#if !defined(POSITION_H_INCLUDED)
#define POSITION_H_INCLUDED
+#include <cassert>
+
#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;
-
-class Position;
-/// 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.
struct CheckInfo {
explicit CheckInfo(const Position&);
Bitboard dcCandidates;
+ Bitboard pinned;
Bitboard checkSq[8];
- Square ksq;
-};
-
-/// Castle rights, encoded as bit fields
-
-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
};
/// 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
/// must be passed as a parameter.
+class Position;
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 defaul, copy c'tor or assignment allowed, default c'tor will not be
+ // generated anyhow because of user-defined c'tors.
+ Position(const Position&);
+ Position& operator=(const Position&);
public:
- enum GamePhase {
- MidGame,
- EndGame
- };
-
- // Constructors
Position(const Position& pos, int threadID);
Position(const std::string& fen, bool isChess960, int threadID);
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;
// 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_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;
// 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 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);
void undo_null_move();
// Static exchange evaluation
- int see(Square from, Square to) const;
int see(Move m) const;
int see_sign(Move m) 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;
+ template<bool SkipRepetition> bool is_draw() const;
- // Check if side to move could be mated in one
- bool has_mate_threat();
-
- // Number of plies from starting position
+ // Plies from start position to the beginning of search
int startpos_ply_counter() const;
// Other properties of the position
// Position consistency check, for debugging
bool is_ok(int* failedStep = NULL) const;
+ void flip();
- // 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 detach();
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(int f, Square ksq, Square rsq);
+ void set_castling_rights(char token);
+ 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;
+ 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]
// 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 chess960;
- 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]
+ 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 int64_t Position::nodes_searched() const {
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)];
-}
-
inline Color Position::side_to_move() const {
return sideToMove;
}
return ~occupied_squares();
}
-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(CastleRight f) const {
+ return st->castleRights & f;
}
-inline bool Position::can_castle(Color side) const {
- return can_castle_kingside(side) || can_castle_queenside(side);
+inline bool Position::can_castle(Color c) const {
+ return st->castleRights & ((WHITE_OO | WHITE_OOO) << c);
}
-inline Square Position::initial_kr_square(Color c) const {
- return relative_square(c, make_square(initialKRFile, RANK_1));
-}
-
-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<>
return st->checkersBB;
}
-inline bool Position::is_check() const {
+inline bool Position::in_check() const {
return st->checkersBB != EmptyBoardBB;
}
return !(pieces(PAWN, opposite_color(c)) & passed_pawn_mask(c, s));
}
-inline bool Position::square_is_weak(Square s, Color c) const {
- return !(pieces(PAWN, opposite_color(c)) & attack_span_mask(c, s));
-}
-
inline Key Position::get_key() const {
return st->key;
}
return st->materialKey;
}
-inline Score Position::pst(Color c, PieceType pt, Square s) {
- return PieceSquareTable[make_piece(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 {
}
inline int Position::startpos_ply_counter() const {
- return startPosPlyCounter;
+ return startPosPly;
}
inline bool Position::opposite_colored_bishops() 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 piece_count(WHITE, BISHOP) == 1
+ && piece_count(BLACK, BISHOP) == 1
+ && opposite_color_squares(piece_list(WHITE, BISHOP)[0], piece_list(BLACK, BISHOP)[0]);
}
inline bool Position::has_pawn_on_7th(Color c) const {
return chess960;
}
-inline bool Position::move_is_capture(Move m) const {
+inline bool Position::move_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(move_is_ok(m));
+ return move_is_special(m) ? !move_is_castle(m) : !square_is_empty(move_to(m));
}
-inline bool Position::move_is_capture_or_promotion(Move m) const {
+inline bool Position::move_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(move_is_ok(m));
+ return (!square_is_empty(move_to(m)) && !move_is_castle(m)) || move_is_ep(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