csharp: implement ecs world resources

guests/csharp/dotnet-guest-test/ExampleWorldImpl.cs

@@ -1,39 +1,10 @@
 namespace ExampleWorld;
 
-using System.Diagnostics.CodeAnalysis;
-using System.Runtime.CompilerServices;
-using System.Runtime.InteropServices;
 using ExampleWorld.wit.imports.lyra.api;
-using LyraApi;
+
 using LyraApi.Ecs;
-
-[StructLayout(LayoutKind.Sequential)]
-struct Vec3(float x, float y, float z) : IComponent
-{
-    /// <summary>
-    /// The X component.
-    /// </summary>
-    public float X { get; set; } = x;
-    /// <summary>
-    /// The Y component
-    /// </summary>
-    public float Y { get; set; } = y;
-    /// <summary>
-    /// The Z component
-    /// </summary>
-    public float Z { get; set; } = z;
-
-    public static string HostName => "Vec3";
-    public static ulong HostSize => (ulong)Marshal.SizeOf<Vec3>();
-    public static ulong HostAlignment => (ulong)MarshalUtils.AlignmentOf<Vec3>();
-    public static ulong TypeId => 4124409524;
-
-    public static object? TakeFromBytes(byte[] bytes)
-    {
-        byte[] taken = bytes.Take((int)HostSize).ToArray();
-        return MarshalUtils.FromBytes<Vec3>(taken);
-    }
-}
+using LyraApi.Engine;
+using LyraApi.Math;
 
 public class ExampleWorldImpl : IExampleWorld
 {
@@ -47,6 +18,11 @@ public class ExampleWorldImpl : IExampleWorld
         {
             Console.WriteLine("C#:   Found entity at ({0}, {1}, {2})", comp.X, comp.Y, comp.Z);
         }
+
+        DeltaTime? dt = world.GetResource<DeltaTime>();
+        if (dt != null) {
+            Console.WriteLine($"C#:   Delta time: {dt?.Seconds:0.##}");
+        }
     }
 
     public static void OnUpdate(IEcs.EcsWorld gameWorld, IEcs.Entity owningEntity)

guests/csharp/dotnet-guest-test/LyraApi/Ecs/IResource.cs

@@ -0,0 +1,10 @@
+using static ExampleWorld.wit.imports.lyra.api.IEcs;
+
+namespace LyraApi.Ecs;
+
+public interface IResource
+{
+    public abstract static ulong TypeId { get; }
+
+    public abstract static object? FromWasmResult(WorldResourceResult result);
+}

guests/csharp/dotnet-guest-test/LyraApi/Ecs/World.cs

@@ -27,4 +27,10 @@ public class World(IEcs.EcsWorld world)
         IEcs.EcsDynamicView dynamicView = Inner.View(infos);
         return new ViewResult(comps, dynamicView).Get<T1>();
     }
+
+    public T? GetResource<T>() where T : IResource
+    {
+        IEcs.WorldResourceResult result = Inner.GetResource(Utils.ToWasmTypeId(T.TypeId));
+        return (T?) T.FromWasmResult(result);
+    }
 }

guests/csharp/dotnet-guest-test/LyraApi/Engine/DeltaTime.cs

@@ -0,0 +1,23 @@
+using System.Runtime.InteropServices;
+using LyraApi;
+using LyraApi.Ecs;
+using static ExampleWorld.wit.imports.lyra.api.IEcs;
+
+namespace LyraApi.Engine;
+
+[StructLayout(LayoutKind.Sequential)]
+public struct DeltaTime : IResource {
+    public float Seconds;
+
+    public static ulong TypeId => 83716348954;
+
+    public static object? FromWasmResult(WorldResourceResult result)
+    {
+        return result.Tag switch
+        {
+            WorldResourceResult.NONE | WorldResourceResult.WASM_RESOURCE_REP => null,
+            WorldResourceResult.BYTES => MarshalUtils.FromBytes<DeltaTime>(result.AsBytes),
+            _ => null,
+        };
+    }
+}

