Tween.js

/**
 * Tween.js - Licensed under the MIT license
 * https://github.com/sole/tween.js
 * ----------------------------------------------
 *
 * See https://github.com/sole/tween.js/graphs/contributors for the full list of contributors.
 * Thank you all, you're awesome!
 */

// 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: '14',

		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;

		}

	}

};

if(typeof module !== 'undefined' && module.exports) {
	module.exports = TWEEN;
}