1642693 - Artifacts sometimes appear at the edges of filtered elements

Status: RESOLVED WORKSFORME

(Core :: Graphics: WebRender, defect)

Description

[Connor Brewster [:cbrewster]]

Attachment: test-case.html

Sometimes artifacts can be seen on the edge of filtered elements. The artifacts can be reproduced more often if a perspective transform is also applied to the filtered element. Additionally, pinch-zooming can cause the artifact to disappear/reappear.

I think this is because we are not insetting the UV sample bounds by 0.5 pixels in all directions in the brush_blend shader. The inset ensures that bordering pixels are not included when sampling from the render task region.

see comment here: https://searchfox.org/mozilla-central/source/gfx/wr/webrender/res/brush_blend.glsl#87-88

Comment 1

[Connor Brewster [:cbrewster]]

Attachment: artifacts.png

Comment 2

[Jessie [:jbonisteel] pls NI]

Seems like this has been around for a while, probably not an S2

Comment 3

[Mayank Bansal]

Cant repro anymore.