public RenderingSystem(SpriteBatch batch) {
        // gets all entities with a TransofmComponent and TextureComponent
        super(Family.all(TransformComponent.class, TextureComponent.class).get(), new ZComparator());

        //creates out componentMappers
        textureM = ComponentMapper.getFor(TextureComponent.class);
        transformM = ComponentMapper.getFor(TransformComponent.class);

        // create the array for sorting entities
        renderQueue = new Array<Entity>();

        this.batch = batch;  // set our batch to the one supplied in constructor

        // set up the camera to match our screen size
        cam = new OrthographicCamera(FRUSTUM_WIDTH, FRUSTUM_HEIGHT);
        cam.position.set(FRUSTUM_WIDTH / 2f, FRUSTUM_HEIGHT / 2f, 0);
    }

    @Override
    public void update(float deltaTime) {
        super.update(deltaTime);

        // sort the renderQueue based on z index
        renderQueue.sort(comparator);

        // update camera and sprite batch
        cam.update();
        batch.setProjectionMatrix(cam.combined);
        batch.enableBlending();
        batch.begin();

        // loop through each entity in our render queue
        for (Entity entity : renderQueue) {
            TextureComponent tex = textureM.get(entity);
            TransformComponent t = transformM.get(entity);

            if (tex.region == null || t.isHidden) {
                continue;
            }


            float width = tex.region.getRegionWidth();
            float height = tex.region.getRegionHeight();

            float originX = width/2f;
            float originY = height/2f;

            batch.draw(tex.region,
                    t.position.x - originX, t.position.y - originY,
                    originX, originY,
                    width, height,
                    PixelsToMeters(t.scale.x), PixelsToMeters(t.scale.y),
                    t.rotation);
        }

        batch.end();
        renderQueue.clear();
    }