📄 Timer.js¶
📊 Analysis Summary¶
| Metric | Count |
|---|---|
| 🔧 Functions | 10 |
| 🧱 Classes | 1 |
📚 Table of Contents¶
🛠️ File Location:¶
📂 src/core/Timer.js
Functions¶
Timer.connect(document: Document): void¶
JSDoc:
/**
* Connect the timer to the given document.Calling this method is not mandatory to
* use the timer but enables the usage of the Page Visibility API to avoid large time
* delta values.
*
* @param {Document} document - The document.
*/
Parameters:
documentDocument
Returns: void
Calls:
handleVisibilityChange.binddocument.addEventListener
Internal Comments:
Code
connect( document ) {
this._document = document;
// use Page Visibility API to avoid large time delta values
if ( document.hidden !== undefined ) {
this._pageVisibilityHandler = handleVisibilityChange.bind( this );
document.addEventListener( 'visibilitychange', this._pageVisibilityHandler, false );
}
}
Timer.disconnect(): void¶
JSDoc:
Returns: void
Calls:
this._document.removeEventListener
Code
Timer.getDelta(): number¶
JSDoc:
Returns: number
Timer.getElapsed(): number¶
JSDoc:
Returns: number
Timer.getTimescale(): number¶
JSDoc:
Returns: number
Timer.setTimescale(timescale: number): Timer¶
JSDoc:
/**
* Sets the given timescale which scale the time delta computation
* in `update()`.
*
* @param {number} timescale - The timescale to set.
* @return {Timer} A reference to this timer.
*/
Parameters:
timescalenumber
Returns: Timer
Timer.reset(): Timer¶
JSDoc:
/**
* Resets the time computation for the current simulation step.
*
* @return {Timer} A reference to this timer.
*/
Returns: Timer
Calls:
performance.now
Timer.dispose(): void¶
JSDoc:
/**
* Can be used to free all internal resources. Usually called when
* the timer instance isn't required anymore.
*/
Returns: void
Calls:
this.disconnect
Timer.update(timestamp: number): Timer¶
JSDoc:
/**
* Updates the internal state of the timer. This method should be called
* once per simulation step and before you perform queries against the timer
* (e.g. via `getDelta()`).
*
* @param {number} timestamp - The current time in milliseconds. Can be obtained
* from the `requestAnimationFrame` callback argument. If not provided, the current
* time will be determined with `performance.now`.
* @return {Timer} A reference to this timer.
*/
Parameters:
timestampnumber
Returns: Timer
Calls:
performance.now
Code
update( timestamp ) {
if ( this._pageVisibilityHandler !== null && this._document.hidden === true ) {
this._delta = 0;
} else {
this._previousTime = this._currentTime;
this._currentTime = ( timestamp !== undefined ? timestamp : performance.now() ) - this._startTime;
this._delta = ( this._currentTime - this._previousTime ) * this._timescale;
this._elapsed += this._delta; // _elapsed is the accumulation of all previous deltas
}
return this;
}
handleVisibilityChange(): void¶
Returns: void
Calls:
this.reset
Classes¶
Timer¶
Class Code
class Timer {
/**
* Constructs a new timer.
*/
constructor() {
this._previousTime = 0;
this._currentTime = 0;
this._startTime = performance.now();
this._delta = 0;
this._elapsed = 0;
this._timescale = 1;
this._document = null;
this._pageVisibilityHandler = null;
}
/**
* Connect the timer to the given document.Calling this method is not mandatory to
* use the timer but enables the usage of the Page Visibility API to avoid large time
* delta values.
*
* @param {Document} document - The document.
*/
connect( document ) {
this._document = document;
// use Page Visibility API to avoid large time delta values
if ( document.hidden !== undefined ) {
this._pageVisibilityHandler = handleVisibilityChange.bind( this );
document.addEventListener( 'visibilitychange', this._pageVisibilityHandler, false );
}
}
/**
* Disconnects the timer from the DOM and also disables the usage of the Page Visibility API.
*/
disconnect() {
if ( this._pageVisibilityHandler !== null ) {
this._document.removeEventListener( 'visibilitychange', this._pageVisibilityHandler );
this._pageVisibilityHandler = null;
}
this._document = null;
}
/**
* Returns the time delta in seconds.
*
* @return {number} The time delta in second.
*/
getDelta() {
return this._delta / 1000;
}
/**
* Returns the elapsed time in seconds.
*
* @return {number} The elapsed time in second.
*/
getElapsed() {
return this._elapsed / 1000;
}
/**
* Returns the timescale.
*
* @return {number} The timescale.
*/
getTimescale() {
return this._timescale;
}
/**
* Sets the given timescale which scale the time delta computation
* in `update()`.
*
* @param {number} timescale - The timescale to set.
* @return {Timer} A reference to this timer.
*/
setTimescale( timescale ) {
this._timescale = timescale;
return this;
}
/**
* Resets the time computation for the current simulation step.
*
* @return {Timer} A reference to this timer.
*/
reset() {
this._currentTime = performance.now() - this._startTime;
return this;
}
/**
* Can be used to free all internal resources. Usually called when
* the timer instance isn't required anymore.
*/
dispose() {
this.disconnect();
}
/**
* Updates the internal state of the timer. This method should be called
* once per simulation step and before you perform queries against the timer
* (e.g. via `getDelta()`).
*
* @param {number} timestamp - The current time in milliseconds. Can be obtained
* from the `requestAnimationFrame` callback argument. If not provided, the current
* time will be determined with `performance.now`.
* @return {Timer} A reference to this timer.
*/
update( timestamp ) {
if ( this._pageVisibilityHandler !== null && this._document.hidden === true ) {
this._delta = 0;
} else {
this._previousTime = this._currentTime;
this._currentTime = ( timestamp !== undefined ? timestamp : performance.now() ) - this._startTime;
this._delta = ( this._currentTime - this._previousTime ) * this._timescale;
this._elapsed += this._delta; // _elapsed is the accumulation of all previous deltas
}
return this;
}
}
Methods¶
connect(document: Document): void¶
Code
connect( document ) {
this._document = document;
// use Page Visibility API to avoid large time delta values
if ( document.hidden !== undefined ) {
this._pageVisibilityHandler = handleVisibilityChange.bind( this );
document.addEventListener( 'visibilitychange', this._pageVisibilityHandler, false );
}
}
disconnect(): void¶
Code
getDelta(): number¶
getElapsed(): number¶
getTimescale(): number¶
setTimescale(timescale: number): Timer¶
reset(): Timer¶
dispose(): void¶
update(timestamp: number): Timer¶
Code
update( timestamp ) {
if ( this._pageVisibilityHandler !== null && this._document.hidden === true ) {
this._delta = 0;
} else {
this._previousTime = this._currentTime;
this._currentTime = ( timestamp !== undefined ? timestamp : performance.now() ) - this._startTime;
this._delta = ( this._currentTime - this._previousTime ) * this._timescale;
this._elapsed += this._delta; // _elapsed is the accumulation of all previous deltas
}
return this;
}