Share Scene logic client & server side

scene.js

var isClient = (typeof global === "undefined") ? true : false;

(function(arkanoid) {
  var arkanoid = arkanoid || {};

  if (!isClient){
    arkanoid.Ball = require('./Ball.js');
    arkanoid.Padd = require('./Padd.js');
  }

  var Scene = function() { 
    this.ball = new arkanoid.Ball();
    this.padd = new arkanoid.Padd();
  };

  Scene.prototype.update = function() {
    this.ball.update();
    this.padd.update();
  };

  Scene.prototype.draw = function() {
    this.ball.draw();
    this.padd.draw();
  };

  arkanoid.Scene = Scene;

})(isClient ? window.arkanoid : exports);