src/movepick.h

   1 /*
   2   Glaurung, a UCI chess playing engine.
   3   Copyright (C) 2004-2008 Tord Romstad
   4
   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.
   9
  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.
  14
  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/>.
  17 */
  18
  19
  20 #if !defined MOVEPICK_H_INCLUDED
  21 #define MOVEPICK_H_INCLUDED
  22
  23 ////
  24 //// Includes
  25 ////
  26
  27 #include "depth.h"
  28 #include "lock.h"
  29 #include "position.h"
  30
  31
  32 ////
  33 //// Types
  34 ////
  35
  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.
  43
  44 class MovePicker {
  45
  46 public:
  47   MovePicker(Position &p, bool pvnode, Move ttm, Move mk, Move k1, Move k2,
  48              Depth dpth);
  49   Move get_next_move();
  50   Move get_next_move(Lock &lock);
  51   int number_of_moves() const;
  52   int current_move_score() const;
  53   Bitboard discovered_check_candidates();
  54
  55   static void init_phase_table();
  56
  57 private:
  58   void score_captures();
  59   void score_noncaptures();
  60   void score_evasions();
  61   void score_qcaptures();
  62   Move pick_move_from_list();
  63
  64   Position *pos;
  65   Move ttMove, mateKiller, killer1, killer2;
  66   Bitboard pinned, dc;
  67   MoveStack moves[256], badCaptures[64];
  68   bool pvNode;
  69   Depth depth;
  70   int phaseIndex;
  71   int numOfMoves, numOfBadCaptures;
  72   int movesPicked, badCapturesPicked;
  73   bool finished;
  74 };
  75
  76
  77 ////
  78 //// Inline functions
  79 ////
  80
  81 /// MovePicker::discovered_check_candidates() returns a bitboard containing
  82 /// all pieces which can possibly give discovered check.  This bitboard is
  83 /// computed by the constructor function.
  84
  85 inline Bitboard MovePicker::discovered_check_candidates() {
  86   return dc;
  87 }
  88
  89 #endif // !defined(MOVEPICK_H_INCLUDED)