<div id="angle" class="angle"></div>
<div id="lastAngle" class="lastAngle"></div>
<div id="angleRot" class="angleRot"></div>
<div class="arrow"></div>

<script>
	/*
 * Easing Functions
 * only considering the t value for the range [0, 1] => [0, 1]
 */
	var EasingFunctions = {
		// no easing, no acceleration
		linear: function linear(t) {
			return t;
		},
		// accelerating from zero velocity
		easeInQuad: function easeInQuad(t) {
			return t * t;
		},
		// decelerating to zero velocity
		easeOutQuad: function easeOutQuad(t) {
			return t * (2 - t);
		},
		// acceleration until halfway, then deceleration
		easeInOutQuad: function easeInOutQuad(t) {
			return t < .5 ? 2 * t * t : -1 + (4 - 2 * t) * t;
		},
		// accelerating from zero velocity
		easeInCubic: function easeInCubic(t) {
			return t * t * t;
		},
		// decelerating to zero velocity
		easeOutCubic: function easeOutCubic(t) {
			return --t * t * t + 1;
		},
		// acceleration until halfway, then deceleration
		easeInOutCubic: function easeInOutCubic(t) {
			return t < .5 ? 4 * t * t * t : (t - 1) * (2 * t - 2) * (2 * t - 2) + 1;
		},
		// accelerating from zero velocity
		easeInQuart: function easeInQuart(t) {
			return t * t * t * t;
		},
		// decelerating to zero velocity
		easeOutQuart: function easeOutQuart(t) {
			return 1 - --t * t * t * t;
		},
		// acceleration until halfway, then deceleration
		easeInOutQuart: function easeInOutQuart(t) {
			return t < .5 ? 8 * t * t * t * t : 1 - 8 * --t * t * t * t;
		},
		// accelerating from zero velocity
		easeInQuint: function easeInQuint(t) {
			return t * t * t * t * t;
		},
		// decelerating to zero velocity
		easeOutQuint: function easeOutQuint(t) {
			return 1 + --t * t * t * t * t;
		},
		// acceleration until halfway, then deceleration
		easeInOutQuint: function easeInOutQuint(t) {
			return t < .5 ? 16 * t * t * t * t * t : 1 + 16 * --t * t * t * t * t;
		},
		// elastic bounce effect at the beginning
		easeInElastic: function easeInElastic(t) {
			return (.04 - .04 / t) * Math.sin(25 * t) + 1;
		},
		// elastic bounce effect at the end
		easeOutElastic: function easeOutElastic(t) {
			return .04 * t / --t * Math.sin(25 * t);
		},
		// elastic bounce effect at the beginning and end
		easeInOutElastic: function easeInOutElastic(t) {
			return (t -= .5) < 0 ? (.01 + .01 / t) * Math.sin(50 * t) : (.02 - .01 / t) * Math.sin(50 * t) + 1;
		}
	};
</script>