Render graph: native pass merging & heap-based aliasing

Major architecture upgrade:
- Add native render pass merging (hardware pass grouping, load/store op inference)
- Implement heap-based aliasing for textures & buffers (D3D12-style)
- Unify resource model: buffers and textures in one registry
- Extend builder API for buffer creation/usage, access flags, hints
- Improve barrier/state tracking (buffer hints, indirect argument state)
- Update caching, hashing, and debug output for new model
- Add enums/structs: AttachmentLoadOp, StoreOp, BufferHint, etc.
- D3D12 backend: support named resources, temp upload buffers, correct heap usage
- Update docs, benchmarks, and project files for new features

Brings render graph closer to AAA engine standards, enabling efficient memory usage, lower driver overhead, and a more flexible API.

Ghost.Core/Utilities/EnumUtility.cs

@@ -0,0 +1,9 @@
+using System;
+using System.Collections.Generic;
+using System.Text;
+
+namespace Ghost.Core.Utilities;
+
+internal class EnumUtility
+{
+}

Ghost.Core/Utilities/Win32Utility.cs

@@ -2,8 +2,10 @@ using Misaki.HighPerformance.LowLevel;
 using System.ComponentModel;
 using System.Diagnostics;
 using System.Runtime.CompilerServices;
+using System.Runtime.InteropServices;
 using System.Runtime.Versioning;
 using TerraFX.Interop.Windows;
+using TerraFX.Interop.WinRT;
 
 namespace Ghost.Core.Utilities;
 

Ghost.Editor.Core/Controls/BasicInput/Float3Field.xaml

@@ -4,10 +4,10 @@
     xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
     xmlns:local="using:Ghost.Editor.Core.Controls">
 
-    <Style TargetType="local:Vector3Field">
+    <Style TargetType="local:Float3Field">
         <Setter Property="Template">
             <Setter.Value>
-                <ControlTemplate TargetType="local:Vector3Field">
+                <ControlTemplate TargetType="local:Float3Field">
                     <Grid ColumnSpacing="4">
                         <Grid.ColumnDefinitions>
                             <ColumnDefinition Width="Auto" />

Ghost.Entities/World.cs

@@ -57,7 +57,7 @@ public partial class World
         var world = s_worlds[id.Value];
         return world is null ? throw new InvalidOperationException("World not found.") : world;
 #else
-        return s_worlds[id.value]!;
+        return s_worlds[id.Value]!;
 #endif
     }
 

Ghost.Graphics.Test/Ghost.Graphics.Test.csproj

@@ -12,11 +12,6 @@
     <EnableMsixTooling>true</EnableMsixTooling>
     <Nullable>enable</Nullable>
   </PropertyGroup>
-  <ItemGroup>
-    <None Remove="Controls\DebugConsole.xaml" />
-    <None Remove="Windows\DebugOutputWindow.xaml" />
-    <None Remove="Windows\WorkGraphTestWindow.xaml" />
-  </ItemGroup>
 
   <ItemGroup>
     <Page Remove="UnitTestApp.xaml" />
@@ -48,8 +43,8 @@
   </ItemGroup>
   <ItemGroup>
     <PackageReference Include="Microsoft.TestPlatform.TestHost" Version="18.0.1" />
-    <PackageReference Include="Microsoft.Windows.SDK.BuildTools" Version="10.0.26100.7175" />
+    <PackageReference Include="Microsoft.Windows.SDK.BuildTools" Version="10.0.26100.7463" />
-    <PackageReference Include="Microsoft.WindowsAppSDK" Version="1.8.251106002" />
+    <PackageReference Include="Microsoft.WindowsAppSDK" Version="1.8.260101001" />
     <PackageReference Include="MSTest.TestAdapter" Version="4.0.2" />
     <PackageReference Include="MSTest.TestFramework" Version="4.0.2" />
   </ItemGroup>
@@ -57,11 +52,6 @@
     <ProjectReference Include="..\Ghost.Engine\Ghost.Engine.csproj" />
     <ProjectReference Include="..\Ghost.Test.Core\Ghost.Test.Core.csproj" />
   </ItemGroup>
-  <ItemGroup>
-    <Page Update="Windows\WorkGraphTestWindow.xaml">
-      <Generator>MSBuild:Compile</Generator>
-    </Page>
-  </ItemGroup>
 
