Improve font layout in Linux / Freetype platforms.
This patch contains two small changes:
* Fix the font size calculation that is passed to Freetype. This
now matches exactly how Webrender and Gecko calculate font size
to pass to layout.
* Enable light hinting by default for fonts when using Freetype.
We should make this configurable in the future, but this is a
better default than no hinting (and matches what most Linux
distros default to).
These two changes (along with the pending WR update) fix a lot
of the font layout issues on Linux. There is still at least one
remaining issue with hidpi displays on Linux that will be fixed
in a follow up patch.
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This patch contains two small changes:
* Fix the font size calculation that is passed to Freetype. This
now matches exactly how Webrender and Gecko calculate font size
to pass to layout.
* Enable light hinting by default for fonts when using Freetype.
We should make this configurable in the future, but this is a
better default than no hinting (and matches what most Linux
distros default to).
These two changes (along with the pending WR update) fix a lot
of the font layout issues on Linux. There is still at least one
remaining issue with hidpi displays on Linux that will be fixed
in a follow up patch.
The clip for overflow:scroll clip was not including the space for
padding, which could lead to some content being clipped when it
shouldn't. This changes fixes that issue.
A test is skipped because this fix also stops hiding a failure due to
mispositioned text.
Fixes#16576.
Instead of passing down a complex clipping region to each item, used
shared clipping to handle overflow:hidden and CSS clips. In addition to
being more efficient, this should also fix quite a few issues related
to absolutely positioned elements.
One existing reftest is slightly modified to avoid tickling a quirk
with the way that WebRender rasterizes masks. We are working out how to
best express these combined masks with the API or need to. The change
does not affect the original subject of the reftest.
Fixes#13109.
Fixes#10151.
Fixes#7575.
Fixes#8074.
Fixes#8780.
This includes a WR update that improves pixel snapping. Specifically,
the non-transform shader now snaps to device pixels in world space,
rather than local space.
This makes 31 new tests pass, and adds 4 new failures.
Of the new failures:
- The three background size tests appear to be an OSMesa accuracy
issue. Near the bottom of the image, a small number of pixels
are different from the reference by a value of 1.0 / 255.0. I've
confirmed on 3 real GPUs and also on llvmpipe that the tests
match on those devices. This would be a good case for fuzzy test
support in WPT.
- The other failing test appears to have unreasonable accuracy
requirements as it also fails on Gecko and Chromium in the same
way that the test now fails on WR.
The height test is removed in mime_sniffing_font_context because of rounding
changes in app_units. The rest of that test is still useful though, given it
will timeout if the font fails to be sniffed.
