diff options
Diffstat (limited to 'layout/svg/SVGClipPathFrame.cpp')
| -rw-r--r-- | layout/svg/SVGClipPathFrame.cpp | 475 |
1 files changed, 475 insertions, 0 deletions
diff --git a/layout/svg/SVGClipPathFrame.cpp b/layout/svg/SVGClipPathFrame.cpp new file mode 100644 index 0000000000..b7691f0647 --- /dev/null +++ b/layout/svg/SVGClipPathFrame.cpp @@ -0,0 +1,475 @@ +/* -*- 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 "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 |