X-Git-Url: https://git.sesse.net/?p=remoteglot;a=blobdiff_plain;f=Board.pm;h=a867c74162cefde898c6f25d3fd37442c02bc2c5;hp=feb48937ebe94a5f7036b80f697ced09699b89f5;hb=352d2a6829b4144ba1ad156c08f9b3332bc73d0f;hpb=c26cad3df9d1b65031c26b65f4cfbe89aef18de7

diff --git a/Board.pm b/Board.pm
index feb4893..a867c74 100644
--- a/Board.pm
+++ b/Board.pm
@@ -25,9 +25,7 @@ sub clone {
 	my $nb = [];
 
 	for my $row (0..7) {
-		for my $col (0..7) {
-			$nb->[$row][$col] = $board->[$row][$col];
-		}
+		$nb->[$row] = [ @{$board->[$row]} ];
 	}
 
 	return bless $nb;
@@ -36,7 +34,7 @@ sub clone {
 # Returns a new board.
 sub make_move {
 	my ($board, $from_row, $from_col, $to_row, $to_col, $promo) = @_;
-	my $move = _move_to_uci_notation($from_row, $from_col, $to_row, $to_col, $promo);
+	my $move = move_to_uci_notation($from_row, $from_col, $to_row, $to_col, $promo);
 	my $piece = $board->[$from_row][$from_col];
 	my $nb = $board->clone();
 
@@ -103,20 +101,19 @@ sub make_move {
 			# en passant?
 			if ($board->[$to_row][$to_col] eq '-') {
 				if ($piece eq 'p') {
-					$nb->[$to_row + 1][$to_col] = '-';
-				} else {
 					$nb->[$to_row - 1][$to_col] = '-';
-				}
-			}
-		} else {
-			if ($promo ne '') {
-				if ($piece eq 'p') {
-					$piece = $promo;
 				} else {
-					$piece = uc($promo);
+					$nb->[$to_row + 1][$to_col] = '-';
 				}
 			}
 		}
+		if (defined($promo) && $promo ne '') {
+			if ($piece eq 'p') {
+				$piece = lc($promo);
+			} else {
+				$piece = uc($promo);
+			}
+		}
 	}
 
 	# update the board
@@ -126,10 +123,87 @@ sub make_move {
 	return $nb;
 }
 
-sub _move_to_uci_notation {
+sub _pos_to_square {
+	my ($row, $col) = @_;
+	return sprintf("%c%d", ord('a') + $col, 8 - $row);
+}
+
+sub _col_letter_to_num {
+        return ord(shift) - ord('a');
+}
+
+sub _row_letter_to_num {
+        return 7 - (ord(shift) - ord('1'));
+}
+
+sub _square_to_pos {
+	my ($square) = @_;
+	$square =~ /^([a-h])([1-8])$/ or die "Invalid square $square";	
+	return (_row_letter_to_num($2), _col_letter_to_num($1));
+}
+
+sub move_to_uci_notation {
 	my ($from_row, $from_col, $to_row, $to_col, $promo) = @_;
 	$promo //= "";
-	return sprintf("%c%d%c%d%s", ord('a') + $from_col, 8 - $from_row, ord('a') + $to_col, 8 - $to_row, $promo);
+	return _pos_to_square($from_row, $from_col) . _pos_to_square($to_row, $to_col) . $promo;
+}
+
+sub parse_pretty_move {
+	my ($board, $move, $toplay) = @_;
+
+	# 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'));
+		} 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'));
+		} else {
+			return (_square_to_pos('e8'), _square_to_pos('c8'));
+		}
+	}
+
+	# Parse promo
+	my $promo;
+	if ($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 $from_col = defined($2) ? _col_letter_to_num($2) : undef;
+	my $from_row = defined($3) ? _row_letter_to_num($3) : undef;
+	my ($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);
+		$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));
+			push @squares, [ $row, $col ];
+		}
+	}
+	if (scalar @squares != 1) {
+		die "Ambigious or impossible move $move";
+	}
+	return (@{$squares[0]}, $to_row, $to_col, $promo);
 }
 
 sub fen {
@@ -152,10 +226,46 @@ sub can_reach {
 	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);
 
@@ -218,99 +328,56 @@ sub can_reach {
 		return (can_reach($board, 'R', $from_row, $from_col, $to_row, $to_col) ||
 		        can_reach($board, 'B', $from_row, $from_col, $to_row, $to_col));
 	}
-
-	# TODO: en passant
-	if ($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 == $from_row + 1) {
-			return ($dest_piece ne '-');
-		}
-		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 == $from_row - 1) {
-			return ($dest_piece ne '-');
-		}
-		return 0;
+	if (lc($piece) eq 'k') {
+		return (abs($from_row - $to_row) <= 1 && abs($from_col - $to_col) <= 1);
 	}
-	
+
 	# unknown piece
 	return 0;
 }
 
-# Returns 'none', 'white', 'black' or 'both', depending on which sides are in check.
-# The latter naturally indicates an invalid position.
-sub in_check {
-	my $board = shift;
-	my ($black_check, $white_check) = (0, 0);
+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 },
+);
 
-	my ($wkr, $wkc, $bkr, $bkc) = _find_kings($board);
+# Returns whether the given side (given as k or K for black and white) is in check.
+sub in_check {
+	my ($board, $side) = @_;
+	my ($kr, $kc) = _find_piece($board, $side);
 
