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Diffstat (limited to 'Build/source/libs/freetype2/freetype-src/src/smooth/ftgrays.c')
-rw-r--r--Build/source/libs/freetype2/freetype-src/src/smooth/ftgrays.c95
1 files changed, 39 insertions, 56 deletions
diff --git a/Build/source/libs/freetype2/freetype-src/src/smooth/ftgrays.c b/Build/source/libs/freetype2/freetype-src/src/smooth/ftgrays.c
index ba42c9ca968..e9a3ce7a7c7 100644
--- a/Build/source/libs/freetype2/freetype-src/src/smooth/ftgrays.c
+++ b/Build/source/libs/freetype2/freetype-src/src/smooth/ftgrays.c
@@ -4,7 +4,7 @@
/* */
/* A new `perfect' anti-aliasing renderer (body). */
/* */
-/* Copyright 2000-2016 by */
+/* Copyright 2000-2017 by */
/* David Turner, Robert Wilhelm, and Werner Lemberg. */
/* */
/* This file is part of the FreeType project, and may only be used, */
@@ -341,7 +341,8 @@ typedef ptrdiff_t FT_PtrDist;
/* Compute `dividend / divisor' and return both its quotient and */
/* remainder, cast to a specific type. This macro also ensures that */
- /* the remainder is always positive. */
+ /* the remainder is always positive. We use the remainder to keep */
+ /* track of accumulating errors and compensate for them. */
#define FT_DIV_MOD( type, dividend, divisor, quotient, remainder ) \
FT_BEGIN_STMNT \
(quotient) = (type)( (dividend) / (divisor) ); \
@@ -567,9 +568,6 @@ 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. */
- /* All cells that are on the left of the clipping region go to the */
- /* min_ex - 1 horizontal position. */
-
if ( ex < ras.min_ex )
ex = ras.min_ex - 1;
@@ -600,7 +598,7 @@ typedef ptrdiff_t FT_PtrDist;
TPos x2,
TCoord y2 )
{
- TCoord ex1, ex2, fx1, fx2, first, delta, mod;
+ TCoord ex1, ex2, fx1, fx2, first, dy, delta, mod;
TPos p, dx;
int incr;
@@ -617,31 +615,27 @@ typedef ptrdiff_t FT_PtrDist;
fx1 = (TCoord)( x1 - SUBPIXELS( ex1 ) );
fx2 = (TCoord)( x2 - SUBPIXELS( ex2 ) );
- delta = y2 - y1;
/* everything is located in a single cell. That is easy! */
/* */
if ( ex1 == ex2 )
- {
- ras.area += (TArea)(( fx1 + fx2 ) * delta);
- ras.cover += delta;
- return;
- }
+ goto End;
/* ok, we'll have to render a run of adjacent cells on the same */
/* scanline... */
/* */
dx = x2 - x1;
+ dy = y2 - y1;
if ( dx > 0 )
{
- p = ( ONE_PIXEL - fx1 ) * delta;
+ p = ( ONE_PIXEL - fx1 ) * dy;
first = ONE_PIXEL;
incr = 1;
}
else
{
- p = fx1 * delta;
+ p = fx1 * dy;
first = 0;
incr = -1;
dx = -dx;
@@ -649,34 +643,31 @@ typedef ptrdiff_t FT_PtrDist;
FT_DIV_MOD( TCoord, p, dx, delta, mod );
- ras.area += (TArea)(( fx1 + first ) * delta);
+ ras.area += (TArea)( ( fx1 + first ) * delta );
ras.cover += delta;
-
- ex1 += incr;
+ y1 += delta;
+ ex1 += incr;
gray_set_cell( RAS_VAR_ ex1, ey );
- y1 += delta;
if ( ex1 != ex2 )
{
TCoord lift, rem;
- p = ONE_PIXEL * ( y2 - y1 + delta );
+ p = ONE_PIXEL * dy;
FT_DIV_MOD( TCoord, p, dx, lift, rem );
- mod -= (int)dx;
