public void update(float delta)
    {
        if(player != null && !player.isDeleted())
        {
            int x = (int)transform_player.x;
            int y = (int)transform_player.y;
            if(xo + screen_width_2 <= x && x <= xo + w - screen_width_2 )
            {
                camera.position.x = transform_player.x;
            }
            if(yo + screen_height_4 <= y && y <= yo + h - screen_height_4)
            {
                camera.position.y = transform_player.y;
            }
        }
    }