Commit 9eacbb81bd4823f185d1b1a3f188b3d82a325ff0
2012-02-29T14:47:47
[truetype] Make SHC instruction behave similar to MS rasterizer. * src/truetype/ttinterp.c (Ins_SHC): Handle virtual contour in twilight zone.
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diff --git a/ChangeLog b/ChangeLog
index 9fb0b92..618700d 100644
--- a/ChangeLog
+++ b/ChangeLog
@@ -1,3 +1,10 @@
+2012-02-29 Werner Lemberg <wl@gnu.org>
+
+ [truetype] Make SHC instruction behave similar to MS rasterizer.
+
+ * src/truetype/ttinterp.c (Ins_SHC): Handle virtual contour in
+ twilight zone.
+
2012-02-29 Alexei Podtelezhnikov <apodtele@gmail.com>
Avoid modulo operators against a power-of-two denominator.
diff --git a/src/truetype/ttinterp.c b/src/truetype/ttinterp.c
index 62f7327..b742d78 100644
--- a/src/truetype/ttinterp.c
+++ b/src/truetype/ttinterp.c
@@ -5770,6 +5770,10 @@
/* Opcode range: 0x34-35 */
/* Stack: uint32 --> */
/* */
+ /* UNDOCUMENTED: According to Greg Hitchcock, there is one (virtual) */
+ /* contour in the twilight zone, namely contour number */
+ /* zero. */
+ /* */
static void
Ins_SHC( INS_ARG )
{
@@ -5777,13 +5781,14 @@
FT_UShort refp;
FT_F26Dot6 dx, dy;
- FT_Short contour;
- FT_UShort first_point, last_point, i;
+ FT_Short contour, bounds;
+ FT_UShort start, limit, i;
contour = (FT_UShort)args[0];
+ bounds = ( CUR.GS.gep2 == 0 ) ? 1 : CUR.zp2.n_contours;
- if ( BOUNDS( contour, CUR.pts.n_contours ) )
+ if ( BOUNDS( contour, bounds ) )
{
if ( CUR.pedantic_hinting )
CUR.error = TT_Err_Invalid_Reference;
@@ -5794,25 +5799,19 @@
return;
if ( contour == 0 )
- first_point = 0;
+ start = 0;
else
- first_point = (FT_UShort)( CUR.pts.contours[contour - 1] + 1 -
- CUR.pts.first_point );
-
- last_point = (FT_UShort)( CUR.pts.contours[contour] -
- CUR.pts.first_point );
+ start = (FT_UShort)( CUR.zp2.contours[contour - 1] + 1 -
+ CUR.zp2.first_point );
- /* XXX: this is probably wrong... at least it prevents memory */
- /* corruption when zp2 is the twilight zone */
- if ( BOUNDS( last_point, CUR.zp2.n_points ) )
- {
- if ( CUR.zp2.n_points > 0 )
- last_point = (FT_UShort)(CUR.zp2.n_points - 1);
- else
- last_point = 0;
- }
+ /* we use the number of points if in the twilight zone */
+ if ( CUR.GS.gep2 == 0 )
+ limit = CUR.zp2.n_points;
+ else
+ limit = (FT_UShort)( CUR.zp2.contours[contour] -
+ CUR.zp2.first_point + 1 );
- for ( i = first_point; i <= last_point; i++ )
+ for ( i = start; i < limit; i++ )
{
if ( zp.cur != CUR.zp2.cur || refp != i )
MOVE_Zp2_Point( i, dx, dy, TRUE );