-	# check all pieces for the possibility of threatening the two kings
+	# check all pieces for the possibility of threatening this king
 	for my $row (0..7) {
+		next unless grep { exists($pieces_against_side{$side}{$_}) } @{$board->[$row]};
 		for my $col (0..7) {
 			my $piece = $board->[$row][$col];
 			next if ($piece eq '-');
-		
-			if (uc($piece) eq $piece) {
-				# white piece
-				$black_check = 1 if ($board->can_reach($piece, $row, $col, $bkr, $bkc));
-			} else {
-				# black piece
-				$white_check = 1 if ($board->can_reach($piece, $row, $col, $wkr, $wkc));
-			}
+			return 1 if ($board->can_reach($piece, $row, $col, $kr, $kc));
 		}
 	}
 
-	if ($black_check && $white_check) {
-		return 'both';
-	} elsif ($black_check) {
-		return 'black';
-	} elsif ($white_check) {
-		return 'white';
-	} else {
-		return 'none';
-	}
+	return 0;
 }
 
-sub _find_kings {
-	my $board = shift;
-	my ($wkr, $wkc, $bkr, $bkc);
+sub _find_piece {
+	my ($board, $piece) = @_;
 
 	for my $row (0..7) {
+		next unless grep { $_ eq $piece } @{$board->[$row]};
 		for my $col (0..7) {
-			my $piece = $board->[$row][$col];
-			if ($piece eq 'K') {
-				($wkr, $wkc) = ($row, $col);
-			} elsif ($piece eq 'k') {
-				($bkr, $bkc) = ($row, $col);
+			if ($board->[$row][$col] eq $piece) {
+				return ($row, $col);
 			}
 		}
 	}
 
-	return ($wkr, $wkc, $bkr, $bkc);
+	return (undef, undef);
 }
 
-# Returns if any side is in mate.
+# Returns if the given side (given as k or K) is in mate.
 sub in_mate {
-	my $board = shift;
-	my $check = $board->in_check();
-	return 0 if ($check eq 'none');
+	my ($board, $side, $in_check) = @_;
+	return 0 if (!$in_check);
 
 	# try all possible moves for the side in check
 	for my $row (0..7) {
@@ -318,7 +385,7 @@ sub in_mate {
 			my $piece = $board->[$row][$col];
 			next if ($piece eq '-');
 
-			if ($check eq 'white') {
+			if ($side eq 'K') {
 				next if ($piece eq lc($piece));
 			} else {
 				next if ($piece eq uc($piece));
@@ -329,11 +396,8 @@ sub in_mate {
 					next if ($row == $dest_row && $col == $dest_col);
 					next unless ($board->can_reach($piece, $row, $col, $dest_row, $dest_col));
 
-					my $nb = $board->clone();
-					$nb->[$row][$col] = '-';
-					$nb->[$dest_row][$dest_col] = $piece;
-					my $new_check = $nb->in_check();
-					return 0 if ($new_check ne $check && $new_check ne 'both');
+					my $nb = $board->make_move($row, $col, $dest_row, $dest_col);
+					return 0 if (!$nb->in_check($side));
 				}
 			}
 		}
@@ -343,4 +407,115 @@ sub in_mate {
 	return 1;
 }
 
+# Returns the short algebraic form of the move, as well as the new position.
+sub prettyprint_move {
+	my ($board, $from_row, $from_col, $to_row, $to_col, $promo) = @_;
+	my $pretty = $board->_prettyprint_move_no_check_or_mate($from_row, $from_col, $to_row, $to_col, $promo);
+
+	my $nb = $board->make_move($from_row, $from_col, $to_row, $to_col, $promo);
+
+	my $piece = $board->[$from_row][$from_col];
+	my $other_side = (uc($piece) eq $piece) ? 'k' : 'K';
+	my $in_check = $nb->in_check($other_side);
+	if ($nb->in_mate($other_side, $in_check)) {
+		$pretty .= '#';
+	} elsif ($in_check) {
+		$pretty .= '+';
+	}
+	return ($pretty, $nb);
+}
+
+sub _prettyprint_move_no_check_or_mate {
+        my ($board, $from_row, $from_col, $to_row, $to_col, $promo) = @_;
+	my $piece = $board->[$from_row][$from_col];
+	my $move = move_to_uci_notation($from_row, $from_col, $to_row, $to_col, $promo);
+
+	if ($piece eq '-') {
+		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' && $piece eq 'k') {
+		return '0-0';
+	}
+
+	# black long castling
+	if ($move eq 'e8c8' && $piece eq 'k') {
+		return '0-0-0';
+	}
+
+	my $pretty;
+
+	# check if the from-piece is a pawn
+	if (lc($piece) eq 'p') {
+		# attack?
+		if ($from_col != $to_col) {
+			$pretty = substr($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);
+			}
+		}
+		return $pretty;
+	}
+
+	$pretty = uc($piece);
+
+	# see how many of these pieces could go here, in all
+	my $num_total = 0;
+	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));
+		}
+	}
+
+	# see how many of these pieces from the given row could go here
+	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));
+	}
+
+	# 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, $to_col));
+	}
+
+	# see if we need to disambiguate
+	if ($num_total > 1) {
+		if ($num_col == 1) {
+			$pretty .= substr($move, 0, 1);
+		} elsif ($num_row == 1) {
+			$pretty .= substr($move, 1, 1);
+		} else {
+			$pretty .= substr($move, 0, 2);
+		}
+	}
+
+	# attack?
+	if ($board->[$to_row][$to_col] ne '-') {
+		$pretty .= 'x';
+	}
+
+	$pretty .= _pos_to_square($to_row, $to_col);
+	return $pretty;
+}
+
 1;