/**
* @author Richard Davey <rich@photonstorm.com>
* @copyright 2014 Photon Storm Ltd.
* @license {@link https://github.com/photonstorm/phaser/blob/master/license.txt|MIT License}
*/
/**
* This is the core internal game clock.
*
* It manages the elapsed time and calculation of elapsed values, used for game object motion and tweens,
* and also handlers the standard Timer pool.
*
* To create a general timed event, use the master {@link Phaser.Timer} accessible through {@link Phaser.Time.events events}.
*
* @class Phaser.Time
* @constructor
* @param {Phaser.Game} game A reference to the currently running game.
*/
Phaser.Time = function (game) {
/**
* @property {Phaser.Game} game - Local reference to game.
* @protected
*/
this.game = game;
/**
* The `Date.now()` value when the time was last updated.
* @property {integer} time
* @protected
*/
this.time = 0;
/**
* The `now` when the previous update occurred.
* @property {number} prevTime
* @protected
*/
this.prevTime = 0;
/**
* An increasing value representing cumulative milliseconds since an undisclosed epoch.
*
* While this value is in milliseconds and can be used to compute time deltas,
* it must must _not_ be used with `Date.now()` as it may not use the same epoch / starting reference.
*
* The source may either be from a high-res source (eg. if RAF is available) or the standard Date.now;
* the value can only be relied upon within a particular game instance.
*
* @property {number} now
* @protected
*/
this.now = 0;
/**
* Elapsed time since the last time update, in milliseconds, based on `now`.
*
* This value _may_ include time that the game is paused/inactive.
*
* _Note:_ This is updated only once per game loop - even if multiple logic update steps are done.
* Use {@link Phaser.Timer#physicsTime physicsTime} as a basis of game/logic calculations instead.
*
* @property {number} elapsed
* @see Phaser.Time.time
* @protected
*/
this.elapsed = 0;
/**
* The time in ms since the last time update, in milliseconds, based on `time`.
*
* This value is corrected for game pauses and will be "about zero" after a game is resumed.
*
* _Note:_ This is updated once per game loop - even if multiple logic update steps are done.
* Use {@link Phaser.Timer#physicsTime physicsTime} as a basis of game/logic calculations instead.
*
* @property {integer} elapsedMS
* @protected
*/
this.elapsedMS = 0;
/**
* The physics update delta, in fractional seconds.
*
* This should be used as an applicable multiplier by all logic update steps (eg. `preUpdate/postUpdate/update`)
* to ensure consistent game timing. Game/logic timing can drift from real-world time if the system
* is unable to consistently maintain the desired FPS.
*
* With fixed-step updates this is normally equivalent to `1.0 / desiredFps`.
*
* @property {number} physicsElapsed
*/
this.physicsElapsed = 0;
/**
* The physics update delta, in milliseconds - equivalent to `physicsElapsed * 1000`.
*
* @property {number} physicsElapsedMS
*/
this.physicsElapsedMS = 0;
/**
* The desired frame rate of the game.
*
* This is used is used to calculate the physic/logic multiplier and how to apply catch-up logic updates.
*
* @property {number} desiredFps
* @default
*/
this.desiredFps = 60;
/**
* The suggested frame rate for your game, based on an averaged real frame rate.
*
* _Note:_ This is not available until after a few frames have passed; use it after a few seconds (eg. after the menus)
*
* @property {number} suggestedFps
* @default
*/
this.suggestedFps = null;
/**
* Scaling factor to make the game move smoothly in slow motion
* - 1.0 = normal speed
* - 2.0 = half speed
* @property {number} slowMotion
* @default
*/
this.slowMotion = 1.0;
/**
* If true then advanced profiling, including the fps rate, fps min/max and msMin/msMax are updated.
* @property {boolean} advancedTiming
* @default
*/
this.advancedTiming = false;
/**
* Advanced timing result: The number of render frames record in the last second.
*
* Only calculated if {@link Phaser.Time#advancedTiming advancedTiming} is enabled.
* @property {integer} frames
* @readonly
*/
this.frames = 0;
/**
* Advanced timing result: Frames per second.
*
* Only calculated if {@link Phaser.Time#advancedTiming advancedTiming} is enabled.
* @property {number} fps
* @readonly
*/
this.fps = 0;
/**
* Advanced timing result: The lowest rate the fps has dropped to.
