bold atlas
I have a component with a NativeHashSet as one of the variables. When I add the component with the ECB I use hs = new NativeHashSet<int>(0, Allocator.Persistent).
Later in the code I want to add things to the hash set and I think I need to dispose it when I destroy the entity.
I cannot figure out how to do that with the AddBuffer, SetComponent and Dispose methods of the ECB.
Can anyone tell me how to do that?
short vigil
You can use a cleanup component, then have a separate system that disposes it. https://docs.unity3d.com/Packages/com.unity.entities@1.3/manual/components-cleanup.html
river anvil
^ remember this alone won't cleanup leaving play mode
Or if you leave play mode before ecb plays back
bold atlas
I wondered about those errors (and if I should care about them)
short vigil
^ remember this alone won't cleanup leaving play mode
O, did not know that actually. Haven't used cleanup for native containers yet.
I'm guessing it'd work to just to add an OnDestroy to the system and clean up any remaining containers there?
Alternatively just having a world bound allocator
river anvil
O, did not know that actually. Haven't used cleanup for native containers yet.
...
as long as the entity isn't in a subscene
bold atlas
It is.
river anvil
there's a reason all the experienced devs on discord constantly harp on about not putting native containers on entities (that aren't singletons though)
bold atlas
Yeah, it is difficult and I have a lot of leaks.
river anvil
causes so many unnecessary issues
bold atlas
My problem is so common, that I think I make some fundamental thing very complicated
river anvil
don't get me wrong, putting containers on entities can be very useful
i personally just took the approach of writing custom dynamic containers (based off dynamicbuffer) instead of using native containers
so memory is a automatically managed for you
bold atlas
I have damage zones and I want to damage every enemie that is inside the trigger collider. I want to cause damage every tick, different for each zone. I also want to damage every enemy only once per tick, per damage zone. So currently I have a NativeHashSet on every DamageZone that keeps track of HashCodes it has damaged during that tick. After tick time is zero, I clear the HashSet and start again.
That has to be a popular mechanic in Dots.
short vigil
I have damage zones and I want to damage every enemie that is inside the trigger...
How many items do you think you'll damage per tick? If it's low enough then just doing a linear search is fast enough. If it's not super super huge then just doing a binary search can be enough too
bold atlas
How would I know if I damaged them previously, if I do not keep track?
I cannot give them a tag, as they might be in several damage zones at once
and as I understand the component system, each entity can only have one of each type
short vigil
How many items do you think you'll damage per tick? If it's low enough then just...
To specify, I mean with a dynamic buffer
Just doing a linear or logarithmic lookup is often fast enough
bold atlas
I don't really know how to use them
short vigil
Dynamic buffers are basically just lists
bold atlas
I think so. Might be less than 5 most of the time. I think in the lategame 100 per zone?
river anvil
probably just better using a dynamic buffer then
bold atlas
I'll look that up. Auto cleanup sounds good for my leak problems
river anvil
probably faster than a hashmap at those counts
short vigil
^ That too
bold atlas
Thanks for the idea.
short vigil
HashMaps are not super efficient for low amount of entries
bold atlas
Is there a good tutorial for dynamic buffers that you can recommend?
river anvil
just the manual