diff options
author | Qt Forward Merge Bot <qt_forward_merge_bot@qt-project.org> | 2019-11-08 09:11:01 +0100 |
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committer | Qt Forward Merge Bot <qt_forward_merge_bot@qt-project.org> | 2019-11-08 09:11:15 +0100 |
commit | dd1bb0de7b141c3f37068b49b0181ec829dc1aee (patch) | |
tree | d984a3298f5dff4cc4af339bf83e91630186c458 /src/3rdparty/freetype/src/smooth/ftgrays.c | |
parent | f0a43a9def456784fd9408e3026d6689c8b715c1 (diff) | |
parent | 78c687f98eabb3da00026ac2375cdb4bb5770a0a (diff) |
Merge "Merge remote-tracking branch 'origin/5.14' into 5.15"
Diffstat (limited to 'src/3rdparty/freetype/src/smooth/ftgrays.c')
-rw-r--r-- | src/3rdparty/freetype/src/smooth/ftgrays.c | 724 |
1 files changed, 315 insertions, 409 deletions
diff --git a/src/3rdparty/freetype/src/smooth/ftgrays.c b/src/3rdparty/freetype/src/smooth/ftgrays.c index 803a19e415..fd357a50fc 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) 2000-2019 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 ), \ @@ -222,10 +230,10 @@ typedef ptrdiff_t FT_PtrDist; #endif #define FT_THROW( e ) \ - ( FT_Throw( FT_ERR_CAT( ErrRaster, e ), \ + ( FT_Throw( FT_ERR_CAT( ErrRaster_, e ), \ __LINE__, \ __FILE__ ) | \ - FT_ERR_CAT( ErrRaster, e ) ) + FT_ERR_CAT( ErrRaster_, e ) ) #else /* !FT_DEBUG_LEVEL_TRACE */ @@ -279,8 +287,6 @@ typedef ptrdiff_t FT_PtrDist; #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 @@ -329,17 +335,9 @@ 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 ) +#define TRUNC( x ) (TCoord)( (x) >> PIXEL_BITS ) +#define FRACT( x ) (TCoord)( (x) & ( ONE_PIXEL - 1 ) ) #if PIXEL_BITS >= 6 #define UPSCALE( x ) ( (x) * ( ONE_PIXEL >> 6 ) ) @@ -390,15 +388,15 @@ typedef ptrdiff_t FT_PtrDist; #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 ) ) +#define FT_UDIV( a, b ) \ + (TCoord)( ( (unsigned long)( a ) * (unsigned long)( b ## _r ) ) >> \ + ( sizeof( long ) * FT_CHAR_BIT - PIXEL_BITS ) ) - /*************************************************************************/ - /* */ - /* 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 +432,9 @@ 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 10 + #if defined( _MSC_VER ) /* Visual C++ (and Intel C++) */ /* We disable the warning `structure was padded due to */ @@ -467,6 +468,8 @@ typedef ptrdiff_t FT_PtrDist; FT_Raster_Span_Func render_span; void* render_span_data; + FT_Span spans[FT_MAX_GRAY_SPANS]; + int num_spans; } gray_TWorker, *gray_PWorker; @@ -516,10 +519,10 @@ typedef ptrdiff_t FT_PtrDist; #endif /* FT_DEBUG_LEVEL_TRACE */ - /*************************************************************************/ - /* */ - /* Record the current cell in the table. */ - /* */ + /************************************************************************** + * + * Record the current cell in the linked list. + */ static void gray_record_cell( RAS_ARG ) { @@ -528,10 +531,9 @@ typedef ptrdiff_t FT_PtrDist; pcell = &ras.ycells[ras.ey - ras.min_ey]; - for (;;) + while ( ( cell = *pcell ) ) { - cell = *pcell; - if ( !cell || cell->x > x ) + if ( cell->x > x ) break; if ( cell->x == x ) @@ -561,10 +563,10 @@ typedef ptrdiff_t FT_PtrDist; } - /*************************************************************************/ - /* */ - /* Set the current cell to a new position. */ - /* */ + /************************************************************************** + * + * Set the current cell to a new position. + */ static void gray_set_cell( RAS_ARG_ TCoord ex, TCoord ey ) @@ -579,16 +581,13 @@ typedef ptrdiff_t FT_PtrDist; /* 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 ( ex < ras.min_ex ) - ex = ras.min_ex - 1; - /* record the current one if it is valid and substantial */ if ( !ras.invalid && ( ras.area || ras.cover ) ) gray_record_cell( RAS_VAR ); ras.area = 0; ras.cover = 0; - ras.ex = ex; + ras.ex = FT_MAX( ex, ras.min_ex - 1 ); ras.ey = ey; ras.invalid = ( ey >= ras.max_ey || ey < ras.min_ey || @@ -598,10 +597,10 @@ typedef ptrdiff_t FT_PtrDist; #ifndef FT_LONG64 - /*************************************************************************/ - /* */ - /* 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 +623,8 @@ 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! */ /* */ @@ -652,6 +651,9 @@ 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 ); @@ -696,10 +698,10 @@ typedef ptrdiff_t FT_PtrDist; } - /*************************************************************************/ - /* */ - /* 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 +719,8 @@ 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 ) @@ -734,7 +736,7 @@ typedef ptrdiff_t FT_PtrDist; if ( dx == 0 ) { TCoord ex = TRUNC( ras.x ); - TCoord two_fx = (TCoord)( ( ras.x - SUBPIXELS( ex ) ) << 1 ); + TCoord two_fx = FRACT( ras.x ) << 1; TArea area; @@ -789,6 +791,8 @@ 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 +841,17 @@ 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 +865,8 @@ 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 +875,8 @@ 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 ) { @@ -898,7 +903,7 @@ typedef ptrdiff_t FT_PtrDist; } else /* any other line */ { - TPos prod = dx * fy1 - dy * fx1; + TPos prod = dx * (TPos)fy1 - dy * (TPos)fx1; FT_UDIVPREP( ex1 != ex2, dx ); FT_UDIVPREP( ey1 != ey2, dy ); @@ -912,7 +917,7 @@ typedef ptrdiff_t FT_PtrDist; prod - dx * ONE_PIXEL > 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 ); @@ -924,7 +929,7 @@ typedef ptrdiff_t FT_PtrDist; prod - dx * ONE_PIXEL + dy * 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 ); @@ -937,7 +942,7 @@ typedef ptrdiff_t FT_PtrDist; { prod += dy * ONE_PIXEL; fx2 = ONE_PIXEL; - fy2 = (TPos)FT_UDIV( prod, dx ); + fy2 = FT_UDIV( prod, dx ); ras.cover += ( fy2 - fy1 ); ras.area += ( fy2 - fy1 ) * ( fx1 + fx2 ); fx1 = 0; @@ -947,7 +952,7 @@ typedef ptrdiff_t FT_PtrDist; else /* ( prod + dy * ONE_PIXEL < 0 && prod > 0 ) down */ { - fx2 = (TPos)FT_UDIV( prod, -dy ); + fx2 = FT_UDIV( prod, -dy ); fy2 = 0; prod += dx * ONE_PIXEL; ras.cover += ( fy2 - fy1 ); @@ -961,8 +966,8 @@ typedef ptrdiff_t FT_PtrDist; } 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 ); @@ -981,16 +986,18 @@ 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; } @@ -1044,12 +1051,11 @@ typedef ptrdiff_t FT_PtrDist; /* many times as there are trailing zeros in the counter. */ do { - split = 1; - while ( ( draw & split ) == 0 ) + 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 ); @@ -1062,28 +1068,32 @@ typedef ptrdiff_t FT_PtrDist; 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 +1104,6 @@ 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 +1132,13 @@ 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 ); @@ -1238,8 +1213,6 @@ typedef ptrdiff_t FT_PtrDist; { /* 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; /* compute the line's coverage depending on the outline fill rule */ if ( ras.outline.flags & FT_OUTLINE_EVEN_ODD_FILL ) @@ -1249,23 +1222,30 @@ typedef ptrdiff_t FT_PtrDist; if ( coverage >= 256 ) coverage = 511 - coverage; } - else + else /* default non-zero winding rule */ { - /* normal non-zero winding rule */ + if ( coverage < 0 ) + coverage = ~coverage; /* the same as -coverage - 1 */ + if ( coverage >= 256 ) coverage = 255; } - if ( ras.render_span ) /* for FT_RASTER_FLAG_DIRECT only */ + if ( ras.num_spans >= 0 ) /* for FT_RASTER_FLAG_DIRECT only */ { - FT_Span span; + FT_Span* span = ras.spans + ras.num_spans++; - span.x = (short)x; - span.len = (unsigned short)acount; - span.coverage = (unsigned char)coverage; + span->x = (short)x; + span->len = (unsigned short)acount; + span->coverage = (unsigned char)coverage; - ras.render_span( y, 1, &span, ras.render_span_data ); + if ( ras.num_spans == FT_MAX_GRAY_SPANS ) + { + /* flush the span buffer and reset the count */ + ras.render_span( y, ras.num_spans, ras.spans, ras.render_span_data ); + ras.num_spans = 0; + } } else { @@ -1279,14 +1259,29 @@ typedef ptrdiff_t FT_PtrDist; */ switch ( acount ) { - 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; + case 7: + *q++ = c; + /* fall through */ + case 6: + *q++ = c; + /* fall through */ + case 5: + *q++ = c; + /* fall through */ + case 4: + *q++ = c; + /* fall through */ + case 3: + *q++ = c; + /* fall through */ + case 2: + *q++ = c; + /* fall through */ + case 1: + *q = c; + /* fall through */ + case 0: + break; default: FT_MEM_SET( q, c, acount ); } @@ -1324,53 +1319,63 @@ typedef ptrdiff_t FT_PtrDist; if ( cover != 0 ) gray_hline( RAS_VAR_ x, y, cover, ras.max_ex - x ); + + if ( ras.num_spans > 0 ) /* for FT_RASTER_FLAG_DIRECT only */ + { + /* flush the span buffer and reset the count */ + ras.render_span( y, ras.num_spans, ras.spans, ras.render_span_data ); + ras.num_spans = 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; @@ -1610,81 +1615,6 @@ 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_ */ @@ -1702,19 +1632,20 @@ typedef ptrdiff_t FT_PtrDist; static int - gray_convert_glyph_inner( RAS_ARG ) + gray_convert_glyph_inner( RAS_ARG, + int continued ) { + 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 ( continued ) + FT_Trace_Enable(); + if ( !ras.invalid ) gray_record_cell( RAS_VAR ); @@ -1741,8 +1672,6 @@ 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 ); @@ -1751,6 +1680,8 @@ typedef ptrdiff_t FT_PtrDist; TCoord bands[32]; /* enough to accommodate bisections */ TCoord* band; + int continued = 0; + /* set up vertical bands */ if ( height > n ) @@ -1774,8 +1705,8 @@ 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 { @@ -1787,10 +1718,11 @@ typedef ptrdiff_t FT_PtrDist; ras.num_cells = 0; ras.invalid = 1; - ras.min_ex = band[1]; - ras.max_ex = band[0]; + ras.min_ey = band[1]; + ras.max_ey = band[0]; - error = gray_convert_glyph_inner( RAS_VAR ); + error = gray_convert_glyph_inner( RAS_VAR, continued ); + continued = 1; if ( !error ) { @@ -1827,7 +1759,6 @@ 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]; @@ -1864,6 +1795,12 @@ typedef ptrdiff_t FT_PtrDist; ras.render_span = (FT_Raster_Span_Func)params->gray_spans; ras.render_span_data = params->user; + ras.num_spans = 0; + + 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 { @@ -1888,46 +1825,15 @@ 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; + ras.num_spans = -1; /* invalid */ - /* 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; + ras.min_ex = 0; + ras.min_ey = 0; + ras.max_ex = (FT_Pos)target_map->width; + ras.max_ey = (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; - } - - /* 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; |