die "Invalid move $move";
}
- # white short castling
- if ($move eq 'e1g1' && $piece eq 'K') {
- # king
- $nb->[7][4] = '-';
- $nb->[7][6] = $piece;
+ if ($piece eq 'K') {
+ my $dst_piece = $board->[$to_row][$to_col];
- # rook
- $nb->[7][7] = '-';
- $nb->[7][5] = 'R';
+ # White short castling (regular or Chess960 king-takes-rook)
+ if ($move eq 'e1g1' || $dst_piece eq 'R') {
+ # king
+ $nb->[7][$from_col] = '-';
+ $nb->[7][6] = $piece;
- return $nb;
- }
+ # rook
+ $nb->[7][$to_col] = '-';
+ $nb->[7][5] = 'R';
- # white long castling
- if ($move eq 'e1c1' && $piece eq 'K') {
- # king
- $nb->[7][4] = '-';
- $nb->[7][2] = $piece;
+ return $nb;
+ }
- # rook
- $nb->[7][0] = '-';
- $nb->[7][3] = 'R';
+ # White long castling (regular or Chess960 king-takes-rook)
+ if ($move eq 'e1c1' || $dst_piece eq 'R') {
+ # king
+ $nb->[7][$from_col] = '-';
+ $nb->[7][2] = $piece;
- return $nb;
- }
+ # rook
+ $nb->[7][$to_col] = '-';
+ $nb->[7][3] = 'R';
- # black short castling
- if ($move eq 'e8g8' && $piece eq 'k') {
- # king
- $nb->[0][4] = '-';
- $nb->[0][6] = $piece;
+ return $nb;
+ }
+ } elsif ($piece eq 'k') {
+ my $dst_piece = $board->[$to_row][$to_col];
- # rook
- $nb->[0][7] = '-';
- $nb->[0][5] = 'r';
+ # Black short castling (regular or Chess960 king-takes-rook)
+ if ($move eq 'e8g8' || $dst_piece eq 'r') {
+ # king
+ $nb->[0][$from_col] = '-';
+ $nb->[0][6] = $piece;
- return $nb;
- }
+ # rook
+ $nb->[0][$from_col] = '-';
+ $nb->[0][5] = 'r';
+
+ return $nb;
+ }
- # black long castling
- if ($move eq 'e8c8' && $piece eq 'k') {
- # king
- $nb->[0][4] = '-';
- $nb->[0][2] = $piece;
+ # black long castling
+ if ($move eq 'e8c8' || $dst_piece eq 'r') {
+ # king
+ $nb->[0][$from_col] = '-';
+ $nb->[0][2] = $piece;
- # rook
- $nb->[0][0] = '-';
- $nb->[0][3] = 'r';
+ # rook
+ $nb->[0][$to_col] = '-';
+ $nb->[0][3] = 'r';
- return $nb;
+ return $nb;
+ }
}
# check if the from-piece is a pawn
return 7 - (ord(shift) - ord('1'));
}
+use Carp;
+
sub _square_to_pos {
my ($square) = @_;
- $square =~ /^([a-h])([1-8])$/ or die "Invalid square $square";
+ #$square =~ /^([a-h])([1-8])$/ or die "Invalid square $square";
+ $square =~ /^([a-h])([1-8])$/ or Carp::confess("Invalid square $square");
return (_row_letter_to_num($2), _col_letter_to_num($1));
}
return _pos_to_square($from_row, $from_col) . _pos_to_square($to_row, $to_col) . $promo;
}
+sub _find_piece_col {
+ my ($row, $piece) = @_;
+ for my $col (0..7) {
+ return $col if ($row->[$col] eq $piece);
+ }
+ die "Could not find piece $piece";
+}
+
# Note: This is in general not a validation that the move is actually allowed
# (e.g. you can castle even though you're in check).
sub parse_pretty_move {
- my ($board, $move, $toplay) = @_;
+ my ($board, $move, $toplay, $chess960, $white_castle_k, $white_castle_q, $black_castle_k, $black_castle_q) = @_;
# Strip check or mate
$move =~ s/[+#]$//;
if ($move eq '0-0' or $move eq 'O-O') {
if ($toplay eq 'W') {
- return (_square_to_pos('e1'), _square_to_pos('g1'));
+ if ($chess960) {
+ # King takes rook.
