p5.jsでランダムに音を鳴らす

/*
 * random percussion sound
 *
 * @author aadebdeb
 * @date 2017/01/31
 */

var osc, env;

function setup() {
  createCanvas(windowWidth, windowHeight);
  noCursor();
  
  env = new p5.Env();
  env.setADSR(0.01, 0, 1, 0.2);
  env.setExp(true);
  
  osc = new p5.Oscillator();
  osc.setType('sine');
  osc.amp(env);
  osc.freq(250);
  osc.start();
  
  background(0);
}

function draw() {
  noStroke();
  fill(0, 100)
  rect(0, 0, width, height);
  if(random(1) < map(sqrt(sq(mouseX - pmouseX) + sq(mouseY - pmouseY)), 0, 200, 0.05, 0.5)) {
    var r = random(1);
    var h = random(height);
    stroke(255, map(random(1), 0, 1, 100, 255));
    line(0, h, width, h);
    osc.freq(map(random(1), 0, 1, 100, 2000));
    env.play();
  }
}