Refactor render pipeline and resource management APIs

Split IFenceSynchronizer/IRenderSystem interfaces for clarity. Refactor D3D12GraphicsEngine to use IFenceSynchronizer. Update RenderGraph and context to use explicit resource manager/database/allocator references. Add multi-buffering methods to IRGBuilder (stub). Support history access for multi-frame resources. Remove legacy RenderPipelineBase; introduce IRenderPipelineSettings and sealed GhostRenderPipeline. Clean up resource aliasing and pool logic. Improve modularity and future extensibility.

src/.editorconfig

@@ -1,5 +1,5 @@
 [*]
-max_line_length = 400
+max_line_length = 200
 
 [*.cs]
 csharp_new_line_before_open_brace = all

src/Runtime/Ghost.Graphics.D3D12/D3D12CommandBuffer.cs

@@ -6,7 +6,6 @@ using Misaki.HighPerformance.LowLevel.Utilities;
 using System.Diagnostics;
 using System.Runtime.CompilerServices;
 using TerraFX.Interop.DirectX;
-using TerraFX.Interop.Gdiplus;
 using TerraFX.Interop.Windows;
 
 using static TerraFX.Aliases.D3D_Alias;

src/Runtime/Ghost.Graphics.D3D12/D3D12GraphicsEngine.cs

@@ -13,9 +13,9 @@ namespace Ghost.Graphics.D3D12;
 
 public static class D3D12GraphicsEngineFactory
 {
-    public static IGraphicsEngine Create(IRenderSystem renderSystem)
+    public static IGraphicsEngine Create(IFenceSynchronizer fenceSynchronizer)
     {
-        return new D3D12GraphicsEngine(renderSystem);
+        return new D3D12GraphicsEngine(fenceSynchronizer);
     }
 }
 
@@ -23,7 +23,7 @@ internal class D3D12GraphicsEngine : IGraphicsEngine
 {
     private GCHandle _thisHandle;
 
-    private readonly IRenderSystem _renderSystem;
+    private readonly IFenceSynchronizer _fenceSynchronizer;
 
 #if ENABLE_DEBUG
     private readonly D3D12DebugLayer _debugLayer;
@@ -45,9 +45,9 @@ internal class D3D12GraphicsEngine : IGraphicsEngine
     public IResourceDatabase ResourceDatabase => _resourceDatabase;
     public IResourceAllocator ResourceAllocator => _resourceAllocator;
 
-    public D3D12GraphicsEngine(IRenderSystem renderSystem)
+    public D3D12GraphicsEngine(IFenceSynchronizer fenceSynchronizer)
     {
-        _renderSystem = renderSystem;
+        _fenceSynchronizer = fenceSynchronizer;
 
 #if ENABLE_DEBUG
         _debugLayer = new D3D12DebugLayer();
@@ -56,7 +56,7 @@ internal class D3D12GraphicsEngine : IGraphicsEngine
         _shaderCompiler = new DxcShaderCompiler();
         _descriptorAllocator = new D3D12DescriptorAllocator(_device);
 
-        _resourceDatabase = new D3D12ResourceDatabase(renderSystem, _descriptorAllocator);
+        _resourceDatabase = new D3D12ResourceDatabase(_fenceSynchronizer, _descriptorAllocator);
         _pipelineLibrary = new D3D12PipelineLibrary(_device, _resourceDatabase);
         _resourceAllocator = new D3D12ResourceAllocator(_device, _descriptorAllocator, _resourceDatabase, _pipelineLibrary);
 
@@ -118,7 +118,7 @@ internal class D3D12GraphicsEngine : IGraphicsEngine
     public ISwapChain CreateSwapChain(SwapChainDesc desc)
     {
         ThrowIfDisposed();
-        return new D3D12SwapChain(_resourceDatabase, _descriptorAllocator, _device, desc, _renderSystem.MaxFrameLatency);
+        return new D3D12SwapChain(_resourceDatabase, _descriptorAllocator, _device, desc, _fenceSynchronizer.MaxFrameLatency);
     }
 
     public Result RenderFrame(ICommandAllocator commandAllocator)

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

@@ -28,20 +28,3 @@ public interface IFenceSynchronizer
     void SignalCPUReady();
     void WaitIdle();
 }
-
-public interface IRenderSystem : IFenceSynchronizer, IDisposable
-{
-    IGraphicsEngine GraphicsEngine
-    {
-        get;
-    }
-
-    bool IsRunning
-    {
-        get;
-    }
-
-    void Start();
-    void Stop();
-    void RequestSwapChainResize(ISwapChain swapChain, uint2 newSize);
-}

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

@@ -148,6 +148,11 @@ public struct RenderList : IDisposable
 
     public void Dispose()
     {
+        if (!IsCreated)
+        {
+            return;
+        }
+
         for (int i = 0; i < _threadLocalRecords.Length; i++)
         {
             _threadLocalRecords[i].Dispose();

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

@@ -46,9 +46,8 @@ public struct Frustum
 [StructLayout(LayoutKind.Sequential, Pack = 4)]
 public struct RenderView
 {
-    public float4x4 view;
+    public float4x4 viewMatrix;
-    public float4x4 projection;
+    public float4x4 projectionMatrix;
-    public float4x4 viewProjection;
     public float3 position;
 
     public Frustum frustum; // 192 bytes
@@ -69,8 +68,13 @@ public struct RenderView
 public unsafe struct RenderRequest
 {
     public RenderView view;
+
     public Handle<Texture> colorTarget;
     public Handle<Texture> depthTarget;
 
