Commit 4881f75b7ca04a35da4b467b46b28ae52b176482
2019-09-23T22:57:00
* src/base/ftstroke.c (ft_stroke_border_arcto): Speed up calculations.
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diff --git a/ChangeLog b/ChangeLog
index 3e9cf75..fd20d92 100644
--- a/ChangeLog
+++ b/ChangeLog
@@ -1,3 +1,7 @@
+2019-09-23 Alexei Podtelezhnikov <apodtele@gmail.com>
+
+ * src/base/ftstroke.c (ft_stroke_border_arcto): Speed up calculations.
+
2019-09-20 Nikhil Ramakrishnan <ramakrishnan.nikhil@gmail.com>
[woff2] Fix memory leaks.
diff --git a/src/base/ftstroke.c b/src/base/ftstroke.c
index 1b2c0f6..18c746f 100644
--- a/src/base/ftstroke.c
+++ b/src/base/ftstroke.c
@@ -540,63 +540,52 @@
FT_Angle angle_start,
FT_Angle angle_diff )
{
- FT_Angle total, angle, step, rotate, next, theta;
- FT_Vector a, b, a2, b2;
- FT_Fixed length;
+ FT_Fixed coef;
+ FT_Vector a0, a1, a2, a3;
+ FT_Int i, arcs = 1;
FT_Error error = FT_Err_Ok;
- /* compute start point */
- FT_Vector_From_Polar( &a, radius, angle_start );
- a.x += center->x;
- a.y += center->y;
+ /* number of cubic arcs to draw */
+ while ( angle_diff > FT_ARC_CUBIC_ANGLE * arcs ||
+ -angle_diff > FT_ARC_CUBIC_ANGLE * arcs )
+ arcs++;
- total = angle_diff;
- angle = angle_start;
- rotate = ( angle_diff >= 0 ) ? FT_ANGLE_PI2 : -FT_ANGLE_PI2;
+ /* control tangents */
+ coef = FT_Tan( angle_diff / ( 4 * arcs ) );
+ coef += coef / 3;
- while ( total != 0 )
- {
- step = total;
- if ( step > FT_ARC_CUBIC_ANGLE )
- step = FT_ARC_CUBIC_ANGLE;
-
- else if ( step < -FT_ARC_CUBIC_ANGLE )
- step = -FT_ARC_CUBIC_ANGLE;
-
- next = angle + step;
- theta = step;
- if ( theta < 0 )
- theta = -theta;
+ /* compute start and first control point */
+ FT_Vector_From_Polar( &a0, radius, angle_start );
+ a1.x = FT_MulFix( -a0.y, coef );
+ a1.y = FT_MulFix( a0.x, coef );
- theta >>= 1;
+ a0.x += center->x;
+ a0.y += center->y;
+ a1.x += a0.x;
+ a1.y += a0.y;
- /* compute end point */
- FT_Vector_From_Polar( &b, radius, next );
- b.x += center->x;
- b.y += center->y;
-
- /* compute first and second control points */
- length = FT_MulDiv( radius, FT_Sin( theta ) * 4,
- ( 0x10000L + FT_Cos( theta ) ) * 3 );
-
- FT_Vector_From_Polar( &a2, length, angle + rotate );
- a2.x += a.x;
- a2.y += a.y;
+ for ( i = 1; i <= arcs; i++ )
+ {
+ /* compute end and second control point */
+ FT_Vector_From_Polar( &a3, radius,
+ angle_start + i * angle_diff / arcs );
+ a2.x = FT_MulFix( a3.y, coef );
+ a2.y = FT_MulFix( -a3.x, coef );
- FT_Vector_From_Polar( &b2, length, next - rotate );
- b2.x += b.x;
- b2.y += b.y;
+ a3.x += center->x;
+ a3.y += center->y;
+ a2.x += a3.x;
+ a2.y += a3.y;
/* add cubic arc */
- error = ft_stroke_border_cubicto( border, &a2, &b2, &b );
+ error = ft_stroke_border_cubicto( border, &a1, &a2, &a3 );
if ( error )
break;
- /* process the rest of the arc ?? */
- a = b;
- total -= step;
- angle = next;
+ /* a0 = a3; */
+ a1.x = a3.x - a2.x + a3.x;
+ a1.y = a3.y - a2.y + a3.y;
}
return error;