1857854 - Scintillations on the inside edge of a CSS transformation

Status: RESOLVED WORKSFORME

(Core :: Graphics: WebRender, defect)

Description

[Mayank Bansal]

Open the testcase from bug 767622 (https://bug767622.bmoattachments.org/attachment.cgi?id=636280)

White scintillations inside the right edge. You may need to pinch-zoom and/or use a desktop magnifier app to see them.

Regression:
Bug 1836690 - Add support for complex + tiled paths to new clip-mask rendering path r=gfx-reviewers,lsalzman

Differential Revision: https://phabricator.services.mozilla.com/D179901

Comment 1

[Mayank Bansal]

Attachment: about:support

Comment 2

[Mayank Bansal]

Attachment: bandicam 2023-10-09 11-52-20-806.mp4

Comment 3

[Mayank Bansal]

Attachment: Bug 767622.htm

Comment 4

[Mayank Bansal]

This bug feels like nitpicking, so feel free to wontfox or move it down the priority.

Comment 5

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

Set release status flags based on info from the regressing bug 1836690

Comment 6

[Nicolas Silva [:nical]]

It looks correct to me (that's the anti-aliasing).

Comment 7

[Glenn Watson [:gw]]

I can see the bug in the video. There is the anti-aliasing on the edges which looks correct, but the occasional white pixel inside the primitive which shouldn't be there. This looks like a case of the primitive being rendered in segments where the vertex positions are not exactly equal, resulting in slight rasterization issues on some hardware under some rotations, I think.

Comment 8

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

Set release status flags based on info from the regressing bug 1836690

Comment 9

[Mayank Bansal]

Does not repro now.