Azerothcore-wotlk: [Improvement] Guid system [$150]

Created on 21 Nov 2020 · 5Comments · Source: azerothcore/azerothcore-wotlk

Hello,
More than a year ago I was working on implementing GOMove and I noticed that we have an issue on our .gob move command. See here : https://github.com/azerothcore/azerothcore-wotlk/issues/1588
Fact it, .gob move is working as intended, but the problem is : client isn't notified of the update (new coords, rotation...).
This problem is coming from our guid system.

This is what our dear friend @Rochet2 explained to me (here is a part of our conversation) :

Rochet2 _18/03/2019_

that same issue was on TC before they moved to the new guid system
.gob move just relocates the existing object and does not change the in game guid.
however the game is coded so that a gameobject cannot be moved.
So the only way around this is to use different guids every time a gameobject is moved.
TC's system uses different guid in game and in DB.
on TC the gameobject's DB guid will not change, but in game guid will
so DB keeps having 1000, but the in game guid is something like 123, 124, 125 and so on
However AC (and the old TC guid system) uses same guid in game and in DB.

Shard _18/03/2019_

Isn't creatures using the same guid system ? Because .npc move works

Rochet2 _18/03/2019_

yes, but creatures can be moved.
gameobjects cannot
the game client was probably coded to assume all objects are static.
maybe its some kind of optimization

I think implementing TC's guid system will solve the issue, and some related too issues like this one (maybe?) https://github.com/azerothcore/azerothcore-wotlk/issues/2518

TC source code: https://github.com/TrinityCore/TrinityCore/tree/3.3.5

CURRENT BEHAVIOUR:

Check : https://github.com/azerothcore/azerothcore-wotlk/issues/1588

EXPECTED BLIZZLIKE BEHAVIOUR:

Player should be notified about his environment changes

STEPS TO REPRODUCE THE PROBLEM:

Check https://github.com/azerothcore/azerothcore-wotlk/issues/1588

EXTRA INFO!

Here is Rochet's commit to adapt GOMove to the new TC guid system + some info he sent to me :)

here is the commit that removes the hack
https://github.com/Rochet2/TrinityCore/commit/1ad9187474649b1e28a33de1013e4f5fdf01c26d#diff-d8682ec190918750ac5c6535e5ab55f1
the way it worked was that when you move an object a new object is spawned with a guid that has a custom highguid value.
I guess the core could have tracked the custom guids, but the way I implemented it was that the server sends the fake guids to the client as hex. That way you can in client see what object is fake and what is real.
The fake objects were not saved. You had to click a save button to save them, which respawned them with a real guid.
the fake guid thing is in src/server/game/Entities/Object/ObjectGuid.h