static HexagonBoard()
{
randomNumbers = new Dictionary <Player, long[, ]>();
neighborLookup = new HexCoordinate[BOARD_WIDTH, BOARD_WIDTH][];
var blackRandomNumbers = new long[BOARD_WIDTH, BOARD_WIDTH];
var whiteRandomNumbers = new long[BOARD_WIDTH, BOARD_WIDTH];
var random = new Random(1); // always use the same seed for deterministic results
var byteBuffer = new byte[64];
for (var r = -BOARD_RADIUS; r <= BOARD_RADIUS; r++)
{
var q_start = Math.Max(-BOARD_RADIUS - r, -BOARD_RADIUS);
var q_end = Math.Min(BOARD_RADIUS - r, BOARD_RADIUS);
for (var q = q_start; q <= q_end; q++)
{
// Generate random numbers for zobris hashing
var arrayPos = new HexCoordinate(r + BOARD_RADIUS, q + BOARD_RADIUS);
random.NextBytes(byteBuffer);
blackRandomNumbers[arrayPos.R, arrayPos.Q] = Math.Abs(BitConverter.ToInt64(byteBuffer, 0));
random.NextBytes(byteBuffer);
whiteRandomNumbers[arrayPos.R, arrayPos.Q] = Math.Abs(BitConverter.ToInt64(byteBuffer, 0));
// Generate valid neighbors for faster access
var pos = new HexCoordinate(r, q);
neighborLookup[arrayPos.R, arrayPos.Q] = pos.GetNeighborsClockwise().Where(x => x.Distance(new HexCoordinate(0, 0)) <= BOARD_RADIUS).ToArray();
}
}
randomNumbers.Add(Player.Black, blackRandomNumbers);
randomNumbers.Add(Player.White, whiteRandomNumbers);
}