public PositionLongHash CalculateHash(Position.Position position)
{
var result = new PositionLongHash();
result = result.CalculateXor(
CalculatePiecesHash(
position.Board.GetPieces(Player.Black),
Player.Black));
result = result.CalculateXor(
CalculatePiecesHash(
position.Board.GetPieces(Player.White),
Player.White));
result = result.CalculateXor(playerToMoveHashesTable[(int)position.PlayerToMove]);
result = result.CalculateXor(
GetEnPassantCaptureColumnHash(position.EnPassantCaptureColumn));
result = result.CalculateXor(
GetCastlingAvailabilityHash(
position.GetCastlingAvailability(Player.Black),
Player.Black));
result = result.CalculateXor(
GetCastlingAvailabilityHash(
position.GetCastlingAvailability(Player.White),
Player.White));
return(result);
}
private static PositionLongHash[] GenerateHashesTable(Random random, int tableSize)
{
var hashesTable = new PositionLongHash[tableSize];
for (int i = 0; i < hashesTable.Length; ++i)
{
hashesTable[i] = GenerateLongHash(random);
}
return(hashesTable);
}
private PositionLongHash CalculatePiecesHash(
IEnumerable <PieceOnBoard> pieces,
Player player)
{
var result = new PositionLongHash();
foreach (var pieceOnBoard in pieces)
{
var pieceHash = GetPieceHash(player, pieceOnBoard.piece, pieceOnBoard.square);
result = result.CalculateXor(pieceHash);
}
return(result);
}
private PositionLongHash GetCastlingAvailabilityHash(
CastlingAvailability castlingAvailability,
Player player)
{
var result = new PositionLongHash();
if (castlingAvailability.CanCastleShort)
{
result = result.CalculateXor(shortCastlingHashesTable[(int)player]);
}
if (castlingAvailability.CanCastleLong)
{
result = result.CalculateXor(longCastlingHashesTable[(int)player]);
}
return(result);
}