I'd like to be able to use a laptop (or desktop) as a gamepad connected to another laptop. Is there any way this is possible? Google searches haven't come up with anything. In my situation, either a PC running Windows, a PC running a Linux distro, or a Mac running OSX could serve as the controller, so a solution for any platform will work.
I am hoping to find that software exists to do this automatically, but if the solution involves creating/running a script or using terminal commands, I am happy to do that. If I need to buy a special adapter (e.g. to connect two computers via USB) I am happy to do that as well.