/// Constructors
-Position::Position(const Position &pos) {
+Position::Position(const Position& pos) {
copy(pos);
}
-Position::Position(const std::string &fen) {
+Position::Position(const std::string& fen) {
from_fen(fen);
}
/// string. This function is not very robust - make sure that input FENs are
/// correct (this is assumed to be the responsibility of the GUI).
-void Position::from_fen(const std::string &fen) {
+void Position::from_fen(const std::string& fen) {
static const std::string pieceLetters = "KQRBNPkqrbnp";
static const Piece pieces[] = { WK, WQ, WR, WB, WN, WP, BK, BQ, BR, BB, BN, BP };
}
+/// Position::update_checkers() updates checkers info, used in do_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:pinned_pieces() returns a bitboard of all pinned (against the
/// king) pieces for the given color.
Bitboard Position::pinned_pieces(Color c) const {
}
-/// Position::square_is_attacked() checks whether the given side attacks the
-/// given square.
-
-bool Position::square_is_attacked(Square s, Color c) const {
-
- return (pawn_attacks(opposite_color(c), s) & pawns(c))
- || (piece_attacks<KNIGHT>(s) & knights(c))
- || (piece_attacks<KING>(s) & kings(c))
- || (piece_attacks<ROOK>(s) & rooks_and_queens(c))
- || (piece_attacks<BISHOP>(s) & bishops_and_queens(c));
-}
-
-
/// Position::attacks_to() computes a bitboard containing all pieces which
/// attacks a given square. There are two versions of this function: One
/// which finds attackers of both colors, and one which only finds the
| (piece_attacks<KING>(s) & pieces_of_type(KING));
}
-Bitboard Position::attacks_to(Square s, Color c) const {
-
- return attacks_to(s) & pieces_of_color(c);
-}
-
-
/// Position::piece_attacks_square() tests whether the piece on square f
/// attacks square t.
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)
{
case PAWN:
- if (bit_is_set(pawn_attacks(them, 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<PAWN>(&checkersBB, ksq, from, to, dcCandidates);
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.
// Find all attackers to the destination square, with the moving piece
// removed, but possibly an X-ray attacker added behind it.
occ = occupied_squares();
+
+ // Handle enpassant moves
+ if (ep_square() == to && type_of_piece_on(from) == PAWN)
+ {
+ assert(capture == EMPTY);
+
+ Square capQq = (side_to_move() == WHITE)? (to - DELTA_N) : (to - DELTA_S);
+ capture = piece_on(capQq);
+
+ assert(type_of_piece_on(capQq) == PAWN);
+
+ // Remove the captured pawn
+ clear_bit(&occ, capQq);
+ }
+
while (true)
{
clear_bit(&occ, from);
/// side to move is checkmated. Note that this function is currently very
/// slow, and shouldn't be used frequently inside the search.
-bool Position::is_mate() {
+bool Position::is_mate() const {
if (is_check())
{
projects / stockfish / blobdiff