diff --git a/dlls/gdi32/dibdrv/graphics.c b/dlls/gdi32/dibdrv/graphics.c
index 2c865c0..b222610 100644
--- a/dlls/gdi32/dibdrv/graphics.c
+++ b/dlls/gdi32/dibdrv/graphics.c
@@ -172,40 +172,33 @@ static void add_pen_lines_bounds( dibdrv_physdev *dev, int count, const POINT *p
     add_clipped_bounds( dev, &bounds, dev->clip );
 }
 
-/* compute the points for the first quadrant of an ellipse, counterclockwise from the x axis */
+/* compute the points for the first quadrant of an ellipse */
 /* 'data' must contain enough space, (width+height)/2 is a reasonable upper bound */
 static int ellipse_first_quadrant( int width, int height, POINT *data )
 {
-    const int a = width - 1;
-    const int b = height - 1;
-    const INT64 asq = (INT64)8 * a * a;
-    const INT64 bsq = (INT64)8 * b * b;
-    INT64 dx  = (INT64)4 * b * b * (1 - a);
-    INT64 dy  = (INT64)4 * a * a * (1 + (b % 2));
-    INT64 err = dx + dy + a * a * (b % 2);
-    int pos = 0;
     POINT pt;
+    const int a = width/2;
+    const int b = height/2;
+    int pos = 0;
+    INT64 de, dx, dy, err;
 
-    pt.x = a;
-    pt.y = height / 2;
+    de = b;
+    pt.x = -a;
+    pt.y = 0;
+    dx = ( 1 + 2 * pt.x) * de * de;
+    dy = pt.x * pt.x;
+    err = dx + dy ;
 
-    /* based on an algorithm by Alois Zingl */
+    do{
+	    data[ pos++ ] = pt;
+        data[ pos-1 ].x = a - data[ pos-1 ].x;
+        data[ pos-1 ].y = b + data[ pos-1 ].y;
+        de = 2 * err;
+
+        if(de >= dx) { pt.x ++; err += dx += 2 * b * b; }
+        if(de <= dy) { pt.y ++; err += dy += 2 * a * a; }
+    }while( pt.x <= 0);
 
-    while (pt.x >= width / 2)
-    {
-        INT64 e2 = 2 * err;
-        data[pos++] = pt;
-        if (e2 >= dx)
-        {
-            pt.x--;
-            err += dx += bsq;
-        }
-        if (e2 <= dy)
-        {
-            pt.y++;
-            err += dy += asq;
-        }
-    }
     return pos;
 }