Refactor MeshInstance

src/Runtime/Ghost.Engine/Components/MeshInstance.cs

@@ -1,47 +1,15 @@
 using Ghost.Core;
 using Ghost.Entities;
 using Ghost.Graphics.Core;
-using Misaki.HighPerformance.LowLevel.Collections;
 
 namespace Ghost.Engine.Components;
 
-public struct MeshPalette : ISharedComponent, IEquatable<MeshPalette>
-{
-    public UnsafeArray<Handle<Mesh>> meshes;
-    public UnsafeArray<Handle<Material>> materials;
-
-    public bool Equals(MeshPalette other)
-    {
-        throw new NotImplementedException();
-    }
-
-    public override int GetHashCode()
-    {
-        throw new NotImplementedException();
-    }
-
-    public override bool Equals(object? obj)
-    {
-        return obj is MeshPalette palette && Equals(palette);
-    }
-
-    public static bool operator ==(MeshPalette left, MeshPalette right)
-    {
-        return left.Equals(right);
-    }
-
-    public static bool operator !=(MeshPalette left, MeshPalette right)
-    {
-        return !(left == right);
-    }
-}
-
 public struct MeshInstance : IComponent
 {
-    public int meshIndex;
-    public int materialIndex;
+    public Handle<Mesh> mesh;
+    // NOTE: This will be the first material, we can access other materials by the bindless index of the first material + the local index stored in the meshlet.
+    public Handle<Material> materialStart;
     public ShadowCastingMode shadowCastingMode;
     public RenderingLayerMask renderingLayerMask;
-    public byte subMeshIndex;
     public bool staticShadowCaster;
 }

src/Runtime/Ghost.Engine/Systems/RenderExtractionSystem.cs

@@ -3,7 +3,6 @@ using Ghost.Engine.Components;
 using Ghost.Entities;
 using Ghost.Graphics.Core;
 using Misaki.HighPerformance.LowLevel.Buffer;
-using Misaki.HighPerformance.LowLevel.Utilities;
 
 namespace Ghost.Engine.Systems;
 
@@ -14,7 +13,6 @@ public class RenderExtractionSystem : ISystem
     public void Initialize(ref readonly SystemAPI systemAPI)
     {
         _queryID = new QueryBuilder()
-            // TODO: We also need to filter by MeshPalette.
             .WithAll<MeshInstance, LocalToWorld>()
             .Build(systemAPI.World);
     }
@@ -30,6 +28,7 @@ public class RenderExtractionSystem : ISystem
         var renderList = new RenderList(1, 64, Allocator.Temp);
 
         // TODO: We should extract the render record for each camera because different cameras may have different culling results.
+        // TODO: This chould be done in parallel jobs.
         foreach (var chunk in query.GetChunkIterator())
         {
             var meshInstances = chunk.GetComponentData<MeshInstance>();
@@ -47,7 +46,6 @@ public class RenderExtractionSystem : ISystem
                     // mesh = meshInstance.meshIndex,
                     // material = meshInstance.materialIndex,
                     renderingLayerMask = meshInstance.renderingLayerMask,
-                    subMeshIndex = meshInstance.subMeshIndex,
 
                 }, 0);
             }

src/Runtime/Ghost.Graphics.D3D12/D3D12ResourceDatabase.cs

@@ -341,6 +341,23 @@ internal class D3D12ResourceDatabase : IResourceDatabase
         _descriptorAllocator.Release(new Identifier<SamplerDescriptor>(id.Value));
     }
 
+    public Error Swap(Handle<GPUResource> handleA, Handle<GPUResource> handleB)
+    {
+        ref var recordA = ref _resources.GetElementReferenceAt(handleA.ID, handleA.Generation, out var existA);
+        ref var recordB = ref _resources.GetElementReferenceAt(handleB.ID, handleB.Generation, out var existB);
+
+        if (!existA || !existB)
+        {
+            return Error.NotFound;
+        }
+
+        var temp = recordA;
+        recordA = recordB;
+        recordB = temp;
+
+        return Error.None;
+    }
+
     public void BeginFrame(uint currentFrameFenceValue)
     {
         ObjectDisposedException.ThrowIf(_disposed, this);

src/Runtime/Ghost.Graphics.RHI/IResourceDatabase.cs

@@ -127,4 +127,12 @@ public interface IResourceDatabase : IDisposable
     /// </summary>
     /// <param name="id">The identifier of the sampler to release. Must reference a valid, existing sampler.</param>
     void ReleaseSampler(Identifier<Sampler> id);
+
+    /// <summary>
+    /// Swaps the resources associated with the two specified handles, effectively exchanging their identities and all associated data.
+    /// </summary>
+    /// <param name="handleA">The first handle whose associated resource is to be swapped.</param>
+    /// <param name="handleB">The second handle whose associated resource is to be swapped.</param>
+    /// <returns>An Error indicating the success or failure of the swap operation.</returns>
+    Error Swap(Handle<GPUResource> handleA, Handle<GPUResource> handleB);
 }

src/Runtime/Ghost.Graphics/Core/RenderList.cs

@@ -8,10 +8,9 @@ namespace Ghost.Graphics.Core;
 public record struct RenderRecord
 {
     public float4x4 localToWorld;
-    public Handle<Material> material;
     public Handle<Mesh> mesh;
+    public Handle<Material> materialOffset;
     public RenderingLayerMask renderingLayerMask;
-    public byte subMeshIndex;
 }
 
 public struct RenderList : IDisposable

src/Runtime/Ghost.Graphics/SwapChainManager.cs

@@ -20,7 +20,10 @@ internal sealed class SwapChainRecord
         while (true)
         {
             int current = Volatile.Read(ref _refCount);
-            if (current == 0) return false; // It's dead, let it go.
+            if (current == 0)
+            {
+                return false; // It's dead, let it go.
+            }
 
             if (Interlocked.CompareExchange(ref _refCount, current + 1, current) == current)
             {
@@ -66,7 +69,10 @@ internal class SwapChainManager
 
             if (record != null)
             {
-                if (record.TryAddRef()) return record.SwapChain;
+                if (record.TryAddRef())
+                {
+                    return record.SwapChain;
+                }
 
                 Thread.Yield();
                 continue;