From 8106275008346b0cceb090f7317ff4240a3ba44f Mon Sep 17 00:00:00 2001
From: Dirk Koopman <djk@tobit.co.uk>
Date: Wed, 3 Jun 2020 20:42:27 +0100
Subject: [PATCH] fix regex parse in sh/dx, add DXBearing::distance

---
 cmd/show/dx.pl    | 10 ++++++++++
 perl/DXBearing.pm | 14 ++++++++++++++
 2 files changed, 24 insertions(+)

diff --git a/cmd/show/dx.pl b/cmd/show/dx.pl
index c0c43fa3..655630ce 100644
--- a/cmd/show/dx.pl
+++ b/cmd/show/dx.pl
@@ -11,10 +11,20 @@ sub handle
 {
 	my ($self, $line) = @_;
 
+	# disguise regexes
+	$line =~ s/\{(.*)\}/'{'. unpack('H*', $1) . '}'/eg;
+	dbg("sh/dx disguise any regex: '$line'") if isdbg('sh/dx');
+
+	# now space out brackets and !
 	$line =~ s/([\(\!\)])/ $1 /g;
 	
 	my @list = split /[\s]+/, $line; # split the line up
 
+	# put back the regexes 
+	@list = map { my $l = $_; $l =~ s/\{([0-9a-fA-F]+)\}/'{' . pack('H*', $1) . '}'/eg; $l } @list;
+
+	dbg("sh/dx after regex return: " . join(' ', @list)) if isdbg('sh/dx');
+	
 	my @out;
 	my $f;
 	my $call = $self->call;
diff --git a/perl/DXBearing.pm b/perl/DXBearing.pm
index b98d746a..db6f4686 100644
--- a/perl/DXBearing.pm
+++ b/perl/DXBearing.pm
@@ -101,6 +101,20 @@ sub bdist
 	return (rd($az), $dx);
 }
 
+# just the distance - parameters as above
+sub distance
+{
+	my $hn = dr(shift);
+	my $he = dr(shift);
+	my $n = dr(shift);
+	my $e = dr(shift);
+	return (0, 0) if $hn == $n && $he == $e;
+	my $co = cos($he-$e)*cos($hn)*cos($n)+sin($hn)*sin($n);
+	my $ca = $co ? atan(abs(sqrt(1-$co*$co)/$co)) : $pi;
+	$ca = $pi-$ca if $co < 0;
+	my $dx = 6367*$ca;
+}
+
 # turn a lat long string into floating point lat and long
 sub stoll
 {
-- 
2.34.1