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-rw-r--r--src/smooth/ftgrays.c196
1 files changed, 164 insertions, 32 deletions
diff --git a/src/smooth/ftgrays.c b/src/smooth/ftgrays.c
index 77b58f2..9a43c07 100644
--- a/src/smooth/ftgrays.c
+++ b/src/smooth/ftgrays.c
@@ -24,8 +24,8 @@
/* */
/* - copy `src/smooth/ftgrays.c' (this file) to your current directory */
/* */
- /* - copy `include/ftimage.h' and `src/smooth/ftgrays.h' to the same */
- /* directory */
+ /* - copy `include/freetype/ftimage.h' and `src/smooth/ftgrays.h' to the */
+ /* same directory */
/* */
/* - compile `ftgrays' with the _STANDALONE_ macro defined, as in */
/* */
@@ -135,8 +135,10 @@
#include <string.h>
#include <setjmp.h>
#include <limits.h>
-#define FT_UINT_MAX UINT_MAX
-#define FT_INT_MAX INT_MAX
+#define FT_CHAR_BIT CHAR_BIT
+#define FT_UINT_MAX UINT_MAX
+#define FT_INT_MAX INT_MAX
+#define FT_ULONG_MAX ULONG_MAX
#define ft_memset memset
@@ -317,7 +319,6 @@ typedef ptrdiff_t FT_PtrDist;
#undef SCALED
#define ONE_PIXEL ( 1L << PIXEL_BITS )
-#define PIXEL_MASK ( -1L << PIXEL_BITS )
#define TRUNC( x ) ( (TCoord)( (x) >> PIXEL_BITS ) )
#define SUBPIXELS( x ) ( (TPos)(x) << PIXEL_BITS )
#define FLOOR( x ) ( (x) & -ONE_PIXEL )
@@ -367,6 +368,15 @@ typedef ptrdiff_t FT_PtrDist;
#endif /* __arm__ */
+ /* These macros speed up repetitive divisions by replacing them */
+ /* with multiplications and right shifts. */
+#define FT_UDIVPREP( b ) \
+ long b ## _r = (long)( FT_ULONG_MAX >> PIXEL_BITS ) / ( b )
+#define FT_UDIV( a, b ) \
+ ( ( (unsigned long)( a ) * (unsigned long)( b ## _r ) ) >> \
+ ( sizeof( long ) * FT_CHAR_BIT - PIXEL_BITS ) )
+
+
/*************************************************************************/
/* */
/* TYPE DEFINITIONS */
@@ -440,11 +450,8 @@ typedef ptrdiff_t FT_PtrDist;
FT_PtrDist max_cells;
FT_PtrDist num_cells;
- TCoord cx, cy;
TPos x, y;
- TPos last_ey;
-
FT_Vector bez_stack[32 * 3 + 1];
int lev_stack[32];
@@ -677,12 +684,12 @@ typedef ptrdiff_t FT_PtrDist;
ras.cover = 0;
ras.ex = ex - ras.min_ex;
ras.ey = ey - ras.min_ey;
- ras.last_ey = SUBPIXELS( ey );
ras.invalid = 0;
gray_set_cell( RAS_VAR_ ex, ey );
}
+#if 0
/*************************************************************************/
/* */
@@ -758,7 +765,7 @@ typedef ptrdiff_t FT_PtrDist;
mod -= (int)dx;
- while ( ex1 != ex2 )
+ do
{
delta = lift;
mod += rem;
@@ -773,7 +780,7 @@ typedef ptrdiff_t FT_PtrDist;
y1 += delta;
ex1 += incr;
gray_set_cell( RAS_VAR_ ex1, ey );
- }
+ } while ( ex1 != ex2 );
}
delta = y2 - y1;
@@ -796,29 +803,18 @@ typedef ptrdiff_t FT_PtrDist;
int delta, rem, lift, incr;
- ey1 = TRUNC( ras.last_ey );
+ ey1 = TRUNC( ras.y );
ey2 = TRUNC( to_y ); /* if (ey2 >= ras.max_ey) ey2 = ras.max_ey-1; */
- fy1 = (TCoord)( ras.y - ras.last_ey );
+ fy1 = (TCoord)( ras.y - SUBPIXELS( ey1 ) );
fy2 = (TCoord)( to_y - SUBPIXELS( ey2 ) );
dx = to_x - ras.x;
dy = to_y - ras.y;
/* perform vertical clipping */
- {
- TCoord min, max;
-
-
- min = ey1;
- max = ey2;
- if ( ey1 > ey2 )
- {
- min = ey2;
- max = ey1;
- }
- if ( min >= ras.max_ey || max < ras.min_ey )
- goto End;
- }
+ if ( ( ey1 >= ras.max_ey && ey2 >= ras.max_ey ) ||
+ ( ey1 < ras.min_ey && ey2 < ras.min_ey ) )
+ goto End;
/* everything is on a single scanline */
if ( ey1 == ey2 )
@@ -896,7 +892,7 @@ typedef ptrdiff_t FT_PtrDist;
