I'm working on a linux platform for running games. On that platform, while a game is running in full screen, I need to be able to on certain hardware input, e.g. a flip of a switch, to freeze and disable all input to the game and overlay information on top of it, like the steam in-game overlay for example. I have no control over the game running.
From what I've been able find while searching, overlaying on top of an OpenGL application is not an easy task.
The only other way I can think of is somehow force the game into a borderless fullscreen window mode and then render a layer on top of that. Not sure how feasible that would be
Is there a way I would be able to accomplish this?
