Erratic resizing of lv-tool window under GNOME Shell

Question

Erratic resizing of lv-tool window under GNOME Shell

kaixiong opened this issue 2 years ago · 10 comments

When I try to resize the lv-tool visualization window on my GNOME Wayland desktop, the window jumps around erratically and resizes itself like it's suffering from a seizure.

Answer 1 · 2023-01-12T18:17:38.000Z

@kaixiong is this with original SDL 1.2.x or with sdl12-compat? If I can trust my eyes, I get it (with X11!) on master with sdl12-compat (1.2.60) but not with plain SDL 1 (1.2.15_p20221201). You?

Answer 2 · 2023-01-12T18:24:54.000Z

@kaixiong update: Even my SDL 1 toy at https://github.com/hartwork/sdl_video_demo shows this behavior with sdl12-compat 1.2.60. Are you okay with me taking this to sdl12-compat upstream for feedback? We could try sdl12-compat Git master before that, though. What do you think?

Answer 3 · 2023-01-12T18:24:56.000Z

@hartwork I am on SDL 1.2.15, which comes with Pop_OS! 22.04.

Here's all the SDL packages on my system.

ii  libsdl-image1.2:amd64      1.2.12-13build1              amd64        Image loading library for Simple DirectMedia Layer 1.2, libraries
ii  libsdl1.2-dev              1.2.15+dfsg2-6               amd64        Simple DirectMedia Layer development files
ii  libsdl1.2debian:amd64      1.2.15+dfsg2-6               amd64        Simple DirectMedia Layer
ii  libsdl2-2.0-0:amd64        2.0.20+dfsg-2ubuntu1.22.04.1 amd64        Simple DirectMedia Layer
ii  libsdl2-dev:amd64          2.0.20+dfsg-2ubuntu1.22.04.1 amd64        Simple DirectMedia Layer development files
ii  libsdl2-image-2.0-0:amd64  2.0.5+dfsg1-3build1          amd64        Image loading library for Simple DirectMedia Layer 2, libraries
ii  libsdl2-image-dev:amd64    2.0.5+dfsg1-3build1          amd64        Image loading library for Simple DirectMedia Layer 2, development files
ii  libsdl2-mixer-2.0-0:amd64  2.0.4+dfsg1-4build1          amd64        Mixer library for Simple DirectMedia Layer 2, libraries
ii  libsdl2-mixer-dev:amd64    2.0.4+dfsg1-4build1          amd64        Mixer library for Simple DirectMedia Layer 2, development files

Answer 4 · 2023-01-12T18:27:12.000Z

@kaixiong interesting. Does my demo show the same behavior for you? If it does, we can e.g. rule out any problems from the way lv-tool is draining all events in one go.

Answer 5 · 2023-01-12T18:29:17.000Z

@kaixiong PS: I should note that (unlike SDL 2) SDL 1 does not yet have explicit support for Wayland. Maybe use of Wayland is an important part of this.

Answer 6 · 2023-01-12T19:17:51.000Z

@hartwork so I tested lv-tool and your demo under GNOME/Wayland, GNOME/X.Org and Sway.

The issue only appears with SDL 1.2. Using GNOME/X.Org did not make much difference.

Under Sway, which is Wayland based, I did notice that the SDL 1.2 window auto-centers itself at the end of each resize drag. It is somewhat well behaved.

The same is probably happening on GNOME but much less consistently or gracefully.

Answer 7 · 2023-02-03T04:25:51.000Z

@kaixiong I believe I have a fix at hartwork/sdl_video_demo#8 . What do you think?

Answer 8 · 2023-02-03T19:33:52.000Z

@hartwork Thanks, I have replied there. But just to keep the main discussion here, I'll repeat the basic points:

It works, although content resizes still happen frequently. Slow content resize causes rather heavy flickering.
Debouncing based on time may be better. When a resize event is received, a short time window follows where subsequent resize events are 'absorbed'. Once the window expires, the content resize happens based on the latest dimensions. A subsequent resize event restarts the process.

Answer 9 · 2023-02-03T23:38:01.000Z

For the record @kaixiong and I agreed on debouncing at hartwork/sdl_video_demo#8 (comment) now.

Answer 10 · 2023-02-07T18:16:00.000Z

Should be fixed on both master and 0.4.x, closing as fixed. Please re-open as needed.