​

function setup() {

  createCanvas(400, 400);

  osc = new p5.Oscillator();

  osc.start();

}

​

function draw() {

  background(220);

  let pitch = map(mouseX, 0, width, 200, 800);

  pitch = constrain(pitch, 200, 800);

  osc.freq(pitch);

​

  let vol = map(mouseY, 0, height, 1, 0, true);

  osc.amp(vol);

​

  rect(width / 2 - 25, mouseY, 50, height - mouseY);

}

​