X-Git-Url: https://git.sesse.net/?p=stockfish;a=blobdiff_plain;f=src%2Fposition.h;h=ece3f44232e9411222248dcc0fe4519aab09523a;hp=6b77a7378c0efe24e81fa9a4b0ac1a4737bbb52a;hb=e53774bc49dd0aaa1c129ee98c09e1a56ef974fb;hpb=f7742669cb52dff7a64bd1a9ba466e333abb87bc diff --git a/src/position.h b/src/position.h index 6b77a737..ece3f442 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) 2008-2013 Marco Costalba, Joona Kiiski, Tord Romstad + Copyright (C) 2008-2015 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 @@ -21,17 +21,18 @@ #define POSITION_H_INCLUDED #include -#include +#include // For offsetof() +#include #include "bitboard.h" #include "types.h" - -/// The checkInfo struct is initialized at c'tor time and keeps info used -/// to detect if a move gives check. class Position; struct Thread; +/// CheckInfo struct is initialized at c'tor time and keeps info used to detect +/// if a move gives check. + struct CheckInfo { explicit CheckInfo(const Position&); @@ -39,51 +40,55 @@ struct CheckInfo { Bitboard dcCandidates; Bitboard pinned; Bitboard checkSq[PIECE_TYPE_NB]; - Square ksq; + Square ksq; }; -/// The StateInfo struct stores information needed 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), a StateInfo -/// object must be passed as a parameter. +/// StateInfo struct stores information needed 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), a StateInfo object must be passed. struct StateInfo { - Key pawnKey, materialKey; - Value npMaterial[COLOR_NB]; - int castlingFlags, rule50, pliesFromNull; - Score psq; + + // Copied when making a move + Key pawnKey; + Key materialKey; + Value nonPawnMaterial[COLOR_NB]; + int castlingRights; + int rule50; + int pliesFromNull; + Score psq; Square epSquare; - Key key; - Bitboard checkersBB; - PieceType capturedType; + // Not copied when making a move + Key key; + Bitboard checkersBB; + PieceType capturedType; StateInfo* previous; }; -/// 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; +/// Position class stores information regarding the board representation as +/// pieces, side to move, hash keys, castling info, etc. Important methods are +/// do_move() and undo_move(), used by the search to update node info when +/// traversing the search tree. +class Position { -/// The Position class stores the information regarding the board representation -/// like pieces, side to move, hash keys, castling info, etc. The most important -/// methods are do_move() and undo_move(), used by the search to update node info -/// when traversing the search tree. + friend std::ostream& operator<<(std::ostream&, const Position&); -class Position { public: - 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 + Position() = default; // To define the global object RootPos + Position(const Position&) = delete; + Position(const Position& pos, Thread* th) { *this = pos; thisThread = th; } + Position(const std::string& f, bool c960, Thread* th) { set(f, c960, th); } + Position& operator=(const Position&); // To assign RootPos from UCI + + // FEN string input/output void set(const std::string& fenStr, bool isChess960, Thread* th); const std::string fen() const; - const std::string pretty(Move m = MOVE_NONE) const; // Position representation Bitboard pieces() const; @@ -100,10 +105,10 @@ public: template const Square* list(Color c) const; // Castling - int can_castle(CastlingFlag f) const; int can_castle(Color c) const; - bool castling_impeded(Color c, CastlingSide s) const; - Square castling_rook_square(Color c, CastlingSide s) const; + int can_castle(CastlingRight cr) const; + bool castling_impeded(CastlingRight cr) const; + Square castling_rook_square(CastlingRight cr) const; // Checking Bitboard checkers() const; @@ -112,8 +117,8 @@ public: // 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; + Bitboard attackers_to(Square s, Bitboard occupied) const; + Bitboard attacks_from(Piece pc, Square s) const; template Bitboard attacks_from(Square s) const; template Bitboard attacks_from(Square s, Color c) const; @@ -130,91 +135,81 @@ public: // Piece specific bool pawn_passed(Color c, Square s) const; bool pawn_on_7th(Color c) const; - bool bishop_pair(Color c) const; bool opposite_bishops() const; // Doing and undoing moves - void do_move(Move m, StateInfo& st); - void do_move(Move m, StateInfo& st, const CheckInfo& ci, bool moveIsCheck); + void do_move(Move m, StateInfo& st, bool givesCheck); void undo_move(Move m); void do_null_move(StateInfo& st); void undo_null_move(); // Static exchange evaluation - int see(Move m) const; - int see_sign(Move m) const; + Value see(Move