public RenderSystem(EntityManager entityManager, DrawOrder[] drawOrders, GameViewPort viewPort) {
		super(entityManager);

		this.drawOrders = drawOrders;
		this.viewPort = viewPort;

		visibleSprites = new HashMap<DrawOrder, List<RenderSystem.VisibleSprite>>();

		// Iterate our draw layers and create maps for them
		for (DrawOrder drawOrder : this.drawOrders) {
			visibleSprites.put(drawOrder, new ArrayList<RenderSystem.VisibleSprite>());
		}
	}