Lua扩展函数 #Cpp #Lua

LuaMgr.h

#pragma once

#define LUA_REGISTRYINDEX  (10000)
#define LUA_ENVIRONINDEX    (10001)
#define LUA_GLOBALSINDEX    (10002)
#define lua_upvalueindex(i) (LUA_GLOBALSINDEX(i))

typedef struct lua_State lua_State;
typedef double lua_Number;
typedef int (*lua_CFunction) (lua_State *L);

typedef struct luaL_Reg
{
    const char *name;
    lua_CFunction func;
} luaL_Reg;

typedef lua_State *(*luaL_newstate_cdecl)(void);
typedef int (*luaL_newmetatable_cdecl)(lua_State *L, const char *tname);
typedef void *(*lua_newuserdata_cdecl)(lua_State *L, size_t size);

typedef void (*lua_rawset_cdecl)(lua_State *L, int index);
typedef void (*lua_setfield_cdecl)(lua_State *L, int index, const char *k);
typedef void (*lua_getfield_cdecl)(lua_State *L, int index, const char *k);
typedef void (*lua_gettable_cdecl)(lua_State *L, int index);
typedef int (*lua_setmetatable_cdecl)(lua_State *L, int index);

typedef lua_Number (*lua_tonumber_cdecl)(lua_State *L, int index);
typedef const char *(*luaL_checklstring_cdecl)(lua_State *L, int narg, size_t *l);

typedef void (*lua_pushcclosure_cdecl) (lua_State *L, lua_CFunction fn, int n);
typedef void (*lua_pushnumber_cdecl)(lua_State *L, lua_Number n);
typedef void (*lua_pushstring_cdecl)(lua_State *L, const char *s);
typedef void (*lua_pushboolean_cdecl)(lua_State *L, int b);
typedef void (*lua_pushvalue_cdecl)(lua_State *L, int index);

typedef void *(*luaL_checkudata_cdecl)(lua_State *L, int narg, const char *tname);
typedef int (*luaL_loadbuffer_cdecl)(lua_State *L, const char *buff, size_t sz, const char *name);

typedef struct LuaInterface
{
    luaL_newstate_cdecl luaL_newstate_dll;
    luaL_newmetatable_cdecl luaL_newmetatable_dll;
    lua_newuserdata_cdecl lua_newuserdata_dll;
    lua_setfield_cdecl lua_setfield_dll;
    lua_rawset_cdecl lua_rawset_dll;
    lua_getfield_cdecl lua_getfield_dll;
    lua_setmetatable_cdecl lua_setmetatable_dll;
    lua_gettable_cdecl    lua_gettable_dll;
    lua_pushcclosure_cdecl lua_pushcclosure_dll;
    lua_pushnumber_cdecl lua_pushnumber_dll;
    lua_pushstring_cdecl lua_pushstring_dll;
    lua_pushboolean_cdecl lua_pushboolean_dll;
    lua_pushvalue_cdecl lua_pushvalue_dll;
    luaL_checkudata_cdecl luaL_checkudata_dll;
    lua_tonumber_cdecl lua_tonumber_dll;
    luaL_loadbuffer_cdecl luaL_loadbuffer_dll;
    luaL_checklstring_cdecl luaL_checklstring_dll;
} LuaInterface;

template <class T> class LuaMgr
{
public:
    static void Register(lua_State *L)
    {
        //构造函数
        luaInterface.lua_pushcclosure_dll(L, &LuaMgr <T>::constructor, 0);
        luaInterface.lua_setfield_dll(L, LUA_GLOBALSINDEX, T::classname);

        //建立元表
        luaInterface.luaL_newmetatable_dll(L, T::classname);

        //设置垃圾回收
        luaInterface.lua_pushstring_dll(L, "__gc");
        luaInterface.lua_pushcclosure_dll(L, &LuaMgr <T>::gc_obj, 0);
        luaInterface.lua_rawset_dll(L, 3);

        //设置index
        luaInterface.lua_pushstring_dll(L, "__index");
        luaInterface.lua_pushvalue_dll(L, 2);
        luaInterface.lua_rawset_dll(L, 3);

        //设置类成员函数
        for (int i = 0; T::function[i].name; i++)
        {
            luaInterface.lua_pushstring_dll(L, T::function[i].name);
            luaInterface.lua_pushnumber_dll(L, i);
            luaInterface.lua_pushcclosure_dll(L, &LuaMgr<T>::thunk, 1);
            luaInterface.lua_rawset_dll(L, 3);
        }
    }

    static int constructor(lua_State *L)
    {
        T *obj = new T(L);
        T **u = (T **)luaInterface.lua_newuserdata_dll(L, sizeof(T *));
        *u = obj;
        luaInterface.lua_getfield_dll(L, LUA_REGISTRYINDEX, T::classname);
        luaInterface.lua_setmetatable_dll(L, 2);
        return 1;
    }

    static int thunk(lua_State *L)
    {
        int i = (int)luaInterface.lua_tonumber_dll(L, lua_upvalueindex(1));
        T **obj = static_cast <T **>(luaInterface.luaL_checkudata_dll(L, 1, T::classname));
        return ((*obj) > *(T::function[i].mfunc))(L);
    }

    static int gc_obj(lua_State *L)
    {
        T **obj = static_cast <T **>(luaInterface.luaL_checkudata_dll(L, 1, T::classname));
        delete (*obj);
        return 0;
    }

    struct RegType
    {
        const char *name;
        int (T::*mfunc)(lua_State *);
    };

private:
    LuaMgr();
};

/*
class Foo
{
public:
    Foo(lua_State *L)
    {
    }
    int foo(lua_State *L)
    {
        return 0;
    }
    friend class LuaMgr<Foo>;
private:
    static const LuaMgr <Foo>::RegType function[];
    static const char classname[];
};
const char Foo::classname[] = "Foo";
const LuaMgr <Foo>::RegType Foo::function[] =
{
    { "foo", &Foo::foo},
    { NULL , NULL}
};
*/