code: def _draw_tile_layer(self, tile, layer_name, c_filters, colour, t_filters, x, y, bg):
          
          # Don't bother rendering if the tile is not visible
          left = (x + self._screen.width // 4) * 2
          top = y + self._screen.height // 2
          if (left > self._screen.width or left + self._size * 2 < 0 or
                  top > self._screen.height or top + self._size < 0):
              return 0
  
          # Not all layers are available in every tile.
          try:
              _layer = tile[layer_name]
              _extent = float(_layer["extent"])
          except KeyError:
              return 0
  
          for _feature in _layer["features"]:
              try:
                  if c_filters and _feature["properties"]["class"] not in c_filters:
                      continue
                  if (t_filters and _feature["type"] not in t_filters and
                          _feature["properties"]["type"] not in t_filters):
                      continue
                  self._draw_feature(
                      _feature, _extent, colour, bg,
                      (x + self._screen.width // 4) * 2, y + self._screen.height // 2)
              except KeyError:
                  pass
          return 1
docs: Draw the visible geometry in the specified map tile.