FT_DIV_MOD( int, p, dy, lift, rem );
mod -= (int)dy;
- while ( ey1 != ey2 )
+ do
{
delta = lift;
mod += rem;
@@ -914,7 +910,7 @@ typedef ptrdiff_t FT_PtrDist;
ey1 += incr;
gray_set_cell( RAS_VAR_ TRUNC( x ), ey1 );
- }
+ } while ( ey1 != ey2 );
}
gray_render_scanline( RAS_VAR_ ey1, x,
@@ -924,9 +920,145 @@ typedef ptrdiff_t FT_PtrDist;
End:
ras.x = to_x;
ras.y = to_y;
- ras.last_ey = SUBPIXELS( ey2 );
}
+#else
+
+ /*************************************************************************/
+ /* */
+ /* 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;
+
+
+ ex1 = TRUNC( ras.x );
+ ex2 = TRUNC( to_x );
+ ey1 = TRUNC( ras.y );
+ ey2 = TRUNC( to_y );
+
+ /* perform vertical clipping */
+ if ( ( ey1 >= ras.max_ey && ey2 >= ras.max_ey ) ||
+ ( ey1 < ras.min_ey && ey2 < ras.min_ey ) )
+ goto End;
+
+ dx = to_x - ras.x;
+ dy = to_y - ras.y;
+
+ fx1 = ras.x - SUBPIXELS( ex1 );
+ fy1 = ras.y - SUBPIXELS( ey1 );
+
+ if ( ex1 == ex2 && ey1 == ey2 ) /* inside one cell */
+ ;
+ else if ( dy == 0 ) /* ex1 != ex2 */ /* any horizontal line */
+ {
+ ex1 = ex2;
+ gray_set_cell( RAS_VAR_ ex1, ey1 );
+ }
+ else if ( dx == 0 )
+ {
+ if ( dy > 0 ) /* vertical line up */
+ do
+ {
+ fy2 = ONE_PIXEL;
+ ras.cover += ( fy2 - fy1 );
+ ras.area += ( fy2 - fy1 ) * fx1 * 2;
+ fy1 = 0;
+ ey1++;
+ gray_set_cell( RAS_VAR_ ex1, ey1 );
+ } while ( ey1 != ey2 );
+ else /* vertical line down */
+ do
+ {
+ fy2 = 0;
+ ras.cover += ( fy2 - fy1 );
+ ras.area += ( fy2 - fy1 ) * fx1 * 2;
+ fy1 = ONE_PIXEL;
+ ey1--;
+ gray_set_cell( RAS_VAR_ ex1, ey1 );
+ } while ( ey1 != ey2 );
+ }
+ else /* any other line */
+ {
+ TArea prod = dx * fy1 - dy * fx1;
+ FT_UDIVPREP( dx );
+ FT_UDIVPREP( dy );
+
+
+ /* The fundamental value `prod' determines which side and the */
+ /* exact coordinate where the line exits current cell. It is */
+ /* also easily updated when moving from one cell to the next. */
+ do
+ {
+ if ( prod <= 0 &&
+ prod - dx * ONE_PIXEL > 0 ) /* left */
+ {
+ fx2 = 0;
+ fy2 = (TPos)FT_UDIV( -prod, -dx );
+ prod -= dy * ONE_PIXEL;
+ ras.cover += ( fy2 - fy1 );
+ ras.area += ( 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 */
+ {
+ prod -= dx * ONE_PIXEL;
+ fx2 = (TPos)FT_UDIV( -prod, dy );
+ fy2 = ONE_PIXEL;
+ ras.cover += ( fy2 - fy1 );
+ ras.area += ( 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 */
+ {
+ prod += dy * ONE_PIXEL;
+ fx2 = ONE_PIXEL;
+ fy2 = (TPos)FT_UDIV( prod, dx );
+ ras.cover += ( fy2 - fy1 );
+ ras.area += ( fy2 - fy1 ) * ( fx1 + fx2 );
+ fx1 = 0;
+ fy1 = fy2;
+ ex1++;
+ }
+ else /* ( prod + dy * ONE_PIXEL < 0 &&
+ prod > 0 ) down */
+ {
+ fx2 = (TPos)FT_UDIV( prod, -dy );
+ fy2 = 0;
+ prod += dx * ONE_PIXEL;
+ ras.cover += ( fy2 - fy1 );
+ ras.area += ( 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 );
+
+ ras.cover += ( fy2 - fy1 );
+ ras.area += ( fy2 - fy1 ) * ( fx1 + fx2 );
+
+ End:
+ ras.x = to_x;
+ ras.y = to_y;
+ }
+
+#endif
static void
gray_split_conic( FT_Vector* base )
@@ -1847,7 +1979,7 @@ typedef ptrdiff_t FT_PtrDist;
bands[0].max = max;
band = bands;
- while ( band >= bands )
+ do
{
TPos bottom, top, middle;
int error;
@@ -1923,7 +2055,7 @@ typedef ptrdiff_t FT_PtrDist;
band[0].min = middle;
band[0].max = top;
band++;
- }
+ } while ( band >= bands );
}
if ( ras.band_shoot > 8 && ras.band_size > 16 )
generated by cgit v1.2.3 (git 2.25.1) at 2024-04-18 01:53:00 +0000