/
Board.cs
1565 lines (1436 loc) · 61.9 KB
/
Board.cs
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//#define HashDebug
//#define PawnHashDebug
//#define MoveToIsEmptyDebug
using System;
using System.Collections.Generic;
using System.Text;
namespace LousyChess
{
public struct SquareContentInfo
{
public int pieceType; // king, queen, rook, bishop, knight, pawn : 0..5
public int pieceColor; // White, Black : 0..1
public int pieceIndex; // index in PiecePos
}
public struct BoardState
{
// the state of the board. Used in MakeMove and UnMakeMove.
public bool canCastleKingSide_White;
public bool canCastleQueenSide_White;
public bool canCastleKingSide_Black;
public bool canCastleQueenSide_Black;
public bool hasCastled_White;
public bool hasCastled_Black;
public int enPassantPosition;
public int fiftyMoveNr;
public int capturedPieceType;
public int capturedPiecePosition;
public int repeatedPosition_SearchOffset;
public ulong hashValue;
public ulong bwPawnsHashValue;
}
public class Board
{
// pointers to other classes
public MagicMoves magicMoves;
public TranspositionTable transpositionTable;
public MoveGenerator moveGenerator;
public Evaluator evaluator;
public BitBoard bitboard;
#region board state data
// for all 2-position arrays : index 0=white, index 1=black
// bitboards
public ulong[] pieces = new ulong[Const.NrColors];
public ulong allPiecesBB;
// the bitboards of each PieceType of each color
public ulong[,] pieceBB = new ulong[Const.NrColors, Const.NrPieceTypes];
// these hold the positions (0..63) of the pieces
public int[, ,] PiecePos = new int[Const.NrColors, Const.NrPieceTypes, Const.MaxNrPiecesPerType]; // always filled from low to high
// these hold the number of each pieceType
public int[,] NrPieces = new int[Const.NrColors, Const.NrPieceTypes];
// these hold the total nr of pieces (pawns + the rest) of each color
public int[] TotalNrPieces = new int[Const.NrColors];
// describes the contents of each square
public SquareContentInfo[] SquareContents = new SquareContentInfo[Const.NrSquares];
// state of the game info
public int colorToMove; // 0=white, 1=black
public int enemyColor;
public bool[] canCastleKingSide = new bool[Const.NrColors];
public bool[] canCastleQueenSide = new bool[Const.NrColors];
public bool[] hasCastled = new bool[Const.NrColors];
public int enPassantPosition; // If the last move was not a 2-step pawn move : -1
// If it was, this value holds the position where it can be captured.
public int halfMoveNr; // starts at 0, and is incremented AFTER each move
int fiftyMoveNr; // incremented after each move. Reset on pawn-move or capture.
int capturedPiecePosition;
int capturedPieceType;
int repeatedPosition_SearchOffset; // the move-nr from which a 3x repeated position should be searched.
// These stores the state of the board for deeper ply-nrs
int maxNrStoredBoardStates = 100; // will be increased if necessary
int nrStoredBoardStates = 0;
BoardState[] storedBoardStates;
public ulong HashValue = 0;
public ulong bwPawnsHashValue = 0;
// The static material score (queen = 900, etc).
// For both black and white holds : The larger the better.
public int[] StaticMaterialScore = new int[Const.NrColors];
// The static positional score (calculated from Evaluation.PieceSquareValues).
// For both black and white holds : The larger the better.
public int[] StaticPositionalScore = new int[Const.NrColors];
#endregion
// Just a 1 at the position bit, a 0 on all other bits
private ulong[] Identity = new ulong[64];
// The hashvalue of the board after _each_ move is made, also those in the AB_Search
int nrHashValuesInHistory;
ulong[] HashValueHistory; // HashValueHistory[0] = Initial state
public Board(bool isInitialBoard)
{
if (isInitialBoard)
{
CreateIdentity();
//
storedBoardStates = new BoardState[maxNrStoredBoardStates];
HashValueHistory = new ulong[100];
}
}
#region initialization
private void CreateIdentity()
{
ulong q = 1;
for (int i = 0; i < 64; i++)
{
Identity[i] = q;
q <<= 1;
}
}
#endregion
#region Clone Board & Compare
public Board Clone()
{
// use the empty creator : otherwise to many things are set.