+ return (7, _find_piece_col($board->[7], 'K'), _square_to_pos($white_castle_k . '1'));
+ } else {
+ return (_square_to_pos('e1'), _square_to_pos('g1'));
+ }
} else {
- return (_square_to_pos('e8'), _square_to_pos('g8'));
+ if ($chess960) {
+ # King takes rook.
+ return (0, _find_piece_col($board->[0], 'k'), _square_to_pos($black_castle_k . '8'));
+ } else {
+ return (_square_to_pos('e8'), _square_to_pos('g8'));
+ }
}
} elsif ($move eq '0-0-0' or $move eq 'O-O-O') {
if ($toplay eq 'W') {
- return (_square_to_pos('e1'), _square_to_pos('c1'));
+ if ($chess960) {
+ # King takes rook.
+ return (7, _find_piece_col($board->[7], 'K'), _square_to_pos($white_castle_q . '1'));
+ } else {
+ return (_square_to_pos('e1'), _square_to_pos('c1'));
+ }
} else {
- return (_square_to_pos('e8'), _square_to_pos('c8'));
+ if ($chess960) {
+ # King takes rook.
+ return (0, _find_piece_col($board->[0], 'k'), _square_to_pos($black_castle_q . '8'));
+ } else {
+ return (_square_to_pos('e8'), _square_to_pos('c8'));
+ }
}
}
sub can_reach {
my ($board, $piece, $from_row, $from_col, $to_row, $to_col) = @_;
- # can't eat your own piece
+ # Can't eat your own piece (Chess960 uses king-takes-rook for castling,
+ # but castling is irrelevant for reachability)
my $dest_piece = $board->[$to_row][$to_col];
if ($dest_piece ne '-') {
return 0 if (($piece eq lc($piece)) == ($dest_piece eq lc($dest_piece)));
die "Invalid move $move";
}
- # white short castling
- if ($move eq 'e1g1' && $piece eq 'K') {
- return 'O-O';
- }
-
- # white long castling
- if ($move eq 'e1c1' && $piece eq 'K') {
- return 'O-O-O';
- }
+ if ($piece eq 'K') {
+ # white short/long castling
+ return 'O-O' if ($move eq 'e1g1');
+ return 'O-O-O' if ($move eq 'e1c1');
- # black short castling
- if ($move eq 'e8g8' && $piece eq 'k') {
- return 'O-O';
- }
-
- # black long castling
- if ($move eq 'e8c8' && $piece eq 'k') {
- return 'O-O-O';
+ # white short/long chess960-style castling (king takes own rook)
+ my $dst_piece = $board->[$to_row][$to_col];
+ if ($dst_piece eq 'R') {
+ return ($to_col > $from_col) ? 'O-O' : 'O-O-O';
+ }
+ } elsif ($piece eq 'k') {
+ # black short/long castling
+ return 'O-O' if ($move eq 'e8g8');
+ return 'O-O-O' if ($move eq 'e8c8');
+
+ # black short/long chess960-style castling (king takes own rook)
+ my $dst_piece = $board->[$to_row][$to_col];
+ if ($dst_piece eq 'r') {
+ return ($to_col > $from_col) ? 'O-O' : 'O-O-O';
+ }
}
my $pretty;
$pos->{'board'} = Board->new(@x[1..8]);
$pos->{'toplay'} = $x[9];
$pos->{'ep_file_num'} = $x[10];
- $pos->{'white_castle_k'} = $x[11];
- $pos->{'white_castle_q'} = $x[12];
- $pos->{'black_castle_k'} = $x[13];
- $pos->{'black_castle_q'} = $x[14];
+ $pos->{'white_castle_k'} = $x[11] ? 'h' : undef;
+ $pos->{'white_castle_q'} = $x[12] ? 'a' : undef;
+ $pos->{'black_castle_k'} = $x[13] ? 'h' : undef;
+ $pos->{'black_castle_q'} = $x[14] ? 'a' : undef;
$pos->{'time_since_100move_rule_reset'} = $x[15];
$pos->{'player_w'} = $x[17];
$pos->{'player_b'} = $x[18];
my $pos = {};
$board =~ s/(\d)/"-"x$1/ge;
$pos->{'board'} = Board->new(split /\//, $board);
+ $board = $pos->{'board'};
$pos->{'toplay'} = uc($toplay);
if ($ep_square =~ /^([a-h])/) {
$pos->{'ep_file_num'} = -1;
}
- $pos->{'white_castle_k'} = ($castling =~ /K/) ? 1 : 0;
- $pos->{'white_castle_q'} = ($castling =~ /Q/) ? 1 : 0;
- $pos->{'black_castle_k'} = ($castling =~ /k/) ? 1 : 0;
- $pos->{'black_castle_q'} = ($castling =~ /q/) ? 1 : 0;
+ # X-FEN castling rights parsing.
