template < class T > class Luna {
typedef struct {
T *pT;
} userdataType;
public:
enum {
NUMBER,
STRING
};
struct PropertyType {
const char *name;
int (T::*getter) (lua_State *);
int (T::*setter) (lua_State *);
};
struct FunctionType {
const char *name;
int (T::*function) (lua_State *);
};
/*
@ check
Arguments:
* L - Lua State
* narg - Position to check
Description:
Retrieves a wrapped class from the arguments passed to the function, specified by narg (position).
This function will raise an exception if the argument is not of the correct type.
*/
static T *check(lua_State * L, int narg) {
// Check to see whether we are a table
if (lua_istable(L,narg+1))
{
lua_gettablevalue(L,narg+1,0);
userdataType *ud =
static_cast <userdataType * >(luaL_checkudata(L, -1, T::className));
if (!ud)
luaL_typerror(L, narg+1, T::className);
lua_pop(L,1);
return ud->pT; // pointer to T object
}
else
{
luaL_typerror(L, narg+1, T::className);
}
}
/*
@ lightcheck
Arguments:
* L - Lua State
* narg - Position to check
Description:
Retrieves a wrapped class from the arguments passed to the function, specified by narg (position).
This function will return NULL if the argument is not of the correct type. Useful for supporting
multiple types of arguments passed to the function
*/
static T *lightcheck(lua_State * L, int narg) {
// Check to see whether we are a table
if (lua_istable(L,narg+1))
{
lua_gettablevalue(L,narg+1,0);
userdataType *ud =
static_cast <userdataType * >(luaL_testudata(L, -1, T::className));
if (!ud)
return NULL; // lightcheck returns NULL if not found.
lua_pop(L,1);
return ud->pT; // pointer to T object
}
else
{
return NULL;
}
}
/*
@ Register
Arguments:
* L - Lua State
* namespac - Namespace to load into
Description:
Registers your class with Lua. Leave namespac "" if you want to load it into the global space.
*/
// REGISTER CLASS AS A GLOBAL TABLE
static void Register(lua_State * L, const char *namespac) {
if (strcmp(namespac, "") != 0) {
lua_getglobal(L, namespac);
lua_pushcfunction(L, &Luna < T >::constructor);
lua_setfield(L, -2, T::className);
lua_pop(L, 1);
} else {
lua_pushcfunction(L, &Luna < T >::constructor);
lua_setglobal(L, T::className);
}
luaL_newmetatable(L, T::className);
int metatable = lua_gettop(L);
lua_pushstring(L, "__gc");
lua_pushcfunction(L, &Luna < T >::gc_obj);
lua_settable(L, metatable);
lua_pushstring(L, "__index");
lua_pushcfunction(L, &Luna < T >::property_getter);
lua_settable(L, metatable);
lua_pushstring(L, "__newindex");
lua_pushcfunction(L, &Luna < T >::property_setter);
lua_settable(L, metatable);
}
/*
@ constructor (internal)
Arguments:
* L - Lua State
*/
static int constructor(lua_State * L) {
lua_newtable(L);
int newtable = lua_gettop(L);
lua_pushnumber(L, 0);
T **a = (T **) lua_newuserdata(L, sizeof(T *));
T *obj = new T(L, true);
*a = obj;
int userdata = lua_gettop(L);
luaL_getmetatable(L, T::className);
lua_setmetatable(L, userdata);
lua_settable(L, newtable);
luaL_getmetatable(L, T::className);
lua_setmetatable(L, newtable);
luaL_getmetatable(L, T::className);
for (int i = 0; T::Properties[i].name; i++) {
lua_pushstring(L, T::Properties[i].name);
lua_pushnumber(L, i);
lua_settable(L, -3);
}
lua_pop(L, 1);
for (int i = 0; T::Functions[i].name; i++) {
lua_pushstring(L, T::Functions[i].name);
lua_pushnumber(L, i);
lua_pushcclosure(L, &Luna < T >::function_dispatch, 1);
lua_settable(L, newtable);
}
return 1;
}
/*
@ createNew
Arguments:
* L - Lua State
Description:
Loads an instance of the class into the Lua stack, and provides you a pointer so you can modify it.
