// tween.js - http://github.com/sole/tween.js
/**
 * @author sole / http://soledadpenades.com
 * @author mrdoob / http://mrdoob.com
 * @author Robert Eisele / http://www.xarg.org
 * @author Philippe / http://philippe.elsass.me
 * @author Robert Penner / http://www.robertpenner.com/easing_terms_of_use.html
 * @author Paul Lewis / http://www.aerotwist.com/
 * @author lechecacharro
 * @author Josh Faul / http://jocafa.com/
 * @author egraether / http://egraether.com/
 * @author endel / http://endel.me
 * @author Ben Delarre / http://delarre.net
 */

// Date.now shim for (ahem) Internet Explo(d|r)er
if (Date.now === undefined) {

    Date.now = function () {

        return new Date().valueOf();

    };

}

var TWEEN = TWEEN || (function () {

    var _tweens = [];

    return {

        REVISION: '13',

        getAll: function () {

            return _tweens;

        },

        removeAll: function () {

            _tweens = [];

        },

        add: function (tween) {

            _tweens.push(tween);

        },

        remove: function (tween) {

            var i = _tweens.indexOf(tween);

            if (i !== -1) {

                _tweens.splice(i, 1);

            }

        },

        update: function (time) {

            if (_tweens.length === 0) return false;

            var i = 0;

            time = time !== undefined ? time : (typeof window !== 'undefined' && window.performance !== undefined && window.performance.now !== undefined ? window.performance.now() : Date.now());

            while (i < _tweens.length) {

                if (_tweens[i].update(time)) {

                    i++;

                } else {

                    _tweens.splice(i, 1);

                }

            }

            return true;

        }
    };

})();

TWEEN.Tween = function (object) {

    var _object = object;
    var _valuesStart = {};
    var _valuesEnd = {};
    var _valuesStartRepeat = {};
    var _duration = 1000;
    var _repeat = 0;
    var _yoyo = false;
    var _isPlaying = false;
    var _reversed = false;
    var _delayTime = 0;
    var _startTime = null;
    var _easingFunction = TWEEN.Easing.Linear.None;
    var _interpolationFunction = TWEEN.Interpolation.Linear;
    var _chainedTweens = [];
    var _onStartCallback = null;
    var _onStartCallbackFired = false;
    var _onUpdateCallback = null;
    var _onCompleteCallback = null;
    var _onStopCallback = null;

    // Set all starting values present on the target object
    for (var field in object) {

        _valuesStart[field] = parseFloat(object[field], 10);

    }

    this.to = function (properties, duration) {

        if (duration !== undefined) {

            _duration = duration;

        }

        _valuesEnd = properties;

        return this;

    };

    this.start = function (time) {

        TWEEN.add(this);

        _isPlaying = true;

        _onStartCallbackFired = false;

        _startTime = time !== undefined ? time : (typeof window !== 'undefined' && window.performance !== undefined && window.performance.now !== undefined ? window.performance.now() : Date.now());
        _startTime += _delayTime;

        for (var property in _valuesEnd) {

            // check if an Array was provided as property value
            if (_valuesEnd[property] instanceof Array) {

                if (_valuesEnd[property].length === 0) {

                    continue;

                }

                // create a local copy of the Array with the start value at the front
                _valuesEnd[property] = [_object[property]].concat(_valuesEnd[property]);

            }

            _valuesStart[property] = _object[property];

            if ((_valuesStart[property] instanceof Array) === false) {
                _valuesStart[property] *= 1.0; // Ensures we're using numbers, not strings
            }

            _valuesStartRepeat[property] = _valuesStart[property] || 0;

        }

        return this;

    };

    this.stop = function () {

        if (!_isPlaying) {
            return this;
        }

        TWEEN.remove(this);
        _isPlaying = false;

        if (_onStopCallback !== null) {

            _onStopCallback.call(_object);

        }

        this.stopChainedTweens();
        return this;

    };

    this.stopChainedTweens = function () {

        for (var i = 0, numChainedTweens = _chainedTweens.length; i < numChainedTweens; i++) {

            _chainedTweens[i].stop();

        }

    };

    this.delay = function (amount) {

        _delayTime = amount;
        return this;

    };

    this.repeat = function (times) {

        _repeat = times;
        return this;

    };

    this.yoyo = function (yoyo) {

        _yoyo = yoyo;
        return this;

    };


    this.easing = function (easing) {

        _easingFunction = easing;
        return this;

    };

    this.interpolation = function (interpolation) {

        _interpolationFunction = interpolation;
        return this;

    };

    this.chain = function () {

        _chainedTweens = arguments;
        return this;

    };

    this.onStart = function (callback) {

        _onStartCallback = callback;
        return this;

    };

    this.onUpdate = function (callback) {

        _onUpdateCallback = callback;
        return this;

    };

    this.onComplete = function (callback) {

        _onCompleteCallback = callback;
        return this;

