UnityScripting

Unity scripting with Beef

Based on https://www.jacksondunstan.com/articles/3938.

Articles and Topics

• How to build Dynamic Library for Beef: https://m0n7y5.github.io/beef-dll-creation-and-research-2/
• Unity Native Plugins: https://docs.unity3d.com/Manual/NativePlugins.html
• Mono Interop with Native Libraries: https://www.mono-project.com/docs/advanced/pinvoke/
• Unity Scripting architecture: https://docs.unity3d.com/Manual/overview-of-dot-net-in-unity.html
• C# function pointer: https://learn.microsoft.com/en-us/dotnet/csharp/language-reference/proposals/csharp-9.0/function-pointers
• Other approachs: https://github.com/i-saint/UnityCppScript

Disclaimer

• This use dynamic dispatch (marshaling, pinvoke) to call Unity API, so avoid heavy working with Unity API in Beef
• If your framework, game have good performance, dont do more works
• Hybrid ECS, Burst/Job can support, have better C# compatibility, and have native support by Unity

Suggestions

• Use a framework in Unity to prototype your game first: Game Creator 2, TopDown Engine
• Port the framework to Beef for native performance (advanced tech skills required)
• Port the gameplay use the new framework
• Finish your game
• Upgrade your framework, create features to help make game faster, better
• Repeat

Solutions

• You need glue code, glue runtime to make C# and Beef work togethers
• Use object store and output handle to native side
• Use object pointer
• Marshalling function pointer from delegate and vice versa
• Directly use function pointer in C#
• Fast data marshalling use C struct layout (required, blittable type):
  • C# side: StructLayoutAttribute and pointer
  • Beef side: CRepr
• Fast iterations using dynamic serialization with JSON and Custom Editor:
  • Create a custom type store json and dictionary
    • JsonStr field store as string, can be serialized by Unity
    • Fields/Objects to do coding editor logic
  • Create a custom type store schema information of json structure
  • Create a custom editor to handle editting data, load and save in json
• Auto codegen C# class wrapper, use existed Unity serialization and property system
• Memory managements:
  • Object return to C#, should be use custom allocator, to avoid Leak Detector complains
• Bindings:
  • Another tricky problem
  • We must use dynamic loading in editor:
    • Once DLL loaded on by Editor, its cannot be unload
    • Dynamic loading help you do hot reload
  • We must provide C ABI to export Beef functions that can call from C#
  • We must convert C# functions to Function Pointer, and pass to Beef plugin init function