# Source: src/tween/Tween.js

    /**
    * @author       Richard Davey <rich@photonstorm.com>
    * @copyright    2016 Photon Storm Ltd.
    * @license      {@link https://github.com/photonstorm/phaser/blob/master/license.txt|MIT License}
    */

    /**
    * A Tween allows you to alter one or more properties of a target object over a defined period of time.
    * This can be used for things such as alpha fading Sprites, scaling them or motion.
    * Use `Tween.to` or `Tween.from` to set-up the tween values. You can create multiple tweens on the same object
    * by calling Tween.to multiple times on the same Tween. Additional tweens specified in this way become "child" tweens and
    * are played through in sequence. You can use Tween.timeScale and Tween.reverse to control the playback of this Tween and all of its children.
    *
    * @class Phaser.Tween
    * @constructor
    * @param {object} target - The target object, such as a Phaser.Sprite or Phaser.Sprite.scale.
    * @param {Phaser.Game} game - Current game instance.
    * @param {Phaser.TweenManager} manager - The TweenManager responsible for looking after this Tween.
    */
    Phaser.Tween = function (target, game, manager) {

        /**
        * @property {Phaser.Game} game - A reference to the currently running Game.
        */
        this.game = game;

        /**
        * @property {object} target - The target object, such as a Phaser.Sprite or property like Phaser.Sprite.scale.
        */
        this.target = target;

        /**
        * @property {Phaser.TweenManager} manager - Reference to the TweenManager responsible for updating this Tween.
        */
        this.manager = manager;

        /**
        * @property {Array} timeline - An Array of TweenData objects that comprise the different parts of this Tween.
        */
        this.timeline = [];

        /**
        * If set to `true` the current tween will play in reverse.
        * If the tween hasn't yet started this has no effect.
        * If there are child tweens then all child tweens will play in reverse from the current point.
        * @property {boolean} reverse
        * @default
        */
        this.reverse = false;

        /**
        * The speed at which the tweens will run. A value of 1 means it will match the game frame rate. 0.5 will run at half the frame rate. 2 at double the frame rate, etc.
        * If a tweens duration is 1 second but timeScale is 0.5 then it will take 2 seconds to complete.
        *
        * @property {number} timeScale
        * @default
        */
        this.timeScale = 1;

        /**
        * @property {number} repeatCounter - If the Tween and any child tweens are set to repeat this contains the current repeat count.
        */
        this.repeatCounter = 0;

        /**
        * @property {boolean} pendingDelete - True if this Tween is ready to be deleted by the TweenManager.
        * @default
        * @readonly
        */
        this.pendingDelete = false;

        /**
        * The onStart event is fired when the Tween begins. If there is a delay before the tween starts then onStart fires after the delay is finished.
        * It will be sent 2 parameters: the target object and this tween.
        * @property {Phaser.Signal} onStart
        */
        this.onStart = new Phaser.Signal();

        /**
        * The onLoop event is fired if the Tween, or any child tweens loop.
        * It will be sent 2 parameters: the target object and this tween.
        *
        * @property {Phaser.Signal} onLoop
        */
        this.onLoop = new Phaser.Signal();

        /**
        * The onRepeat event is fired if the Tween and all of its children repeats. If this tween has no children this will never be fired.
        * It will be sent 2 parameters: the target object and this tween.
        * @property {Phaser.Signal} onRepeat
        */
        this.onRepeat = new Phaser.Signal();

        /**
        * The onChildComplete event is fired when the Tween or any of its children completes.
        * Fires every time a child completes unless a child is set to repeat forever.
        * It will be sent 2 parameters: the target object and this tween.
        * @property {Phaser.Signal} onChildComplete
        */
        this.onChildComplete = new Phaser.Signal();

        /**
        * The onComplete event is fired when the Tween and all of its children completes. Does not fire if the Tween is set to loop or repeatAll(-1).
        * It will be sent 2 parameters: the target object and this tween.
        * @property {Phaser.Signal} onComplete
        */
        this.onComplete = new Phaser.Signal();

