/// <summary>
/// Adds a piece to the board, and updates the hash keys if needed
/// </summary>
/// <param name="square">The square for the piece</param>
/// <param name="side">For which side the piece is to be added</param>
/// <param name="pieceType">The type of piece to add</param>
private void AddPiece(Square square, Player side, EPieceType pieceType)
{
Piece piece = (int)pieceType | (side << 3);
Position.AddPiece(piece, square);
State.Key ^= piece.GetZobristPst(square);
if (pieceType == EPieceType.Pawn)
{
State.PawnStructureKey ^= piece.GetZobristPst(square);
}
State.Material.Add(piece);
}
/// <summary>
/// Apply a FEN string board setup to the board structure.
/// </summary>
/// <param name="fenString">The string to set</param>
/// <param name="validate">If true, the fen string is validated, otherwise not</param>
/// <returns>
/// 0 = all ok.
/// -1 = Error in piece file layout parsing
/// -2 = Error in piece rank layout parsing
/// -3 = Unknown piece detected
/// -4 = Error while parsing moving side
/// -5 = Error while parsing castleling
/// -6 = Error while parsing en-passant square
/// -9 = FEN length exceeding maximum
/// </returns>
public FenError SetFen(FenData fen, bool validate = false)
{
if (validate)
{
Fen.Fen.Validate(fen.Fen.ToString());
}
// correctly clear all pieces and invoke possible notification(s)
var bb = Occupied;
while (bb)
{
var square = bb.Lsb();
Position.RemovePiece(square, Position.BoardLayout[square.AsInt()]);
BitBoards.ResetLsb(ref bb);
}
var chunk = fen.Chunk();
if (chunk.IsEmpty)
{
return(new FenError());
}
var f = 1; // file (column)
var r = 8; // rank (row)
Player player;
foreach (var c in chunk)
{
if (char.IsDigit(c))
{
f += c - '0';
if (f > 9)
{
return(new FenError(-1, fen.Index));
}
}
else if (c == '/')
{
if (f != 9)
{
return(new FenError(-2, fen.Index));
}
r--;
f = 1;
}
else
{
var pieceIndex = PieceExtensions.PieceChars.IndexOf(c);
if (pieceIndex == -1)
{
return(new FenError(-3, fen.Index));
}
player = char.IsLower(PieceExtensions.PieceChars[pieceIndex]);
var square = new Square(r - 1, f - 1);
AddPiece(square, player, (EPieceType)pieceIndex);
f++;
}
}
// player
chunk = fen.Chunk();
if (chunk.IsEmpty || chunk.Length != 1)
{
return(new FenError(-3, fen.Index));
}
player = (chunk[0] != 'w').ToInt();
// castleling
chunk = fen.Chunk();
if (!SetupCastleling(chunk))
{
return(new FenError(-5, fen.Index));
}
// en-passant
chunk = fen.Chunk();
if (chunk.Length == 1 || chunk[0] == '-' || !chunk[0].InBetween('a', 'h'))
{
State.EnPassantSquare = ESquare.none;
}
else
{
State.EnPassantSquare = chunk[1].InBetween('3', '6') ? ESquare.none : new Square(chunk[1] - '1', chunk[0] - 'a').Value;
}
// move number
chunk = fen.Chunk();
var moveNum = 0;
var halfMoveNum = 0;
if (!chunk.IsEmpty)
{
chunk.ToIntegral(out halfMoveNum);
// half move number
chunk = fen.Chunk();
chunk.ToIntegral(out moveNum);
if (moveNum > 0)
{
moveNum--;
}
}
PositionIndex = PositionStart = moveNum;
Position.State = _stateList[PositionIndex];
State.ReversibleHalfMoveCount = halfMoveNum;
State.SideToMove = player;
if (player.IsBlack())
{
State.Key ^= Zobrist.GetZobristSide();
State.PawnStructureKey ^= Zobrist.GetZobristSide();
}
State.Key ^= State.CastlelingRights.GetZobristCastleling();
if (State.EnPassantSquare != ESquare.none)
{
State.Key ^= State.EnPassantSquare.File().GetZobristEnPessant();
}
Position.InCheck = Position.IsAttacked(Position.GetPieceSquare(EPieceType.King, player), ~player);
return(0);
}
/// <summary>
/// Apply a FEN string board setup to the board structure.
