mirror of https://github.com/freetype/freetype
[raster] Modify the split condition.
While curving close to a pixel center, vertical and horizontal pass might split the curve differently and cause a rare dropout. This makes the split condition invariant of the sweep direction and more robust. * src/raster/ftraster.c (Bezier_Up): Modify the split condition.
This commit is contained in:
parent
f2e76e8356
commit
6d6607b8b3
|
@ -1124,7 +1124,8 @@
|
|||
Long miny,
|
||||
Long maxy )
|
||||
{
|
||||
Long y1, y2, e, e2, e0;
|
||||
Long y1, y2, e, e2, e0, dy;
|
||||
Long dx, x2;
|
||||
|
||||
TPoint* start_arc;
|
||||
|
||||
|
@ -1189,19 +1190,25 @@
|
|||
ras.joint = FALSE;
|
||||
|
||||
y2 = arc[0].y;
|
||||
x2 = arc[0].x;
|
||||
|
||||
if ( y2 > e )
|
||||
{
|
||||
y1 = arc[degree].y;
|
||||
if ( y2 - y1 >= ras.precision_step )
|
||||
dy = y2 - arc[degree].y;
|
||||
dx = x2 - arc[degree].x;
|
||||
|
||||
|
||||
/* split condition should be invariant of direction */
|
||||
if ( dy > ras.precision_step ||
|
||||
dx > ras.precision_step ||
|
||||
-dx > ras.precision_step )
|
||||
{
|
||||
splitter( arc );
|
||||
arc += degree;
|
||||
}
|
||||
else
|
||||
{
|
||||
*top++ = arc[degree].x + FMulDiv( arc[0].x - arc[degree].x,
|
||||
e - y1, y2 - y1 );
|
||||
*top++ = x2 - FMulDiv( y2 - e, dx, dy );
|
||||
arc -= degree;
|
||||
e += ras.precision;
|
||||
}
|
||||
|
@ -1211,7 +1218,7 @@
|
|||
if ( y2 == e )
|
||||
{
|
||||
ras.joint = TRUE;
|
||||
*top++ = arc[0].x;
|
||||
*top++ = x2;
|
||||
|
||||
e += ras.precision;
|
||||
}
|
||||
|
|
Loading…
Reference in New Issue