-
do
{
delta = lift;
mod += rem;
- if ( mod >= 0 )
+ if ( mod >= (TCoord)dx )
{
mod -= (TCoord)dx;
delta++;
}
- ras.area += (TArea)(ONE_PIXEL * delta);
+ ras.area += (TArea)( ONE_PIXEL * delta );
ras.cover += delta;
y1 += delta;
ex1 += incr;
@@ -684,9 +675,13 @@ typedef ptrdiff_t FT_PtrDist;
} while ( ex1 != ex2 );
}
- delta = y2 - y1;
- ras.area += (TArea)(( fx2 + ONE_PIXEL - first ) * delta);
- ras.cover += delta;
+ fx1 = ONE_PIXEL - first;
+
+ End:
+ dy = y2 - y1;
+
+ ras.area += (TArea)( ( fx1 + fx2 ) * dy );
+ ras.cover += dy;
}
@@ -798,13 +793,12 @@ typedef ptrdiff_t FT_PtrDist;
p = ONE_PIXEL * dx;
FT_DIV_MOD( TCoord, p, dy, lift, rem );
- mod -= (TCoord)dy;
do
{
delta = lift;
mod += rem;
- if ( mod >= 0 )
+ if ( mod >= (TCoord)dy )
{
mod -= (TCoord)dy;
delta++;
@@ -1228,31 +1222,21 @@ typedef ptrdiff_t FT_PtrDist;
static void
gray_hline( RAS_ARG_ TCoord x,
TCoord y,
- TArea area,
+ TArea coverage,
TCoord acount )
{
- int coverage;
- FT_Span span;
-
-
- /* compute the coverage line's coverage, depending on the */
- /* outline fill rule */
- /* */
- /* the coverage percentage is area/(PIXEL_BITS*PIXEL_BITS*2) */
- /* */
- coverage = (int)( area >> ( PIXEL_BITS * 2 + 1 - 8 ) );
- /* use range 0..256 */
+ /* scale the coverage from 0..(ONE_PIXEL*ONE_PIXEL*2) to 0..256 */
+ coverage >>= PIXEL_BITS * 2 + 1 - 8;
if ( coverage < 0 )
- coverage = -coverage;
+ coverage = -coverage - 1;
+ /* 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 = 512 - coverage;
- else if ( coverage == 256 )
- coverage = 255;
+ if ( coverage >= 256 )
+ coverage = 511 - coverage;
}
else
{
@@ -1263,6 +1247,9 @@ typedef ptrdiff_t FT_PtrDist;
if ( ras.render_span ) /* for FT_RASTER_FLAG_DIRECT only */
{
+ FT_Span span;
+
+
span.x = (short)x;
span.len = (unsigned short)acount;
span.coverage = (unsigned char)coverage;
@@ -1307,21 +1294,18 @@ typedef ptrdiff_t FT_PtrDist;
for ( y = ras.min_ey; y < ras.max_ey; y++ )
{
PCell cell = ras.ycells[y - ras.min_ey];
- TCoord cover = 0;
TCoord x = ras.min_ex;
+ TArea cover = 0;
+ TArea area;
for ( ; cell != NULL; cell = cell->next )
{
- TArea area;
-
-
if ( cover != 0 && cell->x > x )
- gray_hline( RAS_VAR_ x, y, (TArea)cover * ( ONE_PIXEL * 2 ),
- cell->x - x );
+ gray_hline( RAS_VAR_ x, y, cover, cell->x - x );
- cover += cell->cover;
- area = (TArea)cover * ( ONE_PIXEL * 2 ) - cell->area;
+ 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 );
@@ -1330,8 +1314,7 @@ typedef ptrdiff_t FT_PtrDist;
}
if ( cover != 0 )
- gray_hline( RAS_VAR_ x, y, (TArea)cover * ( ONE_PIXEL * 2 ),
- ras.max_ex - x );
+ gray_hline( RAS_VAR_ x, y, cover, ras.max_ex - x );
}
FT_TRACE7(( "gray_sweep: end\n" ));
@@ -1613,7 +1596,7 @@ typedef ptrdiff_t FT_PtrDist;
return 0;
Exit:
- FT_TRACE5(( "FT_Outline_Decompose: Error %d\n", error ));
+ FT_TRACE5(( "FT_Outline_Decompose: Error 0x%x\n", error ));
return error;
Invalid_Outline: