diff options
Diffstat (limited to 'src/3rdparty/freetype/src/smooth/ftgrays.c')
| -rw-r--r-- | src/3rdparty/freetype/src/smooth/ftgrays.c | 1472 |
1 files changed, 837 insertions, 635 deletions
diff --git a/src/3rdparty/freetype/src/smooth/ftgrays.c b/src/3rdparty/freetype/src/smooth/ftgrays.c index 803a19e415..0918272f87 100644 --- a/src/3rdparty/freetype/src/smooth/ftgrays.c +++ b/src/3rdparty/freetype/src/smooth/ftgrays.c @@ -1,94 +1,102 @@ -/***************************************************************************/ -/* */ -/* ftgrays.c */ -/* */ -/* A new `perfect' anti-aliasing renderer (body). */ -/* */ -/* Copyright 2000-2018 by */ -/* David Turner, Robert Wilhelm, and Werner Lemberg. */ -/* */ -/* This file is part of the FreeType project, and may only be used, */ -/* modified, and distributed under the terms of the FreeType project */ -/* license, LICENSE.TXT. By continuing to use, modify, or distribute */ -/* this file you indicate that you have read the license and */ -/* understand and accept it fully. */ -/* */ -/***************************************************************************/ - - /*************************************************************************/ - /* */ - /* This file can be compiled without the rest of the FreeType engine, by */ - /* defining the STANDALONE_ macro when compiling it. You also need to */ - /* put the files `ftgrays.h' and `ftimage.h' into the current */ - /* compilation directory. Typically, you could do something like */ - /* */ - /* - copy `src/smooth/ftgrays.c' (this file) to your current directory */ - /* */ - /* - copy `include/freetype/ftimage.h' and `src/smooth/ftgrays.h' to the */ - /* same directory */ - /* */ - /* - compile `ftgrays' with the STANDALONE_ macro defined, as in */ - /* */ - /* cc -c -DSTANDALONE_ ftgrays.c */ - /* */ - /* The renderer can be initialized with a call to */ - /* `ft_gray_raster.raster_new'; an anti-aliased bitmap can be generated */ - /* with a call to `ft_gray_raster.raster_render'. */ - /* */ - /* See the comments and documentation in the file `ftimage.h' for more */ - /* details on how the raster works. */ - /* */ - /*************************************************************************/ - - /*************************************************************************/ - /* */ - /* This is a new anti-aliasing scan-converter for FreeType 2. The */ - /* algorithm used here is _very_ different from the one in the standard */ - /* `ftraster' module. Actually, `ftgrays' computes the _exact_ */ - /* coverage of the outline on each pixel cell. */ - /* */ - /* It is based on ideas that I initially found in Raph Levien's */ - /* excellent LibArt graphics library (see http://www.levien.com/libart */ - /* for more information, though the web pages do not tell anything */ - /* about the renderer; you'll have to dive into the source code to */ - /* understand how it works). */ - /* */ - /* Note, however, that this is a _very_ different implementation */ - /* compared to Raph's. Coverage information is stored in a very */ - /* different way, and I don't use sorted vector paths. Also, it doesn't */ - /* use floating point values. */ - /* */ - /* This renderer has the following advantages: */ - /* */ - /* - It doesn't need an intermediate bitmap. Instead, one can supply a */ - /* callback function that will be called by the renderer to draw gray */ - /* spans on any target surface. You can thus do direct composition on */ - /* any kind of bitmap, provided that you give the renderer the right */ - /* callback. */ - /* */ - /* - A perfect anti-aliaser, i.e., it computes the _exact_ coverage on */ - /* each pixel cell. */ - /* */ - /* - It performs a single pass on the outline (the `standard' FT2 */ - /* renderer makes two passes). */ - /* */ - /* - It can easily be modified to render to _any_ number of gray levels */ - /* cheaply. */ - /* */ - /* - For small (< 20) pixel sizes, it is faster than the standard */ - /* renderer. */ - /* */ - /*************************************************************************/ - - - /*************************************************************************/ - /* */ - /* The macro FT_COMPONENT is used in trace mode. It is an implicit */ - /* parameter of the FT_TRACE() and FT_ERROR() macros, used to print/log */ - /* messages during execution. */ - /* */ +/**************************************************************************** + * + * ftgrays.c + * + * A new `perfect' anti-aliasing renderer (body). + * + * Copyright (C) 2000-2023 by + * David Turner, Robert Wilhelm, and Werner Lemberg. + * + * This file is part of the FreeType project, and may only be used, + * modified, and distributed under the terms of the FreeType project + * license, LICENSE.TXT. By continuing to use, modify, or distribute + * this file you indicate that you have read the license and + * understand and accept it fully. + * + */ + + /************************************************************************** + * + * This file can be compiled without the rest of the FreeType engine, by + * defining the STANDALONE_ macro when compiling it. You also need to + * put the files `ftgrays.h' and `ftimage.h' into the current + * compilation directory. Typically, you could do something like + * + * - copy `src/smooth/ftgrays.c' (this file) to your current directory + * + * - copy `include/freetype/ftimage.h' and `src/smooth/ftgrays.h' to the + * same directory + * + * - compile `ftgrays' with the STANDALONE_ macro defined, as in + * + * cc -c -DSTANDALONE_ ftgrays.c + * + * The renderer can be initialized with a call to + * `ft_gray_raster.raster_new'; an anti-aliased bitmap can be generated + * with a call to `ft_gray_raster.raster_render'. + * + * See the comments and documentation in the file `ftimage.h' for more + * details on how the raster works. + * + */ + + /************************************************************************** + * + * This is a new anti-aliasing scan-converter for FreeType 2. The + * algorithm used here is _very_ different from the one in the standard + * `ftraster' module. Actually, `ftgrays' computes the _exact_ + * coverage of the outline on each pixel cell by straight segments. + * + * It is based on ideas that I initially found in Raph Levien's + * excellent LibArt graphics library (see https://www.levien.com/libart + * for more information, though the web pages do not tell anything + * about the renderer; you'll have to dive into the source code to + * understand how it works). + * + * Note, however, that this is a _very_ different implementation + * compared to Raph's. Coverage information is stored in a very + * different way, and I don't use sorted vector paths. Also, it doesn't + * use floating point values. + * + * Bézier segments are flattened by splitting them until their deviation + * from straight line becomes much smaller than a pixel. Therefore, the + * pixel coverage by a Bézier curve is calculated approximately. To + * estimate the deviation, we use the distance from the control point + * to the conic chord centre or the cubic chord trisection. These + * distances vanish fast after each split. In the conic case, they vanish + * predictably and the number of necessary splits can be calculated. + * + * This renderer has the following advantages: + * + * - It doesn't need an intermediate bitmap. Instead, one can supply a + * callback function that will be called by the renderer to draw gray + * spans on any target surface. You can thus do direct composition on + * any kind of bitmap, provided that you give the renderer the right + * callback. + * + * - A perfect anti-aliaser, i.e., it computes the _exact_ coverage on + * each pixel cell by straight segments. + * + * - It performs a single pass on the outline (the `standard' FT2 + * renderer makes two passes). + * + * - It can easily be modified to render to _any_ number of gray levels + * cheaply. + * + * - For small (< 80) pixel sizes, it is faster than the standard + * renderer. + * + */ + + + /************************************************************************** + * + * The macro FT_COMPONENT is used in trace mode. It is an implicit + * parameter of the FT_TRACE() and FT_ERROR() macros, used to print/log + * messages during execution. + */ #undef FT_COMPONENT -#define FT_COMPONENT trace_smooth +#define FT_COMPONENT smooth #ifdef STANDALONE_ @@ -112,9 +120,9 @@ /* - * Approximate sqrt(x*x+y*y) using the `alpha max plus beta min' - * algorithm. We use alpha = 1, beta = 3/8, giving us results with a - * largest error less than 7% compared to the exact value. + * Approximate sqrt(x*x+y*y) using the `alpha max plus beta min' + * algorithm. We use alpha = 1, beta = 3/8, giving us results with a + * largest error less than 7% compared to the exact value. */ #define FT_HYPOT( x, y ) \ ( x = FT_ABS( x ), \ @@ -141,14 +149,10 @@ #define FT_INT_MAX INT_MAX #define FT_ULONG_MAX ULONG_MAX -#define ADD_LONG( a, b ) \ - (long)( (unsigned long)(a) + (unsigned long)(b) ) -#define SUB_LONG( a, b ) \ - (long)( (unsigned long)(a) - (unsigned long)(b) ) -#define MUL_LONG( a, b ) \ - (long)( (unsigned long)(a) * (unsigned long)(b) ) -#define NEG_LONG( a ) \ - (long)( -(unsigned long)(a) ) +#define ADD_INT( a, b ) \ + (int)( (unsigned int)(a) + (unsigned int)(b) ) + +#define FT_STATIC_BYTE_CAST( type, var ) (type)(unsigned char)(var) #define ft_memset memset @@ -160,10 +164,11 @@ typedef ptrdiff_t FT_PtrDist; -#define ErrRaster_Invalid_Mode -2 -#define ErrRaster_Invalid_Outline -1 -#define ErrRaster_Invalid_Argument -3 -#define ErrRaster_Memory_Overflow -4 +#define Smooth_Err_Ok 0 +#define Smooth_Err_Invalid_Outline -1 +#define Smooth_Err_Cannot_Render_Glyph -2 +#define Smooth_Err_Invalid_Argument -3 +#define Smooth_Err_Raster_Overflow -4 #define FT_BEGIN_HEADER #define FT_END_HEADER @@ -221,23 +226,26 @@ typedef ptrdiff_t FT_PtrDist; #define FT_ERROR( varformat ) FT_Message varformat #endif -#define FT_THROW( e ) \ - ( FT_Throw( FT_ERR_CAT( ErrRaster, e ), \ - __LINE__, \ - __FILE__ ) | \ - FT_ERR_CAT( ErrRaster, e ) ) +#define FT_THROW( e ) \ + ( FT_Throw( FT_ERR_CAT( Smooth_Err_, e ), \ + __LINE__, \ + __FILE__ ) | \ + FT_ERR_CAT( Smooth_Err_, e ) ) #else /* !FT_DEBUG_LEVEL_TRACE */ #define FT_TRACE5( x ) do { } while ( 0 ) /* nothing */ #define FT_TRACE7( x ) do { } while ( 0 ) /* nothing */ #define FT_ERROR( x ) do { } while ( 0 ) /* nothing */ -#define FT_THROW( e ) FT_ERR_CAT( ErrRaster_, e ) - +#define FT_THROW( e ) FT_ERR_CAT( Smooth_Err_, e ) #endif /* !FT_DEBUG_LEVEL_TRACE */ +#define FT_Trace_Enable() do { } while ( 0 ) /* nothing */ +#define FT_Trace_Disable() do { } while ( 0 ) /* nothing */ + + #define FT_DEFINE_OUTLINE_FUNCS( class_, \ move_to_, line_to_, \ conic_to_, cubic_to_, \ @@ -271,20 +279,15 @@ typedef ptrdiff_t FT_PtrDist; #include <ft2build.h> +#include FT_CONFIG_CONFIG_H #include "ftgrays.h" -#include FT_INTERNAL_OBJECTS_H -#include FT_INTERNAL_DEBUG_H -#include FT_INTERNAL_CALC_H -#include FT_OUTLINE_H +#include <freetype/internal/ftobjs.h> +#include <freetype/internal/ftdebug.h> +#include <freetype/internal/ftcalc.h> +#include <freetype/ftoutln.h> #include "ftsmerrs.h" -#include "ftspic.h" - -#define Smooth_Err_Invalid_Mode Smooth_Err_Cannot_Render_Glyph -#define Smooth_Err_Memory_Overflow Smooth_Err_Out_Of_Memory -#define ErrRaster_Memory_Overflow Smooth_Err_Out_Of_Memory - #endif /* !STANDALONE_ */ @@ -329,17 +332,11 @@ typedef ptrdiff_t FT_PtrDist; /* must be at least 6 bits! */ #define PIXEL_BITS 8 -#undef FLOOR -#undef CEILING -#undef TRUNC -#undef SCALED - #define ONE_PIXEL ( 1 << PIXEL_BITS ) -#define TRUNC( x ) ( (TCoord)( (x) >> PIXEL_BITS ) ) -#define SUBPIXELS( x ) ( (TPos)(x) * ONE_PIXEL ) -#define FLOOR( x ) ( (x) & -ONE_PIXEL ) -#define CEILING( x ) ( ( (x) + ONE_PIXEL - 1 ) & -ONE_PIXEL ) -#define ROUND( x ) ( ( (x) + ONE_PIXEL / 2 ) & -ONE_PIXEL ) +#undef TRUNC +#define TRUNC( x ) (TCoord)( (x) >> PIXEL_BITS ) +#undef FRACT +#define FRACT( x ) (TCoord)( (x) & ( ONE_PIXEL - 1 ) ) #if PIXEL_BITS >= 6 #define UPSCALE( x ) ( (x) * ( ONE_PIXEL >> 6 ) ) @@ -365,7 +362,7 @@ typedef ptrdiff_t FT_PtrDist; } \ FT_END_STMNT -#ifdef __arm__ +#if defined( __GNUC__ ) && __GNUC__ < 7 && defined( __arm__ ) /* Work around a bug specific to GCC which make the compiler fail to */ /* optimize a division and modulo operation on the same parameters */ /* into a single call to `__aeabi_idivmod'. See */ @@ -385,20 +382,64 @@ typedef ptrdiff_t FT_PtrDist; #endif /* __arm__ */ - /* These macros speed up repetitive divisions by replacing them */ - /* with multiplications and right shifts. */ -#define FT_UDIVPREP( c, b ) \ - long b ## _r = c ? (long)( FT_ULONG_MAX >> PIXEL_BITS ) / ( b ) \ - : 0 -#define FT_UDIV( a, b ) \ - ( ( (unsigned long)( a ) * (unsigned long)( b ## _r ) ) >> \ - ( sizeof( long ) * FT_CHAR_BIT - PIXEL_BITS ) ) + /* Calculating coverages for a slanted line requires a division each */ + /* time the line crosses from cell to cell. These macros speed up */ + /* the repetitive divisions by replacing them with multiplications */ + /* and right shifts so that at most two divisions are performed for */ + /* each slanted line. Nevertheless, these divisions are noticeable */ + /* in the overall performance because flattened curves produce a */ + /* very large number of slanted lines. */ + /* */ + /* The division results here are always within ONE_PIXEL. Therefore */ + /* the shift magnitude should be at least PIXEL_BITS wider than the */ + /* divisors to provide sufficient accuracy of the multiply-shift. */ + /* It should not exceed (64 - PIXEL_BITS) to prevent overflowing and */ + /* leave enough room for 64-bit unsigned multiplication however. */ +#define FT_UDIVPREP( c, b ) \ + FT_Int64 b ## _r = c ? (FT_Int64)0xFFFFFFFF / ( b ) : 0 +#define FT_UDIV( a, b ) \ + (TCoord)( ( (FT_UInt64)( a ) * (FT_UInt64)( b ## _r ) ) >> 32 ) + + + /* Scale area and apply fill rule to calculate the coverage byte. */ + /* The top fill bit is used for the non-zero rule. The eighth */ + /* fill bit is