let playing = false;

let notes = [60, 62, 64, 65, 67, 69, 71];

​

function setup() {

  backgroundColor = color(255, 0, 255);

  textAlign(CENTER);

​

  //osc = new p5.SinOsc();

  //osc = new p5.TriOsc();

  osc = new p5.SqrOsc();

  //osc = new p5.SawOsc();

  //osc.setType('sine');

  //osc.freq(240);

  osc.amp(0);

  osc.start();

}

​

function draw() {

  background(backgroundColor)

  text('click to play', width / 2, height / 2);

}

​

function playNote(note, duration) {

  osc.freq(midiToFreq(note));

  // Fade it in

  osc.fade(0.5, 0.2);

​

  // If we sest a duration, fade it out

  if (duration) {

    setTimeout(function() {

      osc.fade(0, 0.2);

    }, duration - 50);

  }

}

​

function mouseClicked() {

  if (mouseX > 0 && mouseX < width && mouseY < height && mouseY > 0) {

    if (!playing) {

      // ramp amplitude to 0.5 over 0.05 seconds

      osc.amp(0.5, 0.05);

      playing = true;

      playNote(71);

      backgroundColor = color(0, 255, 255);

    } else {

      // ramp amplitude to 0 over 0.5 seconds

      osc.amp(0, 0.5);

      playing = false;

      osc.fade(0, 0.5);

      backgroundColor = color(255, 0, 255);

    }

  }

}