RookValueEndgame, QueenValueEndgame
};
-
-namespace {
-
- // Bonus for having the side to move (modified by Joona Kiiski)
- const Score Tempo = make_score(48, 22);
-
- // To convert a Piece to and from a FEN char
- const string PieceToChar(" PNBRQK pnbrqk .");
-}
+// To convert a Piece to and from a FEN char
+static const string PieceToChar(" PNBRQK pnbrqk .");
/// CheckInfo c'tor
}
-/// Position::copy() creates a copy of 'pos'. We want the new born Position
+/// Position::operator=() creates a copy of 'pos'. We want the new born Position
/// object do not depend on any external data so we detach state pointer from
/// the source one.
-void Position::copy(const Position& pos, Thread* th) {
+void Position::operator=(const Position& pos) {
memcpy(this, &pos, sizeof(Position));
startState = *st;
st = &startState;
- thisThread = th;
nodes = 0;
assert(pos_is_ok());
{
st->epSquare = make_square(File(col - 'a'), Rank(row - '1'));
- if (!(attackers_to(st->epSquare) & pieces(PAWN, sideToMove)))
+ if (!(attackers_to(st->epSquare) & pieces(sideToMove, PAWN)))
st->epSquare = SQ_NONE;
}
void Position::set_castle_right(Color c, Square rfrom) {
Square kfrom = king_square(c);
- bool kingSide = kfrom < rfrom;
- int cr = (kingSide ? WHITE_OO : WHITE_OOO) << c;
+ CastlingSide cs = kfrom < rfrom ? KING_SIDE : QUEEN_SIDE;
+ CastleRight cr = make_castle_right(c, cs);
st->castleRights |= cr;
castleRightsMask[kfrom] |= cr;
castleRightsMask[rfrom] |= cr;
- castleRookSquare[cr] = rfrom;
+ castleRookSquare[c][cs] = rfrom;
- Square kto = relative_square(c, kingSide ? SQ_G1 : SQ_C1);
- Square rto = relative_square(c, kingSide ? SQ_F1 : SQ_D1);
+ Square kto = relative_square(c, cs == KING_SIDE ? SQ_G1 : SQ_C1);
+ Square rto = relative_square(c, cs == KING_SIDE ? SQ_F1 : SQ_D1);
for (Square s = std::min(rfrom, rto); s <= std::max(rfrom, rto); s++)
if (s != kfrom && s != rfrom)
- castlePath[cr] |= s;
+ castlePath[c][cs] |= s;
for (Square s = std::min(kfrom, kto); s <= std::max(kfrom, kto); s++)
if (s != kfrom && s != rfrom)
- castlePath[cr] |= s;
+ castlePath[c][cs] |= s;
}
{
sq = make_square(file, rank);
- if (square_empty(sq))
+ if (is_empty(sq))
emptyCnt++;
else
{
fen << (sideToMove == WHITE ? " w " : " b ");
if (can_castle(WHITE_OO))
- fen << (chess960 ? char(toupper(file_to_char(file_of(castle_rook_square(WHITE_OO))))) : 'K');
+ fen << (chess960 ? char(toupper(file_to_char(file_of(castle_rook_square(WHITE, KING_SIDE))))) : 'K');
if (can_castle(WHITE_OOO))
- fen << (chess960 ? char(toupper(file_to_char(file_of(castle_rook_square(WHITE_OOO))))) : 'Q');
+ fen << (chess960 ? char(toupper(file_to_char(file_of(castle_rook_square(WHITE, QUEEN_SIDE))))) : 'Q');
if (can_castle(BLACK_OO))
- fen << (chess960 ? file_to_char(file_of(castle_rook_square(BLACK_OO))) : 'k');
+ fen << (chess960 ? file_to_char(file_of(castle_rook_square(BLACK, KING_SIDE))) : 'k');
if (can_castle(BLACK_OOO))
- fen << (chess960 ? file_to_char(file_of(castle_rook_square(BLACK_OOO))) : 'q');
+ fen << (chess960 ? file_to_char(file_of(castle_rook_square(BLACK, QUEEN_SIDE))) : 'q');
if (st->castleRights == CASTLES_NONE)
fen << '-';
if (move)
{
- Position p(*this, thisThread);
+ Position p(*this);
cout << "\nMove is: " << (sideToMove == BLACK ? ".." : "") << move_to_san(p, move);
}
while (pinners)
{
- b = squares_between(ksq, pop_1st_bit(&pinners)) & pieces();
+ b = between_bb(ksq, pop_1st_bit(&pinners)) & pieces();
- if (b && single_bit(b) && (b & pieces(sideToMove)))
