X-Git-Url: https://git.sesse.net/?p=stockfish;a=blobdiff_plain;f=src%2Fposition.cpp;h=e33b65fc050e4988f646cbdc2324c9962ccb4eb8;hp=200416c7bba550900755e6f8d07847cf07a0d35e;hb=af59cb1d63234fe5c711f4a0dc28d56fe79d1274;hpb=d316b0277192c3ecca125fbc8a2355aa54ffb3c0 diff --git a/src/position.cpp b/src/position.cpp index 200416c7..e33b65fc 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. @@ -295,40 +296,53 @@ void Position::copy(const Position &pos) { } -/// Position:pinned_pieces() returns a bitboard of all pinned (against the -/// king) pieces for the given color. +/// Position:pinned_pieces<>() returns a bitboard of all pinned (against the +/// king) pieces for the given color and for the given pinner type. +template +Bitboard Position::pinned_pieces(Color c, Square ksq) const { -Bitboard Position::pinned_pieces(Color c) const { - Bitboard b1, b2, pinned, pinners, sliders; - Square ksq = king_square(c), s; - Color them = opposite_color(c); + Square s; + Bitboard sliders, pinned = EmptyBoardBB; + + if (Piece == ROOK) // Resolved at compile time + sliders = rooks_and_queens(opposite_color(c)) & RookPseudoAttacks[ksq]; + else + sliders = bishops_and_queens(opposite_color(c)) & BishopPseudoAttacks[ksq]; - pinned = EmptyBoardBB; - b1 = occupied_squares(); + if (sliders && (sliders & ~checkersBB)) + { + // Our 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 = sliders & ~checkersBB; + if (Piece == ROOK) + pinners &= rook_attacks_bb(ksq, occupied_squares() ^ candidate_pinned); + else + pinners &= bishop_attacks_bb(ksq, occupied_squares() ^ candidate_pinned); - sliders = rooks_and_queens(them) & ~checkers(); - if(sliders & RookPseudoAttacks[ksq]) { - b2 = piece_attacks(ksq) & 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); - } + // Finally for each pinner find the corresponding pinned piece + // among the candidates. + while (pinners) + { + s = pop_1st_bit(&pinners); + pinned |= (squares_between(s, ksq) & candidate_pinned); + } } + return pinned; +} - sliders = bishops_and_queens(them) & ~checkers(); - if(sliders & BishopPseudoAttacks[ksq]) { - b2 = piece_attacks(ksq) & 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; +/// Position:pinned_pieces() returns a bitboard of all pinned (against the +/// king) pieces for the given color. +Bitboard Position::pinned_pieces(Color c) const { + + Square ksq = king_square(c); + return pinned_pieces(c, ksq) | pinned_pieces(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 @@ -406,13 +420,13 @@ bool Position::piece_attacks_square(Square f, Square t) const { assert(square_is_ok(t)); switch(piece_on(f)) { - case WP: return white_pawn_attacks_square(f, t); - case BP: return black_pawn_attacks_square(f, t); - case WN: case BN: return knight_attacks_square(f, t); - case WB: case BB: return bishop_attacks_square(f, t); - case WR: case BR: return rook_attacks_square(f, t); - case WQ: case BQ: return queen_attacks_square(f, t); - case WK: case BK: return king_attacks_square(f, t); + 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; } @@ -549,7 +563,7 @@ bool Position::move_is_check(Move m, Bitboard dcCandidates) const { switch(move_promotion(m)) { case KNIGHT: - return knight_attacks_square(to, ksq); + return piece_attacks_square(to, ksq); case BISHOP: return bit_is_set(bishop_attacks_bb(to, b), ksq); case ROOK: @@ -668,13 +682,13 @@ bool Position::move_attacks_square(Move m, Square s) const { assert(square_is_occupied(f)); switch(piece_on(f)) { - case WP: return white_pawn_attacks_square(t, s); - case BP: return black_pawn_attacks_square(t, s); - case WN: case BN: return knight_attacks_square(t, s); - case WB: case BB: return bishop_attacks_square(t, s); - case WR: case BR: return rook_attacks_square(t, s); - case WQ: case BQ: return queen_attacks_square(t, s); - case WK: case BK: return king_attacks_square(t, s); + 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); }