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/* -*- 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
// Main header first:
#include "SVGClipPathFrame.h"
// Keep others in (case-insensitive) order:
#include "AutoReferenceChainGuard.h"
#include "ImgDrawResult.h"
#include "gfxContext.h"
#include "mozilla/PresShell.h"
#include "mozilla/SVGGeometryFrame.h"
#include "mozilla/SVGObserverUtils.h"
#include "mozilla/SVGUtils.h"
#include "mozilla/dom/SVGClipPathElement.h"
#include "mozilla/dom/SVGGeometryElement.h"
#include "nsGkAtoms.h"
using namespace mozilla::dom;
using namespace mozilla::gfx;
using namespace mozilla::image;
//----------------------------------------------------------------------
// Implementation
nsIFrame* NS_NewSVGClipPathFrame(mozilla::PresShell* aPresShell,
mozilla::ComputedStyle* aStyle) {
return new (aPresShell)
mozilla::SVGClipPathFrame(aStyle, aPresShell->GetPresContext());
}
namespace mozilla {
NS_IMPL_FRAMEARENA_HELPERS(SVGClipPathFrame)
void SVGClipPathFrame::ApplyClipPath(gfxContext& aContext,
nsIFrame* aClippedFrame,
const gfxMatrix& aMatrix) {
ISVGDisplayableFrame* singleClipPathChild = nullptr;
DebugOnly<bool> trivial = IsTrivial(&singleClipPathChild);
MOZ_ASSERT(trivial, "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 autoRestoreTransform(&aContext);
RefPtr<Path> clipPath;
if (singleClipPathChild) {
SVGGeometryFrame* pathFrame = do_QueryFrame(singleClipPathChild);
if (pathFrame && pathFrame->StyleVisibility()->IsVisible()) {
SVGGeometryElement* pathElement =
static_cast<SVGGeometryElement*>(pathFrame->GetContent());
gfxMatrix toChildsUserSpace =
SVGUtils::GetTransformMatrixInUserSpace(pathFrame) *
(GetClipPathTransform(aClippedFrame) * aMatrix);
gfxMatrix newMatrix = aContext.CurrentMatrixDouble()
.PreMultiply(toChildsUserSpace)
.NudgeToIntegers();
if (!newMatrix.IsSingular()) {
aContext.SetMatrixDouble(newMatrix);
FillRule clipRule =
SVGUtils::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());
}
}
static void ComposeExtraMask(DrawTarget* aTarget, SourceSurface* aExtraMask) {
MOZ_ASSERT(aExtraMask);
Matrix origin = aTarget->GetTransform();
aTarget->SetTransform(Matrix());
aTarget->MaskSurface(ColorPattern(DeviceColor(0.0, 0.0, 0.0, 1.0)),
aExtraMask, Point(0, 0),
DrawOptions(1.0, CompositionOp::OP_IN));
aTarget->SetTransform(origin);
}
void SVGClipPathFrame::PaintChildren(gfxContext& aMaskContext,
nsIFrame* aClippedFrame,
const gfxMatrix& aMatrix) {
// Check if this clipPath is itself clipped by another clipPath:
SVGClipPathFrame* clipPathThatClipsClipPath;
// XXX check return value?
SVGObserverUtils::GetAndObserveClipPath(this, &clipPathThatClipsClipPath);
SVGUtils::MaskUsage maskUsage = SVGUtils::DetermineMaskUsage(this, true);
gfxGroupForBlendAutoSaveRestore autoGroupForBlend(&aMaskContext);
if (maskUsage.ShouldApplyClipPath()) {
clipPathThatClipsClipPath->ApplyClipPath(aMaskContext, aClippedFrame,
aMatrix);
} else if (maskUsage.ShouldGenerateClipMaskLayer()) {
RefPtr<SourceSurface> maskSurface = clipPathThatClipsClipPath->GetClipMask(
aMaskContext, aClippedFrame, aMatrix);
// We want the mask to be untransformed so use the inverse of the current
// transform as the maskTransform to compensate.
Matrix maskTransform = aMaskContext.CurrentMatrix();
maskTransform.Invert();
autoGroupForBlend.PushGroupForBlendBack(gfxContentType::ALPHA, 1.0f,
maskSurface, maskTransform);
}
// Paint our children into the mask:
for (auto* kid : mFrames) {
PaintFrameIntoMask(kid, aClippedFrame, aMaskContext);
}
if (maskUsage.ShouldApplyClipPath()) {
aMaskContext.PopClip();
}
}
void SVGClipPathFrame::PaintClipMask(gfxContext& aMaskContext,
nsIFrame* aClippedFrame,
const gfxMatrix& aMatrix,
SourceSurface* aExtraMask) {
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
}
if (!IsValid()) {
return;
}
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;
PaintChildren(aMaskContext, aClippedFrame, aMatrix);
if (aExtraMask) {
ComposeExtraMask(maskDT, aExtraMask);
}
}
void SVGClipPathFrame::PaintFrameIntoMask(nsIFrame* aFrame,
nsIFrame* aClippedFrame,
gfxContext& aTarget) {
ISVGDisplayableFrame* frame = do_QueryFrame(aFrame);
if (!frame) {
return;
}
// The CTM of each frame referencing us can be different.
frame->NotifySVGChanged(ISVGDisplayableFrame::TRANSFORM_CHANGED);
// Children of this clipPath may themselves be clipped.
