yy-loop

Simple and configurable game/main loop

features

• emits events (using eventemitter3)
• run every frame or after an interval
• control how many times each function runs
• loop pauses when app loses focus
• uses requestAnimationFrame()

rationale

This is a replacement for YY-Update. I use this in all my games, and as a base class for my other libraries, including pixi-ease and pixi-viewport.

installation

npm i yy-loop

simple example

const Loop = require('yy-loop')

const loop = new Loop()

// add a function to the loop that logs the elapsed time
loop.add((elapsed) => console.log(elapsed))

// add a function to the loop that runs ever second for 5 times
const entry = loop.add((elapsed) => console.log(elapsed), 1000, 5)

// run each time entry is called
entry.on('each', () => console.log('It has been one second.'))

// run after entry is complete
entry.on('done', () => console.log('completed'))

live example

https://davidfig.github.io/loop/

API

src/loop.js

    /**
     * basic loop support
     * @param {object} [options]
     * @param {number} [options.maxFrameTime=1000/60] maximum time in milliseconds for a frame
     * @param {object} [options.pauseOnBlur] pause loop when app loses focus, start it when app regains focus
     *
     * @event each(elapsed, Loop)
     * @event start(Loop)
     * @event stop(Loop)
     */
    constructor(options)

    /**
     * start requestAnimationFrame() loop
     * @return {Loop} this
     */
    start()

    /**
     * stop loop
     * @return {Loop} this
     */
    stop()

    /**
     * loop through updates; can be called manually each frame, or called automatically as part of start()
     * @param {number} elapsed time since last call (will be clamped to this.maxFrameTime)
     */
    update(elapsed)

    /**
     * adds a callback to the loop
     * @deprecated use add() instead
     * @param {function} callback
     * @param {number} [time=0] in milliseconds to call this update (0=every frame)
     * @param {number} [count=0] number of times to run this update (0=infinite)
     * @return {object} entry - used to remove or change the parameters of the update
     */
    interval(callback, time, count)

    /**
     * adds a callback to the loop
     * @param {function} callback
     * @param {number} [time=0] in milliseconds to call this update (0=every frame)
     * @param {number} [count=0] number of times to run this update (0=infinite)
     * @return {object} entry - used to remove or change the parameters of the update
     */
    add(callback, time, count)

    /**
     * adds a one-time callback to the loop
     * @param {function} callback
     * @param {number} time in milliseconds to call this update
     * @return {object} entry - used to remove or change the parameters of the update
     */
    timeout(callback, time)

    /**
     * remove a callback from the loop
     * @param {object} entry - returned by add()
     */
    remove(entry)

    /**
     * removes all callbacks from the loop
     */
    removeAll()

    /**
     * @type {number} count of all animations
     */
    get count()

    /**
     * @type {number} count of running animations
     */
    get countRunning()

src/entry.js

/** Entry class for Loop */
class Entry extends Events
{
    /**
     * create an entry in the update loop
     * used by Loop
     * @param {function} callback
     * @param {number} [time=0] in milliseconds to call this update
     * @param {number} [count] number of times to run this update (undefined=infinite)
     */
    constructor(callback, time, count)

    /**
     * update checks time and runs the callback
     * @param {number} elapsed
     * @return {boolean} whether entry is complete and may be removed from list
     */
    update(elapsed)

    /**
     * @type {boolean} pause this entry
     */
    set pause(value)

License

MIT License
(c) 2017 YOPEY YOPEY LLC by David Figatner