/* -*- Mode: C++; tab-width: 8; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
/* vim: set ts=8 sts=2 et sw=2 tw=80: */
/* This Source Code Form is subject to the terms of the Mozilla Public
* License, v. 2.0. If a copy of the MPL was not distributed with this
* file, You can obtain one at http://mozilla.org/MPL/2.0/. */
// Main header first:
#include "nsSVGClipPathFrame.h"
// Keep others in (case-insensitive) order:
#include "AutoReferenceChainGuard.h"
#include "ImgDrawResult.h"
#include "gfxContext.h"
#include "mozilla/dom/SVGClipPathElement.h"
#include "nsGkAtoms.h"
#include "SVGObserverUtils.h"
#include "SVGGeometryElement.h"
#include "SVGGeometryFrame.h"
#include "nsSVGUtils.h"
using namespace mozilla;
using namespace mozilla::dom;
using namespace mozilla::gfx;
using namespace mozilla::image;
//----------------------------------------------------------------------
// Implementation
nsIFrame* NS_NewSVGClipPathFrame(nsIPresShell* aPresShell,
nsStyleContext* aContext) {
return new (aPresShell) nsSVGClipPathFrame(aContext);
}
NS_IMPL_FRAMEARENA_HELPERS(nsSVGClipPathFrame)
void nsSVGClipPathFrame::ApplyClipPath(gfxContext& aContext,
nsIFrame* aClippedFrame,
const gfxMatrix& aMatrix) {
MOZ_ASSERT(IsTrivial(), "Caller needs to use GetClipMask");
const DrawTarget* drawTarget = aContext.GetDrawTarget();
// No need for AutoReferenceChainGuard since simple clip paths by definition
// don't reference another clip path.
// Restore current transform after applying clip path:
gfxContextMatrixAutoSaveRestore autoRestore(&aContext);
RefPtr<Path> clipPath;
nsSVGDisplayableFrame* singleClipPathChild = nullptr;
IsTrivial(&singleClipPathChild);
if (singleClipPathChild) {
SVGGeometryFrame* pathFrame = do_QueryFrame(singleClipPathChild);
if (pathFrame) {
SVGGeometryElement* pathElement =
static_cast<SVGGeometryElement*>(pathFrame->GetContent());
gfxMatrix toChildsUserSpace = pathElement->PrependLocalTransformsTo(
GetClipPathTransform(aClippedFrame) * aMatrix, eUserSpaceToParent);
gfxMatrix newMatrix = aContext.CurrentMatrixDouble()
.PreMultiply(toChildsUserSpace)
.NudgeToIntegers();
if (!newMatrix.IsSingular()) {
aContext.SetMatrixDouble(newMatrix);
FillRule clipRule =
nsSVGUtils::ToFillRule(pathFrame->StyleSVG()->mClipRule);
clipPath = pathElement->GetOrBuildPath(drawTarget, clipRule);
}
}
}
if (clipPath) {
aContext.Clip(clipPath);
} else {
// The spec says clip away everything if we have no children or the
// clipping path otherwise can't be resolved:
aContext.Clip(Rect());
}
}
already_AddRefed<DrawTarget> nsSVGClipPathFrame::CreateClipMask(
gfxContext& aReferenceContext, IntPoint& aOffset) {
IntRect bounds = RoundedOut(
ToRect(aReferenceContext.GetClipExtents(gfxContext::eDeviceSpace)));
if (bounds.IsEmpty()) {
// We don't need to create a mask surface, all drawing is clipped anyway.
