ref: 7fb3ef64a24489189113f693696eaf935f500c3f
parent: ad61f178e2dc59e03ca8769a238f208412b24478
author: Graham Asher <[email protected]>
date: Thu Jun 10 04:10:57 EDT 2010
ftgrays: Speed up rendering of small cubic splines. * src/smooth/ftgrays.c (gray_render_cubic): Implement new, simplified algorithm to find out whether the spline can be replaced with two straight lines. See this thread for more: http://lists.gnu.org/archive/html/freetype-devel/2010-06/msg00000.html
--- a/ChangeLog
+++ b/ChangeLog
@@ -1,3 +1,13 @@
+2010-06-10 Graham Asher <[email protected]>
+
+ ftgrays: Speed up rendering of small cubic splines.
+
+ * src/smooth/ftgrays.c (gray_render_cubic): Implement new,
+ simplified algorithm to find out whether the spline can be replaced
+ with two straight lines. See this thread for more:
+
+ http://lists.gnu.org/archive/html/freetype-devel/2010-06/msg00000.html
+
2010-06-09 Werner Lemberg <[email protected]>
Fix Savannah bug #30082.
--- a/src/smooth/ftgrays.c
+++ b/src/smooth/ftgrays.c
@@ -4,7 +4,7 @@
/* */
/* A new `perfect' anti-aliasing renderer (body). */
/* */
-/* Copyright 2000-2001, 2002, 2003, 2005, 2006, 2007, 2008, 2009 by */
+/* Copyright 2000-2001, 2002, 2003, 2005, 2006, 2007, 2008, 2009, 2010 by */
/* David Turner, Robert Wilhelm, and Werner Lemberg. */
/* */
/* This file is part of the FreeType project, and may only be used, */
@@ -1007,56 +1007,53 @@
const FT_Vector* control2,
const FT_Vector* to )
{- TPos dx, dy, da, db;
int top, level;
int* levels;
FT_Vector* arc;
+ int mid_x = ( DOWNSCALE( ras.x ) + to->x +
+ 3 * (control1->x + control2->x ) ) / 8;
+ int mid_y = ( DOWNSCALE( ras.y ) + to->y +
+ 3 * (control1->y + control2->y ) ) / 8;
+ TPos dx = DOWNSCALE( ras.x ) + to->x - ( mid_x << 1 );
+ TPos dy = DOWNSCALE( ras.y ) + to->y - ( mid_y << 1 );
- dx = DOWNSCALE( ras.x ) + to->x - ( control1->x << 1 );
if ( dx < 0 )
dx = -dx;
- dy = DOWNSCALE( ras.y ) + to->y - ( control1->y << 1 );
if ( dy < 0 )
dy = -dy;
if ( dx < dy )
dx = dy;
- da = dx;
- dx = DOWNSCALE( ras.x ) + to->x - 3 * ( control1->x + control2->x );
- if ( dx < 0 )
- dx = -dx;
- dy = DOWNSCALE( ras.y ) + to->y - 3 * ( control1->x + control2->y );
- if ( dy < 0 )
- dy = -dy;
- if ( dx < dy )
- dx = dy;
- db = dx;
-
level = 1;
- da = da / ras.cubic_level;
- db = db / ras.conic_level;
- while ( da > 0 || db > 0 )
+ dx /= ras.cubic_level;
+ while ( dx > 0 )
{- da >>= 2;
- db >>= 3;
+ dx >>= 3;
level++;
}
if ( level <= 1 )
{- TPos to_x, to_y, mid_x, mid_y;
+ TPos to_x, to_y;
to_x = UPSCALE( to->x );
to_y = UPSCALE( to->y );
+
+ /* Recalculation of midpoint is needed only if */
+ /* UPSCALE and DOWNSCALE have any effect. */
+
+#if ( PIXEL_BITS != 6 )
mid_x = ( ras.x + to_x +
3 * UPSCALE( control1->x + control2->x ) ) / 8;
mid_y = ( ras.y + to_y +
3 * UPSCALE( control1->y + control2->y ) ) / 8;
+#endif
gray_render_line( RAS_VAR_ mid_x, mid_y );
gray_render_line( RAS_VAR_ to_x, to_y );
+
return;
}
@@ -1104,7 +1101,7 @@
Draw:
{- TPos to_x, to_y, mid_x, mid_y;
+ TPos to_x, to_y;
to_x = arc[0].x;