        /**
        * @property {boolean} isRunning - If the tween is running this is set to true, otherwise false. Tweens that are in a delayed state or waiting to start are considered as being running.
        * @default
        */
        this.isRunning = false;

        /**
        * @property {number} current - The current Tween child being run.
        * @default
        * @readonly
        */
        this.current = 0;

        /**
        * @property {object} properties - Target property cache used when building the child data values.
        */
        this.properties = {};

        /**
        * @property {Phaser.Tween} chainedTween - If this Tween is chained to another this holds a reference to it.
        */
        this.chainedTween = null;

        /**
        * @property {boolean} isPaused - Is this Tween paused or not?
        * @default
        */
        this.isPaused = false;

        /**
        * Is this Tween frame or time based? A frame based tween will use the physics elapsed timer when updating. This means
        * it will retain the same consistent frame rate, regardless of the speed of the device. The duration value given should
        * be given in frames.
        *
        * If the Tween uses a time based update (which is the default) then the duration is given in milliseconds.
        * In this situation a 2000ms tween will last exactly 2 seconds, regardless of the device and how many visual updates the tween
        * has actually been through. For very short tweens you may wish to experiment with a frame based update instead.
        *
        * The default value is whatever you've set in TweenManager.frameBased.
        *
        * @property {boolean} frameBased
        * @default
        */
        this.frameBased = manager.frameBased;

        /**
        * @property {function} _onUpdateCallback - An onUpdate callback.
        * @private
        * @default null
        */
        this._onUpdateCallback = null;

        /**
        * @property {object} _onUpdateCallbackContext - The context in which to call the onUpdate callback.
        * @private
        * @default null
        */
        this._onUpdateCallbackContext = null;

        /**
        * @property {number} _pausedTime - Private pause timer.
        * @private
        * @default
        */
        this._pausedTime = 0;

        /**
        * @property {boolean} _codePaused - Was the Tween paused by code or by Game focus loss?
        * @private
        */
        this._codePaused = false;

        /**
        * @property {boolean} _hasStarted - Internal var to track if the Tween has started yet or not.
        * @private
        */
        this._hasStarted = false;
    };

    Phaser.Tween.prototype = {

        /**
        * Sets this tween to be a `to` tween on the properties given. A `to` tween starts at the current value and tweens to the destination value given.
        * For example a Sprite with an `x` coordinate of 100 could be tweened to `x` 200 by giving a properties object of `{ x: 200 }`.
        * The ease function allows you define the rate of change. You can pass either a function such as Phaser.Easing.Circular.Out or a string such as "Circ".
        * ".easeIn", ".easeOut" and "easeInOut" variants are all supported for all ease types.
        *
        * @method Phaser.Tween#to
        * @param {object} properties - An object containing the properties you want to tween, such as `Sprite.x` or `Sound.volume`. Given as a JavaScript object.
        * @param {number} [duration=1000] - Duration of this tween in ms. Or if `Tween.frameBased` is true this represents the number of frames that should elapse.
        * @param {function|string} [ease=null] - Easing function. If not set it will default to Phaser.Easing.Default, which is Phaser.Easing.Linear.None by default but can be over-ridden.
        * @param {boolean} [autoStart=false] - Set to `true` to allow this tween to start automatically. Otherwise call Tween.start().
        * @param {number} [delay=0] - Delay before this tween will start in milliseconds. Defaults to 0, no delay.
        * @param {number} [repeat=0] - Should the tween automatically restart once complete? If you want it to run forever set as -1. This only effects this individual tween, not any chained tweens.
        * @param {boolean} [yoyo=false] - A tween that yoyos will reverse itself and play backwards automatically. A yoyo'd tween doesn't fire the Tween.onComplete event, so listen for Tween.onLoop instead.
        * @return {Phaser.Tween} This Tween object.
        */
        to: function (properties, duration, ease, autoStart, delay, repeat, yoyo) {

