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;
}
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));
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, $to_col) = @_;
if ($dest_piece ne '-') {
return 0 if (($piece eq lc($piece)) == ($dest_piece eq lc($dest_piece)));
}
-
- if (lc($piece) eq 'k') {
- return (abs($from_row - $to_row) <= 1 && abs($from_col - $to_col) <= 1);
+
+ if ($piece eq 'p') {
+ # black pawn
+ if ($to_col == $from_col && $to_row == $from_row + 1) {
+ return ($dest_piece eq '-');
+ }
+ if ($to_col == $from_col && $from_row == 1 && $to_row == 3) {
+ my $middle_piece = $board->[2][$to_col];
+ return ($dest_piece eq '-' && $middle_piece eq '-');
+ }
+ if (abs($to_col - $from_col) == 1 && $to_row == $from_row + 1) {
+ if ($dest_piece eq '-') {
+ # En passant. TODO: check that the last move was indeed an EP move
+ return ($to_row == 5 && $board->[4][$to_col] eq 'P');
+ } else {
+ return 1;
+ }
+ }
+ return 0;
}
+ if ($piece eq 'P') {
+ # white pawn
+ if ($to_col == $from_col && $to_row == $from_row - 1) {
+ return ($dest_piece eq '-');
+ }
+ if ($to_col == $from_col && $from_row == 6 && $to_row == 4) {
+ my $middle_piece = $board->[5][$to_col];
+ return ($dest_piece eq '-' && $middle_piece eq '-');
+ }
+ if (abs($to_col - $from_col) == 1 && $to_row == $from_row - 1) {
+ if ($dest_piece eq '-') {
+ # En passant. TODO: check that the last move was indeed an EP move
+ return ($to_row == 2 && $board->[3][$to_col] eq 'p');
+ } else {
+ return 1;
+ }
+ }
+ return 0;
+ }
+
if (lc($piece) eq 'r') {
return 0 unless ($from_row == $to_row || $from_col == $to_col);
return (can_reach($board, 'R', $from_row, $from_col, $to_row, $to_col) ||
can_reach($board, 'B', $from_row, $from_col, $to_row, $to_col));
}
-
- if ($piece eq 'p') {
- # black pawn
- if ($to_col == $from_col && $to_row == $from_row + 1) {
- return ($dest_piece eq '-');
- }
- if ($to_col == $from_col && $from_row == 1 && $to_row == 3) {
- my $middle_piece = $board->[2][$to_col];
- return ($dest_piece eq '-' && $middle_piece eq '-');
- }
- if (abs($to_col - $from_col) == 1 && $to_row == $from_row + 1) {
- if ($dest_piece eq '-') {
- # En passant. TODO: check that the last move was indeed an EP move
- return ($to_row == 5 && $board->[4][$to_col] eq 'P');
- } else {
- return 1;
- }
- }
- return 0;
- }
- if ($piece eq 'P') {
- # white pawn
- if ($to_col == $from_col && $to_row == $from_row - 1) {
- return ($dest_piece eq '-');
- }
- if ($to_col == $from_col && $from_row == 6 && $to_row == 4) {
- my $middle_piece = $board->[5][$to_col];
- return ($dest_piece eq '-' && $middle_piece eq '-');
- }
- if (abs($to_col - $from_col) == 1 && $to_row == $from_row - 1) {
- if ($dest_piece eq '-') {
- # En passant. TODO: check that the last move was indeed an EP move
- return ($to_row == 2 && $board->[3][$to_col] eq 'p');
- } else {
- return 1;
- }
- }
- return 0;
+ if (lc($piece) eq 'k') {
+ return (abs($from_row - $to_row) <= 1 && abs($from_col - $to_col) <= 1);
}
-
+
# unknown piece
return 0;
}
return ($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;
projects / remoteglot / blobdiff