/// string. This function is not very robust - make sure that input FENs are
/// correct (this is assumed to be the responsibility of the GUI).
-void Position::from_fen(const string& fen, bool c960) {
+void Position::from_fen(const string& fen, bool isChess960) {
/*
A FEN string defines a particular position using only the ASCII character set.
castleRightsMask[make_square(initialQRFile, RANK_1)] ^= WHITE_OOO;
castleRightsMask[make_square(initialQRFile, RANK_8)] ^= BLACK_OOO;
- isChess960 = c960;
+ chess960 = isChess960;
find_checkers();
st->key = compute_key();
if (st->castleRights != CASTLES_NONE)
{
if (can_castle_kingside(WHITE))
- fen += isChess960 ? char(toupper(file_to_char(initialKRFile))) : 'K';
+ fen += chess960 ? char(toupper(file_to_char(initialKRFile))) : 'K';
if (can_castle_queenside(WHITE))
- fen += isChess960 ? char(toupper(file_to_char(initialQRFile))) : 'Q';
+ fen += chess960 ? char(toupper(file_to_char(initialQRFile))) : 'Q';
if (can_castle_kingside(BLACK))
- fen += isChess960 ? file_to_char(initialKRFile) : 'k';
+ fen += chess960 ? file_to_char(initialKRFile) : 'k';
if (can_castle_queenside(BLACK))
- fen += isChess960 ? file_to_char(initialQRFile) : 'q';
+ fen += chess960 ? file_to_char(initialQRFile) : 'q';
} else
fen += '-';
case WB: case BB: return attacks_from<BISHOP>(s);
case WR: case BR: return attacks_from<ROOK>(s);
case WQ: case BQ: return attacks_from<QUEEN>(s);
- default: return NonSlidingAttacksBB[p][s];
+ default: return StepAttacksBB[p][s];
}
}
case WB: case BB: return bishop_attacks_bb(s, occ);
case WR: case BR: return rook_attacks_bb(s, occ);
case WQ: case BQ: return bishop_attacks_bb(s, occ) | rook_attacks_bb(s, occ);
- default: return NonSlidingAttacksBB[p][s];
+ default: return StepAttacksBB[p][s];
}
}
return bit_is_set(target, to) && pl_move_is_legal(m, pinned);
}
+/// Position::move_is_legal() takes a position and a (not necessarily pseudo-legal)
+/// move and tests whether the move is legal. This version is not very fast and
+/// should be used only in non time-critical paths.
+
+bool Position::move_is_legal(const Move m) const {
+
+ MoveStack mlist[MAX_MOVES];
+ MoveStack *cur, *last = generate<MV_PSEUDO_LEGAL>(*this, mlist);
+
+ for (cur = mlist; cur != last; cur++)
+ if (cur->move == m)
+ return pl_move_is_legal(m, pinned_pieces(sideToMove));
+
+ return false;
+}
+
+
+/// Fast version of Position::move_is_legal() that takes a position a move and
+/// a bitboard of pinned pieces as input, and tests whether the move is legal.
+
+bool Position::move_is_legal(const Move m, Bitboard pinned) const {
+
+ assert(is_ok());
+ assert(pinned == pinned_pieces(sideToMove));
+
+ Color us = sideToMove;
+ Color them = opposite_color(sideToMove);
+ Square from = move_from(m);
+ Square to = move_to(m);
+ Piece pc = piece_on(from);
+
+ // Use a slower but simpler function for uncommon cases
+ if (move_is_special(m))
+ return move_is_legal(m);
+
+ // If the from square is not occupied by a piece belonging to the side to
+ // move, the move is obviously not legal.
+ if (color_of_piece(pc) != us)
+ return false;
+
+ // The destination square cannot be occupied by a friendly piece
+ if (color_of_piece_on(to) == us)
+ return false;
+
+ // Handle the special case of a pawn move
+ if (type_of_piece(pc) == PAWN)
+ {
+ // Move direction must be compatible with pawn color
+ int direction = to - from;
+ if ((us == WHITE) != (direction > 0))
+ return false;
+
+ // We have already handled promotion moves, so destination
+ // cannot be on the 8/1th rank.
+ if (square_rank(to) == RANK_8 || square_rank(to) == RANK_1)
+ return false;
+
+ // Proceed according to the square delta between the origin and
+ // destination squares.
