diff options
Diffstat (limited to 'gfx/skia/skia/src/utils/SkCanvasStack.cpp')
-rw-r--r-- | gfx/skia/skia/src/utils/SkCanvasStack.cpp | 117 |
1 files changed, 117 insertions, 0 deletions
diff --git a/gfx/skia/skia/src/utils/SkCanvasStack.cpp b/gfx/skia/skia/src/utils/SkCanvasStack.cpp new file mode 100644 index 0000000000..ea3918b8bc --- /dev/null +++ b/gfx/skia/skia/src/utils/SkCanvasStack.cpp @@ -0,0 +1,117 @@ +/* + * 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" + +#include "include/core/SkRect.h" +#include "include/core/SkScalar.h" +#include "include/core/SkShader.h" +#include "include/private/base/SkTDArray.h" +#include <utility> + +class SkPath; +class SkRRect; + +SkCanvasStack::SkCanvasStack(int width, int height) + : INHERITED(width, height) {} + +SkCanvasStack::~SkCanvasStack() { + this->removeAll(); +} + +void SkCanvasStack::pushCanvas(std::unique_ptr<SkCanvas> 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.size() - 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.size() == fCanvasData.size()); +} + +void SkCanvasStack::removeAll() { + this->INHERITED::removeAll(); // call the baseclass *before* we actually delete the canvases + fCanvasData.clear(); +} + +/** + * 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.size() == fCanvasData.size()); + for (int i = 0; i < fList.size(); ++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::didSetM44(const SkM44& mx) { + SkASSERT(fList.size() == fCanvasData.size()); + for (int i = 0; i < fList.size(); ++i) { + fList[i]->setMatrix(SkM44::Translate(SkIntToScalar(-fCanvasData[i].origin.x()), + SkIntToScalar(-fCanvasData[i].origin.y())) * mx); + } + this->SkCanvas::didSetM44(mx); +} + +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::onClipShader(sk_sp<SkShader> cs, SkClipOp op) { + this->INHERITED::onClipShader(std::move(cs), op); + // we don't change the "bounds" of the clip, so we don't need to update zorder +} + +void SkCanvasStack::onClipRegion(const SkRegion& deviceRgn, SkClipOp op) { + SkASSERT(fList.size() == fCanvasData.size()); + for (int i = 0; i < fList.size(); ++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); +} |