Implement filter primitive subregion for reference CSS filters. This required refactoring determin…

Source/core/rendering/FilterEffectRenderer.cpp

Index: Source/core/rendering/FilterEffectRenderer.cpp
diff --git a/Source/core/rendering/FilterEffectRenderer.cpp b/Source/core/rendering/FilterEffectRenderer.cpp
index 992fb55066cabc2d9d8110e42375c9fe7a393c18..df4fef70b06fdfc965efccc31378b7bb729b821e 100644
--- a/Source/core/rendering/FilterEffectRenderer.cpp
+++ b/Source/core/rendering/FilterEffectRenderer.cpp
@@ -50,6 +50,7 @@
 #include "core/rendering/RenderView.h"
 
 #if ENABLE(SVG)
+#include "SVGNames.h"
 #include "core/loader/cache/CachedSVGDocument.h"
 #include "core/loader/cache/CachedSVGDocumentReference.h"
 #include "core/platform/graphics/filters/SourceAlpha.h"
@@ -143,6 +144,11 @@ PassRefPtr<FilterEffect> FilterEffectRenderer::buildReferenceFilter(RenderObject
         return 0;
     }
 
+    if (!filter->hasTagName(SVGNames::filterTag))
+        return 0;
+
+    SVGFilterElement* filterElement = static_cast<SVGFilterElement*>(filter);

[Stephen Chennney, 2013/05/02 16:53:55]

To we have a "toSVGFilterElement" method to avoid the static_cast?

+
     RefPtr<FilterEffect> effect;
 
     // FIXME: Figure out what to do with SourceAlpha. Right now, we're
@@ -152,7 +158,7 @@ PassRefPtr<FilterEffect> FilterEffectRenderer::buildReferenceFilter(RenderObject
     // This may need a spec clarification.
     RefPtr<SVGFilterBuilder> builder = SVGFilterBuilder::create(previousEffect, SourceAlpha::create(this));
 
-    for (Node* node = filter->firstChild(); node; node = node->nextSibling()) {
+    for (Node* node = filterElement->firstChild(); node; node = node->nextSibling()) {
         if (!node->isSVGElement())
             continue;
 
@@ -167,6 +173,7 @@ PassRefPtr<FilterEffect> FilterEffectRenderer::buildReferenceFilter(RenderObject
             continue;
 
         effectElement->setStandardAttributes(effect.get());
+        effect->setEffectBoundaries(SVGLengthContext::resolveRectangle<SVGFilterPrimitiveStandardAttributes>(effectElement, filterElement->primitiveUnits(), sourceImageRect()));
         builder->add(effectElement->result(), effect);
         m_effects.append(effect);
     }
@@ -351,11 +358,11 @@ bool FilterEffectRenderer::build(RenderObject* renderer, const FilterOperations&
         }
 
         if (effect) {
-            // Unlike SVG, filters applied here should not clip to their primitive subregions.
-            effect->setClipsToBounds(false);
             effect->setOperatingColorSpace(ColorSpaceDeviceRGB);
             
             if (filterOperation->getOperationType() != FilterOperation::REFERENCE) {
+                // Unlike SVG, filters applied here should not clip to their primitive subregions.
+                effect->setClipsToBounds(false);
                 effect->inputEffects().append(previousEffect);
                 m_effects.append(effect);
             }
@@ -367,8 +374,9 @@ bool FilterEffectRenderer::build(RenderObject* renderer, const FilterOperations&
     if (!m_effects.size())
         return false;
 
-    setMaxEffectRects(m_sourceDrawingRegion);
-    
+    if (previousEffect)
+        previousEffect->determineFilterPrimitiveSubregion();
+
     return true;
 }