1639860 - No subpixel-aa on google.com home page application menu even though Chrome does

Status: NEW

(Core :: Graphics: WebRender, defect)

Description

[Jeff Muizelaar [:jrmuizel]]

See https://bugzilla.mozilla.org/show_bug.cgi?id=1600472#c57

Comment 1

[Glenn Watson [:gw]]

I just tested this on Linux with current m-c, and I see subpixel AA on all the content elements on the google home page (logged out).

Are you still able to reproduce this on current nightly? If so, could you post a screenshot - perhaps the layout is different depending on region or something like that?

Comment 2

[Loïc Yhuel]

Attachment: Google.png

I now have subpixel AA on google home page, except the applications menu (with has subpixel AA with Chrome).
I don't know what changed, of if there is something random like I see on gmail.

Comment 3

[Glenn Watson [:gw]]

That matches with what I see locally now too - thanks for following up.

Comment 4

[Glenn Watson [:gw]]

I can see what is happening for the applications menu.

There is a non-scrolling background rect with rounded-rect clip, and then the content (icons and text) are on a scrolling root with no background rect that scrolls. WR doesn't detect that this is a case where the background is actually opaque (we end up with two different slices here due to the combination of a difference in clips + scroll-root).

This is a case that comes up every now and then - I'm going to have a ponder about how we can better handle cases such as this. It's definitely feasible, since this case is typically a fixed slice with a single opaque background - just need to work out the simplest way to handle it in the picture cache subpixel detection code.