/**
*  
* @module Tweens
* @submodule Easing 
* 
*/
module Kiwi.Animations.Tweens.Easing {

	/**
	*
	*
	* @class Circular
	* @namespace Kiwi.Animations.Tweens.Easing
	*
	*/
	export class Circular {

		/**
		* The type of object that this is.
		* @method objType
		* @return {String} "Circular"
		* @public
		*/
		public objType() {
			return "Circular";
		}

		/** 
		* 
		* @method In
		* @param k {Any}
		* @return {Number}
		* @static
		*/
		public static In(k) {

			return 1 - Math.sqrt(1 - k * k);

		}

		/** 
		* 
		* @method Out
		* @param k {Any}
		* @return {Number}
		* @static
		*/
		public static Out(k) {

			return Math.sqrt(1 - (--k * k));

		}

		/** 
		* 
		* @method InOut
		* @param k {Any}
		* @return {Number}
		* @static
		*/
		public static InOut(k) {

			if ((k *= 2) < 1) return -0.5 * (Math.sqrt(1 - k * k) - 1);
			return 0.5 * (Math.sqrt(1 - (k -= 2) * k) + 1);

		}

	}

}