RE: Passing pointer between Lua and C/C++

["Kevin Baca" <lualist@...>]

Have you checked the wiki?  It contains quite a lot of information about
what you're asking.

http://lua-users.org/wiki/

Do a search for "userdata".

Do a separate search for "binding".

That will be a good start.

-Kevin

-----Original Message-----
From: lua-bounces@bazar2.conectiva.com.br
[mailto:lua-bounces@bazar2.conectiva.com.br] On Behalf Of Initial-N
Sent: Thursday, December 16, 2004 4:03 AM
To: lua@bazar2.conectiva.com.br
Subject: Passing pointer between Lua and C/C++


HI all,

I have a question regarding to passing pointer between Lua and C/C++.
Hope any Lua expert can give me a hand and any reference point!! 
I want to do something like that.

(I use tolua to bind my C/C++ code)
In C/C++ code.
----------------------
Object *o = new Object();
... Do something with this Object, 
Push o (address) to lua stack
Run Lua script(s), which will pick up this pointer,  and continue do
something (AI logic, mainly I intend to script entire state machine in
lua), so that C/C++ code get the update right away.

It does not have to be exactly this way, but I want to figure out if it
is possible to pass any reference to lua from native code, run the
script(s) for some logic, and update this reference in lua script.  Any
other ideas are very welcome.

I know I should push some kind of tag or use Userdata thing, but I was
not able to find any good examples of using Userdata in Lua page.

Once of the reason I want to try this idea, is performance. I just
simply want to prevent doing "pass by value" as much as possible.

Sorry for the newbie question, and thank you very much for the help.

Nelson







Post your free ad now! Yahoo! Canada Personals