private void GenerateQueenMoves(MoveGeneration MoveGeneration, ulong FromSquareMask, ulong ToSquareMask)
{
ulong queens;
ulong unOrEnemyOccupiedSquares;
ulong enemyOccupiedSquares;
int attacker;
if (WhiteMove)
{
// White Move
queens = WhiteQueens & FromSquareMask;
unOrEnemyOccupiedSquares = ~OccupancyWhite;
enemyOccupiedSquares = OccupancyBlack;
attacker = Piece.WhiteQueen;
}
else
{
// Black Move
queens = BlackQueens & FromSquareMask;
unOrEnemyOccupiedSquares = ~OccupancyBlack;
enemyOccupiedSquares = OccupancyWhite;
attacker = Piece.BlackQueen;
}
int fromSquare;
while ((fromSquare = Bitwise.FindFirstSetBit(queens)) != Square.Illegal)
{
var bishopOccupancy = Board.BishopMoveMasks[fromSquare] & Occupancy;
var rookOccupancy = Board.RookMoveMasks[fromSquare] & Occupancy;
var queenDestinations = MoveGeneration switch
{
MoveGeneration.AllMoves => (Board.PrecalculatedMoves.GetBishopMovesMask(fromSquare, bishopOccupancy) | Board.PrecalculatedMoves.GetRookMovesMask(fromSquare, rookOccupancy)) & unOrEnemyOccupiedSquares & ToSquareMask,
MoveGeneration.OnlyCaptures => (Board.PrecalculatedMoves.GetBishopMovesMask(fromSquare, bishopOccupancy) | Board.PrecalculatedMoves.GetRookMovesMask(fromSquare, rookOccupancy)) & enemyOccupiedSquares & ToSquareMask,
MoveGeneration.OnlyNonCaptures => (Board.PrecalculatedMoves.GetBishopMovesMask(fromSquare, bishopOccupancy) | Board.PrecalculatedMoves.GetRookMovesMask(fromSquare, rookOccupancy)) & ~Occupancy & ToSquareMask,
_ => throw new Exception($"{MoveGeneration} move generation not supported.")
};
int toSquare;
while ((toSquare = Bitwise.FindFirstSetBit(queenDestinations)) != Square.Illegal)
{
var victim = GetPiece(toSquare);
var move = Move.Null;
Move.SetFrom(ref move, fromSquare);
Move.SetTo(ref move, toSquare);
if (victim != Piece.None)
{
Move.SetCaptureAttacker(ref move, attacker);
}
Move.SetCaptureVictim(ref move, victim);
Move.SetIsQuiet(ref move, victim == Piece.None);
Moves[MoveIndex] = move;
MoveIndex++;
Bitwise.ClearBit(ref queenDestinations, toSquare);
}
Bitwise.ClearBit(ref queens, fromSquare);
}
}
private void GenerateKnightMoves(MoveGeneration MoveGeneration, ulong FromSquareMask, ulong ToSquareMask)
{
ulong knights;
ulong unOrEnemyOccupiedSquares;
ulong enemyOccupiedSquares;
int attacker;
if (WhiteMove)
{
// White Move
knights = WhiteKnights & FromSquareMask;
unOrEnemyOccupiedSquares = ~OccupancyWhite;
enemyOccupiedSquares = OccupancyBlack;
attacker = Piece.WhiteKnight;
}
else
{
// Black Move
knights = BlackKnights & FromSquareMask;
unOrEnemyOccupiedSquares = ~OccupancyBlack;
enemyOccupiedSquares = OccupancyWhite;
attacker = Piece.BlackKnight;
}
int fromSquare;
while ((fromSquare = Bitwise.FindFirstSetBit(knights)) != Square.Illegal)
{
var knightDestinations = MoveGeneration switch
{
MoveGeneration.AllMoves => Board.KnightMoveMasks[fromSquare] & unOrEnemyOccupiedSquares & ToSquareMask,
MoveGeneration.OnlyCaptures => Board.KnightMoveMasks[fromSquare] & enemyOccupiedSquares & ToSquareMask,
MoveGeneration.OnlyNonCaptures => Board.KnightMoveMasks[fromSquare] & ~Occupancy & ToSquareMask,
_ => throw new Exception($"{MoveGeneration} move generation not supported.")
