/*
* Create an ASCII representation of a position
*/
public static String asciiBoard(Position position)
{
StringBuilder boardRepresentation = new StringBuilder(400);
String newLine = Environment.NewLine;
boardRepresentation.Append(" +----+----+----+----+----+----+----+----+");
boardRepresentation.Append(newLine);
for (int rank = 7; rank >= 0; rank--)
{
boardRepresentation.Append(" |");
for (int file = 0; file < 8; file++)
{
boardRepresentation.Append(" ");
PieceType piece = position.getPiece(Position.getSquare(file, rank));
if (piece == PieceType.Empty)
{
Boolean isDark = Position.darkSquare(file, rank);
boardRepresentation.Append(isDark ? ".. |" : " |");
}
else
{
//A black piece has prefaced with a *
boardRepresentation.Append(((int)piece < 6) ? ' ' : '*');
String pieceName = "" + piece;
boardRepresentation.Append(pieceName);
boardRepresentation.Append(" |");
}
}
boardRepresentation.Append(newLine);
boardRepresentation.Append(" +----+----+----+----+----+----+----+----+");
boardRepresentation.Append(newLine);
}
return boardRepresentation.ToString();
}
/*
* Returns true if a move results in a caputre for a given
* position
*/
public static Boolean isMoveCapture(Move move, Position position)
{
if (position.getPiece(move.destination) == PieceType.Empty)
{
//Deal with En Passant capture
PieceType piece = position.getPiece(move.origin);
if ((piece == (position.whiteMove ? PieceType.P : PieceType.p)) && (move.destination == position.getEpSquare()))
{
return true;
}
else
{
return false;
}
}
else
{
return true;
}
}
/*
* Converts a move object into a UCI move string (long algebraic
* notation), a move list can be supplied to search through.
*/
public static String moveObjectToString(Move move, Position position, ArrayList moves)
{
if ((move == null) || move.Equals(new Move(0, 0, 0)))
{
return "--";
}
StringBuilder moveString = new StringBuilder();
int whiteKingOrigin = Position.getSquare(4, 0);
int blackKingOrigin = Position.getSquare(4, 7);
if ((move.origin == whiteKingOrigin) && (position.getPiece(whiteKingOrigin) == PieceType.K))
{
//Check white castle
if (move.destination == Position.getSquare(6, 0))
{
moveString.Append("O-O");
}
else if (move.destination == Position.getSquare(2, 0))
{
moveString.Append("O-O-O");
}
}
else if ((move.origin == blackKingOrigin) && (position.getPiece(blackKingOrigin) == PieceType.k))
{
//Check black castle
if (move.destination == Position.getSquare(6, 7))
{
moveString.Append("O-O");
}
else if (move.destination == Position.getSquare(2, 7))
{
moveString.Append("O-O-O");
}
}
if (moveString.Length == 0)
{
PieceType piece = position.getPiece(move.origin);
moveString.Append("" + piece);
int originFile = Position.getRank(move.origin);
int originRank = Position.getFile(move.origin);
int destinationFile = Position.getRank(move.destination);
int destinationRank = Position.getFile(move.destination);
//Long Algebraic Notation-----
moveString.Append((char)(originFile + 'a'));
moveString.Append((char)(originRank + '1'));
moveString.Append(isMoveCapture(move, position) ? 'x' : '-');
//----------------------------
moveString.Append((char)(destinationFile + 'a'));
moveString.Append((char)(destinationRank + '1'));
if (move.promoteTo != PieceType.Empty)
{
moveString.Append("" + piece);
}
}
UnMakeInfo unMake = new UnMakeInfo();
position.makeMove(move, unMake);
Boolean inCheck = MoveGenerator.inCheck(position);
if (inCheck)
{
ArrayList nextMoves = MoveGenerator.mgInstance.legalMoves(position);
if (nextMoves.Count == 0)
{
moveString.Append('#');
}
else
{
moveString.Append('+');
}
}
position.unMakeMove(move, unMake);
return moveString.ToString();
}
/*
* Converts a UCI move string (long algebraic notation into
* a move object, a list of moves can be supplied to search
* through.
