[Request] Disable VRR per application

[Dirleye]

Many VRR monitors have flickering issues at lower refresh rates intrinsic to the specific monitor's implementation.
Applications that are limited to 30/60fps for me will always flicker unless VRR is off.

Since it's pretty inconvenient to have to toggle VRR in Cosmic's settings just to use one application and then change it back again, I request a way to turn off VRR per app and preferably have Cosmic remember this choice for when that app is opened next.

KDE does this by allowing the option in the window settings accessible on right-click of the window's title bar.

[Drakulix]

Yeah we currently don't the infrastructure to identify windows reliably and store this information. So while this would certainly be nice to have, I am afraid this issue will remain open for quite some time.

However I am interested in hearing a bit more. As far as I understood the issue (talking a lot to the KDE maintainers as well), cheaper VRR monitors suffer from flickering, if the framerate varies to much, because of the associated brightness control. Reasonably stable framerates should however not produce flickering as long as the display can go low enough.

Cosmic explicitly queries and tracks the lowest possible refresh rate of the display, so we don't run into Low-Framerate-Compensation, which will double the framerate quickly and thus cause flickering.

Additionally with the "Automatic" setting for VRR you only get VRR enabled, when something is fullscreen. Which should cover the two biggest uses cases: Media-consumption and Gaming.

What does your usage pattern look like, that this doesn't apply here?

[Dirleye]

My monitor is pretty modern and high end with FreeSync Premium Pro, but I am using an Nvidia card. It tops out at 165Hz.

The monitor provides it's own on-screen monitor displaying the refresh rate at any given time which is how I usually verify VRR is working. The flickering only occurs when it's forced down to ~60fps or below (I think this monitor goes as low as 40 with VRR?). Games such as Elden Ring or emulators that are locked to 60fps cause it to flicker, as do YouTube videos when fullscreen. I can see with the on-screen monitor that VRR is working, but it does seem to jump around.

I had been running with the assumption that this was the classic OLED VRR flicker that's been reported with OLED monitors at lower refresh rates for a while. It's the same for me on Plasma 6 but I haven't tested on Windows.

[Dirleye]

So after a bit more testing, it definitely a lot better at a very stable 60fps. For whatever reason, some stuff reports 60fps (the Steam overlay fps counter in Elden Ring for example) but the monitor's refresh rate monitor jumps around from 60 to 50 to 165 occasionally. I assume this is what's causing the worse flickering. I'm not sure why only some apps make it do this when they all report a reasonably consistent fps.