[Feature Request]: Improve key binding in Fullscreen mode

[Zetta1Reid0]

Description

Rigth now , when you map a keyboard key/gamepad button in fullscreen mode it actually resets all the binding assigned to the virtual controller button.

Reason

Well certainly, no one wants to exit fullscreen mode just to change the bindings, either per game or global. Also if you rebind via the fullscreen mode, when you press a gamepad button , all backup keyboard binds are deleted and vice versa.

Examples

Look at how Retroarch does the bindings.