let x = [];

let y = [];

​

function setup() {

  createCanvas(240, 120);

  noStroke();

​

  for (let i = 0; i < num; i++) {

    x[i] = 0;

    y[i] = 0;

  }

}

​

function draw() {

  background(0);

  // Copy array values from back to front

  for (let i = x.length-1; i > 0; i--) {

    x[i] = x[i-1];

    y[i] = y[i-1];

  }

  x[0] = mouseX; // Set the first element

  y[0] = mouseY; // Set the first element

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

    fill(i * 4);

    ellipse(x[i], y[i], 40, 40);

  }

}

​

// https://editor.p5js.org/jht1493/sketches/pVd3PT6U3

// Ex_11_08 Track Mouse Movements

​

// https://github.com/lmccart/gswp5.js-code/blob/master/11_Arrays/Ex_11_08.js

​