X-Git-Url: https://git.sesse.net/?p=stockfish;a=blobdiff_plain;f=src%2Fposition.h;h=c25244a6504cc27033554117ee029460a3581b7b;hp=2c94f42af9c32da7de2837d785da10de75e71f7e;hb=a6e0f62a4f83bf4303e920d5f689de7cbc0467e8;hpb=69f4954df1de3ed264212a6e871986781d717e08

diff --git a/src/position.h b/src/position.h
index 2c94f42a..c25244a6 100644
--- a/src/position.h
+++ b/src/position.h
@@ -1,7 +1,7 @@
 /*
   Stockfish, a UCI chess playing engine derived from Glaurung 2.1
   Copyright (C) 2004-2008 Tord Romstad (Glaurung author)
-  Copyright (C) 2008-2010 Marco Costalba, Joona Kiiski, Tord Romstad
+  Copyright (C) 2008-2013 Marco Costalba, Joona Kiiski, Tord Romstad
 
   Stockfish is free software: you can redistribute it and/or modify
   it under the terms of the GNU General Public License as published by
@@ -21,42 +21,39 @@
 #define POSITION_H_INCLUDED
 
 #include <cassert>
+#include <cstddef>
 
 #include "bitboard.h"
-#include "move.h"
 #include "types.h"
 
-/// Maximum number of plies per game (220 should be enough, because the
-/// maximum search depth is 100, and during position setup we reset the
-/// move counter for every non-reversible move).
-const int MaxGameLength = 220;
-
 
 /// The checkInfo struct is initialized at c'tor time and keeps info used
 /// to detect if a move gives check.
+class Position;
+struct Thread;
 
 struct CheckInfo {
 
-    explicit CheckInfo(const Position&);
+  explicit CheckInfo(const Position&);
 
-    Bitboard dcCandidates;
-    Bitboard pinned;
-    Bitboard checkSq[8];
+  Bitboard dcCandidates;
+  Bitboard pinned;
+  Bitboard checkSq[PIECE_TYPE_NB];
+  Square ksq;
 };
 
 
 /// The StateInfo struct stores information we need to restore a Position
 /// object to its previous state when we retract a move. Whenever a move
-/// is made on the board (by calling Position::do_move), an StateInfo object
+/// is made on the board (by calling Position::do_move), a StateInfo object
 /// must be passed as a parameter.
-class Position;
 
 struct StateInfo {
   Key pawnKey, materialKey;
-  int castleRights, rule50, gamePly, pliesFromNull;
+  Value npMaterial[COLOR_NB];
+  int castleRights, rule50, pliesFromNull;
+  Score psq;
   Square epSquare;
-  Score value;
-  Value npMaterial[2];
 
   Key key;
   Bitboard checkersBB;
@@ -65,6 +62,11 @@ struct StateInfo {
 };
 
 
+/// When making a move the current StateInfo up to 'key' excluded is copied to
+/// the new one. Here we calculate the quad words (64bits) needed to be copied.
+const size_t StateCopySize64 = offsetof(StateInfo, key) / sizeof(uint64_t) + 1;
+
+
 /// The position data structure. A position consists of the following data:
 ///
 ///    * For each piece type, a bitboard representing the squares occupied
@@ -88,62 +90,44 @@ struct StateInfo {
 ///    * A counter for detecting 50 move rule draws.
 
 class Position {
-
-  // No default or copy c'tor allowed, default c'tor will not be generated
-  // anyhow because of user-defined c'tors.
-  Position(const Position&);
-
 public:
-  Position(const Position& pos, int threadID);
-  Position(const std::string& fen, bool isChess960, int threadID);
+  Position() {}
+  Position(const Position& p, Thread* t) { *this = p; thisThread = t; }
+  Position(const std::string& f, bool c960, Thread* t) { set(f, c960, t); }
+  Position& operator=(const Position&);
+  static void init();
 
   // Text input/output
-  void from_fen(const std::string& fen, bool isChess960);
-  const std::string to_fen() const;
-  void print(Move m = MOVE_NONE) const;
-
-  // The piece on a given square
-  Piece piece_on(Square s) const;
-  bool square_is_empty(Square s) const;
+  void set(const std::string& fen, bool isChess960, Thread* th);
+  const std::string fen() const;
+  const std::string pretty(Move m = MOVE_NONE) const;
 