Board clone = new Board(false);
clone.magicMoves = magicMoves;
clone.transpositionTable = transpositionTable;
clone.evaluator = evaluator;
clone.ClearBoard();
clone.moveGenerator = moveGenerator;
//
clone.pieces = new ulong[pieces.Length];
for (int i = 0; i < pieces.Length; i++)
clone.pieces[i] = pieces[i];
clone.allPiecesBB = allPiecesBB;
for (int i = 0; i < Const.NrColors; i++)
for (int j = 0; j < Const.NrPieceTypes; j++)
clone.pieceBB[i, j] = pieceBB[i, j];
// PiecePos
for (int i = 0; i < Const.NrColors; i++)
for (int j = 0; j < Const.NrPieceTypes; j++)
for (int k = 0; k < Const.MaxNrPiecesPerType; k++)
clone.PiecePos[i, j, k] = PiecePos[i, j, k];
// nrPieces
for (int i = 0; i < Const.NrColors; i++)
{
clone.TotalNrPieces[i] = TotalNrPieces[i];
for (int j = 0; j < Const.NrPieceTypes; j++)
clone.NrPieces[i, j] = NrPieces[i, j];
}
// SquareContents
for (int i = 0; i < Const.NrSquares; i++)
clone.SquareContents[i] = SquareContents[i];
//
// state of the game info
clone.colorToMove = colorToMove;
clone.enemyColor = enemyColor;
for (int i = 0; i < Const.NrColors; i++)
{
clone.canCastleKingSide[i] = canCastleKingSide[i];
clone.canCastleQueenSide[i] = canCastleQueenSide[i];
clone.hasCastled[i] = hasCastled[i];
}
// ..
clone.enPassantPosition = enPassantPosition;
//
clone.halfMoveNr = halfMoveNr;
clone.fiftyMoveNr = fiftyMoveNr;
clone.capturedPiecePosition = capturedPiecePosition;
clone.capturedPieceType = capturedPieceType;
clone.repeatedPosition_SearchOffset = repeatedPosition_SearchOffset;
//
clone.maxNrStoredBoardStates = maxNrStoredBoardStates;
clone.nrStoredBoardStates = nrStoredBoardStates;
clone.storedBoardStates = new BoardState[storedBoardStates.Length];
for (int i = 0; i < storedBoardStates.Length; i++)
clone.storedBoardStates[i] = storedBoardStates[i];
//
clone.HashValue = HashValue;
clone.bwPawnsHashValue = bwPawnsHashValue;
for (int i = 0; i < Const.NrColors; i++)
{
clone.StaticMaterialScore[i] = StaticMaterialScore[i];
clone.StaticPositionalScore[i] = StaticPositionalScore[i];
}
//
clone.nrHashValuesInHistory = nrHashValuesInHistory;
clone.HashValueHistory = new ulong[HashValueHistory.Length];
for (int i = 0; i < HashValueHistory.Length; i++)
clone.HashValueHistory[i] = HashValueHistory[i];
//
return clone;
}
public void LoadFrom(Board clone)
{
// load the entire contents from a clone
magicMoves = clone.magicMoves;
transpositionTable = clone.transpositionTable;
evaluator = clone.evaluator;
ClearBoard();
moveGenerator = clone.moveGenerator;
//
pieces = new ulong[clone.pieces.Length];
for (int i = 0; i < clone.pieces.Length; i++)
pieces[i] = clone.pieces[i];
allPiecesBB = clone.allPiecesBB;
for (int i = 0; i < Const.NrColors; i++)
for (int j = 0; j < Const.NrPieceTypes; j++)
pieceBB[i, j] = clone.pieceBB[i, j];
// PiecePos
for (int i = 0; i < Const.NrColors; i++)
for (int j = 0; j < Const.NrPieceTypes; j++)
for (int k = 0; k < Const.MaxNrPiecesPerType; k++)
PiecePos[i, j, k] = clone.PiecePos[i, j, k];
//..
