Cocos2d-x中Lua与C++交互

交互主要是通过栈进行交互，一个lua_State表示一个栈，使用完记得清空栈，栈从下到上分别是1,2,3,4.....，从上到下分别是-1，-2，-3....

 

头文件

#ifndef _SCRIPT_MANAGER_H
#define _SCRIPT_MANAGER_H
#include "Common.h"
extern "C"
{
#include "..\\libs\\lua\\lua.h"
#include "..\\libs\\lua\\lualib.h"
#include "..\\libs\\lua\\lauxlib.h"
};
class ScriptManager
{
	DECLARE_SINGLETON(ScriptManager);
public:
	ScriptManager();
	~ScriptManager();
	static int average(lua_State * m_State);
private:
	lua_State * m_State;
};
#endif

 源文件

 

#include "ScriptManager.h"

DEFINE_SINGLETON(ScriptManager,_scriptManager);
int ScriptManager::average(lua_State * m_State)
{
	//每个函数都有自己的局部私有栈，每当Lua调用一个C函数时，第一个参数总是这个局部栈的索引1，
	//即使这个C函数调用了Lua代码，Lua代码又调用了相同的C函数，这些C函数只看到自己的私有栈，他们的第一个
	//参数都是索引1,完成后会自动清栈
	CCLog("lua call average");
	int size=lua_gettop(m_State);
	CCLog("size fun:%d",size);
	int i=lua_tonumber(m_State,1);
	int j=lua_tonumber(m_State,2);
	lua_pushnumber(m_State,i);
	lua_pushnumber(m_State,j);
	return 2;//结果的数量（一般压人几个就是几）
}

ScriptManager::ScriptManager()//需要注意清空栈
{
	//初始化Lua库
	m_State=lua_open();
	luaL_openlibs(m_State);	
	const luaL_reg libs[]={
		{"average",&ScriptManager::average},
		{NULL,NULL}
	};
	
	luaL_register(m_State,"go",libs);//将Lua要调用的函数注册进来
	lua_pop(m_State,1);//弹出栈的n个元素
	luaL_dofile(m_State,"simple.lua");
	
	//s_100这个table此时位于栈低，从下到上是1，2，3，4递增，从上到下是-1，-2，-3
	lua_getglobal(m_State,"s_s");
	lua_getfield(m_State,1,"name");
	const char * name=lua_tostring(m_State,-1);
	CCLog("name:%s",name);

	lua_getfield(m_State,1,"loop");
	bool loop=lua_toboolean(m_State,-1);
	CCLog("loop:%d",loop);

	lua_getfield(m_State,1,"time");
	int time=lua_tonumber(m_State,-1);
	CCLog("time:%d",time);

	lua_getfield(m_State,1,"script");
	if(!lua_isfunction(m_State,-1))
	{
		CCLog("not function");
	}
	lua_pushnumber(m_State,10);
	lua_pushnumber(m_State,20);
	lua_pcall(m_State,2,1,0);//调用该函数后，会自动清空函数的栈

	int max=lua_tonumber(m_State,-1);
	CCLog("max:%d",max);
	int size=lua_gettop(m_State);
	CCLog("%d",size);

	lua_getglobal(m_State,"width");
	int width=lua_tonumber(m_State,-1);
	CCLog("width:%d",width);

	size=lua_gettop(m_State);
	CCLog("size1:%d",size);

	lua_newtable(m_State);//创建一个table
	lua_pushnumber(m_State,1);//向栈顶压入一个元素
	lua_setfield(m_State,-2,"test");//设置到table中去，这时候栈顶的number弹出栈

	size=lua_gettop(m_State);
	CCLog("size3:%d",size);
}

ScriptManager::~ScriptManager()
{
	lua_close(m_State);
}

 

 simple.lua

s_s=
{
	name="gameone";
	loop=false;
	time=20;

	script=function(x,y)
	i,j=go.average(x,y);

		if x>=y then
				return x+i;
		else
				return y+j;
		end
	
	end
}

width=10;
height=20;