Compton: Compton & Vsync: reduce input latency (request)

[aufkrawall]

As you might have noticed, Compton can add quite some input latency due to vsync.

There are differences between the available vsync settings. vsync=opengl seems to be better than other solutions. However, even with vsync=opengl, there is quite some more input latency than with e.g. Gnome-Mutter when moving windows.

Input latency can be reduced further by starting Compton with variable "vblank_mode=0", vsync=opengl will still continue to work and preventing tearing when moving windows or tearing inside of OpenGL windows.
Edit: Ok, not exactly true. I can spot a very small stripe of tearing at the very top of the screen.

However, tearing inside of Vulkan (radv) windows is not eliminated anymore by 100%, e.g. not when the application doesn't request its own vsync and fps fall below display's refresh rate.

So, it would be nice to have as low latency as with Gnome-Mutter, but without having negative side effects as described above.
It would be nice if someone could take a look at it ( @yshui @DelusionalLogic ...).
Thanks.

[DelusionalLogic]

That's one of my major goals. There's still a lot to be done (Like stopping my fork from constantly crashing), but here's the current input latency comparison between my fork and mainline, using typometer into alacritty:

[aufkrawall]

That's one impressive reduction, really glad you put your efforts into it. :)