// nrPieces
for (int i = 0; i < Const.NrColors; i++)
{
TotalNrPieces[i] = clone.TotalNrPieces[i];
for (int j = 0; j < Const.NrPieceTypes; j++)
NrPieces[i, j] = clone.NrPieces[i, j];
}
// SquareContents
for (int i = 0; i < Const.NrSquares; i++)
SquareContents[i] = clone.SquareContents[i];
//
// state of the game info
colorToMove = clone.colorToMove;
enemyColor = clone.enemyColor;
for (int i = 0; i < Const.NrColors; i++)
{
canCastleKingSide[i] = clone.canCastleKingSide[i];
canCastleQueenSide[i] = clone.canCastleQueenSide[i];
hasCastled[i] = clone.hasCastled[i];
}
// ..
enPassantPosition = clone.enPassantPosition;
//
halfMoveNr = clone.halfMoveNr;
fiftyMoveNr = clone.fiftyMoveNr;
capturedPiecePosition = clone.capturedPiecePosition;
capturedPieceType = clone.capturedPieceType;
repeatedPosition_SearchOffset = clone.repeatedPosition_SearchOffset;
//
maxNrStoredBoardStates = clone.maxNrStoredBoardStates;
nrStoredBoardStates = clone.nrStoredBoardStates;
storedBoardStates = new BoardState[clone.storedBoardStates.Length];
for (int i = 0; i < clone.storedBoardStates.Length; i++)
storedBoardStates[i] = clone.storedBoardStates[i];
//
HashValue = clone.HashValue;
bwPawnsHashValue = clone.bwPawnsHashValue;
for (int i = 0; i < Const.NrColors; i++)
{
StaticMaterialScore[i] = clone.StaticMaterialScore[i];
StaticPositionalScore[i] = clone.StaticPositionalScore[i];
}
//
nrHashValuesInHistory = clone.nrHashValuesInHistory;
HashValueHistory = new ulong[clone.HashValueHistory.Length];
for (int i = 0; i < clone.HashValueHistory.Length; i++)
HashValueHistory[i] = clone.HashValueHistory[i];
}
public bool Compare(Board clone)
{
for (int i = 0; i < pieces.Length; i++)
if (clone.pieces[i] != pieces[i])
return false;
if (clone.allPiecesBB != allPiecesBB)
return false;
for (int i = 0; i < Const.NrColors; i++)
for (int j = 0; j < Const.NrPieceTypes; j++)
if (clone.pieceBB[i, j] != pieceBB[i, j])
return false;
// PiecePos
int nrPiecePosErrors = 0;
for (int i = 0; i < Const.NrColors; i++)
for (int j = 0; j < Const.NrPieceTypes; j++)
for (int k = 0; k < Const.MaxNrPiecesPerType; k++)
if (clone.PiecePos[i, j, k] != PiecePos[i, j, k])
nrPiecePosErrors++;
if (nrPiecePosErrors > 0)
return false;
// nrPieces
for (int i = 0; i < Const.NrColors; i++)
{
if (clone.TotalNrPieces[i] != TotalNrPieces[i])
return false;
for (int j = 0; j < Const.NrPieceTypes; j++)
if (clone.NrPieces[i, j] != NrPieces[i, j])
return false;
}
// SquareContents
for (int i = 0; i < Const.NrSquares; i++)
{
if (clone.SquareContents[i].pieceColor != SquareContents[i].pieceColor)
return false;
if (clone.SquareContents[i].pieceIndex != SquareContents[i].pieceIndex)
return false;
if (clone.SquareContents[i].pieceType != SquareContents[i].pieceType)
return false;
}
//
// state of the game info
if (clone.colorToMove != colorToMove)
return false;
if (clone.enemyColor != enemyColor)
return false;
for (int i = 0; i < Const.NrColors; i++)
{
if (clone.canCastleKingSide[i] != canCastleKingSide[i])
return false;
if (clone.canCastleQueenSide[i] != canCastleQueenSide[i])
return false;
if (clone.hasCastled[i] != hasCastled[i])
return false;
}
if (clone.enPassantPosition != enPassantPosition)
return false;
//
if (clone.halfMoveNr != halfMoveNr)
return false;
if (clone.fiftyMoveNr != fiftyMoveNr)
return false;
if (clone.capturedPiecePosition != capturedPiecePosition)
return false;
if (clone.capturedPieceType != capturedPieceType)
return false;
if (clone.repeatedPosition_SearchOffset != repeatedPosition_SearchOffset)
return false;
//
if (clone.maxNrStoredBoardStates != maxNrStoredBoardStates)
return false;
if (clone.nrStoredBoardStates != nrStoredBoardStates)
