From 578af00b0d48100c540154f54293a1b77a0655fe Mon Sep 17 00:00:00 2001
From: jmt <jmt>
Date: Thu, 31 Dec 2009 16:48:03 +0000
Subject: [PATCH] Allow geocentric distance computations to return radians.

---
 simgear/math/SGGeodesy.cxx | 11 +++++++++--
 simgear/math/SGGeodesy.hxx |  1 +
 2 files changed, 10 insertions(+), 2 deletions(-)

diff --git a/simgear/math/SGGeodesy.cxx b/simgear/math/SGGeodesy.cxx
index 208218b7..b9974f14 100644
--- a/simgear/math/SGGeodesy.cxx
+++ b/simgear/math/SGGeodesy.cxx
@@ -540,7 +540,7 @@ SGGeodesy::courseRad(const SGGeoc& from, const SGGeoc& to)
 }
 
 double
-SGGeodesy::distanceM(const SGGeoc& from, const SGGeoc& to)
+SGGeodesy::distanceRad(const SGGeoc& from, const SGGeoc& to)
 {
   // d = 2*asin(sqrt((sin((lat1-lat2)/2))^2 +
   //            cos(lat1)*cos(lat2)*(sin((lon1-lon2)/2))^2))
@@ -550,5 +550,12 @@ SGGeodesy::distanceM(const SGGeoc& from, const SGGeoc& to)
   double tmp2 = sin(0.5*(from.getLongitudeRad() - to.getLongitudeRad()));
   double square = tmp1*tmp1 + cosLatFrom*cosLatTo*tmp2*tmp2;
   double s = SGMiscd::min(sqrt(SGMiscd::max(square, 0)), 1);
-  return 2 * asin(s) * SG_RAD_TO_NM * SG_NM_TO_METER;
+  return 2 * asin(s);
+}
+
+
+double
+SGGeodesy::distanceM(const SGGeoc& from, const SGGeoc& to)
+{
+  return distanceRad(from, to) * SG_RAD_TO_NM * SG_NM_TO_METER;
 }
diff --git a/simgear/math/SGGeodesy.hxx b/simgear/math/SGGeodesy.hxx
index 53e2cbb3..ef1be21f 100644
--- a/simgear/math/SGGeodesy.hxx
+++ b/simgear/math/SGGeodesy.hxx
@@ -61,6 +61,7 @@ public:
   static void advanceRadM(const SGGeoc& geoc, double course, double distance,
                           SGGeoc& result);
   static double courseRad(const SGGeoc& from, const SGGeoc& to);
+  static double distanceRad(const SGGeoc& from, const SGGeoc& to);
   static double distanceM(const SGGeoc& from, const SGGeoc& to);
 };
 
-- 
2.39.5