moz-glweb-canvas-wrapper.js

/** An example of a installation of a backend for a canvas.
 */
SceneJs.Backend.installCanvasBackend(new (function() {

    this.canvasType = 'awesome-new-canvas-0.1';

    /** SceneJs.Backend's acquireCanvas method calls this method on each installed 
     *  canvas backend to poll them for a context on the given canvas. As soon as one
     *  is able to provide a context, the canvas and the successful backend become active.
     * 
     *  Then, when a node requests a node backend from SceneJs.Backend getNodeBackend, that
     *  method will attempt to provide a node backend for the canvas.
     *
     *  The context is returned wrapped in an object that may bundle resources 
     *  alongside the context.
     */
     this.getConfig = function(canvas) {
        var cfg = null;
        var context = null;
        if (!canvas) {
            throw 'canvas is undefined';
        }
        try {
            context = canvas.getContext(this.canvasType);
        } catch(e) {
        }
        return context ? {  canvas: canvas,  context: context } : null;
    };

    /** SceneJs.aquireCanvas calls this method to signal this canvas plugin that it 
     * has just acquired a context on a canvas of the type this plugin supports.
     *
     * The cfg parameter is the same object returned by this plugin's getConfig method.
     * In this method, the plugin has a chance to intercept the acquisition and
     * maybe do some pre-acquire operations on the cfg object or the canvas context 
     * it wraps.
     */ 
    this.aquire = function(cfg) {
        var context = cfg.context;
        //...
    };

    /** SceneJs.releaseCanvas calls this method to signal this canvas plugin that it 
     * is about to release a context that was previously acquired on a canvas of 
     * the type this plugin supports.
     * The cfg parameter is the same object returned by this plugin's getConfig method.
     * In this method, the plugin has a chance to intercept the release and
     * maybe do some pre-release operations on the cfg object or the canvas context 
     * it wraps.
     */ 
    this.release = function(cfg) {
        cfg.context.swapBuffers();
    };
})());