   <!-- 
     Defining the "HasPackageAndPublishMenuAddedByProject" property here allows the Solution 

Ghost.Graphics.Test/UnitTestApp.xaml.cs

@@ -1,3 +1,4 @@
+using Ghost.Core;
 using Ghost.Graphics.Test.Windows;
 
 using Microsoft.UI.Xaml;
@@ -49,13 +50,15 @@ public partial class UnitTestApp : Application
     {
         LoadDll();
 
-        Microsoft.VisualStudio.TestPlatform.TestExecutor.UnitTestClient.CreateDefaultUI();
-
         _window = new GraphicsTestWindow();
         _window.Activate();
 
-        UITestMethodAttribute.DispatcherQueue = _window.DispatcherQueue;
+        UnhandledException += (sender, e) =>
-
+        {
-        Microsoft.VisualStudio.TestPlatform.TestExecutor.UnitTestClient.Run(Environment.CommandLine);
+            Logger.LogError(e.Exception);
+#if DEBUG
+            System.Diagnostics.Debugger.Break();
+#endif
+        };
     }
 }

Ghost.Graphics.Test/Windows/GraphicsTestWindow.xaml

@@ -34,14 +34,5 @@
             Height="4"
             HorizontalAlignment="Stretch"
             Background="{ThemeResource SystemControlBackgroundBaseLowBrush}" />
-
-        <!--  Debug Console  -->
-        <Border
-            Grid.Row="2"
-            Background="{ThemeResource SystemControlBackgroundAltHighBrush}"
-            BorderBrush="{ThemeResource SystemControlForegroundBaseLowBrush}"
-            BorderThickness="0,1,0,0">
-            <controls:DebugConsole x:Name="DebugConsole" />
-        </Border>
     </Grid>
 </Window>

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

@@ -71,9 +71,7 @@ public sealed partial class GraphicsTestWindow : Window
         _swapChain?.Dispose();
         _renderSystem?.Dispose();
 
-#if DEBUG
         Misaki.HighPerformance.LowLevel.Buffer.AllocationManager.Dispose();
-#endif
     }
 
     private void SwapChainPanel_SizeChanged(object sender, SizeChangedEventArgs e)
@@ -110,10 +108,7 @@ public sealed partial class GraphicsTestWindow : Window
 
         if (_renderSystem.CPUFenceValue < _renderSystem.GPUFenceValue + _renderSystem.MaxFrameLatency)
         {
-            DispatcherQueue.TryEnqueue(Microsoft.UI.Dispatching.DispatcherQueuePriority.High, () =>
+            _renderSystem.SignalCPUReady();
-            {
-                _renderSystem.SignalCPUReady();
-            });
         }
     }
 }

Ghost.Graphics.Test/Windows/WorkGraphTestWindow.xaml

@@ -1,22 +0,0 @@
-<?xml version="1.0" encoding="utf-8" ?>
-<Window
-    x:Class="Ghost.Graphics.Test.Windows.WorkGraphTestWindow"
-    xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
-    xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
-    xmlns:d="http://schemas.microsoft.com/expression/blend/2008"
-    xmlns:local="using:Ghost.Graphics.Test.Windows"
-    xmlns:mc="http://schemas.openxmlformats.org/markup-compatibility/2006"
-    Title="WorkGraphTestWindow"
-    mc:Ignorable="d">
-
-    <Window.SystemBackdrop>
-        <MicaBackdrop />
-    </Window.SystemBackdrop>
-
-    <Grid>
-        <SwapChainPanel
-            x:Name="Panel"
-            HorizontalAlignment="Stretch"
-            VerticalAlignment="Stretch" />
-    </Grid>
-</Window>