*/
static T *createNew(lua_State * L) {
lua_newtable(L);
int newtable = lua_gettop(L);
lua_pushnumber(L, 0);
T **a = (T **) lua_newuserdata(L, sizeof(T *));
T *obj = new T(L, false);
obj->isExisting = false;
*a = obj;
int userdata = lua_gettop(L);
luaL_getmetatable(L, T::className);
lua_setmetatable(L, userdata);
lua_settable(L, newtable);
luaL_getmetatable(L, T::className);
lua_setmetatable(L, newtable);
luaL_getmetatable(L, T::className);
for (int i = 0; T::Properties[i].name; i++) {
// ADD NAME KEY
lua_pushstring(L, T::Properties[i].name);
lua_pushnumber(L, i);
lua_settable(L, -3);
}
lua_pop(L, 1);
for (int i = 0; T::Functions[i].name; i++) {
lua_pushstring(L, T::Functions[i].name);
lua_pushnumber(L, i);
lua_pushcclosure(L, &Luna < T >::function_dispatch, 1);
lua_settable(L, newtable);
}
return obj;
}
/*
@ createFromExisting
Arguments:
* L - Lua State
* existingobj - Existing instance of object
Description:
Loads an instance of the class into the Lua stack, instead using an existing object rather than creating a new one.
Returns the existing object.
*/
static T *createFromExisting(lua_State * L, T * existingobj) {
lua_newtable(L);
int newtable = lua_gettop(L);
lua_pushnumber(L, 0);
T **a = (T **) lua_newuserdata(L, sizeof(T *));
T *obj = existingobj;
obj->isExisting = true;
*a = obj;
int userdata = lua_gettop(L);
luaL_getmetatable(L, T::className);
lua_setmetatable(L, userdata);
lua_settable(L, newtable);
luaL_getmetatable(L, T::className);
lua_setmetatable(L, newtable);
luaL_getmetatable(L, T::className);
for (int i = 0; T::Properties[i].name; i++) {
lua_pushstring(L, T::Properties[i].name);
lua_pushnumber(L, i);
lua_settable(L, -3);
}
lua_pop(L, 1);
for (int i = 0; T::Functions[i].name; i++) {
lua_pushstring(L, T::Functions[i].name);
lua_pushnumber(L, i);
lua_pushcclosure(L, &Luna < T >::function_dispatch, 1);
lua_settable(L, newtable);
}
return obj;
}
/*
@ property_getter (internal)
Arguments:
* L - Lua State
*/
static int property_getter(lua_State * L) {
lua_pushvalue(L, 2);
lua_getmetatable(L, 1);
lua_pushvalue(L, 2);
lua_rawget(L, -2);
if (lua_isnumber(L, -1)) {
int _index = lua_tonumber(L, -1);
lua_pushnumber(L, 0);
lua_rawget(L, 1);
T **obj =
static_cast < T ** >(lua_touserdata(L, -1));
lua_pushvalue(L, 3);
const PropertyType *_properties = (*obj)->T::Properties;
int result = ((*obj)->*(T::Properties[_index].getter)) (L);
return result;
}
// PUSH NIL
lua_pushnil(L);
return 1;
}
/*
@ property_setter (internal)
Arguments:
* L - Lua State
*/
static int property_setter(lua_State * L) {
lua_getmetatable(L, 1);
lua_pushvalue(L, 2);
lua_rawget(L, -2);
if (lua_isnil(L, -1)) {
lua_pop(L, 2);
lua_rawset(L, 1);
return 0;
} else {
int _index = lua_tonumber(L, -1);
lua_pushnumber(L, 0);
lua_rawget(L, 1);
T **obj =
static_cast < T ** >(lua_touserdata(L, -1));
lua_pushvalue(L, 3);
const PropertyType *_properties = (*obj)->T::Properties;
return ((*obj)->*(T::Properties[_index].setter)) (L);
}
}
/*
@ function_dispatch (internal)
Arguments:
* L - Lua State
*/
static int function_dispatch(lua_State * L) {
int i = (int) lua_tonumber(L, lua_upvalueindex(1));
lua_pushnumber(L, 0);
lua_rawget(L, 1);
T **obj = static_cast < T ** >(lua_touserdata(L, -1));
lua_pop(L, 1);
return ((*obj)->*(T::Functions[i].function)) (L);
}
/*
@ gc_obj (internal)
Arguments:
* L - Lua State
*/
static int gc_obj(lua_State * L) {
T **obj =
static_cast < T ** >(luaL_checkudata(L, -1, T::className));
if (!(*obj)->isExisting && !(*obj)->isPrecious)
{
cout << "Cleaning up a " << T::className << "." << endl;
delete(*obj);
}
return 0;
}
};
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Last edited December 21, 2012 10:52 pm GMT (diff)