-  // Side to move
-  Color side_to_move() const;
-
-  // Bitboard representation of the position
-  Bitboard empty_squares() const;
-  Bitboard occupied_squares() const;
-  Bitboard pieces(Color c) const;
+  // Position representation
+  Bitboard pieces() const;
   Bitboard pieces(PieceType pt) const;
-  Bitboard pieces(PieceType pt, Color c) const;
   Bitboard pieces(PieceType pt1, PieceType pt2) const;
-  Bitboard pieces(PieceType pt1, PieceType pt2, Color c) const;
-
-  // Number of pieces of each color and type
-  int piece_count(Color c, PieceType pt) const;
-
-  // The en passant square
-  Square ep_square() const;
-
-  // Current king position for each color
+  Bitboard pieces(Color c) const;
+  Bitboard pieces(Color c, PieceType pt) const;
+  Bitboard pieces(Color c, PieceType pt1, PieceType pt2) const;
+  Piece piece_on(Square s) const;
   Square king_square(Color c) const;
+  Square ep_square() const;
+  bool is_empty(Square s) const;
+  const Square* piece_list(Color c, PieceType pt) const;
+  int piece_count(Color c, PieceType pt) const;
 
-  // Castling rights
-  bool can_castle(CastleRight f) const;
-  bool can_castle(Color c) const;
-  Square castle_rook_square(CastleRight f) const;
+  // Castling
+  int can_castle(CastleRight f) const;
+  int can_castle(Color c) const;
+  bool castle_impeded(Color c, CastlingSide s) const;
+  Square castle_rook_square(Color c, CastlingSide s) const;
 
-  // Bitboards for pinned pieces and discovered check candidates
+  // Checking
+  Bitboard checkers() const;
   Bitboard discovered_check_candidates() const;
   Bitboard pinned_pieces() const;
 
-  // Checking pieces and under check information
-  Bitboard checkers() const;
-  bool in_check() const;
-
-  // Piece lists
-  const Square* piece_list(Color c, PieceType pt) const;
-
-  // Information about attacks to or from a given square
+  // Attacks to/from a given square
   Bitboard attackers_to(Square s) const;
   Bitboard attackers_to(Square s, Bitboard occ) const;
   Bitboard attacks_from(Piece p, Square s) const;
@@ -152,22 +136,22 @@ public:
   template<PieceType> Bitboard attacks_from(Square s, Color c) const;
 
   // Properties of moves
-  bool pl_move_is_legal(Move m, Bitboard pinned) const;
-  bool move_is_pl(const Move m) const;
   bool move_gives_check(Move m, const CheckInfo& ci) const;
-  bool move_is_capture(Move m) const;
-  bool move_is_capture_or_promotion(Move m) const;
-  bool move_is_passed_pawn_push(Move m) const;
-  bool move_attacks_square(Move m, Square s) const;
-
-  // Piece captured with previous moves
+  bool pl_move_is_legal(Move m, Bitboard pinned) const;
+  bool is_pseudo_legal(const Move m) const;
+  bool is_capture(Move m) const;
+  bool is_capture_or_promotion(Move m) const;
+  bool is_passed_pawn_push(Move m) const;
+  Piece piece_moved(Move m) const;
   PieceType captured_piece_type() const;
 
-  // Information about pawns
+  // Piece specific
   bool pawn_is_passed(Color c, Square s) const;
+  bool pawn_on_7th(Color c) const;
+  bool opposite_bishops() const;
+  bool bishop_pair(Color c) const;
 
   // Doing and undoing moves
-  void do_setup_move(Move m);
   void do_move(Move m, StateInfo& st);
   void do_move(Move m, StateInfo& st, const CheckInfo& ci, bool moveIsCheck);
   void undo_move(Move m);
@@ -175,62 +159,41 @@ public:
   void undo_null_move();
 
   // Static exchange evaluation
-  int see(Move m) const;
+  int see(Move m, int asymmThreshold = 0) const;
   int see_sign(Move m) const;
 
   // Accessing hash keys
-  Key get_key() const;
-  Key get_exclusion_key() const;
-  Key get_pawn_key() const;
-  Key get_material_key() const;
+  Key key() const;
+  Key exclusion_key() const;
+  Key pawn_key() const;
+  Key material_key() const;
 
-  // Incremental evaluation
-  Score value() const;
+  // Incremental piece-square evaluation
+  Score psq_score() const;
   Value non_pawn_material(Color c) const;
-  Score pst_delta(Piece piece, Square from, Square to) const;
-
-  // Game termination checks
-  bool is_mate() const;
-  template<bool SkipRepetition> bool is_draw() const;
-
-  // Number of plies from starting position
-  int startpos_ply_counter() const;
 