*/
public static Move moveStringToObject(String moveString, Position position, ArrayList moves)
{
if (moveString.Equals("--"))
{
return new Move(0, 0, 0);
}
moveString = moveString.Replace("=", "");
moveString = moveString.Replace("\\+", "");
moveString = moveString.Replace("#", "");
Boolean whiteToMove = position.whiteMove;
MoveComposition moveComp = new MoveComposition();
Boolean capture = false;
if (moveString.Equals("O-O") || moveString.Equals("0-0") || moveString.Equals("o-o"))
{
moveComp.piece = whiteToMove ? PieceType.K : PieceType.k;
moveComp.originFile = 4;
moveComp.destinationFile = 6;
moveComp.originRank = moveComp.destinationRank = whiteToMove ? 0 : 7;
moveComp.promotionPiece = PieceType.Empty;
}
else if (moveString.Equals("O-O-O") || moveString.Equals("0-0-0") || moveString.Equals("o-o-o"))
{
moveComp.piece = whiteToMove ? PieceType.K : PieceType.k;
moveComp.originFile = 4;
moveComp.destinationFile = 2;
moveComp.originRank = moveComp.destinationRank = whiteToMove ? 0 : 7;
moveComp.promotionPiece = PieceType.Empty;
}
else
{
Boolean attackToSquare = false;
for (int i = 0; i < moveString.Length; i++)
{
char c = moveString[i];
if (i == 0)
{
PieceType piece = charToPieceType(c);
if (piece != PieceType.Empty)
{
moveComp.piece = piece;
continue;
}
}
int tempFile = c - 'a';
if ((tempFile >= 0) && (tempFile < 8))
{
if (attackToSquare || (moveComp.originFile >= 0))
{
moveComp.destinationFile = tempFile;
}
else
{
moveComp.originFile = tempFile;
}
}
int tempRank = c - '1';
if ((tempRank >= 0) && (tempFile < 8))
{
if (attackToSquare || (moveComp.originRank >= 0))
{
moveComp.destinationRank = tempRank;
}
else
{
moveComp.originRank = tempRank;
}
}
if ((c == 'x') || (c == '-'))
{
attackToSquare = true;
if (c == 'x')
{
capture = true;
}
}
if (i == moveString.Length - 1)
{
PieceType promotionPiece = charToPieceType(c);
if (promotionPiece != PieceType.Empty)
{
moveComp.promotionPiece = promotionPiece;
}
}
}
if ((moveComp.originFile >= 0) && (moveComp.destinationFile < 0))
{
moveComp.destinationFile = moveComp.originFile;
moveComp.originFile = -1;
}
if ((moveComp.originRank >= 0) && (moveComp.destinationRank < 0))
{
moveComp.destinationRank = moveComp.originRank;
moveComp.originFile = -1;
}
if (moveComp.piece == PieceType.Empty)
{
Boolean haveAll = (moveComp.originFile >= 0) && (moveComp.destinationFile >= 0) &&
(moveComp.originRank >= 0) && (moveComp.destinationRank >= 0);
if (!haveAll)
{
moveComp.piece = whiteToMove ? PieceType.P : PieceType.p;
}
}
}
if (moves == null)
{
moves = MoveGenerator.mgInstance.legalMoves(position);
}
ArrayList matches = new ArrayList(2);
foreach (Move listMove in moves)
{
PieceType piece = position.getPiece(listMove.origin);
Boolean match = true;
if ((moveComp.piece >= 0) && (moveComp.piece != piece))
{
match = false;
}
if ((moveComp.originFile >= 0) && (moveComp.originFile != Position.getFile(listMove.origin)))
{
match = false;
}
if ((moveComp.originRank >= 0) && (moveComp.originRank != Position.getRank(listMove.origin)))
{
match = false;
}
if ((moveComp.destinationFile >= 0) && (moveComp.destinationFile != Position.getFile(listMove.destination)))
{
match = false;
}
if ((moveComp.destinationRank >= 0) && (moveComp.destinationRank != Position.getRank(listMove.destination)))
{
match = false;
}
if ((moveComp.promotionPiece >= 0) && (moveComp.promotionPiece != listMove.promoteTo))
{
match = false;
}
if (match)
{
matches.Add(listMove);
}
}
int numMatches = matches.Count;
if (numMatches == 0)
{
return null;
}
else if (numMatches == 1)
