feat(core,rendering)!: add cleanup component support, refactor render pipeline

Introduce ICleanupComponent and cleanup archetype logic in ECS. Refactor component versioning to uint. Update IResourceDatabase to use map/unmap pattern. Decouple per-frame render requests from RenderSystem via IRenderPayload. Update render pipeline and extraction system to new API.

BREAKING CHANGE: Entity destruction and render pipeline APIs have changed. IResourceDatabase.MapResource signature is updated; all callers must use map/memcpy/unmap. RenderSystem no longer manages per-frame render requests directly.

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

@@ -0,0 +1,8 @@
+using Ghost.Entities;
+
+namespace Ghost.Engine.Components;
+
+public struct GPUInstanceRef : IComponent
+{
+    public uint gpuSceneIndex;
+}

src/Runtime/Ghost.Entities/Archetype.cs

@@ -109,10 +109,9 @@ internal unsafe struct Chunk : IDisposable
     public const int BIT_ALIGNMENT_MINUS_ONE = BIT_ALIGNMENT - 1;
 
     private UnsafeArray<byte> _data;
-    private UnsafeArray<int> _versions;
+    private UnsafeArray<uint> _versions;
 
-    // TODO: Add structual change versioning, similar to DidOrderChange in unity ecs.
+    internal uint _structuralVersion;
-    internal int _structuralVersion;
 
     internal int _count;
     internal readonly int _capacity;
@@ -123,10 +122,10 @@ internal unsafe struct Chunk : IDisposable
     internal int _archetypeID;
 #endif
 
-    public Chunk(int bufferSize, int capacity, int componentCount, int globalVersion)
+    public Chunk(int bufferSize, int capacity, int componentCount, uint globalVersion)
     {
         _data = new UnsafeArray<byte>(bufferSize, Allocator.Persistent, AllocationOption.Clear);
-        _versions = new UnsafeArray<int>(componentCount, Allocator.Persistent);
+        _versions = new UnsafeArray<uint>(componentCount, Allocator.Persistent);
         _capacity = capacity;
         _count = 0;
 
@@ -141,9 +140,9 @@ internal unsafe struct Chunk : IDisposable
     }
 
     [MethodImpl(MethodImplOptions.AggressiveInlining)]
-    public readonly int* GetVersionUnsafePtr()
+    public readonly uint* GetVersionUnsafePtr()
     {
-        return (int*)_versions.GetUnsafePtr();
+        return (uint*)_versions.GetUnsafePtr();
     }
 
     public void Dispose()
@@ -175,7 +174,6 @@ internal unsafe struct Archetype : IDisposable
     internal UnsafeArray<ComponentMemoryLayout> _layouts;
     internal UnsafeArray<int> _componentIDToLayoutIndex;
 
-    // TODO: Is hash map better?
     private UnsafeList<Edge> _edgesAdd;
     private UnsafeList<Edge> _edgesRemove;
 
@@ -187,6 +185,9 @@ internal unsafe struct Archetype : IDisposable
     private int _maxComponentID;
     private int _entityIdsOffset;
 
+    // -1 means no cleanup component, 0 means haven't computed yet (since 0 is the empty archetype), positive value means the archetype id of the cleanup edge.
+    internal int _cleanupEdge;
+
     public readonly Identifier<Archetype> ID => _id;
     public readonly Identifier<World> WorldID => _worldID;
 
@@ -235,10 +236,21 @@ internal unsafe struct Archetype : IDisposable
         var entityAlign = (int)MemoryUtility.AlignOf<Entity>();
 
         var components = (Span<ComponentInfo>)stackalloc ComponentInfo[componentIds.Length];
+
+        var cleanupCount = 0;
         for (var i = 0; i < componentIds.Length; i++)
         {
             _signature.SetBit(componentIds[i]);
             components[i] = ComponentRegistry.GetComponentInfo(componentIds[i]);
+            if (components[i].isCleanup)
+            {
+                cleanupCount++;
+            }
+        }
+
+        if (cleanupCount == 0)
+        {
+            _cleanupEdge = -1;
         }
 
         // Calculate total size per entity to get an initial capacity estimate
@@ -456,7 +468,7 @@ internal unsafe struct Archetype : IDisposable
     }
 
     [MethodImpl(MethodImplOptions.AggressiveInlining)]
-    public readonly Error MarkChanged(int chunkIndex, int componentTypeId, int globalVersion)
+    public readonly Error MarkChanged(int chunkIndex, int componentTypeId, uint globalVersion)
     {
         var layoutResult = GetLayout(componentTypeId);
         if (layoutResult.IsFailure)
@@ -471,7 +483,7 @@ internal unsafe struct Archetype : IDisposable
     }
 
     [MethodImpl(MethodImplOptions.AggressiveInlining)]
-    public readonly Result<int, Error> GetVersion(int chunkIndex, int componentTypeId)
+    public readonly Result<uint, Error> GetVersion(int chunkIndex, int componentTypeId)
     {
         var layoutResult = GetLayout(componentTypeId);
         if (layoutResult.Error != Error.None)

src/Runtime/Ghost.Entities/Component.cs

@@ -8,6 +8,7 @@ namespace Ghost.Entities;
 
 public interface IComponent;
 public interface IEnableableComponent : IComponent;
+public interface ICleanupComponent : IComponent;
 
 [AttributeUsage(AttributeTargets.Struct)]
 public class RequireComponentAttribute<T> : Attribute
@@ -24,6 +25,7 @@ internal struct ComponentInfo
     public int alignment;
     public bool isEnableable;
     public bool isSharedWarper;
+    public bool isCleanup;
 }
 
 /// <summary>
@@ -69,6 +71,7 @@ internal static class ComponentRegistry
                 alignment = (int)MemoryUtility.AlignOf<T>(),
                 isEnableable = typeof(IEnableableComponent).IsAssignableFrom(type),
                 isSharedWarper = typeof(ISharedWarper).IsAssignableFrom(type),
+                isCleanup = typeof(ICleanupComponent).IsAssignableFrom(type),
             };
 
             s_registeredComponents.Add(info);

src/Runtime/Ghost.Entities/EntityManager.cs

@@ -85,6 +85,29 @@ public unsafe partial class EntityManager : IDisposable
         return Error.NotFound;
     }
 
