This ensures that for layers with both transforms and mask layers, the
mask layer is properly positioned outside of the transform and relative
to the proper stacking context.
MozReview-Commit-ID: 79yvhxQCykW
For various reasons, we want to be pushing the layer's local clip rect
outside of the stacking context rather than inside it. Not only is this
more correct with respect to the semantics of the layer tree, we also
need it in order to properly handle fixed-positioning of layers with
async scrolling.
This patch does the bulk of the work to make this happen. Most of the code
in the individual layer classes to process the layer's local clip rect
is removed, and instead a function in ScrollingLayersHelper is added to
deal with it. There are a couple of places that individual layer classes
still handle this but those will be removed in future patches. Note that
the individual layer classes still need to provide a clip rect of some
sort in order to push their display items, and now they simply use their
visible region bounds for this purpose.
MozReview-Commit-ID: IBmfUdJwYx1
These functions also have built-in assumptions about the stacking
context structure mapping to the layer tree structure which are not
necessarily valid. So we remove these functions and update code that
uses them.
MozReview-Commit-ID: UkXXAF59qv
The only remaining callers of RelativeToParent() are in
StackingContextHelper itself, which we can remove now by having the SCH
take a parent SCH and use it instead of RelativeToParent(). This patch
implements this change.
This makes a failing test pass, because of how preserve-3d container
layers work. Specifically, preserve-3d container layers render their
descendants in z-order, not in tree order. If those children were assuming
that their parent had already pushed a stacking context, that assumption
may have been false because the parent might have not yet been rendered
because of z-ordering. By using the StackingContextHelper chain instead
of the layer tree ancestry, we fix the stacking-context-relative coordinates
being used in the descendant subtree of preserve-3d container layers.
MozReview-Commit-ID: HzZvBuAlMdB
This uses the StackingContextHelper and typed helper functions in
WebRenderLayer to simplify WebRenderTextLayer::RenderLayer. It also
removes the implicit assumption in WebRenderTextLayer that the parent
layer pushed a stacking context, which is an assumption we will
probably break in the future.
MozReview-Commit-ID: CARoGVQd56i
This is needed in part 3 to update WebRenderTextLayer::RenderLayer, so
that it no longer assumes the parent container layer has pushed a
stacking context, and instead explicitly uses the StackingContextHelper.
MozReview-Commit-ID: 9twUmDgUipX
This class is a RAII class that can be used to push a stacking context
with properties from a WebRenderLayer. It can also then be used to
convert rects in the layer coordinate system to be relative to the
stacking context, which is what we want for passing to WR.
MozReview-Commit-ID: 1WVrfRYqLqc
As we are often converting from LayoutDevicePixel to LayerPixel types
in WebRenderDisplayItem code, I added a convenience overload of
RelativeToParent that takes a LayoutDeviceRect and returns a LayerRect,
even though this is a potential footgun if abused.
MozReview-Commit-ID: DABAWdOBsbV
This extracts a strongly-typed ClipRect() function from GetWrClipRect.
GetWrClipRect is left as a weakly-typed wrapper for existing call sites,
and also does the necessary reference point conversions.
MozReview-Commit-ID: EuyzYIYLR6S
This moves the bulk of the meaningful work done by GetWrRelBounds into
strongly-typed helper functions. GetWrRelBounds is left as a wrapper so
call sites don't need to be updated yet. Note also that the
strongly-typed functions do not do any conversions from one reference
point from another (e.g. by calling the RelativeToXXX functions).
MozReview-Commit-ID: B3nPbOJOf9o
