--- ray/src/hd/sm_qtree.h	2003/06/20 00:25:49	3.15
+++ ray/src/hd/sm_qtree.h	2003/07/14 22:24:00	3.16
@@ -1,10 +1,16 @@
-/* RCSid: $Id: sm_qtree.h,v 3.15 2003/06/20 00:25:49 greg Exp $ */
+/* RCSid: $Id: sm_qtree.h,v 3.16 2003/07/14 22:24:00 schorsch Exp $ */
 /*
  *  sm_qtree.h - header file for routines using spherical quadtrees.
  *
  *    adapted from octree.h 
  */
+#ifndef _RAD_CONE_H_
+#define _RAD_CONE_H_
 
+#ifdef __cplusplus
+extern "C" {
+#endif
+
 /*
  *	An quadtree is expressed as an integer which is either
  *	an index to 4 other nodes, the empty tree, or an index
@@ -153,7 +159,8 @@ extern QUADTREE qtRoot_visit_tri_edges();
 extern QUADTREE qtRoot_trace_ray();
 
 
-
-
-
+#ifdef __cplusplus
+}
+#endif
+#endif /* _RAD_CONE_H_ */