-    public delegate*<ref readonly RenderingContext, ref readonly RenderRequest, void> renderFunc;
+    public RenderList opaqueRenderList;
+    public RenderList transparentRenderList;
+    public RenderList shadowCasterRenderList;
+
+    public delegate*<ref readonly RenderContext, ref readonly RenderRequest, void> renderFunc;
 }

src/Runtime/Ghost.Graphics/RenderGraphModule/RenderGraph.cs

@@ -9,6 +9,8 @@ namespace Ghost.Graphics.RenderGraphModule;
 public sealed class RenderGraph : IDisposable
 {
     private readonly IResourceManager _resourceManager;
+    private readonly IResourceAllocator _resourceAllocator;
+    private readonly IResourceDatabase _resourceDatabase;
 
     private readonly RenderGraphObjectPool _objectPool;
     private readonly RenderGraphResourceRegistry _resources;
@@ -35,9 +37,11 @@ public sealed class RenderGraph : IDisposable
 
     public RenderGraphBlackboard Blackboard => _blackboard;
 
-    public RenderGraph(IResourceManager resourceManager, IPipelineLibrary pipelineLibrary, IShaderCompiler shaderCompiler)
+    public RenderGraph(IResourceManager resourceManager, IResourceAllocator resourceAllocator, IResourceDatabase resourceDatabase, IPipelineLibrary pipelineLibrary, IShaderCompiler shaderCompiler)
     {
         _resourceManager = resourceManager;
+        _resourceAllocator = resourceAllocator;
+        _resourceDatabase = resourceDatabase;
 
         _objectPool = new RenderGraphObjectPool();
         _resources = new RenderGraphResourceRegistry(_objectPool);
@@ -47,20 +51,21 @@ public sealed class RenderGraph : IDisposable
         _nativePasses = new List<NativeRenderPass>(32);
 
         _builder = new RenderGraphBuilder();
-        _aliasingManager = new ResourceAliasingManager(resourceManager.ResourceAllocator, _objectPool);
+        _aliasingManager = new ResourceAliasingManager(_resourceAllocator, _objectPool);
 
         _compilationCache = new RenderGraphCompilationCache();
 
         _context = new RenderGraphContext(
-            resourceManager,
+            _resourceManager,
+            _resourceDatabase,
             pipelineLibrary,
             shaderCompiler,
             _resources
         );
 
         _nativePassBuilder = new RenderGraphNativePassBuilder(_objectPool, _resources);
-        _compiler = new RenderGraphCompiler(resourceManager, _resources, _aliasingManager, _nativePassBuilder, _compilationCache);
+        _compiler = new RenderGraphCompiler(_resourceManager, _resources, _aliasingManager, _nativePassBuilder, _compilationCache);
-        _executor = new RenderGraphExecutor(resourceManager, _resources, _context);
+        _executor = new RenderGraphExecutor(_resourceManager, _resourceDatabase, _resources, _context);
 
         _blackboard = new RenderGraphBlackboard();
     }
@@ -103,7 +108,7 @@ public sealed class RenderGraph : IDisposable
         Color128 clearColor = default, float clearDepth = 1.0f, byte clearStencil = 0,
         bool clearAtFirstUse = true, bool discardAtLastUse = true)
     {
-        var r = _resourceManager.ResourceDatabase.GetResourceDescription(texture.AsResource());
+        var r = _resourceDatabase.GetResourceDescription(texture.AsResource());
         if (r.IsFailure)
         {
             return Identifier<RGTexture>.Invalid;
@@ -120,7 +125,7 @@ public sealed class RenderGraph : IDisposable
     /// <returns>The identifier of the imported render graph buffer. Invalid if import fails.</returns>
     public Identifier<RGBuffer> ImportBuffer(Handle<GraphicsBuffer> buffer, string name)
     {
-        var r = _resourceManager.ResourceDatabase.GetResourceDescription(buffer.AsResource());
+        var r = _resourceDatabase.GetResourceDescription(buffer.AsResource());
         if (r.IsFailure)
         {
             return Identifier<RGBuffer>.Invalid;
@@ -195,14 +200,14 @@ public sealed class RenderGraph : IDisposable
     /// <summary>
     /// Executes all compiled passes using native render passes where possible.
     /// </summary>
-    public Error Execute(ICommandBuffer cmd)
+    public Error Execute(ICommandBuffer commandBuffer)
     {
         if (!_compiled)
         {
             return Error.InvalidState;
         }
 
-        return _executor.Execute(cmd, _compiledPasses, _nativePasses, _compiledBarriers);
+        return _executor.Execute(commandBuffer, _compiledPasses, _nativePasses, _compiledBarriers);
     }
 
     public void Dispose()

src/Runtime/Ghost.Graphics/RenderGraphModule/RenderGraphAliasing.cs

@@ -1,12 +1,10 @@
 using Ghost.Core.Utilities;
 using Ghost.Graphics.RHI;
+using System.Diagnostics;
 using System.Runtime.InteropServices;
 
 namespace Ghost.Graphics.RenderGraphModule;
 
-/// <summary>
-/// Represents a memory block within a heap.
-/// </summary>
 internal struct MemoryBlock
 {
     public ulong offset;
@@ -35,17 +33,12 @@ internal struct MemoryBlock
     }
 }
 
