equations.as

Papervision3d的源码

			return c/2 * (Math.sqrt(1 - (t-=2)*t) + 1) + b;
		}
	
		/**
		 * Easing equation function for a circular (sqrt(1-t^2)) easing out/in: deceleration until halfway, then acceleration.
		 *
		 * @param t		Current time (in frames or seconds).
		 * @param b		Starting value.
		 * @param c		Change needed in value.
		 * @param d		Expected easing duration (in frames or seconds).
		 * @return		The correct value.
		 */
		public static function easeOutInCirc (t:Number, b:Number, c:Number, d:Number, p_params:Object = null):Number {
			if (t < d/2) return easeOutCirc (t*2, b, c/2, d, p_params);
			return easeInCirc((t*2)-d, b+c/2, c/2, d, p_params);
		}
	
		/**
		 * Easing equation function for an elastic (exponentially decaying sine wave) easing in: accelerating from zero velocity.
		 *
		 * @param t		Current time (in frames or seconds).
		 * @param b		Starting value.
		 * @param c		Change needed in value.
		 * @param d		Expected easing duration (in frames or seconds).
		 * @param a		Amplitude.
		 * @param p		Period.
		 * @return		The correct value.
		 */
		public static function easeInElastic (t:Number, b:Number, c:Number, d:Number, p_params:Object = null):Number {
			if (t==0) return b;
			if ((t/=d)==1) return b+c;
			var p:Number = !Boolean(p_params) || isNaN(p_params.period) ? d*.3 : p_params.period;
			var s:Number;
			var a:Number = !Boolean(p_params) || isNaN(p_params.amplitude) ? 0 : p_params.amplitude;
			if (!Boolean(a) || a < Math.abs(c)) {
				a = c;
				s = p/4;
			} else {
				s = p/(2*Math.PI) * Math.asin (c/a);
			}
			return -(a*Math.pow(2,10*(t-=1)) * Math.sin( (t*d-s)*(2*Math.PI)/p )) + b;
		}
	
		/**
		 * Easing equation function for an elastic (exponentially decaying sine wave) easing out: decelerating from zero velocity.
		 *
		 * @param t		Current time (in frames or seconds).
		 * @param b		Starting value.
		 * @param c		Change needed in value.
		 * @param d		Expected easing duration (in frames or seconds).
		 * @param a		Amplitude.
		 * @param p		Period.
		 * @return		The correct value.
		 */
		public static function easeOutElastic (t:Number, b:Number, c:Number, d:Number, p_params:Object = null):Number {
			if (t==0) return b;
			if ((t/=d)==1) return b+c;
			var p:Number = !Boolean(p_params) || isNaN(p_params.period) ? d*.3 : p_params.period;
			var s:Number;
			var a:Number = !Boolean(p_params) || isNaN(p_params.amplitude) ? 0 : p_params.amplitude;
			if (!Boolean(a) || a < Math.abs(c)) {
				a = c;
				s = p/4;
			} else {
				s = p/(2*Math.PI) * Math.asin (c/a);
			}
			return (a*Math.pow(2,-10*t) * Math.sin( (t*d-s)*(2*Math.PI)/p ) + c + b);
		}
	
		/**
		 * Easing equation function for an elastic (exponentially decaying sine wave) easing in/out: acceleration until halfway, then deceleration.
		 *
		 * @param t		Current time (in frames or seconds).
		 * @param b		Starting value.
		 * @param c		Change needed in value.
		 * @param d		Expected easing duration (in frames or seconds).
		 * @param a		Amplitude.
		 * @param p		Period.
		 * @return		The correct value.
		 */
		public static function easeInOutElastic (t:Number, b:Number, c:Number, d:Number, p_params:Object = null):Number {
			if (t==0) return b;
			if ((t/=d/2)==2) return b+c;
			var p:Number = !Boolean(p_params) || isNaN(p_params.period) ? d*(.3*1.5) : p_params.period;
			var s:Number;
			var a:Number = !Boolean(p_params) || isNaN(p_params.amplitude) ? 0 : p_params.amplitude;
			if (!Boolean(a) || a < Math.abs(c)) {
				a = c;
				s = p/4;
			} else {
				s = p/(2*Math.PI) * Math.asin (c/a);
			}
			if (t < 1) return -.5*(a*Math.pow(2,10*(t-=1)) * Math.sin( (t*d-s)*(2*Math.PI)/p )) + b;
			return a*Math.pow(2,-10*(t-=1)) * Math.sin( (t*d-s)*(2*Math.PI)/p )*.5 + c + b;
		}
	