{
return (Move)matches[0];
}
if (!capture)
{
return null;
}
Move move = null;
foreach (Move listMove in matches)
{
PieceType capturedPiece = position.getPiece(listMove.destination);
if (capturedPiece != PieceType.Empty)
{
if (move == null)
{
move = listMove;
}
else
{
return null;
}
}
}
return move;
}
/*
* Parse a FEN string and return a position object
*/
public static Position convertFENToPosition(String fen)
{
Position position = new Position();
String[] terms = fen.Split(' ');
if (terms.Length < 2)
{
System.Console.WriteLine("Too few terms");
}
for (int i = 0; i < terms.Length; i++)
{
terms[i] = terms[i].Trim();
}
//Piece placement
int rank = 7;
int file = 0;
for (int i = 0; i < terms[0].Length; i++)
{
char c = (char)terms[0].ToCharArray().GetValue(i);
switch (c)
{
case '1': file += 1; break;
case '2': file += 2; break;
case '3': file += 3; break;
case '4': file += 4; break;
case '5': file += 5; break;
case '6': file += 6; break;
case '7': file += 7; break;
case '8': file += 8; break;
case '/': rank--; file = 0; break;
case 'P': setPieceSafely(position, file, rank, PieceType.P); file++; break;
case 'N': setPieceSafely(position, file, rank, PieceType.N); file++; break;
case 'B': setPieceSafely(position, file, rank, PieceType.B); file++; break;
case 'R': setPieceSafely(position, file, rank, PieceType.R); file++; break;
case 'Q': setPieceSafely(position, file, rank, PieceType.Q); file++; break;
case 'K': setPieceSafely(position, file, rank, PieceType.K); file++; break;
case 'p': setPieceSafely(position, file, rank, PieceType.p); file++; break;
case 'n': setPieceSafely(position, file, rank, PieceType.n); file++; break;
case 'b': setPieceSafely(position, file, rank, PieceType.b); file++; break;
case 'r': setPieceSafely(position, file, rank, PieceType.r); file++; break;
case 'q': setPieceSafely(position, file, rank, PieceType.q); file++; break;
case 'k': setPieceSafely(position, file, rank, PieceType.k); file++; break;
default: throw new ParserError("Invalid Piece", position);
}
}
//Active Colour
if (terms[1].Length > 0)
{
Boolean whiteToMove;
char c = (char)terms[1].ToCharArray().GetValue(0);
switch (c)
{
case 'w': whiteToMove = true; break;
case 'b': whiteToMove = false; break;
default: throw new ParserError("Invalid Active Colour", position);
}
position.setWhiteMove(whiteToMove);
}
else
{
throw new ParserError("Invalid Active Colour", position);
}
//Castling Rights
int castleMask = 0;
if (terms.Length > 2)
{
for (int i = 0; i < terms[2].Length; i++)
{
char c = (char)terms[2].ToCharArray().GetValue(i);
switch (c)
{
case 'K':
castleMask |= (1 << Position.H1_CASTLE);
break;
case 'Q':
castleMask |= (1 << Position.A1_CASTLE);
break;
case 'k':
castleMask |= (1 << Position.H8_CASTLE);
break;
case 'q':
castleMask |= (1 << Position.A8_CASTLE);
break;
case '-':
break;
default:
throw new ParserError("Invalid castling flags", position);
}
}
}
position.setCastleMask(castleMask);
removeInvalidCastleFlags(position);
//En Passant Target Square
if (terms.Length > 3)
{
String epString = terms[3];
if (!epString.Equals("-"))
{
if (epString.Length < 2)
{
throw new ParserError("Invalid En Passent Square", position);
}
position.setEpSquare(getSquare(epString));
}
}
try
{
//Halfmove Clock
if (terms.Length > 4)
{
position.halfMoveClock = Convert.ToInt32(terms[4]);
}
//Full Move Counter
if (terms.Length > 5)
{
position.fullMoveCounter = Convert.ToInt32(terms[5]);
}
}
catch (ArgumentException ae)
{
//Ignore errors here since fields are optional
}
