2 Stockfish, a UCI chess playing engine derived from Glaurung 2.1
3 Copyright (C) 2004-2008 Tord Romstad (Glaurung author)
4 Copyright (C) 2008-2009 Marco Costalba
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/>.
21 #if !defined MOVEPICK_H_INCLUDED
22 #define MOVEPICK_H_INCLUDED
41 PH_NULL_MOVE, // Null move
42 PH_TT_MOVES, // Transposition table move and mate killer
43 PH_GOOD_CAPTURES, // Queen promotions and captures with SEE values >= 0
44 PH_KILLERS, // Killer moves from the current ply
45 PH_NONCAPTURES, // Non-captures and underpromotions
46 PH_BAD_CAPTURES, // Queen promotions and captures with SEE values < 0
47 PH_EVASIONS, // Check evasions
48 PH_QCAPTURES, // Captures in quiescence search
49 PH_QCHECKS, // Non-capture checks in quiescence search
53 typedef uint8_t MovegenPhaseT;
55 /// MovePicker is a class which is used to pick one legal move at a time from
56 /// the current position. It is initialized with a Position object and a few
57 /// moves we have reason to believe are good. The most important method is
58 /// MovePicker::pick_next_move(), which returns a new legal move each time it
59 /// is called, until there are no legal moves left, when MOVE_NONE is returned.
60 /// In order to improve the efficiency of the alpha beta algorithm, MovePicker
61 /// attempts to return the moves which are most likely to be strongest first.
65 MovePicker& operator=(const MovePicker&); // silence a warning under MSVC
68 MovePicker(const Position& p, Move ttm, Depth d, const History& h, SearchStack* ss = NULL, bool useNullMove = false);
70 Move get_next_move(Lock& lock);
71 int number_of_moves() const;
72 Bitboard discovered_check_candidates() const;
75 void score_captures();
76 void score_noncaptures();
77 void score_evasions();
78 Move pick_move_from_list();
82 Move ttMoves[2], killers[2];
83 const MovegenPhaseT* phasePtr;
84 int movesPicked, numOfMoves, numOfBadCaptures;
87 MoveStack moves[256], badCaptures[64];
95 /// MovePicker::number_of_moves() simply returns the numOfMoves member
96 /// variable. It is intended to be used in positions where the side to move
97 /// is in check, for detecting checkmates or situations where there is only
98 /// a single reply to check.
100 inline int MovePicker::number_of_moves() const {
104 /// MovePicker::discovered_check_candidates() returns a bitboard containing
105 /// all pieces which can possibly give discovered check. This bitboard is
106 /// computed by the constructor function.
108 inline Bitboard MovePicker::discovered_check_candidates() const {
112 #endif // !defined(MOVEPICK_H_INCLUDED)