X-Git-Url: https://git.sesse.net/?p=remoteglot;a=blobdiff_plain;f=Board.pm;h=3e0fd33a52b4fa72a4264a4eff58962dc93cc197;hp=91d1a15f7f42b29d5057c2cb9205ae4874a52361;hb=960b6ea34239ae508e3ab9841665fd7ba390fba3;hpb=f13c8e4fac44bf27a87cc34aed44a8b95fc2a508

diff --git a/Board.pm b/Board.pm
index 91d1a15..3e0fd33 100644
--- a/Board.pm
+++ b/Board.pm
@@ -387,6 +387,20 @@ sub can_reach {
 	return 0;
 }
 
+# Like can_reach, but also checks the move doesn't put the side in check.
+# We use this in prettyprint_move to reduce the disambiguation, because Chess.js
+# needs moves to be in minimally disambiguated form.
+sub can_legally_reach {
+	my ($board, $piece, $from_row, $from_col, $to_row, $to_col) = @_;
+
+	return 0 if (!can_reach($board, $piece, $from_row, $from_col, $to_row, $to_col));
+
+	my $nb = $board->make_move($from_row, $from_col, $to_row, $to_col);
+	my $side = ($piece eq lc($piece)) ? 'k' : 'K';
+
+	return !in_check($nb, $side);
+}
+
 my %pieces_against_side = (
 	k => { K => 1, Q => 1, R => 1, N => 1, B => 1, P => 1 },
 	K => { k => 1, q => 1, r => 1, n => 1, b => 1, p => 1 },
@@ -500,22 +514,22 @@ sub _prettyprint_move_no_check_or_mate {
 
 	# white short castling
 	if ($move eq 'e1g1' && $piece eq 'K') {
-		return '0-0';
+		return 'O-O';
 	}
 
 	# white long castling
 	if ($move eq 'e1c1' && $piece eq 'K') {
-		return '0-0-0';
+		return 'O-O-O';
 	}
 
 	# black short castling
 	if ($move eq 'e8g8' && $piece eq 'k') {
-		return '0-0';
+		return 'O-O';
 	}
 
 	# black long castling
 	if ($move eq 'e8c8' && $piece eq 'k') {
-		return '0-0-0';
+		return 'O-O-O';
 	}
 
 	my $pretty;
@@ -527,12 +541,12 @@ sub _prettyprint_move_no_check_or_mate {
 			$pretty = substr($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;
 	}
@@ -544,7 +558,7 @@ sub _prettyprint_move_no_check_or_mate {
 	for my $col (0..7) {
 		for my $row (0..7) {
 			next unless ($board->[$row][$col] eq $piece);
-			++$num_total if ($board->can_reach($piece, $row, $col, $to_row, $to_col));
+			++$num_total if ($board->can_legally_reach($piece, $row, $col, $to_row, $to_col));
 		}
 	}
 
@@ -552,14 +566,14 @@ sub _prettyprint_move_no_check_or_mate {
 	my $num_row = 0;
 	for my $col (0..7) {
 		next unless ($board->[$from_row][$col] eq $piece);
-		++$num_row if ($board->can_reach($piece, $from_row, $col, $to_row, $to_col));
+		++$num_row if ($board->can_legally_reach($piece, $from_row, $col, $to_row, $to_col));
 	}
 
 	# and same for columns
 	my $num_col = 0;
 	for my $row (0..7) {
 		next unless ($board->[$row][$from_col] eq $piece);
-		++$num_col if ($board->can_reach($piece, $row, $from_col, $to_row, $to_col));
+		++$num_col if ($board->can_legally_reach($piece, $row, $from_col, $to_row, $to_col));
 	}
 
 	# see if we need to disambiguate