+    private static void CopyData(ref Archetype oldArch, int oldChunk, int oldRow,
+                                 ref Archetype newArch, int newChunk, int newRow)
+    {
+        // Iterate every component space in the OLD archetype
+        for (var i = 0; i < oldArch._layouts.Count; i++)
+        {
+            var layout = oldArch._layouts[i];
+
+            var src = oldArch._chunks[oldChunk].GetUnsafePtr() + layout.offset + (layout.size * oldRow);
+            var r = newArch.GetLayout(layout.componentID);
+            if (r.Error != Error.None)
+            {
+                // New archetype does not have this component, skip it.
+                // This can happen when removing components.
+                continue;
+            }
+
+            var dst = newArch._chunks[newChunk].GetUnsafePtr() + r.Value.offset + (layout.size * newRow);
+
+            MemoryUtility.MemCpy(dst, src, (nuint)layout.size);
+        }
+    }
+
     /// <summary>
     /// Create an entity with no components.
     /// </summary>
@@ -227,29 +250,20 @@ public unsafe partial class EntityManager : IDisposable
         }
     }
 
-    private void DestoryManagedEntityIfExists(ref readonly Archetype archetype, EntityLocation location)
+    // private void DestoryManagedEntityIfExists(ref readonly Archetype archetype, EntityLocation location)
-    {
+    // {
-        var pManagedRef = archetype.GetComponentData(location.chunkIndex, location.rowIndex, ComponentTypeID<ManagedEntityRef>.Value);
+    //     var pManagedRef = archetype.GetComponentData(location.chunkIndex, location.rowIndex, ComponentTypeID<ManagedEntityRef>.Value);
-        if (pManagedRef != null)
+    //     if (pManagedRef != null)
-        {
+    //     {
-            DestroyManagedEntity(((ManagedEntityRef*)pManagedRef)->entity);
+    //         DestroyManagedEntity(((ManagedEntityRef*)pManagedRef)->entity);
-        }
+    //     }
-    }
+    // }
 
-    /// <summary>
+    private Error DestroyEntity_Internal(Entity entity, EntityLocation location)
-    /// Destroy the specified entity.
-    /// </summary>
-    /// <returns>The result status of the operation.</returns>
-    public Error DestroyEntity(Entity entity)
     {
-        if (!_entityLocations.TryGetElementAt(entity.ID, entity.Generation, out var location))
-        {
-            return Error.NotFound;
-        }
-
         ref var archetype = ref _world.ComponentManager.GetArchetypeReference(location.archetypeID);
 
-        DestoryManagedEntityIfExists(in archetype, location);
+        // DestoryManagedEntityIfExists(in archetype, location);
         var r = archetype.RemoveEntity(location.chunkIndex, location.rowIndex);
         if (r != Error.None)
         {
@@ -264,27 +278,100 @@ public unsafe partial class EntityManager : IDisposable
         return Error.None;
     }
 
+    /// <summary>
+    /// Destroy the specified entity.
+    /// </summary>
+    /// <returns>The result status of the operation.</returns>
+    public Error DestroyEntity(Entity entity)
+    {
+        if (!_entityLocations.TryGetElementAt(entity.ID, entity.Generation, out var location))
+        {
+            return Error.NotFound;
+        }
+
+        ref var archetype = ref _world.ComponentManager.GetArchetypeReference(location.archetypeID);
+
+        if (archetype._cleanupEdge < 0)
+        {
+            return DestroyEntity_Internal(entity, location);
+        }
+        else
+        {
+            Identifier<Archetype> newArcID = default;
+            if (archetype._cleanupEdge == 0)
+            {
+                ref var signature = ref archetype._signature;
+
+                using var scope = AllocationManager.CreateStackScope();
+                using var newSignature = new UnsafeBitSet(signature.Count, scope.AllocationHandle);
+
+                var compCount = 0;
+                var it = signature.GetIterator();
+                while (it.Next(out var componentID))
+                {
+                    if (ComponentRegistry.GetComponentInfo(componentID).isCleanup)
+                    {
+                        newSignature.SetBit(componentID);
+                        compCount++;
+                    }
+                }
+
+                var newSignatureHash = newSignature.GetHashCode();
+                newArcID = _world.ComponentManager.GetArchetypeIDBySignatureHash(newSignatureHash);
+                if (newArcID.IsInvalid)
+                {
+                    // Create new archetype
+                    Span<Identifier<IComponent>> componentTypeIDs = stackalloc Identifier<IComponent>[compCount];
+
+                    var newIt = newSignature.GetIterator();
+                    var i = 0;
+                    while (newIt.Next(out var index))
+                    {
+                        componentTypeIDs[i++] = index;
+                    }
+
+                    newArcID = _world.ComponentManager.CreateArchetype(componentTypeIDs, newSignatureHash);
+                }
+
+                archetype._cleanupEdge = newArcID;
+            }
+            else
+            {
+                newArcID = archetype._cleanupEdge;
+            }
+
+            ref var newArchetype = ref _world.ComponentManager.GetArchetypeReference(newArcID);
+            newArchetype.AllocateEntity(out var newChunkIndex, out var newRowIndex);
+            CopyData(ref archetype, location.chunkIndex, location.rowIndex,
+                    ref newArchetype, newChunkIndex, newRowIndex);
+
+            newArchetype.SetEntity(newChunkIndex, newRowIndex, entity);
+        }
+
+        return Error.None;
+    }
+
     /// <summary>
     /// Destroy the specified entities.
     /// </summary>
     /// <param name="entities">The entities to destroy.</param>
     public void DestroyEntities(ReadOnlySpan<Entity> entities)
     {
-        void RemoveManagedEntity(ReadOnlySpan<int> rowIndicesCache, ref readonly Archetype archetype, int chunkIndex)
+        // void RemoveManagedEntity(ReadOnlySpan<int> rowIndicesCache, ref readonly Archetype archetype, int chunkIndex)
-        {
+        // {
-            for (var j = 0; j < rowIndicesCache.Length; j++)
+        //     for (var j = 0; j < rowIndicesCache.Length; j++)
-            {
+        //     {
-                var rowIndex = rowIndicesCache[j];
+        //         var rowIndex = rowIndicesCache[j];
-                var location = new EntityLocation
+        //         var location = new EntityLocation
-                {
+        //         {
-                    archetypeID = archetype.ID,
+        //             archetypeID = archetype.ID,
-                    chunkIndex = chunkIndex,
+        //             chunkIndex = chunkIndex,
-                    rowIndex = rowIndex
+        //             rowIndex = rowIndex
-                };
+        //         };
-
+        //
-                DestoryManagedEntityIfExists(in archetype, location);
+        //         DestoryManagedEntityIfExists(in archetype, location);
-            }
+        //     }
-        }
+        // }
 