//Each side must have exactly one king
int maxNumber = (int)PieceType.Empty + 1;
int[] numPieces = new int[maxNumber];
for (int i = 0; i < maxNumber; i++)
{
numPieces[i] = 0;
}
for (file = 0; file < 8; file++)
{
for (rank = 0; rank < 8; rank++)
{
numPieces[(int)position.getPiece(Position.getSquare(file, rank))]++;
}
}
if (numPieces[(int)PieceType.K] != 1)
{
throw new ParserError("Too many white kings", position);
}
if (numPieces[(int)PieceType.k] != 1)
{
throw new ParserError("Too many black kings", position);
}
//White must not have too many pieces
int maxWPawns = 8;
maxWPawns -= Math.Max(0, numPieces[(int)PieceType.N] - 2);
maxWPawns -= Math.Max(0, numPieces[(int)PieceType.B] - 2);
maxWPawns -= Math.Max(0, numPieces[(int)PieceType.R] - 2);
maxWPawns -= Math.Max(0, numPieces[(int)PieceType.Q] - 1);
if (numPieces[(int)PieceType.P] > maxWPawns)
{
throw new ParserError("Too many white pieces", position);
}
//Black must not have too many pieces
int maxBPawns = 8;
maxBPawns -= Math.Max(0, numPieces[(int)PieceType.n] - 2);
maxBPawns -= Math.Max(0, numPieces[(int)PieceType.b] - 2);
maxBPawns -= Math.Max(0, numPieces[(int)PieceType.r] - 2);
maxBPawns -= Math.Max(0, numPieces[(int)PieceType.q] - 1);
//Make sure king can not be captured
Position pos2 = new Position(position);
pos2.setWhiteMove(!position.whiteMove);
if (MoveGenerator.inCheck(pos2))
{
throw new ParserError("King capture possible", position);
}
fixupEPSquare(position);
return position;
}
/*
* Remove castling flags that arent valid
*/
private static void removeInvalidCastleFlags(Position position)
{
int castleMask = position.getCastleMask();
int validCastle = 0;
if (position.getPiece(4) == PieceType.K)
{
if (position.getPiece(0) == PieceType.R) validCastle |= (1 << Position.A1_CASTLE);
if (position.getPiece(7) == PieceType.R) validCastle |= (1 << Position.H1_CASTLE);
}
if (position.getPiece(60) == PieceType.k)
{
if (position.getPiece(56) == PieceType.r) validCastle |= (1 << Position.A8_CASTLE);
if (position.getPiece(63) == PieceType.r) validCastle |= (1 << Position.H8_CASTLE);
}
castleMask &= validCastle;
position.setCastleMask(castleMask);
}
/*
* Remove EPSquare from position if it is not legal
*/
private static void fixupEPSquare(Position position)
{
int epSquare = position.getEpSquare();
if (epSquare >= 0)
{
ArrayList moves = MoveGenerator.mgInstance.legalMoves(position);
Boolean epValid = false;
foreach (Move move in moves)
{
if (move.destination == epSquare)
{
if (position.getPiece(move.origin) == (position.whiteMove ? PieceType.P : PieceType.p))
{
epValid = true;
break;
}
}
}
if (!epValid)
{
position.setEpSquare(-1);
}
}
}
/*
* Return a Forsyth-Edwards Notation string corresponding to a Position object
*/
public static String convertPositionToFEN(Position position)
{
StringBuilder feNotation = new StringBuilder();
//Piece placement
for (int rank = 7; rank >= 0; rank--)
{
int emptySquares = 0;
for (int file = 0; file < 8; file++)
{
PieceType piece = position.getPiece(Position.getSquare(file, rank));
if (piece == PieceType.Empty)
{
emptySquares++;
}
else
{
if (emptySquares > 0)
{
feNotation.Append(emptySquares);
emptySquares = 0;
}
switch (piece)
{
case PieceType.K: feNotation.Append('K'); break;
case PieceType.Q: feNotation.Append('Q'); break;
case PieceType.R: feNotation.Append('R'); break;
case PieceType.B: feNotation.Append('B'); break;
case PieceType.N: feNotation.Append('N'); break;
case PieceType.P: feNotation.Append('P'); break;
case PieceType.k: feNotation.Append('k'); break;
