Added support for decoration of the osgTerrain::DataSet generated databases

with a CoordinateSystemNode which reflect the coordinate system of the
database.

Added support for reading and writing CoordianteSystemNode into the .osg
and .ive formats.

src/osgPlugins/osg/EllipsoidModel.cpp

@@ -0,0 +1,67 @@
+#include "osg/CoordinateSystemNode"
+#include "osg/Notify"
+
+#include "osgDB/Registry"
+#include "osgDB/Input"
+#include "osgDB/Output"
+
+using namespace osg;
+using namespace osgDB;
+
+// forward declare functions to use later.
+bool EllipsoidModel_readLocalData(Object& obj, Input& fr);
+bool EllipsoidModel_writeLocalData(const Object& obj, Output& fw);
+
+// register the read and write functions with the osgDB::Registry.
+RegisterDotOsgWrapperProxy g_EllipsoidModelFuncProxy
+(
+    new osg::EllipsoidModel,
+    "EllipsoidModel",
+    "Object EllipsoidModel",
+    &EllipsoidModel_readLocalData,
+    &EllipsoidModel_writeLocalData,
+    DotOsgWrapper::READ_AND_WRITE
+);
+
+bool EllipsoidModel_readLocalData(Object& obj, Input& fr)
+{
+    bool iteratorAdvanced = false;
+
+    EllipsoidModel& em = static_cast<EllipsoidModel&>(obj);
+
+    if (fr.matchSequence("RadiusEquator %f"))
+    {
+        double radius;
+        fr[1].getFloat(radius);
+        em.setRadiusEquator(radius);
+        fr += 2;
+        iteratorAdvanced = true;
+    }
+
+    if (fr.matchSequence("RadiusPolar %f"))
+    {
+        double radius;
+        fr[1].getFloat(radius);
+        em.setRadiusPolar(radius);
+        fr += 2;
+        iteratorAdvanced = true;
+    }
+
+    return iteratorAdvanced;
+}
+
+
+bool EllipsoidModel_writeLocalData(const Object& obj, Output& fw)
+{
+    const EllipsoidModel& em = static_cast<const EllipsoidModel&>(obj);
+
+    int prec = fw.precision();
+    fw.precision(15);
+
+    fw.indent()<<"RadiusEquator "<<em.getRadiusEquator()<<std::endl;
+    fw.indent()<<"RadiusPolar "<<em.getRadiusPolar()<<std::endl;
+
+    fw.precision(prec);
+
+    return true;
+}