/// <summary>
        /// Allows the game to run logic.
        /// </summary>
        protected override void Update(GameTime gameTime)
        {
            HandleInput();

            if (NextButtonPressed())
            {
                currentEffect++;

                if (currentEffect > DemoEffect.Normalmap)
                {
                    currentEffect = 0;
                }
            }

            base.Update(gameTime);
        }
		/// <summary>
		/// Allows the game to run logic.
		/// </summary>
		protected override void Update (GameTime gameTime)
		{
			HandleInput ();

			if (NextButtonPressed ()) {
				currentEffect++;

				if (currentEffect > DemoEffect.Normalmap)
					currentEffect = 0;
			}

			base.Update (gameTime);
		}