-/// <summary>
-/// Represents a GPU memory heap for placed resources.
-/// Supports D3D12-style heap tier 2 (buffers and textures can alias).
-/// </summary>
 internal sealed class ResourceHeap
 {
     public int index;
     public ulong size;
     private readonly List<MemoryBlock> _blocks = new(32);
 
-    // D3D12 heap alignment requirement (64KB for MSAA textures, 4KB for others)
     public const ulong DEFAULT_ALIGNMENT = 65536; // 64KB
 
     public ResourceHeap(int index, ulong initialSize = 16 * 1024 * 1024) // 16MB default
@@ -81,6 +74,7 @@ internal sealed class ResourceHeap
         var smallestWaste = ulong.MaxValue;
 
         // Find the best fit block that doesn't overlap with lifetime
+        // TODO: Is first-fit better? Since we already sort by size beforehand.
         var blockSpan = CollectionsMarshal.AsSpan(_blocks);
         for (var i = 0; i < blockSpan.Length; i++)
         {
@@ -166,10 +160,6 @@ internal sealed class ResourceHeap
         return (true, bestFitOffset, bestFit);
     }
 
-    /// <summary>
-    /// Checks if a resource can be placed at the given offset without lifetime conflicts.
-    /// Must check ALL blocks that overlap with this offset range.
-    /// </summary>
     private bool CanPlaceAtOffset(ulong offset, ulong size, int firstUsePass, int lastUsePass)
     {
         var endOffset = offset + size;
@@ -202,12 +192,9 @@ internal sealed class ResourceHeap
         return true;
     }
 
-    /// <summary>
-    /// Gets the total memory that would be used if no aliasing occurred.
-    /// </summary>
     public ulong GetTotalAllocatedWithoutAliasing()
     {
-        ulong total = 0;
+        var total = 0ul;
         foreach (var block in _blocks)
         {
             if (!block.isFree)
@@ -219,12 +206,9 @@ internal sealed class ResourceHeap
         return total;
     }
 
-    /// <summary>
-    /// Gets the peak memory usage considering aliasing (max offset + size).
-    /// </summary>
     public ulong GetPeakUsage()
     {
-        ulong peak = 0;
+        var peak = 0ul;
         foreach (var block in _blocks)
         {
             if (!block.isFree)
@@ -242,9 +226,6 @@ internal sealed class ResourceHeap
     }
 }
 
-/// <summary>
-/// Represents a placed resource within a heap.
-/// </summary>
 internal sealed class PlacedResource
 {
     public int index;
@@ -279,10 +260,6 @@ internal sealed class PlacedResource
     }
 }
 
-/// <summary>
-/// Manages physical resource allocation and aliasing using heap-based allocation.
-/// Supports D3D12 heap tier 2: buffers and textures can alias as long as lifetimes don't overlap.
-/// </summary>
 internal sealed class ResourceAliasingManager
 {
     private readonly IResourceAllocator _allocator;
@@ -293,15 +270,11 @@ internal sealed class ResourceAliasingManager
     // Mapping from logical resource index to placed resource index
     private readonly Dictionary<int, int> _logicalToPlaced;
 
-    // D3D12 alignment constants
     private const ulong _DEFAULT_TEXTURE_ALIGNMENT = 65536; // 64KB
-    private const ulong _DEFAULT_BUFFER_ALIGNMENT = 65536;  // 64KB for D3D12
+    private const ulong _DEFAULT_BUFFER_ALIGNMENT = 65536;  // 64KB
 
     public ResourceHeap Heap => _heap;
 
-    /// <summary>
-    /// Helper method to get the size of a resource
-    /// </summary>
     private ulong GetResourceSize(RenderGraphResource resource)
     {
         if (resource.type == RenderGraphResourceType.Texture)
@@ -311,7 +284,6 @@ internal sealed class ResourceAliasingManager
         }
         else // Buffer
         {
-            //return resource.bufferDesc.Size;
             return _allocator.GetSizeInfo(ResourceDesc.Buffer(resource.bufferDesc)).Size;
         }
     }
@@ -339,13 +311,6 @@ internal sealed class ResourceAliasingManager
         _heap.Reset();
     }
 
-    /// <summary>
-    /// Assigns physical resources (placed resources) to logical resources using heap-based allocation.
-    /// This is the modern D3D12 approach: check if resource fits in a hole, not if it matches size/format.
-    /// Uses a two-pass algorithm:
-    /// 1. First pass: Simulate allocation to determine peak memory usage
-    /// 2. Second pass: Create a single heap of the peak size and do the real allocation
-    /// </summary>
     public void AssignPhysicalResources(RenderGraphResourceRegistry registry, int passCount)
     {
         // Build list of all logical resources (both textures and buffers) with their lifetimes
@@ -369,7 +334,16 @@ internal sealed class ResourceAliasingManager
             return sizeB.CompareTo(sizeA); // Descending
         });
 