return nullptr;
}
DrawTarget* referenceDT = aReferenceContext.GetDrawTarget();
RefPtr<DrawTarget> maskDT =
referenceDT->CreateSimilarDrawTarget(bounds.Size(), SurfaceFormat::A8);
aOffset = bounds.TopLeft();
return maskDT.forget();
}
static void ComposeExtraMask(DrawTarget* aTarget, SourceSurface* aExtraMask,
const Matrix& aExtraMasksTransform) {
MOZ_ASSERT(aExtraMask);
Matrix origin = aTarget->GetTransform();
aTarget->SetTransform(aExtraMasksTransform * aTarget->GetTransform());
aTarget->MaskSurface(ColorPattern(Color(0.0, 0.0, 0.0, 1.0)), aExtraMask,
Point(0, 0), DrawOptions(1.0, CompositionOp::OP_IN));
aTarget->SetTransform(origin);
}
void nsSVGClipPathFrame::PaintClipMask(gfxContext& aMaskContext,
nsIFrame* aClippedFrame,
const gfxMatrix& aMatrix,
Matrix* aMaskTransform,
SourceSurface* aExtraMask,
const Matrix& aExtraMasksTransform) {
static int16_t sRefChainLengthCounter = AutoReferenceChainGuard::noChain;
// A clipPath can reference another clipPath, creating a chain of clipPaths
// that must all be applied. We re-enter this method for each clipPath in a
// chain, so we need to protect against reference chain related crashes etc.:
AutoReferenceChainGuard refChainGuard(this, &mIsBeingProcessed,
&sRefChainLengthCounter);
if (MOZ_UNLIKELY(!refChainGuard.Reference())) {
return; // Break reference chain
}
DrawTarget* maskDT = aMaskContext.GetDrawTarget();
MOZ_ASSERT(maskDT->GetFormat() == SurfaceFormat::A8);
// Paint this clipPath's contents into aMaskDT:
// We need to set mMatrixForChildren here so that under the PaintSVG calls
// on our children (below) our GetCanvasTM() method will return the correct
// transform.
mMatrixForChildren = GetClipPathTransform(aClippedFrame) * aMatrix;
// Check if this clipPath is itself clipped by another clipPath:
nsSVGClipPathFrame* clipPathThatClipsClipPath =
SVGObserverUtils::GetEffectProperties(this).GetClipPathFrame();
nsSVGUtils::MaskUsage maskUsage;
nsSVGUtils::DetermineMaskUsage(this, true, maskUsage);
if (maskUsage.shouldApplyClipPath) {
clipPathThatClipsClipPath->ApplyClipPath(aMaskContext, aClippedFrame,
aMatrix);
} else if (maskUsage.shouldGenerateClipMaskLayer) {
Matrix maskTransform;
RefPtr<SourceSurface> maskSurface = clipPathThatClipsClipPath->GetClipMask(
aMaskContext, aClippedFrame, aMatrix, &maskTransform);
aMaskContext.PushGroupForBlendBack(gfxContentType::ALPHA, 1.0, maskSurface,
maskTransform);
// The corresponding PopGroupAndBlend call below will mask the
// blend using |maskSurface|.
}
// Paint our children into the mask:
for (nsIFrame* kid = mFrames.FirstChild(); kid; kid = kid->GetNextSibling()) {
PaintFrameIntoMask(kid, aClippedFrame, aMaskContext, aMatrix);
}
if (maskUsage.shouldGenerateClipMaskLayer) {
aMaskContext.PopGroupAndBlend();
} else if (maskUsage.shouldApplyClipPath) {
aMaskContext.PopClip();
}
// Moz2D transforms in the opposite direction to Thebes
Matrix maskTransfrom = aMaskContext.CurrentMatrix();
maskTransfrom.Invert();
if (aExtraMask) {
ComposeExtraMask(maskDT, aExtraMask, aExtraMasksTransform);
}
*aMaskTransform = maskTransfrom;
}
void nsSVGClipPathFrame::PaintFrameIntoMask(nsIFrame* aFrame,
nsIFrame* aClippedFrame,
gfxContext& aTarget,
const gfxMatrix& aMatrix) {
nsSVGDisplayableFrame* frame = do_QueryFrame(aFrame);
if (!frame) {
return;
}
// The CTM of each frame referencing us can be different.
frame->NotifySVGChanged(nsSVGDisplayableFrame::TRANSFORM_CHANGED);
// Children of this clipPath may themselves be clipped.
