1766498 - `backdrop-filter` blur incorrect when pinch-zooming

Status: RESOLVED FIXED

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

Description

[cc.glows]

Attachment: ezgif-5-3326320899.gif

Steps to reproduce:

1. Visit https://developer.mozilla.org/en-US/docs/Web/CSS/backdrop-filter#result
2. Pinch-zoom with trackpad

Version 101.0a1 (2022-04-26) (64-bit)

Actual results:

The blur is offset/scales incorrectly. It should take into account the visual viewport zoom.

Expected results:

Remains constant.

Comment 1

[BugBot [:suhaib / :marco/ :calixte]]

The Bugbug bot thinks this bug should belong to the 'Core::Panning and Zooming' component, and is moving the bug to that component. Please correct in case you think the bot is wrong.

Comment 2

[Glenn Watson [:gw]]

Attachment: Bug 1766498 - Disable raster root adjustment for backdrop-filters

This breaks an assumption that the surface spatial node for the
resolve surface matches that of the backdrop root. In future we
might be able to support snapping in this use case, but I'm not
convinced it's actually useful to have that anyway yet.

Comment 3

[Pulsebot]

Pushed by [e-mail]:
https://hg.mozilla.org/integration/autoland/rev/899daaf2bc16
Disable raster root adjustment for backdrop-filters r=gfx-reviewers,lsalzman

Comment 4

[Iulian Moraru]

https://hg.mozilla.org/mozilla-central/rev/899daaf2bc16