            if (duration === undefined || duration <= 0) { duration = 1000; }
            if (ease === undefined || ease === null) { ease = Phaser.Easing.Default; }
            if (autoStart === undefined) { autoStart = false; }
            if (delay === undefined) { delay = 0; }
            if (repeat === undefined) { repeat = 0; }
            if (yoyo === undefined) { yoyo = false; }

            if (typeof ease === 'string' && this.manager.easeMap[ease])
            {
                ease = this.manager.easeMap[ease];
            }

            if (this.isRunning)
            {
                console.warn('Phaser.Tween.to cannot be called after Tween.start');
                return this;
            }

            this.timeline.push(new Phaser.TweenData(this).to(properties, duration, ease, delay, repeat, yoyo));

            if (autoStart)
            {
                this.start();
            }

            return this;

        },

        /**
        * Sets this tween to be a `from` tween on the properties given. A `from` tween sets the target to the destination value and tweens to its current value.
        * For example a Sprite with an `x` coordinate of 100 tweened from `x` 500 would be set to `x` 500 and then tweened to `x` 100 by giving a properties object of `{ x: 500 }`.
        * The ease function allows you define the rate of change. You can pass either a function such as Phaser.Easing.Circular.Out or a string such as "Circ".
        * ".easeIn", ".easeOut" and "easeInOut" variants are all supported for all ease types.
        *
        * @method Phaser.Tween#from
        * @param {object} properties - An object containing the properties you want to tween., such as `Sprite.x` or `Sound.volume`. Given as a JavaScript object.
        * @param {number} [duration=1000] - Duration of this tween in ms. Or if `Tween.frameBased` is true this represents the number of frames that should elapse.
        * @param {function|string} [ease=null] - Easing function. If not set it will default to Phaser.Easing.Default, which is Phaser.Easing.Linear.None by default but can be over-ridden.
        * @param {boolean} [autoStart=false] - Set to `true` to allow this tween to start automatically. Otherwise call Tween.start().
        * @param {number} [delay=0] - Delay before this tween will start in milliseconds. Defaults to 0, no delay.
        * @param {number} [repeat=0] - Should the tween automatically restart once complete? If you want it to run forever set as -1. This only effects this individual tween, not any chained tweens.
        * @param {boolean} [yoyo=false] - A tween that yoyos will reverse itself and play backwards automatically. A yoyo'd tween doesn't fire the Tween.onComplete event, so listen for Tween.onLoop instead.
        * @return {Phaser.Tween} This Tween object.
        */
        from: function (properties, duration, ease, autoStart, delay, repeat, yoyo) {

            if (duration === undefined) { duration = 1000; }
            if (ease === undefined || ease === null) { ease = Phaser.Easing.Default; }
            if (autoStart === undefined) { autoStart = false; }
            if (delay === undefined) { delay = 0; }
            if (repeat === undefined) { repeat = 0; }
            if (yoyo === undefined) { yoyo = false; }

            if (typeof ease === 'string' && this.manager.easeMap[ease])
            {
                ease = this.manager.easeMap[ease];
            }

            if (this.isRunning)
            {
                console.warn('Phaser.Tween.from cannot be called after Tween.start');
                return this;
            }

            this.timeline.push(new Phaser.TweenData(this).from(properties, duration, ease, delay, repeat, yoyo));

            if (autoStart)
            {
                this.start();
            }

            return this;

        },

        /**
        * Starts the tween running. Can also be called by the autoStart parameter of `Tween.to` or `Tween.from`.
        * This sets the `Tween.isRunning` property to `true` and dispatches a `Tween.onStart` signal.
        * If the Tween has a delay set then nothing will start tweening until the delay has expired.
        *
        * @method Phaser.Tween#start
        * @param {number} [index=0] - If this Tween contains child tweens you can specify which one to start from. The default is zero, i.e. the first tween created.
        * @return {Phaser.Tween} This tween. Useful for method chaining.
        */
        start: function (index) {

            if (index === undefined) { index = 0; }

            if (this.game === null || this.target === null || this.timeline.length === 0 || this.isRunning)
            {
                return this;
            }

