DynamicBuffer in EntityQuery (non-Job)?

Unity Engine
1

Hi all,

I’m trying to run a specific type of ForEach loop that doesn’t seem to be implemented in the default ECS implementation (1 Entity, 2x ref IComponentData, and 2x DynamicBuffer) in a main thread ComponentSystem, therefore I’ve been trying to use EntityQuery for that.

I have been able to get my entities (EntityQuery.ToEntityArray) and my two sets of data components (EntityQuery.ToComponentDataArray) pretty fine, but I can’t find how to get the dynamic buffers (the only thing I found was GetBufferFromEntity, which seem to be limited to jobs).

Is there a way to do that? or do I need to use something else (job system, other type of query…) ?

Thanks

2

There is no overload for what you want to do in a ComponentSystem.
But why don’t you do that in a job IJobForEachWithEntity_EBBCC<> which is exactly the overload you want. Then instead of scheduling you can just run it in the main thread with .Run() ?

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3

I didn’t realize that was a possibility, I’ll try that, thanks!

ps: what’s the difference between D and C btw? I thought I was trying to do a EDDBB (or EBBDD)…

4

In Entities.ForEach D is ComponentData and C UnityEngine.Component. Unfortunately in IJobForEach_X, C is for ComponentData.

[ ]'s

1 Like
5

I’m running into another issue with this approach: despite running from the main thread (afaik) with Run(), I still get the following errors as if I was scheduling the job:

UnityException: get_frameCount can only be called from the main thread.
Constructors and field initializers will be executed from the loading thread when loading a scene.
Don't use this function in the constructor or field initializers, instead move initialization code to the Awake or Start function.

What do you think?

note: the Profiler shows the job being executed on the main thread as intended

6

You can’t use Unity APIs that are restricted to main thread in jobs even if you use Run. You’ll need to pass the data at scheduling time.

[ ]'s

1 Like
7

Are you calling Time.frameCount from within that job? If so you can’t do that.
But can you show the code for that job?

8

@GilCat pretty intricate structure with multiple layers of dependencies + NDA stuff so it would take some time to show :). I’m not calling frameCount directly, but some managed Unity code must be doing that (part of that “job” is to call some Unity UI code)

@elcionap note I’m not originally trying to run a job specifically, but using one was mentioned as the only way to simulate an EBBCC/EBBDD component system. Back to the drawing board? ^_^;

9

Then your solution is to do manual chunk iteration on the main thread. which is basically what Entities.ForEach does in ComponentSystem behind the scenes.

1 Like
10

You can do something like this or create your own extension with lambda expressions from this.

var entityType = GetArchetypeChunkEntityType();
    var chunkComponentType0 = GetArchetypeChunkComponentType<YourComponentType01>();
    var chunkComponentType1 = GetArchetypeChunkComponentType<YourComponentType02>();
    var chunkBufferComponentType1 = GetArchetypeChunkBufferType<YourBufferType01>();
    var chunkBufferComponentType2 = GetArchetypeChunkBufferType<YourBufferType02>();

    using (var chunks = m_query.CreateArchetypeChunkArray(Allocator.TempJob)) {
      for (var chunkIndex = 0; chunkIndex < chunks.Length; ++chunkIndex) {
        var chunk = chunks[chunkIndex];
        var array0 = chunk.GetNativeArray(chunkComponentType0);
        var array1 = chunk.GetNativeArray(chunkComponentType1);
        var array2 = chunk.GetBufferAccessor(chunkBufferComponentType1);
        var array3 = chunk.GetBufferAccessor(chunkBufferComponentType2);
        var entityArray = chunk.GetNativeArray(entityType);

        for (var i = 0; i < chunk.Count; ++i) {
          var c0 = array0[i];
          var c1 = array1[i];
          var b0 = array2[i];
          var b1 = array3[i];

          // Do your stuff here

        }
      }
    }
1 Like
11

Thanks for the heads up! All my iterations are in generic classes, I’ll have a look at cooking something with that :slight_smile:

12

Seems like you can also do:

    Entities
      .WithoutBurst()
      .WithName("MyJob")
      .ForEach((Entity entity, int entityInQueryIndex, DynamicBuffer<Buffer01> b1, DynamicBuffer<Buffer02> b2, ref Component1 c1, ref Component2 c2) =>
    {
      // Now you can call Unity API here
    }).Run();