From 7beaf3705ec3e58abc7c5d06b31a5e8724102de1 Mon Sep 17 00:00:00 2001
From: James Turner <zakalawe@mac.com>
Date: Fri, 23 Jul 2010 13:04:09 +0100
Subject: [PATCH] Add closest-point calculation to SGRay, to replace a vector.h
 helper.

---
 simgear/math/SGRay.hxx | 6 ++++++
 1 file changed, 6 insertions(+)

diff --git a/simgear/math/SGRay.hxx b/simgear/math/SGRay.hxx
index afd7b041..eef28cc4 100644
--- a/simgear/math/SGRay.hxx
+++ b/simgear/math/SGRay.hxx
@@ -47,6 +47,12 @@ public:
   SGVec3<T> getNormalizedDirection() const
   { return normalize(getDirection()); }
 
+  SGVec3<T> getClosestPointTo(const SGVec3<T>& point)
+  {
+      SGVec3<T> u(getNormalizedDirection()),
+          v(point - _origin);
+      return (dot(u, v) * u) + _origin; 
+  }
 private:
   SGVec3<T> _origin;
   SGVec3<T> _direction;
-- 
2.39.5