case PieceType.q: feNotation.Append('q'); break;
case PieceType.r: feNotation.Append('r'); break;
case PieceType.b: feNotation.Append('b'); break;
case PieceType.n: feNotation.Append('n'); break;
case PieceType.p: feNotation.Append('p'); break;
default: throw new ParserError("Error creating FEN String");
}
}
}
if (emptySquares > 0)
{
feNotation.Append(emptySquares);
}
if (rank > 0)
{
feNotation.Append("/");
}
}
//Active Colour
feNotation.Append(position.whiteMove ? " w " : " b ");
//Castling Rights
Boolean anyCastle = false;
if (position.h1Castle())
{
feNotation.Append('K');
anyCastle = true;
}
if (position.a1Castle())
{
feNotation.Append('Q');
anyCastle = true;
}
if (position.h8Castle())
{
feNotation.Append('k');
anyCastle = true;
}
if (position.a8Castle())
{
feNotation.Append('q');
anyCastle = true;
}
if (!anyCastle)
{
feNotation.Append('-');
}
//En Passant Target Square
{
feNotation.Append(" ");
if (position.getEpSquare() >= 0)
{
int file = Position.getFile(position.getEpSquare());
int rank = Position.getRank(position.getEpSquare());
feNotation.Append((char)(file + 'a'));
feNotation.Append((char)(rank + '1'));
}
else
{
feNotation.Append('-');
}
}
//Move Counters
feNotation.Append(' ');
feNotation.Append(position.halfMoveClock);
feNotation.Append(' ');
feNotation.Append(position.fullMoveCounter);
return feNotation.ToString();
}
/**
* Gets a list of all the Square numbers of Sqaures controlled by the enemy player
*/
private List<int> getEnemyControlledSquares(Position position)
{
List<int> controlledSquares = new List<int>();
for (int i = 0; i < 64; i++)
{
if (position.getPiece(i).Equals(PieceType.Empty)) continue;
if ((Char.IsLower(position.getPiece(i).ToString()[0]) && position.whiteMove) | (Char.IsUpper(position.getPiece(i).ToString()[0]) && !position.whiteMove))
{
controlledSquares.Add(i);
}
}
return controlledSquares;
}
/*
* Add all moves from a given square in direction delta
* @param maxSteps Max steps until reaching a border, Set to 1 for non-sliding pieces
* Returns True if the enemy king could be captured, false otherwise
*/
private Boolean addDirection(ArrayList moveList, Position position, int square, int maxSteps, int delta)
{
int destination = square;
Boolean whiteToMove = position.whiteMove;
PieceType opppositeKing = (whiteToMove ? PieceType.k : PieceType.K);
while (maxSteps > 0)
{
destination += delta;
PieceType piece = position.getPiece(destination);
if (piece == PieceType.Empty)
{
moveList.Add(getMoveObject(square, destination, PieceType.Empty));
}
else
{
//check if piece is white
if (((int)piece < 6) != whiteToMove)
{
if (piece == opppositeKing)
{
returnMoveList(moveList);
moveList = getMoveListObject();
moveList.Add(getMoveObject(square, destination, PieceType.Empty));
return true;
}
else
{
moveList.Add(getMoveObject(square, destination, PieceType.Empty));
}
}
break;
}
maxSteps--;
}
return false;
}
/*
* Check if there is an attacking piece in a given direction starting from
* a given square. The direction is given by delta
* @param maxSteps Max steps until reaching a border, Set to 1 for non-sliding pieces
* Returns the first piece in the given direction, or Empty if there is no piece
* in that direction
*/
private static PieceType checkDirection(Position position, int square, int maxSteps, int delta)
{
while (maxSteps > 0)
{
square += delta;
PieceType piece = position.getPiece(square);
if (piece != PieceType.Empty)
{
return piece;
}
maxSteps--;
}
return PieceType.Empty;
}
/*
* Generate and return a list of psuedo-legal moves.
