CCEffectStack - Update the padding of an effect stack from its contained effects

If the padding of any contained effects is greater than the padding set directly on the
stack, use the contained effects value.

Author: Thayer J Andrews

cocos2d/CCEffectStack.m

@@ -116,6 +116,8 @@ - (CCEffectPrepareStatus)prepareForRendering
     CCEffectPrepareStatus result = CCEffectPrepareNothingToDo;
     if (_passesDirty)
     {
+        CGSize maxPadding = self.padding;
+        
         // Start by populating the flattened list with this stack's effects.
         NSMutableArray *flattenedEffects = [[NSMutableArray alloc] initWithArray:_effects];
         NSUInteger index = 0;
@@ -141,11 +143,22 @@ - (CCEffectPrepareStatus)prepareForRendering
             }
         }
 
-        // Make sure all the contained effects are ready for rendering
-        // before we do anything else.
         for (CCEffect *effect in flattenedEffects)
         {
+            // Make sure all the contained effects are ready for rendering
+            // before we do anything else.
             [effect prepareForRendering];
+            
+            // And find the max padding values of all contained effects.
+            if (effect.padding.width > maxPadding.width)
+            {
+                maxPadding.width = effect.padding.width;
+            }
+            
+            if (effect.padding.height > maxPadding.height)
+            {
+                maxPadding.height = effect.padding.height;
+            }
         }
 
         NSMutableArray *stitchedEffects = [[NSMutableArray alloc] init];
@@ -194,8 +207,9 @@ - (CCEffectPrepareStatus)prepareForRendering
         }
         self.renderPasses = [passes copy];
         self.shaderUniforms = uniforms;
-        _passesDirty = NO;
+        self.padding = maxPadding;
 
+        _passesDirty = NO;
         result = CCEffectPrepareSuccess;
     }
     return result;