SVGClipPathFrame* clipPathThatClipsChild;
// XXX check return value?
if (SVGObserverUtils::GetAndObserveClipPath(aFrame,
&clipPathThatClipsChild) ==
SVGObserverUtils::eHasRefsSomeInvalid) {
return;
}
SVGUtils::MaskUsage maskUsage = SVGUtils::DetermineMaskUsage(aFrame, true);
gfxGroupForBlendAutoSaveRestore autoGroupForBlend(&aTarget);
if (maskUsage.ShouldApplyClipPath()) {
clipPathThatClipsChild->ApplyClipPath(
aTarget, aClippedFrame,
SVGUtils::GetTransformMatrixInUserSpace(aFrame) * mMatrixForChildren);
} else if (maskUsage.ShouldGenerateClipMaskLayer()) {
RefPtr<SourceSurface> maskSurface = clipPathThatClipsChild->GetClipMask(
aTarget, aClippedFrame,
SVGUtils::GetTransformMatrixInUserSpace(aFrame) * mMatrixForChildren);
// We want the mask to be untransformed so use the inverse of the current
// transform as the maskTransform to compensate.
Matrix maskTransform = aTarget.CurrentMatrix();
maskTransform.Invert();
autoGroupForBlend.PushGroupForBlendBack(gfxContentType::ALPHA, 1.0f,
maskSurface, maskTransform);
}
gfxMatrix toChildsUserSpace = mMatrixForChildren;
nsIFrame* child = do_QueryFrame(frame);
nsIContent* childContent = child->GetContent();
if (childContent->IsSVGElement()) {
toChildsUserSpace =
SVGUtils::GetTransformMatrixInUserSpace(child) * mMatrixForChildren;
}
// 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.ShouldApplyClipPath()) {
aTarget.PopClip();
}
}
already_AddRefed<SourceSurface> SVGClipPathFrame::GetClipMask(
gfxContext& aReferenceContext, nsIFrame* aClippedFrame,
const gfxMatrix& aMatrix, SourceSurface* aExtraMask) {
RefPtr<DrawTarget> maskDT =
aReferenceContext.GetDrawTarget()->CreateClippedDrawTarget(
Rect(), SurfaceFormat::A8);
if (!maskDT) {
return nullptr;
}
gfxContext maskContext(maskDT, /* aPreserveTransform */ true);
PaintClipMask(maskContext, aClippedFrame, aMatrix, aExtraMask);
RefPtr<SourceSurface> surface = maskDT->Snapshot();
return surface.forget();
}
bool SVGClipPathFrame::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
}
if (!IsValid()) {
return false;
}
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 receiving events at aPoint:
SVGClipPathFrame* clipPathFrame;
// XXX check return value?
SVGObserverUtils::GetAndObserveClipPath(this, &clipPathFrame);
if (clipPathFrame &&
!clipPathFrame->PointIsInsideClipPath(aClippedFrame, aPoint)) {
return false;
}
for (auto* kid : mFrames) {
ISVGDisplayableFrame* SVGFrame = do_QueryFrame(kid);
if (SVGFrame) {
gfxPoint pointForChild = point;
gfxMatrix m = SVGUtils::GetTransformMatrixInUserSpace(kid);
if (!m.IsIdentity()) {
if (!m.Invert()) {
return false;
}
pointForChild = m.TransformPoint(point);
}
if (SVGFrame->GetFrameForPoint(pointForChild)) {
return true;
}
}
}
return false;
}
bool SVGClipPathFrame::IsTrivial(ISVGDisplayableFrame** aSingleChild) {
// If the clip path is clipped then it's non-trivial
if (SVGObserverUtils::GetAndObserveClipPath(this, nullptr) ==
SVGObserverUtils::eHasRefsAllValid) {
return false;
}
if (aSingleChild) {
*aSingleChild = nullptr;
}
ISVGDisplayableFrame* foundChild = nullptr;
for (auto* kid : mFrames) {
ISVGDisplayableFrame* 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::GetAndObserveClipPath(kid, nullptr) ==
SVGObserverUtils::eHasRefsAllValid) {
return false;
}
foundChild = svgChild;
}
}
if (aSingleChild) {
*aSingleChild = foundChild;
}
return true;
}
