move particles to gfx.particles

src/logic/scripting/lua/lua_util.hpp

@@ -599,6 +599,23 @@ namespace lua {
         setglobal(L, name);
     }
 
+    inline void openlib(
+        lua::State* L,
+        const std::string& package,
+        const std::string& name,
+        const luaL_Reg* libfuncs
+    ) {
+        if (!hasglobal(L, package)) {
+            createtable(L, 0, 1);
+            setglobal(L, package);
+        }
+        getglobal(L, package);
+        createtable(L, 0, 0);
+        luaL_setfuncs(L, libfuncs, 0);
+        setfield(L, name);
+        pop(L);
+    }
+
     inline const char* require_string_field(
         lua::State* L, const std::string& name, int idx=-1
     ) {