1/*
2 Stockfish, a UCI chess playing engine derived from Glaurung 2.1
3 Copyright (C) 2004-2008 Tord Romstad (Glaurung author)
4 Copyright (C) 2008-2015 Marco Costalba, Joona Kiiski, Tord Romstad
5 Copyright (C) 2015-2019 Marco Costalba, Joona Kiiski, Gary Linscott, Tord Romstad
6
7 Stockfish is free software: you can redistribute it and/or modify
8 it under the terms of the GNU General Public License as published by
9 the Free Software Foundation, either version 3 of the License, or
10 (at your option) any later version.
11
12 Stockfish is distributed in the hope that it will be useful,
13 but WITHOUT ANY WARRANTY; without even the implied warranty of
14 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
15 GNU General Public License for more details.
16
17 You should have received a copy of the GNU General Public License
18 along with this program. If not, see <http://www.gnu.org/licenses/>.
19*/
20
21#ifndef PAWNS_H_INCLUDED
22#define PAWNS_H_INCLUDED
23
24#include "misc.h"
25#include "position.h"
26#include "types.h"
27
28namespace Pawns {
29
30/// Pawns::Entry contains various information about a pawn structure. A lookup
31/// to the pawn hash table (performed by calling the probe function) returns a
32/// pointer to an Entry object.
33
34struct Entry {
35
36 Score pawn_score(Color c) const { return scores[c]; }
37 Bitboard pawn_attacks(Color c) const { return pawnAttacks[c]; }
38 Bitboard passed_pawns(Color c) const { return passedPawns[c]; }
39 Bitboard pawn_attacks_span(Color c) const { return pawnAttacksSpan[c]; }
40 int passed_count() const { return popcount(passedPawns[WHITE] | passedPawns[BLACK]); }
41
42 template<Color Us>
43 Score king_safety(const Position& pos) {
44 return kingSquares[Us] == pos.square<KING>(Us) && castlingRights[Us] == pos.castling_rights(Us)
45 ? kingSafety[Us] : (kingSafety[Us] = do_king_safety<Us>(pos));
46 }
47
48 template<Color Us>
49 Score do_king_safety(const Position& pos);
50
51 template<Color Us>
52 void evaluate_shelter(const Position& pos, Square ksq, Score& shelter);
53
54 Key key;
55 Score scores[COLOR_NB];
56 Bitboard passedPawns[COLOR_NB];
57 Bitboard pawnAttacks[COLOR_NB];
58 Bitboard pawnAttacksSpan[COLOR_NB];
59 Square kingSquares[COLOR_NB];
60 Score kingSafety[COLOR_NB];
61 int castlingRights[COLOR_NB];
62};
63
64typedef HashTable<Entry, 131072> Table;
65
66Entry* probe(const Position& pos);
67
68} // namespace Pawns
69
70#endif // #ifndef PAWNS_H_INCLUDED
71