What's the best place to find out more about the rb_const_get family of 
functions for writing C extensions?  I'm writing my first C library for 
Ruby, and struggling with how to get VALUEs for Classes and Modules 
provided by Ruby and other extensions.  The Pickaxe 2.0 has a wonderful 
section on C extensions, for the most part, but it seems to omit mention 
of rb_const_get completely.  Took me an hour of searching the ml to even 
discover its existence.

A few pressing questions:
(1) What does the rb_cObject parameter that I'm always passing in do?  
What other things might I pass in for this argument?
(2) How do I get a handle to a Class that's inside a module?  I tried 
calling (for example) rb_const_get(rc_cObject, rb_intern("GLIT::Vec")) 
but I get an error.  However, calling GLIT::Vec.new from a ruby script 
that's using the C extension works fine, so I must have the syntax wrong.

Thanks a bundle for any help you all can provide.  I appreciate it.

-- Brian Palmer