These specifically return local state without network latency and can be used to locally display information/action previews.
Some examples:
You don't have to use these in majority of cases.
Synchronization in NTT
NTT's networking uses deterministic lockstep model. This has a few implications:
- Adding more instances does not increase bandwidth.
This is sort of important given what Nuclear Throne is. - There's input latency dependent on ping between players.
- Mods don't have to explicitly sync anything to work online.
- However, mods should avoid certain non-deterministic logic.
This page covers some things to be aware of.
Instance IDs will not match between players, but you can still use these to tell that instance A has been created before instance B (because it has a lower ID).
GameMaker re-uses IDs for data structures, surfaces, and so on.
You should not rely on these being the same or appearing in any particular order relative to each other - only that if ID A is not the same as ID B, they're different things.
Same as above, but you are incredibly unlikely to see an address line up on two computers.
Sorting same-weight values is deterministic in GM so long as they appear in the same order, though still you should strive to have a secondary criteria if you re-sort an array/grid often to avoid any other potential oddities.