SVGObserverUtils::EffectProperties effectProperties =
SVGObserverUtils::GetEffectProperties(aFrame);
if (effectProperties.HasInvalidClipPath()) {
return;
}
nsSVGClipPathFrame* clipPathThatClipsChild =
effectProperties.GetClipPathFrame();
nsSVGUtils::MaskUsage maskUsage;
nsSVGUtils::DetermineMaskUsage(aFrame, true, maskUsage);
if (maskUsage.shouldApplyClipPath) {
clipPathThatClipsChild->ApplyClipPath(aTarget, aClippedFrame, aMatrix);
} else if (maskUsage.shouldGenerateClipMaskLayer) {
Matrix maskTransform;
RefPtr<SourceSurface> maskSurface = clipPathThatClipsChild->GetClipMask(
aTarget, aClippedFrame, aMatrix, &maskTransform);
aTarget.PushGroupForBlendBack(gfxContentType::ALPHA, 1.0, maskSurface,
maskTransform);
// The corresponding PopGroupAndBlend call below will mask the
// blend using |maskSurface|.
}
gfxMatrix toChildsUserSpace = mMatrixForChildren;
nsIFrame* child = do_QueryFrame(frame);
nsIContent* childContent = child->GetContent();
if (childContent->IsSVGElement()) {
toChildsUserSpace =
static_cast<const nsSVGElement*>(childContent)
->PrependLocalTransformsTo(mMatrixForChildren, eUserSpaceToParent);
}
// clipPath does not result in any image rendering, so we just use a dummy
// imgDrawingParams instead of requiring our caller to pass one.
image::imgDrawingParams imgParams;
// Our children have NS_STATE_SVG_CLIPPATH_CHILD set on them, and
// SVGGeometryFrame::Render checks for that state bit and paints
// only the geometry (opaque black) if set.
frame->PaintSVG(aTarget, toChildsUserSpace, imgParams);
if (maskUsage.shouldGenerateClipMaskLayer) {
aTarget.PopGroupAndBlend();
} else if (maskUsage.shouldApplyClipPath) {
aTarget.PopClip();
}
}
already_AddRefed<SourceSurface> nsSVGClipPathFrame::GetClipMask(
gfxContext& aReferenceContext, nsIFrame* aClippedFrame,
const gfxMatrix& aMatrix, Matrix* aMaskTransform, SourceSurface* aExtraMask,
const Matrix& aExtraMasksTransform) {
IntPoint offset;
RefPtr<DrawTarget> maskDT = CreateClipMask(aReferenceContext, offset);
if (!maskDT) {
return nullptr;
}
RefPtr<gfxContext> maskContext = gfxContext::CreateOrNull(maskDT);
if (!maskContext) {
gfxCriticalError() << "SVGClipPath context problem " << gfx::hexa(maskDT);
return nullptr;
}
maskContext->SetMatrix(aReferenceContext.CurrentMatrix() *
Matrix::Translation(-offset));
PaintClipMask(*maskContext, aClippedFrame, aMatrix, aMaskTransform,
aExtraMask, aExtraMasksTransform);
RefPtr<SourceSurface> surface = maskDT->Snapshot();
return surface.forget();
}
bool nsSVGClipPathFrame::PointIsInsideClipPath(nsIFrame* aClippedFrame,
const gfxPoint& aPoint) {
static int16_t sRefChainLengthCounter = AutoReferenceChainGuard::noChain;
// A clipPath can reference another clipPath, creating a chain of clipPaths
// that must all be applied. We re-enter this method for each clipPath in a
// chain, so we need to protect against reference chain related crashes etc.:
AutoReferenceChainGuard refChainGuard(this, &mIsBeingProcessed,
&sRefChainLengthCounter);
if (MOZ_UNLIKELY(!refChainGuard.Reference())) {