            //  Populate the tween data
            for (var i = 0; i < this.timeline.length; i++)
            {
                //  Build our master property list with the starting values
                for (var property in this.timeline[i].vEnd)
                {
                    this.properties[property] = this.target[property] || 0;

                    if (!Array.isArray(this.properties[property]))
                    {
                        //  Ensures we're using numbers, not strings
                        this.properties[property] *= 1.0;
                    }
                }
            }

            for (var i = 0; i < this.timeline.length; i++)
            {
                this.timeline[i].loadValues();
            }

            this.manager.add(this);

            this.isRunning = true;

            if (index < 0 || index > this.timeline.length - 1)
            {
                index = 0;
            }

            this.current = index;

            this.timeline[this.current].start();

            return this;

        },

        /**
        * Stops the tween if running and flags it for deletion from the TweenManager.
        * If called directly the `Tween.onComplete` signal is not dispatched and no chained tweens are started unless the complete parameter is set to `true`.
        * If you just wish to pause a tween then use Tween.pause instead.
        *
        * @method Phaser.Tween#stop
        * @param {boolean} [complete=false] - Set to `true` to dispatch the Tween.onComplete signal.
        * @return {Phaser.Tween} This tween. Useful for method chaining.
        */
        stop: function (complete) {

            if (complete === undefined) { complete = false; }

            this.isRunning = false;

            this._onUpdateCallback = null;
            this._onUpdateCallbackContext = null;

            if (complete)
            {
                this.onComplete.dispatch(this.target, this);
                this._hasStarted = false;

                if (this.chainedTween)
                {
                    this.chainedTween.start();
                }
            }

            this.manager.remove(this);

            return this;

        },

        /**
        * Updates either a single TweenData or all TweenData objects properties to the given value.
        * Used internally by methods like Tween.delay, Tween.yoyo, etc. but can also be called directly if you know which property you want to tweak.
        * The property is not checked, so if you pass an invalid one you'll generate a run-time error.
        *
        * @method Phaser.Tween#updateTweenData
        * @param {string} property - The property to update.
        * @param {number|function} value - The value to set the property to.
        * @param {number} [index=0] - If this tween has more than one child this allows you to target a specific child. If set to -1 it will set the delay on all the children.
        * @return {Phaser.Tween} This tween. Useful for method chaining.
        */
        updateTweenData: function (property, value, index) {

            if (this.timeline.length === 0) { return this; }

            if (index === undefined) { index = 0; }

            if (index === -1)
            {
                for (var i = 0; i < this.timeline.length; i++)
                {
                    this.timeline[i][property] = value;
                }
            }
            else
            {
                this.timeline[index][property] = value;
            }

            return this;

        },

        /**
        * Sets the delay in milliseconds before this tween will start. If there are child tweens it sets the delay before the first child starts.
        * The delay is invoked as soon as you call `Tween.start`. If the tween is already running this method doesn't do anything for the current active tween.
        * If you have not yet called `Tween.to` or `Tween.from` at least once then this method will do nothing, as there are no tweens to delay.
        * If you have child tweens and pass -1 as the index value it sets the delay across all of them.
        *
        * @method Phaser.Tween#delay
        * @param {number} duration - The amount of time in ms that the Tween should wait until it begins once started is called. Set to zero to remove any active delay.
        * @param {number} [index=0] - If this tween has more than one child this allows you to target a specific child. If set to -1 it will set the delay on all the children.
        * @return {Phaser.Tween} This tween. Useful for method chaining.
        */
        delay: function (duration, index) {

            return this.updateTweenData('delay', duration, index);

