From 339e79fbeabae18a8b9ea094293c7c25eaf9dd68 Mon Sep 17 00:00:00 2001 From: "djsollen@google.com" Date: Wed, 4 Sep 2013 17:16:00 +0000 Subject: Add SkCanvasStack and update the Canvas utilities to use it. BUG= R=reed@google.com Review URL: https://codereview.chromium.org/23865004 git-svn-id: http://skia.googlecode.com/svn/trunk@11081 2bbb7eff-a529-9590-31e7-b0007b416f81 --- src/utils/SkCanvasStack.cpp | 108 +++++++++++++++++++++++++++++++++++++++ src/utils/SkCanvasStack.h | 52 +++++++++++++++++++ src/utils/SkCanvasStateUtils.cpp | 9 ++-- 3 files changed, 165 insertions(+), 4 deletions(-) create mode 100644 src/utils/SkCanvasStack.cpp create mode 100644 src/utils/SkCanvasStack.h (limited to 'src') diff --git a/src/utils/SkCanvasStack.cpp b/src/utils/SkCanvasStack.cpp new file mode 100644 index 0000000000..db5a8b2740 --- /dev/null +++ b/src/utils/SkCanvasStack.cpp @@ -0,0 +1,108 @@ + +/* + * 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-i]->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::setMatrix(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::setMatrix(matrix); +} + +bool SkCanvasStack::clipRect(const SkRect& r, SkRegion::Op op, bool aa) { + bool result = this->INHERITED::clipRect(r, op, aa); + this->clipToZOrderedBounds(); + return result; +} + +bool SkCanvasStack::clipRRect(const SkRRect& rr, SkRegion::Op op, bool aa) { + bool result = this->INHERITED::clipRRect(rr, op, aa); + this->clipToZOrderedBounds(); + return result; +} + +bool SkCanvasStack::clipPath(const SkPath& p, SkRegion::Op op, bool aa) { + bool result = this->INHERITED::clipPath(p, op, aa); + this->clipToZOrderedBounds(); + return result; +} + +bool SkCanvasStack::clipRegion(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); + } + return this->SkCanvas::clipRegion(deviceRgn, op); +} diff --git a/src/utils/SkCanvasStack.h b/src/utils/SkCanvasStack.h new file mode 100644 index 0000000000..2137d308b8 --- /dev/null +++ b/src/utils/SkCanvasStack.h @@ -0,0 +1,52 @@ + +/* + * Copyright 2013 Google Inc. + * + * Use of this source code is governed by a BSD-style license that can be + * found in the LICENSE file. + */ + +#ifndef SkCanvasStack_DEFINED +#define SkCanvasStack_DEFINED + +#include "SkNWayCanvas.h" +#include "SkTArray.h" + +class SkCanvasStack : public SkNWayCanvas { +public: + SkCanvasStack(int width, int height); + virtual ~SkCanvasStack(); + + void pushCanvas(SkCanvas* canvas, const SkIPoint& origin); + virtual void removeAll() SK_OVERRIDE; + + /* + * The following add/remove canvas methods are overrides from SkNWayCanvas + * that do not make sense in the context of our CanvasStack, but since we + * can share most of the other implementation of NWay we override those + * methods to be no-ops. + */ + virtual void addCanvas(SkCanvas*) SK_OVERRIDE { SkASSERT(!"Invalid Op"); } + virtual void removeCanvas(SkCanvas*) SK_OVERRIDE { SkASSERT(!"Invalid Op"); } + + virtual void setMatrix(const SkMatrix& matrix) SK_OVERRIDE; + virtual bool clipRect(const SkRect&, SkRegion::Op, bool) SK_OVERRIDE; + virtual bool clipRRect(const SkRRect&, SkRegion::Op, bool) SK_OVERRIDE; + virtual bool clipPath(const SkPath&, SkRegion::Op, bool) SK_OVERRIDE; + virtual bool clipRegion(const SkRegion& deviceRgn, + SkRegion::Op) SK_OVERRIDE; + +private: + void clipToZOrderedBounds(); + + struct CanvasData { + SkIPoint origin; + SkRegion requiredClip; + }; + + SkTArray fCanvasData; + + typedef SkNWayCanvas INHERITED; +}; + +#endif diff --git a/src/utils/SkCanvasStateUtils.cpp b/src/utils/SkCanvasStateUtils.cpp index c4232c2f5b..cd79a44f50 100644 --- a/src/utils/SkCanvasStateUtils.cpp +++ b/src/utils/SkCanvasStateUtils.cpp @@ -9,7 +9,7 @@ #include "SkBitmapDevice.h" #include "SkCanvas.h" -#include "SkNWayCanvas.h" +#include "SkCanvasStack.h" #include "SkWriter32.h" #define CANVAS_STATE_VERSION 1 @@ -316,18 +316,19 @@ SkCanvas* SkCanvasStateUtils::CreateFromCanvasState(const SkCanvasState* state) return NULL; } - SkAutoTUnref canvas(SkNEW_ARGS(SkNWayCanvas, (state->width, state->height))); + SkAutoTUnref canvas(SkNEW_ARGS(SkCanvasStack, (state->width, state->height))); // setup the matrix and clip on the n-way canvas setup_canvas_from_MC_state(state->mcState, canvas); // Iterate over the layers and add them to the n-way canvas - for (int i = 0; i < state->layerCount; ++i) { + for (int i = state->layerCount - 1; i >= 0; --i) { SkAutoTUnref canvasLayer(create_canvas_from_canvas_layer(state->layers[i])); if (!canvasLayer.get()) { return NULL; } - canvas->addCanvas(canvasLayer.get()); + canvas->pushCanvas(canvasLayer.get(), SkIPoint::Make(state->layers[i].x, + state->layers[i].y)); } return canvas.detach(); -- cgit v1.2.3