[Lua]Lua调用C/C++函数/库(函数压栈方式)

test.cpp文件

/*C/C++调用Lua*/#include<iostream>using namespace std;#include<lua.hpp>/*当我们需要在Lua里面调用C/C++函数时，所有的函数都必须满足以下函数签名：typedef int (*lua_CFunction) (lua_State *L);换句话说，，所有的函数必须接收一个lua_State作为参数，同时返回一个整数值。因为这个函数使用Lua栈作为参数，所以它可以从栈里面读取任意数量和任意类型的参数。而这个函数的返回值则表示函数返回时有多少返回值被压入Lua栈。（因为Lua的函数是可以返回多个值的）*/static int math_abs(lua_State *L){lua_pushnumber(L, abs((int)luaL_checknumber(L, 1))); //获取传入的参数return 1;}static int math_cos(lua_State *L){lua_pushnumber(L, cos((double)luaL_checknumber(L, 1)));return 1;}static int math_sin(lua_State *L){lua_pushnumber(L, sin((double)luaL_checknumber(L, 1)));return 1;}static int ShowMessage(lua_State * L){lua_pushnumber(L, 1000);printf("show message and push 1000 \n");return -1;}//注册函数void regist_function(lua_State *L){//压栈后设置一个lua可调用的全局函数名lua_pushcfunction(L, ShowMessage);lua_setglobal(L, "showmessage");//c调用lualua_getglobal(L, "SHOWMESSAGE");lua_pcall(L, 0, 0, 0);printf("get the showmessage pushed value %f \n", lua_tonumber(L, -1));//#define lua_register(L,n,f) (lua_pushcfunction(L, (f)), lua_setglobal(L, (n)))//lua_register的定义如上，所有 lua_pushcfunction(L, ShowMessage);lua_setglobal(L, "showmessage"); <==>lua_register(L, "showmessage", ShowMessage);lua_register(L, "cos", math_cos);//测试lua_getglobal(L, "COS");lua_pushnumber(L, 0.5);if (0 != lua_pcall(L, 1, 1, 0)){printf("cpp call lua function failed\n");}printf("cos(0.5)=%f\n", lua_tonumber(L, -1));lua_pop(L, 1);}//注册库函数void regist_lib(lua_State *L){static const luaL_reg mathlib[] = {{ "abs", math_abs },{ "cos", math_cos },{ "sin", math_sin },{ NULL, NULL }};luaL_register(L, "DY_MATH", mathlib);//测试double sinv = 30*3.1415926/180.0;lua_getglobal(L, "SIN");lua_pushnumber(L, sinv);if (0 != lua_pcall(L, 1, 1, 0)){printf("cpp call lua function failed\n");}printf("sin(%f)=%f\n", sinv, lua_tonumber(L, -1));lua_pop(L, 1);}int main(){lua_State *L = luaL_newstate();luaL_openlibs(L);char *luapath="LuaCallCTest.lua";luaL_dofile(L, luapath);regist_function(L);regist_lib(L);lua_close(L);system("pause");return 0;}LuaCallCTest.lua文件

–region LuaCallCTest.luafunction COS(a)print("called COS in lua script")–lua调用c/c++函数return cos(a)endfunction SIN(a)print("called SIN in lua script")–lua调用c/c++库函数return DY_MATH.sin(a)endfunction SHOWMESSAGE()showmessage()end–end region结果

我走得很慢！但我从不后退！