Separate Index/Array for SingleEntity Components

This issue is slightly related to https://github.com/sschmid/Entitas-CSharp/issues/112 An entity stores components in an array. As SingleEntity component is stored only in one entity, it is wasteful to have a space for them in Entity component array. Instead we could have separate array for SingleEntity components, which would contain the component and the reference to the entity which is associated with this component. This way we can keep the API:

e.AddResources(resources);

Internally however it would not store the resources in the entities component array.

This improvement would reduce entity memory size.

[mzaks]

We do throw GroupSingleEntityException when we ask for single entity and find two entities in the pool. It would be much better if we would already throw when we add the component so that we know where the bug is.

[sschmid]

Hi, no, it’s not implemented. I talked to Maxim a few times, but I never felt like implementing it. There always seem to be tasks with a higher prio, so I probably will never do it, and since it’s over a year old, I just closed it. I hesitate to introduce more complexity… things like e.GetComponents() and other areas have to be updated, but I don’t think it’s a problem right now.