[raster] Keep only bottom y-turns.
This results in noticeable performance improvement.
* src/raster/ftraster.c (Insert_Y_Turns): All bottom y-turns are still
sorted and stored; only the maximum top y-turn is recorded now. The
function is renamed.
(End_Profile): Updated accordingly.
(Convert_Glyph): Reserve space for the top value.
diff --git a/src/raster/ftraster.c b/src/raster/ftraster.c
index ea87ab1..7f1077c 100644
--- a/src/raster/ftraster.c
+++ b/src/raster/ftraster.c
@@ -116,8 +116,8 @@
* generated until the end of the outline.
*
* Note that, for all generated profiles, the function End_Profile()
- * is used to record their bottom-most scanline as well as the
- * scanline above its upmost boundary. These positions are called
+ * is used to record all their bottom-most scanlines as well as the
+ * scanline above their upmost boundary. These positions are called
* `y-turns' because they (sort of) correspond to local extrema.
* They are stored in a sorted list built from the top of the render
* pool as a downwards stack:
@@ -579,12 +579,17 @@
* SUCCESS on success. FAILURE in case of overflow.
*/
static Bool
- Insert_Y_Turn( RAS_ARGS Int y )
+ Insert_Y_Turns( RAS_ARGS Int y,
+ Int top )
{
Int n = ras.numTurns;
PLong y_turns = ras.maxBuff;
+ /* update top value */
+ if ( n == 0 || top > y_turns[n] )
+ y_turns[n] = top;
+
/* look for first y value that is <= */
while ( n-- && y < y_turns[n] )
;
@@ -751,8 +756,7 @@
p->X = p->x[h - 1];
}
- if ( Insert_Y_Turn( RAS_VARS bottom ) ||
- Insert_Y_Turn( RAS_VARS top ) )
+ if ( Insert_Y_Turns( RAS_VARS bottom, top ) )
return FAILURE;
if ( !ras.gProfile )
@@ -1820,7 +1824,7 @@
ras.cProfile = NULL;
ras.top = ras.buff;
- ras.maxBuff = ras.sizeBuff;
+ ras.maxBuff = ras.sizeBuff - 1; /* top reserve */
ras.numTurns = 0;
ras.num_Profs = 0;
