Fixed a precision issue and some divide-by-zero problems with the col…

…or dodge blend.
hankbao · May 25, 2012 · 6361d93 · 6361d93
1 parent 837b942
commit 6361d93
Showing 1 changed file with 2 additions and 2 deletions.
diff --git a/framework/Source/GPUImageColorDodgeBlendFilter.m b/framework/Source/GPUImageColorDodgeBlendFilter.m
@@ -3,7 +3,7 @@
 NSString *const kGPUImageColorDodgeBlendFragmentShaderString = SHADER_STRING
 ( 
 
- precision lowp float;
+ precision mediump float;
 
  varying highp vec2 textureCoordinate;
  varying highp vec2 textureCoordinate2;
@@ -20,7 +20,7 @@ void main()
      vec3 rightHandProduct = overlay.rgb * (1.0 - base.a) + base.rgb * (1.0 - overlay.a);
 
      vec3 firstBlendColor = baseOverlayAlphaProduct + rightHandProduct;
-     vec3 overlayRGB = (overlay.rgb / overlay.a) * step(0.0, overlay.a);
+     vec3 overlayRGB = clamp((overlay.rgb / clamp(overlay.a, 0.01, 1.0)) * step(0.0, overlay.a), 0.0, 0.99);
 
      vec3 secondBlendColor = (base.rgb * overlay.a) / (1.0 - overlayRGB) + rightHandProduct;