(function () {
  var canvas = document.getElementById("c");
  canvas.width = window.innerWidth;
  canvas.height = window.innerHeight;

  var ctx = canvas.getContext("2d");
  var points = [];
  var x, y;
  var angle = 0;
  var r = 100;
  var leftMargin = 10;
  var speed = 0.02;
  ctx.strokeStyle = "white";
  ctx.fillStyle = "black";

  function draw() {
    ctx.fillRect(0, 0, canvas.width, canvas.height);

    ctx.beginPath();
    ctx.arc(r + leftMargin, canvas.height/2, r, 0, Math.PI*2, true);
    ctx.stroke();
    
    x = Math.cos(angle) * r + r + leftMargin;
    y = Math.sin(angle) * r + canvas.height/2;
    points.push(y); // Ticking bomb, it just grows...
    ctx.beginPath();
    ctx.arc(x, y, 4, 0, Math.PI*2, true);
    ctx.fill();
    for(var xx = 0; xx < points.length; ++xx) {
      ctx.lineTo(r * 2 + leftMargin +xx, points[points.length-xx]);
    }
    ctx.stroke();
    
    angle += speed;
    window.requestAnimationFrame(draw);
  }
  
  window.requestAnimationFrame(draw);
  
  
  var speedSlider = document.getElementById("speedSlider");
  speedSlider.step = 0.001;
  speedSlider.min = 0.001;
  speedSlider.max = 0.3;
  speedSlider.value = speed;
  speedSlider.addEventListener("change", function () {
    speed = parseFloat(this.value);
  });
  
  var radiusSlider = document.getElementById("radiusSlider");
  radiusSlider.max = 300;
  radiusSlider.value = r;
  radiusSlider.addEventListener("change", function () {
    r = parseInt(this.value);
  });
  
  function resize () {
    if(canvas.width != window.innerWidth) {
    	canvas.width = window.innerWidth;
    }
    if(canvas.height != window.innerHeight) {
    	canvas.height = window.innerHeight;
    }
    ctx.strokeStyle = "white";
    ctx.fillStyle = "black";
  }
  
  function debounce(func, wait, immediate) {
    var timeout;
    return function() {
      var context = this, args = arguments;
      var later = function() {
        timeout = null;
        if (!immediate) func.apply(context, args);
      };
      var callNow = immediate && !timeout;
      clearTimeout(timeout);
      timeout = setTimeout(later, wait);
      if (callNow) func.apply(context, args);
    };
  };
  var debouncedResize = debounce(resize, 250);
  
  window.addEventListener("resize", debouncedResize, false);
  
})();