X-Git-Url: https://git.sesse.net/?p=stockfish;a=blobdiff_plain;f=src%2Fposition.cpp;h=701a1c0f9b08615b051893f2e5d2c3ab91e199f5;hp=e73e1e5dc3a2dd99b119b35cb0549106f289e14b;hb=d155cd88d1ca914c8a9d398c0164b5a92a5b9629;hpb=f56af8e84db25c0d26fe762fbe171ec5518177bb diff --git a/src/position.cpp b/src/position.cpp index e73e1e5d..701a1c0f 100644 --- a/src/position.cpp +++ b/src/position.cpp @@ -1,13 +1,14 @@ /* - Glaurung, a UCI chess playing engine. - Copyright (C) 2004-2008 Tord Romstad + Stockfish, a UCI chess playing engine derived from Glaurung 2.1 + Copyright (C) 2004-2008 Tord Romstad (Glaurung author) + Copyright (C) 2008 Marco Costalba - Glaurung is free software: you can redistribute it and/or modify + Stockfish is free software: you can redistribute it and/or modify it under the terms of the GNU General Public License as published by the Free Software Foundation, either version 3 of the License, or (at your option) any later version. - Glaurung is distributed in the hope that it will be useful, + Stockfish is distributed in the hope that it will be useful, but WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for more details. @@ -55,14 +56,12 @@ Value Position::EgPieceSquareTable[16][64]; /// Constructors -Position::Position() { } // Do we really need this one? - Position::Position(const Position &pos) { - this->copy(pos); + copy(pos); } Position::Position(const std::string &fen) { - this->from_fen(fen); + from_fen(fen); } @@ -71,59 +70,56 @@ Position::Position(const std::string &fen) { /// correct (this is assumed to be the responsibility of the GUI). void Position::from_fen(const std::string &fen) { - File file; - Rank rank; - int i; - this->clear(); + static const std::string pieceLetters = "KQRBNPkqrbnp"; + static const Piece pieces[] = { WK, WQ, WR, WB, WN, WP, BK, BQ, BR, BB, BN, BP }; + + clear(); // Board - rank = RANK_8; - file = FILE_A; - for(i = 0; fen[i] != ' '; i++) { - if(isdigit(fen[i])) - // Skip the given number of files - file += (fen[i] - '1' + 1); - else { - Square square = make_square(file, rank); - switch(fen[i]) { - case 'K': this->put_piece(WK, square); file++; break; - case 'Q': this->put_piece(WQ, square); file++; break; - case 'R': this->put_piece(WR, square); file++; break; - case 'B': this->put_piece(WB, square); file++; break; - case 'N': this->put_piece(WN, square); file++; break; - case 'P': this->put_piece(WP, square); file++; break; - case 'k': this->put_piece(BK, square); file++; break; - case 'q': this->put_piece(BQ, square); file++; break; - case 'r': this->put_piece(BR, square); file++; break; - case 'b': this->put_piece(BB, square); file++; break; - case 'n': this->put_piece(BN, square); file++; break; - case 'p': this->put_piece(BP, square); file++; break; - case '/': file = FILE_A; rank--; break; - case ' ': break; - default: - std::cout << "Error in FEN at character " << i << std::endl; - return; + Rank rank = RANK_8; + File file = FILE_A; + size_t i = 0; + for ( ; fen[i] != ' '; i++) + { + if (isdigit(fen[i])) + { + // Skip the given number of files + file += (fen[i] - '1' + 1); + continue; } - } + else if (fen[i] == '/') + { + file = FILE_A; + rank--; + continue; + } + size_t idx = pieceLetters.find(fen[i]); + if (idx == std::string::npos) + { + std::cout << "Error in FEN at character " << i << std::endl; + return; + } + Square square = make_square(file, rank); + put_piece(pieces[idx], square); + file++; } // Side to move i++; - if(fen[i] == 'w') - sideToMove = WHITE; - else if(fen[i] == 'b') - sideToMove = BLACK; - else { - std::cout << "Error in FEN at character " << i << std::endl; - return; + if (fen[i] != 'w' && fen[i] != 'b') + { + std::cout << "Error in FEN at character " << i << std::endl; + return; } + sideToMove = (fen[i] == 'w' ? WHITE : BLACK); // Castling rights: i++; - if(fen[i] != ' ') { - std::cout << "Error in FEN at character " << i << std::endl; - return; + if (fen[i] != ' ') + { + std::cout << "Error in FEN at character " << i << std::endl; + return; } i++; @@ -131,14 +127,14 @@ void Position::from_fen(const std::string &fen) { if(fen[i] == '-') { i++; break; } - else if(fen[i] == 'K') this->allow_oo(WHITE); - else if(fen[i] == 'Q') this->allow_ooo(WHITE); - else if(fen[i] == 'k') this->allow_oo(BLACK); - else if(fen[i] == 'q') this->allow_ooo(BLACK); + else if(fen[i] == 'K') allow_oo(WHITE); + else if(fen[i] == 'Q') allow_ooo(WHITE); + else if(fen[i] == 'k') allow_oo(BLACK); + else if(fen[i] == 'q') allow_ooo(BLACK); else if(fen[i] >= 'A' && fen[i] <= 'H') { File rookFile, kingFile = FILE_NONE; for(Square square = SQ_B1; square <= SQ_G1; square++) - if(this->piece_on(square) == WK) + if(piece_on(square) == WK) kingFile = square_file(square); if(kingFile == FILE_NONE) { std::cout << "Error in FEN at character " << i << std::endl; @@ -147,18 +143,18 @@ void Position::from_fen(const std::string &fen) { initialKFile = kingFile; rookFile = File(fen[i] - 'A') + FILE_A; if(rookFile < initialKFile) { - this->allow_ooo(WHITE); + allow_ooo(WHITE); initialQRFile = rookFile; } else { - this->allow_oo(WHITE); + allow_oo(WHITE); initialKRFile = rookFile; } } else if(fen[i] >= 'a' && fen[i] <= 'h') { File rookFile, kingFile = FILE_NONE; for(Square square = SQ_B8; square <= SQ_G8; square++) - if(this->piece_on(square) == BK) + if(piece_on(square) == BK) kingFile = square_file(square); if(kingFile == FILE_NONE) { std::cout << "Error in FEN at character " << i << std::endl; @@ -167,11 +163,11 @@ void Position::from_fen(const std::string &fen) { initialKFile = kingFile; rookFile = File(fen[i] - 'a') + FILE_A; if(rookFile < initialKFile) { - this->allow_ooo(BLACK); + allow_ooo(BLACK); initialQRFile = rookFile; } else { - this->allow_oo(BLACK); + allow_oo(BLACK); initialKRFile = rookFile; } } @@ -182,36 +178,36 @@ void Position::from_fen(const std::string &fen) { i++; } - while(fen[i] == ' ') - i++; + // Skip blanks + while (fen[i] == ' ') + i++; // En passant square - if(i < int(fen.length()) - 2) - if(fen[i] >= 'a' && fen[i] <= 'h' && (fen[i+1] == '3' || fen[i+1] == '6')) + if ( i < fen.length() - 2 + && (fen[i] >= 'a' && fen[i] <= 'h') + && (fen[i+1] == '3' || fen[i+1] == '6')) epSquare = square_from_string(fen.substr(i, 2)); // Various initialisation + for (Square sq = SQ_A1; sq <= SQ_H8; sq++) + castleRightsMask[sq] = ALL_CASTLES; - for(Square sq = SQ_A1; sq <= SQ_H8; sq++) - castleRightsMask[sq] = ALL_CASTLES; - castleRightsMask[make_square(initialKFile, RANK_1)] ^= - (WHITE_OO|WHITE_OOO); - castleRightsMask[make_square(initialKFile, RANK_8)] ^= - (BLACK_OO|BLACK_OOO); + castleRightsMask[make_square(initialKFile, RANK_1)] ^= (WHITE_OO|WHITE_OOO); + castleRightsMask[make_square(initialKFile, RANK_8)] ^= (BLACK_OO|BLACK_OOO); castleRightsMask[make_square(initialKRFile, RANK_1)] ^= WHITE_OO; castleRightsMask[make_square(initialKRFile, RANK_8)] ^= BLACK_OO; castleRightsMask[make_square(initialQRFile, RANK_1)] ^= WHITE_OOO; castleRightsMask[make_square(initialQRFile, RANK_8)] ^= BLACK_OOO; - this->find_checkers(); + find_checkers(); - key = this->compute_key(); - pawnKey = this->compute_pawn_key(); - materialKey = this->compute_material_key(); - mgValue = this->compute_mg_value(); - egValue = this->compute_eg_value(); - npMaterial[WHITE] = this->compute_non_pawn_material(WHITE); - npMaterial[BLACK] = this->compute_non_pawn_material(BLACK); + key = compute_key(); + pawnKey = compute_pawn_key(); + materialKey = compute_material_key(); + mgValue = compute_mg_value(); + egValue = compute_eg_value(); + npMaterial[WHITE] = compute_non_pawn_material(WHITE); + npMaterial[BLACK] = compute_non_pawn_material(BLACK); } @@ -219,40 +215,50 @@ void Position::from_fen(const std::string &fen) { /// probably only useful for debugging. const std::string Position::to_fen() const { - char pieceLetters[] = " PNBRQK pnbrqk"; - std::string result; + + static const std::string pieceLetters = " PNBRQK pnbrqk"; + std::string fen; int skip; - for(Rank rank = RANK_8; rank >= RANK_1; rank--) { - skip = 0; - for(File file = FILE_A; file <= FILE_H; file++) { - Square square = make_square(file, rank); - if(this->square_is_occupied(square)) { - if(skip > 0) result += (char)skip + '0'; - result += pieceLetters[this->piece_on(square)]; - skip = 0; + for (Rank rank = RANK_8; rank >= RANK_1; rank--) + { + skip = 0; + for (File file = FILE_A; file <= FILE_H; file++) + { + Square sq = make_square(file, rank); + if (!square_is_occupied(sq)) + { skip++; + continue; + } + if (skip > 0) + { + fen += (char)skip + '0'; + skip = 0; + } + fen += pieceLetters[piece_on(sq)]; } - else skip++; - } - if(skip > 0) result += (char)skip + '0'; - result += (rank > RANK_1)? '/' : ' '; - } + if (skip > 0) + fen += (char)skip + '0'; - result += (sideToMove == WHITE)? 'w' : 'b'; - result += ' '; - if(castleRights == NO_CASTLES) result += '-'; - else { - if(this->can_castle_kingside(WHITE)) result += 'K'; - if(this->can_castle_queenside(WHITE)) result += 'Q'; - if(this->can_castle_kingside(BLACK)) result += 'k'; - if(this->can_castle_queenside(BLACK)) result += 'q'; + fen += (rank > RANK_1 ? '/' : ' '); } + fen += (sideToMove == WHITE ? 'w' : 'b') + ' '; + if (castleRights != NO_CASTLES) + { + if (can_castle_kingside(WHITE)) fen += 'K'; + if (can_castle_queenside(WHITE)) fen += 'Q'; + if (can_castle_kingside(BLACK)) fen += 'k'; + if (can_castle_queenside(BLACK)) fen += 'q'; + } else + fen += '-'; + + fen += ' '; + if (ep_square() != SQ_NONE) + fen += square_to_string(ep_square()); + else + fen += '-'; - result += ' '; - if(this->ep_square() == SQ_NONE) result += '-'; - else result += square_to_string(this->ep_square()); - - return result; + return fen; } @@ -269,7 +275,7 @@ void Position::print() const { std::cout << "+---+---+---+---+---+---+---+---+\n"; for(File file = FILE_A; file <= FILE_H; file++) { Square sq = make_square(file, rank); - Piece piece = this->piece_on(sq); + Piece piece = piece_on(sq); if(piece == EMPTY) std::cout << ((square_color(sq) == WHITE)? "| " : "| . "); else @@ -278,7 +284,7 @@ void Position::print() const { std::cout << "|\n"; } std::cout << "+---+---+---+---+---+---+---+---+\n"; - std::cout << this->to_fen() << std::endl; + std::cout << to_fen() << std::endl; std::cout << key << std::endl; } @@ -286,77 +292,70 @@ void Position::print() const { /// Position::copy() creates a copy of the input position. void Position::copy(const Position &pos) { + memcpy(this, &pos, sizeof(Position)); } /// Position:pinned_pieces() returns a bitboard of all pinned (against the /// king) pieces for the given color. - Bitboard Position::pinned_pieces(Color c) const { - Bitboard b1, b2, pinned, pinners, sliders; - Square ksq = this->king_square(c), s; - Color them = opposite_color(c); - - pinned = EmptyBoardBB; - b1 = this->occupied_squares(); - - sliders = this->rooks_and_queens(them) & ~this->checkers(); - if(sliders & RookPseudoAttacks[ksq]) { - b2 = this->rook_attacks(ksq) & this->pieces_of_color(c); - pinners = rook_attacks_bb(ksq, b1 ^ b2) & sliders; - while(pinners) { - s = pop_1st_bit(&pinners); - pinned |= (squares_between(s, ksq) & b2); - } - } - sliders = this->bishops_and_queens(them) & ~this->checkers(); - if(sliders & BishopPseudoAttacks[ksq]) { - b2 = this->bishop_attacks(ksq) & this->pieces_of_color(c); - pinners = bishop_attacks_bb(ksq, b1 ^ b2) & sliders; - while(pinners) { - s = pop_1st_bit(&pinners); - pinned |= (squares_between(s, ksq) & b2); - } - } - - return pinned; + Square ksq = king_square(c); + return hidden_checks(c, ksq) | hidden_checks(c, ksq); } + /// Position:discovered_check_candidates() returns a bitboard containing all /// pieces for the given side which are candidates for giving a discovered /// check. The code is almost the same as the function for finding pinned /// pieces. Bitboard Position::discovered_check_candidates(Color c) const { - Bitboard b1, b2, dc, checkers, sliders; - Square ksq = this->king_square(opposite_color(c)), s; - - dc = EmptyBoardBB; - b1 = this->occupied_squares(); - - sliders = this->rooks_and_queens(c); - if(sliders & RookPseudoAttacks[ksq]) { - b2 = this->rook_attacks(ksq) & this->pieces_of_color(c); - checkers = rook_attacks_bb(ksq, b1 ^ b2) & sliders; - while(checkers) { - s = pop_1st_bit(&checkers); - dc |= (squares_between(s, ksq) & b2); - } - } - sliders = this->bishops_and_queens(c); - if(sliders & BishopPseudoAttacks[ksq]) { - b2 = this->bishop_attacks(ksq) & this->pieces_of_color(c); - checkers = bishop_attacks_bb(ksq, b1 ^ b2) & sliders; - while(checkers) { - s = pop_1st_bit(&checkers); - dc |= (squares_between(s, ksq) & b2); - } - } + Square ksq = king_square(opposite_color(c)); + return hidden_checks(c, ksq) | hidden_checks(c, ksq); +} + + +/// Position:hidden_checks<>() returns a bitboard of all pinned (against the +/// king) pieces for the given color and for the given pinner type. Or, when +/// template parameter FindPinned is false, the pinned pieces of opposite color +/// that are, indeed, the pieces candidate for a discovery check. +template +Bitboard Position::hidden_checks(Color c, Square ksq) const { + + 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 + sliders = bishops_and_queens(FindPinned ? opposite_color(c) : c) & BishopPseudoAttacks[ksq]; + + if (sliders && (!FindPinned || (sliders & ~checkersBB))) + { + // King blockers are candidate pinned pieces + Bitboard candidate_pinned = piece_attacks(ksq) & pieces_of_color(c); + + // Pinners are sliders, not checkers, that give check when + // candidate pinned are removed. + Bitboard pinners = (FindPinned ? sliders & ~checkersBB : sliders); - return dc; + if (Piece == ROOK) + pinners &= rook_attacks_bb(ksq, occupied_squares() ^ candidate_pinned); + else + pinners &= bishop_attacks_bb(ksq, occupied_squares() ^ candidate_pinned); + + // Finally for each pinner find the corresponding pinned piece (if same color of king) + // or discovery checker (if opposite color) among the candidates. + while (pinners) + { + s = pop_1st_bit(&pinners); + result |= (squares_between(s, ksq) & candidate_pinned); + } + } + return result; } @@ -364,12 +363,12 @@ Bitboard Position::discovered_check_candidates(Color c) const { /// given square. bool Position::square_is_attacked(Square s, Color c) const { - return - (this->pawn_attacks(opposite_color(c), s) & this->pawns(c)) || - (this->knight_attacks(s) & this->knights(c)) || - (this->king_attacks(s) & this->kings(c)) || - (this->rook_attacks(s) & this->rooks_and_queens(c)) || - (this->bishop_attacks(s) & this->bishops_and_queens(c)); + + return (pawn_attacks(opposite_color(c), s) & pawns(c)) + || (piece_attacks(s) & knights(c)) + || (piece_attacks(s) & kings(c)) + || (piece_attacks(s) & rooks_and_queens(c)) + || (piece_attacks(s) & bishops_and_queens(c)); } @@ -379,17 +378,18 @@ bool Position::square_is_attacked(Square s, Color c) const { /// attackers for