class Game_Map
  def create_mask_events
    @mask_event_count = 0
    (0...width).each do |x|
      (0...height).each do |y|
        [2, 1, 0].each do |z|
          tile_id = data[x, y, z]
          if tile_id != nil && @terrain_tags[tile_id] == 7
            ev = RPG::Event.new(x, y)
            ev.id = 1000 + @mask_event_count
            ev.pages[0].graphic.tile_id = tile_id
            ev.pages[0].always_on_top = true
            events[ev.id] = Game_Event.new(map_id, ev)
            @mask_event_count += 1
            break
          end
        end
      end
    end
  end
  alias rb_setup_20170317 setup
  def setup(map_id)
    rb_setup_20170317(map_id)
    create_mask_events
  end
end