+ if (b && !more_than_one(b) && (b & pieces(sideToMove)))
result |= b;
}
return result;
Bitboard Position::attackers_to(Square s, Bitboard occ) const {
- return (attacks_from<PAWN>(s, BLACK) & pieces(PAWN, WHITE))
- | (attacks_from<PAWN>(s, WHITE) & pieces(PAWN, BLACK))
+ return (attacks_from<PAWN>(s, BLACK) & pieces(WHITE, PAWN))
+ | (attacks_from<PAWN>(s, WHITE) & pieces(BLACK, PAWN))
| (attacks_from<KNIGHT>(s) & pieces(KNIGHT))
| (attacks_bb<ROOK>(s, occ) & pieces(ROOK, QUEEN))
| (attacks_bb<BISHOP>(s, occ) & pieces(BISHOP, QUEEN))
Square to = to_sq(m);
Piece piece = piece_moved(m);
- assert(!square_empty(from));
+ assert(!is_empty(from));
// Update occupancy as if the piece is moving
occ = pieces() ^ from ^ to;
return true;
// Scan for possible X-ray attackers behind the moved piece
- xray = (attacks_bb<ROOK>(s, occ) & pieces(ROOK, QUEEN, color_of(piece)))
- |(attacks_bb<BISHOP>(s, occ) & pieces(BISHOP, QUEEN, color_of(piece)));
+ xray = (attacks_bb< ROOK>(s, occ) & pieces(color_of(piece), QUEEN, ROOK))
+ | (attacks_bb<BISHOP>(s, occ) & pieces(color_of(piece), QUEEN, BISHOP));
// Verify attackers are triggered by our move and not already existing
return xray && (xray ^ (xray & attacks_from<QUEEN>(s)));
assert(piece_on(capsq) == make_piece(them, PAWN));
assert(piece_on(to) == NO_PIECE);
- return !(attacks_bb<ROOK>(ksq, b) & pieces(ROOK, QUEEN, them))
- && !(attacks_bb<BISHOP>(ksq, b) & pieces(BISHOP, QUEEN, them));
+ return !(attacks_bb< ROOK>(ksq, b) & pieces(them, QUEEN, ROOK))
+ && !(attacks_bb<BISHOP>(ksq, b) & pieces(them, QUEEN, BISHOP));
}
// If the moving piece is a king, check whether the destination
case DELTA_N:
case DELTA_S:
// Pawn push. The destination square must be empty.
- if (!square_empty(to))
+ if (!is_empty(to))
return false;
break;
// Double white pawn push. The destination square must be on the fourth
// rank, and both the destination square and the square between the
// source and destination squares must be empty.
- if ( rank_of(to) != RANK_4
- || !square_empty(to)
- || !square_empty(from + DELTA_N))
+ if ( rank_of(to) != RANK_4
+ || !is_empty(to)
+ || !is_empty(from + DELTA_N))
return false;
break;
// Double black pawn push. The destination square must be on the fifth
// rank, and both the destination square and the square between the
// source and destination squares must be empty.
- if ( rank_of(to) != RANK_5
- || !square_empty(to)
- || !square_empty(from + DELTA_S))
+ if ( rank_of(to) != RANK_5
+ || !is_empty(to)
+ || !is_empty(from + DELTA_S))
return false;
break;
return false;
// Our move must be a blocking evasion or a capture of the checking piece
- if (!((squares_between(checksq, king_square(us)) | checkers()) & to))
+ if (!((between_bb(checksq, king_square(us)) | checkers()) & to))
return false;
}
// In case of king moves under check we have to remove king so to catch
if (ci.dcCandidates && (ci.dcCandidates & from))
{
// For pawn and king moves we need to verify also direction
- if ( (pt != PAWN && pt != KING)
+ if ( (pt != PAWN && pt != KING)
|| !squares_aligned(from, to, king_square(~sideToMove)))
return true;
}
Square capsq = make_square(file_of(to), rank_of(from));
Bitboard b = (pieces() ^ from ^ capsq) | to;
- return (attacks_bb< ROOK>(ksq, b) & pieces( ROOK, QUEEN, us))
- | (attacks_bb<BISHOP>(ksq, b) & pieces(BISHOP, QUEEN, us));
+ return (attacks_bb< ROOK>(ksq, b) & pieces(us, QUEEN, ROOK))
+ | (attacks_bb<BISHOP>(ksq, b) & pieces(us, QUEEN, BISHOP));
}
// Castling with check ?
