/* * Copyright 2013 Google Inc. * * Use of this source code is governed by a BSD-style license that can be * found in the LICENSE file. */ #include "src/utils/SkCanvasStack.h" SkCanvasStack::SkCanvasStack(int width, int height) : INHERITED(width, height) {} SkCanvasStack::~SkCanvasStack() { this->removeAll(); } void SkCanvasStack::pushCanvas(std::unique_ptr canvas, const SkIPoint& origin) { if (canvas) { // compute the bounds of this canvas const SkIRect canvasBounds = SkIRect::MakeSize(canvas->getBaseLayerSize()); // push the canvas onto the stack this->INHERITED::addCanvas(canvas.get()); // push the canvas data onto the stack CanvasData* data = &fCanvasData.push_back(); data->origin = origin; data->requiredClip.setRect(canvasBounds); data->ownedCanvas = std::move(canvas); // subtract this region from the canvas objects already on the stack. // This ensures they do not draw into the space occupied by the layers // above them. for (int i = fList.count() - 1; i > 0; --i) { SkIRect localBounds = canvasBounds; localBounds.offset(origin - fCanvasData[i-1].origin); fCanvasData[i-1].requiredClip.op(localBounds, SkRegion::kDifference_Op); fList[i-1]->clipRegion(fCanvasData[i-1].requiredClip); } } SkASSERT(fList.count() == fCanvasData.count()); } void SkCanvasStack::removeAll() { this->INHERITED::removeAll(); // call the baseclass *before* we actually delete the canvases fCanvasData.reset(); } /** * Traverse all canvases (e.g. layers) the stack and ensure that they are clipped * to their bounds and that the area covered by any canvas higher in the stack is * also clipped out. */ void SkCanvasStack::clipToZOrderedBounds() { SkASSERT(fList.count() == fCanvasData.count()); for (int i = 0; i < fList.count(); ++i) { fList[i]->clipRegion(fCanvasData[i].requiredClip); } } //////////////////////////////////////////////////////////////////////////////// /** * We need to handle setMatrix specially as it overwrites the matrix in each * canvas unlike all other matrix operations (i.e. translate, scale, etc) which * just pre-concatenate with the existing matrix. */ void SkCanvasStack::didSetMatrix(const SkMatrix& matrix) { SkASSERT(fList.count() == fCanvasData.count()); for (int i = 0; i < fList.count(); ++i) { SkMatrix tempMatrix = matrix; tempMatrix.postTranslate(SkIntToScalar(-fCanvasData[i].origin.x()), SkIntToScalar(-fCanvasData[i].origin.y())); fList[i]->setMatrix(tempMatrix); } this->SkCanvas::didSetMatrix(matrix); } void SkCanvasStack::onClipRect(const SkRect& r, SkClipOp op, ClipEdgeStyle edgeStyle) { this->INHERITED::onClipRect(r, op, edgeStyle); this->clipToZOrderedBounds(); } void SkCanvasStack::onClipRRect(const SkRRect& rr, SkClipOp op, ClipEdgeStyle edgeStyle) { this->INHERITED::onClipRRect(rr, op, edgeStyle); this->clipToZOrderedBounds(); } void SkCanvasStack::onClipPath(const SkPath& p, SkClipOp op, ClipEdgeStyle edgeStyle) { this->INHERITED::onClipPath(p, op, edgeStyle); this->clipToZOrderedBounds(); } void SkCanvasStack::onClipRegion(const SkRegion& deviceRgn, SkClipOp op) { SkASSERT(fList.count() == fCanvasData.count()); for (int i = 0; i < fList.count(); ++i) { SkRegion tempRegion; deviceRgn.translate(-fCanvasData[i].origin.x(), -fCanvasData[i].origin.y(), &tempRegion); tempRegion.op(fCanvasData[i].requiredClip, SkRegion::kIntersect_Op); fList[i]->clipRegion(tempRegion, op); } this->SkCanvas::onClipRegion(deviceRgn, op); }