DrawResult
nsSVGClipPathFrame::PaintFrameIntoMask(nsIFrame *aFrame,
nsIFrame* aClippedFrame,
gfxContext& aTarget,
const gfxMatrix& aMatrix)
{
nsISVGChildFrame* frame = do_QueryFrame(aFrame);
if (!frame) {
return DrawResult::SUCCESS;
}
// The CTM of each frame referencing us can be different.
frame->NotifySVGChanged(nsISVGChildFrame::TRANSFORM_CHANGED);
// Children of this clipPath may themselves be clipped.
nsSVGEffects::EffectProperties effectProperties =
nsSVGEffects::GetEffectProperties(aFrame);
if (effectProperties.HasInvalidClipPath()) {
return DrawResult::SUCCESS;
}
nsSVGClipPathFrame *clipPathThatClipsChild =
effectProperties.GetClipPathFrame();
nsSVGUtils::MaskUsage maskUsage;
nsSVGUtils::DetermineMaskUsage(aFrame, true, maskUsage);
DrawResult result = DrawResult::SUCCESS;
if (maskUsage.shouldApplyClipPath) {
clipPathThatClipsChild->ApplyClipPath(aTarget, aClippedFrame, aMatrix);
} else if (maskUsage.shouldGenerateClipMaskLayer) {
Matrix maskTransform;
RefPtr<SourceSurface> maskSurface;
Tie(result, 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);
}
// 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.
result &= frame->PaintSVG(aTarget, toChildsUserSpace);
if (maskUsage.shouldGenerateClipMaskLayer) {
aTarget.PopGroupAndBlend();
} else if (maskUsage.shouldApplyClipPath) {
aTarget.PopClip();
}
return result;
}
DrawResult
nsSVGClipPathFrame::PaintClipMask(gfxContext& aMaskContext,
nsIFrame* aClippedFrame,
const gfxMatrix& aMatrix,
Matrix* aMaskTransform,
SourceSurface* aExtraMask,
const Matrix& aExtraMasksTransform)
{
// A clipPath can reference another clipPath. We re-enter this method for
// each clipPath in a reference chain, so here we limit chain length:
static int16_t sRefChainLengthCounter = AutoReferenceLimiter::notReferencing;
AutoReferenceLimiter
refChainLengthLimiter(&sRefChainLengthCounter,
MAX_SVG_CLIP_PATH_REFERENCE_CHAIN_LENGTH);
if (!refChainLengthLimiter.Reference()) {
return DrawResult::SUCCESS; // Reference chain is too long!
}
// And to prevent reference loops we check that this clipPath only appears
// once in the reference chain (if any) that we're currently processing:
AutoReferenceLimiter refLoopDetector(&mReferencing, 1);
if (!refLoopDetector.Reference()) {
return DrawResult::SUCCESS; // Reference loop!
}
DrawResult result = DrawResult::SUCCESS;
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 =
nsSVGEffects::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;
Tie(result, 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()) {
result &= PaintFrameIntoMask(kid, aClippedFrame, aMaskContext, aMatrix);
}
if (maskUsage.shouldGenerateClipMaskLayer) {
aMaskContext.PopGroupAndBlend();
} else if (maskUsage.shouldApplyClipPath) {
aMaskContext.PopClip();
}
// Moz2D transforms in the opposite direction to Thebes
gfxMatrix maskTransfrom = aMaskContext.CurrentMatrix();
maskTransfrom.Invert();
if (aExtraMask) {
ComposeExtraMask(maskDT, maskTransfrom, aExtraMask, aExtraMasksTransform);
}
*aMaskTransform = ToMatrix(maskTransfrom);
return result;
}