         if (entities.Length == 0)
         {
@@ -292,8 +379,8 @@ public unsafe partial class EntityManager : IDisposable
         }
 
         using var scope = AllocationManager.CreateStackScope();
-        var batchDestroy = new UnsafeList<EntityLocation>(entities.Length, scope.AllocationHandle);
+        using var batchDestroy = new UnsafeList<EntityLocation>(entities.Length, scope.AllocationHandle);
-        var rowIndicesCache = new UnsafeList<int>(32, scope.AllocationHandle);
+        using var rowIndicesCache = new UnsafeList<int>(32, scope.AllocationHandle);
 
         // 1. GATHER
         // Resolve all entities to their locations
@@ -335,7 +422,9 @@ public unsafe partial class EntityManager : IDisposable
                 ref var prevArchetype = ref _world.ComponentManager.GetArchetypeReference(prevArchetypeID);
 
                 // Remove Managed Entities first
-                RemoveManagedEntity(rowIndicesCache.AsSpan(), in prevArchetype, prevChunkIndex);
+                // RemoveManagedEntity(rowIndicesCache.AsSpan(), in prevArchetype, prevChunkIndex);
+
+                // TODO: Handle ICleanupComponent here before we remove the entities from the archetype.
 
                 // Execute the hole-filling/swap logic
                 prevArchetype.RemoveEntities(prevChunkIndex, rowIndicesCache.AsSpan());
@@ -355,7 +444,7 @@ public unsafe partial class EntityManager : IDisposable
         {
             ref var lastArchetype = ref _world.ComponentManager.GetArchetypeReference(prevArchetypeID);
 
-            RemoveManagedEntity(rowIndicesCache.AsSpan(), in lastArchetype, prevChunkIndex);
+            // RemoveManagedEntity(rowIndicesCache.AsSpan(), in lastArchetype, prevChunkIndex);
             lastArchetype.RemoveEntities(prevChunkIndex, rowIndicesCache.AsSpan());
         }
 
@@ -470,29 +559,6 @@ public unsafe partial class EntityManager : IDisposable
         return ref *(T*)ptr; // This will return null ref if ptr is null.
     }
 
-    private static void CopyData(ref Archetype oldArch, int oldChunk, int oldRow,
-                                 ref Archetype newArch, int newChunk, int newRow)
-    {
-        // Iterate every component space in the OLD archetype
-        for (var i = 0; i < oldArch._layouts.Count; i++)
-        {
-            var layout = oldArch._layouts[i];
-
-            var src = oldArch._chunks[oldChunk].GetUnsafePtr() + layout.offset + (layout.size * oldRow);
-            var r = newArch.GetLayout(layout.componentID);
-            if (r.Error != Error.None)
-            {
-                // New archetype does not have this component, skip it.
-                // This can happen when removing components.
-                continue;
-            }
-
-            var dst = newArch._chunks[newChunk].GetUnsafePtr() + r.Value.offset + (layout.size * newRow);
-
-            MemoryUtility.MemCpy(dst, src, (nuint)layout.size);
-        }
-    }
-
     /// <summary>
     /// Add a component to the specified entity.
     /// </summary>
@@ -640,6 +706,12 @@ public unsafe partial class EntityManager : IDisposable
                 }
             }
 
+            if (compCount == 0)
+            {
+                // If there is no component left, we destroy the entity directly.
+                return DestroyEntity_Internal(entity, location);
+            }
+
             // Find or create new archetype
             var newSignatureHash = newSignature.GetHashCode();
             newArcID = _world.ComponentManager.GetArchetypeIDBySignatureHash(newSignatureHash);
@@ -676,11 +748,11 @@ public unsafe partial class EntityManager : IDisposable
             return r;
         }
 
-        var pManagedRef = oldArchetype.GetComponentData(location.chunkIndex, location.rowIndex, ComponentTypeID<ManagedEntityRef>.Value);
+        // var pManagedRef = oldArchetype.GetComponentData(location.chunkIndex, location.rowIndex, ComponentTypeID<ManagedEntityRef>.Value);
-        if (pManagedRef != null)
+        // if (pManagedRef != null)
-        {
+        // {
-            DestroyManagedEntity(((ManagedEntityRef*)pManagedRef)->entity);
+        //     DestroyManagedEntity(((ManagedEntityRef*)pManagedRef)->entity);
-        }
+        // }
 
         // Update location
         location.archetypeID = newArcID;
@@ -833,6 +905,8 @@ public unsafe partial class EntityManager : IDisposable
             maskBase[byteIndex] &= (byte)~(1 << bitIndex);
         }
 
+        chunk.GetVersionUnsafePtr()[layoutResult.Value.versionIndex] = _world.Version;
+
         return Error.None;
     }
 

src/Runtime/Ghost.Entities/Query.cs

@@ -90,11 +90,11 @@ public readonly unsafe ref struct ChunkView
     private readonly ReadOnlyUnsafeCollection<Archetype.ComponentMemoryLayout> _layouts;
     private readonly ReadOnlyUnsafeCollection<int> _layoutIndexLookup;
     private readonly byte* _pChunkData;
-    private readonly int* _pVersion;
+    private readonly uint* _pVersion;
     private readonly int _entityOffset;
     private readonly int _entityCount;
-    private readonly int _structuralVersion;
+    private readonly uint _structuralVersion;
-    private readonly int _currentVersion;
+    private readonly uint _currentVersion;
 
     public readonly int EntityCount => _entityCount;
 