return false;
for (int i = 0; i < storedBoardStates.Length; i++)
{
if (!clone.storedBoardStates[i].Equals(storedBoardStates[i]) )
return false;
}
//
if (clone.HashValue != HashValue)
return false;
if (clone.bwPawnsHashValue != bwPawnsHashValue)
return false;
for (int i = 0; i < Const.NrColors; i++)
{
if (clone.StaticMaterialScore[i] != StaticMaterialScore[i])
return false;
if (clone.StaticPositionalScore[i] != StaticPositionalScore[i])
return false;
}
//
if (clone.nrHashValuesInHistory != nrHashValuesInHistory)
return false;
for (int i = 0; i < HashValueHistory.Length; i++)
if (clone.HashValueHistory[i] != HashValueHistory[i])
return false;
//
return true;
}
#endregion
public void ToggleMoveColor()
{
if (colorToMove == Const.White)
{
colorToMove = Const.Black;
enemyColor = Const.White;
}
else
{
colorToMove = Const.White;
enemyColor = Const.Black;
}
HashValue ^= transpositionTable.ChangeMoveColor;
}
public ulong CalcHashValue()
{
ulong result = 0;
// the pieces
for (int i = 0; i < 64; i++)
{
int pieceType = SquareContents[i].pieceType;
int color = SquareContents[i].pieceColor;
if (pieceType != Const.EmptyID)
result ^= transpositionTable.SquareHashValue[i, pieceType, color];
}
if (colorToMove == Const.Black)
result ^= transpositionTable.ChangeMoveColor;
// en-passant
if (enPassantPosition != Const.InvalidID)
result ^= transpositionTable.EPSquareValue[enPassantPosition];
for (int i = 0; i < Const.NrColors; i++)
{
if (canCastleQueenSide[i])
result ^= transpositionTable.CanCastleQSHashValue[i];
if (canCastleKingSide[i])
result ^= transpositionTable.CanCastleKSHashValue[i];
}
return result;
}
public ulong CalcBWPawnsHashValue()
{
ulong result = 0;
for (int i = 0; i < Const.NrColors; i++)
{
for (int j=0; j<NrPieces[i,Const.PawnID]; j++)
result ^= transpositionTable.SquareHashValue[PiecePos[i,Const.PawnID,j], Const.PawnID, i];
}
return result;
}
#region Setup board : empty & from EPD
public void ClearBoard()
{
colorToMove = Const.White;
enemyColor = Const.Black;
// the bitboards
pieces[Const.White] = 0;
pieces[Const.Black] = 0;
allPiecesBB = 0;
for (int i = 0; i < Const.NrColors; i++)
for (int j = 0; j < Const.NrPieceTypes; j++)
pieceBB[i, j] = 0;
// en passant
enPassantPosition = Const.InvalidID;
// the pieces
for (int colorNr = 0; colorNr < Const.NrColors; colorNr++)
{
TotalNrPieces[colorNr] = 0;
for (int pieceType = 0; pieceType < Const.NrPieceTypes; pieceType++)
{
NrPieces[colorNr, pieceType] = 0;
for (int index = 0; index < Const.MaxNrPiecesPerType; index++)
PiecePos[colorNr, pieceType, index] = Const.InvalidID;
}
// Castle info
canCastleKingSide[colorNr] = false;
canCastleQueenSide[colorNr] = false;
hasCastled[colorNr] = false;
// the static scores
StaticMaterialScore[colorNr] = 0;
StaticPositionalScore[colorNr] = 0;
//
}
// the squares
for (int i = 0; i < Const.NrSquares; i++)
{
SquareContents[i].pieceType = Const.EmptyID;
SquareContents[i].pieceColor = Const.InvalidID;
SquareContents[i].pieceIndex = Const.InvalidID;
}
canCastleQueenSide[Const.White] = false;
canCastleKingSide[Const.White] = false;
canCastleQueenSide[Const.Black] = false;
canCastleKingSide[Const.Black] = false;
// hash
HashValue = 0;
bwPawnsHashValue = 0;
// history
nrHashValuesInHistory = 0;
// miscillaneous
nrStoredBoardStates = 0;
repeatedPosition_SearchOffset = 0;
}
private void FEN_To_Board(string[] fenStrings)
{
// NB : starts from rank 8 !!, so use flip, to go from normal square-nr to flipped square nr
int[] flip = {
56, 57, 58, 59, 60, 61, 62, 63,
48, 49, 50, 51, 52, 53, 54, 55,
40, 41, 42, 43, 44, 45, 46, 47,
32, 33, 34, 35, 36, 37, 38, 39,
24, 25, 26, 27, 28, 29, 30, 31,
