Tile connection

    public class ConnectionInfo
    {
        public static readonly Dictionary<uint, ConnectionInfo> Infos = new Dictionary<uint, ConnectionInfo>();
        public static readonly Dictionary<Tuple<ConnectionType, int>, ConnectionInfo> Infos2 = new Dictionary<Tuple<ConnectionType, int>, ConnectionInfo>();
        static ConnectionInfo()
        {
            Build(0x02020202, ConnectionType.Dot);          //1111
            Build(0x01020202, ConnectionType.ShortLine);    //0111
            Build(0x01010202, ConnectionType.L);            //0011
            Build(0x01020102, ConnectionType.Line);         //0101
            Build(0x01010201, ConnectionType.T);            //0010
            Build(0x01010101, ConnectionType.Cross);        //0000
        }

        static void Build(uint bits, ConnectionType type)
        {
            for (int i = 0; i < 4; i++)
                if (!Infos.ContainsKey(bits))
                {
                    Infos[bits] = Infos2[Tuple.Create(type, i * 90)] = new ConnectionInfo(bits, type, i * 90);
                    bits = (bits >> 8) | (bits << 24);
                }
        }


        public ConnectionType Type { get; private set; }
        public int Rotation { get; private set; }
        public uint Bits { get; private set; }

        private ConnectionInfo(uint bits, ConnectionType type, int rotation)
        {
            Bits = bits;
            Type = type;
            Rotation = rotation;
        }
    }