void
AppendToString(std::stringstream& aStream, const Matrix4x4& m,
const char* pfx, const char* sfx)
{
aStream << pfx;
if (m.Is2D()) {
Matrix matrix = m.As2D();
if (matrix.IsIdentity()) {
aStream << "[ I ]";
aStream << sfx;
return;
}
aStream << nsPrintfCString(
"[ %g %g; %g %g; %g %g; ]",
matrix._11, matrix._12, matrix._21, matrix._22, matrix._31, matrix._32).get();
} else {
aStream << nsPrintfCString(
"[ %g %g %g %g; %g %g %g %g; %g %g %g %g; %g %g %g %g; ]",
m._11, m._12, m._13, m._14,
m._21, m._22, m._23, m._24,
m._31, m._32, m._33, m._34,
m._41, m._42, m._43, m._44).get();
}
aStream << sfx;
}
Matrix4x4
Layer::SnapTransformTranslation(const Matrix4x4& aTransform,
Matrix* aResidualTransform)
{
if (aResidualTransform) {
*aResidualTransform = Matrix();
}
Matrix matrix2D;
Matrix4x4 result;
if (mManager->IsSnappingEffectiveTransforms() &&
aTransform.Is2D(&matrix2D) &&
!matrix2D.HasNonTranslation() &&
matrix2D.HasNonIntegerTranslation()) {
IntPoint snappedTranslation = RoundedToInt(matrix2D.GetTranslation());
Matrix snappedMatrix = Matrix::Translation(snappedTranslation.x,
snappedTranslation.y);
result = Matrix4x4::From2D(snappedMatrix);
if (aResidualTransform) {
// set aResidualTransform so that aResidual * snappedMatrix == matrix2D.
// (I.e., appying snappedMatrix after aResidualTransform gives the
// ideal transform.)
*aResidualTransform =
Matrix::Translation(matrix2D._31 - snappedTranslation.x,
matrix2D._32 - snappedTranslation.y);
}
} else {
result = aTransform;
}
return result;
}
void
AppendToString(std::stringstream& aStream, const Matrix4x4& m,
const char* pfx, const char* sfx)
{
if (m.Is2D()) {
Matrix matrix = m.As2D();
AppendToString(aStream, matrix, pfx, sfx);
return;
}
aStream << pfx;
aStream << nsPrintfCString(
"[ %g %g %g %g; %g %g %g %g; %g %g %g %g; %g %g %g %g; ]",
m._11, m._12, m._13, m._14,
m._21, m._22, m._23, m._24,
m._31, m._32, m._33, m._34,
m._41, m._42, m._43, m._44).get();
aStream << sfx;
}
static void
IncrementScaleRestyleCountIfNeeded(nsIFrame* aFrame, LayerActivity* aActivity)
{
const nsStyleDisplay* display = aFrame->StyleDisplay();
if (!display->mSpecifiedTransform) {
// The transform was removed.
aActivity->mPreviousTransformScale = Nothing();
IncrementMutationCount(&aActivity->mScaleRestyleCount);
return;
}
// Compute the new scale due to the CSS transform property.
nsPresContext* presContext = aFrame->PresContext();
RuleNodeCacheConditions dummy;
nsStyleTransformMatrix::TransformReferenceBox refBox(aFrame);
Matrix4x4 transform =
nsStyleTransformMatrix::ReadTransforms(display->mSpecifiedTransform->mHead,
aFrame->StyleContext(),
presContext,
dummy, refBox,
presContext->AppUnitsPerCSSPixel());
Matrix transform2D;
if (!transform.Is2D(&transform2D)) {
// We don't attempt to handle 3D transforms; just assume the scale changed.
aActivity->mPreviousTransformScale = Nothing();
IncrementMutationCount(&aActivity->mScaleRestyleCount);
return;
}
gfxSize scale = ThebesMatrix(transform2D).ScaleFactors(true);
if (aActivity->mPreviousTransformScale == Some(scale)) {
return; // Nothing changed.