16, 17, 18, 19, 20, 21, 22, 23,
8, 9, 10, 11, 12, 13, 14, 15,
0, 1, 2, 3, 4, 5, 6, 7 };
if (fenStrings.Length < 4)
throw new ArgumentException("Not enough FEN strings");
//
ClearBoard();
//
// **** The positions ****
string boardString = fenStrings[0];
int squareNr = 0;
int n = 0;
while (n<boardString.Length)
{
char c = boardString[n];
if (char.IsDigit(c))
squareNr += (int)(c - '0'); // advance position
else if (c == '/')
{ // simply skip '/'
}
else if (char.IsLetter(c))
{
int color = char.IsUpper(c) ? Const.White : Const.Black;
switch (Char.ToUpper(c))
{
case 'P': AddNewPieceToBoard(color, Const.PawnID, flip[squareNr]); break;
case 'N': AddNewPieceToBoard(color, Const.KnightID, flip[squareNr]); break;
case 'B': AddNewPieceToBoard(color, Const.BishopID, flip[squareNr]); break;
case 'R': AddNewPieceToBoard(color, Const.RookID, flip[squareNr]); break;
case 'Q': AddNewPieceToBoard(color, Const.QueenID, flip[squareNr]); break;
case 'K': AddNewPieceToBoard(color, Const.KingID, flip[squareNr]); break;
default:
throw new ArgumentException("FEN_to_Board : invalid piece char");
}
squareNr++;
}
else
throw new ArgumentException("FEN_to_Board : invalid char");
n++;
}
if (squareNr != 64)
throw new ArgumentException("FEN_to_Board : not all squares are assigned");
//
// **** Side to move ****
string colorString = fenStrings[1];
if (colorString.Length != 1)
throw new ArgumentException("FEN_to_Board : 'b' or 'w' expected");
if (colorString[0] == 'w')
{
colorToMove = Const.White;
enemyColor = Const.Black;
}
else if (colorString[0] == 'b')
{
colorToMove = Const.Black;
enemyColor = Const.White;
}
else
throw new ArgumentException("FEN_to_Board : 'b' or 'w' expected");
//
// **** Castling ****
string castlingString = fenStrings[Const.NrColors];
canCastleQueenSide[Const.White] = false;
canCastleKingSide[Const.White] = false;
canCastleQueenSide[Const.Black] = false;
canCastleKingSide[Const.Black] = false;
n = 0;
while (n < castlingString.Length)
{
switch (castlingString[n])
{
case '-': break;
case 'q': canCastleQueenSide[Const.Black] = true; break;
case 'k': canCastleKingSide[Const.Black] = true; break;
case 'Q': canCastleQueenSide[Const.White] = true; break;
case 'K': canCastleKingSide[Const.White] = true; break;
}
n++;
}
//
// **** en-passant position ****
string epString = fenStrings[3];
if (epString.Length == 1 && epString[0] == '-')
enPassantPosition = Const.InvalidID;
else
{
if (epString.Length != 2)
throw new ArgumentException("FEN_to_Board : wrong ep-string length");
if (!EPD.IsFileChar(epString[0]))
throw new ArgumentException("FEN_to_Board : 'a'-'h' expected");
if (!EPD.IsRankChar(epString[1]))
throw new ArgumentException("FEN_to_Board : '1'-'8' expected");
enPassantPosition = (int)(epString[0] - 'a') + 8 * (int)(epString[1] - '1');
}
//
if (fenStrings.Length < 6)
{
// 50-move rule && full move nr were ommitted. Use defaults
fiftyMoveNr = 0;
halfMoveNr = 0;
}
else
{
if (!int.TryParse(fenStrings[4], out fiftyMoveNr))
throw new ArgumentException("Invalid Fifty-Move nr");
int fullMoveNr;
if (!int.TryParse(fenStrings[5], out fullMoveNr))
throw new ArgumentException("Invalid Full-Move nr");
if (fullMoveNr < 1)
throw new ArgumentException("Invalid Full-Move nr ( <1 ) ");
halfMoveNr = (fullMoveNr - 1) * 2;
}
if (colorToMove == Const.Black)
halfMoveNr++;
//
// initialize hashvalues
HashValue = CalcHashValue();
// bwPawnsHashValue is already been done by AddNewPieceToBoard
#if PawnHashDebug
if (bwPawnsHashValue != CalcBWPawnsHashValue())
throw new ApplicationException("Invalid PawnHashValue");
#endif
// all done. Now also store the current state of the board. This also stores the HashValues.
