Added ability to mute a synth/sound after it was triggered

[klibardi]

I would like to introduce an ability to control synth or sample after it was triggered. For now I just need the ability to mute, but I am open to implementing control over other aspects of sound too.

Here is an example of what I'm using this for:

await WebMidi.enable()
const myInput = WebMidi.inputs[0];
const noteControls = Array.from(Array(128)).map(x => null)
myInput.removeListener('noteon');
myInput.removeListener('noteoff');
myInput.addListener('noteon', e => {
  const [n, vel] = e.dataBytes;
  superdough({ note: n, s: 'piano', postgain: vel / 127 }, 0.05, 10).then(function (x) {
    noteControls[n] = x;
  });
});
myInput.addListener('noteoff', e => {
  const [note] = e.dataBytes;
  const { mute } = noteControls[note]
  mute(0.1);
  noteControls[note] = null
})

sound("metal casio casio casio")

[klibardi]

Just a link for reference of what I'd like to accomplish in the long run:
https://club.tidalcycles.org/t/baked-in-support-for-midi-in-audio-in-and-audio-devices-channels/5098

[felixroos]

thanks! this looks useful, tho it might be limiting in the context of note in, because superdough currently does not support triggering the attack / decay phase without knowing the total duration, so as you did, you need to set duration to a high number, meaning you could theoretically run out of time.. This used to work before this PR, where the envelope was returning a stop function, which turned out to impractical due to browser differences as outlined here.

The idea we had to fix this was to write a custom envelope with an audio worklet that supports the desired behavior.
It might still make sense to merge this, as it provides pragmatic workaround to the problem. @Jader what do you think?