Ghost.Graphics.Test/Windows/WorkGraphTestWindow.xaml.cs

@@ -1,16 +0,0 @@
-using Microsoft.UI.Xaml;
-
-// To learn more about WinUI, the WinUI project structure,
-// and more about our project templates, see: http://aka.ms/winui-project-info.
-
-namespace Ghost.Graphics.Test.Windows;
-/// <summary>
-/// An empty window that can be used on its own or navigated to within a Frame.
-/// </summary>
-public sealed unsafe partial class WorkGraphTestWindow : Window
-{
-    public WorkGraphTestWindow()
-    {
-        InitializeComponent();
-    }
-}

Ghost.Graphics/AssemblyInfo.cs

@@ -4,7 +4,6 @@ global using static TerraFX.Interop.DirectX.DXGI;
 global using static TerraFX.Interop.Windows.Windows;
 
 using Ghost.Core.Attributes;
-using Ghost.Core.Utilities;
 using System.Runtime.CompilerServices;
 using System.Runtime.Versioning;
 
@@ -12,6 +11,7 @@ using System.Runtime.Versioning;
 [assembly: InternalsVisibleTo("Ghost.Editor")]
 [assembly: InternalsVisibleTo("Ghost.Editor.Core")]
 [assembly: InternalsVisibleTo("Ghost.Graphics.Test")]
+[assembly: InternalsVisibleTo("Ghost.Graphics.Test-Winui")]
 [assembly: SupportedOSPlatform("windows10.0.19041.0")]
 
 

Ghost.Graphics/Core/Keyword.cs

@@ -42,7 +42,7 @@ public unsafe struct LocalKeywordSet
 
     public ulong GetHash64()
     {
-        ulong hash = 14695981039346656037ul; // FNV offset basis
+        ulong hash = 14695981039346656037ul; // FNV Offset basis
 
         for (var i = 0; i < _DATA_ARRAY_LENGTH; i++)
         {

Ghost.Graphics/Core/Material.cs

@@ -111,7 +111,7 @@ public struct Material : IResourceReleasable
                 MemoryType = ResourceMemoryType.Default,
             };
 
-            var buffer = allocator.CreateBuffer(ref desc);
+            var buffer = allocator.CreateBuffer(ref desc, "MaterialCBuffer");
             _cBufferCache = new CBufferCache(buffer, shader.CBufferSize);
         }
 
@@ -214,14 +214,15 @@ public struct Material : IResourceReleasable
     }
 
     [MethodImpl(MethodImplOptions.AggressiveInlining)]
-    public readonly void UploadData(ICommandBuffer cmb, bool pixelOnlyResource = true)
+    public readonly void UploadData(ICommandBuffer cmd, bool pixelOnlyResource = true)
     {
-        cmb.UploadBuffer(_cBufferCache.GpuResource, _cBufferCache.CpuData.AsSpan());
+        cmd.ResourceBarrier(_cBufferCache.GpuResource.AsResource(), ResourceState.CopyDest);
+        cmd.UploadBuffer(_cBufferCache.GpuResource, _cBufferCache.CpuData.AsSpan());
 
         var state = pixelOnlyResource
             ? ResourceState.PixelShaderResource
             : ResourceState.NonPixelShaderResource | ResourceState.PixelShaderResource;
-        cmb.ResourceBarrier(_cBufferCache.GpuResource.AsResource(), state);
+        cmd.ResourceBarrier(_cBufferCache.GpuResource.AsResource(), state);
     }
 
     [MethodImpl(MethodImplOptions.AggressiveInlining)]

Ghost.Graphics/Core/RenderingContext.cs

@@ -127,10 +127,10 @@ public readonly unsafe ref struct RenderingContext
         _directCmd.ResourceBarrier(bufferHandle, ResourceState.NonPixelShaderResource | ResourceState.PixelShaderResource);
     }
 