prefetch((char*)TT.first_entry(k));
// Move the piece
- Bitboard from_to_bb = SquareBB[from] | SquareBB[to];
+ Bitboard from_to_bb = SquareBB[from] ^ SquareBB[to];
byTypeBB[ALL_PIECES] ^= from_to_bb;
byTypeBB[pt] ^= from_to_bb;
byColorBB[us] ^= from_to_bb;
{
// Set en-passant square, only if moved pawn can be captured
if ( (int(to) ^ int(from)) == 16
- && (attacks_from<PAWN>(from + pawn_push(us), us) & pieces(PAWN, them)))
+ && (attacks_from<PAWN>(from + pawn_push(us), us) & pieces(them, PAWN)))
{
st->epSquare = Square((from + to) / 2);
k ^= zobEp[file_of(st->epSquare)];
if (ci.dcCandidates && (ci.dcCandidates & from))
{
if (pt != ROOK)
- st->checkersBB |= attacks_from<ROOK>(king_square(them)) & pieces(ROOK, QUEEN, us);
+ st->checkersBB |= attacks_from<ROOK>(king_square(them)) & pieces(us, QUEEN, ROOK);
if (pt != BISHOP)
- st->checkersBB |= attacks_from<BISHOP>(king_square(them)) & pieces(BISHOP, QUEEN, us);
+ st->checkersBB |= attacks_from<BISHOP>(king_square(them)) & pieces(us, QUEEN, BISHOP);
}
}
}
- // Finish
sideToMove = ~sideToMove;
- st->psqScore += (sideToMove == WHITE ? Tempo : -Tempo);
assert(pos_is_ok());
}
PieceType pt = type_of(piece);
PieceType capture = st->capturedType;
- assert(square_empty(from));
+ assert(is_empty(from));
assert(color_of(piece) == us);
assert(capture != KING);
}
// Put the piece back at the source square
- Bitboard from_to_bb = SquareBB[from] | SquareBB[to];
+ Bitboard from_to_bb = SquareBB[from] ^ SquareBB[to];
byTypeBB[ALL_PIECES] ^= from_to_bb;
byTypeBB[pt] ^= from_to_bb;
byColorBB[us] ^= from_to_bb;
assert(piece_on(kfrom) == make_piece(us, KING));
assert(piece_on(rfrom) == make_piece(us, ROOK));
- // Remove pieces from source squares
- byTypeBB[ALL_PIECES] ^= kfrom;
- byTypeBB[KING] ^= kfrom;
- byColorBB[us] ^= kfrom;
- byTypeBB[ALL_PIECES] ^= rfrom;
- byTypeBB[ROOK] ^= rfrom;
- byColorBB[us] ^= rfrom;
-
- // Put pieces on destination squares
- byTypeBB[ALL_PIECES] |= kto;
- byTypeBB[KING] |= kto;
- byColorBB[us] |= kto;
- byTypeBB[ALL_PIECES] |= rto;
- byTypeBB[ROOK] |= rto;
- byColorBB[us] |= rto;
+ // Move the pieces, with some care; in chess960 could be kto == rfrom
+ Bitboard k_from_to_bb = SquareBB[kfrom] ^ SquareBB[kto];
+ Bitboard r_from_to_bb = SquareBB[rfrom] ^ SquareBB[rto];
+ byTypeBB[KING] ^= k_from_to_bb;
+ byTypeBB[ROOK] ^= r_from_to_bb;
+ byTypeBB[ALL_PIECES] ^= k_from_to_bb ^ r_from_to_bb;
+ byColorBB[us] ^= k_from_to_bb ^ r_from_to_bb;
// Update board
Piece king = make_piece(us, KING);
// Update checkers BB
st->checkersBB = attackers_to(king_square(~us)) & pieces(us);
- // Finish
sideToMove = ~sideToMove;
- st->psqScore += (sideToMove == WHITE ? Tempo : -Tempo);
}
else
// Undo: point our state pointer back to the previous state
st->epSquare = SQ_NONE;
st->rule50++;
st->pliesFromNull = 0;
- st->psqScore += (sideToMove == WHITE ? Tempo : -Tempo);
}
assert(pos_is_ok());
Key Position::compute_key() const {
- Key result = zobCastle[st->castleRights];
+ Key k = zobCastle[st->castleRights];
- for (Square s = SQ_A1; s <= SQ_H8; s++)
- if (!square_empty(s))
- result ^= zobrist[color_of(piece_on(s))][type_of(piece_on(s))][s];
+ for (Bitboard b = pieces(); b; )
+ {
+ Square s = pop_1st_bit(&b);
+ k ^= zobrist[color_of(piece_on(s))][type_of(piece_on(s))][s];
+ }
if (ep_square() != SQ_NONE)
- result ^= zobEp[file_of(ep_square())];