@@ -168,7 +168,7 @@ public readonly unsafe ref struct ChunkView
     /// <param name="id">The identifier of the component for which to retrieve the version number. Must reference a valid component.</param>
     /// <returns>The version number of the specified component.</returns>
     [MethodImpl(MethodImplOptions.AggressiveInlining)]
-    public readonly int GetComponentVersion(Identifier<IComponent> id)
+    public readonly uint GetComponentVersion(Identifier<IComponent> id)
     {
         return _pVersion[id];
     }
@@ -179,7 +179,7 @@ public readonly unsafe ref struct ChunkView
     /// <typeparam name="T">The component space for which to retrieve the version. Must be an unmanaged space that implements <see cref="IComponent"/>.</typeparam>
     /// <returns>The version number of the component space <typeparamref name="T"/>.</returns>
     [MethodImpl(MethodImplOptions.AggressiveInlining)]
-    public readonly int GetComponentVersion<T>()
+    public readonly uint GetComponentVersion<T>()
         where T : unmanaged, IComponent
     {
         return _pVersion[ComponentTypeID<T>.Value];

src/Runtime/Ghost.Entities/World.cs

@@ -88,7 +88,7 @@ public partial class World : IDisposable, IEquatable<World>
 
     private readonly Dictionary<Type, object> _services;
 
-    private int _version;
+    private uint _version;
     private bool _disposed = false;
 
     /// <summary>
@@ -119,7 +119,7 @@ public partial class World : IDisposable, IEquatable<World>
     /// <summary>
     /// Gets the current version number of the world.
     /// </summary>
-    public int Version => Interlocked.CompareExchange(ref _version, 0, 0);
+    public uint Version => Interlocked.CompareExchange(ref _version, 0, 0);
 
     /// <summary>
     /// Gets the main entity command buffer for this world.
@@ -172,7 +172,7 @@ public partial class World : IDisposable, IEquatable<World>
     }
 
     [MethodImpl(MethodImplOptions.AggressiveInlining)]
-    internal int AdvanceVersion()
+    internal uint AdvanceVersion()
     {
         return Interlocked.Increment(ref _version);
     }

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

@@ -401,7 +401,24 @@ internal unsafe class D3D12ResourceDatabase : IResourceDatabase
         return Error.None;
     }
 
-    public Error MapResource(Handle<GPUResource> handle, uint subResource, ResourceRange? readRange, ResourceRange? writeRange, void* pData, nuint size)
+    public void* MapResource(Handle<GPUResource> handle, uint subResource, ResourceRange? readRange)
+    {
+        var r = GetResourceRecord(handle);
+        if (r.IsFailure)
+        {
+            return null;
+        }
+
+        var resource = r.Value.ResourcePtr;
+        var rRange = readRange.HasValue ? new D3D12_RANGE { Begin = readRange.Value.Start, End = readRange.Value.End } : default;
+
+        void* mappedData = null;
+        resource.Get()->Map(subResource, readRange.HasValue ? &rRange : null, &mappedData);
+
+        return mappedData;
+    }
+
+    public Error UnmapResource(Handle<GPUResource> handle, uint subResource, ResourceRange? writtenRange)
     {
         var r = GetResourceRecord(handle);
         if (r.IsFailure)
@@ -410,14 +427,9 @@ internal unsafe class D3D12ResourceDatabase : IResourceDatabase
         }
 
         var resource = r.Value.ResourcePtr;
+        var wRange = writtenRange.HasValue ? new D3D12_RANGE { Begin = writtenRange.Value.Start, End = writtenRange.Value.End } : default;
 
-        var rRange = readRange.HasValue ? new D3D12_RANGE { Begin = readRange.Value.Start, End = readRange.Value.End } : default;
+        resource.Get()->Unmap(subResource, writtenRange.HasValue ? &wRange : null);
-        var wRange = writeRange.HasValue ? new D3D12_RANGE { Begin = writeRange.Value.Start, End = writeRange.Value.End } : default;
-
-        void* mappedData = null;
-        resource.Get()->Map(subResource, readRange.HasValue ? &rRange : null, &mappedData);
-        MemoryUtility.MemCpy(mappedData, pData, size);
-        resource.Get()->Unmap(subResource, writeRange.HasValue ? &wRange : null);
 
         return Error.None;
     }

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

@@ -33,8 +33,14 @@ public enum BindlessAccess
 
 public unsafe interface IResourceDatabase : IDisposable
 {
+    /// <summary>
+    /// Enters a parallel read section, allowing multiple threads to read from the resource database concurrently and block any write operations until all readers have exited.
+    /// </summary>
     void EnterParallelRead();
 
+    /// <summary>
+    /// Exits a parallel read section, allowing write operations to proceed once all readers have exited.
+    /// </summary>
     void ExitParallelRead();
 
     /// <summary>
@@ -126,7 +132,30 @@ public unsafe interface IResourceDatabase : IDisposable
     /// <returns>An Error indicating the success or failure of the swap operation.</returns>
     Error Swap(Handle<GPUResource> handleA, Handle<GPUResource> handleB);
 
-    Error MapResource(Handle<GPUResource> handle, uint subResource, ResourceRange? readRange, ResourceRange? writeRange, void* pData, nuint size);
+    /// <summary>
+    /// Maps a subresource of a GPU resource for CPU access, specifying read and write ranges.
+    /// </summary>
+    /// <param name="handle">A handle to the GPU resource to be mapped.</param>
+    /// <param name="subResource">The zero-based index of the subresource to map.</param>
+    /// <param name="readRange">The range of the resource to be read by the CPU. Specify null to indicate read access to the entire resource.</param>
+    /// <returns>A pointer to the mapped subresource data, or null if the mapping operation fails.</returns>
+    void* MapResource(Handle<GPUResource> handle, uint subResource, ResourceRange? readRange);
 
