1 /* 2 * Copyright 2013 Google Inc. 3 * 4 * Use of this source code is governed by a BSD-style license that can be 5 * found in the LICENSE file. 6 */ 7 #include "SkCanvasStack.h" 8 9 SkCanvasStack::SkCanvasStack(int width, int height) 10 : INHERITED(width, height) {} 11 12 SkCanvasStack::~SkCanvasStack() { 13 this->removeAll(); 14 } 15 16 void SkCanvasStack::pushCanvas(std::unique_ptr<SkCanvas> canvas, const SkIPoint& origin) { 17 if (canvas) { 18 // compute the bounds of this canvas 19 const SkIRect canvasBounds = SkIRect::MakeSize(canvas->getBaseLayerSize()); 20 21 // push the canvas onto the stack 22 this->INHERITED::addCanvas(canvas.get()); 23 24 // push the canvas data onto the stack 25 CanvasData* data = &fCanvasData.push_back(); 26 data->origin = origin; 27 data->requiredClip.setRect(canvasBounds); 28 data->ownedCanvas = std::move(canvas); 29 30 // subtract this region from the canvas objects already on the stack. 31 // This ensures they do not draw into the space occupied by the layers 32 // above them. 33 for (int i = fList.count() - 1; i > 0; --i) { 34 SkIRect localBounds = canvasBounds; 35 localBounds.offset(origin - fCanvasData[i-1].origin); 36 37 fCanvasData[i-1].requiredClip.op(localBounds, SkRegion::kDifference_Op); 38 fList[i-1]->clipRegion(fCanvasData[i-1].requiredClip); 39 } 40 } 41 SkASSERT(fList.count() == fCanvasData.count()); 42 } 43 44 void SkCanvasStack::removeAll() { 45 this->INHERITED::removeAll(); // call the baseclass *before* we actually delete the canvases 46 fCanvasData.reset(); 47 } 48 49 /** 50 * Traverse all canvases (e.g. layers) the stack and ensure that they are clipped 51 * to their bounds and that the area covered by any canvas higher in the stack is 52 * also clipped out. 53 */ 54 void SkCanvasStack::clipToZOrderedBounds() { 55 SkASSERT(fList.count() == fCanvasData.count()); 56 for (int i = 0; i < fList.count(); ++i) { 57 fList[i]->clipRegion(fCanvasData[i].requiredClip); 58 } 59 } 60 61 //////////////////////////////////////////////////////////////////////////////// 62 63 /** 64 * We need to handle setMatrix specially as it overwrites the matrix in each 65 * canvas unlike all other matrix operations (i.e. translate, scale, etc) which 66 * just pre-concatenate with the existing matrix. 67 */ 68 void SkCanvasStack::didSetMatrix(const SkMatrix& matrix) { 69 SkASSERT(fList.count() == fCanvasData.count()); 70 for (int i = 0; i < fList.count(); ++i) { 71 72 SkMatrix tempMatrix = matrix; 73 tempMatrix.postTranslate(SkIntToScalar(-fCanvasData[i].origin.x()), 74 SkIntToScalar(-fCanvasData[i].origin.y())); 75 fList[i]->setMatrix(tempMatrix); 76 } 77 this->SkCanvas::didSetMatrix(matrix); 78 } 79 80 void SkCanvasStack::onClipRect(const SkRect& r, SkClipOp op, ClipEdgeStyle edgeStyle) { 81 this->INHERITED::onClipRect(r, op, edgeStyle); 82 this->clipToZOrderedBounds(); 83 } 84 85 void SkCanvasStack::onClipRRect(const SkRRect& rr, SkClipOp op, ClipEdgeStyle edgeStyle) { 86 this->INHERITED::onClipRRect(rr, op, edgeStyle); 87 this->clipToZOrderedBounds(); 88 } 89 90 void SkCanvasStack::onClipPath(const SkPath& p, SkClipOp op, ClipEdgeStyle edgeStyle) { 91 this->INHERITED::onClipPath(p, op, edgeStyle); 92 this->clipToZOrderedBounds(); 93 } 94 95 void SkCanvasStack::onClipRegion(const SkRegion& deviceRgn, SkClipOp op) { 96 SkASSERT(fList.count() == fCanvasData.count()); 97 for (int i = 0; i < fList.count(); ++i) { 98 SkRegion tempRegion; 99 deviceRgn.translate(-fCanvasData[i].origin.x(), 100 -fCanvasData[i].origin.y(), &tempRegion); 101 tempRegion.op(fCanvasData[i].requiredClip, SkRegion::kIntersect_Op); 102 fList[i]->clipRegion(tempRegion, op); 103 } 104 this->SkCanvas::onClipRegion(deviceRgn, op); 105 } 106
