /* Success (maybe) - really uncompress the chunk. */ + png_size_t new_size = 0; + png_charp text = png_malloc_warn(png_ptr, + prefix_size + expanded_size + 1); + + if (text != NULL) + { + png_memcpy(text, png_ptr->chunkdata, prefix_size); + new_size = png_inflate(png_ptr, + (png_bytep)(png_ptr->chunkdata + prefix_size), + chunklength - prefix_size, + (png_bytep)(text + prefix_size), expanded_size); + text[prefix_size + expanded_size] = 0; /* just in case */ + + if (new_size == expanded_size) + { + png_free(png_ptr, png_ptr->chunkdata); + png_ptr->chunkdata = text; + *newlength = prefix_size + expanded_size; + return; /* The success return! */ + } + + png_warning(png_ptr, "png_inflate logic error"); + png_free(png_ptr, text); + } + + else + png_warning(png_ptr, "Not enough memory to decompress chunk"); + } + } + + else /* if (comp_type != PNG_COMPRESSION_TYPE_BASE) */ + { +#ifdef PNG_STDIO_SUPPORTED + char umsg[50]; + + png_snprintf(umsg, sizeof umsg, + "Unknown zTXt compression type %d", comp_type); + png_warning(png_ptr, umsg); +#else + png_warning(png_ptr, "Unknown zTXt compression type"); +#endif + + /* The recovery is to simply drop the data. */ + } + + /* Generic error return - leave the prefix, delete the compressed + * data, reallocate the chunkdata to remove the potentially large + * amount of compressed data. + */ + { + png_charp text = png_malloc_warn(png_ptr, prefix_size + 1); + + if (text != NULL) + { + if (prefix_size > 0) + png_memcpy(text, png_ptr->chunkdata, prefix_size); + + png_free(png_ptr, png_ptr->chunkdata); + png_ptr->chunkdata = text; + + /* This is an extra zero in the 'uncompressed' part. */ + *(png_ptr->chunkdata + prefix_size) = 0x00; + } + /* Ignore a malloc error here - it is safe. */ + } + + *newlength = prefix_size; +} +#endif + +/* Read and check the IDHR chunk */ +void /* PRIVATE */ +png_handle_IHDR(png_structp png_ptr, png_infop info_ptr, png_uint_32 length) +{ + png_byte buf[13]; + png_uint_32 width, height; + int bit_depth, color_type, compression_type, filter_type; + int interlace_type; + + png_debug(1, "in png_handle_IHDR"); + + if (png_ptr->mode & PNG_HAVE_IHDR) + png_error(png_ptr, "Out of place IHDR"); + + /* Check the length */ + if (length != 13) + png_error(png_ptr, "Invalid IHDR chunk"); + + png_ptr->mode |= PNG_HAVE_IHDR; + + png_crc_read(png_ptr, buf, 13); + png_crc_finish(png_ptr, 0); + + width = png_get_uint_31(png_ptr, buf); + height = png_get_uint_31(png_ptr, buf + 4); + bit_depth = buf[8]; + color_type = buf[9]; + compression_type = buf[10]; + filter_type = buf[11]; + interlace_type = buf[12]; + + /* Set internal variables */ + png_ptr->width = width; + png_ptr->height = height; + png_ptr->bit_depth = (png_byte)bit_depth; + png_ptr->interlaced = (png_byte)interlace_type; + png_ptr->color_type = (png_byte)color_type; +#ifdef PNG_MNG_FEATURES_SUPPORTED + png_ptr->filter_type = (png_byte)filter_type; +#endif + png_ptr->compression_type = (png_byte)compression_type; + + /* Find number of channels */ + switch (png_ptr->color_type) + { + default: /* invalid, png_set_IHDR calls png_error */ + case PNG_COLOR_TYPE_GRAY: + case PNG_COLOR_TYPE_PALETTE: + png_ptr->channels = 1; + break; + + case PNG_COLOR_TYPE_RGB: + png_ptr->channels = 3; + break; + + case PNG_COLOR_TYPE_GRAY_ALPHA: + png_ptr->channels = 2; + break; + + case PNG_COLOR_TYPE_RGB_ALPHA: + png_ptr->channels = 4; + break; + } + + /* Set up other useful info */ + png_ptr->pixel_depth = (png_byte)(png_ptr->bit_depth * + png_ptr->channels); + png_ptr->rowbytes = PNG_ROWBYTES(png_ptr->pixel_depth, png_ptr->width); + png_debug1(3, "bit_depth = %d", png_ptr->bit_depth); + png_debug1(3, "channels = %d", png_ptr->channels); + png_debug1(3, "rowbytes = %lu", (unsigned long)png_ptr->rowbytes); + png_set_IHDR(png_ptr, info_ptr, width, height, bit_depth, + color_type, interlace_type, compression_type, filter_type); +} + +/* Read and check the palette */ +void /* PRIVATE */ +png_handle_PLTE(png_structp png_ptr, png_infop info_ptr, png_uint_32 length) +{ + png_color palette[PNG_MAX_PALETTE_LENGTH]; + int num, i; +#ifdef PNG_POINTER_INDEXING_SUPPORTED + png_colorp pal_ptr; +#endif + + png_debug(1, "in png_handle_PLTE"); + + if (!(png_ptr->mode & PNG_HAVE_IHDR)) + png_error(png_ptr, "Missing IHDR before PLTE"); + + else if (png_ptr->mode & PNG_HAVE_IDAT) + { + png_warning(png_ptr, "Invalid PLTE after IDAT"); + png_crc_finish(png_ptr, length); + return; + } + + else if (png_ptr->mode & PNG_HAVE_PLTE) + png_error(png_ptr, "Duplicate PLTE chunk"); + + png_ptr->mode |= PNG_HAVE_PLTE; + + if (!(png_ptr->color_type&PNG_COLOR_MASK_COLOR)) + { + png_warning(png_ptr, + "Ignoring PLTE chunk in grayscale PNG"); + png_crc_finish(png_ptr, length); + return; + } + +#ifndef PNG_READ_OPT_PLTE_SUPPORTED + if (png_ptr->color_type != PNG_COLOR_TYPE_PALETTE) + { + png_crc_finish(png_ptr, length); + return; + } +#endif + + if (length > 3*PNG_MAX_PALETTE_LENGTH || length % 3) + { + if (png_ptr->color_type != PNG_COLOR_TYPE_PALETTE) + { + png_warning(png_ptr, "Invalid palette chunk"); + png_crc_finish(png_ptr, length); + return; + } + + else + { + png_error(png_ptr, "Invalid palette chunk"); + } + } + + num = (int)length / 3; + +#ifdef PNG_POINTER_INDEXING_SUPPORTED + for (i = 0, pal_ptr = palette; i < num; i++, pal_ptr++) + { + png_byte buf[3]; + + png_crc_read(png_ptr, buf, 3); + pal_ptr->red = buf[0]; + pal_ptr->green = buf[1]; + pal_ptr->blue = buf[2]; + } +#else + for (i = 0; i < num; i++) + { + png_byte buf[3]; + + png_crc_read(png_ptr, buf, 3); + /* Don't depend upon png_color being any order */ + palette[i].red = buf[0]; + palette[i].green = buf[1]; + palette[i].blue = buf[2]; + } +#endif + + /* If we actually need the PLTE chunk (ie for a paletted image), we do + * whatever the normal CRC configuration tells us. However, if we + * have an RGB image, the PLTE can be considered ancillary, so + * we will act as though it is. + */ +#ifndef PNG_READ_OPT_PLTE_SUPPORTED + if (png_ptr->color_type == PNG_COLOR_TYPE_PALETTE) +#endif + { + png_crc_finish(png_ptr, 0); + } + +#ifndef PNG_READ_OPT_PLTE_SUPPORTED + else if (png_crc_error(png_ptr)) /* Only if we have a CRC error */ + { + /* If we don't want to use the data from an ancillary chunk, + * we have two options: an error abort, or a warning and we + * ignore the data in this chunk (which should be OK, since + * it's considered ancillary for a RGB or RGBA image). + */ + if (!(png_ptr->flags & PNG_FLAG_CRC_ANCILLARY_USE)) + { + if (png_ptr->flags & PNG_FLAG_CRC_ANCILLARY_NOWARN) + { + png_chunk_benign_error(png_ptr, "CRC error"); + } + + else + { + png_chunk_warning(png_ptr, "CRC error"); + return; + } + } + + /* Otherwise, we (optionally) emit a warning and use the chunk. */ + else if (!(png_ptr->flags & PNG_FLAG_CRC_ANCILLARY_NOWARN)) + { + png_chunk_warning(png_ptr, "CRC error"); + } + } +#endif + + png_set_PLTE(png_ptr, info_ptr, palette, num); + +#ifdef PNG_READ_tRNS_SUPPORTED + if (png_ptr->color_type == PNG_COLOR_TYPE_PALETTE) + { + if (info_ptr != NULL && (info_ptr->valid & PNG_INFO_tRNS)) + { + if (png_ptr->num_trans > (png_uint_16)num) + { + png_warning(png_ptr, "Truncating incorrect tRNS chunk length"); + png_ptr->num_trans = (png_uint_16)num; + } + + if (info_ptr->num_trans > (png_uint_16)num) + { + png_warning(png_ptr, "Truncating incorrect info tRNS chunk length"); + info_ptr->num_trans = (png_uint_16)num; + } + } + } +#endif + +} + +void /* PRIVATE */ +png_handle_IEND(png_structp png_ptr, png_infop info_ptr, png_uint_32 length) +{ + png_debug(1, "in png_handle_IEND"); + + if (!(png_ptr->mode & PNG_HAVE_IHDR) || !(png_ptr->mode & PNG_HAVE_IDAT)) + { + png_error(png_ptr, "No image in file"); + } + + png_ptr->mode |= (PNG_AFTER_IDAT | PNG_HAVE_IEND); + + if (length != 0) + { + png_warning(png_ptr, "Incorrect IEND chunk length"); + } + + png_crc_finish(png_ptr, length); + + PNG_UNUSED(info_ptr) /* Quiet compiler warnings about unused info_ptr */ +} + +#ifdef PNG_READ_gAMA_SUPPORTED +void /* PRIVATE */ +png_handle_gAMA(png_structp png_ptr, png_infop info_ptr, png_uint_32 length) +{ + png_fixed_point igamma; + png_byte buf[4]; + + png_debug(1, "in png_handle_gAMA"); + + if (!(png_ptr->mode & PNG_HAVE_IHDR)) + png_error(png_ptr, "Missing IHDR before gAMA"); + + else if (png_ptr->mode & PNG_HAVE_IDAT) + { + png_warning(png_ptr, "Invalid gAMA after IDAT"); + png_crc_finish(png_ptr, length); + return; + } + + else if (png_ptr->mode & PNG_HAVE_PLTE) + /* Should be an error, but we can cope with it */ + png_warning(png_ptr, "Out of place gAMA chunk"); + + if (info_ptr != NULL && (info_ptr->valid & PNG_INFO_gAMA) +#ifdef PNG_READ_sRGB_SUPPORTED + && !(info_ptr->valid & PNG_INFO_sRGB) +#endif + ) + { + png_warning(png_ptr, "Duplicate gAMA chunk"); + png_crc_finish(png_ptr, length); + return; + } + + if (length != 4) + { + png_warning(png_ptr, "Incorrect gAMA chunk length"); + png_crc_finish(png_ptr, length); + return; + } + + png_crc_read(png_ptr, buf, 4); + + if (png_crc_finish(png_ptr, 0)) + return; + + igamma = png_get_fixed_point(NULL, buf); + + /* Check for zero gamma or an error. */ + if (igamma <= 0) + { + png_warning(png_ptr, + "Ignoring gAMA chunk with out of range gamma"); + + return; + } + +# ifdef PNG_READ_sRGB_SUPPORTED + if (info_ptr != NULL && (info_ptr->valid & PNG_INFO_sRGB)) + { + if (PNG_OUT_OF_RANGE(igamma, 45500L, 500)) + { + png_warning(png_ptr, + "Ignoring incorrect gAMA value when sRGB is also present"); + +# ifdef PNG_CONSOLE_IO_SUPPORTED + fprintf(stderr, "gamma = (%d/100000)", (int)igamma); +# endif + return; + } + } +# endif /* PNG_READ_sRGB_SUPPORTED */ + +# ifdef PNG_READ_GAMMA_SUPPORTED + /* Gamma correction on read is supported. */ + png_ptr->gamma = igamma; +# endif + /* And set the 'info' structure members. */ + png_set_gAMA_fixed(png_ptr, info_ptr, igamma); +} +#endif + +#ifdef PNG_READ_sBIT_SUPPORTED +void /* PRIVATE */ +png_handle_sBIT(png_structp png_ptr, png_infop info_ptr, png_uint_32 length) +{ + png_size_t truelen; + png_byte buf[4]; + + png_debug(1, "in png_handle_sBIT"); + + buf[0] = buf[1] = buf[2] = buf[3] = 0; + + if (!(png_ptr->mode & PNG_HAVE_IHDR)) + png_error(png_ptr, "Missing IHDR before sBIT"); + + else if (png_ptr->mode & PNG_HAVE_IDAT) + { + png_warning(png_ptr, "Invalid sBIT after IDAT"); + png_crc_finish(png_ptr, length); + return; + } + + else if (png_ptr->mode & PNG_HAVE_PLTE) + { + /* Should be an error, but we can cope with it */ + png_warning(png_ptr, "Out of place sBIT chunk"); + } + + if (info_ptr != NULL && (info_ptr->valid & PNG_INFO_sBIT)) + { + png_warning(png_ptr, "Duplicate sBIT chunk"); + png_crc_finish(png_ptr, length); + return; + } + + if (png_ptr->color_type == PNG_COLOR_TYPE_PALETTE) + truelen = 3; + + else + truelen = (png_size_t)png_ptr->channels; + + if (length != truelen || length > 4) + { + png_warning(png_ptr, "Incorrect sBIT chunk length"); + png_crc_finish(png_ptr, length); + return; + } + + png_crc_read(png_ptr, buf, truelen); + + if (png_crc_finish(png_ptr, 0)) + return; + + if (png_ptr->color_type & PNG_COLOR_MASK_COLOR) + { + png_ptr->sig_bit.red = buf[0]; + png_ptr->sig_bit.green = buf[1]; + png_ptr->sig_bit.blue = buf[2]; + png_ptr->sig_bit.alpha = buf[3]; + } + + else + { + png_ptr->sig_bit.gray = buf[0]; + png_ptr->sig_bit.red = buf[0]; + png_ptr->sig_bit.green = buf[0]; + png_ptr->sig_bit.blue = buf[0]; + png_ptr->sig_bit.alpha = buf[1]; + } + + png_set_sBIT(png_ptr, info_ptr, &(png_ptr->sig_bit)); +} +#endif + +#ifdef PNG_READ_cHRM_SUPPORTED +void /* PRIVATE */ +png_handle_cHRM(png_structp png_ptr, png_infop info_ptr, png_uint_32 length) +{ + png_byte buf[32]; + png_fixed_point x_white, y_white, x_red, y_red, x_green, y_green, x_blue, + y_blue; + + png_debug(1, "in png_handle_cHRM"); + + if (!(png_ptr->mode & PNG_HAVE_IHDR)) + png_error(png_ptr, "Missing IHDR before cHRM"); + + else if (png_ptr->mode & PNG_HAVE_IDAT) + { + png_warning(png_ptr, "Invalid cHRM after IDAT"); + png_crc_finish(png_ptr, length); + return; + } + + else if (png_ptr->mode & PNG_HAVE_PLTE) + /* Should be an error, but we can cope with it */ + png_warning(png_ptr, "Missing PLTE before cHRM"); + + if (info_ptr != NULL && (info_ptr->valid & PNG_INFO_cHRM) +# ifdef PNG_READ_sRGB_SUPPORTED + && !(info_ptr->valid & PNG_INFO_sRGB) +# endif + ) + { + png_warning(png_ptr, "Duplicate cHRM chunk"); + png_crc_finish(png_ptr, length); + return; + } + + if (length != 32) + { + png_warning(png_ptr, "Incorrect cHRM chunk length"); + png_crc_finish(png_ptr, length); + return; + } + + png_crc_read(png_ptr, buf, 32); + + if (png_crc_finish(png_ptr, 0)) + return; + + x_white = png_get_fixed_point(NULL, buf); + y_white = png_get_fixed_point(NULL, buf + 4); + x_red = png_get_fixed_point(NULL, buf + 8); + y_red = png_get_fixed_point(NULL, buf + 12); + x_green = png_get_fixed_point(NULL, buf + 16); + y_green = png_get_fixed_point(NULL, buf + 20); + x_blue = png_get_fixed_point(NULL, buf + 24); + y_blue = png_get_fixed_point(NULL, buf + 28); + + if (x_white == PNG_FIXED_ERROR || + y_white == PNG_FIXED_ERROR || + x_red == PNG_FIXED_ERROR || + y_red == PNG_FIXED_ERROR || + x_green == PNG_FIXED_ERROR || + y_green == PNG_FIXED_ERROR || + x_blue == PNG_FIXED_ERROR || + y_blue == PNG_FIXED_ERROR) + { + png_warning(png_ptr, "Ignoring cHRM chunk with negative chromaticities"); + return; + } + +#ifdef PNG_READ_sRGB_SUPPORTED + if ((info_ptr != NULL) && (info_ptr->valid & PNG_INFO_sRGB)) + { + if (PNG_OUT_OF_RANGE(x_white, 31270, 1000) || + PNG_OUT_OF_RANGE(y_white, 32900, 1000) || + PNG_OUT_OF_RANGE(x_red, 64000L, 1000) || + PNG_OUT_OF_RANGE(y_red, 33000, 1000) || + PNG_OUT_OF_RANGE(x_green, 30000, 1000) || + PNG_OUT_OF_RANGE(y_green, 60000L, 1000) || + PNG_OUT_OF_RANGE(x_blue, 15000, 1000) || + PNG_OUT_OF_RANGE(y_blue, 6000, 1000)) + { + png_warning(png_ptr, + "Ignoring incorrect cHRM value when sRGB is also present"); + +#ifdef PNG_CONSOLE_IO_SUPPORTED + fprintf(stderr, "wx=%d, wy=%d, rx=%d, ry=%d\n", + x_white, y_white, x_red, y_red); + + fprintf(stderr, "gx=%d, gy=%d, bx=%d, by=%d\n", + x_green, y_green, x_blue, y_blue); +#endif /* PNG_CONSOLE_IO_SUPPORTED */ + } + return; + } +#endif /* PNG_READ_sRGB_SUPPORTED */ + + png_set_cHRM_fixed(png_ptr, info_ptr, x_white, y_white, x_red, y_red, + x_green, y_green, x_blue, y_blue); +} +#endif + +#ifdef PNG_READ_sRGB_SUPPORTED +void /* PRIVATE */ +png_handle_sRGB(png_structp png_ptr, png_infop info_ptr, png_uint_32 length) +{ + int intent; + png_byte buf[1]; + + png_debug(1, "in png_handle_sRGB"); + + if (!(png_ptr->mode & PNG_HAVE_IHDR)) + png_error(png_ptr, "Missing IHDR before sRGB"); + + else if (png_ptr->mode & PNG_HAVE_IDAT) + { + png_warning(png_ptr, "Invalid sRGB after IDAT"); + png_crc_finish(png_ptr, length); + return; + } + + else if (png_ptr->mode & PNG_HAVE_PLTE) + /* Should be an error, but we can cope with it */ + png_warning(png_ptr, "Out of place sRGB chunk"); + + if (info_ptr != NULL && (info_ptr->valid & PNG_INFO_sRGB)) + { + png_warning(png_ptr, "Duplicate sRGB chunk"); + png_crc_finish(png_ptr, length); + return; + } + + if (length != 1) + { + png_warning(png_ptr, "Incorrect sRGB chunk length"); + png_crc_finish(png_ptr, length); + return; + } + + png_crc_read(png_ptr, buf, 1); + + if (png_crc_finish(png_ptr, 0)) + return; + + intent = buf[0]; + + /* Check for bad intent */ + if (intent >= PNG_sRGB_INTENT_LAST) + { + png_warning(png_ptr, "Unknown sRGB intent"); + return; + } + +#if defined(PNG_READ_gAMA_SUPPORTED) && defined(PNG_READ_GAMMA_SUPPORTED) + if (info_ptr != NULL && (info_ptr->valid & PNG_INFO_gAMA)) + { + if (PNG_OUT_OF_RANGE(info_ptr->gamma, 45500L, 500)) + { + png_warning(png_ptr, + "Ignoring incorrect gAMA value when sRGB is also present"); +#ifdef PNG_CONSOLE_IO_SUPPORTED + fprintf(stderr, "incorrect gamma=(%d/100000)\n", info_ptr->gamma); +#endif + } + } +#endif /* PNG_READ_gAMA_SUPPORTED */ + +#ifdef PNG_READ_cHRM_SUPPORTED + if (info_ptr != NULL && (info_ptr->valid & PNG_INFO_cHRM)) + if (PNG_OUT_OF_RANGE(info_ptr->x_white, 31270, 1000) || + PNG_OUT_OF_RANGE(info_ptr->y_white, 32900, 1000) || + PNG_OUT_OF_RANGE(info_ptr->x_red, 64000L, 1000) || + PNG_OUT_OF_RANGE(info_ptr->y_red, 33000, 1000) || + PNG_OUT_OF_RANGE(info_ptr->x_green, 30000, 1000) || + PNG_OUT_OF_RANGE(info_ptr->y_green, 60000L, 1000) || + PNG_OUT_OF_RANGE(info_ptr->x_blue, 15000, 1000) || + PNG_OUT_OF_RANGE(info_ptr->y_blue, 6000, 1000)) + { + png_warning(png_ptr, + "Ignoring incorrect cHRM value when sRGB is also present"); + } +#endif /* PNG_READ_cHRM_SUPPORTED */ + + png_set_sRGB_gAMA_and_cHRM(png_ptr, info_ptr, intent); +} +#endif /* PNG_READ_sRGB_SUPPORTED */ + +#ifdef PNG_READ_iCCP_SUPPORTED +void /* PRIVATE */ +png_handle_iCCP(png_structp png_ptr, png_infop info_ptr, png_uint_32 length) +/* Note: this does not properly handle chunks that are > 64K under DOS */ +{ + png_byte compression_type; + png_bytep pC; + png_charp profile; + png_uint_32 skip = 0; + png_uint_32 profile_size; + png_alloc_size_t profile_length; + png_size_t slength, prefix_length, data_length; + + png_debug(1, "in png_handle_iCCP"); + + if (!(png_ptr->mode & PNG_HAVE_IHDR)) + png_error(png_ptr, "Missing IHDR before iCCP"); + + else if (png_ptr->mode & PNG_HAVE_IDAT) + { + png_warning(png_ptr, "Invalid iCCP after IDAT"); + png_crc_finish(png_ptr, length); + return; + } + + else if (png_ptr->mode & PNG_HAVE_PLTE) + /* Should be an error, but we can cope with it */ + png_warning(png_ptr, "Out of place iCCP chunk"); + + if (info_ptr != NULL && (info_ptr->valid & PNG_INFO_iCCP)) + { + png_warning(png_ptr, "Duplicate iCCP chunk"); + png_crc_finish(png_ptr, length); + return; + } + +#ifdef PNG_MAX_MALLOC_64K + if (length > (png_uint_32)65535L) + { + png_warning(png_ptr, "iCCP chunk too large to fit in memory"); + skip = length - (png_uint_32)65535L; + length = (png_uint_32)65535L; + } +#endif + + png_free(png_ptr, png_ptr->chunkdata); + png_ptr->chunkdata = (png_charp)png_malloc(png_ptr, length + 1); + slength = (png_size_t)length; + png_crc_read(png_ptr, (png_bytep)png_ptr->chunkdata, slength); + + if (png_crc_finish(png_ptr, skip)) + { + png_free(png_ptr, png_ptr->chunkdata); + png_ptr->chunkdata = NULL; + return; + } + + png_ptr->chunkdata[slength] = 0x00; + + for (profile = png_ptr->chunkdata; *profile; profile++) + /* Empty loop to find end of name */ ; + + ++profile; + + /* There should be at least one zero (the compression type byte) + * following the separator, and we should be on it + */ + if (profile >= png_ptr->chunkdata + slength - 1) + { + png_free(png_ptr, png_ptr->chunkdata); + png_ptr->chunkdata = NULL; + png_warning(png_ptr, "Malformed iCCP chunk"); + return; + } + + /* Compression_type should always be zero */ + compression_type = *profile++; + + if (compression_type) + { + png_warning(png_ptr, "Ignoring nonzero compression type in iCCP chunk"); + compression_type = 0x00; /* Reset it to zero (libpng-1.0.6 through 1.0.8 + wrote nonzero) */ + } + + prefix_length = profile - png_ptr->chunkdata; + png_decompress_chunk(png_ptr, compression_type, + slength, prefix_length, &data_length); + + profile_length = data_length - prefix_length; + + if (prefix_length > data_length || profile_length < 4) + { + png_free(png_ptr, png_ptr->chunkdata); + png_ptr->chunkdata = NULL; + png_warning(png_ptr, "Profile size field missing from iCCP chunk"); + return; + } + + /* Check the profile_size recorded in the first 32 bits of the ICC profile */ + pC = (png_bytep)(png_ptr->chunkdata + prefix_length); + profile_size = ((*(pC )) << 24) | + ((*(pC + 1)) << 16) | + ((*(pC + 2)) << 8) | + ((*(pC + 3)) ); + + /* NOTE: the following guarantees that 'profile_length' fits into 32 bits, + * because profile_size is a 32 bit value. + */ + if (profile_size < profile_length) + profile_length = profile_size; + + /* And the following guarantees that profile_size == profile_length. */ + if (profile_size > profile_length) + { + png_free(png_ptr, png_ptr->chunkdata); + png_ptr->chunkdata = NULL; +#ifdef PNG_STDIO_SUPPORTED + { + char umsg[80]; + + png_snprintf2(umsg, 80, + "Ignoring iCCP chunk with declared size = %u " + "and actual length = %u", + (unsigned int) profile_size, + (unsigned int) profile_length); + png_warning(png_ptr, umsg); + } +#else + png_warning(png_ptr, + "Ignoring iCCP chunk with uncompressed size mismatch"); +#endif + return; + } + + png_set_iCCP(png_ptr, info_ptr, png_ptr->chunkdata, + compression_type, (png_bytep)png_ptr->chunkdata + prefix_length, + profile_size); + png_free(png_ptr, png_ptr->chunkdata); + png_ptr->chunkdata = NULL; +} +#endif /* PNG_READ_iCCP_SUPPORTED */ + +#ifdef PNG_READ_sPLT_SUPPORTED +void /* PRIVATE */ +png_handle_sPLT(png_structp png_ptr, png_infop info_ptr, png_uint_32 length) +/* Note: this does not properly handle chunks that are > 64K under DOS */ +{ + png_bytep entry_start; + png_sPLT_t new_palette; +#ifdef PNG_POINTER_INDEXING_SUPPORTED + png_sPLT_entryp pp; +#endif + png_uint_32 data_length; + int entry_size, i; + png_uint_32 skip = 0; + png_size_t slength; + png_uint_32 dl; + png_size_t max_dl; + + png_debug(1, "in png_handle_sPLT"); + +#ifdef PNG_USER_LIMITS_SUPPORTED + + if (png_ptr->user_chunk_cache_max != 0) + { + if (png_ptr->user_chunk_cache_max == 1) + { + png_crc_finish(png_ptr, length); + return; + } + + if (--png_ptr->user_chunk_cache_max == 1) + { + png_warning(png_ptr, "No space in chunk cache for sPLT"); + png_crc_finish(png_ptr, length); + return; + } + } +#endif + + if (!(png_ptr->mode & PNG_HAVE_IHDR)) + png_error(png_ptr, "Missing IHDR before sPLT"); + + else if (png_ptr->mode & PNG_HAVE_IDAT) + { + png_warning(png_ptr, "Invalid sPLT after IDAT"); + png_crc_finish(png_ptr, length); + return; + } + +#ifdef PNG_MAX_MALLOC_64K + if (length > (png_uint_32)65535L) + { + png_warning(png_ptr, "sPLT chunk too large to fit in memory"); + skip = length - (png_uint_32)65535L; + length = (png_uint_32)65535L; + } +#endif + + png_free(png_ptr, png_ptr->chunkdata); + png_ptr->chunkdata = (png_charp)png_malloc(png_ptr, length + 1); + + /* WARNING: this may break if size_t is less than 32 bits; it is assumed + * that the PNG_MAX_MALLOC_64K test is enabled in this case, but this is a + * potential breakage point if the types in pngconf.h aren't exactly right. + */ + slength = (png_size_t)length; + png_crc_read(png_ptr, (png_bytep)png_ptr->chunkdata, slength); + + if (png_crc_finish(png_ptr, skip)) + { + png_free(png_ptr, png_ptr->chunkdata); + png_ptr->chunkdata = NULL; + return; + } + + png_ptr->chunkdata[slength] = 0x00; + + for (entry_start = (png_bytep)png_ptr->chunkdata; *entry_start; + entry_start++) + /* Empty loop to find end of name */ ; + + ++entry_start; + + /* A sample depth should follow the separator, and we should be on it */ + if (entry_start > (png_bytep)png_ptr->chunkdata + slength - 2) + { + png_free(png_ptr, png_ptr->chunkdata); + png_ptr->chunkdata = NULL; + png_warning(png_ptr, "malformed sPLT chunk"); + return; + } + + new_palette.depth = *entry_start++; + entry_size = (new_palette.depth == 8 ? 6 : 10); + /* This must fit in a png_uint_32 because it is derived from the original + * chunk data length (and use 'length', not 'slength' here for clarity - + * they are guaranteed to be the same, see the tests above.) + */ + data_length = length - (png_uint_32)(entry_start - + (png_bytep)png_ptr->chunkdata); + + /* Integrity-check the data length */ + if (data_length % entry_size) + { + png_free(png_ptr, png_ptr->chunkdata); + png_ptr->chunkdata = NULL; + png_warning(png_ptr, "sPLT chunk has bad length"); + return; + } + + dl = (png_int_32)(data_length / entry_size); + max_dl = PNG_SIZE_MAX / png_sizeof(png_sPLT_entry); + + if (dl > max_dl) + { + png_warning(png_ptr, "sPLT chunk too long"); + return; + } + + new_palette.nentries = (png_int_32)(data_length / entry_size); + + new_palette.entries = (png_sPLT_entryp)png_malloc_warn( + png_ptr, new_palette.nentries * png_sizeof(png_sPLT_entry)); + + if (new_palette.entries == NULL) + { + png_warning(png_ptr, "sPLT chunk requires too much memory"); + return; + } + +#ifdef PNG_POINTER_INDEXING_SUPPORTED + for (i = 0; i < new_palette.nentries; i++) + { + pp = new_palette.entries + i; + + if (new_palette.depth == 8) + { + pp->red = *entry_start++; + pp->green = *entry_start++; + pp->blue = *entry_start++; + pp->alpha = *entry_start++; + } + + else + { + pp->red = png_get_uint_16(entry_start); entry_start += 2; + pp->green = png_get_uint_16(entry_start); entry_start += 2; + pp->blue = png_get_uint_16(entry_start); entry_start += 2; + pp->alpha = png_get_uint_16(entry_start); entry_start += 2; + } + + pp->frequency = png_get_uint_16(entry_start); entry_start += 2; + } +#else + pp = new_palette.entries; + + for (i = 0; i < new_palette.nentries; i++) + { + + if (new_palette.depth == 8) + { + pp[i].red = *entry_start++; + pp[i].green = *entry_start++; + pp[i].blue = *entry_start++; + pp[i].alpha = *entry_start++; + } + + else + { + pp[i].red = png_get_uint_16(entry_start); entry_start += 2; + pp[i].green = png_get_uint_16(entry_start); entry_start += 2; + pp[i].blue = png_get_uint_16(entry_start); entry_start += 2; + pp[i].alpha = png_get_uint_16(entry_start); entry_start += 2; + } + + pp->frequency = png_get_uint_16(entry_start); entry_start += 2; + } +#endif + + /* Discard all chunk data except the name and stash that */ + new_palette.name = png_ptr->chunkdata; + + png_set_sPLT(png_ptr, info_ptr, &new_palette, 1); + + png_free(png_ptr, png_ptr->chunkdata); + png_ptr->chunkdata = NULL; + png_free(png_ptr, new_palette.entries); +} +#endif /* PNG_READ_sPLT_SUPPORTED */ + +#ifdef PNG_READ_tRNS_SUPPORTED +void /* PRIVATE */ +png_handle_tRNS(png_structp png_ptr, png_infop info_ptr, png_uint_32 length) +{ + png_byte readbuf[PNG_MAX_PALETTE_LENGTH]; + + png_debug(1, "in png_handle_tRNS"); + + if (!(png_ptr->mode & PNG_HAVE_IHDR)) + png_error(png_ptr, "Missing IHDR before tRNS"); + + else if (png_ptr->mode & PNG_HAVE_IDAT) + { + png_warning(png_ptr, "Invalid tRNS after IDAT"); + png_crc_finish(png_ptr, length); + return; + } + + else if (info_ptr != NULL && (info_ptr->valid & PNG_INFO_tRNS)) + { + png_warning(png_ptr, "Duplicate tRNS chunk"); + png_crc_finish(png_ptr, length); + return; + } + + if (png_ptr->color_type == PNG_COLOR_TYPE_GRAY) + { + png_byte buf[2]; + + if (length != 2) + { + png_warning(png_ptr, "Incorrect tRNS chunk length"); + png_crc_finish(png_ptr, length); + return; + } + + png_crc_read(png_ptr, buf, 2); + png_ptr->num_trans = 1; + png_ptr->trans_color.gray = png_get_uint_16(buf); + } + + else if (png_ptr->color_type == PNG_COLOR_TYPE_RGB) + { + png_byte buf[6]; + + if (length != 6) + { + png_warning(png_ptr, "Incorrect tRNS chunk length"); + png_crc_finish(png_ptr, length); + return; + } + + png_crc_read(png_ptr, buf, (png_size_t)length); + png_ptr->num_trans = 1; + png_ptr->trans_color.red = png_get_uint_16(buf); + png_ptr->trans_color.green = png_get_uint_16(buf + 2); + png_ptr->trans_color.blue = png_get_uint_16(buf + 4); + } + + else if (png_ptr->color_type == PNG_COLOR_TYPE_PALETTE) + { + if (!(png_ptr->mode & PNG_HAVE_PLTE)) + { + /* Should be an error, but we can cope with it. */ + png_warning(png_ptr, "Missing PLTE before tRNS"); + } + + if (length > (png_uint_32)png_ptr->num_palette || + length > PNG_MAX_PALETTE_LENGTH) + { + png_warning(png_ptr, "Incorrect tRNS chunk length"); + png_crc_finish(png_ptr, length); + return; + } + + if (length == 0) + { + png_warning(png_ptr, "Zero length tRNS chunk"); + png_crc_finish(png_ptr, length); + return; + } + + png_crc_read(png_ptr, readbuf, (png_size_t)length); + png_ptr->num_trans = (png_uint_16)length; + } + + else + { + png_warning(png_ptr, "tRNS chunk not allowed with alpha channel"); + png_crc_finish(png_ptr, length); + return; + } + + if (png_crc_finish(png_ptr, 0)) + { + png_ptr->num_trans = 0; + return; + } + + png_set_tRNS(png_ptr, info_ptr, readbuf, png_ptr->num_trans, + &(png_ptr->trans_color)); +} +#endif + +#ifdef PNG_READ_bKGD_SUPPORTED +void /* PRIVATE */ +png_handle_bKGD(png_structp png_ptr, png_infop info_ptr, png_uint_32 length) +{ + png_size_t truelen; + png_byte buf[6]; + + png_debug(1, "in png_handle_bKGD"); + + if (!(png_ptr->mode & PNG_HAVE_IHDR)) + png_error(png_ptr, "Missing IHDR before bKGD"); + + else if (png_ptr->mode & PNG_HAVE_IDAT) + { + png_warning(png_ptr, "Invalid bKGD after IDAT"); + png_crc_finish(png_ptr, length); + return; + } + + else if (png_ptr->color_type == PNG_COLOR_TYPE_PALETTE && + !(png_ptr->mode & PNG_HAVE_PLTE)) + { + png_warning(png_ptr, "Missing PLTE before bKGD"); + png_crc_finish(png_ptr, length); + return; + } + + else if (info_ptr != NULL && (info_ptr->valid & PNG_INFO_bKGD)) + { + png_warning(png_ptr, "Duplicate bKGD chunk"); + png_crc_finish(png_ptr, length); + return; + } + + if (png_ptr->color_type == PNG_COLOR_TYPE_PALETTE) + truelen = 1; + + else if (png_ptr->color_type & PNG_COLOR_MASK_COLOR) + truelen = 6; + + else + truelen = 2; + + if (length != truelen) + { + png_warning(png_ptr, "Incorrect bKGD chunk length"); + png_crc_finish(png_ptr, length); + return; + } + + png_crc_read(png_ptr, buf, truelen); + + if (png_crc_finish(png_ptr, 0)) + return; + + /* We convert the index value into RGB components so that we can allow + * arbitrary RGB values for background when we have transparency, and + * so it is easy to determine the RGB values of the background color + * from the info_ptr struct. + */ + if (png_ptr->color_type == PNG_COLOR_TYPE_PALETTE) + { + png_ptr->background.index = buf[0]; + + if (info_ptr && info_ptr->num_palette) + { + if (buf[0] >= info_ptr->num_palette) + { + png_warning(png_ptr, "Incorrect bKGD chunk index value"); + return; + } + + png_ptr->background.red = + (png_uint_16)png_ptr->palette[buf[0]].red; + + png_ptr->background.green = + (png_uint_16)png_ptr->palette[buf[0]].green; + + png_ptr->background.blue = + (png_uint_16)png_ptr->palette[buf[0]].blue; + } + } + + else if (!(png_ptr->color_type & PNG_COLOR_MASK_COLOR)) /* GRAY */ + { + png_ptr->background.red = + png_ptr->background.green = + png_ptr->background.blue = + png_ptr->background.gray = png_get_uint_16(buf); + } + + else + { + png_ptr->background.red = png_get_uint_16(buf); + png_ptr->background.green = png_get_uint_16(buf + 2); + png_ptr->background.blue = png_get_uint_16(buf + 4); + } + + png_set_bKGD(png_ptr, info_ptr, &(png_ptr->background)); +} +#endif + +#ifdef PNG_READ_hIST_SUPPORTED +void /* PRIVATE */ +png_handle_hIST(png_structp png_ptr, png_infop info_ptr, png_uint_32 length) +{ + unsigned int num, i; + png_uint_16 readbuf[PNG_MAX_PALETTE_LENGTH]; + + png_debug(1, "in png_handle_hIST"); + + if (!(png_ptr->mode & PNG_HAVE_IHDR)) + png_error(png_ptr, "Missing IHDR before hIST"); + + else if (png_ptr->mode & PNG_HAVE_IDAT) + { + png_warning(png_ptr, "Invalid hIST after IDAT"); + png_crc_finish(png_ptr, length); + return; + } + + else if (!(png_ptr->mode & PNG_HAVE_PLTE)) + { + png_warning(png_ptr, "Missing PLTE before hIST"); + png_crc_finish(png_ptr, length); + return; + } + + else if (info_ptr != NULL && (info_ptr->valid & PNG_INFO_hIST)) + { + png_warning(png_ptr, "Duplicate hIST chunk"); + png_crc_finish(png_ptr, length); + return; + } + + num = length / 2 ; + + if (num != (unsigned int)png_ptr->num_palette || num > + (unsigned int)PNG_MAX_PALETTE_LENGTH) + { + png_warning(png_ptr, "Incorrect hIST chunk length"); + png_crc_finish(png_ptr, length); + return; + } + + for (i = 0; i < num; i++) + { + png_byte buf[2]; + + png_crc_read(png_ptr, buf, 2); + readbuf[i] = png_get_uint_16(buf); + } + + if (png_crc_finish(png_ptr, 0)) + return; + + png_set_hIST(png_ptr, info_ptr, readbuf); +} +#endif + +#ifdef PNG_READ_pHYs_SUPPORTED +void /* PRIVATE */ +png_handle_pHYs(png_structp png_ptr, png_infop info_ptr, png_uint_32 length) +{ + png_byte buf[9]; + png_uint_32 res_x, res_y; + int unit_type; + + png_debug(1, "in png_handle_pHYs"); + + if (!(png_ptr->mode & PNG_HAVE_IHDR)) + png_error(png_ptr, "Missing IHDR before pHYs"); + + else if (png_ptr->mode & PNG_HAVE_IDAT) + { + png_warning(png_ptr, "Invalid pHYs after IDAT"); + png_crc_finish(png_ptr, length); + return; + } + + else if (info_ptr != NULL && (info_ptr->valid & PNG_INFO_pHYs)) + { + png_warning(png_ptr, "Duplicate pHYs chunk"); + png_crc_finish(png_ptr, length); + return; + } + + if (length != 9) + { + png_warning(png_ptr, "Incorrect pHYs chunk length"); + png_crc_finish(png_ptr, length); + return; + } + + png_crc_read(png_ptr, buf, 9); + + if (png_crc_finish(png_ptr, 0)) + return; + + res_x = png_get_uint_32(buf); + res_y = png_get_uint_32(buf + 4); + unit_type = buf[8]; + png_set_pHYs(png_ptr, info_ptr, res_x, res_y, unit_type); +} +#endif + +#ifdef PNG_READ_oFFs_SUPPORTED +void /* PRIVATE */ +png_handle_oFFs(png_structp png_ptr, png_infop info_ptr, png_uint_32 length) +{ + png_byte buf[9]; + png_int_32 offset_x, offset_y; + int unit_type; + + png_debug(1, "in png_handle_oFFs"); + + if (!(png_ptr->mode & PNG_HAVE_IHDR)) + png_error(png_ptr, "Missing IHDR before oFFs"); + + else if (png_ptr->mode & PNG_HAVE_IDAT) + { + png_warning(png_ptr, "Invalid oFFs after IDAT"); + png_crc_finish(png_ptr, length); + return; + } + + else if (info_ptr != NULL && (info_ptr->valid & PNG_INFO_oFFs)) + { + png_warning(png_ptr, "Duplicate oFFs chunk"); + png_crc_finish(png_ptr, length); + return; + } + + if (length != 9) + { + png_warning(png_ptr, "Incorrect oFFs chunk length"); + png_crc_finish(png_ptr, length); + return; + } + + png_crc_read(png_ptr, buf, 9); + + if (png_crc_finish(png_ptr, 0)) + return; + + offset_x = png_get_int_32(buf); + offset_y = png_get_int_32(buf + 4); + unit_type = buf[8]; + png_set_oFFs(png_ptr, info_ptr, offset_x, offset_y, unit_type); +} +#endif + +#ifdef PNG_READ_pCAL_SUPPORTED +/* Read the pCAL chunk (described in the PNG Extensions document) */ +void /* PRIVATE */ +png_handle_pCAL(png_structp png_ptr, png_infop info_ptr, png_uint_32 length) +{ + png_int_32 X0, X1; + png_byte type, nparams; + png_charp buf, units, endptr; + png_charpp params; + png_size_t slength; + int i; + + png_debug(1, "in png_handle_pCAL"); + + if (!(png_ptr->mode & PNG_HAVE_IHDR)) + png_error(png_ptr, "Missing IHDR before pCAL"); + + else if (png_ptr->mode & PNG_HAVE_IDAT) + { + png_warning(png_ptr, "Invalid pCAL after IDAT"); + png_crc_finish(png_ptr, length); + return; + } + + else if (info_ptr != NULL && (info_ptr->valid & PNG_INFO_pCAL)) + { + png_warning(png_ptr, "Duplicate pCAL chunk"); + png_crc_finish(png_ptr, length); + return; + } + + png_debug1(2, "Allocating and reading pCAL chunk data (%u bytes)", + length + 1); + png_free(png_ptr, png_ptr->chunkdata); + png_ptr->chunkdata = (png_charp)png_malloc_warn(png_ptr, length + 1); + + if (png_ptr->chunkdata == NULL) + { + png_warning(png_ptr, "No memory for pCAL purpose"); + return; + } + + slength = (png_size_t)length; + png_crc_read(png_ptr, (png_bytep)png_ptr->chunkdata, slength); + + if (png_crc_finish(png_ptr, 0)) + { + png_free(png_ptr, png_ptr->chunkdata); + png_ptr->chunkdata = NULL; + return; + } + + png_ptr->chunkdata[slength] = 0x00; /* Null terminate the last string */ + + png_debug(3, "Finding end of pCAL purpose string"); + for (buf = png_ptr->chunkdata; *buf; buf++) + /* Empty loop */ ; + + endptr = png_ptr->chunkdata + slength; + + /* We need to have at least 12 bytes after the purpose string + * in order to get the parameter information. + */ + if (endptr <= buf + 12) + { + png_warning(png_ptr, "Invalid pCAL data"); + png_free(png_ptr, png_ptr->chunkdata); + png_ptr->chunkdata = NULL; + return; + } + + png_debug(3, "Reading pCAL X0, X1, type, nparams, and units"); + X0 = png_get_int_32((png_bytep)buf+1); + X1 = png_get_int_32((png_bytep)buf+5); + type = buf[9]; + nparams = buf[10]; + units = buf + 11; + + png_debug(3, "Checking pCAL equation type and number of parameters"); + /* Check that we have the right number of parameters for known + * equation types. + */ + if ((type == PNG_EQUATION_LINEAR && nparams != 2) || + (type == PNG_EQUATION_BASE_E && nparams != 3) || + (type == PNG_EQUATION_ARBITRARY && nparams != 3) || + (type == PNG_EQUATION_HYPERBOLIC && nparams != 4)) + { + png_warning(png_ptr, "Invalid pCAL parameters for equation type"); + png_free(png_ptr, png_ptr->chunkdata); + png_ptr->chunkdata = NULL; + return; + } + + else if (type >= PNG_EQUATION_LAST) + { + png_warning(png_ptr, "Unrecognized equation type for pCAL chunk"); + } + + for (buf = units; *buf; buf++) + /* Empty loop to move past the units string. */ ; + + png_debug(3, "Allocating pCAL parameters array"); + + params = (png_charpp)png_malloc_warn(png_ptr, + (png_size_t)(nparams * png_sizeof(png_charp))); + + if (params == NULL) + { + png_free(png_ptr, png_ptr->chunkdata); + png_ptr->chunkdata = NULL; + png_warning(png_ptr, "No memory for pCAL params"); + return; + } + + /* Get pointers to the start of each parameter string. */ + for (i = 0; i < (int)nparams; i++) + { + buf++; /* Skip the null string terminator from previous parameter. */ + + png_debug1(3, "Reading pCAL parameter %d", i); + + for (params[i] = buf; buf <= endptr && *buf != 0x00; buf++) + /* Empty loop to move past each parameter string */ ; + + /* Make sure we haven't run out of data yet */ + if (buf > endptr) + { + png_warning(png_ptr, "Invalid pCAL data"); + png_free(png_ptr, png_ptr->chunkdata); + png_ptr->chunkdata = NULL; + png_free(png_ptr, params); + return; + } + } + + png_set_pCAL(png_ptr, info_ptr, png_ptr->chunkdata, X0, X1, type, nparams, + units, params); + + png_free(png_ptr, png_ptr->chunkdata); + png_ptr->chunkdata = NULL; + png_free(png_ptr, params); +} +#endif + +#ifdef PNG_READ_sCAL_SUPPORTED +/* Read the sCAL chunk */ +void /* PRIVATE */ +png_handle_sCAL(png_structp png_ptr, png_infop info_ptr, png_uint_32 length) +{ + png_size_t slength, i; + int state; + + png_debug(1, "in png_handle_sCAL"); + + if (!(png_ptr->mode & PNG_HAVE_IHDR)) + png_error(png_ptr, "Missing IHDR before sCAL"); + + else if (png_ptr->mode & PNG_HAVE_IDAT) + { + png_warning(png_ptr, "Invalid sCAL after IDAT"); + png_crc_finish(png_ptr, length); + return; + } + + else if (info_ptr != NULL && (info_ptr->valid & PNG_INFO_sCAL)) + { + png_warning(png_ptr, "Duplicate sCAL chunk"); + png_crc_finish(png_ptr, length); + return; + } + + png_debug1(2, "Allocating and reading sCAL chunk data (%u bytes)", + length + 1); + + png_ptr->chunkdata = (png_charp)png_malloc_warn(png_ptr, length + 1); + + if (png_ptr->chunkdata == NULL) + { + png_warning(png_ptr, "Out of memory while processing sCAL chunk"); + png_crc_finish(png_ptr, length); + return; + } + + slength = (png_size_t)length; + png_crc_read(png_ptr, (png_bytep)png_ptr->chunkdata, slength); + png_ptr->chunkdata[slength] = 0x00; /* Null terminate the last string */ + + if (png_crc_finish(png_ptr, 0)) + { + png_free(png_ptr, png_ptr->chunkdata); + png_ptr->chunkdata = NULL; + return; + } + + /* Validate the unit. */ + if (png_ptr->chunkdata[0] != 1 && png_ptr->chunkdata[0] != 2) + { + png_warning(png_ptr, "Invalid sCAL ignored: invalid unit"); + png_free(png_ptr, png_ptr->chunkdata); + png_ptr->chunkdata = NULL; + return; + } + + /* Validate the ASCII numbers, need two ASCII numbers separated by + * a '\0' and they need to fit exactly in the chunk data. + */ + i = 0; + state = 0; + + if (png_ptr->chunkdata[1] == 45 /* negative width */ || + !png_check_fp_number(png_ptr->chunkdata, slength, &state, &i) || + i >= slength || png_ptr->chunkdata[i++] != 0) + png_warning(png_ptr, "Invalid sCAL chunk ignored: bad width format"); + + else + { + png_size_t heighti = i; + + if (png_ptr->chunkdata[i] == 45 /* negative height */ || + !png_check_fp_number(png_ptr->chunkdata, slength, &state, &i) || + i != slength) + png_warning(png_ptr, "Invalid sCAL chunk ignored: bad height format"); + + else + /* This is the (only) success case. */ + png_set_sCAL_s(png_ptr, info_ptr, png_ptr->chunkdata[0], + png_ptr->chunkdata+1, png_ptr->chunkdata+heighti); + } + + /* Clean up - just free the temporarily allocated buffer. */ + png_free(png_ptr, png_ptr->chunkdata); + png_ptr->chunkdata = NULL; +} +#endif + +#ifdef PNG_READ_tIME_SUPPORTED +void /* PRIVATE */ +png_handle_tIME(png_structp png_ptr, png_infop info_ptr, png_uint_32 length) +{ + png_byte buf[7]; + png_time mod_time; + + png_debug(1, "in png_handle_tIME"); + + if (!(png_ptr->mode & PNG_HAVE_IHDR)) + png_error(png_ptr, "Out of place tIME chunk"); + + else if (info_ptr != NULL && (info_ptr->valid & PNG_INFO_tIME)) + { + png_warning(png_ptr, "Duplicate tIME chunk"); + png_crc_finish(png_ptr, length); + return; + } + + if (png_ptr->mode & PNG_HAVE_IDAT) + png_ptr->mode |= PNG_AFTER_IDAT; + + if (length != 7) + { + png_warning(png_ptr, "Incorrect tIME chunk length"); + png_crc_finish(png_ptr, length); + return; + } + + png_crc_read(png_ptr, buf, 7); + + if (png_crc_finish(png_ptr, 0)) + return; + + mod_time.second = buf[6]; + mod_time.minute = buf[5]; + mod_time.hour = buf[4]; + mod_time.day = buf[3]; + mod_time.month = buf[2]; + mod_time.year = png_get_uint_16(buf); + + png_set_tIME(png_ptr, info_ptr, &mod_time); +} +#endif + +#ifdef PNG_READ_tEXt_SUPPORTED +/* Note: this does not properly handle chunks that are > 64K under DOS */ +void /* PRIVATE */ +png_handle_tEXt(png_structp png_ptr, png_infop info_ptr, png_uint_32 length) +{ + png_textp text_ptr; + png_charp key; + png_charp text; + png_uint_32 skip = 0; + png_size_t slength; + int ret; + + png_debug(1, "in png_handle_tEXt"); + +#ifdef PNG_USER_LIMITS_SUPPORTED + if (png_ptr->user_chunk_cache_max != 0) + { + if (png_ptr->user_chunk_cache_max == 1) + { + png_crc_finish(png_ptr, length); + return; + } + + if (--png_ptr->user_chunk_cache_max == 1) + { + png_warning(png_ptr, "No space in chunk cache for tEXt"); + png_crc_finish(png_ptr, length); + return; + } + } +#endif + + if (!(png_ptr->mode & PNG_HAVE_IHDR)) + png_error(png_ptr, "Missing IHDR before tEXt"); + + if (png_ptr->mode & PNG_HAVE_IDAT) + png_ptr->mode |= PNG_AFTER_IDAT; + +#ifdef PNG_MAX_MALLOC_64K + if (length > (png_uint_32)65535L) + { + png_warning(png_ptr, "tEXt chunk too large to fit in memory"); + skip = length - (png_uint_32)65535L; + length = (png_uint_32)65535L; + } +#endif + + png_free(png_ptr, png_ptr->chunkdata); + + png_ptr->chunkdata = (png_charp)png_malloc_warn(png_ptr, length + 1); + + if (png_ptr->chunkdata == NULL) + { + png_warning(png_ptr, "No memory to process text chunk"); + return; + } + + slength = (png_size_t)length; + png_crc_read(png_ptr, (png_bytep)png_ptr->chunkdata, slength); + + if (png_crc_finish(png_ptr, skip)) + { + png_free(png_ptr, png_ptr->chunkdata); + png_ptr->chunkdata = NULL; + return; + } + + key = png_ptr->chunkdata; + + key[slength] = 0x00; + + for (text = key; *text; text++) + /* Empty loop to find end of key */ ; + + if (text != key + slength) + text++; + + text_ptr = (png_textp)png_malloc_warn(png_ptr, + png_sizeof(png_text)); + + if (text_ptr == NULL) + { + png_warning(png_ptr, "Not enough memory to process text chunk"); + png_free(png_ptr, png_ptr->chunkdata); + png_ptr->chunkdata = NULL; + return; + } + + text_ptr->compression = PNG_TEXT_COMPRESSION_NONE; + text_ptr->key = key; + text_ptr->lang = NULL; + text_ptr->lang_key = NULL; + text_ptr->itxt_length = 0; + text_ptr->text = text; + text_ptr->text_length = png_strlen(text); + + ret = png_set_text_2(png_ptr, info_ptr, text_ptr, 1); + + png_free(png_ptr, png_ptr->chunkdata); + png_ptr->chunkdata = NULL; + png_free(png_ptr, text_ptr); + + if (ret) + png_warning(png_ptr, "Insufficient memory to process text chunk"); +} +#endif + +#ifdef PNG_READ_zTXt_SUPPORTED +/* Note: this does not correctly handle chunks that are > 64K under DOS */ +void /* PRIVATE */ +png_handle_zTXt(png_structp png_ptr, png_infop info_ptr, png_uint_32 length) +{ + png_textp text_ptr; + png_charp text; + int comp_type; + int ret; + png_size_t slength, prefix_len, data_len; + + png_debug(1, "in png_handle_zTXt"); + +#ifdef PNG_USER_LIMITS_SUPPORTED + if (png_ptr->user_chunk_cache_max != 0) + { + if (png_ptr->user_chunk_cache_max == 1) + { + png_crc_finish(png_ptr, length); + return; + } + + if (--png_ptr->user_chunk_cache_max == 1) + { + png_warning(png_ptr, "No space in chunk cache for zTXt"); + png_crc_finish(png_ptr, length); + return; + } + } +#endif + + if (!(png_ptr->mode & PNG_HAVE_IHDR)) + png_error(png_ptr, "Missing IHDR before zTXt"); + + if (png_ptr->mode & PNG_HAVE_IDAT) + png_ptr->mode |= PNG_AFTER_IDAT; + +#ifdef PNG_MAX_MALLOC_64K + /* We will no doubt have problems with chunks even half this size, but + * there is no hard and fast rule to tell us where to stop. + */ + if (length > (png_uint_32)65535L) + { + png_warning(png_ptr, "zTXt chunk too large to fit in memory"); + png_crc_finish(png_ptr, length); + return; + } +#endif + + png_free(png_ptr, png_ptr->chunkdata); + png_ptr->chunkdata = (png_charp)png_malloc_warn(png_ptr, length + 1); + + if (png_ptr->chunkdata == NULL) + { + png_warning(png_ptr, "Out of memory processing zTXt chunk"); + return; + } + + slength = (png_size_t)length; + png_crc_read(png_ptr, (png_bytep)png_ptr->chunkdata, slength); + + if (png_crc_finish(png_ptr, 0)) + { + png_free(png_ptr, png_ptr->chunkdata); + png_ptr->chunkdata = NULL; + return; + } + + png_ptr->chunkdata[slength] = 0x00; + + for (text = png_ptr->chunkdata; *text; text++) + /* Empty loop */ ; + + /* zTXt must have some text after the chunkdataword */ + if (text >= png_ptr->chunkdata + slength - 2) + { + png_warning(png_ptr, "Truncated zTXt chunk"); + png_free(png_ptr, png_ptr->chunkdata); + png_ptr->chunkdata = NULL; + return; + } + + else + { + comp_type = *(++text); + + if (comp_type != PNG_TEXT_COMPRESSION_zTXt) + { + png_warning(png_ptr, "Unknown compression type in zTXt chunk"); + comp_type = PNG_TEXT_COMPRESSION_zTXt; + } + + text++; /* Skip the compression_method byte */ + } + + prefix_len = text - png_ptr->chunkdata; + + png_decompress_chunk(png_ptr, comp_type, + (png_size_t)length, prefix_len, &data_len); + + text_ptr = (png_textp)png_malloc_warn(png_ptr, + png_sizeof(png_text)); + + if (text_ptr == NULL) + { + png_warning(png_ptr, "Not enough memory to process zTXt chunk"); + png_free(png_ptr, png_ptr->chunkdata); + png_ptr->chunkdata = NULL; + return; + } + + text_ptr->compression = comp_type; + text_ptr->key = png_ptr->chunkdata; + text_ptr->lang = NULL; + text_ptr->lang_key = NULL; + text_ptr->itxt_length = 0; + text_ptr->text = png_ptr->chunkdata + prefix_len; + text_ptr->text_length = data_len; + + ret = png_set_text_2(png_ptr, info_ptr, text_ptr, 1); + + png_free(png_ptr, text_ptr); + png_free(png_ptr, png_ptr->chunkdata); + png_ptr->chunkdata = NULL; + + if (ret) + png_error(png_ptr, "Insufficient memory to store zTXt chunk"); +} +#endif + +#ifdef PNG_READ_iTXt_SUPPORTED +/* Note: this does not correctly handle chunks that are > 64K under DOS */ +void /* PRIVATE */ +png_handle_iTXt(png_structp png_ptr, png_infop info_ptr, png_uint_32 length) +{ + png_textp text_ptr; + png_charp key, lang, text, lang_key; + int comp_flag; + int comp_type = 0; + int ret; + png_size_t slength, prefix_len, data_len; + + png_debug(1, "in png_handle_iTXt"); + +#ifdef PNG_USER_LIMITS_SUPPORTED + if (png_ptr->user_chunk_cache_max != 0) + { + if (png_ptr->user_chunk_cache_max == 1) + { + png_crc_finish(png_ptr, length); + return; + } + + if (--png_ptr->user_chunk_cache_max == 1) + { + png_warning(png_ptr, "No space in chunk cache for iTXt"); + png_crc_finish(png_ptr, length); + return; + } + } +#endif + + if (!(png_ptr->mode & PNG_HAVE_IHDR)) + png_error(png_ptr, "Missing IHDR before iTXt"); + + if (png_ptr->mode & PNG_HAVE_IDAT) + png_ptr->mode |= PNG_AFTER_IDAT; + +#ifdef PNG_MAX_MALLOC_64K + /* We will no doubt have problems with chunks even half this size, but + * there is no hard and fast rule to tell us where to stop. + */ + if (length > (png_uint_32)65535L) + { + png_warning(png_ptr, "iTXt chunk too large to fit in memory"); + png_crc_finish(png_ptr, length); + return; + } +#endif + + png_free(png_ptr, png_ptr->chunkdata); + png_ptr->chunkdata = (png_charp)png_malloc_warn(png_ptr, length + 1); + + if (png_ptr->chunkdata == NULL) + { + png_warning(png_ptr, "No memory to process iTXt chunk"); + return; + } + + slength = (png_size_t)length; + png_crc_read(png_ptr, (png_bytep)png_ptr->chunkdata, slength); + + if (png_crc_finish(png_ptr, 0)) + { + png_free(png_ptr, png_ptr->chunkdata); + png_ptr->chunkdata = NULL; + return; + } + + png_ptr->chunkdata[slength] = 0x00; + + for (lang = png_ptr->chunkdata; *lang; lang++) + /* Empty loop */ ; + + lang++; /* Skip NUL separator */ + + /* iTXt must have a language tag (possibly empty), two compression bytes, + * translated keyword (possibly empty), and possibly some text after the + * keyword + */ + + if (lang >= png_ptr->chunkdata + slength - 3) + { + png_warning(png_ptr, "Truncated iTXt chunk"); + png_free(png_ptr, png_ptr->chunkdata); + png_ptr->chunkdata = NULL; + return; + } + + else + { + comp_flag = *lang++; + comp_type = *lang++; + } + + for (lang_key = lang; *lang_key; lang_key++) + /* Empty loop */ ; + + lang_key++; /* Skip NUL separator */ + + if (lang_key >= png_ptr->chunkdata + slength) + { + png_warning(png_ptr, "Truncated iTXt chunk"); + png_free(png_ptr, png_ptr->chunkdata); + png_ptr->chunkdata = NULL; + return; + } + + for (text = lang_key; *text; text++) + /* Empty loop */ ; + + text++; /* Skip NUL separator */ + + if (text >= png_ptr->chunkdata + slength) + { + png_warning(png_ptr, "Malformed iTXt chunk"); + png_free(png_ptr, png_ptr->chunkdata); + png_ptr->chunkdata = NULL; + return; + } + + prefix_len = text - png_ptr->chunkdata; + + key=png_ptr->chunkdata; + + if (comp_flag) + png_decompress_chunk(png_ptr, comp_type, + (size_t)length, prefix_len, &data_len); + + else + data_len = png_strlen(png_ptr->chunkdata + prefix_len); + + text_ptr = (png_textp)png_malloc_warn(png_ptr, + png_sizeof(png_text)); + + if (text_ptr == NULL) + { + png_warning(png_ptr, "Not enough memory to process iTXt chunk"); + png_free(png_ptr, png_ptr->chunkdata); + png_ptr->chunkdata = NULL; + return; + } + + text_ptr->compression = (int)comp_flag + 1; + text_ptr->lang_key = png_ptr->chunkdata + (lang_key - key); + text_ptr->lang = png_ptr->chunkdata + (lang - key); + text_ptr->itxt_length = data_len; + text_ptr->text_length = 0; + text_ptr->key = png_ptr->chunkdata; + text_ptr->text = png_ptr->chunkdata + prefix_len; + + ret = png_set_text_2(png_ptr, info_ptr, text_ptr, 1); + + png_free(png_ptr, text_ptr); + png_free(png_ptr, png_ptr->chunkdata); + png_ptr->chunkdata = NULL; + + if (ret) + png_error(png_ptr, "Insufficient memory to store iTXt chunk"); +} +#endif + +/* This function is called when we haven't found a handler for a + * chunk. If there isn't a problem with the chunk itself (ie bad + * chunk name, CRC, or a critical chunk), the chunk is silently ignored + * -- unless the PNG_FLAG_UNKNOWN_CHUNKS_SUPPORTED flag is on in which + * case it will be saved away to be written out later. + */ +void /* PRIVATE */ +png_handle_unknown(png_structp png_ptr, png_infop info_ptr, png_uint_32 length) +{ + png_uint_32 skip = 0; + + png_debug(1, "in png_handle_unknown"); + +#ifdef PNG_USER_LIMITS_SUPPORTED + if (png_ptr->user_chunk_cache_max != 0) + { + if (png_ptr->user_chunk_cache_max == 1) + { + png_crc_finish(png_ptr, length); + return; + } + + if (--png_ptr->user_chunk_cache_max == 1) + { + png_warning(png_ptr, "No space in chunk cache for unknown chunk"); + png_crc_finish(png_ptr, length); + return; + } + } +#endif + + if (png_ptr->mode & PNG_HAVE_IDAT) + { + PNG_IDAT; + + if (png_memcmp(png_ptr->chunk_name, png_IDAT, 4)) /* Not an IDAT */ + png_ptr->mode |= PNG_AFTER_IDAT; + } + + if (!(png_ptr->chunk_name[0] & 0x20)) + { +#ifdef PNG_HANDLE_AS_UNKNOWN_SUPPORTED + if (png_handle_as_unknown(png_ptr, png_ptr->chunk_name) != + PNG_HANDLE_CHUNK_ALWAYS +#ifdef PNG_READ_USER_CHUNKS_SUPPORTED + && png_ptr->read_user_chunk_fn == NULL +#endif + ) +#endif + png_chunk_error(png_ptr, "unknown critical chunk"); + } + +#ifdef PNG_READ_UNKNOWN_CHUNKS_SUPPORTED + if ((png_ptr->flags & PNG_FLAG_KEEP_UNKNOWN_CHUNKS) +#ifdef PNG_READ_USER_CHUNKS_SUPPORTED + || (png_ptr->read_user_chunk_fn != NULL) +#endif + ) + { +#ifdef PNG_MAX_MALLOC_64K + if (length > (png_uint_32)65535L) + { + png_warning(png_ptr, "unknown chunk too large to fit in memory"); + skip = length - (png_uint_32)65535L; + length = (png_uint_32)65535L; + } +#endif + + png_memcpy((png_charp)png_ptr->unknown_chunk.name, + (png_charp)png_ptr->chunk_name, + png_sizeof(png_ptr->unknown_chunk.name)); + + png_ptr->unknown_chunk.name[png_sizeof(png_ptr->unknown_chunk.name)-1] + = '\0'; + + png_ptr->unknown_chunk.size = (png_size_t)length; + + if (length == 0) + png_ptr->unknown_chunk.data = NULL; + + else + { + png_ptr->unknown_chunk.data = (png_bytep)png_malloc(png_ptr, length); + png_crc_read(png_ptr, (png_bytep)png_ptr->unknown_chunk.data, length); + } + +#ifdef PNG_READ_USER_CHUNKS_SUPPORTED + if (png_ptr->read_user_chunk_fn != NULL) + { + /* Callback to user unknown chunk handler */ + int ret; + + ret = (*(png_ptr->read_user_chunk_fn)) + (png_ptr, &png_ptr->unknown_chunk); + + if (ret < 0) + png_chunk_error(png_ptr, "error in user chunk"); + + if (ret == 0) + { + if (!(png_ptr->chunk_name[0] & 0x20)) + { +#ifdef PNG_HANDLE_AS_UNKNOWN_SUPPORTED + if (png_handle_as_unknown(png_ptr, png_ptr->chunk_name) != + PNG_HANDLE_CHUNK_ALWAYS) +#endif + png_chunk_error(png_ptr, "unknown critical chunk"); + } + + png_set_unknown_chunks(png_ptr, info_ptr, + &png_ptr->unknown_chunk, 1); + } + } + + else +#endif + png_set_unknown_chunks(png_ptr, info_ptr, &png_ptr->unknown_chunk, 1); + + png_free(png_ptr, png_ptr->unknown_chunk.data); + png_ptr->unknown_chunk.data = NULL; + } + + else +#endif + skip = length; + + png_crc_finish(png_ptr, skip); + +#ifndef PNG_READ_USER_CHUNKS_SUPPORTED + PNG_UNUSED(info_ptr) /* Quiet compiler warnings about unused info_ptr */ +#endif +} + +/* This function is called to verify that a chunk name is valid. + * This function can't have the "critical chunk check" incorporated + * into it, since in the future we will need to be able to call user + * functions to handle unknown critical chunks after we check that + * the chunk name itself is valid. + */ + +#define isnonalpha(c) ((c) < 65 || (c) > 122 || ((c) > 90 && (c) < 97)) + +void /* PRIVATE */ +png_check_chunk_name(png_structp png_ptr, png_const_bytep chunk_name) +{ + png_debug(1, "in png_check_chunk_name"); + if (isnonalpha(chunk_name[0]) || isnonalpha(chunk_name[1]) || + isnonalpha(chunk_name[2]) || isnonalpha(chunk_name[3])) + { + png_chunk_error(png_ptr, "invalid chunk type"); + } +} + +/* Combines the row recently read in with the existing pixels in the + * row. This routine takes care of alpha and transparency if requested. + * This routine also handles the two methods of progressive display + * of interlaced images, depending on the mask value. + * The mask value describes which pixels are to be combined with + * the row. The pattern always repeats every 8 pixels, so just 8 + * bits are needed. A one indicates the pixel is to be combined, + * a zero indicates the pixel is to be skipped. This is in addition + * to any alpha or transparency value associated with the pixel. If + * you want all pixels to be combined, pass 0xff (255) in mask. + */ + +void /* PRIVATE */ +png_combine_row(png_structp png_ptr, png_bytep row, int mask) +{ + png_debug(1, "in png_combine_row"); + + if (mask == 0xff) + { + png_memcpy(row, png_ptr->row_buf + 1, + PNG_ROWBYTES(png_ptr->row_info.pixel_depth, png_ptr->width)); + } + + else + { + switch (png_ptr->row_info.pixel_depth) + { + case 1: + { + png_bytep sp = png_ptr->row_buf + 1; + png_bytep dp = row; + int s_inc, s_start, s_end; + int m = 0x80; + int shift; + png_uint_32 i; + png_uint_32 row_width = png_ptr->width; + +#ifdef PNG_READ_PACKSWAP_SUPPORTED + if (png_ptr->transformations & PNG_PACKSWAP) + { + s_start = 0; + s_end = 7; + s_inc = 1; + } + + else +#endif + { + s_start = 7; + s_end = 0; + s_inc = -1; + } + + shift = s_start; + + for (i = 0; i < row_width; i++) + { + if (m & mask) + { + int value; + + value = (*sp >> shift) & 0x01; + *dp &= (png_byte)((0x7f7f >> (7 - shift)) & 0xff); + *dp |= (png_byte)(value << shift); + } + + if (shift == s_end) + { + shift = s_start; + sp++; + dp++; + } + + else + shift += s_inc; + + if (m == 1) + m = 0x80; + + else + m >>= 1; + } + break; + } + + case 2: + { + png_bytep sp = png_ptr->row_buf + 1; + png_bytep dp = row; + int s_start, s_end, s_inc; + int m = 0x80; + int shift; + png_uint_32 i; + png_uint_32 row_width = png_ptr->width; + int value; + +#ifdef PNG_READ_PACKSWAP_SUPPORTED + if (png_ptr->transformations & PNG_PACKSWAP) + { + s_start = 0; + s_end = 6; + s_inc = 2; + } + + else +#endif + { + s_start = 6; + s_end = 0; + s_inc = -2; + } + + shift = s_start; + + for (i = 0; i < row_width; i++) + { + if (m & mask) + { + value = (*sp >> shift) & 0x03; + *dp &= (png_byte)((0x3f3f >> (6 - shift)) & 0xff); + *dp |= (png_byte)(value << shift); + } + + if (shift == s_end) + { + shift = s_start; + sp++; + dp++; + } + + else + shift += s_inc; + + if (m == 1) + m = 0x80; + + else + m >>= 1; + } + break; + } + + case 4: + { + png_bytep sp = png_ptr->row_buf + 1; + png_bytep dp = row; + int s_start, s_end, s_inc; + int m = 0x80; + int shift; + png_uint_32 i; + png_uint_32 row_width = png_ptr->width; + int value; + +#ifdef PNG_READ_PACKSWAP_SUPPORTED + if (png_ptr->transformations & PNG_PACKSWAP) + { + s_start = 0; + s_end = 4; + s_inc = 4; + } + + else +#endif + { + s_start = 4; + s_end = 0; + s_inc = -4; + } + shift = s_start; + + for (i = 0; i < row_width; i++) + { + if (m & mask) + { + value = (*sp >> shift) & 0xf; + *dp &= (png_byte)((0xf0f >> (4 - shift)) & 0xff); + *dp |= (png_byte)(value << shift); + } + + if (shift == s_end) + { + shift = s_start; + sp++; + dp++; + } + + else + shift += s_inc; + + if (m == 1) + m = 0x80; + + else + m >>= 1; + } + break; + } + + default: + { + png_bytep sp = png_ptr->row_buf + 1; + png_bytep dp = row; + png_size_t pixel_bytes = (png_ptr->row_info.pixel_depth >> 3); + png_uint_32 i; + png_uint_32 row_width = png_ptr->width; + png_byte m = 0x80; + + for (i = 0; i < row_width; i++) + { + if (m & mask) + { + png_memcpy(dp, sp, pixel_bytes); + } + + sp += pixel_bytes; + dp += pixel_bytes; + + if (m == 1) + m = 0x80; + + else + m >>= 1; + } + break; + } + } + } +} + +#ifdef PNG_READ_INTERLACING_SUPPORTED +void /* PRIVATE */ +png_do_read_interlace(png_structp png_ptr) +{ + png_row_infop row_info = &(png_ptr->row_info); + png_bytep row = png_ptr->row_buf + 1; + int pass = png_ptr->pass; + png_uint_32 transformations = png_ptr->transformations; + /* Arrays to facilitate easy interlacing - use pass (0 - 6) as index */ + /* Offset to next interlace block */ + PNG_CONST int png_pass_inc[7] = {8, 8, 4, 4, 2, 2, 1}; + + png_debug(1, "in png_do_read_interlace"); + if (row != NULL && row_info != NULL) + { + png_uint_32 final_width; + + final_width = row_info->width * png_pass_inc[pass]; + + switch (row_info->pixel_depth) + { + case 1: + { + png_bytep sp = row + (png_size_t)((row_info->width - 1) >> 3); + png_bytep dp = row + (png_size_t)((final_width - 1) >> 3); + int sshift, dshift; + int s_start, s_end, s_inc; + int jstop = png_pass_inc[pass]; + png_byte v; + png_uint_32 i; + int j; + +#ifdef PNG_READ_PACKSWAP_SUPPORTED + if (transformations & PNG_PACKSWAP) + { + sshift = (int)((row_info->width + 7) & 0x07); + dshift = (int)((final_width + 7) & 0x07); + s_start = 7; + s_end = 0; + s_inc = -1; + } + + else +#endif + { + sshift = 7 - (int)((row_info->width + 7) & 0x07); + dshift = 7 - (int)((final_width + 7) & 0x07); + s_start = 0; + s_end = 7; + s_inc = 1; + } + + for (i = 0; i < row_info->width; i++) + { + v = (png_byte)((*sp >> sshift) & 0x01); + for (j = 0; j < jstop; j++) + { + *dp &= (png_byte)((0x7f7f >> (7 - dshift)) & 0xff); + *dp |= (png_byte)(v << dshift); + + if (dshift == s_end) + { + dshift = s_start; + dp--; + } + + else + dshift += s_inc; + } + + if (sshift == s_end) + { + sshift = s_start; + sp--; + } + + else + sshift += s_inc; + } + break; + } + + case 2: + { + png_bytep sp = row + (png_uint_32)((row_info->width - 1) >> 2); + png_bytep dp = row + (png_uint_32)((final_width - 1) >> 2); + int sshift, dshift; + int s_start, s_end, s_inc; + int jstop = png_pass_inc[pass]; + png_uint_32 i; + +#ifdef PNG_READ_PACKSWAP_SUPPORTED + if (transformations & PNG_PACKSWAP) + { + sshift = (int)(((row_info->width + 3) & 0x03) << 1); + dshift = (int)(((final_width + 3) & 0x03) << 1); + s_start = 6; + s_end = 0; + s_inc = -2; + } + + else +#endif + { + sshift = (int)((3 - ((row_info->width + 3) & 0x03)) << 1); + dshift = (int)((3 - ((final_width + 3) & 0x03)) << 1); + s_start = 0; + s_end = 6; + s_inc = 2; + } + + for (i = 0; i < row_info->width; i++) + { + png_byte v; + int j; + + v = (png_byte)((*sp >> sshift) & 0x03); + for (j = 0; j < jstop; j++) + { + *dp &= (png_byte)((0x3f3f >> (6 - dshift)) & 0xff); + *dp |= (png_byte)(v << dshift); + + if (dshift == s_end) + { + dshift = s_start; + dp--; + } + + else + dshift += s_inc; + } + + if (sshift == s_end) + { + sshift = s_start; + sp--; + } + + else + sshift += s_inc; + } + break; + } + + case 4: + { + png_bytep sp = row + (png_size_t)((row_info->width - 1) >> 1); + png_bytep dp = row + (png_size_t)((final_width - 1) >> 1); + int sshift, dshift; + int s_start, s_end, s_inc; + png_uint_32 i; + int jstop = png_pass_inc[pass]; + +#ifdef PNG_READ_PACKSWAP_SUPPORTED + if (transformations & PNG_PACKSWAP) + { + sshift = (int)(((row_info->width + 1) & 0x01) << 2); + dshift = (int)(((final_width + 1) & 0x01) << 2); + s_start = 4; + s_end = 0; + s_inc = -4; + } + + else +#endif + { + sshift = (int)((1 - ((row_info->width + 1) & 0x01)) << 2); + dshift = (int)((1 - ((final_width + 1) & 0x01)) << 2); + s_start = 0; + s_end = 4; + s_inc = 4; + } + + for (i = 0; i < row_info->width; i++) + { + png_byte v = (png_byte)((*sp >> sshift) & 0xf); + int j; + + for (j = 0; j < jstop; j++) + { + *dp &= (png_byte)((0xf0f >> (4 - dshift)) & 0xff); + *dp |= (png_byte)(v << dshift); + + if (dshift == s_end) + { + dshift = s_start; + dp--; + } + + else + dshift += s_inc; + } + + if (sshift == s_end) + { + sshift = s_start; + sp--; + } + + else + sshift += s_inc; + } + break; + } + default: + { + png_size_t pixel_bytes = (row_info->pixel_depth >> 3); + + png_bytep sp = row + (png_size_t)(row_info->width - 1) + * pixel_bytes; + + png_bytep dp = row + (png_size_t)(final_width - 1) * pixel_bytes; + + int jstop = png_pass_inc[pass]; + png_uint_32 i; + + for (i = 0; i < row_info->width; i++) + { + png_byte v[8]; + int j; + + png_memcpy(v, sp, pixel_bytes); + + for (j = 0; j < jstop; j++) + { + png_memcpy(dp, v, pixel_bytes); + dp -= pixel_bytes; + } + + sp -= pixel_bytes; + } + break; + } + } + row_info->width = final_width; + row_info->rowbytes = PNG_ROWBYTES(row_info->pixel_depth, final_width); + } +#ifndef PNG_READ_PACKSWAP_SUPPORTED + PNG_UNUSED(transformations) /* Silence compiler warning */ +#endif +} +#endif /* PNG_READ_INTERLACING_SUPPORTED */ + +void /* PRIVATE */ +png_read_filter_row(png_structp png_ptr, png_row_infop row_info, png_bytep row, + png_const_bytep prev_row, int filter) +{ + png_debug(1, "in png_read_filter_row"); + png_debug2(2, "row = %u, filter = %d", png_ptr->row_number, filter); + switch (filter) + { + case PNG_FILTER_VALUE_NONE: + break; + + case PNG_FILTER_VALUE_SUB: + { + png_size_t i; + png_size_t istop = row_info->rowbytes; + unsigned int bpp = (row_info->pixel_depth + 7) >> 3; + png_bytep rp = row + bpp; + png_bytep lp = row; + + for (i = bpp; i < istop; i++) + { + *rp = (png_byte)(((int)(*rp) + (int)(*lp++)) & 0xff); + rp++; + } + break; + } + case PNG_FILTER_VALUE_UP: + { + png_size_t i; + png_size_t istop = row_info->rowbytes; + png_bytep rp = row; + png_const_bytep pp = prev_row; + + for (i = 0; i < istop; i++) + { + *rp = (png_byte)(((int)(*rp) + (int)(*pp++)) & 0xff); + rp++; + } + break; + } + case PNG_FILTER_VALUE_AVG: + { + png_size_t i; + png_bytep rp = row; + png_const_bytep pp = prev_row; + png_bytep lp = row; + unsigned int bpp = (row_info->pixel_depth + 7) >> 3; + png_size_t istop = row_info->rowbytes - bpp; + + for (i = 0; i < bpp; i++) + { + *rp = (png_byte)(((int)(*rp) + + ((int)(*pp++) / 2 )) & 0xff); + + rp++; + } + + for (i = 0; i < istop; i++) + { + *rp = (png_byte)(((int)(*rp) + + (int)(*pp++ + *lp++) / 2 ) & 0xff); + + rp++; + } + break; + } + case PNG_FILTER_VALUE_PAETH: + { + png_size_t i; + png_bytep rp = row; + png_const_bytep pp = prev_row; + png_bytep lp = row; + png_const_bytep cp = prev_row; + unsigned int bpp = (row_info->pixel_depth + 7) >> 3; + png_size_t istop=row_info->rowbytes - bpp; + + for (i = 0; i < bpp; i++) + { + *rp = (png_byte)(((int)(*rp) + (int)(*pp++)) & 0xff); + rp++; + } + + for (i = 0; i < istop; i++) /* Use leftover rp,pp */ + { + int a, b, c, pa, pb, pc, p; + + a = *lp++; + b = *pp++; + c = *cp++; + + p = b - c; + pc = a - c; + +#ifdef PNG_USE_ABS + pa = abs(p); + pb = abs(pc); + pc = abs(p + pc); +#else + pa = p < 0 ? -p : p; + pb = pc < 0 ? -pc : pc; + pc = (p + pc) < 0 ? -(p + pc) : p + pc; +#endif + + /* + if (pa <= pb && pa <= pc) + p = a; + + else if (pb <= pc) + p = b; + + else + p = c; + */ + + p = (pa <= pb && pa <= pc) ? a : (pb <= pc) ? b : c; + + *rp = (png_byte)(((int)(*rp) + p) & 0xff); + rp++; + } + break; + } + default: + png_error(png_ptr, "Ignoring bad adaptive filter type"); + /*NOT REACHED */ + break; + } +} + +#ifdef PNG_SEQUENTIAL_READ_SUPPORTED +void /* PRIVATE */ +png_read_finish_row(png_structp png_ptr) +{ +#ifdef PNG_READ_INTERLACING_SUPPORTED + /* Arrays to facilitate easy interlacing - use pass (0 - 6) as index */ + + /* Start of interlace block */ + PNG_CONST int png_pass_start[7] = {0, 4, 0, 2, 0, 1, 0}; + + /* Offset to next interlace block */ + PNG_CONST int png_pass_inc[7] = {8, 8, 4, 4, 2, 2, 1}; + + /* Start of interlace block in the y direction */ + PNG_CONST int png_pass_ystart[7] = {0, 0, 4, 0, 2, 0, 1}; + + /* Offset to next interlace block in the y direction */ + PNG_CONST int png_pass_yinc[7] = {8, 8, 8, 4, 4, 2, 2}; +#endif /* PNG_READ_INTERLACING_SUPPORTED */ + + png_debug(1, "in png_read_finish_row"); + png_ptr->row_number++; + if (png_ptr->row_number < png_ptr->num_rows) + return; + +#ifdef PNG_READ_INTERLACING_SUPPORTED + if (png_ptr->interlaced) + { + png_ptr->row_number = 0; + + png_memset(png_ptr->prev_row, 0, png_ptr->rowbytes + 1); + + do + { + png_ptr->pass++; + + if (png_ptr->pass >= 7) + break; + + png_ptr->iwidth = (png_ptr->width + + png_pass_inc[png_ptr->pass] - 1 - + png_pass_start[png_ptr->pass]) / + png_pass_inc[png_ptr->pass]; + + if (!