From c08d4b1480eb253c6407a98a2b58fd5294178709 Mon Sep 17 00:00:00 2001
From: lecoanet
Date: Fri, 20 Dec 2002 13:54:28 +0000
Subject: 	* (ZnComputeRadialGradient): Clamping des pourcentages
 d�finissant 	  le centre du gradient afin d'�viter des d�fauts de
 couverture 	  par calcul erron� du cercle englobant. Il faudrait trouver
 un 	  meilleur algo pour calculer ce dernier.         *
 (ZnComputeRadialGradient): Correction d'une erreur lorsque le 	  centre d'un
 gradient radial est au centre d'un arc elliptique

---
 generic/Draw.c | 30 +++++++++++++++++++++---------
 1 file changed, 21 insertions(+), 9 deletions(-)

(limited to 'generic/Draw.c')

diff --git a/generic/Draw.c b/generic/Draw.c
index 6ddad6a..9a5fa87 100644
--- a/generic/Draw.c
+++ b/generic/Draw.c
@@ -1394,7 +1394,13 @@ ZnComputeRadialGradient(WidgetInfo	*wi,
 
   /*
    * Find the gradient focal point in the item space.
+   * The excursion of the focal point outside the item
+   * bbox is clamped to avoid distorsions that take
+   * place due to the rather simple algorithm used to
+   * compute the maximum radius of the gradient.
    */
+  focal_pp->x = fmod(focal_pp->x, 500.0);
+  focal_pp->y = fmod(focal_pp->y, 500.0);
   offset.x = focal_pp->x * (bbox.corner.x-bbox.orig.x)/100.0;
   offset.y = focal_pp->y * (bbox.corner.y-bbox.orig.y)/100.0;
   focal_point.x = (bbox.corner.x+bbox.orig.x)/2 + offset.x; 
@@ -1403,7 +1409,7 @@ ZnComputeRadialGradient(WidgetInfo	*wi,
   /*
    * Find the max distance from the focal point.
    */
-  if (oval) {
+  if (1/*oval*/) {
     /*
      * radius.x and radius.y are the shape radiuses.
      * ff is the distance from the bbox center to
@@ -1415,14 +1421,20 @@ ZnComputeRadialGradient(WidgetInfo	*wi,
     /*
      * Compute the farthest point from the focal point 
      * on a unit circle, then map it to the oval and
-     * compute the distance between both points.
+     * compute the distance between the two points.
      */
-    x = offset.x/ff;
-    y = offset.y/ff;
-    x *= radius.x;
-    y *= radius.y;
-    x = x + offset.x;
-    y = y + offset.y;
+    if (ff > PRECISION_LIMIT) {
+      x = offset.x/ff;
+      y = offset.y/ff;
+      x *= radius.x;
+      y *= radius.y;
+      x = x + offset.x;
+      y = y + offset.y;
+    }
+    else {
+      x = 0;
+      y = MAX(radius.x, radius.y);
+    }
     dist = x*x + y*y;
   }
   else {
@@ -1626,7 +1638,7 @@ ZnRenderGradient(WidgetInfo	*wi,
     ZnTransformPoints((ZnTransfo *) quad, genarc, tarc, num_p);
     p.x = p.y = 0;
     ZnTransformPoint((ZnTransfo *) quad, &p, &focalp);
-
+    
     position = 0.0;
     color = gradient->colors[0].rgb;
     alpha = ZnComposeAlpha(gradient->colors[0].alpha, wi->alpha);
-- 
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