+ if ($castling =~ /K/) {
+ $pos->{'white_castle_k'} = _col_num_to_letter(_find_piece_col_from_right($board->[7], 'R'));
+ }
+ if ($castling =~ /Q/) {
+ $pos->{'white_castle_q'} = _col_num_to_letter(_find_piece_col($board->[7], 'R'));
+ }
+ while ($castling =~ s/([A-H])//g) {
+ my $rook_col = lc($1);
+ my $king_col = _find_piece_col($board->[7], 'K');
+ if ($rook_col < $king_col) {
+ $pos->{'white_castle_q'} = _col_num_to_letter($rook_col);
+ } else {
+ $pos->{'white_castle_k'} = _col_num_to_letter($rook_col);
+ }
+ }
+ if ($castling =~ /k/) {
+ $pos->{'white_castle_k'} = _col_num_to_letter(_find_piece_col_from_right($board->[0], 'r'));
+ }
+ if ($castling =~ /q/) {
+ $pos->{'black_castle_q'} = _col_num_to_letter(_find_piece_col($board->[0], 'r'));
+ }
+ while ($castling =~ s/([a-h])//g) {
+ my $rook_col = $1;
+ my $king_col = _find_piece_col($board->[0], 'k');
+ if ($rook_col < $king_col) {
+ $pos->{'black_castle_q'} = _col_num_to_letter($rook_col);
+ } else {
+ $pos->{'black_castle_k'} = _col_num_to_letter($rook_col);
+ }
+ }
$pos->{'time_since_100move_rule_reset'} = $halfmove_clock // 0;
$pos->{'player_w'} = 'white';
$pos->{'player_b'} = 'black';
$fen .= " ";
$fen .= lc($pos->{'toplay'});
- # castling
+ # Castling (X-FEN compatible).
my $castling = "";
- $castling .= "K" if ($pos->{'white_castle_k'} == 1);
- $castling .= "Q" if ($pos->{'white_castle_q'} == 1);
- $castling .= "k" if ($pos->{'black_castle_k'} == 1);
- $castling .= "q" if ($pos->{'black_castle_q'} == 1);
+ if (defined($pos->{'white_castle_k'})) {
+ my $outer_rook_col = _col_num_to_letter(_find_piece_col_from_right($pos->{'board'}[7], 'R'));
+ if ($outer_rook_col eq $pos->{'white_castle_k'}) {
+ $castling .= "K";
+ } else {
+ $castling .= uc($pos->{'white_castle_k'});
+ }
+ }
+ if (defined($pos->{'white_castle_q'})) {
+ my $outer_rook_col = _col_num_to_letter(_find_piece_col($pos->{'board'}[7], 'R'));
+ if ($outer_rook_col eq $pos->{'white_castle_q'}) {
+ $castling .= "Q";
+ } else {
+ $castling .= uc($pos->{'white_castle_q'});
+ }
+ }
+ if (defined($pos->{'black_castle_k'})) {
+ my $outer_rook_col = _col_num_to_letter(_find_piece_col_from_right($pos->{'board'}[0], 'r'));
+ if ($outer_rook_col eq $pos->{'black_castle_k'}) {
+ $castling .= "k";
+ } else {
+ $castling .= $pos->{'black_castle_k'};
+ }
+ }
+ if (defined($pos->{'black_castle_q'})) {
+ my $outer_rook_col = _col_num_to_letter(_find_piece_col($pos->{'board'}[0], 'r'));
+ if ($outer_rook_col eq $pos->{'black_castle_q'}) {
+ $castling .= "q";
+ } else {
+ $castling .= $pos->{'black_castle_q'};
+ }
+ }