   // Other properties of the position
-  bool opposite_colored_bishops() const;
-  bool has_pawn_on_7th(Color c) const;
+  Color side_to_move() const;
+  int game_ply() const;
   bool is_chess960() const;
-
-  // Current thread ID searching on the position
-  int thread() const;
-
+  Thread* this_thread() const;
   int64_t nodes_searched() const;
   void set_nodes_searched(int64_t n);
+  bool is_draw() const;
 
   // Position consistency check, for debugging
-  bool is_ok(int* failedStep = NULL) const;
+  bool pos_is_ok(int* failedStep = NULL) const;
   void flip();
 
-  // Global initialization
-  static void init();
-
 private:
-
-  // Initialization helper functions (used while setting up a position)
+  // Initialization helpers (used while setting up a position)
   void clear();
-  void detach();
   void put_piece(Piece p, Square s);
-  void set_castle(int f, Square ksq, Square rsq);
-  void set_castling_rights(char token);
-  bool move_is_legal(const Move m) const;
+  void set_castle_right(Color c, Square rfrom);
 
-  // Helper functions for doing and undoing moves
-  void do_capture_move(Key& key, PieceType capture, Color them, Square to, bool ep);
-  void do_castle_move(Move m);
-  void undo_castle_move(Move m);
-
-  template<bool FindPinned>
-  Bitboard hidden_checkers() const;
+  // Helper functions
+  void do_castle(Square kfrom, Square kto, Square rfrom, Square rto);
+  template<bool FindPinned> Bitboard hidden_checkers() const;
 
   // Computing hash keys from scratch (for initialization and debugging)
   Key compute_key() const;
@@ -238,43 +201,28 @@ private:
   Key compute_material_key() const;
 
   // Computing incremental evaluation scores and material counts
-  Score pst(Piece p, Square s) const;
-  Score compute_value() const;
+  Score compute_psq_score() const;
   Value compute_non_pawn_material(Color c) const;
 
-  // Board
-  Piece board[64];             // [square]
-
-  // Bitboards
-  Bitboard byTypeBB[8];        // [pieceType]
-  Bitboard byColorBB[2];       // [color]
-
-  // Piece counts
-  int pieceCount[2][8];        // [color][pieceType]
-
-  // Piece lists
-  Square pieceList[2][8][16];  // [color][pieceType][index]
-  int index[64];               // [square]
+  // Board and pieces
+  Piece board[SQUARE_NB];
+  Bitboard byTypeBB[PIECE_TYPE_NB];
+  Bitboard byColorBB[COLOR_NB];
+  int pieceCount[COLOR_NB][PIECE_TYPE_NB];
+  Square pieceList[COLOR_NB][PIECE_TYPE_NB][16];
+  int index[SQUARE_NB];
 
   // Other info
-  Key history[MaxGameLength];
-  int castleRightsMask[64];    // [square]
-  Square castleRookSquare[16]; // [castleRight]
+  int castleRightsMask[SQUARE_NB];
+  Square castleRookSquare[COLOR_NB][CASTLING_SIDE_NB];
+  Bitboard castlePath[COLOR_NB][CASTLING_SIDE_NB];
   StateInfo startState;
   int64_t nodes;
+  int gamePly;
   Color sideToMove;
-  int fullMoves;
-  int threadID;
+  Thread* thisThread;
   StateInfo* st;
   int chess960;
-
-  // Static variables
-  static Score pieceSquareTable[16][64]; // [piece][square]
-  static Key zobrist[2][8][64];          // [color][pieceType][square]
-  static Key zobEp[64];                  // [square]
-  static Key zobCastle[16];              // [castleRight]
-  static Key zobSideToMove;
-  static Key zobExclusion;
 };
 
 inline int64_t Position::nodes_searched() const {
@@ -289,40 +237,40 @@ inline Piece Position::piece_on(Square s) const {
   return board[s];
 }
 
-inline bool Position::square_is_empty(Square s) const {
-  return piece_on(s) == PIECE_NONE;
+inline Piece Position::piece_moved(Move m) const {
+  return board[from_sq(m)];
 }
 
-inline Color Position::side_to_move() const {
-  return sideToMove;
+inline bool Position::is_empty(Square s) const {
+  return board[s] == NO_PIECE;
 }
 