}
aActivity->mPreviousTransformScale = Some(scale);
IncrementMutationCount(&aActivity->mScaleRestyleCount);
}
Matrix4x4
Layer::SnapTransform(const Matrix4x4& aTransform,
const gfxRect& aSnapRect,
Matrix* aResidualTransform)
{
if (aResidualTransform) {
*aResidualTransform = Matrix();
}
Matrix matrix2D;
Matrix4x4 result;
if (mManager->IsSnappingEffectiveTransforms() &&
aTransform.Is2D(&matrix2D) &&
gfx::Size(1.0, 1.0) <= ToSize(aSnapRect.Size()) &&
matrix2D.PreservesAxisAlignedRectangles()) {
IntPoint transformedTopLeft = RoundedToInt(matrix2D * ToPoint(aSnapRect.TopLeft()));
IntPoint transformedTopRight = RoundedToInt(matrix2D * ToPoint(aSnapRect.TopRight()));
IntPoint transformedBottomRight = RoundedToInt(matrix2D * ToPoint(aSnapRect.BottomRight()));
Matrix snappedMatrix = gfxUtils::TransformRectToRect(aSnapRect,
transformedTopLeft, transformedTopRight, transformedBottomRight);
result = Matrix4x4::From2D(snappedMatrix);
if (aResidualTransform && !snappedMatrix.IsSingular()) {
// set aResidualTransform so that aResidual * snappedMatrix == matrix2D.
// (i.e., appying snappedMatrix after aResidualTransform gives the
// ideal transform.
Matrix snappedMatrixInverse = snappedMatrix;
snappedMatrixInverse.Invert();
*aResidualTransform = matrix2D * snappedMatrixInverse;
}
} else {
result = aTransform;
}
return result;
}
void
LayerManagerComposite::PostProcessLayers(Layer* aLayer,
nsIntRegion& aOpaqueRegion,
LayerIntRegion& aVisibleRegion,
const Maybe<ParentLayerIntRect>& aClipFromAncestors)
{
if (aLayer->Extend3DContext()) {
// For layers participating 3D rendering context, their visible
// region should be empty (invisible), so we pass through them
// without doing anything.
// Direct children of the establisher may have a clip, becaue the
// item containing it; ex. of nsHTMLScrollFrame, may give it one.
Maybe<ParentLayerIntRect> layerClip =
aLayer->AsHostLayer()->GetShadowClipRect();
Maybe<ParentLayerIntRect> ancestorClipForChildren =
IntersectMaybeRects(layerClip, aClipFromAncestors);
MOZ_ASSERT(!layerClip || !aLayer->Combines3DTransformWithAncestors(),
"Only direct children of the establisher could have a clip");
for (Layer* child = aLayer->GetLastChild();
child;
child = child->GetPrevSibling()) {
PostProcessLayers(child, aOpaqueRegion, aVisibleRegion,
ancestorClipForChildren);
}
return;
}
nsIntRegion localOpaque;
// Treat layers on the path to the root of the 3D rendering context as
// a giant layer if it is a leaf.
Matrix4x4 transform = GetAccTransformIn3DContext(aLayer);
Matrix transform2d;
Maybe<IntPoint> integerTranslation;
// If aLayer has a simple transform (only an integer translation) then we
// can easily convert aOpaqueRegion into pre-transform coordinates and include
// that region.
if (transform.Is2D(&transform2d)) {
if (transform2d.IsIntegerTranslation()) {
integerTranslation = Some(IntPoint::Truncate(transform2d.GetTranslation()));
localOpaque = aOpaqueRegion;
localOpaque.MoveBy(-*integerTranslation);
}
}
// Compute a clip that's the combination of our layer clip with the clip
// from our ancestors.
LayerComposite* composite = static_cast<LayerComposite*>(aLayer->AsHostLayer());
Maybe<ParentLayerIntRect> layerClip = composite->GetShadowClipRect();
MOZ_ASSERT(!layerClip || !aLayer->Combines3DTransformWithAncestors(),
"The layer with a clip should not participate "
"a 3D rendering context");
Maybe<ParentLayerIntRect> outsideClip =
IntersectMaybeRects(layerClip, aClipFromAncestors);
// Convert the combined clip into our pre-transform coordinate space, so
// that it can later be intersected with our visible region.
