Please add SDL3 backend

[HolyBlackCat]

SDL v3 is available as a prerelease. The SDL backend should probably be updated to allow either v2 or v3.

[ThreeDeeJay]

What benefits would SDL bring to the table?
From my understanding, SDL audio is pretty barebones and even for surround sound, you'd need SDL_mixer, let alone more advanced features like HRTF/3D audio, unless that's changed in newer versions and even then, I don't think it'd get the chance to use them since backends get the audio already mixed by OpenAL Soft
Kinda like how Source engine games on Linux use SDL for mixing and OpenAL (Soft) for output, so I don't think 3D audio is possible.

[kcat]

It would be useful as a generic output API, along the lines of PortAudio. If there's a platform audio API that OpenAL Soft doesn't support but SDL does, you could use the SDL backend to let OpenAL Soft work on the platform.

OpenAL Soft already has an SDL2 backend for this purpose, but SDL3 is a little different (different header location and library, at least) and will be the primary version going into the future.