Avoid div by 0 in some video cards

adobe · Jun 20, 2012 · 7f81f4f · 7f81f4f
1 parent cd44da9
commit 7f81f4f
Showing 1 changed file with 2 additions and 0 deletions.
diff --git a/Source/WebCore/platform/graphics/chromium/ShaderChromium.cpp b/Source/WebCore/platform/graphics/chromium/ShaderChromium.cpp
@@ -276,6 +276,8 @@ static String formulaForBlendMode(EBlendMode blendMode, EAlphaCompositingMode al
     builder.append(
         SHADER(
             vec4 unmultiply(vec4 premultipliedSourceColor) {
+                if (premultipliedSourceColor.a == 0.0)
+                    return vec4(1.0, 1.0, 1.0, 0.0);
                 return vec4(clamp(premultipliedSourceColor.rgb / premultipliedSourceColor.a, 0.0, 1.0), premultipliedSourceColor.a);
             }
             vec4 composite(float alphaA, float Fa, vec3 Ca,