Vincent Povirk : gdiplus: Don' t calculate the number of points in the arc by dividing.

[Alexandre Julliard]

Module: wine
Branch: master
Commit: 0acfffc17bb6583161306434de3a09a9a2d727bf
URL:    http://source.winehq.org/git/wine.git/?a=commit;h=0acfffc17bb6583161306434de...

Author: Vincent Povirk <vincent(a)codeweavers.com>
Date:   Fri Sep  4 16:14:32 2009 -0500

gdiplus: Don't calculate the number of points in the arc by dividing.

---

 dlls/gdiplus/gdiplus.c |   25 ++++++++++++-------------
 1 files changed, 12 insertions(+), 13 deletions(-)

diff --git a/dlls/gdiplus/gdiplus.c b/dlls/gdiplus/gdiplus.c
index ec956f3..3c13a28 100644
--- a/dlls/gdiplus/gdiplus.c
+++ b/dlls/gdiplus/gdiplus.c
@@ -211,38 +211,37 @@ static void unstretch_angle(REAL * angle, REAL rad_x, REAL rad_y)
 INT arc2polybezier(GpPointF * points, REAL x1, REAL y1, REAL x2, REAL y2,
     REAL startAngle, REAL sweepAngle)
 {
-    INT i, count;
+    INT i;
     REAL end_angle, start_angle, endAngle;
 
     endAngle = startAngle + sweepAngle;
     unstretch_angle(&startAngle, x2 / 2.0, y2 / 2.0);
     unstretch_angle(&endAngle, x2 / 2.0, y2 / 2.0);
 
-    count = ceilf(fabs(endAngle - startAngle) / M_PI_2) * 3 + 1;
-    /* don't make more than a full circle */
-    count = min(MAX_ARC_PTS, count);
-
-    if(count == 1)
-        return 0;
-    if(!points)
-        return count;
-
     /* start_angle and end_angle are the iterative variables */
     start_angle = startAngle;
 
-    for(i = 0; i < count - 1; i += 3){
+    for(i = 0; i < MAX_ARC_PTS - 1; i += 3){
         /* check if we've overshot the end angle */
         if( sweepAngle > 0.0 )
+        {
+            if (start_angle >= endAngle) break;
             end_angle = min(start_angle + M_PI_2, endAngle);
+        }
         else
+        {
+            if (start_angle <= endAngle) break;
             end_angle = max(start_angle - M_PI_2, endAngle);
+        }
 
-        add_arc_part(&points[i], x1, y1, x2, y2, start_angle, end_angle, i == 0);
+        if (points)
+            add_arc_part(&points[i], x1, y1, x2, y2, start_angle, end_angle, i == 0);
 
         start_angle += M_PI_2 * (sweepAngle < 0.0 ? -1.0 : 1.0);
     }
 
-    return count;
+    if (i == 0) return 0;
+    else return i+1;
 }
 
 COLORREF ARGB2COLORREF(ARGB color)