Do I need to use ''ref'' when pass ArchetypeChunk to another function?

I saw 'ArchetypeChunk' is unsafe struct. But the example i saw from coffeebraingame is just like below. So I got a little confuse, since struct is pass by value not sure if pass it without 'ref' might slower or Burst compiler can figure it out.

I still new with the whole ECS things so if anyone have any better code example in current state of ECS. I will gladly take it

Edit: I just realize we have IJobChunk. So I guess i will switch to that

Spoiler

Code (CSharp):

1. public class MoveForwardSystem : JobComponentSystem
2. {
3.     private ComponentGroup m_group;
4.  
5.     // Replace normal Inject group
6.     protected override void OnCreateManager() {
7.         this.m_group = GetComponentGroup(typeof(Position), typeof(Rotation), typeof(MoveForwardSpeed));
8.     }
9.  
10.     protected override JobHandle OnUpdate(JobHandle inputDeps) {
11.         NativeArray<ArchetypeChunk> chunks = m_group.CreateArchetypeChunkArray(Allocator.TempJob);
12.         JobProcessMoveForward job = new JobProcessMoveForward() {
13.             deltaTime = Time.deltaTime,
14.             position  = GetArchetypeChunkComponentType<Position>(),
15.             rotation  = GetArchetypeChunkComponentType<Rotation>(),
16.             speed     = GetArchetypeChunkComponentType<MoveForwardSpeed>(),
17.             chunks    = chunks
18.         };
19.         //Chunks got dispose after inside job complete
20.         return job.Schedule(chunks.Length, 32, inputDeps);
21.     }
22.  
23.     [BurstCompile]
24.     private struct JobProcessMoveForward : IJobParallelFor
25.     {
26.         public            ArchetypeChunkComponentType<Position>         position;
27.         [ReadOnly] public ArchetypeChunkComponentType<Rotation>         rotation;
28.         [ReadOnly] public ArchetypeChunkComponentType<MoveForwardSpeed> speed;
29.         [ReadOnly] public float                                         deltaTime;
30.  
31.         // Dispose
32.         [ReadOnly] [DeallocateOnJobCompletion] public NativeArray<ArchetypeChunk> chunks;
33.  
34.         public void Execute(int index) { Process(chunks[index]); }
35.  
36.         private void Process(ArchetypeChunk chunk) { // Does this one need to use ref
37.             var positions = chunk.GetNativeArray(position);
38.             var rotations = chunk.GetNativeArray(rotation);
39.             var speeds    = chunk.GetNativeArray(speed);
40.  
41.             for (int i = 0; i < chunk.Count; i++) {
42.                 positions[i] = new Position() {
43.                     Value = positions[i].Value +
44.                             math.forward(rotations[i].Value) * speeds[i].moveSpeed * deltaTime
45.                 };
46.             }
47.         }
48.     }
49. }

 

No, but this is something I consider could be quite a confusing for new users.

Basically all these structs just hold pointers (which is why they're unsafe). If you pass a pointer by value it is still going to point to the same location in memory.

 

That make a lot of sense. Thanks for fast answer after new year eve.