guests/csharp/dotnet-guest-test/LyraApi/Math/Vec3.cs

@@ -0,0 +1,32 @@
+using System.Runtime.InteropServices;
+using LyraApi.Ecs;
+
+namespace LyraApi.Math;
+
+[StructLayout(LayoutKind.Sequential)]
+struct Vec3(float x, float y, float z) : IComponent
+{
+    /// <summary>
+    /// The X component.
+    /// </summary>
+    public float X { get; set; } = x;
+    /// <summary>
+    /// The Y component
+    /// </summary>
+    public float Y { get; set; } = y;
+    /// <summary>
+    /// The Z component
+    /// </summary>
+    public float Z { get; set; } = z;
+
+    public static string HostName => "Vec3";
+    public static ulong HostSize => (ulong)Marshal.SizeOf<Vec3>();
+    public static ulong HostAlignment => (ulong)MarshalUtils.AlignmentOf<Vec3>();
+    public static ulong TypeId => 4124409524;
+
+    public static object? TakeFromBytes(byte[] bytes)
+    {
+        byte[] taken = bytes.Take((int)HostSize).ToArray();
+        return MarshalUtils.FromBytes<Vec3>(taken);
+    }
+}

guests/csharp/dotnet-guest-test/LyraApi/Utils.cs

@@ -0,0 +1,8 @@
+using static ExampleWorld.wit.imports.lyra.api.IEcs;
+
+internal static class Utils {
+    public static WasmTypeId ToWasmTypeId(ulong typeId)
+    {
+        return new WasmTypeId((typeId, 0));
+    }
+}

guests/csharp/dotnet-guest-test/dotnet-guest-test.csproj

@@ -18,12 +18,12 @@
   </PropertyGroup>
 
   <!-- Copy WIT files from LyraApi to lyra-api wit folder. -->
-  <!-- <Target Name="CopyFolderOnBuild" BeforeTargets="WitCompile_InvokeTool">
+  <Target Name="CopyFolderOnBuild" BeforeTargets="WitCompile_InvokeTool">
     <ItemGroup>
-      <MyFiles Include="..\LyraApi\wit\**\*.wit" />
+      <MyFiles Include="..\..\rust\common-api\wit\**\*.wit" />
     </ItemGroup>
     <Copy SourceFiles="@(MyFiles)" DestinationFolder="wit\deps\lyraapi\%(RecursiveDir)" />
-  </Target> -->
+  </Target>
 
   <!-- Remove bindgen of LyraApi WIT .-->
   <!-- <Target Name="RemoveBindgenLyraApi" AfterTargets="WitCompile_InvokeTool">

guests/csharp/dotnet-guest-test/wit/deps/lyraapi/ecs.wit

@@ -37,6 +37,12 @@ interface ecs {
         next: func() -> option<tuple<entity, list<u8>>>;
     }
 
+    variant world-resource-result {
+        none,
+        wasm-resource-rep(u32),
+        bytes(list<u8>),
+    }
+
     resource ecs-world {
         constructor();
 
@@ -76,6 +82,8 @@ interface ecs {
         /// Returns: A row of components serialized as bytes. The buffer is tighly packed.
         view-one: func(en: entity, component-infos: list<component-info>) -> option<list<u8>>;
 
+        get-resource: func(type-id: wasm-type-id) -> world-resource-result;
+
         //with_system: func(stage: string, component-infos: list<component-info>, system: func(components: list<u8>));
     }
 }

src/main.rs

@@ -462,8 +462,8 @@ async fn main() -> wasmtime::Result<()> {
     );
 
     // Load the component from disk
-    let bytes = std::fs::read("target/wasm32-wasip1/debug/witguest-component.wasm")?;
-    //let bytes = std::fs::read("guests/csharp/dotnet-guest-test/bin/Debug/net9.0/wasi-wasm/native/dotnet-guest-test.wasm")?;
+    //let bytes = std::fs::read("target/wasm32-wasip1/debug/witguest-component.wasm")?;
+    let bytes = std::fs::read("guests/csharp/dotnet-guest-test/bin/Debug/net9.0/wasi-wasm/native/dotnet-guest-test.wasm")?;
     let component = wasmtime::component::Component::new(&engine, bytes)?;
 
     let (script_en, (world_res_a, world_res_b)) = {