$castling = "-" if ($castling eq "");
# $castling = "-"; # chess960
$fen .= " ";
sub parse_pretty_move {
my ($pos, $move) = @_;
- return $pos->{'board'}->parse_pretty_move($move, $pos->{'toplay'});
+ return $pos->{'board'}->parse_pretty_move($move, $pos->{'toplay'}, $pos->{'chess960'}, $pos->{'white_castle_k'}, $pos->{'white_castle_q'}, $pos->{'black_castle_k'}, $pos->{'black_castle_q'});
}
sub num_pieces {
$np->{'black_castle_k'} = $pos->{'black_castle_k'};
$np->{'black_castle_q'} = $pos->{'black_castle_q'};
if ($piece eq 'K') {
- $np->{'white_castle_k'} = 0;
- $np->{'white_castle_q'} = 0;
+ $np->{'white_castle_k'} = undef;
+ $np->{'white_castle_q'} = undef;
} elsif ($piece eq 'k') {
- $np->{'black_castle_k'} = 0;
- $np->{'black_castle_q'} = 0;
- } elsif ($from_square eq 'a1' || $to_square eq 'a1') {
- $np->{'white_castle_q'} = 0;
- } elsif ($from_square eq 'h1' || $to_square eq 'h1') {
- $np->{'white_castle_k'} = 0;
- } elsif ($from_square eq 'a8' || $to_square eq 'a8') {
- $np->{'black_castle_q'} = 0;
- } elsif ($from_square eq 'h8' || $to_square eq 'h8') {
- $np->{'black_castle_k'} = 0;
+ $np->{'black_castle_k'} = undef;
+ $np->{'black_castle_q'} = undef;
+ } elsif (defined($np->{'white_castle_q'}) &&
+ ($from_square eq ($np->{'white_castle_q'} . '1') ||
+ $to_square eq ($np->{'white_castle_q'} . '1'))) {
+ $np->{'white_castle_q'} = undef;
+ } elsif (defined($np->{'white_castle_k'}) &&
+ ($from_square eq ($np->{'white_castle_k'} . '1') ||
+ $to_square eq ($np->{'white_castle_k'} . '1'))) {
+ $np->{'white_castle_k'} = undef;
+ } elsif (defined($np->{'black_castle_q'}) &&
+ ($from_square eq ($np->{'black_castle_q'} . '8') ||
+ $to_square eq ($np->{'black_castle_q'} . '8'))) {
+ $np->{'black_castle_q'} = undef;
+ } elsif (defined($np->{'black_castle_k'}) &&
+ ($from_square eq ($np->{'black_castle_k'} . '8') ||
+ $to_square eq ($np->{'black_castle_k'} . '8'))) {
+ $np->{'black_castle_k'} = undef;
}
# 50-move rule.
return $pvpos;
}
+sub _col_num_to_letter {
+ my $col = shift;
+ return sprintf("%c", ord('a') + $col);
+}
+
sub _col_letter_to_num {
return ord(shift) - ord('a');
}
return 7 - (ord(shift) - ord('1'));
}
+sub _find_piece_col {
+ my ($row, $piece) = @_;
+ for my $col (0..7) {
+ return $col if ($row->[$col] eq $piece);
+ }
+ die "Could not find piece $piece";
+}
+
+sub _find_piece_col_from_right {
+ my ($row, $piece) = @_;
+ for my $col (reverse 0..7) {
+ return $col if ($row->[$col] eq $piece);
+ }
+ die "Could not find piece $piece";
+}
+
sub _parse_uci_move {
my $move = shift;
my $from_col = _col_letter_to_num(substr($move, 0, 1));