};
int toSquare;
while ((toSquare = Bitwise.FindFirstSetBit(knightDestinations)) != Square.Illegal)
{
var victim = GetPiece(toSquare);
var move = Move.Null;
Move.SetFrom(ref move, fromSquare);
Move.SetTo(ref move, toSquare);
if (victim != Piece.None)
{
Move.SetCaptureAttacker(ref move, attacker);
}
Move.SetCaptureVictim(ref move, victim);
Move.SetIsQuiet(ref move, victim == Piece.None);
Moves[MoveIndex] = move;
MoveIndex++;
Bitwise.ClearBit(ref knightDestinations, toSquare);
}
Bitwise.ClearBit(ref knights, fromSquare);
}
}
public void FindPinnedPieces()
{
int ownKingSquare;
ulong ownPieces;
ulong enemyRankFileAttackers;
ulong enemyDiagonalAttackers;
ulong enemyPieces;
if (WhiteMove)
{
// White Move
ownKingSquare = Bitwise.FindFirstSetBit(WhiteKing);
ownPieces = OccupancyWhite;
enemyRankFileAttackers = BlackRooks | BlackQueens;
enemyDiagonalAttackers = BlackBishops | BlackQueens;
enemyPieces = OccupancyBlack;
}
else
{
// Black Move
ownKingSquare = Bitwise.FindFirstSetBit(BlackKing);
ownPieces = OccupancyBlack;
enemyRankFileAttackers = WhiteRooks | WhiteQueens;
enemyDiagonalAttackers = WhiteBishops | WhiteQueens;
enemyPieces = OccupancyWhite;
}
// Find pieces pinned to own king by enemy rank / file attackers.
PinnedPieces = 0;
int attackerSquare;
while ((attackerSquare = Bitwise.FindFirstSetBit(enemyRankFileAttackers)) != Square.Illegal)
{
var betweenSquares = Board.RankFileBetweenSquares[attackerSquare][ownKingSquare];
if (betweenSquares == 0)
{
Bitwise.ClearBit(ref enemyRankFileAttackers, attackerSquare);
continue;
}
if ((betweenSquares & enemyPieces) == 0)
{
// No enemy pieces between enemy attacker and own king.
var potentiallyPinnedPieces = betweenSquares & ownPieces;
if (Bitwise.CountSetBits(potentiallyPinnedPieces) == 1)
{
// Exactly one own piece between enemy attacker and own king.
// Piece is pinned to own king.
PinnedPieces |= potentiallyPinnedPieces;
}
}
Bitwise.ClearBit(ref enemyRankFileAttackers, attackerSquare);
}
// Find pieces pinned to own king by enemy diagonal attackers.
while ((attackerSquare = Bitwise.FindFirstSetBit(enemyDiagonalAttackers)) != Square.Illegal)
{
var betweenSquares = Board.DiagonalBetweenSquares[attackerSquare][ownKingSquare];
if (betweenSquares == 0)
{
Bitwise.ClearBit(ref enemyDiagonalAttackers, attackerSquare);
continue;
}
if ((betweenSquares & enemyPieces) == 0)
{
// No enemy pieces between enemy attacker and own king.
var potentiallyPinnedPieces = betweenSquares & ownPieces;
if (Bitwise.CountSetBits(potentiallyPinnedPieces) == 1)
{
// Exactly one own piece between enemy attacker and own king.
// Piece is pinned to own king.
