ImageBuffer-less SVG masking and clipping.

Source/core/rendering/svg/RenderSVGResourceClipper.h

 /*
  * Copyright (C) Research In Motion Limited 2009-2010. All rights reserved.
  *
  * This library is free software; you can redistribute it and/or
  * modify it under the terms of the GNU Library General Public
  * License as published by the Free Software Foundation; either
  * version 2 of the License, or (at your option) any later version.
  *
  * This library is distributed in the hope that it will be useful,
  * but WITHOUT ANY WARRANTY; without even the implied warranty of
@@ skipping 10 matching lines @@
 #define RenderSVGResourceClipper_h
 
 #include "core/rendering/svg/RenderSVGResourceContainer.h"
 #include "core/svg/SVGClipPathElement.h"
 
 namespace WebCore {
 
 struct ClipperData {
     WTF_MAKE_FAST_ALLOCATED;
 public:
-    OwnPtr<ImageBuffer> clipMaskImage;
+    enum ClipMode { PathOnlyClipMode, MaskClipMode };
+
+    // 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.
+    ClipMode clipMode;
 };
 
 class RenderSVGResourceClipper FINAL : public RenderSVGResourceContainer {
 public:
     RenderSVGResourceClipper(SVGClipPathElement*);
     virtual ~RenderSVGResourceClipper();
 
     virtual const char* renderName() const { return "RenderSVGResourceClipper"; }
 
     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
     // 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; }
 
     bool hitTestClipContent(const FloatRect&, const FloatPoint&);
 
     SVGUnitTypes::SVGUnitType clipPathUnits() const { return toSVGClipPathElement(node())->clipPathUnitsCurrentValue(); }
 
     static RenderSVGResourceType s_resourceType;
 private:
-    bool pathOnlyClipping(GraphicsContext*, const AffineTransform&, const FloatRect&);
-    bool drawContentIntoMaskImage(ClipperData*, const FloatRect& objectBoundingBox);
+    bool tryPathOnlyClipping(GraphicsContext*, const AffineTransform&, const FloatRect&);
+    void drawMaskContent(GraphicsContext*, const FloatRect& targetBoundingBox);
     void calculateClipContentRepaintRect();
 
     FloatRect m_clipBoundaries;
-    HashMap<RenderObject*, ClipperData*> m_clipper;
+    HashMap<const RenderObject*, OwnPtr<ClipperData> > m_rendererToClipperMap;
+
+    // Reference cycle detection.
+    bool m_inClipExpansion;
 };
 
 }
 
 #endif