ImageBuffer-less SVG masking and clipping.

Source/core/rendering/svg/RenderSVGResourceClipper.h

Index: Source/core/rendering/svg/RenderSVGResourceClipper.h
diff --git a/Source/core/rendering/svg/RenderSVGResourceClipper.h b/Source/core/rendering/svg/RenderSVGResourceClipper.h
index 69ee9865220a65a4369cf1da26cd3bbb93caf5be..fcc6ae48580f71a74c6553e89dec6060bbbf4ef1 100644
--- a/Source/core/rendering/svg/RenderSVGResourceClipper.h
+++ b/Source/core/rendering/svg/RenderSVGResourceClipper.h
@@ -28,7 +28,14 @@ namespace WebCore {
 struct ClipperData {
     WTF_MAKE_FAST_ALLOCATED;
 public:
-    OwnPtr<ImageBuffer> clipMaskImage;
+    ClipperData()
+        : pathOnly(false)
+    {
+    }
+
+    // We should eventually cache the combined clip path here, when switching to path ops clipping.
+    // For now we only cache a marker to let postApply know whether it needs to perform any work.
+    bool pathOnly : 1;

[pdr., 2013/08/28 03:32:36]

Using an enum may make this easier to understand.

[f(malita), 2013/08/28 19:54:38]

Done.

 };
 
 class RenderSVGResourceClipper FINAL : public RenderSVGResourceContainer {
@@ -41,11 +48,13 @@ public:
     virtual void removeAllClientsFromCache(bool markForInvalidation = true);
     virtual void removeClientFromCache(RenderObject*, bool markForInvalidation = true);
 
-    virtual bool applyResource(RenderObject*, RenderStyle*, GraphicsContext*&, unsigned short resourceMode);
+    virtual bool applyResource(RenderObject*, RenderStyle*, GraphicsContext*&, unsigned short resourceMode) OVERRIDE;
+    virtual void postApplyResource(RenderObject*, GraphicsContext*&, unsigned short, const Path*, const RenderSVGShape*) OVERRIDE;
     // clipPath can be clipped too, but don't have a boundingBox or repaintRect. So we can't call

[pdr., 2013/08/28 03:32:36]

Not your fault, but this comment is more confusing than helpful.

     // applyResource directly and use the rects from the object, since they are empty for RenderSVGResources
     // FIXME: We made applyClippingToContext public because we cannot call applyResource on HTML elements (it asserts on RenderObject::objectBoundingBox)
     bool applyClippingToContext(RenderObject*, const FloatRect&, const FloatRect&, GraphicsContext*);
+
     virtual FloatRect resourceBoundingBox(RenderObject*);
 
     virtual RenderSVGResourceType resourceType() const { return ClipperResourceType; }
@@ -57,11 +66,14 @@ public:
     static RenderSVGResourceType s_resourceType;
 private:
     bool pathOnlyClipping(GraphicsContext*, const AffineTransform&, const FloatRect&);
-    bool drawContentIntoMaskImage(ClipperData*, const FloatRect& objectBoundingBox);
+    void drawMaskContent(GraphicsContext*, const FloatRect& targetBoundingBox);
     void calculateClipContentRepaintRect();
 
     FloatRect m_clipBoundaries;
-    HashMap<RenderObject*, ClipperData*> m_clipper;
+    HashMap<const RenderObject*, OwnPtr<ClipperData> > m_clipperMap;

[pdr., 2013/08/28 03:32:36]

<bikeshed> m_rendererToClipperMap?

[f(malita), 2013/08/28 19:54:38]

Done.

+
+    // Reference cycle detection.
+    bool m_inClipExpansion;
 };
 
 }