		/**
		 * Easing equation function for an elastic (exponentially decaying sine wave) easing out/in: deceleration until halfway, then acceleration.
		 *
		 * @param t		Current time (in frames or seconds).
		 * @param b		Starting value.
		 * @param c		Change needed in value.
		 * @param d		Expected easing duration (in frames or seconds).
		 * @param a		Amplitude.
		 * @param p		Period.
		 * @return		The correct value.
		 */
		public static function easeOutInElastic (t:Number, b:Number, c:Number, d:Number, p_params:Object = null):Number {
			if (t < d/2) return easeOutElastic (t*2, b, c/2, d, p_params);
			return easeInElastic((t*2)-d, b+c/2, c/2, d, p_params);
		}
	
		/**
		 * Easing equation function for a back (overshooting cubic easing: (s+1)*t^3 - s*t^2) easing in: accelerating from zero velocity.
		 *
		 * @param t		Current time (in frames or seconds).
		 * @param b		Starting value.
		 * @param c		Change needed in value.
		 * @param d		Expected easing duration (in frames or seconds).
		 * @param s		Overshoot ammount: higher s means greater overshoot (0 produces cubic easing with no overshoot, and the default value of 1.70158 produces an overshoot of 10 percent).
		 * @return		The correct value.
		 */
		public static function easeInBack (t:Number, b:Number, c:Number, d:Number, p_params:Object = null):Number {
			var s:Number = !Boolean(p_params) || isNaN(p_params.overshoot) ? 1.70158 : p_params.overshoot;
			return c*(t/=d)*t*((s+1)*t - s) + b;
		}
	
		/**
		 * Easing equation function for a back (overshooting cubic easing: (s+1)*t^3 - s*t^2) easing out: decelerating from zero velocity.
		 *
		 * @param t		Current time (in frames or seconds).
		 * @param b		Starting value.
		 * @param c		Change needed in value.
		 * @param d		Expected easing duration (in frames or seconds).
		 * @param s		Overshoot ammount: higher s means greater overshoot (0 produces cubic easing with no overshoot, and the default value of 1.70158 produces an overshoot of 10 percent).
		 * @return		The correct value.
		 */
		public static function easeOutBack (t:Number, b:Number, c:Number, d:Number, p_params:Object = null):Number {
			var s:Number = !Boolean(p_params) || isNaN(p_params.overshoot) ? 1.70158 : p_params.overshoot;
			return c*((t=t/d-1)*t*((s+1)*t + s) + 1) + b;
		}
	
		/**
		 * Easing equation function for a back (overshooting cubic easing: (s+1)*t^3 - s*t^2) easing in/out: acceleration until halfway, then deceleration.
		 *
		 * @param t		Current time (in frames or seconds).
		 * @param b		Starting value.
		 * @param c		Change needed in value.
		 * @param d		Expected easing duration (in frames or seconds).
		 * @param s		Overshoot ammount: higher s means greater overshoot (0 produces cubic easing with no overshoot, and the default value of 1.70158 produces an overshoot of 10 percent).
		 * @return		The correct value.
		 */
		public static function easeInOutBack (t:Number, b:Number, c:Number, d:Number, p_params:Object = null):Number {
			var s:Number = !Boolean(p_params) || isNaN(p_params.overshoot) ? 1.70158 : p_params.overshoot;
			if ((t/=d/2) < 1) return c/2*(t*t*(((s*=(1.525))+1)*t - s)) + b;
			return c/2*((t-=2)*t*(((s*=(1.525))+1)*t + s) + 2) + b;
		}
	