bool SVGClipPathFrame::IsValid() {
if (SVGObserverUtils::GetAndObserveClipPath(this, nullptr) ==
SVGObserverUtils::eHasRefsSomeInvalid) {
return false;
}
for (auto* kid : mFrames) {
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 SVGClipPathFrame::AttributeChanged(int32_t aNameSpaceID,
nsAtom* aAttribute,
int32_t aModType) {
if (aNameSpaceID == kNameSpaceID_None) {
if (aAttribute == nsGkAtoms::transform) {
SVGObserverUtils::InvalidateRenderingObservers(this);
SVGUtils::NotifyChildrenOfSVGChange(
this, ISVGDisplayableFrame::TRANSFORM_CHANGED);
}
if (aAttribute == nsGkAtoms::clipPathUnits) {
SVGObserverUtils::InvalidateRenderingObservers(this);
}
}
return SVGContainerFrame::AttributeChanged(aNameSpaceID, aAttribute,
aModType);
}
#ifdef DEBUG
void SVGClipPathFrame::Init(nsIContent* aContent, nsContainerFrame* aParent,
nsIFrame* aPrevInFlow) {
NS_ASSERTION(aContent->IsSVGElement(nsGkAtoms::clipPath),
"Content is not an SVG clipPath!");
SVGContainerFrame::Init(aContent, aParent, aPrevInFlow);
}
#endif
gfxMatrix SVGClipPathFrame::GetCanvasTM() { return mMatrixForChildren; }
gfxMatrix SVGClipPathFrame::GetClipPathTransform(nsIFrame* aClippedFrame) {
SVGClipPathElement* content = static_cast<SVGClipPathElement*>(GetContent());
gfxMatrix tm = content->PrependLocalTransformsTo({}, eChildToUserSpace) *
SVGUtils::GetTransformMatrixInUserSpace(this);
SVGAnimatedEnumeration* clipPathUnits =
&content->mEnumAttributes[SVGClipPathElement::CLIPPATHUNITS];
uint32_t flags = SVGUtils::eBBoxIncludeFillGeometry |
(aClippedFrame->StyleBorder()->mBoxDecorationBreak ==
StyleBoxDecorationBreak::Clone
? SVGUtils::eIncludeOnlyCurrentFrameForNonSVGElement
: 0);
return SVGUtils::AdjustMatrixForUnits(tm, clipPathUnits, aClippedFrame,
flags);
}
SVGBBox SVGClipPathFrame::GetBBoxForClipPathFrame(const SVGBBox& aBBox,
const gfxMatrix& aMatrix,
uint32_t aFlags) {
SVGClipPathFrame* clipPathThatClipsClipPath;
if (SVGObserverUtils::GetAndObserveClipPath(this,
&clipPathThatClipsClipPath) ==
SVGObserverUtils::eHasRefsSomeInvalid) {
return SVGBBox();
}
nsIContent* node = GetContent()->GetFirstChild();
SVGBBox unionBBox, tmpBBox;
for (; node; node = node->GetNextSibling()) {
if (nsIFrame* frame = node->GetPrimaryFrame()) {
ISVGDisplayableFrame* svg = do_QueryFrame(frame);
if (svg) {
gfxMatrix matrix =
SVGUtils::GetTransformMatrixInUserSpace(frame) * aMatrix;
tmpBBox = svg->GetBBoxContribution(gfx::ToMatrix(matrix),
SVGUtils::eBBoxIncludeFill);
SVGClipPathFrame* clipPathFrame;
if (SVGObserverUtils::GetAndObserveClipPath(frame, &clipPathFrame) !=
SVGObserverUtils::eHasRefsSomeInvalid &&
clipPathFrame) {
tmpBBox =
clipPathFrame->GetBBoxForClipPathFrame(tmpBBox, aMatrix, aFlags);
}
if (!(aFlags & SVGUtils::eDoNotClipToBBoxOfContentInsideClipPath)) {
tmpBBox.Intersect(aBBox);
}
unionBBox.UnionEdges(tmpBBox);
}
}
}
if (clipPathThatClipsClipPath) {
tmpBBox = clipPathThatClipsClipPath->GetBBoxForClipPathFrame(aBBox, aMatrix,
aFlags);
unionBBox.Intersect(tmpBBox);
}
return unionBBox;
}
bool SVGClipPathFrame::IsSVGTransformed(Matrix* aOwnTransforms,
Matrix* aFromParentTransforms) const {
const auto* e = static_cast<SVGElement const*>(GetContent());
Matrix m = ToMatrix(e->PrependLocalTransformsTo({}, eUserSpaceToParent));
if (m.IsIdentity()) {
return false;
}
if (aOwnTransforms) {
*aOwnTransforms = m;
}
return true;
}
} // namespace mozilla