Entities referencing

[mrazorvin]

Is there a way (or plans) to implement one to many weak references between entities, in ideally world I just want to tell that some entity belongs to another one, so I can query specific components from related entities

Pseudo code

world.ref(EntityID1, (EntityID2, EntityID3));
...
ComponentsView.filter_by_ref(EntityID1).for_each(|component|{
  // component from EntityID2 or EntityID3 if they exists
}) ;

Preamble:
I tried to implement attributes system in my game (int, str, dex, hp, mana etc...)

The problem: Every entity can have only one component of type, but I need to have multiple attribute of same type (since they come from different sources). So I can't use components.

This means that I need to implement attributes as separate entities. Since every unit in my game will have more than 5 attributes, I can't simple iterate over all attributes and find which one relate to main hero when I want to calculate something.

I red part about parent-child relation, but I don't want to add parent component for each attribute, and create parent child hierarchy for each component type

Is there a way or plans to implement one to many weak references between entities

[leudz]

No there is no plan for something like this at the moment.
Obligatory link to bevy's relations, an automated way to have entities reference other entities allowing all kinds of patterns.

I red part about parent-child relation, but I don't want to add parent component for each attribute, and create parent child hierarchy for each component type

Why not? You might be able to use or adapt @dakom's hierarchy crate.

At work we use an "indexing pattern".
You'd have an attribute hierarchy (or re-use an already existing hierarchy maybe?). When the hierarchy or BonusAttribute changes you update the Attribute component using all BonusAttribute affecting it.

struct BonusAttribute {
    int: u32,
    str: u32,
    dex: u32,
    hp: u32,
    mana: u32,
    ... 
}

struct Attribute {
    int: u32,
    str: u32,
    dex: u32,
    hp: u32,
    mana: u32,
    ... 
}

[mrazorvin]

indexing pattern sounds good, I will try to implement attributes with hierarchy and see if I like it.