Re: How to call functions inside a table from C?

[Link Hughes <link@...>]

Been doing this a lot lately.

You just need to get the function onto the stack so that you can use a 
lua_pcall() on it and any appropriate arguments.

So first you need to get the table that the function is in.  Personally, 
I also like to note the stack index of the table when I do something 
like this since it makes the code more readable and helps with clean-up.

 int MinhaTabela;
 lua_getglobal( L, "MinhaTabela" );
 MinhaTabela = lua_gettop( L );

Then you'll need to get the function into the stack as well.

 lua_getfield( L, MinhaTabela, "variosCirculos2" );

Then, finally, push any arguments and make the call.

 if ( lua_pcall( L, 0, 0, 0 ) != 0 ) { /* Error Handling */ }

And if you have the table's index, then cleaning up the stack is easy 
because you don't have to remember how many elements to pop.

 lua_settop( L, (MinhaTabela - 1) );

In your case, it looks like you'll need a new C function for calling Lua 
functions resident in tables, so you'd need something like:

 void ScriptInterface::CallTableFunction(int tableIdx, char *funcName)
 {
   lua_getfield( L, tableIdx, funcName );
   if ( lua_pcall( L, 0, 0, 0 ) != 0 ) { /* Error Handling */ }
 }

Hope that helps.

-Link

--
Link Hughes
Lead Programmer
1st Playable Productions
http://www.1stplayable.com


Edmar wrote:
> **Sorry for my bad English. **
>
> Good day.
>
> I'm trying to call a function declared inside a lua table, from my 
> code in "C". This is my lua code:
>
>
> MinhaTabela=
> {
> textos =
> {
>  textoSair = "Aperter ESC para sair a qualquer momento",
>  textoEnter = "Aperte enter para jogar"
> },
>
> variosCirculos2 =
> function ()
>  for X=1, 30 do Circulo(X * 10,X * 10,X * 5,X * 10,X * 5,0); end
>  Atualizar();
> end,
>
>
> relogio =
> function ()
>
>  ty = ty + 2;
>  tx = tx + 5;
>
> end
>
> }
>
>
> So, how can I call the functions 'variosCirculos2" or "relogio" from 
> C? This is the code that I use to call Lua functions:
>
> void ScriptInterface::CallFunction(char *funcName)
> {
> lua_getglobal(L, funcName);
> if(lua_pcall(L, 0, 0, 0) != 0)
> {
> cout << "Erro ao chamar função: "
> << lua_tostring(L, -1)
> << endl;
> }
> }
>
> Thanx for the atention.