Updated aplitude.disconnect() method documentation

[Nitesh639]

Updated documentation of amplitude.disconnect() method with an example.

[davepagurek]

Hi, sorry for the delay! I was testing this out some more because, ideally, we want examples to show a clear cause and effect of the method being applied, and I was having trouble getting amplitude.disconnect to actually do anything. I ended up arriving at this modified version of your code (comments around the modified parts):

let sound, amplitude, fft, button;
function preload(){
  sound = loadSound('assets/beat.mp3');
}

function setup() {
  let cnv = createCanvas(100,100);
  cnv.mouseClicked(togglePlay);

  amplitude = new p5.Amplitude();
  button = createButton("tap to disconnect amp");
  button.mouseClicked(amp_disconnect);
  button.position(0,110);
  fft = new p5.FFT();

  // By default the gain value is 0, so without this, anything
  // connecting it to anything doesn't do anything. Unfortunately
  // this also causes us to hear the source sound twice.
  amplitude.output.gain.value = 1;

  // It doesn't seem to work if I use `amplitude.connect(fft) here,
  // I suspect because the fft is already connected to p5.sound's
  // master output
  fft.setInput(amplitude);
  sound.loop();
}

function draw() {
  background(220);

  // Drawing the FFT spectrum, copy-and-pasted from the FFT
  // example, to make it clear that it's actually getting connected
  // and disconnected
  let spectrum = fft.analyze();
  push();
  noStroke();
  fill(255, 0, 255);
  for (let i = 0; i< spectrum.length; i++){
    let x = map(i, 0, spectrum.length, 0, width);
    let h = -height + map(spectrum[i], 0, 255, height, 0);
    rect(x, height, width / spectrum.length, h )
  }
  pop();

  text('tap to play', 20, 20);
  let level = amplitude.getLevel();
  let size = map(level, 0, 1, 0, 200);
  ellipse(width/2, height/2, size, size);
}

function togglePlay() {
  if (sound.isPlaying()){
    sound.pause();
  } else {
  sound.play();
  }
}
function amp_disconnect(){
  if (button.html()=="tap to disconnect amp"){
    amplitude.disconnect();
    button.html("tap to connect fft");
  } else{
    amplitude.connect(fft);
    button.html("tap to disconnect amp");
  }
}

Now the FFT connects and disconnects, but the doubled sound output isn't great. I wonder if this means connect and disconnect on the Amplitude class are not meant to be publicly used? I noticed this line in the source code which might indicate that it's only there to fix a bug: https://github.com/processing/p5.js-sound/blob/main/src/amplitude.js#L97 Unfortunately I'm not familiar enough with the inner workings of this library to know for sure, @therewasaguy maybe you'll have some more insight?

[Nitesh639]

@davepagurek @therewasaguy, I think connect, disconnect and dispose method is available almost all the classes of p5 sound. But it's not explained anywhere properly.

[Nitesh639]

  amplitude.output.gain.value = 1;

  // It doesn't seem to work if I use `amplitude.connect(fft) here,
  // I suspect because the fft is already connected to p5.sound's
  // master output
  fft.setInput(amplitude);
  sound.loop();

Yes @davepagurek, you are right, that's the default setting, but once you disconnect manually, then you are unable to connect it. For this, we need to use amplitude.connect(fft) method.