// If our transform is a perspective, there's no meaningful insideClip rect
// we can compute (it would need to be a cone).
Maybe<LayerIntRect> insideClip;
if (outsideClip && !transform.HasPerspectiveComponent()) {
Matrix4x4 inverse = transform;
if (inverse.Invert()) {
Maybe<LayerRect> insideClipFloat =
UntransformBy(ViewAs<ParentLayerToLayerMatrix4x4>(inverse),
ParentLayerRect(*outsideClip),
LayerRect::MaxIntRect());
if (insideClipFloat) {
insideClipFloat->RoundOut();
LayerIntRect insideClipInt;
if (insideClipFloat->ToIntRect(&insideClipInt)) {
insideClip = Some(insideClipInt);
}
}
}
}
Maybe<ParentLayerIntRect> ancestorClipForChildren;
if (insideClip) {
ancestorClipForChildren =
Some(ViewAs<ParentLayerPixel>(*insideClip, PixelCastJustification::MovingDownToChildren));
}
// Save the value of localOpaque, which currently stores the region obscured
// by siblings (and uncles and such), before our descendants contribute to it.
nsIntRegion obscured = localOpaque;
// Recurse on our descendants, in front-to-back order. In this process:
// - Occlusions are computed for them, and they contribute to localOpaque.
// - They recalculate their visible regions, taking ancestorClipForChildren
// into account, and accumulate them into descendantsVisibleRegion.
LayerIntRegion descendantsVisibleRegion;
bool hasPreserve3DChild = false;
for (Layer* child = aLayer->GetLastChild(); child; child = child->GetPrevSibling()) {
PostProcessLayers(child, localOpaque, descendantsVisibleRegion, ancestorClipForChildren);
if (child->Extend3DContext()) {
hasPreserve3DChild = true;
}
}
// Recalculate our visible region.
LayerIntRegion visible = composite->GetShadowVisibleRegion();
// If we have descendants, throw away the visible region stored on this
// layer, and use the region accumulated by our descendants instead.
if (aLayer->GetFirstChild() && !hasPreserve3DChild) {
visible = descendantsVisibleRegion;
}
// Subtract any areas that we know to be opaque.
if (!obscured.IsEmpty()) {
visible.SubOut(LayerIntRegion::FromUnknownRegion(obscured));
}
// Clip the visible region using the combined clip.
if (insideClip) {
visible.AndWith(*insideClip);
}
composite->SetShadowVisibleRegion(visible);
// Transform the newly calculated visible region into our parent's space,
// apply our clip to it (if any), and accumulate it into |aVisibleRegion|
// for the caller to use.
ParentLayerIntRegion visibleParentSpace = TransformBy(
ViewAs<LayerToParentLayerMatrix4x4>(transform), visible);
if (const Maybe<ParentLayerIntRect>& clipRect = composite->GetShadowClipRect()) {
visibleParentSpace.AndWith(*clipRect);
}
aVisibleRegion.OrWith(ViewAs<LayerPixel>(visibleParentSpace,
PixelCastJustification::MovingDownToChildren));
// If we have a simple transform, then we can add our opaque area into
// aOpaqueRegion.
if (integerTranslation &&
!aLayer->HasMaskLayers() &&
aLayer->IsOpaqueForVisibility()) {
if (aLayer->IsOpaque()) {
localOpaque.OrWith(composite->GetFullyRenderedRegion());
}
localOpaque.MoveBy(*integerTranslation);
if (layerClip) {
localOpaque.AndWith(layerClip->ToUnknownRect());
}
aOpaqueRegion.OrWith(localOpaque);
}
}
void
AsyncCompositionManager::AlignFixedAndStickyLayers(Layer* aLayer,
Layer* aTransformedSubtreeRoot,
const Matrix4x4& aPreviousTransformForRoot,
const Matrix4x4& aCurrentTransformForRoot,
const LayerMargin& aFixedLayerMargins)
{
bool isRootFixed = aLayer->GetIsFixedPosition() &&
!aLayer->GetParent()->GetIsFixedPosition();
bool isStickyForSubtree = aLayer->GetIsStickyPosition() &&
aLayer->GetStickyScrollContainerId() ==
aTransformedSubtreeRoot->GetFrameMetrics().GetScrollId();
if (aLayer != aTransformedSubtreeRoot && (isRootFixed || isStickyForSubtree)) {
// Insert a translation so that the position of the anchor point is the same
// before and after the change to the transform of aTransformedSubtreeRoot.
