/*
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) 2008-2012 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
along with this program. If not, see <http://www.gnu.org/licenses/>.
*/
-
#if !defined(POSITION_H_INCLUDED)
#define POSITION_H_INCLUDED
-////
-//// Includes
-////
+#include <cassert>
#include "bitboard.h"
-#include "color.h"
-#include "direction.h"
-#include "move.h"
-#include "piece.h"
-#include "square.h"
-#include "value.h"
-
-
-////
-//// Constants
-////
-
-/// 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;
+#include "types.h"
-////
-//// Types
-////
-
-/// struct checkInfo is initialized at c'tor time and keeps
-/// info used to detect if a move gives check.
+/// The checkInfo struct is initialized at c'tor time and keeps info used
+/// to detect if a move gives check.
+class Position;
struct CheckInfo {
- explicit CheckInfo(const Position&);
-
- Bitboard dcCandidates;
- Bitboard checkSq[8];
- Square ksq;
-};
-
-/// Castle rights, encoded as bit fields
+ explicit CheckInfo(const Position&);
-enum CastleRights {
- CASTLES_NONE = 0,
- WHITE_OO = 1,
- BLACK_OO = 2,
- WHITE_OOO = 4,
- BLACK_OOO = 8,
- ALL_CASTLES = 15
-};
-
-/// Game phase
-enum Phase {
- PHASE_ENDGAME = 0,
- PHASE_MIDGAME = 128
+ Bitboard dcCandidates;
+ Bitboard pinned;
+ Bitboard checkSq[8];
};
struct StateInfo {
Key pawnKey, materialKey;
- int castleRights, rule50, gamePly, pliesFromNull;
- Square epSquare;
- Score value;
Value npMaterial[2];
+ int castleRights, rule50, pliesFromNull;
+ Score value;
+ Square epSquare;
- PieceType capturedType;
Key key;
Bitboard checkersBB;
+ PieceType capturedType;
StateInfo* previous;
};
class Position {
- friend class MaterialInfo;
- friend class EndgameFunctions;
-
- Position(); // No default or copy c'tor allowed
- Position(const Position& pos);
+ // No copy c'tor or assignment operator allowed
+ Position(const Position&);
+ Position& operator=(const Position&);
public:
- enum GamePhase {
- MidGame,
- EndGame
- };
-
- // Constructors
- Position(const Position& pos, int threadID);
- Position(const std::string& fen, int threadID);
+ Position() {}
+ Position(const Position& pos, int th) { copy(pos, th); }
+ Position(const std::string& fen, bool isChess960, int th);
// Text input/output
- void from_fen(const std::string& fen);
+ void copy(const Position& pos, int th);
+ void from_fen(const std::string& fen, bool isChess960);
const std::string to_fen() const;
void print(Move m = MOVE_NONE) const;
- // Copying
- void flipped_copy(const Position& pos);
-
// The piece on a given square
Piece piece_on(Square s) const;
- PieceType type_of_piece_on(Square s) const;
- Color color_of_piece_on(Square s) const;
bool square_is_empty(Square s) const;
- bool square_is_occupied(Square s) const;
- Value midgame_value_of_piece_on(Square s) const;
- Value endgame_value_of_piece_on(Square s) const;
// Side to move
Color side_to_move() const;
// Bitboard representation of the position
Bitboard empty_squares() const;
Bitboard occupied_squares() const;
- Bitboard pieces_of_color(Color c) const;
+ Bitboard pieces(Color c) const;
Bitboard pieces(PieceType pt) const;
Bitboard pieces(PieceType pt, Color c) const;
Bitboard pieces(PieceType pt1, PieceType pt2) const;
Square king_square(Color c) const;
// Castling rights
- bool can_castle_kingside(Color c) const;
- bool can_castle_queenside(Color c) const;
+ bool can_castle(CastleRight f) const;
bool can_castle(Color c) const;
- Square initial_kr_square(Color c) const;
- Square initial_qr_square(Color c) const;
+ Square castle_rook_square(CastleRight f) const;
// Bitboards for pinned pieces and discovered check candidates
- Bitboard discovered_check_candidates(Color c) const;
- Bitboard pinned_pieces(Color c) const;
+ Bitboard discovered_check_candidates() const;
+ Bitboard pinned_pieces() const;
// Checking pieces and under check information
Bitboard checkers() const;
- bool is_check() const;
+ bool in_check() const;
// Piece lists
