p5.js Render test

function setup() {
  createCanvas(400, 400);
  frameRate(60);
}

function draw() {
  time = millis() / 1000.0;
  background(0);

  hw = width/2;
  hh = height/2;

  t = time * 4.0;

  x = 1 + 0.5 * Math.sin(t);
  y = 1 + 0.5 * Math.cos(t);
  s = 0.75 + 0.25 * Math.cos(t/2.0);

  fill(255);
  circle(hw * x, hh * y, min(hw, hh)*0.75 * s);
}