        },

        /**
        * Sets the number of times this tween will repeat.
        * If you have not yet called `Tween.to` or `Tween.from` at least once then this method will do nothing, as there are no tweens to repeat.
        * If you have child tweens and pass -1 as the index value it sets the number of times they'll repeat across all of them.
        * If you wish to define how many times this Tween and all children will repeat see Tween.repeatAll.
        *
        * @method Phaser.Tween#repeat
        * @param {number} total - How many times a tween should repeat before completing. Set to zero to remove an active repeat. Set to -1 to repeat forever.
        * @param {number} [repeat=0] - This is the amount of time to pause (in ms) before the repeat will start.
        * @param {number} [index=0] - If this tween has more than one child this allows you to target a specific child. If set to -1 it will set the repeat value on all the children.
        * @return {Phaser.Tween} This tween. Useful for method chaining.
        */
        repeat: function (total, repeatDelay, index) {

            if (repeatDelay === undefined) { repeatDelay = 0; }

            this.updateTweenData('repeatCounter', total, index);

            return this.updateTweenData('repeatDelay', repeatDelay, index);

        },

        /**
        * Sets the delay in milliseconds before this tween will repeat itself.
        * The repeatDelay is invoked as soon as you call `Tween.start`. If the tween is already running this method doesn't do anything for the current active tween.
        * If you have not yet called `Tween.to` or `Tween.from` at least once then this method will do nothing, as there are no tweens to set repeatDelay on.
        * If you have child tweens and pass -1 as the index value it sets the repeatDelay across all of them.
        *
        * @method Phaser.Tween#repeatDelay
        * @param {number} duration - The amount of time in ms that the Tween should wait until it repeats or yoyos once start is called. Set to zero to remove any active repeatDelay.
        * @param {number} [index=0] - If this tween has more than one child this allows you to target a specific child. If set to -1 it will set the repeatDelay on all the children.
        * @return {Phaser.Tween} This tween. Useful for method chaining.
        */
        repeatDelay: function (duration, index) {

            return this.updateTweenData('repeatDelay', duration, index);

        },

        /**
        * A Tween that has yoyo set to true will run through from its starting values to its end values and then play back in reverse from end to start.
        * Used in combination with repeat you can create endless loops.
        * If you have not yet called `Tween.to` or `Tween.from` at least once then this method will do nothing, as there are no tweens to yoyo.
        * If you have child tweens and pass -1 as the index value it sets the yoyo property across all of them.
        * If you wish to yoyo this Tween and all of its children then see Tween.yoyoAll.
        *
        * @method Phaser.Tween#yoyo
        * @param {boolean} enable - Set to true to yoyo this tween, or false to disable an already active yoyo.
        * @param {number} [yoyoDelay=0] - This is the amount of time to pause (in ms) before the yoyo will start.
        * @param {number} [index=0] - If this tween has more than one child this allows you to target a specific child. If set to -1 it will set yoyo on all the children.
        * @return {Phaser.Tween} This tween. Useful for method chaining.
        */
        yoyo: function(enable, yoyoDelay, index) {

            if (yoyoDelay === undefined) { yoyoDelay = 0; }

            this.updateTweenData('yoyo', enable, index);

            return this.updateTweenData('yoyoDelay', yoyoDelay, index);

        },

        /**
        * Sets the delay in milliseconds before this tween will run a yoyo (only applies if yoyo is enabled).
        * The repeatDelay is invoked as soon as you call `Tween.start`. If the tween is already running this method doesn't do anything for the current active tween.
        * If you have not yet called `Tween.to` or `Tween.from` at least once then this method will do nothing, as there are no tweens to set repeatDelay on.
        * If you have child tweens and pass -1 as the index value it sets the repeatDelay across all of them.
        *
        * @method Phaser.Tween#yoyoDelay
        * @param {number} duration - The amount of time in ms that the Tween should wait until it repeats or yoyos once start is called. Set to zero to remove any active yoyoDelay.
        * @param {number} [index=0] - If this tween has more than one child this allows you to target a specific child. If set to -1 it will set the yoyoDelay on all the children.
        * @return {Phaser.Tween} This tween. Useful for method chaining.
        */
        yoyoDelay: function (duration, index) {

            return this.updateTweenData('yoyoDelay', duration, index);