(png_ptr->transformations & PNG_INTERLACE)) + { + png_ptr->num_rows = (png_ptr->height + + png_pass_yinc[png_ptr->pass] - 1 - + png_pass_ystart[png_ptr->pass]) / + png_pass_yinc[png_ptr->pass]; + } + + else /* if (png_ptr->transformations & PNG_INTERLACE) */ + break; /* libpng deinterlacing sees every row */ + + } while (png_ptr->num_rows == 0 || png_ptr->iwidth == 0); + + if (png_ptr->pass < 7) + return; + } +#endif /* PNG_READ_INTERLACING_SUPPORTED */ + + if (!(png_ptr->flags & PNG_FLAG_ZLIB_FINISHED)) + { + PNG_IDAT; + char extra; + int ret; + + png_ptr->zstream.next_out = (Byte *)&extra; + png_ptr->zstream.avail_out = (uInt)1; + + for (;;) + { + if (!(png_ptr->zstream.avail_in)) + { + while (!png_ptr->idat_size) + { + png_crc_finish(png_ptr, 0); + png_ptr->idat_size = png_read_chunk_header(png_ptr); + if (png_memcmp(png_ptr->chunk_name, png_IDAT, 4)) + png_error(png_ptr, "Not enough image data"); + } + + png_ptr->zstream.avail_in = (uInt)png_ptr->zbuf_size; + png_ptr->zstream.next_in = png_ptr->zbuf; + + if (png_ptr->zbuf_size > png_ptr->idat_size) + png_ptr->zstream.avail_in = (uInt)png_ptr->idat_size; + + png_crc_read(png_ptr, png_ptr->zbuf, png_ptr->zstream.avail_in); + png_ptr->idat_size -= png_ptr->zstream.avail_in; + } + + ret = inflate(&png_ptr->zstream, Z_PARTIAL_FLUSH); + + if (ret == Z_STREAM_END) + { + if (!(png_ptr->zstream.avail_out) || png_ptr->zstream.avail_in || + png_ptr->idat_size) + png_warning(png_ptr, "Extra compressed data"); + + png_ptr->mode |= PNG_AFTER_IDAT; + png_ptr->flags |= PNG_FLAG_ZLIB_FINISHED; + break; + } + + if (ret != Z_OK) + png_error(png_ptr, png_ptr->zstream.msg ? png_ptr->zstream.msg : + "Decompression Error"); + + if (!(png_ptr->zstream.avail_out)) + { + png_warning(png_ptr, "Extra compressed data"); + png_ptr->mode |= PNG_AFTER_IDAT; + png_ptr->flags |= PNG_FLAG_ZLIB_FINISHED; + break; + } + + } + png_ptr->zstream.avail_out = 0; + } + + if (png_ptr->idat_size || png_ptr->zstream.avail_in) + png_warning(png_ptr, "Extra compression data"); + + inflateReset(&png_ptr->zstream); + + png_ptr->mode |= PNG_AFTER_IDAT; +} +#endif /* PNG_SEQUENTIAL_READ_SUPPORTED */ + +void /* PRIVATE */ +png_read_start_row(png_structp png_ptr) +{ +#ifdef PNG_READ_INTERLACING_SUPPORTED + /* Arrays to facilitate easy interlacing - use pass (0 - 6) as index */ + + /* Start of interlace block */ + PNG_CONST int png_pass_start[7] = {0, 4, 0, 2, 0, 1, 0}; + + /* Offset to next interlace block */ + PNG_CONST int png_pass_inc[7] = {8, 8, 4, 4, 2, 2, 1}; + + /* Start of interlace block in the y direction */ + PNG_CONST int png_pass_ystart[7] = {0, 0, 4, 0, 2, 0, 1}; + + /* Offset to next interlace block in the y direction */ + PNG_CONST int png_pass_yinc[7] = {8, 8, 8, 4, 4, 2, 2}; +#endif + + int max_pixel_depth; + png_size_t row_bytes; + + png_debug(1, "in png_read_start_row"); + png_ptr->zstream.avail_in = 0; + png_init_read_transformations(png_ptr); +#ifdef PNG_READ_INTERLACING_SUPPORTED + if (png_ptr->interlaced) + { + if (!(png_ptr->transformations & PNG_INTERLACE)) + png_ptr->num_rows = (png_ptr->height + png_pass_yinc[0] - 1 - + png_pass_ystart[0]) / png_pass_yinc[0]; + + else + png_ptr->num_rows = png_ptr->height; + + png_ptr->iwidth = (png_ptr->width + + png_pass_inc[png_ptr->pass] - 1 - + png_pass_start[png_ptr->pass]) / + png_pass_inc[png_ptr->pass]; + } + + else +#endif /* PNG_READ_INTERLACING_SUPPORTED */ + { + png_ptr->num_rows = png_ptr->height; + png_ptr->iwidth = png_ptr->width; + } + + max_pixel_depth = png_ptr->pixel_depth; + +#ifdef PNG_READ_PACK_SUPPORTED + if ((png_ptr->transformations & PNG_PACK) && png_ptr->bit_depth < 8) + max_pixel_depth = 8; +#endif + +#ifdef PNG_READ_EXPAND_SUPPORTED + if (png_ptr->transformations & PNG_EXPAND) + { + if (png_ptr->color_type == PNG_COLOR_TYPE_PALETTE) + { + if (png_ptr->num_trans) + max_pixel_depth = 32; + + else + max_pixel_depth = 24; + } + + else if (png_ptr->color_type == PNG_COLOR_TYPE_GRAY) + { + if (max_pixel_depth < 8) + max_pixel_depth = 8; + + if (png_ptr->num_trans) + max_pixel_depth *= 2; + } + + else if (png_ptr->color_type == PNG_COLOR_TYPE_RGB) + { + if (png_ptr->num_trans) + { + max_pixel_depth *= 4; + max_pixel_depth /= 3; + } + } + } +#endif + +#ifdef PNG_READ_FILLER_SUPPORTED + if (png_ptr->transformations & (PNG_FILLER)) + { + if (png_ptr->color_type == PNG_COLOR_TYPE_PALETTE) + max_pixel_depth = 32; + + else if (png_ptr->color_type == PNG_COLOR_TYPE_GRAY) + { + if (max_pixel_depth <= 8) + max_pixel_depth = 16; + + else + max_pixel_depth = 32; + } + + else if (png_ptr->color_type == PNG_COLOR_TYPE_RGB) + { + if (max_pixel_depth <= 32) + max_pixel_depth = 32; + + else + max_pixel_depth = 64; + } + } +#endif + +#ifdef PNG_READ_GRAY_TO_RGB_SUPPORTED + if (png_ptr->transformations & PNG_GRAY_TO_RGB) + { + if ( +#ifdef PNG_READ_EXPAND_SUPPORTED + (png_ptr->num_trans && (png_ptr->transformations & PNG_EXPAND)) || +#endif +#ifdef PNG_READ_FILLER_SUPPORTED + (png_ptr->transformations & (PNG_FILLER)) || +#endif + png_ptr->color_type == PNG_COLOR_TYPE_GRAY_ALPHA) + { + if (max_pixel_depth <= 16) + max_pixel_depth = 32; + + else + max_pixel_depth = 64; + } + + else + { + if (max_pixel_depth <= 8) + { + if (png_ptr->color_type == PNG_COLOR_TYPE_RGB_ALPHA) + max_pixel_depth = 32; + + else + max_pixel_depth = 24; + } + + else if (png_ptr->color_type == PNG_COLOR_TYPE_RGB_ALPHA) + max_pixel_depth = 64; + + else + max_pixel_depth = 48; + } + } +#endif + +#if defined(PNG_READ_USER_TRANSFORM_SUPPORTED) && \ +defined(PNG_USER_TRANSFORM_PTR_SUPPORTED) + if (png_ptr->transformations & PNG_USER_TRANSFORM) + { + int user_pixel_depth = png_ptr->user_transform_depth* + png_ptr->user_transform_channels; + + if (user_pixel_depth > max_pixel_depth) + max_pixel_depth=user_pixel_depth; + } +#endif + + /* Align the width on the next larger 8 pixels. Mainly used + * for interlacing + */ + row_bytes = ((png_ptr->width + 7) & ~((png_uint_32)7)); + /* Calculate the maximum bytes needed, adding a byte and a pixel + * for safety's sake + */ + row_bytes = PNG_ROWBYTES(max_pixel_depth, row_bytes) + + 1 + ((max_pixel_depth + 7) >> 3); + +#ifdef PNG_MAX_MALLOC_64K + if (row_bytes > (png_uint_32)65536L) + png_error(png_ptr, "This image requires a row greater than 64KB"); +#endif + + if (row_bytes + 48 > png_ptr->old_big_row_buf_size) + { + png_free(png_ptr, png_ptr->big_row_buf); + + if (png_ptr->interlaced) + png_ptr->big_row_buf = (png_bytep)png_calloc(png_ptr, + row_bytes + 48); + + else + png_ptr->big_row_buf = (png_bytep)png_malloc(png_ptr, + row_bytes + 48); + + png_ptr->old_big_row_buf_size = row_bytes + 48; + +#ifdef PNG_ALIGNED_MEMORY_SUPPORTED + /* Use 16-byte aligned memory for row_buf with at least 16 bytes + * of padding before and after row_buf. + */ + png_ptr->row_buf = png_ptr->big_row_buf + 32 - + (((png_alloc_size_t)png_ptr->big_row_buf + 15) & 0x0F); + + png_ptr->old_big_row_buf_size = row_bytes + 48; +#else + /* Use 32 bytes of padding before and 16 bytes after row_buf. */ + png_ptr->row_buf = png_ptr->big_row_buf + 32; +#endif + png_ptr->old_big_row_buf_size = row_bytes + 48; + } + +#ifdef PNG_MAX_MALLOC_64K + if (png_ptr->rowbytes > 65535) + png_error(png_ptr, "This image requires a row greater than 64KB"); + +#endif + if (png_ptr->rowbytes > (PNG_SIZE_MAX - 1)) + png_error(png_ptr, "Row has too many bytes to allocate in memory"); + + if (png_ptr->rowbytes + 1 > png_ptr->old_prev_row_size) + { + png_free(png_ptr, png_ptr->prev_row); + + png_ptr->prev_row = (png_bytep)png_malloc(png_ptr, png_ptr->rowbytes + 1); + + png_ptr->old_prev_row_size = png_ptr->rowbytes + 1; + } + + png_memset(png_ptr->prev_row, 0, png_ptr->rowbytes + 1); + + png_debug1(3, "width = %u,", png_ptr->width); + png_debug1(3, "height = %u,", png_ptr->height); + png_debug1(3, "iwidth = %u,", png_ptr->iwidth); + png_debug1(3, "num_rows = %u,", png_ptr->num_rows); + png_debug1(3, "rowbytes = %lu,", (unsigned long)png_ptr->rowbytes); + png_debug1(3, "irowbytes = %lu", + (unsigned long)PNG_ROWBYTES(png_ptr->pixel_depth, png_ptr->iwidth) + 1); + + png_ptr->flags |= PNG_FLAG_ROW_INIT; +} +#endif /* PNG_READ_SUPPORTED */ diff --git a/src/3rdparty/libpng/pngset.c b/src/3rdparty/libpng/pngset.c new file mode 100644 index 0000000000..2cfcf33bdf --- /dev/null +++ b/src/3rdparty/libpng/pngset.c @@ -0,0 +1,1225 @@ + +/* pngset.c - storage of image information into info struct + * + * Last changed in libpng 1.5.1 [February 3, 2011] + * Copyright (c) 1998-2011 Glenn Randers-Pehrson + * (Version 0.96 Copyright (c) 1996, 1997 Andreas Dilger) + * (Version 0.88 Copyright (c) 1995, 1996 Guy Eric Schalnat, Group 42, Inc.) + * + * This code is released under the libpng license. + * For conditions of distribution and use, see the disclaimer + * and license in png.h + * + * The functions here are used during reads to store data from the file + * into the info struct, and during writes to store application data + * into the info struct for writing into the file. This abstracts the + * info struct and allows us to change the structure in the future. + */ + +#include "pngpriv.h" + +#if defined(PNG_READ_SUPPORTED) || defined(PNG_WRITE_SUPPORTED) + +#ifdef PNG_bKGD_SUPPORTED +void PNGAPI +png_set_bKGD(png_structp png_ptr, png_infop info_ptr, + png_const_color_16p background) +{ + png_debug1(1, "in %s storage function", "bKGD"); + + if (png_ptr == NULL || info_ptr == NULL) + return; + + png_memcpy(&(info_ptr->background), background, png_sizeof(png_color_16)); + info_ptr->valid |= PNG_INFO_bKGD; +} +#endif + +#ifdef PNG_cHRM_SUPPORTED +void PNGFAPI +png_set_cHRM_fixed(png_structp png_ptr, png_infop info_ptr, + png_fixed_point white_x, png_fixed_point white_y, png_fixed_point red_x, + png_fixed_point red_y, png_fixed_point green_x, png_fixed_point green_y, + png_fixed_point blue_x, png_fixed_point blue_y) +{ + png_debug1(1, "in %s storage function", "cHRM fixed"); + + if (png_ptr == NULL || info_ptr == NULL) + return; + +# ifdef PNG_CHECK_cHRM_SUPPORTED + if (png_check_cHRM_fixed(png_ptr, + white_x, white_y, red_x, red_y, green_x, green_y, blue_x, blue_y)) +# endif + { + info_ptr->x_white = white_x; + info_ptr->y_white = white_y; + info_ptr->x_red = red_x; + info_ptr->y_red = red_y; + info_ptr->x_green = green_x; + info_ptr->y_green = green_y; + info_ptr->x_blue = blue_x; + info_ptr->y_blue = blue_y; + info_ptr->valid |= PNG_INFO_cHRM; + } +} + +# ifdef PNG_FLOATING_POINT_SUPPORTED +void PNGAPI +png_set_cHRM(png_structp png_ptr, png_infop info_ptr, + double white_x, double white_y, double red_x, double red_y, + double green_x, double green_y, double blue_x, double blue_y) +{ + png_set_cHRM_fixed(png_ptr, info_ptr, + png_fixed(png_ptr, white_x, "cHRM White X"), + png_fixed(png_ptr, white_y, "cHRM White Y"), + png_fixed(png_ptr, red_x, "cHRM Red X"), + png_fixed(png_ptr, red_y, "cHRM Red Y"), + png_fixed(png_ptr, green_x, "cHRM Green X"), + png_fixed(png_ptr, green_y, "cHRM Green Y"), + png_fixed(png_ptr, blue_x, "cHRM Blue X"), + png_fixed(png_ptr, blue_y, "cHRM Blue Y")); +} +# endif /* PNG_FLOATING_POINT_SUPPORTED */ + +#endif /* PNG_cHRM_SUPPORTED */ + +#ifdef PNG_gAMA_SUPPORTED +void PNGFAPI +png_set_gAMA_fixed(png_structp png_ptr, png_infop info_ptr, png_fixed_point + file_gamma) +{ + png_debug1(1, "in %s storage function", "gAMA"); + + if (png_ptr == NULL || info_ptr == NULL) + return; + + /* Previously these values were limited, however they must be + * wrong, therefore storing them (and setting PNG_INFO_gAMA) + * must be wrong too. + */ + if (file_gamma > (png_fixed_point)PNG_UINT_31_MAX) + png_warning(png_ptr, "Gamma too large, ignored"); + + else if (file_gamma <= 0) + png_warning(png_ptr, "Negative or zero gamma ignored"); + + else + { + info_ptr->gamma = file_gamma; + info_ptr->valid |= PNG_INFO_gAMA; + } +} + +# ifdef PNG_FLOATING_POINT_SUPPORTED +void PNGAPI +png_set_gAMA(png_structp png_ptr, png_infop info_ptr, double file_gamma) +{ + png_set_gAMA_fixed(png_ptr, info_ptr, png_fixed(png_ptr, file_gamma, + "png_set_gAMA")); +} +# endif +#endif + +#ifdef PNG_hIST_SUPPORTED +void PNGAPI +png_set_hIST(png_structp png_ptr, png_infop info_ptr, png_const_uint_16p hist) +{ + int i; + + png_debug1(1, "in %s storage function", "hIST"); + + if (png_ptr == NULL || info_ptr == NULL) + return; + + if (info_ptr->num_palette == 0 || info_ptr->num_palette + > PNG_MAX_PALETTE_LENGTH) + { + png_warning(png_ptr, + "Invalid palette size, hIST allocation skipped"); + + return; + } + + png_free_data(png_ptr, info_ptr, PNG_FREE_HIST, 0); + + /* Changed from info->num_palette to PNG_MAX_PALETTE_LENGTH in + * version 1.2.1 + */ + png_ptr->hist = (png_uint_16p)png_malloc_warn(png_ptr, + PNG_MAX_PALETTE_LENGTH * png_sizeof(png_uint_16)); + + if (png_ptr->hist == NULL) + { + png_warning(png_ptr, "Insufficient memory for hIST chunk data"); + return; + } + + for (i = 0; i < info_ptr->num_palette; i++) + png_ptr->hist[i] = hist[i]; + + info_ptr->hist = png_ptr->hist; + info_ptr->valid |= PNG_INFO_hIST; + info_ptr->free_me |= PNG_FREE_HIST; +} +#endif + +void PNGAPI +png_set_IHDR(png_structp png_ptr, png_infop info_ptr, + png_uint_32 width, png_uint_32 height, int bit_depth, + int color_type, int interlace_type, int compression_type, + int filter_type) +{ + png_debug1(1, "in %s storage function", "IHDR"); + + if (png_ptr == NULL || info_ptr == NULL) + return; + + info_ptr->width = width; + info_ptr->height = height; + info_ptr->bit_depth = (png_byte)bit_depth; + info_ptr->color_type = (png_byte)color_type; + info_ptr->compression_type = (png_byte)compression_type; + info_ptr->filter_type = (png_byte)filter_type; + info_ptr->interlace_type = (png_byte)interlace_type; + + png_check_IHDR (png_ptr, info_ptr->width, info_ptr->height, + info_ptr->bit_depth, info_ptr->color_type, info_ptr->interlace_type, + info_ptr->compression_type, info_ptr->filter_type); + + if (info_ptr->color_type == PNG_COLOR_TYPE_PALETTE) + info_ptr->channels = 1; + + else if (info_ptr->color_type & PNG_COLOR_MASK_COLOR) + info_ptr->channels = 3; + + else + info_ptr->channels = 1; + + if (info_ptr->color_type & PNG_COLOR_MASK_ALPHA) + info_ptr->channels++; + + info_ptr->pixel_depth = (png_byte)(info_ptr->channels * info_ptr->bit_depth); + + /* Check for potential overflow */ + if (width > + (PNG_UINT_32_MAX >> 3) /* 8-byte RRGGBBAA pixels */ + - 48 /* bigrowbuf hack */ + - 1 /* filter byte */ + - 7*8 /* rounding of width to multiple of 8 pixels */ + - 8) /* extra max_pixel_depth pad */ + info_ptr->rowbytes = 0; + else + info_ptr->rowbytes = PNG_ROWBYTES(info_ptr->pixel_depth, width); +} + +#ifdef PNG_oFFs_SUPPORTED +void PNGAPI +png_set_oFFs(png_structp png_ptr, png_infop info_ptr, + png_int_32 offset_x, png_int_32 offset_y, int unit_type) +{ + png_debug1(1, "in %s storage function", "oFFs"); + + if (png_ptr == NULL || info_ptr == NULL) + return; + + info_ptr->x_offset = offset_x; + info_ptr->y_offset = offset_y; + info_ptr->offset_unit_type = (png_byte)unit_type; + info_ptr->valid |= PNG_INFO_oFFs; +} +#endif + +#ifdef PNG_pCAL_SUPPORTED +void PNGAPI +png_set_pCAL(png_structp png_ptr, png_infop info_ptr, + png_const_charp purpose, png_int_32 X0, png_int_32 X1, int type, + int nparams, png_const_charp units, png_charpp params) +{ + png_size_t length; + int i; + + png_debug1(1, "in %s storage function", "pCAL"); + + if (png_ptr == NULL || info_ptr == NULL) + return; + + length = png_strlen(purpose) + 1; + png_debug1(3, "allocating purpose for info (%lu bytes)", + (unsigned long)length); + + /* TODO: validate format of calibration name and unit name */ + + /* Check that the type matches the specification. */ + if (type < 0 || type > 3) + png_error(png_ptr, "Invalid pCAL equation type"); + + /* Validate params[nparams] */ + for (i=0; i<nparams; ++i) + if (!png_check_fp_string(params[i], png_strlen(params[i]))) + png_error(png_ptr, "Invalid format for pCAL parameter"); + + info_ptr->pcal_purpose = (png_charp)png_malloc_warn(png_ptr, length); + + if (info_ptr->pcal_purpose == NULL) + { + png_warning(png_ptr, "Insufficient memory for pCAL purpose"); + return; + } + + png_memcpy(info_ptr->pcal_purpose, purpose, length); + + png_debug(3, "storing X0, X1, type, and nparams in info"); + info_ptr->pcal_X0 = X0; + info_ptr->pcal_X1 = X1; + info_ptr->pcal_type = (png_byte)type; + info_ptr->pcal_nparams = (png_byte)nparams; + + length = png_strlen(units) + 1; + png_debug1(3, "allocating units for info (%lu bytes)", + (unsigned long)length); + + info_ptr->pcal_units = (png_charp)png_malloc_warn(png_ptr, length); + + if (info_ptr->pcal_units == NULL) + { + png_warning(png_ptr, "Insufficient memory for pCAL units"); + return; + } + + png_memcpy(info_ptr->pcal_units, units, length); + + info_ptr->pcal_params = (png_charpp)png_malloc_warn(png_ptr, + (png_size_t)((nparams + 1) * png_sizeof(png_charp))); + + if (info_ptr->pcal_params == NULL) + { + png_warning(png_ptr, "Insufficient memory for pCAL params"); + return; + } + + png_memset(info_ptr->pcal_params, 0, (nparams + 1) * png_sizeof(png_charp)); + + for (i = 0; i < nparams; i++) + { + length = png_strlen(params[i]) + 1; + png_debug2(3, "allocating parameter %d for info (%lu bytes)", i, + (unsigned long)length); + + info_ptr->pcal_params[i] = (png_charp)png_malloc_warn(png_ptr, length); + + if (info_ptr->pcal_params[i] == NULL) + { + png_warning(png_ptr, "Insufficient memory for pCAL parameter"); + return; + } + + png_memcpy(info_ptr->pcal_params[i], params[i], length); + } + + info_ptr->valid |= PNG_INFO_pCAL; + info_ptr->free_me |= PNG_FREE_PCAL; +} +#endif + +#ifdef PNG_sCAL_SUPPORTED +void PNGAPI +png_set_sCAL_s(png_structp png_ptr, png_infop info_ptr, + int unit, png_const_charp swidth, png_const_charp sheight) +{ + png_size_t lengthw = 0, lengthh = 0; + + png_debug1(1, "in %s storage function", "sCAL"); + + if (png_ptr == NULL || info_ptr == NULL) + return; + + /* Double check the unit (should never get here with an invalid + * unit unless this is an API call.) + */ + if (unit != 1 && unit != 2) + png_error(png_ptr, "Invalid sCAL unit"); + + if (swidth == NULL || (lengthw = png_strlen(swidth)) <= 0 || + swidth[0] == 45 /*'-'*/ || !png_check_fp_string(swidth, lengthw)) + png_error(png_ptr, "Invalid sCAL width"); + + if (sheight == NULL || (lengthh = png_strlen(sheight)) <= 0 || + sheight[0] == 45 /*'-'*/ || !png_check_fp_string(sheight, lengthh)) + png_error(png_ptr, "Invalid sCAL height"); + + info_ptr->scal_unit = (png_byte)unit; + + ++lengthw; + + png_debug1(3, "allocating unit for info (%u bytes)", (unsigned int)lengthw); + + info_ptr->scal_s_width = (png_charp)png_malloc_warn(png_ptr, lengthw); + + if (info_ptr->scal_s_width == NULL) + { + png_warning(png_ptr, "Memory allocation failed while processing sCAL"); + return; + } + + png_memcpy(info_ptr->scal_s_width, swidth, lengthw); + + ++lengthh; + + png_debug1(3, "allocating unit for info (%u bytes)", (unsigned int)lengthh); + + info_ptr->scal_s_height = (png_charp)png_malloc_warn(png_ptr, lengthh); + + if (info_ptr->scal_s_height == NULL) + { + png_free (png_ptr, info_ptr->scal_s_width); + info_ptr->scal_s_width = NULL; + + png_warning(png_ptr, "Memory allocation failed while processing sCAL"); + return; + } + + png_memcpy(info_ptr->scal_s_height, sheight, lengthh); + + info_ptr->valid |= PNG_INFO_sCAL; + info_ptr->free_me |= PNG_FREE_SCAL; +} + +# ifdef PNG_FLOATING_POINT_SUPPORTED +void PNGAPI +png_set_sCAL(png_structp png_ptr, png_infop info_ptr, int unit, double width, + double height) +{ + png_debug1(1, "in %s storage function", "sCAL"); + + /* Check the arguments. */ + if (width <= 0) + png_warning(png_ptr, "Invalid sCAL width ignored"); + + else if (height <= 0) + png_warning(png_ptr, "Invalid sCAL height ignored"); + + else + { + /* Convert 'width' and 'height' to ASCII. */ + char swidth[PNG_sCAL_MAX_DIGITS+1]; + char sheight[PNG_sCAL_MAX_DIGITS+1]; + + png_ascii_from_fp(png_ptr, swidth, sizeof swidth, width, + PNG_sCAL_PRECISION); + png_ascii_from_fp(png_ptr, sheight, sizeof sheight, height, + PNG_sCAL_PRECISION); + + png_set_sCAL_s(png_ptr, info_ptr, unit, swidth, sheight); + } +} +# endif + +# ifdef PNG_FIXED_POINT_SUPPORTED +void PNGAPI +png_set_sCAL_fixed(png_structp png_ptr, png_infop info_ptr, int unit, + png_fixed_point width, png_fixed_point height) +{ + png_debug1(1, "in %s storage function", "sCAL"); + + /* Check the arguments. */ + if (width <= 0) + png_warning(png_ptr, "Invalid sCAL width ignored"); + + else if (height <= 0) + png_warning(png_ptr, "Invalid sCAL height ignored"); + + else + { + /* Convert 'width' and 'height' to ASCII. */ + char swidth[PNG_sCAL_MAX_DIGITS+1]; + char sheight[PNG_sCAL_MAX_DIGITS+1]; + + png_ascii_from_fixed(png_ptr, swidth, sizeof swidth, width); + png_ascii_from_fixed(png_ptr, sheight, sizeof sheight, height); + + png_set_sCAL_s(png_ptr, info_ptr, unit, swidth, sheight); + } +} +# endif +#endif + +#ifdef PNG_pHYs_SUPPORTED +void PNGAPI +png_set_pHYs(png_structp png_ptr, png_infop info_ptr, + png_uint_32 res_x, png_uint_32 res_y, int unit_type) +{ + png_debug1(1, "in %s storage function", "pHYs"); + + if (png_ptr == NULL || info_ptr == NULL) + return; + + info_ptr->x_pixels_per_unit = res_x; + info_ptr->y_pixels_per_unit = res_y; + info_ptr->phys_unit_type = (png_byte)unit_type; + info_ptr->valid |= PNG_INFO_pHYs; +} +#endif + +void PNGAPI +png_set_PLTE(png_structp png_ptr, png_infop info_ptr, + png_const_colorp palette, int num_palette) +{ + + png_debug1(1, "in %s storage function", "PLTE"); + + if (png_ptr == NULL || info_ptr == NULL) + return; + + if (num_palette < 0 || num_palette > PNG_MAX_PALETTE_LENGTH) + { + if (info_ptr->color_type == PNG_COLOR_TYPE_PALETTE) + png_error(png_ptr, "Invalid palette length"); + + else + { + png_warning(png_ptr, "Invalid palette length"); + return; + } + } + + /* It may not actually be necessary to set png_ptr->palette here; + * we do it for backward compatibility with the way the png_handle_tRNS + * function used to do the allocation. + */ + png_free_data(png_ptr, info_ptr, PNG_FREE_PLTE, 0); + + /* Changed in libpng-1.2.1 to allocate PNG_MAX_PALETTE_LENGTH instead + * of num_palette entries, in case of an invalid PNG file that has + * too-large sample values. + */ + png_ptr->palette = (png_colorp)png_calloc(png_ptr, + PNG_MAX_PALETTE_LENGTH * png_sizeof(png_color)); + + png_memcpy(png_ptr->palette, palette, num_palette * png_sizeof(png_color)); + info_ptr->palette = png_ptr->palette; + info_ptr->num_palette = png_ptr->num_palette = (png_uint_16)num_palette; + + info_ptr->free_me |= PNG_FREE_PLTE; + + info_ptr->valid |= PNG_INFO_PLTE; +} + +#ifdef PNG_sBIT_SUPPORTED +void PNGAPI +png_set_sBIT(png_structp png_ptr, png_infop info_ptr, + png_const_color_8p sig_bit) +{ + png_debug1(1, "in %s storage function", "sBIT"); + + if (png_ptr == NULL || info_ptr == NULL) + return; + + png_memcpy(&(info_ptr->sig_bit), sig_bit, png_sizeof(png_color_8)); + info_ptr->valid |= PNG_INFO_sBIT; +} +#endif + +#ifdef PNG_sRGB_SUPPORTED +void PNGAPI +png_set_sRGB(png_structp png_ptr, png_infop info_ptr, int srgb_intent) +{ + png_debug1(1, "in %s storage function", "sRGB"); + + if (png_ptr == NULL || info_ptr == NULL) + return; + + info_ptr->srgb_intent = (png_byte)srgb_intent; + info_ptr->valid |= PNG_INFO_sRGB; +} + +void PNGAPI +png_set_sRGB_gAMA_and_cHRM(png_structp png_ptr, png_infop info_ptr, + int srgb_intent) +{ + png_debug1(1, "in %s storage function", "sRGB_gAMA_and_cHRM"); + + if (png_ptr == NULL || info_ptr == NULL) + return; + + png_set_sRGB(png_ptr, info_ptr, srgb_intent); + +# ifdef PNG_gAMA_SUPPORTED + png_set_gAMA_fixed(png_ptr, info_ptr, 45455L); +# endif + +# ifdef PNG_cHRM_SUPPORTED + png_set_cHRM_fixed(png_ptr, info_ptr, + /* color x y */ + /* white */ 31270L, 32900L, + /* red */ 64000L, 33000L, + /* green */ 30000L, 60000L, + /* blue */ 15000L, 6000L + ); +# endif /* cHRM */ +} +#endif /* sRGB */ + + +#ifdef PNG_iCCP_SUPPORTED +void PNGAPI +png_set_iCCP(png_structp png_ptr, png_infop info_ptr, + png_const_charp name, int compression_type, + png_const_bytep profile, png_uint_32 proflen) +{ + png_charp new_iccp_name; + png_bytep new_iccp_profile; + png_uint_32 length; + + png_debug1(1, "in %s storage function", "iCCP"); + + if (png_ptr == NULL || info_ptr == NULL || name == NULL || profile == NULL) + return; + + length = png_strlen(name)+1; + new_iccp_name = (png_charp)png_malloc_warn(png_ptr, length); + + if (new_iccp_name == NULL) + { + png_warning(png_ptr, "Insufficient memory to process iCCP chunk"); + return; + } + + png_memcpy(new_iccp_name, name, length); + new_iccp_profile = (png_bytep)png_malloc_warn(png_ptr, proflen); + + if (new_iccp_profile == NULL) + { + png_free (png_ptr, new_iccp_name); + png_warning(png_ptr, + "Insufficient memory to process iCCP profile"); + return; + } + + png_memcpy(new_iccp_profile, profile, (png_size_t)proflen); + + png_free_data(png_ptr, info_ptr, PNG_FREE_ICCP, 0); + + info_ptr->iccp_proflen = proflen; + info_ptr->iccp_name = new_iccp_name; + info_ptr->iccp_profile = new_iccp_profile; + /* Compression is always zero but is here so the API and info structure + * does not have to change if we introduce multiple compression types + */ + info_ptr->iccp_compression = (png_byte)compression_type; + info_ptr->free_me |= PNG_FREE_ICCP; + info_ptr->valid |= PNG_INFO_iCCP; +} +#endif + +#ifdef PNG_TEXT_SUPPORTED +void PNGAPI +png_set_text(png_structp png_ptr, png_infop info_ptr, png_const_textp text_ptr, + int num_text) +{ + int ret; + ret = png_set_text_2(png_ptr, info_ptr, text_ptr, num_text); + + if (ret) + png_error(png_ptr, "Insufficient memory to store text"); +} + +int /* PRIVATE */ +png_set_text_2(png_structp png_ptr, png_infop info_ptr, + png_const_textp text_ptr, int num_text) +{ + int i; + + png_debug1(1, "in %s storage function", ((png_ptr == NULL || + png_ptr->chunk_name[0] == '\0') ? + "text" : (png_const_charp)png_ptr->chunk_name)); + + if (png_ptr == NULL || info_ptr == NULL || num_text == 0) + return(0); + + /* Make sure we have enough space in the "text" array in info_struct + * to hold all of the incoming text_ptr objects. + */ + if (info_ptr->num_text + num_text > info_ptr->max_text) + { + if (info_ptr->text != NULL) + { + png_textp old_text; + int old_max; + + old_max = info_ptr->max_text; + info_ptr->max_text = info_ptr->num_text + num_text + 8; + old_text = info_ptr->text; + info_ptr->text = (png_textp)png_malloc_warn(png_ptr, + (png_size_t)(info_ptr->max_text * png_sizeof(png_text))); + + if (info_ptr->text == NULL) + { + png_free(png_ptr, old_text); + return(1); + } + + png_memcpy(info_ptr->text, old_text, (png_size_t)(old_max * + png_sizeof(png_text))); + png_free(png_ptr, old_text); + } + + else + { + info_ptr->max_text = num_text + 8; + info_ptr->num_text = 0; + info_ptr->text = (png_textp)png_malloc_warn(png_ptr, + (png_size_t)(info_ptr->max_text * png_sizeof(png_text))); + if (info_ptr->text == NULL) + return(1); + info_ptr->free_me |= PNG_FREE_TEXT; + } + + png_debug1(3, "allocated %d entries for info_ptr->text", + info_ptr->max_text); + } + for (i = 0; i < num_text; i++) + { + png_size_t text_length, key_len; + png_size_t lang_len, lang_key_len; + png_textp textp = &(info_ptr->text[info_ptr->num_text]); + + if (text_ptr[i].key == NULL) + continue; + + if (text_ptr[i].compression < PNG_TEXT_COMPRESSION_NONE || + text_ptr[i].compression >= PNG_TEXT_COMPRESSION_LAST) + { + png_warning(png_ptr, "text compression mode is out of range"); + continue; + } + + key_len = png_strlen(text_ptr[i].key); + + if (text_ptr[i].compression <= 0) + { + lang_len = 0; + lang_key_len = 0; + } + + else +# ifdef PNG_iTXt_SUPPORTED + { + /* Set iTXt data */ + + if (text_ptr[i].lang != NULL) + lang_len = png_strlen(text_ptr[i].lang); + + else + lang_len = 0; + + if (text_ptr[i].lang_key != NULL) + lang_key_len = png_strlen(text_ptr[i].lang_key); + + else + lang_key_len = 0; + } +# else /* PNG_iTXt_SUPPORTED */ + { + png_warning(png_ptr, "iTXt chunk not supported"); + continue; + } +# endif + + if (text_ptr[i].text == NULL || text_ptr[i].text[0] == '\0') + { + text_length = 0; +# ifdef PNG_iTXt_SUPPORTED + if (text_ptr[i].compression > 0) + textp->compression = PNG_ITXT_COMPRESSION_NONE; + + else +# endif + textp->compression = PNG_TEXT_COMPRESSION_NONE; + } + + else + { + text_length = png_strlen(text_ptr[i].text); + textp->compression = text_ptr[i].compression; + } + + textp->key = (png_charp)png_malloc_warn(png_ptr, + (png_size_t) + (key_len + text_length + lang_len + lang_key_len + 4)); + + if (textp->key == NULL) + return(1); + + png_debug2(2, "Allocated %lu bytes at %p in png_set_text", + (unsigned long)(png_uint_32) + (key_len + lang_len + lang_key_len + text_length + 4), + textp->key); + + png_memcpy(textp->key, text_ptr[i].key,(png_size_t)(key_len)); + *(textp->key + key_len) = '\0'; + + if (text_ptr[i].compression > 0) + { + textp->lang = textp->key + key_len + 1; + png_memcpy(textp->lang, text_ptr[i].lang, lang_len); + *(textp->lang + lang_len) = '\0'; + textp->lang_key = textp->lang + lang_len + 1; + png_memcpy(textp->lang_key, text_ptr[i].lang_key, lang_key_len); + *(textp->lang_key + lang_key_len) = '\0'; + textp->text = textp->lang_key + lang_key_len + 1; + } + + else + { + textp->lang=NULL; + textp->lang_key=NULL; + textp->text = textp->key + key_len + 1; + } + + if (text_length) + png_memcpy(textp->text, text_ptr[i].text, + (png_size_t)(text_length)); + + *(textp->text + text_length) = '\0'; + +# ifdef PNG_iTXt_SUPPORTED + if (textp->compression > 0) + { + textp->text_length = 0; + textp->itxt_length = text_length; + } + + else +# endif + { + textp->text_length = text_length; + textp->itxt_length = 0; + } + + info_ptr->num_text++; + png_debug1(3, "transferred text chunk %d", info_ptr->num_text); + } + return(0); +} +#endif + +#ifdef PNG_tIME_SUPPORTED +void PNGAPI +png_set_tIME(png_structp png_ptr, png_infop info_ptr, png_const_timep mod_time) +{ + png_debug1(1, "in %s storage function", "tIME"); + + if (png_ptr == NULL || info_ptr == NULL || + (png_ptr->mode & PNG_WROTE_tIME)) + return; + + png_memcpy(&(info_ptr->mod_time), mod_time, png_sizeof(png_time)); + info_ptr->valid |= PNG_INFO_tIME; +} +#endif + +#ifdef PNG_tRNS_SUPPORTED +void PNGAPI +png_set_tRNS(png_structp png_ptr, png_infop info_ptr, + png_const_bytep trans_alpha, int num_trans, png_const_color_16p trans_color) +{ + png_debug1(1, "in %s storage function", "tRNS"); + + if (png_ptr == NULL || info_ptr == NULL) + return; + + if (trans_alpha != NULL) + { + /* It may not actually be necessary to set png_ptr->trans_alpha here; + * we do it for backward compatibility with the way the png_handle_tRNS + * function used to do the allocation. + */ + + png_free_data(png_ptr, info_ptr, PNG_FREE_TRNS, 0); + + /* Changed from num_trans to PNG_MAX_PALETTE_LENGTH in version 1.2.1 */ + png_ptr->trans_alpha = info_ptr->trans_alpha = + (png_bytep)png_malloc(png_ptr, (png_size_t)PNG_MAX_PALETTE_LENGTH); + + if (num_trans > 0 && num_trans <= PNG_MAX_PALETTE_LENGTH) + png_memcpy(info_ptr->trans_alpha, trans_alpha, (png_size_t)num_trans); + } + + if (trans_color != NULL) + { + int sample_max = (1 << info_ptr->bit_depth); + + if ((info_ptr->color_type == PNG_COLOR_TYPE_GRAY && + (int)trans_color->gray > sample_max) || + (info_ptr->color_type == PNG_COLOR_TYPE_RGB && + ((int)trans_color->red > sample_max || + (int)trans_color->green > sample_max || + (int)trans_color->blue > sample_max))) + png_warning(png_ptr, + "tRNS chunk has out-of-range samples for bit_depth"); + + png_memcpy(&(info_ptr->trans_color), trans_color, + png_sizeof(png_color_16)); + + if (num_trans == 0) + num_trans = 1; + } + + info_ptr->num_trans = (png_uint_16)num_trans; + + if (num_trans != 0) + { + info_ptr->valid |= PNG_INFO_tRNS; + info_ptr->free_me |= PNG_FREE_TRNS; + } +} +#endif + +#ifdef PNG_sPLT_SUPPORTED +void PNGAPI +png_set_sPLT(png_structp png_ptr, + png_infop info_ptr, png_const_sPLT_tp entries, int nentries) +/* + * entries - array of png_sPLT_t structures + * to be added to the list of palettes + * in the info structure. + * + * nentries - number of palette structures to be + * added. + */ +{ + png_sPLT_tp np; + int i; + + if (png_ptr == NULL || info_ptr == NULL) + return; + + np = (png_sPLT_tp)png_malloc_warn(png_ptr, + (info_ptr->splt_palettes_num + nentries) * + (png_size_t)png_sizeof(png_sPLT_t)); + + if (np == NULL) + { + png_warning(png_ptr, "No memory for sPLT palettes"); + return; + } + + png_memcpy(np, info_ptr->splt_palettes, + info_ptr->splt_palettes_num * png_sizeof(png_sPLT_t)); + + png_free(png_ptr, info_ptr->splt_palettes); + info_ptr->splt_palettes=NULL; + + for (i = 0; i < nentries; i++) + { + png_sPLT_tp to = np + info_ptr->splt_palettes_num + i; + png_const_sPLT_tp from = entries + i; + png_uint_32 length; + + length = png_strlen(from->name) + 1; + to->name = (png_charp)png_malloc_warn(png_ptr, (png_size_t)length); + + if (to->name == NULL) + { + png_warning(png_ptr, + "Out of memory while processing sPLT chunk"); + continue; + } + + png_memcpy(to->name, from->name, length); + to->entries = (png_sPLT_entryp)png_malloc_warn(png_ptr, + (png_size_t)(from->nentries * png_sizeof(png_sPLT_entry))); + + if (to->entries == NULL) + { + png_warning(png_ptr, + "Out of memory while processing sPLT chunk"); + png_free(png_ptr, to->name); + to->name = NULL; + continue; + } + + png_memcpy(to->entries, from->entries, + from->nentries * png_sizeof(png_sPLT_entry)); + + to->nentries = from->nentries; + to->depth = from->depth; + } + + info_ptr->splt_palettes = np; + info_ptr->splt_palettes_num += nentries; + info_ptr->valid |= PNG_INFO_sPLT; + info_ptr->free_me |= PNG_FREE_SPLT; +} +#endif /* PNG_sPLT_SUPPORTED */ + +#ifdef PNG_UNKNOWN_CHUNKS_SUPPORTED +void PNGAPI +png_set_unknown_chunks(png_structp png_ptr, + png_infop info_ptr, png_const_unknown_chunkp unknowns, int num_unknowns) +{ + png_unknown_chunkp np; + int i; + + if (png_ptr == NULL || info_ptr == NULL || num_unknowns == 0) + return; + + np = (png_unknown_chunkp)png_malloc_warn(png_ptr, + (png_size_t)(info_ptr->unknown_chunks_num + num_unknowns) * + png_sizeof(png_unknown_chunk)); + + if (np == NULL) + { + png_warning(png_ptr, + "Out of memory while processing unknown chunk"); + return; + } + + png_memcpy(np, info_ptr->unknown_chunks, + (png_size_t)info_ptr->unknown_chunks_num * + png_sizeof(png_unknown_chunk)); + + png_free(png_ptr, info_ptr->unknown_chunks); + info_ptr->unknown_chunks = NULL; + + for (i = 0; i < num_unknowns; i++) + { + png_unknown_chunkp to = np + info_ptr->unknown_chunks_num + i; + png_const_unknown_chunkp from = unknowns + i; + + png_memcpy(to->name, from->name, png_sizeof(from->name)); + to->name[png_sizeof(to->name)-1] = '\0'; + to->size = from->size; + + /* Note our location in the read or write sequence */ + to->location = (png_byte)(png_ptr->mode & 0xff); + + if (from->size == 0) + to->data=NULL; + + else + { + to->data = (png_bytep)png_malloc_warn(png_ptr, + (png_size_t)from->size); + + if (to->data == NULL) + { + png_warning(png_ptr, + "Out of memory while processing unknown chunk"); + to->size = 0; + } + + else + png_memcpy(to->data, from->data, from->size); + } + } + + info_ptr->unknown_chunks = np; + info_ptr->unknown_chunks_num += num_unknowns; + info_ptr->free_me |= PNG_FREE_UNKN; +} + +void PNGAPI +png_set_unknown_chunk_location(png_structp png_ptr, png_infop info_ptr, + int chunk, int location) +{ + if (png_ptr != NULL && info_ptr != NULL && chunk >= 0 && chunk < + info_ptr->unknown_chunks_num) + info_ptr->unknown_chunks[chunk].location = (png_byte)location; +} +#endif + + +#ifdef PNG_MNG_FEATURES_SUPPORTED +png_uint_32 PNGAPI +png_permit_mng_features (png_structp png_ptr, png_uint_32 mng_features) +{ + png_debug(1, "in png_permit_mng_features"); + + if (png_ptr == NULL) + return (png_uint_32)0; + + png_ptr->mng_features_permitted = + (png_byte)(mng_features & PNG_ALL_MNG_FEATURES); + + return (png_uint_32)png_ptr->mng_features_permitted; +} +#endif + +#ifdef PNG_HANDLE_AS_UNKNOWN_SUPPORTED +void PNGAPI +png_set_keep_unknown_chunks(png_structp png_ptr, int keep, png_const_bytep + chunk_list, int num_chunks) +{ + png_bytep new_list, p; + int i, old_num_chunks; + if (png_ptr == NULL) + return; + + if (num_chunks == 0) + { + if (keep == PNG_HANDLE_CHUNK_ALWAYS || keep == PNG_HANDLE_CHUNK_IF_SAFE) + png_ptr->flags |= PNG_FLAG_KEEP_UNKNOWN_CHUNKS; + + else + png_ptr->flags &= ~PNG_FLAG_KEEP_UNKNOWN_CHUNKS; + + if (keep == PNG_HANDLE_CHUNK_ALWAYS) + png_ptr->flags |= PNG_FLAG_KEEP_UNSAFE_CHUNKS; + + else + png_ptr->flags &= ~PNG_FLAG_KEEP_UNSAFE_CHUNKS; + + return; + } + + if (chunk_list == NULL) + return; + + old_num_chunks = png_ptr->num_chunk_list; + new_list=(png_bytep)png_malloc(png_ptr, + (png_size_t)(5*(num_chunks + old_num_chunks))); + + if (png_ptr->chunk_list != NULL) + { + png_memcpy(new_list, png_ptr->chunk_list, + (png_size_t)(5*old_num_chunks)); + png_free(png_ptr, png_ptr->chunk_list); + png_ptr->chunk_list=NULL; + } + + png_memcpy(new_list + 5*old_num_chunks, chunk_list, + (png_size_t)(5*num_chunks)); + + for (p = new_list + 5*old_num_chunks + 4, i = 0; i<num_chunks; i++, p += 5) + *p=(png_byte)keep; + + png_ptr->num_chunk_list = old_num_chunks + num_chunks; + png_ptr->chunk_list = new_list; + png_ptr->free_me |= PNG_FREE_LIST; +} +#endif + +#ifdef PNG_READ_USER_CHUNKS_SUPPORTED +void PNGAPI +png_set_read_user_chunk_fn(png_structp png_ptr, png_voidp user_chunk_ptr, + png_user_chunk_ptr read_user_chunk_fn) +{ + png_debug(1, "in png_set_read_user_chunk_fn"); + + if (png_ptr == NULL) + return; + + png_ptr->read_user_chunk_fn = read_user_chunk_fn; + png_ptr->user_chunk_ptr = user_chunk_ptr; +} +#endif + +#ifdef PNG_INFO_IMAGE_SUPPORTED +void PNGAPI +png_set_rows(png_structp png_ptr, png_infop info_ptr, png_bytepp row_pointers) +{ + png_debug1(1, "in %s storage function", "rows"); + + if (png_ptr == NULL || info_ptr == NULL) + return; + + if (info_ptr->row_pointers && (info_ptr->row_pointers != row_pointers)) + png_free_data(png_ptr, info_ptr, PNG_FREE_ROWS, 0); + + info_ptr->row_pointers = row_pointers; + + if (row_pointers) + info_ptr->valid |= PNG_INFO_IDAT; +} +#endif + +void PNGAPI +png_set_compression_buffer_size(png_structp png_ptr, png_size_t size) +{ + if (png_ptr == NULL) + return; + + png_free(png_ptr, png_ptr->zbuf); + + if (size > ZLIB_IO_MAX) + { + png_warning(png_ptr, "Attempt to set buffer size beyond max ignored"); + png_ptr->zbuf_size = ZLIB_IO_MAX; + size = ZLIB_IO_MAX; /* must fit */ + } + + else + png_ptr->zbuf_size = (uInt)size; + + png_ptr->zbuf = (png_bytep)png_malloc(png_ptr, size); + + /* The following ensures a relatively safe failure if this gets called while + * the buffer is actually in use. + */ + png_ptr->zstream.next_out = png_ptr->zbuf; + png_ptr->zstream.avail_out = 0; + png_ptr->zstream.avail_in = 0; +} + +void PNGAPI +png_set_invalid(png_structp png_ptr, png_infop info_ptr, int mask) +{ + if (png_ptr && info_ptr) + info_ptr->valid &= ~mask; +} + + + +#ifdef PNG_SET_USER_LIMITS_SUPPORTED +/* This function was added to libpng 1.2.6 */ +void PNGAPI +png_set_user_limits (png_structp png_ptr, png_uint_32 user_width_max, + png_uint_32 user_height_max) +{ + /* Images with dimensions larger than these limits will be + * rejected by png_set_IHDR(). To accept any PNG datastream + * regardless of dimensions, set both limits to 0x7ffffffL. + */ + if (png_ptr == NULL) + return; + + png_ptr->user_width_max = user_width_max; + png_ptr->user_height_max = user_height_max; +} + +/* This function was added to libpng 1.4.0 */ +void PNGAPI +png_set_chunk_cache_max (png_structp png_ptr, + png_uint_32 user_chunk_cache_max) +{ + if (png_ptr) + png_ptr->user_chunk_cache_max = user_chunk_cache_max; +} + +/* This function was added to libpng 1.4.1 */ +void PNGAPI +png_set_chunk_malloc_max (png_structp png_ptr, + png_alloc_size_t user_chunk_malloc_max) +{ + if (png_ptr) + png_ptr->user_chunk_malloc_max = user_chunk_malloc_max; +} +#endif /* ?PNG_SET_USER_LIMITS_SUPPORTED */ + + +#ifdef PNG_BENIGN_ERRORS_SUPPORTED +void PNGAPI +png_set_benign_errors(png_structp png_ptr, int allowed) +{ + png_debug(1, "in png_set_benign_errors"); + + if (allowed) + png_ptr->flags |= PNG_FLAG_BENIGN_ERRORS_WARN; + + else + png_ptr->flags &= ~PNG_FLAG_BENIGN_ERRORS_WARN; +} +#endif /* PNG_BENIGN_ERRORS_SUPPORTED */ +#endif /* PNG_READ_SUPPORTED || PNG_WRITE_SUPPORTED */ diff --git a/src/3rdparty/libpng/pngstruct.h b/src/3rdparty/libpng/pngstruct.h new file mode 100644 index 0000000000..8d781faefe --- /dev/null +++ b/src/3rdparty/libpng/pngstruct.h @@ -0,0 +1,308 @@ + +/* pngstruct.h - header file for PNG reference library + * + * Copyright (c) 1998-2011 Glenn Randers-Pehrson + * (Version 0.96 Copyright (c) 1996, 1997 Andreas Dilger) + * (Version 0.88 Copyright (c) 1995, 1996 Guy Eric Schalnat, Group 42, Inc.) + * + * Last changed in libpng 1.5.0 [January 6, 2011] + * + * This code is released under the libpng license. + * For conditions of distribution and use, see the disclaimer + * and license in png.h + */ + +/* The structure that holds the information to read and write PNG files. + * The only people who need to care about what is inside of this are the + * people who will be modifying the library for their own special needs. + * It should NOT be accessed directly by an application. + */ + +#ifndef PNGSTRUCT_H +#define PNGSTRUCT_H +/* zlib.h defines the structure z_stream, an instance of which is included + * in this structure and is required for decompressing the LZ compressed + * data in PNG files. + */ +#include "zlib.h" + +struct png_struct_def +{ +#ifdef PNG_SETJMP_SUPPORTED + jmp_buf png_jmpbuf; /* used in png_error */ + png_longjmp_ptr longjmp_fn;/* setjmp non-local goto function. */ +#endif + png_error_ptr error_fn; /* function for printing errors and aborting */ + png_error_ptr warning_fn; /* function for printing warnings */ + png_voidp error_ptr; /* user supplied struct for error functions */ + png_rw_ptr write_data_fn; /* function for writing output data */ + png_rw_ptr read_data_fn; /* function for reading input data */ + png_voidp io_ptr; /* ptr to application struct for I/O functions */ + +#ifdef PNG_READ_USER_TRANSFORM_SUPPORTED + png_user_transform_ptr read_user_transform_fn; /* user read transform */ +#endif + +#ifdef PNG_WRITE_USER_TRANSFORM_SUPPORTED + png_user_transform_ptr write_user_transform_fn; /* user write transform */ +#endif + +/* These were added in libpng-1.0.2 */ +#ifdef PNG_USER_TRANSFORM_PTR_SUPPORTED +#if defined(PNG_READ_USER_TRANSFORM_SUPPORTED) || \ + defined(PNG_WRITE_USER_TRANSFORM_SUPPORTED) + png_voidp user_transform_ptr; /* user supplied struct for user transform */ + png_byte user_transform_depth; /* bit depth of user transformed pixels */ + png_byte user_transform_channels; /* channels in user transformed pixels */ +#endif +#endif + + png_uint_32 mode; /* tells us where we are in the PNG file */ + png_uint_32 flags; /* flags indicating various things to libpng */ + png_uint_32 transformations; /* which transformations to perform */ + + z_stream zstream; /* pointer to decompression structure (below) */ + png_bytep zbuf; /* buffer for zlib */ + uInt zbuf_size; /* size of zbuf (typically 65536) */ + int zlib_level; /* holds zlib compression level */ + int zlib_method; /* holds zlib compression method */ + int zlib_window_bits; /* holds zlib compression window bits */ + int zlib_mem_level; /* holds zlib compression memory level */ + int zlib_strategy; /* holds zlib compression strategy */ + + png_uint_32 width; /* width of image in pixels */ + png_uint_32 height; /* height of image in pixels */ + png_uint_32 num_rows; /* number of rows in current pass */ + png_uint_32 usr_width; /* width of row at start of write */ + png_size_t rowbytes; /* size of row in bytes */ + png_uint_32 iwidth; /* width of current interlaced row in pixels */ + png_uint_32 row_number; /* current row in interlace pass */ + png_bytep prev_row; /* buffer to save previous (unfiltered) row */ + png_bytep row_buf; /* buffer to save current (unfiltered) row */ + png_bytep sub_row; /* buffer to save "sub" row when filtering */ + png_bytep up_row; /* buffer to save "up" row when filtering */ + png_bytep avg_row; /* buffer to save "avg" row when filtering */ + png_bytep paeth_row; /* buffer to save "Paeth" row when filtering */ + png_row_info row_info; /* used for transformation routines */ + + png_uint_32 idat_size; /* current IDAT size for read */ + png_uint_32 crc; /* current chunk CRC value */ + png_colorp palette; /* palette from the input file */ + png_uint_16 num_palette; /* number of color entries in palette */ + png_uint_16 num_trans; /* number of transparency values */ + png_byte chunk_name[5]; /* null-terminated name of current chunk */ + png_byte compression; /* file compression type (always 0) */ + png_byte filter; /* file filter type (always 0) */ + png_byte interlaced; /* PNG_INTERLACE_NONE, PNG_INTERLACE_ADAM7 */ + png_byte pass; /* current interlace pass (0 - 6) */ + png_byte do_filter; /* row filter flags (see PNG_FILTER_ below ) */ + png_byte color_type; /* color type of file */ + png_byte bit_depth; /* bit depth of file */ + png_byte usr_bit_depth; /* bit depth of users row */ + png_byte pixel_depth; /* number of bits per pixel */ + png_byte channels; /* number of channels in file */ + png_byte usr_channels; /* channels at start of write */ + png_byte sig_bytes; /* magic bytes read/written from start of file */ + +#if defined(PNG_READ_FILLER_SUPPORTED) || defined(PNG_WRITE_FILLER_SUPPORTED) + png_uint_16 filler; /* filler bytes for pixel expansion */ +#endif + +#ifdef PNG_bKGD_SUPPORTED + png_byte background_gamma_type; + png_fixed_point background_gamma; + png_color_16 background; /* background color in screen gamma space */ +#ifdef PNG_READ_GAMMA_SUPPORTED + png_color_16 background_1; /* background normalized to gamma 1.0 */ +#endif +#endif /* PNG_bKGD_SUPPORTED */ + +#ifdef PNG_WRITE_FLUSH_SUPPORTED + png_flush_ptr output_flush_fn; /* Function for flushing output */ + png_uint_32 flush_dist; /* how many rows apart to flush, 0 - no flush */ + png_uint_32 flush_rows; /* number of rows written since last flush */ +#endif + +#if defined(PNG_READ_GAMMA_SUPPORTED) || defined(PNG_READ_BACKGROUND_SUPPORTED) + int gamma_shift; /* number of "insignificant" bits in 16-bit gamma */ + png_fixed_point gamma; /* file gamma value */ + png_fixed_point screen_gamma; /* screen gamma value (display_exponent) */ +#endif + +#if defined(PNG_READ_GAMMA_SUPPORTED) || defined(PNG_READ_BACKGROUND_SUPPORTED) + png_bytep gamma_table; /* gamma table for 8-bit depth files */ + png_bytep gamma_from_1; /* converts from 1.0 to screen */ + png_bytep gamma_to_1; /* converts from file to 1.0 */ + png_uint_16pp gamma_16_table; /* gamma table for 16-bit depth files */ + png_uint_16pp gamma_16_from_1; /* converts from 1.0 to screen */ + png_uint_16pp gamma_16_to_1; /* converts from file to 1.0 */ +#endif + +#if defined(PNG_READ_GAMMA_SUPPORTED) || defined(PNG_sBIT_SUPPORTED) + png_color_8 sig_bit; /* significant bits in each available channel */ +#endif + +#if defined(PNG_READ_SHIFT_SUPPORTED) || defined(PNG_WRITE_SHIFT_SUPPORTED) + png_color_8 shift; /* shift for significant bit tranformation */ +#endif + +#if defined(PNG_tRNS_SUPPORTED) || defined(PNG_READ_BACKGROUND_SUPPORTED) \ + || defined(PNG_READ_EXPAND_SUPPORTED) || defined(PNG_READ_BACKGROUND_SUPPORTED) + png_bytep trans_alpha; /* alpha values for paletted files */ + png_color_16 trans_color; /* transparent color for non-paletted files */ +#endif + + png_read_status_ptr read_row_fn; /* called after each row is decoded */ + png_write_status_ptr write_row_fn; /* called after each row is encoded */ +#ifdef PNG_PROGRESSIVE_READ_SUPPORTED + png_progressive_info_ptr info_fn; /* called after header data fully read */ + png_progressive_row_ptr row_fn; /* called after a prog. row is decoded */ + png_progressive_end_ptr end_fn; /* called after image is complete */ + png_bytep save_buffer_ptr; /* current location in save_buffer */ + png_bytep save_buffer; /* buffer for previously read data */ + png_bytep current_buffer_ptr; /* current location in current_buffer */ + png_bytep current_buffer; /* buffer for recently used data */ + png_uint_32 push_length; /* size of current input chunk */ + png_uint_32 skip_length; /* bytes to skip in input data */ + png_size_t save_buffer_size; /* amount of data now in save_buffer */ + png_size_t save_buffer_max; /* total size of save_buffer */ + png_size_t buffer_size; /* total amount of available input data */ + png_size_t current_buffer_size; /* amount of data now in current_buffer */ + int process_mode; /* what push library is currently doing */ + int cur_palette; /* current push library palette index */ + +# ifdef PNG_TEXT_SUPPORTED + png_size_t current_text_size; /* current size of text input data */ + png_size_t current_text_left; /* how much text left to read in input */ + png_charp current_text; /* current text chunk buffer */ + png_charp current_text_ptr; /* current location in current_text */ +# endif /* PNG_PROGRESSIVE_READ_SUPPORTED && PNG_TEXT_SUPPORTED */ + +#endif /* PNG_PROGRESSIVE_READ_SUPPORTED */ + +#if defined(__TURBOC__) && !defined(_Windows) && !defined(__FLAT__) +/* For the Borland special 64K segment handler */ + png_bytepp offset_table_ptr; + png_bytep offset_table; + png_uint_16 offset_table_number; + png_uint_16 offset_table_count; + png_uint_16 offset_table_count_free; +#endif + +#ifdef PNG_READ_QUANTIZE_SUPPORTED + png_bytep palette_lookup; /* lookup table for quantizing */ + png_bytep quantize_index; /* index translation for palette files */ +#endif + +#if defined(PNG_READ_QUANTIZE_SUPPORTED) || defined(PNG_hIST_SUPPORTED) + png_uint_16p hist; /* histogram */ +#endif + +#ifdef PNG_WRITE_WEIGHTED_FILTER_SUPPORTED + png_byte heuristic_method; /* heuristic for row filter selection */ + png_byte num_prev_filters; /* number of weights for previous rows */ + png_bytep prev_filters; /* filter type(s) of previous row(s) */ + png_uint_16p filter_weights; /* weight(s) for previous line(s) */ + png_uint_16p inv_filter_weights; /* 1/weight(s) for previous line(s) */ + png_uint_16p filter_costs; /* relative filter calculation cost */ + png_uint_16p inv_filter_costs; /* 1/relative filter calculation cost */ +#endif + +#ifdef PNG_TIME_RFC1123_SUPPORTED + png_charp time_buffer; /* String to hold RFC 1123 time text */ +#endif + +/* New members added in libpng-1.0.6 */ + + png_uint_32 free_me; /* flags items libpng is responsible for freeing */ + +#ifdef PNG_USER_CHUNKS_SUPPORTED + png_voidp user_chunk_ptr; + png_user_chunk_ptr read_user_chunk_fn; /* user read chunk handler */ +#endif + +#ifdef PNG_HANDLE_AS_UNKNOWN_SUPPORTED + int num_chunk_list; + png_bytep chunk_list; +#endif + +/* New members added in libpng-1.0.3 */ +#ifdef PNG_READ_RGB_TO_GRAY_SUPPORTED + png_byte rgb_to_gray_status; + /* These were changed from png_byte in libpng-1.0.6 */ + png_uint_16 rgb_to_gray_red_coeff; + png_uint_16 rgb_to_gray_green_coeff; + png_uint_16 rgb_to_gray_blue_coeff; +#endif + +/* New member added in libpng-1.0.4 (renamed in 1.0.9) */ +#if defined(PNG_MNG_FEATURES_SUPPORTED) || \ + defined(PNG_READ_EMPTY_PLTE_SUPPORTED) || \ + defined(PNG_WRITE_EMPTY_PLTE_SUPPORTED) +/* Changed from png_byte to png_uint_32 at version 1.2.0 */ + png_uint_32 mng_features_permitted; +#endif + +/* New member added in libpng-1.0.9, ifdef'ed out in 1.0.12, enabled in 1.2.0 */ +#ifdef PNG_MNG_FEATURES_SUPPORTED + png_byte filter_type; +#endif + +/* New members added in libpng-1.2.0 */ + +/* New members added in libpng-1.0.2 but first enabled by default in 1.2.0 */ +#ifdef PNG_USER_MEM_SUPPORTED + png_voidp mem_ptr; /* user supplied struct for mem functions */ + png_malloc_ptr malloc_fn; /* function for allocating memory */ + png_free_ptr free_fn; /* function for freeing memory */ +#endif + +/* New member added in libpng-1.0.13 and 1.2.0 */ + png_bytep big_row_buf; /* buffer to save current (unfiltered) row */ + +#ifdef PNG_READ_QUANTIZE_SUPPORTED +/* The following three members were added at version 1.0.14 and 1.2.4 */ + png_bytep quantize_sort; /* working sort array */ + png_bytep index_to_palette; /* where the original index currently is + in the palette */ + png_bytep palette_to_index; /* which original index points to this + palette color */ +#endif + +/* New members added in libpng-1.0.16 and 1.2.6 */ + png_byte compression_type; + +#ifdef PNG_USER_LIMITS_SUPPORTED + png_uint_32 user_width_max; + png_uint_32 user_height_max; + + /* Added in libpng-1.4.0: Total number of sPLT, text, and unknown + * chunks that can be stored (0 means unlimited). + */ + png_uint_32 user_chunk_cache_max; + + /* Total memory that a zTXt, sPLT, iTXt, iCCP, or unknown chunk + * can occupy when decompressed. 