1618486 - [Wayland] Opaque region is misplaced on second screen on mutter

Status: RESOLVED FIXED

(Core :: Widget: Gtk, defect, P3)

Description

[Martin Stránský [:stransky] (ni? me)]

When two monitors are used and have a different scale factor (say 1 and 2), when Firefox window is move from one to another opaque region is not updated accordingly.

Comment 1

[Martin Stránský [:stransky] (ni? me)]

I see that with both basic and GL backend and patch from Bug 1609538 applied.

Comment 2

[Martin Stránský [:stransky] (ni? me)]

There's also a small regression from Bug 1609538 - when Firefox is tiled it runs in "fullscreen" mode which is wrong.

Comment 3

[Martin Stránský [:stransky] (ni? me)]

This comes from opaque region set by mozcontainer.

Comment 4

[Martin Stránský [:stransky] (ni? me)]

Seems to be mutter issue, filed as https://gitlab.gnome.org/GNOME/mutter/issues/1095
Robert, any idea here?

Comment 5

[Martin Stránský [:stransky] (ni? me)]

The scale is not important - it's broken when both screens use the same scale.

Comment 6

[Robert Mader [:rmader]]

This can be resolved as we do not set the opaque region on the container surface any more (bug 1615098). Apart from that a fix for Mutter is pending (https://gitlab.gnome.org/GNOME/mutter/-/merge_requests/1108) and will land soon the one way or the other.

Comment 7

[Martin Stránský [:stransky] (ni? me)]

When the fix lands, can we re-enable opaque regions for subsurfaces or not? If not I'd rather remove the dead code from Firefox.
Thanks.

Comment 8

[Robert Mader [:rmader]]

Just landed. Unfortunately we can't yet reenable it as we likely would regress bug 1615098. That being said, we are currently investigating other frame callback / input issues in Mutter/GTK that appear related (1, 2). I'd thus rather leave the code in - especially as it's quite performance relevant (although not measurable within firefox but only on compositor level). I also promise to continue working on it ;)

1: https://gitlab.gnome.org/GNOME/mutter/issues/817
2: https://gitlab.gnome.org/GNOME/gtk/-/issues/2511

Comment 9

[Robert Mader [:rmader]]

P.S.: maybe we can repurpose widget.wayland.use-opaque-region for this? It shouldn't be needed any more for the toplevel.

Comment 11

[Martin Stránský [:stransky] (ni? me)]

(In reply to Robert Mader [:rmader] from comment #9)

P.S.: maybe we can repurpose widget.wayland.use-opaque-region for this? It shouldn't be needed any more for the toplevel.

What do you exactly mean Robert?
Thanks.

Comment 12

[Robert Mader [:rmader]]

I meant it would be useful to trigger the disabled container opaque version with a preference - will come back to it with a patch at some point.

By the way, this bug can be closed. The issue was in Mutter and has been solved and shipped for a while now :)

Comment 13

[Robert Mader [:rmader]]

This issue was solved by https://gitlab.gnome.org/GNOME/mutter/-/merge_requests/1108, other occurrences should be fixed by bug 1617002. So closing - please reopen if you still see this.