    };

    this.onStop = function (callback) {

        _onStopCallback = callback;
        return this;

    };

    this.update = function (time) {

        var property;

        if (time < _startTime) {

            return true;

        }

        if (_onStartCallbackFired === false) {

            if (_onStartCallback !== null) {

                _onStartCallback.call(_object);

            }

            _onStartCallbackFired = true;

        }

        var elapsed = (time - _startTime) / _duration;
        elapsed = elapsed > 1 ? 1 : elapsed;

        var value = _easingFunction(elapsed);

        for (property in _valuesEnd) {

            var start = _valuesStart[property] || 0;
            var end = _valuesEnd[property];

            if (end instanceof Array) {

                _object[property] = _interpolationFunction(end, value);

            } else {

                // Parses relative end values with start as base (e.g.: +10, -3)
                if (typeof (end) === "string") {
                    end = start + parseFloat(end, 10);
                }

                // protect against non numeric properties.
                if (typeof (end) === "number") {
                    _object[property] = start + (end - start) * value;
                }

            }

        }

        if (_onUpdateCallback !== null) {

            _onUpdateCallback.call(_object, value);

        }

        if (elapsed == 1) {

            if (_repeat > 0) {

                if (isFinite(_repeat)) {
                    _repeat--;
                }

                // reassign starting values, restart by making startTime = now
                for (property in _valuesStartRepeat) {

                    if (typeof (_valuesEnd[property]) === "string") {
                        _valuesStartRepeat[property] = _valuesStartRepeat[property] + parseFloat(_valuesEnd[property], 10);
                    }

                    if (_yoyo) {
                        var tmp = _valuesStartRepeat[property];
                        _valuesStartRepeat[property] = _valuesEnd[property];
                        _valuesEnd[property] = tmp;
                    }

                    _valuesStart[property] = _valuesStartRepeat[property];

                }

                if (_yoyo) {
                    _reversed = !_reversed;
                }

                _startTime = time + _delayTime;

                return true;

            } else {

                if (_onCompleteCallback !== null) {

                    _onCompleteCallback.call(_object);

                }

                for (var i = 0, numChainedTweens = _chainedTweens.length; i < numChainedTweens; i++) {

                    _chainedTweens[i].start(time);

                }

                return false;

            }

        }

        return true;

    };

};


TWEEN.Easing = {

    Linear: {

        None: function (k) {

            return k;

        }

    },

    Quadratic: {

        In: function (k) {

            return k * k;

        },

        Out: function (k) {

            return k * (2 - k);

        },

        InOut: function (k) {

            if ((k *= 2) < 1) return 0.5 * k * k;
            return -0.5 * (--k * (k - 2) - 1);

        }

    },

    Cubic: {

        In: function (k) {

            return k * k * k;

        },

        Out: function (k) {

            return --k * k * k + 1;

        },

        InOut: function (k) {

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

        }

    },

    Quartic: {

        In: function (k) {

            return k * k * k * k;

        },

        Out: function (k) {

            return 1 - (--k * k * k * k);

        },

        InOut: function (k) {

            if ((k *= 2) < 1) return 0.5 * k * k * k * k;
            return -0.5 * ((k -= 2) * k * k * k - 2);

        }

    },

    Quintic: {

        In: function (k) {

            return k * k * k * k * k;

        },

        Out: function (k) {

            return --k * k * k * k * k + 1;

        },

        InOut: function (k) {

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

        }

    },

    Sinusoidal: {

        In: function (k) {

            return 1 - Math.cos(k * Math.PI / 2);

        },

        Out: function (k) {

            return Math.sin(k * Math.PI / 2);

        },

        InOut: function (k) {

            return 0.5 * (1 - Math.cos(Math.PI * k));

        }

    },

    Exponential: {

        In: function (k) {

            return k === 0 ? 0 : Math.pow(1024, k - 1);

        },

        Out: function (k) {

            return k === 1 ? 1 : 1 - Math.pow(2, -10 * k);

        },

        InOut: function (k) {

            if (k === 0) return 0;
            if (k === 1) return 1;
            if ((k *= 2) < 1) return 0.5 * Math.pow(1024, k - 1);
            return 0.5 * (-Math.pow(2, -10 * (k - 1)) + 2);

        }

    },

    Circular: {

        In: function (k) {

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

        },

        Out: function (k) {

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

        },

        InOut: function (k) {

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

        }

    },

    Elastic: {

        In: function (k) {

            var s, a = 0.1, p = 0.4;
            if (k === 0) return 0;
            if (k === 1) return 1;
            if (!a || a < 1) { a = 1; s = p / 4; }
            else s = p * Math.asin(1 / a) / (2 * Math.PI);
            return -(a * Math.pow(2, 10 * (k -= 1)) * Math.sin((k - s) * (2 * Math.PI) / p));