0 means unlimited. + */ + png_alloc_size_t user_chunk_malloc_max; +#endif + +/* New member added in libpng-1.0.25 and 1.2.17 */ +#ifdef PNG_UNKNOWN_CHUNKS_SUPPORTED + /* Storage for unknown chunk that the library doesn't recognize. */ + png_unknown_chunk unknown_chunk; +#endif + +/* New members added in libpng-1.2.26 */ + png_size_t old_big_row_buf_size; + png_size_t old_prev_row_size; + +/* New member added in libpng-1.2.30 */ + png_charp chunkdata; /* buffer for reading chunk data */ + +#ifdef PNG_IO_STATE_SUPPORTED +/* New member added in libpng-1.4.0 */ + png_uint_32 io_state; +#endif +}; +#endif /* PNGSTRUCT_H */ diff --git a/src/3rdparty/libpng/pngtest.c b/src/3rdparty/libpng/pngtest.c new file mode 100644 index 0000000000..cbb7eb276f --- /dev/null +++ b/src/3rdparty/libpng/pngtest.c @@ -0,0 +1,1787 @@ + +/* pngtest.c - a simple test program to test libpng + * + * Last changed in libpng 1.5.0 [January 6, 2011] + * Copyright (c) 1998-2011 Glenn Randers-Pehrson + * (Version 0.96 Copyright (c) 1996, 1997 Andreas Dilger) + * (Version 0.88 Copyright (c) 1995, 1996 Guy Eric Schalnat, Group 42, Inc.) + * + * This code is released under the libpng license. + * For conditions of distribution and use, see the disclaimer + * and license in png.h + * + * This program reads in a PNG image, writes it out again, and then + * compares the two files. If the files are identical, this shows that + * the basic chunk handling, filtering, and (de)compression code is working + * properly. It does not currently test all of the transforms, although + * it probably should. + * + * The program will report "FAIL" in certain legitimate cases: + * 1) when the compression level or filter selection method is changed. + * 2) when the maximum IDAT size (PNG_ZBUF_SIZE in pngconf.h) is not 8192. + * 3) unknown unsafe-to-copy ancillary chunks or unknown critical chunks + * exist in the input file. + * 4) others not listed here... + * In these cases, it is best to check with another tool such as "pngcheck" + * to see what the differences between the two files are. + * + * If a filename is given on the command-line, then this file is used + * for the input, rather than the default "pngtest.png". This allows + * testing a wide variety of files easily. You can also test a number + * of files at once by typing "pngtest -m file1.png file2.png ..." + */ + +#include "zlib.h" +#include "png.h" +/* Copied from pngpriv.h but only used in error messages below. */ +#ifndef PNG_ZBUF_SIZE +# define PNG_ZBUF_SIZE 8192 +#endif +# include <stdio.h> +# include <stdlib.h> +# include <string.h> +# define FCLOSE(file) fclose(file) + +#ifndef PNG_STDIO_SUPPORTED +typedef FILE * png_FILE_p; +#endif + +/* Makes pngtest verbose so we can find problems. */ +#ifndef PNG_DEBUG +# define PNG_DEBUG 0 +#endif + +#if PNG_DEBUG > 1 +# define pngtest_debug(m) ((void)fprintf(stderr, m "\n")) +# define pngtest_debug1(m,p1) ((void)fprintf(stderr, m "\n", p1)) +# define pngtest_debug2(m,p1,p2) ((void)fprintf(stderr, m "\n", p1, p2)) +#else +# define pngtest_debug(m) ((void)0) +# define pngtest_debug1(m,p1) ((void)0) +# define pngtest_debug2(m,p1,p2) ((void)0) +#endif + +#if !PNG_DEBUG +# define SINGLE_ROWBUF_ALLOC /* Makes buffer overruns easier to nail */ +#endif + +/* The code uses memcmp and memcpy on large objects (typically row pointers) so + * it is necessary to do soemthing special on certain architectures, note that + * the actual support for this was effectively removed in 1.4, so only the + * memory remains in this program: + */ +#define CVT_PTR(ptr) (ptr) +#define CVT_PTR_NOCHECK(ptr) (ptr) +#define png_memcmp memcmp +#define png_memcpy memcpy +#define png_memset memset + +/* Turn on CPU timing +#define PNGTEST_TIMING +*/ + +#ifndef PNG_FLOATING_POINT_SUPPORTED +#undef PNGTEST_TIMING +#endif + +#ifdef PNGTEST_TIMING +static float t_start, t_stop, t_decode, t_encode, t_misc; +#include <time.h> +#endif + +#ifdef PNG_TIME_RFC1123_SUPPORTED +#define PNG_tIME_STRING_LENGTH 29 +static int tIME_chunk_present = 0; +static char tIME_string[PNG_tIME_STRING_LENGTH] = "tIME chunk is not present"; +#endif + +static int verbose = 0; + +int test_one_file PNGARG((PNG_CONST char *inname, PNG_CONST char *outname)); + +#ifdef __TURBOC__ +#include <mem.h> +#endif + +/* Defined so I can write to a file on gui/windowing platforms */ +/* #define STDERR stderr */ +#define STDERR stdout /* For DOS */ + +/* Define png_jmpbuf() in case we are using a pre-1.0.6 version of libpng */ +#ifndef png_jmpbuf +# define png_jmpbuf(png_ptr) png_ptr->jmpbuf +#endif + +/* Example of using row callbacks to make a simple progress meter */ +static int status_pass = 1; +static int status_dots_requested = 0; +static int status_dots = 1; + +void PNGCBAPI +read_row_callback(png_structp png_ptr, png_uint_32 row_number, int pass); +void PNGCBAPI +read_row_callback(png_structp png_ptr, png_uint_32 row_number, int pass) +{ + if (png_ptr == NULL || row_number > PNG_UINT_31_MAX) + return; + + if (status_pass != pass) + { + fprintf(stdout, "\n Pass %d: ", pass); + status_pass = pass; + status_dots = 31; + } + + status_dots--; + + if (status_dots == 0) + { + fprintf(stdout, "\n "); + status_dots=30; + } + + fprintf(stdout, "r"); +} + +void PNGCBAPI +write_row_callback(png_structp png_ptr, png_uint_32 row_number, int pass); +void PNGCBAPI +write_row_callback(png_structp png_ptr, png_uint_32 row_number, int pass) +{ + if (png_ptr == NULL || row_number > PNG_UINT_31_MAX || pass > 7) + return; + + fprintf(stdout, "w"); +} + + +#ifdef PNG_READ_USER_TRANSFORM_SUPPORTED +/* Example of using user transform callback (we don't transform anything, + * but merely examine the row filters. We set this to 256 rather than + * 5 in case illegal filter values are present.) + */ +static png_uint_32 filters_used[256]; +void PNGCBAPI +count_filters(png_structp png_ptr, png_row_infop row_info, png_bytep data); +void PNGCBAPI +count_filters(png_structp png_ptr, png_row_infop row_info, png_bytep data) +{ + if (png_ptr != NULL && row_info != NULL) + ++filters_used[*(data - 1)]; +} +#endif + +#ifdef PNG_WRITE_USER_TRANSFORM_SUPPORTED +/* Example of using user transform callback (we don't transform anything, + * but merely count the zero samples) + */ + +static png_uint_32 zero_samples; + +void PNGCBAPI +count_zero_samples(png_structp png_ptr, png_row_infop row_info, png_bytep data); +void PNGCBAPI +count_zero_samples(png_structp png_ptr, png_row_infop row_info, png_bytep data) +{ + png_bytep dp = data; + if (png_ptr == NULL) + return; + + /* Contents of row_info: + * png_uint_32 width width of row + * png_uint_32 rowbytes number of bytes in row + * png_byte color_type color type of pixels + * png_byte bit_depth bit depth of samples + * png_byte channels number of channels (1-4) + * png_byte pixel_depth bits per pixel (depth*channels) + */ + + /* Counts the number of zero samples (or zero pixels if color_type is 3 */ + + if (row_info->color_type == 0 || row_info->color_type == 3) + { + int pos = 0; + png_uint_32 n, nstop; + + for (n = 0, nstop=row_info->width; n<nstop; n++) + { + if (row_info->bit_depth == 1) + { + if (((*dp << pos++ ) & 0x80) == 0) + zero_samples++; + + if (pos == 8) + { + pos = 0; + dp++; + } + } + + if (row_info->bit_depth == 2) + { + if (((*dp << (pos+=2)) & 0xc0) == 0) + zero_samples++; + + if (pos == 8) + { + pos = 0; + dp++; + } + } + + if (row_info->bit_depth == 4) + { + if (((*dp << (pos+=4)) & 0xf0) == 0) + zero_samples++; + + if (pos == 8) + { + pos = 0; + dp++; + } + } + + if (row_info->bit_depth == 8) + if (*dp++ == 0) + zero_samples++; + + if (row_info->bit_depth == 16) + { + if ((*dp | *(dp+1)) == 0) + zero_samples++; + dp+=2; + } + } + } + else /* Other color types */ + { + png_uint_32 n, nstop; + int channel; + int color_channels = row_info->channels; + if (row_info->color_type > 3)color_channels--; + + for (n = 0, nstop=row_info->width; n<nstop; n++) + { + for (channel = 0; channel < color_channels; channel++) + { + if (row_info->bit_depth == 8) + if (*dp++ == 0) + zero_samples++; + + if (row_info->bit_depth == 16) + { + if ((*dp | *(dp+1)) == 0) + zero_samples++; + + dp+=2; + } + } + if (row_info->color_type > 3) + { + dp++; + if (row_info->bit_depth == 16) + dp++; + } + } + } +} +#endif /* PNG_WRITE_USER_TRANSFORM_SUPPORTED */ + +static int wrote_question = 0; + +#ifndef PNG_STDIO_SUPPORTED +/* START of code to validate stdio-free compilation */ +/* These copies of the default read/write functions come from pngrio.c and + * pngwio.c. They allow "don't include stdio" testing of the library. + * This is the function that does the actual reading of data. If you are + * not reading from a standard C stream, you should create a replacement + * read_data function and use it at run time with png_set_read_fn(), rather + * than changing the library. + */ + +#ifdef PNG_IO_STATE_SUPPORTED +void +pngtest_check_io_state(png_structp png_ptr, png_size_t data_length, + png_uint_32 io_op); +void +pngtest_check_io_state(png_structp png_ptr, png_size_t data_length, + png_uint_32 io_op) +{ + png_uint_32 io_state = png_get_io_state(png_ptr); + int err = 0; + + /* Check if the current operation (reading / writing) is as expected. */ + if ((io_state & PNG_IO_MASK_OP) != io_op) + png_error(png_ptr, "Incorrect operation in I/O state"); + + /* Check if the buffer size specific to the current location + * (file signature / header / data / crc) is as expected. + */ + switch (io_state & PNG_IO_MASK_LOC) + { + case PNG_IO_SIGNATURE: + if (data_length > 8) + err = 1; + break; + case PNG_IO_CHUNK_HDR: + if (data_length != 8) + err = 1; + break; + case PNG_IO_CHUNK_DATA: + break; /* no restrictions here */ + case PNG_IO_CHUNK_CRC: + if (data_length != 4) + err = 1; + break; + default: + err = 1; /* uninitialized */ + } + if (err) + png_error(png_ptr, "Bad I/O state or buffer size"); +} +#endif + +#ifndef USE_FAR_KEYWORD +static void PNGCBAPI +pngtest_read_data(png_structp png_ptr, png_bytep data, png_size_t length) +{ + png_size_t check = 0; + png_voidp io_ptr; + + /* fread() returns 0 on error, so it is OK to store this in a png_size_t + * instead of an int, which is what fread() actually returns. + */ + io_ptr = png_get_io_ptr(png_ptr); + if (io_ptr != NULL) + { + check = fread(data, 1, length, (png_FILE_p)io_ptr); + } + + if (check != length) + { + png_error(png_ptr, "Read Error"); + } + +#ifdef PNG_IO_STATE_SUPPORTED + pngtest_check_io_state(png_ptr, length, PNG_IO_READING); +#endif +} +#else +/* This is the model-independent version. Since the standard I/O library + can't handle far buffers in the medium and small models, we have to copy + the data. +*/ + +#define NEAR_BUF_SIZE 1024 +#define MIN(a,b) (a <= b ? a : b) + +static void PNGCBAPI +pngtest_read_data(png_structp png_ptr, png_bytep data, png_size_t length) +{ + png_size_t check; + png_byte *n_data; + png_FILE_p io_ptr; + + /* Check if data really is near. If so, use usual code. */ + n_data = (png_byte *)CVT_PTR_NOCHECK(data); + io_ptr = (png_FILE_p)CVT_PTR(png_get_io_ptr(png_ptr)); + if ((png_bytep)n_data == data) + { + check = fread(n_data, 1, length, io_ptr); + } + else + { + png_byte buf[NEAR_BUF_SIZE]; + png_size_t read, remaining, err; + check = 0; + remaining = length; + + do + { + read = MIN(NEAR_BUF_SIZE, remaining); + err = fread(buf, 1, 1, io_ptr); + png_memcpy(data, buf, read); /* Copy far buffer to near buffer */ + if (err != read) + break; + else + check += err; + data += read; + remaining -= read; + } + while (remaining != 0); + } + + if (check != length) + png_error(png_ptr, "Read Error"); + +#ifdef PNG_IO_STATE_SUPPORTED + pngtest_check_io_state(png_ptr, length, PNG_IO_READING); +#endif +} +#endif /* USE_FAR_KEYWORD */ + +#ifdef PNG_WRITE_FLUSH_SUPPORTED +static void PNGCBAPI +pngtest_flush(png_structp png_ptr) +{ + /* Do nothing; fflush() is said to be just a waste of energy. */ + PNG_UNUSED(png_ptr) /* Stifle compiler warning */ +} +#endif + +/* This is the function that does the actual writing of data. If you are + * not writing to a standard C stream, you should create a replacement + * write_data function and use it at run time with png_set_write_fn(), rather + * than changing the library. + */ +#ifndef USE_FAR_KEYWORD +static void PNGCBAPI +pngtest_write_data(png_structp png_ptr, png_bytep data, png_size_t length) +{ + png_size_t check; + + check = fwrite(data, 1, length, (png_FILE_p)png_get_io_ptr(png_ptr)); + + if (check != length) + { + png_error(png_ptr, "Write Error"); + } + +#ifdef PNG_IO_STATE_SUPPORTED + pngtest_check_io_state(png_ptr, length, PNG_IO_WRITING); +#endif +} +#else +/* This is the model-independent version. Since the standard I/O library + can't handle far buffers in the medium and small models, we have to copy + the data. +*/ + +#define NEAR_BUF_SIZE 1024 +#define MIN(a,b) (a <= b ? a : b) + +static void PNGCBAPI +pngtest_write_data(png_structp png_ptr, png_bytep data, png_size_t length) +{ + png_size_t check; + png_byte *near_data; /* Needs to be "png_byte *" instead of "png_bytep" */ + png_FILE_p io_ptr; + + /* Check if data really is near. If so, use usual code. */ + near_data = (png_byte *)CVT_PTR_NOCHECK(data); + io_ptr = (png_FILE_p)CVT_PTR(png_get_io_ptr(png_ptr)); + + if ((png_bytep)near_data == data) + { + check = fwrite(near_data, 1, length, io_ptr); + } + + else + { + png_byte buf[NEAR_BUF_SIZE]; + png_size_t written, remaining, err; + check = 0; + remaining = length; + + do + { + written = MIN(NEAR_BUF_SIZE, remaining); + png_memcpy(buf, data, written); /* Copy far buffer to near buffer */ + err = fwrite(buf, 1, written, io_ptr); + if (err != written) + break; + else + check += err; + data += written; + remaining -= written; + } + while (remaining != 0); + } + + if (check != length) + { + png_error(png_ptr, "Write Error"); + } + +#ifdef PNG_IO_STATE_SUPPORTED + pngtest_check_io_state(png_ptr, length, PNG_IO_WRITING); +#endif +} +#endif /* USE_FAR_KEYWORD */ + +/* This function is called when there is a warning, but the library thinks + * it can continue anyway. Replacement functions don't have to do anything + * here if you don't want to. In the default configuration, png_ptr is + * not used, but it is passed in case it may be useful. + */ +static void PNGCBAPI +pngtest_warning(png_structp png_ptr, png_const_charp message) +{ + PNG_CONST char *name = "UNKNOWN (ERROR!)"; + char *test; + test = png_get_error_ptr(png_ptr); + + if (test == NULL) + fprintf(STDERR, "%s: libpng warning: %s\n", name, message); + + else + fprintf(STDERR, "%s: libpng warning: %s\n", test, message); +} + +/* This is the default error handling function. Note that replacements for + * this function MUST NOT RETURN, or the program will likely crash. This + * function is used by default, or if the program supplies NULL for the + * error function pointer in png_set_error_fn(). + */ +static void PNGCBAPI +pngtest_error(png_structp png_ptr, png_const_charp message) +{ + pngtest_warning(png_ptr, message); + /* We can return because png_error calls the default handler, which is + * actually OK in this case. + */ +} +#endif /* !PNG_STDIO_SUPPORTED */ +/* END of code to validate stdio-free compilation */ + +/* START of code to validate memory allocation and deallocation */ +#if defined(PNG_USER_MEM_SUPPORTED) && PNG_DEBUG + +/* Allocate memory. For reasonable files, size should never exceed + * 64K. However, zlib may allocate more then 64K if you don't tell + * it not to. See zconf.h and png.h for more information. zlib does + * need to allocate exactly 64K, so whatever you call here must + * have the ability to do that. + * + * This piece of code can be compiled to validate max 64K allocations + * by setting MAXSEG_64K in zlib zconf.h *or* PNG_MAX_MALLOC_64K. + */ +typedef struct memory_information +{ + png_alloc_size_t size; + png_voidp pointer; + struct memory_information FAR *next; +} memory_information; +typedef memory_information FAR *memory_infop; + +static memory_infop pinformation = NULL; +static int current_allocation = 0; +static int maximum_allocation = 0; +static int total_allocation = 0; +static int num_allocations = 0; + +png_voidp PNGCBAPI png_debug_malloc PNGARG((png_structp png_ptr, + png_alloc_size_t size)); +void PNGCBAPI png_debug_free PNGARG((png_structp png_ptr, png_voidp ptr)); + +png_voidp +PNGCBAPI png_debug_malloc(png_structp png_ptr, png_alloc_size_t size) +{ + + /* png_malloc has already tested for NULL; png_create_struct calls + * png_debug_malloc directly, with png_ptr == NULL which is OK + */ + + if (size == 0) + return (NULL); + + /* This calls the library allocator twice, once to get the requested + buffer and once to get a new free list entry. */ + { + /* Disable malloc_fn and free_fn */ + memory_infop pinfo; + png_set_mem_fn(png_ptr, NULL, NULL, NULL); + pinfo = (memory_infop)png_malloc(png_ptr, + png_sizeof(*pinfo)); + pinfo->size = size; + current_allocation += size; + total_allocation += size; + num_allocations ++; + + if (current_allocation > maximum_allocation) + maximum_allocation = current_allocation; + + pinfo->pointer = png_malloc(png_ptr, size); + /* Restore malloc_fn and free_fn */ + + png_set_mem_fn(png_ptr, + NULL, png_debug_malloc, png_debug_free); + + if (size != 0 && pinfo->pointer == NULL) + { + current_allocation -= size; + total_allocation -= size; + png_error(png_ptr, + "out of memory in pngtest->png_debug_malloc"); + } + + pinfo->next = pinformation; + pinformation = pinfo; + /* Make sure the caller isn't assuming zeroed memory. */ + png_memset(pinfo->pointer, 0xdd, pinfo->size); + + if (verbose) + printf("png_malloc %lu bytes at %p\n", (unsigned long)size, + pinfo->pointer); + + return (png_voidp)(pinfo->pointer); + } +} + +/* Free a pointer. It is removed from the list at the same time. */ +void PNGCBAPI +png_debug_free(png_structp png_ptr, png_voidp ptr) +{ + if (png_ptr == NULL) + fprintf(STDERR, "NULL pointer to png_debug_free.\n"); + + if (ptr == 0) + { +#if 0 /* This happens all the time. */ + fprintf(STDERR, "WARNING: freeing NULL pointer\n"); +#endif + return; + } + + /* Unlink the element from the list. */ + { + memory_infop FAR *ppinfo = &pinformation; + + for (;;) + { + memory_infop pinfo = *ppinfo; + + if (pinfo->pointer == ptr) + { + *ppinfo = pinfo->next; + current_allocation -= pinfo->size; + if (current_allocation < 0) + fprintf(STDERR, "Duplicate free of memory\n"); + /* We must free the list element too, but first kill + the memory that is to be freed. */ + png_memset(ptr, 0x55, pinfo->size); + png_free_default(png_ptr, pinfo); + pinfo = NULL; + break; + } + + if (pinfo->next == NULL) + { + fprintf(STDERR, "Pointer %x not found\n", (unsigned int)ptr); + break; + } + + ppinfo = &pinfo->next; + } + } + + /* Finally free the data. */ + if (verbose) + printf("Freeing %p\n", ptr); + + png_free_default(png_ptr, ptr); + ptr = NULL; +} +#endif /* PNG_USER_MEM_SUPPORTED && PNG_DEBUG */ +/* END of code to test memory allocation/deallocation */ + + +/* Demonstration of user chunk support of the sTER and vpAg chunks */ +#ifdef PNG_UNKNOWN_CHUNKS_SUPPORTED + +/* (sTER is a public chunk not yet known by libpng. vpAg is a private +chunk used in ImageMagick to store "virtual page" size). */ + +static png_uint_32 user_chunk_data[4]; + + /* 0: sTER mode + 1 + * 1: vpAg width + * 2: vpAg height + * 3: vpAg units + */ + +static int PNGCBAPI read_user_chunk_callback(png_struct *png_ptr, + png_unknown_chunkp chunk) +{ + png_uint_32 + *my_user_chunk_data; + + /* Return one of the following: + * return (-n); chunk had an error + * return (0); did not recognize + * return (n); success + * + * The unknown chunk structure contains the chunk data: + * png_byte name[5]; + * png_byte *data; + * png_size_t size; + * + * Note that libpng has already taken care of the CRC handling. + */ + + if (chunk->name[0] == 115 && chunk->name[1] == 84 && /* s T */ + chunk->name[2] == 69 && chunk->name[3] == 82) /* E R */ + { + /* Found sTER chunk */ + if (chunk->size != 1) + return (-1); /* Error return */ + + if (chunk->data[0] != 0 && chunk->data[0] != 1) + return (-1); /* Invalid mode */ + + my_user_chunk_data=(png_uint_32 *) png_get_user_chunk_ptr(png_ptr); + my_user_chunk_data[0]=chunk->data[0]+1; + return (1); + } + + if (chunk->name[0] != 118 || chunk->name[1] != 112 || /* v p */ + chunk->name[2] != 65 || chunk->name[3] != 103) /* A g */ + return (0); /* Did not recognize */ + + /* Found ImageMagick vpAg chunk */ + + if (chunk->size != 9) + return (-1); /* Error return */ + + my_user_chunk_data=(png_uint_32 *) png_get_user_chunk_ptr(png_ptr); + + my_user_chunk_data[1]=png_get_uint_31(png_ptr, chunk->data); + my_user_chunk_data[2]=png_get_uint_31(png_ptr, chunk->data + 4); + my_user_chunk_data[3]=(png_uint_32)chunk->data[8]; + + return (1); + +} +#endif +/* END of code to demonstrate user chunk support */ + +/* Test one file */ +int +test_one_file(PNG_CONST char *inname, PNG_CONST char *outname) +{ + static png_FILE_p fpin; + static png_FILE_p fpout; /* "static" prevents setjmp corruption */ + png_structp read_ptr; + png_infop read_info_ptr, end_info_ptr; +#ifdef PNG_WRITE_SUPPORTED + png_structp write_ptr; + png_infop write_info_ptr; + png_infop write_end_info_ptr; +#else + png_structp write_ptr = NULL; + png_infop write_info_ptr = NULL; + png_infop write_end_info_ptr = NULL; +#endif + png_bytep row_buf; + png_uint_32 y; + png_uint_32 width, height; + int num_pass, pass; + int bit_depth, color_type; +#ifdef PNG_SETJMP_SUPPORTED +#ifdef USE_FAR_KEYWORD + jmp_buf png_jmpbuf; +#endif +#endif + + char inbuf[256], outbuf[256]; + + row_buf = NULL; + + if ((fpin = fopen(inname, "rb")) == NULL) + { + fprintf(STDERR, "Could not find input file %s\n", inname); + return (1); + } + + if ((fpout = fopen(outname, "wb")) == NULL) + { + fprintf(STDERR, "Could not open output file %s\n", outname); + FCLOSE(fpin); + return (1); + } + + pngtest_debug("Allocating read and write structures"); +#if defined(PNG_USER_MEM_SUPPORTED) && PNG_DEBUG + read_ptr = + png_create_read_struct_2(PNG_LIBPNG_VER_STRING, NULL, + NULL, NULL, NULL, png_debug_malloc, png_debug_free); +#else + read_ptr = + png_create_read_struct(PNG_LIBPNG_VER_STRING, NULL, NULL, NULL); +#endif +#ifndef PNG_STDIO_SUPPORTED + png_set_error_fn(read_ptr, (png_voidp)inname, pngtest_error, + pngtest_warning); +#endif + +#ifdef PNG_UNKNOWN_CHUNKS_SUPPORTED + user_chunk_data[0] = 0; + user_chunk_data[1] = 0; + user_chunk_data[2] = 0; + user_chunk_data[3] = 0; + png_set_read_user_chunk_fn(read_ptr, user_chunk_data, + read_user_chunk_callback); + +#endif +#ifdef PNG_WRITE_SUPPORTED +#if defined(PNG_USER_MEM_SUPPORTED) && PNG_DEBUG + write_ptr = + png_create_write_struct_2(PNG_LIBPNG_VER_STRING, NULL, + NULL, NULL, NULL, png_debug_malloc, png_debug_free); +#else + write_ptr = + png_create_write_struct(PNG_LIBPNG_VER_STRING, NULL, NULL, NULL); +#endif +#ifndef PNG_STDIO_SUPPORTED + png_set_error_fn(write_ptr, (png_voidp)inname, pngtest_error, + pngtest_warning); +#endif +#endif + pngtest_debug("Allocating read_info, write_info and end_info structures"); + read_info_ptr = png_create_info_struct(read_ptr); + end_info_ptr = png_create_info_struct(read_ptr); +#ifdef PNG_WRITE_SUPPORTED + write_info_ptr = png_create_info_struct(write_ptr); + write_end_info_ptr = png_create_info_struct(write_ptr); +#endif + +#ifdef PNG_SETJMP_SUPPORTED + pngtest_debug("Setting jmpbuf for read struct"); +#ifdef USE_FAR_KEYWORD + if (setjmp(png_jmpbuf)) +#else + if (setjmp(png_jmpbuf(read_ptr))) +#endif + { + fprintf(STDERR, "%s -> %s: libpng read error\n", inname, outname); + png_free(read_ptr, row_buf); + row_buf = NULL; + png_destroy_read_struct(&read_ptr, &read_info_ptr, &end_info_ptr); +#ifdef PNG_WRITE_SUPPORTED + png_destroy_info_struct(write_ptr, &write_end_info_ptr); + png_destroy_write_struct(&write_ptr, &write_info_ptr); +#endif + FCLOSE(fpin); + FCLOSE(fpout); + return (1); + } +#ifdef USE_FAR_KEYWORD + png_memcpy(png_jmpbuf(read_ptr), png_jmpbuf, png_sizeof(jmp_buf)); +#endif + +#ifdef PNG_WRITE_SUPPORTED + pngtest_debug("Setting jmpbuf for write struct"); +#ifdef USE_FAR_KEYWORD + + if (setjmp(png_jmpbuf)) +#else + if (setjmp(png_jmpbuf(write_ptr))) +#endif + { + fprintf(STDERR, "%s -> %s: libpng write error\n", inname, outname); + png_destroy_read_struct(&read_ptr, &read_info_ptr, &end_info_ptr); + png_destroy_info_struct(write_ptr, &write_end_info_ptr); +#ifdef PNG_WRITE_SUPPORTED + png_destroy_write_struct(&write_ptr, &write_info_ptr); +#endif + FCLOSE(fpin); + FCLOSE(fpout); + return (1); + } + +#ifdef USE_FAR_KEYWORD + png_memcpy(png_jmpbuf(write_ptr), png_jmpbuf, png_sizeof(jmp_buf)); +#endif +#endif +#endif + + pngtest_debug("Initializing input and output streams"); +#ifdef PNG_STDIO_SUPPORTED + png_init_io(read_ptr, fpin); +# ifdef PNG_WRITE_SUPPORTED + png_init_io(write_ptr, fpout); +# endif +#else + png_set_read_fn(read_ptr, (png_voidp)fpin, pngtest_read_data); +# ifdef PNG_WRITE_SUPPORTED + png_set_write_fn(write_ptr, (png_voidp)fpout, pngtest_write_data, +# ifdef PNG_WRITE_FLUSH_SUPPORTED + pngtest_flush); +# else + NULL); +# endif +# endif +#endif + + if (status_dots_requested == 1) + { +#ifdef PNG_WRITE_SUPPORTED + png_set_write_status_fn(write_ptr, write_row_callback); +#endif + png_set_read_status_fn(read_ptr, read_row_callback); + } + + else + { +#ifdef PNG_WRITE_SUPPORTED + png_set_write_status_fn(write_ptr, NULL); +#endif + png_set_read_status_fn(read_ptr, NULL); + } + +#ifdef PNG_READ_USER_TRANSFORM_SUPPORTED + { + int i; + + for (i = 0; i<256; i++) + filters_used[i] = 0; + + png_set_read_user_transform_fn(read_ptr, count_filters); + } +#endif +#ifdef PNG_WRITE_USER_TRANSFORM_SUPPORTED + zero_samples = 0; + png_set_write_user_transform_fn(write_ptr, count_zero_samples); +#endif + +#ifdef PNG_READ_UNKNOWN_CHUNKS_SUPPORTED +# ifndef PNG_HANDLE_CHUNK_ALWAYS +# define PNG_HANDLE_CHUNK_ALWAYS 3 +# endif + png_set_keep_unknown_chunks(read_ptr, PNG_HANDLE_CHUNK_ALWAYS, + NULL, 0); +#endif +#ifdef PNG_WRITE_UNKNOWN_CHUNKS_SUPPORTED +# ifndef PNG_HANDLE_CHUNK_IF_SAFE +# define PNG_HANDLE_CHUNK_IF_SAFE 2 +# endif + png_set_keep_unknown_chunks(write_ptr, PNG_HANDLE_CHUNK_IF_SAFE, + NULL, 0); +#endif + + pngtest_debug("Reading info struct"); + png_read_info(read_ptr, read_info_ptr); + + pngtest_debug("Transferring info struct"); + { + int interlace_type, compression_type, filter_type; + + if (png_get_IHDR(read_ptr, read_info_ptr, &width, &height, &bit_depth, + &color_type, &interlace_type, &compression_type, &filter_type)) + { + png_set_IHDR(write_ptr, write_info_ptr, width, height, bit_depth, +#ifdef PNG_WRITE_INTERLACING_SUPPORTED + color_type, interlace_type, compression_type, filter_type); +#else + color_type, PNG_INTERLACE_NONE, compression_type, filter_type); +#endif + } + } +#ifdef PNG_FIXED_POINT_SUPPORTED +#ifdef PNG_cHRM_SUPPORTED + { + png_fixed_point white_x, white_y, red_x, red_y, green_x, green_y, blue_x, + blue_y; + + if (png_get_cHRM_fixed(read_ptr, read_info_ptr, &white_x, &white_y, + &red_x, &red_y, &green_x, &green_y, &blue_x, &blue_y)) + { + png_set_cHRM_fixed(write_ptr, write_info_ptr, white_x, white_y, red_x, + red_y, green_x, green_y, blue_x, blue_y); + } + } +#endif +#ifdef PNG_gAMA_SUPPORTED + { + png_fixed_point gamma; + + if (png_get_gAMA_fixed(read_ptr, read_info_ptr, &gamma)) + png_set_gAMA_fixed(write_ptr, write_info_ptr, gamma); + } +#endif +#else /* Use floating point versions */ +#ifdef PNG_FLOATING_POINT_SUPPORTED +#ifdef PNG_cHRM_SUPPORTED + { + double white_x, white_y, red_x, red_y, green_x, green_y, blue_x, + blue_y; + + if (png_get_cHRM(read_ptr, read_info_ptr, &white_x, &white_y, &red_x, + &red_y, &green_x, &green_y, &blue_x, &blue_y)) + { + png_set_cHRM(write_ptr, write_info_ptr, white_x, white_y, red_x, + red_y, green_x, green_y, blue_x, blue_y); + } + } +#endif +#ifdef PNG_gAMA_SUPPORTED + { + double gamma; + + if (png_get_gAMA(read_ptr, read_info_ptr, &gamma)) + png_set_gAMA(write_ptr, write_info_ptr, gamma); + } +#endif +#endif /* Floating point */ +#endif /* Fixed point */ +#ifdef PNG_iCCP_SUPPORTED + { + png_charp name; + png_bytep profile; + png_uint_32 proflen; + int compression_type; + + if (png_get_iCCP(read_ptr, read_info_ptr, &name, &compression_type, + &profile, &proflen)) + { + png_set_iCCP(write_ptr, write_info_ptr, name, compression_type, + profile, proflen); + } + } +#endif +#ifdef PNG_sRGB_SUPPORTED + { + int intent; + + if (png_get_sRGB(read_ptr, read_info_ptr, &intent)) + png_set_sRGB(write_ptr, write_info_ptr, intent); + } +#endif + { + png_colorp palette; + int num_palette; + + if (png_get_PLTE(read_ptr, read_info_ptr, &palette, &num_palette)) + png_set_PLTE(write_ptr, write_info_ptr, palette, num_palette); + } +#ifdef PNG_bKGD_SUPPORTED + { + png_color_16p background; + + if (png_get_bKGD(read_ptr, read_info_ptr, &background)) + { + png_set_bKGD(write_ptr, write_info_ptr, background); + } + } +#endif +#ifdef PNG_hIST_SUPPORTED + { + png_uint_16p hist; + + if (png_get_hIST(read_ptr, read_info_ptr, &hist)) + png_set_hIST(write_ptr, write_info_ptr, hist); + } +#endif +#ifdef PNG_oFFs_SUPPORTED + { + png_int_32 offset_x, offset_y; + int unit_type; + + if (png_get_oFFs(read_ptr, read_info_ptr, &offset_x, &offset_y, + &unit_type)) + { + png_set_oFFs(write_ptr, write_info_ptr, offset_x, offset_y, unit_type); + } + } +#endif +#ifdef PNG_pCAL_SUPPORTED + { + png_charp purpose, units; + png_charpp params; + png_int_32 X0, X1; + int type, nparams; + + if (png_get_pCAL(read_ptr, read_info_ptr, &purpose, &X0, &X1, &type, + &nparams, &units, ¶ms)) + { + png_set_pCAL(write_ptr, write_info_ptr, purpose, X0, X1, type, + nparams, units, params); + } + } +#endif +#ifdef PNG_pHYs_SUPPORTED + { + png_uint_32 res_x, res_y; + int unit_type; + + if (png_get_pHYs(read_ptr, read_info_ptr, &res_x, &res_y, &unit_type)) + png_set_pHYs(write_ptr, write_info_ptr, res_x, res_y, unit_type); + } +#endif +#ifdef PNG_sBIT_SUPPORTED + { + png_color_8p sig_bit; + + if (png_get_sBIT(read_ptr, read_info_ptr, &sig_bit)) + png_set_sBIT(write_ptr, write_info_ptr, sig_bit); + } +#endif +#ifdef PNG_sCAL_SUPPORTED +#ifdef PNG_FLOATING_POINT_SUPPORTED + { + int unit; + double scal_width, scal_height; + + if (png_get_sCAL(read_ptr, read_info_ptr, &unit, &scal_width, + &scal_height)) + { + png_set_sCAL(write_ptr, write_info_ptr, unit, scal_width, scal_height); + } + } +#else +#ifdef PNG_FIXED_POINT_SUPPORTED + { + int unit; + png_charp scal_width, scal_height; + + if (png_get_sCAL_s(read_ptr, read_info_ptr, &unit, &scal_width, + &scal_height)) + { + png_set_sCAL_s(write_ptr, write_info_ptr, unit, scal_width, + scal_height); + } + } +#endif +#endif +#endif +#ifdef PNG_TEXT_SUPPORTED + { + png_textp text_ptr; + int num_text; + + if (png_get_text(read_ptr, read_info_ptr, &text_ptr, &num_text) > 0) + { + pngtest_debug1("Handling %d iTXt/tEXt/zTXt chunks", num_text); + png_set_text(write_ptr, write_info_ptr, text_ptr, num_text); + } + } +#endif +#ifdef PNG_tIME_SUPPORTED + { + png_timep mod_time; + + if (png_get_tIME(read_ptr, read_info_ptr, &mod_time)) + { + png_set_tIME(write_ptr, write_info_ptr, mod_time); +#ifdef PNG_TIME_RFC1123_SUPPORTED + /* We have to use png_memcpy instead of "=" because the string + * pointed to by png_convert_to_rfc1123() gets free'ed before + * we use it. + */ + png_memcpy(tIME_string, + png_convert_to_rfc1123(read_ptr, mod_time), + png_sizeof(tIME_string)); + + tIME_string[png_sizeof(tIME_string) - 1] = '\0'; + tIME_chunk_present++; +#endif /* PNG_TIME_RFC1123_SUPPORTED */ + } + } +#endif +#ifdef PNG_tRNS_SUPPORTED + { + png_bytep trans_alpha; + int num_trans; + png_color_16p trans_color; + + if (png_get_tRNS(read_ptr, read_info_ptr, &trans_alpha, &num_trans, + &trans_color)) + { + int sample_max = (1 << bit_depth); + /* libpng doesn't reject a tRNS chunk with out-of-range samples */ + if (!((color_type == PNG_COLOR_TYPE_GRAY && + (int)trans_color->gray > sample_max) || + (color_type == PNG_COLOR_TYPE_RGB && + ((int)trans_color->red > sample_max || + (int)trans_color->green > sample_max || + (int)trans_color->blue > sample_max)))) + png_set_tRNS(write_ptr, write_info_ptr, trans_alpha, num_trans, + trans_color); + } + } +#endif +#ifdef PNG_WRITE_UNKNOWN_CHUNKS_SUPPORTED + { + png_unknown_chunkp unknowns; + int num_unknowns = png_get_unknown_chunks(read_ptr, read_info_ptr, + &unknowns); + + if (num_unknowns) + { + int i; + png_set_unknown_chunks(write_ptr, write_info_ptr, unknowns, + num_unknowns); + /* Copy the locations from the read_info_ptr. The automatically + * generated locations in write_info_ptr are wrong because we + * haven't written anything yet. + */ + for (i = 0; i < num_unknowns; i++) + png_set_unknown_chunk_location(write_ptr, write_info_ptr, i, + unknowns[i].location); + } + } +#endif + +#ifdef PNG_WRITE_SUPPORTED + pngtest_debug("Writing info struct"); + +/* If we wanted, we could write info in two steps: + * png_write_info_before_PLTE(write_ptr, write_info_ptr); + */ + png_write_info(write_ptr, write_info_ptr); + +#ifdef PNG_UNKNOWN_CHUNKS_SUPPORTED + if (user_chunk_data[0] != 0) + { + png_byte png_sTER[5] = {115, 84, 69, 82, '\0'}; + + unsigned char + ster_chunk_data[1]; + + if (verbose) + fprintf(STDERR, "\n stereo mode = %lu\n", + (unsigned long)(user_chunk_data[0] - 1)); + + ster_chunk_data[0]=(unsigned char)(user_chunk_data[0] - 1); + png_write_chunk(write_ptr, png_sTER, ster_chunk_data, 1); + } + + if (user_chunk_data[1] != 0 || user_chunk_data[2] != 0) + { + png_byte png_vpAg[5] = {118, 112, 65, 103, '\0'}; + + unsigned char + vpag_chunk_data[9]; + + if (verbose) + fprintf(STDERR, " vpAg = %lu x %lu, units = %lu\n", + (unsigned long)user_chunk_data[1], + (unsigned long)user_chunk_data[2], + (unsigned long)user_chunk_data[3]); + + png_save_uint_32(vpag_chunk_data, user_chunk_data[1]); + png_save_uint_32(vpag_chunk_data + 4, user_chunk_data[2]); + vpag_chunk_data[8] = (unsigned char)(user_chunk_data[3] & 0xff); + png_write_chunk(write_ptr, png_vpAg, vpag_chunk_data, 9); + } + +#endif +#endif + +#ifdef SINGLE_ROWBUF_ALLOC + pngtest_debug("Allocating row buffer..."); + row_buf = (png_bytep)png_malloc(read_ptr, + png_get_rowbytes(read_ptr, read_info_ptr)); + + pngtest_debug1("\t0x%08lx", (unsigned long)row_buf); +#endif /* SINGLE_ROWBUF_ALLOC */ + pngtest_debug("Writing row data"); + +#if defined(PNG_READ_INTERLACING_SUPPORTED) || \ + defined(PNG_WRITE_INTERLACING_SUPPORTED) + num_pass = png_set_interlace_handling(read_ptr); +# ifdef PNG_WRITE_SUPPORTED + png_set_interlace_handling(write_ptr); +# endif +#else + num_pass = 1; +#endif + +#ifdef PNGTEST_TIMING + t_stop = (float)clock(); + t_misc += (t_stop - t_start); + t_start = t_stop; +#endif + for (pass = 0; pass < num_pass; pass++) + { + pngtest_debug1("Writing row data for pass %d", pass); + for (y = 0; y < height; y++) + { +#ifndef SINGLE_ROWBUF_ALLOC + pngtest_debug2("Allocating row buffer (pass %d, y = %u)...", pass, y); + row_buf = (png_bytep)png_malloc(read_ptr, + png_get_rowbytes(read_ptr, read_info_ptr)); + + pngtest_debug2("\t0x%08lx (%u bytes)", (unsigned long)row_buf, + png_get_rowbytes(read_ptr, read_info_ptr)); + +#endif /* !SINGLE_ROWBUF_ALLOC */ + png_read_rows(read_ptr, (png_bytepp)&row_buf, NULL, 1); + +#ifdef PNG_WRITE_SUPPORTED +#ifdef PNGTEST_TIMING + t_stop = (float)clock(); + t_decode += (t_stop - t_start); + t_start = t_stop; +#endif + png_write_rows(write_ptr, (png_bytepp)&row_buf, 1); +#ifdef PNGTEST_TIMING + t_stop = (float)clock(); + t_encode += (t_stop - t_start); + t_start = t_stop; +#endif +#endif /* PNG_WRITE_SUPPORTED */ + +#ifndef SINGLE_ROWBUF_ALLOC + pngtest_debug2("Freeing row buffer (pass %d, y = %u)", pass, y); + png_free(read_ptr, row_buf); + row_buf = NULL; +#endif /* !SINGLE_ROWBUF_ALLOC */ + } + } + +#ifdef PNG_READ_UNKNOWN_CHUNKS_SUPPORTED + png_free_data(read_ptr, read_info_ptr, PNG_FREE_UNKN, -1); +#endif +#ifdef PNG_WRITE_UNKNOWN_CHUNKS_SUPPORTED + png_free_data(write_ptr, write_info_ptr, PNG_FREE_UNKN, -1); +#endif + + pngtest_debug("Reading and writing end_info data"); + + png_read_end(read_ptr, end_info_ptr); +#ifdef PNG_TEXT_SUPPORTED + { + png_textp text_ptr; + int num_text; + + if (png_get_text(read_ptr, end_info_ptr, &text_ptr, &num_text) > 0) + { + pngtest_debug1("Handling %d iTXt/tEXt/zTXt chunks", num_text); + png_set_text(write_ptr, write_end_info_ptr, text_ptr, num_text); + } + } +#endif +#ifdef PNG_tIME_SUPPORTED + { + png_timep mod_time; + + if (png_get_tIME(read_ptr, end_info_ptr, &mod_time)) + { + png_set_tIME(write_ptr, write_end_info_ptr, mod_time); +#ifdef PNG_TIME_RFC1123_SUPPORTED + /* We have to use png_memcpy instead of "=" because the string + pointed to by png_convert_to_rfc1123() gets free'ed before + we use it */ + png_memcpy(tIME_string, + png_convert_to_rfc1123(read_ptr, mod_time), + png_sizeof(tIME_string)); + + tIME_string[png_sizeof(tIME_string) - 1] = '\0'; + tIME_chunk_present++; +#endif /* PNG_TIME_RFC1123_SUPPORTED */ + } + } +#endif +#ifdef PNG_WRITE_UNKNOWN_CHUNKS_SUPPORTED + { + png_unknown_chunkp unknowns; + int num_unknowns = png_get_unknown_chunks(read_ptr, end_info_ptr, + &unknowns); + + if (num_unknowns) + { + int i; + png_set_unknown_chunks(write_ptr, write_end_info_ptr, unknowns, + num_unknowns); + /* Copy the locations from the read_info_ptr. The automatically + * generated locations in write_end_info_ptr are wrong because we + * haven't written the end_info yet. + */ + for (i = 0; i < num_unknowns; i++) + png_set_unknown_chunk_location(write_ptr, write_end_info_ptr, i, + unknowns[i].location); + } + } +#endif +#ifdef PNG_WRITE_SUPPORTED + png_write_end(write_ptr, write_end_info_ptr); +#endif + +#ifdef PNG_EASY_ACCESS_SUPPORTED + if (verbose) + { + png_uint_32 iwidth, iheight; + iwidth = png_get_image_width(write_ptr, write_info_ptr); + iheight = png_get_image_height(write_ptr, write_info_ptr); + fprintf(STDERR, "\n Image width = %lu, height = %lu\n", + (unsigned long)iwidth, (unsigned long)iheight); + } +#endif + + pngtest_debug("Destroying data structs"); +#ifdef SINGLE_ROWBUF_ALLOC + pngtest_debug("destroying row_buf for read_ptr"); + png_free(read_ptr, row_buf); + row_buf = NULL; +#endif /* SINGLE_ROWBUF_ALLOC */ + pngtest_debug("destroying read_ptr, read_info_ptr, end_info_ptr"); + png_destroy_read_struct(&read_ptr, &read_info_ptr, &end_info_ptr); +#ifdef PNG_WRITE_SUPPORTED + pngtest_debug("destroying write_end_info_ptr"); + png_destroy_info_struct(write_ptr, &write_end_info_ptr); + pngtest_debug("destroying write_ptr, write_info_ptr"); + png_destroy_write_struct(&write_ptr, &write_info_ptr); +#endif + pngtest_debug("Destruction complete."); + + FCLOSE(fpin); + FCLOSE(fpout); + + pngtest_debug("Opening files for comparison"); + if ((fpin = fopen(inname, "rb")) == NULL) + { + fprintf(STDERR, "Could not find file %s\n", inname); + return (1); + } + + if ((fpout = fopen(outname, "rb")) == NULL) + { + fprintf(STDERR, "Could not find file %s\n", outname); + FCLOSE(fpin); + return (1); + } + + for (;;) + { + png_size_t num_in, num_out; + + num_in = fread(inbuf, 1, 1, fpin); + num_out = fread(outbuf, 1, 1, fpout); + + if (num_in != num_out) + { + fprintf(STDERR, "\nFiles %s and %s are of a different size\n", + inname, outname); + + if (wrote_question == 0) + { + fprintf(STDERR, + " Was %s written with the same maximum IDAT chunk size (%d bytes),", + inname, PNG_ZBUF_SIZE); + fprintf(STDERR, + "\n filtering heuristic (libpng default), compression"); + fprintf(STDERR, + " level (zlib default),\n and zlib version (%s)?\n\n", + ZLIB_VERSION); + wrote_question = 1; + } + + FCLOSE(fpin); + FCLOSE(fpout); + return (0); + } + + if (!num_in) + break; + + if (png_memcmp(inbuf, outbuf, num_in)) + { + fprintf(STDERR, "\nFiles %s and %s are different\n", inname, outname); + + if (wrote_question == 0) + { + fprintf(STDERR, + " Was %s written with the same maximum IDAT chunk size (%d bytes),", + inname, PNG_ZBUF_SIZE); + fprintf(STDERR, + "\n filtering heuristic (libpng default), compression"); + fprintf(STDERR, + " level (zlib default),\n and zlib version (%s)?\n\n", + ZLIB_VERSION); + wrote_question = 1; + } + + FCLOSE(fpin); + FCLOSE(fpout); + return (0); + } + } + + FCLOSE(fpin); + FCLOSE(fpout); + + return (0); +} + +/* Input and output filenames */ +#ifdef RISCOS +static PNG_CONST char *inname = "pngtest/png"; +static PNG_CONST char *outname = "pngout/png"; +#else +static PNG_CONST char *inname = "pngtest.png"; +static PNG_CONST char *outname = "pngout.png"; +#endif + +int +main(int argc, char *argv[]) +{ + int multiple = 0; + int ierror = 0; + + fprintf(STDERR, "\n Testing libpng version %s\n", PNG_LIBPNG_VER_STRING); + fprintf(STDERR, " with zlib version %s\n", ZLIB_VERSION); + fprintf(STDERR, "%s", png_get_copyright(NULL)); + /* Show the version of libpng used in building the library */ + fprintf(STDERR, " library (%lu):%s", + (unsigned long)png_access_version_number(), + png_get_header_version(NULL)); + + /* Show the version of libpng used in building the application */ + fprintf(STDERR, " pngtest (%lu):%s", (unsigned long)PNG_LIBPNG_VER, + PNG_HEADER_VERSION_STRING); + + /* Do some consistency checking on the memory allocation settings, I'm + * not sure this matters, but it is nice to know, the first of these + * tests should be impossible because of the way the macros are set + * in pngconf.h + */ +#if defined(MAXSEG_64K) && !defined(PNG_MAX_MALLOC_64K) + fprintf(STDERR, " NOTE: Zlib compiled for max 64k, libpng not\n"); +#endif + /* I think the following can happen. */ +#if !defined(MAXSEG_64K) && defined(PNG_MAX_MALLOC_64K) + fprintf(STDERR, " NOTE: libpng compiled for max 64k, zlib not\n"); +#endif + + if (strcmp(png_libpng_ver, PNG_LIBPNG_VER_STRING)) + { + fprintf(STDERR, + "Warning: versions are different between png.h and png.c\n"); + fprintf(STDERR, " png.h version: %s\n", PNG_LIBPNG_VER_STRING); + fprintf(STDERR, " png.c version: %s\n\n", png_libpng_ver); + ++ierror; + } + + if (argc > 1) + { + if (strcmp(argv[1], "-m") == 0) + { + multiple = 1; + status_dots_requested = 0; + } + + else if (strcmp(argv[1], "-mv") == 0 || + strcmp(argv[1], "-vm") == 0 ) + { + multiple = 1; + verbose = 1; + status_dots_requested = 1; + } + + else if (strcmp(argv[1], "-v") == 0) + { + verbose = 1; + status_dots_requested = 1; + inname = argv[2]; + } + + else + { + inname = argv[1]; + status_dots_requested = 0; + } + } + + if (!multiple && argc == 3 + verbose) + outname = argv[2 + verbose]; + + if ((!multiple && argc > 3 + verbose) || (multiple && argc < 2)) + { + fprintf(STDERR, + "usage: %s [infile.png] [outfile.png]\n\t%s -m {infile.png}\n", + argv[0], argv[0]); + fprintf(STDERR, + " reads/writes one PNG file (without -m) or multiple files (-m)\n"); + fprintf(STDERR, + " with -m %s is used as a temporary file\n", outname); + exit(1); + } + + if (multiple) + { + int i; +#if defined(PNG_USER_MEM_SUPPORTED) && PNG_DEBUG + int allocation_now = current_allocation; +#endif + for (i=2; i<argc; ++i) + { + int kerror; + fprintf(STDERR, "\n Testing %s:", argv[i]); + kerror = test_one_file(argv[i], outname); + if (kerror == 0) + { +#ifdef PNG_READ_USER_TRANSFORM_SUPPORTED + int k; +#endif +#ifdef PNG_WRITE_USER_TRANSFORM_SUPPORTED + fprintf(STDERR, "\n PASS (%lu zero samples)\n", + (unsigned long)zero_samples); +#else + fprintf(STDERR, " PASS\n"); +#endif +#ifdef PNG_READ_USER_TRANSFORM_SUPPORTED + for (k = 0; k<256; k++) + if (filters_used[k]) + fprintf(STDERR, " Filter %d was used %lu times\n", + k, (unsigned long)filters_used[k]); +#endif +#ifdef PNG_TIME_RFC1123_SUPPORTED + if (tIME_chunk_present != 0) + fprintf(STDERR, " tIME = %s\n", tIME_string); + + tIME_chunk_present = 0; +#endif /* PNG_TIME_RFC1123_SUPPORTED */ + } + + else + { + fprintf(STDERR, " FAIL\n"); + ierror += kerror; + } +#if defined(PNG_USER_MEM_SUPPORTED) && PNG_DEBUG + if (allocation_now != current_allocation) + fprintf(STDERR, "MEMORY ERROR: %d bytes lost\n", + current_allocation - allocation_now); + + if (current_allocation != 0) + { + memory_infop pinfo = pinformation; + + fprintf(STDERR, "MEMORY ERROR: %d bytes still allocated\n", + current_allocation); + + while (pinfo != NULL) + { + fprintf(STDERR, " %lu bytes at %x\n", + (unsigned long)pinfo->size, + (unsigned int)pinfo->pointer); + pinfo = pinfo->next; + } + } +#endif + } +#if defined(PNG_USER_MEM_SUPPORTED) && PNG_DEBUG + fprintf(STDERR, " Current memory allocation: %10d bytes\n", + current_allocation); + fprintf(STDERR, " Maximum memory allocation: %10d bytes\n", + maximum_allocation); + fprintf(STDERR, " Total memory allocation: %10d bytes\n", + total_allocation); + fprintf(STDERR, " Number of allocations: %10d\n", + num_allocations); +#endif + } + + else + { + int i; + for (i = 0; i<3; ++i) + { + int kerror; +#if defined(PNG_USER_MEM_SUPPORTED) && PNG_DEBUG + int allocation_now = current_allocation; +#endif + if (i == 1) + status_dots_requested = 1; + + else if (verbose == 0) + status_dots_requested = 0; + + if (i == 0 || verbose == 1 || ierror != 0) + fprintf(STDERR, "\n Testing %s:", inname); + + kerror = test_one_file(inname, outname); + + if (kerror == 0) + { + if (verbose == 1 || i == 2) + { +#ifdef PNG_READ_USER_TRANSFORM_SUPPORTED + int k; +#endif +#ifdef PNG_WRITE_USER_TRANSFORM_SUPPORTED + fprintf(STDERR, "\n PASS (%lu zero samples)\n", + (unsigned long)zero_samples); +#else + fprintf(STDERR, " PASS\n"); +#endif +#ifdef PNG_READ_USER_TRANSFORM_SUPPORTED + for (k = 0; k<256; k++) + if (filters_used[k]) + fprintf(STDERR, " Filter %d was used %lu times\n", + k, (unsigned long)filters_used[k]); +#endif +#ifdef PNG_TIME_RFC1123_SUPPORTED + if (tIME_chunk_present != 0) + fprintf(STDERR, " tIME = %s\n", tIME_string); +#endif /* PNG_TIME_RFC1123_SUPPORTED */ + } + } + + else + { + if (verbose == 0 && i != 2) + fprintf(STDERR, "\n Testing %s:", inname); + + fprintf(STDERR, " FAIL\n"); + ierror += kerror; + } +#if defined(PNG_USER_MEM_SUPPORTED) && PNG_DEBUG + if (allocation_now != current_allocation) + fprintf(STDERR, "MEMORY ERROR: %d bytes lost\n", + current_allocation - allocation_now); + + if (current_allocation != 0) + { + memory_infop pinfo = pinformation; + + fprintf(STDERR, "MEMORY ERROR: %d bytes still allocated\n", + current_allocation); + + while (pinfo != NULL) + { + fprintf(STDERR, " %lu bytes at %x\n", + (unsigned long)pinfo->size, (unsigned int)pinfo->pointer); + pinfo = pinfo->next; + } + } +#endif + } +#if defined(PNG_USER_MEM_SUPPORTED) && PNG_DEBUG + fprintf(STDERR, " Current memory allocation: %10d bytes\n", + current_allocation); + fprintf(STDERR, " Maximum memory allocation: %10d bytes\n", + maximum_allocation); + fprintf(STDERR, " Total memory allocation: %10d bytes\n", + total_allocation); + fprintf(STDERR, " Number of allocations: %10d\n", + num_allocations); +#endif + } + +#ifdef PNGTEST_TIMING + t_stop = (float)clock(); + t_misc += (t_stop - t_start); + t_start = t_stop; + fprintf(STDERR, " CPU time used = %.3f seconds", + (t_misc+t_decode+t_encode)/(float)CLOCKS_PER_SEC); + fprintf(STDERR, " (decoding %.3f,\n", + t_decode/(float)CLOCKS_PER_SEC); + fprintf(STDERR, " encoding %.3f ,", + t_encode/(float)CLOCKS_PER_SEC); + fprintf(STDERR, " other %.3f seconds)\n\n", + t_misc/(float)CLOCKS_PER_SEC); +#endif + + if (ierror == 0) + fprintf(STDERR, " libpng passes test\n"); + + else + fprintf(STDERR, " libpng FAILS test\n"); + + return (int)(ierror != 0); +} + +/* Generate a compiler error if there is an old png.h in the search path. */ +typedef png_libpng_version_1_5_1 Your_png_h_is_not_version_1_5_1; diff --git a/src/3rdparty/libpng/pngtrans.c b/src/3rdparty/libpng/pngtrans.c new file mode 100644 index 0000000000..137f555a62 --- /dev/null +++ b/src/3rdparty/libpng/pngtrans.c @@ -0,0 +1,723 @@ + +/* pngtrans.c - transforms the data in a row (used by both readers and writers) + * + * Last changed in libpng 1.5.1 [February 3, 2011] + * Copyright (c) 1998-2011 Glenn Randers-Pehrson + * (Version 0.96 Copyright (c) 1996, 1997 Andreas Dilger) + * (Version 0.88 Copyright (c) 1995, 1996 Guy Eric Schalnat, Group 42, Inc.) + * + * This code is released under the libpng license. + * For conditions of distribution and use, see the disclaimer + * and license in png.h + */ + +#include "pngpriv.h" + +#if defined(PNG_READ_SUPPORTED) || defined(PNG_WRITE_SUPPORTED) + +#if defined(PNG_READ_BGR_SUPPORTED) || defined(PNG_WRITE_BGR_SUPPORTED) +/* Turn on BGR-to-RGB mapping */ +void PNGAPI +png_set_bgr(png_structp png_ptr) +{ + png_debug(1, "in png_set_bgr"); + + if (png_ptr == NULL) + return; + + png_ptr->transformations |= PNG_BGR; +} +#endif + +#if defined(PNG_READ_SWAP_SUPPORTED) || defined(PNG_WRITE_SWAP_SUPPORTED) +/* Turn on 16 bit byte swapping */ +void PNGAPI +png_set_swap(png_structp png_ptr) +{ + png_debug(1, "in png_set_swap"); + + if (png_ptr == NULL) + return; + + if (png_ptr->bit_depth == 16) + png_ptr->transformations |= PNG_SWAP_BYTES; +} +#endif + +#if defined(PNG_READ_PACK_SUPPORTED) || defined(PNG_WRITE_PACK_SUPPORTED) +/* Turn on pixel packing */ +void PNGAPI +png_set_packing(png_structp png_ptr) +{ + png_debug(1, "in png_set_packing"); + + if (png_ptr == NULL) + return; + + if (png_ptr->bit_depth < 8) + { + png_ptr->transformations |= PNG_PACK; + png_ptr->usr_bit_depth = 8; + } +} +#endif + +#if defined(PNG_READ_PACKSWAP_SUPPORTED)||defined(PNG_WRITE_PACKSWAP_SUPPORTED) +/* Turn on packed pixel swapping */ +void PNGAPI +png_set_packswap(png_structp png_ptr) +{ + png_debug(1, "in png_set_packswap"); + + if (png_ptr == NULL) + return; + + if (png_ptr->bit_depth < 8) + png_ptr->transformations |= PNG_PACKSWAP; +} +#endif + +#if defined(PNG_READ_SHIFT_SUPPORTED) || defined(PNG_WRITE_SHIFT_SUPPORTED) +void PNGAPI +png_set_shift(png_structp png_ptr, png_const_color_8p true_bits) +{ + png_debug(1, "in png_set_shift"); + + if (png_ptr == NULL) + return; + + png_ptr->transformations |= PNG_SHIFT; + png_ptr->shift = *true_bits; +} +#endif + +#if defined(PNG_READ_INTERLACING_SUPPORTED) || \ + defined(PNG_WRITE_INTERLACING_SUPPORTED) +int PNGAPI +png_set_interlace_handling(png_structp png_ptr) +{ + png_debug(1, "in png_set_interlace handling"); + + if (png_ptr && png_ptr->interlaced) + { + png_ptr->transformations |= PNG_INTERLACE; + return (7); + } + + return (1); +} +#endif + +#if defined(PNG_READ_FILLER_SUPPORTED) || defined(PNG_WRITE_FILLER_SUPPORTED) +/* Add a filler byte on read, or remove a filler or alpha byte on write. + * The filler type has changed in v0.95 to allow future 2-byte fillers + * for 48-bit input data, as well as to avoid problems with some compilers + * that don't like bytes as parameters. + */ +void PNGAPI +png_set_filler(png_structp png_ptr, png_uint_32 filler, int filler_loc) +{ + png_debug(1, "in png_set_filler"); + + if (png_ptr == NULL) + return; + + png_ptr->transformations |= PNG_FILLER; + png_ptr->filler = (png_uint_16)filler; + + if (filler_loc == PNG_FILLER_AFTER) + png_ptr->flags |= PNG_FLAG_FILLER_AFTER; + + else + png_ptr->flags &= ~PNG_FLAG_FILLER_AFTER; + + /* This should probably go in the "do_read_filler" routine. + * I attempted to do that in libpng-1.0.1a but that caused problems + * so I restored it in libpng-1.0.2a + */ + + if (png_ptr->color_type == PNG_COLOR_TYPE_RGB) + { + png_ptr->usr_channels = 4; + } + + /* Also I added this in libpng-1.0.2a (what happens when we expand + * a less-than-8-bit grayscale to GA?) */ + + if (png_ptr->color_type == PNG_COLOR_TYPE_GRAY && png_ptr->bit_depth >= 8) + { + png_ptr->usr_channels = 2; + } +} + +/* Added to libpng-1.2.7 */ +void PNGAPI +png_set_add_alpha(png_structp png_ptr, png_uint_32 filler, int filler_loc) +{ + png_debug(1, "in png_set_add_alpha"); + + if (png_ptr == NULL) + return; + + png_set_filler(png_ptr, filler, filler_loc); + png_ptr->transformations |= PNG_ADD_ALPHA; +} + +#endif + +#if defined(PNG_READ_SWAP_ALPHA_SUPPORTED) || \ + defined(PNG_WRITE_SWAP_ALPHA_SUPPORTED) +void PNGAPI +png_set_swap_alpha(png_structp png_ptr) +{ + png_debug(1, "in png_set_swap_alpha"); + + if (png_ptr == NULL) + return; + + png_ptr->transformations |= PNG_SWAP_ALPHA; +} +#endif + +#if defined(PNG_READ_INVERT_ALPHA_SUPPORTED) || \ + defined(PNG_WRITE_INVERT_ALPHA_SUPPORTED) +void PNGAPI +png_set_invert_alpha(png_structp png_ptr) +{ + png_debug(1, "in png_set_invert_alpha"); + + if (png_ptr == NULL) + return; + + png_ptr->transformations |= PNG_INVERT_ALPHA; +} +#endif + +#if defined(PNG_READ_INVERT_SUPPORTED) || defined(PNG_WRITE_INVERT_SUPPORTED) +void PNGAPI +png_set_invert_mono(png_structp png_ptr) +{ + png_debug(1, "in png_set_invert_mono"); + + if (png_ptr == NULL) + return; + + png_ptr->transformations |= PNG_INVERT_MONO; +} + +/* Invert monochrome grayscale data */ +void /* PRIVATE */ +png_do_invert(png_row_infop row_info, png_bytep row) +{ + png_debug(1, "in png_do_invert"); + + /* This test removed from libpng version 1.0.13 and 1.2.0: + * if (row_info->bit_depth == 1 && + */ + if (row_info->color_type == PNG_COLOR_TYPE_GRAY) + { + png_bytep rp = row; + png_size_t i; + png_size_t istop = row_info->rowbytes; + + for (i = 0; i < istop; i++) + { + *rp = (png_byte)(~(*rp)); + rp++; + } + } + + else if (row_info->color_type == PNG_COLOR_TYPE_GRAY_ALPHA && + row_info->bit_depth == 8) + { + png_bytep rp = row; + png_size_t i; + png_size_t istop = row_info->rowbytes; + + for (i = 0; i < istop; i += 2) + { + *rp = (png_byte)(~(*rp)); + rp += 2; + } + } + +#ifdef PNG_16BIT_SUPPORTED + else if (row_info->color_type == PNG_COLOR_TYPE_GRAY_ALPHA && + row_info->bit_depth == 16) + { + png_bytep rp = row; + png_size_t i; + png_size_t istop = row_info->rowbytes; + + for (i = 0; i < istop; i += 4) + { + *rp = (png_byte)(~(*rp)); + *(rp + 1) = (png_byte)(~(*(rp + 1))); + rp += 4; + } + } +#endif +} +#endif + +#ifdef PNG_16BIT_SUPPORTED +#if defined(PNG_READ_SWAP_SUPPORTED) || defined(PNG_WRITE_SWAP_SUPPORTED) +/* Swaps byte order on 16 bit depth images */ +void /* PRIVATE */ +png_do_swap(png_row_infop row_info, png_bytep row) +{ + png_debug(1, "in png_do_swap"); + + if (row_info->bit_depth == 16) + { + png_bytep rp = row; + png_uint_32 i; + png_uint_32 istop= row_info->width * row_info->channels; + + for (i = 0; i < istop; i++, rp += 2) + { + png_byte t = *rp; + *rp = *(rp + 1); + *(rp + 1) = t; + } + } +} +#endif +#endif + +#if defined(PNG_READ_PACKSWAP_SUPPORTED)||defined(PNG_WRITE_PACKSWAP_SUPPORTED) +static PNG_CONST png_byte onebppswaptable[256] = { + 0x00, 0x80, 0x40, 0xC0, 0x20, 0xA0, 0x60, 0xE0, + 0x10, 0x90, 0x50, 0xD0, 0x30, 0xB0, 0x70, 0xF0, + 0x08, 0x88, 0x48, 0xC8, 0x28, 0xA8, 0x68, 0xE8, + 0x18, 0x98, 0x58, 0xD8, 0x38, 0xB8, 0x78, 0xF8, + 0x04, 0x84, 0x44, 0xC4, 0x24, 0xA4, 0x64, 0xE4, + 0x14, 0x94, 0x54, 0xD4, 0x34, 0xB4, 0x74, 0xF4, + 0x0C, 0x8C, 0x4C, 0xCC, 0x2C, 0xAC, 0x6C, 0xEC, + 0x1C, 0x9C, 0x5C, 0xDC, 0x3C, 0xBC, 0x7C, 0xFC, + 0x02, 0x82, 0x42, 0xC2, 0x22, 0xA2, 0x62, 0xE2, + 0x12, 0x92, 0x52, 0xD2, 0x32, 0xB2, 0x72, 0xF2, + 0x0A, 0x8A, 0x4A, 0xCA, 0x2A, 0xAA, 0x6A, 0xEA, + 0x1A, 0x9A, 0x5A, 0xDA, 0x3A, 0xBA, 0x7A, 0xFA, + 0x06, 0x86, 0x46, 0xC6, 0x26, 0xA6, 0x66, 0xE6, + 0x16, 0x96, 0x56, 0xD6, 0x36, 0xB6, 0x76, 0xF6, + 0x0E, 0x8E, 0x4E, 0xCE, 0x2E, 0xAE, 0x6E, 0xEE, + 0x1E, 0x9E, 0x5E, 0xDE, 0x3E, 0xBE, 0x7E, 0xFE, + 0x01, 0x81, 0x41, 0xC1, 0x21, 0xA1, 0x61, 0xE1, + 0x11, 0x91, 0x51, 0xD1, 0x31, 0xB1, 0x71, 0xF1, + 0x09, 0x89, 0x49, 0xC9, 0x29, 0xA9, 0x69, 0xE9, + 0x19, 0x99, 0x59, 0xD9, 0x39, 0xB9, 0x79, 0xF9, + 0x05, 0x85, 0x45, 0xC5, 0x25, 0xA5, 0x65, 0xE5, + 0x15, 0x95, 0x55, 0xD5, 0x35, 0xB5, 0x75, 0xF5, + 0x0D, 0x8D, 0x4D, 0xCD, 0x2D, 0xAD, 0x6D, 0xED, + 0x1D, 0x9D, 0x5D, 0xDD, 0x3D, 0xBD, 0x7D, 0xFD, + 0x03, 0x83, 0x43, 0xC3, 0x23, 0xA3, 0x63, 0xE3, + 0x13, 0x93, 0x53, 0xD3, 0x33, 0xB3, 0x73, 0xF3, + 0x0B, 0x8B, 0x4B, 0xCB, 0x2B, 0xAB, 0x6B, 0xEB, + 0x1B, 0x9B, 0x5B, 0xDB, 0x3B, 0xBB, 0x7B, 0xFB, + 0x07, 0x87, 0x47, 0xC7, 0x27, 0xA7, 0x67, 0xE7, + 0x17, 0x97, 0x57, 0xD7, 0x37, 0xB7, 0x77, 0xF7, + 0x0F, 0x8F, 0x4F, 0xCF, 0x2F, 0xAF, 0x6F, 0xEF, + 0x1F, 0x9F, 0x5F, 0xDF, 0x3F, 0xBF, 0x7F, 0xFF +}; + +static PNG_CONST png_byte twobppswaptable[256] = { + 0x00, 0x40, 0x80, 0xC0, 0x10, 0x50, 0x90, 0xD0, + 0x20, 0x60, 0xA0, 0xE0, 0x30, 0x70, 0xB0, 0xF0, + 0x04, 0x44, 0x84, 0xC4, 0x14, 0x54, 0x94, 0xD4, + 0x24, 0x64, 0xA4, 0xE4, 0x34, 0x74, 0xB4, 0xF4, + 0x08, 0x48, 0x88, 0xC8, 0x18, 0x58, 0x98, 0xD8, + 0x28, 0x68, 0xA8, 0xE8, 0x38, 0x78, 0xB8, 0xF8, + 0x0C, 0x4C, 0x8C, 0xCC, 0x1C, 0x5C, 0x9C, 0xDC, + 0x2C, 0x6C, 0xAC, 0xEC, 0x3C, 0x7C, 0xBC, 0xFC, + 0x01, 0x41, 0x81, 0xC1, 0x11, 0x51, 0x91, 0xD1, + 0x21, 0x61, 0xA1, 0xE1, 0x31, 0x71, 0xB1, 0xF1, + 0x05, 0x45, 0x85, 0xC5, 0x15, 0x55, 0x95, 0xD5, + 0x25, 0x65, 0xA5, 0xE5, 0x35, 0x75, 0xB5, 0xF5, + 0x09, 0x49, 0x89, 0xC9, 0x19, 0x59, 0x99, 0xD9, + 0x29, 0x69, 0xA9, 0xE9, 0x39, 0x79, 0xB9, 0xF9, + 0x0D, 0x4D, 0x8D, 0xCD, 0x1D, 0x5D, 0x9D, 0xDD, + 0x2D, 0x6D, 0xAD, 0xED, 0x3D, 0x7D, 0xBD, 0xFD, + 0x02, 0x42, 0x82, 0xC2, 0x12, 0x52, 0x92, 0xD2, + 0x22, 0x62, 0xA2, 0xE2, 0x32, 0x72, 0xB2, 0xF2, + 0x06, 0x46, 0x86, 0xC6, 0x16, 0x56, 0x96, 0xD6, + 0x26, 0x66, 0xA6, 0xE6, 0x36, 0x76, 0xB6, 0xF6, + 0x0A, 0x4A, 0x8A, 0xCA, 0x1A, 0x5A, 0x9A, 0xDA, + 0x2A, 0x6A, 0xAA, 0xEA, 0x3A, 0x7A, 0xBA, 0xFA, + 0x0E, 0x4E, 0x8E, 0xCE, 0x1E, 0x5E, 0x9E, 0xDE, + 0x2E, 0x6E, 0xAE, 0xEE, 0x3E, 0x7E, 0xBE, 0xFE, + 0x03, 0x43, 0x83, 0xC3, 0x13, 0x53, 0x93, 0xD3, + 0x23, 0x63, 0xA3, 0xE3, 0x33, 0x73, 0xB3, 0xF3, + 0x07, 0x47, 0x87, 0xC7, 0x17, 0x57, 0x97, 0xD7, + 0x27, 0x67, 0xA7, 0xE7, 0x37, 0x77, 0xB7, 0xF7, + 0x0B, 0x4B, 0x8B, 0xCB, 0x1B, 0x5B, 0x9B, 0xDB, + 0x2B, 0x6B, 0xAB, 0xEB, 0x3B, 0x7B, 0xBB, 0xFB, + 0x0F, 0x4F, 0x8F, 0xCF, 0x1F, 0x5F, 0x9F, 0xDF, + 0x2F, 0x6F, 0xAF, 0xEF, 0x3F, 0x7F, 0xBF, 0xFF +}; + +static PNG_CONST png_byte fourbppswaptable[256] = { + 0x00, 0x10, 0x20, 0x30, 0x40, 0x50, 0x60, 0x70, + 0x80, 0x90, 0xA0, 0xB0, 0xC0, 0xD0, 0xE0, 0xF0, + 0x01, 0x11, 0x21, 0x31, 0x41, 0x51, 0x61, 0x71, + 0x81, 0x91, 0xA1, 0xB1, 0xC1, 0xD1, 0xE1, 0xF1, + 0x02, 0x12, 0x22, 0x32, 0x42, 0x52, 0x62, 0x72, + 0x82, 0x92, 0xA2, 0xB2, 0xC2, 0xD2, 0xE2, 0xF2, + 0x03, 0x13, 0x23, 0x33, 0x43, 0x53, 0x63, 0x73, + 0x83, 0x93, 0xA3, 0xB3, 0xC3, 0xD3, 0xE3, 0xF3, + 0x04, 0x14, 0x24, 0x34, 0x44, 0x54, 0x64, 0x74, + 0x84, 0x94, 0xA4, 0xB4, 0xC4, 0xD4, 0xE4, 0xF4, + 0x05, 0x15, 0x25, 0x35, 0x45, 0x55, 0x65, 0x75, + 0x85, 0x95, 0xA5, 0xB5, 0xC5, 0xD5, 0xE5, 0xF5, + 0x06, 0x16, 0x26, 0x36, 0x46, 0x56, 0x66, 0x76, + 0x86, 0x96, 0xA6, 0xB6, 0xC6, 0xD6, 0xE6, 0xF6, + 0x07, 0x17, 0x27, 0x37, 0x47, 0x57, 0x67, 0x77, + 0x87, 0x97, 0xA7, 0xB7, 0xC7, 0xD7, 0xE7, 0xF7, + 0x08, 0x18, 0x28, 0x38, 0x48, 0x58, 0x68, 0x78, + 0x88, 0x98, 0xA8, 0xB8, 0xC8, 0xD8, 0xE8, 0xF8, + 0x09, 0x19, 0x29, 0x39, 0x49, 0x59, 0x69, 0x79, + 0x89, 0x99, 0xA9, 0xB9, 0xC9, 0xD9, 0xE9, 0xF9, + 0x0A, 0x1A, 0x2A, 0x3A, 0x4A, 0x5A, 0x6A, 0x7A, + 0x8A, 0x9A, 0xAA, 0xBA, 0xCA, 0xDA, 0xEA, 0xFA, + 0x0B, 0x1B, 0x2B, 0x3B, 0x4B, 0x5B, 0x6B, 0x7B, + 0x8B, 0x9B, 0xAB, 0xBB, 0xCB, 0xDB, 0xEB, 0xFB, + 0x0C, 0x1C, 0x2C, 0x3C, 0x4C, 0x5C, 0x6C, 0x7C, + 0x8C, 0x9C, 0xAC, 0xBC, 0xCC, 0xDC, 0xEC, 0xFC, + 0x0D, 0x1D, 0x2D, 0x3D, 0x4D, 0x5D, 0x6D, 0x7D, + 0x8D, 0x9D, 0xAD, 0xBD, 0xCD, 0xDD, 0xED, 0xFD, + 0x0E, 0x1E, 0x2E, 0x3E, 0x4E, 0x5E, 0x6E, 0x7E, + 0x8E, 0x9E, 0xAE, 0xBE, 0xCE, 0xDE, 0xEE, 0xFE, + 0x0F, 0x1F, 0x2F, 0x3F, 0x4F, 0x5F, 0x6F, 0x7F, + 0x8F, 0x9F, 0xAF, 0xBF, 0xCF, 0xDF, 0xEF, 0xFF +}; + +/* Swaps pixel packing order within bytes */ +void /* PRIVATE */ +png_do_packswap(png_row_infop row_info, png_bytep row) +{ + png_debug(1, "in png_do_packswap"); + + if (row_info->bit_depth < 8) + { + png_bytep rp; + png_const_bytep end, table; + + end = row + row_info->rowbytes; + + if (row_info->bit_depth == 1) + table = onebppswaptable; + + else if (row_info->bit_depth == 2) + table = twobppswaptable; + + else if (row_info->bit_depth == 4) + table = fourbppswaptable; + + else + return; + + for (rp = row; rp < end; rp++) + *rp = table[*rp]; + } +} +#endif /* PNG_READ_PACKSWAP_SUPPORTED or PNG_WRITE_PACKSWAP_SUPPORTED */ + +#if defined(PNG_WRITE_FILLER_SUPPORTED) || \ + defined(PNG_READ_STRIP_ALPHA_SUPPORTED) +/* Remove filler or alpha byte(s) */ +void /* PRIVATE */ +png_do_strip_filler(png_row_infop row_info, png_bytep row, png_uint_32 flags) +{ + png_debug(1, "in png_do_strip_filler"); + + { + png_bytep sp = row; + png_bytep dp = row; + png_uint_32 row_width = row_info->width; + png_uint_32 i; + + if ((row_info->color_type == PNG_COLOR_TYPE_RGB || + (row_info->color_type == PNG_COLOR_TYPE_RGB_ALPHA && + (flags & PNG_FLAG_STRIP_ALPHA))) && + row_info->channels == 4) + { + if (row_info->bit_depth == 8) + { + /* This converts from RGBX or RGBA to RGB */ + if (flags & PNG_FLAG_FILLER_AFTER) + { + dp += 3; sp += 4; + for (i = 1; i < row_width; i++) + { + *dp++ = *sp++; + *dp++ = *sp++; + *dp++ = *sp++; + sp++; + } + } + + /* This converts from XRGB or ARGB to RGB */ + else + { + for (i = 0; i < row_width; i++) + { + sp++; + *dp++ = *sp++; + *dp++ = *sp++; + *dp++ = *sp++; + } + } + row_info->pixel_depth = 24; + row_info->rowbytes = row_width * 3; + } + + else /* if (row_info->bit_depth == 16) */ + { + if (flags & PNG_FLAG_FILLER_AFTER) + { + /* This converts from RRGGBBXX or RRGGBBAA to RRGGBB */ + sp += 8; dp += 6; + for (i = 1; i < row_width; i++) + { + /* This could be (although png_memcpy is probably slower): + png_memcpy(dp, sp, 6); + sp += 8; + dp += 6; + */ + + *dp++ = *sp++; + *dp++ = *sp++; + *dp++ = *sp++; + *dp++ = *sp++; + *dp++ = *sp++; + *dp++ = *sp++; + sp += 2; + } + } + + else + { + /* This converts from XXRRGGBB or AARRGGBB to RRGGBB */ + for (i = 0; i < row_width; i++) + { + /* This could be (although png_memcpy is probably slower): + png_memcpy(dp, sp, 6); + sp += 8; + dp += 6; + */ + + sp += 2; + *dp++ = *sp++; + *dp++ = *sp++; + *dp++ = *sp++; + *dp++ = *sp++; + *dp++ = *sp++; + *dp++ = *sp++; + } + } + + row_info->pixel_depth = 48; + row_info->rowbytes = row_width * 6; + } + row_info->channels = 3; + } + + else if ((row_info->color_type == PNG_COLOR_TYPE_GRAY || + (row_info->color_type == PNG_COLOR_TYPE_GRAY_ALPHA && + (flags & PNG_FLAG_STRIP_ALPHA))) && + row_info->channels == 2) + { + if (row_info->bit_depth == 8) + { + if (flags & PNG_FLAG_FILLER_AFTER) + { + /* This converts from GX or GA to G */ + for (i = 0; i < row_width; i++) + { + *dp++ = *sp++; + sp++; + } + } + + else + { + /* This converts from XG or AG to G */ + for (i = 0; i < row_width; i++) + { + sp++; + *dp++ = *sp++; + } + } + + row_info->pixel_depth = 8; + row_info->rowbytes = row_width; + } + + else /* if (row_info->bit_depth == 16) */ + { + if (flags & PNG_FLAG_FILLER_AFTER) + { + /* This converts from GGXX or GGAA to GG */ + sp += 4; dp += 2; + for (i = 1; i < row_width; i++) + { + *dp++ = *sp++; + *dp++ = *sp++; + sp += 2; + } + } + + else + { + /* This converts from XXGG or AAGG to GG */ + for (i = 0; i < row_width; i++) + { + sp += 2; + *dp++ = *sp++; + *dp++ = *sp++; + } + } + + row_info->pixel_depth = 16; + row_info->rowbytes = row_width * 2; + } + row_info->channels = 1; + } + + if (flags & PNG_FLAG_STRIP_ALPHA) + row_info->color_type = (png_byte)(row_info->color_type & + ~PNG_COLOR_MASK_ALPHA); + } +} +#endif + +#if defined(PNG_READ_BGR_SUPPORTED) || defined(PNG_WRITE_BGR_SUPPORTED) +/* Swaps red and blue bytes within a pixel */ +void /* PRIVATE */ +png_do_bgr(png_row_infop row_info, png_bytep row) +{ + png_debug(1, "in png_do_bgr"); + + if ((row_info->color_type & PNG_COLOR_MASK_COLOR)) + { + png_uint_32 row_width = row_info->width; + if (row_info->bit_depth == 8) + { + if (row_info->color_type == PNG_COLOR_TYPE_RGB) + { + png_bytep rp; + png_uint_32 i; + + for (i = 0, rp = row; i < row_width; i++, rp += 3) + { + png_byte save = *rp; + *rp = *(rp + 2); + *(rp + 2) = save; + } + } + + else if (row_info->color_type == PNG_COLOR_TYPE_RGB_ALPHA) + { + png_bytep rp; + png_uint_32 i; + + for (i = 0, rp = row; i < row_width; i++, rp += 4) + { + png_byte save = *rp; + *rp = *(rp + 2); + *(rp + 2) = save; + } + } + } + +#ifdef PNG_16BIT_SUPPORTED + else if (row_info->bit_depth == 16) + { + if (row_info->color_type == PNG_COLOR_TYPE_RGB) + { + png_bytep rp; + png_uint_32 i; + + for (i = 0, rp = row; i < row_width; i++, rp += 6) + { + png_byte save = *rp; + *rp = *(rp + 4); + *(rp + 4) = save; + save = *(rp + 1); + *(rp + 1) = *(rp + 5); + *(rp + 5) = save; + } + } + + else if (row_info->color_type == PNG_COLOR_TYPE_RGB_ALPHA) + { + png_bytep rp; + png_uint_32 i; + + for (i = 0, rp = row; i < row_width; i++, rp += 8) + { + png_byte save = *rp; + *rp = *(rp + 4); + *(rp + 4) = save; + save = *(rp + 1); + *(rp + 1) = *(rp + 5); + *(rp + 5) = save; + } + } + } +#endif + } +} +#endif /* PNG_READ_BGR_SUPPORTED or PNG_WRITE_BGR_SUPPORTED */ + +#if defined(PNG_READ_USER_TRANSFORM_SUPPORTED) || \ + defined(PNG_WRITE_USER_TRANSFORM_SUPPORTED) +#ifdef PNG_USER_TRANSFORM_PTR_SUPPORTED +void PNGAPI +png_set_user_transform_info(png_structp png_ptr, png_voidp + user_transform_ptr, int user_transform_depth, int user_transform_channels) +{ + png_debug(1, "in png_set_user_transform_info"); + + if (png_ptr == NULL) + return; + png_ptr->user_transform_ptr = user_transform_ptr; + png_ptr->user_transform_depth = (png_byte)user_transform_depth; + png_ptr->user_transform_channels = (png_byte)user_transform_channels; +} +#endif + +/* This function returns a pointer to the user_transform_ptr associated with + * the user transform functions. The application should free any memory + * associated with this pointer before png_write_destroy and png_read_destroy + * are called. + */ +#ifdef PNG_USER_TRANSFORM_PTR_SUPPORTED +png_voidp PNGAPI +png_get_user_transform_ptr(png_const_structp png_ptr) +{ + if (png_ptr == NULL) + return (NULL); + + return ((png_voidp)png_ptr->user_transform_ptr); +} +#endif + +png_uint_32 PNGAPI +png_get_current_row_number(png_const_structp png_ptr) +{ + if (png_ptr != NULL) + return png_ptr->row_number; + return PNG_UINT_32_MAX; /* help the app not to fail silently */ +} + +png_byte PNGAPI +png_get_current_pass_number(png_const_structp png_ptr) +{ + if (png_ptr != NULL) + return png_ptr->pass; + return 8; /* invalid */ +} +#endif /* PNG_READ_USER_TRANSFORM_SUPPORTED || + PNG_WRITE_USER_TRANSFORM_SUPPORTED */ +#endif /* PNG_READ_SUPPORTED || PNG_WRITE_SUPPORTED */ diff --git a/src/3rdparty/libpng/pngvalid.c b/src/3rdparty/libpng/pngvalid.c new file mode 100644 index 0000000000..faebe4b8b7 --- /dev/null +++ b/src/3rdparty/libpng/pngvalid.c @@ -0,0 +1,6658 @@ + +/* pngvalid.c - validate libpng by constructing then reading png files. + * + * Last changed in libpng 1.5.1 [February 3, 2011] + * Copyright (c) 2011 Glenn Randers-Pehrson + * Written by John Cunningham Bowler + * + * This code is released under the libpng license. + * For conditions of distribution and use, see the disclaimer + * and license in png.h + * + * NOTES: + * This is a C program that is intended to be linked against libpng. It + * generates bitmaps internally, stores them as PNG files (using the + * sequential write code) then reads them back (using the sequential + * read code) and validates that the result has the correct data. + * + * The program can be modified and extended to test the correctness of + * transformations performed by libpng. + */ + +#include "png.h" +#if PNG_LIBPNG_VER < 10500 +/* This delibarately lacks the PNG_CONST. */ +typedef png_byte *png_const_bytep; + +/* This is copied from 1.5.1 png.h: */ +#define PNG_INTERLACE_ADAM7_PASSES 7 +#define PNG_PASS_START_ROW(pass) (((1U&~(pass))<<(3-((pass)>>1)))&7) +#define PNG_PASS_START_COL(pass) (((1U& (pass))<<(3-(((pass)+1)>>1)))&7) +#define PNG_PASS_ROW_SHIFT(pass) ((pass)>2?(8-(pass))>>1:3) +#define PNG_PASS_COL_SHIFT(pass) ((pass)>1?(7-(pass))>>1:3) +#define PNG_PASS_ROWS(height, pass) (((height)+(((1<<PNG_PASS_ROW_SHIFT(pass))\ + -1)-PNG_PASS_START_ROW(pass)))>>PNG_PASS_ROW_SHIFT(pass)) +#define PNG_PASS_COLS(width, pass) (((width)+(((1<<PNG_PASS_COL_SHIFT(pass))\ + -1)-PNG_PASS_START_COL(pass)))>>PNG_PASS_COL_SHIFT(pass)) +#define PNG_ROW_FROM_PASS_ROW(yIn, pass) \ + (((yIn)<<PNG_PASS_ROW_SHIFT(pass))+PNG_PASS_START_ROW(pass)) +#define PNG_COL_FROM_PASS_COL(xIn, pass) \ + (((xIn)<<PNG_PASS_COL_SHIFT(pass))+PNG_PASS_START_COL(pass)) +#define PNG_PASS_MASK(pass,off) ( \ + ((0x110145AFU>>(((7-(off))-(pass))<<2)) & 0xFU) | \ + ((0x01145AF0U>>(((7-(off))-(pass))<<2)) & 0xF0U)) +#define PNG_ROW_IN_INTERLACE_PASS(y, pass) \ + ((PNG_PASS_MASK(pass,0) >> ((y)&7)) & 1) +#define PNG_COL_IN_INTERLACE_PASS(x, pass) \ + ((PNG_PASS_MASK(pass,1) >> ((x)&7)) & 1) + +/* These are needed too for the defualt build: */ +#define PNG_WRITE_16BIT_SUPPORTED +#define PNG_READ_16BIT_SUPPORTED +#endif + +#include "zlib.h" /* For crc32 */ + +#include <float.h> /* For floating point constants */ +#include <stdlib.h> /* For malloc */ +#include <string.h> /* For memcpy, memset */ +#include <math.h> /* For floor */ + +/* Unused formal parameter errors are removed using the following macro which is + * expected to have no bad effects on performance. + */ +#ifndef UNUSED +# if defined(__GNUC__) || defined(_MSC_VER) +# define UNUSED(param) (void)param; +# else +# define UNUSED(param) +# endif +#endif + +/***************************** EXCEPTION HANDLING *****************************/ +#include "contrib/visupng/cexcept.h" +struct png_store; +define_exception_type(struct png_store*); + +/* The following are macros to reduce typing everywhere where the well known + * name 'the_exception_context' must be defined. + */ +#define anon_context(ps) struct exception_context *the_exception_context = \ + &(ps)->exception_context +#define context(ps,fault) anon_context(ps); png_store *fault + +/******************************* UTILITIES ************************************/ +/* Error handling is particularly problematic in production code - error + * handlers often themselves have bugs which lead to programs that detect + * minor errors crashing. The following functions deal with one very + * common class of errors in error handlers - attempting to format error or + * warning messages into buffers that are too small. + */ +static size_t safecat(char *buffer, size_t bufsize, size_t pos, + PNG_CONST char *cat) +{ + while (pos < bufsize && cat != NULL && *cat != 0) + buffer[pos++] = *cat++; + + if (pos >= bufsize) + pos = bufsize-1; + + buffer[pos] = 0; + return pos; +} + +static size_t safecatn(char *buffer, size_t bufsize, size_t pos, int n) +{ + char number[64]; + sprintf(number, "%d", n); + return safecat(buffer, bufsize, pos, number); +} + +static size_t safecatd(char *buffer, size_t bufsize, size_t pos, double d, + int precision) +{ + char number[64]; + sprintf(number, "%.*f", precision, d); + return safecat(buffer, bufsize, pos, number); +} + +static PNG_CONST char invalid[] = "invalid"; +static PNG_CONST char sep[] = ": "; + +/* NOTE: this is indexed by ln2(bit_depth)! */ +static PNG_CONST char *bit_depths[8] = +{ + "1", "2", "4", "8", "16", invalid, invalid, invalid +}; + +static PNG_CONST char *colour_types[8] = +{ + "greyscale", invalid, "truecolour", "indexed-colour", + "greyscale with alpha", invalid, "truecolour with alpha", invalid +}; + +/* To get log-bit-depth from bit depth, returns 0 to 7 (7 on error). */ +static unsigned int +log2depth(png_byte bit_depth) +{ + switch (bit_depth) + { + case 1: + return 0; + + case 2: + return 1; + + case 4: + return 2; + + case 8: + return 3; + + case 16: + return 4; + + default: + return 7; + } +} + +/* A numeric ID based on PNG file characteristics. The 'do_interlace' field + * simply records whether pngvalid did the interlace itself or whether it + * was done by libpng. Width and height must be less than 256. + */ +#define FILEID(col, depth, interlace, width, height, do_interlace) \ + ((png_uint_32)((col) + ((depth)<<3) + ((interlace)<<8) + \ + (((do_interlace)!