- Square piece_list(Color c, PieceType pt, int index) const;
- const Square* piece_list_begin(Color c, PieceType pt) const;
+ const Square* piece_list(Color c, PieceType pt) const;
// Information about attacks to or 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;
static Bitboard attacks_from(Piece p, Square s, Bitboard occ);
template<PieceType> Bitboard attacks_from(Square s) const;
template<PieceType> Bitboard attacks_from(Square s, Color c) const;
// Properties of moves
- bool pl_move_is_legal(Move m, Bitboard pinned) const;
- bool pl_move_is_evasion(Move m, Bitboard pinned) const;
- bool move_is_check(Move m) const;
- bool move_is_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_gives_check(Move m, const CheckInfo& ci) const;
bool move_attacks_square(Move m, Square s) const;
+ 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 captured with previous moves
PieceType captured_piece_type() const;
// Information about pawns
bool pawn_is_passed(Color c, Square s) const;
- // Weak squares
- bool square_is_weak(Square s, Color c) const;
-
// Doing and undoing moves
- void detach();
void do_move(Move m, StateInfo& st);
void do_move(Move m, StateInfo& st, const CheckInfo& ci, bool moveIsCheck);
void undo_move(Move m);
- void do_null_move(StateInfo& st);
- void undo_null_move();
+ template<bool Do> void do_null_move(StateInfo& st);
// Static exchange evaluation
- int see(Square from, Square to) const;
int see(Move m) 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;
Value non_pawn_material(Color c) const;
- static Score pst_delta(Piece piece, Square from, Square to);
+ Score pst_delta(Piece piece, Square from, Square to) const;
// Game termination checks
bool is_mate() const;
- bool is_draw() const;
-
- // Check if side to move could be mated in one
- bool has_mate_threat();
-
- // Number of plies since the last non-reversible move
- int rule_50_counter() const;
+ template<bool SkipRepetition> bool is_draw() const;
+ // Plies from start position to the beginning of search
int startpos_ply_counter() const;
// Other properties of the position
// Current thread ID searching on the position
int thread() const;
- // Reset the gamePly variable to 0
- void reset_game_ply();
- void inc_startpos_ply_counter();
int64_t nodes_searched() const;
void set_nodes_searched(int64_t n);
// Position consistency check, for debugging
- bool is_ok(int* failedStep = NULL) const;
+ bool pos_is_ok(int* failedStep = NULL) const;
+ void flip_me();
- // Static member functions
- static void init_zobrist();
- static void init_piece_square_tables();
+ // Global initialization
+ static void init();
private:
// Initialization helper functions (used while setting up a position)
void clear();
void put_piece(Piece p, Square s);
- void do_allow_oo(Color c);
- void do_allow_ooo(Color c);
- bool set_castling_rights(char token);
+ void set_castle_right(Square ksq, Square rsq);
+ bool move_is_legal(const Move m) const;
- // 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);
- void find_checkers();
-
- template<bool FindPinned>
- Bitboard hidden_checkers(Color c) const;
+ // Helper template functions
+ template<bool Do> void do_castle_move(Move m);
+ template<bool FindPinned> Bitboard hidden_checkers() const;
// Computing hash keys from scratch (for initialization and debugging)
Key compute_key() const;
Key compute_material_key() const;
// Computing incremental evaluation scores and material counts
- static Score pst(Color c, PieceType pt, Square s);
+ Score pst(Piece p, Square s) const;
Score compute_value() const;
Value compute_non_pawn_material(Color c) const;
// Board
- Piece board[64];
+ Piece board[64]; // [square]
// Bitboards
- Bitboard byTypeBB[8], byColorBB[2];
+ Bitboard byTypeBB[8]; // [pieceType]
+ Bitboard byColorBB[2]; // [color]
+ Bitboard occupied;
// Piece counts
- int pieceCount[2][8]; // [color][pieceType]
+ int pieceCount[2][8]; // [color][pieceType]
// Piece lists
- Square pieceList[2][8][16]; // [color][pieceType][index]