/// *EXCEPTION FREE FUNCTION*
/// </summary>
/// <param name="fenString">The string to set</param>
/// <param name="validate">If true, the fen string is validated, otherwise not</param>
/// <returns>
/// 0 = all ok.
/// -1 = Error in piece file layout parsing
/// -2 = Error in piece rank layout parsing
/// -3 = Unknown piece detected
/// -4 = Error while parsing moving side
/// -5 = Error while parsing castleling
/// -6 = Error while parsing en-passant square
/// -9 = FEN length exceeding maximum
/// </returns>
public FenError SetFen(string fenString, bool validate = false)
{
// TODO : Replace with stream at some point
// basic validation, catches format errors
if (validate)
{
Fen.Fen.Validate(fenString);
}
foreach (var square in Occupied)
{
Position.RemovePiece(square, Position.BoardLayout[square.AsInt()]);
}
//for (var i = 0; i <= PositionIndex; i++)
// _stateList[i].Clear();
Position.Clear();
var fen = new FenData(fenString);
Player player;
var c = fen.GetAdvance;
var f = 1; // file (column)
var r = 8; // rank (row)
// map pieces to data structure
while (c != 0 && !(f == 9 && r == 1))
{
if (char.IsDigit(c))
{
f += c - '0';
if (f > 9)
{
return(new FenError(-1, fen.Index));
}
c = fen.GetAdvance;
continue;
}
if (c == '/')
{
if (f != 9)
{
return(new FenError(-2, fen.Index));
}
r--;
f = 1;
c = fen.GetAdvance;
continue;
}
var pieceIndex = PieceExtensions.PieceChars.IndexOf(c);
if (pieceIndex == -1)
{
return(new FenError(-3, fen.Index));
}
player = char.IsLower(PieceExtensions.PieceChars[pieceIndex]);
var square = new Square(r - 1, f - 1);
AddPiece(square, player, (EPieceType)pieceIndex);
c = fen.GetAdvance;
f++;
}
if (!Fen.Fen.IsDelimiter(c))
{
return(new FenError(-4, fen.Index));
}
c = fen.GetAdvance;
player = c == 'w' ? 0 : 1;
if (player == -1)
{
return(new FenError(-4, fen.Index));
}
if (!Fen.Fen.IsDelimiter(fen.GetAdvance))
{
return(new FenError(-5, fen.Index));
}
if (!SetupCastleling(fen))
{
return(new FenError(-5, fen.Index));
}
if (!Fen.Fen.IsDelimiter(fen.GetAdvance))
{
return(new FenError(-6, fen.Index));
}
State.EnPassantSquare = fen.GetEpSquare();
// temporary.. the whole method should be using this, but this will do for now.
var moveCounters = fen.Fen.Split(new[] { ' ' }, StringSplitOptions.RemoveEmptyEntries);
var first = moveCounters[moveCounters.Length - 2];
var second = moveCounters[moveCounters.Length - 1];
second.ToIntegral(out int number);
if (number > 0)
{
number -= 1;
}
PositionIndex = PositionStart = number;
first.ToIntegral(out number);
State = Position.State = _stateList[PositionIndex];
State.ReversibleHalfMoveCount = number;
State.SideToMove = player;
if (player.IsBlack())
{
var zobristSide = Zobrist.GetZobristSide();
State.Key ^= zobristSide;
State.PawnStructureKey ^= zobristSide;
}
State.Key ^= Zobrist.GetZobristCastleling(State.CastlelingRights);
if (State.EnPassantSquare != ESquare.none)
{
State.Key ^= Zobrist.GetZobristEnPessant(State.EnPassantSquare.File().AsInt());
}
Position.InCheck = Position.IsAttacked(Position.GetPieceSquare(EPieceType.King, State.SideToMove), ~State.SideToMove);
//State.GenerateMoves(true);
return(0);
}