let radius;

let percent = 0;

​

function setup() {

  createCanvas(400, 400);

  radius = width / 2 - 16;

}

​

function draw() {

  background(0);

  push();

  translate(width / 2, height / 2);

  var angle = TWO_PI / npoints;

  fill(150,0,100);

  stroke(255);

  strokeWeight(4);

  beginShape();

  for (var a = 0; a < TWO_PI; a += angle) {

    // cardioid

    let ac = a;

    let r = (1 - sin(ac)) * 0.66;

    let cx = cos(ac) * r * radius;

    let cy = ((sin(ac) * r) + 0.5) * radius;

    // heart 1

    let ah = PI / 2 - a;

    let hx = 16 * pow(sin(ah), 3) * radius * 0.05;

    let hy = (13 * cos(ah) - 5 * cos( 2 * ah) - 2 * cos(3 * ah) - cos(4 * ah)) * radius * 0.05;

    let coef = sin(percent * PI);

    let sx = cx * coef + hx * (1 - coef);

    let sy = cy * coef + hy * (1 - coef);

    vertex(sx, -sy);

  }

  endShape(CLOSE);

  pop();

  percent += 0.02;

  if (percent >= 1)

  {

    percent = 0;

  }

}