LIBLOOPER

Looper implementation for use in conjonction with the HJS-MESSAGE messaging API. This is the browser version of the looper.

Looper classes: Looper, MessageLooper.

Installation

Node:

npm install liblooper --save

Usage

The Looper is used to run messages synchronized with animation frames. requestAnimationFrame by default do not have a message loop associated with them; to create one, call Looper.createLoopHandler in the script that is to run the loop.

Most interaction with a message loop is through the MessageLooper that is a subclass class of MessageHandler.

Your can create any number of MessageLooper's but only one loop is running in the entire application. But it's recommanded to use only one global instance of Looper.

Create a MessageLooper

import {Looper} from 'liblooper';

// this create an instanceof MessageHandler that run in the loop
let ML = Looper.createLoopHandler({
    
    fps: 40 /* An optional FPS is accepted (60 is default) */,
    
    quitAllowed: false /* An optional quit flag is accepted (true is default) */,
    
    handleMessage(msg) {
        // enter frame here
        // handle messages interactions
        return true;
    },
    
    handleRender(interpolation) {
        // render frame here
        // handle drawing on canvas for ex.
    },
    
    handleExit(fps, panic=false) {
        // exit frame here
        // clean code for example
    }

});

Pause/Resume/Exit from a loop

import {Looper} from 'liblooper';

const START_CMD = 0xffddcc;
const PAUSE_CMD = 0xffddcd;
const RESUME_CMD = 0xffddce;
const EXIT_CMD = 0xffddde;

// this create an instance of MessageLooper that run in the loop
// All parameters accepted by a MessageHandler are accepted by MessageLooper's
let ML = Looper.createLoopHandler({
    
    handleMessage(msg) {
        let what = msg.what;
        switch(what) {
            case START_MSG:
                this.sendEmptyMessage(PAUSE_CMD);
                break;
            case PAUSE_CMD:
                this.pause();
                // now messages are sending only with the message queue
                // handle render and handle exit are no more called
                this.sendEmptyMessage(RESUME_CMD);
                break;
            case RESUME_CMD:
                this.resume();
                // now messages are sending throw the loop
                // handle render and handle exit are called
                this.sendEmptyMessage(EXIT_CMD);
                break;
            case EXIT_CMD:
                this.exit();
                break;
        }
        return true;
    },
    
    handleRender(interpolation) {
        console.log(interpolation);
    },
    
    handleExit(fps, panic=false) {
        console.log(fps);
    }

});

ML.sendEmptyMessage(START_MSG);

Contacts

Aime - [email protected]

Distributed under the MIT license. See LICENSE for more information.