| // Copyright 2012 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 CC_OCCLUSION_TRACKER_H_ |
| #define CC_OCCLUSION_TRACKER_H_ |
| |
| #include "base/basictypes.h" |
| #include "cc/cc_export.h" |
| #include "cc/layer_iterator.h" |
| #include "cc/region.h" |
| #include "ui/gfx/rect.h" |
| |
| namespace cc { |
| class OverdrawMetrics; |
| class LayerImpl; |
| class RenderSurfaceImpl; |
| class Layer; |
| class RenderSurface; |
| |
| // This class is used to track occlusion of layers while traversing them in a front-to-back order. As each layer is visited, one of the |
| // methods in this class is called to notify it about the current target surface. |
| // Then, occlusion in the content space of the current layer may be queried, via methods such as occluded() and unoccludedContentRect(). |
| // If the current layer owns a RenderSurfaceImpl, then occlusion on that RenderSurfaceImpl may also be queried via surfaceOccluded() and surfaceUnoccludedContentRect(). |
| // Finally, once finished with the layer, occlusion behind the layer should be marked by calling markOccludedBehindLayer(). |
| template<typename LayerType, typename RenderSurfaceType> |
| class CC_EXPORT OcclusionTrackerBase { |
| public: |
| OcclusionTrackerBase(gfx::Rect screenSpaceClipRect, bool recordMetricsForFrame); |
| ~OcclusionTrackerBase(); |
| |
| // Called at the beginning of each step in the LayerIterator's front-to-back traversal. |
| void enterLayer(const LayerIteratorPosition<LayerType>&); |
| // Called at the end of each step in the LayerIterator's front-to-back traversal. |
| void leaveLayer(const LayerIteratorPosition<LayerType>&); |
| |
| // Returns true if the given rect in content space for a layer is fully occluded in either screen space or the layer's target surface. |renderTarget| is the contributing layer's render target, and |drawTransform|, |transformsToTargetKnown| and |clippedRectInTarget| are relative to that. |
| bool occluded(const LayerType* renderTarget, const gfx::Rect& contentRect, const gfx::Transform& drawTransform, bool implDrawTransformIsUnknown, const gfx::Rect& clippedRectInTarget, bool* hasOcclusionFromOutsideTargetSurface = 0) const; |
| // Gives an unoccluded sub-rect of |contentRect| in the content space of a layer. Used when considering occlusion for a layer that paints/draws something. |renderTarget| is the contributing layer's render target, and |drawTransform|, |transformsToTargetKnown| and |clippedRectInTarget| are relative to that. |
| gfx::Rect unoccludedContentRect(const LayerType* renderTarget, const gfx::Rect& contentRect, const gfx::Transform& drawTransform, bool implDrawTransformIsUnknown, const gfx::Rect& clippedRectInTarget, bool* hasOcclusionFromOutsideTargetSurface = 0) const; |
| |
| // Gives an unoccluded sub-rect of |contentRect| in the content space of the renderTarget owned by the layer. |
| // Used when considering occlusion for a contributing surface that is rendering into another target. |
| gfx::Rect unoccludedContributingSurfaceContentRect(const LayerType*, bool forReplica, const gfx::Rect& contentRect, bool* hasOcclusionFromOutsideTargetSurface = 0) const; |
| |
| // Report operations for recording overdraw metrics. |
| OverdrawMetrics& overdrawMetrics() const { return *m_overdrawMetrics.get(); } |
| |
| // Gives the region of the screen that is not occluded by something opaque. |
| Region computeVisibleRegionInScreen() const { |
| DCHECK(!m_stack.back().target->parent()); |
| return SubtractRegions(m_screenSpaceClipRect, m_stack.back().occlusionFromInsideTarget); |
| } |
| |
| void setMinimumTrackingSize(const gfx::Size& size) { m_minimumTrackingSize = size; } |
| |
| // The following is used for visualization purposes. |
| void setOccludingScreenSpaceRectsContainer(std::vector<gfx::Rect>* rects) { m_occludingScreenSpaceRects = rects; } |
| void setNonOccludingScreenSpaceRectsContainer(std::vector<gfx::Rect>* rects) { m_nonOccludingScreenSpaceRects = rects; } |
| |
| protected: |
| struct StackObject { |
| StackObject() : target(0) { } |
| StackObject(const LayerType* target) : target(target) { } |
| const LayerType* target; |
| Region occlusionFromOutsideTarget; |
| Region occlusionFromInsideTarget; |
| }; |
| |
| // The stack holds occluded regions for subtrees in the RenderSurfaceImpl-Layer tree, so that when we leave a subtree we may |
| // apply a mask to it, but not to the parts outside the subtree. |
| // - The first time we see a new subtree under a target, we add that target to the top of the stack. This can happen as a layer representing itself, or as a target surface. |
| // - When we visit a target surface, we apply its mask to its subtree, which is at the top of the stack. |
| // - When we visit a layer representing itself, we add its occlusion to the current subtree, which is at the top of the stack. |
| // - When we visit a layer representing a contributing surface, the current target will never be the top of the stack since we just came from the contributing surface. |
| // We merge the occlusion at the top of the stack with the new current subtree. This new target is pushed onto the stack if not already there. |
| std::vector<StackObject> m_stack; |
| |
| // Allow tests to override this. |
| virtual gfx::Rect layerClipRectInTarget(const LayerType*) const; |
| |
| private: |
| // Called when visiting a layer representing itself. If the target was not already current, then this indicates we have entered a new surface subtree. |
| void enterRenderTarget(const LayerType* newTarget); |
| |
| // Called when visiting a layer representing a target surface. This indicates we have visited all the layers within the surface, and we may |
| // perform any surface-wide operations. |
| void finishedRenderTarget(const LayerType* finishedTarget); |
| |
| // Called when visiting a layer representing a contributing surface. This indicates that we are leaving our current surface, and |
| // entering the new one. We then perform any operations required for merging results from the child subtree into its parent. |
| void leaveToRenderTarget(const LayerType* newTarget); |
| |
| // Add the layer's occlusion to the tracked state. |
| void markOccludedBehindLayer(const LayerType*); |
| |
| gfx::Rect m_screenSpaceClipRect; |
| scoped_ptr<OverdrawMetrics> m_overdrawMetrics; |
| gfx::Size m_minimumTrackingSize; |
| |
| // This is used for visualizing the occlusion tracking process. |
| std::vector<gfx::Rect>* m_occludingScreenSpaceRects; |
| std::vector<gfx::Rect>* m_nonOccludingScreenSpaceRects; |
| |
| DISALLOW_COPY_AND_ASSIGN(OcclusionTrackerBase); |
| }; |
| |
| typedef OcclusionTrackerBase<Layer, RenderSurface> OcclusionTracker; |
| typedef OcclusionTrackerBase<LayerImpl, RenderSurfaceImpl> OcclusionTrackerImpl; |
| #if !defined(COMPILER_MSVC) |
| extern template class OcclusionTrackerBase<Layer, RenderSurface>; |
| extern template class OcclusionTrackerBase<LayerImpl, RenderSurfaceImpl>; |
| #endif |
| |
| } // namespace cc |
| |
| #endif // CC_OCCLUSION_TRACKER_H_ |