Games which require rotation mid-game are horribly inconvenient in RetroArch.

[vaguerant]

I'm pretty sure I filed an issue on this back when the Mednafen cores were all on a single GitHub project, but that project and its issues seem to be gone, so I'll quickly run through the problem again.

Obviously, the WonderSwan as a platform is intended to be physically rotated in the hands of the player. This maps poorly to platforms which aren't intended to be physically rotated, which is probably all of the platforms RetroArch is compiled for.

This can mostly be worked around on RetroArch by using rotation in the video settings and some per-game remap files, which allow vertical games to be played in the correct orientation and button layout. It could still be more convenient, but it's workable.

However, there are games which require the player to alternate rotation mid-game, the most notable of these being Kaze no Klonoa. Levels in this game take place in alternating orientations, i.e. the first level is horizontal, the second level is vertical, etc. It's still possible to play this game with extreme dedication by returning to RGUI constantly to swap the button mapping and screen rotation, but frankly only going to be enjoyable to a vanishingly small segment of users.

A partial solution I would suggest is a core option, specific to WonderSwan/Color, which rotates the display by 270 degrees (90 degrees left) and remaps the controls such that the Y buttons are positioned on the RetroPad D-Pad, the X buttons are positioned on the face buttons, and the A/B buttons are positioned on the L/R shoulder buttons.

In this way, a single core option toggle would swap both the game and inputs to be sensible for rotated play, rather than having to swap both screen rotation and button mapping separately.

An even better solution would be if this behavior could be mapped to a single button press (best candidate is RetroPad Select; the WonderSwan has no Select button).

There is one major problem here, which is what happens if users have custom remapped their buttons so the rotated button layout becomes non-sensible? Bad stuff, I guess. WonderSwan is such an awkward edge case for this stuff, I know.