2 Stockfish, a UCI chess playing engine derived from Glaurung 2.1
3 Copyright (C) 2004-2008 Tord Romstad (Glaurung author)
4 Copyright (C) 2008-2013 Marco Costalba, Joona Kiiski, Tord Romstad
6 Stockfish is free software: you can redistribute it and/or modify
7 it under the terms of the GNU General Public License as published by
8 the Free Software Foundation, either version 3 of the License, or
9 (at your option) any later version.
11 Stockfish is distributed in the hope that it will be useful,
12 but WITHOUT ANY WARRANTY; without even the implied warranty of
13 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
14 GNU General Public License for more details.
16 You should have received a copy of the GNU General Public License
17 along with this program. If not, see <http://www.gnu.org/licenses/>.
20 #if !defined(EVALUATE_H_INCLUDED)
21 #define EVALUATE_H_INCLUDED
31 // Struct Eval::Info contains various information computed and collected
32 // by the evaluation functions.
35 // Pointers to material and pawn hash table entries
39 // attackedBy[color][piece type] is a bitboard representing all squares
40 // attacked by a given color and piece type, attackedBy[color][ALL_PIECES]
41 // contains all squares attacked by the given color.
42 Bitboard attackedBy[COLOR_NB][PIECE_TYPE_NB];
44 // kingRing[color] is the zone around the king which is considered
45 // by the king safety evaluation. This consists of the squares directly
46 // adjacent to the king, and the three (or two, for a king on an edge file)
47 // squares two ranks in front of the king. For instance, if black's king
48 // is on g8, kingRing[BLACK] is a bitboard containing the squares f8, h8,
49 // f7, g7, h7, f6, g6 and h6.
50 Bitboard kingRing[COLOR_NB];
52 // kingAttackersCount[color] is the number of pieces of the given color
53 // which attack a square in the kingRing of the enemy king.
54 int kingAttackersCount[COLOR_NB];
56 // kingAttackersWeight[color] is the sum of the "weight" of the pieces of the
57 // given color which attack a square in the kingRing of the enemy king. The
58 // weights of the individual piece types are given by the variables
59 // QueenAttackWeight, RookAttackWeight, BishopAttackWeight and
60 // KnightAttackWeight in evaluate.cpp
61 int kingAttackersWeight[COLOR_NB];
63 // kingAdjacentZoneAttacksCount[color] is the number of attacks to squares
64 // directly adjacent to the king of the given color. Pieces which attack
65 // more than one square are counted multiple times. For instance, if black's
66 // king is on g8 and there's a white knight on g5, this knight adds
67 // 2 to kingAdjacentZoneAttacksCount[BLACK].
68 int kingAdjacentZoneAttacksCount[COLOR_NB];
72 extern Value evaluate(const Position& pos, Value& margin, Info* ei);
73 extern std::string trace(const Position& pos);
77 #endif // !defined(EVALUATE_H_INCLUDED)