- int index[64]; // [square]
+ Square pieceList[2][8][16]; // [color][pieceType][index]
+ int index[64]; // [square]
// Other info
- Color sideToMove;
- Key history[MaxGameLength];
- int castleRightsMask[64];
+ int castleRightsMask[64]; // [square]
+ Square castleRookSquare[16]; // [castleRight]
StateInfo startState;
- File initialKFile, initialKRFile, initialQRFile;
- bool isChess960;
- int startPosPlyCounter;
- int threadID;
int64_t nodes;
+ int startPosPly;
+ Color sideToMove;
+ int threadID;
StateInfo* st;
+ int chess960;
// Static variables
- static Key zobrist[2][8][64];
- static Key zobEp[64];
- static Key zobCastle[16];
+ static Score pieceSquareTable[16][64]; // [piece][square]
+ static Key zobrist[2][8][64]; // [color][pieceType][square]/[piece count]
+ static Key zobEp[64]; // [square]
+ static Key zobCastle[16]; // [castleRight]
static Key zobSideToMove;
- static Score PieceSquareTable[16][64];
static Key zobExclusion;
- static const Value seeValues[8];
- static const Value PieceValueMidgame[17];
- static const Value PieceValueEndgame[17];
};
-
-////
-//// Inline functions
-////
-
inline int64_t Position::nodes_searched() const {
return nodes;
}
return board[s];
}
-inline Color Position::color_of_piece_on(Square s) const {
- return color_of_piece(piece_on(s));
-}
-
-inline PieceType Position::type_of_piece_on(Square s) const {
- return type_of_piece(piece_on(s));
-}
-
inline bool Position::square_is_empty(Square s) const {
- return piece_on(s) == PIECE_NONE;
-}
-
-inline bool Position::square_is_occupied(Square s) const {
- return !square_is_empty(s);
-}
-
-inline Value Position::midgame_value_of_piece_on(Square s) const {
- return PieceValueMidgame[piece_on(s)];
-}
-
-inline Value Position::endgame_value_of_piece_on(Square s) const {
- return PieceValueEndgame[piece_on(s)];
+ return board[s] == NO_PIECE;
}
inline Color Position::side_to_move() const {
}
inline Bitboard Position::occupied_squares() const {
- return byTypeBB[0];
+ return occupied;
}
inline Bitboard Position::empty_squares() const {
- return ~occupied_squares();
+ return ~occupied;
}
-inline Bitboard Position::pieces_of_color(Color c) const {
+inline Bitboard Position::pieces(Color c) const {
return byColorBB[c];
}
return pieceCount[c][pt];
}
-inline Square Position::piece_list(Color c, PieceType pt, int idx) const {
- return pieceList[c][pt][idx];
-}
-
-inline const Square* Position::piece_list_begin(Color c, PieceType pt) const {
+inline const Square* Position::piece_list(Color c, PieceType pt) const {
return pieceList[c][pt];
}
return pieceList[c][KING][0];
}
-inline bool Position::can_castle_kingside(Color side) const {
- return st->castleRights & (1+int(side));
-}
-
-inline bool Position::can_castle_queenside(Color side) const {
- return st->castleRights & (4+4*int(side));
-}
-
-inline bool Position::can_castle(Color side) const {
- return can_castle_kingside(side) || can_castle_queenside(side);
+inline bool Position::can_castle(CastleRight f) const {
+ return st->castleRights & f;
}
-inline Square Position::initial_kr_square(Color c) const {
- return relative_square(c, make_square(initialKRFile, RANK_1));
+inline bool Position::can_castle(Color c) const {
+ return st->castleRights & ((WHITE_OO | WHITE_OOO) << c);
}
-inline Square Position::initial_qr_square(Color c) const {
- return relative_square(c, make_square(initialQRFile, RANK_1));
+inline Square Position::castle_rook_square(CastleRight f) const {
+ return castleRookSquare[f];
}
template<>
inline Bitboard Position::attacks_from<PAWN>(Square s, Color c) const {
- return StepAttackBB[piece_of_color_and_type(c, PAWN)][s];
+ return StepAttacksBB[make_piece(c, PAWN)][s];
}
template<PieceType Piece> // Knight and King and white pawns
inline Bitboard Position::attacks_from(Square s) const {
- return StepAttackBB[Piece][s];
+ return StepAttacksBB[Piece][s];
}
template<>
return attacks_from<ROOK>(s) | attacks_from<BISHOP>(s);
}
