/**
@license
tween.js - https://github.com/sole/tween.js

Copyright (c) 2010-2012 Tween.js authors.

Easing equations Copyright (c) 2001 Robert Penner http://robertpenner.com/easing/

Permission is hereby granted, free of charge, to any person obtaining a copy
of this software and associated documentation files (the "Software"), to deal
in the Software without restriction, including without limitation the rights
to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
copies of the Software, and to permit persons to whom the Software is
furnished to do so, subject to the following conditions:

The above copyright notice and this permission notice shall be included in
all copies or substantial portions of the Software.

THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
THE SOFTWARE.
*/

/**
 * @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
 */

define(function() {

    // 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;

            }

        }

    };

return TWEEN;
});
