1564698 - gfx.webrender.all=true is causing unexpected filter effect (from nowhere) during animation

Status: RESOLVED DUPLICATE of bug 1569215

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

Description

[violet.bugreport]

Attachment: filter-from-no-where.html

STR:

1. On Ubuntu 18.04, with hardware acceleration enabled.
2. Set gfx.webrender.all=true. no need to set gfx.webrender.enabled.
3. Open the attached file.
4. Click the "Animate" button.

Expected:
The path is rotating, with no other effects.

Actually:
The path is severely blurred during rotation, as if there is a filter applied during animation.

NOTE: This behavior is very bizarre, since there is no filter at all in the attached file.

Comment 1

[violet.bugreport]

In Bug 1561225, a decimal width is affecting color opacity when gfx.webrender.all=true. It also needs hardware acceleration enabled to reproduce.

I believe they have the same root cause, even if this bug doesn't involve decimal value.

Comment 2

[Timothy Nikkel (:tnikkel)]

The scale we choose in StackingContextHelper::StackingContextHelper is wrong somehow maybe?

Comment 3

[Timothy Nikkel (:tnikkel)]

Bug 1569215 fixes this, but regression range is different (pretty sure I remember checking), so not technically the same bug.