// This currently only works for fixed layers with 2D transforms.
// Accumulate the transforms between this layer and the subtree root layer.
Matrix ancestorTransform;
if (!AccumulateLayerTransforms2D(aLayer->GetParent(), aTransformedSubtreeRoot,
ancestorTransform)) {
return;
}
Matrix oldRootTransform;
Matrix newRootTransform;
if (!aPreviousTransformForRoot.Is2D(&oldRootTransform) ||
!aCurrentTransformForRoot.Is2D(&newRootTransform)) {
return;
}
// Calculate the cumulative transforms between the subtree root with the
// old transform and the current transform.
Matrix oldCumulativeTransform = ancestorTransform * oldRootTransform;
Matrix newCumulativeTransform = ancestorTransform * newRootTransform;
if (newCumulativeTransform.IsSingular()) {
return;
}
Matrix newCumulativeTransformInverse = newCumulativeTransform;
newCumulativeTransformInverse.Invert();
// Now work out the translation necessary to make sure the layer doesn't
// move given the new sub-tree root transform.
Matrix layerTransform;
if (!GetBaseTransform2D(aLayer, &layerTransform)) {
return;
}
// Calculate any offset necessary, in previous transform sub-tree root
// space. This is used to make sure fixed position content respects
// content document fixed position margins.
LayerPoint offsetInOldSubtreeLayerSpace = GetLayerFixedMarginsOffset(aLayer, aFixedLayerMargins);
// Add the above offset to the anchor point so we can offset the layer by
// and amount that's specified in old subtree layer space.
const LayerPoint& anchorInOldSubtreeLayerSpace = aLayer->GetFixedPositionAnchor();
LayerPoint offsetAnchorInOldSubtreeLayerSpace = anchorInOldSubtreeLayerSpace + offsetInOldSubtreeLayerSpace;
// Add the local layer transform to the two points to make the equation
// below this section more convenient.
Point anchor(anchorInOldSubtreeLayerSpace.x, anchorInOldSubtreeLayerSpace.y);
Point offsetAnchor(offsetAnchorInOldSubtreeLayerSpace.x, offsetAnchorInOldSubtreeLayerSpace.y);
Point locallyTransformedAnchor = layerTransform * anchor;
Point locallyTransformedOffsetAnchor = layerTransform * offsetAnchor;
// Transforming the locallyTransformedAnchor by oldCumulativeTransform
// returns the layer's anchor point relative to the parent of
// aTransformedSubtreeRoot, before the new transform was applied.
// Then, applying newCumulativeTransformInverse maps that point relative
// to the layer's parent, which is the same coordinate space as
// locallyTransformedAnchor again, allowing us to subtract them and find
// out the offset necessary to make sure the layer stays stationary.
Point oldAnchorPositionInNewSpace =
newCumulativeTransformInverse * (oldCumulativeTransform * locallyTransformedOffsetAnchor);
Point translation = oldAnchorPositionInNewSpace - locallyTransformedAnchor;
if (aLayer->GetIsStickyPosition()) {
// For sticky positioned layers, the difference between the two rectangles
// defines a pair of translation intervals in each dimension through which
// the layer should not move relative to the scroll container. To
// accomplish this, we limit each dimension of the |translation| to that
// part of it which overlaps those intervals.
const LayerRect& stickyOuter = aLayer->GetStickyScrollRangeOuter();
const LayerRect& stickyInner = aLayer->GetStickyScrollRangeInner();
translation.y = IntervalOverlap(translation.y, stickyOuter.y, stickyOuter.YMost()) -
IntervalOverlap(translation.y, stickyInner.y, stickyInner.YMost());
translation.x = IntervalOverlap(translation.x, stickyOuter.x, stickyOuter.XMost()) -
IntervalOverlap(translation.x, stickyInner.x, stickyInner.XMost());
}
// Finally, apply the 2D translation to the layer transform.