=0)<<15) + ((width)<<16) + ((height)<<24))) + +#define COL_FROM_ID(id) ((png_byte)((id)& 0x7U)) +#define DEPTH_FROM_ID(id) ((png_byte)(((id) >> 3) & 0x1fU)) +#define INTERLACE_FROM_ID(id) ((int)(((id) >> 8) & 0x3)) +#define DO_INTERLACE_FROM_ID(id) ((int)(((id)>>15) & 1)) +#define WIDTH_FROM_ID(id) (((id)>>16) & 0xff) +#define HEIGHT_FROM_ID(id) (((id)>>24) & 0xff) + +/* Utility to construct a standard name for a standard image. */ +static size_t +standard_name(char *buffer, size_t bufsize, size_t pos, png_byte colour_type, + int log_bit_depth, int interlace_type, png_uint_32 w, png_uint_32 h, + int do_interlace) +{ + pos = safecat(buffer, bufsize, pos, colour_types[colour_type]); + pos = safecat(buffer, bufsize, pos, " "); + pos = safecat(buffer, bufsize, pos, bit_depths[log_bit_depth]); + pos = safecat(buffer, bufsize, pos, " bit "); + + if (interlace_type != PNG_INTERLACE_NONE) + pos = safecat(buffer, bufsize, pos, "interlaced"); + if (do_interlace) + pos = safecat(buffer, bufsize, pos, "(pngvalid)"); + else + pos = safecat(buffer, bufsize, pos, "(libpng)"); + if (w > 0 || h > 0) + { + pos = safecat(buffer, bufsize, pos, " "); + pos = safecatn(buffer, bufsize, pos, w); + pos = safecat(buffer, bufsize, pos, "x"); + pos = safecatn(buffer, bufsize, pos, h); + } + + return pos; +} + +static size_t +standard_name_from_id(char *buffer, size_t bufsize, size_t pos, png_uint_32 id) +{ + return standard_name(buffer, bufsize, pos, COL_FROM_ID(id), + log2depth(DEPTH_FROM_ID(id)), INTERLACE_FROM_ID(id), + WIDTH_FROM_ID(id), HEIGHT_FROM_ID(id), DO_INTERLACE_FROM_ID(id)); +} + +/* Convenience API and defines to list valid formats. Note that 16 bit read and + * write support is required to do 16 bit read tests (we must be able to make a + * 16 bit image to test!) + */ +#ifdef PNG_WRITE_16BIT_SUPPORTED +# define WRITE_BDHI 4 +# ifdef PNG_READ_16BIT_SUPPORTED +# define READ_BDHI 4 +# define DO_16BIT +# endif +#else +# define WRITE_BDHI 3 +#endif +#ifndef DO_16BIT +# define READ_BDHI 3 +#endif + +static int +next_format(png_bytep colour_type, png_bytep bit_depth) +{ + if (*bit_depth == 0) + { + *colour_type = 0, *bit_depth = 1; + return 1; + } + + *bit_depth = (png_byte)(*bit_depth << 1); + + /* Palette images are restricted to 8 bit depth */ + if (*bit_depth <= 8 +# ifdef DO_16BIT + || (*colour_type != 3 && *bit_depth <= 16) +# endif + ) + return 1; + + /* Move to the next color type, or return 0 at the end. */ + switch (*colour_type) + { + case 0: + *colour_type = 2; + *bit_depth = 8; + return 1; + + case 2: + *colour_type = 3; + *bit_depth = 1; + return 1; + + case 3: + *colour_type = 4; + *bit_depth = 8; + return 1; + + case 4: + *colour_type = 6; + *bit_depth = 8; + return 1; + + default: + return 0; + } +} + +static unsigned int +sample(png_const_bytep row, png_byte colour_type, png_byte bit_depth, + png_uint_32 x, unsigned int sample_index) +{ + png_uint_32 bit_index, result; + + /* Find a sample index for the desired sample: */ + x *= bit_depth; + bit_index = x; + + if ((colour_type & 1) == 0) /* !palette */ + { + if (colour_type & 2) + bit_index *= 3; + + if (colour_type & 4) + bit_index += x; /* Alpha channel */ + + if (colour_type & (2+4)) + bit_index += sample_index * bit_depth; /* Multiple channels: select one */ + } + + /* Return the sample from the row as an integer. */ + row += bit_index >> 3; + result = *row; + + if (bit_depth == 8) + return result; + + else if (bit_depth > 8) + return (result << 8) + *++row; + + /* Less than 8 bits per sample. */ + bit_index &= 7; + return (result >> (8-bit_index-bit_depth)) & ((1U<<bit_depth)-1); +} + +/* Copy a single pixel, of a given size, from one buffer to another - + * while this is basically bit addressed there is an implicit assumption + * that pixels 8 or more bits in size are byte aligned and that pixels + * do not otherwise cross byte boundaries. (This is, so far as I know, + * universally true in bitmap computer graphics. [JCB 20101212]) + * + * NOTE: The to and from buffers may be the same. + */ +static void +pixel_copy(png_bytep toBuffer, png_uint_32 toIndex, + png_const_bytep fromBuffer, png_uint_32 fromIndex, unsigned int pixelSize) +{ + /* Assume we can multiply by 'size' without overflow because we are + * just working in a single buffer. + */ + toIndex *= pixelSize; + fromIndex *= pixelSize; + if (pixelSize < 8) /* Sub-byte */ + { + /* Mask to select the location of the copied pixel: */ + unsigned int destMask = ((1U<<pixelSize)-1) << (8-pixelSize-(toIndex&7)); + /* The following read the entire pixels and clears the extra: */ + unsigned int destByte = toBuffer[toIndex >> 3] & ~destMask; + unsigned int sourceByte = fromBuffer[fromIndex >> 3]; + + /* Don't rely on << or >> supporting '0' here, just in case: */ + fromIndex &= 7; + if (fromIndex > 0) sourceByte <<= fromIndex; + if ((toIndex & 7) > 0) sourceByte >>= toIndex & 7; + + toBuffer[toIndex >> 3] = (png_byte)(destByte | (sourceByte & destMask)); + } + else /* One or more bytes */ + memmove(toBuffer+(toIndex>>3), fromBuffer+(fromIndex>>3), pixelSize>>3); +} + +/* Compare pixels - they are assumed to start at the first byte in the + * given buffers. + */ +static int +pixel_cmp(png_const_bytep pa, png_const_bytep pb, png_uint_32 bit_width) +{ + if (memcmp(pa, pb, bit_width>>3) == 0) + { + png_uint_32 p; + + if ((bit_width & 7) == 0) return 0; + + /* Ok, any differences? */ + p = pa[bit_width >> 3]; + p ^= pb[bit_width >> 3]; + + if (p == 0) return 0; + + /* There are, but they may not be significant, remove the bits + * after the end (the low order bits in PNG.) + */ + bit_width &= 7; + p >>= 8-bit_width; + + if (p == 0) return 0; + } + + return 1; /* Different */ +} + +/*************************** BASIC PNG FILE WRITING ***************************/ +/* A png_store takes data from the sequential writer or provides data + * to the sequential reader. It can also store the result of a PNG + * write for later retrieval. + */ +#define STORE_BUFFER_SIZE 500 /* arbitrary */ +typedef struct png_store_buffer +{ + struct png_store_buffer* prev; /* NOTE: stored in reverse order */ + png_byte buffer[STORE_BUFFER_SIZE]; +} png_store_buffer; + +#define FILE_NAME_SIZE 64 + +typedef struct png_store_file +{ + struct png_store_file* next; /* as many as you like... */ + char name[FILE_NAME_SIZE]; + png_uint_32 id; /* must be correct (see FILEID) */ + png_size_t datacount; /* In this (the last) buffer */ + png_store_buffer data; /* Last buffer in file */ +} png_store_file; + +/* The following is a pool of memory allocated by a single libpng read or write + * operation. + */ +typedef struct store_pool +{ + struct png_store *store; /* Back pointer */ + struct store_memory *list; /* List of allocated memory */ + png_byte mark[4]; /* Before and after data */ + + /* Statistics for this run. */ + png_alloc_size_t max; /* Maximum single allocation */ + png_alloc_size_t current; /* Current allocation */ + png_alloc_size_t limit; /* Highest current allocation */ + png_alloc_size_t total; /* Total allocation */ + + /* Overall statistics (retained across successive runs). */ + png_alloc_size_t max_max; + png_alloc_size_t max_limit; + png_alloc_size_t max_total; +} store_pool; + +typedef struct png_store +{ + /* For cexcept.h exception handling - simply store one of these; + * the context is a self pointer but it may point to a different + * png_store (in fact it never does in this program.) + */ + struct exception_context + exception_context; + + unsigned int verbose :1; + unsigned int treat_warnings_as_errors :1; + unsigned int expect_error :1; + unsigned int expect_warning :1; + unsigned int saw_warning :1; + unsigned int speed :1; + unsigned int progressive :1; /* use progressive read */ + unsigned int validated :1; /* used as a temporary flag */ + int nerrors; + int nwarnings; + char test[128]; /* Name of test */ + char error[256]; + + /* Read fields */ + png_structp pread; /* Used to read a saved file */ + png_infop piread; + png_store_file* current; /* Set when reading */ + png_store_buffer* next; /* Set when reading */ + png_size_t readpos; /* Position in *next */ + png_byte* image; /* Buffer for reading interlaced images */ + size_t cb_image; /* Size of this buffer */ + store_pool read_memory_pool; + + /* Write fields */ + png_store_file* saved; + png_structp pwrite; /* Used when writing a new file */ + png_infop piwrite; + png_size_t writepos; /* Position in .new */ + char wname[FILE_NAME_SIZE]; + png_store_buffer new; /* The end of the new PNG file being written. */ + store_pool write_memory_pool; +} png_store; + +/* Initialization and cleanup */ +static void +store_pool_mark(png_byte *mark) +{ + /* Generate a new mark. This uses a boring repeatable algorithm and it is + * implemented here so that it gives the same set of numbers on every + * architecture. It's a linear congruential generator (Knuth or Sedgewick + * "Algorithms") but it comes from the 'feedback taps' table in Horowitz and + * Hill, "The Art of Electronics". + */ + static png_uint_32 u0 = 0x12345678, u1 = 1; + + /* There are thirty three bits, the next bit in the sequence is bit-33 XOR + * bit-20. The top 1 bit is in u1, the bottom 32 are in u0. + */ + int i; + for (i=0; i<4; ++i) + { + /* First generate 8 new bits then shift them in at the end. */ + png_uint_32 u = ((u0 >> (20-8)) ^ ((u1 << 7) | (u0 >> (32-7)))) & 0xff; + u1 <<= 8; + u1 |= u0 >> 24; + u0 <<= 8; + u0 |= u; + *mark++ = (png_byte)u; + } +} + +/* Use this for random 32 bit values, this function makes sure the result is + * non-zero. + */ +static png_uint_32 +random_32(void) +{ + + for(;;) + { + png_byte mark[4]; + png_uint_32 result; + + store_pool_mark(mark); + result = png_get_uint_32(mark); + + if (result != 0) + return result; + } +} + +static void +store_pool_init(png_store *ps, store_pool *pool) +{ + memset(pool, 0, sizeof *pool); + + pool->store = ps; + pool->list = NULL; + pool->max = pool->current = pool->limit = pool->total = 0; + pool->max_max = pool->max_limit = pool->max_total = 0; + store_pool_mark(pool->mark); +} + +static void +store_init(png_store* ps) +{ + memset(ps, 0, sizeof *ps); + init_exception_context(&ps->exception_context); + store_pool_init(ps, &ps->read_memory_pool); + store_pool_init(ps, &ps->write_memory_pool); + ps->verbose = 0; + ps->treat_warnings_as_errors = 0; + ps->expect_error = 0; + ps->expect_warning = 0; + ps->saw_warning = 0; + ps->speed = 0; + ps->progressive = 0; + ps->validated = 0; + ps->nerrors = ps->nwarnings = 0; + ps->pread = NULL; + ps->piread = NULL; + ps->saved = ps->current = NULL; + ps->next = NULL; + ps->readpos = 0; + ps->image = NULL; + ps->cb_image = 0; + ps->pwrite = NULL; + ps->piwrite = NULL; + ps->writepos = 0; + ps->new.prev = NULL; +} + +/* This somewhat odd function is used when reading an image to ensure that the + * buffer is big enough - this is why a png_structp is available. + */ +static void +store_ensure_image(png_store *ps, png_structp pp, size_t cb) +{ + if (ps->cb_image < cb) + { + if (ps->image != NULL) + { + free(ps->image-1); + ps->cb_image = 0; + } + + /* The buffer is deliberately mis-aligned. */ + ps->image = malloc(cb+1); + if (ps->image == NULL) + png_error(pp, "OOM allocating image buffer"); + + ++(ps->image); + ps->cb_image = cb; + } + + /* And, for error checking, the whole buffer is set to '1' - this + * matches what happens with the 'size' test images on write and also + * matches the unused bits in the test rows. + */ + memset(ps->image, 0xff, cb); +} + +static void +store_freebuffer(png_store_buffer* psb) +{ + if (psb->prev) + { + store_freebuffer(psb->prev); + free(psb->prev); + psb->prev = NULL; + } +} + +static void +store_freenew(png_store *ps) +{ + store_freebuffer(&ps->new); + ps->writepos = 0; +} + +static void +store_storenew(png_store *ps) +{ + png_store_buffer *pb; + + if (ps->writepos != STORE_BUFFER_SIZE) + png_error(ps->pwrite, "invalid store call"); + + pb = malloc(sizeof *pb); + + if (pb == NULL) + png_error(ps->pwrite, "store new: OOM"); + + *pb = ps->new; + ps->new.prev = pb; + ps->writepos = 0; +} + +static void +store_freefile(png_store_file **ppf) +{ + if (*ppf != NULL) + { + store_freefile(&(*ppf)->next); + + store_freebuffer(&(*ppf)->data); + (*ppf)->datacount = 0; + free(*ppf); + *ppf = NULL; + } +} + +/* Main interface to file storeage, after writing a new PNG file (see the API + * below) call store_storefile to store the result with the given name and id. + */ +static void +store_storefile(png_store *ps, png_uint_32 id) +{ + png_store_file *pf = malloc(sizeof *pf); + if (pf == NULL) + png_error(ps->pwrite, "storefile: OOM"); + safecat(pf->name, sizeof pf->name, 0, ps->wname); + pf->id = id; + pf->data = ps->new; + pf->datacount = ps->writepos; + ps->new.prev = NULL; + ps->writepos = 0; + + /* And save it. */ + pf->next = ps->saved; + ps->saved = pf; +} + +/* Generate an error message (in the given buffer) */ +static size_t +store_message(png_store *ps, png_structp pp, char *buffer, size_t bufsize, + size_t pos, PNG_CONST char *msg) +{ + if (pp != NULL && pp == ps->pread) + { + /* Reading a file */ + pos = safecat(buffer, bufsize, pos, "read: "); + + if (ps->current != NULL) + { + pos = safecat(buffer, bufsize, pos, ps->current->name); + pos = safecat(buffer, bufsize, pos, sep); + } + } + + else if (pp != NULL && pp == ps->pwrite) + { + /* Writing a file */ + pos = safecat(buffer, bufsize, pos, "write: "); + pos = safecat(buffer, bufsize, pos, ps->wname); + pos = safecat(buffer, bufsize, pos, sep); + } + + else + { + /* Neither reading nor writing (or a memory error in struct delete) */ + pos = safecat(buffer, bufsize, pos, "pngvalid: "); + } + + if (ps->test[0] != 0) + { + pos = safecat(buffer, bufsize, pos, ps->test); + pos = safecat(buffer, bufsize, pos, sep); + } + pos = safecat(buffer, bufsize, pos, msg); + return pos; +} + +/* Log an error or warning - the relevant count is always incremented. */ +static void +store_log(png_store* ps, png_structp pp, png_const_charp message, int is_error) +{ + /* The warning is copied to the error buffer if there are no errors and it is + * the first warning. The error is copied to the error buffer if it is the + * first error (overwriting any prior warnings). + */ + if (is_error ? (ps->nerrors)++ == 0 : + (ps->nwarnings)++ == 0 && ps->nerrors == 0) + store_message(ps, pp, ps->error, sizeof ps->error, 0, message); + + if (ps->verbose) + { + char buffer[256]; + size_t pos; + + if (is_error) + pos = safecat(buffer, sizeof buffer, 0, "error: "); + else + pos = safecat(buffer, sizeof buffer, 0, "warning: "); + + store_message(ps, pp, buffer, sizeof buffer, pos, message); + fputs(buffer, stderr); + fputc('\n', stderr); + } +} + +/* Functions to use as PNG callbacks. */ +static void +store_error(png_structp pp, png_const_charp message) /* PNG_NORETURN */ +{ + png_store *ps = png_get_error_ptr(pp); + + if (!ps->expect_error) + store_log(ps, pp, message, 1 /* error */); + + /* And finally throw an exception. */ + { + struct exception_context *the_exception_context = &ps->exception_context; + Throw ps; + } +} + +static void +store_warning(png_structp pp, png_const_charp message) +{ + png_store *ps = png_get_error_ptr(pp); + + if (!ps->expect_warning) + store_log(ps, pp, message, 0 /* warning */); + else + ps->saw_warning = 1; +} + +static void +store_write(png_structp pp, png_bytep pb, png_size_t st) +{ + png_store *ps = png_get_io_ptr(pp); + + if (ps->pwrite != pp) + png_error(pp, "store state damaged"); + + while (st > 0) + { + size_t cb; + + if (ps->writepos >= STORE_BUFFER_SIZE) + store_storenew(ps); + + cb = st; + + if (cb > STORE_BUFFER_SIZE - ps->writepos) + cb = STORE_BUFFER_SIZE - ps->writepos; + + memcpy(ps->new.buffer + ps->writepos, pb, cb); + pb += cb; + st -= cb; + ps->writepos += cb; + } +} + +static void +store_flush(png_structp pp) +{ + UNUSED(pp) /*DOES NOTHING*/ +} + +static size_t +store_read_buffer_size(png_store *ps) +{ + /* Return the bytes available for read in the current buffer. */ + if (ps->next != &ps->current->data) + return STORE_BUFFER_SIZE; + + return ps->current->datacount; +} + +/* Return total bytes available for read. */ +static size_t +store_read_buffer_avail(png_store *ps) +{ + if (ps->current != NULL && ps->next != NULL) + { + png_store_buffer *next = &ps->current->data; + size_t cbAvail = ps->current->datacount; + + while (next != ps->next && next != NULL) + { + next = next->prev; + cbAvail += STORE_BUFFER_SIZE; + } + + if (next != ps->next) + png_error(ps->pread, "buffer read error"); + + if (cbAvail > ps->readpos) + return cbAvail - ps->readpos; + } + + return 0; +} + +static int +store_read_buffer_next(png_store *ps) +{ + png_store_buffer *pbOld = ps->next; + png_store_buffer *pbNew = &ps->current->data; + if (pbOld != pbNew) + { + while (pbNew != NULL && pbNew->prev != pbOld) + pbNew = pbNew->prev; + + if (pbNew != NULL) + { + ps->next = pbNew; + ps->readpos = 0; + return 1; + } + + png_error(ps->pread, "buffer lost"); + } + + return 0; /* EOF or error */ +} + +/* Need separate implementation and callback to allow use of the same code + * during progressive read, where the io_ptr is set internally by libpng. + */ +static void +store_read_imp(png_store *ps, png_bytep pb, png_size_t st) +{ + if (ps->current == NULL || ps->next == NULL) + png_error(ps->pread, "store state damaged"); + + while (st > 0) + { + size_t cbAvail = store_read_buffer_size(ps) - ps->readpos; + + if (cbAvail > 0) + { + if (cbAvail > st) cbAvail = st; + memcpy(pb, ps->next->buffer + ps->readpos, cbAvail); + st -= cbAvail; + pb += cbAvail; + ps->readpos += cbAvail; + } + + else if (!store_read_buffer_next(ps)) + png_error(ps->pread, "read beyond end of file"); + } +} + +static void +store_read(png_structp pp, png_bytep pb, png_size_t st) +{ + png_store *ps = png_get_io_ptr(pp); + + if (ps == NULL || ps->pread != pp) + png_error(pp, "bad store read call"); + + store_read_imp(ps, pb, st); +} + +static void +store_progressive_read(png_store *ps, png_structp pp, png_infop pi) +{ + /* Notice that a call to store_read will cause this function to fail because + * readpos will be set. + */ + if (ps->pread != pp || ps->current == NULL || ps->next == NULL) + png_error(pp, "store state damaged (progressive)"); + + do + { + if (ps->readpos != 0) + png_error(pp, "store_read called during progressive read"); + + png_process_data(pp, pi, ps->next->buffer, store_read_buffer_size(ps)); + } + while (store_read_buffer_next(ps)); +} + +/***************************** MEMORY MANAGEMENT*** ***************************/ +/* A store_memory is simply the header for an allocated block of memory. The + * pointer returned to libpng is just after the end of the header block, the + * allocated memory is followed by a second copy of the 'mark'. + */ +typedef struct store_memory +{ + store_pool *pool; /* Originating pool */ + struct store_memory *next; /* Singly linked list */ + png_alloc_size_t size; /* Size of memory allocated */ + png_byte mark[4]; /* ID marker */ +} store_memory; + +/* Handle a fatal error in memory allocation. This calls png_error if the + * libpng struct is non-NULL, else it outputs a message and returns. This means + * that a memory problem while libpng is running will abort (png_error) the + * handling of particular file while one in cleanup (after the destroy of the + * struct has returned) will simply keep going and free (or attempt to free) + * all the memory. + */ +static void +store_pool_error(png_store *ps, png_structp pp, PNG_CONST char *msg) +{ + if (pp != NULL) + png_error(pp, msg); + + /* Else we have to do it ourselves. png_error eventually calls store_log, + * above. store_log accepts a NULL png_structp - it just changes what gets + * output by store_message. + */ + store_log(ps, pp, msg, 1 /* error */); +} + +static void +store_memory_free(png_structp pp, store_pool *pool, store_memory *memory) +{ + /* Note that pp may be NULL (see store_pool_delete below), the caller has + * found 'memory' in pool->list *and* unlinked this entry, so this is a valid + * pointer (for sure), but the contents may have been trashed. + */ + if (memory->pool != pool) + store_pool_error(pool->store, pp, "memory corrupted (pool)"); + + else if (memcmp(memory->mark, pool->mark, sizeof memory->mark) != 0) + store_pool_error(pool->store, pp, "memory corrupted (start)"); + + /* It should be safe to read the size field now. */ + else + { + png_alloc_size_t cb = memory->size; + + if (cb > pool->max) + store_pool_error(pool->store, pp, "memory corrupted (size)"); + + else if (memcmp((png_bytep)(memory+1)+cb, pool->mark, sizeof pool->mark) + != 0) + store_pool_error(pool->store, pp, "memory corrupted (end)"); + + /* Finally give the library a chance to find problems too: */ + else + { + pool->current -= cb; + free(memory); + } + } +} + +static void +store_pool_delete(png_store *ps, store_pool *pool) +{ + if (pool->list != NULL) + { + fprintf(stderr, "%s: %s %s: memory lost (list follows):\n", ps->test, + pool == &ps->read_memory_pool ? "read" : "write", + pool == &ps->read_memory_pool ? (ps->current != NULL ? + ps->current->name : "unknown file") : ps->wname); + ++ps->nerrors; + + do + { + store_memory *next = pool->list; + pool->list = next->next; + next->next = NULL; + + fprintf(stderr, "\t%lu bytes @ %p\n", + (unsigned long)next->size, next+1); + /* The NULL means this will always return, even if the memory is + * corrupted. + */ + store_memory_free(NULL, pool, next); + } + while (pool->list != NULL); + } + + /* And reset the other fields too for the next time. */ + if (pool->max > pool->max_max) pool->max_max = pool->max; + pool->max = 0; + if (pool->current != 0) /* unexpected internal error */ + fprintf(stderr, "%s: %s %s: memory counter mismatch (internal error)\n", + ps->test, pool == &ps->read_memory_pool ? "read" : "write", + pool == &ps->read_memory_pool ? (ps->current != NULL ? + ps->current->name : "unknown file") : ps->wname); + pool->current = 0; + + if (pool->limit > pool->max_limit) + pool->max_limit = pool->limit; + + pool->limit = 0; + + if (pool->total > pool->max_total) + pool->max_total = pool->total; + + pool->total = 0; + + /* Get a new mark too. */ + store_pool_mark(pool->mark); +} + +/* The memory callbacks: */ +static png_voidp +store_malloc(png_structp pp, png_alloc_size_t cb) +{ + store_pool *pool = png_get_mem_ptr(pp); + store_memory *new = malloc(cb + (sizeof *new) + (sizeof pool->mark)); + + if (new != NULL) + { + if (cb > pool->max) + pool->max = cb; + + pool->current += cb; + + if (pool->current > pool->limit) + pool->limit = pool->current; + + pool->total += cb; + + new->size = cb; + memcpy(new->mark, pool->mark, sizeof new->mark); + memcpy((png_byte*)(new+1) + cb, pool->mark, sizeof pool->mark); + new->pool = pool; + new->next = pool->list; + pool->list = new; + ++new; + } + + else + store_pool_error(pool->store, pp, "out of memory"); + + return new; +} + +static void +store_free(png_structp pp, png_voidp memory) +{ + store_pool *pool = png_get_mem_ptr(pp); + store_memory *this = memory, **test; + + /* First check that this 'memory' really is valid memory - it must be in the + * pool list. If it is, use the shared memory_free function to free it. + */ + --this; + for (test = &pool->list; *test != this; test = &(*test)->next) + { + if (*test == NULL) + { + store_pool_error(pool->store, pp, "bad pointer to free"); + return; + } + } + + /* Unlink this entry, *test == this. */ + *test = this->next; + this->next = NULL; + store_memory_free(pp, pool, this); +} + +/* Setup functions. */ +/* Cleanup when aborting a write or after storing the new file. */ +static void +store_write_reset(png_store *ps) +{ + if (ps->pwrite != NULL) + { + anon_context(ps); + + Try + png_destroy_write_struct(&ps->pwrite, &ps->piwrite); + + Catch_anonymous + { + /* memory corruption: continue. */ + } + + ps->pwrite = NULL; + ps->piwrite = NULL; + } + + /* And make sure that all the memory has been freed - this will output + * spurious errors in the case of memory corruption above, but this is safe. + */ + store_pool_delete(ps, &ps->write_memory_pool); + + store_freenew(ps); +} + +/* The following is the main write function, it returns a png_struct and, + * optionally, a png_info suitable for writiing a new PNG file. Use + * store_storefile above to record this file after it has been written. The + * returned libpng structures as destroyed by store_write_reset above. + */ +static png_structp +set_store_for_write(png_store *ps, png_infopp ppi, + PNG_CONST char * volatile name) +{ + anon_context(ps); + + Try + { + if (ps->pwrite != NULL) + png_error(ps->pwrite, "write store already in use"); + + store_write_reset(ps); + safecat(ps->wname, sizeof ps->wname, 0, name); + + /* Don't do the slow memory checks if doing a speed test. */ + if (ps->speed) + ps->pwrite = png_create_write_struct(PNG_LIBPNG_VER_STRING, + ps, store_error, store_warning); + + else + ps->pwrite = png_create_write_struct_2(PNG_LIBPNG_VER_STRING, + ps, store_error, store_warning, &ps->write_memory_pool, + store_malloc, store_free); + + png_set_write_fn(ps->pwrite, ps, store_write, store_flush); + + if (ppi != NULL) + *ppi = ps->piwrite = png_create_info_struct(ps->pwrite); + } + + Catch_anonymous + return NULL; + + return ps->pwrite; +} + +/* Cleanup when finished reading (either due to error or in the success case). + */ +static void +store_read_reset(png_store *ps) +{ + if (ps->pread != NULL) + { + anon_context(ps); + + Try + png_destroy_read_struct(&ps->pread, &ps->piread, NULL); + + Catch_anonymous + { + /* error already output: continue */ + } + + ps->pread = NULL; + ps->piread = NULL; + } + + /* Always do this to be safe. */ + store_pool_delete(ps, &ps->read_memory_pool); + + ps->current = NULL; + ps->next = NULL; + ps->readpos = 0; + ps->validated = 0; +} + +static void +store_read_set(png_store *ps, png_uint_32 id) +{ + png_store_file *pf = ps->saved; + + while (pf != NULL) + { + if (pf->id == id) + { + ps->current = pf; + ps->next = NULL; + store_read_buffer_next(ps); + return; + } + + pf = pf->next; + } + + { + size_t pos; + char msg[FILE_NAME_SIZE+64]; + + pos = standard_name_from_id(msg, sizeof msg, 0, id); + pos = safecat(msg, sizeof msg, pos, ": file not found"); + png_error(ps->pread, msg); + } +} + +/* The main interface for reading a saved file - pass the id number of the file + * to retrieve. Ids must be unique or the earlier file will be hidden. The API + * returns a png_struct and, optionally, a png_info. Both of these will be + * destroyed by store_read_reset above. + */ +static png_structp +set_store_for_read(png_store *ps, png_infopp ppi, png_uint_32 id, + PNG_CONST char *name) +{ + /* Set the name for png_error */ + safecat(ps->test, sizeof ps->test, 0, name); + + if (ps->pread != NULL) + png_error(ps->pread, "read store already in use"); + + store_read_reset(ps); + + /* Both the create APIs can return NULL if used in their default mode + * (because there is no other way of handling an error because the jmp_buf + * by default is stored in png_struct and that has not been allocated!) + * However, given that store_error works correctly in these circumstances + * we don't ever expect NULL in this program. + */ + if (ps->speed) + ps->pread = png_create_read_struct(PNG_LIBPNG_VER_STRING, ps, + store_error, store_warning); + + else + ps->pread = png_create_read_struct_2(PNG_LIBPNG_VER_STRING, ps, + store_error, store_warning, &ps->read_memory_pool, store_malloc, + store_free); + + if (ps->pread == NULL) + { + struct exception_context *the_exception_context = &ps->exception_context; + + store_log(ps, NULL, "png_create_read_struct returned NULL (unexpected)", + 1 /*error*/); + + Throw ps; + } + + store_read_set(ps, id); + + if (ppi != NULL) + *ppi = ps->piread = png_create_info_struct(ps->pread); + + return ps->pread; +} + +/* The overall cleanup of a store simply calls the above then removes all the + * saved files. This does not delete the store itself. + */ +static void +store_delete(png_store *ps) +{ + store_write_reset(ps); + store_read_reset(ps); + store_freefile(&ps->saved); + + if (ps->image != NULL) + { + free(ps->image-1); + ps->image = NULL; + ps->cb_image = 0; + } +} + +/*********************** PNG FILE MODIFICATION ON READ ************************/ +/* Files may be modified on read. The following structure contains a complete + * png_store together with extra members to handle modification and a special + * read callback for libpng. To use this the 'modifications' field must be set + * to a list of png_modification structures that actually perform the + * modification, otherwise a png_modifier is functionally equivalent to a + * png_store. There is a special read function, set_modifier_for_read, which + * replaces set_store_for_read. + */ +typedef struct png_modifier +{ + png_store this; /* I am a png_store */ + struct png_modification *modifications; /* Changes to make */ + + enum modifier_state + { + modifier_start, /* Initial value */ + modifier_signature, /* Have a signature */ + modifier_IHDR /* Have an IHDR */ + } state; /* My state */ + + /* Information from IHDR: */ + png_byte bit_depth; /* From IHDR */ + png_byte colour_type; /* From IHDR */ + + /* While handling PLTE, IDAT and IEND these chunks may be pended to allow + * other chunks to be inserted. + */ + png_uint_32 pending_len; + png_uint_32 pending_chunk; + + /* Test values */ + double *gammas; + unsigned int ngammas; + + /* Lowest sbit to test (libpng fails for sbit < 8) */ + png_byte sbitlow; + + /* Error control - these are the limits on errors accepted by the gamma tests + * below. + */ + double maxout8; /* Maximum output value error */ + double maxabs8; /* Absolute sample error 0..1 */ + double maxpc8; /* Percentage sample error 0..100% */ + double maxout16; /* Maximum output value error */ + double maxabs16; /* Absolute sample error 0..1 */ + double maxpc16; /* Percentage sample error 0..100% */ + + /* Logged 8 and 16 bit errors ('output' values): */ + double error_gray_2; + double error_gray_4; + double error_gray_8; + double error_gray_16; + double error_color_8; + double error_color_16; + + /* Flags: */ + /* Whether or not to interlace. */ + int interlace_type :9; /* int, but must store '1' */ + + /* Run the standard tests? */ + unsigned int test_standard :1; + + /* Run the odd-sized image and interlace read/write tests? */ + unsigned int test_size :1; + + /* Run tests on reading with a combiniation of transforms, */ + unsigned int test_transform :1; + + /* When to use the use_input_precision option: */ + unsigned int use_input_precision :1; + unsigned int use_input_precision_sbit :1; + unsigned int use_input_precision_16to8 :1; + + /* Which gamma tests to run: */ + unsigned int test_gamma_threshold :1; + unsigned int test_gamma_transform :1; /* main tests */ + unsigned int test_gamma_sbit :1; + unsigned int test_gamma_strip16 :1; + + unsigned int log :1; /* Log max error */ + + /* Buffer information, the buffer size limits the size of the chunks that can + * be modified - they must fit (including header and CRC) into the buffer! + */ + size_t flush; /* Count of bytes to flush */ + size_t buffer_count; /* Bytes in buffer */ + size_t buffer_position; /* Position in buffer */ + png_byte buffer[1024]; +} png_modifier; + +static double abserr(png_modifier *pm, png_byte bit_depth) +{ + return bit_depth == 16 ? pm->maxabs16 : pm->maxabs8; +} + +static double pcerr(png_modifier *pm, png_byte bit_depth) +{ + return (bit_depth == 16 ? pm->maxpc16 : pm->maxpc8) * .01; +} + +static double outerr(png_modifier *pm, png_byte bit_depth) +{ + /* There is a serious error in the 2 and 4 bit grayscale transform because + * the gamma table value (8 bits) is simply shifted, not rounded, so the + * error in 4 bit greyscale gamma is up to the value below. This is a hack + * to allow pngvalid to succeed: + */ + if (bit_depth == 2) + return .73182-.5; + + if (bit_depth == 4) + return .90644-.5; + + if (bit_depth == 16) + return pm->maxout16; + + return pm->maxout8; +} + +/* This returns true if the test should be stopped now because it has already + * failed and it is running silently. + */ +static int fail(png_modifier *pm) +{ + return !pm->log && !pm->this.verbose && (pm->this.nerrors > 0 || + (pm->this.treat_warnings_as_errors && pm->this.nwarnings > 0)); +} + +static void +modifier_init(png_modifier *pm) +{ + memset(pm, 0, sizeof *pm); + store_init(&pm->this); + pm->modifications = NULL; + pm->state = modifier_start; + pm->sbitlow = 1U; + pm->maxout8 = pm->maxpc8 = pm->maxabs8 = 0; + pm->maxout16 = pm->maxpc16 = pm->maxabs16 = 0; + pm->error_gray_2 = pm->error_gray_4 = pm->error_gray_8 = 0; + pm->error_gray_16 = pm->error_color_8 = pm->error_color_16 = 0; + pm->interlace_type = PNG_INTERLACE_NONE; + pm->test_standard = 0; + pm->test_size = 0; + pm->test_transform = 0; + pm->use_input_precision = 0; + pm->use_input_precision_sbit = 0; + pm->use_input_precision_16to8 = 0; + pm->test_gamma_threshold = 0; + pm->test_gamma_transform = 0; + pm->test_gamma_sbit = 0; + pm->test_gamma_strip16 = 0; + pm->log = 0; + + /* Rely on the memset for all the other fields - there are no pointers */ +} + +/* One modification structure must be provided for each chunk to be modified (in + * fact more than one can be provided if multiple separate changes are desired + * for a single chunk.) Modifications include adding a new chunk when a + * suitable chunk does not exist. + * + * The caller of modify_fn will reset the CRC of the chunk and record 'modified' + * or 'added' as appropriate if the modify_fn returns 1 (true). If the + * modify_fn is NULL the chunk is simply removed. + */ +typedef struct png_modification +{ + struct png_modification *next; + png_uint_32 chunk; + + /* If the following is NULL all matching chunks will be removed: */ + int (*modify_fn)(struct png_modifier *pm, + struct png_modification *me, int add); + + /* If the following is set to PLTE, IDAT or IEND and the chunk has not been + * found and modified (and there is a modify_fn) the modify_fn will be called + * to add the chunk before the relevant chunk. + */ + png_uint_32 add; + unsigned int modified :1; /* Chunk was modified */ + unsigned int added :1; /* Chunk was added */ + unsigned int removed :1; /* Chunk was removed */ +} png_modification; + +static void modification_reset(png_modification *pmm) +{ + if (pmm != NULL) + { + pmm->modified = 0; + pmm->added = 0; + pmm->removed = 0; + modification_reset(pmm->next); + } +} + +static void +modification_init(png_modification *pmm) +{ + memset(pmm, 0, sizeof *pmm); + pmm->next = NULL; + pmm->chunk = 0; + pmm->modify_fn = NULL; + pmm->add = 0; + modification_reset(pmm); +} + +static void +modifier_reset(png_modifier *pm) +{ + store_read_reset(&pm->this); + pm->modifications = NULL; + pm->state = modifier_start; + pm->bit_depth = pm->colour_type = 0; + pm->pending_len = pm->pending_chunk = 0; + pm->flush = pm->buffer_count = pm->buffer_position = 0; +} + +/* Convenience macros. */ +#define CHUNK(a,b,c,d) (((a)<<24)+((b)<<16)+((c)<<8)+(d)) +#define CHUNK_IHDR CHUNK(73,72,68,82) +#define CHUNK_PLTE CHUNK(80,76,84,69) +#define CHUNK_IDAT CHUNK(73,68,65,84) +#define CHUNK_IEND CHUNK(73,69,78,68) +#define CHUNK_cHRM CHUNK(99,72,82,77) +#define CHUNK_gAMA CHUNK(103,65,77,65) +#define CHUNK_sBIT CHUNK(115,66,73,84) +#define CHUNK_sRGB CHUNK(115,82,71,66) + +/* The guts of modification are performed during a read. */ +static void +modifier_crc(png_bytep buffer) +{ + /* Recalculate the chunk CRC - a complete chunk must be in + * the buffer, at the start. + */ + uInt datalen = png_get_uint_32(buffer); + png_save_uint_32(buffer+datalen+8, crc32(0L, buffer+4, datalen+4)); +} + +static void +modifier_setbuffer(png_modifier *pm) +{ + modifier_crc(pm->buffer); + pm->buffer_count = png_get_uint_32(pm->buffer)+12; + pm->buffer_position = 0; +} + +/* Separate the callback into the actual implementation (which is passed the + * png_modifier explicitly) and the callback, which gets the modifier from the + * png_struct. + */ +static void +modifier_read_imp(png_modifier *pm, png_bytep pb, png_size_t st) +{ + while (st > 0) + { + size_t cb; + png_uint_32 len, chunk; + png_modification *mod; + + if (pm->buffer_position >= pm->buffer_count) switch (pm->state) + { + static png_byte sign[8] = { 137, 80, 78, 71, 13, 10, 26, 10 }; + case modifier_start: + store_read_imp(&pm->this, pm->buffer, 8); /* size of signature. */ + pm->buffer_count = 8; + pm->buffer_position = 0; + + if (memcmp(pm->buffer, sign, 8) != 0) + png_error(pm->this.pread, "invalid PNG file signature"); + pm->state = modifier_signature; + break; + + case modifier_signature: + store_read_imp(&pm->this, pm->buffer, 13+12); /* size of IHDR */ + pm->buffer_count = 13+12; + pm->buffer_position = 0; + + if (png_get_uint_32(pm->buffer) != 13 || + png_get_uint_32(pm->buffer+4) != CHUNK_IHDR) + png_error(pm->this.pread, "invalid IHDR"); + + /* Check the list of modifiers for modifications to the IHDR. */ + mod = pm->modifications; + while (mod != NULL) + { + if (mod->chunk == CHUNK_IHDR && mod->modify_fn && + (*mod->modify_fn)(pm, mod, 0)) + { + mod->modified = 1; + modifier_setbuffer(pm); + } + + /* Ignore removal or add if IHDR! */ + mod = mod->next; + } + + /* Cache information from the IHDR (the modified one.) */ + pm->bit_depth = pm->buffer[8+8]; + pm->colour_type = pm->buffer[8+8+1]; + + pm->state = modifier_IHDR; + pm->flush = 0; + break; + + case modifier_IHDR: + default: + /* Read a new chunk and process it until we see PLTE, IDAT or + * IEND. 'flush' indicates that there is still some data to + * output from the preceding chunk. + */ + if ((cb = pm->flush) > 0) + { + if (cb > st) cb = st; + pm->flush -= cb; + store_read_imp(&pm->this, pb, cb); + pb += cb; + st -= cb; + if (st <= 0) return; + } + + /* No more bytes to flush, read a header, or handle a pending + * chunk. + */ + if (pm->pending_chunk != 0) + { + png_save_uint_32(pm->buffer, pm->pending_len); + png_save_uint_32(pm->buffer+4, pm->pending_chunk); + pm->pending_len = 0; + pm->pending_chunk = 0; + } + else + store_read_imp(&pm->this, pm->buffer, 8); + + pm->buffer_count = 8; + pm->buffer_position = 0; + + /* Check for something to modify or a terminator chunk. */ + len = png_get_uint_32(pm->buffer); + chunk = png_get_uint_32(pm->buffer+4); + + /* Terminators first, they may have to be delayed for added + * chunks + */ + if (chunk == CHUNK_PLTE || chunk == CHUNK_IDAT || + chunk == CHUNK_IEND) + { + mod = pm->modifications; + + while (mod != NULL) + { + if ((mod->add == chunk || + (mod->add == CHUNK_PLTE && chunk == CHUNK_IDAT)) && + mod->modify_fn != NULL && !mod->modified && !mod->added) + { + /* Regardless of what the modify function does do not run + * this again. + */ + mod->added = 1; + + if ((*mod->modify_fn)(pm, mod, 1 /*add*/)) + { + /* Reset the CRC on a new chunk */ + if (pm->buffer_count > 0) + modifier_setbuffer(pm); + + else + { + pm->buffer_position = 0; + mod->removed = 1; + } + + /* The buffer has been filled with something (we assume) + * so output this. Pend the current chunk. + */ + pm->pending_len = len; + pm->pending_chunk = chunk; + break; /* out of while */ + } + } + + mod = mod->next; + } + + /* Don't do any further processing if the buffer was modified - + * otherwise the code will end up modifying a chunk that was + * just added. + */ + if (mod != NULL) + break; /* out of switch */ + } + + /* If we get to here then this chunk may need to be modified. To + * do this it must be less than 1024 bytes in total size, otherwise + * it just gets flushed. + */ + if (len+12 <= sizeof pm->buffer) + { + store_read_imp(&pm->this, pm->buffer+pm->buffer_count, + len+12-pm->buffer_count); + pm->buffer_count = len+12; + + /* Check for a modification, else leave it be. */ + mod = pm->modifications; + while (mod != NULL) + { + if (mod->chunk == chunk) + { + if (mod->modify_fn == NULL) + { + /* Remove this chunk */ + pm->buffer_count = pm->buffer_position = 0; + mod->removed = 1; + break; /* Terminate the while loop */ + } + + else if ((*mod->modify_fn)(pm, mod, 0)) + { + mod->modified = 1; + /* The chunk may have been removed: */ + if (pm->buffer_count == 0) + { + pm->buffer_position = 0; + break; + } + modifier_setbuffer(pm); + } + } + + mod = mod->next; + } + } + + else + pm->flush = len+12 - pm->buffer_count; /* data + crc */ + + /* Take the data from the buffer (if there is any). */ + break; + } + + /* Here to read from the modifier buffer (not directly from + * the store, as in the flush case above.) + */ + cb = pm->buffer_count - pm->buffer_position; + + if (cb > st) + cb = st; + + memcpy(pb, pm->buffer + pm->buffer_position, cb); + st -= cb; + pb += cb; + pm->buffer_position += cb; + } +} + +/* The callback: */ +static void +modifier_read(png_structp pp, png_bytep pb, png_size_t st) +{ + png_modifier *pm = png_get_io_ptr(pp); + + if (pm == NULL || pm->this.pread != pp) + png_error(pp, "bad modifier_read call"); + + modifier_read_imp(pm, pb, st); +} + +/* Like store_progressive_read but the data is getting changed as we go so we + * need a local buffer. + */ +static void +modifier_progressive_read(png_modifier *pm, png_structp pp, png_infop pi) +{ + if (pm->this.pread != pp || pm->this.current == NULL || + pm->this.next == NULL) + png_error(pp, "store state damaged (progressive)"); + + /* This is another Horowitz and Hill random noise generator. In this case + * the aim is to stress the progressive reader with truely horrible variable + * buffer sizes in the range 1..500, so a sequence of 9 bit random numbers + * is generated. We could probably just count from 1 to 32767 and get as + * good a result. + */ + for (;;) + { + static png_uint_32 noise = 1; + png_size_t cb, cbAvail; + png_byte buffer[512]; + + /* Generate 15 more bits of stuff: */ + noise = (noise << 9) | ((noise ^ (noise >> (9-5))) & 0x1ff); + cb = noise & 0x1ff; + + /* Check that this number of bytes are available (in the current buffer.) + * (This doesn't quite work - the modifier might delete a chunk; unlikely + * but possible, it doesn't happen at present because the modifier only + * adds chunks to standard images.) + */ + cbAvail = store_read_buffer_avail(&pm->this); + if (pm->buffer_count > pm->buffer_position) + cbAvail += pm->buffer_count - pm->buffer_position; + + if (cb > cbAvail) + { + /* Check for EOF: */ + if (cbAvail == 0) + break; + + cb = cbAvail; + } + + modifier_read_imp(pm, buffer, cb); + png_process_data(pp, pi, buffer, cb); + } + + /* Check the invariants at the end (if this fails it's a problem in this + * file!) + */ + if (pm->buffer_count > pm->buffer_position || + pm->this.next != &pm->this.current->data || + pm->this.readpos < pm->this.current->datacount) + png_error(pp, "progressive read implementation error"); +} + +/* Set up a modifier. */ +static png_structp +set_modifier_for_read(png_modifier *pm, png_infopp ppi, png_uint_32 id, + PNG_CONST char *name) +{ + /* Do this first so that the modifier fields are cleared even if an error + * happens allocating the png_struct. No allocation is done here so no + * cleanup is required. + */ + pm->state = modifier_start; + pm->bit_depth = 0; + pm->colour_type = 255; + + pm->pending_len = 0; + pm->pending_chunk = 0; + pm->flush = 0; + pm->buffer_count = 0; + pm->buffer_position = 0; + + return set_store_for_read(&pm->this, ppi, id, name); +} + +/***************************** STANDARD PNG FILES *****************************/ +/* Standard files - write and save standard files. */ +/* There are two basic forms of standard images. Those which attempt to have + * all the possible pixel values (not possible for 16bpp images, but a range of + * values are produced) and those which have a range of image sizes. The former + * are used for testing transforms, in particular gamma correction and bit + * reduction and increase. The latter are reserved for testing the behavior of + * libpng with respect to 'odd' image sizes - particularly small images where + * rows become 1 byte and interlace passes disappear. + * + * The first, most useful, set are the 'transform' images, the second set of + * small images are the 'size' images. + * + * The transform files are constructed with rows which fit into a 1024 byte row + * buffer. This makes allocation easier below. Further regardless of the file + * format every row has 128 pixels (giving 1024 bytes for 64bpp formats). + * + * Files are stored with no gAMA or sBIT chunks, with a PLTE only when needed + * and with an ID derived from the colour type, bit depth and interlace type + * as above (FILEID). The width (128) and height (variable) are not stored in + * the FILEID - instead the fields are set to 0, indicating a transform file. + * + * The size files ar constructed with rows a maximum of 128 bytes wide, allowing + * a maximum width of 16 pixels (for the 64bpp case.) They also have a maximum + * height of 16 rows. The width and height are stored in the FILEID and, being + * non-zero, indicate a size file. + */ + +/* The number of passes is related to the interlace type. There wass no libpng + * API to determine this prior to 1.5, so we need an inquiry function: + */ +static int +npasses_from_interlace_type(png_structp pp, int interlace_type) +{ + switch (interlace_type) + { + default: + png_error(pp, "invalid interlace type"); + + case PNG_INTERLACE_NONE: + return 1; + + case PNG_INTERLACE_ADAM7: + return PNG_INTERLACE_ADAM7_PASSES; + } +} + +static unsigned int +bit_size(png_structp pp, png_byte colour_type, png_byte bit_depth) +{ + switch (colour_type) + { + case 0: return bit_depth; + + case 2: return 3*bit_depth; + + case 3: return bit_depth; + + case 4: return 2*bit_depth; + + case 6: return 4*bit_depth; + + default: png_error(pp, "invalid color type"); + } +} + +#define TRANSFORM_WIDTH 128U +#define TRANSFORM_ROWMAX (TRANSFORM_WIDTH*8U) +#define SIZE_ROWMAX (16*8U) /* 16 pixels, max 8 bytes each - 128 bytes */ +#define STANDARD_ROWMAX TRANSFORM_ROWMAX /* The larger of the two */ + +/* So the maximum image sizes are as follows. A 'transform' image may require + * more than 65535 bytes. The size images are a maximum of 2046 bytes. + */ +#define TRANSFORM_IMAGEMAX (TRANSFORM_ROWMAX * (png_uint_32)2048) +#define SIZE_IMAGEMAX (SIZE_ROWMAX * 16U) + +static size_t +transform_rowsize(png_structp pp, png_byte colour_type, png_byte bit_depth) +{ + return (TRANSFORM_WIDTH * bit_size(pp, colour_type, bit_depth)) / 8; +} + +/* transform_width(pp, colour_type, bit_depth) current returns the same number + * every time, so just use a macro: + */ +#define transform_width(pp, colour_type, bit_depth) TRANSFORM_WIDTH + +static png_uint_32 +transform_height(png_structp pp, png_byte colour_type, png_byte bit_depth) +{ + switch (bit_size(pp, colour_type, bit_depth)) + { + case 1: + case 2: + case 4: + return 1; /* Total of 128 pixels */ + + case 8: + return 2; /* Total of 256 pixels/bytes */ + + case 16: + return 512; /* Total of 65536 pixels */ + + case 24: + case 32: + return 512; /* 65536 pixels */ + + case 48: + case 64: + return 2048;/* 4 x 65536 pixels. */ + + default: + return 0; /* Error, will be caught later */ + } +} + +/* The following can only be defined here, now we have the definitions + * of the transform image sizes. + */ +static png_uint_32 +standard_width(png_structp pp, png_uint_32 id) +{ + png_uint_32 width = WIDTH_FROM_ID(id); + UNUSED(pp) + + if (width == 0) + width = transform_width(pp, COL_FROM_ID(id), DEPTH_FROM_ID(id)); + + return width; +} + +static png_uint_32 +standard_height(png_structp pp, png_uint_32 id) +{ + png_uint_32 height = HEIGHT_FROM_ID(id); + + if (height == 0) + height = transform_height(pp, COL_FROM_ID(id), DEPTH_FROM_ID(id)); + + return height; +} + +static png_uint_32 +standard_rowsize(png_structp pp, png_uint_32 id) +{ + png_uint_32 width = standard_width(pp, id); + + /* This won't overflow: */ + width *= bit_size(pp, COL_FROM_ID(id), DEPTH_FROM_ID(id)); + return (width + 7) / 8; +} + +static void +transform_row(png_structp pp, png_byte buffer[TRANSFORM_ROWMAX], + png_byte colour_type, png_byte bit_depth, png_uint_32 y) +{ + png_uint_32 v = y << 7; + png_uint_32 i = 0; + + switch (bit_size(pp, colour_type, bit_depth)) + { + case 1: + while (i<128/8) buffer[i] = v & 0xff, v += 17, ++i; + return; + + case 2: + while (i<128/4) buffer[i] = v & 0xff, v += 33, ++i; + return; + + case 4: + while (i<128/2) buffer[i] = v & 0xff, v += 65, ++i; + return; + + case 8: + /* 256 bytes total, 128 bytes in each row set as follows: */ + while (i<128) buffer[i] = v & 0xff, ++v, ++i; + return; + + case 16: + /* Generate all 65536 pixel values in order, which includes the 8 bit + * GA case as well as the 16 bit G case. + */ + while (i<128) + buffer[2*i] = (v>>8) & 0xff, buffer[2*i+1] = v & 0xff, ++v, ++i; + + return; + + case 24: + /* 65535 pixels, but rotate the values. */ + while (i<128) + { + /* Three bytes per pixel, r, g, b, make b by r^g */ + buffer[3*i+0] = (v >> 8) & 0xff; + buffer[3*i+1] = v & 0xff; + buffer[3*i+2] = ((v >> 8) ^ v) & 0xff; + ++v; + ++i; + } + + return; + + case 32: + /* 65535 pixels, r, g, b, a; just replicate */ + while (i<128) + { + buffer[4*i+0] = (v >> 8) & 0xff; + buffer[4*i+1] = v & 0xff; + buffer[4*i+2] = (v >> 8) & 0xff; + buffer[4*i+3] = v & 0xff; + ++v; + ++i; + } + + return; + + case 48: + /* y is maximum 2047, giving 4x65536 pixels, make 'r' increase by 1 at + * each pixel, g increase by 257 (0x101) and 'b' by 0x1111: + */ + while (i<128) + { + png_uint_32 t = v++; + buffer[6*i+0] = (t >> 8) & 0xff; + buffer[6*i+1] = t & 0xff; + t *= 257; + buffer[6*i+2] = (t >> 8) & 0xff; + buffer[6*i+3] = t & 0xff; + t *= 17; + buffer[6*i+4] = (t >> 8) & 0xff; + buffer[6*i+5] = t & 0xff; + ++i; + } + + return; + + case 64: + /* As above in the 32 bit case. */ + while (i<128) + { + png_uint_32 t = v++; + buffer[8*i+0] = (t >> 8) & 0xff; + buffer[8*i+1] = t & 0xff; + buffer[8*i+4] = (t >> 8) & 0xff; + buffer[8*i+5] = t & 0xff; + t *= 257; + buffer[8*i+2] = (t >> 8) & 0xff; + buffer[8*i+3] = t & 0xff; + buffer[8*i+6] = (t >> 8) & 0xff; + buffer[8*i+7] = t & 0xff; + ++i; + } + return; + + default: + break; + } + + png_error(pp, "internal error"); +} + +/* This is just to do the right cast - could be changed to a function to check + * 'bd' but there isn't much point. + */ +#define DEPTH(bd) ((png_byte)(1U << (bd))) + +/* Make a standardized image given a an image colour type, bit depth and + * interlace type. The standard images have a very restricted range of + * rows and heights and are used for testing transforms rather than image + * layout details. See make_size_images below for a way to make images + * that test odd sizes along with the libpng interlace handling. + */ +static void +make_transform_image(png_store* PNG_CONST ps, png_byte PNG_CONST colour_type, + png_byte PNG_CONST bit_depth, int interlace_type, png_const_charp name) +{ + context(ps, fault); + + Try + { + png_infop pi; + png_structp pp = set_store_for_write(ps, &pi, name); + png_uint_32 h; + + /* In the event of a problem return control to the Catch statement below + * to do the clean up - it is not possible to 'return' directly from a Try + * block. + */ + if (pp == NULL) + Throw ps; + + h = transform_height(pp, colour_type, bit_depth); + + png_set_IHDR(pp, pi, transform_width(pp, colour_type, bit_depth), h, + bit_depth, colour_type, interlace_type, + PNG_COMPRESSION_TYPE_BASE, PNG_FILTER_TYPE_BASE); + + if (colour_type == 3) /* palette */ + { + unsigned int i = 0; + png_color pal[256]; + + do + pal[i].red = pal[i].green = pal[i].blue = (png_byte)i; + while(++i < 256U); + + png_set_PLTE(pp, pi, pal, 256); + } + + png_write_info(pp, pi); + + if (png_get_rowbytes(pp, pi) != + transform_rowsize(pp, colour_type, bit_depth)) + png_error(pp, "row size incorrect"); + + else + { + /* Somewhat confusingly this must be called *after* png_write_info + * because if it is called before, the information in *pp has not been + * updated to reflect the interlaced image. + */ + int npasses = png_set_interlace_handling(pp); + int pass; + + if (npasses != npasses_from_interlace_type(pp, interlace_type)) + png_error(pp, "write: png_set_interlace_handling failed"); + + for (pass=0; pass<npasses; ++pass) + { + png_uint_32 y; + + for (y=0; y<h; ++y) + { + png_byte buffer[TRANSFORM_ROWMAX]; + + transform_row(pp, buffer, colour_type, bit_depth, y); + png_write_row(pp, buffer); + } + } + } + + png_write_end(pp, pi); + + /* And store this under the appropriate id, then clean up. */ + store_storefile(ps, FILEID(colour_type, bit_depth, interlace_type, + 0, 0, 0)); + + store_write_reset(ps); + } + + Catch(fault) + { + /* Use the png_store returned by the exception. This may help the compiler + * because 'ps' is not used in this branch of the setjmp. Note that fault + * and ps will always be the same value. + */ + store_write_reset(fault); + } +} + +static void +make_standard(png_store* PNG_CONST ps, png_byte PNG_CONST colour_type, int bdlo, + int PNG_CONST bdhi) +{ + for (; bdlo <= bdhi; ++bdlo) + { + int interlace_type; + + for (interlace_type = PNG_INTERLACE_NONE; + interlace_type < PNG_INTERLACE_LAST; ++interlace_type) + { + char name[FILE_NAME_SIZE]; + + standard_name(name, sizeof name, 0, colour_type, bdlo, interlace_type, + 0, 0, 0); + make_transform_image(ps, colour_type, DEPTH(bdlo), interlace_type, + name); + } + } +} + +static void +make_transform_images(png_store *ps) +{ + /* This is in case of errors. */ + safecat(ps->test, sizeof ps->test, 0, "make standard images"); + + /* Arguments are colour_type, low bit depth, high bit depth + */ + make_standard(ps, 0, 0, WRITE_BDHI); + make_standard(ps, 2, 3, WRITE_BDHI); + make_standard(ps, 3, 0, 3 /*palette: max 8 bits*/); + make_standard(ps, 4, 3, WRITE_BDHI); + make_standard(ps, 6, 3, WRITE_BDHI); +} + +/* The following two routines use the PNG interlace support macros from + * png.h to interlace or deinterlace rows. + */ +static void +interlace_row(png_bytep buffer, png_const_bytep imageRow, + unsigned int pixel_size, png_uint_32 w, int pass) +{ + png_uint_32 xin, xout, xstep; + + /* Note that this can, trivially, be optimized to a memcpy on pass 7, the + * code is presented this way to make it easier to understand. In practice + * consult the code in the libpng source to see other ways of doing this. + */ + xin = PNG_PASS_START_COL(pass); + xstep = 1U<<PNG_PASS_COL_SHIFT(pass); + + for (xout=0; xin<w; xin+=xstep) + { + pixel_copy(buffer, xout, imageRow, xin, pixel_size); + ++xout; + } +} + +static void +deinterlace_row(png_bytep buffer, png_const_bytep row, + unsigned int pixel_size, png_uint_32 w, int pass) +{ + /* The inverse of the above, 'row' is part of row 'y' of the output image, + * in 'buffer'. The image is 'w' wide and this is pass 'pass', distribute + * the pixels of row into buffer and return the number written (to allow + * this to be checked). + */ + png_uint_32 xin, xout, xstep; + + xout = PNG_PASS_START_COL(pass); + xstep = 1U<<PNG_PASS_COL_SHIFT(pass); + + for (xin=0; xout<w; xout+=xstep) + { + pixel_copy(buffer, xout, row, xin, pixel_size); + ++xin; + } +} + +/* Build a single row for the 'size' test images, this fills in only the + * first bit_width bits of the sample row. + */ +static void +size_row(png_byte buffer[SIZE_ROWMAX], png_uint_32 bit_width, png_uint_32 y) +{ + /* height is in the range 1 to 16, so: */ + y = ((y & 1) << 7) + ((y & 2) << 6) + ((y & 4) << 5) + ((y & 8) << 4); + /* the following ensures bits are set in small images: */ + y ^= 0xA5; + + while (bit_width >= 8) + *buffer++ = (png_byte)y++, bit_width -= 8; + + /* There may be up to 7 remaining bits, these go in the most significant + * bits of the byte. + */ + if (bit_width > 0) + { + png_uint_32 mask = (1U<<(8-bit_width))-1; + *buffer = (png_byte)((*buffer & mask) | (y & ~mask)); + } +} + +static void +make_size_image(png_store* PNG_CONST ps, png_byte PNG_CONST colour_type, + png_byte PNG_CONST bit_depth, int PNG_CONST interlace_type, + png_uint_32 PNG_CONST w, png_uint_32 PNG_CONST h, + int PNG_CONST do_interlace) +{ + context(ps, fault); + + Try + { + png_infop pi; + png_structp pp; + unsigned int pixel_size; + + /* Make a name and get an appropriate id for the store: */ + char name[FILE_NAME_SIZE]; + PNG_CONST png_uint_32 id = FILEID(colour_type, bit_depth, interlace_type, + w, h, do_interlace); + + standard_name_from_id(name, sizeof name, 0, id); + pp = set_store_for_write(ps, &pi, name); + + /* In the event of a problem return control to the Catch statement below + * to do the clean up - it is not possible to 'return' directly from a Try + * block. + */ + if (pp == NULL) + Throw ps; + + png_set_IHDR(pp, pi, w, h, bit_depth, colour_type, interlace_type, + PNG_COMPRESSION_TYPE_BASE, PNG_FILTER_TYPE_BASE); + + /* Same palette as make_transform_image - I don' think there is any + * benefit from using a different one (JB 20101211) + */ + if (colour_type == 3) /* palette */ + { + unsigned int i = 0; + png_color pal[256]; + + do + pal[i].red = pal[i].green = pal[i].blue = (png_byte)i; + while(++i < 256U); + + png_set_PLTE(pp, pi, pal, 256); + } + + png_write_info(pp, pi); + + /* Calculate the bit size, divide by 8 to get the byte size - this won't + * overflow because we know the w values are all small enough even for + * a system where 'unsigned int' is only 16 bits. + */ + pixel_size = bit_size(pp, colour_type, bit_depth); + if (png_get_rowbytes(pp, pi) != ((w * pixel_size) + 7) / 8) + png_error(pp, "row size incorrect"); + + else + { + int npasses = npasses_from_interlace_type(pp, interlace_type); + png_uint_32 y; + int pass; + png_byte image[16][SIZE_ROWMAX]; + + /* To help consistent error detection make the parts of this buffer + * that aren't set below all '1': + */ + memset(image, 0xff, sizeof image); + + if (!do_interlace && npasses != png_set_interlace_handling(pp)) + png_error(pp, "write: png_set_interlace_handling failed"); + + /* Prepare the whole image first to avoid making it 7 times: */ + for (y=0; y<h; ++y) + size_row(image[y], w * pixel_size, y); + + for (pass=0; pass<npasses; ++pass) + { + /* The following two are for checking the macros: */ + PNG_CONST png_uint_32 wPass = PNG_PASS_COLS(w, pass); + + /* If do_interlace is set we don't call png_write_row for every + * row because some of them are empty. In fact, for a 1x1 image, + * most of them are empty! + */ + for (y=0; y<h; ++y) + { + png_const_bytep row = image[y]; + png_byte tempRow[SIZE_ROWMAX]; + + /* If do_interlace *and* the image is interlaced we + * need a reduced interlace row, this may be reduced + * to empty. + */ + if (do_interlace && interlace_type == PNG_INTERLACE_ADAM7) + { + /* The row must not be written if it doesn't exist, notice + * that there are two conditions here, either the row isn't + * ever in the pass or the row would be but isn't wide + * enough to contribute any pixels. In fact the wPass test + * can be used to skip the whole y loop in this case. + */ + if (PNG_ROW_IN_INTERLACE_PASS(y, pass) && wPass > 0) + { + /* Set to all 1's for error detection (libpng tends to + * set unset things to 0). + */ + memset(tempRow, 0xff, sizeof tempRow); + interlace_row(tempRow, row, pixel_size, w, pass); + row = tempRow; + } + else + continue; + } + + /* Only get to here if the row has some pixels in it. */ + png_write_row(pp, row); + } + } + } + + png_write_end(pp, pi); + + /* And store this under the appropriate id, then clean up. */ + store_storefile(ps, id); + + store_write_reset(ps); + } + + Catch(fault) + { + /* Use the png_store returned by the exception. This may help the compiler + * because 'ps' is not used in this branch of the setjmp. Note that fault + * and ps will always be the same value. + */ + store_write_reset(fault); + } +} + +static void +make_size(png_store* PNG_CONST ps, png_byte PNG_CONST colour_type, int bdlo, + int PNG_CONST bdhi) +{ + for (; bdlo <= bdhi; ++bdlo) + { + png_uint_32 width; + + for (width = 1; width <= 16; ++width) + { + png_uint_32 height; + + for (height = 1; height <= 16; ++height) + { + /* The four combinations of DIY interlace and interlace or not - + * no interlace + DIY should be identical to no interlace with + * libpng doing it. + */ + make_size_image(ps, colour_type, DEPTH(bdlo), PNG_INTERLACE_NONE, + width, height, 0); + make_size_image(ps, colour_type, DEPTH(bdlo), PNG_INTERLACE_NONE, + width, height, 1); + make_size_image(ps, colour_type, DEPTH(bdlo), PNG_INTERLACE_ADAM7, + width, height, 0); + make_size_image(ps, colour_type, DEPTH(bdlo), PNG_INTERLACE_ADAM7, + width, height, 1); + } + } + } +} + +static void +make_size_images(png_store *ps) +{ + /* This is in case of errors. */ + safecat(ps->test, sizeof ps->test, 0, "make size images"); + + /* Arguments are colour_type, low bit depth, high bit depth + */ + make_size(ps, 0, 0, WRITE_BDHI); + make_size(ps, 2, 3, WRITE_BDHI); + make_size(ps, 3, 0, 3 /*palette: max 8 bits*/); + make_size(ps, 4, 3, WRITE_BDHI); + make_size(ps, 6, 3, WRITE_BDHI); +} + +/* Return a row based on image id and 'y' for checking: */ +static void +standard_row(png_structp pp, png_byte std[STANDARD_ROWMAX], png_uint_32 id, + png_uint_32 y) +{ + if (WIDTH_FROM_ID(id) == 0) + transform_row(pp, std, COL_FROM_ID(id), DEPTH_FROM_ID(id), y); + else + size_row(std, WIDTH_FROM_ID(id) * bit_size(pp, COL_FROM_ID(id), + DEPTH_FROM_ID(id)), y); +} + +/* Tests - individual test cases */ +/* Like 'make_standard' but errors are deliberately introduced into the calls + * to ensure that they get detected - it should not be possible to write an + * invalid image with libpng! + */ +static void +sBIT0_error_fn(png_structp pp, png_infop pi) +{ + /* 0 is invalid... */ + png_color_8 bad; + bad.red = bad.green = bad.blue = bad.gray = bad.alpha = 0; + png_set_sBIT(pp, pi, &bad); +} + +static void +sBIT_error_fn(png_structp pp, png_infop pi) +{ + png_byte bit_depth; + png_color_8 bad; + + if (png_get_color_type(pp, pi) == PNG_COLOR_TYPE_PALETTE) + bit_depth = 8; + + else + bit_depth = png_get_bit_depth(pp, pi); + + /* Now we know the bit depth we can easily generate an invalid sBIT entry */ + bad.red = bad.green = bad.blue = bad.gray = bad.alpha = + (png_byte)(bit_depth+1); + png_set_sBIT(pp, pi, &bad); +} + +static PNG_CONST struct +{ + void (*fn)(png_structp, png_infop); + PNG_CONST char *msg; + unsigned int warning :1; /* the error is a warning... */ +} error_test[] = + { + { sBIT0_error_fn, "sBIT(0): failed to detect error", 1 }, + { sBIT_error_fn, "sBIT(too big): failed to detect error", 1 }, + }; + +static void +make_error(png_store* volatile ps, png_byte PNG_CONST colour_type, + png_byte bit_depth, int interlace_type, int test, png_const_charp name) +{ + context(ps, fault); + + Try + { + png_structp pp; + png_infop pi; + + pp = set_store_for_write(ps, &pi, name); + + if (pp == NULL) + Throw ps; + + png_set_IHDR(pp, pi, transform_width(pp, colour_type, bit_depth), + transform_height(pp, colour_type, bit_depth), bit_depth, colour_type, + interlace_type, PNG_COMPRESSION_TYPE_BASE, PNG_FILTER_TYPE_BASE); + + if (colour_type == 3) /* palette */ + { + unsigned int i = 0; + png_color pal[256]; + + do + pal[i].red = pal[i].green = pal[i].blue = (png_byte)i; + while(++i < 256U); + + png_set_PLTE(pp, pi, pal, 256); + } + + /* Time for a few errors, these are in various optional chunks, the + * standard tests test the standard chunks pretty well. + */ +# define exception__prev exception_prev_1 +# define exception__env exception_env_1 + Try + { + /* Expect this to throw: */ + ps->expect_error = !error_test[test].warning; + ps->expect_warning = error_test[test].warning; + ps->saw_warning = 0; + error_test[test].fn(pp, pi); + + /* Normally the error is only detected here: */ + png_write_info(pp, pi); + + /* And handle the case where it was only a warning: */ + if (ps->expect_warning && ps->saw_warning) + Throw ps; + + /* If we get here there is a problem, we have success - no error or + * no warning - when we shouldn't have success. Log an error. + */ + store_log(ps, pp, error_test[test].msg, 1 /*error*/); + } + + Catch (fault) + ps = fault; /* expected exit, make sure ps is not clobbered */ +#undef exception__prev +#undef exception__env + + /* And clear these flags */ + ps->expect_error = 0; + ps->expect_warning = 0; + + /* Now write the whole image, just to make sure that the detected, or + * undetected, errro has not created problems inside libpng. + */ + if (png_get_rowbytes(pp, pi) != + transform_rowsize(pp, colour_type, bit_depth)) + png_error(pp, "row size incorrect"); + + else + { + png_uint_32 h = transform_height(pp, colour_type, bit_depth); + int npasses = png_set_interlace_handling(pp); + int pass; + + if (npasses != npasses_from_interlace_type(pp, interlace_type)) + png_error(pp, "write: png_set_interlace_handling failed"); + + for (pass=0; pass<npasses; ++pass) + { + png_uint_32 y; + + for (y=0; y<h; ++y) + { + png_byte buffer[TRANSFORM_ROWMAX]; + + transform_row(pp, buffer, colour_type, bit_depth, y); + png_write_row(pp, buffer); + } + } + } + + png_write_end(pp, pi); + + /* The following deletes the file that was just written. */ + store_write_reset(ps); + } + + Catch(fault) + { + store_write_reset(fault); + } +} + +static int +make_errors(png_modifier* PNG_CONST pm, png_byte PNG_CONST colour_type, + int bdlo, int PNG_CONST bdhi) +{ + for (; bdlo <= bdhi; ++bdlo) + { + int interlace_type; + + for (interlace_type = PNG_INTERLACE_NONE; + interlace_type < PNG_INTERLACE_LAST; ++interlace_type) + { + unsigned int test; + char name[FILE_NAME_SIZE]; + + standard_name(name, sizeof name, 0, colour_type, bdlo, interlace_type, + 0, 0, 0); + + for (test=0; test<(sizeof error_test)/(sizeof error_test[0]); ++test) + { + make_error(&pm->this, colour_type, DEPTH(bdlo), interlace_type, + test, name); + + if (fail(pm)) + return 0; + } + } + } + + return 1; /* keep going */ +} + +static void +perform_error_test(png_modifier *pm) +{ + /* Need to do this here because we just write in this test. */ + safecat(pm->this.test, sizeof pm->this.test, 0, "error test"); + + if (!make_errors(pm, 0, 0, WRITE_BDHI)) + return; + + if (!make_errors(pm, 2, 3, WRITE_BDHI)) + return; + + if (!make_errors(pm, 3, 0, 3)) + return; + + if (!make_errors(pm, 4, 3, WRITE_BDHI)) + return; + + if (!make_errors(pm, 6, 3, WRITE_BDHI)) + return; +} + +/* Because we want to use the same code in both the progressive reader and the + * sequential reader it is necessary to deal with the fact that the progressive + * reader callbacks only have one parameter (png_get_progressive_ptr()), so this + * must contain all the test parameters and all the local variables directly + * accessible to the sequential reader implementation. + * + * The technique adopted is to reinvent part of what Dijkstra termed a + * 'display'; an array of pointers to the stack frames of enclosing functions so + * that a nested function definition can access the local (C auto) variables of + * the functions that contain its definition. In fact C provides the first + * pointer (the local variables - the stack frame pointer) and the last (the + * global variables - the BCPL global vector typically implemented as global + * addresses), this code requires one more pointer to make the display - the + * local variables (and function call parameters) of the function that actually + * invokes either the progressive or sequential reader. + * + * Perhaps confusingly this technique is confounded with classes - the + * 'standard_display' defined here is sub-classed as the 'gamma_display' below. + * A gamma_display is a standard_display, taking advantage of the ANSI-C + * requirement that the pointer to the first member of a structure must be the + * same as the pointer to the structure. This allows us to reuse standard_ + * functions in the gamma test code; something that could not be done with + * nested funtions! + */ +typedef struct standard_palette_entry /* pngvalid format palette! */ +{ + png_byte red; + png_byte green; + png_byte blue; + png_byte alpha; +} standard_palette[256]; + +typedef struct standard_display +{ + png_store* ps; /* Test parameters (passed to the function) */ + png_byte colour_type; + png_byte bit_depth; + png_byte red_sBIT; /* Input data sBIT values. */ + png_byte green_sBIT; + png_byte blue_sBIT; + png_byte alpha_sBIT; + int interlace_type; + png_uint_32 id; /* Calculated file ID */ + png_uint_32 w; /* Width of image */ + png_uint_32 h; /* Height of image */ + int npasses; /* Number of interlaced passes */ + png_uint_32 pixel_size; /* Width of one pixel in bits */ + png_uint_32 bit_width; /* Width of output row in bits */ + size_t cbRow; /* Bytes in a row of the output image */ + int do_interlace; /* Do interlacing internally */ + int is_transparent; /* Transparecy information was present. */ + struct + { + png_uint_16 red; + png_uint_16 green; + png_uint_16 blue; + } transparent; /* The transparent color, if set. */ + standard_palette + palette; +} standard_display; + +static void +standard_display_init(standard_display *dp, png_store* ps, png_uint_32 id, + int do_interlace) +{ + dp->ps = ps; + dp->colour_type = COL_FROM_ID(id); + dp->bit_depth = DEPTH_FROM_ID(id); + dp->alpha_sBIT = dp->blue_sBIT = dp->green_sBIT = dp->alpha_sBIT = + dp->bit_depth; + dp->interlace_type = INTERLACE_FROM_ID(id); + dp->id = id; + /* All the rest are filled in after the read_info: */ + dp->w = 0; + dp->h = 0; + dp->npasses = 0; + dp->pixel_size = 0; + dp->bit_width = 0; + dp->cbRow = 0; + dp->do_interlace = do_interlace; + dp->is_transparent = 0; + /* Preset the transparent color to black: */ + memset(&dp->transparent, 0, sizeof dp->transparent); + /* Preset the palette to full intensity/opaque througout: */ + memset(dp->palette, 0xff, sizeof dp->palette); + +} + +/* Call this only if the colour type is 3 - PNG_COLOR_TYPE_PALETTE - otherwise + * it will png_error out. The API returns true if tRNS information was + * present. + */ +static int +standard_palette_init(standard_palette palette, png_structp pp, png_infop pi) +{ + png_colorp pal; + png_bytep trans_alpha; + int num; + + pal = 0; + num = -1; + if (png_get_PLTE(pp, pi, &pal, &num) & PNG_INFO_PLTE) + { + int i; + + for (i=0; i<num; ++i) + { + palette[i].red = pal[i].red; + palette[i].green = pal[i].green; + palette[i].blue = pal[i].blue; + } + + /* Mark the remainder of the entries with a flag value: */ + for (; i<256; ++i) + palette[i].red = palette[i].green = palette[i].blue = 126; + } + + else /* !png_get_PLTE */ + png_error(pp, "validate: missing PLTE with color type 3"); + + trans_alpha = 0; + num = -1; + if (png_get_tRNS(pp, pi, &trans_alpha, &num, 0) & PNG_INFO_tRNS) + { + int i; + + /* Any of these are crash-worthy - given the implementation of + * png_get_tRNS up to 1.5 an app won't crash if it just checks the + * result above and fails to check that the variables it passed have + * actually been filled in! Note that if the app were to pass the + * last, png_color_16p, variable too it couldn't rely on this. + */ + if (trans_alpha == 0 || num <= 0 || num > 256) + png_error(pp, "validate: unexpected png_get_tRNS (palette) result"); + + for (i=0; i<num; ++i) + palette[i].alpha = trans_alpha[i]; + + for (; i<256; ++i) + palette[i].alpha = 255; + + return 1; /* transparency */ + } + + else + { + /* No transparency - just set the alpha channel to opaque. */ + int i; + + for (i=0; i<256; ++i) + palette[i].alpha = 255; + + return 0; /* no transparency */ + } +} + +/* By passing a 'standard_display' the progressive callbacks can be used + * directly by the sequential code, the functions suffixed "_imp" are the + * implementations, the functions without the suffix are the callbacks. + * + * The code for the info callback is split into two because this callback calls + * png_read_update_info or png_start_read_image and what gets called depends on + * whether the info needs updating (we want to test both calls in pngvalid.) + */ +static void +standard_info_part1(standard_display *dp, png_structp pp, png_infop pi) +{ + if (png_get_bit_depth(pp, pi) != dp->bit_depth) + png_error(pp, "validate: bit depth changed"); + + if (png_get_color_type(pp, pi) != dp->colour_type) + png_error(pp, "validate: color type changed"); + + if (png_get_filter_type(pp, pi) != PNG_FILTER_TYPE_BASE) + png_error(pp, "validate: filter type changed"); + + if (png_get_interlace_type(pp, pi) != dp->interlace_type) + png_error(pp, "validate: interlacing changed"); + + if (png_get_compression_type(pp, pi) != PNG_COMPRESSION_TYPE_BASE) + png_error(pp, "validate: compression type changed"); + + dp->w = png_get_image_width(pp, pi); + + if (dp->w != standard_width(pp, dp->id)) + png_error(pp, "validate: image width changed"); + + dp->h = png_get_image_height(pp, pi); + + if (dp->h != standard_height(pp, dp->id)) + png_error(pp, "validate: image height changed"); + + /* Record (but don't check at present) the input sBIT according to the colour + * type information. + */ + { + png_color_8p sBIT = 0; + + if (png_get_sBIT(pp, pi, &sBIT) & PNG_INFO_sBIT) + { + int sBIT_invalid = 0; + + if (sBIT == 0) + png_error(pp, "validate: unexpected png_get_sBIT result"); + + if (dp->colour_type & PNG_COLOR_MASK_COLOR) + { + if (sBIT->red == 0 || sBIT->red > dp->bit_depth) + sBIT_invalid = 1; + else + dp->red_sBIT = sBIT->red; + + if (sBIT->green == 0 || sBIT->green > dp->bit_depth) + sBIT_invalid = 1; + else + dp->green_sBIT = sBIT->green; + + if (sBIT->blue == 0 || sBIT->blue > dp->bit_depth) + sBIT_invalid = 1; + else + dp->blue_sBIT = sBIT->blue; + } + + else /* !COLOR */ + { + if (sBIT->gray == 0 || sBIT->gray > dp->bit_depth) + sBIT_invalid = 1; + else + dp->blue_sBIT = dp->green_sBIT = dp->red_sBIT = sBIT->gray; + } + + /* All 8 bits in tRNS for a palette image are significant - see the + * spec. + */ + if (dp->colour_type & PNG_COLOR_MASK_ALPHA) + { + if (sBIT->alpha == 0 || sBIT->alpha > dp->bit_depth) + sBIT_invalid = 1; + else + dp->alpha_sBIT = sBIT->alpha; + } + + if (sBIT_invalid) + png_error(pp, "validate: sBIT value out of range"); + } + } + + /* Important: this is validating the value *before* any transforms have been + * put in place. It doesn't matter for the standard tests, where there are + * no transforms, but it does for other tests where rowbytes may change after + * png_read_update_info. + */ + if (png_get_rowbytes(pp, pi) != standard_rowsize(pp, dp->id)) + png_error(pp, "validate: row size changed"); + + /* The palette is never read for non-palette images, even though it is valid + * - this could be changed. + */ + if (dp->colour_type == 3) /* palette */ + { + int i; + + dp->is_transparent = standard_palette_init(dp->palette, pp, pi); + + /* And validate the result. */ + for (i=0; i<256; ++i) + if (dp->palette[i].red != i || dp->palette[i].green != i || + dp->palette[i].blue != i) + png_error(pp, "validate: color type 3 PLTE chunk changed"); + } + + /* In any case always check for a tranparent color: */ + { + png_color_16p trans_color = 0; + + if (png_get_tRNS(pp, pi, 0, 0, &trans_color) & PNG_INFO_tRNS) + { + if (trans_color == 0) + png_error(pp, "validate: unexpected png_get_tRNS (color) result"); + + switch (dp->colour_type) + { + case 0: + dp->transparent.red = dp->transparent.green = dp->transparent.blue = + trans_color->gray; + dp->is_transparent = 1; + break; + + case 2: + dp->transparent.red = trans_color->red; + dp->transparent.green = trans_color->green; + dp->transparent.blue = trans_color->blue; + dp->is_transparent = 1; + break; + + case 3: + /* Not expected because it should result in the array case + * above. + */ + png_error(pp, "validate: unexpected png_get_tRNS result"); + break; + + default: + png_error(pp, "validate: invalid tRNS chunk with alpha image"); + } + } + } + + /* Read the number of passes - expected to match the value used when + * creating the image (interlaced or not). This has the side effect of + * turning on interlace handling (if do_interlace is not set.) + */ + dp->npasses = npasses_from_interlace_type(pp, dp->interlace_type); + if (!dp->do_interlace && dp->npasses != png_set_interlace_handling(pp)) + png_error(pp, "validate: file changed interlace type"); + + /* Caller calls png_read_update_info or png_start_read_image now, then calls + * part2. + */ +} + +/* This must be called *after* the png_read_update_info call to get the correct + * 'rowbytes' value, otherwise png_get_rowbytes will refer to the untransformed + * image. + */ +static void +standard_info_part2(standard_display *dp, png_structp pp, png_infop pi, + int nImages) +{ + /* Record cbRow now that it can be found. */ + dp->pixel_size = bit_size(pp, png_get_color_type(pp, pi), + png_get_bit_depth(pp, pi)); + dp->bit_width = png_get_image_width(pp, pi) * dp->pixel_size; + dp->cbRow = png_get_rowbytes(pp, pi); + + /* Validate the rowbytes here again. */ + if (dp->cbRow != (dp->bit_width+7)/8) + png_error(pp, "bad png_get_rowbytes calculation"); + + /* Then ensure there is enough space for the output image(s). */ + store_ensure_image(dp->ps, pp, nImages * dp->cbRow * dp->h); +} + +static void +standard_info_imp(standard_display *dp, png_structp pp, png_infop pi, + int nImages) +{ + /* Note that the validation routine has the side effect of turning on + * interlace handling in the subsequent code. + */ + standard_info_part1(dp, pp, pi); + + /* And the info callback has to call this (or png_read_update_info - see + * below in the png_modifier code for that variant. + */ + png_start_read_image(pp); + + /* Validate the height, width and rowbytes plus ensure that sufficient buffer + * exists for decoding the image. + */ + standard_info_part2(dp, pp, pi, nImages); +} + +static void +standard_info(png_structp pp, png_infop pi) +{ + standard_display *dp = png_get_progressive_ptr(pp); + + /* Call with nImages==1 because the progressive reader can only produce one + * image. + */ + standard_info_imp(dp, pp, pi, 1 /*only one image*/); +} + +static void +progressive_row(png_structp pp, png_bytep new_row, png_uint_32 y, int pass) +{ + PNG_CONST standard_display *dp = png_get_progressive_ptr(pp); + + /* When handling interlacing some rows will be absent in each pass, the + * callback still gets called, but with a NULL pointer. This is checked + * in the 'else' clause below. We need our own 'cbRow', but we can't call + * png_get_rowbytes because we got no info structure. + */ + if (new_row != NULL) + { + png_bytep row; + + /* In the case where the reader doesn't do the interlace it gives + * us the y in the sub-image: + */ + if (dp->do_interlace && dp->interlace_type == PNG_INTERLACE_ADAM7) + y = PNG_ROW_FROM_PASS_ROW(y, pass); + + /* Validate this just in case. */ + if (y >= dp->h) + png_error(pp, "invalid y to progressive row callback"); + + row = dp->ps->image + y * dp->cbRow; + + /* Combine the new row into the old: */ + if (dp->do_interlace) + { + if (dp->interlace_type == PNG_INTERLACE_ADAM7) + deinterlace_row(row, new_row, dp->pixel_size, dp->w, pass); + else + memcpy(row, new_row, dp->cbRow); + } + else + png_progressive_combine_row(pp, row, new_row); + } else if (dp->interlace_type == PNG_INTERLACE_ADAM7 && + PNG_ROW_IN_INTERLACE_PASS(y, pass) && + PNG_PASS_COLS(dp->w, pass) > 0) + png_error(pp, "missing row in progressive de-interlacing"); +} + +static void +sequential_row(standard_display *dp, png_structp pp, png_infop pi, + PNG_CONST png_bytep pImage, PNG_CONST png_bytep pDisplay) +{ + PNG_CONST int npasses = dp->npasses; + PNG_CONST int do_interlace = dp->do_interlace && + dp->interlace_type == PNG_INTERLACE_ADAM7; + PNG_CONST png_uint_32 height = standard_height(pp, dp->id); + PNG_CONST png_uint_32 width = standard_width(pp, dp->id); + PNG_CONST size_t cbRow = dp->cbRow; + int pass; + + for (pass=0; pass<npasses; ++pass) + { + png_uint_32 y; + png_uint_32 wPass = PNG_PASS_COLS(width, pass); + png_bytep pRow1 = pImage; + png_bytep pRow2 = pDisplay; + + for (y=0; y<height; ++y) + { + if (do_interlace) + { + /* wPass may be zero or this row may not be in this pass. + * png_read_row must not be called in either case. + */ + if (wPass > 0 && PNG_ROW_IN_INTERLACE_PASS(y, pass)) + { + /* Read the row into a pair of temporary buffers, then do the + * merge here into the output rows. + */ + png_byte row[STANDARD_ROWMAX], display[STANDARD_ROWMAX]; + + /* The following aids (to some extent) error detection - we can + * see where png_read_row wrote. Use opposite values in row and + * display to make this easier. + */ + memset(row, 0xff, sizeof row); + memset(display, 0, sizeof display); + + png_read_row(pp, row, display); + + if (pRow1 != NULL) + deinterlace_row(pRow1, row, dp->pixel_size, dp->w, pass); + + if (pRow2 != NULL) + deinterlace_row(pRow2, display, dp->pixel_size, dp->w, pass); + } + } + else + png_read_row(pp, pRow1, pRow2); + + if (pRow1 != NULL) + pRow1 += cbRow; + + if (pRow2 != NULL) + pRow2 += cbRow; + } + } + + /* And finish the read operation (only really necessary if the caller wants + * to find additional data in png_info from chunks after the last IDAT.) + */ + png_read_end(pp, pi); +} + +static void +standard_row_validate(standard_display *dp, png_structp pp, png_const_bytep row, + png_const_bytep display, png_uint_32 y) +{ + png_byte std[STANDARD_ROWMAX]; + + memset(std, 0xff, sizeof std); + standard_row(pp, std, dp->id, y); + + /* At the end both the 'row' and 'display' arrays should end up identical. + * In earlier passes 'row' will be partially filled in, with only the pixels + * that have been read so far, but 'display' will have those pixels + * replicated to fill the unread pixels while reading an interlaced image. + * The side effect inside the libpng sequential reader is that the 'row' + * array retains the correct values for unwritten pixels within the row + * bytes, while the 'display' array gets bits off the end of the image (in + * the last byte) trashed. Unfortunately in the progressive reader the + * row bytes are always trashed, so we always do a pixel_cmp here even though + * a memcmp of all cbRow bytes will succeed for the sequential reader. + */ + if (row != NULL && pixel_cmp(std, row, dp->bit_width) != 0) + { + char msg[64]; + sprintf(msg, "PNG image row %d changed", y); + png_error(pp, msg); + } + + /* In this case use pixel_cmp because we need to compare a partial + * byte at the end of the row if the row is not an exact multiple + * of 8 bits wide. + */ + if (display != NULL && pixel_cmp(std, display, dp->bit_width) != 0) + { + char msg[64]; + sprintf(msg, "display row %d changed", y); + png_error(pp, msg); + } +} + +static void +standard_image_validate(standard_display *dp, png_structp pp, + png_const_bytep pImage, png_const_bytep pDisplay) +{ + png_uint_32 y; + + for (y=0; y<dp->h; ++y) + { + standard_row_validate(dp, pp, pImage, pDisplay, y); + + if (pImage != NULL) + pImage += dp->cbRow; + + if (pDisplay != NULL) + pDisplay += dp->cbRow; + } + + /* This avoids false positives if the validation code is never called! */ + dp->ps->validated = 1; +} + +static void +standard_end(png_structp pp, png_infop pi) +{ + standard_display *dp = png_get_progressive_ptr(pp); + + UNUSED(pi) + + /* Validate the image - progressive reading only produces one variant for + * interlaced images. + */ + standard_image_validate(dp, pp, dp->ps->image, NULL); +} + +/* A single test run checking the standard image to ensure it is not damaged. */ +static void +standard_test(png_store* PNG_CONST psIn, png_uint_32 PNG_CONST id, + int do_interlace) +{ + standard_display d; + context(psIn, fault); + + /* Set up the display (stack frame) variables from the arguments to the + * function and initialize the locals that are filled in later. + */ + standard_display_init(&d, psIn, id, do_interlace); + + /* Everything is protected by a Try/Catch. The functions called also + * typically have local Try/Catch blocks. + */ + Try + { + png_structp pp; + png_infop pi; + + /* Get a png_struct for reading the image. This will throw an error if it + * fails, so we don't need to check the result. + */ + pp = set_store_for_read(d.ps, &pi, d.id, + d.do_interlace ? (d.ps->progressive ? + "pngvalid progressive deinterlacer" : + "pngvalid sequential deinterlacer") : (d.ps->progressive ? + "progressive reader" : "sequential reader")); + + /* Introduce the correct read function. */ + if (d.ps->progressive) + { + png_set_progressive_read_fn(pp, &d, standard_info, progressive_row, + standard_end); + + /* Now feed data into the reader until we reach the end: */ + store_progressive_read(d.ps, pp, pi); + } + else + { + /* Note that this takes the store, not the display. */ + png_set_read_fn(pp, d.ps, store_read); + + /* Check the header values: */ + png_read_info(pp, pi); + + /* The code tests both versions of the images that the sequential + * reader can produce. + */ + standard_info_imp(&d, pp, pi, 2 /*images*/); + + /* Need the total bytes in the image below; we can't get to this point + * unless the PNG file values have been checked against the expected + * values. + */ + { + PNG_CONST png_bytep pImage = d.ps->image; + PNG_CONST png_bytep pDisplay = pImage + d.cbRow * d.h; + + sequential_row(&d, pp, pi, pImage, pDisplay); + + /* After the last pass loop over the rows again to check that the + * image is correct. + */ + standard_image_validate(&d, pp, pImage, pDisplay); + } + } + + /* Check for validation. */ + if (!d.ps->validated) + png_error(pp, "image read failed silently"); + + /* Successful completion. */ + } + + Catch(fault) + d.ps = fault; /* make sure this hasn't been clobbered. */ + + /* In either case clean up the store. */ + store_read_reset(d.ps); +} + +static int +test_standard(png_modifier* PNG_CONST pm, png_byte PNG_CONST colour_type, + int bdlo, int PNG_CONST bdhi) +{ + for (; bdlo <= bdhi; ++bdlo) + { + int interlace_type; + + for (interlace_type = PNG_INTERLACE_NONE; + interlace_type < PNG_INTERLACE_LAST; ++interlace_type) + { + standard_test(&pm->this, FILEID(colour_type, DEPTH(bdlo), + interlace_type, 0, 0, 0), 0/*do_interlace*/); + + if (fail(pm)) + return 0; + } + } + + return 1; /* keep going */ +} + +static void +perform_standard_test(png_modifier *pm) +{ + /* Test each colour type over the valid range of bit depths (expressed as + * log2(bit_depth) in turn, stop as soon as any error is detected. + */ + if (!test_standard(pm, 0, 0, READ_BDHI)) + return; + + if (!test_standard(pm, 2, 3, READ_BDHI)) + return; + + if (!test_standard(pm, 3, 0, 3)) + return; + + if (!test_standard(pm, 4, 3, READ_BDHI)) + return; + + if (!test_standard(pm, 6, 3, READ_BDHI)) + return; +} + + +/********************************** SIZE TESTS ********************************/ +static int +test_size(png_modifier* PNG_CONST pm, png_byte PNG_CONST colour_type, + int bdlo, int PNG_CONST bdhi) +{ + /* Run the tests on each combination. + * + * NOTE: on my 32 bit x86 each of the following blocks takes + * a total of 3.5 seconds if done across every combo of bit depth + * width and height. This is a waste of time in practice, hence the + * hinc and winc stuff: + */ + static PNG_CONST png_byte hinc[] = {1, 3, 11, 1, 5}; + static PNG_CONST png_byte winc[] = {1, 9, 5, 7, 1}; + for (; bdlo <= bdhi; ++bdlo) + { + png_uint_32 h, w; + + for (h=1; h<=16; h+=hinc[bdlo]) for (w=1; w<=16; w+=winc[bdlo]) + { + /* First test all the 'size' images against the sequential + * reader using libpng to deinterlace (where required.) This + * validates the write side of libpng. There are four possibilities + * to validate. + */ + standard_test(&pm->this, FILEID(colour_type, DEPTH(bdlo), + PNG_INTERLACE_NONE, w, h, 0), 0/*do_interlace*/); + + if (fail(pm)) + return 0; + + standard_test(&pm->this, FILEID(colour_type, DEPTH(bdlo), + PNG_INTERLACE_NONE, w, h, 1), 0/*do_interlace*/); + + if (fail(pm)) + return 0; + + standard_test(&pm->this, FILEID(colour_type, DEPTH(bdlo), + PNG_INTERLACE_ADAM7, w, h, 0), 0/*do_interlace*/); + + if (fail(pm)) + return 0; + + standard_test(&pm->this, FILEID(colour_type, DEPTH(bdlo), + PNG_INTERLACE_ADAM7, w, h, 1), 0/*do_interlace*/); + + if (fail(pm)) + return 0; + + /* Now validate the interlaced read side - do_interlace true, + * in the progressive case this does actually make a difference + * to the code used in the non-interlaced case too. + */ + standard_test(&pm->this, FILEID(colour_type, DEPTH(bdlo), + PNG_INTERLACE_NONE, w, h, 0), 1/*do_interlace*/); + + if (fail(pm)) + return 0; + + standard_test(&pm->this, FILEID(colour_type, DEPTH(bdlo), + PNG_INTERLACE_ADAM7, w, h, 0), 1/*do_interlace*/); + + if (fail(pm)) + return 0; + } + } + + return 1; /* keep going */ +} + +static void +perform_size_test(png_modifier *pm) +{ + /* Test each colour type over the valid range of bit depths (expressed as + * log2(bit_depth) in turn, stop as soon as any error is detected. + */ + if (!test_size(pm, 0, 0, READ_BDHI)) + return; + + if (!test_size(pm, 2, 3, READ_BDHI)) + return; + + /* For the moment don't do the palette test - it's a waste of time when + * compared to the greyscale test. + */ +#if 0 + if (!test_size(pm, 3, 0, 3)) + return; +#endif + + if (!test_size(pm, 4, 3, READ_BDHI)) + return; + + if (!test_size(pm, 6, 3, READ_BDHI)) + return; +} + + +/******************************* TRANSFORM TESTS ******************************/ +/* A set of tests to validate libpng image transforms. The possibilities here + * are legion because the transforms can be combined in a combinatorial + * fashion. To deal with this some measure of restraint is required, otherwise + * the tests would take forever. + */ +typedef struct image_pixel +{ + /* A local (pngvalid) representation of a PNG pixel, in all its + * various forms. + */ + unsigned int red, green, blue, alpha; /* For non-palette images. */ + unsigned int palette_index; /* For a palette image. */ + png_byte colour_type; /* As in the spec. */ + png_byte bit_depth; /* Defines bit size in row */ + png_byte sample_depth; /* Scale of samples */ + int have_tRNS; /* tRNS chunk may need processing */ + + /* For checking the code calculates double precision floating point values + * along with an error value, accumulated from the transforms. Because an + * sBIT setting allows larger error bounds (indeed, by the spec, apparently + * up to just less than +/-1 in the scaled value) the *lowest* sBIT for each + * channel is stored. This sBIT value is folded in to the stored error value + * at the end of the application of the transforms to the pixel. + */ + double redf, greenf, bluef, alphaf; + double rede, greene, bluee, alphae; + png_byte red_sBIT, green_sBIT, blue_sBIT, alpha_sBIT; +} image_pixel; + +/* Shared utility function, see below. */ +static void +image_pixel_setf(image_pixel *this, unsigned int max) +{ + this->redf = this->red / (double)max; + this->greenf = this->green / (double)max; + this->bluef = this->blue / (double)max; + this->alphaf = this->alpha / (double)max; + + if (this->red < max) + this->rede = this->redf * DBL_EPSILON; + else + this->rede = 0; + if (this->green < max) + this->greene = this->greenf * DBL_EPSILON; + else + this->greene = 0; + if (this->blue < max) + this->bluee = this->bluef * DBL_EPSILON; + else + this->bluee = 0; + if (this->alpha < max) + this->alphae = this->alphaf * DBL_EPSILON; + else + this->alphae = 0; +} + +/* Initialize the structure for the next pixel - call this before doing any + * transforms and call it for each pixel since all the fields may need to be + * reset. + */ +static void +image_pixel_init(image_pixel *this, png_const_bytep row, png_byte colour_type, + png_byte bit_depth, png_uint_32 x, standard_palette palette) +{ + PNG_CONST png_byte sample_depth = (png_byte)(colour_type == + PNG_COLOR_TYPE_PALETTE ? 8 : bit_depth); + PNG_CONST unsigned int max = (1U<<sample_depth)-1; + + /* Initially just set everything to the same number and the alpha to opaque. + * Note that this currently assumes a simple palette where entry x has colour + * rgb(x,x,x)! + */ + this->palette_index = this->red = this->green = this->blue = + sample(row, colour_type, bit_depth, x, 0); + this->alpha = max; + this->red_sBIT = this->green_sBIT = this->blue_sBIT = this->alpha_sBIT = + sample_depth; + + /* Then override as appropriate: */ + if (colour_type == 3) /* palette */ + { + /* This permits the caller to default to the sample value. */ + if (palette != 0) + { + PNG_CONST unsigned int i = this->palette_index; + + this->red = palette[i].red; + this->green = palette[i].green; + this->blue = palette[i].blue; + this->alpha = palette[i].alpha; + } + } + + else /* not palette */ + { + unsigned int i = 0; + + if (colour_type & 2) + { + this->green = sample(row, colour_type, bit_depth, x, 1); + this->blue = sample(row, colour_type, bit_depth, x, 2); + i = 2; + } + if (colour_type & 4) + this->alpha = sample(row, colour_type, bit_depth, x, ++i); + } + + /* Calculate the scaled values, these are simply the values divided by + * 'max' and the error is initialized to the double precision epsilon value + * from the header file. + */ + image_pixel_setf(this, max); + + /* Store the input information for use in the transforms - these will + * modify the information. + */ + this->colour_type = colour_type; + this->bit_depth = bit_depth; + this->sample_depth = sample_depth; + this->have_tRNS = 0; +} + +/* Convert a palette image to an rgb image. This necessarily converts the tRNS + * chunk at the same time, because the tRNS will be in palette form. + */ +static void +image_pixel_convert_PLTE(image_pixel *this, const standard_display *display) +{ + if (this->colour_type == PNG_COLOR_TYPE_PALETTE) + { + PNG_CONST unsigned int i = this->palette_index; + + this->bit_depth = this->sample_depth; + this->red = display->palette[i].red; + this->green = display->palette[i].green; + this->blue = display->palette[i].blue; + this->red_sBIT = display->red_sBIT; + this->green_sBIT = display->green_sBIT; + this->blue_sBIT = display->blue_sBIT; + + if (this->have_tRNS) + { + this->alpha = display->palette[i].alpha; + this->colour_type = PNG_COLOR_TYPE_RGB_ALPHA; + this->have_tRNS = 0; + } + else + { + this->alpha = 255; + this->colour_type = PNG_COLOR_TYPE_RGB; + } + this->alpha_sBIT = 8; + + /* And regenerate the scaled values and all the errors, which are now set + * back to the initial values. + */ + image_pixel_setf(this, 255); + } +} + +/* Add an alpha channel, this will glom in the tRNS information because tRNS is + * not valid in an alpha image. The bit depth will invariably be set to at + * least 8. Palette images will be converted to alpha (using the above API). + */ +static void +image_pixel_add_alpha(image_pixel *this, const standard_display *display) +{ + if (this->colour_type == PNG_COLOR_TYPE_PALETTE) + image_pixel_convert_PLTE(this, display); + + if ((this->colour_type & PNG_COLOR_MASK_ALPHA) == 0) + { + if (this->colour_type == PNG_COLOR_TYPE_GRAY) + { + if (this->bit_depth < 8) + this->bit_depth = 8; + + if (this->have_tRNS) + { + this->have_tRNS = 0; + + /* Check the input, original, channel value here against the + * original tRNS gray chunk valie. + */ + if (this->red == display->transparent.red) + this->alphaf = 0; + else + this->alphaf = 1; + } + else + this->alphaf = 1; + + this->colour_type = PNG_COLOR_TYPE_GRAY_ALPHA; + } + + else if (this->colour_type == PNG_COLOR_TYPE_RGB) + { + if (this->have_tRNS) + { + this->have_tRNS = 0; + + /* Again, check the exact input values, not the current transformed + * value! + */ + if (this->red == display->transparent.red && + this->green == display->transparent.green && + this->blue == display->transparent.blue) + this->alphaf = 0; + else + this->alphaf = 1; + + this->colour_type = PNG_COLOR_TYPE_RGB_ALPHA; + } + } + + /* The error in the alpha is zero and the sBIT value comes from the + * original sBIT data (actually it will always be the original bit depth). + */ + this->alphae = 0; + this->alpha_sBIT = display->alpha_sBIT; + } +} + +struct transform_display; +typedef struct image_transform +{ + /* The name of this transform: a string. */ + PNG_CONST char *name; + + /* Each transform can be disabled from the command line: */ + int enable; + + /* The global list of transforms; read only. */ + struct image_transform *PNG_CONST list; + + /* The global count of the number of times this transform has been set on an + * image. + */ + unsigned int global_use; + + /* The local count of the number of times this transform has been set. */ + unsigned int local_use; + + /* The next transform in the list, each transform must call its own next + * transform after it has processed the pixel successfully. + */ + PNG_CONST struct image_transform *next; + + /* A single transform for the image, expressed as a series of function + * callbacks and some space for values. + * + * First a callback to set the transform on the current png_read_struct: + */ + void (*set)(PNG_CONST struct image_transform *this, + struct transform_display *that, png_structp pp, png_infop pi); + + /* Then a transform that takes an input pixel in one PNG format or another + * and modifies it by a pngvalid implementation of the transform (thus + * duplicating the libpng intent without, we hope, duplicating the bugs + * in the libpng implementation!) The png_structp is solely to allow error + * reporting via png_error and png_warning. + */ + void (*mod)(PNG_CONST struct image_transform *this, image_pixel *that, + png_structp pp, PNG_CONST struct transform_display *display); + + /* Add this transform to the list and return true if the transform is + * meaningful for this colour type and bit depth - if false then the + * transform should have no effect on the image so there's not a lot of + * point running it. + */ + int (*add)(struct image_transform *this, + PNG_CONST struct image_transform **that, png_byte colour_type, + png_byte bit_depth); +} image_transform; + +typedef struct transform_display +{ + standard_display this; + + /* Parameters */ + png_modifier* pm; + PNG_CONST image_transform* transform_list; + + /* Local variables */ + png_byte output_colour_type; + png_byte output_bit_depth; +} transform_display; + +/* Two functions to end the list: */ +static void +image_transform_set_end(PNG_CONST image_transform *this, + transform_display *that, png_structp pp, png_infop pi) +{ + UNUSED(this) + UNUSED(that) + UNUSED(pp) + UNUSED(pi) +} + +/* At the end of the list recalculate the output image pixel value from the + * double precision values set up by the preceding 'mod' calls: + */ +static unsigned int +sample_scale(double sample_value, unsigned int scale) +{ + sample_value = floor(sample_value * scale + .5); + + /* Return NaN as 0: */ + if (!(sample_value > 0)) + sample_value = 0; + else if (sample_value > scale) + sample_value = scale; + + return (unsigned int)sample_value; +} + +static void +image_transform_mod_end(PNG_CONST image_transform *this, image_pixel *that, + png_structp pp, PNG_CONST transform_display *display) +{ + PNG_CONST unsigned int scale = (1U<<that->sample_depth)-1; + + UNUSED(this) + UNUSED(pp) + UNUSED(display) + + /* At the end recalculate the digitized red green and blue values according + * to the current sample_depth of the pixel. + * + * The sample value is simply scaled to the maximum, checking for over + * and underflow (which can both happen for some image transforms, + * including simple size scaling, though libpng doesn't do that at present. + */ + that->red = sample_scale(that->redf, scale); + + /* The error value is increased, at the end, according to the lowest sBIT + * value seen. Common sense tells us that the intermediate integer + * representations are no more accurate than +/- 0.5 in the integral values, + * the sBIT allows the implementation to be worse than this. In addition the + * PNG specification actually permits any error within the range (-1..+1), + * but that is ignored here. Instead the final digitized value is compared, + * below to the digitized value of the error limits - this has the net effect + * of allowing (almost) +/-1 in the output value. It's difficult to see how + * any algorithm that digitizes intermediate results can be more accurate. + */ + that->rede += 1./(2*((1U<<that->red_sBIT)-1)); + + if (that->colour_type & PNG_COLOR_MASK_COLOR) + { + that->green = sample_scale(that->greenf, scale); + that->blue = sample_scale(that->bluef, scale); + that->greene += 1./(2*((1U<<that->green_sBIT)-1)); + that->bluee += 1./(2*((1U<<that->blue_sBIT)-1)); + } + else + { + that->blue = that->green = that->red; + that->bluef = that->greenf = that->redf; + that->bluee = that->greene = that->rede; + } + + if ((that->colour_type & PNG_COLOR_MASK_ALPHA) || + that->colour_type == PNG_COLOR_TYPE_PALETTE) + { + that->alpha = sample_scale(that->alphaf, scale); + that->alphae += 1./(2*((1U<<that->alpha_sBIT)-1)); + } + else + { + that->alpha = scale; /* opaque */ + that->alpha = 1; /* Override this. */ + that->alphae = 0; /* It's exact ;-) */ + } +} + +/* Static 'end' structure: */ +static image_transform image_transform_end = +{ + "(end)", /* name */ + 1, /* enable */ + 0, /* list */ + 0, /* global_use */ + 0, /* local_use */ + 0, /* next */ + image_transform_set_end, + image_transform_mod_end, + 0 /* never called, I want it to crash if it is! */ +}; + +/* Reader callbacks and implementations, where they differ from the standard + * ones. + */ +static void +transform_display_init(transform_display *dp, png_modifier *pm, png_uint_32 id, + PNG_CONST image_transform *transform_list) +{ + /* Standard fields */ + standard_display_init(&dp->this, &pm->this, id, 0/*do_interlace*/); + + /* Parameter fields */ + dp->pm = pm; + dp->transform_list = transform_list; + + /* Local variable fields */ + dp->output_colour_type = 255; /* invalid */ + dp->output_bit_depth = 255; /* invalid */ +} + +static void +transform_info_imp(transform_display *dp, png_structp pp, png_infop pi) +{ + /* Reuse the standard stuff as appropriate. */ + standard_info_part1(&dp->this, pp, pi); + + /* Now set the list of transforms. */ + dp->transform_list->set(dp->transform_list, dp, pp, pi); + + /* Update the info structure for these transforms: */ + png_read_update_info(pp, pi); + + /* And get the output information into the standard_display */ + standard_info_part2(&dp->this, pp, pi, 1/*images*/); + + /* Plus the extra stuff we need for the transform tests: */ + dp->output_colour_type = png_get_color_type(pp, pi); + dp->output_bit_depth = png_get_bit_depth(pp, pi); + + /* Validate the combination of colour type and bit depth that we are getting + * out of libpng; the semantics of something not in the PNG spec are, at + * best, unclear. + */ + switch (dp->output_colour_type) + { + case PNG_COLOR_TYPE_PALETTE: + if (dp->output_bit_depth > 8) goto error; + /*FALL THROUGH*/ + case PNG_COLOR_TYPE_GRAY: + if (dp->output_bit_depth == 1 || dp->output_bit_depth == 2 || + dp->output_bit_depth == 4) + break; + /*FALL THROUGH*/ + default: + if (dp->output_bit_depth == 8 || dp->output_bit_depth == 16) + break; + /*FALL THROUGH*/ + error: + { + char message[128]; + size_t pos; + + pos = safecat(message, sizeof message, 0, + "invalid final bit depth: colour type("); + pos = safecatn(message, sizeof message, pos, dp->output_colour_type); + pos = safecat(message, sizeof message, pos, ") with bit depth: "); + pos = safecatn(message, sizeof message, pos, dp->output_bit_depth); + + png_error(pp, message); + } + } + + /* Use a test pixel to check that the output agrees with what we expect - + * this avoids running the whole test if the output is unexpected. + */ + { + image_pixel test_pixel; + + memset(&test_pixel, 0, sizeof test_pixel); + test_pixel.colour_type = dp->this.colour_type; /* input */ + test_pixel.bit_depth = dp->this.bit_depth; + if (test_pixel.colour_type == PNG_COLOR_TYPE_PALETTE) + test_pixel.sample_depth = 8; + else + test_pixel.sample_depth = test_pixel.bit_depth; + /* Don't need sBIT here */ + test_pixel.have_tRNS = dp->this.is_transparent; + + dp->transform_list->mod(dp->transform_list, &test_pixel, pp, dp); + + if (test_pixel.colour_type != dp->output_colour_type) + { + char message[128]; + size_t pos = safecat(message, sizeof message, 0, "colour type "); + + pos = safecatn(message, sizeof message, pos, dp->output_colour_type); + pos = safecat(message, sizeof message, pos, " expected "); + pos = safecatn(message, sizeof message, pos, test_pixel.colour_type); + + png_error(pp, message); + } + + if (test_pixel.bit_depth != dp->output_bit_depth) + { + char message[128]; + size_t pos = safecat(message, sizeof message, 0, "bit depth "); + + pos = safecatn(message, sizeof message, pos, dp->output_bit_depth); + pos = safecat(message, sizeof message, pos, " expected "); + pos = safecatn(message, sizeof message, pos, test_pixel.bit_depth); + + png_error(pp, message); + } + + /* If both bit depth and colour type are correct check the sample depth. + * I believe these are both internal errors. + */ + if (test_pixel.colour_type == PNG_COLOR_TYPE_PALETTE) + { + if (test_pixel.sample_depth != 8) /* oops - internal error! */ + png_error(pp, "pngvalid: internal: palette sample depth not 8"); + } + else if (test_pixel.sample_depth != dp->output_bit_depth) + { + char message[128]; + size_t pos = safecat(message, sizeof message, 0, + "internal: sample depth "); + + pos = safecatn(message, sizeof message, pos, dp->output_bit_depth); + pos = safecat(message, sizeof message, pos, " expected "); + pos = safecatn(message, sizeof message, pos, test_pixel.sample_depth); + + png_error(pp, message); + } + } +} + +static void +transform_info(png_structp pp, png_infop pi) +{ + transform_info_imp(png_get_progressive_ptr(pp), pp, pi); +} + +static void +transform_range_check(png_structp pp, unsigned int r, unsigned int g, + unsigned int b, unsigned int a, unsigned int in_digitized, double in, + unsigned int out, png_byte sample_depth, double err, PNG_CONST char *name) +{ + /* Compare the scaled, digitzed, values of our local calculation (in+-err) + * with the digitized values libpng produced; 'sample_depth' is the actual + * digitization depth of the libpng output colors (the bit depth except for + * palette images where it is always 8.) + */ + unsigned int max = (1U<<sample_depth)-1; + double in_min = ceil((in-err)*max - .5); + double in_max = floor((in+err)*max + .5); + if (!(out >= in_min && out <= in_max)) + { + char message[256]; + size_t pos; + + pos = safecat(message, sizeof message, 0, name); + pos = safecat(message, sizeof message, pos, " output value error: rgba("); + pos = safecatn(message, sizeof message, pos, r); + pos = safecat(message, sizeof message, pos, ","); + pos = safecatn(message, sizeof message, pos, g); + pos = safecat(message, sizeof message, pos, ","); + pos = safecatn(message, sizeof message, pos, b); + pos = safecat(message, sizeof message, pos, ","); + pos = safecatn(message, sizeof message, pos, a); + pos = safecat(message, sizeof message, pos, "): "); + pos = safecatn(message, sizeof message, pos, out); + pos = safecat(message, sizeof message, pos, " expected: "); + pos = safecatn(message, sizeof message, pos, in_digitized); + pos = safecat(message, sizeof message, pos, " ("); + pos = safecatd(message, sizeof message, pos, (in-err)*max, 3); + pos = safecat(message, sizeof message, pos, ".."); + pos = safecatd(message, sizeof message, pos, (in+err)*max, 3); + pos = safecat(message, sizeof message, pos, ")"); + + png_error(pp, message); + } +} + +static void +transform_image_validate(transform_display *dp, png_structp pp, png_infop pi, + png_const_bytep pRow) +{ + /* Constants for the loop below: */ + PNG_CONST png_byte in_ct = dp->this.colour_type; + PNG_CONST png_byte in_bd = dp->this.bit_depth; + PNG_CONST png_uint_32 w = dp->this.w; + PNG_CONST png_uint_32 h = dp->this.h; + PNG_CONST size_t cbRow = dp->this.cbRow; + PNG_CONST png_byte out_ct = dp->output_colour_type; + PNG_CONST png_byte out_bd = dp->output_bit_depth; + PNG_CONST png_byte sample_depth = (png_byte)(out_ct == + PNG_COLOR_TYPE_PALETTE ? 8 : out_bd); + PNG_CONST png_byte red_sBIT = dp->this.red_sBIT; + PNG_CONST png_byte green_sBIT = dp->this.green_sBIT; + PNG_CONST png_byte blue_sBIT = dp->this.blue_sBIT; + PNG_CONST png_byte alpha_sBIT = dp->this.alpha_sBIT; + PNG_CONST int have_tRNS = dp->this.is_transparent; + + standard_palette out_palette; + png_uint_32 y; + + UNUSED(pi) + + /* Read the palette corresponding to the output if the output colour type + * indicates a palette, othewise set out_palette to garbage. + */ + if (out_ct == PNG_COLOR_TYPE_PALETTE) + (void)standard_palette_init(out_palette, pp, pi); + else + memset(out_palette, 0x5e, sizeof out_palette); + + for (y=0; y<h; ++y, pRow += cbRow) + { + png_uint_32 x; + + /* The original, standard, row pre-transforms. */ + png_byte std[STANDARD_ROWMAX]; + + transform_row(pp, std, in_ct, in_bd, y); + + /* Go through each original pixel transforming it and comparing with what + * libpng did to the same pixel. + */ + for (x=0; x<w; ++x) + { + image_pixel in_pixel, out_pixel; + unsigned int r, g, b, a; + + /* Find out what we think the pixel should be: */ + image_pixel_init(&in_pixel, std, in_ct, in_bd, x, dp->this.palette); + + in_pixel.red_sBIT = red_sBIT; + in_pixel.green_sBIT = green_sBIT; + in_pixel.blue_sBIT = blue_sBIT; + in_pixel.alpha_sBIT = alpha_sBIT; + in_pixel.have_tRNS = have_tRNS; + + /* For error detection, below. */ + r = in_pixel.red; + g = in_pixel.green; + b = in_pixel.blue; + a = in_pixel.alpha; + + dp->transform_list->mod(dp->transform_list, &in_pixel, pp, dp); + + /* Read the output pixel and compare it to what we got, we don't + * use the error field here, so no need to update sBIT. + */ + image_pixel_init(&out_pixel, pRow, out_ct, out_bd, x, out_palette); + + /* We don't expect changes to the index here even if the bit depth is + * changed. + */ + if (in_ct == PNG_COLOR_TYPE_PALETTE && + out_ct == PNG_COLOR_TYPE_PALETTE) + { + if (in_pixel.palette_index != out_pixel.palette_index) + png_error(pp, "unexpected transformed palette index"); + } + + /* Check the colours for palette images too - in fact the palette could + * be separately verified itself in most cases. + */ + if (in_pixel.red != out_pixel.red) + transform_range_check(pp, r, g, b, a, in_pixel.red, in_pixel.redf, + out_pixel.red, sample_depth, in_pixel.rede, "red/gray"); + + if ((out_ct & PNG_COLOR_MASK_COLOR) != 0 && + in_pixel.green != out_pixel.green) + transform_range_check(pp, r, g, b, a, in_pixel.green, + in_pixel.greenf, out_pixel.green, sample_depth, in_pixel.greene, + "green"); + + if ((out_ct & PNG_COLOR_MASK_COLOR) != 0 && + in_pixel.blue != out_pixel.blue) + transform_range_check(pp, r, g, b, a, in_pixel.blue, in_pixel.bluef, + out_pixel.blue, sample_depth, in_pixel.bluee, "blue"); + + if ((out_ct & PNG_COLOR_MASK_ALPHA) != 0 && + in_pixel.alpha != out_pixel.alpha) + transform_range_check(pp, r, g, b, a, in_pixel.alpha, + in_pixel.alphaf, out_pixel.alpha, sample_depth, in_pixel.alphae, + "alpha"); + } /* pixel (x) loop */ + } /* row (y) loop */ + + /* Record that something was actually checked to avoid a false positive. */ + dp->this.ps->validated = 1; +} + +static void +transform_end(png_structp pp, png_infop pi) +{ + transform_display *dp = png_get_progressive_ptr(pp); + + transform_image_validate(dp, pp, pi, dp->this.ps->image); +} + +/* A single test run. */ +static void +transform_test(png_modifier *pmIn, PNG_CONST png_uint_32 idIn, + PNG_CONST image_transform* transform_listIn, PNG_CONST char *name) +{ + transform_display d; + context(&pmIn->this, fault); + + transform_display_init(&d, pmIn, idIn, transform_listIn); + + Try + { + png_structp pp; + png_infop pi; + + /* Get a png_struct for writing the image. */ + pp = set_modifier_for_read(d.pm, &pi, d.this.id, name); + +# if 0 + /* Logging (debugging only) */ + { + char buffer[256]; + + (void)store_message(&d.pm->this, pp, buffer, sizeof buffer, 0, + "running test"); + + fprintf(stderr, "%s\n", buffer); + } +# endif + + /* Introduce the correct read function. */ + if (d.pm->this.progressive) + { + /* Share the row function with the standard implementation. */ + png_set_progressive_read_fn(pp, &d, transform_info, progressive_row, + transform_end); + + /* Now feed data into the reader until we reach the end: */ + modifier_progressive_read(d.pm, pp, pi); + } + else + { + /* modifier_read expects a png_modifier* */ + png_set_read_fn(pp, d.pm, modifier_read); + + /* Check the header values: */ + png_read_info(pp, pi); + + /* Process the 'info' requirements. Only one image is generated */ + transform_info_imp(&d, pp, pi); + + sequential_row(&d.this, pp, pi, NULL, d.this.ps->image); + + transform_image_validate(&d, pp, pi, d.this.ps->image); + } + + modifier_reset(d.pm); + } + + Catch(fault) + modifier_reset((png_modifier*)fault); +} + +/* The transforms: */ +#define ITSTRUCT(name) image_transform_##name +#define IT(name,prev)\ +static image_transform ITSTRUCT(name) =\ +{\ + #name,\ + 1, /*enable*/\ + &ITSTRUCT(prev), /*list*/\ + 0, /*global_use*/\ + 0, /*local_use*/\ + 0, /*next*/\ + image_transform_png_set_##name##_set,\ + image_transform_png_set_##name##_mod,\ + image_transform_png_set_##name##_add\ +} + +/* To save code: */ +static int +image_transform_default_add(image_transform *this, + PNG_CONST image_transform **that, png_byte colour_type, png_byte bit_depth) +{ + UNUSED(colour_type) + UNUSED(bit_depth) + + this->next = *that; + *that = this; + + return 1; +} + +/* png_set_palette_to_rgb */ +static void +image_transform_png_set_palette_to_rgb_set(PNG_CONST image_transform *this, + transform_display *that, png_structp pp, png_infop pi) +{ + png_set_palette_to_rgb(pp); + this->next->set(this->next, that, pp, pi); +} + +static void +image_transform_png_set_palette_to_rgb_mod(PNG_CONST image_transform *this, + image_pixel *that, png_structp pp, PNG_CONST transform_display *display) +{ + if (that->colour_type == PNG_COLOR_TYPE_PALETTE) + image_pixel_convert_PLTE(that, &display->this); + + this->next->mod(this->next, that, pp, display); +} + +static int +image_transform_png_set_palette_to_rgb_add(image_transform *this, + PNG_CONST image_transform **that, png_byte colour_type, png_byte bit_depth) +{ + UNUSED(bit_depth) + + this->next = *that; + *that = this; + + return colour_type == PNG_COLOR_TYPE_PALETTE; +} + +IT(palette_to_rgb, end); + + +/* png_set_tRNS_to_alpha */ +static void +image_transform_png_set_tRNS_to_alpha_set(PNG_CONST image_transform *this, + transform_display *that, png_structp pp, png_infop pi) +{ + png_set_tRNS_to_alpha(pp); + this->next->set(this->next, that, pp, pi); +} + +static void +image_transform_png_set_tRNS_to_alpha_mod(PNG_CONST image_transform *this, + image_pixel *that, png_structp pp, PNG_CONST transform_display *display) +{ + /* LIBPNG BUG: this always forces palette images to RGB. */ + if (that->colour_type == PNG_COLOR_TYPE_PALETTE) + image_pixel_convert_PLTE(that, &display->this); + + /* This effectively does an 'expand' only if there is some transparency to + * covert to an alpha channel. + */ + if (that->have_tRNS) + image_pixel_add_alpha(that, &display->this); + + /* LIBPNG BUG: otherwise libpng still expands to 8 bits! */ + else + { + if (that->bit_depth < 8) + that->bit_depth =8; + if (that->sample_depth < 8) + that->sample_depth = 8; + } + + this->next->mod(this->next, that, pp, display); +} + +static int +image_transform_png_set_tRNS_to_alpha_add(image_transform *this, + PNG_CONST image_transform **that, png_byte colour_type, png_byte bit_depth) +{ + UNUSED(bit_depth) + + this->next = *that; + *that = this; + + /* We don't know yet whether there will be a tRNS chunk, but we know that + * this transformation should do nothing if there already is an alpha + * channel. + */ + return (colour_type & PNG_COLOR_MASK_ALPHA) == 0; +} + +IT(tRNS_to_alpha,palette_to_rgb); + +/* png_set_gray_to_rgb */ +static void +image_transform_png_set_gray_to_rgb_set(PNG_CONST image_transform *this, + transform_display *that, png_structp pp, png_infop pi) +{ + png_set_gray_to_rgb(pp); + this->next->set(this->next, that, pp, pi); +} + +static void +image_transform_png_set_gray_to_rgb_mod(PNG_CONST image_transform *this, + image_pixel *that, png_structp pp, PNG_CONST transform_display *display) +{ + /* NOTE: we can actually pend the tRNS processing at this point because we + * can correctly recognize the original pixel value even though we have + * mapped the one gray channel to the three RGB ones, but in fact libpng + * doesn't do this, so we don't either. + */ + if ((that->colour_type & PNG_COLOR_MASK_COLOR) == 0 && that->have_tRNS) + image_pixel_add_alpha(that, &display->this); + + /* Simply expand the bit depth and alter the colour type as required. */ + if (that->colour_type == PNG_COLOR_TYPE_GRAY) + { + /* RGB images have a bit depth at least equal to '8' */ + if (that->bit_depth < 8) + that->sample_depth = that->bit_depth = 8; + + /* And just changing the colour type works here because the green and blue + * channels are being maintained in lock-step with the red/gray: + */ + that->colour_type = PNG_COLOR_TYPE_RGB; + } + + else if (that->colour_type == PNG_COLOR_TYPE_GRAY_ALPHA) + that->colour_type = PNG_COLOR_TYPE_RGB_ALPHA; + + this->next->mod(this->next, that, pp, display); +} + +static int +image_transform_png_set_gray_to_rgb_add(image_transform *this, + PNG_CONST image_transform **that, png_byte colour_type, png_byte bit_depth) +{ + UNUSED(bit_depth) + + this->next = *that; + *that = this; + + return (colour_type & PNG_COLOR_MASK_COLOR) == 0; +} + +IT(gray_to_rgb,tRNS_to_alpha); + +/* png_set_expand */ +static void +image_transform_png_set_expand_set(PNG_CONST image_transform *this, + transform_display *that, png_structp pp, png_infop pi) +{ + png_set_expand(pp); + this->next->set(this->next, that, pp, pi); +} + +static void +image_transform_png_set_expand_mod(PNG_CONST image_transform *this, + image_pixel *that, png_structp pp, PNG_CONST transform_display *display) +{ + /* The general expand case depends on what the colour type is: */ + if (that->colour_type == PNG_COLOR_TYPE_PALETTE) + image_pixel_convert_PLTE(that, &display->this); + else if (that->bit_depth < 8) /* grayscale */ + that->sample_depth = that->bit_depth = 8; + + if (that->have_tRNS) + image_pixel_add_alpha(that, &display->this); + + this->next->mod(this->next, that, pp, display); +} + +static int +image_transform_png_set_expand_add(image_transform *this, + PNG_CONST image_transform **that, png_byte colour_type, png_byte bit_depth) +{ + UNUSED(bit_depth) + + this->next = *that; + *that = this; + + /* 'expand' should do nothing for RGBA or GA input - no tRNS and the bit + * depth is at least 8 already. + */ + return (colour_type & PNG_COLOR_MASK_ALPHA) == 0; +} + +IT(expand,gray_to_rgb); + +/* png_set_expand_gray_1_2_4_to_8 + * LIBPNG BUG: this just does an 'expand' + */ +static void +image_transform_png_set_expand_gray_1_2_4_to_8_set( + PNG_CONST image_transform *this, transform_display *that, png_structp pp, + png_infop pi) +{ + png_set_expand_gray_1_2_4_to_8(pp); + this->next->set(this->next, that, pp, pi); +} + +static void +image_transform_png_set_expand_gray_1_2_4_to_8_mod( + PNG_CONST image_transform *this, image_pixel *that, png_structp pp, + PNG_CONST transform_display *display) +{ + image_transform_png_set_expand_mod(this, that, pp, display); +} + +static int +image_transform_png_set_expand_gray_1_2_4_to_8_add(image_transform *this, + PNG_CONST image_transform **that, png_byte colour_type, png_byte bit_depth) +{ + return image_transform_png_set_expand_add(this, that, colour_type, + bit_depth); +} + +IT(expand_gray_1_2_4_to_8, expand); + +/* png_set_strip_16 */ +static void +image_transform_png_set_strip_16_set(PNG_CONST image_transform *this, + transform_display *that, png_structp pp, png_infop pi) +{ + png_set_strip_16(pp); + this->next->set(this->next, that, pp, pi); +} + +static void +image_transform_png_set_strip_16_mod(PNG_CONST image_transform *this, + image_pixel *that, png_structp pp, PNG_CONST transform_display *display) +{ + if (that->bit_depth == 16) + { + that->sample_depth = that->bit_depth = 8; + if (that->red_sBIT > 8) that->red_sBIT = 8; + if (that->green_sBIT > 8) that->green_sBIT = 8; + if (that->blue_sBIT > 8) that->blue_sBIT = 8; + if (that->alpha_sBIT > 8) that->alpha_sBIT = 8; + +# ifndef PNG_READ_16_TO_8_ACCURATE_SCALE_SUPPORTED + /* The strip 16 algoirithm drops the low 8 bits rather than calculating + * 1/257, so we need to adjust the permitted errors appropriately: + */ + { + PNG_CONST double d = (255-128.5)/65535; + that->rede += d; + that->greene += d; + that->bluee += d; + that->alphae += d; + } +# endif + } + + this->next->mod(this->next, that, pp, display); +} + +static int +image_transform_png_set_strip_16_add(image_transform *this, + PNG_CONST image_transform **that, png_byte colour_type, png_byte bit_depth) +{ + UNUSED(colour_type) + + this->next = *that; + *that = this; + + return bit_depth > 8; +} + +IT(strip_16, expand_gray_1_2_4_to_8); + +/* png_set_strip_alpha */ +static void +image_transform_png_set_strip_alpha_set(PNG_CONST image_transform *this, + transform_display *that, png_structp pp, png_infop pi) +{ + png_set_strip_alpha(pp); + this->next->set(this->next, that, pp, pi); +} + +static void +image_transform_png_set_strip_alpha_mod(PNG_CONST image_transform *this, + image_pixel *that, png_structp pp, PNG_CONST transform_display *display) +{ + if (that->colour_type == PNG_COLOR_TYPE_GRAY_ALPHA) + that->colour_type = PNG_COLOR_TYPE_GRAY; + else if (that->colour_type == PNG_COLOR_TYPE_RGB_ALPHA) + that->colour_type = PNG_COLOR_TYPE_RGB; + + that->have_tRNS = 0; + that->alphaf = 1; + that->alphae = 0; + + this->next->mod(this->next, that, pp, display); +} + +static int +image_transform_png_set_strip_alpha_add(image_transform *this, + PNG_CONST image_transform **that, png_byte colour_type, png_byte bit_depth) +{ + UNUSED(bit_depth) + + this->next = *that; + *that = this; + + return (colour_type & PNG_COLOR_MASK_ALPHA) != 0; +} + +IT(strip_alpha,strip_16); + +/* png_set_rgb_to_gray(png_structp, int err_action, double red, double green) + * png_set_rgb_to_gray_fixed(png_structp, int err_action, png_fixed_point red, + * png_fixed_point green) + * png_get_rgb_to_gray_status + * + * At present the APIs are simply tested using the 16.16 fixed point conversion + * values known to be used inside libpng: + * + * red: 6968 + * green: 23434 + * blue: 2366 + * + * NOTE: this currently ignores the gamma because no gamma is being set, the + * tests on gamma need to happen in the gamma test set. + */ +static void +image_transform_png_set_rgb_to_gray_set(PNG_CONST image_transform *this, + transform_display *that, png_structp pp, png_infop pi) +{ + PNG_CONST int error_action = 1; /* no error, no defines in png.h */ + +# ifdef PNG_FLOATING_POINT_SUPPORTED + png_set_rgb_to_gray(pp, error_action, -1, -1); +# else + png_set_rgb_to_gray_fixed(pp, error_action, -1, -1); +# endif + + this->next->set(this->next, that, pp, pi); +} + +static void +image_transform_png_set_rgb_to_gray_mod(PNG_CONST image_transform *this, + image_pixel *that, png_structp pp, PNG_CONST transform_display *display) +{ + if ((that->colour_type & PNG_COLOR_MASK_COLOR) != 0) + { + if (that->colour_type == PNG_COLOR_TYPE_PALETTE) + image_pixel_convert_PLTE(that, &display->this); + + /* Image now has RGB channels... */ + that->bluef = that->greenf = that->redf = (that->redf * 6968 + + that->greenf * 23434 + that->bluef * 2366) / 32768; + that->bluee = that->greene = that->rede = (that->rede * 6968 + + that->greene * 23434 + that->bluee * 2366) / 32768 * + (1 + DBL_EPSILON * 6); + + /* The sBIT is the minium of the three colour channel sBITs. */ + if (that->red_sBIT > that->green_sBIT) + that->red_sBIT = that->green_sBIT; + if (that->red_sBIT > that->blue_sBIT) + that->red_sBIT = that->blue_sBIT; + that->blue_sBIT = that->green_sBIT = that->red_sBIT; + + /* And zap the colour bit in the type: */ + if (that->colour_type == PNG_COLOR_TYPE_RGB) + that->colour_type = PNG_COLOR_TYPE_GRAY; + else if (that->colour_type == PNG_COLOR_TYPE_RGB_ALPHA) + that->colour_type = PNG_COLOR_TYPE_GRAY_ALPHA; + } + + this->next->mod(this->next, that, pp, display); +} + +static int +image_transform_png_set_rgb_to_gray_add(image_transform *this, + PNG_CONST image_transform **that, png_byte colour_type, png_byte bit_depth) +{ + UNUSED(bit_depth) + + this->next = *that; + *that = this; + + return (colour_type & PNG_COLOR_MASK_COLOR) != 0; +} + +IT(rgb_to_gray,strip_alpha); + +/* png_set_background(png_structp, png_const_color_16p background_color, + * int background_gamma_code, int need_expand, double background_gamma) + * png_set_background_fixed(png_structp, png_const_color_16p background_color, + * int background_gamma_code, int need_expand, + * png_fixed_point background_gamma) + * + * As with rgb_to_gray this ignores the gamma. +*/ +static void +image_transform_png_set_background_set(PNG_CONST image_transform *this, + transform_display *that, png_structp pp, png_infop pi) +{ + png_color_16 back; + + /* Since we don't know the output bit depth at this point we must use the + * input values and ask libpng to expand the chunk as required. + */ + back.index = 255; /* Should not be used */ + back.gray = back.blue = back.green = back.red = + (png_uint_16)((1U << that->this.bit_depth) >> 1); + +# ifdef PNG_FLOATING_POINT_SUPPORTED + png_set_background(pp, &back, PNG_BACKGROUND_GAMMA_FILE, 1, 0); +# else + png_set_background_fixed(pp, &back, PNG_BACKGROUND_GAMMA_FILE, 1, 0); +# endif + + this->next->set(this->next, that, pp, pi); +} + +static void +image_transform_png_set_background_mod(PNG_CONST image_transform *this, + image_pixel *that, png_structp pp, PNG_CONST transform_display *display) +{ + /* Check for tRNS first: */ + if (that->have_tRNS && that->colour_type != PNG_COLOR_TYPE_PALETTE) + image_pixel_add_alpha(that, &display->this); + + /* This is only necessary if the alpha value is less than 1. */ + if (that->alphaf < 1) + { + /* Repeat the calculation above and scale the result: */ + unsigned int tmp = (1U << display->this.bit_depth); + double component = (tmp >> 1)/(double)(tmp-1); + + /* Now we do the background calculation without any gamma correction. */ + if (that->alphaf <= 0) + { + that->bluef = that->greenf = that->redf = component; + that->bluee = that->greene = that->rede = component * DBL_EPSILON; + that->blue_sBIT = that->green_sBIT = that->red_sBIT = that->bit_depth; + } + + else + { + component *= 1-that->alphaf; + that->redf = that->redf * that->alphaf + component; + that->rede = that->rede * that->alphaf + that->redf * 3 * DBL_EPSILON; + that->greenf = that->greenf * that->alphaf + component; + that->greene = that->greene * that->alphaf + that->greenf * 3 * + DBL_EPSILON; + that->bluef = that->bluef * that->alphaf + component; + that->bluee = that->bluee * that->alphaf + that->bluef * 3 * + DBL_EPSILON; + } + + /* Remove the alpha type and set the alpha. */ + that->alphaf = 1; + that->alphae = 0; + + if (that->colour_type == PNG_COLOR_TYPE_RGB_ALPHA) + that->colour_type = PNG_COLOR_TYPE_RGB; + else if (that->colour_type == PNG_COLOR_TYPE_GRAY_ALPHA) + that->colour_type = PNG_COLOR_TYPE_GRAY; + } + + this->next->mod(this->next, that, pp, display); +} + +#define image_transform_png_set_background_add