// u.capture is restored in undo_move()
}
+template<PieceType Piece>
+inline void Position::update_checkers(Bitboard* pCheckersBB, Square ksq, Square from, Square to, Bitboard dcCandidates) {
+
+ if (Piece != KING && bit_is_set(piece_attacks<Piece>(ksq), to))
+ set_bit(pCheckersBB, to);
+
+ if (Piece != QUEEN && bit_is_set(dcCandidates, from))
+ {
+ if (Piece != ROOK)
+ (*pCheckersBB) |= (piece_attacks<ROOK>(ksq) & rooks_and_queens(side_to_move()));
+
+ if (Piece != BISHOP)
+ (*pCheckersBB) |= (piece_attacks<BISHOP>(ksq) & bishops_and_queens(side_to_move()));
+ }
+}
+
/// Position::do_move() makes a move, and backs up all information necessary
/// to undo the move to an UndoInfo object. The move is assumed to be legal.
/// Pseudo-legal moves should be filtered out before this function is called.
if (piece == KING)
kingSquare[us] = to;
- // If the move was a double pawn push, set the en passant square.
- // This code is a bit ugly right now, and should be cleaned up later.
- // FIXME
+ // Reset en passant square
if (epSquare != SQ_NONE)
{
key ^= zobEp[epSquare];
epSquare = SQ_NONE;
}
+
+ // If the moving piece was a pawn do some special extra work
if (piece == PAWN)
{
+ // Reset rule 50 draw counter
+ rule50 = 0;
+
+ // Update pawn hash key
+ pawnKey ^= zobrist[us][PAWN][from] ^ zobrist[us][PAWN][to];
+
+ // Set en passant square, only if moved pawn can be captured
if (abs(int(to) - int(from)) == 16)
{
- if( ( us == WHITE
- && (pawn_attacks(WHITE, from + DELTA_N) & pawns(BLACK)))
- || ( us == BLACK
- && (pawn_attacks(BLACK, from + DELTA_S) & pawns(WHITE))))
+ if ( (us == WHITE && (pawn_attacks(WHITE, from + DELTA_N) & pawns(BLACK)))
+ || (us == BLACK && (pawn_attacks(BLACK, from + DELTA_S) & pawns(WHITE))))
{
epSquare = Square((int(from) + int(to)) / 2);
key ^= zobEp[epSquare];
}
}
- // Reset rule 50 draw counter
- rule50 = 0;
-
- // Update pawn hash key
- pawnKey ^= zobrist[us][PAWN][from] ^ zobrist[us][PAWN][to];
}
+
// Update piece lists
pieceList[us][piece][index[from]] = to;
index[to] = index[from];
castleRights &= castleRightsMask[to];
key ^= zobCastle[castleRights];
- // Update checkers bitboard
+ // Update checkers bitboard, piece must be already moved
checkersBB = EmptyBoardBB;
Square ksq = king_square(them);
switch (piece)
break;
case KNIGHT:
- if (bit_is_set(piece_attacks<KNIGHT>(ksq), to))
- set_bit(&checkersBB, to);
-
- if (bit_is_set(dcCandidates, from))
- checkersBB |= ( (piece_attacks<ROOK>(ksq) & rooks_and_queens(us))
- |(piece_attacks<BISHOP>(ksq) & bishops_and_queens(us)));
+ update_checkers<KNIGHT>(&checkersBB, ksq, from, to, dcCandidates);
break;
case BISHOP:
- if (bit_is_set(piece_attacks<BISHOP>(ksq), to))
- set_bit(&checkersBB, to);
-
- if (bit_is_set(dcCandidates, from))
- checkersBB |= (piece_attacks<ROOK>(ksq) & rooks_and_queens(us));
+ update_checkers<BISHOP>(&checkersBB, ksq, from, to, dcCandidates);
break;
case ROOK:
- if (bit_is_set(piece_attacks<ROOK>(ksq), to))
- set_bit(&checkersBB, to);
-
- if (bit_is_set(dcCandidates, from))
- checkersBB |= (piece_attacks<BISHOP>(ksq) & bishops_and_queens(us));
+ update_checkers<ROOK>(&checkersBB, ksq, from, to, dcCandidates);
break;
case QUEEN:
- if (bit_is_set(piece_attacks<QUEEN>(ksq), to))
- set_bit(&checkersBB, to);
+ update_checkers<QUEEN>(&checkersBB, ksq, from, to, dcCandidates);
break;
case KING:
- if (bit_is_set(dcCandidates, from))
- checkersBB |= ( (piece_attacks<ROOK>(ksq) & rooks_and_queens(us))
- |(piece_attacks<BISHOP>(ksq) & bishops_and_queens(us)));
+ update_checkers<KING>(&checkersBB, ksq, from, to, dcCandidates);
break;
default:
assert(is_ok());
}
-
/// Position::do_capture_move() is a private method used to update captured
/// piece info. It is called from the main Position::do_move function.