lua调用cpp的DLL

首先新建一个cpp项目，命名为cppLibForLua，把lua的库引入，添加如下文件，编译成DLL

GameHelp.h

#pragma once

#include "lua.hpp"

#ifdef GAME_HELP_API
#define API __declspec(dllexport)
#else
#define API __declspec(dllimport)
#endif

extern "C"
{
    API int luaopen_cppLibForLua(lua_State* L);
}

 

GameHelp.cpp

#define GAME_HELP_API
#include "GameHelp.h"

static int mi2[] = {
0x80000000,0x40000000,0x20000000,0x10000000,
0x08000000,0x04000000,0x02000000,0x01000000,
0x00800000,0x00400000,0x00200000,0x00100000,
0x00080000,0x00040000,0x00020000,0x00010000,
0x00008000,0x00004000,0x00002000,0x00001000,
0x00000800,0x00000400,0x00000200,0x00000100,
0x00000080,0x00000040,0x00000020,0x00000010,
0x00000008,0x00000004,0x00000002,0x00000001,
};

static int l_fastPow(lua_State *L)
{
    double v_num = lua_tonumber(L, -2);//第一个参数
    int v_index = lua_tonumber(L, -1);//第二个参数
    double rst = 1.0;
    int neg = v_index & 0x80000000;
    v_index = v_index > 0 ? v_index : -v_index;
    int i;
    for (i = 0; i < 32; i++)
    {
        if (v_index & mi2[i])
        {
            rst = rst * rst * v_num;
        }
        else
        {
            rst = rst * rst;
        }
    }
    if (neg) rst = 1 / rst;

    lua_pushnumber(L, rst);
    return 1;
}

static const luaL_Reg MyLuaDLLFunctions[] =
{
    { "fastPow",l_fastPow },
    { NULL, NULL }
};

int  luaopen_cppLibForLua(lua_State* L)
{
    //luaL_newlib(L, MyLuaDLLFunctions);
    //lua_setglobal(L, "gameHelp");
    luaL_openlibs(L);
    lua_pushcfunction(L, l_fastPow);
    lua_setglobal(L, "fastPow");
    return 1;
}

 

lua调用代码

require "cppLibForLua"
local rst = fastPow(2,5)
print("2^5 = "..rst)

 

任务完成~~~