+    /// <summary>
+    /// Unmaps a previously mapped subresource of a GPU resource, optionally specifying the range of data that was written by the CPU.
+    /// </summary>
+    /// <param name="handle">A handle to the GPU resource to unmap. Must reference a resource that was previously mapped.</param>
+    /// <param name="subResource">The zero-based index of the subresource to unmap.</param>
+    /// <param name="writtenRange">The range within the resource that was written to by the CPU. Specify null if no data was written or if the entire resource was modified.</param>
+    /// <returns>An Error value indicating the result of the operation. Returns Error.None if the resource was successfully unmapped.</returns>
+    Error UnmapResource(Handle<GPUResource> handle, uint subResource, ResourceRange? writtenRange);
+
+    /// <summary>
+    /// Gets the total size in bytes of the specified GPU resource, including all its subresources. This method is useful for determining the memory footprint of a resource and can be used for memory management and optimization purposes.
+    /// </summary>
+    /// <param name="resource">The handle to the GPU resource.</param>
+    /// <param name="firstSubResource">The index of the first subresource to include in the size calculation.</param>
+    /// <param name="numSubResources">The number of subresources to include in the size calculation.</param>
+    /// <returns>The total size in bytes of the specified GPU resource and its subresources.</returns>
     ulong GetIntermediateResourceSize(Handle<GPUResource> resource, uint firstSubResource, uint numSubResources);
 }

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

@@ -2,6 +2,7 @@ using Ghost.Core;
 using Ghost.Graphics.RHI;
 using Misaki.HighPerformance.LowLevel.Buffer;
 using Misaki.HighPerformance.LowLevel.Collections;
+using Misaki.HighPerformance.LowLevel.Utilities;
 using System.Diagnostics;
 
 namespace Ghost.Graphics.Core;
@@ -61,7 +62,9 @@ public readonly unsafe ref struct RenderContext
         {
             fixed (T* pData = data)
             {
-                ResourceDatabase.MapResource(buffer.AsResource(), 0, null, null, pData, sizeInBytes);
+                var mappedData = _engine.ResourceDatabase.MapResource(buffer.AsResource(), 0, null);
+                MemoryUtility.MemCpy(mappedData, pData, sizeInBytes);
+                _engine.ResourceDatabase.UnmapResource(buffer.AsResource(), 0, null);
             }
         }
         else
@@ -81,7 +84,9 @@ public readonly unsafe ref struct RenderContext
 
             fixed (T* pData = data)
             {
-                ResourceDatabase.MapResource(uploadHandle.AsResource(), 0, null, null, pData, sizeInBytes);
+                var mappedData = _engine.ResourceDatabase.MapResource(uploadHandle.AsResource(), 0, null);
+                MemoryUtility.MemCpy(mappedData, pData, sizeInBytes);
+                _engine.ResourceDatabase.UnmapResource(uploadHandle.AsResource(), 0, null);
             }
 
             _cmd.CopyBuffer(buffer, uploadHandle, 0, 0, sizeInBytes);

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

@@ -179,7 +179,7 @@ public struct RenderView
     public RenderingLayerMask renderingLayerMask;
 }
 
-public unsafe struct RenderRequest: IDisposable
+public struct RenderRequest: IDisposable
 {
     public RenderView view;
 
@@ -191,8 +191,6 @@ public unsafe struct RenderRequest: IDisposable
     public RenderList transparentRenderList;
     public RenderList shadowCasterRenderList;
 
-    public delegate*<ref readonly RenderContext, ref readonly RenderRequest, void> renderFunc;
-
     public void Dispose()
     {
         opaqueRenderList.Dispose();

src/Runtime/Ghost.Graphics/GPUScene.cs

@@ -0,0 +1,51 @@
+using Ghost.Core;
+using Ghost.Graphics.RHI;
+using System.Diagnostics;
+
+namespace Ghost.Graphics;
+
+public unsafe class GPUScene : IDisposable
+{
+    private readonly IResourceAllocator _resourceAllocator;
+    private readonly IResourceDatabase _resourceDatabase;
+
+    private Handle<GPUBuffer> _sceneBuffer;
+
+    private bool _disposed;
+
+    internal GPUScene(IResourceAllocator resourceAllocator, IResourceDatabase resourceDatabase, ulong initialCount)
+    {
+        _resourceAllocator = resourceAllocator;
+        _resourceDatabase = resourceDatabase;
+
+        var bufferDesc = new BufferDesc
+        {
+            Size = initialCount * (ulong)sizeof(InstanceData),
+            Stride = (uint)sizeof(InstanceData),
+            Usage = BufferUsage.Structured | BufferUsage.UnorderedAccess | BufferUsage.ShaderResource,
+            HeapType = HeapType.Default,
+        };
+
+        _sceneBuffer = _resourceAllocator.CreateBuffer(in bufferDesc, "SceneBuffer");
+
+        Debug.Assert(_sceneBuffer.IsValid, "Failed to create GPUScene buffer.");
+    }
+
+    ~GPUScene()
+    {
+        Dispose();
+    }
+
+    public void Dispose()
+    {
+        if (_disposed)
+        {
+            return;
+        }
+
+        _resourceDatabase.ReleaseResource(_sceneBuffer.AsResource());
+
+        _disposed = true;
+        GC.SuppressFinalize(this);
+    }
+}

src/Runtime/Ghost.Graphics/RenderPipeline/IRenderPipeline.cs

@@ -1,16 +1,15 @@
-using Ghost.Core;
 using Ghost.Graphics.Core;
-using Ghost.Graphics.RHI;
-using System.Diagnostics;
 
 namespace Ghost.Graphics.RenderPipeline;
 
