fen += (char)skip + '0';
skip = 0;
}
- fen += pieceLetters[piece_on(sq)];
+ fen += pieceLetters[piece_on(sq)];
}
if (skip > 0)
fen += (char)skip + '0';
Square s;
Bitboard sliders, result = EmptyBoardBB;
-
+
if (Piece == ROOK) // Resolved at compile time
sliders = rooks_and_queens(FindPinned ? opposite_color(c) : c) & RookPseudoAttacks[ksq];
else
// King blockers are candidate pinned pieces
Bitboard candidate_pinned = piece_attacks<Piece>(ksq) & pieces_of_color(c);
- // Pinners are sliders, not checkers, that give check when
+ // Pinners are sliders, not checkers, that give check when
// candidate pinned are removed.
Bitboard pinners = (FindPinned ? sliders & ~checkersBB : sliders);
case WR: case BR: return piece_attacks_square<ROOK>(f, t);
case WQ: case BQ: return piece_attacks_square<QUEEN>(f, t);
case WK: case BK: return piece_attacks_square<KING>(f, t);
- default: return false;
}
return false;
}
case WR: case BR: return piece_attacks_square<ROOK>(t, s);
case WQ: case BQ: return piece_attacks_square<QUEEN>(t, s);
case WK: case BK: return piece_attacks_square<KING>(t, s);
- default: assert(false);
}
return false;
}
/// Position::find_checkers() computes the checkersBB bitboard, which
/// contains a nonzero bit for each checking piece (0, 1 or 2). It
/// currently works by calling Position::attacks_to, which is probably
-/// inefficient. Consider rewriting this function to use the last move
+/// inefficient. Consider rewriting this function to use the last move
/// played, like in non-bitboard versions of Glaurung.
void Position::find_checkers() {
- checkersBB = attacks_to(king_square(side_to_move()),opposite_color(side_to_move()));
+ Color us = side_to_move();
+ checkersBB = attacks_to(king_square(us), opposite_color(us));
}
bool Position::pl_move_is_legal(Move m, Bitboard pinned) const {
- Color us, them;
- Square ksq, from;
-
assert(is_ok());
assert(move_is_ok(m));
assert(pinned == pinned_pieces(side_to_move()));
if (move_is_castle(m))
return true;
- us = side_to_move();
- them = opposite_color(us);
- from = move_from(m);
- ksq = king_square(us);
+ Color us = side_to_move();
+ Color them = opposite_color(us);
+ Square from = move_from(m);
+ Square ksq = king_square(us);
assert(color_of_piece_on(from) == us);
assert(piece_on(ksq) == king_of_color(us));
// A non-king move is legal if and only if it is not pinned or it
// is moving along the ray towards or away from the king.
- if ( !bit_is_set(pinned, from)
- || (direction_between_squares(from, ksq) == direction_between_squares(move_to(m), ksq)))
- return true;
-
- return false;
+ return ( !bit_is_set(pinned, from)
+ || (direction_between_squares(from, ksq) == direction_between_squares(move_to(m), ksq)));
}
bool Position::move_is_check(Move m, Bitboard dcCandidates) const {
- Color us, them;
- Square ksq, from, to;
-
assert(is_ok());
assert(move_is_ok(m));
assert(dcCandidates == discovered_check_candidates(side_to_move()));
- us = side_to_move();
- them = opposite_color(us);
- from = move_from(m);
- to = move_to(m);
- ksq = king_square(them);
+ Color us = side_to_move();
+ Color them = opposite_color(us);
+ Square from = move_from(m);
+ Square to = move_to(m);
+ Square ksq = king_square(them);
assert(color_of_piece_on(from) == us);
assert(piece_on(ksq) == king_of_color(them));
switch (type_of_piece_on(from))
{
case PAWN:
-
+
if (bit_is_set(pawn_attacks(them, ksq), to)) // Normal check?
return true;
-
+
if ( bit_is_set(dcCandidates, from) // Discovered check?
&& (direction_between_squares(from, ksq) != direction_between_squares(to, ksq)))
return true;
-
+
if (move_promotion(m)) // Promotion with check?
