This totally might be true, but the fact that he got as far as measuring the same latency on X and Wayland... and then just gave up and is like "well never mind what the measurements say, it's definitely Wayland"... Hmm.

You gotta do the measurements. It's probably not even that hard, all you need is a USB mouse emulator (any microcontroller with USB peripheral support can do this and there are tons of examples) and a photodiode.

You don't even need to worry about display latency if you are just comparing X with Wayland.

[–] Cirk2 6 points 5 days ago

Yeah I really want to see the numbers on this.

It seems to be a absolute breaking issue for them, suggesting a actual noticeable delay. So it should at least be one frame (on 60hz display) of additional latency compared to x11. Especially since there is earlier work Using a Click based measurement setup showing no such delay.

[–] [email protected] 3 points 5 days ago

You gotta do the measurements. It's probably not even that hard, all you need is a USB mouse emulator (any microcontroller with USB peripheral support can do this and there are tons of examples) and a photodiode.

will absolutely do this, the microcontroller and mouse emulation part is solved for me already so I just need to get an appropriate photodiode and... profit

[–] [email protected] 3 points 5 days ago

I noticed on Wayland that VSync on games has much more latency (input in general not just mouse tbf :/) than X11 which is near perfect. Please god tell me this is the issue, and it'll be fixed.

[–] onlinepersona 2 points 5 days ago* (last edited 5 days ago) (1 children)

I don't understand the setup. Please explain what the raspberry pi pico and an LED have to do with this...

Anti Commercial-AI license

[–] Cirk2 4 points 5 days ago* (last edited 5 days ago) (1 children)

The pi is either emitting a mouse move or detecting one on the physical device and measuring the time that passes until the photo diode/resistor (not an led) is detecting the cursor to move away.

It's essentially the same setup you would use to detect input to photon latency if you don't have a high speed camera.

Edit: Ah no there's another setup with a pi pico in there... Yeah it's binding and LED Lighting up to a button press to have two visual indicators (LED and Cursor Reaction) you can measure using a high speed camera. Them only having a 90fps phone camera makes it means the measurements are only in 11ms increments though.

[–] [email protected] 1 points 5 days ago

will try again with a photodiode instead, since it's known to be a valid way to measure stuff like this, and it seems precise enough at that

if it isn't this, then I'll probably have to dig into libinput or something