This is definitely something I can look into.
I don’t think this will require any changes to the existing mouse callback implementation because the current callback is already (x,y,xrel,yrel,focused).
My tentative plan would be to add a function that requests mouse-lock on the host application (sticking the user’s mouse to the center of the screen and hiding it).
This would be similar to
If you could add this as a feature request on the Github (issues) page so I can keep track of it that would be very helpful.
I haven’t had a lot of time to work on Metacade due to my new job, but things are starting to wind down a bit and I’ve got some time to throw at it.