image_transform_default_add + +IT(background,rgb_to_gray); + +static image_transform *PNG_CONST image_transform_first = &ITSTRUCT(background); + +static void +transform_enable(PNG_CONST char *name) +{ + /* Everything starts out enabled, so if we see an 'enable' disabled + * everything else the first time round. + */ + static int all_disabled = 0; + int found_it = 0; + image_transform *list = image_transform_first; + + while (list != &image_transform_end) + { + if (strcmp(list->name, name) == 0) + { + list->enable = 1; + found_it = 1; + } + else if (!all_disabled) + list->enable = 0; + + list = list->list; + } + + all_disabled = 1; + + if (!found_it) + { + fprintf(stderr, "pngvalid: --transform-enable=%s: unknown transform\n", + name); + exit(1); + } +} + +static void +transform_disable(PNG_CONST char *name) +{ + image_transform *list = image_transform_first; + + while (list != &image_transform_end) + { + if (strcmp(list->name, name) == 0) + { + list->enable = 0; + return; + } + + list = list->list; + } + + fprintf(stderr, "pngvalid: --transform-disable=%s: unknown transform\n", + name); + exit(1); +} + +static void +image_transform_reset_count(void) +{ + image_transform *next = image_transform_first; + int count = 0; + + while (next != &image_transform_end) + { + next->local_use = 0; + next->next = 0; + next = next->list; + ++count; + } + + /* This can only happen if we every have more than 32 transforms (excluding + * the end) in the list. + */ + if (count > 32) abort(); +} + +static int +image_transform_test_counter(png_uint_32 counter, unsigned int max) +{ + /* Test the list to see if there is any point contining, given a current + * counter and a 'max' value. + */ + image_transform *next = image_transform_first; + + while (next != &image_transform_end) + { + /* For max 0 or 1 continue until the counter overflows: */ + counter >>= 1; + + /* Continue if any entry hasn't reacked the max. */ + if (max > 1 && next->local_use < max) + return 1; + next = next->list; + } + + return max <= 1 && counter == 0; +} + +static png_uint_32 +image_transform_add(PNG_CONST image_transform **this, unsigned int max, + png_uint_32 counter, char *name, size_t sizeof_name, size_t *pos, + png_byte colour_type, png_byte bit_depth) +{ + for (;;) /* until we manage to add something */ + { + png_uint_32 mask; + image_transform *list; + + /* Find the next counter value, if the counter is zero this is the start + * of the list. This routine always returns the current counter (not the + * next) so it returns 0 at the end and expects 0 at the beginning. + */ + if (counter == 0) /* first time */ + { + image_transform_reset_count(); + if (max <= 1) + counter = 1; + else + counter = random_32(); + } + else /* advance the counter */ + { + switch (max) + { + case 0: ++counter; break; + case 1: counter <<= 1; break; + default: counter = random_32(); break; + } + } + + /* Now add all these items, if possible */ + *this = &image_transform_end; + list = image_transform_first; + mask = 1; + + /* Go through the whole list adding anything that the counter selects: */ + while (list != &image_transform_end) + { + if ((counter & mask) != 0 && list->enable && + (max == 0 || list->local_use < max)) + { + /* Candidate to add: */ + if (list->add(list, this, colour_type, bit_depth) || max == 0) + { + /* Added, so add to the name too. */ + *pos = safecat(name, sizeof_name, *pos, " +"); + *pos = safecat(name, sizeof_name, *pos, list->name); + } + + else + { + /* Not useful and max>0, so remvoe it from *this: */ + *this = list->next; + list->next = 0; + + /* And, since we know it isn't useful, stop it being added again + * in this run: + */ + list->local_use = max; + } + } + + mask <<= 1; + list = list->list; + } + + /* Now if anything was added we have something to do. */ + if (*this != &image_transform_end) + return counter; + + /* Nothing added, but was there anything in there to add? */ + if (!image_transform_test_counter(counter, max)) + return 0; + } +} + +#ifdef THIS_IS_THE_PROFORMA +static void +image_transform_png_set_@_set(PNG_CONST image_transform *this, + transform_display *that, png_structp pp, png_infop pi) +{ + png_set_@(pp); + this->next->set(this->next, that, pp, pi); +} + +static void +image_transform_png_set_@_mod(PNG_CONST image_transform *this, + image_pixel *that, png_structp pp, PNG_CONST transform_display *display) +{ + this->next->mod(this->next, that, pp, display); +} + +static int +image_transform_png_set_@_add(image_transform *this, + PNG_CONST image_transform **that, char *name, size_t sizeof_name, + size_t *pos, png_byte colour_type, png_byte bit_depth) +{ + this->next = *that; + *that = this; + + *pos = safecat(name, sizeof_name, *pos, " +@"); + + return 1; +} + +IT(@); +#endif + +/* png_set_quantize(png_structp, png_colorp palette, int num_palette, + * int maximum_colors, png_const_uint_16p histogram, int full_quantize) + * + * Very difficult to validate this! + */ +/*NOTE: TBD NYI */ + +/* The data layout transforms are handled by swapping our own channel data, + * necessarily these need to happen at the end of the transform list because the + * semantic of the channels changes after these are executed. Some of these, + * like set_shift and set_packing, can't be done at present because they change + * the layout of the data at the sub-sample level so sample() won't get the + * right answer. + */ +/* png_set_invert_alpha */ +/*NOTE: TBD NYI */ + +/* png_set_bgr */ +/*NOTE: TBD NYI */ + +/* png_set_swap_alpha */ +/*NOTE: TBD NYI */ + +/* png_set_swap */ +/*NOTE: TBD NYI */ + +/* png_set_filler, (png_structp png_ptr, png_uint_32 filler, int flags)); */ +/*NOTE: TBD NYI */ + +/* png_set_add_alpha, (png_structp png_ptr, png_uint_32 filler, int flags)); */ +/*NOTE: TBD NYI */ + +/* png_set_packing */ +/*NOTE: TBD NYI */ + +/* png_set_packswap */ +/*NOTE: TBD NYI */ + +/* png_set_invert_mono */ +/*NOTE: TBD NYI */ + +/* png_set_shift(png_structp, png_const_color_8p true_bits) */ +/*NOTE: TBD NYI */ + +static int +test_transform(png_modifier* PNG_CONST pm, png_byte PNG_CONST colour_type, + int bdlo, int PNG_CONST bdhi, png_uint_32 max) +{ + for (; bdlo <= bdhi; ++bdlo) + { + PNG_CONST png_byte bit_depth = DEPTH(bdlo); + png_uint_32 counter = 0; + size_t base_pos; + char name[64]; + + base_pos = safecat(name, sizeof name, 0, "transform:"); + + for (;;) + { + size_t pos = base_pos; + PNG_CONST image_transform *list = 0; + + counter = image_transform_add(&list, max, counter, name, sizeof name, + &pos, colour_type, bit_depth); + + if (counter == 0) + break; + + /* The command line can change this to checking interlaced images. */ + transform_test(pm, FILEID(colour_type, bit_depth, pm->interlace_type, + 0, 0, 0), list, name); + + if (fail(pm)) + return 0; + } + } + + return 1; /* keep going */ +} + +static void +perform_transform_test(png_modifier *pm) +{ + /* Test each colour type over the valid range of bit depths (expressed as + * log2(bit_depth) in turn, stop as soon as any error is detected. + */ + if (!test_transform(pm, 0, 0, READ_BDHI, 1)) + return; + + if (!test_transform(pm, 2, 3, READ_BDHI, 1)) + return; + + if (!test_transform(pm, 3, 0, 3, 1)) + return; + + if (!test_transform(pm, 4, 3, READ_BDHI, 1)) + return; + + if (!test_transform(pm, 6, 3, READ_BDHI, 1)) + return; +} + + +/********************************* GAMMA TESTS ********************************/ +/* Gamma test images. */ +typedef struct gamma_modification +{ + png_modification this; + png_fixed_point gamma; +} gamma_modification; + +static int +gamma_modify(png_modifier *pm, png_modification *me, int add) +{ + UNUSED(add) + /* This simply dumps the given gamma value into the buffer. */ + png_save_uint_32(pm->buffer, 4); + png_save_uint_32(pm->buffer+4, CHUNK_gAMA); + png_save_uint_32(pm->buffer+8, ((gamma_modification*)me)->gamma); + return 1; +} + +static void +gamma_modification_init(gamma_modification *me, png_modifier *pm, double gammad) +{ + double g; + + modification_init(&me->this); + me->this.chunk = CHUNK_gAMA; + me->this.modify_fn = gamma_modify; + me->this.add = CHUNK_PLTE; + g = floor(gammad * 100000 + .5); + me->gamma = (png_fixed_point)g; + me->this.next = pm->modifications; + pm->modifications = &me->this; +} + +typedef struct srgb_modification +{ + png_modification this; + png_byte intent; +} srgb_modification; + +static int +srgb_modify(png_modifier *pm, png_modification *me, int add) +{ + UNUSED(add) + /* As above, ignore add and just make a new chunk */ + png_save_uint_32(pm->buffer, 1); + png_save_uint_32(pm->buffer+4, CHUNK_sRGB); + pm->buffer[8] = ((srgb_modification*)me)->intent; + return 1; +} + +static void +srgb_modification_init(srgb_modification *me, png_modifier *pm, png_byte intent) +{ + modification_init(&me->this); + me->this.chunk = CHUNK_sBIT; + + if (intent <= 3) /* if valid, else *delete* sRGB chunks */ + { + me->this.modify_fn = srgb_modify; + me->this.add = CHUNK_PLTE; + me->intent = intent; + } + + else + { + me->this.modify_fn = 0; + me->this.add = 0; + me->intent = 0; + } + + me->this.next = pm->modifications; + pm->modifications = &me->this; +} + +typedef struct sbit_modification +{ + png_modification this; + png_byte sbit; +} sbit_modification; + +static int +sbit_modify(png_modifier *pm, png_modification *me, int add) +{ + png_byte sbit = ((sbit_modification*)me)->sbit; + if (pm->bit_depth > sbit) + { + int cb = 0; + switch (pm->colour_type) + { + case 0: + cb = 1; + break; + + case 2: + case 3: + cb = 3; + break; + + case 4: + cb = 2; + break; + + case 6: + cb = 4; + break; + + default: + png_error(pm->this.pread, + "unexpected colour type in sBIT modification"); + } + + png_save_uint_32(pm->buffer, cb); + png_save_uint_32(pm->buffer+4, CHUNK_sBIT); + + while (cb > 0) + (pm->buffer+8)[--cb] = sbit; + + return 1; + } + else if (!add) + { + /* Remove the sBIT chunk */ + pm->buffer_count = pm->buffer_position = 0; + return 1; + } + else + return 0; /* do nothing */ +} + +static void +sbit_modification_init(sbit_modification *me, png_modifier *pm, png_byte sbit) +{ + modification_init(&me->this); + me->this.chunk = CHUNK_sBIT; + me->this.modify_fn = sbit_modify; + me->this.add = CHUNK_PLTE; + me->sbit = sbit; + me->this.next = pm->modifications; + pm->modifications = &me->this; +} + +/* Reader callbacks and implementations, where they differ from the standard + * ones. + */ +typedef struct gamma_display +{ + standard_display this; + + /* Parameters */ + png_modifier* pm; + double file_gamma; + double screen_gamma; + png_byte sbit; + int threshold_test; + PNG_CONST char* name; + int speed; + int use_input_precision; + int strip16; + + /* Local variables */ + double maxerrout; + double maxerrpc; + double maxerrabs; +} gamma_display; + +static void +gamma_display_init(gamma_display *dp, png_modifier *pm, png_uint_32 id, + double file_gamma, double screen_gamma, png_byte sbit, int threshold_test, + int speed, int use_input_precision, int strip16) +{ + /* Standard fields */ + standard_display_init(&dp->this, &pm->this, id, 0/*do_interlace*/); + + /* Parameter fields */ + dp->pm = pm; + dp->file_gamma = file_gamma; + dp->screen_gamma = screen_gamma; + dp->sbit = sbit; + dp->threshold_test = threshold_test; + dp->speed = speed; + dp->use_input_precision = use_input_precision; + dp->strip16 = strip16; + + /* Local variable fields */ + dp->maxerrout = dp->maxerrpc = dp->maxerrabs = 0; +} + +static void +gamma_info_imp(gamma_display *dp, png_structp pp, png_infop pi) +{ + /* Reuse the standard stuff as appropriate. */ + standard_info_part1(&dp->this, pp, pi); + + /* If requested strip 16 to 8 bits - this is handled automagically below + * because the output bit depth is read from the library. Note that there + * are interactions with sBIT but, internally, libpng makes sbit at most + * PNG_MAX_GAMMA_8 when doing the following. + */ + if (dp->strip16) +# ifdef PNG_READ_16_TO_8_SUPPORTED + png_set_strip_16(pp); +# else + png_error(pp, "strip16 (16 to 8 bit conversion) not supported"); +# endif + + png_read_update_info(pp, pi); + + /* Now we may get a different cbRow: */ + standard_info_part2(&dp->this, pp, pi, 1 /*images*/); +} + +static void +gamma_info(png_structp pp, png_infop pi) +{ + gamma_info_imp(png_get_progressive_ptr(pp), pp, pi); +} + +static void +gamma_image_validate(gamma_display *dp, png_structp pp, png_infop pi, + png_const_bytep pRow) +{ + /* Get some constants derived from the input and output file formats: */ + PNG_CONST png_byte sbit = dp->sbit; + PNG_CONST double file_gamma = dp->file_gamma; + PNG_CONST double screen_gamma = dp->screen_gamma; + PNG_CONST int use_input_precision = dp->use_input_precision; + PNG_CONST int speed = dp->speed; + PNG_CONST png_byte in_ct = dp->this.colour_type; + PNG_CONST png_byte in_bd = dp->this.bit_depth; + PNG_CONST png_uint_32 w = dp->this.w; + PNG_CONST png_uint_32 h = dp->this.h; + PNG_CONST size_t cbRow = dp->this.cbRow; + PNG_CONST png_byte out_ct = png_get_color_type(pp, pi); + PNG_CONST png_byte out_bd = png_get_bit_depth(pp, pi); + PNG_CONST unsigned int outmax = (1U<<out_bd)-1; + PNG_CONST double maxabs = abserr(dp->pm, out_bd); + PNG_CONST double maxout = outerr(dp->pm, out_bd); + PNG_CONST double maxpc = pcerr(dp->pm, out_bd); + + /* There are three sources of error, firstly the quantization in the + * file encoding, determined by sbit and/or the file depth, secondly + * the output (screen) gamma and thirdly the output file encoding. + * + * Since this API receives the screen and file gamma in double + * precision it is possible to calculate an exact answer given an input + * pixel value. Therefore we assume that the *input* value is exact - + * sample/maxsample - calculate the corresponding gamma corrected + * output to the limits of double precision arithmetic and compare with + * what libpng returns. + * + * Since the library must quantize the output to 8 or 16 bits there is + * a fundamental limit on the accuracy of the output of +/-.5 - this + * quantization limit is included in addition to the other limits + * specified by the paramaters to the API. (Effectively, add .5 + * everywhere.) + * + * The behavior of the 'sbit' paramter is defined by section 12.5 + * (sample depth scaling) of the PNG spec. That section forces the + * decoder to assume that the PNG values have been scaled if sBIT is + * present: + * + * png-sample = floor( input-sample * (max-out/max-in) + .5); + * + * This means that only a subset of the possible PNG values should + * appear in the input. However, the spec allows the encoder to use a + * variety of approximations to the above and doesn't require any + * restriction of the values produced. + * + * Nevertheless the spec requires that the upper 'sBIT' bits of the + * value stored in a PNG file be the original sample bits. + * Consequently the code below simply scales the top sbit bits by + * (1<<sbit)-1 to obtain an original sample value. + * + * Because there is limited precision in the input it is arguable that + * an acceptable result is any valid result from input-.5 to input+.5. + * The basic tests below do not do this, however if + * 'use_input_precision' is set a subsequent test is performed below. + */ + PNG_CONST int processing = (fabs(screen_gamma*file_gamma-1) >= + PNG_GAMMA_THRESHOLD && !dp->threshold_test && !speed && in_ct != 3) || + in_bd != out_bd; + + PNG_CONST unsigned int samples_per_pixel = (out_ct & 2U) ? 3U : 1U; + + PNG_CONST double gamma_correction = 1/(file_gamma*screen_gamma);/* Overall */ + + double maxerrout = 0, maxerrabs = 0, maxerrpc = 0; + png_uint_32 y; + + for (y=0; y<h; ++y, pRow += cbRow) + { + unsigned int s, x; + png_byte std[STANDARD_ROWMAX]; + + transform_row(pp, std, in_ct, in_bd, y); + + if (processing) + { + for (x=0; x<w; ++x) for (s=0; s<samples_per_pixel; ++s) + { + /* Input sample values: */ + PNG_CONST unsigned int + id = sample(std, in_ct, in_bd, x, s); + + PNG_CONST unsigned int + od = sample(pRow, out_ct, out_bd, x, s); + + PNG_CONST unsigned int + isbit = id >> (in_bd-sbit); + + double i, input_sample, encoded_sample, output; + double encoded_error, error; + double es_lo, es_hi; + + /* First check on the 'perfect' result obtained from the + * digitized input value, id, and compare this against the + * actual digitized result, 'od'. 'i' is the input result + * in the range 0..1: + * + * NOTE: sBIT should be taken into account here but isn't, + * as described above. + */ + i = isbit; i /= (1U<<sbit)-1; + + /* Then get the gamma corrected version of 'i' and compare + * to 'od', any error less than .5 is insignificant - just + * quantization of the output value to the nearest digital + * value (nevertheless the error is still recorded - it's + * interesting ;-) + */ + encoded_sample = pow(i, gamma_correction) * outmax; + encoded_error = fabs(od-encoded_sample); + + if (encoded_error > maxerrout) + maxerrout = encoded_error; + + if (encoded_error < .5+maxout) + continue; + + /* There may be an error, so calculate the actual sample + * values - unencoded light intensity values. Note that + * in practice these are not unencoded because they + * include a 'viewing correction' to decrease or + * (normally) increase the perceptual contrast of the + * image. There's nothing we can do about this - we don't + * know what it is - so assume the unencoded value is + * perceptually linear. + */ + input_sample = pow(i, 1/file_gamma); /* In range 0..1 */ + output = od; + output /= outmax; + output = pow(output, screen_gamma); + + /* Now we have the numbers for real errors, both absolute + * values as as a percentage of the correct value (output): + */ + error = fabs(input_sample-output); + + if (error > maxerrabs) + maxerrabs = error; + + /* The following is an attempt to ignore the tendency of + * quantization to dominate the percentage errors for low + * output sample values: + */ + if (input_sample*maxpc > .5+maxabs) + { + double percentage_error = error/input_sample; + if (percentage_error > maxerrpc) maxerrpc = percentage_error; + } + + /* Now calculate the digitization limits for + * 'encoded_sample' using the 'max' values. Note that + * maxout is in the encoded space but maxpc and maxabs are + * in linear light space. + * + * First find the maximum error in linear light space, + * range 0..1: + */ + { + double tmp = input_sample * maxpc; + if (tmp < maxabs) tmp = maxabs; + + /* Low bound - the minimum of the three: */ + es_lo = encoded_sample - maxout; + + if (es_lo > 0 && input_sample-tmp > 0) + { + double low_value = outmax * pow(input_sample-tmp, + 1/screen_gamma); + if (low_value < es_lo) es_lo = low_value; + } + + else + es_lo = 0; + + es_hi = encoded_sample + maxout; + + if (es_hi < outmax && input_sample+tmp < 1) + { + double high_value = outmax * pow(input_sample+tmp, + 1/screen_gamma); + if (high_value > es_hi) es_hi = high_value; + } + + else + es_hi = outmax; + } + + /* The primary test is that the final encoded value + * returned by the library should be between the two limits + * (inclusive) that were calculated above. At this point + * quantization of the output must be taken into account. + */ + if (od+.5 < es_lo || od-.5 > es_hi) + { + /* There has been an error in processing. */ + double is_lo, is_hi; + + if (use_input_precision) + { + /* Ok, something is wrong - this actually happens in + * current libpng sbit processing. Assume that the + * input value (id, adjusted for sbit) can be + * anywhere between value-.5 and value+.5 - quite a + * large range if sbit is low. + */ + double tmp = (isbit - .5)/((1U<<sbit)-1); + + if (tmp > 0) + { + is_lo = outmax * pow(tmp, gamma_correction) - maxout; + if (is_lo < 0) is_lo = 0; + } + + else + is_lo = 0; + + tmp = (isbit + .5)/((1U<<sbit)-1); + + if (tmp < 1) + { + is_hi = outmax * pow(tmp, gamma_correction) + maxout; + if (is_hi > outmax) is_hi = outmax; + } + + else + is_hi = outmax; + + if (!(od+.5 < is_lo || od-.5 > is_hi)) + continue; + } + else + is_lo = es_lo, is_hi = es_hi; + + { + char msg[256]; + + sprintf(msg, + "error: %.3f; %u{%u;%u} -> %u not %.2f (%.1f-%.1f)", + od-encoded_sample, id, sbit, isbit, od, + encoded_sample, is_lo, is_hi); + + png_warning(pp, msg); + } + } + } + } + + else if (!speed && memcmp(std, pRow, cbRow) != 0) + { + char msg[64]; + + /* No transform is expected on the threshold tests. */ + sprintf(msg, "gamma: below threshold row %d changed", y); + + png_error(pp, msg); + } + } /* row (y) loop */ + + dp->maxerrout = maxerrout; + dp->maxerrabs = maxerrabs; + dp->maxerrpc = maxerrpc; + dp->this.ps->validated = 1; +} + +static void +gamma_end(png_structp pp, png_infop pi) +{ + gamma_display *dp = png_get_progressive_ptr(pp); + + gamma_image_validate(dp, pp, pi, dp->this.ps->image); +} + +/* A single test run checking a gamma transformation. + * + * maxabs: maximum absolute error as a fraction + * maxout: maximum output error in the output units + * maxpc: maximum percentage error (as a percentage) + */ +static void +gamma_test(png_modifier *pmIn, PNG_CONST png_byte colour_typeIn, + PNG_CONST png_byte bit_depthIn, PNG_CONST int interlace_typeIn, + PNG_CONST double file_gammaIn, PNG_CONST double screen_gammaIn, + PNG_CONST png_byte sbitIn, PNG_CONST int threshold_testIn, + PNG_CONST char *name, PNG_CONST int speedIn, + PNG_CONST int use_input_precisionIn, PNG_CONST int strip16In) +{ + gamma_display d; + context(&pmIn->this, fault); + + gamma_display_init(&d, pmIn, FILEID(colour_typeIn, bit_depthIn, + interlace_typeIn, 0, 0, 0), file_gammaIn, screen_gammaIn, sbitIn, + threshold_testIn, speedIn, use_input_precisionIn, strip16In); + + Try + { + png_structp pp; + png_infop pi; + gamma_modification gamma_mod; + srgb_modification srgb_mod; + sbit_modification sbit_mod; + + /* Make an appropriate modifier to set the PNG file gamma to the + * given gamma value and the sBIT chunk to the given precision. + */ + d.pm->modifications = NULL; + gamma_modification_init(&gamma_mod, d.pm, d.file_gamma); + srgb_modification_init(&srgb_mod, d.pm, 127 /*delete*/); + sbit_modification_init(&sbit_mod, d.pm, d.sbit); + + modification_reset(d.pm->modifications); + + /* Get a png_struct for writing the image. */ + pp = set_modifier_for_read(d.pm, &pi, d.this.id, name); + + /* Set up gamma processing. */ +#ifdef PNG_FLOATING_POINT_SUPPORTED + png_set_gamma(pp, d.screen_gamma, d.file_gamma); +#else + { + png_fixed_point s = floor(d.screen_gamma*100000+.5); + png_fixed_point f = floor(d.file_gamma*100000+.5); + png_set_gamma_fixed(pp, s, f); + } +#endif + + /* Introduce the correct read function. */ + if (d.pm->this.progressive) + { + /* Share the row function with the standard implementation. */ + png_set_progressive_read_fn(pp, &d, gamma_info, progressive_row, + gamma_end); + + /* Now feed data into the reader until we reach the end: */ + modifier_progressive_read(d.pm, pp, pi); + } + else + { + /* modifier_read expects a png_modifier* */ + png_set_read_fn(pp, d.pm, modifier_read); + + /* Check the header values: */ + png_read_info(pp, pi); + + /* Process the 'info' requirements. Only one image is generated */ + gamma_info_imp(&d, pp, pi); + + sequential_row(&d.this, pp, pi, NULL, d.this.ps->image); + + gamma_image_validate(&d, pp, pi, d.this.ps->image); + } + + modifier_reset(d.pm); + + if (d.pm->log && !d.threshold_test && !d.speed) + fprintf(stderr, "%d bit %s %s: max error %f (%.2g, %2g%%)\n", + d.this.bit_depth, colour_types[d.this.colour_type], d.name, + d.maxerrout, d.maxerrabs, 100*d.maxerrpc); + + /* Log the summary values too. */ + if (d.this.colour_type == 0 || d.this.colour_type == 4) + { + switch (d.this.bit_depth) + { + case 1: + break; + + case 2: + if (d.maxerrout > d.pm->error_gray_2) + d.pm->error_gray_2 = d.maxerrout; + + break; + + case 4: + if (d.maxerrout > d.pm->error_gray_4) + d.pm->error_gray_4 = d.maxerrout; + + break; + + case 8: + if (d.maxerrout > d.pm->error_gray_8) + d.pm->error_gray_8 = d.maxerrout; + + break; + + case 16: + if (d.maxerrout > d.pm->error_gray_16) + d.pm->error_gray_16 = d.maxerrout; + + break; + + default: + png_error(pp, "bad bit depth (internal: 1)"); + } + } + + else if (d.this.colour_type == 2 || d.this.colour_type == 6) + { + switch (d.this.bit_depth) + { + case 8: + + if (d.maxerrout > d.pm->error_color_8) + d.pm->error_color_8 = d.maxerrout; + + break; + + case 16: + + if (d.maxerrout > d.pm->error_color_16) + d.pm->error_color_16 = d.maxerrout; + + break; + + default: + png_error(pp, "bad bit depth (internal: 2)"); + } + } + } + + Catch(fault) + modifier_reset((png_modifier*)fault); +} + +static void gamma_threshold_test(png_modifier *pm, png_byte colour_type, + png_byte bit_depth, int interlace_type, double file_gamma, + double screen_gamma) +{ + size_t pos = 0; + char name[64]; + pos = safecat(name, sizeof name, pos, "threshold "); + pos = safecatd(name, sizeof name, pos, file_gamma, 3); + pos = safecat(name, sizeof name, pos, "/"); + pos = safecatd(name, sizeof name, pos, screen_gamma, 3); + + (void)gamma_test(pm, colour_type, bit_depth, interlace_type, file_gamma, + screen_gamma, bit_depth, 1, name, 0 /*speed*/, 0 /*no input precision*/, + 0 /*no strip16*/); +} + +static void +perform_gamma_threshold_tests(png_modifier *pm) +{ + png_byte colour_type = 0; + png_byte bit_depth = 0; + + while (next_format(&colour_type, &bit_depth)) + { + double test_gamma = 1.0; + while (test_gamma >= .4) + { + /* There's little point testing the interlacing vs non-interlacing, + * but this can be set from the command line. + */ + gamma_threshold_test(pm, colour_type, bit_depth, pm->interlace_type, + test_gamma, 1/test_gamma); + test_gamma *= .95; + } + + /* And a special test for sRGB */ + gamma_threshold_test(pm, colour_type, bit_depth, pm->interlace_type, + .45455, 2.2); + + if (fail(pm)) + return; + } +} + +static void gamma_transform_test(png_modifier *pm, + PNG_CONST png_byte colour_type, PNG_CONST png_byte bit_depth, + PNG_CONST int interlace_type, PNG_CONST double file_gamma, + PNG_CONST double screen_gamma, PNG_CONST png_byte sbit, PNG_CONST int speed, + PNG_CONST int use_input_precision, PNG_CONST int strip16) +{ + size_t pos = 0; + char name[64]; + + if (sbit != bit_depth) + { + pos = safecat(name, sizeof name, pos, "sbit("); + pos = safecatn(name, sizeof name, pos, sbit); + pos = safecat(name, sizeof name, pos, ") "); + } + + else + pos = safecat(name, sizeof name, pos, "gamma "); + + if (strip16) + pos = safecat(name, sizeof name, pos, "16to8 "); + + pos = safecatd(name, sizeof name, pos, file_gamma, 3); + pos = safecat(name, sizeof name, pos, "->"); + pos = safecatd(name, sizeof name, pos, screen_gamma, 3); + + gamma_test(pm, colour_type, bit_depth, interlace_type, file_gamma, + screen_gamma, sbit, 0, name, speed, use_input_precision, strip16); +} + +static void perform_gamma_transform_tests(png_modifier *pm, int speed) +{ + png_byte colour_type = 0; + png_byte bit_depth = 0; + + /* Ignore palette images - the gamma correction happens on the palette entry, + * haven't got the tests for this yet. + */ + while (next_format(&colour_type, &bit_depth)) if (colour_type != 3) + { + unsigned int i, j; + + for (i=0; i<pm->ngammas; ++i) for (j=0; j<pm->ngammas; ++j) if (i != j) + { + gamma_transform_test(pm, colour_type, bit_depth, pm->interlace_type, + 1/pm->gammas[i], pm->gammas[j], bit_depth, speed, + pm->use_input_precision, 0 /*do not strip16*/); + + if (fail(pm)) + return; + } + } +} + +static void perform_gamma_sbit_tests(png_modifier *pm, int speed) +{ + png_byte sbit; + + /* The only interesting cases are colour and grayscale, alpha is ignored here + * for overall speed. Only bit depths 8 and 16 are tested. + */ + for (sbit=pm->sbitlow; sbit<(1<<READ_BDHI); ++sbit) + { + unsigned int i, j; + + for (i=0; i<pm->ngammas; ++i) + { + for (j=0; j<pm->ngammas; ++j) + { + if (i != j) + { + if (sbit < 8) + { + gamma_transform_test(pm, 0, 8, pm->interlace_type, + 1/pm->gammas[i], pm->gammas[j], sbit, speed, + pm->use_input_precision_sbit, 0 /*strip16*/); + + if (fail(pm)) + return; + + gamma_transform_test(pm, 2, 8, pm->interlace_type, + 1/pm->gammas[i], pm->gammas[j], sbit, speed, + pm->use_input_precision_sbit, 0 /*strip16*/); + + if (fail(pm)) + return; + } + +#ifdef DO_16BIT + gamma_transform_test(pm, 0, 16, pm->interlace_type, + 1/pm->gammas[i], pm->gammas[j], sbit, speed, + pm->use_input_precision_sbit, 0 /*strip16*/); + + if (fail(pm)) + return; + + gamma_transform_test(pm, 2, 16, pm->interlace_type, + 1/pm->gammas[i], pm->gammas[j], sbit, speed, + pm->use_input_precision_sbit, 0 /*strip16*/); + + if (fail(pm)) + return; +#endif + } + } + } + } +} + +/* Note that this requires a 16 bit source image but produces 8 bit output, so + * we only need the 16bit write support. + */ +#ifdef PNG_READ_16_TO_8_SUPPORTED +static void perform_gamma_strip16_tests(png_modifier *pm, int speed) +{ +# ifndef PNG_MAX_GAMMA_8 +# define PNG_MAX_GAMMA_8 11 +# endif + /* Include the alpha cases here. Note that sbit matches the internal value + * used by the library - otherwise we will get spurious errors from the + * internal sbit style approximation. + * + * The threshold test is here because otherwise the 16 to 8 conversion will + * proceed *without* gamma correction, and the tests above will fail (but not + * by much) - this could be fixed, it only appears with the -g option. + */ + unsigned int i, j; + for (i=0; i<pm->ngammas; ++i) + { + for (j=0; j<pm->ngammas; ++j) + { + if (i != j && + fabs(pm->gammas[j]/pm->gammas[i]-1) >= PNG_GAMMA_THRESHOLD) + { + gamma_transform_test(pm, 0, 16, pm->interlace_type, 1/pm->gammas[i], + pm->gammas[j], PNG_MAX_GAMMA_8, speed, + pm->use_input_precision_16to8, 1 /*strip16*/); + + if (fail(pm)) + return; + + gamma_transform_test(pm, 2, 16, pm->interlace_type, 1/pm->gammas[i], + pm->gammas[j], PNG_MAX_GAMMA_8, speed, + pm->use_input_precision_16to8, 1 /*strip16*/); + + if (fail(pm)) + return; + + gamma_transform_test(pm, 4, 16, pm->interlace_type, 1/pm->gammas[i], + pm->gammas[j], PNG_MAX_GAMMA_8, speed, + pm->use_input_precision_16to8, 1 /*strip16*/); + + if (fail(pm)) + return; + + gamma_transform_test(pm, 6, 16, pm->interlace_type, 1/pm->gammas[i], + pm->gammas[j], PNG_MAX_GAMMA_8, speed, + pm->use_input_precision_16to8, 1 /*strip16*/); + + if (fail(pm)) + return; + } + } + } +} +#endif /* 16 to 8 bit conversion */ + +static void +perform_gamma_test(png_modifier *pm, int speed, int summary) +{ + /* First some arbitrary no-transform tests: */ + if (!speed && pm->test_gamma_threshold) + { + perform_gamma_threshold_tests(pm); + + if (fail(pm)) + return; + } + + /* Now some real transforms. */ + if (pm->test_gamma_transform) + { + perform_gamma_transform_tests(pm, speed); + + if (summary) + { + printf("Gamma correction error summary\n\n"); + printf("The printed value is the maximum error in the pixel values\n"); + printf("calculated by the libpng gamma correction code. The error\n"); + printf("is calculated as the difference between the output pixel\n"); + printf("value (always an integer) and the ideal value from the\n"); + printf("libpng specification (typically not an integer).\n\n"); + + printf("Expect this value to be less than .5 for 8 bit formats,\n"); + printf("less than 1 for formats with fewer than 8 bits and a small\n"); + printf("number (typically less than 5) for the 16 bit formats.\n"); + printf("For performance reasons the value for 16 bit formats\n"); + printf("increases when the image file includes an sBIT chunk.\n\n"); + + printf(" 2 bit gray: %.5f\n", pm->error_gray_2); + printf(" 4 bit gray: %.5f\n", pm->error_gray_4); + printf(" 8 bit gray: %.5f\n", pm->error_gray_8); + printf(" 8 bit color: %.5f\n", pm->error_color_8); +#ifdef DO_16BIT + printf(" 16 bit gray: %.5f\n", pm->error_gray_16); + printf(" 16 bit color: %.5f\n", pm->error_color_16); +#endif + } + } + + /* The sbit tests produce much larger errors: */ + if (pm->test_gamma_sbit) + { + pm->error_gray_2 = pm->error_gray_4 = pm->error_gray_8 = + pm->error_gray_16 = pm->error_color_8 = pm->error_color_16 = 0; + perform_gamma_sbit_tests(pm, speed); + + if (summary) + { + printf("Gamma correction with sBIT:\n"); + + if (pm->sbitlow < 8U) + { + printf(" 2 bit gray: %.5f\n", pm->error_gray_2); + printf(" 4 bit gray: %.5f\n", pm->error_gray_4); + printf(" 8 bit gray: %.5f\n", pm->error_gray_8); + printf(" 8 bit color: %.5f\n", pm->error_color_8); + } + + #ifdef DO_16BIT + printf(" 16 bit gray: %.5f\n", pm->error_gray_16); + printf(" 16 bit color: %.5f\n", pm->error_color_16); + #endif + } + } + +#ifdef PNG_READ_16_TO_8_SUPPORTED + if (pm->test_gamma_strip16) + { + /* The 16 to 8 bit strip operations: */ + pm->error_gray_2 = pm->error_gray_4 = pm->error_gray_8 = + pm->error_gray_16 = pm->error_color_8 = pm->error_color_16 = 0; + perform_gamma_strip16_tests(pm, speed); + + if (summary) + { + printf("Gamma correction with 16 to 8 bit reduction:\n"); + printf(" 16 bit gray: %.5f\n", pm->error_gray_16); + printf(" 16 bit color: %.5f\n", pm->error_color_16); + } + } +#endif +} + +/* INTERLACE MACRO VALIDATION */ +/* This is copied verbatim from the specification, it is simply the pass + * number in which each pixel in each 8x8 tile appears. The array must + * be indexed adam7[y][x] and notice that the pass numbers are based at + * 1, not 0 - the base libpng uses. + */ +static PNG_CONST +png_byte adam7[8][8] = +{ + { 1,6,4,6,2,6,4,6 }, + { 7,7,7,7,7,7,7,7 }, + { 5,6,5,6,5,6,5,6 }, + { 7,7,7,7,7,7,7,7 }, + { 3,6,4,6,3,6,4,6 }, + { 7,7,7,7,7,7,7,7 }, + { 5,6,5,6,5,6,5,6 }, + { 7,7,7,7,7,7,7,7 } +}; + +/* This routine validates all the interlace support macros in png.h for + * a variety of valid PNG widths and heights. It uses a number of similarly + * named internal routines that feed off the above array. + */ +static png_uint_32 +png_pass_start_row(int pass) +{ + int x, y; + ++pass; + for (y=0; y<8; ++y) for (x=0; x<8; ++x) if (adam7[y][x] == pass) + return y; + return 0xf; +} + +static png_uint_32 +png_pass_start_col(int pass) +{ + int x, y; + ++pass; + for (x=0; x<8; ++x) for (y=0; y<8; ++y) if (adam7[y][x] == pass) + return x; + return 0xf; +} + +static int +png_pass_row_shift(int pass) +{ + int x, y, base=(-1), inc=8; + ++pass; + for (y=0; y<8; ++y) for (x=0; x<8; ++x) if (adam7[y][x] == pass) + { + if (base == (-1)) + base = y; + else if (base == y) + {} + else if (inc == y-base) + base=y; + else if (inc == 8) + inc = y-base, base=y; + else if (inc != y-base) + return 0xff; /* error - more than one 'inc' value! */ + } + + if (base == (-1)) return 0xfe; /* error - no row in pass! */ + + /* The shift is always 1, 2 or 3 - no pass has all the rows! */ + switch (inc) + { +case 2: return 1; +case 4: return 2; +case 8: return 3; +default: break; + } + + /* error - unrecognized 'inc' */ + return (inc << 8) + 0xfd; +} + +static int +png_pass_col_shift(int pass) +{ + int x, y, base=(-1), inc=8; + ++pass; + for (x=0; x<8; ++x) for (y=0; y<8; ++y) if (adam7[y][x] == pass) + { + if (base == (-1)) + base = x; + else if (base == x) + {} + else if (inc == x-base) + base=x; + else if (inc == 8) + inc = x-base, base=x; + else if (inc != x-base) + return 0xff; /* error - more than one 'inc' value! */ + } + + if (base == (-1)) return 0xfe; /* error - no row in pass! */ + + /* The shift is always 1, 2 or 3 - no pass has all the rows! */ + switch (inc) + { +case 1: return 0; /* pass 7 has all the columns */ +case 2: return 1; +case 4: return 2; +case 8: return 3; +default: break; + } + + /* error - unrecognized 'inc' */ + return (inc << 8) + 0xfd; +} + +static png_uint_32 +png_row_from_pass_row(png_uint_32 yIn, int pass) +{ + /* By examination of the array: */ + switch (pass) + { +case 0: return yIn * 8; +case 1: return yIn * 8; +case 2: return yIn * 8 + 4; +case 3: return yIn * 4; +case 4: return yIn * 4 + 2; +case 5: return yIn * 2; +case 6: return yIn * 2 + 1; +default: break; + } + + return 0xff; /* bad pass number */ +} + +static png_uint_32 +png_col_from_pass_col(png_uint_32 xIn, int pass) +{ + /* By examination of the array: */ + switch (pass) + { +case 0: return xIn * 8; +case 1: return xIn * 8 + 4; +case 2: return xIn * 4; +case 3: return xIn * 4 + 2; +case 4: return xIn * 2; +case 5: return xIn * 2 + 1; +case 6: return xIn; +default: break; + } + + return 0xff; /* bad pass number */ +} + +static int +png_row_in_interlace_pass(png_uint_32 y, int pass) +{ + /* Is row 'y' in pass 'pass'? */ + int x; + y &= 7; + ++pass; + for (x=0; x<8; ++x) if (adam7[y][x] == pass) + return 1; + + return 0; +} + +static int +png_col_in_interlace_pass(png_uint_32 x, int pass) +{ + /* Is column 'x' in pass 'pass'? */ + int y; + x &= 7; + ++pass; + for (y=0; y<8; ++y) if (adam7[y][x] == pass) + return 1; + + return 0; +} + +static png_uint_32 +png_pass_rows(png_uint_32 height, int pass) +{ + png_uint_32 tiles = height>>3; + png_uint_32 rows = 0; + unsigned int x, y; + + height &= 7; + ++pass; + for (y=0; y<8; ++y) for (x=0; x<8; ++x) if (adam7[y][x] == pass) + { + rows += tiles; + if (y < height) ++rows; + break; /* i.e. break the 'x', column, loop. */ + } + + return rows; +} + +static png_uint_32 +png_pass_cols(png_uint_32 width, int pass) +{ + png_uint_32 tiles = width>>3; + png_uint_32 cols = 0; + unsigned int x, y; + + width &= 7; + ++pass; + for (x=0; x<8; ++x) for (y=0; y<8; ++y) if (adam7[y][x] == pass) + { + cols += tiles; + if (x < width) ++cols; + break; /* i.e. break the 'y', row, loop. */ + } + + return cols; +} + +static void +perform_interlace_macro_validation(void) +{ + /* The macros to validate, first those that depend only on pass: + * + * PNG_PASS_START_ROW(pass) + * PNG_PASS_START_COL(pass) + * PNG_PASS_ROW_SHIFT(pass) + * PNG_PASS_COL_SHIFT(pass) + */ + int pass; + + for (pass=0; pass<7; ++pass) + { + png_uint_32 m, f, v; + + m = PNG_PASS_START_ROW(pass); + f = png_pass_start_row(pass); + if (m != f) + { + fprintf(stderr, "PNG_PASS_START_ROW(%d) = %u != %x\n", pass, m, f); + exit(1); + } + + m = PNG_PASS_START_COL(pass); + f = png_pass_start_col(pass); + if (m != f) + { + fprintf(stderr, "PNG_PASS_START_COL(%d) = %u != %x\n", pass, m, f); + exit(1); + } + + m = PNG_PASS_ROW_SHIFT(pass); + f = png_pass_row_shift(pass); + if (m != f) + { + fprintf(stderr, "PNG_PASS_ROW_SHIFT(%d) = %u != %x\n", pass, m, f); + exit(1); + } + + m = PNG_PASS_COL_SHIFT(pass); + f = png_pass_col_shift(pass); + if (m != f) + { + fprintf(stderr, "PNG_PASS_COL_SHIFT(%d) = %u != %x\n", pass, m, f); + exit(1); + } + + /* Macros that depend on the image or sub-image height too: + * + * PNG_PASS_ROWS(height, pass) + * PNG_PASS_COLS(width, pass) + * PNG_ROW_FROM_PASS_ROW(yIn, pass) + * PNG_COL_FROM_PASS_COL(xIn, pass) + * PNG_ROW_IN_INTERLACE_PASS(y, pass) + * PNG_COL_IN_INTERLACE_PASS(x, pass) + */ + for (v=0;;) + { + /* First the base 0 stuff: */ + m = PNG_ROW_FROM_PASS_ROW(v, pass); + f = png_row_from_pass_row(v, pass); + if (m != f) + { + fprintf(stderr, "PNG_ROW_FROM_PASS_ROW(%u, %d) = %u != %x\n", + v, pass, m, f); + exit(1); + } + + m = PNG_COL_FROM_PASS_COL(v, pass); + f = png_col_from_pass_col(v, pass); + if (m != f) + { + fprintf(stderr, "PNG_COL_FROM_PASS_COL(%u, %d) = %u != %x\n", + v, pass, m, f); + exit(1); + } + + m = PNG_ROW_IN_INTERLACE_PASS(v, pass); + f = png_row_in_interlace_pass(v, pass); + if (m != f) + { + fprintf(stderr, "PNG_ROW_IN_INTERLACE_PASS(%u, %d) = %u != %x\n", + v, pass, m, f); + exit(1); + } + + m = PNG_COL_IN_INTERLACE_PASS(v, pass); + f = png_col_in_interlace_pass(v, pass); + if (m != f) + { + fprintf(stderr, "PNG_COL_IN_INTERLACE_PASS(%u, %d) = %u != %x\n", + v, pass, m, f); + exit(1); + } + + /* Then the base 1 stuff: */ + ++v; + m = PNG_PASS_ROWS(v, pass); + f = png_pass_rows(v, pass); + if (m != f) + { + fprintf(stderr, "PNG_PASS_ROWS(%u, %d) = %u != %x\n", + v, pass, m, f); + exit(1); + } + + m = PNG_PASS_COLS(v, pass); + f = png_pass_cols(v, pass); + if (m != f) + { + fprintf(stderr, "PNG_PASS_COLS(%u, %d) = %u != %x\n", + v, pass, m, f); + exit(1); + } + + /* Move to the next v - the stepping algorithm starts skipping + * values above 1024. + */ + if (v > 1024) + { + if (v == PNG_UINT_31_MAX) + break; + + v = (v << 1) ^ v; + if (v >= PNG_UINT_31_MAX) + v = PNG_UINT_31_MAX-1; + } + } + } +} + +/* main program */ +int main(int argc, PNG_CONST char **argv) +{ + volatile int summary = 1; /* Print the error summary at the end */ + + /* Create the given output file on success: */ + PNG_CONST char *volatile touch = NULL; + + /* This is an array of standard gamma values (believe it or not I've seen + * every one of these mentioned somewhere.) + * + * In the following list the most useful values are first! + */ + static double + gammas[]={2.2, 1.0, 2.2/1.45, 1.8, 1.5, 2.4, 2.5, 2.62, 2.9}; + + png_modifier pm; + context(&pm.this, fault); + + modifier_init(&pm); + + /* Preallocate the image buffer, because we know how big it needs to be, + * note that, for testing purposes, it is deliberately mis-aligned. + */ + pm.this.image = malloc(2*TRANSFORM_IMAGEMAX+1); + + if (pm.this.image != NULL) + { + /* Ignore OOM at this point - the 'ensure' routine above will allocate + * the array appropriately. + */ + ++(pm.this.image); + pm.this.cb_image = 2*TRANSFORM_IMAGEMAX; + } + + /* Default to error on warning: */ + pm.this.treat_warnings_as_errors = 1; + + /* Store the test gammas */ + pm.gammas = gammas; + pm.ngammas = 0; /* default to off */ + pm.sbitlow = 8U; /* because libpng doesn't do sBIT below 8! */ + pm.use_input_precision_16to8 = 1U; /* Because of the way libpng does it */ + + /* Some default values (set the behavior for 'make check' here). + * These values simply control the maximum error permitted in the gamma + * transformations. The practial limits for human perception are described + * below (the setting for maxpc16), however for 8 bit encodings it isn't + * possible to meet the accepted capabilities of human vision - i.e. 8 bit + * images can never be good enough, regardless of encoding. + */ + pm.maxout8 = .1; /* Arithmetic error in *encoded* value */ + pm.maxabs8 = .00005; /* 1/20000 */ + pm.maxpc8 = .499; /* I.e., .499% fractional error */ + pm.maxout16 = .499; /* Error in *encoded* value */ + pm.maxabs16 = .00005;/* 1/20000 */ + + /* NOTE: this is a reasonable perceptual limit. We assume that humans can + * perceive light level differences of 1% over a 100:1 range, so we need to + * maintain 1 in 10000 accuracy (in linear light space), which is what the + * following guarantees. It also allows significantly higher errors at + * higher 16 bit values, which is important for performance. The actual + * maximum 16 bit error is about +/-1.9 in the fixed point implementation but + * this is only allowed for values >38149 by the following: + */ + pm.maxpc16 = .005; /* I.e., 1/200% - 1/20000 */ + + /* Now parse the command line options. */ + while (--argc >= 1) + { + if (strcmp(*++argv, "-v") == 0) + pm.this.verbose = 1; + + else if (strcmp(*argv, "-l") == 0) + pm.log = 1; + + else if (strcmp(*argv, "-q") == 0) + summary = pm.this.verbose = pm.log = 0; + + else if (strcmp(*argv, "-w") == 0) + pm.this.treat_warnings_as_errors = 0; + + else if (strcmp(*argv, "--speed") == 0) + pm.this.speed = 1, pm.ngammas = (sizeof gammas)/(sizeof gammas[0]), + pm.test_standard = 0; + + else if (strcmp(*argv, "--size") == 0) + pm.test_size = 1; + + else if (strcmp(*argv, "--nosize") == 0) + pm.test_size = 0; + + else if (strcmp(*argv, "--standard") == 0) + pm.test_standard = 1; + + else if (strcmp(*argv, "--nostandard") == 0) + pm.test_standard = 0; + + else if (strcmp(*argv, "--transform") == 0) + pm.test_transform = 1; + + else if (strcmp(*argv, "--notransform") == 0) + pm.test_transform = 0; + + else if (strncmp(*argv, "--transform-disable=", + sizeof "--transform-disable") == 0) + { + pm.test_transform = 1; + transform_disable(*argv + sizeof "--transform-disable"); + } + + else if (strncmp(*argv, "--transform-enable=", + sizeof "--transform-enable") == 0) + { + pm.test_transform = 1; + transform_enable(*argv + sizeof "--transform-enable"); + } + + else if (strcmp(*argv, "--gamma") == 0) + { + /* Just do two gamma tests here (2.2 and linear) for speed: */ + pm.ngammas = 2U; + pm.test_gamma_threshold = 1; + pm.test_gamma_transform = 1; + pm.test_gamma_sbit = 1; + pm.test_gamma_strip16 = 1; + } + + else if (strcmp(*argv, "--nogamma") == 0) + pm.ngammas = 0; + + else if (strcmp(*argv, "--gamma-threshold") == 0) + pm.ngammas = 2U, pm.test_gamma_threshold = 1; + + else if (strcmp(*argv, "--nogamma-threshold") == 0) + pm.test_gamma_threshold = 0; + + else if (strcmp(*argv, "--gamma-transform") == 0) + pm.ngammas = 2U, pm.test_gamma_transform = 1; + + else if (strcmp(*argv, "--nogamma-transform") == 0) + pm.test_gamma_transform = 0; + + else if (strcmp(*argv, "--gamma-sbit") == 0) + pm.ngammas = 2U, pm.test_gamma_sbit = 1; + + else if (strcmp(*argv, "--nogamma-sbit") == 0) + pm.test_gamma_sbit = 0; + + else if (strcmp(*argv, "--gamma-16-to-8") == 0) + pm.ngammas = 2U, pm.test_gamma_strip16 = 1; + + else if (strcmp(*argv, "--nogamma-16-to-8") == 0) + pm.test_gamma_strip16 = 0; + + else if (strcmp(*argv, "--all-gammas") == 0) + pm.ngammas = (sizeof gammas)/(sizeof gammas[0]); + + else if (strcmp(*argv, "--progressive-read") == 0) + pm.this.progressive = 1; + + else if (strcmp(*argv, "--interlace") == 0) + pm.interlace_type = PNG_INTERLACE_ADAM7; + + else if (argc >= 1 && strcmp(*argv, "--sbitlow") == 0) + --argc, pm.sbitlow = (png_byte)atoi(*++argv); + + else if (argc >= 1 && strcmp(*argv, "--touch") == 0) + --argc, touch = *++argv; + + else if (argc >= 1 && strncmp(*argv, "--max", 4) == 0) + { + --argc; + + if (strcmp(4+*argv, "abs8") == 0) + pm.maxabs8 = atof(*++argv); + + else if (strcmp(4+*argv, "abs16") == 0) + pm.maxabs16 = atof(*++argv); + + else if (strcmp(4+*argv, "out8") == 0) + pm.maxout8 = atof(*++argv); + + else if (strcmp(4+*argv, "out16") == 0) + pm.maxout16 = atof(*++argv); + + else if (strcmp(4+*argv, "pc8") == 0) + pm.maxpc8 = atof(*++argv); + + else if (strcmp(4+*argv, "pc16") == 0) + pm.maxpc16 = atof(*++argv); + + else + { + fprintf(stderr, "pngvalid: %s: unknown 'max' option\n", *argv); + exit(1); + } + } + + else + { + fprintf(stderr, "pngvalid: %s: unknown argument\n", *argv); + exit(1); + } + } + + /* If pngvalid is run with no arguments default to a reasonable set of the + * tests. + */ + if (pm.test_standard == 0 && pm.test_size == 0 && pm.test_transform == 0 && + pm.ngammas == 0) + { + pm.test_standard = 1; + pm.test_size = 1; + pm.test_transform = 1; + pm.ngammas = 3U; + } + + if (pm.ngammas > 0 && + pm.test_gamma_threshold == 0 && pm.test_gamma_transform == 0 && + pm.test_gamma_sbit == 0 && pm.test_gamma_strip16 == 0) + { + pm.test_gamma_threshold = 1; + pm.test_gamma_transform = 1; + pm.test_gamma_sbit = 1; + pm.test_gamma_strip16 = 1; + } + + else if (pm.ngammas == 0) + { + /* Nothing to test so turn everything off: */ + pm.test_gamma_threshold = 0; + pm.test_gamma_transform = 0; + pm.test_gamma_sbit = 0; + pm.test_gamma_strip16 = 0; + } + + Try + { + /* Make useful base images */ + make_transform_images(&pm.this); + + /* Perform the standard and gamma tests. */ + if (pm.test_standard) + { + perform_interlace_macro_validation(); + perform_standard_test(&pm); + perform_error_test(&pm); + } + + /* Various oddly sized images: */ + if (pm.test_size) + { + make_size_images(&pm.this); + perform_size_test(&pm); + } + + /* Combinatorial transforms: */ + if (pm.test_transform) + perform_transform_test(&pm); + + if (pm.ngammas > 0) + perform_gamma_test(&pm, pm.this.speed != 0, + summary && !pm.this.speed); + } + + Catch(fault) + { + fprintf(stderr, "pngvalid: test aborted (probably failed in cleanup)\n"); + if (!pm.this.verbose) + { + if (pm.this.error[0] != 0) + fprintf(stderr, "pngvalid: first error: %s\n", pm.this.error); + + fprintf(stderr, "pngvalid: run with -v to see what happened\n"); + } + exit(1); + } + + if (summary && !pm.this.speed) + { + printf("Results using %s point arithmetic %s\n", +#if defined(PNG_FLOATING_ARITHMETIC_SUPPORTED) || PNG_LIBPNG_VER < 10500 + "floating", +#else + "fixed", +#endif + (pm.this.nerrors || (pm.this.treat_warnings_as_errors && + pm.this.nwarnings)) ? "(errors)" : (pm.this.nwarnings ? + "(warnings)" : "(no errors or warnings)") + ); + printf("Allocated memory statistics (in bytes):\n" + "\tread %lu maximum single, %lu peak, %lu total\n" + "\twrite %lu maximum single, %lu peak, %lu total\n", + (unsigned long)pm.this.read_memory_pool.max_max, + (unsigned long)pm.this.read_memory_pool.max_limit, + (unsigned long)pm.this.read_memory_pool.max_total, + (unsigned long)pm.this.write_memory_pool.max_max, + (unsigned long)pm.this.write_memory_pool.max_limit, + (unsigned long)pm.this.write_memory_pool.max_total); + } + + /* Do this here to provoke memory corruption errors in memory not directly + * allocated by libpng - not a complete test, but better than nothing. + */ + store_delete(&pm.this); + + /* Error exit if there are any errors, and maybe if there are any + * warnings. + */ + if (pm.this.nerrors || (pm.this.treat_warnings_as_errors && + pm.this.nwarnings)) + { + if (!pm.this.verbose) + fprintf(stderr, "pngvalid: %s\n", pm.this.error); + + fprintf(stderr, "pngvalid: %d errors, %d warnings\n", pm.this.nerrors, + pm.this.nwarnings); + + exit(1); + } + + /* Success case. */ + if (touch != NULL) + { + FILE *fsuccess = fopen(touch, "wt"); + + if (fsuccess != NULL) + { + int error = 0; + fprintf(fsuccess, "PNG validation succeeded\n"); + fflush(fsuccess); + error = ferror(fsuccess); + + if (fclose(fsuccess) || error) + { + fprintf(stderr, "%s: write failed\n", touch); + exit(1); + } + } + } + + return 0; +} diff --git a/src/3rdparty/libpng/pngwio.c b/src/3rdparty/libpng/pngwio.c new file mode 100644 index 0000000000..95ffb3429f --- /dev/null +++ b/src/3rdparty/libpng/pngwio.c @@ -0,0 +1,254 @@ + +/* pngwio.c - functions for data output + * + * Last changed in libpng 1.5.0 [January 6, 2011] + * Copyright (c) 1998-2011 Glenn Randers-Pehrson + * (Version 0.96 Copyright (c) 1996, 1997 Andreas Dilger) + * (Version 0.88 Copyright (c) 1995, 1996 Guy Eric Schalnat, Group 42, Inc.) + * + * This code is released under the libpng license. + * For conditions of distribution and use, see the disclaimer + * and license in png.h + * + * This file provides a location for all output. Users who need + * special handling are expected to write functions that have the same + * arguments as these and perform similar functions, but that possibly + * use different output methods. Note that you shouldn't change these + * functions, but rather write replacement functions and then change + * them at run time with png_set_write_fn(...). + */ + +#include "pngpriv.h" + +#ifdef PNG_WRITE_SUPPORTED + +/* Write the data to whatever output you are using. The default routine + * writes to a file pointer. Note that this routine sometimes gets called + * with very small lengths, so you should implement some kind of simple + * buffering if you are using unbuffered writes. This should never be asked + * to write more than 64K on a 16 bit machine. + */ + +void /* PRIVATE */ +png_write_data(png_structp png_ptr, png_const_bytep data, png_size_t length) +{ + /* NOTE: write_data_fn must not change the buffer! */ + if (png_ptr->write_data_fn != NULL ) + (*(png_ptr->write_data_fn))(png_ptr, (png_bytep)data, length); + + else + png_error(png_ptr, "Call to NULL write function"); +} + +#ifdef PNG_STDIO_SUPPORTED +/* This is the function that does the actual writing of data. If you are + * not writing to a standard C stream, you should create a replacement + * write_data function and use it at run time with png_set_write_fn(), rather + * than changing the library. + */ +#ifndef USE_FAR_KEYWORD +void PNGCBAPI +png_default_write_data(png_structp png_ptr, png_bytep data, png_size_t length) +{ + png_size_t check; + + if (png_ptr == NULL) + return; + + check = fwrite(data, 1, length, (png_FILE_p)(png_ptr->io_ptr)); + + if (check != length) + png_error(png_ptr, "Write Error"); +} +#else +/* This is the model-independent version. Since the standard I/O library + * can't handle far buffers in the medium and small models, we have to copy + * the data. + */ + +#define NEAR_BUF_SIZE 1024 +#define MIN(a,b) (a <= b ? a : b) + +void PNGCBAPI +png_default_write_data(png_structp png_ptr, png_bytep data, png_size_t length) +{ + png_uint_32 check; + png_byte *near_data; /* Needs to be "png_byte *" instead of "png_bytep" */ + png_FILE_p io_ptr; + + if (png_ptr == NULL) + return; + + /* Check if data really is near. If so, use usual code. */ + near_data = (png_byte *)CVT_PTR_NOCHECK(data); + io_ptr = (png_FILE_p)CVT_PTR(png_ptr->io_ptr); + + if ((png_bytep)near_data == data) + { + check = fwrite(near_data, 1, length, io_ptr); + } + + else + { + png_byte buf[NEAR_BUF_SIZE]; + png_size_t written, remaining, err; + check = 0; + remaining = length; + + do + { + written = MIN(NEAR_BUF_SIZE, remaining); + png_memcpy(buf, data, written); /* Copy far buffer to near buffer */ + err = fwrite(buf, 1, written, io_ptr); + + if (err != written) + break; + + else + check += err; + + data += written; + remaining -= written; + } + while (remaining != 0); + } + + if (check != length) + png_error(png_ptr, "Write Error"); +} + +#endif +#endif + +/* This function is called to output any data pending writing (normally + * to disk). After png_flush is called, there should be no data pending + * writing in any buffers. + */ +#ifdef PNG_WRITE_FLUSH_SUPPORTED +void /* PRIVATE */ +png_flush(png_structp png_ptr) +{ + if (png_ptr->output_flush_fn != NULL) + (*(png_ptr->output_flush_fn))(png_ptr); +} + +# ifdef PNG_STDIO_SUPPORTED +void PNGCBAPI +png_default_flush(png_structp png_ptr) +{ + png_FILE_p io_ptr; + + if (png_ptr == NULL) + return; + + io_ptr = (png_FILE_p)CVT_PTR((png_ptr->io_ptr)); + fflush(io_ptr); +} +# endif +#endif + +/* This function allows the application to supply new output functions for + * libpng if standard C streams aren't being used. + * + * This function takes as its arguments: + * png_ptr - pointer to a png output data structure + * io_ptr - pointer to user supplied structure containing info about + * the output functions. May be NULL. + * write_data_fn - pointer to a new output function that takes as its + * arguments a pointer to a png_struct, a pointer to + * data to be written, and a 32-bit unsigned int that is + * the number of bytes to be written. The new write + * function should call png_error(png_ptr, "Error msg") + * to exit and output any fatal error messages. May be + * NULL, in which case libpng's default function will + * be used. + * flush_data_fn - pointer to a new flush function that takes as its + * arguments a pointer to a png_struct. After a call to + * the flush function, there should be no data in any buffers + * or pending transmission. If the output method doesn't do + * any buffering of output, a function prototype must still be + * supplied although it doesn't have to do anything. If + * PNG_WRITE_FLUSH_SUPPORTED is not defined at libpng compile + * time, output_flush_fn will be ignored, although it must be + * supplied for compatibility. May be NULL, in which case + * libpng's default function will be used, if + * PNG_WRITE_FLUSH_SUPPORTED is defined. This is not + * a good idea if io_ptr does not point to a standard + * *FILE structure. + */ +void PNGAPI +png_set_write_fn(png_structp png_ptr, png_voidp io_ptr, + png_rw_ptr write_data_fn, png_flush_ptr output_flush_fn) +{ + if (png_ptr == NULL) + return; + + png_ptr->io_ptr = io_ptr; + +#ifdef PNG_STDIO_SUPPORTED + if (write_data_fn != NULL) + png_ptr->write_data_fn = write_data_fn; + + else + png_ptr->write_data_fn = png_default_write_data; +#else + png_ptr->write_data_fn = write_data_fn; +#endif + +#ifdef PNG_WRITE_FLUSH_SUPPORTED +# ifdef PNG_STDIO_SUPPORTED + + if (output_flush_fn != NULL) + png_ptr->output_flush_fn = output_flush_fn; + + else + png_ptr->output_flush_fn = png_default_flush; + +# else + png_ptr->output_flush_fn = output_flush_fn; +# endif +#endif /* PNG_WRITE_FLUSH_SUPPORTED */ + + /* It is an error to read while writing a png file */ + if (png_ptr->read_data_fn != NULL) + { + png_ptr->read_data_fn = NULL; + + png_warning(png_ptr, + "Can't set both read_data_fn and write_data_fn in the" + " same structure"); + } +} + +#ifdef USE_FAR_KEYWORD +# ifdef _MSC_VER +void *png_far_to_near(png_structp png_ptr, png_voidp ptr, int check) +{ + void *near_ptr; + void FAR *far_ptr; + FP_OFF(near_ptr) = FP_OFF(ptr); + far_ptr = (void FAR *)near_ptr; + + if (check != 0) + if (FP_SEG(ptr) != FP_SEG(far_ptr)) + png_error(png_ptr, "segment lost in conversion"); + + return(near_ptr); +} +# else +void *png_far_to_near(png_structp png_ptr, png_voidp ptr, int check) +{ + void *near_ptr; + void FAR *far_ptr; + near_ptr = (void FAR *)ptr; + far_ptr = (void FAR *)near_ptr; + + if (check != 0) + if (far_ptr != ptr) + png_error(png_ptr, "segment lost in conversion"); + + return(near_ptr); +} +# endif +#endif +#endif /* PNG_WRITE_SUPPORTED */ diff --git a/src/3rdparty/libpng/pngwrite.c b/src/3rdparty/libpng/pngwrite.c new file mode 100644 index 0000000000..d90f449e30 --- /dev/null +++ b/src/3rdparty/libpng/pngwrite.c @@ -0,0 +1,1605 @@ + +/* pngwrite.c - general routines to write a PNG file + * + * Last changed in libpng 1.5.1 [February 3, 2011] + * Copyright (c) 1998-2011 Glenn Randers-Pehrson + * (Version 0.96 Copyright (c) 1996, 1997 Andreas Dilger) + * (Version 0.88 Copyright (c) 1995, 1996 Guy Eric Schalnat, Group 42, Inc.) + * + * This code is released under the libpng license. + * For conditions of distribution and use, see the disclaimer + * and license in png.h + */ + +#include "pngpriv.h" + +#ifdef PNG_WRITE_SUPPORTED + +/* Writes all the PNG information. This is the suggested way to use the + * library. If you have a new chunk to add, make a function to write it, + * and put it in the correct location here. If you want the chunk written + * after the image data, put it in png_write_end(). I strongly encourage + * you to supply a PNG_INFO_ flag, and check info_ptr->valid before writing + * the chunk, as that will keep the code from breaking if you want to just + * write a plain PNG file. If you have long comments, I suggest writing + * them in png_write_end(), and compressing them. + */ +void PNGAPI +png_write_info_before_PLTE(png_structp png_ptr, png_infop info_ptr) +{ + png_debug(1, "in png_write_info_before_PLTE"); + + if (png_ptr == NULL || info_ptr == NULL) + return; + + if (!(png_ptr->mode & PNG_WROTE_INFO_BEFORE_PLTE)) + { + /* Write PNG signature */ + png_write_sig(png_ptr); + +#ifdef PNG_MNG_FEATURES_SUPPORTED + if ((png_ptr->mode&PNG_HAVE_PNG_SIGNATURE) && \ + (png_ptr->mng_features_permitted)) + { + png_warning(png_ptr, "MNG features are not allowed in a PNG datastream"); + png_ptr->mng_features_permitted = 0; + } +#endif + + /* Write IHDR information. */ + png_write_IHDR(png_ptr, info_ptr->width, info_ptr->height, + info_ptr->bit_depth, info_ptr->color_type, info_ptr->compression_type, + info_ptr->filter_type, +#ifdef PNG_WRITE_INTERLACING_SUPPORTED + info_ptr->interlace_type); +#else + 0); +#endif + /* The rest of these check to see if the valid field has the appropriate + * flag set, and if it does, writes the chunk. + */ +#ifdef PNG_WRITE_gAMA_SUPPORTED + if (info_ptr->valid & PNG_INFO_gAMA) + png_write_gAMA_fixed(png_ptr, info_ptr->gamma); +#endif +#ifdef PNG_WRITE_sRGB_SUPPORTED + if (info_ptr->valid & PNG_INFO_sRGB) + png_write_sRGB(png_ptr, (int)info_ptr->srgb_intent); +#endif + +#ifdef PNG_WRITE_iCCP_SUPPORTED + if (info_ptr->valid & PNG_INFO_iCCP) + png_write_iCCP(png_ptr, info_ptr->iccp_name, PNG_COMPRESSION_TYPE_BASE, + (png_charp)info_ptr->iccp_profile, (int)info_ptr->iccp_proflen); +#endif +#ifdef PNG_WRITE_sBIT_SUPPORTED + if (info_ptr->valid & PNG_INFO_sBIT) + png_write_sBIT(png_ptr, &(info_ptr->sig_bit), info_ptr->color_type); +#endif +#ifdef PNG_WRITE_cHRM_SUPPORTED + if (info_ptr->valid & PNG_INFO_cHRM) + png_write_cHRM_fixed(png_ptr, + info_ptr->x_white, info_ptr->y_white, + info_ptr->x_red, info_ptr->y_red, + info_ptr->x_green, info_ptr->y_green, + info_ptr->x_blue, info_ptr->y_blue); +#endif + +#ifdef PNG_WRITE_UNKNOWN_CHUNKS_SUPPORTED + if (info_ptr->unknown_chunks_num) + { + png_unknown_chunk *up; + + png_debug(5, "writing extra chunks"); + + for (up = info_ptr->unknown_chunks; + up < info_ptr->unknown_chunks + info_ptr->unknown_chunks_num; + up++) + { + int keep = png_handle_as_unknown(png_ptr, up->name); + + if (keep != PNG_HANDLE_CHUNK_NEVER && + up->location && !(up->location & PNG_HAVE_PLTE) && + !(up->location & PNG_HAVE_IDAT) && + ((up->name[3] & 0x20) || keep == PNG_HANDLE_CHUNK_ALWAYS || + (png_ptr->flags & PNG_FLAG_KEEP_UNSAFE_CHUNKS))) + { + if (up->size == 0) + png_warning(png_ptr, "Writing zero-length unknown chunk"); + + png_write_chunk(png_ptr, up->name, up->data, up->size); + } + } + } +#endif + png_ptr->mode |= PNG_WROTE_INFO_BEFORE_PLTE; + } +} + +void PNGAPI +png_write_info(png_structp png_ptr, png_infop info_ptr) +{ +#if defined(PNG_WRITE_TEXT_SUPPORTED) || defined(PNG_WRITE_sPLT_SUPPORTED) + int i; +#endif + + png_debug(1, "in png_write_info"); + + if (png_ptr == NULL || info_ptr == NULL) + return; + + png_write_info_before_PLTE(png_ptr, info_ptr); + + if (info_ptr->valid & PNG_INFO_PLTE) + png_write_PLTE(png_ptr, info_ptr->palette, + (png_uint_32)info_ptr->num_palette); + + else if (info_ptr->color_type == PNG_COLOR_TYPE_PALETTE) + png_error(png_ptr, "Valid palette required for paletted images"); + +#ifdef PNG_WRITE_tRNS_SUPPORTED + if (info_ptr->valid & PNG_INFO_tRNS) + { +#ifdef PNG_WRITE_INVERT_ALPHA_SUPPORTED + /* Invert the alpha channel (in tRNS) */ + if ((png_ptr->transformations & PNG_INVERT_ALPHA) && + info_ptr->color_type == PNG_COLOR_TYPE_PALETTE) + { + int j; + for (j = 0; j<(int)info_ptr->num_trans; j++) + info_ptr->trans_alpha[j] = + (png_byte)(255 - info_ptr->trans_alpha[j]); + } +#endif + png_write_tRNS(png_ptr, info_ptr->trans_alpha, &(info_ptr->trans_color), + info_ptr->num_trans, info_ptr->color_type); + } +#endif +#ifdef PNG_WRITE_bKGD_SUPPORTED + if (info_ptr->valid & PNG_INFO_bKGD) + png_write_bKGD(png_ptr, &(info_ptr->background), info_ptr->color_type); +#endif + +#ifdef PNG_WRITE_hIST_SUPPORTED + if (info_ptr->valid & PNG_INFO_hIST) + png_write_hIST(png_ptr, info_ptr->hist, info_ptr->num_palette); +#endif + +#ifdef PNG_WRITE_oFFs_SUPPORTED + if (info_ptr->valid & PNG_INFO_oFFs) + png_write_oFFs(png_ptr, info_ptr->x_offset, info_ptr->y_offset, + info_ptr->offset_unit_type); +#endif + +#ifdef PNG_WRITE_pCAL_SUPPORTED + if (info_ptr->valid & PNG_INFO_pCAL) + png_write_pCAL(png_ptr, info_ptr->pcal_purpose, info_ptr->pcal_X0, + info_ptr->pcal_X1, info_ptr->pcal_type, info_ptr->pcal_nparams, + info_ptr->pcal_units, info_ptr->pcal_params); +#endif + +#ifdef PNG_WRITE_sCAL_SUPPORTED + if (info_ptr->valid & PNG_INFO_sCAL) + png_write_sCAL_s(png_ptr, (int)info_ptr->scal_unit, + info_ptr->scal_s_width, info_ptr->scal_s_height); +#endif /* sCAL */ + +#ifdef PNG_WRITE_pHYs_SUPPORTED + if (info_ptr->valid & PNG_INFO_pHYs) + png_write_pHYs(png_ptr, info_ptr->x_pixels_per_unit, + info_ptr->y_pixels_per_unit, info_ptr->phys_unit_type); +#endif /* pHYs */ + +#ifdef PNG_WRITE_tIME_SUPPORTED + if (info_ptr->valid & PNG_INFO_tIME) + { + png_write_tIME(png_ptr, &(info_ptr->mod_time)); + png_ptr->mode |= PNG_WROTE_tIME; + } +#endif /* tIME */ + +#ifdef PNG_WRITE_sPLT_SUPPORTED + if (info_ptr->valid & PNG_INFO_sPLT) + for (i = 0; i < (int)info_ptr->splt_palettes_num; i++) + png_write_sPLT(png_ptr, info_ptr->splt_palettes + i); +#endif /* sPLT */ + +#ifdef PNG_WRITE_TEXT_SUPPORTED + /* Check to see if we need to write text chunks */ + for (i = 0; i < info_ptr->num_text; i++) + { + png_debug2(2, "Writing header text chunk %d, type %d", i, + info_ptr->text[i].compression); + /* An internationalized chunk? */ + if (info_ptr->text[i].compression > 0) + { +#ifdef PNG_WRITE_iTXt_SUPPORTED + /* Write international chunk */ + png_write_iTXt(png_ptr, + info_ptr->text[i].compression, + info_ptr->text[i].key, + info_ptr->text[i].lang, + info_ptr->text[i].lang_key, + info_ptr->text[i].text); +#else + png_warning(png_ptr, "Unable to write international text"); +#endif + /* Mark this chunk as written */ + info_ptr->text[i].compression = PNG_TEXT_COMPRESSION_NONE_WR; + } + + /* If we want a compressed text chunk */ + else if (info_ptr->text[i].compression == PNG_TEXT_COMPRESSION_zTXt) + { +#ifdef PNG_WRITE_zTXt_SUPPORTED + /* Write compressed chunk */ + png_write_zTXt(png_ptr, info_ptr->text[i].key, + info_ptr->text[i].text, 0, + info_ptr->text[i].compression); +#else + png_warning(png_ptr, "Unable to write compressed text"); +#endif + /* Mark this chunk as written */ + info_ptr->text[i].compression = PNG_TEXT_COMPRESSION_zTXt_WR; + } + + else if (info_ptr->text[i].compression == PNG_TEXT_COMPRESSION_NONE) + { +#ifdef PNG_WRITE_tEXt_SUPPORTED + /* Write uncompressed chunk */ + png_write_tEXt(png_ptr, info_ptr->text[i].key, + info_ptr->text[i].text, + 0); + /* Mark this chunk as written */ + info_ptr->text[i].compression = PNG_TEXT_COMPRESSION_NONE_WR; +#else + /* Can't get here */ + png_warning(png_ptr, "Unable to write uncompressed text"); +#endif + } + } +#endif /* tEXt */ + +#ifdef PNG_WRITE_UNKNOWN_CHUNKS_SUPPORTED + if (info_ptr->unknown_chunks_num) + { + png_unknown_chunk *up; + + png_debug(5, "writing extra chunks"); + + for (up = info_ptr->unknown_chunks; + up < info_ptr->unknown_chunks + info_ptr->unknown_chunks_num; + up++) + { + int keep = png_handle_as_unknown(png_ptr, up->name); + if (keep != PNG_HANDLE_CHUNK_NEVER && + up->location && (up->location & PNG_HAVE_PLTE) && + !