Fractional scaling on Ubuntu breaks fullscreen

[7RST1]

Enabling fractional scaling on Pop OS 20.10 makes it so Osu doesn't fullscreen properly. The window stays at bottom left with rest of screen black. Choosing the resolution matching PC-screen, which is 1440p, in Window-mode makes it render at that resolution but still much smaller, and is far from covering the whole screen. It looks like when I start reaching 5K in resolution, it covers the whole screen. There is also some artifacting with Osu when moving it around in windowed mode, which might be related. I have two screens set up; 1440p 144hz screen on which I am playing the game. Scaled 100% 4K 60hz secondary screen. Scaled 150% I think this is an universal issue for everyone running fractional scaling on Ubuntu-based systems. I doubt my logs will come in handy as I think it's easy to reproduce. Screenshot of fulscreen, and video of Osu in 1440p winodwed mode glitching out and too small are in details. The video is in the zip.

osu!lazer version: 2020.1204.0

Logs: database.log network.log performance.log runtime.log

Zip with Osu in 1440p winodwed mode glitching out and too small

[bdach]

Sure it's fractional scaling, rather than just any scaling at all?

[7RST1]

Yes. The game fullscreens fine when scaling to 200% without fractional scaling.

[bdach]

Would be useful to know what in particular is used to achieve this fractional scaling (plain xrandr? gnome-tweaks?)

[7RST1]

It has been built into Ubuntu since April, which makes it even bigger of an issue

[bdach]

Thanks for the screenshot, but as an aside, saying that it's "even bigger of an issue" is not really helpful in any capacity.

[7RST1]

Just gave some "dramatic context", but yeah, there isn't really much more useful stuff I can provide. It should be pretty easy to reproduce though, so that people more familiar with the Osu lazer code and the underlying works of fractional scaling can have a shot at fixing it.

[7RST1]

This is embarrasing; I posted the issue in the wrong repo. I have no idea how I managed to do that. I apologize!!

[bdach]

Um, no, it's in the correct place now, I transferred it here on purpose, as this issue will affect all games that use osu!framework, not just lazer.

[7RST1]

Oh XD I didn't notice. Is there any more context I can give?

[bdach]

I think the information provided here from your side should be enough to work with if you're not willing to explore yourself - just need to set up an environment with the fractional scaling option depicted as above available.