-inline Bitboard Position::occupied_squares() const {
-  return byTypeBB[0];
-}
-
-inline Bitboard Position::empty_squares() const {
-  return ~occupied_squares();
+inline Color Position::side_to_move() const {
+  return sideToMove;
 }
 
-inline Bitboard Position::pieces(Color c) const {
-  return byColorBB[c];
+inline Bitboard Position::pieces() const {
+  return byTypeBB[ALL_PIECES];
 }
 
 inline Bitboard Position::pieces(PieceType pt) const {
   return byTypeBB[pt];
 }
 
-inline Bitboard Position::pieces(PieceType pt, Color c) const {
-  return byTypeBB[pt] & byColorBB[c];
-}
-
 inline Bitboard Position::pieces(PieceType pt1, PieceType pt2) const {
   return byTypeBB[pt1] | byTypeBB[pt2];
 }
 
-inline Bitboard Position::pieces(PieceType pt1, PieceType pt2, Color c) const {
-  return (byTypeBB[pt1] | byTypeBB[pt2]) & byColorBB[c];
+inline Bitboard Position::pieces(Color c) const {
+  return byColorBB[c];
+}
+
+inline Bitboard Position::pieces(Color c, PieceType pt) const {
+  return byColorBB[c] & byTypeBB[pt];
+}
+
+inline Bitboard Position::pieces(Color c, PieceType pt1, PieceType pt2) const {
+  return byColorBB[c] & (byTypeBB[pt1] | byTypeBB[pt2]);
 }
 
 inline int Position::piece_count(Color c, PieceType pt) const {
@@ -341,132 +289,133 @@ inline Square Position::king_square(Color c) const {
   return pieceList[c][KING][0];
 }
 
-inline bool Position::can_castle(CastleRight f) const {
+inline int Position::can_castle(CastleRight f) const {
   return st->castleRights & f;
 }
 
-inline bool Position::can_castle(Color c) const {
-  return st->castleRights & ((WHITE_OO | WHITE_OOO) << c);
+inline int Position::can_castle(Color c) const {
+  return st->castleRights & ((WHITE_OO | WHITE_OOO) << (2 * c));
 }
 
-inline Square Position::castle_rook_square(CastleRight f) const {
-  return castleRookSquare[f];
+inline bool Position::castle_impeded(Color c, CastlingSide s) const {
+  return byTypeBB[ALL_PIECES] & castlePath[c][s];
 }
 
-template<>
-inline Bitboard Position::attacks_from<PAWN>(Square s, Color c) const {
-  return StepAttacksBB[make_piece(c, PAWN)][s];
+inline Square Position::castle_rook_square(Color c, CastlingSide s) const {
+  return castleRookSquare[c][s];
 }
 
-template<PieceType Piece> // Knight and King and white pawns
+template<PieceType Pt>
 inline Bitboard Position::attacks_from(Square s) const {
-  return StepAttacksBB[Piece][s];
+
+  return  Pt == BISHOP || Pt == ROOK ? attacks_bb<Pt>(s, pieces())
+        : Pt == QUEEN  ? attacks_from<ROOK>(s) | attacks_from<BISHOP>(s)
+        : StepAttacksBB[Pt][s];
 }
 
 template<>
-inline Bitboard Position::attacks_from<BISHOP>(Square s) const {
-  return bishop_attacks_bb(s, occupied_squares());
+inline Bitboard Position::attacks_from<PAWN>(Square s, Color c) const {
+  return StepAttacksBB[make_piece(c, PAWN)][s];
 }
 
-template<>
-inline Bitboard Position::attacks_from<ROOK>(Square s) const {
-  return rook_attacks_bb(s, occupied_squares());
+inline Bitboard Position::attacks_from(Piece p, Square s) const {
+  return attacks_from(p, s, byTypeBB[ALL_PIECES]);
 }
 
-template<>
-inline Bitboard Position::attacks_from<QUEEN>(Square s) const {
-  return attacks_from<ROOK>(s) | attacks_from<BISHOP>(s);
+inline Bitboard Position::attackers_to(Square s) const {
+  return attackers_to(s, byTypeBB[ALL_PIECES]);
 }
 
 inline Bitboard Position::checkers() const {
   return st->checkersBB;
 }
 
-inline bool Position::in_check() const {
-  return st->checkersBB != EmptyBoardBB;
+inline Bitboard Position::discovered_check_candidates() const {
+  return hidden_checkers<false>();
+}
+
+inline Bitboard Position::pinned_pieces() const {
+  return hidden_checkers<true>();
 }
 
 inline bool Position::pawn_is_passed(Color c, Square s) const {
-  return !(pieces(PAWN, opposite_color(c)) & passed_pawn_mask(c, s));
+  return !(pieces(~c, PAWN) & passed_pawn_mask(c, s));
 }
 
