[Feature request] Visual UI for controller remappings

[cuesta4]

[Problem]
Remapping buttons isn't usually necessary for most cores, considering the excellent automap feature for Retroarch. However, if you do need to map the buttons and are not using original hardware, it can be very frustrating to visualize and test if everything is correct. Creating different mappings for the Dolphin core, for example, is very confusing.

[Solution]
I'd like to propose a visual UI, similar to that of Yuzu or CEMU, in which the UI is pooling inputs and showing a live representation of the controller (an image) and status (bright button if pressed, analog stick position, gyro alignment and so on) for each default controller in that system. I'm not that versed in code but I'd be willing to do the busywork of adapting for different cores once we had a base code to draw from.

Sorry if this in the incorrect place or format.

[hizzlekizzle]

It probably belongs more as a feature request for RetroArch, but I think a possible solution could involve the overlays.

That is, if we set overlays to load automatically based on the playlist (just as the dynamic backgrounds currently work), they can display the controller's inputs in a way that somewhat matches the original device (the many 'flat' overlays could do this with just a little modification) and they can reflect input from physical devices (gamepads/keyboards) so you can see what you've remapped in real time. Auto-loading of appropriate overlays is something mobile users have wanted for a long time anyway.

We also already have an option to hide the overlay while menus are active. We could potentially make an option in the overlay menu to force-show them while in the controls menu.