-    public Handle<Texture> CreateTexture<T>(ref readonly TextureDesc desc, ReadOnlySpan<T> data, bool tempResource = false)
+    public Handle<Texture> CreateTexture<T>(ref readonly TextureDesc desc, ReadOnlySpan<T> data, string name)
         where T : unmanaged
     {
-        var handle = ResourceAllocator.CreateTexture(in desc, tempResource);
+        var handle = ResourceAllocator.CreateTexture(in desc, name);
         UploadTexture(handle, data);
 
         return handle;

Ghost.Graphics/Core/SwapChainPresenter.cs

@@ -1,54 +0,0 @@
-using Ghost.Graphics.Contracts;
-
-namespace Ghost.Graphics.Core;
-
-internal readonly struct SwapChainPresenter
-{
-    public enum TargetType
-    {
-        Composition,
-        Hwnd
-    }
-
-    public readonly TargetType Type
-    {
-        get;
-    }
-
-    public readonly ISwapChainPanelNative SwapChainPanelNative
-    {
-        get;
-    }
-
-    public readonly nint Hwnd
-    {
-        get;
-    }
-
-    public readonly uint Width
-    {
-        get;
-    }
-
-    public readonly uint Height
-    {
-        get;
-    }
-
-    public SwapChainPresenter(ISwapChainPanelNative swapChainPanelNative, uint width, uint height)
-    {
-        Type = TargetType.Composition;
-        SwapChainPanelNative = swapChainPanelNative;
-        Hwnd = nint.Zero;
-        Width = width;
-        Height = height;
-    }
-
-    public SwapChainPresenter(nint hwnd, uint width, uint height)
-    {
-        Type = TargetType.Hwnd;
-        Hwnd = hwnd;
-        Width = width;
-        Height = height;
-    }
-}

Ghost.Graphics/D3D12/D3D12CommandBuffer.cs

@@ -151,8 +151,8 @@ internal unsafe class D3D12CommandBuffer : ICommandBuffer
             // Set descriptor heaps for bindless resources and samplers
 
             var heaps = stackalloc ID3D12DescriptorHeap*[2];
-            heaps[0] = _descriptorAllocator.GetCbvSrvUavHeap(); // Bindless resource heap
+            heaps[0] = _descriptorAllocator.GetCbvSrvUavHeap(); // Bindless resource Heap
-            heaps[1] = _descriptorAllocator.GetSamplerHeap();   // Bindless sampler heap
+            heaps[1] = _descriptorAllocator.GetSamplerHeap();   // Bindless sampler Heap
             _commandList.Get()->SetDescriptorHeaps(2, heaps);
         }
 
@@ -401,20 +401,39 @@ internal unsafe class D3D12CommandBuffer : ICommandBuffer
             var format = record.desc.TextureDescription.Format.ToDXGIFormat();
             var clearColor = rtDesc.ClearColor;
 