-inline Key Position::get_key() const {
+inline Key Position::key() const {
   return st->key;
 }
 
-inline Key Position::get_exclusion_key() const {
-  return st->key ^ zobExclusion;
+inline Key Position::exclusion_key() const {
+  return st->key ^ Zobrist::exclusion;
 }
 
-inline Key Position::get_pawn_key() const {
+inline Key Position::pawn_key() const {
   return st->pawnKey;
 }
 
-inline Key Position::get_material_key() const {
+inline Key Position::material_key() const {
   return st->materialKey;
 }
 
-inline Score Position::pst(Piece p, Square s) const {
-  return pieceSquareTable[p][s];
-}
-
-inline Score Position::pst_delta(Piece piece, Square from, Square to) const {
-  return pieceSquareTable[piece][to] - pieceSquareTable[piece][from];
-}
-
-inline Score Position::value() const {
-  return st->value;
+inline Score Position::psq_score() const {
+  return st->psq;
 }
 
 inline Value Position::non_pawn_material(Color c) const {
   return st->npMaterial[c];
 }
 
-inline bool Position::move_is_passed_pawn_push(Move m) const {
+inline bool Position::is_passed_pawn_push(Move m) const {
+
+  return   type_of(piece_moved(m)) == PAWN
+        && pawn_is_passed(sideToMove, to_sq(m));
+}
 
-  Color c = side_to_move();
-  return   piece_on(move_from(m)) == make_piece(c, PAWN)
-        && pawn_is_passed(c, move_to(m));
+inline int Position::game_ply() const {
+  return gamePly;
 }
 
-inline int Position::startpos_ply_counter() const {
-  return Max(2 * (fullMoves - 1), 0) + int(sideToMove == BLACK);
+inline bool Position::opposite_bishops() const {
+
+  return   pieceCount[WHITE][BISHOP] == 1
+        && pieceCount[BLACK][BISHOP] == 1
+        && opposite_colors(pieceList[WHITE][BISHOP][0], pieceList[BLACK][BISHOP][0]);
 }
 
-inline bool Position::opposite_colored_bishops() const {
+inline bool Position::bishop_pair(Color c) const {
 
-  return   piece_count(WHITE, BISHOP) == 1
-        && piece_count(BLACK, BISHOP) == 1
-        && opposite_color_squares(piece_list(WHITE, BISHOP)[0], piece_list(BLACK, BISHOP)[0]);
+  return   pieceCount[c][BISHOP] >= 2
+        && opposite_colors(pieceList[c][BISHOP][0], pieceList[c][BISHOP][1]);
 }
 
-inline bool Position::has_pawn_on_7th(Color c) const {
-  return pieces(PAWN, c) & rank_bb(relative_rank(c, RANK_7));
+inline bool Position::pawn_on_7th(Color c) const {
+  return pieces(c, PAWN) & rank_bb(relative_rank(c, RANK_7));
 }
 
 inline bool Position::is_chess960() const {
   return chess960;
 }
 
-inline bool Position::move_is_capture_or_promotion(Move m) const {
+inline bool Position::is_capture_or_promotion(Move m) const {
 
-  assert(move_is_ok(m));
-  return move_is_special(m) ? !move_is_castle(m) : !square_is_empty(move_to(m));
+  assert(is_ok(m));
+  return type_of(m) ? type_of(m) != CASTLE : !is_empty(to_sq(m));
 }
 
-inline bool Position::move_is_capture(Move m) const {
+inline bool Position::is_capture(Move m) const {
 
   // Note that castle is coded as "king captures the rook"
-  assert(move_is_ok(m));
-  return (!square_is_empty(move_to(m)) && !move_is_castle(m)) || move_is_ep(m);
+  assert(is_ok(m));
+  return (!is_empty(to_sq(m)) && type_of(m) != CASTLE) || type_of(m) == ENPASSANT;
 }
 
 inline PieceType Position::captured_piece_type() const {
   return st->capturedType;
 }
 
-inline int Position::thread() const {
-  return threadID;
+inline Thread* Position::this_thread() const {
+  return thisThread;
 }
 
 #endif // !defined(POSITION_H_INCLUDED)