return false; // Break reference chain
}
gfxMatrix matrix = GetClipPathTransform(aClippedFrame);
if (!matrix.Invert()) {
return false;
}
gfxPoint point = matrix.TransformPoint(aPoint);
// clipPath elements can themselves be clipped by a different clip path. In
// that case the other clip path further clips away the element that is being
// clipped by the original clipPath. If this clipPath is being clipped by a
// different clip path we need to check if it prevents the original element
// from recieving events at aPoint:
nsSVGClipPathFrame* clipPathFrame =
SVGObserverUtils::GetEffectProperties(this).GetClipPathFrame();
if (clipPathFrame &&
!clipPathFrame->PointIsInsideClipPath(aClippedFrame, aPoint)) {
return false;
}
for (nsIFrame* kid = mFrames.FirstChild(); kid; kid = kid->GetNextSibling()) {
nsSVGDisplayableFrame* SVGFrame = do_QueryFrame(kid);
if (SVGFrame) {
gfxPoint pointForChild = point;
gfxMatrix m =
static_cast<nsSVGElement*>(kid->GetContent())
->PrependLocalTransformsTo(gfxMatrix(), eUserSpaceToParent);
if (!m.IsIdentity()) {
if (!m.Invert()) {
return false;
}
pointForChild = m.TransformPoint(point);
}
if (SVGFrame->GetFrameForPoint(pointForChild)) {
return true;
}
}
}
return false;
}
bool nsSVGClipPathFrame::IsTrivial(nsSVGDisplayableFrame** aSingleChild) {
// If the clip path is clipped then it's non-trivial
if (SVGObserverUtils::GetEffectProperties(this).GetClipPathFrame())
return false;
if (aSingleChild) {
*aSingleChild = nullptr;
}
nsSVGDisplayableFrame* foundChild = nullptr;
for (nsIFrame* kid = mFrames.FirstChild(); kid; kid = kid->GetNextSibling()) {
nsSVGDisplayableFrame* svgChild = do_QueryFrame(kid);
if (svgChild) {
// We consider a non-trivial clipPath to be one containing
// either more than one svg child and/or a svg container
if (foundChild || svgChild->IsDisplayContainer()) return false;
// or where the child is itself clipped
if (SVGObserverUtils::GetEffectProperties(kid).GetClipPathFrame())
return false;
foundChild = svgChild;
}
}
if (aSingleChild) {
*aSingleChild = foundChild;
}
return true;
}
bool nsSVGClipPathFrame::IsValid() {
static int16_t sRefChainLengthCounter = AutoReferenceChainGuard::noChain;
// A clipPath can reference another clipPath, creating a chain of clipPaths
// that must all be applied. We re-enter this method for each clipPath in a
// chain, so we need to protect against reference chain related crashes etc.:
AutoReferenceChainGuard refChainGuard(this, &mIsBeingProcessed,
&sRefChainLengthCounter);
if (MOZ_UNLIKELY(!refChainGuard.Reference())) {
return false; // Break reference chain
}
if (SVGObserverUtils::GetEffectProperties(this).HasInvalidClipPath()) {
return false;
}
for (nsIFrame* kid = mFrames.FirstChild(); kid; kid = kid->GetNextSibling()) {
LayoutFrameType kidType = kid->Type();
if (kidType == LayoutFrameType::SVGUse) {
for (nsIFrame* grandKid : kid->PrincipalChildList()) {
LayoutFrameType grandKidType = grandKid->Type();
if (grandKidType != LayoutFrameType::SVGGeometry &&
grandKidType != LayoutFrameType::SVGText) {
