Single Thread iterate over all entities without allocating

Currently the only way I know to do this is to Query.ToEntityArray() + Query.ToComponentDataArray() and iterate over these NativeArrays, is there any type of Job that lets me do the same without allocating those arrays?
I want to check which Entity is closest to a Ray, so I need to linearly iterate over them.

 

Chunk iteration in an IJob or Job.WithCode

 

I just noticed that

Query.GetArchetypeChunkIterator() 

do not allocate. That's exactly what I needed.
I was somehow expecting it to return a

NativeArray<ArchetypeChunk>

for some reason.

 

No actually, how do one use

ArchetypeChunkIterator

? I can't figure out what to do with it, in the end I am still allocating with

CreateArchetypeChunkArray

 

Easiest way would be a system.

.Run()

instead of

.Schedule()

will run it on the main thread.

Doesn't need to be linear; if you have a ton of entities you can do this in parallel. For example, split into 12 chunks of 100,000 entities, find the closest in each chunk (along with the distance), and then select the one with the smallest distance.

 

It will be about a 100, maybe 200 max, it's for checking if I should display a tooltip or not, all static tooltip sources use an octree, while this system is only for mobile sources like NPCs.

So there is little to no difference between Schedule().Complete() and Run()? Or maybe Run() is just better?

 

There is a difference between

Schedule().Complete()

and

Run()

. The former will hand over the work to a worker thread and wait for it to complete. The latter will immediately run the work on the main thread to completion.

 

Run also writes back the captured values as a bonus convenience.