cross-posted from: https://lemmy.dbzer0.com/post/37717114
A while ago I got a Retroid Pocket 3+, but as I didn't end up using it much, I recently reconfigured it to give to someone who could make better use of it.
As the joysticks aren't ideal for games that make substantial use of them, I also gave them a 8BitDo controller to use as an alternative control option, oddly listed as being a Nintendo Switch Pro Controller in the Bluetooth menu. After they told me that the controller didn't work with the games I had installed on the device—twelve native Android games with controller support and several emulated games accessed via Daijisho—I realized that I'd have to dual map the Player 1 controller port in emulators to both the Retroid and the 8BitDo controllers.
Unless I'm mistaken, RetroArch doesn't appear to support dual-mapping controllers to the same player slot, so I only have the dual-mapping set up so far for standalone emulators that support that functionality. Testing indicated that such emulators include AetherSX2 for PS2, DuckStation for PS1, and Drastic for DS, so I'll have to conduct more testing to find other standalone emulators for the remaining systems.
What I've yet to figure out is how to do the same for native Android games, as Stardew Valley did not recognize inputs from the 8BitDo controller, despite inputs from the Retroid's own buttons working fine. Is that something that relies on multi-controller support on a game-by-game basis, or is there a way I could make Android switch which controller it considers to be the main one?