nrStoredBoardStates = 0;
StoreBoardState();
// history
HashValueHistory[0] = HashValue;
nrHashValuesInHistory++;
}
public void FEN_to_Board(string fenString)
{
// epd = fen + extensions , like 'bm' etc
string[] fenStrings;
string[] restStrings;
EPD.SplitEPD_fen_rest(fenString, out fenStrings, out restStrings);
// setup the board
FEN_To_Board(fenStrings);
}
#endregion
#region SAN & LAN string <-> Move
public string MoveToLANString(Move move)
{
// e.g. e2e4 e1g1 (KS castle), e7e8q (promotion)
string s = EPD.PositionToFileString(move.fromPosition) + EPD.PositionToFileString(move.toPosition);
if (move.moveType >= Const.SpecialMoveID)
switch (move.moveType)
{
case Const.PawnPromoteQueenID:
case Const.PawnPromoteRookID:
case Const.PawnPromoteBishopID:
case Const.PawnPromoteKnightID:
s += EPD.PromotionPieceToString(move.moveType).ToLower();
break;
}
return s;
}
public string MoveToSANString(Move move)
{
int fromPosition = move.fromPosition;
int toPosition = move.toPosition;
// first generate all (pseudo-legal) moves :
Move[] moves = moveGenerator.GenerateMoves(null);
int nrMoves = moveGenerator.nrGeneratedMoves;
// Check the list to see if the move is present
int moveNr = -1;
for (int i=0; i<nrMoves; i++)
if (moves[i] == move)
{
moveNr = i;
break;
}
if (moveNr == -1)
return "???";
// maybe it's a special move
if (move.moveType >= Const.SpecialMoveID)
{
// these are never ambiguous
switch (move.moveType)
{
case Const.CastleQSID: return "O-O-O";
case Const.CastleKSID: return "O-O";
case Const.EnPassantCaptureID:
return EPD.PositionToFileString(fromPosition) + "x" +EPD.PositionToString(toPosition);
case Const.PawnPromoteQueenID:
case Const.PawnPromoteRookID:
case Const.PawnPromoteBishopID:
case Const.PawnPromoteKnightID:
string s = EPD.PositionToFileString(fromPosition);
if (move.captureInfo == Const.NoCaptureID)
s += EPD.PositionToRankString(toPosition);
else
{
s += "x" + EPD.PositionToString(toPosition);
}
return s + "=" + EPD.PromotionPieceToString(move.moveType);
case Const.Pawn2StepID:
return EPD.PositionToString(toPosition);
default:
throw new ArgumentException("Invalid Special MoveType");
}
}
// maybe it's a pawn move :
if (move.moveType == Const.PawnID)
{
// is never ambiguous
if (move.captureInfo == Const.NoCaptureID)
return EPD.PositionToString(toPosition);
else
return EPD.PositionToFileString(fromPosition) + "x" + EPD.PositionToString(toPosition);
}
// It's a major piece move.
string ss = EPD.PieceTypeToString(move.moveType);
// check whetter multiple moves of the same type end on the same square
int nrAmbiguousMoves = 0;
Move ambiguousMove = Move.NoMove();
for (int i = 0; i < nrMoves; i++)
{
if (i == moveNr)
continue;
if (move.moveType == moves[i].moveType && toPosition == moves[i].toPosition)
{
nrAmbiguousMoves++;
if (nrAmbiguousMoves > 1)
break; // more then 1, always specify both file and rank
// only need to store 1
ambiguousMove = moves[i];
}
}
if (nrAmbiguousMoves > 0)
{
// add either a FileChar, a RankChar or both
if (nrAmbiguousMoves == 1)
{
// different files ?
