WingNews logo WingNews
top | item 46417039

(no title)

timmytokyo | 2 months ago

>We don't use IL2CPP because we use many features that are not compatible with it. For example DLC and mods loading at runtime via DLLs, reflection for custom serialization, things like [FieldOffset] for efficient struct packing and for GPU communication, etc.

FieldOffset is supported by IL2CPP at compile time [0]. You can also install new DLLs and force the player to restart if you want downloadable mod support.

It's true that you can't do reflection for serialization, but there are better, more performant alternatives for that use case, in my experience.

[0] https://docs.unity3d.com/Manual/scripting-restrictions.html

discuss

order

iliketrains|2 months ago

> You can also install new DLLs and force the player to restart if you want downloadable mod support.

I am not aware of an easy way to load (managed) mods as DLLs to IL2CPP-compiled game. I am thinking about `Assembly.LoadFrom("Mod.dll")`.

Can you elaborate how this is done?

> there are better, more performant alternatives for that use case, in my experience.

We actually use reflection to emit optimal code for generic serializers that avoid boxing and increase performance.

There may be alternatives, we explored things like FlatBuffers and their variants, but nothing came close to our system in terms of ease of use, versioning support, and performance.

If you have some suggestions, I'd be interested to see what options are out there for C#.

> FieldOffset is supported by IL2CPP at compile time

You are right, I miss-remembered this one, you cannot get it via reflection, but it works.

timmytokyo|2 months ago

>I am not aware of an easy way to load (managed) mods as DLLs to IL2CPP-compiled game. I am thinking about `Assembly.LoadFrom("Mod.dll")`.

Ah, I was thinking native DLLs (which is what we're using on a project I'm working on). I think you're right that it's impossible for an IL2CPP-built player to interoperate with a managed (Mono) DLL.

>If you have some suggestions [re: serialization], I'd be interested to see what options are out there for C#.

We wrote a custom, garbage-free JSON serializer/deserializer that uses a fluent API style. We also explored a custom codegen solution (similar to FlatBuffers or protobuf) but abandoned it because the expected perf (and ergonomic) benefits would have been minor. The trickiest part with Unity codegen is generating code that creates little to no garbage.