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

src/core/SkPictureStateTree.cpp

 
 /*
  * Copyright 2012 Google Inc.
  *
  * Use of this source code is governed by a BSD-style license that can be
  * found in the LICENSE file.
  */
 
 #include "SkPictureStateTree.h"
 #include "SkCanvas.h"
 
 SK_DEFINE_INST_COUNT(SkPictureStateTree)
 
 SkPictureStateTree::SkPictureStateTree()
     : fAlloc(2048)
     , fRoot(NULL)
+    , fLastRestoredNode(NULL)
     , fStateStack(sizeof(Draw), 16) {
     SkMatrix* identity = static_cast<SkMatrix*>(fAlloc.allocThrow(sizeof(SkMatrix)));
     identity->reset();
     fRoot = static_cast<Node*>(fAlloc.allocThrow(sizeof(Node)));
     fRoot->fParent = NULL;
     fRoot->fMatrix = identity;
     fRoot->fFlags = Node::kSave_Flag;
     fRoot->fOffset = 0;
     fRoot->fLevel = 0;
     fCurrentState.fNode = fRoot;
@@ skipping 15 matching lines @@
     *static_cast<Draw*>(fStateStack.push_back()) = fCurrentState;
     fCurrentState.fNode->fFlags |= Node::kSave_Flag;
 }
 
 void SkPictureStateTree::appendSaveLayer(uint32_t offset) {
     *static_cast<Draw*>(fStateStack.push_back()) = fCurrentState;
     this->appendNode(offset);
     fCurrentState.fNode->fFlags |= Node::kSaveLayer_Flag;
 }
 
+void SkPictureStateTree::saveCollapsed() {
+    SkASSERT(NULL != fLastRestoredNode);
+    SkASSERT(SkToBool(fLastRestoredNode->fFlags & \
+        (Node::kSaveLayer_Flag | Node::kSave_Flag)));
+    SkASSERT(fLastRestoredNode->fParent == fCurrentState.fNode);
+    // The structure of the tree is not modified here. We just turn off
+    // the save or saveLayer flag to prevent the iterator from making state
+    // changing calls on the playback canvas when traversing a save or
+    // saveLayerNode node.
+    fLastRestoredNode->fFlags = 0;
+}
+
 void SkPictureStateTree::appendRestore() {
+    fLastRestoredNode = fCurrentState.fNode;
     fCurrentState = *static_cast<Draw*>(fStateStack.back());
     fStateStack.pop_back();
 }
 
 void SkPictureStateTree::appendTransform(const SkMatrix& trans) {
     SkMatrix* m = static_cast<SkMatrix*>(fAlloc.allocThrow(sizeof(SkMatrix)));
     *m = trans;
     fCurrentState.fMatrix = m;
 }
 
@@ skipping 105 matching lines @@
     if (fCurrentMatrix != draw->fMatrix) {
         SkMatrix tmp = *draw->fMatrix;
         tmp.postConcat(fPlaybackMatrix);
         fCanvas->setMatrix(tmp);
         fCurrentMatrix = draw->fMatrix;
     }
 
     ++fPlaybackIndex;
     return draw->fOffset;
 }