        },

        /**
        * Set easing function this tween will use, i.e. Phaser.Easing.Linear.None.
        * The ease function allows you define the rate of change. You can pass either a function such as Phaser.Easing.Circular.Out or a string such as "Circ".
        * ".easeIn", ".easeOut" and "easeInOut" variants are all supported for all ease types.
        * If you have child tweens and pass -1 as the index value it sets the easing function defined here across all of them.
        *
        * @method Phaser.Tween#easing
        * @param {function|string} ease - The easing function this tween will use, i.e. Phaser.Easing.Linear.None.
        * @param {number} [index=0] - If this tween has more than one child this allows you to target a specific child. If set to -1 it will set the easing function on all children.
        * @return {Phaser.Tween} This tween. Useful for method chaining.
        */
        easing: function (ease, index) {

            if (typeof ease === 'string' && this.manager.easeMap[ease])
            {
                ease = this.manager.easeMap[ease];
            }

            return this.updateTweenData('easingFunction', ease, index);

        },

        /**
        * Sets the interpolation function the tween will use. By default it uses Phaser.Math.linearInterpolation.
        * Also available: Phaser.Math.bezierInterpolation and Phaser.Math.catmullRomInterpolation.
        * The interpolation function is only used if the target properties is an array.
        * If you have child tweens and pass -1 as the index value and it will set the interpolation function across all of them.
        *
        * @method Phaser.Tween#interpolation
        * @param {function} interpolation - The interpolation function to use (Phaser.Math.linearInterpolation by default)
        * @param {object} [context] - The context under which the interpolation function will be run.
        * @param {number} [index=0] - If this tween has more than one child this allows you to target a specific child. If set to -1 it will set the interpolation function on all children.
        * @return {Phaser.Tween} This tween. Useful for method chaining.
        */
        interpolation: function (interpolation, context, index) {

            if (context === undefined) { context = Phaser.Math; }

            this.updateTweenData('interpolationFunction', interpolation, index);

            return this.updateTweenData('interpolationContext', context, index);

        },

        /**
        * Set how many times this tween and all of its children will repeat.
        * A tween (A) with 3 children (B,C,D) with a `repeatAll` value of 2 would play as: ABCDABCD before completing.
        *
        * @method Phaser.Tween#repeatAll
        * @param {number} [total=0] - How many times this tween and all children should repeat before completing. Set to zero to remove an active repeat. Set to -1 to repeat forever.
        * @return {Phaser.Tween} This tween. Useful for method chaining.
        */
        repeatAll: function (total) {

            if (total === undefined) { total = 0; }

            this.repeatCounter = total;

            return this;

        },

        /**
        * This method allows you to chain tweens together. Any tween chained to this tween will have its `Tween.start` method called
        * as soon as this tween completes. If this tween never completes (i.e. repeatAll or loop is set) then the chain will never progress.
        * Note that `Tween.onComplete` will fire when *this* tween completes, not when the whole chain completes.
        * For that you should listen to `onComplete` on the final tween in your chain.
        *
        * If you pass multiple tweens to this method they will be joined into a single long chain.
        * For example if this is Tween A and you pass in B, C and D then B will be chained to A, C will be chained to B and D will be chained to C.
        * Any previously chained tweens that may have been set will be overwritten.
        *
        * @method Phaser.Tween#chain
        * @param {...Phaser.Tween} tweens - One or more tweens that will be chained to this one.
        * @return {Phaser.Tween} This tween. Useful for method chaining.
        */
        chain: function () {

            var i = arguments.length;

            while (i--)
            {
                if (i > 0)
                {
                    arguments[i - 1].chainedTween = arguments[i];
                }
                else
                {
                    this.chainedTween = arguments[i];
                }
            }

            return this;