+inline Bitboard Position::attacks_from(Piece p, Square s) const {
+ return attacks_from(p, s, occupied_squares());
+}
+
+inline Bitboard Position::attackers_to(Square s) const {
+ return attackers_to(s, occupied_squares());
+}
+
inline Bitboard Position::checkers() const {
return st->checkersBB;
}
-inline bool Position::is_check() const {
- return st->checkersBB != EmptyBoardBB;
+inline bool Position::in_check() const {
+ return st->checkersBB != 0;
}
-inline bool Position::pawn_is_passed(Color c, Square s) const {
- return !(pieces(PAWN, opposite_color(c)) & passed_pawn_mask(c, s));
+inline Bitboard Position::discovered_check_candidates() const {
+ return hidden_checkers<false>();
}
-inline bool Position::square_is_weak(Square s, Color c) const {
- return !(pieces(PAWN, opposite_color(c)) & attack_span_mask(c, s));
+inline Bitboard Position::pinned_pieces() const {
+ return hidden_checkers<true>();
}
-inline Key Position::get_key() const {
+inline bool Position::pawn_is_passed(Color c, Square s) const {
+ return !(pieces(PAWN, flip(c)) & passed_pawn_mask(c, s));
+}
+
+inline Key Position::key() const {
return st->key;
}
-inline Key Position::get_exclusion_key() const {
+inline Key Position::exclusion_key() const {
return st->key ^ zobExclusion;
}
-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(Color c, PieceType pt, Square s) {
- return PieceSquareTable[piece_of_color_and_type(c, pt)][s];
+inline Score Position::pst(Piece p, Square s) const {
+ return pieceSquareTable[p][s];
}
-inline Score Position::pst_delta(Piece piece, Square from, Square to) {
- return PieceSquareTable[piece][to] - PieceSquareTable[piece][from];
+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->npMaterial[c];
}
-inline bool Position::move_is_passed_pawn_push(Move m) const {
-
- Color c = side_to_move();
- return piece_on(move_from(m)) == piece_of_color_and_type(c, PAWN)
- && pawn_is_passed(c, move_to(m));
-}
+inline bool Position::is_passed_pawn_push(Move m) const {
-inline int Position::rule_50_counter() const {
- return st->rule50;
+ return board[from_sq(m)] == make_piece(sideToMove, PAWN)
+ && pawn_is_passed(sideToMove, to_sq(m));
}
inline int Position::startpos_ply_counter() const {
- return startPosPlyCounter;
+ return startPosPly + st->pliesFromNull; // HACK
}
inline bool Position::opposite_colored_bishops() const {
- return piece_count(WHITE, BISHOP) == 1
- && piece_count(BLACK, BISHOP) == 1
- && !same_color_squares(piece_list(WHITE, BISHOP, 0), piece_list(BLACK, BISHOP, 0));
+ return pieceCount[WHITE][BISHOP] == 1
+ && pieceCount[BLACK][BISHOP] == 1
+ && opposite_colors(pieceList[WHITE][BISHOP][0], pieceList[BLACK][BISHOP][0]);
}
inline bool Position::has_pawn_on_7th(Color c) const {
- return pieces(PAWN, c) & relative_rank_bb(c, RANK_7);
+ return pieces(PAWN, c) & rank_bb(relative_rank(c, RANK_7));
}
inline bool Position::is_chess960() const {
- return isChess960;
+ return chess960;
}
-inline bool Position::move_is_capture(Move m) const {
+inline bool Position::is_capture_or_promotion(Move m) const {
- // Move must not be MOVE_NONE !
- return (m & (3 << 15)) ? !move_is_castle(m) : !square_is_empty(move_to(m));
+ assert(is_ok(m));
+ return is_special(m) ? !is_castle(m) : !square_is_empty(to_sq(m));
}
-inline bool Position::move_is_capture_or_promotion(Move m) const {
+inline bool Position::is_capture(Move m) const {
- // Move must not be MOVE_NONE !
- return (m & (0x1F << 12)) ? !move_is_castle(m) : !square_is_empty(move_to(m));
+ // Note that castle is coded as "king captures the rook"
+ assert(is_ok(m));
+ return (!square_is_empty(to_sq(m)) && !is_castle(m)) || is_enpassant(m);
}
inline PieceType Position::captured_piece_type() const {
return threadID;
}
-inline void Position::do_allow_oo(Color c) {
- st->castleRights |= (1 + int(c));
-}
-
-inline void Position::do_allow_ooo(Color c) {
- st->castleRights |= (4 + 4*int(c));
-}
-
#endif // !defined(POSITION_H_INCLUDED)
projects / stockfish / blobdiff