void board_from_fen(board_t * board, const char fen[]) { int pos; int file, rank, sq; int c; int i, len; int piece; int pawn; ASSERT(board!=NULL); ASSERT(fen!=NULL); board_clear(board); pos = 0; c = fen[pos]; // piece placement for (rank = Rank8; rank >= Rank1; rank--) { for (file = FileA; file <= FileH;) { if (c >= '1' && c <= '8') { // empty square(s) len = c - '0'; for (i = 0; i < len; i++) { if (file > FileH) my_fatal("board_from_fen(): bad FEN (pos=%d)\n",pos); board->square[SQUARE_MAKE(file,rank)] = Empty; file++; } } else { // piece piece = piece_from_char(c); if (piece == PieceNone256) my_fatal("board_from_fen(): bad FEN (pos=%d)\n",pos); board->square[SQUARE_MAKE(file,rank)] = piece; file++; } c = fen[++pos]; } if (rank > Rank1) { if (c != '/') my_fatal("board_from_fen(): bad FEN (pos=%d)\n",pos); c = fen[++pos]; } } // active colour if (c != ' ') my_fatal("board_from_fen(): bad FEN (pos=%d)\n",pos); c = fen[++pos]; switch (c) { case 'w': board->turn = White; break; case 'b': board->turn = Black; break; default: my_fatal("board_from_fen(): bad FEN (pos=%d)\n",pos); break; } c = fen[++pos]; // castling if (c != ' ') my_fatal("board_from_fen(): bad FEN (pos=%d)\n",pos); c = fen[++pos]; board->flags = FlagsNone; if (c == '-') { // no castling rights c = fen[++pos]; } else { if (c == 'K') { if (board->square[E1] == WK && board->square[H1] == WR) board->flags |= FlagsWhiteKingCastle; c = fen[++pos]; } if (c == 'Q') { if (board->square[E1] == WK && board->square[A1] == WR) board->flags |= FlagsWhiteQueenCastle; c = fen[++pos]; } if (c == 'k') { if (board->square[E8] == BK && board->square[H8] == BR) board->flags |= FlagsBlackKingCastle; c = fen[++pos]; } if (c == 'q') { if (board->square[E8] == BK && board->square[A8] == BR) board->flags |= FlagsBlackQueenCastle; c = fen[++pos]; } } // en-passant if (c != ' ') my_fatal("board_from_fen(): bad FEN (pos=%d)\n",pos); c = fen[++pos]; if (c == '-') { // no en-passant sq = SquareNone; c = fen[++pos]; } else { if (c < 'a' || c > 'h') my_fatal("board_from_fen(): bad FEN (pos=%d)\n",pos); file = file_from_char(c); c = fen[++pos]; if (c != (COLOUR_IS_WHITE(board->turn) ? '6' : '3')) my_fatal("board_from_fen(): bad FEN (pos=%d)\n",pos); rank = rank_from_char(c); c = fen[++pos]; sq = SQUARE_MAKE(file,rank); pawn = SQUARE_EP_DUAL(sq); if (board->square[sq] != Empty || board->square[pawn] != PAWN_MAKE(COLOUR_OPP(board->turn)) || (board->square[pawn-1] != PAWN_MAKE(board->turn) && board->square[pawn+1] != PAWN_MAKE(board->turn))) { sq = SquareNone; } } board->ep_square = sq; // halfmove clock board->ply_nb = 0; if (c != ' ') { if (!Strict) goto update; my_fatal("board_from_fen(): bad FEN (pos=%d)\n",pos); } c = fen[++pos]; if (!isdigit(c)) { if (!Strict) goto update; my_fatal("board_from_fen(): bad FEN (pos=%d)\n",pos); } board->ply_nb = atoi(&fen[pos]); // board update update: board_init_list(board); }
bool board_from_fen(board_t * board, const char string[]) { int pos; int file, rank, sq; int c; int i, len; int piece; int king_pos[ColourNb]; ASSERT(board!=NULL); ASSERT(string!