1574036 - [Wayland] Entire window flickers when resizing, showing underlying desktop

Status: VERIFIED FIXED

(Core :: Widget: Gtk, defect, P2)

Description

[Simonas Kazlauskas [:nagisa/:simukis]]

Attachment: Recording of flickering

Resizing a Firefox window running in Wayland mode (under sway) makes the window flicker as Firefox redraws the window for the new size.

Comment 1

[Simonas Kazlauskas [:nagisa/:simukis]]

It seems that I’m bad at encoding videos for browsers to use. Please download the video and use a more featured player than Firefox to watch it.

Comment 2

[Kestrel]

Easier to reproduce with the Basic compositor but it can still happen with OpenGL/WebRender (tested with Ubuntu 19.04).

Regression window:
https://hg.mozilla.org/integration/autoland/pushloghtml?fromchange=9c8180108cfa432f24743410e25d3b35d07b8584&tochange=82dedcf5872c0df663393a190c1179f1346d2e23

Regressed by Bug 1555899.

Comment 3

[Ryan VanderMeulen [:RyanVM]]

Hi Martin, is this something we need to fix for Fx69? We're building the RC next week.

Comment 4

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

(In reply to Ryan VanderMeulen [:RyanVM] from comment #3)

Hi Martin, is this something we need to fix for Fx69? We're building the RC next week.

Hi Ryan, I don't have a fix for that right now.
Thanks.

Comment 5

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

Simonas, can you please try to upload the video again? Thanks.

Comment 6

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

I think I can reproduce it now, Thanks.

Comment 7

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

If that happens with WebRender/GL compositor it's completely different bug - Bug 1555899 was in basic compositor only.

Comment 8

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

Looks like the bug happens when window is shrunk and e10s content is rendered. It's less visible/frequent on in-content pages like about:config.

Comment 9

[Simonas Kazlauskas [:nagisa/:simukis]]

Martin, to see the video please watch it locally on a player like mpv.

Comment 10

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

Attachment: Bug 1574036 - [Wayland] Fix flickering during window resize, r=jhorak

Recently window resize on Wayland produces flickering/rendering artifacts because
window background is randomly cleared due to actual window size changes.
We recently query widget size and do clear/fullscreen update when the size changes.

To avoid that, get widget size once at WindowSurfaceWayland::Lock() and use it
until next WindowSurfaceWayland::Lock(). Also don't to switch wayland back buffers
until there's really fullscreen update from compositor.

This patch:

• Use mLockedScreenRect to store window size at WindowSurfaceWayland::Lock(). It's used
  to detect widget resize, when it happens throw away all cached painting and wait for
  full screen update.

• Use mBufferScreenRect to store size of wayland back buffer and pass it
  instead of actual widget size we used before this patch. This ensures all our
  drawing matches the buffer size.

• Rename aFullScreenUpdate to aCanSwitchBuffer at LockWaylandBuffer() to stress
  actual meaning - we can/can't switch back buffers for partial drawing and we need to
  wait until recent back buffer is released by compositor.

Comment 11

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

https://treeherder.mozilla.org/#/jobs?repo=try&revision=902b873f63874131126a53824dd3530b1000793e

Comment 12

[Pulsebot]

Pushed by [e-mail]:
https://hg.mozilla.org/integration/autoland/rev/e351a8f6c71e
[Wayland] Fix flickering during window resize, r=jhorak

Comment 13

[Stefan Hindli [:stefan_hindli]]

https://hg.mozilla.org/mozilla-central/rev/e351a8f6c71e

Comment 14

[michaelaquilina]

Attachment: Firefox 71 flashing in sway

I can still manage to reproduce this issue in Firefox 71. I've attached a video showing the behaviour I am seeing

Comment 15

[Simonas Kazlauskas [:nagisa/:simukis]]

Attachment: Flickering when resizing

Still reproducible indeed. Attaching a video where this is significantly more prominent.

Comment 16

[Simonas Kazlauskas [:nagisa/:simukis]]

Attachment: Flickering when resizing (VP8 version, something that should actually play in firefox)

Comment 17

[Kestrel]

This patch fixed it for me on Ubuntu 19.04 and it is still fixed. Please file a new bug if you are still seeing it on Sway.