-
Notifications
You must be signed in to change notification settings - Fork 0
/
lunar.h
214 lines (187 loc) · 6.94 KB
/
lunar.h
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
extern "C" {
#include "lua.h"
#include "lauxlib.h"
}
template <typename T> class Lunar {
typedef struct { T *pT; } userdataType;
public:
typedef int (T::*mfp)(lua_State *L);
typedef struct { const char *name; mfp mfunc; } RegType;
static void Register(lua_State *L) {
lua_newtable(L);
int methods = lua_gettop(L);
luaL_newmetatable(L, T::className);
int metatable = lua_gettop(L);
// store method table in globals so that
// scripts can add functions written in Lua.
lua_pushvalue(L, methods);
set(L, LUA_GLOBALSINDEX, T::className);
// hide metatable from Lua getmetatable()
lua_pushvalue(L, methods);
set(L, metatable, "__metatable");
lua_pushvalue(L, methods);
set(L, metatable, "__index");
lua_pushcfunction(L, tostring_T);
set(L, metatable, "__tostring");
lua_pushcfunction(L, gc_T);
set(L, metatable, "__gc");
lua_newtable(L); // mt for method table
lua_pushcfunction(L, new_T);
lua_pushvalue(L, -1); // dup new_T function
set(L, methods, "new"); // add new_T to method table
set(L, -3, "__call"); // mt.__call = new_T
lua_setmetatable(L, methods);
// fill method table with methods from class T
for (RegType *l = T::methods; l->name; l++) {
lua_pushstring(L, l->name);
lua_pushlightuserdata(L, (void*)l);
lua_pushcclosure(L, thunk, 1);
lua_settable(L, methods);
}
lua_pop(L, 2); // drop metatable and method table
}
// call named lua method from userdata method table
static int call(lua_State *L, const char *method,
int nargs=0, int nresults=LUA_MULTRET, int errfunc=0)
{
int base = lua_gettop(L) - nargs; // userdata index
if (!luaL_checkudata(L, base, T::className)) {
lua_settop(L, base-1); // drop userdata and args
lua_pushfstring(L, "not a valid %s userdata", T::className);
return -1;
}
lua_pushstring(L, method); // method name
lua_gettable(L, base); // get method from userdata
if (lua_isnil(L, -1)) { // no method?
lua_settop(L, base-1); // drop userdata and args
lua_pushfstring(L, "%s missing method '%s'", T::className, method);
return -1;
}
lua_insert(L, base); // put method under userdata, args
int status = lua_pcall(L, 1+nargs, nresults, errfunc); // call method
if (status) {
const char *msg = lua_tostring(L, -1);
if (msg == NULL) msg = "(error with no message)";
lua_pushfstring(L, "%s:%s status = %d\n%s",
T::className, method, status, msg);
lua_remove(L, base); // remove old message
return -1;
}
return lua_gettop(L) - base + 1; // number of results
}
// push onto the Lua stack a userdata containing a pointer to T object
static int push(lua_State *L, T *obj, bool gc=false) {
if (!obj) { lua_pushnil(L); return 0; }
luaL_getmetatable(L, T::className); // lookup metatable in Lua registry
if (lua_isnil(L, -1)) luaL_error(L, "%s missing metatable", T::className);
int mt = lua_gettop(L);
subtable(L, mt, "userdata", "v");
userdataType *ud =
static_cast<userdataType*>(pushuserdata(L, obj, sizeof(userdataType)));
if (ud) {
ud->pT = obj; // store pointer to object in userdata
lua_pushvalue(L, mt);
lua_setmetatable(L, -2);
if (gc == false) {
lua_checkstack(L, 3);
subtable(L, mt, "do not trash", "k");
lua_pushvalue(L, -2);
lua_pushboolean(L, 1);
lua_settable(L, -3);
lua_pop(L, 1);
}
}
lua_replace(L, mt);
lua_settop(L, mt);
return mt; // index of userdata containing pointer to T object
}
// get userdata from Lua stack and return pointer to T object
static T *check(lua_State *L, int narg) {
userdataType *ud =
static_cast<userdataType*>(luaL_checkudata(L, narg, T::className));
if(!ud) {
luaL_typerror(L, narg, T::className);
return NULL;
}
return ud->pT; // pointer to T object
}
private:
Lunar(); // hide default constructor
// member function dispatcher
static int thunk(lua_State *L) {
// stack has userdata, followed by method args
T *obj = check(L, 1); // get 'self', or if you prefer, 'this'
lua_remove(L, 1); // remove self so member function args start at index 1
// get member function from upvalue
RegType *l = static_cast<RegType*>(lua_touserdata(L, lua_upvalueindex(1)));
return (obj->*(l->mfunc))(L); // call member function
}
// create a new T object and
// push onto the Lua stack a userdata containing a pointer to T object
static int new_T(lua_State *L) {
lua_remove(L, 1); // use classname:new(), instead of classname.new()
T *obj = new T(L); // call constructor for T objects
push(L, obj, true); // gc_T will delete this object
return 1; // userdata containing pointer to T object
}
// garbage collection metamethod
static int gc_T(lua_State *L) {
if (luaL_getmetafield(L, 1, "do not trash")) {
lua_pushvalue(L, 1); // dup userdata
lua_gettable(L, -2);
if (!lua_isnil(L, -1)) return 0; // do not delete object
}
userdataType *ud = static_cast<userdataType*>(lua_touserdata(L, 1));
T *obj = ud->pT;
if (obj) delete obj; // call destructor for T objects
return 0;
}
static int tostring_T (lua_State *L) {
char buff[32];
userdataType *ud = static_cast<userdataType*>(lua_touserdata(L, 1));
T *obj = ud->pT;
sprintf(buff, "%p", (void*)obj);
lua_pushfstring(L, "%s (%s)", T::className, buff);
return 1;
}
static void set(lua_State *L, int table_index, const char *key) {
lua_pushstring(L, key);
lua_insert(L, -2); // swap value and key
lua_settable(L, table_index);
}
static void weaktable(lua_State *L, const char *mode) {
lua_newtable(L);
lua_pushvalue(L, -1); // table is its own metatable
lua_setmetatable(L, -2);
lua_pushliteral(L, "__mode");
lua_pushstring(L, mode);
lua_settable(L, -3); // metatable.__mode = mode
}
static void subtable(lua_State *L, int tindex, const char *name, const char *mode) {
lua_pushstring(L, name);
lua_gettable(L, tindex);
if (lua_isnil(L, -1)) {
lua_pop(L, 1);
lua_checkstack(L, 3);
weaktable(L, mode);
lua_pushstring(L, name);
lua_pushvalue(L, -2);
lua_settable(L, tindex);
}
}
static void *pushuserdata(lua_State *L, void *key, size_t sz) {
void *ud = 0;
lua_pushlightuserdata(L, key);
lua_gettable(L, -2); // lookup[key]
if (lua_isnil(L, -1)) {
lua_pop(L, 1); // drop nil
lua_checkstack(L, 3);
ud = lua_newuserdata(L, sz); // create new userdata
lua_pushlightuserdata(L, key);
lua_pushvalue(L, -2); // dup userdata
lua_settable(L, -4); // lookup[key] = userdata
}
return ud;
}
};
#define LUNAR_DECLARE_METHOD(Class, Name) {#Name, &Class::Name}