if (ambiguousMove.fromPosition %8 != move.fromPosition % 8)
ss += EPD.PositionToFileString(move.fromPosition);
else
// no, so differnent ranks
ss += EPD.PositionToRankString(move.fromPosition);
}
else
// more then 1 ambiguous move. Use both file and rank
ss += EPD.PositionToString(move.fromPosition);
}
if (move.captureInfo != Const.NoCaptureID)
ss += "x";
return ss + EPD.PositionToString(toPosition);
}
private Move FindLANMoveOnBoard(string s)
{
// something like e2e4, e1g1 (KS castle), e7e8q (promotion)
// first generate all (pseudo-legal) moves :
int fromPos = EPD.StringToPosition(s.Substring(0, 2));
int toPos = EPD.StringToPosition(s.Substring(2, 2));
int promotionType = -1;
if (s.Length == 5)
{
// it contains the promotion piece
promotionType = EPD.CharToPromotionMoveType(char.ToUpper(s[4]));
}
Move[] moves = moveGenerator.GenerateMoves(null);
int nrMoves = moveGenerator.nrGeneratedMoves;
for (int i = 0; i < nrMoves; i++)
{
if (moves[i].fromPosition == fromPos && moves[i].toPosition == toPos)
{
if (promotionType == -1)
return moves[i]; // it's not a promotion
else if (moves[i].moveType == promotionType)
return moves[i];
}
}
// nothing found
return Move.NoMove();
}
/// <summary>
/// Generate all possible moves & compare them to the SAN string. Return the move if found.
/// </summary>
/// <param name="s">The SAN string.</param>
/// <returns>The generated move which correspondents to the SAN-string, or NoMove if not found.</returns>
private Move FindSANMoveOnBoard(string s)
{
// first generate all (pseudo-legal) moves :
Move[] moves = moveGenerator.GenerateMoves(null);
int nrMoves = moveGenerator.nrGeneratedMoves;
// a3 Nb2 Bxc7 axb4 O-O O-O-O h8=Q . Can end on +, ! etc
int nrChars = s.Length;
// First do the castlings
if (s == "O-O" || s == "0-0")
{
// king side castle
for (int i = 0; i < nrMoves; i++)
if (moves[i].moveType == Const.CastleKSID)
return moves[i];
return Move.NoMove();
}
if (s == "O-O-O" || s == "0-0-0")
{
// queen side castle
for (int i = 0; i < nrMoves; i++)
if (moves[i].moveType == Const.CastleQSID)
return moves[i];
return Move.NoMove();
}
// Test for non-capturing pawn moves : a3 , a8=Q , a8Q : these all start with a1
if (nrChars >= 2 && EPD.IsFileChar(s[0]) && EPD.IsRankChar(s[1]))
{
int toPos = EPD.StringToPosition(s.Substring(0, 2));
// maybe it's a promotion
char promotionChar = ' ';
if (nrChars >= 3 && EPD.IsPieceChar(s[2]))
promotionChar = s[2];
else if (nrChars >= 4 && EPD.IsPieceChar(s[3]))
promotionChar = s[3];
if (promotionChar != ' ')
{
int moveType = Const.InvalidID;
switch (promotionChar)
{
case 'Q': moveType = Const.PawnPromoteQueenID; break;
case 'R': moveType = Const.PawnPromoteRookID; break;
case 'B': moveType = Const.PawnPromoteBishopID; break;
case 'N': moveType = Const.PawnPromoteKnightID; break;
}
for (int i = 0; i < nrMoves; i++)
if (moves[i].moveType == moveType
&& moves[i].toPosition == toPos
&& moves[i].captureInfo == Const.NoCaptureID
)
return moves[i];
// nothing found :
return Move.NoMove();
}
// it is not a promotion, but a normal move
for (int i = 0; i < nrMoves; i++)
if ((moves[i].moveType == Const.PawnID || moves[i].moveType == Const.Pawn2StepID)
&& moves[i].toPosition == toPos
&& moves[i].captureInfo == Const.NoCaptureID
)
return moves[i];
// nothing found :
return Move.NoMove();
}