one side. Bitboard Position::attacks_to(Square s) const { - return - (this->black_pawn_attacks(s) & this->pawns(WHITE)) | - (this->white_pawn_attacks(s) & this->pawns(BLACK)) | - (this->knight_attacks(s) & this->pieces_of_type(KNIGHT)) | - (this->rook_attacks(s) & this->rooks_and_queens()) | - (this->bishop_attacks(s) & this->bishops_and_queens()) | - (this->king_attacks(s) & this->pieces_of_type(KING)); + + return (pawn_attacks(BLACK, s) & pawns(WHITE)) + | (pawn_attacks(WHITE, s) & pawns(BLACK)) + | (piece_attacks(s) & pieces_of_type(KNIGHT)) + | (piece_attacks(s) & rooks_and_queens()) + | (piece_attacks(s) & bishops_and_queens()) + | (piece_attacks(s) & pieces_of_type(KING)); } Bitboard Position::attacks_to(Square s, Color c) const { - return this->attacks_to(s) & this->pieces_of_color(c); + + return attacks_to(s) & pieces_of_color(c); } @@ -397,20 +397,49 @@ Bitboard Position::attacks_to(Square s, Color c) const { /// attacks square t. bool Position::piece_attacks_square(Square f, Square t) const { + assert(square_is_ok(f)); assert(square_is_ok(t)); - switch(this->piece_on(f)) { - case WP: return this->white_pawn_attacks_square(f, t); - case BP: return this->black_pawn_attacks_square(f, t); - case WN: case BN: return this->knight_attacks_square(f, t); - case WB: case BB: return this->bishop_attacks_square(f, t); - case WR: case BR: return this->rook_attacks_square(f, t); - case WQ: case BQ: return this->queen_attacks_square(f, t); - case WK: case BK: return this->king_attacks_square(f, t); - default: return false; + switch (piece_on(f)) + { + case WP: return pawn_attacks_square(WHITE, f, t); + case BP: return pawn_attacks_square(BLACK, f, t); + case WN: case BN: return piece_attacks_square(f, t); + case WB: case BB: return piece_attacks_square(f, t); + case WR: case BR: return piece_attacks_square(f, t); + case WQ: case BQ: return piece_attacks_square(f, t); + case WK: case BK: return piece_attacks_square(f, t); + default: return false; } + return false; +} + + +/// Position::move_attacks_square() tests whether a move from the current +/// position attacks a given square. Only attacks by the moving piece are +/// considered; the function does not handle X-ray attacks. +bool Position::move_attacks_square(Move m, Square s) const { + + assert(move_is_ok(m)); + assert(square_is_ok(s)); + + Square f = move_from(m), t = move_to(m); + + assert(square_is_occupied(f)); + + switch (piece_on(f)) + { + case WP: return pawn_attacks_square(WHITE, t, s); + case BP: return pawn_attacks_square(BLACK, t, s); + case WN: case BN: return piece_attacks_square(t, s); + case WB: case BB: return piece_attacks_square(t, s); + case WR: case BR: return piece_attacks_square(t, s); + case WQ: case BQ: return piece_attacks_square(t, s); + case WK: case BK: return piece_attacks_square(t, s); + default: assert(false); + } return false; } @@ -422,75 +451,80 @@ bool Position::piece_attacks_square(Square f, Square t) const { /// played, like in non-bitboard versions of Glaurung. void Position::find_checkers() { - checkersBB = attacks_to(this->king_square(this->side_to_move()), - opposite_color(this->side_to_move())); + + checkersBB = attacks_to(king_square(side_to_move()),opposite_color(side_to_move())); } /// Position::move_is_legal() tests whether a pseudo-legal move is legal. /// There are two versions of this function: One which takes only a /// move as input, and one which takes a move and a bitboard of pinned -/// pieces. The latter function is faster, and should always be preferred +/// pieces. The latter function is faster, and should always be preferred /// when a pinned piece bitboard has already been computed. bool Position::move_is_legal(Move m) const { - return this->move_is_legal(m, this->pinned_pieces(this->side_to_move())); -} + return move_is_legal(m, pinned_pieces(side_to_move())); +} bool Position::move_is_legal(Move m, Bitboard pinned) const { + Color us, them; Square ksq, from; - assert(this->is_ok()); + assert(is_ok()); assert(move_is_ok(m)); - assert(pinned == this->pinned_pieces(this->side_to_move())); + assert(pinned == pinned_pieces(side_to_move())); // If we're in check, all pseudo-legal moves are legal, because our // check evasion generator only generates true legal moves. - if(this->is_check()) return true; + if (is_check()) + return true; // Castling moves are checked for legality during move generation. - if(move_is_castle(m)) return true; + if (move_is_castle(m)) + return true; - us = this->side_to_move(); + us = side_to_move(); them = opposite_color(us); - from = move_from(m); - ksq = this->king_square(us); + ksq = king_square(us); - assert(this->color_of_piece_on(from) == us); - assert(this->piece_on(ksq) == king_of_color(us)); + assert(color_of_piece_on(from) == us); + assert(piece_on(ksq) == king_of_color(us)); // En passant captures are a tricky special case. Because they are // rather uncommon, we do it simply by testing whether the king is attacked - // after the move is made: - if(move_is_ep(m)) { - Square to = move_to(m); - Square capsq = make_square(square_file(to), square_rank(from)); - Bitboard b = this->occupied_squares(); - - assert(to == this->ep_square()); - assert(this->piece_on(from) == pawn_of_color(us)); - assert(this->piece_on(capsq) == pawn_of_color(them)); - assert(this->piece_on(to) == EMPTY); - - clear_bit(&b, from); clear_bit(&b, capsq); set_bit(&b, to); - return - (!(rook_attacks_bb(ksq, b) & this->rooks_and_queens(them)) && - !(bishop_attacks_bb(ksq, b) & this->bishops_and_queens(them))); + // after the move is made + if (move_is_ep(m)) + { + Square to = move_to(m); + Square capsq = make_square(square_file(to), square_rank(from)); + Bitboard b = occupied_squares(); + + assert(to == ep_square()); + assert(piece_on(from) == pawn_of_color(us)); + assert(piece_on(capsq) == pawn_of_color(them)); + assert(piece_on(to) == EMPTY); + + clear_bit(&b, from); + clear_bit(&b, capsq); + set_bit(&b, to); + + return !(rook_attacks_bb(ksq, b) & rooks_and_queens(them)) + && !(bishop_attacks_bb(ksq, b) & bishops_and_queens(them)); } // If the moving piece is a king, check whether the destination // square is attacked by the opponent. - if(from == ksq) return !(this->square_is_attacked(move_to(m), them)); + if (from == ksq) + return !(square_is_attacked(move_to(m), them)); // 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)) return true; - if(direction_between_squares(from, ksq) == - direction_between_squares(move_to(m), ksq)) - return true; + if ( !bit_is_set(pinned, from) + || (direction_between_squares(from, ksq) == direction_between_squares(move_to(m), ksq))) + return true; return false; } @@ -503,138 +537,126 @@ bool Position::move_is_legal(Move m, Bitboard pinned) const { /// when a discovered check candidates bitboard has already been computed. bool Position::move_is_check(Move m) const { - Bitboard dc = this->discovered_check_candidates(this->side_to_move()); - return this->move_is_check(m, dc); -} + Bitboard dc = discovered_check_candidates(side_to_move()); + return move_is_check(m, dc); +} bool Position::move_is_check(Move m, Bitboard dcCandidates) const { + Color us, them; Square ksq, from, to; - assert(this->is_ok()); + assert(is_ok()); assert(move_is_ok(m)); - assert(dcCandidates == - this->discovered_check_candidates(this->side_to_move())); + assert(dcCandidates == discovered_check_candidates(side_to_move())); - us = this->side_to_move(); + us = side_to_move(); them = opposite_color(us); - from = move_from(m); to = move_to(m); - ksq = this->king_square(them); - assert(this->color_of_piece_on(from) == us); - assert(this->piece_on(ksq) == king_of_color(them)); + ksq = king_square(them); - // Proceed according to the type of the moving piece: - switch(this->type_of_piece_on(from)) { - case PAWN: - // Normal check? - if(bit_is_set(this->pawn_attacks(them, ksq), to)) - return true; - // Discovered check? - else if(bit_is_set(dcCandidates, from) && - direction_between_squares(from, ksq) != - direction_between_squares(to, ksq)) - return true; - // Promotion with check? - else if(move_promotion(m)) { - Bitboard b = this->occupied_squares(); - clear_bit(&b, from); + assert(color_of_piece_on(from) == us); + assert(piece_on(ksq) == king_of_color(them)); - switch(move_promotion(m)) { - case KNIGHT: - return this->knight_attacks_square(to, ksq); - case BISHOP: - return bit_is_set(bishop_attacks_bb(to, b), ksq); - case ROOK: - return bit_is_set(rook_attacks_bb(to, b), ksq); - case QUEEN: - return bit_is_set(queen_attacks_bb(to, b), ksq); - default: - assert(false); + // Proceed according to the type of the moving piece + 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(); + clear_bit(&b, from); + + switch (move_promotion(m)) + { + case KNIGHT: + return bit_is_set(piece_attacks(to), ksq); + case BISHOP: + return bit_is_set(bishop_attacks_bb(to, b), ksq); + case ROOK: + return bit_is_set(rook_attacks_bb(to, b), ksq); + case QUEEN: + return bit_is_set(queen_attacks_bb(to, b), ksq); + default: + assert(false); + } } - } - // En passant capture with check? We have already handled the case - // of direct checks and ordinary discovered check, the only case we - // need to handle is the unusual case of a discovered check through the - // captured pawn. - else if(move_is_ep(m)) { - Square capsq = make_square(square_file(to), square_rank(from)); - Bitboard b = this->occupied_squares(); - - clear_bit(&b, from); clear_bit(&b, capsq); set_bit(&b, to); - return - ((rook_attacks_bb(ksq, b) & this->rooks_and_queens(us)) || - (bishop_attacks_bb(ksq, b) & this->bishops_and_queens(us))); - } - return false; + // En passant capture with check? We have already handled the case + // of direct checks and ordinary discovered check, the only case we + // need to handle is the unusual case of a discovered check through the + // captured pawn. + else if (move_is_ep(m)) + { + Square capsq = make_square(square_file(to), square_rank(from)); + Bitboard b = occupied_squares(); + clear_bit(&b, from); + clear_bit(&b, capsq); + set_bit(&b, to); + return (rook_attacks_bb(ksq, b) & rooks_and_queens(us)) + ||(bishop_attacks_bb(ksq, b) & bishops_and_queens(us)); + } + return false; - case KNIGHT: - // Discovered check? - if(bit_is_set(dcCandidates, from)) - return true; - // Normal check? - else - return bit_is_set(this->knight_attacks(ksq), to); + case KNIGHT: + return bit_is_set(dcCandidates, from) // Discovered check? + || bit_is_set(piece_attacks(ksq), to); // Normal check? case BISHOP: - // Discovered check? - if(bit_is_set(dcCandidates, from)) - return true; - // Normal check? - else - return bit_is_set(this->bishop_attacks(ksq), to); + return bit_is_set(dcCandidates, from) // Discovered check? + || bit_is_set(piece_attacks(ksq), to); // Normal check? case ROOK: - // Discovered check? - if(bit_is_set(dcCandidates, from)) - return true; - // Normal check? - else - return bit_is_set(this->rook_attacks(ksq), to); + return bit_is_set(dcCandidates, from) // Discovered check? + || bit_is_set(piece_attacks(ksq), to); // Normal check? case QUEEN: - // Discovered checks are impossible! - assert(!bit_is_set(dcCandidates, from)); - // Normal check? - return bit_is_set(this->queen_attacks(ksq), to); + // Discovered checks are impossible! + assert(!bit_is_set(dcCandidates, from)); + return bit_is_set(piece_attacks(ksq), to); // Normal check? case KING: - // Discovered check? - if(bit_is_set(dcCandidates, from) && - direction_between_squares(from, ksq) != - direction_between_squares(to, ksq)) - return true; - // Castling with check? - if(move_is_castle(m)) { - Square kfrom, kto, rfrom, rto; - Bitboard b = this->occupied_squares(); - - kfrom = from; - rfrom = to; - if(rfrom > kfrom) { - kto = relative_square(us, SQ_G1); - rto = relative_square(us, SQ_F1); - } - else { - kto = relative_square(us, SQ_C1); - rto = relative_square(us, SQ_D1); + // Discovered check? + if ( bit_is_set(dcCandidates, from) + && (direction_between_squares(from, ksq) != direction_between_squares(to, ksq))) + return true; + + // Castling with check? + if (move_is_castle(m)) + { + Square kfrom, kto, rfrom, rto; + Bitboard b = occupied_squares(); + kfrom = from; + rfrom = to; + + if (rfrom > kfrom) + { + kto = relative_square(us, SQ_G1); + rto = relative_square(us, SQ_F1); + } else { + kto = relative_square(us, SQ_C1); + rto = relative_square(us, SQ_D1); + } + clear_bit(&b, kfrom); + clear_bit(&b, rfrom); + set_bit(&b, rto); + set_bit(&b, kto); + return bit_is_set(rook_attacks_bb(rto, b), ksq); } - - clear_bit(&b, kfrom); clear_bit(&b, rfrom); - set_bit(&b, rto); set_bit(&b, kto); - - return bit_is_set(rook_attacks_bb(rto, b), ksq); - } - - return false; + return false; default: - assert(false); - return false; + assert(false); } - assert(false); return false; } @@ -644,40 +666,12 @@ bool Position::move_is_check(Move m, Bitboard dcCandidates) const { /// position is a capture. bool Position::move_is_capture(Move m) const { - return - this->color_of_piece_on(move_to(m)) == opposite_color(this->side_to_move()) - || move_is_ep(m); -} - -/// Position::move_attacks_square() tests whether a move from the current -/// position attacks a given square. Only attacks by the moving piece are -/// considered; the function does not handle X-ray attacks. - -bool Position::move_attacks_square(Move m, Square s) const { - assert(move_is_ok(m)); - assert(square_is_ok(s)); - - Square f = move_from(m), t = move_to(m); - - assert(this->square_is_occupied(f)); - - switch(this->piece_on(f)) { - case WP: return this->white_pawn_attacks_square(t, s); - case BP: return this->black_pawn_attacks_square(t, s); - case WN: case BN: return this->knight_attacks_square(t, s); - case WB: case BB: return this->bishop_attacks_square(t, s); - case WR: case BR: return this->rook_attacks_square(t, s); - case WQ: case BQ: return this->queen_attacks_square(t, s); - case WK: case BK: return this->king_attacks_square(t, s); - default: assert(false); - } - - return false; + return color_of_piece_on(move_to(m)) == opposite_color(side_to_move()) + || move_is_ep(m); } - /// Position::backup() is called when making a move. All information /// necessary to restore the position when the move is later unmade /// is saved to an UndoInfo object. The function Position::restore @@ -727,16 +721,16 @@ void Position::restore(const UndoInfo &u) { /// member variable in the position object. void Position::do_move(Move m, UndoInfo &u) { - this->do_move(m, u, this->discovered_check_candidates(this->side_to_move())); + do_move(m, u, discovered_check_candidates(side_to_move())); } void Position::do_move(Move m, UndoInfo &u, Bitboard dcCandidates) { - assert(this->is_ok()); + assert(is_ok()); assert(move_is_ok(m)); // Back up the necessary information to our UndoInfo object (except the // captured piece, which is taken care of later: - this->backup(u); + backup(u); // Save the current key to the history[] array, in order to be able to // detect repetition draws: @@ -747,27 +741,27 @@ void Position::do_move(Move m, UndoInfo &u, Bitboard dcCandidates) { rule50++; if(move_is_castle(m)) - this->do_castle_move(m); + do_castle_move(m); else if(move_promotion(m)) - this->do_promotion_move(m, u); + do_promotion_move(m, u); else if(move_is_ep(m)) - this->do_ep_move(m); + do_ep_move(m); else { Color us, them; Square from, to; PieceType piece, capture; - us = this->side_to_move(); + us = side_to_move(); them = opposite_color(us); from = move_from(m); to = move_to(m); - assert(this->color_of_piece_on(from) == us); - assert(this->color_of_piece_on(to) == them || this->piece_on(to) == EMPTY); + assert(color_of_piece_on(from) == us); + assert(color_of_piece_on(to) == them || piece_on(to) == EMPTY); - piece = this->type_of_piece_on(from); - capture = this->type_of_piece_on(to); + piece = type_of_piece_on(from); + capture = type_of_piece_on(to); if(capture) { assert(capture != KING); @@ -784,8 +778,8 @@ void Position::do_move(Move m, UndoInfo &u, Bitboard dcCandidates) { pawnKey ^= zobrist[them][PAWN][to]; // Update incremental scores: - mgValue -= this->mg_pst(them, capture, to); - egValue -= this->eg_pst(them, capture, to); + mgValue -= mg_pst(them, capture, to); + egValue -= eg_pst(them, capture, to); // Update material: if(capture != PAWN) @@ -824,10 +818,10 @@ void Position::do_move(Move m, UndoInfo &u, Bitboard dcCandidates) { key ^= zobrist[us][piece][from] ^ zobrist[us][piece][to]; // Update incremental scores: - mgValue -= this->mg_pst(us, piece, from); - mgValue += this->mg_pst(us, piece, to); - egValue -= this->eg_pst(us, piece, from); - egValue += this->eg_pst(us, piece, to); + mgValue -= mg_pst(us, piece, from); + mgValue += mg_pst(us, piece, to); + egValue -= eg_pst(us, piece, from); + egValue += eg_pst(us, piece, to); // If the moving piece was a king, update the king square: if(piece == KING) @@ -842,10 +836,10 @@ void Position::do_move(Move m, UndoInfo &u, Bitboard dcCandidates) { } if(piece == PAWN) { if(abs(int(to) - int(from)) == 16) { - if((us == WHITE && (this->white_pawn_attacks(from + DELTA_N) & - this->pawns(BLACK))) || - (us == BLACK && (this->black_pawn_attacks(from + DELTA_S) & - this->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]; } @@ -868,54 +862,54 @@ void Position::do_move(Move m, UndoInfo &u, Bitboard dcCandidates) { // Update checkers bitboard: checkersBB = EmptyBoardBB; - Square ksq = this->king_square(them); + Square ksq = king_square(them); switch(piece) { case PAWN: - if(bit_is_set(this->pawn_attacks(them, ksq), to)) + if(bit_is_set(pawn_attacks(them, ksq), to)) set_bit(&checkersBB, to); if(bit_is_set(dcCandidates, from)) checkersBB |= - ((this->rook_attacks(ksq) & this->rooks_and_queens(us)) | - (this->bishop_attacks(ksq) & this->bishops_and_queens(us))); + ((piece_attacks(ksq) & rooks_and_queens(us)) | + (piece_attacks(ksq) & bishops_and_queens(us))); break; case KNIGHT: - if(bit_is_set(this->knight_attacks(ksq), to)) + if(bit_is_set(piece_attacks(ksq), to)) set_bit(&checkersBB, to); if(bit_is_set(dcCandidates, from)) checkersBB |= - ((this->rook_attacks(ksq) & this->rooks_and_queens(us)) | - (this->bishop_attacks(ksq) & this->bishops_and_queens(us))); + ((piece_attacks(ksq) & rooks_and_queens(us)) | + (piece_attacks(ksq) & bishops_and_queens(us))); break; case BISHOP: - if(bit_is_set(this->bishop_attacks(ksq), to)) + if(bit_is_set(piece_attacks(ksq), to)) set_bit(&checkersBB, to); if(bit_is_set(dcCandidates, from)) checkersBB |= - (this->rook_attacks(ksq) & this->rooks_and_queens(us)); + (piece_attacks(ksq) & rooks_and_queens(us)); break; case ROOK: - if(bit_is_set(this->rook_attacks(ksq), to)) + if(bit_is_set(piece_attacks(ksq), to)) set_bit(&checkersBB, to); if(bit_is_set(dcCandidates, from)) checkersBB |= - (this->bishop_attacks(ksq) & this->bishops_and_queens(us)); + (piece_attacks(ksq) & bishops_and_queens(us)); break; case QUEEN: - if(bit_is_set(this->queen_attacks(ksq), to)) + if(bit_is_set(piece_attacks(ksq), to)) set_bit(&checkersBB, to); break; case KING: if(bit_is_set(dcCandidates, from)) checkersBB |= - ((this->rook_attacks(ksq) & this->rooks_and_queens(us)) | - (this->bishop_attacks(ksq) & this->bishops_and_queens(us))); + ((piece_attacks(ksq) & rooks_and_queens(us)) | + (piece_attacks(ksq) & bishops_and_queens(us))); break; default: @@ -932,7 +926,7 @@ void Position::do_move(Move m, UndoInfo &u, Bitboard dcCandidates) { mgValue += (sideToMove == WHITE)? TempoValueMidgame : -TempoValueMidgame; egValue += (sideToMove == WHITE)? TempoValueEndgame : -TempoValueEndgame; - assert(this->is_ok()); + assert(is_ok()); } @@ -945,19 +939,19 @@ void Position::do_castle_move(Move m) { Color us, them; Square kfrom, kto, rfrom, rto; - assert(this->is_ok()); + assert(is_ok()); assert(move_is_ok(m)); assert(move_is_castle(m)); - us = this->side_to_move(); + us = side_to_move(); them = opposite_color(us); // Find source squares for king and rook: kfrom = move_from(m); rfrom = move_to(m); // HACK: See comment at beginning of function. - assert(this->piece_on(kfrom) == king_of_color(us)); - assert(this->piece_on(rfrom) == rook_of_color(us)); + assert(piece_on(kfrom) == king_of_color(us)); + assert(piece_on(rfrom) == rook_of_color(us)); // Find destination squares for king and rook: if(rfrom > kfrom) { // O-O @@ -1001,14 +995,14 @@ void Position::do_castle_move(Move m) { index[rto] = tmp; // Update incremental scores: - mgValue -= this->mg_pst(us, KING, kfrom); - mgValue += this->mg_pst(us, KING, kto); - egValue -= this->eg_pst(us, KING, kfrom); - egValue += this->eg_pst(us, KING, kto); - mgValue -= this->mg_pst(us, ROOK, rfrom); - mgValue += this->mg_pst(us, ROOK, rto); - egValue -= this->eg_pst(us, ROOK, rfrom); - egValue += this->eg_pst(us, ROOK, rto); + mgValue -= mg_pst(us, KING, kfrom); + mgValue += mg_pst(us, KING, kto); + egValue -= eg_pst(us, KING, kfrom); + egValue += eg_pst(us, KING, kto); + mgValue -= mg_pst(us, ROOK, rfrom); + mgValue += mg_pst(us, ROOK, rto); + egValue -= eg_pst(us, ROOK, rfrom); + egValue += eg_pst(us, ROOK, rto); // Update hash key: key ^= zobrist[us][KING][kfrom] ^ zobrist[us][KING][kto]; @@ -1029,7 +1023,7 @@ void Position::do_castle_move(Move m) { rule50 = 0; // Update checkers BB: - checkersBB = attacks_to(this->king_square(them), us); + checkersBB = attacks_to(king_square(them), us); } @@ -1043,21 +1037,21 @@ void Position::do_promotion_move(Move m, UndoInfo &u) { Square from, to; PieceType capture, promotion; - assert(this->is_ok()); + assert(is_ok()); assert(move_is_ok(m)); assert(move_promotion(m)); - us = this->side_to_move(); + us = side_to_move(); them = opposite_color(us); from = move_from(m); to = move_to(m); assert(relative_rank(us, to) == RANK_8); - assert(this->piece_on(from) == pawn_of_color(us)); - assert(this->color_of_piece_on(to) == them || this->square_is_empty(to)); + assert(piece_on(from) == pawn_of_color(us)); + assert(color_of_piece_on(to) == them || square_is_empty(to)); - capture = this->type_of_piece_on(to); + capture = type_of_piece_on(to); if(capture) { assert(capture != KING); @@ -1070,8 +1064,8 @@ void Position::do_promotion_move(Move m, UndoInfo &u) { key ^= zobrist[them][capture][to]; // Update incremental scores: - mgValue -= this->mg_pst(them, capture, to); - egValue -= this->eg_pst(them, capture, to); + 