m) const; + Value see_sign(Move m) const; // Accessing hash keys Key key() const; + Key key_after(Move m) const; Key exclusion_key() const; - Key pawn_key() const; Key material_key() const; - - // Incremental piece-square evaluation - Score psq_score() const; - Value non_pawn_material(Color c) const; + Key pawn_key() const; // Other properties of the position Color side_to_move() const; + Phase game_phase() const; int game_ply() const; bool is_chess960() const; Thread* this_thread() const; - int64_t nodes_searched() const; - void set_nodes_searched(int64_t n); + uint64_t nodes_searched() const; + void set_nodes_searched(uint64_t n); bool is_draw() const; + int rule50_count() const; + Score psq_score() const; + Value non_pawn_material(Color c) const; // Position consistency check, for debugging - bool pos_is_ok(int* failedStep = NULL) const; + bool pos_is_ok(int* failedStep = nullptr) const; void flip(); private: // Initialization helpers (used while setting up a position) void clear(); - void set_castling_flag(Color c, Square rfrom); - - // Helper functions - void do_castling(Square kfrom, Square kto, Square rfrom, Square rto); - Bitboard hidden_checkers(Color c, Color kingColor) const; - void put_piece(Square s, Color c, PieceType pt); - void remove_piece(Square s, Color c, PieceType pt); - void move_piece(Square from, Square to, Color c, PieceType pt); - - // Computing hash keys from scratch (for initialization and debugging) - Key compute_key() const; - Key compute_pawn_key() const; - Key compute_material_key() const; - - // Computing incremental evaluation scores and material counts - Score compute_psq_score() const; - Value compute_non_pawn_material(Color c) const; - - // Board and pieces + void set_castling_right(Color c, Square rfrom); + void set_state(StateInfo* si) const; + + // Other helpers + Bitboard check_blockers(Color c, Color kingColor) const; + void put_piece(Color c, PieceType pt, Square s); + void remove_piece(Color c, PieceType pt, Square s); + void move_piece(Color c, PieceType pt, Square from, Square to); + template + void do_castling(Color us, Square from, Square& to, Square& rfrom, Square& rto); + + // Data members 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 - int castlingFlagsMask[SQUARE_NB]; - Square castlingRookSquare[COLOR_NB][CASTLING_SIDE_NB]; - Bitboard castlingPath[COLOR_NB][CASTLING_SIDE_NB]; + int castlingRightsMask[SQUARE_NB]; + Square castlingRookSquare[CASTLING_RIGHT_NB]; + Bitboard castlingPath[CASTLING_RIGHT_NB]; StateInfo startState; - int64_t nodes; + uint64_t nodes; int gamePly; Color sideToMove; Thread* thisThread; StateInfo* st; - int chess960; + bool chess960; }; -inline int64_t Position::nodes_searched() const { - return nodes; +inline Color Position::side_to_move() const { + return sideToMove; } -inline void Position::set_nodes_searched(int64_t n) { - nodes = n; +inline bool Position::empty(Square s) const { + return board[s] == NO_PIECE; } inline Piece Position::piece_on(Square s) const { @@ -225,14 +220,6 @@ inline Piece Position::moved_piece(Move m) const { return board[from_sq(m)]; } -inline bool Position::empty(Square s) const { - return board[s] == NO_PIECE; -} - -inline Color Position::side_to_move() const { - return sideToMove; -} - inline Bitboard Position::pieces() const { return byTypeBB[ALL_PIECES]; } @@ -265,34 +252,33 @@ template inline const Square* Position::list(Color c) const { return pieceList[c][Pt]; } -inline Square Position::ep_square() const { - return st->epSquare; -} - inline Square Position::king_square(Color c) const { return pieceList[c][KING][0]; } -inline int Position::can_castle(CastlingFlag f) const { - return st->castlingFlags & f; +inline Square Position::ep_square() const { + return st->epSquare; +} + +inline int Position::can_castle(CastlingRight cr) const { + return st->castlingRights & cr; } inline int Position::can_castle(Color c) const { - return st->castlingFlags & ((WHITE_OO | WHITE_OOO) << (2 * c)); + return st->castlingRights & ((WHITE_OO | WHITE_OOO) << (2 * c)); } -inline bool Position::castling_impeded(Color c, CastlingSide s) const { - return byTypeBB[ALL_PIECES] & castlingPath[c][s]; +inline bool Position::castling_impeded(CastlingRight cr) const { + return byTypeBB[ALL_PIECES] & castlingPath[cr]; } -inline Square Position::castling_rook_square(Color c, CastlingSide s) const { - return castlingRookSquare[c][s]; +inline Square Position::castling_rook_square(CastlingRight cr) const { + return castlingRookSquare[cr]; } template inline Bitboard Position::attacks_from(Square s) const { - - return Pt == BISHOP || Pt == ROOK ? attacks_bb(s, pieces()) + return Pt == BISHOP || Pt == ROOK ? attacks_bb(s, byTypeBB[ALL_PIECES]) : Pt == QUEEN ? attacks_from(s) | attacks_from(s) : StepAttacksBB[Pt][s]; } @@ -302,8 +288,8 @@ inline Bitboard Position::attacks_from(Square s, Color c) const { return StepAttacksBB[make_piece(c, PAWN)][s]; } -inline Bitboard Position::attacks_from(Piece p, Square s) const { - return attacks_bb(p, s, byTypeBB[ALL_PIECES]); +inline Bitboard Position::attacks_from(Piece pc, Square s) const { + return attacks_bb(pc, s, byTypeBB[ALL_PIECES]); } inline Bitboard Position::attackers_to(Square s) const { @@ -315,11 +301,11 @@ inline Bitboard Position::checkers() const { } inline Bitboard Position::discovered_check_candidates() const { - return hidden_checkers(sideToMove, ~sideToMove); + return check_blockers(sideToMove, ~sideToMove); } inline Bitboard Position::pinned_pieces(Color c) const { - return hidden_checkers(c, c); + return check_blockers(c, c); } inline bool Position::pawn_passed(Color c, Square s) const { @@ -348,24 +334,29 @@ inline Score Position::psq_score() const { } inline Value Position::non_pawn_material(Color c) const { - return st->npMaterial[c]; + return st->nonPawnMaterial[c]; } inline int Position::game_ply() const { return gamePly; } -inline bool Position::opposite_bishops() const { +inline int Position::rule50_count() const { + return st->rule50; +} - return pieceCount[WHITE][BISHOP] == 1 - && pieceCount[BLACK][BISHOP] == 1 - && opposite_colors(pieceList[WHITE][BISHOP][0], pieceList[BLACK][BISHOP][0]); +inline uint64_t Position::nodes_searched() const { + return nodes; } -inline bool Position::bishop_pair(Color c) const { +inline void Position::set_nodes_searched(uint64_t n) { + nodes = n; +} - return pieceCount[c][BISHOP] >= 2 - && opposite_colors(pieceList[c][BISHOP][0], pieceList[c][BISHOP][1]); +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::pawn_on_7th(Color c) const { @@ -384,7 +375,7 @@ inline bool Position::capture_or_promotion(Move m) const { inline bool Position::capture(Move m) const { - // Note that castling is encoded as "king captures the rook" + // Castling is encoded as "king captures the rook" assert(is_ok(m)); return (!empty(to_sq(m)) && type_of(m) != CASTLING) || type_of(m) == ENPASSANT; } @@ -397,32 +388,18 @@ inline Thread* Position::this_thread() const { return thisThread; } -inline void Position::put_piece(Square s, Color c, PieceType pt) { +inline void Position::put_piece(Color c, PieceType pt, Square s) { board[s] = make_piece(c, pt); byTypeBB[ALL_PIECES] |= s; byTypeBB[pt] |= s; byColorBB[c] |= s; - pieceCount[c][ALL_PIECES]++; index[s] = pieceCount[c][pt]++; pieceList[c][pt][index[s]] = s; + pieceCount[c][ALL_PIECES]++; } -inline void Position::move_piece(Square from, Square to, Color c, PieceType pt) { - - // index[from] is not updated and becomes stale. This works as long - // as index[] is accessed just by known occupied squares. - Bitboard from_to_bb = SquareBB[from] ^ SquareBB[to]; - byTypeBB[ALL_PIECES] ^= from_to_bb; - byTypeBB[pt] ^= from_to_bb; - byColorBB[c] ^= from_to_bb; - board[from] = NO_PIECE; - board[to] = make_piece(c, pt); - index[to] = index[from]; - pieceList[c][pt][index[to]] = to; -} - -inline void Position::remove_piece(Square s, Color c, PieceType pt) { +inline void Position::remove_piece(Color c, PieceType pt, Square s) { // WARNING: This is not a reversible operation. If we remove a piece in // do_move() and then replace it in undo_move() we will put it at the end of @@ -431,12 +408,26 @@ inline void Position::remove_piece(Square s, Color c, PieceType pt) { byTypeBB[ALL_PIECES] ^= s; byTypeBB[pt] ^= s; byColorBB[c] ^= s; - /* board[s] = NO_PIECE; */ // Not needed, will be overwritten by capturing - pieceCount[c][ALL_PIECES]--; + /* board[s] = NO_PIECE; Not needed, overwritten by the capturing one */ Square lastSquare = pieceList[c][pt][--pieceCount[c][pt]]; index[lastSquare] = index[s]; pieceList[c][pt][index[lastSquare]] = lastSquare; pieceList[c][pt][pieceCount[c][pt]] = SQ_NONE; + pieceCount[c][ALL_PIECES]--; +} + +inline void Position::move_piece(Color c, PieceType pt, Square from, Square to) { + + // index[from] is not updated and becomes stale. This works as long as index[] + // is accessed just by known occupied squares. + Bitboard from_to_bb = SquareBB[from] ^ SquareBB[to]; + byTypeBB[ALL_PIECES] ^= from_to_bb; + byTypeBB[pt] ^= from_to_bb; + byColorBB[c] ^= from_to_bb; + board[from] = NO_PIECE; + board[to] = make_piece(c, pt); + index[to] = index[from]; + pieceList[c][pt][index[to]] = to; } #endif // #ifndef POSITION_H_INCLUDED