(function() { window.Game = function(canvas, players, index) { this._canvas = canvas; this._ctx = canvas.getContext("2d"); this._players = players; this._player = players[index]; this._sock = sock; this._keys = []; //Keep track of which keys are pressed and which aren't canvas.addEventListener("keydown", function(evt) { this._keys[evt.keyCode] = true; }.bind(this)); canvas.addEventListener("keyup", function(evt) { this._keys[evt.keyCode] = false; }.bind(this)); } Game.prototype.start = function() { console.log("starting game"); } Game.prototype.stop = function() { console.log("Stopping game"); } })();