used for the even-odd rule. The higher coverage */ + /* bytes are either clamped for the non-zero-rule or discarded */ + /* later for the even-odd rule. */ +#define FT_FILL_RULE( coverage, area, fill ) \ + FT_BEGIN_STMNT \ + coverage = (int)( area >> ( PIXEL_BITS * 2 + 1 - 8 ) ); \ + if ( coverage & fill ) \ + coverage = ~coverage; \ + if ( coverage > 255 && fill & INT_MIN ) \ + coverage = 255; \ + FT_END_STMNT + + + /* It is faster to write small spans byte-by-byte than calling */ + /* `memset'. This is mainly due to the cost of the function call. */ +#define FT_GRAY_SET( d, s, count ) \ + FT_BEGIN_STMNT \ + unsigned char* q = d; \ + switch ( count ) \ + { \ + case 7: *q++ = (unsigned char)s; FALL_THROUGH; \ + case 6: *q++ = (unsigned char)s; FALL_THROUGH; \ + case 5: *q++ = (unsigned char)s; FALL_THROUGH; \ + case 4: *q++ = (unsigned char)s; FALL_THROUGH; \ + case 3: *q++ = (unsigned char)s; FALL_THROUGH; \ + case 2: *q++ = (unsigned char)s; FALL_THROUGH; \ + case 1: *q = (unsigned char)s; FALL_THROUGH; \ + case 0: break; \ + default: FT_MEM_SET( d, s, count ); \ + } \ + FT_END_STMNT - /*************************************************************************/ - /* */ - /* TYPE DEFINITIONS */ - /* */ + /************************************************************************** + * + * TYPE DEFINITIONS + */ /* don't change the following types to FT_Int or FT_Pos, since we might */ /* need to define them to "float" or "double" when experimenting with */ @@ -434,6 +475,9 @@ typedef ptrdiff_t FT_PtrDist; #define FT_MAX_GRAY_POOL ( 2048 / sizeof ( TCell ) ) #endif + /* FT_Span buffer size for direct rendering only */ +#define FT_MAX_GRAY_SPANS 16 + #if defined( _MSC_VER ) /* Visual C++ (and Intel C++) */ /* We disable the warning `structure was padded due to */ @@ -447,23 +491,21 @@ typedef ptrdiff_t FT_PtrDist; { ft_jmp_buf jump_buffer; - TCoord ex, ey; - TCoord min_ex, max_ex; + TCoord min_ex, max_ex; /* min and max integer pixel coordinates */ TCoord min_ey, max_ey; + TCoord count_ey; /* same as (max_ey - min_ey) */ - TArea area; - TCoord cover; - int invalid; + PCell cell; /* current cell */ + PCell cell_free; /* call allocation next free slot */ + PCell cell_null; /* last cell, used as dumpster and limit */ - PCell* ycells; - PCell cells; - FT_PtrDist max_cells; - FT_PtrDist num_cells; + PCell* ycells; /* array of cell linked-lists; one per */ + /* vertical coordinate in the current band */ - TPos x, y; + TPos x, y; /* last point position */ - FT_Outline outline; - TPixmap target; + FT_Outline outline; /* input outline */ + TPixmap target; /* target pixmap */ FT_Raster_Span_Func render_span; void* render_span_data; @@ -474,17 +516,25 @@ typedef ptrdiff_t FT_PtrDist; #pragma warning( pop ) #endif - #ifndef FT_STATIC_RASTER #define ras (*worker) #else static gray_TWorker ras; #endif + /* The |x| value of the null cell. Must be the largest possible */ + /* integer value stored in a `TCell.x` field. */ +#define CELL_MAX_X_VALUE INT_MAX + + +#define FT_INTEGRATE( ras, a, b ) \ + ras.cell->cover = ADD_INT( ras.cell->cover, a ), \ + ras.cell->area = ADD_INT( ras.cell->area, (a) * (TArea)(b) ) + typedef struct gray_TRaster_ { - void* memory; + void* memory; } gray_TRaster, *gray_PRaster; @@ -506,7 +556,7 @@ typedef ptrdiff_t FT_PtrDist; printf( "%3d:", y ); - for ( ; cell != NULL; cell = cell->next ) + for ( ; cell != ras.cell_null; cell = cell->next ) printf( " (%3d, c:%4d, a:%6d)", cell->x, cell->cover, cell->area ); printf( "\n" ); @@ -516,92 +566,74 @@ typedef ptrdiff_t FT_PtrDist; #endif /* FT_DEBUG_LEVEL_TRACE */ - /*************************************************************************/ - /* */ - /* Record the current cell in the table. */ - /* */ + /************************************************************************** + * + * Set the current cell to a new position. + */ static void - gray_record_cell( RAS_ARG ) + gray_set_cell( RAS_ARG_ TCoord ex, + TCoord ey ) { - PCell *pcell, cell; - TCoord x = ras.ex; - - - pcell = &ras.ycells[ras.ey - ras.min_ey]; - for (;;) - { - cell = *pcell; - if ( !cell || cell->x > x ) - break; + /* Move the cell pointer to a new position in the linked list. We use */ + /* a dumpster null cell for everything outside of the clipping region */ + /* during the render phase. This means that: */ + /* */ + /* . the new vertical position must be within min_ey..max_ey-1. */ + /* . the new horizontal position must be strictly less than max_ex */ + /* */ + /* Note that if a cell is to the left of the clipping region, it is */ + /* actually set to the (min_ex-1) horizontal position. */ - if ( cell->x == x ) - goto Found; + TCoord ey_index = ey - ras.min_ey; - pcell = &cell->next; - } - if ( ras.num_cells >= ras.max_cells ) - ft_longjmp( ras.jump_buffer, 1 ); + if ( ey_index < 0 || ey_index >= ras.count_ey || ex >= ras.max_ex ) + ras.cell = ras.cell_null; + else + { + PCell* pcell = ras.ycells + ey_index; + PCell cell; - /* insert new cell */ - cell = ras.cells + ras.num_cells++; - cell->x = x; - cell->area = ras.area; - cell->cover = ras.cover; - cell->next = *pcell; - *pcell = cell; + ex = FT_MAX( ex, ras.min_ex - 1 ); - return; + while ( 1 ) + { + cell = *pcell; - Found: - /* update old cell */ - cell->area += ras.area; - cell->cover += ras.cover; - } + if ( cell->x > ex ) + break; + if ( cell->x == ex ) + goto Found; - /*************************************************************************/ - /* */ - /* Set the current cell to a new position. */ - /* */ - static void - gray_set_cell( RAS_ARG_ TCoord ex, - TCoord ey ) - { - /* Move the cell pointer to a new position. We set the `invalid' */ - /* flag to indicate that the cell isn't part of those we're interested */ - /* in during the render phase. This means that: */ - /* */ - /* . the new vertical position must be within min_ey..max_ey-1. */ - /* . the new horizontal position must be strictly less than max_ex */ - /* */ - /* Note that if a cell is to the left of the clipping region, it is */ - /* actually set to the (min_ex-1) horizontal position. */ + pcell = &cell->next; + } - if ( ex < ras.min_ex ) - ex = ras.min_ex - 1; + /* insert new cell */ + cell = ras.cell_free++; + if ( cell >= ras.cell_null ) + ft_longjmp( ras.jump_buffer, 1 ); - /* record the current one if it is valid and substantial */ - if ( !ras.invalid && ( ras.area || ras.cover ) ) - gray_record_cell( RAS_VAR ); + cell->x = ex; + cell->area = 0; + cell->cover = 0; - ras.area = 0; - ras.cover = 0; - ras.ex = ex; - ras.ey = ey; + cell->next = *pcell; + *pcell = cell; - ras.invalid = ( ey >= ras.max_ey || ey < ras.min_ey || - ex >= ras.max_ex ); + Found: + ras.cell = cell; + } } -#ifndef FT_LONG64 +#ifndef FT_INT64 - /*************************************************************************/ - /* */ - /* Render a scanline as one or more cells. */ - /* */ + /************************************************************************** + * + * Render a scanline as one or more cells. + */ static void gray_render_scanline( RAS_ARG_ TCoord ey, TPos