// Copyright 2011 The Chromium Authors. All rights reserved. // Use of this source code is governed by a BSD-style license that can be // found in the LICENSE file. #ifndef CCDamageTracker_h #define CCDamageTracker_h #include "base/hash_tables.h" #include "base/memory/scoped_ptr.h" #include "FloatRect.h" #include namespace WebKit { class WebFilterOperations; } class SkImageFilter; namespace cc { class LayerImpl; class RenderSurfaceImpl; // Computes the region where pixels have actually changed on a RenderSurfaceImpl. This region is used // to scissor what is actually drawn to the screen to save GPU computation and bandwidth. class DamageTracker { public: static scoped_ptr create(); ~DamageTracker(); void didDrawDamagedArea() { m_currentDamageRect = FloatRect(); } void forceFullDamageNextUpdate() { m_forceFullDamageNextUpdate = true; } void updateDamageTrackingState(const std::vector& layerList, int targetSurfaceLayerID, bool targetSurfacePropertyChangedOnlyFromDescendant, const IntRect& targetSurfaceContentRect, LayerImpl* targetSurfaceMaskLayer, const WebKit::WebFilterOperations&, SkImageFilter* filter); const FloatRect& currentDamageRect() { return m_currentDamageRect; } private: DamageTracker(); FloatRect trackDamageFromActiveLayers(const std::vector& layerList, int targetSurfaceLayerID); FloatRect trackDamageFromSurfaceMask(LayerImpl* targetSurfaceMaskLayer); FloatRect trackDamageFromLeftoverRects(); FloatRect removeRectFromCurrentFrame(int layerID, bool& layerIsNew); void saveRectForNextFrame(int layerID, const FloatRect& targetSpaceRect); // These helper functions are used only in trackDamageFromActiveLayers(). void extendDamageForLayer(LayerImpl*, FloatRect& targetDamageRect); void extendDamageForRenderSurface(LayerImpl*, FloatRect& targetDamageRect); // To correctly track exposed regions, two hashtables of rects are maintained. // The "current" map is used to compute exposed regions of the current frame, while // the "next" map is used to collect layer rects that are used in the next frame. typedef base::hash_map RectMap; scoped_ptr m_currentRectHistory; scoped_ptr m_nextRectHistory; FloatRect m_currentDamageRect; bool m_forceFullDamageNextUpdate; }; } // namespace cc #endif // CCDamageTracker_h