public TileID(TerrainID _terrainID, int _nscode)
 {
     terrainID = _terrainID;
     nscode    = _nscode;
 }
        public static List <TileID> CreateList(TerrainID t0, TerrainID t1, TerrainID t2, TerrainID t3)
        {
            List <TileID> list = new List <TileID>();
            TileID        tt0  = new TileID(t0, 1);
            TileID        tt1  = new TileID(t1, 2);
            TileID        tt2  = new TileID(t2, 4);
            TileID        tt3  = new TileID(t3, 8);
            bool          added;


            list.Add(tt0);

            added = false;

            foreach (var item in list)
            {
                if (item.Add(tt1))
                {
                    added = true;
                }
            }

            if (!added)
            {
                list.Add(tt1);
            }



            added = false;

            foreach (var item in list)
            {
                if (item.Add(tt2))
                {
                    added = true;
                }
            }

            if (!added)
            {
                list.Add(tt2);
            }



            added = false;

            foreach (var item in list)
            {
                if (item.Add(tt3))
                {
                    added = true;
                }
            }

            if (!added)
            {
                list.Add(tt3);
            }

            return(list);
        }