X-Git-Url: https://git.sesse.net/?p=remoteglot;a=blobdiff_plain;f=Board.pm;h=921de3d9c45f715e7084796aeb1a005bc5270093;hp=1bedd56a23d704f458384a858f69b4120cf652d4;hb=46280f671364dbc49270404d6c5b4c45d5ac59f7;hpb=3f2c87e7a476de25d87fd413dba7fef912838bee

diff --git a/Board.pm b/Board.pm
index 1bedd56..921de3d 100644
--- a/Board.pm
+++ b/Board.pm
@@ -148,6 +148,8 @@ sub move_to_uci_notation {
 	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) = @_;
 
@@ -170,7 +172,7 @@ sub parse_pretty_move {
 
 	# Parse promo
 	my $promo;
-	if ($move =~ s/=([QRNB])$//) {
+	if ($move =~ s/=?([QRNB])$//) {
 		$promo = $1;
 	}
 
@@ -192,16 +194,23 @@ sub parse_pretty_move {
 		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);
 }
@@ -218,6 +227,45 @@ sub fen {
 	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) = @_;
 	
@@ -226,10 +274,46 @@ 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);
 
@@ -292,57 +376,27 @@ 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, $to_col));
 	}
-
-	if ($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;
 }
 
+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 },
+);
+
 # Returns whether the given side (given as k or K for black and white) is in check.
 sub in_check {
-	my ($board, $piece) = @_;
-	my ($kr, $kc) = _find_piece($board, $piece);
+	my ($board, $side) = @_;
+	my ($kr, $kc) = _find_piece($board, $side);
 
 	# 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 '-');
@@ -419,6 +473,19 @@ sub prettyprint_move {
 	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][$from_col];
@@ -461,7 +528,7 @@ sub _prettyprint_move_no_check_or_mate {
 			if (defined($promo) && $promo ne '') {
 				# promotion
 				$pretty .= "=";
-				$pretty .= $promo;
+				$pretty .= uc($promo);
 			}
 		}
 		return $pretty;