// Test for a capturing pawn moves : axb7 , axb8Q , axb8=Q : these start with a FileChar & 'x'
if (EPD.IsFileChar(s[0]))
{
if (nrChars < 4 || s[1] != 'x')
return Move.NoMove();
int toPos = EPD.StringToPosition(s.Substring(2, 2));
int fromFileNr = EPD.CharToFile(s[0]);
// maybe it's a capturing promotion
char promotionChar = ' ';
if (nrChars >= 5 && EPD.IsPieceChar(s[4]))
promotionChar = s[4];
else if (nrChars >= 6 && EPD.IsPieceChar(s[5]))
promotionChar = s[5];
if (promotionChar != ' ')
{
int moveType = EPD.CharToPromotionMoveType(promotionChar);
for (int i = 0; i < nrMoves; i++)
if (moves[i].moveType == moveType
&& moves[i].fromPosition % 8 == fromFileNr
&& moves[i].toPosition == toPos
&& moves[i].captureInfo != Const.NoCaptureID
)
return moves[i];
// nothing found :
return Move.NoMove();
}
// it is not a promotion, but a normal capture
for (int i = 0; i < nrMoves; i++)
if ((moves[i].moveType == Const.PawnID || moves[i].moveType == Const.EnPassantCaptureID)
&& moves[i].fromPosition % 8 == fromFileNr
&& moves[i].toPosition == toPos
&& moves[i].captureInfo != Const.NoCaptureID
)
return moves[i];
// nothing found :
return Move.NoMove();
}
// So, handled all the pawn moves, now the Piece moves
// Ne4 , Ngf3 , N5e4 , Ng5f3 , Bxe6 , Bgxe6 , B1xe6 , Be2xe3
int moveType2 = EPD.CharToPieceType(s[0]);
// normal moves can be treated just as capturing moves
bool isCapture = s.Contains("x");
if (isCapture)
{
s = s.Replace("x", "");
nrChars = s.Length;
}
// now left with : Ne4 , Ngf3 , N5e4 , Ng5f3
int fromRankNr2 = -1;
int fromFileNr2 = -1;
// First handle a few special cases where the FromFile and/or FromRank is specified
if (nrChars >= 4 && EPD.IsRankChar(s[1]))
{
// N5e4 : has FromRank
fromRankNr2 = EPD.CharToRank(s[1]) * 8;
s = s.Remove(1, 1); // remove the fromRankChar
nrChars = s.Length;
}
// now left with Ne4 , Ngf3 , Ng5f3
if (nrChars >= 4 && EPD.IsFileChar(s[2]))
{
// Ngf3 : has FromFile
fromFileNr2 = EPD.CharToFile(s[1]);
s = s.Remove(1, 1); // remove the fromFileChar
nrChars = s.Length;
}
// now left with Ne4 , Ng5f3
if (nrChars >= 5 && EPD.IsFileChar(s[3]) && EPD.IsRankChar(s[4]))
{
// has both FromFile and FromRank
fromFileNr2 = EPD.CharToFile(s[1]);
fromRankNr2 = EPD.CharToRank(s[2]) * 8;
s = s.Remove(1, 2); // remove the fromFileChar * fromRankChar
nrChars = s.Length;
}
// now left with Ne4
int toPos2 = EPD.StringToPosition(s.Substring(1,2));
// now loop over all the moves
for (int i = 0; i < nrMoves; i++)
if (moves[i].moveType == moveType2
&& moves[i].toPosition == toPos2
&& (fromFileNr2 < 0 || moves[i].fromPosition % 8 == fromFileNr2)
&& (fromRankNr2 < 0 || moves[i].fromPosition / 8 == fromRankNr2)
&& (isCapture == (moves[i].captureInfo != Const.NoCaptureID) )
)
return moves[i];
// nothing found :
return Move.NoMove();
}
public Move FindMoveOnBoard(string s)
{
Move move;
// moveString is either a SAN or a e2e4 type string;
if (EPD.StringIsLANMove(s))
move = FindLANMoveOnBoard(s);
else if (EPD.StringIsSanMove(s))
move = FindSANMoveOnBoard(s);
else
return Move.NoMove();
return move;
}
#endregion
#region Add, remove, move piece
public void AddNewPieceToBoard(int color, int pieceTypeNr, int position)
{
if (SquareContents[position].pieceType != Const.EmptyID)
throw new ArgumentException("Square is not empty");
int newIndex = NrPieces[color, pieceTypeNr];