class interface DRAWABLE_POLYGON

creation
   make
      --  Create.


feature(s) from DRAWABLE_POLYLINE
   --  Position

   empty: BOOLEAN
      --  Is the polyline empty (no points)?


   reset
      --  Reset the point list representing the polyline.

      ensure
         done: empty

   add_point (pt: POINT)
      --  Add a new point at the end of the polyline.

      require
         valid_point: pt /= Void
      ensure
         ok: not empty

feature(s) from DRAWABLE_POLYGON
   --  Drawing mode

   reset_filling_mode
      --  Set default filling mode (fill everything inside the 
      --  polygon).

      ensure
         done: alternate_fill = false

feature(s) from DRAWABLE_POLYGON
   --  Drawing mode

   set_filling_mode_winding
      --  Set default filling mode (fill everything inside the 
      --  polygon).

      ensure
         done: alternate_fill = false

   set_filling_mode_alternate
      --  Set alternate filling mode (fill area between odd-numbered and 
      --  even-numbered polygon sides on each scan line).

      ensure
         done: alternate_fill = true

invariant
   valid_position: line /= Void;

end of DRAWABLE_POLYGON