x1, @@ -624,8 +656,8 @@ typedef ptrdiff_t FT_PtrDist; return; } - fx1 = (TCoord)( x1 - SUBPIXELS( ex1 ) ); - fx2 = (TCoord)( x2 - SUBPIXELS( ex2 ) ); + fx1 = FRACT( x1 ); + fx2 = FRACT( x2 ); /* everything is located in a single cell. That is easy! */ /* */ @@ -652,12 +684,14 @@ typedef ptrdiff_t FT_PtrDist; dx = -dx; } + /* the fractional part of y-delta is mod/dx. It is essential to */ + /* keep track of its accumulation for accurate rendering. */ + /* XXX: y-delta and x-delta below should be related. */ FT_DIV_MOD( TCoord, p, dx, delta, mod ); - ras.area += (TArea)( ( fx1 + first ) * delta ); - ras.cover += delta; - y1 += delta; - ex1 += incr; + FT_INTEGRATE( ras, delta, fx1 + first ); + y1 += delta; + ex1 += incr; gray_set_cell( RAS_VAR_ ex1, ey ); if ( ex1 != ex2 ) @@ -678,10 +712,9 @@ typedef ptrdiff_t FT_PtrDist; delta++; } - ras.area += (TArea)( ONE_PIXEL * delta ); - ras.cover += delta; - y1 += delta; - ex1 += incr; + FT_INTEGRATE( ras, delta, ONE_PIXEL ); + y1 += delta; + ex1 += incr; gray_set_cell( RAS_VAR_ ex1, ey ); } while ( ex1 != ex2 ); } @@ -689,17 +722,14 @@ typedef ptrdiff_t FT_PtrDist; fx1 = ONE_PIXEL - first; End: - dy = y2 - y1; - - ras.area += (TArea)( ( fx1 + fx2 ) * dy ); - ras.cover += dy; + FT_INTEGRATE( ras, y2 - y1, fx1 + fx2 ); } - /*************************************************************************/ - /* */ - /* Render a given line as a series of scanlines. */ - /* */ + /************************************************************************** + * + * Render a given line as a series of scanlines. + */ static void gray_render_line( RAS_ARG_ TPos to_x, TPos to_y ) @@ -717,8 +747,8 @@ typedef ptrdiff_t FT_PtrDist; ( ey1 < ras.min_ey && ey2 < ras.min_ey ) ) goto End; - fy1 = (TCoord)( ras.y - SUBPIXELS( ey1 ) ); - fy2 = (TCoord)( to_y - SUBPIXELS( ey2 ) ); + fy1 = FRACT( ras.y ); + fy2 = FRACT( to_y ); /* everything is on a single scanline */ if ( ey1 == ey2 ) @@ -734,8 +764,7 @@ typedef ptrdiff_t FT_PtrDist; if ( dx == 0 ) { TCoord ex = TRUNC( ras.x ); - TCoord two_fx = (TCoord)( ( ras.x - SUBPIXELS( ex ) ) << 1 ); - TArea area; + TCoord two_fx = FRACT( ras.x ) << 1; if ( dy > 0) @@ -749,27 +778,23 @@ typedef ptrdiff_t FT_PtrDist; incr = -1; } - delta = first - fy1; - ras.area += (TArea)two_fx * delta; - ras.cover += delta; - ey1 += incr; + delta = first - fy1; + FT_INTEGRATE( ras, delta, two_fx); + ey1 += incr; gray_set_cell( RAS_VAR_ ex, ey1 ); delta = first + first - ONE_PIXEL; - area = (TArea)two_fx * delta; while ( ey1 != ey2 ) { - ras.area += area; - ras.cover += delta; - ey1 += incr; + FT_INTEGRATE( ras, delta, two_fx); + ey1 += incr; gray_set_cell( RAS_VAR_ ex, ey1 ); } - delta = fy2 - ONE_PIXEL + first; - ras.area += (TArea)two_fx * delta; - ras.cover += delta; + delta = fy2 - ONE_PIXEL + first; + FT_INTEGRATE( ras, delta, two_fx); goto End; } @@ -789,6 +814,8 @@ typedef ptrdiff_t FT_PtrDist; dy = -dy; } + /* the fractional part of x-delta is mod/dy. It is essential to */ + /* keep track of its accumulation for accurate rendering. */ FT_DIV_MOD( TCoord, p, dy, delta, mod ); x = ras.x + delta; @@ -837,16 +864,17 @@ typedef ptrdiff_t FT_PtrDist; #else - /*************************************************************************/ - /* */ - /* Render a straight line across multiple cells in any direction. */ - /* */ + /************************************************************************** + * + * Render a straight line across multiple cells in any direction. + */ static void gray_render_line( RAS_ARG_ TPos to_x, TPos to_y ) { - TPos dx, dy, fx1, fy1, fx2, fy2; - TCoord ex1, ex2, ey1, ey2; + TPos dx, dy; + TCoord fx1, fy1, fx2, fy2; + TCoord ex1, ey1, ex2, ey2; ey1 = TRUNC( ras.y ); @@ -860,8 +888,8 @@ typedef ptrdiff_t FT_PtrDist; ex1 = TRUNC( ras.x ); ex2 = TRUNC( to_x ); - fx1 = ras.x - SUBPIXELS( ex1 ); - fy1 = ras.y - SUBPIXELS( ey1 ); + fx1 = FRACT( ras.x ); + fy1 = FRACT( ras.y ); dx = to_x - ras.x; dy = to_y - ras.y; @@ -870,8 +898,8 @@ typedef ptrdiff_t FT_PtrDist; ; else if ( dy == 0 ) /* ex1 != ex2 */ /* any horizontal line */ { - ex1 = ex2; - gray_set_cell( RAS_VAR_ ex1, ey1 ); + gray_set_cell( RAS_VAR_ ex2, ey2 ); + goto End; } else if ( dx == 0 ) { @@ -879,8 +907,7 @@ typedef ptrdiff_t FT_PtrDist; do { fy2 = ONE_PIXEL; - ras.cover += ( fy2 - fy1 ); - ras.area += ( fy2 - fy1 ) * fx1 * 2; + FT_INTEGRATE( ras, fy2 - fy1, fx1 * 2 ); fy1 = 0; ey1++; gray_set_cell( RAS_VAR_ ex1, ey1 ); @@ -889,8 +916,7 @@ typedef ptrdiff_t FT_PtrDist; do { fy2 = 0; - ras.cover += ( fy2 - fy1 ); - ras.area += ( fy2 - fy1 ) * fx1 * 2; + FT_INTEGRATE( ras, fy2 - fy1, fx1 * 2 ); fy1 = ONE_PIXEL; ey1--; gray_set_cell( RAS_VAR_ ex1, ey1 ); @@ -898,7 +924,7 @@ typedef ptrdiff_t FT_PtrDist; } else /* any other line */ { - TPos prod = dx * fy1 - dy * fx1; + FT_Int64 prod = dx * (FT_Int64)fy1 - dy * (FT_Int64)fx1; FT_UDIVPREP( ex1 != ex2, dx ); FT_UDIVPREP( ey1 != ey2, dy ); @@ -908,72 +934,309 @@ typedef ptrdiff_t FT_PtrDist; /* also easily updated when moving from one cell to the next. */ do { - if ( prod <= 0 && - prod - dx * ONE_PIXEL > 0 ) /* left */ + if ( prod - dx * ONE_PIXEL > 0 && + prod <= 0 ) /* left */ { fx2 = 0; - fy2 = (TPos)FT_UDIV( -prod, -dx ); + fy2 = FT_UDIV( -prod, -dx ); prod -= dy * ONE_PIXEL; - ras.cover += ( fy2 - fy1 ); - ras.area += ( fy2 - fy1 ) * ( fx1 + fx2 ); + FT_INTEGRATE( ras, fy2 - fy1, fx1 + fx2 ); fx1 = ONE_PIXEL; fy1 = fy2; ex1--; } - else if ( prod - dx * ONE_PIXEL <= 0 && - prod - dx * ONE_PIXEL + dy * ONE_PIXEL > 0 ) /* up */ + else if ( prod - dx * ONE_PIXEL + dy * ONE_PIXEL > 0 && + prod - dx * ONE_PIXEL <= 0 ) /* up */ { prod -= dx * ONE_PIXEL; - fx2 = (TPos)FT_UDIV( -prod, dy ); + fx2 = FT_UDIV( -prod, dy ); fy2 = ONE_PIXEL; - ras.cover += ( fy2 - fy1 ); - ras.area += ( fy2 - fy1 ) * ( fx1 + fx2 ); + FT_INTEGRATE( ras, fy2 - fy1, fx1 + fx2 ); fx1 = fx2; fy1 = 0; ey1++; } - else if ( prod - dx * ONE_PIXEL + dy * ONE_PIXEL <= 0 && - prod + dy * ONE_PIXEL >= 0 ) /* right */ + else if ( prod + dy * ONE_PIXEL >= 0 && + prod - dx * ONE_PIXEL + dy * ONE_PIXEL <= 0 ) /* right */ { prod += dy * ONE_PIXEL; fx2 = ONE_PIXEL; - fy2 = (TPos)FT_UDIV( prod, dx ); - ras.cover += ( fy2 - fy1 ); - ras.area += ( fy2 - fy1 ) * ( fx1 + fx2 ); + fy2 = FT_UDIV( prod, dx ); + FT_INTEGRATE( ras, fy2 - fy1, fx1 + fx2 ); fx1 = 0; fy1 = fy2; ex1++; } - else /* ( prod + dy * ONE_PIXEL < 0 && - prod > 0 ) down */ + else /* ( prod > 0 && + prod + dy * ONE_PIXEL < 0 ) down */ { - fx2 = (TPos)FT_UDIV( prod, -dy ); + fx2 = FT_UDIV( prod, -dy ); fy2 = 0; prod += dx * ONE_PIXEL; - ras.cover += ( fy2 - fy1 ); - ras.area += ( fy2 - fy1 ) * ( fx1 + fx2 ); + FT_INTEGRATE( ras, fy2 - fy1, fx1 + fx2 ); fx1 = fx2; fy1 = ONE_PIXEL; ey1--; } gray_set_cell( RAS_VAR_ ex1, ey1 ); + } while ( ex1 != ex2 || ey1 != ey2 ); } - fx2 = to_x - SUBPIXELS( ex2 ); - fy2 = to_y - SUBPIXELS( ey2 ); + fx2 = FRACT( to_x ); + fy2 = FRACT( to_y ); - ras.cover += ( fy2 - fy1 ); - ras.area += ( fy2 - fy1 ) * ( fx1 + fx2 ); + FT_INTEGRATE( ras, fy2 - fy1, fx1 + fx2 ); End: - ras.x = to_x; - ras.y = to_y; + ras.x = to_x; + ras.y = to_y; } #endif + /* + * Benchmarking shows that using DDA to flatten the quadratic Bézier arcs + * is slightly faster in the following cases: + * + * - When the host CPU is 64-bit. + * - When SSE2 SIMD registers and instructions are available (even on + * x86). + * + * For other cases, using binary splits is actually slightly faster. + */ +#if ( defined( __SSE2__ ) || \ + defined( __x86_64__ ) || \ + defined( _M_AMD64 ) || \ + ( defined( _M_IX86_FP ) && _M_IX86_FP >= 2 ) ) && \ + !defined( __VMS ) +# define FT_SSE2 1 +#else +# define FT_SSE2 0 +#endif + +#if FT_SSE2 || \ + defined( __aarch64__ ) || \ + defined( _M_ARM64 ) +# define BEZIER_USE_DDA 1 +#else +# define BEZIER_USE_DDA 0 +#endif + + /* + * For now, the code that depends on `BEZIER_USE_DDA` requires `FT_Int64` + * to be defined. If `FT_INT64` is not defined, meaning there is no + * 64-bit type available, disable it to avoid compilation errors. See for + * example https://gitlab.freedesktop.org/freetype/freetype/-/issues/1071. + */ +#if !defined( FT_INT64 ) +# undef BEZIER_USE_DDA +# define BEZIER_USE_DDA 0 +#endif + +#if BEZIER_USE_DDA + +#if FT_SSE2 +# include <emmintrin.h> +#endif + +#define LEFT_SHIFT( a, b ) (FT_Int64)( (FT_UInt64)(a) << (b) ) + + + static void + gray_render_conic( RAS_ARG_ const FT_Vector* control, + const FT_Vector* to ) + { + FT_Vector p0, p1, p2; + TPos ax, ay, bx, by, dx, dy; + int shift; + + FT_Int64 rx, ry; + FT_Int64 qx, qy; + FT_Int64 px, py; + + FT_UInt count; + + + p0.x = ras.x; + p0.y = ras.y; + p1.x = UPSCALE( control->x ); + p1.y = UPSCALE( control->y ); + p2.x = UPSCALE( to->x ); + p2.y = UPSCALE( to->y ); + + /* short-cut the arc that crosses the current band */ + if ( ( TRUNC( p0.y ) >= ras.max_ey && + TRUNC( p1.y ) >= ras.max_ey && + TRUNC( p2.y ) >= ras.max_ey ) || + ( TRUNC( p0.y ) < ras.min_ey && + TRUNC( p1.y ) < ras.min_ey && + TRUNC( p2.y ) < ras.min_ey ) ) + { + ras.x = p2.x; + ras.y = p2.y; + return; + } + + bx = p1.x - p0.x; + by = p1.y - p0.y; + ax = p2.x - p1.x - bx; /* p0.x + p2.x - 2 * p1.x */ + ay = p2.y - p1.y - by; /* p0.y + p2.y - 2 * p1.y */ + + dx = FT_ABS( ax ); + dy = FT_ABS( ay ); + if ( dx < dy ) + dx = dy; + + if ( dx <= ONE_PIXEL / 4 ) + { + gray_render_line( RAS_VAR_ p2.x, p2.y ); + return; + } + + /* We can calculate the number of necessary bisections because */ + /* each bisection predictably reduces deviation exactly 4-fold. */ + /* Even 32-bit deviation would vanish after 16 bisections. */ + shift = 0; + do + { + dx >>= 2; + shift += 1; + + } while ( dx > ONE_PIXEL / 4 ); + + /* + * The (P0,P1,P2) arc equation, for t in [0,1] range: + * + * P(t) = P0*(1-t)^2 + P1*2*t*(1-t) + P2*t^2 + * + * P(t) = P0 + 2*(P1-P0)*t + (P0+P2-2*P1)*t^2 + * = P0 + 2*B*t + A*t^2 + * + * for A = P0 + P2 - 2*P1 + * and B = P1 - P0 + * + * Let's consider the difference when advancing by a small + * parameter h: + * + * Q(h,t) = P(t+h) - P(t) = 2*B*h + A*h^2 + 2*A*h*t + * + * And then its own difference: + * + * R(h,t) = Q(h,t+h) - Q(h,t) = 2*A*h*h = R (constant) + * + * Since R is always a constant, it is possible to compute + * successive positions with: + * + * P = P0 + * Q = Q(h,0) = 2*B*h + A*h*h + * R = 2*A*h*h + * + * loop: + * P += Q + * Q += R + * EMIT(P) + * + * To ensure accurate results, perform computations on 64-bit + * values, after scaling them by 2^32. + * + * h = 1 / 2^N + * + * R << 32 = 2 * A << (32 - N - N) + * = A << (33 - 2*N) + * + * Q << 32 = (2 * B << (32 - N)) + (A << (32 - N - N)) + * = (B << (33 - N)) + (A << (32 - 2*N)) + */ + +#if FT_SSE2 + /* Experience shows that for small shift values, */ + /* SSE2 is actually slower. */ + if ( shift > 2 ) + { + union + { + struct { FT_Int64 ax, ay, bx, by; } i; + struct { __m128i a, b; } vec; + + } u; + + union + { + struct { FT_Int32 px_lo, px_hi, py_lo, py_hi; } i; + __m128i vec; + + } v; + + __m128i a, b; + __m128i r, q, q2; + __m128i p; + + + u.i.ax = ax; + u.i.ay = ay; + u.i.bx = bx; + u.i.by = by; + + a = _mm_load_si128( &u.vec.a ); + b = _mm_load_si128( &u.vec.b ); + + r = _mm_slli_epi64( a, 33 - 2 * shift ); + q = _mm_slli_epi64( b, 33 - shift ); + q2 = _mm_slli_epi64( a, 32 - 2 * shift ); + + q = _mm_add_epi64( q2, q ); + + v.i.px_lo = 0; + v.i.px_hi = p0.x; + v.i.py_lo = 0; + v.i.py_hi = p0.y; + + p = _mm_load_si128( &v.vec ); + + for ( count = 1U << shift; count > 0; count-- ) + { + p = _mm_add_epi64( p, q ); + q = _mm_add_epi64( q, r ); + + _mm_store_si128( &v.vec, p ); + + gray_render_line( RAS_VAR_ v.i.px_hi, v.i.py_hi ); + } + + return; + } +#endif /* FT_SSE2 */ + + rx = LEFT_SHIFT( ax, 33 - 2 * shift ); + ry = LEFT_SHIFT( ay, 33 - 2 * shift ); + + qx = LEFT_SHIFT( bx, 33 - shift ) + LEFT_SHIFT( ax, 32 - 2 * shift ); + qy = LEFT_SHIFT( by, 33 - shift ) + LEFT_SHIFT( ay, 32 - 2 * shift ); + + px = LEFT_SHIFT( p0.x, 32 ); + py = LEFT_SHIFT( p0.y, 32 ); + + for ( count = 1U << shift; count > 0; count-- ) + { + px += qx; + py += qy; + qx += rx; + qy += ry; + + gray_render_line( RAS_VAR_ (FT_Pos)( px >> 32 ), + (FT_Pos)( py >> 32 ) ); + } + } + +#else /* !BEZIER_USE_DDA */ + + /* + * Note that multiple attempts to speed up the function below + * with SSE2 intrinsics, using various data layouts, have turned + * out to be slower than the non-SIMD code below. + */ static void gray_split_conic( FT_Vector* base ) { @@ -981,16 +1244,18 @@ typedef ptrdiff_t FT_PtrDist; base[4].x = base[2].x; - b = base[1].x; - a = base[3].x = ( base[2].x + b ) / 2; - b = base[1].x = ( base[0].x + b ) / 2; - base[2].x = ( a + b ) / 2; + a = base[0].x + base[1].x; + b = base[1].x + base[2].x; + base[3].x = b >> 1; + base[2].x = ( a + b ) >> 2; + base[1].x = a >> 1; base[4].y = base[2].y; - b = base[1].y; - a = base[3].y = ( base[2].y + b ) / 2; - b = base[1].y = ( base[0].y + b ) / 2; - base[2].y = ( a + b ) / 2; + a = base[0].y + base[1].y; + b = base[1].y + base[2].y; + base[3].y = b >> 1; + base[2].y = ( a + b ) >> 2; + base[1].y = a >> 1; } @@ -1001,7 +1266,7 @@ typedef ptrdiff_t FT_PtrDist; FT_Vector bez_stack[16 * 2 + 1]; /* enough to accommodate bisections */ FT_Vector* arc = bez_stack; TPos dx, dy; - int draw, split; + int draw; arc[0].x = UPSCALE( to->x ); @@ -1044,12 +1309,13 @@ typedef ptrdiff_t FT_PtrDist; /* many times as there are trailing zeros in the counter. */ do { - split = 1; - while ( ( draw & split ) == 0 ) + int split = draw & ( -draw ); /* isolate the rightmost 1-bit */ + + + while ( ( split >>= 1 ) ) { gray_split_conic( arc ); arc += 2; - split <<= 1; } gray_render_line( RAS_VAR_ arc[0].x, arc[0].y ); @@ -1058,32 +1324,46 @@ typedef ptrdiff_t FT_PtrDist; } while ( --draw ); } +#endif /* !BEZIER_USE_DDA */ + + /* + * For cubic Bézier, binary splits are still faster than DDA + * because the splits are adaptive to how quickly each sub-arc + * approaches their chord trisection points. + * + * It might be useful to experiment with SSE2 to speed up + * `gray_split_cubic`, though. + */ static void gray_split_cubic( FT_Vector* base ) { - TPos a, b, c, d; + TPos a, b, c; base[6].x = base[3].x; - c = base[1].x; - d = base[2].x; - base[1].x = a = ( base[0].x + c ) / 2; - base[5].x = b = ( base[3].x + d ) / 2; - c = ( c + d ) / 2; - base[2].x = a = ( a + c ) / 2; - base[4].x = b = ( b + c ) / 2; - base[3].x = ( a + b ) / 2; + a = base[0].x + base[1].x; + b = base[1].x + base[2].x; + c = base[2].x + base[3].x; + base[5].x = c >> 1; + c += b; + base[4].x = c >> 2; + base[1].x = a >> 1; + a += b; + base[2].x = a >> 2; + base[3].x = ( a + c ) >> 3; base[6].y = base[3].y; - c = base[1].y; - d = base[2].y; - base[1].y = a = ( base[0].y + c ) / 2; - base[5].y = b = ( base[3].y + d ) / 2; - c = ( c + d ) / 2; - base[2].y = a = ( a + c ) / 2; - base[4].y = b = ( b + c ) / 2; - base[3].y = ( a + b ) / 2; + a = base[0].y + base[1].y; + b = base[1].y + base[2].y; + c = base[2].y + base[3].y; + base[5].y = c >> 1; + c += b; + base[4].y = c >> 2; + base[1].y = a >> 1; + a += b; + base[2].y = a >> 2; + base[3].y = ( a + c ) >> 3; } @@ -1094,9 +1374,6 @@ typedef ptrdiff_t FT_PtrDist; { FT_Vector bez_stack[16 * 3 + 1]; /* enough to accommodate bisections */ FT_Vector* arc = bez_stack; - TPos dx, dy, dx_, dy_; - TPos dx1, dy1, dx2, dy2; - TPos L, s, s_limit; arc[0].x = UPSCALE( to->x ); @@ -1125,45 +1402,13 @@ typedef ptrdiff_t FT_PtrDist; for (;;) { - /* Decide whether to split or draw. See `Rapid Termination */ - /* Evaluation for Recursive Subdivision of Bezier Curves' by Thomas */ - /* F. Hain, at */ - /* http://www.cis.southalabama.edu/~hain/general/Publications/Bezier/Camera-ready%20CISST02%202.pdf */ - - /* dx and dy are x and y components of the P0-P3 chord vector. */ - dx = dx_ = arc[3].x - arc[0].x; - dy = dy_ = arc[3].y - arc[0].y; - - L = FT_HYPOT( dx_, dy_ ); - - /* Avoid possible arithmetic overflow below by splitting. */ - if ( L > 32767 ) - goto Split; - - /* Max deviation may be as much as (s/L) * 3/4 (if Hain's v = 1). */ - s_limit = L * (TPos)( ONE_PIXEL / 6 ); - - /* s is L * the perpendicular distance from P1 to the line P0-P3. */ - dx1 = arc[1].x - arc[0].x; - dy1 = arc[1].y - arc[0].y; - s = FT_ABS( SUB_LONG( MUL_LONG( dy, dx1 ), MUL_LONG( dx, dy1 ) ) ); - - if ( s > s_limit ) - goto Split; - - /* s is L * the perpendicular distance from P2 to the line P0-P3. */ - dx2 = arc[2].x - arc[0].x; - dy2 = arc[2].y - arc[0].y; - s = FT_ABS( SUB_LONG( MUL_LONG( dy, dx2 ), MUL_LONG( dx, dy2 ) ) ); - - if ( s > s_limit ) - goto Split; - - /* Split super curvy segments where the off points are so far - from the chord that the angles P0-P1-P3 or P0-P2-P3 become - acute as detected by appropriate dot products. */ - if ( dx1 * ( dx1 - dx ) + dy1 * ( dy1 - dy ) > 0 || - dx2 * ( dx2 - dx ) + dy2 * ( dy2 - dy ) > 0 ) + /* with each split, control points quickly converge towards */ + /* chord trisection points and the vanishing distances below */ + /* indicate when the segment is flat enough to draw */ + if ( FT_ABS( 2 * arc[0].x - 3 * arc[1].x + arc[3].x ) > ONE_PIXEL / 2 || + FT_ABS( 2 * arc[0].y - 3 * arc[1].y + arc[3].y ) > ONE_PIXEL / 2 || + FT_ABS( arc[0].x - 3 * arc[2].x + 2 * arc[3].x ) > ONE_PIXEL / 2 || + FT_ABS( arc[0].y - 3 * arc[2].y + 2 * arc[3].y ) > ONE_PIXEL / 2 ) goto Split; gray_render_line( RAS_VAR_ arc[0].x, arc[0].y ); @@ -1183,8 +1428,10 @@ typedef ptrdiff_t FT_PtrDist; static int gray_move_to( const FT_Vector* to, - gray_PWorker worker ) + void* worker_ ) /* gray_PWorker */ { + gray_PWorker worker = (gray_PWorker)worker_; + TPos x, y; @@ -1202,8 +1449,11 @@ typedef ptrdiff_t FT_PtrDist; static int gray_line_to( const FT_Vector* to, - gray_PWorker worker ) + void* worker_ ) /* gray_PWorker */ { + gray_PWorker worker = (gray_PWorker)worker_; + + gray_render_line( RAS_VAR_ UPSCALE( to->x ), UPSCALE( to->y ) ); return 0; } @@ -1212,8 +1462,11 @@ typedef ptrdiff_t FT_PtrDist; static int gray_conic_to( const FT_Vector* control, const FT_Vector* to, - gray_PWorker worker ) + void* worker_ ) /* gray_PWorker */ { + gray_PWorker worker = (gray_PWorker)worker_; + + gray_render_conic( RAS_VAR_ control, to ); return 0; } @@ -1223,154 +1476,195 @@ typedef ptrdiff_t FT_PtrDist; gray_cubic_to( const FT_Vector* control1, const FT_Vector* control2, const FT_Vector* to, - gray_PWorker worker ) + void* worker_ ) /* gray_PWorker */ { + gray_PWorker worker = (gray_PWorker)worker_; + + gray_render_cubic( RAS_VAR_ control1, control2, to ); return 0; } static void - gray_hline( RAS_ARG_ TCoord x, - TCoord y, - TArea coverage, - TCoord acount ) + gray_sweep( RAS_ARG ) { - /* scale the coverage from 0..(ONE_PIXEL*ONE_PIXEL*2) to 0..256 */ - coverage >>= PIXEL_BITS * 2 + 1 - 8; - if ( coverage < 0 ) - coverage = -coverage - 1; + int fill = ( ras.outline.flags & FT_OUTLINE_EVEN_ODD_FILL ) ? 0x100 + : INT_MIN; + int coverage; + int y; - /* compute the line's coverage depending on the outline fill rule */ - if ( ras.outline.flags & FT_OUTLINE_EVEN_ODD_FILL ) - { - coverage &= 511; - if ( coverage >= 256 ) - coverage = 511 - coverage; - } - else + for ( y = ras.min_ey; y < ras.max_ey; y++ ) { - /* normal non-zero winding rule */ - if ( coverage >= 256 ) - coverage = 255; - } + PCell cell = ras.ycells[y - ras.min_ey]; + TCoord x = ras.min_ex; + TArea cover = 0; - if ( ras.render_span ) /* for FT_RASTER_FLAG_DIRECT only */ - { - FT_Span span; + unsigned char* line = ras.target.origin - ras.target.pitch * y; - span.x = (short)x; - span.len = (unsigned short)acount; - span.coverage = (unsigned char)coverage; + for ( ; cell != ras.cell_null; cell = cell->next ) + { + TArea area; - ras.render_span( y, 1, &span, ras.render_span_data ); - } - else - { - unsigned char* q = ras.target.origin - ras.target.pitch * y + x; - unsigned char c = (unsigned char)coverage; + if ( cover != 0 && cell->x > x ) + { + FT_FILL_RULE( coverage, cover, fill ); + FT_GRAY_SET( line + x, coverage, cell->x - x ); + } - /* For small-spans it is faster to do it by ourselves than - * calling `memset'. This is mainly due to the cost of the - * function call. - */ - switch ( acount ) + cover += (TArea)cell->cover * ( ONE_PIXEL * 2 ); + area = cover - cell->area; + + if ( area != 0 && cell->x >= ras.min_ex ) + { + FT_FILL_RULE( coverage, area, fill ); + line[cell->x] = (unsigned char)coverage; + } + + x = cell->x + 1; + } + + if ( cover != 0 ) /* only if cropped */ { - case 7: *q++ = c; - case 6: *q++ = c; - case 5: *q++ = c; - case 4: *q++ = c; - case 3: *q++ = c; - case 2: *q++ = c; - case 1: *q = c; - case 0: break; - default: - FT_MEM_SET( q, c, acount ); + FT_FILL_RULE( coverage, cover, fill ); + FT_GRAY_SET( line + x, coverage, ras.max_ex - x ); } } } static void - gray_sweep( RAS_ARG ) + gray_sweep_direct( RAS_ARG ) { + int fill = ( ras.outline.flags & FT_OUTLINE_EVEN_ODD_FILL ) ? 