[SVG] DisplayList-based patterns.

Source/core/rendering/svg/RenderSVGResourcePattern.h

 /*
  * Copyright (C) 2006 Nikolas Zimmermann <zimmermann@kde.org>
  * Copyright (C) Research In Motion Limited 2010. All rights reserved.
+ * Copyright (C) 2014 Google Inc. 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
  * 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 RenderSVGResourcePattern_h
 #define RenderSVGResourcePattern_h
 
 #include "core/rendering/svg/RenderSVGResourceContainer.h"
 #include "core/svg/PatternAttributes.h"
-#include "core/svg/SVGPatternElement.h"
-#include "core/svg/SVGUnitTypes.h"
-#include "platform/geometry/FloatRect.h"
-#include "platform/graphics/ImageBuffer.h"
-#include "platform/graphics/Pattern.h"
-#include "platform/transforms/AffineTransform.h"
 
 #include "wtf/HashMap.h"
 #include "wtf/OwnPtr.h"
+#include "wtf/RefPtr.h"
 
 namespace blink {
 
-struct PatternData {
-    WTF_MAKE_FAST_ALLOCATED;
-public:
-    RefPtr<Pattern> pattern;
-    AffineTransform transform;
-};
+class AffineTransform;
+class DisplayList;
+class FloatRect;
+class GraphicsContext;
+class ImageBuffer;
+class SVGPatternElement;
+struct PatternData;
 
 class RenderSVGResourcePattern FINAL : public RenderSVGResourceContainer {
 public:
     explicit RenderSVGResourcePattern(SVGPatternElement*);
 
     virtual const char* renderName() const OVERRIDE { return "RenderSVGResourcePattern"; }
 
     virtual void removeAllClientsFromCache(bool markForInvalidation = true) OVERRIDE;
     virtual void removeClientFromCache(RenderObject*, bool markForInvalidation = true) OVERRIDE;
 
     virtual bool applyResource(RenderObject*, RenderStyle*, GraphicsContext*&, unsigned short resourceMode) OVERRIDE;
     virtual void postApplyResource(RenderObject*, GraphicsContext*&, unsigned short resourceMode, const Path*, const RenderSVGShape*) OVERRIDE;
 
     virtual RenderSVGResourceType resourceType() const OVERRIDE { return s_resourceType; }
     static const RenderSVGResourceType s_resourceType;
 
 private:
-    bool buildTileImageTransform(RenderObject*, const PatternAttributes&, const SVGPatternElement*, FloatRect& patternBoundaries, AffineTransform& tileImageTransform) const;
-
-    PassOwnPtr<ImageBuffer> createTileImage(const PatternAttributes&, const FloatRect& tileBoundaries,
-                                            const FloatRect& absoluteTileBoundaries, const AffineTransform& tileImageTransform) const;
-
-    PatternData* buildPattern(RenderObject*, unsigned short resourceMode);
+    bool computeTileMetrics(const RenderObject&, const SVGPatternElement&, FloatRect& bounds,
+        AffineTransform&) const;
+    PassOwnPtr<PatternData> buildPatternData(GraphicsContext&, RenderObject&);
+    PassRefPtr<DisplayList> asDisplayList(GraphicsContext&, const FloatRect& tileBounds,
+        const AffineTransform&) const;
+    PatternData* patternForRenderer(GraphicsContext&, RenderObject&);
 
     bool m_shouldCollectPatternAttributes : 1;
     PatternAttributes m_attributes;
+
+    // FIXME: we can almost do away with this per-object map, but not quite: the tile size can be
+    // relative to the client bounding box, and it gets captured in the cached Pattern shader.
+    // Hence, we need one Pattern shader per client. The display list OTOH is the same => we
+    // should be able to cache a single display list per RenderSVGResourcePattern + one
+    // Pattern(shader) for each client -- this would avoid re-recording when multiple clients
+    // share the same pattern.
     HashMap<RenderObject*, OwnPtr<PatternData> > m_patternMap;
 };
 
 }
 
 #endif