1 /* 2 * Copyright (c) 2012, Google Inc. All rights reserved. 3 * 4 * Redistribution and use in source and binary forms, with or without 5 * modification, are permitted provided that the following conditions are 6 * met: 7 * 8 * * Redistributions of source code must retain the above copyright 9 * notice, this list of conditions and the following disclaimer. 10 * * Redistributions in binary form must reproduce the above 11 * copyright notice, this list of conditions and the following disclaimer 12 * in the documentation and/or other materials provided with the 13 * distribution. 14 * * Neither the name of Google Inc. nor the names of its 15 * contributors may be used to endorse or promote products derived from 16 * this software without specific prior written permission. 17 * 18 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS 19 * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT 20 * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR 21 * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT 22 * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, 23 * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT 24 * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, 25 * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY 26 * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT 27 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE 28 * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. 29 */ 30 31 #ifndef RegionTracker_h 32 #define RegionTracker_h 33 34 #include "platform/PlatformExport.h" 35 #include "platform/geometry/IntRect.h" 36 #include "third_party/skia/include/core/SkBitmap.h" 37 #include "third_party/skia/include/core/SkCanvas.h" 38 #include "third_party/skia/include/core/SkPaint.h" 39 #include "third_party/skia/include/core/SkPoint.h" 40 #include "third_party/skia/include/core/SkRect.h" 41 42 namespace blink { 43 class GraphicsContext; 44 45 enum RegionTrackingMode { 46 TrackOpaqueRegion, 47 TRackOverwriteRegion 48 }; 49 50 // This class is an encapsulation of functionality for GraphicsContext, and its methods are mirrored 51 // there for the outside world. It tracks paints and computes what area will be opaque. 52 class PLATFORM_EXPORT RegionTracker FINAL { 53 public: 54 RegionTracker(); 55 56 // The resulting opaque region as a single rect. 57 IntRect asRect() const; 58 59 void pushCanvasLayer(const SkPaint*); 60 void popCanvasLayer(const GraphicsContext*); 61 62 void setImageMask(const SkRect& imageOpaqueRect); 63 64 enum RegionType { 65 Opaque, 66 Overwrite 67 }; 68 69 // Set this to true to track regions that occlude the destination instead of only regions that produce opaque pixels. 70 void setTrackedRegionType(RegionType type) { m_trackedRegionType = type; } 71 72 enum DrawType { 73 FillOnly, 74 FillOrStroke 75 }; 76 77 void didDrawRect(const GraphicsContext*, const SkRect&, const SkPaint&, const SkBitmap* sourceBitmap); 78 void didDrawPath(const GraphicsContext*, const SkPath&, const SkPaint&); 79 void didDrawPoints(const GraphicsContext*, SkCanvas::PointMode, int numPoints, const SkPoint[], const SkPaint&); 80 void didDrawBounded(const GraphicsContext*, const SkRect&, const SkPaint&); 81 void didDrawUnbounded(const GraphicsContext*, const SkPaint&, DrawType); 82 83 struct CanvasLayerState { 84 CanvasLayerState() 85 : hasImageMask(false) 86 , opaqueRect(SkRect::MakeEmpty()) 87 { } 88 89 SkPaint paint; 90 91 // An image mask is being applied to the layer. 92 bool hasImageMask; 93 // The opaque area in the image mask. 94 SkRect imageOpaqueRect; 95 96 SkRect opaqueRect; 97 }; 98 99 void reset(); 100 101 private: 102 void didDraw(const GraphicsContext*, const SkRect&, const SkPaint&, const SkBitmap* sourceBitmap, bool fillsBounds, DrawType); 103 void applyOpaqueRegionFromLayer(const GraphicsContext*, const SkRect& layerOpaqueRect, const SkPaint&); 104 void markRectAsOpaque(const SkRect&); 105 void markRectAsNonOpaque(const SkRect&); 106 void markAllAsNonOpaque(); 107 108 SkRect& currentTrackingOpaqueRect(); 109 110 SkRect m_opaqueRect; 111 RegionType m_trackedRegionType; 112 113 Vector<CanvasLayerState, 3> m_canvasLayerStack; 114 }; 115 116 } // namespace blink 117 118 #endif // RegionTracker_h 119