+ k ^= zobEp[file_of(ep_square())];
if (sideToMove == BLACK)
- result ^= zobSideToMove;
+ k ^= zobSideToMove;
- return result;
+ return k;
}
Key Position::compute_pawn_key() const {
- Bitboard b;
- Key result = 0;
+ Key k = 0;
- for (Color c = WHITE; c <= BLACK; c++)
+ for (Bitboard b = pieces(PAWN); b; )
{
- b = pieces(PAWN, c);
- while (b)
- result ^= zobrist[c][PAWN][pop_1st_bit(&b)];
+ Square s = pop_1st_bit(&b);
+ k ^= zobrist[color_of(piece_on(s))][PAWN][s];
}
- return result;
+
+ return k;
}
Key Position::compute_material_key() const {
- Key result = 0;
+ Key k = 0;
for (Color c = WHITE; c <= BLACK; c++)
for (PieceType pt = PAWN; pt <= QUEEN; pt++)
- for (int i = 0; i < piece_count(c, pt); i++)
- result ^= zobrist[c][pt][i];
+ for (int cnt = 0; cnt < piece_count(c, pt); cnt++)
+ k ^= zobrist[c][pt][cnt];
- return result;
+ return k;
}
/// updated by do_move and undo_move when the program is running in debug mode.
Score Position::compute_psq_score() const {
- Bitboard b;
- Score result = SCORE_ZERO;
+ Score score = SCORE_ZERO;
- for (Color c = WHITE; c <= BLACK; c++)
- for (PieceType pt = PAWN; pt <= KING; pt++)
- {
- b = pieces(pt, c);
- while (b)
- result += pieceSquareTable[make_piece(c, pt)][pop_1st_bit(&b)];
- }
+ for (Bitboard b = pieces(); b; )
+ {
+ Square s = pop_1st_bit(&b);
+ score += pieceSquareTable[piece_on(s)][s];
+ }
- result += (sideToMove == WHITE ? Tempo / 2 : -Tempo / 2);
- return result;
+ return score;
}
Value Position::compute_non_pawn_material(Color c) const {
- Value result = VALUE_ZERO;
+ Value value = VALUE_ZERO;
for (PieceType pt = KNIGHT; pt <= QUEEN; pt++)
- result += piece_count(c, pt) * PieceValueMidgame[pt];
+ value += piece_count(c, pt) * PieceValueMidgame[pt];
- return result;
+ return value;
}
zobSideToMove = rk.rand<Key>();
zobExclusion = rk.rand<Key>();
- for (Piece p = W_PAWN; p <= W_KING; p++)
+ for (PieceType pt = PAWN; pt <= KING; pt++)
{
- Score ps = make_score(PieceValueMidgame[p], PieceValueEndgame[p]);
+ Score v = make_score(PieceValueMidgame[pt], PieceValueEndgame[pt]);
for (Square s = SQ_A1; s <= SQ_H8; s++)
{
- pieceSquareTable[p][s] = ps + PSQT[p][s];
- pieceSquareTable[p+8][~s] = -pieceSquareTable[p][s];
+ pieceSquareTable[make_piece(WHITE, pt)][ s] = (v + PSQT[pt][s]);
+ pieceSquareTable[make_piece(BLACK, pt)][~s] = -(v + PSQT[pt][s]);
}
}
}
void Position::flip() {
- // Make a copy of current position before to start changing
- const Position pos(*this, thisThread);
+ const Position pos(*this);
clear();
- thisThread = &pos.this_thread();
- // Board
+ sideToMove = ~pos.side_to_move();
+ thisThread = pos.this_thread();
+ nodes = pos.nodes_searched();
+ chess960 = pos.is_chess960();
+ startPosPly = pos.startpos_ply_counter();
+
for (Square s = SQ_A1; s <= SQ_H8; s++)
- if (!pos.square_empty(s))
+ if (!pos.is_empty(s))
put_piece(Piece(pos.piece_on(s) ^ 8), ~s);
- // Side to move
- sideToMove = ~pos.side_to_move();
-
- // Castling rights
if (pos.can_castle(WHITE_OO))
- set_castle_right(BLACK, ~pos.castle_rook_square(WHITE_OO));
+ set_castle_right(BLACK, ~pos.castle_rook_square(WHITE, KING_SIDE));
if (pos.can_castle(WHITE_OOO))
- set_castle_right(BLACK, ~pos.castle_rook_square(WHITE_OOO));
+ set_castle_right(BLACK, ~pos.castle_rook_square(WHITE, QUEEN_SIDE));
if (pos.can_castle(BLACK_OO))
