ECS Design Problem - Cross Components System

Hi all,

Suppose I would like to have a system combining data with component groups "A, B" and "C, D" affecting component groups "E, F" and "G, H", does anyone has a suggested way to do it with Unity ECS?

 

Do you have a proper case example? It's very difficult to understand the problem if it's that generic, component groups as in Struct containing datatype ready for injection? A B C D E F G and H are datatype in the struct or the struct itself?

 

Does shared component would do the job for you?

 

Thanks for all your responses.

Here is my concrete example, I am not sure if Shared Component can help on this.

I have a game has Entity "Player, Pet, Speaker, Light", suppose there is a logic like this:

There is an ownerId in PetComponent and playerId in PlayerComponent, if ownerId and playerId match, check playSound (boolean) and playLight (boolean) in PlayerComponent to trigger the number of LightComponent and SpeakerComponent in the Scene.


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Can anyone suggest me a correct way to implement this kind of logic with Unity ECS?

 

Let me know if you guys find a better way to do this

Code (CSharp):

1.  
2. class SceneDynamicSystem : ComponentSystem
3. {
4.     struct Players
5.     {
6.         public readonly int Length;
7.         public ComponentArray<PlayerComponent> value;
8.     }
9.  
10.     struct Pets
11.     {
12.         public readonly int Length;
13.         public ComponentArray<PetComponent> value;
14.     }
15.  
16.     struct Lights
17.     {
18.         public readonly int Length;
19.         public ComponentArray<Light> value;
20.     }
21.  
22.     struct Speakers
23.     {
24.         public readonly int Length;
25.         public ComponentArray<SpeakerComponent> value;
26.     }
27.  
28.     [Inject] private Players _players;
29.     [Inject] private Pets _pets;
30.     [Inject] private Lights _lights;
31.     [Inject] private Speakers _speakers;
32.  
33.  
34.     protected override void OnUpdate()
35.     {
36.         int playSoundCounter = 0;
37.         int playLightCounter = 0;
38.         for (int i = 0; i < _players.Length; ++i)
39.         {
40.             for (int j = 0; j < _pets.Length; ++j)
41.             {
42.                 if (_players.value[i].playerId == _pets.value[i].ownerId)
43.                 {
44.                     if (_players.value[i].playSound) { ++playSoundCounter; }
45.                     if (_players.value[i].playLight) { ++playLightCounter; }
46.                 }
47.             }
48.         }
49.  
50.         //Turn on light
51.         for (int i = 0; i < _lights.Length; ++i)
52.         {
53.             _lights.value[i].gameObject.SetActive(true);
54.  
55.             if (i >= playLightCounter) { break; }
56.         }
57.  
58.         //Turn on speakers
59.         for (int i = 0; i < _speakers.Length; ++i)
60.         {
61.             _speakers.value[i].gameObject.SetActive(true);
62.  
63.             if (i >= playSoundCounter) { break; }
64.         }
65.  
66.  
67.         //Update once on init, stop the system
68.         //supposed you only want to update once, else remove
69.         //to keep updating, but you may want to restructure
70.         //player with petid matching to improve performance.
71.         Enabled = false;
72.     }
73. }
74.  
75.  

 

If you were using ComponentDatas you could use GetComponentDataFromEntity instead of looping so much

Code (CSharp):

1.  
2.             var players = EntityManager.GetComponentDataFromEntity<PlayerComponent>();
3.  
4.             int playSoundCounter = 0;
5.             int playLightCounter = 0;
6.             for (int j = 0; j < _pets.Length; ++j)
7.             {
8.                 var player = players[_pets.value[i].ownerId];
9.                 if (player.playSound) { ++playSoundCounter; }
10.                 if (player.playLight) { ++playLightCounter; }
11.             }

If not all pets have owners, do a

if (players.Exists(_pets.value[i].ownerId))

 

My current approach is to create a separated component group for storing the linked player pet group

Code (CSharp):

1. public class Logic01Component : MonoBehaviour
2. {
3.     public bool dirty;
4.     public List<LinkedPlayerPetGroup> LinkedPlayerPetGroupList = new List<LinkedPlayerPetGroup>();
5. }
6.  
7. public class LinkedPlayerPetGroup
8. {
9.     public PlayerComponent PlayerComponent;
10.     public PetComponent PetComponent;
11.  
12.     public LinkedPlayerPetGroup(PlayerComponent _PlayerComponent, PetComponent _PetComponent)
13.     {
14.         PlayerComponent = _PlayerComponent;
15.         PetComponent = _PetComponent;
16.     }
17. }

Code (CSharp):

1. public class GameLogic1System : ComponentSystem {
2.     private struct Logic01ComponentGroup
3.     {
4.         public Logic01Component Logic01Component;
5.     }
6.  
7.     private struct SpeakerComponentGroup
8.     {
9.         public SpeakerComponent SpeakerComponent;
10.     }
11.  
12.     private struct LightComponentGroup
13.     {
14.         public LightComponent LightComponent;
15.     }
16.  
17.     protected override void OnUpdate()
18.     {
19.         int lightCount = 0;
20.         int soundCount = 0;
21.         foreach (var entity in GetEntities<Logic01ComponentGroup>())
22.         {
23.             // Currently only have 1 Logic01ComponentGroup
24.             if (!entity.Logic01Component.dirty)
25.               return;
26.             foreach (var lc in entity.Logic01Component.LinkedPlayerPetGroupList)
27.             {
28.                 lightCount += lc.PlayerComponent.playLight ? 1 : 0;
29.                 soundCount += lc.PlayerComponent.playSound ? 1 : 0;
30.             }
31.         }
32.    
33.         int speakerIndex = 0;
34.         foreach (var entity in GetEntities<SpeakerComponentGroup>())
35.             entity.SpeakerComponent.isActive = speakerIndex++ < lightCount;
36.  
37.         int lightIndex = 0;
38.         foreach (var entity in GetEntities<LightComponentGroup>())
39.             entity.LightComponent.isActive = lightIndex++ < soundCount;
40.     }
41. }

But this approach still has problem such as:

1. The order of SpeakerComponent and LightComponent turned on is not following the scene hierarchy in Hybrid ECS
2. The selection of components required for a system being another system ( Or this is acceptable? )
3. There are so many sub-classes for each pair of linkage