=NULL); board_clear(board); king_pos[White] = SquareNone; king_pos[Black] = SquareNone; pos = 0; c = string[pos]; // piece placement for (rank = 7; rank >= 0; rank--) { for (file = 0; file < 8;) { sq = square_make(file,rank); if (c >= '1' && c <= '8') { // empty square(s) len = c - '0'; if (file + len > 8) my_fatal("board_from_fen(): bad FEN (pos=%d)\n",pos); for (i = 0; i < len; i++) { board->square[sq++] = Empty; file++; } } else { // piece piece = piece_from_char(c); if (piece == PieceNone256) my_fatal("board_from_fen(): bad FEN (pos=%d)\n",pos); if (piece_is_king(piece)) king_pos[piece_colour(piece)] = sq; board->square[sq++] = piece; file++; } c = string[++pos]; } if (rank > 0) { if (c != '/') my_fatal("board_from_fen(): bad FEN (pos=%d)\n",pos); c = string[++pos]; } } // active colour if (c != ' ') my_fatal("board_from_fen(): bad FEN (pos=%d)\n",pos); c = string[++pos]; switch (c) { case 'w': board->turn = White; break; case 'b': board->turn = Black; break; default: my_fatal("board_from_fen(): bad FEN (pos=%d)\n",pos); break; } c = string[++pos]; // castling if (c != ' ') my_fatal("board_from_fen(): bad FEN (pos=%d)\n",pos); c = string[++pos]; board->castle[White][SideH] = SquareNone; board->castle[White][SideA] = SquareNone; board->castle[Black][SideH] = SquareNone; board->castle[Black][SideA] = SquareNone; if (c == '-') { // no castling rights c = string[++pos]; } else { // TODO: filter out illegal rights do { if (false) { } else if (c == 'K') { for (sq = H1; sq > king_pos[White]; sq--) { if (board->square[sq] == WhiteRook256) { board->castle[White][SideH] = sq; break; } } } else if (c == 'Q') { for (sq = A1; sq < king_pos[White]; sq++) { if (board->square[sq] == WhiteRook256) { board->castle[White][SideA] = sq; break; } } } else if (c == 'k') { for (sq = H8; sq > king_pos[Black]; sq--) { if (board->square[sq] == BlackRook256) { board->castle[Black][SideH] = sq; break; } } } else if (c == 'q') { for (sq = A8; sq < king_pos[Black]; sq++) { if (board->square[sq] == BlackRook256) { board->castle[Black][SideA] = sq; break; } } } else if (c >= 'A' && c <= 'H') { // white castling right sq = square_make(file_from_char(tolower(c)),Rank1); if (sq > king_pos[White]) { // h side board->castle[White][SideH] = sq; } else { // a side board->castle[White][SideA] = sq; } } else if (c >= 'a' && c <= 'h') { // black castling right sq = square_make(file_from_char(tolower(c)),Rank8); if (sq > king_pos[Black]) { // h side board->castle[Black][SideH] = sq; } else { // a side board->castle[Black][SideA] = sq; } } else { my_fatal("board_from_fen(): bad FEN (pos=%d)\n",pos); } c = string[++pos]; } while (c != ' '); } // en-passant if (c != ' ') my_fatal("board_from_fen(): bad FEN (pos=%d)\n",pos); c = string[++pos]; if (c == '-') { // no en-passant sq = SquareNone; c = string[++pos]; } else { if (c < 'a' || c > 'h') my_fatal("board_from_fen(): bad FEN (pos=%d)\n",pos); file = file_from_char(c); c = string[++pos]; if (c < '1' || c > '8') my_fatal("board_from_fen(): bad FEN (pos=%d)\n",pos); rank = rank_from_char(c); c = string[++pos]; sq = square_make(file,rank); } board->ep_square = sq; // halfmove clock board->ply_nb = 0; board->move_nb = 0; // HACK, in case of broken syntax if (c != ' ') { if (!Strict) goto update; my_fatal("board_from_fen(): bad FEN (pos=%d)\n",pos); } c = string[++pos]; if (!isdigit(c)) { if (!Strict) goto update; my_fatal("board_from_fen(): bad FEN (pos=%d)\n",pos); } board->ply_nb = atoi(&string[pos]); do c = string[++pos]; while (isdigit(c)); // fullmove number board->move_nb = 0; if (c != ' ') { if (!Strict) goto update; my_fatal("board_from_fen(): bad FEN (pos=%d)\n",pos); } c = string[++pos]; if (!isdigit(c)) { if (!Strict) goto update; my_fatal("board_from_fen(): bad FEN (pos=%d)\n",pos); } board->move_nb = atoi(&string[pos]) - 1; do c = string[++pos]; while (isdigit(c)); // board update update: board_init_list(board); return true; }