sink-agnostic api?

[Alloyed]

So thanks in advance for writing this: I've thought about doing something like this myself for a while and I just happened upon this repo maybe yesterday~

I'd like to use it in the love2d engine, which we've already got an integration for (nice), but because it directly uses portaudio I'd have to run two audio engines in my game: one for 3d sound fx, and one just for music. love has introduced a new API for providing a streaming source of audio I'd like to use instead. Here's what an integration with that might look like:

-- a source is analogous to a sample, you can play/pause/apply effects to it
local source = love.audio.newQueueableSource(...)
-- this is just a chunk of memory
local data = love.audio.newSoundData(...)
function love.update(dt) -- game update, runs at 60fps
    if shouldUpdateAudio then
        -- this would do the work of update()
        modipulate.fill_buffer(data, len, samplerate, etc...)
        source:queue(data)
        source:play()
    end
end

Is modipulate in a good place for this kind of change? If I wanted to do it myself where should I start?

[MrEricSir]

Just had a quick chat with @hryx and we both agree that this makes sense. We'd be open to this change although I'm not sure either of us would have the time to test it out. (You're also of course welcome to fork the project.)

As for where to get started, I'd say get it up and running and see if it meets your use case first. When it comes to implementation there's a few ways you could go.

One would be to leave the code mostly unchanged, but add some new flag to the build system where you could either compile the code more or less as is, or to skip the PortAudio stuff for those who want to use an arbitrary sink.

A second option would be to rip out PortAudio entirely and move that logic into the demo projects. That would be cleaner in a way, but might be complex for the non-binary demos since PortAudio requires a C callback that's run in the context of a high performance thread.

Either way, the logic for adjusting the global volume should ideally be moved out of the PortAudio callback function.