/*
    transitions.js

    Based on Easing Equations v2.0
    (c) 2003 Robert Penner, all rights reserved.
    This work is subject to the terms in http://www.robertpenner.com/easing_terms_of_use.html

    Adapted for Scriptaculous by Ken Snyder (kendsnyder ~at~ gmail ~dot~ com) June 2006
    */

    /*
    Overshooting Transitions
    */
    // Elastic (adapted from "EaseOutElastic")
    Effect.Transitions.Elastic = function(pos) {
        return -1*Math.pow(4,-8*pos) * Math.sin((pos*6-1)*(2*Math.PI)/2) + 1;
    };
    // SwingFromTo (adapted from "BackEaseInOut")
    Effect.Transitions.SwingFromTo = function(pos) {
        var s = 1.70158;
        if ((pos/=0.5) < 1) return 0.5*(pos*pos*(((s*=(1.525))+1)*pos - s));
        return 0.5*((pos-=2)*pos*(((s*=(1.525))+1)*pos + s) + 2);
    };
    // SwingFrom (adapted from "BackEaseIn")
    Effect.Transitions.SwingFrom = function(pos) {
        var s = 1.70158;
        return pos*pos*((s+1)*pos - s);
    };
    // SwingTo (adapted from "BackEaseOut")
    Effect.Transitions.SwingTo = function(pos) {
        var s = 1.70158;
        return (pos-=1)*pos*((s+1)*pos + s) + 1;
    };

    /*
    Bouncing Transitions
    */
    // Bounce (adapted from "EaseOutBounce")
    Effect.Transitions.Bounce = function(pos) {
        if (pos < (1/2.75)) {
            return (7.5625*pos*pos);
        } else if (pos < (2/2.75)) {
            return (7.5625*(pos-=(1.5/2.75))*pos + .75);
        } else if (pos < (2.5/2.75)) {
            return (7.5625*(pos-=(2.25/2.75))*pos + .9375);
        } else {
            return (7.5625*(pos-=(2.625/2.75))*pos + .984375);
        }
    };
    // BouncePast (new creation based on "EaseOutBounce")
    Effect.Transitions.BouncePast = function(pos) {
        if (pos < (1/2.75)) {
            return (7.5625*pos*pos);
        } else if (pos < (2/2.75)) {
            return 2 - (7.5625*(pos-=(1.5/2.75))*pos + .75);
        } else if (pos < (2.5/2.75)) {
            return 2 - (7.5625*(pos-=(2.25/2.75))*pos + .9375);
        } else {
            return 2 - (7.5625*(pos-=(2.625/2.75))*pos + .984375);
        }
    };

    /*
    Gradual Transitions
    */
    // EaseFromTo (adapted from "Quart.EaseInOut")
    Effect.Transitions.EaseFromTo = function(pos) {
        if ((pos/=0.5) < 1) return 0.5*Math.pow(pos,4);
        return -0.5 * ((pos-=2)*Math.pow(pos,3) - 2);   
    };
    // EaseFrom (adapted from "Quart.EaseIn")
    Effect.Transitions.EaseFrom = function(pos) {
        return Math.pow(pos,4);
    };
    // EaseTo (adapted from "Quart.EaseOut")
    Effect.Transitions.EaseTo = function(pos) {
        return Math.pow(pos,0.25);
    };