This will be very difficult to implement due to the way this is handled in the backend, not to mention getting the UI for it right...I can take a look at it, but it's definitely not going to be an easy fix.

This seems like a very useful feature, even if the only part you implement is the "multiple GBA buttons on a single gamepad button" part of it. I'd love to have L+A for Pokémon-like one-handed gameplay on my other GBA games. :)

Only the first half of this is a new request. https://endrift.com/mgba/bugs/show_bug.cgi?id=219

A shitty mockup of a fairly intuitive design: https://moqups.com/tony971/TF8EunlE

This is basically the inverse of what I was thinking about for when I was going to do the input revamp, which was punted from 0.3.

I know it's not the way you would approach it but I just realized that my mockup would allow combining the keyboard mapping with the controller mapping.

Which would be awesome XD

Yes, that was always intended with my revamp.

Don't have much useful to add to this but I'd love to see this! I use an xbox style controller and mapping A to A and B to B is great for most games, but occasionally you have a game where X might make a better B due to the physical button placement. Just my two cents!

I second @teconmoon on this. I use an Xbox One controller, so having B and X as both B would be cool. I'd use B most of the time, but Nintendo muscle memory kicks in quite often and I find myself pressing X instead.