return false;
}
}
continue;
}
if (kidType != LayoutFrameType::SVGGeometry &&
kidType != LayoutFrameType::SVGText) {
return false;
}
}
return true;
}
nsresult nsSVGClipPathFrame::AttributeChanged(int32_t aNameSpaceID,
nsAtom* aAttribute,
int32_t aModType) {
if (aNameSpaceID == kNameSpaceID_None) {
if (aAttribute == nsGkAtoms::transform) {
SVGObserverUtils::InvalidateDirectRenderingObservers(this);
nsSVGUtils::NotifyChildrenOfSVGChange(
this, nsSVGDisplayableFrame::TRANSFORM_CHANGED);
}
if (aAttribute == nsGkAtoms::clipPathUnits) {
SVGObserverUtils::InvalidateDirectRenderingObservers(this);
}
}
return nsSVGContainerFrame::AttributeChanged(aNameSpaceID, aAttribute,
aModType);
}
void nsSVGClipPathFrame::Init(nsIContent* aContent, nsContainerFrame* aParent,
nsIFrame* aPrevInFlow) {
NS_ASSERTION(aContent->IsSVGElement(nsGkAtoms::clipPath),
"Content is not an SVG clipPath!");
AddStateBits(NS_STATE_SVG_CLIPPATH_CHILD);
nsSVGContainerFrame::Init(aContent, aParent, aPrevInFlow);
}
gfxMatrix nsSVGClipPathFrame::GetCanvasTM() { return mMatrixForChildren; }
gfxMatrix nsSVGClipPathFrame::GetClipPathTransform(nsIFrame* aClippedFrame) {
SVGClipPathElement* content = static_cast<SVGClipPathElement*>(GetContent());
gfxMatrix tm = content->PrependLocalTransformsTo(gfxMatrix());
nsSVGEnum* clipPathUnits =
&content->mEnumAttributes[SVGClipPathElement::CLIPPATHUNITS];
uint32_t flags = nsSVGUtils::eBBoxIncludeFillGeometry |
(aClippedFrame->StyleBorder()->mBoxDecorationBreak ==
StyleBoxDecorationBreak::Clone
? nsSVGUtils::eIncludeOnlyCurrentFrameForNonSVGElement
: 0);
return nsSVGUtils::AdjustMatrixForUnits(tm, clipPathUnits, aClippedFrame,
flags);
}
SVGBBox nsSVGClipPathFrame::GetBBoxForClipPathFrame(const SVGBBox& aBBox,
const gfxMatrix& aMatrix) {
nsIContent* node = GetContent()->GetFirstChild();
SVGBBox unionBBox, tmpBBox;
for (; node; node = node->GetNextSibling()) {
nsSVGElement* svgNode = static_cast<nsSVGElement*>(node);
nsIFrame* frame = svgNode->GetPrimaryFrame();
if (frame) {
nsSVGDisplayableFrame* svg = do_QueryFrame(frame);
if (svg) {
gfxMatrix matrix =
svgNode->PrependLocalTransformsTo(aMatrix, eUserSpaceToParent);
tmpBBox = svg->GetBBoxContribution(mozilla::gfx::ToMatrix(matrix),
nsSVGUtils::eBBoxIncludeFill);
SVGObserverUtils::EffectProperties effectProperties =
SVGObserverUtils::GetEffectProperties(frame);
if (effectProperties.HasNoOrValidClipPath()) {
nsSVGClipPathFrame* clipPathFrame =
effectProperties.GetClipPathFrame();
if (clipPathFrame) {
tmpBBox = clipPathFrame->GetBBoxForClipPathFrame(tmpBBox, aMatrix);
}
}
tmpBBox.Intersect(aBBox);
unionBBox.UnionEdges(tmpBBox);
}
}
}
SVGObserverUtils::EffectProperties props =
SVGObserverUtils::GetEffectProperties(this);
if (props.mClipPath) {
if (props.HasInvalidClipPath()) {
unionBBox = SVGBBox();
} else {
nsSVGClipPathFrame* clipPathFrame = props.GetClipPathFrame();
if (clipPathFrame) {
tmpBBox = clipPathFrame->GetBBoxForClipPathFrame(aBBox, aMatrix);
unionBBox.Intersect(tmpBBox);
}
}
}
return unionBBox;
}