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. @@ -1130,10 +1124,10 @@ void Position::do_promotion_move(Move m, UndoInfo &u) { index[to] = pieceCount[us][promotion] - 1; // Update incremental scores: - mgValue -= this->mg_pst(us, PAWN, from); - mgValue += this->mg_pst(us, promotion, to); - egValue -= this->eg_pst(us, PAWN, from); - egValue += this->eg_pst(us, promotion, to); + mgValue -= mg_pst(us, PAWN, from); + mgValue += mg_pst(us, promotion, to); + egValue -= eg_pst(us, PAWN, from); + egValue += eg_pst(us, promotion, to); // Update material: npMaterial[us] += piece_value_midgame(promotion); @@ -1153,7 +1147,7 @@ void Position::do_promotion_move(Move m, UndoInfo &u) { rule50 = 0; // Update checkers BB: - checkersBB = attacks_to(this->king_square(them), us); + checkersBB = attacks_to(king_square(them), us); } @@ -1166,11 +1160,11 @@ void Position::do_ep_move(Move m) { Color us, them; Square from, to, capsq; - assert(this->is_ok()); + assert(is_ok()); assert(move_is_ok(m)); assert(move_is_ep(m)); - us = this->side_to_move(); + us = side_to_move(); them = opposite_color(us); // Find from, to and capture squares: @@ -1180,9 +1174,9 @@ void Position::do_ep_move(Move m) { assert(to == epSquare); assert(relative_rank(us, to) == RANK_6); - assert(this->piece_on(to) == EMPTY); - assert(this->piece_on(from) == pawn_of_color(us)); - assert(this->piece_on(capsq) == pawn_of_color(them)); + assert(piece_on(to) == EMPTY); + assert(piece_on(from) == pawn_of_color(us)); + assert(piece_on(capsq) == pawn_of_color(them)); // Remove captured piece: clear_bit(&(byColorBB[them]), capsq); @@ -1225,12 +1219,12 @@ void Position::do_ep_move(Move m) { pawnKey ^= zobrist[them][PAWN][capsq]; // Update incremental scores: - mgValue -= this->mg_pst(them, PAWN, capsq); - mgValue -= this->mg_pst(us, PAWN, from); - mgValue += this->mg_pst(us, PAWN, to); - egValue -= this->eg_pst(them, PAWN, capsq); - egValue -= this->eg_pst(us, PAWN, from); - egValue += this->eg_pst(us, PAWN, to); + mgValue -= mg_pst(them, PAWN, capsq); + mgValue -= mg_pst(us, PAWN, from); + mgValue += mg_pst(us, PAWN, to); + egValue -= eg_pst(them, PAWN, capsq); + egValue -= eg_pst(us, PAWN, from); + egValue += eg_pst(us, PAWN, to); // Reset en passant square: epSquare = SQ_NONE; @@ -1239,7 +1233,7 @@ void Position::do_ep_move(Move m) { rule50 = 0; // Update checkers BB: - checkersBB = attacks_to(this->king_square(them), us); + checkersBB = attacks_to(king_square(them), us); } @@ -1249,7 +1243,7 @@ void Position::do_ep_move(Move m) { /// object as the earlier call to Position::do_move. void Position::undo_move(Move m, const UndoInfo &u) { - assert(this->is_ok()); + assert(is_ok()); assert(move_is_ok(m)); gamePly--; @@ -1257,30 +1251,30 @@ void Position::undo_move(Move m, const UndoInfo &u) { // Restore information from our UndoInfo object (except the captured piece, // which is taken care of later): - this->restore(u); + restore(u); if(move_is_castle(m)) - this->undo_castle_move(m); + undo_castle_move(m); else if(move_promotion(m)) - this->undo_promotion_move(m, u); + undo_promotion_move(m, u); else if(move_is_ep(m)) - this->undo_ep_move(m); + undo_ep_move(m); else { Color us, them; Square from, to; PieceType piece, capture; - us = this->side_to_move(); + us = side_to_move(); them = opposite_color(us); from = move_from(m); to = move_to(m); - assert(this->piece_on(from) == EMPTY); + assert(piece_on(from) == EMPTY); assert(color_of_piece_on(to) == us); // Put the piece back at the source square: - piece = this->type_of_piece_on(to); + piece = type_of_piece_on(to); set_bit(&(byColorBB[us]), from); set_bit(&(byTypeBB[piece]), from); set_bit(&(byTypeBB[0]), from); // HACK: byTypeBB[0] == occupied squares @@ -1324,7 +1318,7 @@ void Position::undo_move(Move m, const UndoInfo &u) { board[to] = EMPTY; } - assert(this->is_ok()); + assert(is_ok()); } @@ -1343,7 +1337,7 @@ void Position::undo_castle_move(Move m) { // When we have arrived here, some work has already been done by // Position::undo_move. In particular, the side to move has been switched, // so the code below is correct. - us = this->side_to_move(); + us = side_to_move(); them = opposite_color(us); // Find source squares for king and rook: @@ -1360,8 +1354,8 @@ void Position::undo_castle_move(Move m) { rto = relative_square(us, SQ_D1); } - assert(this->piece_on(kto) == king_of_color(us)); - assert(this->piece_on(rto) == rook_of_color(us)); + assert(piece_on(kto) == king_of_color(us)); + assert(piece_on(rto) == rook_of_color(us)); // Remove pieces from destination squares: clear_bit(&(byColorBB[us]), kto); @@ -1412,18 +1406,18 @@ void Position::undo_promotion_move(Move m, const UndoInfo &u) { // When we have arrived here, some work has already been done by // Position::undo_move. In particular, the side to move has been switched, // so the code below is correct. - us = this->side_to_move(); + us = side_to_move(); them = opposite_color(us); from = move_from(m); to = move_to(m); assert(relative_rank(us, to) == RANK_8); - assert(this->piece_on(from) == EMPTY); + assert(piece_on(from) == EMPTY); // Remove promoted piece: promotion = move_promotion(m); - assert(this->piece_on(to)==piece_of_color_and_type(us, promotion)); + assert(piece_on(to)==piece_of_color_and_type(us, promotion)); assert(promotion >= KNIGHT && promotion <= QUEEN); clear_bit(&(byColorBB[us]), to); clear_bit(&(byTypeBB[promotion]), to); @@ -1491,7 +1485,7 @@ void Position::undo_ep_move(Move m) { // When we have arrived here, some work has already been done by // Position::undo_move. In particular, the side to move has been switched, // so the code below is correct. - us = this->side_to_move(); + us = side_to_move(); them = opposite_color(us); // Find from, to and captures squares: @@ -1499,11 +1493,11 @@ void Position::undo_ep_move(Move m) { to = move_to(m); capsq = (us == WHITE)? (to - DELTA_N) : (to - DELTA_S); - assert(to == this->ep_square()); + assert(to == ep_square()); assert(relative_rank(us, to) == RANK_6); - assert(this->piece_on(to) == pawn_of_color(us)); - assert(this->piece_on(from) == EMPTY); - assert(this->piece_on(capsq) == EMPTY); + assert(piece_on(to) == pawn_of_color(us)); + assert(piece_on(from) == EMPTY); + assert(piece_on(capsq) == EMPTY); // Replace captured piece: set_bit(&(byColorBB[them]), capsq); @@ -1538,8 +1532,8 @@ void Position::undo_ep_move(Move m) { /// and updates the hash key without executing any move on the board. void Position::do_null_move(UndoInfo &u) { - assert(this->is_ok()); - assert(!this->is_check()); + assert(is_ok()); + assert(!is_check()); // Back up the information necessary to undo the null move to the supplied // UndoInfo object. In the case of a null move, the only thing we need to @@ -1563,15 +1557,15 @@ void Position::do_null_move(UndoInfo &u) { mgValue += (sideToMove == WHITE)? TempoValueMidgame : -TempoValueMidgame; egValue += (sideToMove == WHITE)? TempoValueEndgame : -TempoValueEndgame; - assert(this->is_ok()); + assert(is_ok()); } /// Position::undo_null_move() unmakes a "null move". void Position::undo_null_move(const UndoInfo &u) { - assert(this->is_ok()); - assert(!this->is_check()); + assert(is_ok()); + assert(!is_check()); // Restore information from the supplied UndoInfo object: lastMove = u.lastMove; @@ -1588,7 +1582,7 @@ void Position::undo_null_move(const UndoInfo &u) { mgValue += (sideToMove == WHITE)? TempoValueMidgame : -TempoValueMidgame; egValue += (sideToMove == WHITE)? TempoValueEndgame : -TempoValueEndgame; - assert(this->is_ok()); + assert(is_ok()); } @@ -1611,28 +1605,28 @@ int Position::see(Square from, Square to) const { assert(square_is_ok(to)); // Initialize colors: - us = this->color_of_piece_on(from); + us = color_of_piece_on(from); them = opposite_color(us); // Initialize pieces: - piece = this->piece_on(from); - capture = this->piece_on(to); + piece = piece_on(from); + capture = piece_on(to); // Find all attackers to the destination square, with the moving piece // removed, but possibly an X-ray attacker added behind it: - occ = this->occupied_squares(); + occ = occupied_squares(); clear_bit(&occ, from); attackers = - (rook_attacks_bb(to, occ) & this->rooks_and_queens()) | - (bishop_attacks_bb(to, occ) & this->bishops_and_queens()) | - (this->knight_attacks(to) & this->knights()) | - (this->king_attacks(to) & this->kings()) | - (this->white_pawn_attacks(to) & this->pawns(BLACK)) | - (this->black_pawn_attacks(to) & this->pawns(WHITE)); + (rook_attacks_bb(to, occ) & rooks_and_queens()) | + (bishop_attacks_bb(to, occ) & bishops_and_queens()) | + (piece_attacks(to) & knights()) | + (piece_attacks(to) & kings()) | + (pawn_attacks(WHITE, to) & pawns(BLACK)) | + (pawn_attacks(BLACK, to) & pawns(WHITE)); attackers &= occ; // If the opponent has no attackers, we are finished: - if((attackers & this->pieces_of_color(them)) == EmptyBoardBB) + if((attackers & pieces_of_color(them)) == EmptyBoardBB) return seeValues[capture]; // The destination square is defended, which makes things rather more @@ -1652,16 +1646,16 @@ int Position::see(Square from, Square to) const { // Locate the least valuable attacker for the side to move. The loop // below looks like it is potentially infinite, but it isn't. We know // that the side to move still has at least one attacker left. - for(pt = PAWN; !(attackers&this->pieces_of_color_and_type(c, pt)); pt++) + for(pt = PAWN; !(attackers&pieces_of_color_and_type(c, pt)); pt++) assert(pt < KING); // Remove the attacker we just found from the 'attackers' bitboard, // and scan for new X-ray attacks behind the attacker: - b = attackers & this->pieces_of_color_and_type(c, pt); + b = attackers & pieces_of_color_and_type(c, pt); occ ^= (b & -b); attackers |= - (rook_attacks_bb(to, occ) & this->rooks_and_queens()) | - (bishop_attacks_bb(to, occ) & this->bishops_and_queens()); + (rook_attacks_bb(to, occ) & rooks_and_queens()) | + (bishop_attacks_bb(to, occ) & bishops_and_queens()); attackers &= occ; // Add the new entry to the swap list: @@ -1675,12 +1669,12 @@ int Position::see(Square from, Square to) const { c = opposite_color(c); // Stop after a king capture: - if(pt == KING && (attackers & this->pieces_of_color(c))) { + if(pt == KING && (attackers & pieces_of_color(c))) { assert(n < 32); swapList[n++] = 100; break; } - } while(attackers & this->pieces_of_color(c)); + } while(attackers & pieces_of_color(c)); // Having built the swap list, we negamax through it to find the best // achievable score from the point of view of the side to move: @@ -1692,7 +1686,7 @@ int Position::see(Square from, Square to) const { int Position::see(Move m) const { assert(move_is_ok(m)); - return this->see(move_from(m), move_to(m)); + return see(move_from(m), move_to(m)); } @@ -1790,14 +1784,14 @@ Key Position::compute_key() const { Key result = Key(0ULL); for(Square s = SQ_A1; s <= SQ_H8; s++) - if(this->square_is_occupied(s)) + if(square_is_occupied(s)) result ^= - zobrist[this->color_of_piece_on(s)][this->type_of_piece_on(s)][s]; + zobrist[color_of_piece_on(s)][type_of_piece_on(s)][s]; - if(this->ep_square() != SQ_NONE) - result ^= zobEp[this->ep_square()]; + if(ep_square() != SQ_NONE) + result ^= zobEp[ep_square()]; result ^= zobCastle[castleRights]; - if(this->side_to_move() == BLACK) result ^= zobSideToMove; + if(side_to_move() == BLACK) result ^= zobSideToMove; return result; } @@ -1815,7 +1809,7 @@ Key Position::compute_pawn_key() const { Square s; for(Color c = WHITE; c <= BLACK; c++) { - b = this->pawns(c); + b = pawns(c); while(b) { s = pop_1st_bit(&b); result ^= zobrist[c][PAWN][s]; @@ -1835,7 +1829,7 @@ Key Position::compute_material_key() const { Key result = Key(0ULL); for(Color c = WHITE; c <= BLACK; c++) for(PieceType pt = PAWN; pt <= QUEEN; pt++) { - int count = this->piece_count(c, pt); + int count = piece_count(c, pt); for(int i = 0; i <= count; i++) result ^= zobMaterial[c][pt][i]; } @@ -1856,14 +1850,14 @@ Value Position::compute_mg_value() const { for(Color c = WHITE; c <= BLACK; c++) for(PieceType pt = PAWN; pt <= KING; pt++) { - b = this->pieces_of_color_and_type(c, pt); + b = pieces_of_color_and_type(c, pt); while(b) { s = pop_1st_bit(&b); - assert(this->piece_on(s) == piece_of_color_and_type(c, pt)); - result += this->mg_pst(c, pt, s); + assert(piece_on(s) == piece_of_color_and_type(c, pt)); + result += mg_pst(c, pt, s); } } - result += (this->side_to_move() == WHITE)? + result += (side_to_move() == WHITE)? (TempoValueMidgame / 2) : -(TempoValueMidgame / 2); return result; } @@ -1875,14 +1869,14 @@ Value Position::compute_eg_value() const { for(Color c = WHITE; c <= BLACK; c++) for(PieceType pt = PAWN; pt <= KING; pt++) { - b = this->pieces_of_color_and_type(c, pt); + b = pieces_of_color_and_type(c, pt); while(b) { s = pop_1st_bit(&b); - assert(this->piece_on(s) == piece_of_color_and_type(c, pt)); - result += this->eg_pst(c, pt, s); + assert(piece_on(s) == piece_of_color_and_type(c, pt)); + result += eg_pst(c, pt, s); } } - result += (this->side_to_move() == WHITE)? + result += (side_to_move() == WHITE)? (TempoValueEndgame / 2) : -(TempoValueEndgame / 2); return result; } @@ -1898,10 +1892,10 @@ Value Position::compute_non_pawn_material(Color c) const { Square s; for(PieceType pt = KNIGHT; pt <= QUEEN; pt++) { - Bitboard b = this->pieces_of_color_and_type(c, pt); + Bitboard b = pieces_of_color_and_type(c, pt); while(b) { s = pop_1st_bit(&b); - assert(this->piece_on(s) == piece_of_color_and_type(c, pt)); + assert(piece_on(s) == piece_of_color_and_type(c, pt)); result += piece_value_midgame(pt); } } @@ -1914,7 +1908,7 @@ Value Position::compute_non_pawn_material(Color c) const { /// slow, and shouldn't be used frequently inside the search. bool Position::is_mate() { - if(this->is_check()) { + if(is_check()) { MovePicker mp = MovePicker(*this, false, MOVE_NONE, MOVE_NONE, MOVE_NONE, MOVE_NONE, Depth(0)); return mp.get_next_move() == MOVE_NONE; @@ -1930,13 +1924,13 @@ bool Position::is_mate() { bool Position::is_draw() const { // Draw by material? - if(!this->pawns() && - this->non_pawn_material(WHITE) + this->non_pawn_material(BLACK) + if(!pawns() && + non_pawn_material(WHITE) + non_pawn_material(BLACK) <= BishopValueMidgame) return true; // Draw by the 50 moves rule? - if(rule50 > 100 || (rule50 == 100 && !this->is_check())) + if(rule50 > 100 || (rule50 == 100 && !is_check())) return true; // Draw by repetition? @@ -1954,7 +1948,7 @@ bool Position::is_draw() const { bool Position::has_mate_threat(Color c) { UndoInfo u1, u2; - Color stm = this->side_to_move(); + Color stm = side_to_move(); // The following lines are useless and silly, but prevents gcc from // emitting a stupid warning stating that u1.lastMove and u1.epSquare might @@ -1962,11 +1956,11 @@ bool Position::has_mate_threat(Color c) { u1.lastMove = lastMove; u1.epSquare = epSquare; - if(this->is_check()) + if(is_check()) return