+public interface IRenderPayload : IDisposable;
+
 public interface IRenderPipelineSettings
 {
-    IRenderPipeline CreatePipeline(RenderSystem renderSystem);
+    void CreatePipeline(RenderSystem renderSystem, out IRenderPipeline renderPipeline, out IRenderPayload renderPayload);
 }
 
 public interface IRenderPipeline : IDisposable
 {
-    void Render(RenderContext ctx, ReadOnlySpan<RenderRequest> requests);
+    void Render(RenderContext ctx, int frameIndex, IRenderPayload payload);
 }

src/Runtime/Ghost.Graphics/RenderSystem.cs

@@ -43,8 +43,6 @@ public class RenderSystem : IDisposable
 {
     private struct FrameResource : IDisposable
     {
-        private UnsafeList<RenderRequest> _renderRequests;
-
         public required AutoResetEvent CpuReadyEvent
         {
             get; init;
@@ -65,26 +63,11 @@ public class RenderSystem : IDisposable
             get; set;
         }
 
-        public bool CpuWriteOpen
+        public readonly void Dispose()
-        {
-            get; set;
-        }
-
-        [UnscopedRef]
-        public ref UnsafeList<RenderRequest> RenderRequests => ref _renderRequests;
-
-        public void Dispose()
         {
             CpuReadyEvent.Dispose();
             GpuReadyEvent.Dispose();
             CommandAllocator.Dispose();
-
-            for (var i = 0; i < _renderRequests.Count; i++)
-            {
-                _renderRequests[i].Dispose();
-            }
-
-            _renderRequests.Dispose();
         }
     }
 
@@ -102,8 +85,8 @@ public class RenderSystem : IDisposable
 
     private IRenderPipelineSettings _renderPipelineSettings;
     private IRenderPipeline _renderPipeline;
+    private IRenderPayload _renderPayload;
 
-    private uint _frameIndex;
     private ulong _cpuFenceValue;
     private ulong _submittedFenceValue;
 
@@ -118,9 +101,10 @@ public class RenderSystem : IDisposable
 
     public ulong CPUFenceValue => _cpuFenceValue;
     public ulong SubmittedFenceValue => _submittedFenceValue;
-    public uint FrameIndex => _frameIndex;
+
     public uint MaxFrameLatency => _config.FrameBufferCount;
 
+    public IRenderPayload RenderPayload => _renderPayload;
     public IRenderPipelineSettings RenderPipelineSettings
     {
         get => _renderPipelineSettings;
@@ -135,8 +119,10 @@ public class RenderSystem : IDisposable
             }
 
             _renderPipeline?.Dispose();
+            _renderPayload?.Dispose();
+
             _renderPipelineSettings = value;
-            _renderPipeline = _renderPipelineSettings.CreatePipeline(this);
+            _renderPipelineSettings.CreatePipeline(this, out _renderPipeline, out _renderPayload);
         }
     }
 
@@ -180,7 +166,6 @@ public class RenderSystem : IDisposable
                 CpuReadyEvent = new AutoResetEvent(false),
                 GpuReadyEvent = new AutoResetEvent(true),
                 CommandAllocator = _graphicsEngine.CreateCommandAllocator(CommandBufferType.Graphics),
-                RenderRequests = new UnsafeList<RenderRequest>(2, Allocator.Persistent)
             };
         }
 
@@ -195,7 +180,7 @@ public class RenderSystem : IDisposable
         _resizeRequest = new ConcurrentDictionary<ISwapChain, uint2>();
 
         _renderPipelineSettings = _config.InitialRenderPipelineSettings ?? new GhostRenderPipelineSettings();
-        _renderPipeline = _renderPipelineSettings.CreatePipeline(this);
+        _renderPipelineSettings.CreatePipeline(this, out _renderPipeline, out _renderPayload);
 
         _isRunning = false;
         _disposed = false;
@@ -225,8 +210,8 @@ public class RenderSystem : IDisposable
         {
             try
             {
-                _frameIndex = (uint)(_submittedFenceValue % _config.FrameBufferCount);
+                var frameIndex = (int)(_submittedFenceValue % _config.FrameBufferCount);
-                ref var frameResource = ref _frameResources[_frameIndex];
+                ref var frameResource = ref _frameResources[frameIndex];
 
                 // Wait for either CPU ready signal or shutdown signal
                 waitHandles[0] = frameResource.CpuReadyEvent;
@@ -276,15 +261,14 @@ public class RenderSystem : IDisposable
 
                 // TODO: How can we support async compute and async copy?
                 var cmd = _graphicsEngine.GetPooledCommandBuffer(CommandBufferType.Graphics);
-                ref var renderRequests = ref frameResource.RenderRequests;
 
                 try
                 {
                     cmd.Begin(frameResource.CommandAllocator);
 
-                    var renderCtx = new RenderContext(_graphicsEngine, _resourceManager, cmd);
+                    var ctx = new RenderContext(_graphicsEngine, _resourceManager, cmd);
 
-                    _renderPipeline.Render(renderCtx, renderRequests.AsSpan());
+                    _renderPipeline.Render(ctx, frameIndex, _renderPayload);
                     _swapChainManager.TransitionToPresent(cmd);
 
                     // End recording commands and submit
@@ -301,13 +285,6 @@ public class RenderSystem : IDisposable
                 finally
                 {
                     _graphicsEngine.ReturnPooledCommandBuffer(cmd);
-
-                    for (var i = 0; i < renderRequests.Count; i++)
-                    {
-                        renderRequests[i].Dispose();
-                    }
-
-                    renderRequests.Clear();
                 }
 
                 _submittedFenceValue++;
@@ -361,9 +338,6 @@ public class RenderSystem : IDisposable
         var eventIndex = (int)(_cpuFenceValue % _config.FrameBufferCount);
         ref var frameResource = ref _frameResources[eventIndex];
 
-        Debug.Assert(frameResource.CpuWriteOpen, "SignalCPUReady called without a matching successful TryAcquireCPUFrame.");
-        frameResource.CpuWriteOpen = false;
-
         frameResource.CpuReadyEvent.Set();
         _cpuFenceValue++;
     }
@@ -388,25 +362,9 @@ public class RenderSystem : IDisposable
         var eventIndex = (int)(_cpuFenceValue % _config.FrameBufferCount);
         ref var frameResource = ref _frameResources[eventIndex];
 
