storing/retrieving objects

[Glenn Randers-Pehrson, WMB]

I would like to be able to store display lists in a file for later
retrieval.  The subroutines might look something like

writeobj

C	writeobj(obj,stream)
	Object obj;
	FILE *stream;

FORTRAN subroutine writeo(obj, file)

Pascal  procedure writeobj(obj:Object, stream:FILE);

DESCRIPTION

	writes graphics object "obj" at the end of the file. Leaves
file positioned at end of information.

--------
writeobj

C	readobj(obj,stream)
	Object obj;
	FILE *stream;

FORTRAN subroutine readob(obj, file)

Pascal  procedure writeobj(obj:Object, stream:FILE);

DESCRIPTION

	Reads the next graphics object from the file and use the information
to create an object "obj" in the symbol table and memory. Leaves
file positioned ready to read or overwrite the next object on the file,
if any.

NOTE

	If the object contains calls to other objects, the user is
responsible for making sure that all such objects exist and have the
same "obj" object identifiers as when the object was written out.
--------

Has anyone written such subroutines or equivalents?  It would help to
have some documentation of the internal structure of the display list.

<glennrp at brl.arpa>