/**https://editor.p5js.org/p5/sketches/Sound:_Mic_Threshold
 * @name Mic Threshold
 * @description <p>Trigger an event (draw a rectangle) when the Audio Input
 * volume surpasses a threshold.</p>
 * <p><em><span class="small"> To run this example locally, you will need the
 * <a href="http://p5js.org/reference/#/libraries/p5.sound">p5.sound library</a>
 * and a running <a href="https://github.com/processing/p5.js/wiki/Local-server">local server</a>.</span></em></p>
 */
// Adapted from Learning Processing, Daniel Shiffman
// learningprocessing.com
let input;
let analyzer;

function setup() {
  createCanvas(710, 200);
  background(255);

  // Create an Audio input
  input = new p5.AudioIn();

  input.start();
}

function draw() {
  // Get the overall volume (between 0 and 1.0)
  let volume = input.getLevel();

  // If the volume > 0.1,  a rect is drawn at a random location.
  // The louder the volume, the larger the rectangle.
  let threshold = 0.1;
  if (volume > threshold) {
    stroke(0);
    fill(0, 100);
    rect(random(40, width), random(height), volume * 50, volume * 50);
  }

  // Graph the overall potential volume, w/ a line at the threshold
  let y = map(volume, 0, 1, height, 0);
  let ythreshold = map(threshold, 0, 1, height, 0);

  noStroke();
  fill(175);
  rect(0, 0, 20, height);
  // Then draw a rectangle on the graph, sized according to volume
  fill(0);
  rect(0, y, 20, y);
  stroke(0);
  line(0, ythreshold, 19, ythreshold);
}