PinnedPieces |= potentiallyPinnedPieces;
}
}
Bitwise.ClearBit(ref enemyDiagonalAttackers, attackerSquare);
}
}
private void GenerateKingMoves(MoveGeneration MoveGeneration, ulong FromSquareMask, ulong ToSquareMask)
{
ulong king;
ulong unOrEnemyOccupiedSquares;
ulong enemyOccupiedSquares;
int attacker;
bool castleQueenside;
ulong castleQueensideMask;
bool castleKingside;
ulong castleKingsideMask;
if (WhiteMove)
{
// White Move
king = WhiteKing & FromSquareMask;
unOrEnemyOccupiedSquares = ~OccupancyWhite;
enemyOccupiedSquares = OccupancyBlack;
attacker = Piece.WhiteKing;
castleQueenside = Engine.Castling.WhiteQueenside(Castling);
castleQueensideMask = Board.WhiteCastleQEmptySquaresMask;
castleKingside = Engine.Castling.WhiteKingside(Castling);
castleKingsideMask = Board.WhiteCastleKEmptySquaresMask;
}
else
{
// Black Move
king = BlackKing & FromSquareMask;
unOrEnemyOccupiedSquares = ~OccupancyBlack;
enemyOccupiedSquares = OccupancyWhite;
attacker = Piece.BlackKing;
castleQueenside = Engine.Castling.BlackQueenside(Castling);
castleQueensideMask = Board.BlackCastleQEmptySquaresMask;
castleKingside = Engine.Castling.BlackKingside(Castling);
castleKingsideMask = Board.BlackCastleKEmptySquaresMask;
}
ulong move;
var fromSquare = Bitwise.FindFirstSetBit(king);
if (fromSquare == Square.Illegal)
{
return;
}
var kingDestinations = MoveGeneration switch
{
MoveGeneration.AllMoves => Board.KingMoveMasks[fromSquare] & unOrEnemyOccupiedSquares & ToSquareMask,
MoveGeneration.OnlyCaptures => Board.KingMoveMasks[fromSquare] & enemyOccupiedSquares & ToSquareMask,
MoveGeneration.OnlyNonCaptures => Board.KingMoveMasks[fromSquare] & ~Occupancy & ToSquareMask,
_ => throw new Exception($"{MoveGeneration} move generation not supported.")
};
int toSquare;
while ((toSquare = Bitwise.FindFirstSetBit(kingDestinations)) != Square.Illegal)
{
var victim = GetPiece(toSquare);
move = Move.Null;
Move.SetFrom(ref move, fromSquare);
Move.SetTo(ref move, toSquare);
if (victim != Piece.None)
{
Move.SetCaptureAttacker(ref move, attacker);
}
Move.SetCaptureVictim(ref move, victim);
Move.SetIsKingMove(ref move, true);
Move.SetIsQuiet(ref move, victim == Piece.None);
Moves[MoveIndex] = move;
MoveIndex++;
Bitwise.ClearBit(ref kingDestinations, toSquare);
}
if (MoveGeneration != MoveGeneration.OnlyCaptures)
{
if (castleQueenside && ((Occupancy & castleQueensideMask) == 0))
{
// Castle Queenside
if (WhiteMove)
{
// White Move
fromSquare = Square.e1;
toSquare = Square.c1;
}
else
{
// Black Move
fromSquare = Square.e8;
toSquare = Square.c8;
}
if ((Board.SquareMasks[toSquare] & ToSquareMask) > 0)
{
move = Move.Null;
Move.SetFrom(ref move, fromSquare);
Move.SetTo(ref move, toSquare);
Move.SetIsCastling(ref move, true);
Move.SetIsKingMove(ref move, true);
Move.SetIsQuiet(ref move, false);
Moves[MoveIndex] = move;
MoveIndex++;
}
}
if (castleKingside && ((Occupancy & castleKingsideMask) == 0))
{
// Castle Kingside
if (WhiteMove)
{
// White Move
fromSquare = Square.e1;
toSquare = Square.g1;
}
else
{
// Black Move
fromSquare = Square.e8;
toSquare = Square.g8;
}
if ((Board.SquareMasks[toSquare] & ToSquareMask) > 0)
{
move = Move.Null;
Move.SetFrom(ref move, fromSquare);
Move.SetTo(ref move, toSquare);
Move.SetIsCastling(ref move, true);
Move.SetIsKingMove(ref move, true);
Move.SetIsQuiet(ref move, false);