false; // If the input color is not equal to the side to move, do a null move - if(c != stm) this->do_null_move(u1); + if(c != stm) do_null_move(u1); MoveStack mlist[120]; int count; @@ -1977,13 +1971,13 @@ bool Position::has_mate_threat(Color c) { // Loop through the moves, and see if one of them is mate. for(int i = 0; i < count; i++) { - this->do_move(mlist[i].move, u2); - if(this->is_mate()) result = true; - this->undo_move(mlist[i].move, u2); + do_move(mlist[i].move, u2); + if(is_mate()) result = true; + undo_move(mlist[i].move, u2); } // Undo null move, if necessary - if(c != stm) this->undo_null_move(u1); + if(c != stm) undo_null_move(u1); return result; } @@ -2048,21 +2042,21 @@ void Position::init_piece_square_tables() { void Position::flipped_copy(const Position &pos) { assert(pos.is_ok()); - this->clear(); + clear(); // Board for(Square s = SQ_A1; s <= SQ_H8; s++) if(!pos.square_is_empty(s)) - this->put_piece(Piece(int(pos.piece_on(s)) ^ 8), flip_square(s)); + put_piece(Piece(int(pos.piece_on(s)) ^ 8), flip_square(s)); // Side to move sideToMove = opposite_color(pos.side_to_move()); // Castling rights - if(pos.can_castle_kingside(WHITE)) this->allow_oo(BLACK); - if(pos.can_castle_queenside(WHITE)) this->allow_ooo(BLACK); - if(pos.can_castle_kingside(BLACK)) this->allow_oo(WHITE); - if(pos.can_castle_queenside(BLACK)) this->allow_ooo(WHITE); + if(pos.can_castle_kingside(WHITE)) allow_oo(BLACK); + if(pos.can_castle_queenside(WHITE)) allow_ooo(BLACK); + if(pos.can_castle_kingside(BLACK)) allow_oo(WHITE); + if(pos.can_castle_queenside(BLACK)) allow_ooo(WHITE); initialKFile = pos.initialKFile; initialKRFile = pos.initialKRFile; @@ -2082,29 +2076,29 @@ void Position::flipped_copy(const Position &pos) { epSquare = flip_square(pos.epSquare); // Checkers - this->find_checkers(); + find_checkers(); // Hash keys - key = this->compute_key(); - pawnKey = this->compute_pawn_key(); - materialKey = this->compute_material_key(); + key = compute_key(); + pawnKey = compute_pawn_key(); + materialKey = compute_material_key(); // Incremental scores - mgValue = this->compute_mg_value(); - egValue = this->compute_eg_value(); + mgValue = compute_mg_value(); + egValue = compute_eg_value(); // Material - npMaterial[WHITE] = this->compute_non_pawn_material(WHITE); - npMaterial[BLACK] = this->compute_non_pawn_material(BLACK); + npMaterial[WHITE] = compute_non_pawn_material(WHITE); + npMaterial[BLACK] = compute_non_pawn_material(BLACK); - assert(this->is_ok()); + assert(is_ok()); } /// Position::is_ok() performs some consitency checks for the position object. /// This is meant to be helpful when debugging. -bool Position::is_ok() const { +bool Position::is_ok(int* failedStep) const { // What features of the position should be verified? static const bool debugBitboards = false; @@ -2119,94 +2113,110 @@ bool Position::is_ok() const { static const bool debugPieceCounts = false; static const bool debugPieceList = false; + if (failedStep) *failedStep = 1; + // Side to move OK? - if(!color_is_ok(this->side_to_move())) + if(!color_is_ok(side_to_move())) return false; // Are the king squares in the position correct? - if(this->piece_on(this->king_square(WHITE)) != WK) + if (failedStep) (*failedStep)++; + if(piece_on(king_square(WHITE)) != WK) return false; - if(this->piece_on(this->king_square(BLACK)) != BK) + + if (failedStep) (*failedStep)++; + if(piece_on(king_square(BLACK)) != BK) return false; // Castle files OK? + if (failedStep) (*failedStep)++; if(!file_is_ok(initialKRFile)) return false; if(!file_is_ok(initialQRFile)) return false; // Do both sides have exactly one king? + if (failedStep) (*failedStep)++; if(debugKingCount) { int kingCount[2] = {0, 0}; for(Square s = SQ_A1; s <= SQ_H8; s++) - if(this->type_of_piece_on(s) == KING) - kingCount[this->color_of_piece_on(s)]++; + if(type_of_piece_on(s) == KING) + kingCount[color_of_piece_on(s)]++; if(kingCount[0] != 1 || kingCount[1] != 1) return false; } // Can the side to move capture the opponent's king? + if (failedStep) (*failedStep)++; if(debugKingCapture) { - Color us = this->side_to_move(); + Color us = side_to_move(); Color them = opposite_color(us); - Square ksq = this->king_square(them); - if(this->square_is_attacked(ksq, us)) + Square ksq = king_square(them); + if(square_is_attacked(ksq, us)) return false; } // Is there more than 2 checkers? + if (failedStep) (*failedStep)++; if(debugCheckerCount && count_1s(checkersBB) > 2) return false; // Bitboards OK? + if (failedStep) (*failedStep)++; if(debugBitboards) { // The intersection of the white and black pieces must be empty: - if((this->pieces_of_color(WHITE) & this->pieces_of_color(BLACK)) + if((pieces_of_color(WHITE) & pieces_of_color(BLACK)) != EmptyBoardBB) return false; // The union of the white and black pieces must be equal to all // occupied squares: - if((this->pieces_of_color(WHITE) | this->pieces_of_color(BLACK)) - != this->occupied_squares()) + if((pieces_of_color(WHITE) | pieces_of_color(BLACK)) + != occupied_squares()) return false; // Separate piece type bitboards must have empty intersections: for(PieceType p1 = PAWN; p1 <= KING; p1++) for(PieceType p2 = PAWN; p2 <= KING; p2++) - if(p1 != p2 && (this->pieces_of_type(p1) & this->pieces_of_type(p2))) + if(p1 != p2 && (pieces_of_type(p1) & pieces_of_type(p2))) return false; } // En passant square OK? - if(this->ep_square() != SQ_NONE) { + 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(this->side_to_move(), this->ep_square()) != RANK_6) + if(relative_rank(side_to_move(), ep_square()) != RANK_6) return false; } // Hash key OK? - if(debugKey && key != this->compute_key()) + if (failedStep) (*failedStep)++; + if(debugKey && key != compute_key()) return false; // Pawn hash key OK? - if(debugPawnKey && pawnKey != this->compute_pawn_key()) + if (failedStep) (*failedStep)++; + if(debugPawnKey && pawnKey != compute_pawn_key()) return false; // Material hash key OK? - if(debugMaterialKey && materialKey != this->compute_material_key()) + if (failedStep) (*failedStep)++; + if(debugMaterialKey && materialKey != compute_material_key()) return false; // Incremental eval OK? + if (failedStep) (*failedStep)++; if(debugIncrementalEval) { - if(mgValue != this->compute_mg_value()) + if(mgValue != compute_mg_value()) return false; - if(egValue != this->compute_eg_value()) + if(egValue != compute_eg_value()) return false; } // Non-pawn material OK? + if (failedStep) (*failedStep)++; if(debugNonPawnMaterial) { if(npMaterial[WHITE] != compute_non_pawn_material(WHITE)) return false; @@ -2215,23 +2225,25 @@ bool Position::is_ok() const { } // Piece counts OK? + if (failedStep) (*failedStep)++; if(debugPieceCounts) for(Color c = WHITE; c <= BLACK; c++) for(PieceType pt = PAWN; pt <= KING; pt++) - if(pieceCount[c][pt] != count_1s(this->pieces_of_color_and_type(c, pt))) + if(pieceCount[c][pt] != count_1s(pieces_of_color_and_type(c, pt))) return false; + if (failedStep) (*failedStep)++; if(debugPieceList) { for(Color c = WHITE; c <= BLACK; c++) for(PieceType pt = PAWN; pt <= KING; pt++) for(int i = 0; i < pieceCount[c][pt]; i++) { - if(this->piece_on(this->piece_list(c, pt, i)) != + if(piece_on(piece_list(c, pt, i)) != piece_of_color_and_type(c, pt)) return false; - if(index[this->piece_list(c, pt, i)] != i) + if(index[piece_list(c, pt, i)] != i) return false; } } - + if (failedStep) *failedStep = 0; return true; }