Calling C dll from love2d

[pgimeno]

I remember someone having a similar problem, here: https://love2d.org/forums/viewtopic.php?f=4&t=88104

Maybe this helps them.

[HDPLocust]

On windows you should use __declspec(dllexport).
Minimal crossplatfom library looks like this.

Code: Select all

#include "lua/lua.h"
#include "lua/lauxlib.h"
 
int lua_summ(lua_State *L){
    double a = luaL_checknumber(L, 1); /* get first arg */
    double b = luaL_checknumber(L, 2); /* get second arg */
    lua_pushnumber(L, a + b);          /* returning value to lua */
    return 1;                          /* count of args returned to lua */
}
 
#if defined(_WIN32) || defined(_WIN64) /* windows compat */
__declspec(dllexport)
#endif
int luaopen_mylib(lua_State *L) {       /* compile it to mylib.dll or libmylib.so */
    lua_newtable(L);                    /* create table */
        lua_pushstring(L, "summ");      /* push "summ" as key*/
        lua_pushcfunction(L, lua_summ); /* push lua_summ as value*/
        lua_rawset(L, -3);              /* assign key and value to this table (it gone from stack, but not table) */
 
    return 1; /* return table to lua */
}

Here no usage of lua_reg, but nothing global is created.

So usage on lua side is:

Code: Select all

local lib = require'mylib'
print(lib.summ(10, 20)) --> 30

Also you should to compile it to target lua version and platform (using luajit lua51.lib and same as your love x86_32/x86_64 target)