Moves[MoveIndex] = move;
MoveIndex++;
}
}
}
}
private void GeneratePawnMoves(MoveGeneration MoveGeneration, ulong FromSquareMask, ulong ToSquareMask)
{
ulong pawns;
ulong[] pawnMoveMasks;
ulong[] pawnDoubleMoveMasks;
ulong[] pawnAttackMasks;
ulong enemyOccupiedSquares;
var unoccupiedSquares = ~Occupancy;
int[] ranks;
int attacker;
int queen;
int rook;
int bishop;
int knight;
int enPassantVictim;
if (WhiteMove)
{
// White Move
pawns = WhitePawns & FromSquareMask;
pawnMoveMasks = Board.WhitePawnMoveMasks;
pawnDoubleMoveMasks = Board.WhitePawnDoubleMoveMasks;
pawnAttackMasks = Board.WhitePawnAttackMasks;
enemyOccupiedSquares = OccupancyBlack;
ranks = Board.WhiteRanks;
attacker = Piece.WhitePawn;
queen = Piece.WhiteQueen;
rook = Piece.WhiteRook;
bishop = Piece.WhiteBishop;
knight = Piece.WhiteKnight;
enPassantVictim = Piece.BlackPawn;
}
else
{
// Black Move
pawns = BlackPawns & FromSquareMask;
pawnMoveMasks = Board.BlackPawnMoveMasks;
pawnDoubleMoveMasks = Board.BlackPawnDoubleMoveMasks;
pawnAttackMasks = Board.BlackPawnAttackMasks;
enemyOccupiedSquares = OccupancyWhite;
ranks = Board.BlackRanks;
attacker = Piece.BlackPawn;
queen = Piece.BlackQueen;
rook = Piece.BlackRook;
bishop = Piece.BlackBishop;
knight = Piece.BlackKnight;
enPassantVictim = Piece.WhitePawn;
}
int fromSquare;
ulong move;
if ((EnPassantSquare != Square.Illegal) && ((Board.SquareMasks[EnPassantSquare] & ToSquareMask) > 0) && (MoveGeneration != MoveGeneration.OnlyNonCaptures))
{
var enPassantAttackers = Board.EnPassantAttackerMasks[EnPassantSquare] & pawns;
while ((fromSquare = Bitwise.FindFirstSetBit(enPassantAttackers)) != Square.Illegal)
{
// Capture pawn en passant.
move = Move.Null;
Move.SetFrom(ref move, fromSquare);
Move.SetTo(ref move, EnPassantSquare);
Move.SetCaptureAttacker(ref move, attacker);
Move.SetCaptureVictim(ref move, enPassantVictim);
Move.SetIsEnPassantCapture(ref move, true);
Move.SetIsPawnMove(ref move, true);
Move.SetIsQuiet(ref move, false);
Moves[MoveIndex] = move;
MoveIndex++;
Bitwise.ClearBit(ref enPassantAttackers, fromSquare);
}
}
while ((fromSquare = Bitwise.FindFirstSetBit(pawns)) != Square.Illegal)
{
ulong pawnDestinations;
int toSquare;
int toSquareRank;
if (MoveGeneration != MoveGeneration.OnlyCaptures)
{
// Pawns may move forward one square (or two if on initial square) if forward squares are unoccupied.
pawnDestinations = pawnMoveMasks[fromSquare] & unoccupiedSquares & ToSquareMask;
while ((toSquare = Bitwise.FindFirstSetBit(pawnDestinations)) != Square.Illegal)
{
var doubleMove = Board.SquareDistances[fromSquare][toSquare] == 2;
if (doubleMove && ((Occupancy & pawnDoubleMoveMasks[fromSquare]) > 0))
{
// Double move is blocked.
Bitwise.ClearBit(ref pawnDestinations, toSquare);
continue;
}
toSquareRank = ranks[toSquare];
if (toSquareRank < 7)
{
move = Move.Null;
Move.SetFrom(ref move, fromSquare);
Move.SetTo(ref move, toSquare);
Move.SetIsDoublePawnMove(ref move, doubleMove);
Move.SetIsPawnMove(ref move, true);
Move.SetIsQuiet(ref move, true);
Moves[MoveIndex] = move;
MoveIndex++;
}
else
{
// Promote pawn to queen.
move = Move.Null;
Move.SetFrom(ref move, fromSquare);
Move.SetTo(ref move, toSquare);
Move.SetPromotedPiece(ref move, queen);
Move.SetIsPawnMove(ref move, true);
Move.SetIsQuiet(ref move, false);
Moves[MoveIndex] = move;
MoveIndex++;
// Promote pawn to rook.
