Serialization

[AlexEne]

First, thanks for doing this, It's a super useful crate.

What are your thoughts on having serialization/deserialization as part of goggles (maybe behind a feature flag) ?
It may go against the original design of having something that's as simple as possible.

Right now, it's possible to provide serialization / deserialization through serde's trick of implementing it for external types, but that's a bit of a hack as it involves relying on the internal structure of certain data types and duplicating it in another crate for the purpose of implementing the serialization.
https://serde.rs/remote-derive.html

I know you mentioned on reddit that you also have a minimal-ECS that's implemented on top of goggles, maybe that's a better place to integrate with serde.

[kyren]

I would be okay with implementing Serialize / Deserialize for specific types, but in my opinion a full serialization of a world with entities is just out of scope. I've implemented a serialization system in a pretty complex project that uses goggles, and naively trying to serialize every resource and every entity and every component breaks down really quickly. specs' serialization system was too simplistic and it was one of several parts of specs that I ended up just ignoring.

Now that I think about it, I'm not even sure there are any types in goggles where implementing Serialize / Deserialize is even a good idea. Maybe I'm not thinking of something, what are you using remote-derive to serialize?

[AlexEne]

So for me it's the Entity type. Right now I just forked this and added #[derive(Serialzie, Deserialize)] to it. I don't think there are many places besides that.

I am in the process of porting from my custom, messy, ECS to goggles so other things might pop-up, but until now it's just the Entity,

[kyren]

I was thinking it might have been Entity. You definitely don't want to serialize Entity at least without also serializing the entity Allocator, and if you do that you usually end up serializing some unique ID per entity and then just re-creating Entity on load. AFAICT that's what the specs serialization system does as well (Marker and MarkerAllocator). If you only serialize / deserialize Entity, then you will end up allocating conflicting entities after a load. An Entity is an allocation of an index for some specific Allocator that exists in memory, that's why there's not a way to just create an Entity from an index and a generation.

I'm sure there are different entity allocation strategies that might be more amenable to direct serialization, and if so, you can still use the rest of goggles and make your own World and Entity types.

[AlexEne]

You're right :).