​

function setup() {

  createCanvas(720, 256);

​

  osc = new p5.TriOsc(); // set frequency and type

  //osc.amp(0.5);

​

  fft = new p5.FFT();

  osc.start();

}

​

function draw() {

  background(255);

​

  let waveform = fft.waveform(); // analyze the waveform

  beginShape();

  strokeWeight(5);

  for (let i = 0; i < waveform.length; i++) {

    let x = map(i, 0, waveform.length, 0, width);

    let y = map(waveform[i], -1, 1, height, 0);

    vertex(x, y);

  }

  endShape();

​

  // change oscillator frequency based on mouseX

  let freq = map(mouseX, 0, width, 40, 880);

  osc.freq(freq);

​

  let amp = map(mouseY, 0, height, 1, 0.01);

  osc.amp(amp);

}