- set_castle_right(WHITE, ~pos.castle_rook_square(BLACK_OO));
+ set_castle_right(WHITE, ~pos.castle_rook_square(BLACK, KING_SIDE));
if (pos.can_castle(BLACK_OOO))
- set_castle_right(WHITE, ~pos.castle_rook_square(BLACK_OOO));
+ set_castle_right(WHITE, ~pos.castle_rook_square(BLACK, QUEEN_SIDE));
- // En passant square
if (pos.st->epSquare != SQ_NONE)
st->epSquare = ~pos.st->epSquare;
- // Checkers
st->checkersBB = attackers_to(king_square(sideToMove)) & pieces(~sideToMove);
- // Hash keys
st->key = compute_key();
st->pawnKey = compute_pawn_key();
st->materialKey = compute_material_key();
-
- // Incremental scores
st->psqScore = compute_psq_score();
-
- // Material
st->npMaterial[WHITE] = compute_non_pawn_material(WHITE);
st->npMaterial[BLACK] = compute_non_pawn_material(BLACK);
bool Position::pos_is_ok(int* failedStep) const {
+ int dummy, *step = failedStep ? failedStep : &dummy;
+
// What features of the position should be verified?
- const bool debugAll = false;
-
- const bool debugBitboards = debugAll || false;
- const bool debugKingCount = debugAll || false;
- const bool debugKingCapture = debugAll || false;
- const bool debugCheckerCount = debugAll || false;
- const bool debugKey = debugAll || false;
- const bool debugMaterialKey = debugAll || false;
- const bool debugPawnKey = debugAll || false;
- const bool debugIncrementalEval = debugAll || false;
- const bool debugNonPawnMaterial = debugAll || false;
- const bool debugPieceCounts = debugAll || false;
- const bool debugPieceList = debugAll || false;
- const bool debugCastleSquares = debugAll || false;
-
- if (failedStep) *failedStep = 1;
-
- // Side to move OK?
+ const bool all = false;
+
+ const bool debugBitboards = all || false;
+ const bool debugKingCount = all || false;
+ const bool debugKingCapture = all || false;
+ const bool debugCheckerCount = all || false;
+ const bool debugKey = all || false;
+ const bool debugMaterialKey = all || false;
+ const bool debugPawnKey = all || false;
+ const bool debugIncrementalEval = all || false;
+ const bool debugNonPawnMaterial = all || false;
+ const bool debugPieceCounts = all || false;
+ const bool debugPieceList = all || false;
+ const bool debugCastleSquares = all || false;
+
+ *step = 1;
+
if (sideToMove != WHITE && sideToMove != BLACK)
return false;
- // Are the king squares in the position correct?
- if (failedStep) (*failedStep)++;
- if (piece_on(king_square(WHITE)) != W_KING)
+ if ((*step)++, piece_on(king_square(WHITE)) != W_KING)
return false;
- if (failedStep) (*failedStep)++;
- if (piece_on(king_square(BLACK)) != B_KING)
+ if ((*step)++, piece_on(king_square(BLACK)) != B_KING)
return false;
- // Do both sides have exactly one king?
- if (failedStep) (*failedStep)++;
- if (debugKingCount)
+ if ((*step)++, debugKingCount)
{
- int kingCount[2] = {0, 0};
+ int kingCount[2] = {};
+
for (Square s = SQ_A1; s <= SQ_H8; s++)
if (type_of(piece_on(s)) == KING)
kingCount[color_of(piece_on(s))]++;
return false;
}
- // Can the side to move capture the opponent's king?
- if (failedStep) (*failedStep)++;
- if (debugKingCapture)
- {
- Color us = sideToMove;
- Color them = ~us;
- Square ksq = king_square(them);
- if (attackers_to(ksq) & pieces(us))
+ if ((*step)++, debugKingCapture)
+ if (attackers_to(king_square(~sideToMove)) & pieces(sideToMove))
return false;
- }
- // Is there more than 2 checkers?