-        Debug.Assert(!frameResource.CpuWriteOpen, "TryAcquireCPUFrame called while the previous CPU frame is still open. Call SignalCPUReady first.");
-
-        frameResource.CpuWriteOpen = true;
-        frameResource.RenderRequests.Clear();
-
         return true;
     }
 
-    public void AddRenderRequest(in RenderRequest request)
-    {
-        Debug.Assert(!_disposed, "Cannot add render request to a disposed RenderSystem.");
-
-        var frameIndex = (int)(_cpuFenceValue % _config.FrameBufferCount);
-        ref var frameResource = ref _frameResources[frameIndex];
-
-        Debug.Assert(frameResource.CpuWriteOpen, "AddRenderRequest requires a successful TryAcquireCPUFrame and must happen before SignalCPUReady.");
-        frameResource.RenderRequests.Add(request);
-    }
-
     public bool WaitForGPUReady(int timeOut = -1)
     {
         Debug.Assert(!_disposed, "Cannot wait for GPU ready on a disposed RenderSystem.");

src/Runtime/Ghost.Graphics/Utilities/RenderingUtility.cs

@@ -1,5 +1,6 @@
 using Ghost.Core;
 using Ghost.Graphics.RHI;
+using Misaki.HighPerformance.LowLevel.Utilities;
 using System.Diagnostics;
 
 namespace Ghost.Graphics.Utilities;
@@ -24,7 +25,9 @@ public static unsafe class RenderingUtility
         {
             fixed (T* pData = data)
             {
-                resourceDatabase.MapResource(buffer.AsResource(), 0, null, null, pData, sizeInBytes);
+                var mappedData = resourceDatabase.MapResource(buffer.AsResource(), 0, null);
+                MemoryUtility.MemCpy(mappedData, pData, sizeInBytes);
+                resourceDatabase.UnmapResource(buffer.AsResource(), 0, null);
             }
         }
         else
@@ -44,7 +47,9 @@ public static unsafe class RenderingUtility
 
             fixed (T* pData = data)
             {
-                resourceDatabase.MapResource(uploadHandle.AsResource(), 0, null, null, pData, sizeInBytes);
+                var mappedData = resourceDatabase.MapResource(uploadHandle.AsResource(), 0, null);
+                MemoryUtility.MemCpy(mappedData, pData, sizeInBytes);
+                resourceDatabase.UnmapResource(uploadHandle.AsResource(), 0, null);
             }
 
             cmd.CopyBuffer(buffer, uploadHandle, 0, 0, sizeInBytes);

src/Test/Ghost.Graphics.Test/RenderPipeline/TestRenderPipeline.cs

@@ -8,15 +8,7 @@ using Misaki.HighPerformance.Mathematics;
 using Misaki.HighPerformance.Mathematics.Geometry;
 using Misaki.HighPerformance.Utilities;
 
-namespace Ghost.Graphics.Test.RenderPasses;
+namespace Ghost.Graphics.Test.RenderPipeline;
-
-public sealed class TestRenderPipelineSettings : IRenderPipelineSettings
-{
-    public IRenderPipeline CreatePipeline(RenderSystem renderSystem)
-    {
-        return new TestRenderPipeline(renderSystem);
-    }
-}
 
 public unsafe partial class TestRenderPipeline : IRenderPipeline
 {
@@ -29,8 +21,9 @@ public unsafe partial class TestRenderPipeline : IRenderPipeline
         public uint instanceIndex;
     }
 
-    private readonly RenderGraph _renderGraph;
     private readonly RenderSystem _renderSystem;
+
+    private readonly RenderGraph _renderGraph;
     private Identifier<Shader> _meshletShader;
     private Handle<Material> _meshletMaterial;
 
@@ -44,6 +37,7 @@ public unsafe partial class TestRenderPipeline : IRenderPipeline
     internal TestRenderPipeline(RenderSystem renderSystem)
     {
         _renderSystem = renderSystem;
+
         _renderGraph = new RenderGraph(renderSystem.ResourceManager,
                 renderSystem.GraphicsEngine.ResourceAllocator,
                 renderSystem.GraphicsEngine.ResourceDatabase,
@@ -106,12 +100,17 @@ public unsafe partial class TestRenderPipeline : IRenderPipeline
         return frustum;
     }
 
-    public void Render(RenderContext ctx, ReadOnlySpan<RenderRequest> requests)
+    public void Render(RenderContext ctx, int frameIndex, IRenderPayload payload)
     {
-        var resourceManager = _renderSystem.ResourceManager;
+        var testPayload = (TestRenderPayload)payload;
-        var resourceDatabase = _renderSystem.GraphicsEngine.ResourceDatabase;
 
-        for (var i = 0; i < requests.Length; i++)
+        var renderSystem = testPayload.RenderSystem;
+        var resourceManager = renderSystem.ResourceManager;
+        var resourceDatabase = renderSystem.GraphicsEngine.ResourceDatabase;
+
+        var requests = testPayload.FrameRequestData[frameIndex].renderRequests;
+
+        for (var i = 0; i < requests.Count; i++)
         {
             ref readonly var request = ref requests[i];
 
@@ -127,7 +126,7 @@ public unsafe partial class TestRenderPipeline : IRenderPipeline
             {
                 rt = request.colorTarget;
             }
-            else if (_renderSystem.SwapChainManager.TryGetSwapChain(request.swapChainIndex, out var swapChain))
+            else if (renderSystem.SwapChainManager.TryGetSwapChain(request.swapChainIndex, out var swapChain))
             {
                 rt = swapChain.GetCurrentBackBuffer();
             }
@@ -138,7 +137,7 @@ public unsafe partial class TestRenderPipeline : IRenderPipeline
 
             try
             {
-                var rtResult = _renderSystem.GraphicsEngine.ResourceDatabase.GetResourceDescription(rt.AsResource());
+                var rtResult = renderSystem.GraphicsEngine.ResourceDatabase.GetResourceDescription(rt.AsResource());
                 if (rtResult.IsFailure)
                 {
                     continue;
@@ -296,12 +295,6 @@ public unsafe partial class TestRenderPipeline : IRenderPipeline
                 //ctx.UploadBuffer(frameBufferHandle, new ReadOnlySpan<FrameData>(in frameData));
                 //ctx.CommandBuffer.Barrier(BarrierDesc.Buffer(frameBufferResource, BarrierSync.AllShading, BarrierAccess.ShaderResource));
 
