X-Git-Url: https://git.sesse.net/?p=remoteglot;a=blobdiff_plain;f=Board.pm;h=720189899045eb72ea25850167e98613c2c374a5;hp=921de3d9c45f715e7084796aeb1a005bc5270093;hb=619f444e5eafb0f602d848ec13d70148cd90a16b;hpb=cd07e136301429ab1f50027c78a9188799f1c9ae

diff --git a/Board.pm b/Board.pm
index 921de3d..7201898 100644
--- a/Board.pm
+++ b/Board.pm
@@ -177,35 +177,37 @@ sub parse_pretty_move {
 	}
 
 	$move =~ /^([KQRBN])?([a-h])?([1-8])?x?([a-h][1-8])$/ 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 $piece);
+			next if (defined($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;
-	}
+
+	# Filter out pieces which cannot reach this square.
+	@squares = grep { $board->can_reach($piece, $_->[0], $_->[1], $to_row, $to_col) } @squares;
+
+	# See if doing this move would put us in check
+	# (yes, there are clients that expect us to do this).
+	@squares = grep { !$board->make_move($_->[0], $_->[1], $to_row, $to_col, $promo)->in_check($side) } @squares;
+
 	if (scalar @squares == 0) {
 		die "Impossible move $move";
 	}
@@ -384,6 +386,20 @@ 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 },
@@ -497,22 +513,22 @@ 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;
@@ -524,12 +540,12 @@ 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;
 	}
@@ -541,7 +557,7 @@ 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));
 		}
 	}
 
@@ -549,14 +565,14 @@ 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