* Pseudo-legal moves are those that don't necessarily defend
* from check threats.
*/
public ArrayList psuedoLegalMoves(Position position)
{
ArrayList moveList = getMoveListObject();
Boolean whiteToMove = position.whiteMove;
for (int file = 0; file < 8; file++)
{
for (int rank = 0; rank < 8; rank++)
{
int square = Position.getSquare(file, rank);
PieceType piece = position.getPiece(square);
if ((piece == PieceType.Empty) || (((int)piece < 6) != whiteToMove))
{
continue;
}
if ((piece == PieceType.R) || (piece == PieceType.r) || (piece == PieceType.Q) || (piece == PieceType.q))
{
if (addDirection(moveList, position, square, 7 - file, 1)) return moveList;
if (addDirection(moveList, position, square, 7 - rank, 8)) return moveList;
if (addDirection(moveList, position, square, file, -1)) return moveList;
if (addDirection(moveList, position, square, rank, -8)) return moveList;
}
if ((piece == PieceType.B) || (piece == PieceType.b) || (piece == PieceType.Q) || (piece == PieceType.q))
{
if (addDirection(moveList, position, square, Math.Min(7 - file, 7 - rank), 9)) return moveList;
if (addDirection(moveList, position, square, Math.Min(file, 7 - rank), 7)) return moveList;
if (addDirection(moveList, position, square, Math.Min(file, rank), -9)) return moveList;
if (addDirection(moveList, position, square, Math.Min(7 - file, rank), -7)) return moveList;
}
if ((piece == PieceType.N) || (piece == PieceType.n))
{
if (file < 6 && rank < 7 && addDirection(moveList, position, square, 1, 10)) return moveList;
if (file < 7 && rank < 6 && addDirection(moveList, position, square, 1, 17)) return moveList;
if (file > 0 && rank < 6 && addDirection(moveList, position, square, 1, 15)) return moveList;
if (file > 1 && rank < 7 && addDirection(moveList, position, square, 1, 6)) return moveList;
if (file > 1 && rank > 0 && addDirection(moveList, position, square, 1, -10)) return moveList;
if (file > 0 && rank > 1 && addDirection(moveList, position, square, 1, -17)) return moveList;
if (file < 7 && rank > 1 && addDirection(moveList, position, square, 1, -15)) return moveList;
if (file < 6 && rank > 0 && addDirection(moveList, position, square, 1, -6)) return moveList;
}
if ((piece == PieceType.K) || (piece == PieceType.k))
{
if (file < 7 && addDirection(moveList, position, square, 1, 1)) return moveList;
if (file < 7 && rank < 7 && addDirection(moveList, position, square, 1, 9)) return moveList;
if (rank < 7 && addDirection(moveList, position, square, 1, 8)) return moveList;
if (file > 0 && rank < 7 && addDirection(moveList, position, square, 1, 7)) return moveList;
if (file > 0 && addDirection(moveList, position, square, 1, -1)) return moveList;
if (file > 0 && rank > 0 && addDirection(moveList, position, square, 1, -9)) return moveList;
if (rank > 0 && addDirection(moveList, position, square, 1, -8)) return moveList;
