Stockfish, a UCI chess playing engine derived from Glaurung 2.1
Copyright (C) 2004-2008 Tord Romstad (Glaurung author)
Copyright (C) 2008-2015 Marco Costalba, Joona Kiiski, Tord Romstad
- Copyright (C) 2015-2016 Marco Costalba, Joona Kiiski, Gary Linscott, Tord Romstad
+ Copyright (C) 2015-2018 Marco Costalba, Joona Kiiski, Gary Linscott, Tord Romstad
Stockfish is free software: you can redistribute it and/or modify
it under the terms of the GNU General Public License as published by
return sq;
}
- // Get the material key of Position out of the given endgame key code
- // like "KBPKN". The trick here is to first forge an ad-hoc FEN string
- // and then let a Position object do the work for us.
- Key key(const string& code, Color c) {
-
- assert(code.length() > 0 && code.length() < 8);
- assert(code[0] == 'K');
-
- string sides[] = { code.substr(code.find('K', 1)), // Weak
- code.substr(0, code.find('K', 1)) }; // Strong
-
- std::transform(sides[c].begin(), sides[c].end(), sides[c].begin(), tolower);
-
- string fen = sides[0] + char(8 - sides[0].length() + '0') + "/8/8/8/8/8/8/"
- + sides[1] + char(8 - sides[1].length() + '0') + " w - - 0 10";
-
- StateInfo st;
- return Position().set(fen, false, &st, nullptr).material_key();
- }
-
} // namespace
}
-template<EndgameType E, typename T>
-void Endgames::add(const string& code) {
- map<T>()[key(code, WHITE)] = std::unique_ptr<EndgameBase<T>>(new Endgame<E>(WHITE));
- map<T>()[key(code, BLACK)] = std::unique_ptr<EndgameBase<T>>(new Endgame<E>(BLACK));
-}
-
-
/// Mate with KX vs K. This function is used to evaluate positions with
/// king and plenty of material vs a lone king. It simply gives the
/// attacking side a bonus for driving the defending king towards the edge
if ( pos.count<QUEEN>(strongSide)
|| pos.count<ROOK>(strongSide)
||(pos.count<BISHOP>(strongSide) && pos.count<KNIGHT>(strongSide))
- ||(pos.count<BISHOP>(strongSide) > 1 && opposite_colors(pos.squares<BISHOP>(strongSide)[0],
- pos.squares<BISHOP>(strongSide)[1])))
+ || ( (pos.pieces(strongSide, BISHOP) & ~DarkSquares)
+ && (pos.pieces(strongSide, BISHOP) & DarkSquares)))
result = std::min(result + VALUE_KNOWN_WIN, VALUE_MATE_IN_MAX_PLY - 1);
return strongSide == pos.side_to_move() ? result : -result;
Square bsq = pos.square<BISHOP>(weakSide);
Square psq = pos.square<PAWN>(strongSide);
Rank rk = relative_rank(strongSide, psq);
- Square push = pawn_push(strongSide);
+ Direction push = pawn_push(strongSide);
// If the pawn is on the 5th rank and the pawn (currently) is on
// the same color square as the bishop then there is a chance of
// If all pawns are ahead of the king, on a single rook file and
// the king is within one file of the pawns, it's a draw.
- if ( !(pawns & ~in_front_bb(weakSide, rank_of(ksq)))
+ if ( !(pawns & ~forward_ranks_bb(weakSide, ksq))
&& !((pawns & ~FileABB) && (pawns & ~FileHBB))
&& distance<File>(ksq, lsb(pawns)) <= 1)
return SCALE_FACTOR_DRAW;
if (relative_rank(strongSide, pawnSq) <= RANK_5)
return SCALE_FACTOR_DRAW;
- else
- {
- Bitboard path = forward_bb(strongSide, pawnSq);
- if (path & pos.pieces(weakSide, KING))
- return SCALE_FACTOR_DRAW;
+ Bitboard path = forward_file_bb(strongSide, pawnSq);
- if ( (pos.attacks_from<BISHOP>(weakBishopSq) & path)
- && distance(weakBishopSq, pawnSq) >= 3)
- return SCALE_FACTOR_DRAW;
- }
+ if (path & pos.pieces(weakSide, KING))
+ return SCALE_FACTOR_DRAW;
+
+ if ( (pos.attacks_from<BISHOP>(weakBishopSq) & path)
+ && distance(weakBishopSq, pawnSq) >= 3)
+ return SCALE_FACTOR_DRAW;
}
return SCALE_FACTOR_NONE;
}
// King needs to get close to promoting pawn to prevent knight from blocking.
// Rules for this are very tricky, so just approximate.
- if (forward_bb(strongSide, pawnSq) & pos.attacks_from<BISHOP>(bishopSq))
+ if (forward_file_bb(strongSide, pawnSq) & pos.attacks_from<BISHOP>(bishopSq))
return ScaleFactor(distance(weakKingSq, pawnSq));
return SCALE_FACTOR_NONE;