Question about Room:GetEntities about isaacdocs HOT 3 CLOSED

i dont remember exactly what the bugs are.
but your code snippet showcases why we don't recommend that people ever use it: typing local entity = roomEntities:Get(i) is a waste of time, and confusing for other people reading the code

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Isaac.GetRoomEntities() will return a table that is a view of the entities in the room at the time the function was called, while Room::GetEntities() will return a userdata that stores a raw pointer to the array in memory that stores the entities in the room. Therefore, iterating over the return value of Room::GetEntities() will always iterate over the entities present in the room during the current logic frame, while iterating over the return value of Isaac.GetRoomEntities() will iterate over the entities that were present at the time the function was called.

I'm not sure if the array in memory is sized in such a way that it can store the max possible amount of each entity to avoid resizes, but that's the risk when working with Room::GetEntities(): since the userdata has a copy of the pointer to the array of entities in memory, if this pointer gets invalidated, which may happen without changing rooms (because resizes), the game may crash when iterating over the content of the userdata. With Isaac.GetRoomEntities(), the game may crash only if you manipulate the entities inside after changing rooms (maybe also if the entity has been removed since, but I don't know when the game actually frees the memory associated with an entity, maybe it is safe).

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Ive improved the descriptions of both functions based on @amaurymaille `s post. Thank you very much for that cool explaination!

if anything other needs to be changed, please reopen the issue :)

Related commit: a877eb7

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