0x100 + : INT_MIN; + int coverage; int y; + FT_Span span[FT_MAX_GRAY_SPANS]; + int n = 0; + for ( y = ras.min_ey; y < ras.max_ey; y++ ) { PCell cell = ras.ycells[y - ras.min_ey]; TCoord x = ras.min_ex; TArea cover = 0; - TArea area; - for ( ; cell != NULL; cell = cell->next ) + for ( ; cell != ras.cell_null; cell = cell->next ) { + TArea area; + + if ( cover != 0 && cell->x > x ) - gray_hline( RAS_VAR_ x, y, cover, cell->x - x ); + { + FT_FILL_RULE( coverage, cover, fill ); + + span[n].coverage = (unsigned char)coverage; + span[n].x = (short)x; + span[n].len = (unsigned short)( cell->x - x ); + + if ( ++n == FT_MAX_GRAY_SPANS ) + { + /* flush the span buffer and reset the count */ + ras.render_span( y, n, span, ras.render_span_data ); + n = 0; + } + } cover += (TArea)cell->cover * ( ONE_PIXEL * 2 ); area = cover - cell->area; if ( area != 0 && cell->x >= ras.min_ex ) - gray_hline( RAS_VAR_ cell->x, y, area, 1 ); + { + FT_FILL_RULE( coverage, area, fill ); + + span[n].coverage = (unsigned char)coverage; + span[n].x = (short)cell->x; + span[n].len = 1; + + if ( ++n == FT_MAX_GRAY_SPANS ) + { + /* flush the span buffer and reset the count */ + ras.render_span( y, n, span, ras.render_span_data ); + n = 0; + } + } x = cell->x + 1; } - if ( cover != 0 ) - gray_hline( RAS_VAR_ x, y, cover, ras.max_ex - x ); + if ( cover != 0 ) /* only if cropped */ + { + FT_FILL_RULE( coverage, cover, fill ); + + span[n].coverage = (unsigned char)coverage; + span[n].x = (short)x; + span[n].len = (unsigned short)( ras.max_ex - x ); + + ++n; + } + + if ( n ) + { + /* flush the span buffer and reset the count */ + ras.render_span( y, n, span, ras.render_span_data ); + n = 0; + } } } #ifdef STANDALONE_ - /*************************************************************************/ - /* */ - /* The following functions should only compile in stand-alone mode, */ - /* i.e., when building this component without the rest of FreeType. */ - /* */ - /*************************************************************************/ - - /*************************************************************************/ - /* */ - /* <Function> */ - /* FT_Outline_Decompose */ - /* */ - /* <Description> */ - /* Walk over an outline's structure to decompose it into individual */ - /* segments and Bézier arcs. This function is also able to emit */ - /* `move to' and `close to' operations to indicate the start and end */ - /* of new contours in the outline. */ - /* */ - /* <Input> */ - /* outline :: A pointer to the source target. */ - /* */ - /* func_interface :: A table of `emitters', i.e., function pointers */ - /* called during decomposition to indicate path */ - /* operations. */ - /* */ - /* <InOut> */ - /* user :: A typeless pointer which is passed to each */ - /* emitter during the decomposition. It can be */ - /* used to store the state during the */ - /* decomposition. */ - /* */ - /* <Return> */ - /* Error code. 0 means success. */ - /* */ + /************************************************************************** + * + * The following functions should only compile in stand-alone mode, + * i.e., when building this component without the rest of FreeType. + * + */ + + /************************************************************************** + * + * @Function: + * FT_Outline_Decompose + * + * @Description: + * Walk over an outline's structure to decompose it into individual + * segments and Bézier arcs. This function is also able to emit + * `move to' and `close to' operations to indicate the start and end + * of new contours in the outline. + * + * @Input: + * outline :: + * A pointer to the source target. + * + * func_interface :: + * A table of `emitters', i.e., function pointers + * called during decomposition to indicate path + * operations. + * + * @InOut: + * user :: + * A typeless pointer which is passed to each + * emitter during the decomposition. It can be + * used to store the state during the + * decomposition. + * + * @Return: + * Error code. 0 means success. + */ static int FT_Outline_Decompose( const FT_Outline* outline, const FT_Outline_Funcs* func_interface, void* user ) { #undef SCALED -#define SCALED( x ) ( ( (x) << shift ) - delta ) +#define SCALED( x ) ( (x) * ( 1L << shift ) - delta ) FT_Vector v_last; FT_Vector v_control; @@ -1384,6 +1678,8 @@ typedef ptrdiff_t FT_PtrDist; int n; /* index of contour in outline */ int first; /* index of first point in contour */ + int last; /* index of last point in contour */ + char tag; /* current point's state */ int shift; @@ -1398,18 +1694,17 @@ typedef ptrdiff_t FT_PtrDist; shift = func_interface->shift; delta = func_interface->delta; - first = 0; + last = -1; for ( n = 0; n < outline->n_contours; n++ ) { - int last; /* index of last point in contour */ - - - FT_TRACE5(( "FT_Outline_Decompose: Outline %d\n", n )); + FT_TRACE5(( "FT_Outline_Decompose: Contour %d\n", n )); + first = last + 1; last = outline->contours[n]; - if ( last < 0 ) + if ( last < first ) goto Invalid_Outline; + limit = outline->points + last; v_start = outline->points[first]; @@ -1592,15 +1887,13 @@ typedef ptrdiff_t FT_PtrDist; v_start.x / 64.0, v_start.y / 64.0 )); error = func_interface->line_to( &v_start, user ); - Close: + Close: if ( error ) goto Exit; - - first = last + 1; } FT_TRACE5(( "FT_Outline_Decompose: Done\n", n )); - return 0; + return Smooth_Err_Ok; Exit: FT_TRACE5(( "FT_Outline_Decompose: Error 0x%x\n", error )); @@ -1610,81 +1903,6 @@ typedef ptrdiff_t FT_PtrDist; return FT_THROW( Invalid_Outline ); } - - /*************************************************************************/ - /* */ - /* <Function> */ - /* FT_Outline_Get_CBox */ - /* */ - /* <Description> */ - /* Return an outline's `control box'. The control box encloses all */ - /* the outline's points, including Bézier control points. Though it */ - /* coincides with the exact bounding box for most glyphs, it can be */ - /* slightly larger in some situations (like when rotating an outline */ - /* that contains Bézier outside arcs). */ - /* */ - /* Computing the control box is very fast, while getting the bounding */ - /* box can take much more time as it needs to walk over all segments */ - /* and arcs in the outline. To get the latter, you can use the */ - /* `ftbbox' component, which is dedicated to this single task. */ - /* */ - /* <Input> */ - /* outline :: A pointer to the source outline descriptor. */ - /* */ - /* <Output> */ - /* acbox :: The outline's control box. */ - /* */ - /* <Note> */ - /* See @FT_Glyph_Get_CBox for a discussion of tricky fonts. */ - /* */ - - static void - FT_Outline_Get_CBox( const FT_Outline* outline, - FT_BBox *acbox ) - { - TPos xMin, yMin, xMax, yMax; - - - if ( outline && acbox ) - { - if ( outline->n_points == 0 ) - { - xMin = 0; - yMin = 0; - xMax = 0; - yMax = 0; - } - else - { - FT_Vector* vec = outline->points; - FT_Vector* limit = vec + outline->n_points; - - - xMin = xMax = vec->x; - yMin = yMax = vec->y; - vec++; - - for ( ; vec < limit; vec++ ) - { - TPos x, y; - - - x = vec->x; - if ( x < xMin ) xMin = x; - if ( x > xMax ) xMax = x; - - y = vec->y; - if ( y < yMin ) yMin = y; - if ( y > yMax ) yMax = y; - } - } - acbox->xMin = xMin; - acbox->xMax = xMax; - acbox->yMin = yMin; - acbox->yMax = yMax; - } - } - #endif /* STANDALONE_ */ @@ -1702,31 +1920,29 @@ typedef ptrdiff_t FT_PtrDist; static int - gray_convert_glyph_inner( RAS_ARG ) + gray_convert_glyph_inner( RAS_ARG_ + int continued ) { + volatile int error; - volatile int error = 0; - -#ifdef FT_CONFIG_OPTION_PIC - FT_Outline_Funcs func_interface; - Init_Class_func_interface(&func_interface); -#endif if ( ft_setjmp( ras.jump_buffer ) == 0 ) { + if ( continued ) + FT_Trace_Disable(); error = FT_Outline_Decompose( &ras.outline, &func_interface, &ras ); - if ( !ras.invalid ) - gray_record_cell( RAS_VAR ); + if ( continued ) + FT_Trace_Enable(); - FT_TRACE7(( "band [%d..