2015805 - Support antialiasing each quad edge individually with SWGL

Status: RESOLVED FIXED

(Core :: Graphics: WebRender, task, P3)

Description

[Nicolas Silva [:nical]]

Bug 2015400 got AA in a better place for hardware WR, but there are some remaining issues in SWGL, as shown by wrench/reftests/gradient/radial-segments-rotated-clipped.yaml.

Comment 1

[Nicolas Silva [:nical]]

Attachment: Bug 2015805 - Fix unwanted anti-aliasing of indirect primitives with SWGL. r=gw

The problem was that the clip prim was baking some anti-aliasing into the indirect task, from the clip itself being anti-aliased. With hardware WR the antialiasing of the clip wasn't affecting the results. It comes down to how SWGL does anti-aliasing in a different way, which we don't need to get into because it does not make sense for the clip to have anti-aliasing. So this patches removes that.
In order to make sure that anti-aliased segments are properly covered by the clip, we inflate primitivce-space clips on the CPU in a qay that is equivalent to the extra coverage it was getting from the shader's AA extrusion. Raster space clips already cover the entire task so they don't need to be inflated.

Comment 2

[Pulsebot]

Pushed by [e-mail]:
https://github.com/mozilla-firefox/firefox/commit/0d22184ff2cd
https://hg.mozilla.org/integration/autoland/rev/5ffa64a6d53d
Fix unwanted anti-aliasing of indirect primitives with SWGL. r=gw

Comment 3

[Pulsebot]

Pushed by [e-mail]:
https://github.com/mozilla-firefox/firefox/commit/036b98bf5ed3
https://hg.mozilla.org/integration/autoland/rev/7df40d9149a3
Revert "Bug 2015805 - Fix unwanted anti-aliasing of indirect primitives with SWGL. r=gw" for causing wrench bustages

Comment 4

[amarc]

Backed out for causing wrench bustages

• Backout link
• Push with failures
• Failure Log

Comment 5

[Pulsebot]

Pushed by [e-mail]:
https://github.com/mozilla-firefox/firefox/commit/6c23ca6f6e14
https://hg.mozilla.org/integration/autoland/rev/87e88fa6aca4
Fix unwanted anti-aliasing of indirect primitives with SWGL. r=gw

Comment 6

[Sebastian Hengst [:aryx] (needinfo me if it's about an intermittent or backout)]

https://hg.mozilla.org/mozilla-central/rev/87e88fa6aca4