1920733 - Disable (and eventually remove) the force-GDI-classic-mode rendering of certain fonts on Windows

Status: RESOLVED FIXED

(Core :: Graphics: Text, enhancement)

Description

[Jonathan Kew [:jfkthame]]

We currently force a small list of legacy fonts to use "GDI Classic" rendering, which tends to apply more aggressive hinting (and therefore affect metrics) than normal DirectWrite rendering modes. For better consistency with rendering in other contexts and applications, it would be nice to remove this hack and apply the same ClearType mode everywhere.

Some users may dislike such a change, if they specifically prefer the "GDI Classic" look for these fonts, but it's difficult to anticipate how it will be received; it should result in more consistent scaling and metrics that better match other browsers, so there may also be significant benefits. (E.g. see bug 1722963.)

As a first step, we can turn the behavior off via a prefs change, while leaving the code in place in case we need to revert.

Comment 1

[Jonathan Kew [:jfkthame]]

Attachment: Bug 1920733 - For Nightly and early Beta, stop forcing GDI Classic rendering on certain core Windows fonts. r=jrmuizel

Comment 2

[Jonathan Kew [:jfkthame]]

Unsurprisingly, tryserver says that a number of reftests will be affected by this: https://treeherder.mozilla.org/jobs?repo=try&revision=c0f201c022b7e74807d6b04a9ea81478e15e4eca. I think (at first glance, anyhow) that the differences are all minor/benign changes in precise glyph positioning, but will need to look them over more carefully and adjust annotations before we land this.

Comment 3

[Jonathan Kew [:jfkthame]]

Attachment: Bug 1920733 - Adjust fuzzy annotations etc for testcases affected by disabling the forced-gdi-classic rendering pref. r=#gfx-reviewers

Comment 4

[Pulsebot]

Pushed by [e-mail]:
https://hg.mozilla.org/integration/autoland/rev/612816a6ef09
For Nightly and early Beta, stop forcing GDI Classic rendering on certain core Windows fonts. r=jrmuizel
https://hg.mozilla.org/integration/autoland/rev/f28e910b3409
Adjust fuzzy annotations etc for testcases affected by disabling the forced-gdi-classic rendering pref. r=gfx-reviewers,lsalzman

Comment 5

[Web Platform Test Sync Bot [:wpt-sync] (Matrix: #interop:mozilla.org)]

Created web-platform-tests PR https://github.com/web-platform-tests/wpt/pull/48558 for changes under testing/web-platform/tests

Comment 6

[Serban Stanca [:SerbanS]]

Backed out for causing windows reftests failures in select-4-ref.html.

• Backout link
• Push with failures
• Failure Log
• Failure line: REFTEST TEST-UNEXPECTED-FAIL | layout/reftests/abs-pos/select-4.html == layout/reftests/abs-pos/select-4-ref.html | image comparison, max difference: 1, number of differing pixels: 8

Comment 7

[Web Platform Test Sync Bot [:wpt-sync] (Matrix: #interop:mozilla.org)]

Upstream PR was closed without merging

Comment 8

[Pulsebot]

Pushed by [e-mail]:
https://hg.mozilla.org/integration/autoland/rev/2250c8b7368f
For Nightly and early Beta, stop forcing GDI Classic rendering on certain core Windows fonts. r=jrmuizel
https://hg.mozilla.org/integration/autoland/rev/250b53008ebe
Adjust fuzzy annotations etc for testcases affected by disabling the forced-gdi-classic rendering pref. r=gfx-reviewers,lsalzman

Comment 9

[Cristian Tuns]

https://hg.mozilla.org/mozilla-central/rev/2250c8b7368f
https://hg.mozilla.org/mozilla-central/rev/250b53008ebe

Comment 10

[Web Platform Test Sync Bot [:wpt-sync] (Matrix: #interop:mozilla.org)]

Upstream PR merged by moz-wptsync-bot