howto: adapting Joe Rossi's lua resource to T3D.

i haven't tested the Lua resource at all beyond the extremely simple example given below, so caveat coder.

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adapting Joe Rossi's lua resource to T3D. orion elenzil 200908.
the resource is here: www.garagegames.com/community/resource/view/9665

* download and unzip the zip.

* make a directory "lua" in Engine/lib

* put the lua files right in there. ie so that you have: engine/lib/lua_inc.h

* add the files to the "FPS Genre Kit DLL" project.

* in mainLoop.cpp, and add these lines up near the top, after other includes:

#include "lua/lua_inc.h"     // all lua includes  
lua_State *L=0;  
#include "lua/lua_export.h"  // main bridge classes

* still in mainLoop.cpp, and add these lines after the call to Sim::init() :

//-----------------------------------------------
   // initialize LUA
   L = lua_open();
   lua_gc(L, LUA_GCSTOP, 0);  
   luaL_openlibs(L); 
   Lunar<game>::Register(L);
   lua_gc(L, LUA_GCRESTART, 0);
   
   // oxe - this needs to go after Sim::init()
   //open our bridge objects  
   Con::evaluate("$LuaObject=new LuaObject(lua); lua.docode("tge=game()"); ",0,0);  
   //change dofile function to our tge function so it will print errors to the console  
   Con::evaluate("dofile = function(s) tge:docode('lua.dofile("' ..string.gsub(s,'', '\' ) ..'");' ) end");" ,0,0);  
   //-----------------------------------------------

* in lua-export.h, and un-comment out ifdef LUA_DEBUG stuff around lua_atpanic,
in the LuaObject::LuaObject() constructor.


* still in lua-export.h, remove the pararameter "2" entirely from this function call:

void LuaObject::doCallback(){  Con::executef(this, "onCallback", "string_variable");

* still in lua-export.h, change "execScript" to "Con::execScript".


* in console.h, after the declaration(s) of executef(), add:

void execScript(const char *scriptFile);

* in console.cpp, after the definition(s) of executef(), add:

//------------------------------------------------------------------------------
// execScript for LUA implementation: Jonathon "dishmal" Stevens  
void execScript(const char *scriptFile)
{  
   // execute the script  
   FileStream str;  

   if (!str.open(scriptFile, Torque::FS::File::Read))  
      return;  

   U32 size = str.getStreamSize();  
   char *script = new char[size + 1];  

   str.read(size, script);  
   str.close();  

   script[size] = 0;  
   Con::executef("eval", script);  
   delete[] script;  
}

* i'm not sure what's up with this line in LuaObject::processArguments():

if(!argc) return true; else return true; return false;

i left it as is (compiler warnings and all) but it's possible the correct version is

if(!argc) return true; else return false;

* test it!
at this point the project should compile and run.
to test it, open the torque console and enter:

lua.docode("x = pow(3,3)");
  echo(lua.geti("x"));

you should see "27".