        },

        Out: function (k) {

            var s, a = 0.1, p = 0.4;
            if (k === 0) return 0;
            if (k === 1) return 1;
            if (!a || a < 1) { a = 1; s = p / 4; }
            else s = p * Math.asin(1 / a) / (2 * Math.PI);
            return (a * Math.pow(2, -10 * k) * Math.sin((k - s) * (2 * Math.PI) / p) + 1);

        },

        InOut: function (k) {

            var s, a = 0.1, p = 0.4;
            if (k === 0) return 0;
            if (k === 1) return 1;
            if (!a || a < 1) { a = 1; s = p / 4; }
            else s = p * Math.asin(1 / a) / (2 * Math.PI);
            if ((k *= 2) < 1) return -0.5 * (a * Math.pow(2, 10 * (k -= 1)) * Math.sin((k - s) * (2 * Math.PI) / p));
            return a * Math.pow(2, -10 * (k -= 1)) * Math.sin((k - s) * (2 * Math.PI) / p) * 0.5 + 1;

        }

    },

    Back: {

        In: function (k) {

            var s = 1.70158;
            return k * k * ((s + 1) * k - s);

        },

        Out: function (k) {

            var s = 1.70158;
            return --k * k * ((s + 1) * k + s) + 1;

        },

        InOut: function (k) {

            var s = 1.70158 * 1.525;
            if ((k *= 2) < 1) return 0.5 * (k * k * ((s + 1) * k - s));
            return 0.5 * ((k -= 2) * k * ((s + 1) * k + s) + 2);

        }

    },

    Bounce: {

        In: function (k) {

            return 1 - TWEEN.Easing.Bounce.Out(1 - k);

        },

        Out: function (k) {

            if (k < (1 / 2.75)) {

                return 7.5625 * k * k;

            } else if (k < (2 / 2.75)) {

                return 7.5625 * (k -= (1.5 / 2.75)) * k + 0.75;

            } else if (k < (2.5 / 2.75)) {

                return 7.5625 * (k -= (2.25 / 2.75)) * k + 0.9375;

            } else {

                return 7.5625 * (k -= (2.625 / 2.75)) * k + 0.984375;

            }

        },

        InOut: function (k) {

            if (k < 0.5) return TWEEN.Easing.Bounce.In(k * 2) * 0.5;
            return TWEEN.Easing.Bounce.Out(k * 2 - 1) * 0.5 + 0.5;

        }

    }

};

TWEEN.Interpolation = {

    Linear: function (v, k) {

        var m = v.length - 1, f = m * k, i = Math.floor(f), fn = TWEEN.Interpolation.Utils.Linear;

        if (k < 0) return fn(v[0], v[1], f);
        if (k > 1) return fn(v[m], v[m - 1], m - f);

        return fn(v[i], v[i + 1 > m ? m : i + 1], f - i);

    },

    Bezier: function (v, k) {

        var b = 0, n = v.length - 1, pw = Math.pow, bn = TWEEN.Interpolation.Utils.Bernstein, i;

        for (i = 0; i <= n; i++) {
            b += pw(1 - k, n - i) * pw(k, i) * v[i] * bn(n, i);
        }

        return b;

    },

    CatmullRom: function (v, k) {

        var m = v.length - 1, f = m * k, i = Math.floor(f), fn = TWEEN.Interpolation.Utils.CatmullRom;

        if (v[0] === v[m]) {

            if (k < 0) i = Math.floor(f = m * (1 + k));

            return fn(v[(i - 1 + m) % m], v[i], v[(i + 1) % m], v[(i + 2) % m], f - i);

        } else {

            if (k < 0) return v[0] - (fn(v[0], v[0], v[1], v[1], -f) - v[0]);
            if (k > 1) return v[m] - (fn(v[m], v[m], v[m - 1], v[m - 1], f - m) - v[m]);

            return fn(v[i ? i - 1 : 0], v[i], v[m < i + 1 ? m : i + 1], v[m < i + 2 ? m : i + 2], f - i);

        }

    },

    Utils: {

        Linear: function (p0, p1, t) {

            return (p1 - p0) * t + p0;

        },

        Bernstein: function (n, i) {

            var fc = TWEEN.Interpolation.Utils.Factorial;
            return fc(n) / fc(i) / fc(n - i);

        },

        Factorial: (function () {

            var a = [1];

            return function (n) {

                var s = 1, i;
                if (a[n]) return a[n];
                for (i = n; i > 1; i--) s *= i;
                return a[n] = s;

            };

        })(),

        CatmullRom: function (p0, p1, p2, p3, t) {

            var v0 = (p2 - p0) * 0.5, v1 = (p3 - p1) * 0.5, t2 = t * t, t3 = t * t2;
            return (2 * p1 - 2 * p2 + v0 + v1) * t3 + (-3 * p1 + 3 * p2 - 2 * v0 - v1) * t2 + v0 * t + p1;

        }

    }

};