+        // NOTE: We assume we are at least D3D12 heap tier 2 (the engine won't even start if the hardware does not supports)
+        // so buffers and textures can alias as long as lifetimes don't overlap.
+
+
+        // TODO: Handle non-aliased resources like history buffers that need to persist across frames.
+        // They will be placed in the same heap but we can mark them as non-aliased and skip them when looking for aliasing candidates.
+        // We do not place them in a separate heap because our buffers are cached and reused across frames as long as the graph topology doesn't change.
+
         // ===== PASS 1: Simulate allocation to determine peak memory usage =====
+
         var simulationHeap = new ResourceHeap(0, ulong.MaxValue); // Unlimited size for simulation
         foreach (var (logicalIndex, logicalResource) in logicalResources)
         {
@@ -385,10 +359,7 @@ internal sealed class ResourceAliasingManager
                 logicalIndex,
                 alignment);
 
-            if (!success)
+            Debug.Assert(success, "Simulation allocation failed - heap should be unlimited in size");
-            {
-                throw new InvalidOperationException("Simulation allocation failed - this should never happen with unlimited heap");
-            }
         }
 
         // Get peak usage from simulation
@@ -398,12 +369,15 @@ internal sealed class ResourceAliasingManager
         peakMemoryUsage = AlignUp(peakMemoryUsage, _DEFAULT_TEXTURE_ALIGNMENT);
 
         // ===== PASS 2: Create a single heap of the peak size and do the real allocation =====
-        _heap.size = peakMemoryUsage;
+
         _heap.Reset();
+        _heap.size = peakMemoryUsage;
 
         // Allocate each logical resource in the heap
         foreach (var (logicalIndex, logicalResource) in logicalResources)
         {
+            // TODO: Currently we are recalculating the aliasing candidates in the real allocation pass.
+            // We can optimize this by caching the candidates from the simulation pass since the heap layout should be the same.
             var size = GetResourceSize(logicalResource);
             var alignment = logicalResource.type == RenderGraphResourceType.Texture
                 ? _DEFAULT_TEXTURE_ALIGNMENT
@@ -488,9 +462,6 @@ internal sealed class ResourceAliasingManager
         return (value + alignment - 1) & ~(alignment - 1);
     }
 
-    /// <summary>
-    /// Restores aliasing state from cache.
-    /// </summary>
     public void RestoreFromCache(Dictionary<int, int> logicalToPlaced, List<PlacedResourceData> placedData)
     {
         _logicalToPlaced.Clear();
@@ -518,9 +489,6 @@ internal sealed class ResourceAliasingManager
         }
     }
 
-    /// <summary>
-    /// Stores current aliasing state to cache.
-    /// </summary>
     public void StoreToCache(Dictionary<int, int> outLogicalToPlaced, List<PlacedResourceData> outPlacedData)
     {
         outLogicalToPlaced.Clear();

src/Runtime/Ghost.Graphics/RenderGraphModule/RenderGraphBuilder.cs

@@ -32,6 +32,17 @@ public interface IRenderGraphBuilder : IDisposable
     /// <returns>An identifier for the newly created texture resource.</returns>
     Identifier<RGTexture> CreateTexture(in RGTextureDesc desc, string name);
 
+    /// <summary>
+    /// Creates multiple texture resources based on the specified desc.
+    /// </summary>
+    /// <remarks>
+    /// Those textures will be used as multi buffering in the render graph automaticlly and not aliasable with other resources.
+    /// </remarks>
+    /// <param name="desc">A structure that defines the properties and configuration of the texture to create.</param>
+    /// <param name="name">The base name of the texture resources. The actual name for each texture will be generated by appending an index to this base name.</param>
+    /// <param name="textureIDs">A span to receive the identifiers for the newly created texture resources. The length of the span determines how many textures will be created.</param>
+    void CreateTextures(in RGTextureDesc desc, string name, Span<Identifier<RGTexture>> textureIDs);
+
     /// <summary>
     /// Creates a new buffer resource based on the specified desc.
     /// </summary>
@@ -40,6 +51,17 @@ public interface IRenderGraphBuilder : IDisposable
     /// <returns>An identifier for the newly created buffer resource.</returns>
     Identifier<RGBuffer> CreateBuffer(in BufferDesc desc, string name);
 
+    /// <summary>
+    /// Creates multiple buffer resources based on the specified desc.
+    /// </summary>
+    /// <remarks>
+    /// Those buffers will be used as multi buffering in the render graph automaticlly and not aliasable with other resources.
+    /// </remarks>
+    /// <param name="desc">A structure that defines the properties and configuration of the buffer to create.</param>
+    /// <param name="name">The base name of the buffer resources. The actual name for each buffer will be generated by appending an index to this base name.</param>
+    /// <param name="bufferIDs">A span to receive the identifiers for the newly created buffer resources. The length of the span determines how many buffers will be created.</param>
+    void CreateBuffers(in BufferDesc desc, string name, Span<Identifier<RGBuffer>> bufferIDs);
+
     /// <summary>
     /// Registers the specified texture for use in the current render graph pass with the given access mode.
     /// </summary>
@@ -140,7 +162,6 @@ public interface IUnsafeRenderGraphBuilder : IRenderGraphBuilder
 
 internal class RenderGraphBuilder : IRasterRenderGraphBuilder, IComputeRenderGraphBuilder, IUnsafeRenderGraphBuilder
 {
-
     private RenderGraph _graph = null!;
     private RenderGraphPassBase _pass = null!;
     private RenderGraphResourceRegistry _resources = null!;
@@ -206,6 +227,18 @@ internal class RenderGraphBuilder : IRasterRenderGraphBuilder, IComputeRenderGra
         return handle;
     }
 
