Strip old backend recording down to essentials

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"
-
-SkPictureStateTree::SkPictureStateTree()
-    : fAlloc(2048)
-    , fLastRestoredNode(NULL)
-    , fStateStack(sizeof(Draw), 16) {
-    fRootMatrix.reset();
-    fRoot.fParent = NULL;
-    fRoot.fMatrix = &fRootMatrix;
-    fRoot.fFlags = Node::kSave_Flag;
-    fRoot.fOffset = 0;
-    fRoot.fLevel = 0;
-    fCurrentState.fNode = &fRoot;
-    fCurrentState.fMatrix = &fRootMatrix;
-    *static_cast<Draw*>(fStateStack.push_back()) = fCurrentState;
-}
-
-SkPictureStateTree::~SkPictureStateTree() {
-}
-
-SkPictureStateTree::Draw* SkPictureStateTree::appendDraw(size_t offset) {
-    Draw* draw = static_cast<Draw*>(fAlloc.allocThrow(sizeof(Draw)));
-    *draw = fCurrentState;
-    draw->fOffset = SkToU32(offset);
-    return draw;
-}
-
-void SkPictureStateTree::appendSave() {
-    *static_cast<Draw*>(fStateStack.push_back()) = fCurrentState;
-    fCurrentState.fNode->fFlags |= Node::kSave_Flag;
-}
-
-void SkPictureStateTree::appendSaveLayer(size_t offset) {
-    *static_cast<Draw*>(fStateStack.push_back()) = fCurrentState;
-    this->appendNode(offset);
-    fCurrentState.fNode->fFlags |= Node::kSaveLayer_Flag;
-}
-
-void SkPictureStateTree::saveCollapsed() {
-    SkASSERT(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;
-}
-
-void SkPictureStateTree::appendClip(size_t offset) {
-    this->appendNode(offset);
-}
-
-void SkPictureStateTree::initIterator(SkPictureStateTree::Iterator* iter,
-                                      const SkTDArray<void*>& draws,
-                                      SkCanvas* canvas) {
-    iter->init(draws, canvas, &fRoot);
-}
-
-void SkPictureStateTree::appendNode(size_t offset) {
-    Node* n = static_cast<Node*>(fAlloc.allocThrow(sizeof(Node)));
-    n->fOffset = SkToU32(offset);
-    n->fFlags = 0;
-    n->fParent = fCurrentState.fNode;
-    n->fLevel = fCurrentState.fNode->fLevel + 1;
-    n->fMatrix = fCurrentState.fMatrix;
-    fCurrentState.fNode = n;
-}
-
-void SkPictureStateTree::Iterator::init(const SkTDArray<void*>& draws, SkCanvas* canvas, Node* root) {
-    SkASSERT(!fValid);
-    fDraws = &draws;
-    fCanvas = canvas;
-    fCurrentNode = root;
-    fPlaybackMatrix = canvas->getTotalMatrix();
-    fCurrentMatrix = NULL;
-    fPlaybackIndex = 0;
-    fSave = false;
-    fValid = true;
-}
-
-void SkPictureStateTree::Iterator::setCurrentMatrix(const SkMatrix* matrix) {
-    SkASSERT(matrix);
-
-    if (matrix == fCurrentMatrix) {
-        return;
-    }
-
-    // The matrix is in recording space, but we also inherit
-    // a playback matrix from out target canvas.
-    SkMatrix m = *matrix;
-    m.postConcat(fPlaybackMatrix);
-    fCanvas->setMatrix(m);
-    fCurrentMatrix = matrix;
-}
-
-uint32_t SkPictureStateTree::Iterator::finish() {
-    if (fCurrentNode->fFlags & Node::kSaveLayer_Flag) {
-        fCanvas->restore();
-    }
-
-    for (fCurrentNode = fCurrentNode->fParent; fCurrentNode;
-            fCurrentNode = fCurrentNode->fParent) {
-        // Note: we call restore() twice when both flags are set.
-        if (fCurrentNode->fFlags & Node::kSave_Flag) {
-            fCanvas->restore();
-        }
-        if (fCurrentNode->fFlags & Node::kSaveLayer_Flag) {
-            fCanvas->restore();
-        }
-    }
-
-    fCanvas->setMatrix(fPlaybackMatrix);
-    fCurrentMatrix = NULL;
-    return kDrawComplete;
-}
-
-uint32_t SkPictureStateTree::Iterator::nextDraw() {
-    SkASSERT(this->isValid());
-    if (fPlaybackIndex >= fDraws->count()) {
-        return this->finish();
-    }
-
-    Draw* draw = static_cast<Draw*>((*fDraws)[fPlaybackIndex]);
-    Node* targetNode = draw->fNode;
-
-    if (fSave) {
-        fCanvas->save();
-        fSave = false;
-    }
-
-    if (fCurrentNode != targetNode) {
-        // If we're not at the target and we don't have a list of nodes to get there, we need to
-        // figure out the path from our current node, to the target
-        if (fNodes.count() == 0) {
-            // Trace back up to a common ancestor, restoring to get our current state to match that
-            // of the ancestor, and saving a list of nodes whose state we need to apply to get to
-            // the target (we can restore up to the ancestor immediately, but we'll need to return
-            // an offset for each node on the way down to the target, to apply the desired clips and
-            // saveLayers, so it may take several draw() calls before the next draw actually occurs)
-            Node* tmp = fCurrentNode;
-            Node* ancestor = targetNode;
-            while (tmp != ancestor) {
-                uint16_t currentLevel = tmp->fLevel;
-                uint16_t targetLevel = ancestor->fLevel;
-                if (currentLevel >= targetLevel) {
-                    if (tmp != fCurrentNode && tmp->fFlags & Node::kSave_Flag) {
-                        fCanvas->restore();
-                        // restore() may change the matrix, so we need to reapply.
-                        fCurrentMatrix = NULL;
-                    }
-                    if (tmp->fFlags & Node::kSaveLayer_Flag) {
-                        fCanvas->restore();
-                        // restore() may change the matrix, so we need to reapply.
-                        fCurrentMatrix = NULL;
-                    }
-                    tmp = tmp->fParent;
-                }
-                if (currentLevel <= targetLevel) {
-                    fNodes.push(ancestor);
-                    ancestor = ancestor->fParent;
-                }
-            }
-
-            if (ancestor->fFlags & Node::kSave_Flag) {
-                if (fCurrentNode != ancestor) {
-                    fCanvas->restore();
-                    // restore() may change the matrix, so we need to reapply.
-                    fCurrentMatrix = NULL;
-                }
-                if (targetNode != ancestor) {
-                    fCanvas->save();
-                }
-            }
-            fCurrentNode = ancestor;
-        }
-
-        // If we're not at the target node yet, we'll need to return an offset to make the caller
-        // apply the next clip or saveLayer.
-        if (fCurrentNode != targetNode) {
-            uint32_t offset = fNodes.top()->fOffset;
-            fCurrentNode = fNodes.top();
-            fSave = fCurrentNode != targetNode && fCurrentNode->fFlags & Node::kSave_Flag;
-            fNodes.pop();
-            this->setCurrentMatrix(fCurrentNode->fMatrix);
-            return offset;
-        }
-    }
-
-    // If we got this far, the clip/saveLayer state is all set, so we can proceed to set the matrix
-    // for the draw, and return its offset.
-    this->setCurrentMatrix(draw->fMatrix);
-
-    ++fPlaybackIndex;
-    return draw->fOffset;
-}