+ switch (direction)
+ {
+ case DELTA_NW:
+ case DELTA_NE:
+ case DELTA_SW:
+ case DELTA_SE:
+ // Capture. The destination square must be occupied by an enemy
+ // piece (en passant captures was handled earlier).
+ if (color_of_piece_on(to) != them)
+ return false;
+ break;
+
+ case DELTA_N:
+ case DELTA_S:
+ // Pawn push. The destination square must be empty.
+ if (!square_is_empty(to))
+ return false;
+ break;
+
+ case DELTA_NN:
+ // Double white pawn push. The destination square must be on the fourth
+ // rank, and both the destination square and the square between the
+ // source and destination squares must be empty.
+ if ( square_rank(to) != RANK_4
+ || !square_is_empty(to)
+ || !square_is_empty(from + DELTA_N))
+ return false;
+ break;
+
+ case DELTA_SS:
+ // Double black pawn push. The destination square must be on the fifth
+ // rank, and both the destination square and the square between the
+ // source and destination squares must be empty.
+ if ( square_rank(to) != RANK_5
+ || !square_is_empty(to)
+ || !square_is_empty(from + DELTA_S))
+ return false;
+ break;
+
+ default:
+ return false;
+ }
+ }
+ else if (!bit_is_set(attacks_from(pc, from), to))
+ return false;
+
+ // The move is pseudo-legal, check if it is also legal
+ return is_check() ? pl_move_is_evasion(m, pinned) : pl_move_is_legal(m, pinned);
+}
+
/// Position::move_is_check() tests whether a pseudo-legal move is a check
// Update pawn hash key and prefetch in L1/L2 cache
st->pawnKey ^= zobrist[us][PAWN][from] ^ zobrist[us][PAWN][to];
- prefetchPawn(st->pawnKey, threadID);
// Set en passant square, only if moved pawn can be captured
if ((to ^ from) == 16)
}
}
+ // Prefetch pawn and material hash tables
+ prefetchTables(st->pawnKey, st->materialKey, threadID);
+
// Update incremental scores
st->value += pst_delta(piece, from, to);
bool Position::is_mate() const {
- MoveStack moves[MOVES_MAX];
+ MoveStack moves[MAX_MOVES];
return is_check() && generate<MV_LEGAL>(*this, moves) == moves;
}
-/// Position::has_mate_threat() tests whether the side to move is under
-/// a threat of being mated in one from the current position.
-
-bool Position::has_mate_threat() {
-
- MoveStack mlist[MOVES_MAX], *last, *cur;
- StateInfo st1, st2;
- bool mateFound = false;
-
- // If we are under check it's up to evasions to do the job
- if (is_check())
- return false;
-
- // First pass the move to our opponent doing a null move
- do_null_move(st1);
-
- // Then generate pseudo-legal moves that could give check
- last = generate<MV_NON_CAPTURE_CHECK>(*this, mlist);
- last = generate<MV_CAPTURE>(*this, last);
-
- // Loop through the moves, and see if one of them gives mate
- Bitboard pinned = pinned_pieces(sideToMove);
- CheckInfo ci(*this);
- for (cur = mlist; cur != last && !mateFound; cur++)
- {
- Move move = cur->move;
- if ( !pl_move_is_legal(move, pinned)
- || !move_is_check(move, ci))
- continue;
-
- do_move(move, st2, ci, true);
-
- if (is_mate())
- mateFound = true;
-
- undo_move(move);
- }
-
- undo_null_move();
- return mateFound;
-}
-
-
/// Position::init_zobrist() is a static member function which initializes at
/// startup the various arrays used to compute hash keys.
if (failedStep) (*failedStep)++;
if (debugPieceList)
- {
for (Color c = WHITE; c <= BLACK; c++)
for (PieceType pt = PAWN; pt <= KING; pt++)
for (int i = 0; i < pieceCount[c][pt]; i++)
if (index[piece_list(c, pt, i)] != i)
return false;
}
- }
if (failedStep) (*failedStep)++;
- if (debugCastleSquares) {
- for (Color c = WHITE; c <= BLACK; c++) {
+ if (debugCastleSquares)
+ {
+ for (Color c = WHITE; c <= BLACK; c++)
+ {
if (can_castle_kingside(c) && piece_on(initial_kr_square(c)) != make_piece(c, ROOK))
return false;
+
if (can_castle_queenside(c) && piece_on(initial_qr_square(c)) != make_piece(c, ROOK))
return false;
}
projects / stockfish / blobdiff