Here presents a new method for lua calling c++. A function “Add” is defined in c++ which returns the sum of two input integers. The function also calls lua method “Show” to print the result.

Using cle to developed c++ extension, c++ externsion should be compiled into a sharelib which exports two functions StarCoreService_Init and StarCoreService_Term. There are four steps:

1.       Create service.

2.       Create interface object, and defines a new function “Add” of it.

3.       Write function code of Add.

4.       Set function address of Add to object’ function definition.

#include "vsopenapi.h"

static class ClassOfSRPInterface *SRPInterface;

//--Step 3 :  Add function body

static VS_INT32 Add(void *Object,VS_INT32 x,VS_INT32 y)

{

     //--Callback script function

     SRPInterface -> ScriptCall(Object,NULL,"Show","(i)",x+y);

         return x + y;

}

VS_BOOL StarCoreService_Init(class ClassOfStarCore *starcore)

{

         void *AtomicClass,*Add_AtomicFunction;

         class ClassOfBasicSRPInterface *BasicSRPInterface;

         //--Step 1 :  Create service

         BasicSRPInterface = starcore ->GetBasicInterface();         

         BasicSRPInterface ->CreateService("","AddFunctionService",NULL,"123",0,0,0,0,0,0);

         //--Step 2 :  Create object and defines a new function “Add”

         SRPInterface = BasicSRPInterface ->GetSRPInterface("AddFunctionService","root","123");

         AtomicClass = SRPInterface ->CreateAtomicObjectSimple("TestItem","TestClass",NULL,NULL,NULL);

         Add_AtomicFunction = SRPInterface ->CreateAtomicFunctionSimple(AtomicClass,"Add","VS_INT32 Add(VS_INT32 x,VS_INT32 y);",NULL,NULL,VS_FALSE,VS_FALSE);

         //--Step 4 :  Set function address to Add function

         SRPInterface -> SetAtomicFunction(Add_AtomicFunction,(void *)Add);

         return VS_TRUE;

}

void StarCoreService_Term(class ClassOfStarCore *starcore)

{

         SRPInterface -> Release();

         return;

}

Compile into sharelibrary, may be named “AddFunctionService.dll”.

For lua code calls the above sharelib, there are three steps;

1.       Init cle, create service group,import sharelibrary,  and create service.

2.       Create Instance of object “TestClass” defined in sharelibrary.

3.       Call function “Add”.

require "libstarcore"

--Step 1 : Init cle, create service group,import sharelibrary,  and create service.

Service=libstarcore._InitSimple("test","123",0,0,"AddFunctionService.dll");

--Step 2: Create Instance of object “TestClass” defined in sharelibrary.

a = Service.TestClass:_New();

--Step 3: call function “Add”

function a:Show( Para )

    print("print from lua call back ".. Para )

end   

print("Add returns : "..a:Add(12,34))

Service._ServiceGroup:_ClearService()

libstarcore._ModuleExit()

Run : starapp -e lua_call.lua