		/**
		 * Easing equation function for a back (overshooting cubic easing: (s+1)*t^3 - s*t^2) easing out/in: deceleration until halfway, then acceleration.
		 *
		 * @param t		Current time (in frames or seconds).
		 * @param b		Starting value.
		 * @param c		Change needed in value.
		 * @param d		Expected easing duration (in frames or seconds).
		 * @param s		Overshoot ammount: higher s means greater overshoot (0 produces cubic easing with no overshoot, and the default value of 1.70158 produces an overshoot of 10 percent).
		 * @return		The correct value.
		 */
		public static function easeOutInBack (t:Number, b:Number, c:Number, d:Number, p_params:Object = null):Number {
			if (t < d/2) return easeOutBack (t*2, b, c/2, d, p_params);
			return easeInBack((t*2)-d, b+c/2, c/2, d, p_params);
		}
	
		/**
		 * Easing equation function for a bounce (exponentially decaying parabolic bounce) easing in: accelerating from zero velocity.
		 *
		 * @param t		Current time (in frames or seconds).
		 * @param b		Starting value.
		 * @param c		Change needed in value.
		 * @param d		Expected easing duration (in frames or seconds).
		 * @return		The correct value.
		 */
		public static function easeInBounce (t:Number, b:Number, c:Number, d:Number, p_params:Object = null):Number {
			return c - easeOutBounce (d-t, 0, c, d) + b;
		}
	
		/**
		 * Easing equation function for a bounce (exponentially decaying parabolic bounce) easing out: decelerating from zero velocity.
		 *
		 * @param t		Current time (in frames or seconds).
		 * @param b		Starting value.
		 * @param c		Change needed in value.
		 * @param d		Expected easing duration (in frames or seconds).
		 * @return		The correct value.
		 */
		public static function easeOutBounce (t:Number, b:Number, c:Number, d:Number, p_params:Object = null):Number {
			if ((t/=d) < (1/2.75)) {
				return c*(7.5625*t*t) + b;
			} else if (t < (2/2.75)) {
				return c*(7.5625*(t-=(1.5/2.75))*t + .75) + b;
			} else if (t < (2.5/2.75)) {
				return c*(7.5625*(t-=(2.25/2.75))*t + .9375) + b;
			} else {
				return c*(7.5625*(t-=(2.625/2.75))*t + .984375) + b;
			}
		}
	
		/**
		 * Easing equation function for a bounce (exponentially decaying parabolic bounce) easing in/out: acceleration until halfway, then deceleration.
		 *
		 * @param t		Current time (in frames or seconds).
		 * @param b		Starting value.
		 * @param c		Change needed in value.
		 * @param d		Expected easing duration (in frames or seconds).
		 * @return		The correct value.
		 */
		public static function easeInOutBounce (t:Number, b:Number, c:Number, d:Number, p_params:Object = null):Number {
			if (t < d/2) return easeInBounce (t*2, 0, c, d) * .5 + b;
			else return easeOutBounce (t*2-d, 0, c, d) * .5 + c*.5 + b;
		}
	
		/**
		 * Easing equation function for a bounce (exponentially decaying parabolic bounce) easing out/in: deceleration until halfway, then acceleration.
		 *
		 * @param t		Current time (in frames or seconds).
		 * @param b		Starting value.
		 * @param c		Change needed in value.
		 * @param d		Expected easing duration (in frames or seconds).
		 * @return		The correct value.
		 */
		public static function easeOutInBounce (t:Number, b:Number, c:Number, d:Number, p_params:Object = null):Number {
			if (t < d/2) return easeOutBounce (t*2, b, c/2, d, p_params);
			return easeInBounce((t*2)-d, b+c/2, c/2, d, p_params);
		}
	}
}