simple-node-backend.js

/**
 * An example of installation of a backend through which nodes of a given type 
 * can drive a canvas of a particular type.
 */
SceneJs.Backend.installNodeBackend(

        new (function() {

            this.canvasType = 'awesome-new-canvas0.1';
            this.nodeType = 'my-node-type';

            var ctx;
            var cfg;

            /** SceneJs.Backend.installNodeBackend calls this method as this node back-end is installed. 
             *
             * The _ctx parameter is a context that is shared within each set of backends for a 
             * supported canvas type.
             *
             * Typically, node backends create resources on the context, such as matrix stacks, shader 
             * script registries etc. 
             *
             * Node backends that share resources on the context will of course need to be installed in 
             * the order of those dependencies.
             */
            this.install = function(_ctx) {
                ctx = _ctx;
            };

            /** SceneJs.Backend.getNodeBackend calls this method just before it returns the node back-end 
             * to the client node that requested it. 
             *
             * The _cfg parameter is the same object provided by the canvas back-end's getConfig method, 
             * which wraps a context on the canvas supported by this node back-end.
             * 
             * This method gives the node backend a chance to do setup operations on the _cfg or on the 
             * canvas context it wraps before the client node starts driving the canvas.
             */ 
            this.configure = function(_cfg) {
                cfg = _cfg;
            };

            /** This is an example of a facade method through which the client node can drive the canvas.
             */  
            this.doSomethingToCanvas = function(someData) {
                cfg.context.doSomething(someData);
            };

            this.doSomethingElseToCanvas = function(someMoreData) {
                cfg.context.doSomethingElse(someMoreData);
            };

        })());