{
Bitboard b = occupied_squares();
}
return false;
- case KNIGHT:
+ case KNIGHT:
return bit_is_set(dcCandidates, from) // Discovered check?
|| bit_is_set(piece_attacks<KNIGHT>(ksq), to); // Normal check?
case QUEEN:
// Discovered checks are impossible!
- assert(!bit_is_set(dcCandidates, from));
+ assert(!bit_is_set(dcCandidates, from));
return bit_is_set(piece_attacks<QUEEN>(ksq), to); // Normal check?
case KING:
return bit_is_set(rook_attacks_bb(rto, b), ksq);
}
return false;
-
- default:
- assert(false);
}
assert(false);
return false;
bool Position::move_is_capture(Move m) const {
- return color_of_piece_on(move_to(m)) == opposite_color(side_to_move())
- || move_is_ep(m);
+ return ( !square_is_empty(move_to(m))
+ && (color_of_piece_on(move_to(m)) == opposite_color(side_to_move()))
+ )
+ || move_is_ep(m);
}
void Position::backup(UndoInfo& u) const {
u.castleRights = castleRights;
- u.epSquare = epSquare;
- u.checkersBB = checkersBB;
- u.key = key;
- u.pawnKey = pawnKey;
- u.materialKey = materialKey;
- u.rule50 = rule50;
- u.lastMove = lastMove;
- u.capture = NO_PIECE_TYPE;
- u.mgValue = mgValue;
- u.egValue = egValue;
+ u.epSquare = epSquare;
+ u.checkersBB = checkersBB;
+ u.key = key;
+ u.pawnKey = pawnKey;
+ u.materialKey = materialKey;
+ u.rule50 = rule50;
+ u.lastMove = lastMove;
+ u.mgValue = mgValue;
+ u.egValue = egValue;
+ u.capture = NO_PIECE_TYPE;
}
void Position::restore(const UndoInfo& u) {
castleRights = u.castleRights;
- epSquare = u.epSquare;
- checkersBB = u.checkersBB;
- key = u.key;
- pawnKey = u.pawnKey;
- materialKey = u.materialKey;
- rule50 = u.rule50;
- lastMove = u.lastMove;
+ epSquare = u.epSquare;
+ checkersBB = u.checkersBB;
+ key = u.key;
+ pawnKey = u.pawnKey;
+ materialKey = u.materialKey;
+ rule50 = u.rule50;
+ lastMove = u.lastMove;
+ mgValue = u.mgValue;
+ egValue = u.egValue;
// u.capture is restored in undo_move()
- mgValue = u.mgValue;
- egValue = u.egValue;
}
-
/// 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.
+/// 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.
/// There are two versions of this function, one which takes only the move and
/// the UndoInfo as input, and one which takes a third parameter, a bitboard of
-/// discovered check candidates. The second version is faster, because knowing
+/// discovered check candidates. The second version is faster, because knowing
/// the discovered check candidates makes it easier to update the checkersBB
/// member variable in the position object.
if (capture)
{
- assert(capture != KING);
-
- // Remove captured piece
- clear_bit(&(byColorBB[them]), to);
- clear_bit(&(byTypeBB[capture]), to);
-
- // Update hash key
- key ^= zobrist[them][capture][to];
-
- // If the captured piece was a pawn, update pawn hash key
- if (capture == PAWN)
- pawnKey ^= zobrist[them][PAWN][to];
-
- // Update incremental scores
- mgValue -= mg_pst(them, capture, to);
- egValue -= eg_pst(them, capture, to);
-
- // Update material
- if (capture != PAWN)
- npMaterial[them] -= piece_value_midgame(capture);
-
- // Update material hash key
- materialKey ^= zobMaterial[them][capture][pieceCount[them][capture]];
-
- // Update piece count
- pieceCount[them][capture]--;
-
- // Update piece list
- pieceList[them][capture][index[to]] = pieceList[them][capture][pieceCount[them][capture]];
- index[pieceList[them][capture][index[to]]] = index[to];
-
- // Remember the captured piece, in order to be able to undo the move correctly
- u.capture = capture;
-
- // Reset rule 50 counter
- rule50 = 0;
+ u.capture = capture;
+ do_capture_move(m, capture, them, to);
}
// Move the piece
}
+/// Position::do_capture_move() is a private method used to update captured
+/// piece info. It is called from the main Position::do_move function.
