Fixing SkPicture command pattern optimizations to make them work correctly with bounding box hierar…

src/core/SkPictureStateTree.h

 
 /*
  * Copyright 2012 Google Inc.
  *
  * Use of this source code is governed by a BSD-style license that can be
  * found in the LICENSE file.
  */
 
 #ifndef SkPictureStateTree_DEFINED
 #define SkPictureStateTree_DEFINED
@@ skipping 45 matching lines @@
      */
     Iterator getIterator(const SkTDArray<void*>& draws, SkCanvas* canvas);
 
     void appendSave();
     void appendSaveLayer(uint32_t offset);
     void appendRestore();
     void appendTransform(const SkMatrix& trans);
     void appendClip(uint32_t offset);
 
     /**
+     * Call this immediately after an appendRestore call that is associated
+     * a save or saveLayer that was removed from the command stream
+     * due to a command pattern optimization in SkPicture.
+     */
+    void saveCollapsed();
+
+    /**
      * Playback helper
      */
     class Iterator {
     public:
         /** Returns the next offset into the picture stream, or kDrawComplete if complete. */
         uint32_t draw();
         static const uint32_t kDrawComplete = SK_MaxU32;
         Iterator() : fPlaybackMatrix(), fValid(false) { }
         bool isValid() const { return fValid; }
     private:
@@ skipping 26 matching lines @@
 
         friend class SkPictureStateTree;
     };
 
 private:
 
     void appendNode(uint32_t offset);
 
     SkChunkAlloc fAlloc;
     Node* fRoot;
+    // Needed by saveCollapsed() because nodes do not currently store
+    // references to their children.  If they did, we could just retrieve the
+    // last added child.
+    Node* fLastRestoredNode; 
 
     // The currently active state
     Draw fCurrentState;
     // A stack of states for tracking save/restores
     SkDeque fStateStack;
 
     // Represents a notable piece of state that requires an offset into the command buffer,
     // corresponding to a clip/saveLayer/etc call, to apply.
     struct Node {
         Node* fParent;
         uint32_t fOffset;
         uint16_t fLevel;
         uint16_t fFlags;
         SkMatrix* fMatrix;
         enum Flags {
             kSave_Flag      = 0x1,
             kSaveLayer_Flag = 0x2
         };
     };
 
     typedef SkRefCnt INHERITED;
 };
 
 #endif