(up->location & PNG_HAVE_IDAT) && + ((up->name[3] & 0x20) || keep == PNG_HANDLE_CHUNK_ALWAYS || + (png_ptr->flags & PNG_FLAG_KEEP_UNSAFE_CHUNKS))) + { + png_write_chunk(png_ptr, up->name, up->data, up->size); + } + } + } +#endif +} + +/* Writes the end of the PNG file. If you don't want to write comments or + * time information, you can pass NULL for info. If you already wrote these + * in png_write_info(), do not write them again here. If you have long + * comments, I suggest writing them here, and compressing them. + */ +void PNGAPI +png_write_end(png_structp png_ptr, png_infop info_ptr) +{ + png_debug(1, "in png_write_end"); + + if (png_ptr == NULL) + return; + + if (!(png_ptr->mode & PNG_HAVE_IDAT)) + png_error(png_ptr, "No IDATs written into file"); + + /* See if user wants us to write information chunks */ + if (info_ptr != NULL) + { +#ifdef PNG_WRITE_TEXT_SUPPORTED + int i; /* local index variable */ +#endif +#ifdef PNG_WRITE_tIME_SUPPORTED + /* Check to see if user has supplied a time chunk */ + if ((info_ptr->valid & PNG_INFO_tIME) && + !(png_ptr->mode & PNG_WROTE_tIME)) + png_write_tIME(png_ptr, &(info_ptr->mod_time)); + +#endif +#ifdef PNG_WRITE_TEXT_SUPPORTED + /* Loop through comment chunks */ + for (i = 0; i < info_ptr->num_text; i++) + { + png_debug2(2, "Writing trailer text chunk %d, type %d", i, + info_ptr->text[i].compression); + /* An internationalized chunk? */ + if (info_ptr->text[i].compression > 0) + { +#ifdef PNG_WRITE_iTXt_SUPPORTED + /* Write international chunk */ + png_write_iTXt(png_ptr, + info_ptr->text[i].compression, + info_ptr->text[i].key, + info_ptr->text[i].lang, + info_ptr->text[i].lang_key, + info_ptr->text[i].text); +#else + png_warning(png_ptr, "Unable to write international text"); +#endif + /* Mark this chunk as written */ + info_ptr->text[i].compression = PNG_TEXT_COMPRESSION_NONE_WR; + } + + else if (info_ptr->text[i].compression >= PNG_TEXT_COMPRESSION_zTXt) + { +#ifdef PNG_WRITE_zTXt_SUPPORTED + /* Write compressed chunk */ + png_write_zTXt(png_ptr, info_ptr->text[i].key, + info_ptr->text[i].text, 0, + info_ptr->text[i].compression); +#else + png_warning(png_ptr, "Unable to write compressed text"); +#endif + /* Mark this chunk as written */ + info_ptr->text[i].compression = PNG_TEXT_COMPRESSION_zTXt_WR; + } + + else if (info_ptr->text[i].compression == PNG_TEXT_COMPRESSION_NONE) + { +#ifdef PNG_WRITE_tEXt_SUPPORTED + /* Write uncompressed chunk */ + png_write_tEXt(png_ptr, info_ptr->text[i].key, + info_ptr->text[i].text, 0); +#else + png_warning(png_ptr, "Unable to write uncompressed text"); +#endif + + /* Mark this chunk as written */ + info_ptr->text[i].compression = PNG_TEXT_COMPRESSION_NONE_WR; + } + } +#endif +#ifdef PNG_WRITE_UNKNOWN_CHUNKS_SUPPORTED + if (info_ptr->unknown_chunks_num) + { + png_unknown_chunk *up; + + png_debug(5, "writing extra chunks"); + + for (up = info_ptr->unknown_chunks; + up < info_ptr->unknown_chunks + info_ptr->unknown_chunks_num; + up++) + { + int keep = png_handle_as_unknown(png_ptr, up->name); + if (keep != PNG_HANDLE_CHUNK_NEVER && + up->location && (up->location & PNG_AFTER_IDAT) && + ((up->name[3] & 0x20) || keep == PNG_HANDLE_CHUNK_ALWAYS || + (png_ptr->flags & PNG_FLAG_KEEP_UNSAFE_CHUNKS))) + { + png_write_chunk(png_ptr, up->name, up->data, up->size); + } + } + } +#endif + } + + png_ptr->mode |= PNG_AFTER_IDAT; + + /* Write end of PNG file */ + png_write_IEND(png_ptr); + /* This flush, added in libpng-1.0.8, removed from libpng-1.0.9beta03, + * and restored again in libpng-1.2.30, may cause some applications that + * do not set png_ptr->output_flush_fn to crash. If your application + * experiences a problem, please try building libpng with + * PNG_WRITE_FLUSH_AFTER_IEND_SUPPORTED defined, and report the event to + * png-mng-implement at lists.sf.net . + */ +#ifdef PNG_WRITE_FLUSH_SUPPORTED +# ifdef PNG_WRITE_FLUSH_AFTER_IEND_SUPPORTED + png_flush(png_ptr); +# endif +#endif +} + +#ifdef PNG_CONVERT_tIME_SUPPORTED +/* "tm" structure is not supported on WindowsCE */ +void PNGAPI +png_convert_from_struct_tm(png_timep ptime, PNG_CONST struct tm FAR * ttime) +{ + png_debug(1, "in png_convert_from_struct_tm"); + + ptime->year = (png_uint_16)(1900 + ttime->tm_year); + ptime->month = (png_byte)(ttime->tm_mon + 1); + ptime->day = (png_byte)ttime->tm_mday; + ptime->hour = (png_byte)ttime->tm_hour; + ptime->minute = (png_byte)ttime->tm_min; + ptime->second = (png_byte)ttime->tm_sec; +} + +void PNGAPI +png_convert_from_time_t(png_timep ptime, time_t ttime) +{ + struct tm *tbuf; + + png_debug(1, "in png_convert_from_time_t"); + + tbuf = gmtime(&ttime); + png_convert_from_struct_tm(ptime, tbuf); +} +#endif + +/* Initialize png_ptr structure, and allocate any memory needed */ +PNG_FUNCTION(png_structp,PNGAPI +png_create_write_struct,(png_const_charp user_png_ver, png_voidp error_ptr, + png_error_ptr error_fn, png_error_ptr warn_fn),PNG_ALLOCATED) +{ +#ifdef PNG_USER_MEM_SUPPORTED + return (png_create_write_struct_2(user_png_ver, error_ptr, error_fn, + warn_fn, NULL, NULL, NULL)); +} + +/* Alternate initialize png_ptr structure, and allocate any memory needed */ +static void png_reset_filter_heuristics(png_structp png_ptr); /* forward decl */ + +PNG_FUNCTION(png_structp,PNGAPI +png_create_write_struct_2,(png_const_charp user_png_ver, png_voidp error_ptr, + png_error_ptr error_fn, png_error_ptr warn_fn, png_voidp mem_ptr, + png_malloc_ptr malloc_fn, png_free_ptr free_fn),PNG_ALLOCATED) +{ +#endif /* PNG_USER_MEM_SUPPORTED */ + volatile int png_cleanup_needed = 0; +#ifdef PNG_SETJMP_SUPPORTED + volatile +#endif + png_structp png_ptr; +#ifdef PNG_SETJMP_SUPPORTED +#ifdef USE_FAR_KEYWORD + jmp_buf png_jmpbuf; +#endif +#endif + int i; + + png_debug(1, "in png_create_write_struct"); + +#ifdef PNG_USER_MEM_SUPPORTED + png_ptr = (png_structp)png_create_struct_2(PNG_STRUCT_PNG, + (png_malloc_ptr)malloc_fn, (png_voidp)mem_ptr); +#else + png_ptr = (png_structp)png_create_struct(PNG_STRUCT_PNG); +#endif /* PNG_USER_MEM_SUPPORTED */ + if (png_ptr == NULL) + return (NULL); + + /* Added at libpng-1.2.6 */ +#ifdef PNG_SET_USER_LIMITS_SUPPORTED + png_ptr->user_width_max = PNG_USER_WIDTH_MAX; + png_ptr->user_height_max = PNG_USER_HEIGHT_MAX; +#endif + +#ifdef PNG_SETJMP_SUPPORTED +/* Applications that neglect to set up their own setjmp() and then + encounter a png_error() will longjmp here. Since the jmpbuf is + then meaningless we abort instead of returning. */ +#ifdef USE_FAR_KEYWORD + if (setjmp(png_jmpbuf)) +#else + if (setjmp(png_jmpbuf(png_ptr))) /* sets longjmp to match setjmp */ +#endif +#ifdef USE_FAR_KEYWORD + png_memcpy(png_jmpbuf(png_ptr), png_jmpbuf, png_sizeof(jmp_buf)); +#endif + PNG_ABORT(); +#endif + +#ifdef PNG_USER_MEM_SUPPORTED + png_set_mem_fn(png_ptr, mem_ptr, malloc_fn, free_fn); +#endif /* PNG_USER_MEM_SUPPORTED */ + png_set_error_fn(png_ptr, error_ptr, error_fn, warn_fn); + + if (user_png_ver) + { + i = 0; + do + { + if (user_png_ver[i] != png_libpng_ver[i]) + png_ptr->flags |= PNG_FLAG_LIBRARY_MISMATCH; + } while (png_libpng_ver[i++]); + } + + if (png_ptr->flags & PNG_FLAG_LIBRARY_MISMATCH) + { + /* Libpng 0.90 and later are binary incompatible with libpng 0.89, so + * we must recompile any applications that use any older library version. + * For versions after libpng 1.0, we will be compatible, so we need + * only check the first digit. + */ + if (user_png_ver == NULL || user_png_ver[0] != png_libpng_ver[0] || + (user_png_ver[0] == '1' && user_png_ver[2] != png_libpng_ver[2]) || + (user_png_ver[0] == '0' && user_png_ver[2] < '9')) + { +#ifdef PNG_CONSOLE_IO_SUPPORTED + char msg[80]; + + if (user_png_ver) + { + png_snprintf2(msg, 80, + "Application built with libpng-%.20s" + " but running with %.20s", + user_png_ver, + png_libpng_ver); + png_warning(png_ptr, msg); + } +#else + png_warning(png_ptr, + "Incompatible libpng version in application and library"); +#endif +#ifdef PNG_ERROR_NUMBERS_SUPPORTED + png_ptr->flags = 0; +#endif + png_cleanup_needed = 1; + } + } + + /* Initialize zbuf - compression buffer */ + png_ptr->zbuf_size = PNG_ZBUF_SIZE; + + if (!png_cleanup_needed) + { + png_ptr->zbuf = (png_bytep)png_malloc_warn(png_ptr, + png_ptr->zbuf_size); + if (png_ptr->zbuf == NULL) + png_cleanup_needed = 1; + } + + if (png_cleanup_needed) + { + /* Clean up PNG structure and deallocate any memory. */ + png_free(png_ptr, png_ptr->zbuf); + png_ptr->zbuf = NULL; +#ifdef PNG_USER_MEM_SUPPORTED + png_destroy_struct_2((png_voidp)png_ptr, + (png_free_ptr)free_fn, (png_voidp)mem_ptr); +#else + png_destroy_struct((png_voidp)png_ptr); +#endif + return (NULL); + } + + png_set_write_fn(png_ptr, NULL, NULL, NULL); + +#ifdef PNG_WRITE_WEIGHTED_FILTER_SUPPORTED + png_reset_filter_heuristics(png_ptr); +#endif + + return (png_ptr); +} + + +/* Write a few rows of image data. If the image is interlaced, + * either you will have to write the 7 sub images, or, if you + * have called png_set_interlace_handling(), you will have to + * "write" the image seven times. + */ +void PNGAPI +png_write_rows(png_structp png_ptr, png_bytepp row, + png_uint_32 num_rows) +{ + png_uint_32 i; /* row counter */ + png_bytepp rp; /* row pointer */ + + png_debug(1, "in png_write_rows"); + + if (png_ptr == NULL) + return; + + /* Loop through the rows */ + for (i = 0, rp = row; i < num_rows; i++, rp++) + { + png_write_row(png_ptr, *rp); + } +} + +/* Write the image. You only need to call this function once, even + * if you are writing an interlaced image. + */ +void PNGAPI +png_write_image(png_structp png_ptr, png_bytepp image) +{ + png_uint_32 i; /* row index */ + int pass, num_pass; /* pass variables */ + png_bytepp rp; /* points to current row */ + + if (png_ptr == NULL) + return; + + png_debug(1, "in png_write_image"); + +#ifdef PNG_WRITE_INTERLACING_SUPPORTED + /* Initialize interlace handling. If image is not interlaced, + * this will set pass to 1 + */ + num_pass = png_set_interlace_handling(png_ptr); +#else + num_pass = 1; +#endif + /* Loop through passes */ + for (pass = 0; pass < num_pass; pass++) + { + /* Loop through image */ + for (i = 0, rp = image; i < png_ptr->height; i++, rp++) + { + png_write_row(png_ptr, *rp); + } + } +} + +/* Called by user to write a row of image data */ +void PNGAPI +png_write_row(png_structp png_ptr, png_const_bytep row) +{ + if (png_ptr == NULL) + return; + + png_debug2(1, "in png_write_row (row %u, pass %d)", + png_ptr->row_number, png_ptr->pass); + + /* Initialize transformations and other stuff if first time */ + if (png_ptr->row_number == 0 && png_ptr->pass == 0) + { + /* Make sure we wrote the header info */ + if (!(png_ptr->mode & PNG_WROTE_INFO_BEFORE_PLTE)) + png_error(png_ptr, + "png_write_info was never called before png_write_row"); + + /* Check for transforms that have been set but were defined out */ +#if !defined(PNG_WRITE_INVERT_SUPPORTED) && defined(PNG_READ_INVERT_SUPPORTED) + if (png_ptr->transformations & PNG_INVERT_MONO) + png_warning(png_ptr, "PNG_WRITE_INVERT_SUPPORTED is not defined"); +#endif + +#if !defined(PNG_WRITE_FILLER_SUPPORTED) && defined(PNG_READ_FILLER_SUPPORTED) + if (png_ptr->transformations & PNG_FILLER) + png_warning(png_ptr, "PNG_WRITE_FILLER_SUPPORTED is not defined"); +#endif +#if !defined(PNG_WRITE_PACKSWAP_SUPPORTED) && \ + defined(PNG_READ_PACKSWAP_SUPPORTED) + if (png_ptr->transformations & PNG_PACKSWAP) + png_warning(png_ptr, + "PNG_WRITE_PACKSWAP_SUPPORTED is not defined"); +#endif + +#if !defined(PNG_WRITE_PACK_SUPPORTED) && defined(PNG_READ_PACK_SUPPORTED) + if (png_ptr->transformations & PNG_PACK) + png_warning(png_ptr, "PNG_WRITE_PACK_SUPPORTED is not defined"); +#endif + +#if !defined(PNG_WRITE_SHIFT_SUPPORTED) && defined(PNG_READ_SHIFT_SUPPORTED) + if (png_ptr->transformations & PNG_SHIFT) + png_warning(png_ptr, "PNG_WRITE_SHIFT_SUPPORTED is not defined"); +#endif + +#if !defined(PNG_WRITE_BGR_SUPPORTED) && defined(PNG_READ_BGR_SUPPORTED) + if (png_ptr->transformations & PNG_BGR) + png_warning(png_ptr, "PNG_WRITE_BGR_SUPPORTED is not defined"); +#endif + +#if !defined(PNG_WRITE_SWAP_SUPPORTED) && defined(PNG_READ_SWAP_SUPPORTED) + if (png_ptr->transformations & PNG_SWAP_BYTES) + png_warning(png_ptr, "PNG_WRITE_SWAP_SUPPORTED is not defined"); +#endif + + png_write_start_row(png_ptr); + } + +#ifdef PNG_WRITE_INTERLACING_SUPPORTED + /* If interlaced and not interested in row, return */ + if (png_ptr->interlaced && (png_ptr->transformations & PNG_INTERLACE)) + { + switch (png_ptr->pass) + { + case 0: + if (png_ptr->row_number & 0x07) + { + png_write_finish_row(png_ptr); + return; + } + break; + + case 1: + if ((png_ptr->row_number & 0x07) || png_ptr->width < 5) + { + png_write_finish_row(png_ptr); + return; + } + break; + + case 2: + if ((png_ptr->row_number & 0x07) != 4) + { + png_write_finish_row(png_ptr); + return; + } + break; + + case 3: + if ((png_ptr->row_number & 0x03) || png_ptr->width < 3) + { + png_write_finish_row(png_ptr); + return; + } + break; + + case 4: + if ((png_ptr->row_number & 0x03) != 2) + { + png_write_finish_row(png_ptr); + return; + } + break; + + case 5: + if ((png_ptr->row_number & 0x01) || png_ptr->width < 2) + { + png_write_finish_row(png_ptr); + return; + } + break; + + case 6: + if (!(png_ptr->row_number & 0x01)) + { + png_write_finish_row(png_ptr); + return; + } + break; + + default: /* error: ignore it */ + break; + } + } +#endif + + /* Set up row info for transformations */ + png_ptr->row_info.color_type = png_ptr->color_type; + png_ptr->row_info.width = png_ptr->usr_width; + png_ptr->row_info.channels = png_ptr->usr_channels; + png_ptr->row_info.bit_depth = png_ptr->usr_bit_depth; + png_ptr->row_info.pixel_depth = (png_byte)(png_ptr->row_info.bit_depth * + png_ptr->row_info.channels); + + png_ptr->row_info.rowbytes = PNG_ROWBYTES(png_ptr->row_info.pixel_depth, + png_ptr->row_info.width); + + png_debug1(3, "row_info->color_type = %d", png_ptr->row_info.color_type); + png_debug1(3, "row_info->width = %u", png_ptr->row_info.width); + png_debug1(3, "row_info->channels = %d", png_ptr->row_info.channels); + png_debug1(3, "row_info->bit_depth = %d", png_ptr->row_info.bit_depth); + png_debug1(3, "row_info->pixel_depth = %d", png_ptr->row_info.pixel_depth); + png_debug1(3, "row_info->rowbytes = %lu", + (unsigned long)png_ptr->row_info.rowbytes); + + /* Copy user's row into buffer, leaving room for filter byte. */ + png_memcpy(png_ptr->row_buf + 1, row, png_ptr->row_info.rowbytes); + +#ifdef PNG_WRITE_INTERLACING_SUPPORTED + /* Handle interlacing */ + if (png_ptr->interlaced && png_ptr->pass < 6 && + (png_ptr->transformations & PNG_INTERLACE)) + { + png_do_write_interlace(&(png_ptr->row_info), + png_ptr->row_buf + 1, png_ptr->pass); + /* This should always get caught above, but still ... */ + if (!(png_ptr->row_info.width)) + { + png_write_finish_row(png_ptr); + return; + } + } +#endif + + /* Handle other transformations */ + if (png_ptr->transformations) + png_do_write_transformations(png_ptr); + +#ifdef PNG_MNG_FEATURES_SUPPORTED + /* Write filter_method 64 (intrapixel differencing) only if + * 1. Libpng was compiled with PNG_MNG_FEATURES_SUPPORTED and + * 2. Libpng did not write a PNG signature (this filter_method is only + * used in PNG datastreams that are embedded in MNG datastreams) and + * 3. The application called png_permit_mng_features with a mask that + * included PNG_FLAG_MNG_FILTER_64 and + * 4. The filter_method is 64 and + * 5. The color_type is RGB or RGBA + */ + if ((png_ptr->mng_features_permitted & PNG_FLAG_MNG_FILTER_64) && + (png_ptr->filter_type == PNG_INTRAPIXEL_DIFFERENCING)) + { + /* Intrapixel differencing */ + png_do_write_intrapixel(&(png_ptr->row_info), png_ptr->row_buf + 1); + } +#endif + + /* Find a filter if necessary, filter the row and write it out. */ + png_write_find_filter(png_ptr, &(png_ptr->row_info)); + + if (png_ptr->write_row_fn != NULL) + (*(png_ptr->write_row_fn))(png_ptr, png_ptr->row_number, png_ptr->pass); +} + +#ifdef PNG_WRITE_FLUSH_SUPPORTED +/* Set the automatic flush interval or 0 to turn flushing off */ +void PNGAPI +png_set_flush(png_structp png_ptr, int nrows) +{ + png_debug(1, "in png_set_flush"); + + if (png_ptr == NULL) + return; + + png_ptr->flush_dist = (nrows < 0 ? 0 : nrows); +} + +/* Flush the current output buffers now */ +void PNGAPI +png_write_flush(png_structp png_ptr) +{ + int wrote_IDAT; + + png_debug(1, "in png_write_flush"); + + if (png_ptr == NULL) + return; + + /* We have already written out all of the data */ + if (png_ptr->row_number >= png_ptr->num_rows) + return; + + do + { + int ret; + + /* Compress the data */ + ret = deflate(&png_ptr->zstream, Z_SYNC_FLUSH); + wrote_IDAT = 0; + + /* Check for compression errors */ + if (ret != Z_OK) + { + if (png_ptr->zstream.msg != NULL) + png_error(png_ptr, png_ptr->zstream.msg); + + else + png_error(png_ptr, "zlib error"); + } + + if (!(png_ptr->zstream.avail_out)) + { + /* Write the IDAT and reset the zlib output buffer */ + png_write_IDAT(png_ptr, png_ptr->zbuf, png_ptr->zbuf_size); + png_ptr->zstream.next_out = png_ptr->zbuf; + png_ptr->zstream.avail_out = (uInt)png_ptr->zbuf_size; + wrote_IDAT = 1; + } + } while (wrote_IDAT == 1); + + /* If there is any data left to be output, write it into a new IDAT */ + if (png_ptr->zbuf_size != png_ptr->zstream.avail_out) + { + /* Write the IDAT and reset the zlib output buffer */ + png_write_IDAT(png_ptr, png_ptr->zbuf, + png_ptr->zbuf_size - png_ptr->zstream.avail_out); + png_ptr->zstream.next_out = png_ptr->zbuf; + png_ptr->zstream.avail_out = (uInt)png_ptr->zbuf_size; + } + png_ptr->flush_rows = 0; + png_flush(png_ptr); +} +#endif /* PNG_WRITE_FLUSH_SUPPORTED */ + +/* Free all memory used by the write */ +void PNGAPI +png_destroy_write_struct(png_structpp png_ptr_ptr, png_infopp info_ptr_ptr) +{ + png_structp png_ptr = NULL; + png_infop info_ptr = NULL; +#ifdef PNG_USER_MEM_SUPPORTED + png_free_ptr free_fn = NULL; + png_voidp mem_ptr = NULL; +#endif + + png_debug(1, "in png_destroy_write_struct"); + + if (png_ptr_ptr != NULL) + { + png_ptr = *png_ptr_ptr; +#ifdef PNG_USER_MEM_SUPPORTED + free_fn = png_ptr->free_fn; + mem_ptr = png_ptr->mem_ptr; +#endif + } + +#ifdef PNG_USER_MEM_SUPPORTED + if (png_ptr != NULL) + { + free_fn = png_ptr->free_fn; + mem_ptr = png_ptr->mem_ptr; + } +#endif + + if (info_ptr_ptr != NULL) + info_ptr = *info_ptr_ptr; + + if (info_ptr != NULL) + { + if (png_ptr != NULL) + { + png_free_data(png_ptr, info_ptr, PNG_FREE_ALL, -1); + +#ifdef PNG_HANDLE_AS_UNKNOWN_SUPPORTED + if (png_ptr->num_chunk_list) + { + png_free(png_ptr, png_ptr->chunk_list); + png_ptr->num_chunk_list = 0; + } +#endif + } + +#ifdef PNG_USER_MEM_SUPPORTED + png_destroy_struct_2((png_voidp)info_ptr, (png_free_ptr)free_fn, + (png_voidp)mem_ptr); +#else + png_destroy_struct((png_voidp)info_ptr); +#endif + *info_ptr_ptr = NULL; + } + + if (png_ptr != NULL) + { + png_write_destroy(png_ptr); +#ifdef PNG_USER_MEM_SUPPORTED + png_destroy_struct_2((png_voidp)png_ptr, (png_free_ptr)free_fn, + (png_voidp)mem_ptr); +#else + png_destroy_struct((png_voidp)png_ptr); +#endif + *png_ptr_ptr = NULL; + } +} + + +/* Free any memory used in png_ptr struct (old method) */ +void /* PRIVATE */ +png_write_destroy(png_structp png_ptr) +{ +#ifdef PNG_SETJMP_SUPPORTED + jmp_buf tmp_jmp; /* Save jump buffer */ +#endif + png_error_ptr error_fn; + png_error_ptr warning_fn; + png_voidp error_ptr; +#ifdef PNG_USER_MEM_SUPPORTED + png_free_ptr free_fn; +#endif + + png_debug(1, "in png_write_destroy"); + + /* Free any memory zlib uses */ + deflateEnd(&png_ptr->zstream); + + /* Free our memory. png_free checks NULL for us. */ + png_free(png_ptr, png_ptr->zbuf); + png_free(png_ptr, png_ptr->row_buf); +#ifdef PNG_WRITE_FILTER_SUPPORTED + png_free(png_ptr, png_ptr->prev_row); + png_free(png_ptr, png_ptr->sub_row); + png_free(png_ptr, png_ptr->up_row); + png_free(png_ptr, png_ptr->avg_row); + png_free(png_ptr, png_ptr->paeth_row); +#endif + +#ifdef PNG_TIME_RFC1123_SUPPORTED + png_free(png_ptr, png_ptr->time_buffer); +#endif + +#ifdef PNG_WRITE_WEIGHTED_FILTER_SUPPORTED + /* Use this to save a little code space, it doesn't free the filter_costs */ + png_reset_filter_heuristics(png_ptr); + png_free(png_ptr, png_ptr->filter_costs); + png_free(png_ptr, png_ptr->inv_filter_costs); +#endif + +#ifdef PNG_SETJMP_SUPPORTED + /* Reset structure */ + png_memcpy(tmp_jmp, png_ptr->png_jmpbuf, png_sizeof(jmp_buf)); +#endif + + error_fn = png_ptr->error_fn; + warning_fn = png_ptr->warning_fn; + error_ptr = png_ptr->error_ptr; +#ifdef PNG_USER_MEM_SUPPORTED + free_fn = png_ptr->free_fn; +#endif + + png_memset(png_ptr, 0, png_sizeof(png_struct)); + + png_ptr->error_fn = error_fn; + png_ptr->warning_fn = warning_fn; + png_ptr->error_ptr = error_ptr; +#ifdef PNG_USER_MEM_SUPPORTED + png_ptr->free_fn = free_fn; +#endif + +#ifdef PNG_SETJMP_SUPPORTED + png_memcpy(png_ptr->png_jmpbuf, tmp_jmp, png_sizeof(jmp_buf)); +#endif +} + +/* Allow the application to select one or more row filters to use. */ +void PNGAPI +png_set_filter(png_structp png_ptr, int method, int filters) +{ + png_debug(1, "in png_set_filter"); + + if (png_ptr == NULL) + return; + +#ifdef PNG_MNG_FEATURES_SUPPORTED + if ((png_ptr->mng_features_permitted & PNG_FLAG_MNG_FILTER_64) && + (method == PNG_INTRAPIXEL_DIFFERENCING)) + method = PNG_FILTER_TYPE_BASE; + +#endif + if (method == PNG_FILTER_TYPE_BASE) + { + switch (filters & (PNG_ALL_FILTERS | 0x07)) + { +#ifdef PNG_WRITE_FILTER_SUPPORTED + case 5: + case 6: + case 7: png_warning(png_ptr, "Unknown row filter for method 0"); +#endif /* PNG_WRITE_FILTER_SUPPORTED */ + case PNG_FILTER_VALUE_NONE: + png_ptr->do_filter = PNG_FILTER_NONE; break; + +#ifdef PNG_WRITE_FILTER_SUPPORTED + case PNG_FILTER_VALUE_SUB: + png_ptr->do_filter = PNG_FILTER_SUB; break; + + case PNG_FILTER_VALUE_UP: + png_ptr->do_filter = PNG_FILTER_UP; break; + + case PNG_FILTER_VALUE_AVG: + png_ptr->do_filter = PNG_FILTER_AVG; break; + + case PNG_FILTER_VALUE_PAETH: + png_ptr->do_filter = PNG_FILTER_PAETH; break; + + default: + png_ptr->do_filter = (png_byte)filters; break; +#else + default: + png_warning(png_ptr, "Unknown row filter for method 0"); +#endif /* PNG_WRITE_FILTER_SUPPORTED */ + } + + /* If we have allocated the row_buf, this means we have already started + * with the image and we should have allocated all of the filter buffers + * that have been selected. If prev_row isn't already allocated, then + * it is too late to start using the filters that need it, since we + * will be missing the data in the previous row. If an application + * wants to start and stop using particular filters during compression, + * it should start out with all of the filters, and then add and + * remove them after the start of compression. + */ + if (png_ptr->row_buf != NULL) + { +#ifdef PNG_WRITE_FILTER_SUPPORTED + if ((png_ptr->do_filter & PNG_FILTER_SUB) && png_ptr->sub_row == NULL) + { + png_ptr->sub_row = (png_bytep)png_malloc(png_ptr, + (png_ptr->rowbytes + 1)); + png_ptr->sub_row[0] = PNG_FILTER_VALUE_SUB; + } + + if ((png_ptr->do_filter & PNG_FILTER_UP) && png_ptr->up_row == NULL) + { + if (png_ptr->prev_row == NULL) + { + png_warning(png_ptr, "Can't add Up filter after starting"); + png_ptr->do_filter = (png_byte)(png_ptr->do_filter & + ~PNG_FILTER_UP); + } + + else + { + png_ptr->up_row = (png_bytep)png_malloc(png_ptr, + (png_ptr->rowbytes + 1)); + png_ptr->up_row[0] = PNG_FILTER_VALUE_UP; + } + } + + if ((png_ptr->do_filter & PNG_FILTER_AVG) && png_ptr->avg_row == NULL) + { + if (png_ptr->prev_row == NULL) + { + png_warning(png_ptr, "Can't add Average filter after starting"); + png_ptr->do_filter = (png_byte)(png_ptr->do_filter & + ~PNG_FILTER_AVG); + } + + else + { + png_ptr->avg_row = (png_bytep)png_malloc(png_ptr, + (png_ptr->rowbytes + 1)); + png_ptr->avg_row[0] = PNG_FILTER_VALUE_AVG; + } + } + + if ((png_ptr->do_filter & PNG_FILTER_PAETH) && + png_ptr->paeth_row == NULL) + { + if (png_ptr->prev_row == NULL) + { + png_warning(png_ptr, "Can't add Paeth filter after starting"); + png_ptr->do_filter &= (png_byte)(~PNG_FILTER_PAETH); + } + + else + { + png_ptr->paeth_row = (png_bytep)png_malloc(png_ptr, + (png_ptr->rowbytes + 1)); + png_ptr->paeth_row[0] = PNG_FILTER_VALUE_PAETH; + } + } + + if (png_ptr->do_filter == PNG_NO_FILTERS) +#endif /* PNG_WRITE_FILTER_SUPPORTED */ + png_ptr->do_filter = PNG_FILTER_NONE; + } + } + else + png_error(png_ptr, "Unknown custom filter method"); +} + +/* This allows us to influence the way in which libpng chooses the "best" + * filter for the current scanline. While the "minimum-sum-of-absolute- + * differences metric is relatively fast and effective, there is some + * question as to whether it can be improved upon by trying to keep the + * filtered data going to zlib more consistent, hopefully resulting in + * better compression. + */ +#ifdef PNG_WRITE_WEIGHTED_FILTER_SUPPORTED /* GRR 970116 */ +/* Conveneince reset API. */ +static void +png_reset_filter_heuristics(png_structp png_ptr) +{ + /* Clear out any old values in the 'weights' - this must be done because if + * the app calls set_filter_heuristics multiple times with different + * 'num_weights' values we would otherwise potentially have wrong sized + * arrays. + */ + png_ptr->num_prev_filters = 0; + png_ptr->heuristic_method = PNG_FILTER_HEURISTIC_UNWEIGHTED; + if (png_ptr->prev_filters != NULL) + { + png_bytep old = png_ptr->prev_filters; + png_ptr->prev_filters = NULL; + png_free(png_ptr, old); + } + if (png_ptr->filter_weights != NULL) + { + png_uint_16p old = png_ptr->filter_weights; + png_ptr->filter_weights = NULL; + png_free(png_ptr, old); + } + + if (png_ptr->inv_filter_weights != NULL) + { + png_uint_16p old = png_ptr->inv_filter_weights; + png_ptr->inv_filter_weights = NULL; + png_free(png_ptr, old); + } + + /* Leave the filter_costs - this array is fixed size. */ +} + +static int +png_init_filter_heuristics(png_structp png_ptr, int heuristic_method, + int num_weights) +{ + if (png_ptr == NULL) + return 0; + + /* Clear out the arrays */ + png_reset_filter_heuristics(png_ptr); + + /* Check arguments; the 'reset' function makes the correct settings for the + * unweighted case, but we must handle the weight case by initializing the + * arrays for the caller. + */ + if (heuristic_method == PNG_FILTER_HEURISTIC_WEIGHTED) + { + int i; + + if (num_weights > 0) + { + png_ptr->prev_filters = (png_bytep)png_malloc(png_ptr, + (png_uint_32)(png_sizeof(png_byte) * num_weights)); + + /* To make sure that the weighting starts out fairly */ + for (i = 0; i < num_weights; i++) + { + png_ptr->prev_filters[i] = 255; + } + + png_ptr->filter_weights = (png_uint_16p)png_malloc(png_ptr, + (png_uint_32)(png_sizeof(png_uint_16) * num_weights)); + + png_ptr->inv_filter_weights = (png_uint_16p)png_malloc(png_ptr, + (png_uint_32)(png_sizeof(png_uint_16) * num_weights)); + + for (i = 0; i < num_weights; i++) + { + png_ptr->inv_filter_weights[i] = + png_ptr->filter_weights[i] = PNG_WEIGHT_FACTOR; + } + + /* Safe to set this now */ + png_ptr->num_prev_filters = (png_byte)num_weights; + } + + /* If, in the future, there are other filter methods, this would + * need to be based on png_ptr->filter. + */ + if (png_ptr->filter_costs == NULL) + { + png_ptr->filter_costs = (png_uint_16p)png_malloc(png_ptr, + (png_uint_32)(png_sizeof(png_uint_16) * PNG_FILTER_VALUE_LAST)); + + png_ptr->inv_filter_costs = (png_uint_16p)png_malloc(png_ptr, + (png_uint_32)(png_sizeof(png_uint_16) * PNG_FILTER_VALUE_LAST)); + } + + for (i = 0; i < PNG_FILTER_VALUE_LAST; i++) + { + png_ptr->inv_filter_costs[i] = + png_ptr->filter_costs[i] = PNG_COST_FACTOR; + } + + /* All the arrays are inited, safe to set this: */ + png_ptr->heuristic_method = PNG_FILTER_HEURISTIC_WEIGHTED; + + /* Return the 'ok' code. */ + return 1; + } + else if (heuristic_method == PNG_FILTER_HEURISTIC_DEFAULT || + heuristic_method == PNG_FILTER_HEURISTIC_UNWEIGHTED) + { + return 1; + } + else + { + png_warning(png_ptr, "Unknown filter heuristic method"); + return 0; + } +} + +/* Provide floating and fixed point APIs */ +#ifdef PNG_FLOATING_POINT_SUPPORTED +void PNGAPI +png_set_filter_heuristics(png_structp png_ptr, int heuristic_method, + int num_weights, png_const_doublep filter_weights, + png_const_doublep filter_costs) +{ + png_debug(1, "in png_set_filter_heuristics"); + + /* The internal API allocates all the arrays and ensures that the elements of + * those arrays are set to the default value. + */ + if (!png_init_filter_heuristics(png_ptr, heuristic_method, num_weights)) + return; + + /* If using the weighted method copy in the weights. */ + if (heuristic_method == PNG_FILTER_HEURISTIC_WEIGHTED) + { + int i; + for (i = 0; i < num_weights; i++) + { + if (filter_weights[i] <= 0.0) + { + png_ptr->inv_filter_weights[i] = + png_ptr->filter_weights[i] = PNG_WEIGHT_FACTOR; + } + + else + { + png_ptr->inv_filter_weights[i] = + (png_uint_16)(PNG_WEIGHT_FACTOR*filter_weights[i]+.5); + + png_ptr->filter_weights[i] = + (png_uint_16)(PNG_WEIGHT_FACTOR/filter_weights[i]+.5); + } + } + + /* Here is where we set the relative costs of the different filters. We + * should take the desired compression level into account when setting + * the costs, so that Paeth, for instance, has a high relative cost at low + * compression levels, while it has a lower relative cost at higher + * compression settings. The filter types are in order of increasing + * relative cost, so it would be possible to do this with an algorithm. + */ + for (i = 0; i < PNG_FILTER_VALUE_LAST; i++) if (filter_costs[i] >= 1.0) + { + png_ptr->inv_filter_costs[i] = + (png_uint_16)(PNG_COST_FACTOR / filter_costs[i] + .5); + + png_ptr->filter_costs[i] = + (png_uint_16)(PNG_COST_FACTOR * filter_costs[i] + .5); + } + } +} +#endif /* FLOATING_POINT */ + +#ifdef PNG_FIXED_POINT_SUPPORTED +void PNGAPI +png_set_filter_heuristics_fixed(png_structp png_ptr, int heuristic_method, + int num_weights, png_const_fixed_point_p filter_weights, + png_const_fixed_point_p filter_costs) +{ + png_debug(1, "in png_set_filter_heuristics_fixed"); + + /* The internal API allocates all the arrays and ensures that the elements of + * those arrays are set to the default value. + */ + if (!png_init_filter_heuristics(png_ptr, heuristic_method, num_weights)) + return; + + /* If using the weighted method copy in the weights. */ + if (heuristic_method == PNG_FILTER_HEURISTIC_WEIGHTED) + { + int i; + for (i = 0; i < num_weights; i++) + { + if (filter_weights[i] <= 0) + { + png_ptr->inv_filter_weights[i] = + png_ptr->filter_weights[i] = PNG_WEIGHT_FACTOR; + } + + else + { + png_ptr->inv_filter_weights[i] = (png_uint_16) + ((PNG_WEIGHT_FACTOR*filter_weights[i]+PNG_FP_HALF)/PNG_FP_1); + + png_ptr->filter_weights[i] = (png_uint_16)((PNG_WEIGHT_FACTOR* + PNG_FP_1+(filter_weights[i]/2))/filter_weights[i]); + } + } + + /* Here is where we set the relative costs of the different filters. We + * should take the desired compression level into account when setting + * the costs, so that Paeth, for instance, has a high relative cost at low + * compression levels, while it has a lower relative cost at higher + * compression settings. The filter types are in order of increasing + * relative cost, so it would be possible to do this with an algorithm. + */ + for (i = 0; i < PNG_FILTER_VALUE_LAST; i++) + if (filter_costs[i] >= PNG_FP_1) + { + png_uint_32 tmp; + + /* Use a 32 bit unsigned temporary here because otherwise the + * intermediate value will be a 32 bit *signed* integer (ANSI rules) + * and this will get the wrong answer on division. + */ + tmp = PNG_COST_FACTOR*PNG_FP_1 + (filter_costs[i]/2); + tmp /= filter_costs[i]; + + png_ptr->inv_filter_costs[i] = (png_uint_16)tmp; + + tmp = PNG_COST_FACTOR * filter_costs[i] + PNG_FP_HALF; + tmp /= PNG_FP_1; + + png_ptr->filter_costs[i] = (png_uint_16)tmp; + } + } +} +#endif /* FIXED_POINT */ +#endif /* PNG_WRITE_WEIGHTED_FILTER_SUPPORTED */ + +void PNGAPI +png_set_compression_level(png_structp png_ptr, int level) +{ + png_debug(1, "in png_set_compression_level"); + + if (png_ptr == NULL) + return; + + png_ptr->flags |= PNG_FLAG_ZLIB_CUSTOM_LEVEL; + png_ptr->zlib_level = level; +} + +void PNGAPI +png_set_compression_mem_level(png_structp png_ptr, int mem_level) +{ + png_debug(1, "in png_set_compression_mem_level"); + + if (png_ptr == NULL) + return; + + png_ptr->flags |= PNG_FLAG_ZLIB_CUSTOM_MEM_LEVEL; + png_ptr->zlib_mem_level = mem_level; +} + +void PNGAPI +png_set_compression_strategy(png_structp png_ptr, int strategy) +{ + png_debug(1, "in png_set_compression_strategy"); + + if (png_ptr == NULL) + return; + + png_ptr->flags |= PNG_FLAG_ZLIB_CUSTOM_STRATEGY; + png_ptr->zlib_strategy = strategy; +} + +void PNGAPI +png_set_compression_window_bits(png_structp png_ptr, int window_bits) +{ + if (png_ptr == NULL) + return; + + if (window_bits > 15) + png_warning(png_ptr, "Only compression windows <= 32k supported by PNG"); + + else if (window_bits < 8) + png_warning(png_ptr, "Only compression windows >= 256 supported by PNG"); + +#ifndef WBITS_8_OK + /* Avoid libpng bug with 256-byte windows */ + if (window_bits == 8) + { + png_warning(png_ptr, "Compression window is being reset to 512"); + window_bits = 9; + } + +#endif + png_ptr->flags |= PNG_FLAG_ZLIB_CUSTOM_WINDOW_BITS; + png_ptr->zlib_window_bits = window_bits; +} + +void PNGAPI +png_set_compression_method(png_structp png_ptr, int method) +{ + png_debug(1, "in png_set_compression_method"); + + if (png_ptr == NULL) + return; + + if (method != 8) + png_warning(png_ptr, "Only compression method 8 is supported by PNG"); + + png_ptr->flags |= PNG_FLAG_ZLIB_CUSTOM_METHOD; + png_ptr->zlib_method = method; +} + +void PNGAPI +png_set_write_status_fn(png_structp png_ptr, png_write_status_ptr write_row_fn) +{ + if (png_ptr == NULL) + return; + + png_ptr->write_row_fn = write_row_fn; +} + +#ifdef PNG_WRITE_USER_TRANSFORM_SUPPORTED +void PNGAPI +png_set_write_user_transform_fn(png_structp png_ptr, png_user_transform_ptr + write_user_transform_fn) +{ + png_debug(1, "in png_set_write_user_transform_fn"); + + if (png_ptr == NULL) + return; + + png_ptr->transformations |= PNG_USER_TRANSFORM; + png_ptr->write_user_transform_fn = write_user_transform_fn; +} +#endif + + +#ifdef PNG_INFO_IMAGE_SUPPORTED +void PNGAPI +png_write_png(png_structp png_ptr, png_infop info_ptr, + int transforms, voidp params) +{ + if (png_ptr == NULL || info_ptr == NULL) + return; + + /* Write the file header information. */ + png_write_info(png_ptr, info_ptr); + + /* ------ these transformations don't touch the info structure ------- */ + +#ifdef PNG_WRITE_INVERT_SUPPORTED + /* Invert monochrome pixels */ + if (transforms & PNG_TRANSFORM_INVERT_MONO) + png_set_invert_mono(png_ptr); +#endif + +#ifdef PNG_WRITE_SHIFT_SUPPORTED + /* Shift the pixels up to a legal bit depth and fill in + * as appropriate to correctly scale the image. + */ + if ((transforms & PNG_TRANSFORM_SHIFT) + && (info_ptr->valid & PNG_INFO_sBIT)) + png_set_shift(png_ptr, &info_ptr->sig_bit); +#endif + +#ifdef PNG_WRITE_PACK_SUPPORTED + /* Pack pixels into bytes */ + if (transforms & PNG_TRANSFORM_PACKING) + png_set_packing(png_ptr); +#endif + +#ifdef PNG_WRITE_SWAP_ALPHA_SUPPORTED + /* Swap location of alpha bytes from ARGB to RGBA */ + if (transforms & PNG_TRANSFORM_SWAP_ALPHA) + png_set_swap_alpha(png_ptr); +#endif + +#ifdef PNG_WRITE_FILLER_SUPPORTED + /* Pack XRGB/RGBX/ARGB/RGBA into * RGB (4 channels -> 3 channels) */ + if (transforms & PNG_TRANSFORM_STRIP_FILLER_AFTER) + png_set_filler(png_ptr, 0, PNG_FILLER_AFTER); + + else if (transforms & PNG_TRANSFORM_STRIP_FILLER_BEFORE) + png_set_filler(png_ptr, 0, PNG_FILLER_BEFORE); +#endif + +#ifdef PNG_WRITE_BGR_SUPPORTED + /* Flip BGR pixels to RGB */ + if (transforms & PNG_TRANSFORM_BGR) + png_set_bgr(png_ptr); +#endif + +#ifdef PNG_WRITE_SWAP_SUPPORTED + /* Swap bytes of 16-bit files to most significant byte first */ + if (transforms & PNG_TRANSFORM_SWAP_ENDIAN) + png_set_swap(png_ptr); +#endif + +#ifdef PNG_WRITE_PACKSWAP_SUPPORTED + /* Swap bits of 1, 2, 4 bit packed pixel formats */ + if (transforms & PNG_TRANSFORM_PACKSWAP) + png_set_packswap(png_ptr); +#endif + +#ifdef PNG_WRITE_INVERT_ALPHA_SUPPORTED + /* Invert the alpha channel from opacity to transparency */ + if (transforms & PNG_TRANSFORM_INVERT_ALPHA) + png_set_invert_alpha(png_ptr); +#endif + + /* ----------------------- end of transformations ------------------- */ + + /* Write the bits */ + if (info_ptr->valid & PNG_INFO_IDAT) + png_write_image(png_ptr, info_ptr->row_pointers); + + /* It is REQUIRED to call this to finish writing the rest of the file */ + png_write_end(png_ptr, info_ptr); + + PNG_UNUSED(transforms) /* Quiet compiler warnings */ + PNG_UNUSED(params) +} +#endif +#endif /* PNG_WRITE_SUPPORTED */ diff --git a/src/3rdparty/libpng/pngwtran.c b/src/3rdparty/libpng/pngwtran.c new file mode 100644 index 0000000000..115ca37212 --- /dev/null +++ b/src/3rdparty/libpng/pngwtran.c @@ -0,0 +1,631 @@ + +/* pngwtran.c - transforms the data in a row for PNG writers + * + * Last changed in libpng 1.5.0 [January 6, 2011] + * Copyright (c) 1998-2011 Glenn Randers-Pehrson + * (Version 0.96 Copyright (c) 1996, 1997 Andreas Dilger) + * (Version 0.88 Copyright (c) 1995, 1996 Guy Eric Schalnat, Group 42, Inc.) + * + * This code is released under the libpng license. + * For conditions of distribution and use, see the disclaimer + * and license in png.h + */ + +#include "pngpriv.h" + +#ifdef PNG_WRITE_SUPPORTED + +/* Transform the data according to the user's wishes. The order of + * transformations is significant. + */ +void /* PRIVATE */ +png_do_write_transformations(png_structp png_ptr) +{ + png_debug(1, "in png_do_write_transformations"); + + if (png_ptr == NULL) + return; + +#ifdef PNG_WRITE_USER_TRANSFORM_SUPPORTED + if (png_ptr->transformations & PNG_USER_TRANSFORM) + if (png_ptr->write_user_transform_fn != NULL) + (*(png_ptr->write_user_transform_fn)) /* User write transform + function */ + (png_ptr, /* png_ptr */ + &(png_ptr->row_info), /* row_info: */ + /* png_uint_32 width; width of row */ + /* png_size_t rowbytes; number of bytes in row */ + /* png_byte color_type; color type of pixels */ + /* png_byte bit_depth; bit depth of samples */ + /* png_byte channels; number of channels (1-4) */ + /* png_byte pixel_depth; bits per pixel (depth*channels) */ + png_ptr->row_buf + 1); /* start of pixel data for row */ +#endif + +#ifdef PNG_WRITE_FILLER_SUPPORTED + if (png_ptr->transformations & PNG_FILLER) + png_do_strip_filler(&(png_ptr->row_info), png_ptr->row_buf + 1, + png_ptr->flags); +#endif + +#ifdef PNG_WRITE_PACKSWAP_SUPPORTED + if (png_ptr->transformations & PNG_PACKSWAP) + png_do_packswap(&(png_ptr->row_info), png_ptr->row_buf + 1); +#endif + +#ifdef PNG_WRITE_PACK_SUPPORTED + if (png_ptr->transformations & PNG_PACK) + png_do_pack(&(png_ptr->row_info), png_ptr->row_buf + 1, + (png_uint_32)png_ptr->bit_depth); +#endif + +#ifdef PNG_WRITE_SWAP_SUPPORTED + if (png_ptr->transformations & PNG_SWAP_BYTES) + png_do_swap(&(png_ptr->row_info), png_ptr->row_buf + 1); +#endif + +#ifdef PNG_WRITE_SHIFT_SUPPORTED + if (png_ptr->transformations & PNG_SHIFT) + png_do_shift(&(png_ptr->row_info), png_ptr->row_buf + 1, + &(png_ptr->shift)); +#endif + +#ifdef PNG_WRITE_SWAP_ALPHA_SUPPORTED + if (png_ptr->transformations & PNG_SWAP_ALPHA) + png_do_write_swap_alpha(&(png_ptr->row_info), png_ptr->row_buf + 1); +#endif + +#ifdef PNG_WRITE_INVERT_ALPHA_SUPPORTED + if (png_ptr->transformations & PNG_INVERT_ALPHA) + png_do_write_invert_alpha(&(png_ptr->row_info), png_ptr->row_buf + 1); +#endif + +#ifdef PNG_WRITE_BGR_SUPPORTED + if (png_ptr->transformations & PNG_BGR) + png_do_bgr(&(png_ptr->row_info), png_ptr->row_buf + 1); +#endif + +#ifdef PNG_WRITE_INVERT_SUPPORTED + if (png_ptr->transformations & PNG_INVERT_MONO) + png_do_invert(&(png_ptr->row_info), png_ptr->row_buf + 1); +#endif +} + +#ifdef PNG_WRITE_PACK_SUPPORTED +/* Pack pixels into bytes. Pass the true bit depth in bit_depth. The + * row_info bit depth should be 8 (one pixel per byte). The channels + * should be 1 (this only happens on grayscale and paletted images). + */ +void /* PRIVATE */ +png_do_pack(png_row_infop row_info, png_bytep row, png_uint_32 bit_depth) +{ + png_debug(1, "in png_do_pack"); + + if (row_info->bit_depth == 8 && + row_info->channels == 1) + { + switch ((int)bit_depth) + { + case 1: + { + png_bytep sp, dp; + int mask, v; + png_uint_32 i; + png_uint_32 row_width = row_info->width; + + sp = row; + dp = row; + mask = 0x80; + v = 0; + + for (i = 0; i < row_width; i++) + { + if (*sp != 0) + v |= mask; + + sp++; + + if (mask > 1) + mask >>= 1; + + else + { + mask = 0x80; + *dp = (png_byte)v; + dp++; + v = 0; + } + } + + if (mask != 0x80) + *dp = (png_byte)v; + + break; + } + + case 2: + { + png_bytep sp, dp; + int shift, v; + png_uint_32 i; + png_uint_32 row_width = row_info->width; + + sp = row; + dp = row; + shift = 6; + v = 0; + + for (i = 0; i < row_width; i++) + { + png_byte value; + + value = (png_byte)(*sp & 0x03); + v |= (value << shift); + + if (shift == 0) + { + shift = 6; + *dp = (png_byte)v; + dp++; + v = 0; + } + + else + shift -= 2; + + sp++; + } + + if (shift != 6) + *dp = (png_byte)v; + + break; + } + + case 4: + { + png_bytep sp, dp; + int shift, v; + png_uint_32 i; + png_uint_32 row_width = row_info->width; + + sp = row; + dp = row; + shift = 4; + v = 0; + + for (i = 0; i < row_width; i++) + { + png_byte value; + + value = (png_byte)(*sp & 0x0f); + v |= (value << shift); + + if (shift == 0) + { + shift = 4; + *dp = (png_byte)v; + dp++; + v = 0; + } + + else + shift -= 4; + + sp++; + } + + if (shift != 4) + *dp = (png_byte)v; + + break; + } + + default: + break; + } + + row_info->bit_depth = (png_byte)bit_depth; + row_info->pixel_depth = (png_byte)(bit_depth * row_info->channels); + row_info->rowbytes = PNG_ROWBYTES(row_info->pixel_depth, + row_info->width); + } +} +#endif + +#ifdef PNG_WRITE_SHIFT_SUPPORTED +/* Shift pixel values to take advantage of whole range. Pass the + * true number of bits in bit_depth. The row should be packed + * according to row_info->bit_depth. Thus, if you had a row of + * bit depth 4, but the pixels only had values from 0 to 7, you + * would pass 3 as bit_depth, and this routine would translate the + * data to 0 to 15. + */ +void /* PRIVATE */ +png_do_shift(png_row_infop row_info, png_bytep row, + png_const_color_8p bit_depth) +{ + png_debug(1, "in png_do_shift"); + + if (row_info->color_type != PNG_COLOR_TYPE_PALETTE) + { + int shift_start[4], shift_dec[4]; + int channels = 0; + + if (row_info->color_type & PNG_COLOR_MASK_COLOR) + { + shift_start[channels] = row_info->bit_depth - bit_depth->red; + shift_dec[channels] = bit_depth->red; + channels++; + + shift_start[channels] = row_info->bit_depth - bit_depth->green; + shift_dec[channels] = bit_depth->green; + channels++; + + shift_start[channels] = row_info->bit_depth - bit_depth->blue; + shift_dec[channels] = bit_depth->blue; + channels++; + } + + else + { + shift_start[channels] = row_info->bit_depth - bit_depth->gray; + shift_dec[channels] = bit_depth->gray; + channels++; + } + + if (row_info->color_type & PNG_COLOR_MASK_ALPHA) + { + shift_start[channels] = row_info->bit_depth - bit_depth->alpha; + shift_dec[channels] = bit_depth->alpha; + channels++; + } + + /* With low row depths, could only be grayscale, so one channel */ + if (row_info->bit_depth < 8) + { + png_bytep bp = row; + png_size_t i; + png_byte mask; + png_size_t row_bytes = row_info->rowbytes; + + if (bit_depth->gray == 1 && row_info->bit_depth == 2) + mask = 0x55; + + else if (row_info->bit_depth == 4 && bit_depth->gray == 3) + mask = 0x11; + + else + mask = 0xff; + + for (i = 0; i < row_bytes; i++, bp++) + { + png_uint_16 v; + int j; + + v = *bp; + *bp = 0; + + for (j = shift_start[0]; j > -shift_dec[0]; j -= shift_dec[0]) + { + if (j > 0) + *bp |= (png_byte)((v << j) & 0xff); + + else + *bp |= (png_byte)((v >> (-j)) & mask); + } + } + } + + else if (row_info->bit_depth == 8) + { + png_bytep bp = row; + png_uint_32 i; + png_uint_32 istop = channels * row_info->width; + + for (i = 0; i < istop; i++, bp++) + { + + png_uint_16 v; + int j; + int c = (int)(i%channels); + + v = *bp; + *bp = 0; + + for (j = shift_start[c]; j > -shift_dec[c]; j -= shift_dec[c]) + { + if (j > 0) + *bp |= (png_byte)((v << j) & 0xff); + + else + *bp |= (png_byte)((v >> (-j)) & 0xff); + } + } + } + + else + { + png_bytep bp; + png_uint_32 i; + png_uint_32 istop = channels * row_info->width; + + for (bp = row, i = 0; i < istop; i++) + { + int c = (int)(i%channels); + png_uint_16 value, v; + int j; + + v = (png_uint_16)(((png_uint_16)(*bp) << 8) + *(bp + 1)); + value = 0; + + for (j = shift_start[c]; j > -shift_dec[c]; j -= shift_dec[c]) + { + if (j > 0) + value |= (png_uint_16)((v << j) & (png_uint_16)0xffff); + + else + value |= (png_uint_16)((v >> (-j)) & (png_uint_16)0xffff); + } + *bp++ = (png_byte)(value >> 8); + *bp++ = (png_byte)(value & 0xff); + } + } + } +} +#endif + +#ifdef PNG_WRITE_SWAP_ALPHA_SUPPORTED +void /* PRIVATE */ +png_do_write_swap_alpha(png_row_infop row_info, png_bytep row) +{ + png_debug(1, "in png_do_write_swap_alpha"); + + { + if (row_info->color_type == PNG_COLOR_TYPE_RGB_ALPHA) + { + if (row_info->bit_depth == 8) + { + /* This converts from ARGB to RGBA */ + png_bytep sp, dp; + png_uint_32 i; + png_uint_32 row_width = row_info->width; + + for (i = 0, sp = dp = row; i < row_width; i++) + { + png_byte save = *(sp++); + *(dp++) = *(sp++); + *(dp++) = *(sp++); + *(dp++) = *(sp++); + *(dp++) = save; + } + } + +#ifdef PNG_WRITE_16BIT_SUPPORTED + else + { + /* This converts from AARRGGBB to RRGGBBAA */ + png_bytep sp, dp; + png_uint_32 i; + png_uint_32 row_width = row_info->width; + + for (i = 0, sp = dp = row; i < row_width; i++) + { + png_byte save[2]; + save[0] = *(sp++); + save[1] = *(sp++); + *(dp++) = *(sp++); + *(dp++) = *(sp++); + *(dp++) = *(sp++); + *(dp++) = *(sp++); + *(dp++) = *(sp++); + *(dp++) = *(sp++); + *(dp++) = save[0]; + *(dp++) = save[1]; + } + } +#endif /* PNG_WRITE_16BIT_SUPPORTED */ + } + + else if (row_info->color_type == PNG_COLOR_TYPE_GRAY_ALPHA) + { + if (row_info->bit_depth == 8) + { + /* This converts from AG to GA */ + png_bytep sp, dp; + png_uint_32 i; + png_uint_32 row_width = row_info->width; + + for (i = 0, sp = dp = row; i < row_width; i++) + { + png_byte save = *(sp++); + *(dp++) = *(sp++); + *(dp++) = save; + } + } + +#ifdef PNG_WRITE_16BIT_SUPPORTED + else + { + /* This converts from AAGG to GGAA */ + png_bytep sp, dp; + png_uint_32 i; + png_uint_32 row_width = row_info->width; + + for (i = 0, sp = dp = row; i < row_width; i++) + { + png_byte save[2]; + save[0] = *(sp++); + save[1] = *(sp++); + *(dp++) = *(sp++); + *(dp++) = *(sp++); + *(dp++) = save[0]; + *(dp++) = save[1]; + } + } +#endif /* PNG_WRITE_16BIT_SUPPORTED */ + } + } +} +#endif + +#ifdef PNG_WRITE_INVERT_ALPHA_SUPPORTED +void /* PRIVATE */ +png_do_write_invert_alpha(png_row_infop row_info, png_bytep row) +{ + png_debug(1, "in png_do_write_invert_alpha"); + + { + if (row_info->color_type == PNG_COLOR_TYPE_RGB_ALPHA) + { + if (row_info->bit_depth == 8) + { + /* This inverts the alpha channel in RGBA */ + png_bytep sp, dp; + png_uint_32 i; + png_uint_32 row_width = row_info->width; + + for (i = 0, sp = dp = row; i < row_width; i++) + { + /* Does nothing + *(dp++) = *(sp++); + *(dp++) = *(sp++); + *(dp++) = *(sp++); + */ + sp+=3; dp = sp; + *(dp++) = (png_byte)(255 - *(sp++)); + } + } + +#ifdef PNG_WRITE_16BIT_SUPPORTED + else + { + /* This inverts the alpha channel in RRGGBBAA */ + png_bytep sp, dp; + png_uint_32 i; + png_uint_32 row_width = row_info->width; + + for (i = 0, sp = dp = row; i < row_width; i++) + { + /* Does nothing + *(dp++) = *(sp++); + *(dp++) = *(sp++); + *(dp++) = *(sp++); + *(dp++) = *(sp++); + *(dp++) = *(sp++); + *(dp++) = *(sp++); + */ + sp+=6; dp = sp; + *(dp++) = (png_byte)(255 - *(sp++)); + *(dp++) = (png_byte)(255 - *(sp++)); + } + } +#endif /* PNG_WRITE_16BIT_SUPPORTED */ + } + + else if (row_info->color_type == PNG_COLOR_TYPE_GRAY_ALPHA) + { + if (row_info->bit_depth == 8) + { + /* This inverts the alpha channel in GA */ + png_bytep sp, dp; + png_uint_32 i; + png_uint_32 row_width = row_info->width; + + for (i = 0, sp = dp = row; i < row_width; i++) + { + *(dp++) = *(sp++); + *(dp++) = (png_byte)(255 - *(sp++)); + } + } + +#ifdef PNG_WRITE_16BIT_SUPPORTED + else + { + /* This inverts the alpha channel in GGAA */ + png_bytep sp, dp; + png_uint_32 i; + png_uint_32 row_width = row_info->width; + + for (i = 0, sp = dp = row; i < row_width; i++) + { + /* Does nothing + *(dp++) = *(sp++); + *(dp++) = *(sp++); + */ + sp+=2; dp = sp; + *(dp++) = (png_byte)(255 - *(sp++)); + *(dp++) = (png_byte)(255 - *(sp++)); + } + } +#endif /* PNG_WRITE_16BIT_SUPPORTED */ + } + } +} +#endif + +#ifdef PNG_MNG_FEATURES_SUPPORTED +/* Undoes intrapixel differencing */ +void /* PRIVATE */ +png_do_write_intrapixel(png_row_infop row_info, png_bytep row) +{ + png_debug(1, "in png_do_write_intrapixel"); + + if ((row_info->color_type & PNG_COLOR_MASK_COLOR)) + { + int bytes_per_pixel; + png_uint_32 row_width = row_info->width; + if (row_info->bit_depth == 8) + { + png_bytep rp; + png_uint_32 i; + + if (row_info->color_type == PNG_COLOR_TYPE_RGB) + bytes_per_pixel = 3; + + else if (row_info->color_type == PNG_COLOR_TYPE_RGB_ALPHA) + bytes_per_pixel = 4; + + else + return; + + for (i = 0, rp = row; i < row_width; i++, rp += bytes_per_pixel) + { + *(rp) = (png_byte)((*rp - *(rp + 1)) & 0xff); + *(rp + 2) = (png_byte)((*(rp + 2) - *(rp + 1)) & 0xff); + } + } + +#ifdef PNG_WRITE_16BIT_SUPPORTED + else if (row_info->bit_depth == 16) + { + png_bytep rp; + png_uint_32 i; + + if (row_info->color_type == PNG_COLOR_TYPE_RGB) + bytes_per_pixel = 6; + + else if (row_info->color_type == PNG_COLOR_TYPE_RGB_ALPHA) + bytes_per_pixel = 8; + + else + return; + + for (i = 0, rp = row; i < row_width; i++, rp += bytes_per_pixel) + { + png_uint_32 s0 = (*(rp ) << 8) | *(rp + 1); + png_uint_32 s1 = (*(rp + 2) << 8) | *(rp + 3); + png_uint_32 s2 = (*(rp + 4) << 8) | *(rp + 5); + png_uint_32 red = (png_uint_32)((s0 - s1) & 0xffffL); + png_uint_32 blue = (png_uint_32)((s2 - s1) & 0xffffL); + *(rp ) = (png_byte)((red >> 8) & 0xff); + *(rp + 1) = (png_byte)(red & 0xff); + *(rp + 4) = (png_byte)((blue >> 8) & 0xff); + *(rp + 5) = (png_byte)(blue & 0xff); + } + } +#endif /* PNG_WRITE_16BIT_SUPPORTED */ + } +} +#endif /* PNG_MNG_FEATURES_SUPPORTED */ +#endif /* PNG_WRITE_SUPPORTED */ diff --git a/src/3rdparty/libpng/pngwutil.c b/src/3rdparty/libpng/pngwutil.c new file mode 100644 index 0000000000..2c35785aa1 --- /dev/null +++ b/src/3rdparty/libpng/pngwutil.c @@ -0,0 +1,2948 @@ + +/* pngwutil.c - utilities to write a PNG file + * + * Last changed in libpng 1.5.0 [January 6, 2011] + * Copyright (c) 1998-2011 Glenn Randers-Pehrson + * (Version 0.96 Copyright (c) 1996, 1997 Andreas Dilger) + * (Version 0.88 Copyright (c) 1995, 1996 Guy Eric Schalnat, Group 42, Inc.) + * + * This code is released under the libpng license. + * For conditions of distribution and use, see the disclaimer + * and license in png.h + */ + +#include "pngpriv.h" + +#ifdef PNG_WRITE_SUPPORTED + +#ifdef PNG_WRITE_INT_FUNCTIONS_SUPPORTED +/* Place a 32-bit number into a buffer in PNG byte order. We work + * with unsigned numbers for convenience, although one supported + * ancillary chunk uses signed (two's complement) numbers. + */ +void PNGAPI +png_save_uint_32(png_bytep buf, png_uint_32 i) +{ + buf[0] = (png_byte)((i >> 24) & 0xff); + buf[1] = (png_byte)((i >> 16) & 0xff); + buf[2] = (png_byte)((i >> 8) & 0xff); + buf[3] = (png_byte)(i & 0xff); +} + +#ifdef PNG_SAVE_INT_32_SUPPORTED +/* The png_save_int_32 function assumes integers are stored in two's + * complement format. If this isn't the case, then this routine needs to + * be modified to write data in two's complement format. Note that, + * the following works correctly even if png_int_32 has more than 32 bits + * (compare the more complex code required on read for sign extention.) + */ +void PNGAPI +png_save_int_32(png_bytep buf, png_int_32 i) +{ + buf[0] = (png_byte)((i >> 24) & 0xff); + buf[1] = (png_byte)((i >> 16) & 0xff); + buf[2] = (png_byte)((i >> 8) & 0xff); + buf[3] = (png_byte)(i & 0xff); +} +#endif + +/* Place a 16-bit number into a buffer in PNG byte order. + * The parameter is declared unsigned int, not png_uint_16, + * just to avoid potential problems on pre-ANSI C compilers. + */ +void PNGAPI +png_save_uint_16(png_bytep buf, unsigned int i) +{ + buf[0] = (png_byte)((i >> 8) & 0xff); + buf[1] = (png_byte)(i & 0xff); +} +#endif + +/* Simple function to write the signature. If we have already written + * the magic bytes of the signature, or more likely, the PNG stream is + * being embedded into another stream and doesn't need its own signature, + * we should call png_set_sig_bytes() to tell libpng how many of the + * bytes have already been written. + */ +void PNGAPI +png_write_sig(png_structp png_ptr) +{ + png_byte png_signature[8] = {137, 80, 78, 71, 13, 10, 26, 10}; + +#ifdef PNG_IO_STATE_SUPPORTED + /* Inform the I/O callback that the signature is being written */ + png_ptr->io_state = PNG_IO_WRITING | PNG_IO_SIGNATURE; +#endif + + /* Write the rest of the 8 byte signature */ + png_write_data(png_ptr, &png_signature[png_ptr->sig_bytes], + (png_size_t)(8 - png_ptr->sig_bytes)); + + if (png_ptr->sig_bytes < 3) + png_ptr->mode |= PNG_HAVE_PNG_SIGNATURE; +} + +/* Write a PNG chunk all at once. The type is an array of ASCII characters + * representing the chunk name. The array must be at least 4 bytes in + * length, and does not need to be null terminated. To be safe, pass the + * pre-defined chunk names here, and if you need a new one, define it + * where the others are defined. The length is the length of the data. + * All the data must be present. If that is not possible, use the + * png_write_chunk_start(), png_write_chunk_data(), and png_write_chunk_end() + * functions instead. + */ +void PNGAPI +png_write_chunk(png_structp png_ptr, png_const_bytep chunk_name, + png_const_bytep data, png_size_t length) +{ + if (png_ptr == NULL) + return; + + png_write_chunk_start(png_ptr, chunk_name, (png_uint_32)length); + png_write_chunk_data(png_ptr, data, (png_size_t)length); + png_write_chunk_end(png_ptr); +} + +/* Write the start of a PNG chunk. The type is the chunk type. + * The total_length is the sum of the lengths of all the data you will be + * passing in png_write_chunk_data(). + */ +void PNGAPI +png_write_chunk_start(png_structp png_ptr, png_const_bytep chunk_name, + png_uint_32 length) +{ + png_byte buf[8]; + + png_debug2(0, "Writing %s chunk, length = %lu", chunk_name, + (unsigned long)length); + + if (png_ptr == NULL) + return; + +#ifdef PNG_IO_STATE_SUPPORTED + /* Inform the I/O callback that the chunk header is being written. + * PNG_IO_CHUNK_HDR requires a single I/O call. + */ + png_ptr->io_state = PNG_IO_WRITING | PNG_IO_CHUNK_HDR; +#endif + + /* Write the length and the chunk name */ + png_save_uint_32(buf, length); + png_memcpy(buf + 4, chunk_name, 4); + png_write_data(png_ptr, buf, (png_size_t)8); + + /* Put the chunk name into png_ptr->chunk_name */ + png_memcpy(png_ptr->chunk_name, chunk_name, 4); + + /* Reset the crc and run it over the chunk name */ + png_reset_crc(png_ptr); + + png_calculate_crc(png_ptr, chunk_name, 4); + +#ifdef PNG_IO_STATE_SUPPORTED + /* Inform the I/O callback that chunk data will (possibly) be written. + * PNG_IO_CHUNK_DATA does NOT require a specific number of I/O calls. + */ + png_ptr->io_state = PNG_IO_WRITING | PNG_IO_CHUNK_DATA; +#endif +} + +/* Write the data of a PNG chunk started with png_write_chunk_start(). + * Note that multiple calls to this function are allowed, and that the + * sum of the lengths from these calls *must* add up to the total_length + * given to png_write_chunk_start(). + */ +void PNGAPI +png_write_chunk_data(png_structp png_ptr, png_const_bytep data, + png_size_t length) +{ + /* Write the data, and run the CRC over it */ + if (png_ptr == NULL) + return; + + if (data != NULL && length > 0) + { + png_write_data(png_ptr, data, length); + + /* Update the CRC after writing the data, + * in case that the user I/O routine alters it. + */ + png_calculate_crc(png_ptr, data, length); + } +} + +/* Finish a chunk started with png_write_chunk_start(). */ +void PNGAPI +png_write_chunk_end(png_structp png_ptr) +{ + png_byte buf[4]; + + if (png_ptr == NULL) return; + +#ifdef PNG_IO_STATE_SUPPORTED + /* Inform the I/O callback that the chunk CRC is being written. + * PNG_IO_CHUNK_CRC requires a single I/O function call. + */ + png_ptr->io_state = PNG_IO_WRITING | PNG_IO_CHUNK_CRC; +#endif + + /* Write the crc in a single operation */ + png_save_uint_32(buf, png_ptr->crc); + + png_write_data(png_ptr, buf, (png_size_t)4); +} + +#if defined(PNG_WRITE_TEXT_SUPPORTED) || defined(PNG_WRITE_iCCP_SUPPORTED) +/* This pair of functions encapsulates the operation of (a) compressing a + * text string, and (b) issuing it later as a series of chunk data writes. + * The compression_state structure is shared context for these functions + * set up by the caller in order to make the whole mess thread-safe. + */ + +typedef struct +{ + png_const_bytep input; /* The uncompressed input data */ + png_size_t input_len; /* Its length */ + int num_output_ptr; /* Number of output pointers used */ + int max_output_ptr; /* Size of output_ptr */ + png_bytep *output_ptr; /* Array of pointers to output */ +} compression_state; + +/* Compress given text into storage in the png_ptr structure */ +static int /* PRIVATE */ +png_text_compress(png_structp png_ptr, + png_const_charp text, png_size_t text_len, int compression, + compression_state *comp) +{ + int ret; + + comp->num_output_ptr = 0; + comp->max_output_ptr = 0; + comp->output_ptr = NULL; + comp->input = NULL; + comp->input_len = 0; + + /* We may just want to pass the text right through */ + if (compression == PNG_TEXT_COMPRESSION_NONE) + { + comp->input = (png_const_bytep)text; + comp->input_len = text_len; + return((int)text_len); + } + + if (compression >= PNG_TEXT_COMPRESSION_LAST) + { +#ifdef PNG_CONSOLE_IO_SUPPORTED + char msg[50]; + png_snprintf(msg, 50, "Unknown compression type %d", compression); + png_warning(png_ptr, msg); +#else + png_warning(png_ptr, "Unknown compression type"); +#endif + } + + /* We can't write the chunk until we find out how much data we have, + * which means we need to run the compressor first and save the + * output. This shouldn't be a problem, as the vast majority of + * comments should be reasonable, but we will set up an array of + * malloc'd pointers to be sure. + * + * If we knew the application was well behaved, we could simplify this + * greatly by assuming we can always malloc an output buffer large + * enough to hold the compressed text ((1001 * text_len / 1000) + 12) + * and malloc this directly. The only time this would be a bad idea is + * if we can't malloc more than 64K and we have 64K of random input + * data, or if the input string is incredibly large (although this + * wouldn't cause a failure, just a slowdown due to swapping). + */ + + /* Set up the compression buffers */ + /* TODO: the following cast hides a potential overflow problem. */ + png_ptr->zstream.avail_in = (uInt)text_len; + /* NOTE: assume zlib doesn't overwrite the input */ + png_ptr->zstream.next_in = (Bytef *)text; + png_ptr->zstream.avail_out = png_ptr->zbuf_size; + png_ptr->zstream.next_out = png_ptr->zbuf; + + /* This is the same compression loop as in png_write_row() */ + do + { + /* Compress the data */ + ret = deflate(&png_ptr->zstream, Z_NO_FLUSH); + + if (ret != Z_OK) + { + /* Error */ + if (png_ptr->zstream.msg != NULL) + png_error(png_ptr, png_ptr->zstream.msg); + + else + png_error(png_ptr, "zlib error"); + } + + /* Check to see if we need more room */ + if (!(png_ptr->zstream.avail_out)) + { + /* Make sure the output array has room */ + if (comp->num_output_ptr >= comp->max_output_ptr) + { + int old_max; + + old_max = comp->max_output_ptr; + comp->max_output_ptr = comp->num_output_ptr + 4; + if (comp->output_ptr != NULL) + { + png_bytepp old_ptr; + + old_ptr = comp->output_ptr; + + comp->output_ptr = (png_bytepp)png_malloc(png_ptr, + (png_alloc_size_t) + (comp->max_output_ptr * png_sizeof(png_charpp))); + + png_memcpy(comp->output_ptr, old_ptr, old_max + * png_sizeof(png_charp)); + + png_free(png_ptr, old_ptr); + } + else + comp->output_ptr = (png_bytepp)png_malloc(png_ptr, + (png_alloc_size_t) + (comp->max_output_ptr * png_sizeof(png_charp))); + } + + /* Save the data */ + comp->output_ptr[comp->num_output_ptr] = + (png_bytep)png_malloc(png_ptr, + (png_alloc_size_t)png_ptr->zbuf_size); + + png_memcpy(comp->output_ptr[comp->num_output_ptr], png_ptr->zbuf, + png_ptr->zbuf_size); + + comp->num_output_ptr++; + + /* and reset the buffer */ + png_ptr->zstream.avail_out = (uInt)png_ptr->zbuf_size; + png_ptr->zstream.next_out = png_ptr->zbuf; + } + /* Continue until we don't have any more to compress */ + } while (png_ptr->zstream.avail_in); + + /* Finish the compression */ + do + { + /* Tell zlib we are finished */ + ret = deflate(&png_ptr->zstream, Z_FINISH); + + if (ret == Z_OK) + { + /* Check to see if we need more room */ + if (!