public FarseerPhysicsGame()
        {
            Window.Title = "Farseer Physics Engine Samples Framework";
            _graphics = new GraphicsDeviceManager(this);

            _graphics.SynchronizeWithVerticalRetrace = false;

            TargetElapsedTime = new TimeSpan(0, 0, 0, 0, 10);
            IsFixedTimeStep = true;

            #if !XBOX
            //windowed
            _graphics.PreferredBackBufferWidth = 1024;
            _graphics.PreferredBackBufferHeight = 768;
            _graphics.IsFullScreen = false;

            //fullscreen
            //_graphics.PreferredBackBufferWidth = GraphicsAdapter.DefaultAdapter.CurrentDisplayMode.Width;
            //_graphics.PreferredBackBufferHeight = GraphicsAdapter.DefaultAdapter.CurrentDisplayMode.Height;
            //_graphics.IsFullScreen = true;

            IsMouseVisible = true;
            #else
            _graphics.PreferredBackBufferWidth = GraphicsAdapter.DefaultAdapter.CurrentDisplayMode.Width;
            _graphics.PreferredBackBufferHeight = GraphicsAdapter.DefaultAdapter.CurrentDisplayMode.Height;
            _graphics.IsFullScreen = true;
            #endif

            //Set window defaults. Parent game can override in constructor
            Window.AllowUserResizing = false;
            Window.ClientSizeChanged += Window_ClientSizeChanged;

            //new-up components and add to Game.Components
            ScreenManager = new ScreenManager(this);
            Components.Add(ScreenManager);

            FrameRateCounter frameRateCounter = new FrameRateCounter(ScreenManager);
            frameRateCounter.DrawOrder = 101;
            Components.Add(frameRateCounter);

            //ScreenManager.MainMenuScreen.AddMainMenuItem(Demo1Screen.GetTitle(), new Demo1Screen());
            //ScreenManager.MainMenuScreen.AddMainMenuItem("Exit", null, true);

            //ScreenManager.GoToMainMenu();

            ScreenManager.AddScreen(new Demo1Screen());
        }