-                if (request.renderFunc != null)
-                {
-                    request.renderFunc(in ctx, in request);
-                }
-                else
-                {
                 _renderGraph.Reset();
 
                 var backBuffer = _renderGraph.ImportTexture(rt, "BackBuffer");
@@ -315,12 +308,11 @@ public unsafe partial class TestRenderPipeline : IRenderPipeline
                 _renderGraph.Compile(viewState);
                 _renderGraph.Execute(ctx.CommandBuffer);
             }
-            }
             finally
             {
                 if (request.swapChainIndex >= 0)
                 {
-                    _renderSystem.SwapChainManager.ReleaseSwapChain(request.swapChainIndex);
+                    renderSystem.SwapChainManager.ReleaseSwapChain(request.swapChainIndex);
                 }
             }
         }

src/Test/Ghost.Graphics.Test/RenderPipeline/TestRenderPipelineSettings.cs

@@ -0,0 +1,54 @@
+using Ghost.Graphics.Core;
+using Ghost.Graphics.RenderPipeline;
+using Misaki.HighPerformance.LowLevel.Buffer;
+using Misaki.HighPerformance.LowLevel.Collections;
+
+namespace Ghost.Graphics.Test.RenderPipeline;
+
+internal sealed class TestRenderPayload : IRenderPayload
+{
+    public class FrameData
+    {
+        public UnsafeList<RenderRequest> renderRequests;
+    }
+
+    private readonly RenderSystem _renderSystem;
+    private readonly FrameData[] _frameData;
+
+    public RenderSystem RenderSystem => _renderSystem;
+    public ReadOnlySpan<FrameData> FrameRequestData => _frameData;
+
+    public TestRenderPayload(RenderSystem renderSystem)
+    {
+        _renderSystem = renderSystem;
+        _frameData = new FrameData[renderSystem.MaxFrameLatency];
+
+        for (int i = 0; i < _frameData.Length; i++)
+        {
+            _frameData[i].renderRequests = new UnsafeList<RenderRequest>(2, Allocator.Persistent);
+        }
+    }
+
+    public void AddRenderRequest(RenderRequest request)
+    {
+        var index = (int)(_renderSystem.CPUFenceValue % (uint)_frameData.Length);
+        _frameData[index].renderRequests.Add(request);
+    }
+
+    public void Dispose()
+    {
+        for (int i = 0; i < _frameData.Length; i++)
+        {
+            _frameData[i].renderRequests.Dispose();
+        }
+    }
+}
+
+internal sealed class TestRenderPipelineSettings : IRenderPipelineSettings
+{
+    public void CreatePipeline(RenderSystem renderSystem, out IRenderPipeline renderPipeline, out IRenderPayload renderPayload)
+    {
+        renderPipeline = new TestRenderPipeline(renderSystem);
+        renderPayload = new TestRenderPayload(renderSystem);
+    }
+}

src/Test/Ghost.Graphics.Test/Systems/RenderExtractionSystem.cs

@@ -1,12 +1,13 @@
 using Ghost.Core;
+using Ghost.Engine;
 using Ghost.Engine.Components;
 using Ghost.Entities;
-using Ghost.Graphics;
 using Ghost.Graphics.Core;
+using Ghost.Graphics.Test.RenderPipeline;
 using Misaki.HighPerformance.LowLevel.Buffer;
 using Misaki.HighPerformance.Mathematics;
 
-namespace Ghost.Engine.Systems;
+namespace Ghost.Graphics.Test.Systems;
 
 public class RenderExtractionSystem : ISystem
 {
@@ -32,7 +33,7 @@ public class RenderExtractionSystem : ISystem
             .Build(systemAPI.World, true);
     }
 
-    public unsafe void Update(ref readonly SystemAPI systemAPI)
+    public void Update(ref readonly SystemAPI systemAPI)
     {
         if (_meshQueryID.IsInvalid)
         {
@@ -52,7 +53,7 @@ public class RenderExtractionSystem : ISystem
             var transparentRenderList = new RenderList(1, 64, Allocator.FreeList);
             var shadowCasterRenderList = new RenderList(1, 64, Allocator.FreeList);
 
-            // TODO: This chould be done in parallel jobs.
+            // TODO: This chould be done in earallel jobs.
             foreach (var chunk in meshQuery.GetChunkIterator())
             {
                 var meshInstances = chunk.GetComponentData<MeshInstance>();
@@ -111,7 +112,6 @@ public class RenderExtractionSystem : ISystem
                 opaqueRenderList = renderList,
                 shadowCasterRenderList = shadowCasterRenderList,
                 transparentRenderList = transparentRenderList,
-                renderFunc = camRef.renderFunc,
                 view = new RenderView
                 {
                     localToWorld = camLtwRef.matrix,
@@ -135,7 +135,7 @@ public class RenderExtractionSystem : ISystem
                 },
             };
 
-            _renderSystem.AddRenderRequest(request);
+            ((TestRenderPayload)_renderSystem.RenderPayload).AddRenderRequest(request);
         }
     }
 

src/Test/Ghost.Graphics.Test/Windows/GraphicsTestWindow.xaml.cs

@@ -10,7 +10,6 @@ using Microsoft.UI.Xaml.Controls;
 using Microsoft.UI.Xaml.Media;
 using Misaki.HighPerformance.LowLevel.Buffer;
 using Misaki.HighPerformance.Mathematics;
-using System.Diagnostics;
 
 namespace Ghost.Graphics.Test.Windows;