var blob1 = createBlob({
  element: document.querySelector("#path1"),
  numPoints: 10,
  centerX: 480,
  centerY: 480,
  minRadius: 300,
  maxRadius: 350,
  minDuration: 1,
  maxDuration: 2
});

var blob2 = createBlob({
  element: document.querySelector("#path2"),
  numPoints: 10,
  centerX: 500,
  centerY: 500,
  minRadius: 280,
  maxRadius: 350,
  minDuration: 2,
  maxDuration: 3
});

var blob3 = createBlob({
  element: document.querySelector("#path3"),
  numPoints: 10,
  centerX: 520,
  centerY: 520,
  minRadius: 300,
  maxRadius: 350,
  minDuration: 1.5,
  maxDuration: 2.5
});

function createBlob(options) {
   
  var points = [];  
  var path = options.element;
  var slice = (Math.PI * 2) / options.numPoints;
  var startAngle = random(Math.PI * 2);
  
  var tl = new TimelineMax({
    onUpdate: update
  });  
  
  for (var i = 0; i < options.numPoints; i++) {
    
    var angle = startAngle + i * slice;
    var duration = random(options.minDuration, options.maxDuration);
    
    var point = {
      x: options.centerX + Math.cos(angle) * options.minRadius,
      y: options.centerY + Math.sin(angle) * options.minRadius
    };   
    
    var tween = TweenMax.to(point, duration, {
      x: options.centerX + Math.cos(angle) * options.maxRadius,
      y: options.centerY + Math.sin(angle) * options.maxRadius,
      repeat: -1,
      yoyo: true,
      ease: Sine.easeInOut
    });
    
    tl.add(tween, -random(duration));
    points.push(point);
  }
  
  options.tl = tl;
  options.points = points;
  
  function update() {
    path.setAttribute("d", cardinal(points, true, 1));
  }
  
  return options;
}

// Cardinal spline - a uniform Catmull-Rom spline with a tension option
function cardinal(data, closed, tension) {
  
  if (data.length < 1) return "M0 0";
  if (tension == null) tension = 1;
  
  var size = data.length - (closed ? 0 : 1);
  var path = "M" + data[0].x + " " + data[0].y + " C";
  
  for (var i = 0; i < size; i++) {
    
    var p0, p1, p2, p3;
    
    if (closed) {
      p0 = data[(i - 1 + size) % size];
      p1 = data[i];
      p2 = data[(i + 1) % size];
      p3 = data[(i + 2) % size];
      
    } else {
      p0 = i == 0 ? data[0] : data[i - 1];
      p1 = data[i];
      p2 = data[i + 1];
      p3 = i == size - 1 ? p2 : data[i + 2];
    }
        
    var x1 = p1.x + (p2.x - p0.x) / 6 * tension;
    var y1 = p1.y + (p2.y - p0.y) / 6 * tension;

    var x2 = p2.x - (p3.x - p1.x) / 6 * tension;
    var y2 = p2.y - (p3.y - p1.y) / 6 * tension;
    
    path += " " + x1 + " " + y1 + " " + x2 + " " + y2 + " " + p2.x + " " + p2.y;
  }
  
  return closed ? path + "z" : path;
}

function random(min, max) {
  if (max == null) { max = min; min = 0; }
  if (min > max) { var tmp = min; min = max; max = tmp; }
  return min + (max - min) * Math.random();
}