die "Invalid move $move";
}
- # white short castling
- if ($move eq 'e1g1' && $piece eq 'K') {
- # king
- $nb->[7][4] = '-';
- $nb->[7][6] = $piece;
-
- # rook
- $nb->[7][7] = '-';
- $nb->[7][5] = 'R';
-
- return $nb;
- }
-
- # white long castling
- if ($move eq 'e1c1' && $piece eq 'K') {
- # king
- $nb->[7][4] = '-';
- $nb->[7][2] = $piece;
-
- # rook
- $nb->[7][0] = '-';
- $nb->[7][3] = 'R';
+ if ($piece eq 'K') {
+ # Convert to Chess960 king-takes-rook.
+ $to_col = 7 if ($move eq 'e1g1' && $board->[$to_row][$to_col] ne 'R');
+ $to_col = 0 if ($move eq 'e1c1' && $board->[$to_row][$to_col] ne 'R');
+
+ my $dst_piece = $board->[$to_row][$to_col];
+
+ # White short castling.
+ if ($dst_piece eq 'R' && $to_col > $from_col) {
+ # king
+ $nb->[7][$from_col] = '-';
+ $nb->[7][$to_col] = '-';
+ $nb->[7][6] = 'K';
+ $nb->[7][5] = 'R';
+
+ return $nb;
+ }
- return $nb;
- }
+ # Black short castling.
+ if ($dst_piece eq 'R' && $to_col < $from_col) {
+ $nb->[7][$from_col] = '-';
+ $nb->[7][$to_col] = '-';
+ $nb->[7][2] = 'K';
+ $nb->[7][3] = 'R';
- # black short castling
- if ($move eq 'e8g8' && $piece eq 'k') {
- # king
- $nb->[0][4] = '-';
- $nb->[0][6] = $piece;
+ return $nb;
+ }
+ } elsif ($piece eq 'k') {
+ # Convert to Chess960 king-takes-rook.
+ $to_col = 7 if ($move eq 'e8g8' && $board->[$to_row][$to_col] ne 'r');
+ $to_col = 0 if ($move eq 'e8c8' && $board->[$to_row][$to_col] ne 'r');
- # rook
- $nb->[0][7] = '-';
- $nb->[0][5] = 'r';
+ my $dst_piece = $board->[$to_row][$to_col];
- return $nb;
- }
+ # Black short castling.
+ if ($dst_piece eq 'r' && $to_col > $from_col) {
+ $nb->[0][$from_col] = '-';
+ $nb->[0][$to_col] = '-';
+ $nb->[0][6] = 'k';
+ $nb->[0][5] = 'r';
- # black long castling
- if ($move eq 'e8c8' && $piece eq 'k') {
- # king
- $nb->[0][4] = '-';
- $nb->[0][2] = $piece;
+ return $nb;
+ }
- # rook
- $nb->[0][0] = '-';
- $nb->[0][3] = 'r';
+ # Black long castling.
+ if ($dst_piece eq 'r' && $to_col < $from_col) {
+ # king
+ $nb->[0][$from_col] = '-';
+ $nb->[0][$to_col] = '-';
+ $nb->[0][2] = 'k';
+ $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'));
+ }
}
}
return join('/', @rows);
}
-# Returns a compact bit string describing the same data as fen().
-# This is encoded using a Huffman-like encoding, and should be
-# typically about 1/3 the number of bytes.
-sub bitpacked_fen {
- my ($board) = @_;
- my $bits = "";
-
- for my $row (0..7) {
- for my $col (0..7) {
- my $piece = $board->[$row][$col];
- if ($piece eq '-') {
- $bits .= "0";
- next;
- }
-
- my $color = (lc($piece) eq $piece) ? 0 : 1;
- $bits .= "1" . $color;
-
- if (lc($piece) eq 'p') {
- $bits .= "0";
- } elsif (lc($piece) eq 'n') {
- $bits .= "100";
- } elsif (lc($piece) eq 'b') {
- $bits .= "101";
- } elsif (lc($piece) eq 'r') {
- $bits .= "1110";
- } elsif (lc($piece) eq 'q') {
- $bits .= "11110";
- } elsif (lc($piece) eq 'k') {
- $bits .= "11111";
- } else {
- die "Unknown piece $piece";
- }
- }
- }
-
- return pack('b*', $bits);
-}
-
sub can_reach {
my ($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' && $piece eq 'K') {
- return '0-0';
- }
-
- # white long castling
- if ($move eq 'e1c1' && $piece eq 'K') {
- return '0-0-0';
- }
-
- # black short castling
- if ($move eq 'e8g8' && $piece eq 'k') {
- return '0-0';
- }
+ if ($piece eq 'K') {
+ # white short/long castling
+ return 'O-O' if ($move eq 'e1g1');
+ return 'O-O-O' if ($move eq 'e1c1');
- # black long castling
- if ($move eq 'e8c8' && $piece eq 'k') {
- return '0-0-0';
+ # 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;
$pretty = substr($move, 0, 1) . 'x' . _pos_to_square($to_row, $to_col);
} else {
$pretty = _pos_to_square($to_row, $to_col);
+ }
- if (defined($promo) && $promo ne '') {
- # promotion
- $pretty .= "=";
- $pretty .= uc($promo);
- }
+ if (defined($promo) && $promo ne '') {
+ # promotion
+ $pretty .= "=";
+ $pretty .= uc($promo);
}
return $pretty;
}