- added implementation for method get_step

src/Objects/matlib.cxx

@@ -61,6 +61,7 @@ FGMaterialLib material_lib;
 
 // Constructor
 FGMaterialLib::FGMaterialLib ( void ) {
+  set_step(0);
 }
 
 
@@ -297,6 +298,14 @@ void FGMaterialLib::set_step ( int step )
 }
 
 
+// Get the step for the state selectors
+int FGMaterialLib::get_step ()
+{
+  material_map_iterator it = begin();
+  return it->second->get_state()->getSelectStep();
+}
+
+
 // Load one pending "deferred" texture.  Return true if a texture
 // loaded successfully, false if no pending, or error.
 void FGMaterialLib::load_next_deferred() {