- if (failedStep) (*failedStep)++;
- if (debugCheckerCount && popcount<Full>(st->checkersBB) > 2)
+ if ((*step)++, debugCheckerCount && popcount<Full>(st->checkersBB) > 2)
return false;
- // Bitboards OK?
- if (failedStep) (*failedStep)++;
- if (debugBitboards)
+ if ((*step)++, debugBitboards)
{
// The intersection of the white and black pieces must be empty
if (pieces(WHITE) & pieces(BLACK))
return false;
}
- // En passant square OK?
- if (failedStep) (*failedStep)++;
- if (ep_square() != SQ_NONE)
- {
- // The en passant square must be on rank 6, from the point of view of the
- // side to move.
- if (relative_rank(sideToMove, ep_square()) != RANK_6)
- return false;
- }
+ if ((*step)++, ep_square() != SQ_NONE && relative_rank(sideToMove, ep_square()) != RANK_6)
+ return false;
- // Hash key OK?
- if (failedStep) (*failedStep)++;
- if (debugKey && st->key != compute_key())
+ if ((*step)++, debugKey && st->key != compute_key())
return false;
- // Pawn hash key OK?
- if (failedStep) (*failedStep)++;
- if (debugPawnKey && st->pawnKey != compute_pawn_key())
+ if ((*step)++, debugPawnKey && st->pawnKey != compute_pawn_key())
return false;
- // Material hash key OK?
- if (failedStep) (*failedStep)++;
- if (debugMaterialKey && st->materialKey != compute_material_key())
+ if ((*step)++, debugMaterialKey && st->materialKey != compute_material_key())
return false;
- // Incremental eval OK?
- if (failedStep) (*failedStep)++;
- if (debugIncrementalEval && st->psqScore != compute_psq_score())
+ if ((*step)++, debugIncrementalEval && st->psqScore != compute_psq_score())
return false;
- // Non-pawn material OK?
- if (failedStep) (*failedStep)++;
- if (debugNonPawnMaterial)
+ if ((*step)++, debugNonPawnMaterial)
{
- if (st->npMaterial[WHITE] != compute_non_pawn_material(WHITE))
- return false;
-
- if (st->npMaterial[BLACK] != compute_non_pawn_material(BLACK))
+ if ( st->npMaterial[WHITE] != compute_non_pawn_material(WHITE)
+ || st->npMaterial[BLACK] != compute_non_pawn_material(BLACK))
return false;
}
- // Piece counts OK?
- if (failedStep) (*failedStep)++;
- if (debugPieceCounts)
+ if ((*step)++, debugPieceCounts)
for (Color c = WHITE; c <= BLACK; c++)
for (PieceType pt = PAWN; pt <= KING; pt++)
- if (pieceCount[c][pt] != popcount<Full>(pieces(pt, c)))
+ if (pieceCount[c][pt] != popcount<Full>(pieces(c, pt)))
return false;
- if (failedStep) (*failedStep)++;
- if (debugPieceList)
+ if ((*step)++, debugPieceList)
for (Color c = WHITE; c <= BLACK; c++)
for (PieceType pt = PAWN; pt <= KING; pt++)
for (int i = 0; i < pieceCount[c][pt]; i++)
return false;
}
- if (failedStep) (*failedStep)++;
- if (debugCastleSquares)
- for (CastleRight f = WHITE_OO; f <= BLACK_OOO; f = CastleRight(f << 1))
- {
- if (!can_castle(f))
- continue;
+ if ((*step)++, debugCastleSquares)
+ for (Color c = WHITE; c <= BLACK; c++)
+ for (CastlingSide s = KING_SIDE; s <= QUEEN_SIDE; s = CastlingSide(s + 1))
+ {
+ CastleRight cr = make_castle_right(c, s);
- Piece rook = (f & (WHITE_OO | WHITE_OOO) ? W_ROOK : B_ROOK);
+ if (!can_castle(cr))
+ continue;
- if ( piece_on(castleRookSquare[f]) != rook
- || castleRightsMask[castleRookSquare[f]] != f)
- return false;
- }
+ if ((castleRightsMask[king_square(c)] & cr) != cr)
+ return false;
+
+ if ( piece_on(castleRookSquare[c][s]) != make_piece(c, ROOK)
+ || castleRightsMask[castleRookSquare[c][s]] != cr)
+ return false;
+ }
- if (failedStep) *failedStep = 0;
+ *step = 0;
return true;
}