+    public void CreateTextures(in RGTextureDesc desc, string name, Span<Identifier<RGTexture>> textureIDs)
+    {
+        // TODO: Create multiple textures, mark them as no aliasable, and add them to the resource registry and current pass.
+        throw new NotImplementedException();
+    }
+
+    public void CreateBuffers(in BufferDesc desc, string name, Span<Identifier<RGBuffer>> bufferIDs)
+    {
+        // TODO: Create multiple buffers, mark them as no aliasable, and add them to the resource registry and current pass.
+        throw new NotImplementedException();
+    }
+
     public Identifier<RGTexture> UseTexture(Identifier<RGTexture> texture, AccessFlags flags)
     {
         ThrowIfDisposed();

src/Runtime/Ghost.Graphics/RenderGraphModule/RenderGraphContext.cs

@@ -12,6 +12,9 @@ public interface IRenderGraphContext
     Handle<GPUResource> GetActualResource(Identifier<RGResource> resource);
     Handle<Texture> GetActualTexture(Identifier<RGTexture> texture);
     Handle<GraphicsBuffer> GetActualBuffer(Identifier<RGBuffer> buffer);
+
+    Handle<Texture> GetHistoryTexture(ReadOnlySpan<Identifier<RGTexture>> texture, int historyOffset);
+    Handle<GraphicsBuffer> GetHistoryBuffer(ReadOnlySpan<Identifier<RGBuffer>> buffer, int historyOffset);
 }
 
 public interface IRasterRenderContext : IRenderGraphContext
@@ -38,11 +41,13 @@ public interface IUnsafeRenderContext : IRasterRenderContext, IRenderGraphContex
 internal sealed class RenderGraphContext : IRasterRenderContext, IComputeRenderContext, IUnsafeRenderContext
 {
     private readonly IResourceManager _resourceManager;
+    private readonly IResourceDatabase _resourceDatabase;
     private readonly IPipelineLibrary _pipelineLibrary;
     private readonly IShaderCompiler _shaderCompiler;
     private readonly RenderGraphResourceRegistry _resources;
 
-    private ICommandBuffer _commandBuffer = null!;
+    private uint _frameIndex;
+    private ICommandBuffer _commandBuffer;
 
     private readonly TextureFormat[] _rtvFormats;
     private TextureFormat _dsvFormat;
@@ -58,19 +63,23 @@ internal sealed class RenderGraphContext : IRasterRenderContext, IComputeRenderC
 
     public ICommandBuffer CommandBuffer => _commandBuffer;
 
-    internal RenderGraphContext(IResourceManager resourceManager, IPipelineLibrary pipelineLibrary, IShaderCompiler shaderCompiler, RenderGraphResourceRegistry resources)
+    internal RenderGraphContext(IResourceManager resourceManager, IResourceDatabase resourceDatabase, IPipelineLibrary pipelineLibrary, IShaderCompiler shaderCompiler, RenderGraphResourceRegistry resources)
     {
         _resourceManager = resourceManager;
+        _resourceDatabase = resourceDatabase;
         _pipelineLibrary = pipelineLibrary;
         _shaderCompiler = shaderCompiler;
         _resources = resources;
 
+        _commandBuffer = null!;
+
         _rtvFormats = new TextureFormat[RHIUtility.MAX_RENDER_TARGETS];
         _dsvFormat = TextureFormat.Unknown;
     }
 
-    internal void SetCommandBuffer(ICommandBuffer commandBuffer)
+    internal void BeginNewFrame(uint frameIndex, ICommandBuffer commandBuffer)
     {
+        _frameIndex = frameIndex;
         _commandBuffer = commandBuffer;
     }
 
@@ -100,6 +109,38 @@ internal sealed class RenderGraphContext : IRasterRenderContext, IComputeRenderC
         return _resources.GetResource(buffer.AsResource()).backingResource.AsGraphicsBuffer();
     }
 
+    public Handle<Texture> GetHistoryTexture(ReadOnlySpan<Identifier<RGTexture>> textures, int historyOffset)
+    {
+        if (historyOffset < 0 || historyOffset >= textures.Length)
+        {
+            return Handle<Texture>.Invalid;
+        }
+
+        var index = (int)(_frameIndex % textures.Length) - historyOffset;
+        if (index < 0)
+        {
+            index += textures.Length;
+        }
+
+        return GetActualTexture(textures[index]);
+    }
+
+    public Handle<GraphicsBuffer> GetHistoryBuffer(ReadOnlySpan<Identifier<RGBuffer>> buffers, int historyOffset)
+    {
+        if (historyOffset < 0 || historyOffset >= buffers.Length)
+        {
+            return Handle<GraphicsBuffer>.Invalid;
+        }
+
+        var index = (int)(_frameIndex % buffers.Length) - historyOffset;
+        if (index < 0)
+        {
+            index += buffers.Length;
+        }
+
+        return GetActualBuffer(buffers[index]);
+    }
+
     public void SetActiveMaterial(Handle<Material> material)
     {
         var r = _resourceManager.GetMaterialReference(material);
@@ -183,8 +224,8 @@ internal sealed class RenderGraphContext : IRasterRenderContext, IComputeRenderC
         // TODO: Global and view constants
         var data = new PushConstantsData
         {
-            objectIndex = _resourceManager.ResourceDatabase.GetBindlessIndex(_activePerMeshData.AsResource()),
+            objectIndex = _resourceDatabase.GetBindlessIndex(_activePerMeshData.AsResource()),
-            materialIndex = _resourceManager.ResourceDatabase.GetBindlessIndex(_activePerMaterialData.AsResource()),
+            materialIndex = _resourceDatabase.GetBindlessIndex(_activePerMaterialData.AsResource()),
         };
 