*
* Only calculated if {@link Phaser.Time#advancedTiming advancedTiming} is enabled.
* This value can be manually reset.
* @property {number} fpsMin
*/
this.fpsMin = 1000;
/**
* Advanced timing result: The highest rate the fps has reached (usually no higher than 60fps).
*
* Only calculated if {@link Phaser.Time#advancedTiming advancedTiming} is enabled.
* This value can be manually reset.
* @property {number} fpsMax
*/
this.fpsMax = 0;
/**
* Advanced timing result: The minimum amount of time the game has taken between consecutive frames.
*
* Only calculated if {@link Phaser.Time#advancedTiming advancedTiming} is enabled.
* This value can be manually reset.
* @property {number} msMin
* @default
*/
this.msMin = 1000;
/**
* Advanced timing result: The maximum amount of time the game has taken between consecutive frames.
*
* Only calculated if {@link Phaser.Time#advancedTiming advancedTiming} is enabled.
* This value can be manually reset.
* @property {number} msMax
*/
this.msMax = 0;
/**
* Records how long the game was last paused, in miliseconds.
* (This is not updated until the game is resumed.)
* @property {number} pauseDuration
*/
this.pauseDuration = 0;
/**
* @property {number} timeToCall - The value that setTimeout needs to work out when to next update
* @protected
*/
this.timeToCall = 0;
/**
* @property {number} timeExpected - The time when the next call is expected when using setTimer to control the update loop
* @protected
*/
this.timeExpected = 0;
/**
* A {@link Phaser.Timer} object bound to the master clock (this Time object) which events can be added to.
* @property {Phaser.Timer} events
*/
this.events = new Phaser.Timer(this.game, false);
/**
* @property {number} _frameCount - count the number of calls to time.update since the last suggestedFps was calculated
* @private
*/
this._frameCount = 0;
/**
* @property {number} _elapsedAcumulator - sum of the elapsed time since the last suggestedFps was calculated
* @private
*/
this._elapsedAccumulator = 0;
/**
* @property {number} _started - The time at which the Game instance started.
* @private
*/
this._started = 0;
/**
* @property {number} _timeLastSecond - The time (in ms) that the last second counter ticked over.
* @private
*/
this._timeLastSecond = 0;
/**
* @property {number} _pauseStarted - The time the game started being paused.
* @private
*/
this._pauseStarted = 0;
/**
* @property {boolean} _justResumed - Internal value used to recover from the game pause state.
* @private
*/
this._justResumed = false;
/**
* @property {Phaser.Timer[]} _timers - Internal store of Phaser.Timer objects.
* @private
*/
this._timers = [];
};
Phaser.Time.prototype = {
/**
* Called automatically by Phaser.Game after boot. Should not be called directly.
*
* @method Phaser.Time#boot
* @protected
*/
boot: function () {
this._started = Date.now();
this.time = Date.now();
this.events.start();
},
/**
* Adds an existing Phaser.Timer object to the Timer pool.
*
* @method Phaser.Time#add
* @param {Phaser.Timer} timer - An existing Phaser.Timer object.
* @return {Phaser.Timer} The given Phaser.Timer object.
*/
add: function (timer) {
this._timers.push(timer);
return timer;
},
/**
* Creates a new stand-alone Phaser.Timer object.
*
* @method Phaser.Time#create
* @param {boolean} [autoDestroy=true] - A Timer that is set to automatically destroy itself will do so after all of its events have been dispatched (assuming no looping events).
* @return {Phaser.Timer} The Timer object that was created.
*/
create: function (autoDestroy) {
if (typeof autoDestroy === 'undefined') { autoDestroy = true; }
var timer = new Phaser.Timer(this.game, autoDestroy);
this._timers.push(timer);
return timer;
},
/**
* Remove all Timer objects, regardless of their state and clears all Timers from the {@link Phaser.Time#events events} timer.
*
* @method Phaser.Time#removeAll
*/
removeAll: function () {
for (var i = 0; i < this._timers.length; i++)
{
this._timers[i].destroy();
}
this._timers = [];
this.events.removeAll();
},
/**
* Updates the game clock and if enabled the advanced timing data. This is called automatically by Phaser.Game.
*
* @method Phaser.Time#update
* @protected
* @param {number} time - The current relative timestamp; see {@link Phaser.Time#now now}.
