Userdata pointers

[Warren Merrifield <wmerrifield@...>]

I think I already know the answer to this, but I'm not sure, so i
thought I would check:

I create some full userdata, using the C API, and get a pointer to a
block of memory back. I create a reference to this userdata so that it
won't get garbage collected until I want it to. Will the address of my
memory remain constant throughout the lifetime of the userdata (i.e.
outside the scope of the function which created it)

I want to be able to do something like

	d0 = AddDisplayObject(def)
	d1 = AddDisplayObject(def)
	rungame()

in Lua, and then get the addresses for the userdata display objects
every frame in C without having to call back into Lua every time.

Thanks for any help,
Warren