         var pushConstantSpan = new ReadOnlySpan<uint>(&data, sizeof(PushConstantsData) / sizeof(uint));
@@ -196,4 +237,4 @@ internal sealed class RenderGraphContext : IRasterRenderContext, IComputeRenderC
     {
         throw new NotImplementedException();
     }
-}
+}

src/Runtime/Ghost.Graphics/RenderGraphModule/RenderGraphExecutor.cs

@@ -3,30 +3,29 @@ using Ghost.Graphics.RHI;
 
 namespace Ghost.Graphics.RenderGraphModule;
 
-/// <summary>
-/// Handles execution of compiled render graphs, including barrier execution and native render passes.
-/// </summary>
 internal sealed class RenderGraphExecutor
 {
     private readonly IResourceManager _resourceManager;
+    private readonly IResourceDatabase _resourceDatabase;
     private readonly RenderGraphResourceRegistry _resources;
     private readonly RenderGraphContext _context;
 
+    private uint _frameIndex;
+
     public RenderGraphExecutor(
         IResourceManager resourceManager,
+        IResourceDatabase resourceDatabase,
         RenderGraphResourceRegistry resources,
         RenderGraphContext context)
     {
         _resourceManager = resourceManager;
+        _resourceDatabase = resourceDatabase;
         _resources = resources;
         _context = context;
     }
 
-    /// <summary>
-    /// Executes all compiled passes using native render passes where possible.
-    /// </summary>
     public unsafe Error Execute(
-        ICommandBuffer cmd,
+        ICommandBuffer commandBuffer,
         List<RenderGraphPassBase> compiledPasses,
         List<NativeRenderPass> nativePasses,
         List<CompiledBarrier> compiledBarriers)
@@ -35,7 +34,7 @@ internal sealed class RenderGraphExecutor
         var nativePassIndex = 0;
         var logicalPassIndex = 0;
 
-        _context.SetCommandBuffer(cmd);
+        _context.BeginNewFrame(_frameIndex++, commandBuffer);
 
         var pPassRTDescs = stackalloc PassRenderTargetDesc[8];
         var pRtFormats = stackalloc TextureFormat[8];
@@ -53,7 +52,7 @@ internal sealed class RenderGraphExecutor
                 for (var i = 0; i < nativePass.mergedPassIndices.Count; i++)
                 {
                     var mergedPassIdx = nativePass.mergedPassIndices[i];
-                    var e = ExecuteBarriersForPass(cmd, mergedPassIdx, ref barrierIndex, compiledBarriers);
+                    var e = ExecuteBarriersForPass(commandBuffer, mergedPassIdx, ref barrierIndex, compiledBarriers);
                     if (e != Error.None)
                     {
                         return e;
@@ -94,7 +93,7 @@ internal sealed class RenderGraphExecutor
                         : AttachmentStoreOp.DontCare
                 };
 
-                cmd.BeginRenderPass(new Span<PassRenderTargetDesc>(pPassRTDescs, nativePass.colorAttachmentCount), depthDesc);
+                commandBuffer.BeginRenderPass(new Span<PassRenderTargetDesc>(pPassRTDescs, nativePass.colorAttachmentCount), depthDesc);
 
                 for (var i = 0; i < nativePass.colorAttachmentCount; i++)
                 {
@@ -117,13 +116,13 @@ internal sealed class RenderGraphExecutor
                     logicalPassIndex++;
                 }
 
-                cmd.EndRenderPass();
+                commandBuffer.EndRenderPass();
                 nativePassIndex++;
             }
             else
             {
                 // Compute pass or standalone raster pass (not merged) or Unsafe pass
-                var e = ExecuteBarriersForPass(cmd, logicalPassIndex, ref barrierIndex, compiledBarriers);
+                var e = ExecuteBarriersForPass(commandBuffer, logicalPassIndex, ref barrierIndex, compiledBarriers);
                 if (e != Error.None)
                 {
                     return e;
@@ -137,10 +136,6 @@ internal sealed class RenderGraphExecutor
         return Error.None;
     }
 
-    /// <summary>
-    /// Executes all barriers for a specific pass.
-    /// Uses pre-compiled barriers and queries before state from ResourceManager.
-    /// </summary>
     private unsafe Error ExecuteBarriersForPass(
         ICommandBuffer cmd,
         int passIndex,
@@ -168,7 +163,7 @@ internal sealed class RenderGraphExecutor
             var resourceHandle = resource.backingResource;
 
             // Always query the before state from ResourceManager (single source of truth)
-            var currentStateResult = _resourceManager.ResourceDatabase.GetResourceBarrierData(resourceHandle);
+            var currentStateResult = _resourceDatabase.GetResourceBarrierData(resourceHandle);
             if (currentStateResult.IsFailure)
             {
                 return currentStateResult.Error;
@@ -184,7 +179,7 @@ internal sealed class RenderGraphExecutor
             if (compiledBarrier.AliasingPredecessor.IsValid)
             {
                 var predHandle = _resources.GetResource(compiledBarrier.AliasingPredecessor).backingResource;
-                var predStateResult = _resourceManager.ResourceDatabase.GetResourceBarrierData(predHandle);
+                var predStateResult = _resourceDatabase.GetResourceBarrierData(predHandle);
                 if (predStateResult.IsFailure)
                 {
                     return predStateResult.Error;

src/Runtime/Ghost.Graphics/RenderGraphModule/RenderGraphResourcePool.cs

@@ -4,10 +4,6 @@ using Misaki.HighPerformance.Buffer;
 
 namespace Ghost.Graphics.RenderGraphModule;
 