+
+void Position::do_capture_move(Move m, PieceType capture, Color them, Square to) {
+
+ assert(capture != KING);
+
+ // Remove captured piece
+ clear_bit(&(byColorBB[them]), to);
+ clear_bit(&(byTypeBB[capture]), to);
+
+ // Update hash key
+ key ^= zobrist[them][capture][to];
+
+ // If the captured piece was a pawn, update pawn hash key
+ if (capture == PAWN)
+ pawnKey ^= zobrist[them][PAWN][to];
+
+ // Update incremental scores
+ mgValue -= mg_pst(them, capture, to);
+ egValue -= eg_pst(them, capture, to);
+
+ assert(!move_promotion(m) || capture != PAWN);
+
+ // Update material
+ if (capture != PAWN)
+ npMaterial[them] -= piece_value_midgame(capture);
+
+ // Update material hash key
+ materialKey ^= zobMaterial[them][capture][pieceCount[them][capture]];
+
+ // Update piece count
+ pieceCount[them][capture]--;
+
+ // Update piece list
+ pieceList[them][capture][index[to]] = pieceList[them][capture][pieceCount[them][capture]];
+ index[pieceList[them][capture][index[to]]] = index[to];
+
+ // Reset rule 50 counter
+ rule50 = 0;
+}
+
+
/// Position::do_castle_move() is a private method used to make a castling
-/// move. It is called from the main Position::do_move function. Note that
+/// move. It is called from the main Position::do_move function. Note that
/// castling moves are encoded as "king captures friendly rook" moves, for
/// instance white short castling in a non-Chess960 game is encoded as e1h1.
if (capture)
{
- assert(capture != KING);
-
- // Remove captured piece
- clear_bit(&(byColorBB[them]), to);
- clear_bit(&(byTypeBB[capture]), to);
-
- // Update hash key
- key ^= zobrist[them][capture][to];
-
- // Update incremental scores
- mgValue -= mg_pst(them, capture, to);
- egValue -= eg_pst(them, capture, to);
-
- // Update material. Because our move is a promotion, we know that the
- // captured piece is not a pawn.
- assert(capture != PAWN);
- npMaterial[them] -= piece_value_midgame(capture);
-
- // Update material hash key
- materialKey ^= zobMaterial[them][capture][pieceCount[them][capture]];
-
- // Update piece count
- pieceCount[them][capture]--;
-
- // Update piece list
- pieceList[them][capture][index[to]] = pieceList[them][capture][pieceCount[them][capture]];
- index[pieceList[them][capture][index[to]]] = index[to];
-
- // Remember the captured piece, in order to be able to undo the move correctly
u.capture = capture;
+ do_capture_move(m, capture, them, to);
}
// Remove pawn
castleRights &= castleRightsMask[to];
key ^= zobCastle[castleRights];
- // Reset rule 50 counter
+ // Reset rule 50 counter\r
rule50 = 0;
// Update checkers BB
// Position::undo_move. In particular, the side to move has been switched,
// so the code below is correct.
Color us = side_to_move();
- Color them = opposite_color(us);
// Find source squares for king and rook
Square kfrom = move_from(m);
/// Position::do_move, is used to put back the captured piece (if any).
void Position::undo_promotion_move(Move m, const UndoInfo &u) {
-
+
Color us, them;
Square from, to;
PieceType capture, promotion;
| (pawn_attacks(WHITE, to) & pawns(BLACK))
| (pawn_attacks(BLACK, to) & pawns(WHITE));
- attackers &= occ; // Re-add removed piece
-
// If the opponent has no attackers, we are finished
if ((attackers & pieces_of_color(them)) == EmptyBoardBB)
return seeValues[capture];
+ attackers &= occ; // Remove the moving piece
+
// The destination square is defended, which makes things rather more
// difficult to compute. We proceed by building up a "swap list" containing
// the material gain or loss at each stop in a sequence of captures to the
- // destianation square, where the sides alternately capture, and always
+ // destination square, where the sides alternately capture, and always
// capture with the least valuable piece. After each capture, we look for
// new X-ray attacks from behind the capturing piece.
int lastCapturingPieceValue = seeValues[piece];
{
if (mgValue != compute_mg_value())
return false;
-
+
if (egValue != compute_eg_value())
return false;
}
projects / stockfish / blobdiff