Re: Registering function

["Jens Wessling" <wessling@...>]

> I'd like to register a function to be called from Lua, however there are
> two issues I'm running into:
>
> 1.  I'd like to avoid passing a lua_state
>
> Granted, this isn't going to be directly possible, but basically I'd
> like to hide Lua from the rest of my application and instead have it go
> through a proxy.  So instead of:
>
> int callback( struct lua_State *pLua );
>
> I'd like to be able have something more like:
>
> int callback( MyProxy *pProxy )
> {
> }
>
> Where "callback" would query pProxy for the arguments supplied.  This
> way I don't have external code dependent on Lua directly.
>
> Is there a clean way of doing this or should I just handle the double
> indirection myself (i.e. the proxy is called back, and then it calls the
> real function with appropriately parsed args)?
>
> 2.  How to pass a "this" pointer?
>
> Is there a standard way of passing a "this" pointer when calling C++
> objects from Lua?  Right now I'm using a global, which seems rather
> nasty.

I have found a way to deal with both of these issues.  I am not sure that it
is exactly what you are looking for, but...

I register all of my C++ functions so they call the same callback handler.
Then I look up the name of the function that was called in a database of all
C++ functions and use the function database to validate all of the
arguments, then call the appropriate function.

I pass the 'this' pointer as the first argument to the function.

I can elaborate on this if you have any questions.

--Jens Wessling