-/// <summary>
-/// Object pool for reusing allocated objects across frames.
-/// This is key to minimizing GC allocations after the first frame.
-/// </summary>
 internal sealed class RenderGraphObjectPool
 {
     private static readonly List<SharedObjectPoolBase> s_allocatedPools = new();
@@ -18,7 +14,8 @@ internal sealed class RenderGraphObjectPool
         public virtual void Clear() { }
     }
 
-    private class SharedObjectPool<T> : SharedObjectPoolBase where T : class, new()
+    private class SharedObjectPool<T> : SharedObjectPoolBase
+        where T : class, new()
     {
         private static readonly ObjectPool<T> s_pool = AllocatePool();
 
@@ -30,28 +27,20 @@ internal sealed class RenderGraphObjectPool
             return newPool;
         }
 
-        /// <summary>
-        /// Clear the pool using SharedObjectPool instance.
-        /// </summary>
-        /// <returns></returns>
         public override void Clear()
         {
             s_pool.Reset();
         }
 
-        /// <summary>
+        public static T Rent()
-        /// Rent a new instance from the pool.
+        {
-        /// </summary>
+            return s_pool.Rent();
-        /// <returns></returns>
+        }
-        // FIX: ObjectPool<T>.Rent() has a critical bug that it will put the newly created object into the pool directly and give out the same instance again.
-        // This will cause multiple renters to get the same instance.
-        public static T Rent() => s_pool.Rent();
 
-        /// <summary>
+        public static void Return(T toRelease)
-        /// Return an object to the pool.
+        {
-        /// </summary>
+            s_pool.Return(toRelease);
-        /// <param name="toRelease">instance to release.</param>
+        }
-        public static void Return(T toRelease) => s_pool.Return(toRelease);
     }
 
     public T Rent<T>()
@@ -75,9 +64,6 @@ internal sealed class RenderGraphObjectPool
     }
 }
 
-/// <summary>
-/// Represents a resource in the render graph (texture or buffer).
-/// </summary>
 internal sealed class RenderGraphResource
 {
     public string name = string.Empty;
@@ -121,11 +107,6 @@ internal sealed class RenderGraphResource
     }
 }
 
-/// <summary>
-/// Registry for managing all resources in the render graph.
-/// Uses pooling to minimize allocations after the first frame.
-/// Uses a single unified list for both textures and buffers with global indexing.
-/// </summary>
 internal sealed class RenderGraphResourceRegistry
 {
     private readonly RenderGraphObjectPool _pool;

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

@@ -1,11 +1,65 @@
 using Ghost.Graphics.Core;
+using Ghost.Graphics.RenderGraphModule;
 using Ghost.Graphics.RHI;
+using System.Runtime.CompilerServices;
 
 namespace Ghost.Graphics.RenderPipeline;
 
-public partial class GhostRenderPipeline : RenderPipelineBase
+public sealed class GhostRenderPipelineSettings : IRenderPipelineSettings
 {
-    public override void Render(RenderContext ctx, ReadOnlySpan<RenderRequest> requests)
+    public static IRenderPipeline CreatePipeline(IRenderSystem renderSystem)
     {
+        return new GhostRenderPipeline(renderSystem);
+    }
+}
+
+public unsafe partial class GhostRenderPipeline : IRenderPipeline
+{
+    private readonly RenderGraph _renderGraph;
+
+    private bool _disposed;
+
+    ~GhostRenderPipeline()
+    {
+        Dispose();
+    }
+
+    [MethodImpl(MethodImplOptions.AggressiveInlining)]
+    protected void ThrowIfDisposed()
+    {
+        ObjectDisposedException.ThrowIf(_disposed, this);
+    }
+
+    internal GhostRenderPipeline(IRenderSystem renderSystem)
+    {
+        _renderGraph = new RenderGraph(renderSystem.ResourceManager,
+                renderSystem.GraphicsEngine.ResourceAllocator,
+                renderSystem.GraphicsEngine.ResourceDatabase,
+                renderSystem.GraphicsEngine.PipelineLibrary,
+                renderSystem.GraphicsEngine.ShaderCompiler);
+    }
+
+    public void Render(RenderContext ctx, ReadOnlySpan<RenderRequest> requests)
+    {
+        for (int i = 0; i < requests.Length; i++)
+        {
+            ref readonly var request = ref requests[i];
+
+            if (request.renderFunc != null)
+            {
+                request.renderFunc(in ctx, in request);
+            }
+        }
+    }
+
+    public void Dispose()
+    {
+        if (_disposed)
+        {
+            return;
+        }
+
+        _disposed = true;
+        GC.SuppressFinalize(this);
     }
 }

