https://p5js.org/reference/#/p5.Oscillator

https://p5js.org/reference/#/p5.FFT

*/

​

let fft;

let osc;

​

function setup() {

  createCanvas(400, 400);

​

  // Create a new oscillator

  osc = new p5.Oscillator();

  osc.setType('sine');

  osc.amp(0.5);

​

  // Create FFT object to draw sound waveform

  fft = new p5.FFT();

  fft.setInput(osc);

}

​

function draw() {

  background(0);

​

  let freqVal = map(mouseX, 0, width, 10, 880, true);

  osc.freq(freqVal)

  console.log(freqVal);

  // Draw the waveform

  let waveform = fft.waveform();

  beginShape();

  noFill();

  stroke(255);

  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();

}

​

function mousePressed() {

  osc.start(); 

}

​

function mouseReleased() {

  osc.stop();

}

​

​