nasal::Ghost tweaking and to_nasal_helper for SGGeod.

simgear/nasal/cppbind/Ghost.hxx

@@ -278,6 +278,14 @@ namespace nasal
         return *getSingletonPtr();
       }
 
+      /**
+       * Check whether ghost type has already been initialized.
+       */
+      static bool isInit()
+      {
+        return getSingletonPtr();
+      }
+
       /**
        * Register a base class for this ghost. The base class needs to be
        * registers on its own before it can be used as base class.

simgear/nasal/cppbind/cppbind_test.cxx

@@ -165,6 +165,7 @@ int main(int argc, char* argv[])
     .member("base", &DoubleDerived2::getBase)
     .method("doIt", &DoubleDerived2::doSomeBaseWork);
 
+  VERIFY( Ghost<BasePtr>::isInit() );
   nasal::to_nasal(c, DoubleDerived2Ptr());
 
   BasePtr d( new Derived );

simgear/nasal/cppbind/detail/to_nasal_helper.cxx

@@ -20,6 +20,7 @@
 #include <simgear/nasal/cppbind/NasalHash.hxx>
 #include <simgear/nasal/cppbind/Ghost.hxx>
 
+#include <simgear/math/SGMath.hxx>
 #include <simgear/misc/sg_path.hxx>
 
 #include <boost/function.hpp>
@@ -52,6 +53,16 @@ namespace nasal
     return ref;
   }
 
+  //------------------------------------------------------------------------------
+  naRef to_nasal_helper(naContext c, const SGGeod& pos)
+  {
+    nasal::Hash hash(c);
+    hash.set("lat", pos.getLatitudeDeg());
+    hash.set("lon", pos.getLongitudeDeg());
+    hash.set("elevation", pos.getElevationM());
+    return hash.get_naRef();
+  }
+
   //----------------------------------------------------------------------------
   naRef to_nasal_helper(naContext c, const SGPath& path)
   {

simgear/nasal/cppbind/detail/to_nasal_helper.hxx

@@ -33,6 +33,7 @@
 #include <string>
 #include <vector>
 
+class SGGeod;
 class SGPath;
 
 namespace nasal
@@ -63,6 +64,8 @@ namespace nasal
    */
   naRef to_nasal_helper(naContext c, const naRef& ref);
 
+  naRef to_nasal_helper(naContext c, const SGGeod& pos);
+
   naRef to_nasal_helper(naContext c, const SGPath& path);
 
   /**