return _pos_to_square($from_row, $from_col) . _pos_to_square($to_row, $to_col) . $promo;
}
+# Note: This is in general not a validation that the move is actually allowed
+# (e.g. you can castle even though you're in check).
sub parse_pretty_move {
my ($board, $move, $toplay) = @_;
# Parse promo
my $promo;
- if ($move =~ s/=([QRNB])$//) {
+ if ($move =~ s/=?([QRNB])$//) {
$promo = $1;
}
$move =~ /^([KQRBN])?([a-h])?([1-8])?x?([a-h][1-8])$/ or die "Invalid move $move";
- my $piece = $1 // 'P';
+ my $piece = $1;
my $from_col = defined($2) ? _col_letter_to_num($2) : undef;
my $from_row = defined($3) ? _row_letter_to_num($3) : undef;
+ if (!defined($piece) && (!defined($from_col) || !defined($from_row))) {
+ $piece = 'P';
+ }
my ($to_row, $to_col) = _square_to_pos($4);
# Find all possible from-squares that could have been meant.
my @squares = ();
my $side = 'K';
if ($toplay eq 'B') {
- $piece = lc($piece);
+ $piece = lc($piece) if defined($piece);
$side = 'k';
}
for my $row (0..7) {
next if (defined($from_row) && $from_row != $row);
for my $col (0..7) {
next if (defined($from_col) && $from_col != $col);
- next if ($board->[$row][$col] ne $piece);
- next if (!$board->can_reach($piece, $row, $col, $to_row, $to_col));
-
- # See if doing this move would put us in check
- # (yes, there are clients that expect us to do this).
- next if ($board->make_move($row, $col, $to_row, $to_col, $promo)->in_check($side));
+ next if (defined($piece) && $board->[$row][$col] ne $piece);
push @squares, [ $row, $col ];
}
}
+ if (scalar @squares > 1) {
+ # Filter out pieces which cannot reach this square.
+ @squares = grep { $board->can_reach($piece, $_->[0], $_->[1], $to_row, $to_col) } @squares;
+ }
+ if (scalar @squares > 1) {
+ # See if doing this move would put us in check
+ # (yes, there are clients that expect us to do this).
+ @squares = grep { !$board->make_move($_->[0], $_->[1], $to_row, $to_col, $promo)->in_check($side) } @squares;
+ }
+ if (scalar @squares == 0) {
+ die "Impossible move $move";
+ }
if (scalar @squares != 1) {
- die "Ambigious or impossible move $move";
+ die "Ambigious move $move";
}
return (@{$squares[0]}, $to_row, $to_col, $promo);
}
return join('/', @rows);
}
+# Returns a compact bit string describing the same data as fen().
+# This is encoded using a Huffman-like encoding, and should be
+# typically about 1/3 the number of bytes.
+sub bitpacked_fen {
+ my ($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, $to_col) = @_;
return ($pretty, $nb);
}
+sub num_pieces {
+ my ($board) = @_;
+
+ my $num = 0;
+ for my $row (0..7) {
+ for my $col (0..7) {
+ my $piece = $board->[$row][$col];
+ ++$num if ($piece ne '-');
+ }
+ }
+ return $num;
+}
+
sub _prettyprint_move_no_check_or_mate {
my ($board, $from_row, $from_col, $to_row, $to_col, $promo) = @_;
my $piece = $board->[$from_row][$from_col];
if (defined($promo) && $promo ne '') {
# promotion
$pretty .= "=";
- $pretty .= $promo;
+ $pretty .= uc($promo);
}
}
return $pretty;