TranslateShadowLayer2D(aLayer, ThebesPoint(translation));
// The transform has now been applied, so there's no need to iterate over
// child layers.
return;
}
// Fixed layers are relative to their nearest scrollable layer, so when we
// encounter a scrollable layer, bail. ApplyAsyncContentTransformToTree will
// have already recursed on this layer and called AlignFixedAndStickyLayers
// on it with its own transforms.
if (aLayer->GetFrameMetrics().IsScrollable() &&
aLayer != aTransformedSubtreeRoot) {
return;
}
for (Layer* child = aLayer->GetFirstChild();
child; child = child->GetNextSibling()) {
AlignFixedAndStickyLayers(child, aTransformedSubtreeRoot,
aPreviousTransformForRoot,
aCurrentTransformForRoot, aFixedLayerMargins);
}
}
void
BasicContainerLayer::ComputeEffectiveTransforms(const Matrix4x4& aTransformToSurface)
{
// We push groups for container layers if we need to, which always
// are aligned in device space, so it doesn't really matter how we snap
// containers.
Matrix residual;
Matrix4x4 idealTransform = GetLocalTransform() * aTransformToSurface;
if (!Extend3DContext() && !Is3DContextLeaf()) {
// For 3D transform leaked from extended parent layer.
idealTransform.ProjectTo2D();
}
if (!idealTransform.CanDraw2D()) {
if (!Extend3DContext() ||
(!idealTransform.Is2D() && Creates3DContextWithExtendingChildren())) {
if (!Creates3DContextWithExtendingChildren()) {
idealTransform.ProjectTo2D();
}
mEffectiveTransform = idealTransform;
ComputeEffectiveTransformsForChildren(Matrix4x4());
ComputeEffectiveTransformForMaskLayers(Matrix4x4());
mUseIntermediateSurface = true;
return;
}
mEffectiveTransform = idealTransform;
ComputeEffectiveTransformsForChildren(idealTransform);
ComputeEffectiveTransformForMaskLayers(idealTransform);
mUseIntermediateSurface = false;
return;
}
// With 2D transform or extended 3D context.
Layer* child = GetFirstChild();
bool hasSingleBlendingChild = false;
if (!HasMultipleChildren() && child) {
hasSingleBlendingChild = child->GetMixBlendMode() != CompositionOp::OP_OVER;
}
/* If we have a single childand it is not blending,, it can just inherit our opacity,
* otherwise we need a PushGroup and we need to mark ourselves as using
* an intermediate surface so our children don't inherit our opacity
* via GetEffectiveOpacity.
* Having a mask layer always forces our own push group
* Having a blend mode also always forces our own push group
*/
mUseIntermediateSurface =
GetMaskLayer() ||
GetForceIsolatedGroup() ||
(GetMixBlendMode() != CompositionOp::OP_OVER && HasMultipleChildren()) ||
(GetEffectiveOpacity() != 1.0 && (HasMultipleChildren() || hasSingleBlendingChild));
if (!Extend3DContext()) {
idealTransform.ProjectTo2D();
}
mEffectiveTransform =
!mUseIntermediateSurface ?
idealTransform : SnapTransformTranslation(idealTransform, &residual);
Matrix4x4 childTransformToSurface =
(!mUseIntermediateSurface ||
(mUseIntermediateSurface && !Extend3DContext() /* 2D */)) ?
idealTransform : Matrix4x4::From2D(residual);
ComputeEffectiveTransformsForChildren(childTransformToSurface);
ComputeEffectiveTransformForMaskLayers(aTransformToSurface);
}