(png_ptr->zstream.avail_out)) + { + /* Check to make sure our output array has room */ + if (comp->num_output_ptr >= comp->max_output_ptr) + { + int old_max; + + old_max = comp->max_output_ptr; + comp->max_output_ptr = comp->num_output_ptr + 4; + if (comp->output_ptr != NULL) + { + png_bytepp old_ptr; + + old_ptr = comp->output_ptr; + + /* This could be optimized to realloc() */ + comp->output_ptr = (png_bytepp)png_malloc(png_ptr, + (png_alloc_size_t)(comp->max_output_ptr * + png_sizeof(png_charp))); + + png_memcpy(comp->output_ptr, old_ptr, + old_max * png_sizeof(png_charp)); + + png_free(png_ptr, old_ptr); + } + + else + comp->output_ptr = (png_bytepp)png_malloc(png_ptr, + (png_alloc_size_t)(comp->max_output_ptr * + png_sizeof(png_charp))); + } + + /* Save the data */ + comp->output_ptr[comp->num_output_ptr] = + (png_bytep)png_malloc(png_ptr, + (png_alloc_size_t)png_ptr->zbuf_size); + + png_memcpy(comp->output_ptr[comp->num_output_ptr], png_ptr->zbuf, + png_ptr->zbuf_size); + + comp->num_output_ptr++; + + /* and reset the buffer pointers */ + png_ptr->zstream.avail_out = (uInt)png_ptr->zbuf_size; + png_ptr->zstream.next_out = png_ptr->zbuf; + } + } + else if (ret != Z_STREAM_END) + { + /* We got an error */ + if (png_ptr->zstream.msg != NULL) + png_error(png_ptr, png_ptr->zstream.msg); + + else + png_error(png_ptr, "zlib error"); + } + } while (ret != Z_STREAM_END); + + /* Text length is number of buffers plus last buffer */ + text_len = png_ptr->zbuf_size * comp->num_output_ptr; + + if (png_ptr->zstream.avail_out < png_ptr->zbuf_size) + text_len += png_ptr->zbuf_size - (png_size_t)png_ptr->zstream.avail_out; + + return((int)text_len); +} + +/* Ship the compressed text out via chunk writes */ +static void /* PRIVATE */ +png_write_compressed_data_out(png_structp png_ptr, compression_state *comp) +{ + int i; + + /* Handle the no-compression case */ + if (comp->input) + { + png_write_chunk_data(png_ptr, comp->input, comp->input_len); + + return; + } + + /* Write saved output buffers, if any */ + for (i = 0; i < comp->num_output_ptr; i++) + { + png_write_chunk_data(png_ptr, comp->output_ptr[i], + (png_size_t)png_ptr->zbuf_size); + + png_free(png_ptr, comp->output_ptr[i]); + } + + if (comp->max_output_ptr != 0) + png_free(png_ptr, comp->output_ptr); + + /* Write anything left in zbuf */ + if (png_ptr->zstream.avail_out < (png_uint_32)png_ptr->zbuf_size) + png_write_chunk_data(png_ptr, png_ptr->zbuf, + (png_size_t)(png_ptr->zbuf_size - png_ptr->zstream.avail_out)); + + /* Reset zlib for another zTXt/iTXt or image data */ + deflateReset(&png_ptr->zstream); + png_ptr->zstream.data_type = Z_BINARY; +} +#endif + +/* Write the IHDR chunk, and update the png_struct with the necessary + * information. Note that the rest of this code depends upon this + * information being correct. + */ +void /* PRIVATE */ +png_write_IHDR(png_structp png_ptr, png_uint_32 width, png_uint_32 height, + int bit_depth, int color_type, int compression_type, int filter_type, + int interlace_type) +{ + PNG_IHDR; + int ret; + + png_byte buf[13]; /* Buffer to store the IHDR info */ + + png_debug(1, "in png_write_IHDR"); + + /* Check that we have valid input data from the application info */ + switch (color_type) + { + case PNG_COLOR_TYPE_GRAY: + switch (bit_depth) + { + case 1: + case 2: + case 4: + case 8: +#ifdef PNG_WRITE_16BIT_SUPPORTED + case 16: +#endif + png_ptr->channels = 1; break; + + default: + png_error(png_ptr, + "Invalid bit depth for grayscale image"); + } + break; + + case PNG_COLOR_TYPE_RGB: +#ifdef PNG_WRITE_16BIT_SUPPORTED + if (bit_depth != 8 && bit_depth != 16) +#else + if (bit_depth != 8) +#endif + png_error(png_ptr, "Invalid bit depth for RGB image"); + + png_ptr->channels = 3; + break; + + case PNG_COLOR_TYPE_PALETTE: + switch (bit_depth) + { + case 1: + case 2: + case 4: + case 8: + png_ptr->channels = 1; + break; + + default: + png_error(png_ptr, "Invalid bit depth for paletted image"); + } + break; + + case PNG_COLOR_TYPE_GRAY_ALPHA: + if (bit_depth != 8 && bit_depth != 16) + png_error(png_ptr, "Invalid bit depth for grayscale+alpha image"); + + png_ptr->channels = 2; + break; + + case PNG_COLOR_TYPE_RGB_ALPHA: +#ifdef PNG_WRITE_16BIT_SUPPORTED + if (bit_depth != 8 && bit_depth != 16) +#else + if (bit_depth != 8) +#endif + png_error(png_ptr, "Invalid bit depth for RGBA image"); + + png_ptr->channels = 4; + break; + + default: + png_error(png_ptr, "Invalid image color type specified"); + } + + if (compression_type != PNG_COMPRESSION_TYPE_BASE) + { + png_warning(png_ptr, "Invalid compression type specified"); + compression_type = PNG_COMPRESSION_TYPE_BASE; + } + + /* Write filter_method 64 (intrapixel differencing) only if + * 1. Libpng was compiled with PNG_MNG_FEATURES_SUPPORTED and + * 2. Libpng did not write a PNG signature (this filter_method is only + * used in PNG datastreams that are embedded in MNG datastreams) and + * 3. The application called png_permit_mng_features with a mask that + * included PNG_FLAG_MNG_FILTER_64 and + * 4. The filter_method is 64 and + * 5. The color_type is RGB or RGBA + */ + if ( +#ifdef PNG_MNG_FEATURES_SUPPORTED + !((png_ptr->mng_features_permitted & PNG_FLAG_MNG_FILTER_64) && + ((png_ptr->mode&PNG_HAVE_PNG_SIGNATURE) == 0) && + (color_type == PNG_COLOR_TYPE_RGB || + color_type == PNG_COLOR_TYPE_RGB_ALPHA) && + (filter_type == PNG_INTRAPIXEL_DIFFERENCING)) && +#endif + filter_type != PNG_FILTER_TYPE_BASE) + { + png_warning(png_ptr, "Invalid filter type specified"); + filter_type = PNG_FILTER_TYPE_BASE; + } + +#ifdef PNG_WRITE_INTERLACING_SUPPORTED + if (interlace_type != PNG_INTERLACE_NONE && + interlace_type != PNG_INTERLACE_ADAM7) + { + png_warning(png_ptr, "Invalid interlace type specified"); + interlace_type = PNG_INTERLACE_ADAM7; + } +#else + interlace_type=PNG_INTERLACE_NONE; +#endif + + /* Save the relevent information */ + png_ptr->bit_depth = (png_byte)bit_depth; + png_ptr->color_type = (png_byte)color_type; + png_ptr->interlaced = (png_byte)interlace_type; +#ifdef PNG_MNG_FEATURES_SUPPORTED + png_ptr->filter_type = (png_byte)filter_type; +#endif + png_ptr->compression_type = (png_byte)compression_type; + png_ptr->width = width; + png_ptr->height = height; + + png_ptr->pixel_depth = (png_byte)(bit_depth * png_ptr->channels); + png_ptr->rowbytes = PNG_ROWBYTES(png_ptr->pixel_depth, width); + /* Set the usr info, so any transformations can modify it */ + png_ptr->usr_width = png_ptr->width; + png_ptr->usr_bit_depth = png_ptr->bit_depth; + png_ptr->usr_channels = png_ptr->channels; + + /* Pack the header information into the buffer */ + png_save_uint_32(buf, width); + png_save_uint_32(buf + 4, height); + buf[8] = (png_byte)bit_depth; + buf[9] = (png_byte)color_type; + buf[10] = (png_byte)compression_type; + buf[11] = (png_byte)filter_type; + buf[12] = (png_byte)interlace_type; + + /* Write the chunk */ + png_write_chunk(png_ptr, png_IHDR, buf, (png_size_t)13); + + /* Initialize zlib with PNG info */ + png_ptr->zstream.zalloc = png_zalloc; + png_ptr->zstream.zfree = png_zfree; + png_ptr->zstream.opaque = (voidpf)png_ptr; + + if (!(png_ptr->do_filter)) + { + if (png_ptr->color_type == PNG_COLOR_TYPE_PALETTE || + png_ptr->bit_depth < 8) + png_ptr->do_filter = PNG_FILTER_NONE; + + else + png_ptr->do_filter = PNG_ALL_FILTERS; + } + + if (!(png_ptr->flags & PNG_FLAG_ZLIB_CUSTOM_STRATEGY)) + { + if (png_ptr->do_filter != PNG_FILTER_NONE) + png_ptr->zlib_strategy = Z_FILTERED; + + else + png_ptr->zlib_strategy = Z_DEFAULT_STRATEGY; + } + + if (!(png_ptr->flags & PNG_FLAG_ZLIB_CUSTOM_LEVEL)) + png_ptr->zlib_level = Z_DEFAULT_COMPRESSION; + + if (!(png_ptr->flags & PNG_FLAG_ZLIB_CUSTOM_MEM_LEVEL)) + png_ptr->zlib_mem_level = 8; + + if (!(png_ptr->flags & PNG_FLAG_ZLIB_CUSTOM_WINDOW_BITS)) + png_ptr->zlib_window_bits = 15; + + if (!(png_ptr->flags & PNG_FLAG_ZLIB_CUSTOM_METHOD)) + png_ptr->zlib_method = 8; + + ret = deflateInit2(&png_ptr->zstream, png_ptr->zlib_level, + png_ptr->zlib_method, png_ptr->zlib_window_bits, + png_ptr->zlib_mem_level, png_ptr->zlib_strategy); + + if (ret != Z_OK) + { + if (ret == Z_VERSION_ERROR) + png_error(png_ptr, + "zlib failed to initialize compressor -- version error"); + + if (ret == Z_STREAM_ERROR) + png_error(png_ptr, + "zlib failed to initialize compressor -- stream error"); + + if (ret == Z_MEM_ERROR) + png_error(png_ptr, + "zlib failed to initialize compressor -- mem error"); + + png_error(png_ptr, "zlib failed to initialize compressor"); + } + + png_ptr->zstream.next_out = png_ptr->zbuf; + png_ptr->zstream.avail_out = (uInt)png_ptr->zbuf_size; + /* libpng is not interested in zstream.data_type, so set it + * to a predefined value, to avoid its evaluation inside zlib + */ + png_ptr->zstream.data_type = Z_BINARY; + + png_ptr->mode = PNG_HAVE_IHDR; +} + +/* Write the palette. We are careful not to trust png_color to be in the + * correct order for PNG, so people can redefine it to any convenient + * structure. + */ +void /* PRIVATE */ +png_write_PLTE(png_structp png_ptr, png_const_colorp palette, + png_uint_32 num_pal) +{ + PNG_PLTE; + png_uint_32 i; + png_const_colorp pal_ptr; + png_byte buf[3]; + + png_debug(1, "in png_write_PLTE"); + + if (( +#ifdef PNG_MNG_FEATURES_SUPPORTED + !(png_ptr->mng_features_permitted & PNG_FLAG_MNG_EMPTY_PLTE) && +#endif + num_pal == 0) || num_pal > 256) + { + if (png_ptr->color_type == PNG_COLOR_TYPE_PALETTE) + { + png_error(png_ptr, "Invalid number of colors in palette"); + } + + else + { + png_warning(png_ptr, "Invalid number of colors in palette"); + return; + } + } + + if (!(png_ptr->color_type&PNG_COLOR_MASK_COLOR)) + { + png_warning(png_ptr, + "Ignoring request to write a PLTE chunk in grayscale PNG"); + + return; + } + + png_ptr->num_palette = (png_uint_16)num_pal; + png_debug1(3, "num_palette = %d", png_ptr->num_palette); + + png_write_chunk_start(png_ptr, png_PLTE, (png_uint_32)(num_pal * 3)); +#ifdef PNG_POINTER_INDEXING_SUPPORTED + + for (i = 0, pal_ptr = palette; i < num_pal; i++, pal_ptr++) + { + buf[0] = pal_ptr->red; + buf[1] = pal_ptr->green; + buf[2] = pal_ptr->blue; + png_write_chunk_data(png_ptr, buf, (png_size_t)3); + } + +#else + /* This is a little slower but some buggy compilers need to do this + * instead + */ + pal_ptr=palette; + + for (i = 0; i < num_pal; i++) + { + buf[0] = pal_ptr[i].red; + buf[1] = pal_ptr[i].green; + buf[2] = pal_ptr[i].blue; + png_write_chunk_data(png_ptr, buf, (png_size_t)3); + } + +#endif + png_write_chunk_end(png_ptr); + png_ptr->mode |= PNG_HAVE_PLTE; +} + +/* Write an IDAT chunk */ +void /* PRIVATE */ +png_write_IDAT(png_structp png_ptr, png_bytep data, png_size_t length) +{ + PNG_IDAT; + + png_debug(1, "in png_write_IDAT"); + + /* Optimize the CMF field in the zlib stream. */ + /* This hack of the zlib stream is compliant to the stream specification. */ + if (!(png_ptr->mode & PNG_HAVE_IDAT) && + png_ptr->compression_type == PNG_COMPRESSION_TYPE_BASE) + { + unsigned int z_cmf = data[0]; /* zlib compression method and flags */ + if ((z_cmf & 0x0f) == 8 && (z_cmf & 0xf0) <= 0x70) + { + /* Avoid memory underflows and multiplication overflows. + * + * The conditions below are practically always satisfied; + * however, they still must be checked. + */ + if (length >= 2 && + png_ptr->height < 16384 && png_ptr->width < 16384) + { + png_uint_32 uncompressed_idat_size = png_ptr->height * + ((png_ptr->width * + png_ptr->channels * png_ptr->bit_depth + 15) >> 3); + unsigned int z_cinfo = z_cmf >> 4; + unsigned int half_z_window_size = 1 << (z_cinfo + 7); + while (uncompressed_idat_size <= half_z_window_size && + half_z_window_size >= 256) + { + z_cinfo--; + half_z_window_size >>= 1; + } + + z_cmf = (z_cmf & 0x0f) | (z_cinfo << 4); + + if (data[0] != z_cmf) + { + int tmp; + data[0] = (png_byte)z_cmf; + tmp = data[1] & 0xe0; + tmp += 0x1f - ((z_cmf << 8) + tmp) % 0x1f; + data[1] = (png_byte)tmp; + } + } + } + + else + png_error(png_ptr, + "Invalid zlib compression method or flags in IDAT"); + } + + png_write_chunk(png_ptr, png_IDAT, data, length); + png_ptr->mode |= PNG_HAVE_IDAT; +} + +/* Write an IEND chunk */ +void /* PRIVATE */ +png_write_IEND(png_structp png_ptr) +{ + PNG_IEND; + + png_debug(1, "in png_write_IEND"); + + png_write_chunk(png_ptr, png_IEND, NULL, (png_size_t)0); + png_ptr->mode |= PNG_HAVE_IEND; +} + +#ifdef PNG_WRITE_gAMA_SUPPORTED +/* Write a gAMA chunk */ +void /* PRIVATE */ +png_write_gAMA_fixed(png_structp png_ptr, png_fixed_point file_gamma) +{ + PNG_gAMA; + png_byte buf[4]; + + png_debug(1, "in png_write_gAMA"); + + /* file_gamma is saved in 1/100,000ths */ + png_save_uint_32(buf, (png_uint_32)file_gamma); + png_write_chunk(png_ptr, png_gAMA, buf, (png_size_t)4); +} +#endif + +#ifdef PNG_WRITE_sRGB_SUPPORTED +/* Write a sRGB chunk */ +void /* PRIVATE */ +png_write_sRGB(png_structp png_ptr, int srgb_intent) +{ + PNG_sRGB; + png_byte buf[1]; + + png_debug(1, "in png_write_sRGB"); + + if (srgb_intent >= PNG_sRGB_INTENT_LAST) + png_warning(png_ptr, + "Invalid sRGB rendering intent specified"); + + buf[0]=(png_byte)srgb_intent; + png_write_chunk(png_ptr, png_sRGB, buf, (png_size_t)1); +} +#endif + +#ifdef PNG_WRITE_iCCP_SUPPORTED +/* Write an iCCP chunk */ +void /* PRIVATE */ +png_write_iCCP(png_structp png_ptr, png_const_charp name, int compression_type, + png_const_charp profile, int profile_len) +{ + PNG_iCCP; + png_size_t name_len; + png_charp new_name; + compression_state comp; + int embedded_profile_len = 0; + + png_debug(1, "in png_write_iCCP"); + + comp.num_output_ptr = 0; + comp.max_output_ptr = 0; + comp.output_ptr = NULL; + comp.input = NULL; + comp.input_len = 0; + + if ((name_len = png_check_keyword(png_ptr, name, &new_name)) == 0) + return; + + if (compression_type != PNG_COMPRESSION_TYPE_BASE) + png_warning(png_ptr, "Unknown compression type in iCCP chunk"); + + if (profile == NULL) + profile_len = 0; + + if (profile_len > 3) + embedded_profile_len = + ((*( (png_const_bytep)profile ))<<24) | + ((*( (png_const_bytep)profile + 1))<<16) | + ((*( (png_const_bytep)profile + 2))<< 8) | + ((*( (png_const_bytep)profile + 3)) ); + + if (embedded_profile_len < 0) + { + png_warning(png_ptr, + "Embedded profile length in iCCP chunk is negative"); + + png_free(png_ptr, new_name); + return; + } + + if (profile_len < embedded_profile_len) + { + png_warning(png_ptr, + "Embedded profile length too large in iCCP chunk"); + + png_free(png_ptr, new_name); + return; + } + + if (profile_len > embedded_profile_len) + { + png_warning(png_ptr, + "Truncating profile to actual length in iCCP chunk"); + + profile_len = embedded_profile_len; + } + + if (profile_len) + profile_len = png_text_compress(png_ptr, profile, + (png_size_t)profile_len, PNG_COMPRESSION_TYPE_BASE, &comp); + + /* Make sure we include the NULL after the name and the compression type */ + png_write_chunk_start(png_ptr, png_iCCP, + (png_uint_32)(name_len + profile_len + 2)); + + new_name[name_len + 1] = 0x00; + + png_write_chunk_data(png_ptr, (png_bytep)new_name, + (png_size_t)(name_len + 2)); + + if (profile_len) + png_write_compressed_data_out(png_ptr, &comp); + + png_write_chunk_end(png_ptr); + png_free(png_ptr, new_name); +} +#endif + +#ifdef PNG_WRITE_sPLT_SUPPORTED +/* Write a sPLT chunk */ +void /* PRIVATE */ +png_write_sPLT(png_structp png_ptr, png_const_sPLT_tp spalette) +{ + PNG_sPLT; + png_size_t name_len; + png_charp new_name; + png_byte entrybuf[10]; + png_size_t entry_size = (spalette->depth == 8 ? 6 : 10); + png_size_t palette_size = entry_size * spalette->nentries; + png_sPLT_entryp ep; +#ifndef PNG_POINTER_INDEXING_SUPPORTED + int i; +#endif + + png_debug(1, "in png_write_sPLT"); + + if ((name_len = png_check_keyword(png_ptr,spalette->name, &new_name))==0) + return; + + /* Make sure we include the NULL after the name */ + png_write_chunk_start(png_ptr, png_sPLT, + (png_uint_32)(name_len + 2 + palette_size)); + + png_write_chunk_data(png_ptr, (png_bytep)new_name, + (png_size_t)(name_len + 1)); + + png_write_chunk_data(png_ptr, &spalette->depth, (png_size_t)1); + + /* Loop through each palette entry, writing appropriately */ +#ifdef PNG_POINTER_INDEXING_SUPPORTED + for (ep = spalette->entries; ep<spalette->entries + spalette->nentries; ep++) + { + if (spalette->depth == 8) + { + entrybuf[0] = (png_byte)ep->red; + entrybuf[1] = (png_byte)ep->green; + entrybuf[2] = (png_byte)ep->blue; + entrybuf[3] = (png_byte)ep->alpha; + png_save_uint_16(entrybuf + 4, ep->frequency); + } + + else + { + png_save_uint_16(entrybuf + 0, ep->red); + png_save_uint_16(entrybuf + 2, ep->green); + png_save_uint_16(entrybuf + 4, ep->blue); + png_save_uint_16(entrybuf + 6, ep->alpha); + png_save_uint_16(entrybuf + 8, ep->frequency); + } + + png_write_chunk_data(png_ptr, entrybuf, (png_size_t)entry_size); + } +#else + ep=spalette->entries; + for (i = 0; i>spalette->nentries; i++) + { + if (spalette->depth == 8) + { + entrybuf[0] = (png_byte)ep[i].red; + entrybuf[1] = (png_byte)ep[i].green; + entrybuf[2] = (png_byte)ep[i].blue; + entrybuf[3] = (png_byte)ep[i].alpha; + png_save_uint_16(entrybuf + 4, ep[i].frequency); + } + + else + { + png_save_uint_16(entrybuf + 0, ep[i].red); + png_save_uint_16(entrybuf + 2, ep[i].green); + png_save_uint_16(entrybuf + 4, ep[i].blue); + png_save_uint_16(entrybuf + 6, ep[i].alpha); + png_save_uint_16(entrybuf + 8, ep[i].frequency); + } + + png_write_chunk_data(png_ptr, entrybuf, (png_size_t)entry_size); + } +#endif + + png_write_chunk_end(png_ptr); + png_free(png_ptr, new_name); +} +#endif + +#ifdef PNG_WRITE_sBIT_SUPPORTED +/* Write the sBIT chunk */ +void /* PRIVATE */ +png_write_sBIT(png_structp png_ptr, png_const_color_8p sbit, int color_type) +{ + PNG_sBIT; + png_byte buf[4]; + png_size_t size; + + png_debug(1, "in png_write_sBIT"); + + /* Make sure we don't depend upon the order of PNG_COLOR_8 */ + if (color_type & PNG_COLOR_MASK_COLOR) + { + png_byte maxbits; + + maxbits = (png_byte)(color_type==PNG_COLOR_TYPE_PALETTE ? 8 : + png_ptr->usr_bit_depth); + + if (sbit->red == 0 || sbit->red > maxbits || + sbit->green == 0 || sbit->green > maxbits || + sbit->blue == 0 || sbit->blue > maxbits) + { + png_warning(png_ptr, "Invalid sBIT depth specified"); + return; + } + + buf[0] = sbit->red; + buf[1] = sbit->green; + buf[2] = sbit->blue; + size = 3; + } + + else + { + if (sbit->gray == 0 || sbit->gray > png_ptr->usr_bit_depth) + { + png_warning(png_ptr, "Invalid sBIT depth specified"); + return; + } + + buf[0] = sbit->gray; + size = 1; + } + + if (color_type & PNG_COLOR_MASK_ALPHA) + { + if (sbit->alpha == 0 || sbit->alpha > png_ptr->usr_bit_depth) + { + png_warning(png_ptr, "Invalid sBIT depth specified"); + return; + } + + buf[size++] = sbit->alpha; + } + + png_write_chunk(png_ptr, png_sBIT, buf, size); +} +#endif + +#ifdef PNG_WRITE_cHRM_SUPPORTED +/* Write the cHRM chunk */ +void /* PRIVATE */ +png_write_cHRM_fixed(png_structp png_ptr, png_fixed_point white_x, + png_fixed_point white_y, png_fixed_point red_x, png_fixed_point red_y, + png_fixed_point green_x, png_fixed_point green_y, png_fixed_point blue_x, + png_fixed_point blue_y) +{ + PNG_cHRM; + png_byte buf[32]; + + png_debug(1, "in png_write_cHRM"); + + /* Each value is saved in 1/100,000ths */ +#ifdef PNG_CHECK_cHRM_SUPPORTED + if (png_check_cHRM_fixed(png_ptr, white_x, white_y, red_x, red_y, + green_x, green_y, blue_x, blue_y)) +#endif + { + png_save_uint_32(buf, (png_uint_32)white_x); + png_save_uint_32(buf + 4, (png_uint_32)white_y); + + png_save_uint_32(buf + 8, (png_uint_32)red_x); + png_save_uint_32(buf + 12, (png_uint_32)red_y); + + png_save_uint_32(buf + 16, (png_uint_32)green_x); + png_save_uint_32(buf + 20, (png_uint_32)green_y); + + png_save_uint_32(buf + 24, (png_uint_32)blue_x); + png_save_uint_32(buf + 28, (png_uint_32)blue_y); + + png_write_chunk(png_ptr, png_cHRM, buf, (png_size_t)32); + } +} +#endif + +#ifdef PNG_WRITE_tRNS_SUPPORTED +/* Write the tRNS chunk */ +void /* PRIVATE */ +png_write_tRNS(png_structp png_ptr, png_const_bytep trans_alpha, + png_const_color_16p tran, int num_trans, int color_type) +{ + PNG_tRNS; + png_byte buf[6]; + + png_debug(1, "in png_write_tRNS"); + + if (color_type == PNG_COLOR_TYPE_PALETTE) + { + if (num_trans <= 0 || num_trans > (int)png_ptr->num_palette) + { + png_warning(png_ptr, "Invalid number of transparent colors specified"); + return; + } + + /* Write the chunk out as it is */ + png_write_chunk(png_ptr, png_tRNS, trans_alpha, (png_size_t)num_trans); + } + + else if (color_type == PNG_COLOR_TYPE_GRAY) + { + /* One 16 bit value */ + if (tran->gray >= (1 << png_ptr->bit_depth)) + { + png_warning(png_ptr, + "Ignoring attempt to write tRNS chunk out-of-range for bit_depth"); + + return; + } + + png_save_uint_16(buf, tran->gray); + png_write_chunk(png_ptr, png_tRNS, buf, (png_size_t)2); + } + + else if (color_type == PNG_COLOR_TYPE_RGB) + { + /* Three 16 bit values */ + png_save_uint_16(buf, tran->red); + png_save_uint_16(buf + 2, tran->green); + png_save_uint_16(buf + 4, tran->blue); +#ifdef PNG_WRITE_16BIT_SUPPORTED + if (png_ptr->bit_depth == 8 && (buf[0] | buf[2] | buf[4])) +#else + if (buf[0] | buf[2] | buf[4]) +#endif + { + png_warning(png_ptr, + "Ignoring attempt to write 16-bit tRNS chunk when bit_depth is 8"); + return; + } + + png_write_chunk(png_ptr, png_tRNS, buf, (png_size_t)6); + } + + else + { + png_warning(png_ptr, "Can't write tRNS with an alpha channel"); + } +} +#endif + +#ifdef PNG_WRITE_bKGD_SUPPORTED +/* Write the background chunk */ +void /* PRIVATE */ +png_write_bKGD(png_structp png_ptr, png_const_color_16p back, int color_type) +{ + PNG_bKGD; + png_byte buf[6]; + + png_debug(1, "in png_write_bKGD"); + + if (color_type == PNG_COLOR_TYPE_PALETTE) + { + if ( +#ifdef PNG_MNG_FEATURES_SUPPORTED + (png_ptr->num_palette || + (!(png_ptr->mng_features_permitted & PNG_FLAG_MNG_EMPTY_PLTE))) && +#endif + back->index >= png_ptr->num_palette) + { + png_warning(png_ptr, "Invalid background palette index"); + return; + } + + buf[0] = back->index; + png_write_chunk(png_ptr, png_bKGD, buf, (png_size_t)1); + } + + else if (color_type & PNG_COLOR_MASK_COLOR) + { + png_save_uint_16(buf, back->red); + png_save_uint_16(buf + 2, back->green); + png_save_uint_16(buf + 4, back->blue); +#ifdef PNG_WRITE_16BIT_SUPPORTED + if (png_ptr->bit_depth == 8 && (buf[0] | buf[2] | buf[4])) +#else + if (buf[0] | buf[2] | buf[4]) +#endif + { + png_warning(png_ptr, + "Ignoring attempt to write 16-bit bKGD chunk when bit_depth is 8"); + + return; + } + + png_write_chunk(png_ptr, png_bKGD, buf, (png_size_t)6); + } + + else + { + if (back->gray >= (1 << png_ptr->bit_depth)) + { + png_warning(png_ptr, + "Ignoring attempt to write bKGD chunk out-of-range for bit_depth"); + + return; + } + + png_save_uint_16(buf, back->gray); + png_write_chunk(png_ptr, png_bKGD, buf, (png_size_t)2); + } +} +#endif + +#ifdef PNG_WRITE_hIST_SUPPORTED +/* Write the histogram */ +void /* PRIVATE */ +png_write_hIST(png_structp png_ptr, png_const_uint_16p hist, int num_hist) +{ + PNG_hIST; + int i; + png_byte buf[3]; + + png_debug(1, "in png_write_hIST"); + + if (num_hist > (int)png_ptr->num_palette) + { + png_debug2(3, "num_hist = %d, num_palette = %d", num_hist, + png_ptr->num_palette); + + png_warning(png_ptr, "Invalid number of histogram entries specified"); + return; + } + + png_write_chunk_start(png_ptr, png_hIST, (png_uint_32)(num_hist * 2)); + + for (i = 0; i < num_hist; i++) + { + png_save_uint_16(buf, hist[i]); + png_write_chunk_data(png_ptr, buf, (png_size_t)2); + } + + png_write_chunk_end(png_ptr); +} +#endif + +#if defined(PNG_WRITE_TEXT_SUPPORTED) || defined(PNG_WRITE_pCAL_SUPPORTED) || \ + defined(PNG_WRITE_iCCP_SUPPORTED) || defined(PNG_WRITE_sPLT_SUPPORTED) +/* Check that the tEXt or zTXt keyword is valid per PNG 1.0 specification, + * and if invalid, correct the keyword rather than discarding the entire + * chunk. The PNG 1.0 specification requires keywords 1-79 characters in + * length, forbids leading or trailing whitespace, multiple internal spaces, + * and the non-break space (0x80) from ISO 8859-1. Returns keyword length. + * + * The new_key is allocated to hold the corrected keyword and must be freed + * by the calling routine. This avoids problems with trying to write to + * static keywords without having to have duplicate copies of the strings. + */ +png_size_t /* PRIVATE */ +png_check_keyword(png_structp png_ptr, png_const_charp key, png_charpp new_key) +{ + png_size_t key_len; + png_const_charp ikp; + png_charp kp, dp; + int kflag; + int kwarn=0; + + png_debug(1, "in png_check_keyword"); + + *new_key = NULL; + + if (key == NULL || (key_len = png_strlen(key)) == 0) + { + png_warning(png_ptr, "zero length keyword"); + return ((png_size_t)0); + } + + png_debug1(2, "Keyword to be checked is '%s'", key); + + *new_key = (png_charp)png_malloc_warn(png_ptr, (png_uint_32)(key_len + 2)); + + if (*new_key == NULL) + { + png_warning(png_ptr, "Out of memory while procesing keyword"); + return ((png_size_t)0); + } + + /* Replace non-printing characters with a blank and print a warning */ + for (ikp = key, dp = *new_key; *ikp != '\0'; ikp++, dp++) + { + if ((png_byte)*ikp < 0x20 || + ((png_byte)*ikp > 0x7E && (png_byte)*ikp < 0xA1)) + { +#ifdef PNG_CONSOLE_IO_SUPPORTED + char msg[40]; + + png_snprintf(msg, 40, + "invalid keyword character 0x%02X", (png_byte)*ikp); + png_warning(png_ptr, msg); +#else + png_warning(png_ptr, "invalid character in keyword"); +#endif + *dp = ' '; + } + + else + { + *dp = *ikp; + } + } + *dp = '\0'; + + /* Remove any trailing white space. */ + kp = *new_key + key_len - 1; + if (*kp == ' ') + { + png_warning(png_ptr, "trailing spaces removed from keyword"); + + while (*kp == ' ') + { + *(kp--) = '\0'; + key_len--; + } + } + + /* Remove any leading white space. */ + kp = *new_key; + if (*kp == ' ') + { + png_warning(png_ptr, "leading spaces removed from keyword"); + + while (*kp == ' ') + { + kp++; + key_len--; + } + } + + png_debug1(2, "Checking for multiple internal spaces in '%s'", kp); + + /* Remove multiple internal spaces. */ + for (kflag = 0, dp = *new_key; *kp != '\0'; kp++) + { + if (*kp == ' ' && kflag == 0) + { + *(dp++) = *kp; + kflag = 1; + } + + else if (*kp == ' ') + { + key_len--; + kwarn = 1; + } + + else + { + *(dp++) = *kp; + kflag = 0; + } + } + *dp = '\0'; + if (kwarn) + png_warning(png_ptr, "extra interior spaces removed from keyword"); + + if (key_len == 0) + { + png_free(png_ptr, *new_key); + png_warning(png_ptr, "Zero length keyword"); + } + + if (key_len > 79) + { + png_warning(png_ptr, "keyword length must be 1 - 79 characters"); + (*new_key)[79] = '\0'; + key_len = 79; + } + + return (key_len); +} +#endif + +#ifdef PNG_WRITE_tEXt_SUPPORTED +/* Write a tEXt chunk */ +void /* PRIVATE */ +png_write_tEXt(png_structp png_ptr, png_const_charp key, png_const_charp text, + png_size_t text_len) +{ + PNG_tEXt; + png_size_t key_len; + png_charp new_key; + + png_debug(1, "in png_write_tEXt"); + + if ((key_len = png_check_keyword(png_ptr, key, &new_key))==0) + return; + + if (text == NULL || *text == '\0') + text_len = 0; + + else + text_len = png_strlen(text); + + /* Make sure we include the 0 after the key */ + png_write_chunk_start(png_ptr, png_tEXt, + (png_uint_32)(key_len + text_len + 1)); + /* + * We leave it to the application to meet PNG-1.0 requirements on the + * contents of the text. PNG-1.0 through PNG-1.2 discourage the use of + * any non-Latin-1 characters except for NEWLINE. ISO PNG will forbid them. + * The NUL character is forbidden by PNG-1.0 through PNG-1.2 and ISO PNG. + */ + png_write_chunk_data(png_ptr, (png_bytep)new_key, + (png_size_t)(key_len + 1)); + + if (text_len) + png_write_chunk_data(png_ptr, (png_const_bytep)text, + (png_size_t)text_len); + + png_write_chunk_end(png_ptr); + png_free(png_ptr, new_key); +} +#endif + +#ifdef PNG_WRITE_zTXt_SUPPORTED +/* Write a compressed text chunk */ +void /* PRIVATE */ +png_write_zTXt(png_structp png_ptr, png_const_charp key, png_const_charp text, + png_size_t text_len, int compression) +{ + PNG_zTXt; + png_size_t key_len; + png_byte buf; + png_charp new_key; + compression_state comp; + + png_debug(1, "in png_write_zTXt"); + + comp.num_output_ptr = 0; + comp.max_output_ptr = 0; + comp.output_ptr = NULL; + comp.input = NULL; + comp.input_len = 0; + + if ((key_len = png_check_keyword(png_ptr, key, &new_key)) == 0) + { + png_free(png_ptr, new_key); + return; + } + + if (text == NULL || *text == '\0' || compression==PNG_TEXT_COMPRESSION_NONE) + { + png_write_tEXt(png_ptr, new_key, text, (png_size_t)0); + png_free(png_ptr, new_key); + return; + } + + text_len = png_strlen(text); + + /* Compute the compressed data; do it now for the length */ + text_len = png_text_compress(png_ptr, text, text_len, compression, + &comp); + + /* Write start of chunk */ + png_write_chunk_start(png_ptr, png_zTXt, + (png_uint_32)(key_len+text_len + 2)); + + /* Write key */ + png_write_chunk_data(png_ptr, (png_bytep)new_key, + (png_size_t)(key_len + 1)); + + png_free(png_ptr, new_key); + + buf = (png_byte)compression; + + /* Write compression */ + png_write_chunk_data(png_ptr, &buf, (png_size_t)1); + + /* Write the compressed data */ + png_write_compressed_data_out(png_ptr, &comp); + + /* Close the chunk */ + png_write_chunk_end(png_ptr); +} +#endif + +#ifdef PNG_WRITE_iTXt_SUPPORTED +/* Write an iTXt chunk */ +void /* PRIVATE */ +png_write_iTXt(png_structp png_ptr, int compression, png_const_charp key, + png_const_charp lang, png_const_charp lang_key, png_const_charp text) +{ + PNG_iTXt; + png_size_t lang_len, key_len, lang_key_len, text_len; + png_charp new_lang; + png_charp new_key = NULL; + png_byte cbuf[2]; + compression_state comp; + + png_debug(1, "in png_write_iTXt"); + + comp.num_output_ptr = 0; + comp.max_output_ptr = 0; + comp.output_ptr = NULL; + comp.input = NULL; + + if ((key_len = png_check_keyword(png_ptr, key, &new_key)) == 0) + return; + + if ((lang_len = png_check_keyword(png_ptr, lang, &new_lang)) == 0) + { + png_warning(png_ptr, "Empty language field in iTXt chunk"); + new_lang = NULL; + lang_len = 0; + } + + if (lang_key == NULL) + lang_key_len = 0; + + else + lang_key_len = png_strlen(lang_key); + + if (text == NULL) + text_len = 0; + + else + text_len = png_strlen(text); + + /* Compute the compressed data; do it now for the length */ + text_len = png_text_compress(png_ptr, text, text_len, compression - 2, + &comp); + + + /* Make sure we include the compression flag, the compression byte, + * and the NULs after the key, lang, and lang_key parts + */ + + png_write_chunk_start(png_ptr, png_iTXt, (png_uint_32)( + 5 /* comp byte, comp flag, terminators for key, lang and lang_key */ + + key_len + + lang_len + + lang_key_len + + text_len)); + + /* We leave it to the application to meet PNG-1.0 requirements on the + * contents of the text. PNG-1.0 through PNG-1.2 discourage the use of + * any non-Latin-1 characters except for NEWLINE. ISO PNG will forbid them. + * The NUL character is forbidden by PNG-1.0 through PNG-1.2 and ISO PNG. + */ + png_write_chunk_data(png_ptr, (png_bytep)new_key, (png_size_t)(key_len + 1)); + + /* Set the compression flag */ + if (compression == PNG_ITXT_COMPRESSION_NONE || + compression == PNG_TEXT_COMPRESSION_NONE) + cbuf[0] = 0; + + else /* compression == PNG_ITXT_COMPRESSION_zTXt */ + cbuf[0] = 1; + + /* Set the compression method */ + cbuf[1] = 0; + + png_write_chunk_data(png_ptr, cbuf, (png_size_t)2); + + cbuf[0] = 0; + png_write_chunk_data(png_ptr, (new_lang ? (png_const_bytep)new_lang : cbuf), + (png_size_t)(lang_len + 1)); + + png_write_chunk_data(png_ptr, (lang_key ? (png_const_bytep)lang_key : cbuf), + (png_size_t)(lang_key_len + 1)); + + png_write_compressed_data_out(png_ptr, &comp); + + png_write_chunk_end(png_ptr); + + png_free(png_ptr, new_key); + png_free(png_ptr, new_lang); +} +#endif + +#ifdef PNG_WRITE_oFFs_SUPPORTED +/* Write the oFFs chunk */ +void /* PRIVATE */ +png_write_oFFs(png_structp png_ptr, png_int_32 x_offset, png_int_32 y_offset, + int unit_type) +{ + PNG_oFFs; + png_byte buf[9]; + + png_debug(1, "in png_write_oFFs"); + + if (unit_type >= PNG_OFFSET_LAST) + png_warning(png_ptr, "Unrecognized unit type for oFFs chunk"); + + png_save_int_32(buf, x_offset); + png_save_int_32(buf + 4, y_offset); + buf[8] = (png_byte)unit_type; + + png_write_chunk(png_ptr, png_oFFs, buf, (png_size_t)9); +} +#endif +#ifdef PNG_WRITE_pCAL_SUPPORTED +/* Write the pCAL chunk (described in the PNG extensions document) */ +void /* PRIVATE */ +png_write_pCAL(png_structp png_ptr, png_charp purpose, png_int_32 X0, + png_int_32 X1, int type, int nparams, png_const_charp units, + png_charpp params) +{ + PNG_pCAL; + png_size_t purpose_len, units_len, total_len; + png_uint_32p params_len; + png_byte buf[10]; + png_charp new_purpose; + int i; + + png_debug1(1, "in png_write_pCAL (%d parameters)", nparams); + + if (type >= PNG_EQUATION_LAST) + png_warning(png_ptr, "Unrecognized equation type for pCAL chunk"); + + purpose_len = png_check_keyword(png_ptr, purpose, &new_purpose) + 1; + png_debug1(3, "pCAL purpose length = %d", (int)purpose_len); + units_len = png_strlen(units) + (nparams == 0 ? 0 : 1); + png_debug1(3, "pCAL units length = %d", (int)units_len); + total_len = purpose_len + units_len + 10; + + params_len = (png_uint_32p)png_malloc(png_ptr, + (png_alloc_size_t)(nparams * png_sizeof(png_uint_32))); + + /* Find the length of each parameter, making sure we don't count the + * null terminator for the last parameter. + */ + for (i = 0; i < nparams; i++) + { + params_len[i] = png_strlen(params[i]) + (i == nparams - 1 ? 0 : 1); + png_debug2(3, "pCAL parameter %d length = %lu", i, + (unsigned long)params_len[i]); + total_len += (png_size_t)params_len[i]; + } + + png_debug1(3, "pCAL total length = %d", (int)total_len); + png_write_chunk_start(png_ptr, png_pCAL, (png_uint_32)total_len); + png_write_chunk_data(png_ptr, (png_const_bytep)new_purpose, + (png_size_t)purpose_len); + png_save_int_32(buf, X0); + png_save_int_32(buf + 4, X1); + buf[8] = (png_byte)type; + buf[9] = (png_byte)nparams; + png_write_chunk_data(png_ptr, buf, (png_size_t)10); + png_write_chunk_data(png_ptr, (png_const_bytep)units, (png_size_t)units_len); + + png_free(png_ptr, new_purpose); + + for (i = 0; i < nparams; i++) + { + png_write_chunk_data(png_ptr, (png_const_bytep)params[i], + (png_size_t)params_len[i]); + } + + png_free(png_ptr, params_len); + png_write_chunk_end(png_ptr); +} +#endif + +#ifdef PNG_WRITE_sCAL_SUPPORTED +/* Write the sCAL chunk */ +void /* PRIVATE */ +png_write_sCAL_s(png_structp png_ptr, int unit, png_const_charp width, + png_const_charp height) +{ + PNG_sCAL; + png_byte buf[64]; + png_size_t wlen, hlen, total_len; + + png_debug(1, "in png_write_sCAL_s"); + + wlen = png_strlen(width); + hlen = png_strlen(height); + total_len = wlen + hlen + 2; + + if (total_len > 64) + { + png_warning(png_ptr, "Can't write sCAL (buffer too small)"); + return; + } + + buf[0] = (png_byte)unit; + png_memcpy(buf + 1, width, wlen + 1); /* Append the '\0' here */ + png_memcpy(buf + wlen + 2, height, hlen); /* Do NOT append the '\0' here */ + + png_debug1(3, "sCAL total length = %u", (unsigned int)total_len); + png_write_chunk(png_ptr, png_sCAL, buf, total_len); +} +#endif + +#ifdef PNG_WRITE_pHYs_SUPPORTED +/* Write the pHYs chunk */ +void /* PRIVATE */ +png_write_pHYs(png_structp png_ptr, png_uint_32 x_pixels_per_unit, + png_uint_32 y_pixels_per_unit, + int unit_type) +{ + PNG_pHYs; + png_byte buf[9]; + + png_debug(1, "in png_write_pHYs"); + + if (unit_type >= PNG_RESOLUTION_LAST) + png_warning(png_ptr, "Unrecognized unit type for pHYs chunk"); + + png_save_uint_32(buf, x_pixels_per_unit); + png_save_uint_32(buf + 4, y_pixels_per_unit); + buf[8] = (png_byte)unit_type; + + png_write_chunk(png_ptr, png_pHYs, buf, (png_size_t)9); +} +#endif + +#ifdef PNG_WRITE_tIME_SUPPORTED +/* Write the tIME chunk. Use either png_convert_from_struct_tm() + * or png_convert_from_time_t(), or fill in the structure yourself. + */ +void /* PRIVATE */ +png_write_tIME(png_structp png_ptr, png_const_timep mod_time) +{ + PNG_tIME; + png_byte buf[7]; + + png_debug(1, "in png_write_tIME"); + + if (mod_time->month > 12 || mod_time->month < 1 || + mod_time->day > 31 || mod_time->day < 1 || + mod_time->hour > 23 || mod_time->second > 60) + { + png_warning(png_ptr, "Invalid time specified for tIME chunk"); + return; + } + + png_save_uint_16(buf, mod_time->year); + buf[2] = mod_time->month; + buf[3] = mod_time->day; + buf[4] = mod_time->hour; + buf[5] = mod_time->minute; + buf[6] = mod_time->second; + + png_write_chunk(png_ptr, png_tIME, buf, (png_size_t)7); +} +#endif + +/* Initializes the row writing capability of libpng */ +void /* PRIVATE */ +png_write_start_row(png_structp png_ptr) +{ +#ifdef PNG_WRITE_INTERLACING_SUPPORTED + /* Arrays to facilitate easy interlacing - use pass (0 - 6) as index */ + + /* Start of interlace block */ + int png_pass_start[7] = {0, 4, 0, 2, 0, 1, 0}; + + /* Offset to next interlace block */ + int png_pass_inc[7] = {8, 8, 4, 4, 2, 2, 1}; + + /* Start of interlace block in the y direction */ + int png_pass_ystart[7] = {0, 0, 4, 0, 2, 0, 1}; + + /* Offset to next interlace block in the y direction */ + int png_pass_yinc[7] = {8, 8, 8, 4, 4, 2, 2}; +#endif + + png_size_t buf_size; + + png_debug(1, "in png_write_start_row"); + + buf_size = (png_size_t)(PNG_ROWBYTES( + png_ptr->usr_channels*png_ptr->usr_bit_depth, png_ptr->width) + 1); + + /* Set up row buffer */ + png_ptr->row_buf = (png_bytep)png_malloc(png_ptr, + (png_alloc_size_t)buf_size); + + png_ptr->row_buf[0] = PNG_FILTER_VALUE_NONE; + +#ifdef PNG_WRITE_FILTER_SUPPORTED + /* Set up filtering buffer, if using this filter */ + if (png_ptr->do_filter & PNG_FILTER_SUB) + { + png_ptr->sub_row = (png_bytep)png_malloc(png_ptr, png_ptr->rowbytes + 1); + + png_ptr->sub_row[0] = PNG_FILTER_VALUE_SUB; + } + + /* We only need to keep the previous row if we are using one of these. */ + if (png_ptr->do_filter & (PNG_FILTER_AVG | PNG_FILTER_UP | PNG_FILTER_PAETH)) + { + /* Set up previous row buffer */ + png_ptr->prev_row = (png_bytep)png_calloc(png_ptr, + (png_alloc_size_t)buf_size); + + if (png_ptr->do_filter & PNG_FILTER_UP) + { + png_ptr->up_row = (png_bytep)png_malloc(png_ptr, + png_ptr->rowbytes + 1); + + png_ptr->up_row[0] = PNG_FILTER_VALUE_UP; + } + + if (png_ptr->do_filter & PNG_FILTER_AVG) + { + png_ptr->avg_row = (png_bytep)png_malloc(png_ptr, + png_ptr->rowbytes + 1); + + png_ptr->avg_row[0] = PNG_FILTER_VALUE_AVG; + } + + if (png_ptr->do_filter & PNG_FILTER_PAETH) + { + png_ptr->paeth_row = (png_bytep)png_malloc(png_ptr, + png_ptr->rowbytes + 1); + + png_ptr->paeth_row[0] = PNG_FILTER_VALUE_PAETH; + } + } +#endif /* PNG_WRITE_FILTER_SUPPORTED */ + +#ifdef PNG_WRITE_INTERLACING_SUPPORTED + /* If interlaced, we need to set up width and height of pass */ + if (png_ptr->interlaced) + { + if (!(png_ptr->transformations & PNG_INTERLACE)) + { + png_ptr->num_rows = (png_ptr->height + png_pass_yinc[0] - 1 - + png_pass_ystart[0]) / png_pass_yinc[0]; + + png_ptr->usr_width = (png_ptr->width + png_pass_inc[0] - 1 - + png_pass_start[0]) / png_pass_inc[0]; + } + + else + { + png_ptr->num_rows = png_ptr->height; + png_ptr->usr_width = png_ptr->width; + } + } + + else +#endif + { + png_ptr->num_rows = png_ptr->height; + png_ptr->usr_width = png_ptr->width; + } + + png_ptr->zstream.avail_out = (uInt)png_ptr->zbuf_size; + png_ptr->zstream.next_out = png_ptr->zbuf; +} + +/* Internal use only. Called when finished processing a row of data. */ +void /* PRIVATE */ +png_write_finish_row(png_structp png_ptr) +{ +#ifdef PNG_WRITE_INTERLACING_SUPPORTED + /* Arrays to facilitate easy interlacing - use pass (0 - 6) as index */ + + /* Start of interlace block */ + int png_pass_start[7] = {0, 4, 0, 2, 0, 1, 0}; + + /* Offset to next interlace block */ + int png_pass_inc[7] = {8, 8, 4, 4, 2, 2, 1}; + + /* Start of interlace block in the y direction */ + int png_pass_ystart[7] = {0, 0, 4, 0, 2, 0, 1}; + + /* Offset to next interlace block in the y direction */ + int png_pass_yinc[7] = {8, 8, 8, 4, 4, 2, 2}; +#endif + + int ret; + + png_debug(1, "in png_write_finish_row"); + + /* Next row */ + png_ptr->row_number++; + + /* See if we are done */ + if (png_ptr->row_number < png_ptr->num_rows) + return; + +#ifdef PNG_WRITE_INTERLACING_SUPPORTED + /* If interlaced, go to next pass */ + if (png_ptr->interlaced) + { + png_ptr->row_number = 0; + if (png_ptr->transformations & PNG_INTERLACE) + { + png_ptr->pass++; + } + + else + { + /* Loop until we find a non-zero width or height pass */ + do + { + png_ptr->pass++; + + if (png_ptr->pass >= 7) + break; + + png_ptr->usr_width = (png_ptr->width + + png_pass_inc[png_ptr->pass] - 1 - + png_pass_start[png_ptr->pass]) / + png_pass_inc[png_ptr->pass]; + + png_ptr->num_rows = (png_ptr->height + + png_pass_yinc[png_ptr->pass] - 1 - + png_pass_ystart[png_ptr->pass]) / + png_pass_yinc[png_ptr->pass]; + + if (png_ptr->transformations & PNG_INTERLACE) + break; + + } while (png_ptr->usr_width == 0 || png_ptr->num_rows == 0); + + } + + /* Reset the row above the image for the next pass */ + if (png_ptr->pass < 7) + { + if (png_ptr->prev_row != NULL) + png_memset(png_ptr->prev_row, 0, + (png_size_t)(PNG_ROWBYTES(png_ptr->usr_channels* + png_ptr->usr_bit_depth, png_ptr->width)) + 1); + + return; + } + } +#endif + + /* If we get here, we've just written the last row, so we need + to flush the compressor */ + do + { + /* Tell the compressor we are done */ + ret = deflate(&png_ptr->zstream, Z_FINISH); + + /* Check for an error */ + if (ret == Z_OK) + { + /* Check to see if we need more room */ + if (!(png_ptr->zstream.avail_out)) + { + png_write_IDAT(png_ptr, png_ptr->zbuf, png_ptr->zbuf_size); + png_ptr->zstream.next_out = png_ptr->zbuf; + png_ptr->zstream.avail_out = (uInt)png_ptr->zbuf_size; + } + } + + else if (ret != Z_STREAM_END) + { + if (png_ptr->zstream.msg != NULL) + png_error(png_ptr, png_ptr->zstream.msg); + + else + png_error(png_ptr, "zlib error"); + } + } while (ret != Z_STREAM_END); + + /* Write any extra space */ + if (png_ptr->zstream.avail_out < png_ptr->zbuf_size) + { + png_write_IDAT(png_ptr, png_ptr->zbuf, png_ptr->zbuf_size - + png_ptr->zstream.avail_out); + } + + deflateReset(&png_ptr->zstream); + png_ptr->zstream.data_type = Z_BINARY; +} + +#ifdef PNG_WRITE_INTERLACING_SUPPORTED +/* Pick out the correct pixels for the interlace pass. + * The basic idea here is to go through the row with a source + * pointer and a destination pointer (sp and dp), and copy the + * correct pixels for the pass. As the row gets compacted, + * sp will always be >= dp, so we should never overwrite anything. + * See the default: case for the easiest code to understand. + */ +void /* PRIVATE */ +png_do_write_interlace(png_row_infop row_info, png_bytep row, int pass) +{ + /* Arrays to facilitate easy interlacing - use pass (0 - 6) as index */ + + /* Start of interlace block */ + int png_pass_start[7] = {0, 4, 0, 2, 0, 1, 0}; + + /* Offset to next interlace block */ + int png_pass_inc[7] = {8, 8, 4, 4, 2, 2, 1}; + + png_debug(1, "in png_do_write_interlace"); + + /* We don't have to do anything on the last pass (6) */ + if (pass < 6) + { + /* Each pixel depth is handled separately */ + switch (row_info->pixel_depth) + { + case 1: + { + png_bytep sp; + png_bytep dp; + int shift; + int d; + int value; + png_uint_32 i; + png_uint_32 row_width = row_info->width; + + dp = row; + d = 0; + shift = 7; + + for (i = png_pass_start[pass]; i < row_width; + i += png_pass_inc[pass]) + { + sp = row + (png_size_t)(i >> 3); + value = (int)(*sp >> (7 - (int)(i & 0x07))) & 0x01; + d |= (value << shift); + + if (shift == 0) + { + shift = 7; + *dp++ = (png_byte)d; + d = 0; + } + + else + shift--; + + } + if (shift != 7) + *dp = (png_byte)d; + + break; + } + + case 2: + { + png_bytep sp; + png_bytep dp; + int shift; + int d; + int value; + png_uint_32 i; + png_uint_32 row_width = row_info->width; + + dp = row; + shift = 6; + d = 0; + + for (i = png_pass_start[pass]; i < row_width; + i += png_pass_inc[pass]) + { + sp = row + (png_size_t)(i >> 2); + value = (*sp >> ((3 - (int)(i & 0x03)) << 1)) & 0x03; + d |= (value << shift); + + if (shift == 0) + { + shift = 6; + *dp++ = (png_byte)d; + d = 0; + } + + else + shift -= 2; + } + if (shift != 6) + *dp = (png_byte)d; + + break; + } + + case 4: + { + png_bytep sp; + png_bytep dp; + int shift; + int d; + int value; + png_uint_32 i; + png_uint_32 row_width = row_info->width; + + dp = row; + shift = 4; + d = 0; + for (i = png_pass_start[pass]; i < row_width; + i += png_pass_inc[pass]) + { + sp = row + (png_size_t)(i >> 1); + value = (*sp >> ((1 - (int)(i & 0x01)) << 2)) & 0x0f; + d |= (value << shift); + + if (shift == 0) + { + shift = 4; + *dp++ = (png_byte)d; + d = 0; + } + + else + shift -= 4; + } + if (shift != 4) + *dp = (png_byte)d; + + break; + } + + default: + { + png_bytep sp; + png_bytep dp; + png_uint_32 i; + png_uint_32 row_width = row_info->width; + png_size_t pixel_bytes; + + /* Start at the beginning */ + dp = row; + + /* Find out how many bytes each pixel takes up */ + pixel_bytes = (row_info->pixel_depth >> 3); + + /* Loop through the row, only looking at the pixels that matter */ + for (i = png_pass_start[pass]; i < row_width; + i += png_pass_inc[pass]) + { + /* Find out where the original pixel is */ + sp = row + (png_size_t)i * pixel_bytes; + + /* Move the pixel */ + if (dp != sp) + png_memcpy(dp, sp, pixel_bytes); + + /* Next pixel */ + dp += pixel_bytes; + } + break; + } + } + /* Set new row width */ + row_info->width = (row_info->width + + png_pass_inc[pass] - 1 - + png_pass_start[pass]) / + png_pass_inc[pass]; + + row_info->rowbytes = PNG_ROWBYTES(row_info->pixel_depth, + row_info->width); + } +} +#endif + +/* This filters the row, chooses which filter to use, if it has not already + * been specified by the application, and then writes the row out with the + * chosen filter. + */ +#define PNG_MAXSUM (((png_uint_32)(-1)) >> 1) +#define PNG_HISHIFT 10 +#define PNG_LOMASK ((png_uint_32)0xffffL) +#define PNG_HIMASK ((png_uint_32)(~PNG_LOMASK >> PNG_HISHIFT)) +void /* PRIVATE */ +png_write_find_filter(png_structp png_ptr, png_row_infop row_info) +{ + png_bytep best_row; +#ifdef PNG_WRITE_FILTER_SUPPORTED + png_bytep prev_row, row_buf; + png_uint_32 mins, bpp; + png_byte filter_to_do = png_ptr->do_filter; + png_size_t row_bytes = row_info->rowbytes; +#ifdef PNG_WRITE_WEIGHTED_FILTER_SUPPORTED + int num_p_filters = (int)png_ptr->num_prev_filters; +#endif + + png_debug(1, "in png_write_find_filter"); + +#ifndef PNG_WRITE_WEIGHTED_FILTER_SUPPORTED + if (png_ptr->row_number == 0 && filter_to_do == PNG_ALL_FILTERS) + { + /* These will never be selected so we need not test them. */ + filter_to_do &= ~(PNG_FILTER_UP | PNG_FILTER_PAETH); + } +#endif + + /* Find out how many bytes offset each pixel is */ + bpp = (row_info->pixel_depth + 7) >> 3; + + prev_row = png_ptr->prev_row; +#endif + best_row = png_ptr->row_buf; +#ifdef PNG_WRITE_FILTER_SUPPORTED + row_buf = best_row; + mins = PNG_MAXSUM; + + /* The prediction method we use is to find which method provides the + * smallest value when summing the absolute values of the distances + * from zero, using anything >= 128 as negative numbers. This is known + * as the "minimum sum of absolute differences" heuristic. Other + * heuristics are the "weighted minimum sum of absolute differences" + * (experimental and can in theory improve compression), and the "zlib + * predictive" method (not implemented yet), which does test compressions + * of lines using different filter methods, and then chooses the + * (series of) filter(s) that give minimum compressed data size (VERY + * computationally expensive). + * + * GRR 980525: consider also + * + * (1) minimum sum of absolute differences from running average (i.e., + * keep running sum of non-absolute differences & count of bytes) + * [track dispersion, too? restart average if dispersion too large?] + * + * (1b) minimum sum of absolute differences from sliding average, probably + * with window size <= deflate window (usually 32K) + * + * (2) minimum sum of squared differences from zero or running average + * (i.e., ~ root-mean-square approach) + */ + + + /* We don't need to test the 'no filter' case if this is the only filter + * that has been chosen, as it doesn't actually do anything to the data. + */ + if ((filter_to_do & PNG_FILTER_NONE) && filter_to_do != PNG_FILTER_NONE) + { + png_bytep rp; + png_uint_32 sum = 0; + png_size_t i; + int v; + + for (i = 0, rp = row_buf + 1; i < row_bytes; i++, rp++) + { + v = *rp; + sum += (v < 128) ? v : 256 - v; + } + +#ifdef PNG_WRITE_WEIGHTED_FILTER_SUPPORTED + if (png_ptr->heuristic_method == PNG_FILTER_HEURISTIC_WEIGHTED) + { + png_uint_32 sumhi, sumlo; + int j; + sumlo = sum & PNG_LOMASK; + sumhi = (sum >> PNG_HISHIFT) & PNG_HIMASK; /* Gives us some footroom */ + + /* Reduce the sum if we match any of the previous rows */ + for (j = 0; j < num_p_filters; j++) + { + if (png_ptr->prev_filters[j] == PNG_FILTER_VALUE_NONE) + { + sumlo = (sumlo * png_ptr->filter_weights[j]) >> + PNG_WEIGHT_SHIFT; + + sumhi = (sumhi * png_ptr->filter_weights[j]) >> + PNG_WEIGHT_SHIFT; + } + } + + /* Factor in the cost of this filter (this is here for completeness, + * but it makes no sense to have a "cost" for the NONE filter, as + * it has the minimum possible computational cost - none). + */ + sumlo = (sumlo * png_ptr->filter_costs[PNG_FILTER_VALUE_NONE]) >> + PNG_COST_SHIFT; + + sumhi = (sumhi * png_ptr->filter_costs[PNG_FILTER_VALUE_NONE]) >> + PNG_COST_SHIFT; + + if (sumhi > PNG_HIMASK) + sum = PNG_MAXSUM; + + else + sum = (sumhi << PNG_HISHIFT) + sumlo; + } +#endif + mins = sum; + } + + /* Sub filter */ + if (filter_to_do == PNG_FILTER_SUB) + /* It's the only filter so no testing is needed */ + { + png_bytep rp, lp, dp; + png_size_t i; + + for (i = 0, rp = row_buf + 1, dp = png_ptr->sub_row + 1; i < bpp; + i++, rp++, dp++) + { + *dp = *rp; + } + + for (lp = row_buf + 1; i < row_bytes; + i++, rp++, lp++, dp++) + { + *dp = (png_byte)(((int)*rp - (int)*lp) & 0xff); + } + + best_row = png_ptr->sub_row; + } + + else if (filter_to_do & PNG_FILTER_SUB) + { + png_bytep rp, dp, lp; + png_uint_32 sum = 0, lmins = mins; + png_size_t i; + int v; + +#ifdef PNG_WRITE_WEIGHTED_FILTER_SUPPORTED + /* We temporarily increase the "minimum sum" by the factor we + * would reduce the sum of this filter, so that we can do the + * early exit comparison without scaling the sum each time. + */ + if (png_ptr->heuristic_method == PNG_FILTER_HEURISTIC_WEIGHTED) + { + int j; + png_uint_32 lmhi, lmlo; + lmlo = lmins & PNG_LOMASK; + lmhi = (lmins >> PNG_HISHIFT) & PNG_HIMASK; + + for (j = 0; j < num_p_filters; j++) + { + if (png_ptr->prev_filters[j] == PNG_FILTER_VALUE_SUB) + { + lmlo = (lmlo * png_ptr->inv_filter_weights[j]) >> + PNG_WEIGHT_SHIFT; + + lmhi = (lmhi * png_ptr->inv_filter_weights[j]) >> + PNG_WEIGHT_SHIFT; + } + } + + lmlo = (lmlo * png_ptr->inv_filter_costs[PNG_FILTER_VALUE_SUB]) >> + PNG_COST_SHIFT; + + lmhi = (lmhi * png_ptr->inv_filter_costs[PNG_FILTER_VALUE_SUB]) >> + PNG_COST_SHIFT; + + if (lmhi > PNG_HIMASK) + lmins = PNG_MAXSUM; + + else + lmins = (lmhi << PNG_HISHIFT) + lmlo; + } +#endif + + for (i = 0, rp = row_buf + 1, dp = png_ptr->sub_row + 1; i < bpp; + i++, rp++, dp++) + { + v = *dp = *rp; + + sum += (v < 128) ? v : 256 - v; + } + + for (lp = row_buf + 1; i < row_bytes; + i++, rp++, lp++, dp++) + { + v = *dp = (png_byte)(((int)*rp - (int)*lp) & 0xff); + + sum += (v < 128) ? v : 256 - v; + + if (sum > lmins) /* We are already worse, don't continue. */ + break; + } + +#ifdef PNG_WRITE_WEIGHTED_FILTER_SUPPORTED + if (png_ptr->heuristic_method == PNG_FILTER_HEURISTIC_WEIGHTED) + { + int j; + png_uint_32 sumhi, sumlo; + sumlo = sum & PNG_LOMASK; + sumhi = (sum >> PNG_HISHIFT) & PNG_HIMASK; + + for (j = 0; j < num_p_filters; j++) + { + if (png_ptr->prev_filters[j] == PNG_FILTER_VALUE_SUB) + { + sumlo = (sumlo * png_ptr->inv_filter_weights[j]) >> + PNG_WEIGHT_SHIFT; + + sumhi = (sumhi * png_ptr->inv_filter_weights[j]) >> + PNG_WEIGHT_SHIFT; + } + } + + sumlo = (sumlo * png_ptr->inv_filter_costs[PNG_FILTER_VALUE_SUB]) >> + PNG_COST_SHIFT; + + sumhi = (sumhi * png_ptr->inv_filter_costs[PNG_FILTER_VALUE_SUB]) >> + PNG_COST_SHIFT; + + if (sumhi > PNG_HIMASK) + sum = PNG_MAXSUM; + + else + sum = (sumhi << PNG_HISHIFT) + sumlo; + } +#endif + + if (sum < mins) + { + mins = sum; + best_row = png_ptr->sub_row; + } + } + + /* Up filter */ + if (filter_to_do == PNG_FILTER_UP) + { + png_bytep rp, dp, pp; + png_size_t i; + + for (i = 0, rp = row_buf + 1, dp = png_ptr->up_row + 1, + pp = prev_row + 1; i < row_bytes; + i++, rp++, pp++, dp++) + { + *dp = (png_byte)(((int)*rp - (int)*pp) & 0xff); + } + + best_row = png_ptr->up_row; + } + + else if (filter_to_do & PNG_FILTER_UP) + { + png_bytep rp, dp, pp; + png_uint_32 sum = 0, lmins = mins; + png_size_t i; + int v; + + +#ifdef PNG_WRITE_WEIGHTED_FILTER_SUPPORTED + if (png_ptr->heuristic_method == PNG_FILTER_HEURISTIC_WEIGHTED) + { + int j; + png_uint_32 lmhi, lmlo; + lmlo = lmins & PNG_LOMASK; + lmhi = (lmins >> PNG_HISHIFT) & PNG_HIMASK; + + for (j = 0; j < num_p_filters; j++) + { + if (png_ptr->prev_filters[j] == PNG_FILTER_VALUE_UP) + { + lmlo = (lmlo * png_ptr->inv_filter_weights[j]) >> + PNG_WEIGHT_SHIFT; + + lmhi = (lmhi * png_ptr->inv_filter_weights[j]) >> + PNG_WEIGHT_SHIFT; + } + } + + lmlo = (lmlo * png_ptr->inv_filter_costs[PNG_FILTER_VALUE_UP]) >> + PNG_COST_SHIFT; + + lmhi = (lmhi * png_ptr->inv_filter_costs[PNG_FILTER_VALUE_UP]) >> + PNG_COST_SHIFT; + + if (lmhi > PNG_HIMASK) + lmins = PNG_MAXSUM; + + else + lmins = (lmhi << PNG_HISHIFT) + lmlo; + } +#endif + + for (i = 0, rp = row_buf + 1, dp = png_ptr->up_row + 1, + pp = prev_row + 1; i < row_bytes; i++) + { + v = *dp++ = (png_byte)(((int)*rp++ - (int)*pp++) & 0xff); + + sum += (v < 128) ? v : 256 - v; + + if (sum > lmins) /* We are already worse, don't continue. */ + break; + } + +#ifdef PNG_WRITE_WEIGHTED_FILTER_SUPPORTED + if (png_ptr->heuristic_method == PNG_FILTER_HEURISTIC_WEIGHTED) + { + int j; + png_uint_32 sumhi, sumlo; + sumlo = sum & PNG_LOMASK; + sumhi = (sum >> PNG_HISHIFT) & PNG_HIMASK; + + for (j = 0; j < num_p_filters; j++) + { + if (png_ptr->prev_filters[j] == PNG_FILTER_VALUE_UP) + { + sumlo = (sumlo * png_ptr->filter_weights[j]) >> + PNG_WEIGHT_SHIFT; + + sumhi = (sumhi * png_ptr->filter_weights[j]) >> + PNG_WEIGHT_SHIFT; + } + } + + sumlo = (sumlo * png_ptr->filter_costs[PNG_FILTER_VALUE_UP]) >> + PNG_COST_SHIFT; + + sumhi = (sumhi * png_ptr->filter_costs[PNG_FILTER_VALUE_UP]) >> + PNG_COST_SHIFT; + + if (sumhi > PNG_HIMASK) + sum = PNG_MAXSUM; + + else + sum = (sumhi << PNG_HISHIFT) + sumlo; + } +#endif + + if (sum < mins) + { + mins = sum; + best_row = png_ptr->up_row; + } + } + + /* Avg filter */ + if (filter_to_do == PNG_FILTER_AVG) + { + png_bytep rp, dp, pp, lp; + png_uint_32 i; + + for (i = 0, rp = row_buf + 1, dp = png_ptr->avg_row + 1, + pp = prev_row + 1; i < bpp; i++) + { + *dp++ = (png_byte)(((int)*rp++ - ((int)*pp++ / 2)) & 0xff); + } + + for (lp = row_buf + 1; i < row_bytes; i++) + { + *dp++ = (png_byte)(((int)*rp++ - (((int)*pp++ + (int)*lp++) / 2)) + & 0xff); + } + best_row = png_ptr->avg_row; + } + + else if (filter_to_do & PNG_FILTER_AVG) + { + png_bytep rp, dp, pp, lp; + png_uint_32 sum = 0, lmins = mins; + png_size_t i; + int v; + +#ifdef PNG_WRITE_WEIGHTED_FILTER_SUPPORTED + if (png_ptr->heuristic_method == PNG_FILTER_HEURISTIC_WEIGHTED) + { + int j; + png_uint_32 lmhi, lmlo; + lmlo = lmins & PNG_LOMASK; + lmhi = (lmins >> PNG_HISHIFT) & PNG_HIMASK; + + for (j = 0; j < num_p_filters; j++) + { + if (png_ptr->prev_filters[j] == PNG_FILTER_VALUE_AVG) + { + lmlo = (lmlo * png_ptr->inv_filter_weights[j]) >> + PNG_WEIGHT_SHIFT; + + lmhi = (lmhi * png_ptr->inv_filter_weights[j]) >> + PNG_WEIGHT_SHIFT; + } + } + + lmlo = (lmlo * png_ptr->inv_filter_costs[PNG_FILTER_VALUE_AVG]) >> + PNG_COST_SHIFT; + + lmhi = (lmhi * png_ptr->inv_filter_costs[PNG_FILTER_VALUE_AVG]) >> + PNG_COST_SHIFT; + + if (lmhi > PNG_HIMASK) + lmins = PNG_MAXSUM; + + else + lmins = (lmhi << PNG_HISHIFT) + lmlo; + } +#endif + + for (i = 0, rp = row_buf + 1, dp = png_ptr->avg_row + 1, + pp = prev_row + 1; i < bpp; i++) + { + v = *dp++ = (png_byte)(((int)*rp++ - ((int)*pp++ / 2)) & 0xff); + + sum += (v < 128) ? v : 256 - v; + } + + for (lp = row_buf + 1; i < row_bytes; i++) + { + v = *dp++ = + (png_byte)(((int)*rp++ - (((int)*pp++ + (int)*lp++) / 2)) & 0xff); + + sum += (v < 128) ? v : 256 - v; + + if (sum > lmins) /* We are already worse, don't continue. */ + break; + } + +#ifdef PNG_WRITE_WEIGHTED_FILTER_SUPPORTED + if (png_ptr->heuristic_method == PNG_FILTER_HEURISTIC_WEIGHTED) + { + int j; + png_uint_32 sumhi, sumlo; + sumlo = sum & PNG_LOMASK; + sumhi = (sum >> PNG_HISHIFT) & PNG_HIMASK; + + for (j = 0; j < num_p_filters; j++) + { + if (png_ptr->prev_filters[j] == PNG_FILTER_VALUE_NONE) + { + sumlo = (sumlo * png_ptr->filter_weights[j]) >> + PNG_WEIGHT_SHIFT; + + sumhi = (sumhi * png_ptr->filter_weights[j]) >> + PNG_WEIGHT_SHIFT; + } + } + + sumlo = (sumlo * png_ptr->filter_costs[PNG_FILTER_VALUE_AVG]) >> + PNG_COST_SHIFT; + + sumhi = (sumhi * png_ptr->filter_costs[PNG_FILTER_VALUE_AVG]) >> + PNG_COST_SHIFT; + + if (sumhi > PNG_HIMASK) + sum = PNG_MAXSUM; + + else + sum = (sumhi << PNG_HISHIFT) + sumlo; + } +#endif + + if (sum < mins) + { + mins = sum; + best_row = png_ptr->avg_row; + } + } + + /* Paeth filter */ + if (filter_to_do == PNG_FILTER_PAETH) + { + png_bytep rp, dp, pp, cp, lp; + png_size_t i; + + for (i = 0, rp = row_buf + 1, dp = png_ptr->paeth_row + 1, + pp = prev_row + 1; i < bpp; i++) + { + *dp++ = (png_byte)(((int)*rp++ - (int)*pp++) & 0xff); + } + + for (lp = row_buf + 1, cp = prev_row + 1; i < row_bytes; i++) + { + int a, b, c, pa, pb, pc, p; + + b = *pp++; + c = *cp++; + a = *lp++; + + p = b - c; + pc = a - c; + +#ifdef PNG_USE_ABS + pa = abs(p); + pb = abs(pc); + pc = abs(p + pc); +#else + pa = p < 0 ? -p : p; + pb = pc < 0 ? -pc : pc; + pc = (p + pc) < 0 ? -(p + pc) : p + pc; +#endif + + p = (pa <= pb && pa <=pc) ? a : (pb <= pc) ? b : c; + + *dp++ = (png_byte)(((int)*rp++ - p) & 0xff); + } + best_row = png_ptr->paeth_row; + } + + else if (filter_to_do & PNG_FILTER_PAETH) + { + png_bytep rp, dp, pp, cp, lp; + png_uint_32 sum = 0, lmins = mins; + png_size_t i; + int v; + +#ifdef PNG_WRITE_WEIGHTED_FILTER_SUPPORTED + if (png_ptr->heuristic_method == PNG_FILTER_HEURISTIC_WEIGHTED) + { + int j; + png_uint_32 lmhi, lmlo; + lmlo = lmins & PNG_LOMASK; + lmhi = (lmins >> PNG_HISHIFT) & PNG_HIMASK; + + for (j = 0; j < num_p_filters; j++) + { + if (png_ptr->prev_filters[j] == PNG_FILTER_VALUE_PAETH) + { + lmlo = (lmlo * png_ptr->inv_filter_weights[j]) >> + PNG_WEIGHT_SHIFT; + + lmhi = (lmhi * png_ptr->inv_filter_weights[j]) >> + PNG_WEIGHT_SHIFT; + } + } + + lmlo = (lmlo * png_ptr->inv_filter_costs[PNG_FILTER_VALUE_PAETH]) >> + PNG_COST_SHIFT; + + lmhi = (lmhi * png_ptr->inv_filter_costs[PNG_FILTER_VALUE_PAETH]) >> + PNG_COST_SHIFT; + + if (lmhi > PNG_HIMASK) + lmins = PNG_MAXSUM; + + else + lmins = (lmhi << PNG_HISHIFT) + lmlo; + } +#endif + + for (i = 0, rp = row_buf + 1, dp = png_ptr->paeth_row + 1, + pp = prev_row + 1; i < bpp; i++) + { + v = *dp++ = (png_byte)(((int)*rp++ - (int)*pp++) & 0xff); + + sum += (v < 128) ? v : 256 - v; + } + + for (lp = row_buf + 1, cp = prev_row + 1; i < row_bytes; i++) + { + int a, b, c, pa, pb, pc, p; + + b = *pp++; + c = *cp++; + a = *lp++; + +#ifndef PNG_SLOW_PAETH + p = b - c; + pc = a - c; +#ifdef PNG_USE_ABS + pa = abs(p); + pb = abs(pc); + pc = abs(p + pc); +#else + pa = p < 0 ? -p : p; + pb = pc < 0 ? -pc : pc; + pc = (p + pc) < 0 ? -(p + pc) : p + pc; +#endif + p = (pa <= pb && pa <=pc) ? a : (pb <= pc) ? b : c; +#else /* PNG_SLOW_PAETH */ + p = a + b - c; + pa = abs(p - a); + pb = abs(p - b); + pc = abs(p - c); + + if (pa <= pb && pa <= pc) + p = a; + + else if (pb <= pc) + p = b; + + else + p = c; +#endif /* PNG_SLOW_PAETH */ + + v = *dp++ = (png_byte)(((int)*rp++ - p) & 0xff); + + sum += (v < 128) ? v : 256 - v; + + if (sum > lmins) /* We are already worse, don't continue. */ + break; + } + +#ifdef PNG_WRITE_WEIGHTED_FILTER_SUPPORTED + if (png_ptr->heuristic_method == PNG_FILTER_HEURISTIC_WEIGHTED) + { + int j; + png_uint_32 sumhi, sumlo; + sumlo = sum & PNG_LOMASK; + sumhi = (sum >> PNG_HISHIFT) & PNG_HIMASK; + + for (j = 0; j < num_p_filters; j++) + { + if (png_ptr->prev_filters[j] == PNG_FILTER_VALUE_PAETH) + { + sumlo = (sumlo * png_ptr->filter_weights[j]) >> + PNG_WEIGHT_SHIFT; + + sumhi = (sumhi * png_ptr->filter_weights[j]) >> + PNG_WEIGHT_SHIFT; + } + } + + sumlo = (sumlo * png_ptr->filter_costs[PNG_FILTER_VALUE_PAETH]) >> + PNG_COST_SHIFT; + + sumhi = (sumhi * png_ptr->filter_costs[PNG_FILTER_VALUE_PAETH]) >> + PNG_COST_SHIFT; + + if (sumhi > PNG_HIMASK) + sum = PNG_MAXSUM; + + else + sum = (sumhi << PNG_HISHIFT) + sumlo; + } +#endif + + if (sum < mins) + { + best_row = png_ptr->paeth_row; + } + } +#endif /* PNG_WRITE_FILTER_SUPPORTED */ + /* Do the actual writing of the filtered row data from the chosen filter. */ + + png_write_filtered_row(png_ptr, best_row); + +#ifdef PNG_WRITE_FILTER_SUPPORTED +#ifdef PNG_WRITE_WEIGHTED_FILTER_SUPPORTED + /* Save the type of filter we picked this time for future calculations */ + if (png_ptr->num_prev_filters > 0) + { + int j; + + for (j = 1; j < num_p_filters; j++) + { + png_ptr->prev_filters[j] = png_ptr->prev_filters[j - 1]; + } + + png_ptr->prev_filters[j] = best_row[0]; + } +#endif +#endif /* PNG_WRITE_FILTER_SUPPORTED */ +} + + +/* Do the actual writing of a previously filtered row. */ +void /* PRIVATE */ +png_write_filtered_row(png_structp png_ptr, png_bytep filtered_row) +{ + png_size_t avail; + + png_debug(1, "in png_write_filtered_row"); + + png_debug1(2, "filter = %d", filtered_row[0]); + /* Set up the zlib input buffer */ + + png_ptr->zstream.next_in = filtered_row; + png_ptr->zstream.avail_in = 0; + avail = png_ptr->row_info.rowbytes + 1; + /* Repeat until we have compressed all the data */ + do + { + int ret; /* Return of zlib */ + + /* Record the number of bytes available - zlib supports at least 65535 + * bytes at one step, depending on the size of the zlib type 'uInt', the + * maximum size zlib can write at once is ZLIB_IO_MAX (from pngpriv.h). + * Use this because on 16 bit systems 'rowbytes' can be up to 65536 (i.e. + * one more than 16 bits) and, in this case 'rowbytes+1' can overflow a + * uInt. ZLIB_IO_MAX can be safely reduced to cause zlib to be called + * with smaller chunks of data. + */ + if (png_ptr->zstream.avail_in == 0) + { + if (avail > ZLIB_IO_MAX) + { + png_ptr->zstream.avail_in = ZLIB_IO_MAX; + avail -= ZLIB_IO_MAX; + } + + else + { + /* So this will fit in the available uInt space: */ + png_ptr->zstream.avail_in = (uInt)avail; + avail = 0; + } + } + + /* Compress the data */ + ret = deflate(&png_ptr->zstream, Z_NO_FLUSH); + + /* Check for compression errors */ + if (ret != Z_OK) + { + if (png_ptr->zstream.msg != NULL) + png_error(png_ptr, png_ptr->zstream.msg); + + else + png_error(png_ptr, "zlib error"); + } + + /* See if it is time to write another IDAT */ + if (!(png_ptr->zstream.avail_out)) + { + /* Write the IDAT and reset the zlib output buffer */ + png_write_IDAT(png_ptr, png_ptr->zbuf, png_ptr->zbuf_size); + png_ptr->zstream.next_out = png_ptr->zbuf; + png_ptr->zstream.avail_out = (uInt)png_ptr->zbuf_size; + } + /* Repeat until all data has been compressed */ + } while (avail > 0 || png_ptr->zstream.avail_in > 0); + + /* Swap the current and previous rows */ + if (png_ptr->prev_row != NULL) + { + png_bytep tptr; + + tptr = png_ptr->prev_row; + png_ptr->prev_row = png_ptr->row_buf; + png_ptr->row_buf = tptr; + } + + /* Finish row - updates counters and flushes zlib if last row */ + png_write_finish_row(png_ptr); + +#ifdef PNG_WRITE_FLUSH_SUPPORTED + png_ptr->flush_rows++; + + if (png_ptr->flush_dist > 0 && + png_ptr->flush_rows >= png_ptr->flush_dist) + { + png_write_flush(png_ptr); + } +#endif +} +#endif /* PNG_WRITE_SUPPORTED */ |