        },

        /**
        * Enables the looping of this tween. The tween will loop forever, and onComplete will never fire.
        *
        * If `value` is `true` then this is the same as setting `Tween.repeatAll(-1)`.
        * If `value` is `false` it is the same as setting `Tween.repeatAll(0)` and will reset the `repeatCounter` to zero.
        *
        * Usage:
        * game.add.tween(p).to({ x: 700 }, 1000, Phaser.Easing.Linear.None, true)
        * .to({ y: 300 }, 1000, Phaser.Easing.Linear.None)
        * .to({ x: 0 }, 1000, Phaser.Easing.Linear.None)
        * .to({ y: 0 }, 1000, Phaser.Easing.Linear.None)
        * .loop();
        * @method Phaser.Tween#loop
        * @param {boolean} [value=true] - If `true` this tween will loop once it reaches the end. Set to `false` to remove an active loop.
        * @return {Phaser.Tween} This tween. Useful for method chaining.
        */
        loop: function (value) {

            if (value === undefined) { value = true; }

            this.repeatCounter = (value) ? -1 : 0;

            return this;

        },

        /**
        * Sets a callback to be fired each time this tween updates.
        *
        * @method Phaser.Tween#onUpdateCallback
        * @param {function} callback - The callback to invoke each time this tween is updated. Set to `null` to remove an already active callback.
        * @param {object} callbackContext - The context in which to call the onUpdate callback.
        * @return {Phaser.Tween} This tween. Useful for method chaining.
        */
        onUpdateCallback: function (callback, callbackContext) {

            this._onUpdateCallback = callback;
            this._onUpdateCallbackContext = callbackContext;

            return this;

        },

        /**
        * Pauses the tween. Resume playback with Tween.resume.
        *
        * @method Phaser.Tween#pause
        */
        pause: function () {

            this.isPaused = true;

            this._codePaused = true;

            this._pausedTime = this.game.time.time;

        },

        /**
        * This is called by the core Game loop. Do not call it directly, instead use Tween.pause.
        *
        * @private
        * @method Phaser.Tween#_pause
        */
        _pause: function () {

            if (!this._codePaused)
            {
                this.isPaused = true;

                this._pausedTime = this.game.time.time;
            }

        },

        /**
        * Resumes a paused tween.
        *
        * @method Phaser.Tween#resume
        */
        resume: function () {

            if (this.isPaused)
            {
                this.isPaused = false;

                this._codePaused = false;

                for (var i = 0; i < this.timeline.length; i++)
                {
                    if (!this.timeline[i].isRunning)
                    {
                        this.timeline[i].startTime += (this.game.time.time - this._pausedTime);
                    }
                }
            }

        },

        /**
        * This is called by the core Game loop. Do not call it directly, instead use Tween.pause.
        * @method Phaser.Tween#_resume
        * @private
        */
        _resume: function () {

            if (this._codePaused)
            {
                return;
            }
            else
            {
                this.resume();
            }

        },

        /**
        * Core tween update function called by the TweenManager. Does not need to be invoked directly.
        *
        * @method Phaser.Tween#update
        * @param {number} time - A timestamp passed in by the TweenManager.
        * @return {boolean} false if the tween and all child tweens have completed and should be deleted from the manager, otherwise true (still active).
        */
        update: function (time) {

            if (this.pendingDelete || !this.target)
            {
                return false;
            }

            if (this.isPaused)
            {
                return true;
            }

            var status = this.timeline[this.current].update(time);

            if (status === Phaser.TweenData.PENDING)
            {
                return true;
            }
            else if (status === Phaser.TweenData.RUNNING)
            {
                if (!this._hasStarted)
                {
                    this.onStart.dispatch(this.target, this);
                    this._hasStarted = true;
                }

                if (this._onUpdateCallback !== null)
                {
                    this._onUpdateCallback.call(this._onUpdateCallbackContext, this, this.timeline[this.current].value, this.timeline[this.current]);
                }

