--- ray/src/hd/rhdobj.h	1998/12/18 11:06:46	3.4
+++ ray/src/hd/rhdobj.h	2003/07/14 22:24:00	3.7
@@ -1,11 +1,14 @@
-/* Copyright (c) 1998 Silicon Graphics, Inc. */
-
-/* SCCSid "$SunId$ SGI" */
-
+/* RCSid: $Id: rhdobj.h,v 3.7 2003/07/14 22:24:00 schorsch Exp $ */
 /*
  * Header file for object display routines for rholo drivers.
  */
+#ifndef _RAD_RHDOBJ_H_
+#define _RAD_RHDOBJ_H_
 
+#ifdef __cplusplus
+extern "C" {
+#endif
+
 				/* additional user commands */
 #define DO_LOAD		0		/* load octree object */
 #define DO_UNLOAD	1		/* unload (free) octree object */
@@ -44,8 +47,9 @@ int
 dobj_command(cmd, args)		: check/run object display command
 char	*cmd, *args;		: command name and argument string
 
-Check to see if this is an object display command, and return the command
-number after running it if it is, or -1 if it isn't.  Error messages should
+Check to see if this is an object display command, and return -1 if
+it isn't.  If it is a valid command that results in some visible
+change, return non-zero, otherwise return 0.  Error messages should
 be printed with error(COMMAND,err).
 
 
@@ -150,3 +154,9 @@ extern double	dobj_trace();
 extern char	rhdcmd[DO_NCMDS][8];
 
 extern int	(*dobj_lightsamp)();	/* pointer to function to get lights */
+
+#ifdef __cplusplus
+}
+#endif
+#endif /* _RAD_RHDOBJ_H_ */
+