%d]: %d cell%s\n", + FT_TRACE7(( "band [%d..%d]: %td cell%s remaining/\n", ras.min_ey, ras.max_ey, - ras.num_cells, - ras.num_cells == 1 ? "" : "s" )); + ras.cell_null - ras.cell_free, + ras.cell_null - ras.cell_free == 1 ? "" : "s" )); } else { - error = FT_THROW( Memory_Overflow ); + error = FT_THROW( Raster_Overflow ); FT_TRACE7(( "band [%d..%d]: to be bisected\n", ras.min_ey, ras.max_ey )); @@ -1741,8 +1957,6 @@ typedef ptrdiff_t FT_PtrDist; { const TCoord yMin = ras.min_ey; const TCoord yMax = ras.max_ey; - const TCoord xMin = ras.min_ex; - const TCoord xMax = ras.max_ex; TCell buffer[FT_MAX_GRAY_POOL]; size_t height = (size_t)( yMax - yMin ); @@ -1751,8 +1965,19 @@ typedef ptrdiff_t FT_PtrDist; TCoord bands[32]; /* enough to accommodate bisections */ TCoord* band; + int continued = 0; + + + /* Initialize the null cell at the end of the poll. */ + ras.cell_null = buffer + FT_MAX_GRAY_POOL - 1; + ras.cell_null->x = CELL_MAX_X_VALUE; + ras.cell_null->area = 0; + ras.cell_null->cover = 0; + ras.cell_null->next = NULL; /* set up vertical bands */ + ras.ycells = (PCell*)buffer; + if ( height > n ) { /* two divisions rounded up */ @@ -1760,13 +1985,6 @@ typedef ptrdiff_t FT_PtrDist; height = ( height + n - 1 ) / n; } - /* memory management */ - n = ( height * sizeof ( PCell ) + sizeof ( TCell ) - 1 ) / sizeof ( TCell ); - - ras.cells = buffer + n; - ras.max_cells = (FT_PtrDist)( FT_MAX_GRAY_POOL - n ); - ras.ycells = (PCell*)buffer; - for ( y = yMin; y < yMax; ) { ras.min_ey = y; @@ -1774,32 +1992,43 @@ typedef ptrdiff_t FT_PtrDist; ras.max_ey = FT_MIN( y, yMax ); band = bands; - band[1] = xMin; - band[0] = xMax; + band[1] = ras.min_ey; + band[0] = ras.max_ey; do { TCoord width = band[0] - band[1]; + TCoord w; int error; - FT_MEM_ZERO( ras.ycells, height * sizeof ( PCell ) ); + for ( w = 0; w < width; ++w ) + ras.ycells[w] = ras.cell_null; + + /* memory management: skip ycells */ + n = ( (size_t)width * sizeof ( PCell ) + sizeof ( TCell ) - 1 ) / + sizeof ( TCell ); - ras.num_cells = 0; - ras.invalid = 1; - ras.min_ex = band[1]; - ras.max_ex = band[0]; + ras.cell_free = buffer + n; + ras.cell = ras.cell_null; + ras.min_ey = band[1]; + ras.max_ey = band[0]; + ras.count_ey = width; - error = gray_convert_glyph_inner( RAS_VAR ); + error = gray_convert_glyph_inner( RAS_VAR_ continued ); + continued = 1; if ( !error ) { - gray_sweep( RAS_VAR ); + if ( ras.render_span ) /* for FT_RASTER_FLAG_DIRECT only */ + gray_sweep_direct( RAS_VAR ); + else + gray_sweep( RAS_VAR ); band--; continue; } - else if ( error != ErrRaster_Memory_Overflow ) - return 1; + else if ( error != Smooth_Err_Raster_Overflow ) + return error; /* render pool overflow; we will reduce the render band by half */ width >>= 1; @@ -1808,7 +2037,7 @@ typedef ptrdiff_t FT_PtrDist; if ( width == 0 ) { FT_TRACE7(( "gray_convert_glyph: rotten glyph\n" )); - return 1; + return FT_THROW( Raster_Overflow ); } band++; @@ -1817,7 +2046,7 @@ typedef ptrdiff_t FT_PtrDist; } while ( band >= bands ); } - return 0; + return Smooth_Err_Ok; } @@ -1827,7 +2056,6 @@ typedef ptrdiff_t FT_PtrDist; { const FT_Outline* outline = (const FT_Outline*)params->source; const FT_Bitmap* target_map = params->target; - FT_BBox cbox, clip; #ifndef FT_STATIC_RASTER gray_TWorker worker[1]; @@ -1839,14 +2067,14 @@ typedef ptrdiff_t FT_PtrDist; /* this version does not support monochrome rendering */ if ( !( params->flags & FT_RASTER_FLAG_AA ) ) - return FT_THROW( Invalid_Mode ); + return FT_THROW( Cannot_Render_Glyph ); if ( !outline ) return FT_THROW( Invalid_Outline ); /* return immediately if the outline is empty */ if ( outline->n_points == 0 || outline->n_contours <= 0 ) - return 0; + return Smooth_Err_Ok; if ( !outline->contours || !outline->points ) return FT_THROW( Invalid_Outline ); @@ -1860,10 +2088,15 @@ typedef ptrdiff_t FT_PtrDist; if ( params->flags & FT_RASTER_FLAG_DIRECT ) { if ( !params->gray_spans ) - return 0; + return Smooth_Err_Ok; ras.render_span = (FT_Raster_Span_Func)params->gray_spans; ras.render_span_data = params->user; + + ras.min_ex = params->clip_box.xMin; + ras.min_ey = params->clip_box.yMin; + ras.max_ex = params->clip_box.xMax; + ras.max_ey = params->clip_box.yMax; } else { @@ -1873,7 +2106,7 @@ typedef ptrdiff_t FT_PtrDist; /* nothing to do */ if ( !target_map->width || !target_map->rows ) - return 0; + return Smooth_Err_Ok; if ( !target_map->buffer ) return FT_THROW( Invalid_Argument ); @@ -1888,48 +2121,16 @@ typedef ptrdiff_t FT_PtrDist; ras.render_span = (FT_Raster_Span_Func)NULL; ras.render_span_data = NULL; - } - FT_Outline_Get_CBox( outline, &cbox ); - - /* reject too large outline coordinates */ - if ( cbox.xMin < -0x1000000L || cbox.xMax > 0x1000000L || - cbox.yMin < -0x1000000L || cbox.yMax > 0x1000000L ) - return FT_THROW( Invalid_Outline ); - - /* truncate the bounding box to integer pixels */ - cbox.xMin = cbox.xMin >> 6; - cbox.yMin = cbox.yMin >> 6; - cbox.xMax = ( cbox.xMax + 63 ) >> 6; - cbox.yMax = ( cbox.yMax + 63 ) >> 6; - - /* compute clipping box */ - if ( !( params->flags & FT_RASTER_FLAG_DIRECT ) ) - { - /* compute clip box from target pixmap */ - clip.xMin = 0; - clip.yMin = 0; - clip.xMax = (FT_Pos)target_map->width; - clip.yMax = (FT_Pos)target_map->rows; - } - else if ( params->flags & FT_RASTER_FLAG_CLIP ) - clip = params->clip_box; - else - { - clip.xMin = -32768L; - clip.yMin = -32768L; - clip.xMax = 32767L; - clip.yMax = 32767L; + ras.min_ex = 0; + ras.min_ey = 0; + ras.max_ex = (FT_Pos)target_map->width; + ras.max_ey = (FT_Pos)target_map->rows; } - /* clip to target bitmap, exit if nothing to do */ - ras.min_ex = FT_MAX( cbox.xMin, clip.xMin ); - ras.min_ey = FT_MAX( cbox.yMin, clip.yMin ); - ras.max_ex = FT_MIN( cbox.xMax, clip.xMax ); - ras.max_ey = FT_MIN( cbox.yMax, clip.yMax ); - + /* exit if nothing to do */ if ( ras.max_ex <= ras.min_ex || ras.max_ey <= ras.min_ey ) - return 0; + return Smooth_Err_Ok; return gray_convert_glyph( RAS_VAR ); } @@ -1966,19 +2167,20 @@ typedef ptrdiff_t FT_PtrDist; #else /* !STANDALONE_ */ static int - gray_raster_new( FT_Memory memory, - FT_Raster* araster ) + gray_raster_new( void* memory_, + FT_Raster* araster_ ) { + FT_Memory memory = (FT_Memory)memory_; + gray_PRaster* araster = (gray_PRaster*)araster_; + FT_Error error; gray_PRaster raster = NULL; - *araster = 0; - if ( !FT_ALLOC( raster, sizeof ( gray_TRaster ) ) ) - { + if ( !FT_NEW( raster ) ) raster->memory = memory; - *araster = (FT_Raster)raster; - } + + *araster = raster; return error; } |