*/
update: function (time) {
// Set to the old Date.now value
var previousDateNow = this.time;
// this.time always holds Date.now, this.now may hold the RAF high resolution time value if RAF is available (otherwise it also holds Date.now)
this.time = Date.now();
// Adjust accorindlgy.
this.elapsedMS = this.time - previousDateNow;
// 'now' is currently still holding the time of the last call, move it into prevTime
this.prevTime = this.now;
// update 'now' to hold the current time
this.now = time;
// elapsed time between previous call and now
this.elapsed = this.now - this.prevTime;
// time to call this function again in ms in case we're using timers instead of RequestAnimationFrame to update the game
this.timeToCall = Math.floor(Math.max(0, (1000.0 / this.desiredFps) - (this.timeCallExpected - time)));
// time when the next call is expected if using timers
this.timeCallExpected = time + this.timeToCall;
// count the number of time.update calls
this._frameCount++;
this._elapsedAccumulator += this.elapsed;
// occasionally recalculate the suggestedFps based on the accumulated elapsed time
if (this._frameCount >= this.desiredFps * 2)
{
// this formula calculates suggestedFps in multiples of 5 fps
this.suggestedFps = Math.floor(200 / (this._elapsedAccumulator / this._frameCount)) * 5;
this._frameCount = 0;
this._elapsedAccumulator = 0;
}
// Set the physics elapsed time... this will always be 1 / this.desiredFps because we're using fixed time steps in game.update now
this.physicsElapsed = 1 / this.desiredFps;
this.physicsElapsedMS = this.physicsElapsed * 1000;
if (this.advancedTiming)
{
this.msMin = Math.min(this.msMin, this.elapsed);
this.msMax = Math.max(this.msMax, this.elapsed);
this.frames++;
if (this.now > this._timeLastSecond + 1000)
{
this.fps = Math.round((this.frames * 1000) / (this.now - this._timeLastSecond));
this.fpsMin = Math.min(this.fpsMin, this.fps);
this.fpsMax = Math.max(this.fpsMax, this.fps);
this._timeLastSecond = this.now;
this.frames = 0;
}
}
// Paused but still running?
if (!this.game.paused)
{
// Our internal Phaser.Timer
this.events.update(this.time);
// Any game level timers
var i = 0;
var len = this._timers.length;
while (i < len)
{
if (this._timers[i].update(this.time))
{
i++;
}
else
{
// Timer requests to be removed
this._timers.splice(i, 1);
len--;
}
}
}
},
/**
* Called when the game enters a paused state.
*
* @method Phaser.Time#gamePaused
* @private
*/
gamePaused: function () {
this._pauseStarted = Date.now();
this.events.pause();
var i = this._timers.length;
while (i--)
{
this._timers[i]._pause();
}
},
/**
* Called when the game resumes from a paused state.
*
* @method Phaser.Time#gameResumed
* @private
*/
gameResumed: function () {
// Set the parameter which stores Date.now() to make sure it's correct on resume
this.time = Date.now();
this.pauseDuration = this.time - this._pauseStarted;
this.events.resume();
var i = this._timers.length;
while (i--)
{
this._timers[i]._resume();
}
},
/**
* The number of seconds that have elapsed since the game was started.
*
* @method Phaser.Time#totalElapsedSeconds
* @return {number} The number of seconds that have elapsed since the game was started.
*/
totalElapsedSeconds: function() {
return (this.time - this._started) * 0.001;
},
/**
* How long has passed since the given time.
*
* @method Phaser.Time#elapsedSince
* @param {number} since - The time you want to measure against.
* @return {number} The difference between the given time and now.
*/
elapsedSince: function (since) {
return this.time - since;
},
/**
* How long has passed since the given time (in seconds).
*
* @method Phaser.Time#elapsedSecondsSince
* @param {number} since - The time you want to measure (in seconds).
* @return {number} Duration between given time and now (in seconds).
*/
elapsedSecondsSince: function (since) {
return (this.time - since) * 0.001;
},
/**
* Resets the private _started value to now and removes all currently running Timers.
*
* @method Phaser.Time#reset
*/
reset: function () {
this._started = this.now;
this.removeAll();
}
};
Phaser.Time.prototype.constructor = Phaser.Time;
