blob: 87e8f653e21b624d8db922b2610312e2f8ded75c [file] [log] [blame]
/*
* 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 "SkCanvasStack.h"
SkCanvasStack::SkCanvasStack(int width, int height)
: INHERITED(width, height) {}
SkCanvasStack::~SkCanvasStack() {
this->removeAll();
}
void SkCanvasStack::pushCanvas(SkCanvas* canvas, const SkIPoint& origin) {
if (canvas) {
// compute the bounds of this canvas
const SkIRect canvasBounds = SkIRect::MakeSize(canvas->getDeviceSize());
// push the canvas onto the stack
this->INHERITED::addCanvas(canvas);
// push the canvas data onto the stack
CanvasData* data = &fCanvasData.push_back();
data->origin = origin;
data->requiredClip.setRect(canvasBounds);
// 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() {
fCanvasData.reset();
this->INHERITED::removeAll();
}
/**
* 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, SkRegion::kIntersect_Op);
}
}
////////////////////////////////////////////////////////////////////////////////
/**
* 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, SkRegion::Op op, ClipEdgeStyle edgeStyle) {
this->INHERITED::onClipRect(r, op, edgeStyle);
this->clipToZOrderedBounds();
}
void SkCanvasStack::onClipRRect(const SkRRect& rr, SkRegion::Op op, ClipEdgeStyle edgeStyle) {
this->INHERITED::onClipRRect(rr, op, edgeStyle);
this->clipToZOrderedBounds();
}
void SkCanvasStack::onClipPath(const SkPath& p, SkRegion::Op op, ClipEdgeStyle edgeStyle) {
this->INHERITED::onClipPath(p, op, edgeStyle);
this->clipToZOrderedBounds();
}
void SkCanvasStack::onClipRegion(const SkRegion& deviceRgn, SkRegion::Op 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);
}