ImageBuffer-less SVG masking and clipping.

Source/core/rendering/svg/SVGRenderingContext.h

 /**
  * Copyright (C) 2007 Rob Buis <buis@kde.org>
  * Copyright (C) 2007 Nikolas Zimmermann <zimmermann@kde.org>
  * Copyright (C) 2007 Eric Seidel <eric@webkit.org>
  * Copyright (C) 2009 Google, Inc.  All rights reserved.
  * Copyright (C) Research In Motion Limited 2010. All rights reserved.
  * Copyright (C) 2012 Zoltan Herczeg <zherczeg@webkit.org>.
  *
  * 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
  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  * Library General Public License for more details.
  *
  * You should have received a copy of the GNU Library General Public License
  * along with this library; see the file COPYING.LIB.  If not, write to
  * the Free Software Foundation, Inc., 51 Franklin Street, Fifth Floor,
  * Boston, MA 02110-1301, USA.
  */
 
 #ifndef SVGRenderingContext_h
 #define SVGRenderingContext_h
 
 #include "core/platform/graphics/ImageBuffer.h"
 #include "core/rendering/PaintInfo.h"
+#include "core/svg/SVGUnitTypes.h"
 
 namespace WebCore {
 
 class AffineTransform;
 class RenderObject;
 class FloatRect;
+class RenderSVGResourceClipper;
 class RenderSVGResourceFilter;
+class RenderSVGResourceMasker;
 
 // SVGRenderingContext
 class SVGRenderingContext {
 public:
     enum NeedsGraphicsContextSave {
         SaveGraphicsContext,
         DontSaveGraphicsContext,
     };
 
     // Does not start rendering.
     SVGRenderingContext()
         : m_renderingFlags(0)
         , m_object(0)
         , m_paintInfo(0)
         , m_savedContext(0)
         , m_filter(0)
+        , m_clipper(0)
+        , m_masker(0)
     {
     }
 
     SVGRenderingContext(RenderObject* object, PaintInfo& paintinfo, NeedsGraphicsContextSave needsGraphicsContextSave = DontSaveGraphicsContext)
         : m_renderingFlags(0)
         , m_object(0)
         , m_paintInfo(0)
         , m_savedContext(0)
         , m_filter(0)
+        , m_clipper(0)
+        , m_masker(0)
     {
         prepareToRenderSVGContent(object, paintinfo, needsGraphicsContextSave);
     }
 
     // Automatically finishes context rendering.
     ~SVGRenderingContext();
 
     // Used by all SVG renderers who apply clip/filter/etc. resources to the renderer content.
     void prepareToRenderSVGContent(RenderObject*, PaintInfo&, NeedsGraphicsContextSave = DontSaveGraphicsContext);
     bool isRenderingPrepared() const { return m_renderingFlags & RenderingPrepared; }
 
     static bool createImageBuffer(const FloatRect& paintRect, const AffineTransform& absoluteTransform, OwnPtr<ImageBuffer>&, RenderingMode);
     // Patterns need a different float-to-integer coordinate mapping.
     static bool createImageBufferForPattern(const FloatRect& absoluteTargetRect, const FloatRect& clampedAbsoluteTargetRect, OwnPtr<ImageBuffer>&, RenderingMode);
 
-    static void renderSubtreeToImageBuffer(ImageBuffer*, RenderObject*, const AffineTransform&);
-    static void clipToImageBuffer(GraphicsContext*, const AffineTransform& absoluteTransform, const FloatRect& targetRect, OwnPtr<ImageBuffer>&, bool safeToClear);
+    static void renderSubtree(GraphicsContext*, RenderObject*, const AffineTransform&);
 
     static float calculateScreenFontSizeScalingFactor(const RenderObject*);
     static void calculateTransformationToOutermostCoordinateSystem(const RenderObject*, AffineTransform& absoluteTransform);
     static IntSize clampedAbsoluteSize(const IntSize&);
     static FloatRect clampedAbsoluteTargetRect(const FloatRect& absoluteTargetRect);
     static void clear2DRotation(AffineTransform&);
 
     static IntRect calculateImageBufferRect(const FloatRect& targetRect, const AffineTransform& absoluteTransform)
     {
         return enclosingIntRect(absoluteTransform.mapRect(targetRect));
     }
 
     // Support for the buffered-rendering hint.
     bool bufferForeground(OwnPtr<ImageBuffer>&);
 
 private:
     // To properly revert partially successful initializtions in the destructor, we record all successful steps.
     enum RenderingFlags {
         RenderingPrepared = 1,
         RestoreGraphicsContext = 1 << 1,
         EndOpacityLayer = 1 << 2,
-        EndFilterLayer = 1 << 3,
+        PostApplyResources = 1 << 3,
         PrepareToRenderSVGContentWasCalled = 1 << 4
     };
 
     // List of those flags which require actions during the destructor.
-    const static int ActionsNeeded = RestoreGraphicsContext | EndOpacityLayer | EndFilterLayer;
+    const static int ActionsNeeded = RestoreGraphicsContext | EndOpacityLayer | PostApplyResources;
 
     int m_renderingFlags;
     RenderObject* m_object;
     PaintInfo* m_paintInfo;
     GraphicsContext* m_savedContext;
     IntRect m_savedPaintRect;
     RenderSVGResourceFilter* m_filter;
+    RenderSVGResourceClipper* m_clipper;
+    RenderSVGResourceMasker* m_masker;
 };
 
 } // namespace WebCore
 
 #endif // SVGRenderingContext_h