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comparison: gfx/skia/trunk/src/core/SkPictureStateTree.h
gfx/skia/trunk/src/core/SkPictureStateTree.h
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- TOR_BUG_9701
- changeset 8
- 97036ab72558
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| -1:000000000000 | 0:4c5ead3c9b89 |
|---|---|
| 1 | |
| 2 /* | |
| 3 * Copyright 2012 Google Inc. | |
| 4 * | |
| 5 * Use of this source code is governed by a BSD-style license that can be | |
| 6 * found in the LICENSE file. | |
| 7 */ | |
| 8 | |
| 9 #ifndef SkPictureStateTree_DEFINED | |
| 10 #define SkPictureStateTree_DEFINED | |
| 11 | |
| 12 #include "SkTDArray.h" | |
| 13 #include "SkChunkAlloc.h" | |
| 14 #include "SkDeque.h" | |
| 15 #include "SkMatrix.h" | |
| 16 #include "SkRefCnt.h" | |
| 17 | |
| 18 class SkCanvas; | |
| 19 | |
| 20 /** | |
| 21 * Provides an interface that, given a sequence of draws into an SkPicture with corresponding | |
| 22 * offsets, allows for playback of an arbitrary subset of the draws (note that Z-order is only | |
| 23 * guaranteed if the draws are explicitly sorted). | |
| 24 */ | |
| 25 class SkPictureStateTree : public SkRefCnt { | |
| 26 private: | |
| 27 struct Node; | |
| 28 public: | |
| 29 SK_DECLARE_INST_COUNT(SkPictureStateTree) | |
| 30 | |
| 31 /** | |
| 32 * A draw call, stores offset into command buffer, a pointer to the matrix, and a pointer to | |
| 33 * the node in the tree that corresponds to its clip/layer state | |
| 34 */ | |
| 35 struct Draw { | |
| 36 SkMatrix* fMatrix; | |
| 37 Node* fNode; | |
| 38 uint32_t fOffset; | |
| 39 bool operator<(const Draw& other) const { return fOffset < other.fOffset; } | |
| 40 }; | |
| 41 | |
| 42 class Iterator; | |
| 43 | |
| 44 SkPictureStateTree(); | |
| 45 ~SkPictureStateTree(); | |
| 46 | |
| 47 /** | |
| 48 * Creates and returns a struct representing a draw at the given offset. | |
| 49 */ | |
| 50 Draw* appendDraw(size_t offset); | |
| 51 | |
| 52 /** | |
| 53 * Given a list of draws, and a canvas, returns an iterator that produces the correct sequence | |
| 54 * of offsets into the command buffer to carry out those calls with correct matrix/clip state. | |
| 55 * This handles saves/restores, and does all necessary matrix setup. | |
| 56 */ | |
| 57 Iterator getIterator(const SkTDArray<void*>& draws, SkCanvas* canvas); | |
| 58 | |
| 59 void appendSave(); | |
| 60 void appendSaveLayer(size_t offset); | |
| 61 void appendRestore(); | |
| 62 void appendTransform(const SkMatrix& trans); | |
| 63 void appendClip(size_t offset); | |
| 64 | |
| 65 /** | |
| 66 * Call this immediately after an appendRestore call that is associated | |
| 67 * a save or saveLayer that was removed from the command stream | |
| 68 * due to a command pattern optimization in SkPicture. | |
| 69 */ | |
| 70 void saveCollapsed(); | |
| 71 | |
| 72 /** | |
| 73 * Playback helper | |
| 74 */ | |
| 75 class Iterator { | |
| 76 public: | |
| 77 /** Returns the next offset into the picture stream, or kDrawComplete if complete. */ | |
| 78 uint32_t draw(); | |
| 79 static const uint32_t kDrawComplete = SK_MaxU32; | |
| 80 Iterator() : fPlaybackMatrix(), fValid(false) { } | |
| 81 bool isValid() const { return fValid; } | |
| 82 private: | |
| 83 Iterator(const SkTDArray<void*>& draws, SkCanvas* canvas, Node* root); | |
| 84 // The draws this iterator is associated with | |
| 85 const SkTDArray<void*>* fDraws; | |
| 86 | |
| 87 // canvas this is playing into (so we can insert saves/restores as necessary) | |
| 88 SkCanvas* fCanvas; | |
| 89 | |
| 90 // current state node | |
| 91 Node* fCurrentNode; | |
| 92 | |
| 93 // List of nodes whose state we need to apply to reach TargetNode | |
| 94 SkTDArray<Node*> fNodes; | |
| 95 | |
| 96 // The matrix of the canvas we're playing back into | |
| 97 const SkMatrix fPlaybackMatrix; | |
| 98 | |
| 99 // Cache of current matrix, so we can avoid redundantly setting it | |
| 100 SkMatrix* fCurrentMatrix; | |
| 101 | |
| 102 // current position in the array of draws | |
| 103 int fPlaybackIndex; | |
| 104 // Whether or not we need to do a save next iteration | |
| 105 bool fSave; | |
| 106 | |
| 107 // Whether or not this is a valid iterator (the default public constructor sets this false) | |
| 108 bool fValid; | |
| 109 | |
| 110 friend class SkPictureStateTree; | |
| 111 }; | |
| 112 | |
| 113 private: | |
| 114 | |
| 115 void appendNode(size_t offset); | |
| 116 | |
| 117 SkChunkAlloc fAlloc; | |
| 118 // Needed by saveCollapsed() because nodes do not currently store | |
| 119 // references to their children. If they did, we could just retrieve the | |
| 120 // last added child. | |
| 121 Node* fLastRestoredNode; | |
| 122 | |
| 123 // The currently active state | |
| 124 Draw fCurrentState; | |
| 125 // A stack of states for tracking save/restores | |
| 126 SkDeque fStateStack; | |
| 127 | |
| 128 // Represents a notable piece of state that requires an offset into the command buffer, | |
| 129 // corresponding to a clip/saveLayer/etc call, to apply. | |
| 130 struct Node { | |
| 131 Node* fParent; | |
| 132 uint32_t fOffset; | |
| 133 uint16_t fLevel; | |
| 134 uint16_t fFlags; | |
| 135 SkMatrix* fMatrix; | |
| 136 enum Flags { | |
| 137 kSave_Flag = 0x1, | |
| 138 kSaveLayer_Flag = 0x2 | |
| 139 }; | |
| 140 }; | |
| 141 | |
| 142 Node fRoot; | |
| 143 SkMatrix fRootMatrix; | |
| 144 | |
| 145 typedef SkRefCnt INHERITED; | |
| 146 }; | |
| 147 | |
| 148 #endif |