move = Move.Null;
Move.SetFrom(ref move, fromSquare);
Move.SetTo(ref move, toSquare);
Move.SetPromotedPiece(ref move, rook);
Move.SetIsPawnMove(ref move, true);
Move.SetIsQuiet(ref move, false);
Moves[MoveIndex] = move;
MoveIndex++;
// Promote pawn to bishop.
move = Move.Null;
Move.SetFrom(ref move, fromSquare);
Move.SetTo(ref move, toSquare);
Move.SetPromotedPiece(ref move, bishop);
Move.SetIsPawnMove(ref move, true);
Move.SetIsQuiet(ref move, false);
Moves[MoveIndex] = move;
MoveIndex++;
// Promote pawn to knight.
move = Move.Null;
Move.SetFrom(ref move, fromSquare);
Move.SetTo(ref move, toSquare);
Move.SetPromotedPiece(ref move, knight);
Move.SetIsPawnMove(ref move, true);
Move.SetIsQuiet(ref move, false);
Moves[MoveIndex] = move;
MoveIndex++;
}
Bitwise.ClearBit(ref pawnDestinations, toSquare);
}
}
if (MoveGeneration != MoveGeneration.OnlyNonCaptures)
{
// Pawns may attack diagonally forward one square if occupied by enemy.
pawnDestinations = pawnAttackMasks[fromSquare] & enemyOccupiedSquares & ToSquareMask;
while ((toSquare = Bitwise.FindFirstSetBit(pawnDestinations)) != Square.Illegal)
{
toSquareRank = ranks[toSquare];
var victim = GetPiece(toSquare);
if (toSquareRank < 7)
{
move = Move.Null;
Move.SetFrom(ref move, fromSquare);
Move.SetTo(ref move, toSquare);
Move.SetCaptureAttacker(ref move, attacker);
Move.SetCaptureVictim(ref move, victim);
Move.SetIsPawnMove(ref move, true);
Move.SetIsQuiet(ref move, false);
Moves[MoveIndex] = move;
MoveIndex++;
}
else
{
// Promote pawn to queen.
move = Move.Null;
Move.SetFrom(ref move, fromSquare);
Move.SetTo(ref move, toSquare);
Move.SetPromotedPiece(ref move, queen);
Move.SetCaptureAttacker(ref move, attacker);
Move.SetCaptureVictim(ref move, victim);
Move.SetIsPawnMove(ref move, true);
Move.SetIsQuiet(ref move, false);
Moves[MoveIndex] = move;
MoveIndex++;
// Promote pawn to rook.
move = Move.Null;
Move.SetFrom(ref move, fromSquare);
Move.SetTo(ref move, toSquare);
Move.SetPromotedPiece(ref move, rook);
Move.SetCaptureAttacker(ref move, attacker);
Move.SetCaptureVictim(ref move, victim);
Move.SetIsPawnMove(ref move, true);
Move.SetIsQuiet(ref move, false);
Moves[MoveIndex] = move;
MoveIndex++;
// Promote pawn to bishop.
move = Move.Null;
Move.SetFrom(ref move, fromSquare);
Move.SetTo(ref move, toSquare);
Move.SetPromotedPiece(ref move, bishop);
Move.SetCaptureAttacker(ref move, attacker);
Move.SetCaptureVictim(ref move, victim);
Move.SetIsPawnMove(ref move, true);
Move.SetIsQuiet(ref move, false);
Moves[MoveIndex] = move;
MoveIndex++;
// Promote pawn to knight.
move = Move.Null;
Move.SetFrom(ref move, fromSquare);
Move.SetTo(ref move, toSquare);
Move.SetPromotedPiece(ref move, knight);
Move.SetCaptureAttacker(ref move, attacker);
Move.SetCaptureVictim(ref move, victim);
Move.SetIsPawnMove(ref move, true);
Move.SetIsQuiet(ref move, false);
Moves[MoveIndex] = move;
MoveIndex++;
}
Bitwise.ClearBit(ref pawnDestinations, toSquare);
}
}
Bitwise.ClearBit(ref pawns, fromSquare);
}
}