Files
Stockfish/src/movepick.h
T
Marco Costalba 74fd57220e Refine "few moves" in "last minute surprise"
It seems that "few moves" works because we extend the good
captures at the last ply of PV, so code it directly.

This version seems defenitly stronger then previous one.

Signed-off-by: Marco Costalba <mcostalba@gmail.com>
2008-11-01 12:46:51 +01:00

117 lines
3.6 KiB
C++

/*
Stockfish, a UCI chess playing engine derived from Glaurung 2.1
Copyright (C) 2004-2008 Tord Romstad (Glaurung author)
Copyright (C) 2008 Marco Costalba
Stockfish is free software: you can redistribute it and/or modify
it under the terms of the GNU General Public License as published by
the Free Software Foundation, either version 3 of the License, or
(at your option) any later version.
Stockfish is distributed in the hope that it will be useful,
but WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
GNU General Public License for more details.
You should have received a copy of the GNU General Public License
along with this program. If not, see <http://www.gnu.org/licenses/>.
*/
#if !defined MOVEPICK_H_INCLUDED
#define MOVEPICK_H_INCLUDED
////
//// Includes
////
#include "depth.h"
#include "lock.h"
#include "position.h"
////
//// Types
////
/// MovePicker is a class which is used to pick one legal move at a time from
/// the current position. It is initialized with a Position object and a few
/// moves we have reason to believe are good. The most important method is
/// MovePicker::pick_next_move(), which returns a new legal move each time it
/// is called, until there are no legal moves left, when MOVE_NONE is returned.
/// In order to improve the efficiency of the alpha beta algorithm, MovePicker
/// attempts to return the moves which are most likely to be strongest first.
class MovePicker {
public:
enum MovegenPhase {
PH_TT_MOVE, // Transposition table move
PH_MATE_KILLER, // Mate killer from the current ply
PH_GOOD_CAPTURES, // Queen promotions and captures with SEE values >= 0
PH_BAD_CAPTURES, // Queen promotions and captures with SEE values < 0
PH_KILLER_1, // Killer move 1 from the current ply (not used yet).
PH_KILLER_2, // Killer move 2 from the current ply (not used yet).
PH_NONCAPTURES, // Non-captures and underpromotions
PH_EVASIONS, // Check evasions
PH_QCAPTURES, // Captures in quiescence search
PH_QCHECKS, // Checks in quiescence search
PH_STOP
};
MovePicker(const Position& p, bool pvnode, Move ttm, Move mk, Move k1, Move k2, Depth d);
Move get_next_move();
Move get_next_move(Lock &lock);
int number_of_moves() const;
int current_move_score() const;
MovegenPhase current_move_type() const;
Bitboard discovered_check_candidates() const;
static void init_phase_table();
private:
void score_captures();
void score_noncaptures();
void score_evasions();
void score_qcaptures();
Move pick_move_from_list();
int find_best_index();
const Position& pos;
Move ttMove, mateKiller, killer1, killer2;
Bitboard pinned, dc;
MoveStack moves[256], badCaptures[64];
bool pvNode;
Depth depth;
int phaseIndex;
int numOfMoves, numOfBadCaptures;
int movesPicked, badCapturesPicked;
bool finished;
};
////
//// Inline functions
////
/// MovePicker::number_of_moves() simply returns the numOfMoves member
/// variable. It is intended to be used in positions where the side to move
/// is in check, for detecting checkmates or situations where there is only
/// a single reply to check.
inline int MovePicker::number_of_moves() const {
return numOfMoves;
}
/// MovePicker::discovered_check_candidates() returns a bitboard containing
/// all pieces which can possibly give discovered check. This bitboard is
/// computed by the constructor function.
inline Bitboard MovePicker::discovered_check_candidates() const {
return dc;
}
#endif // !defined(MOVEPICK_H_INCLUDED)