2 Stockfish, a UCI chess playing engine derived from Glaurung 2.1
3 Copyright (C) 2004-2008 Tord Romstad (Glaurung author)
4 Copyright (C) 2008-2012 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 MOVEPICK_H_INCLUDED
21 #define MOVEPICK_H_INCLUDED
28 /// The History class stores statistics about how often different moves
29 /// have been successful or unsuccessful during the current search. These
30 /// statistics are used for reduction and move ordering decisions. History
31 /// entries are stored according only to moving piece and destination square,
32 /// in particular two moves with different origin but same destination and
33 /// same piece will be considered identical.
38 static const Value Max = Value(2000);
40 const Value* operator[](Piece p) const { return &history[p][0]; }
41 Value gain(Piece p, Square to) const { return gains[p][to]; }
44 void update(Piece p, Square to, Value bonus);
45 void update_gain(Piece p, Square to, Value gain);
48 Value history[PIECE_NB][SQUARE_NB];
49 Value gains[PIECE_NB][SQUARE_NB];
53 /// MovePicker class is used to pick one pseudo legal move at a time from the
54 /// current position. The most important method is next_move(), which returns a
55 /// new pseudo legal move each time it is called, until there are no moves left,
56 /// when MOVE_NONE is returned. In order to improve the efficiency of the alpha
57 /// beta algorithm, MovePicker attempts to return the moves which are most likely
58 /// to get a cut-off first.
62 MovePicker& operator=(const MovePicker&); // Silence a warning under MSVC
65 MovePicker(const Position&, Move, Depth, const History&, Search::Stack*, Value);
66 MovePicker(const Position&, Move, Depth, const History&, Square);
67 MovePicker(const Position&, Move, const History&, PieceType);
68 template<bool SpNode> Move next_move();
71 void score_captures();
72 void score_noncaptures();
73 void score_evasions();
82 Square recaptureSquare;
83 int captureThreshold, phase;
84 MoveStack *cur, *end, *endQuiets, *endBadCaptures;
85 MoveStack moves[MAX_MOVES];
88 #endif // !defined(MOVEPICK_H_INCLUDED)