1457154 - WR: emoji (color glyph) transparency is broken again

Status: RESOLVED FIXED

(Core :: Graphics: WebRender, defect, P1)

Description

[Aria Beingessner [:Gankra]]

See my canary on https://gankro.github.io/blah/webtests/text.html

The "Fade - Shadow - Blur" canary is supposed to have a series of increasingly transparent emoji, but it doesn't.

Comment 1

[Aria Beingessner [:Gankra]]

I've verified it's broken on linux and windows, haven't tried mac yet.

Comment 2

[Darkspirit]

mozregression --good 2017-08-15 --bad 2018-04-26 --pref layers.acceleration.force-enabled:true gfx.webrender.enabled:true gfx.webrendest.enabled:true gfx.webrender.layers-free:true gfx.webrender.blob-images:true image.mem.shared:true layout.display-list.retain:false startup.homepage_welcome_url:'https://gankro.github.io/blah/webtests/text.html'
> 11:52.86 INFO: Last good revision: 834821ca057915b9458ad7c76a130da4c2b59782
> 11:52.86 INFO: First bad revision: 564959d26e8db243ded3d57380842620e60e89e7
> 11:52.86 INFO: Pushlog:
> https://hg.mozilla.org/integration/autoland/pushloghtml?fromchange=834821ca057915b9458ad7c76a130da4c2b59782&tochange=564959d26e8db243ded3d57380842620e60e89e7

> 564959d26e8d	Alexis Beingessner — Bug 1357545 - handle text-shadows/decorations with webrender (layers-free) r=jrmuizel

Comment 3

[Aria Beingessner [:Gankra]]

I think you picked a too wide range, we break this all the time, and it was definitely working a week or two ago.

Comment 4

[Darkspirit]

bad: 2018-03-01, 2018-03-05, 2018-03-10, 2018-03-15, 2018-03-20, 2018-03-25, 2018-03-30, 2018-03-31

> for i in {1..25}; do mozregression --launch 2018-04-${i} --pref gfx.webrender.all:true startup.homepage_welcome_url:'https://gankro.github.io/blah/webtests/text.html'; done
All are bad. And bug 1358240 introduced a new emoji font.

Comment 5

[Aria Beingessner [:Gankra]]

Ah this is still working on mac, so I guess I didn't notice it broke a long time ago. hrm.

Comment 6

[Lee Salzman [:lsalzman]]

Attachment: use fallback for color glyphs with transparency in WR

Color glyphs (used by some emoji fonts) are rendered as many overlapping single color glyphs. With transparency, the result needs to be buffered before it can be blended with the final opacity. We currently can't handle this in WR.

For now, mark such text runs as unsupported so that they are handled by blob images instead.

Comment 7

[Pulsebot]

Pushed by [e-mail]:
https://hg.mozilla.org/integration/mozilla-inbound/rev/693b1b3389fb
use fallback for color glyphs with transparency in WR. r=gankro

Comment 8

[Stefan Hindli [:stefan_hindli]]

https://hg.mozilla.org/mozilla-central/rev/693b1b3389fb