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authorQt Forward Merge Bot <qt_forward_merge_bot@qt-project.org>2019-11-08 09:11:01 +0100
committerQt Forward Merge Bot <qt_forward_merge_bot@qt-project.org>2019-11-08 09:11:02 +0100
commit78c687f98eabb3da00026ac2375cdb4bb5770a0a (patch)
tree0bd20a65aa9051229e813bc6b09cb59f8b5778f1 /src/3rdparty/freetype/src/smooth/ftgrays.c
parent3e529369eb16704aa0d601a7f4b8e490dc8b772c (diff)
parenta866055d18b2c2efc0f3cf5307d8eac78cce26eb (diff)
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.c724
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;