Function Script_Exists

engine/gameobject/src/gameobject/gameobject_script.cpp:2085–2131

check if the specified game object exists * This function can check for game objects in any collection by specifying * the collection name in the URL. * * @name go.exists * @param url [type:string|hash|url] url of the game object to check * @return exists [type:boolean] true if the game object exists * * @examples * Check if game object "my_game_object

     * ```
     */
    int Script_Exists(lua_State* L)
    {
        DM_LUA_STACK_CHECK(L, 1);
        if (lua_isnil(L, 1))
        {
            return luaL_error(L, "The url shouldn't be `nil`");
        }

        // get "this" instance
        ScriptInstance* i = ScriptInstance_Check(L);
        Instance* instance = i->m_Instance;

        // resolve target URL
        dmMessage::URL receiver;
        dmScript::ResolveURL(L, 1, &receiver, 0x0);

        dmMessage::URL sender;
        dmScript::GetURL(L, &sender);
        dmMessage::URL target;
        dmScript::ResolveURL(L, 1, &target, &sender);

        dmGameObject::HInstance target_instance = 0;
        
        // Check if target is in the same collection
        if (receiver.m_Socket == dmGameObject::GetMessageSocket(instance->m_Collection->m_HCollection))
        {
            // Same collection - use current collection
            target_instance = dmGameObject::GetInstanceFromIdentifier(dmGameObject::GetCollection(instance), target.m_Path);
        }
        else
        {
            // Different collection - find target collection by socket
            dmhash_t target_socket_hash = dmMessage::GetSocketNameHash(receiver.m_Socket);
            if (target_socket_hash != 0)
            {
                dmGameObject::HRegister regist = dmGameObject::GetRegister(instance->m_Collection->m_HCollection);
                dmGameObject::HCollection target_collection = dmGameObject::GetCollectionByHash(regist, target_socket_hash);
                if (target_collection != 0)
                {
                    target_instance = dmGameObject::GetInstanceFromIdentifier(target_collection, target.m_Path);
                }
            }
        }

        lua_pushboolean(L, target_instance != 0);
        return 1;
    }


    /*# convert position to game object's coordinate space