                //  In case the update callback modifies this tween
                return this.isRunning;
            }
            else if (status === Phaser.TweenData.LOOPED)
            {
                if (this.timeline[this.current].repeatCounter === -1)
                {
                    this.onLoop.dispatch(this.target, this);
                }
                else
                {
                    this.onRepeat.dispatch(this.target, this);
                }

                return true;
            }
            else if (status === Phaser.TweenData.COMPLETE)
            {
                var complete = false;

                //  What now?
                if (this.reverse)
                {
                    this.current--;

                    if (this.current < 0)
                    {
                        this.current = this.timeline.length - 1;
                        complete = true;
                    }
                }
                else
                {
                    this.current++;

                    if (this.current === this.timeline.length)
                    {
                        this.current = 0;
                        complete = true;
                    }
                }

                if (complete)
                {
                    //  We've reached the start or end of the child tweens (depending on Tween.reverse), should we repeat it?
                    if (this.repeatCounter === -1)
                    {
                        this.timeline[this.current].start();
                        this.onLoop.dispatch(this.target, this);
                        return true;
                    }
                    else if (this.repeatCounter > 0)
                    {
                        this.repeatCounter--;

                        this.timeline[this.current].start();
                        this.onRepeat.dispatch(this.target, this);
                        return true;
                    }
                    else
                    {
                        //  No more repeats and no more children, so we're done
                        this.isRunning = false;
                        this.onComplete.dispatch(this.target, this);
                        this._hasStarted = false;

                        if (this.chainedTween)
                        {
                            this.chainedTween.start();
                        }

                        return false;
                    }
                }
                else
                {
                    //  We've still got some children to go
                    this.onChildComplete.dispatch(this.target, this);
                    this.timeline[this.current].start();
                    return true;
                }
            }

        },

        /**
        * This will generate an array populated with the tweened object values from start to end.
        * It works by running the tween simulation at the given frame rate based on the values set-up in Tween.to and Tween.from.
        * It ignores delay and repeat counts and any chained tweens, but does include child tweens.
        * Just one play through of the tween data is returned, including yoyo if set.
        *
        * @method Phaser.Tween#generateData
        * @param {number} [frameRate=60] - The speed in frames per second that the data should be generated at. The higher the value, the larger the array it creates.
        * @param {array} [data] - If given the generated data will be appended to this array, otherwise a new array will be returned.
        * @return {array} An array of tweened values.
        */
        generateData: function (frameRate, data) {

            if (this.game === null || this.target === null)
            {
                return null;
            }

            if (frameRate === undefined) { frameRate = 60; }
            if (data === undefined) { data = []; }

            //  Populate the tween data
            for (var i = 0; i < this.timeline.length; i++)
            {
                //  Build our master property list with the starting values
                for (var property in this.timeline[i].vEnd)
                {
                    this.properties[property] = this.target[property] || 0;

                    if (!Array.isArray(this.properties[property]))
                    {
                        //  Ensures we're using numbers, not strings
                        this.properties[property] *= 1.0;
                    }
                }
            }

            for (var i = 0; i < this.timeline.length; i++)
            {
                this.timeline[i].loadValues();
            }

            for (var i = 0; i < this.timeline.length; i++)
            {
                data = data.concat(this.timeline[i].generateData(frameRate));
            }

            return data;

        }

    };

    /**
    * @name Phaser.Tween#totalDuration
    * @property {Phaser.TweenData} totalDuration - Gets the total duration of this Tween, including all child tweens, in milliseconds.
    */
    Object.defineProperty(Phaser.Tween.prototype, 'totalDuration', {

        get: function () {

            var total = 0;

            for (var i = 0; i < this.timeline.length; i++)
            {
                total += this.timeline[i].duration;
            }

            return total;

        }

    });

    Phaser.Tween.prototype.constructor = Phaser.Tween;