if (file < 7 && rank > 0 && addDirection(moveList, position, square, 1, -7)) return moveList;
int kingOrigin = whiteToMove ? Position.getSquare(4, 0) : Position.getSquare(4, 7);
if (Position.getSquare(file, rank) == kingOrigin)
{
int aCastle = whiteToMove ? Position.A1_CASTLE : Position.A8_CASTLE;
int hCastle = whiteToMove ? Position.H1_CASTLE : Position.H8_CASTLE;
PieceType rook = whiteToMove ? PieceType.R : PieceType.r;
if (((position.getCastleMask() & (1 << hCastle)) != 0) &&
(position.getPiece(kingOrigin + 1) == PieceType.Empty) &&
(position.getPiece(kingOrigin + 2) == PieceType.Empty) &&
(position.getPiece(kingOrigin + 3) == rook) &&
!squareAttacked(position, kingOrigin) &&
!squareAttacked(position, kingOrigin + 1) &&
!squareAttacked(position, kingOrigin + 2))
{
moveList.Add(getMoveObject(kingOrigin, kingOrigin + 2, PieceType.Empty));
}
if (((position.getCastleMask() & (1 << aCastle)) != 0) &&
(position.getPiece(kingOrigin - 1) == PieceType.Empty) &&
(position.getPiece(kingOrigin - 2) == PieceType.Empty) &&
(position.getPiece(kingOrigin - 3) == PieceType.Empty) &&
(position.getPiece(kingOrigin - 4) == rook) &&
!squareAttacked(position, kingOrigin) &&
!squareAttacked(position, kingOrigin - 1) &&
!squareAttacked(position, kingOrigin - 2))
{
moveList.Add(getMoveObject(kingOrigin, kingOrigin - 2, PieceType.Empty));
}
}
}
if ((piece == PieceType.P) || (piece == PieceType.p))
{
int rankDir = whiteToMove ? 8 : -8;
if (position.getPiece(square + rankDir) == PieceType.Empty)
{
//non capture moves
addPawnMoves(moveList, square, square + rankDir);
if ((rank == (whiteToMove ? 1 : 6)) &&
(position.getPiece(square + 2 * rankDir) == PieceType.Empty))
{
//double step moves
addPawnMoves(moveList, square, square + rankDir * 2);
}
}
//Capture to the left
if (file > 0)
{
int toSquare = square + rankDir - 1;
PieceType captured = position.getPiece(toSquare);
if (captured != PieceType.Empty)
{
if (((int)captured < 6) != whiteToMove)
{
if (captured == (whiteToMove ? PieceType.k : PieceType.K))
{
returnMoveList(moveList);
moveList = getMoveListObject();
moveList.Add(getMoveObject(square, toSquare, PieceType.Empty));
return moveList;
}
else
{
addPawnMoves(moveList, square, toSquare);
}
}
}
else if (toSquare == position.getEpSquare())
{
addPawnMoves(moveList, square, toSquare);
}
}
//Capture to the right
if (file < 7)
{
int toSquare = square + rankDir + 1;
PieceType captured = position.getPiece(toSquare);
if (captured != PieceType.Empty)
{
if (((int)captured < 6) != whiteToMove)
{
if (captured == (whiteToMove ? PieceType.k : PieceType.K))
{
returnMoveList(moveList);
moveList = getMoveListObject();
moveList.Add(getMoveObject(square, toSquare, PieceType.Empty));
return moveList;
}
else
{
addPawnMoves(moveList, square, toSquare);
}
}
}
else if (toSquare == position.getEpSquare())
{
addPawnMoves(moveList, square, toSquare);
}
}
}
}
}
return moveList;
}
