This edge case happens when:
- we have a display item A nested inside another display item B
- B has pushed an out-of-band clip, and
- A's clip chain doesn't connect directly to the end of B's clip chain
but instead connects somewhere farther up the clip chain
See comments in the patch for more details.
MozReview-Commit-ID: 4mCCaVUQuvH
--HG--
extra : rebase_source : 1601a8f0c586d618d395b4e20086b9ecd318945b
My original understanding of the API was flawed, and so while I had
position:sticky working in some cases it didn't work properly in a lot
of other cases. This patch corrects the usage of the API to match what
WR is expecting and fixes a lot of test cases.
MozReview-Commit-ID: AdMux19Fk9U
--HG--
extra : rebase_source : e7f970a710b2079501a91eeeac8c292b603210dc
Most of this change is just fiddling with function signatures so that they take
a LayerManager* instead of a Layer* (or in some cases, both). This allows
the WebRender codepaths to pass a WebRenderLayerManager* instead of having to
produce a Layer* which it doesn't have.
MozReview-Commit-ID: Fb0C8OUVDin
--HG--
extra : rebase_source : e4c3324cfa20c295db85d5c09df8d8d77865bb6a
This does 3 things that were all a bit too intermixed to split out cleanly:
1. Teaches TextDrawTarget to handle rectangular clips (while also completely
forbidding other ones). This is necessary to handle how gecko "overdraws"
decorations with clips to create the illusion of continuous lines when they're
actually made out of multiple lines, possibly from different display items
with different lines. Previously gecko *was* handing these clips to
TextDrawTarget to use these clips, but we were just ignoring them.
This is also necessary work to support partial glyphs natively (which apply
rectangular clips to glyphs). Also note that this currently causes a bug
in webrender if combined with zero-blur shadows, but it's not a regression
since we already mishandle clipped decorations. I will work on fixing this
upstream.
2. Changes the intermediate representation of lines from the old webrender
format to a rect-based one. This is in preperation for webrender adopting
that format in a future update.
3. Changes the way wavy lines are processed, correcting some errors in the
old wavy line bindings that lead to them being positioned incorrectly. Also
introduces a wavyLineThickness property that the will be required in a
future webrender update. Wavy lines are unlike any other line, so it's
ultimately desirable to distinguish them.
The net result of these changes is that a companion upstream change (webrender#1923)
will make decoration rendering nearly identical to gecko, and much nicer.
However the clipped shadows issue will need to be seperately resolved before
actually closing this issue.
MozReview-Commit-ID: 6O2wLA6bU3C
--HG--
extra : rebase_source : 17254c45145229b75f77f87f85874e66e6edd05e
This does 3 things that were all a bit too intermixed to split out cleanly:
1. Teaches TextDrawTarget to handle rectangular clips (while also completely
forbidding other ones). This is necessary to handle how gecko "overdraws"
decorations with clips to create the illusion of continuous lines when they're
actually made out of multiple lines, possibly from different display items
with different lines. Previously gecko *was* handing these clips to
TextDrawTarget to use these clips, but we were just ignoring them.
This is also necessary work to support partial glyphs natively (which apply
rectangular clips to glyphs). Also note that this currently causes a bug
in webrender if combined with zero-blur shadows, but it's not a regression
since we already mishandle clipped decorations. I will work on fixing this
upstream.
2. Changes the intermediate representation of lines from the old webrender
format to a rect-based one. This is in preperation for webrender adopting
that format in a future update.
3. Changes the way wavy lines are processed, correcting some errors in the
old wavy line bindings that lead to them being positioned incorrectly. Also
introduces a wavyLineThickness property that the will be required in a
future webrender update. Wavy lines are unlike any other line, so it's
ultimately desirable to distinguish them.
The net result of these changes is that a companion upstream change (webrender#1923)
will make decoration rendering nearly identical to gecko, and much nicer.
However the clipped shadows issue will need to be seperately resolved before
actually closing this issue.
MozReview-Commit-ID: 6O2wLA6bU3C
--HG--
extra : rebase_source : 98da45bc7f2eaabd63ae226c505cb1580b5c8500
Instead of unconditionally pushing and popping clips per display item,
this patch changes things so that for each recursive display list, we
create an ItemClips struct. We push this onto the stack when we enter
the display list, and pop it off at the end. For each display item, we
check to see if the clips would actually change compared to the previous
display item, and only do the pop/repush in that case.
MozReview-Commit-ID: J0MCc2V9hWT
--HG--
extra : rebase_source : 8617cfaa7391457867f01c1b619cb871a21bf3f5
This makes ScrollingLayersHelper a non-RAII type class, and instead adds
methods to notify it of when we start processing a new transaction or a
new display item within the transaction. This patch has no functional
changes, it's non-obvious refactoring.
MozReview-Commit-ID: GEZzCGbVqB1
--HG--
extra : rebase_source : dd4fab7f34da7c5465ba474db670cf583e8dadf4