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

@@ -0,0 +1,14 @@
+using Ghost.Graphics.Core;
+using Ghost.Graphics.RHI;
+
+namespace Ghost.Graphics.RenderPipeline;
+
+public interface IRenderPipelineSettings
+{
+    static abstract IRenderPipeline CreatePipeline(IRenderSystem renderSystem);
+}
+
+public interface IRenderPipeline : IDisposable
+{
+    void Render(RenderContext ctx, ReadOnlySpan<RenderRequest> requests);
+}

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

@@ -1,70 +0,0 @@
-using Ghost.Graphics.Core;
-using Ghost.Graphics.RHI;
-using System.Runtime.CompilerServices;
-using System.Runtime.InteropServices;
-
-namespace Ghost.Graphics.RenderPipeline;
-
-public interface IRenderPipeline : IDisposable
-{
-    void AddRenderList(RenderList renderList, string key);
-
-    void Render(RenderContext ctx, ReadOnlySpan<RenderRequest> requests);
-}
-
-public abstract class RenderPipelineBase : IRenderPipeline
-{
-    protected readonly Dictionary<string, RenderList> _renderLists = new();
-
-    private bool _disposed;
-
-    ~RenderPipelineBase()
-    {
-        Dispose();
-    }
-
-    [MethodImpl(MethodImplOptions.AggressiveInlining)]
-    protected void ThrowIfDisposed()
-    {
-        ObjectDisposedException.ThrowIf(_disposed, this);
-    }
-
-    public void AddRenderList(RenderList renderList, string key)
-    {
-        ThrowIfDisposed();
-
-        ref var existingList = ref CollectionsMarshal.GetValueRefOrAddDefault(_renderLists, key, out var exists);
-        if (!exists)
-        {
-            existingList = renderList;
-        }
-        else
-        {
-            existingList.Append(renderList);
-        }
-    }
-
-    public abstract void Render(RenderContext ctx, ReadOnlySpan<RenderRequest> requests);
-
-    public void Dispose()
-    {
-        if (_disposed)
-        {
-            return;
-        }
-
-        Dispose(true);
-
-        foreach (var list in _renderLists.Values)
-        {
-            list.Dispose();
-        }
-
-        _disposed = true;
-        GC.SuppressFinalize(this);
-    }
-
-    public virtual void Dispose(bool disposing)
-    {
-    }
-}

src/Runtime/Ghost.Graphics/RenderSystem.cs

@@ -6,6 +6,28 @@ using System.Collections.Concurrent;
 
 namespace Ghost.Graphics;
 
+public interface IRenderSystem : IFenceSynchronizer, IDisposable
+{
+    IGraphicsEngine GraphicsEngine
+    {
+        get;
+    }
+
+    IResourceManager ResourceManager
+    {
+        get;
+    }
+
+    bool IsRunning
+    {
+        get;
+    }
+
+    void Start();
+    void Stop();
+    void RequestSwapChainResize(ISwapChain swapChain, uint2 newSize);
+}
+
 public enum GraphicsAPI
 {
     Direct3D12
@@ -63,6 +85,7 @@ internal class RenderSystem : IRenderSystem
 
     private readonly RenderingConfig _config;
     private readonly IGraphicsEngine _graphicsEngine;
+    private readonly IResourceManager _resourceManager;
 
     private readonly FrameResource[] _frameResources;
     private readonly Thread _renderThread;
@@ -77,6 +100,7 @@ internal class RenderSystem : IRenderSystem
     private bool _disposed;
 
     public IGraphicsEngine GraphicsEngine => _graphicsEngine;
+    public IResourceManager ResourceManager => _resourceManager;
     public bool IsRunning => _isRunning;
 
     public uint CPUFenceValue => _cpuFenceValue;
@@ -107,6 +131,8 @@ internal class RenderSystem : IRenderSystem
                 throw new NotSupportedException($"The specified graphics API '{config.GraphicsAPI}' is not supported.");
         }
 
+        _resourceManager = new ResourceManager(_graphicsEngine.ResourceAllocator, _graphicsEngine.ResourceDatabase);
+
         // Create frame resources for synchronization
         _frameResources = new FrameResource[config.FrameBufferCount];
         for (var i = 0; i < config.FrameBufferCount; i++)

src/Runtime/Ghost.Graphics/ResourceManager.cs

@@ -9,16 +9,6 @@ namespace Ghost.Graphics;
 
 public interface IResourceManager
 {
-    IResourceAllocator ResourceAllocator
-    {
-        get;
-    }
-
-    IResourceDatabase ResourceDatabase
-    {
-        get;
-    }
-
     /// <summary>
     /// Creates a new mesh from the specified vertex and index data.
     /// </summary>
@@ -113,16 +103,13 @@ internal sealed class ResourceManager : IResourceManager, IDisposable
 
     private bool _disposed;
 
-    public IResourceAllocator ResourceAllocator => _resourceAllocator;
-    public IResourceDatabase ResourceDatabase => _resourceDatabase;
-
     public ResourceManager(IResourceAllocator resourceAllocator, IResourceDatabase resourceDatabase)
     {
         _resourceAllocator = resourceAllocator;
         _resourceDatabase = resourceDatabase;
 
         _meshes = new UnsafeSlotMap<Mesh>(64, Allocator.Persistent);
-        _materials = new UnsafeSlotMap<Material>(16, Allocator.Persistent);
+        _materials = new UnsafeSlotMap<Material>(64, Allocator.Persistent);
         _shaders = new UnsafeList<Shader>(16, Allocator.Persistent);
     }