2 Glaurung, a UCI chess playing engine.
3 Copyright (C) 2004-2008 Tord Romstad
5 Glaurung is free software: you can redistribute it and/or modify
6 it under the terms of the GNU General Public License as published by
7 the Free Software Foundation, either version 3 of the License, or
8 (at your option) any later version.
10 Glaurung is distributed in the hope that it will be useful,
11 but WITHOUT ANY WARRANTY; without even the implied warranty of
12 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
13 GNU General Public License for more details.
15 You should have received a copy of the GNU General Public License
16 along with this program. If not, see <http://www.gnu.org/licenses/>.
20 #if !defined MOVEPICK_H_INCLUDED
21 #define MOVEPICK_H_INCLUDED
36 /// MovePicker is a class which is used to pick one legal move at a time from
37 /// the current position. It is initialized with a Position object and a few
38 /// moves we have reason to believe are good. The most important method is
39 /// MovePicker::pick_next_move(), which returns a new legal move each time it
40 /// is called, until there are no legal moves left, when MOVE_NONE is returned.
41 /// In order to improve the efficiency of the alpha beta algorithm, MovePicker
42 /// attempts to return the moves which are most likely to be strongest first.
49 PH_TT_MOVE, // Transposition table move
50 PH_MATE_KILLER, // Mate killer from the current ply
51 PH_GOOD_CAPTURES, // Queen promotions and captures with SEE values >= 0
52 PH_BAD_CAPTURES, // Queen promotions and captures with SEE valuse <= 0
53 PH_KILLER_1, // Killer move 1 from the current ply (not used yet).
54 PH_KILLER_2, // Killer move 2 from the current ply (not used yet).
55 PH_NONCAPTURES, // Non-captures and underpromotions
56 PH_EVASIONS, // Check evasions
57 PH_QCAPTURES, // Captures in quiescence search
58 PH_QCHECKS, // Checks in quiescence search
62 MovePicker(const Position& p, bool pvnode, Move ttm, Move mk, Move k1, Move k2, Depth d);
64 Move get_next_move(Lock &lock);
65 int number_of_moves() const;
66 int current_move_score() const;
67 MovegenPhase current_move_type() const;
68 Bitboard discovered_check_candidates() const;
70 static void init_phase_table();
73 void score_captures();
74 void score_noncaptures();
75 void score_evasions();
76 void score_qcaptures();
77 Move pick_move_from_list();
78 int find_best_index();
81 Move ttMove, mateKiller, killer1, killer2;
83 MoveStack moves[256], badCaptures[64];
87 int numOfMoves, numOfBadCaptures;
88 int movesPicked, badCapturesPicked;
97 /// MovePicker::number_of_moves() simply returns the numOfMoves member
98 /// variable. It is intended to be used in positions where the side to move
99 /// is in check, for detecting checkmates or situations where there is only
100 /// a single reply to check.
102 inline int MovePicker::number_of_moves() const {
106 /// MovePicker::discovered_check_candidates() returns a bitboard containing
107 /// all pieces which can possibly give discovered check. This bitboard is
108 /// computed by the constructor function.
110 inline Bitboard MovePicker::discovered_check_candidates() const {
114 #endif // !defined(MOVEPICK_H_INCLUDED)