[ftsmooth] Improve rendering.

* src/smooth/ftsmooth.c (gray_render_conic): Since version 2.4.3,
cubic deviations have been estimated _after_ UPSCALE, whereas
conic ones have been evaluated _before_ UPSCALE, which produces
inferior rendering results.  Fix this.
Partially undo change from 2010-10-15 by using ONE_PIXEL/4; this has
been tested with demo images sent to the mailing list.  See

  http://lists.gnu.org/archive/html/freetype-devel/2010-10/msg00055.html

and later mails in this thread.
This commit is contained in:
Alexei Podtelezhnikov 2010-11-02 16:01:03 +01:00 committed by Werner Lemberg
parent 6a96bbe275
commit 6aee69096f
2 changed files with 38 additions and 28 deletions

View File

@ -1,3 +1,18 @@
2010-11-01 Alexei Podtelezhnikov <apodtele@gmail.com>
[ftsmooth] Improve rendering.
* src/smooth/ftsmooth.c (gray_render_conic): Since version 2.4.3,
cubic deviations have been estimated _after_ UPSCALE, whereas
conic ones have been evaluated _before_ UPSCALE, which produces
inferior rendering results. Fix this.
Partially undo change from 2010-10-15 by using ONE_PIXEL/4; this has
been tested with demo images sent to the mailing list. See
http://lists.gnu.org/archive/html/freetype-devel/2010-10/msg00055.html
and later mails in this thread.
2010-10-28 Werner Lemberg <wl@gnu.org>
[ftraster] Minor fixes.

View File

@ -877,34 +877,7 @@ typedef ptrdiff_t FT_PtrDist;
FT_Vector* arc;
dx = DOWNSCALE( ras.x ) + to->x - ( control->x << 1 );
if ( dx < 0 )
dx = -dx;
dy = DOWNSCALE( ras.y ) + to->y - ( control->y << 1 );
if ( dy < 0 )
dy = -dy;
if ( dx < dy )
dx = dy;
if ( dx <= ONE_PIXEL / 8 )
{
gray_render_line( RAS_VAR_ UPSCALE( to->x ), UPSCALE( to->y ) );
return;
}
level = 1;
dx /= ONE_PIXEL / 8;
while ( dx > 1 )
{
dx >>= 2;
level++;
}
arc = ras.bez_stack;
levels = ras.lev_stack;
top = 0;
levels[0] = level;
arc = ras.bez_stack;
arc[0].x = UPSCALE( to->x );
arc[0].y = UPSCALE( to->y );
arc[1].x = UPSCALE( control->x );
@ -912,6 +885,28 @@ typedef ptrdiff_t FT_PtrDist;
arc[2].x = ras.x;
arc[2].y = ras.y;
dx = FT_ABS( arc[2].x + arc[0].x - 2 * arc[1].x );
dy = FT_ABS( arc[2].y + arc[0].y - 2 * arc[1].y );
if ( dx < dy )
dx = dy;
if ( dx <= ONE_PIXEL / 4 )
{
gray_render_line( RAS_VAR_ arc[0].x, arc[0].y );
return;
}
level = 0;
while ( dx > ONE_PIXEL / 4 )
{
dx >>= 2;
level++;
}
levels = ras.lev_stack;
levels[0] = level;
top = 0;
while ( top >= 0 )
{
level = levels[top];