+            // Map load operation
+            var loadAccessType = rtDesc.LoadOp switch
+            {
+                AttachmentLoadOp.Load => D3D12_RENDER_PASS_BEGINNING_ACCESS_TYPE_PRESERVE,
+                AttachmentLoadOp.Clear => D3D12_RENDER_PASS_BEGINNING_ACCESS_TYPE_CLEAR,
+                AttachmentLoadOp.DontCare => D3D12_RENDER_PASS_BEGINNING_ACCESS_TYPE_DISCARD,
+                _ => D3D12_RENDER_PASS_BEGINNING_ACCESS_TYPE_PRESERVE
+            };
+
+            // Map store operation
+            var storeAccessType = rtDesc.StoreOp switch
+            {
+                AttachmentStoreOp.Store => D3D12_RENDER_PASS_ENDING_ACCESS_TYPE_PRESERVE,
+                AttachmentStoreOp.DontCare => D3D12_RENDER_PASS_ENDING_ACCESS_TYPE_DISCARD,
+                _ => D3D12_RENDER_PASS_ENDING_ACCESS_TYPE_PRESERVE
+            };
+
             var desc = new D3D12_RENDER_PASS_RENDER_TARGET_DESC
             {
                 cpuDescriptor = cpuHandle,
                 BeginningAccess = new D3D12_RENDER_PASS_BEGINNING_ACCESS
                 {
-                    Type = D3D12_RENDER_PASS_BEGINNING_ACCESS_TYPE_CLEAR,
+                    Type = loadAccessType,
-                    Clear = new D3D12_RENDER_PASS_BEGINNING_ACCESS_CLEAR_PARAMETERS
+                    Clear = loadAccessType == D3D12_RENDER_PASS_BEGINNING_ACCESS_TYPE_CLEAR
-                    {
+                        ? new D3D12_RENDER_PASS_BEGINNING_ACCESS_CLEAR_PARAMETERS
-                        ClearValue = new D3D12_CLEAR_VALUE(format, (float*)&clearColor)
+                        {
-                    }
+                            ClearValue = new D3D12_CLEAR_VALUE(format, (float*)&clearColor)
+                        }
+                        : default
                 },
                 EndingAccess = new D3D12_RENDER_PASS_ENDING_ACCESS
                 {
-                    Type = D3D12_RENDER_PASS_ENDING_ACCESS_TYPE_PRESERVE
+                    Type = storeAccessType
                 }
             };
 
@@ -435,16 +454,70 @@ internal unsafe class D3D12CommandBuffer : ICommandBuffer
             var cpuHandle = _descriptorAllocator.GetCpuHandle(record.viewGroup.dsv);
             var format = record.desc.TextureDescription.Format.ToDXGIFormat();
 
+            // Map depth load operation
+            var depthLoadAccessType = depthDesc.DepthLoadOp switch
+            {
+                AttachmentLoadOp.Load => D3D12_RENDER_PASS_BEGINNING_ACCESS_TYPE_PRESERVE,
+                AttachmentLoadOp.Clear => D3D12_RENDER_PASS_BEGINNING_ACCESS_TYPE_CLEAR,
+                AttachmentLoadOp.DontCare => D3D12_RENDER_PASS_BEGINNING_ACCESS_TYPE_DISCARD,
+                _ => D3D12_RENDER_PASS_BEGINNING_ACCESS_TYPE_PRESERVE
+            };
+
+            // Map depth store operation
+            var depthStoreAccessType = depthDesc.DepthStoreOp switch
+            {
+                AttachmentStoreOp.Store => D3D12_RENDER_PASS_ENDING_ACCESS_TYPE_PRESERVE,
+                AttachmentStoreOp.DontCare => D3D12_RENDER_PASS_ENDING_ACCESS_TYPE_DISCARD,
+                _ => D3D12_RENDER_PASS_ENDING_ACCESS_TYPE_PRESERVE
+            };
+
+            // Map stencil load operation
+            var stencilLoadAccessType = depthDesc.StencilLoadOp switch
+            {
+                AttachmentLoadOp.Load => D3D12_RENDER_PASS_BEGINNING_ACCESS_TYPE_PRESERVE,
+                AttachmentLoadOp.Clear => D3D12_RENDER_PASS_BEGINNING_ACCESS_TYPE_CLEAR,
+                AttachmentLoadOp.DontCare => D3D12_RENDER_PASS_BEGINNING_ACCESS_TYPE_DISCARD,
+                _ => D3D12_RENDER_PASS_BEGINNING_ACCESS_TYPE_PRESERVE
+            };
+
+            // Map stencil store operation
+            var stencilStoreAccessType = depthDesc.StencilStoreOp switch
+            {
+                AttachmentStoreOp.Store => D3D12_RENDER_PASS_ENDING_ACCESS_TYPE_PRESERVE,
+                AttachmentStoreOp.DontCare => D3D12_RENDER_PASS_ENDING_ACCESS_TYPE_DISCARD,
+                _ => D3D12_RENDER_PASS_ENDING_ACCESS_TYPE_PRESERVE
+            };
+
             var desc = new D3D12_RENDER_PASS_DEPTH_STENCIL_DESC
             {
                 cpuDescriptor = cpuHandle,
                 DepthBeginningAccess = new D3D12_RENDER_PASS_BEGINNING_ACCESS
                 {
-                    Type = D3D12_RENDER_PASS_BEGINNING_ACCESS_TYPE_CLEAR,
+                    Type = depthLoadAccessType,
-                    Clear = new D3D12_RENDER_PASS_BEGINNING_ACCESS_CLEAR_PARAMETERS
+                    Clear = depthLoadAccessType == D3D12_RENDER_PASS_BEGINNING_ACCESS_TYPE_CLEAR
-                    {
+                        ? new D3D12_RENDER_PASS_BEGINNING_ACCESS_CLEAR_PARAMETERS
-                        ClearValue = new D3D12_CLEAR_VALUE(format, depthDesc.ClearDepth, depthDesc.ClearStencil)
+                        {
-                    }
+                            ClearValue = new D3D12_CLEAR_VALUE(format, depthDesc.ClearDepth, depthDesc.ClearStencil)
+                        }
+                        : default
+                },
+                DepthEndingAccess = new D3D12_RENDER_PASS_ENDING_ACCESS
+                {
+                    Type = depthStoreAccessType
+                },
+                StencilBeginningAccess = new D3D12_RENDER_PASS_BEGINNING_ACCESS
+                {
+                    Type = stencilLoadAccessType,
+                    Clear = stencilLoadAccessType == D3D12_RENDER_PASS_BEGINNING_ACCESS_TYPE_CLEAR
+                        ? new D3D12_RENDER_PASS_BEGINNING_ACCESS_CLEAR_PARAMETERS
+                        {
+                            ClearValue = new D3D12_CLEAR_VALUE(format, depthDesc.ClearDepth, depthDesc.ClearStencil)
+                        }
+                        : default
+                },
+                StencilEndingAccess = new D3D12_RENDER_PASS_ENDING_ACCESS
+                {
+                    Type = stencilStoreAccessType
                 }
             };
 
@@ -731,22 +804,19 @@ internal unsafe class D3D12CommandBuffer : ICommandBuffer
 
         var sizeInBytes = (uint)(data.Length * sizeof(T));
 
-        var uploadHandle = _resourceAllocator.CreateUploadBuffer(sizeInBytes);
+        var uploadHandle = _resourceAllocator.CreateTempUploadBuffer(sizeInBytes, out var offset);
         var uploadResource = _resourceDatabase.GetResource(uploadHandle.AsResource());
 
         void* pMappedData;
         uploadResource.Get()->Map(0, null, &pMappedData);
         fixed (T* pData = data)
         {
-            MemoryUtility.MemCpy(pMappedData, pData, sizeInBytes);
+            MemoryUtility.MemCpy((byte*)pMappedData + offset, pData, sizeInBytes);
         }
         uploadResource.Get()->Unmap(0, null);
 
         var pResource = _resourceDatabase.GetResource(buffer.AsResource());
-
+        _commandList.Get()->CopyBufferRegion(pResource, 0, uploadResource, offset, sizeInBytes);
-        _commandList.Get()->CopyBufferRegion(pResource, 0, uploadResource, 0, sizeInBytes);
-        // D3D12 transition resource to COPY_DEST when copying
-        _resourceDatabase.SetResourceState(buffer.AsResource(), ResourceState.CopyDest);
     }
 
     public void UploadTexture(Handle<Texture> texture, ReadOnlySpan<SubResourceData> subresources)
@@ -766,7 +836,7 @@ internal unsafe class D3D12CommandBuffer : ICommandBuffer
         var resourceDesc = resource.Get()->GetDesc();
         var requiredSize = GetRequiredIntermediateSize(resource, 0, (uint)subresources.Length);
 
-        var uploadHandle = _resourceAllocator.CreateUploadBuffer(requiredSize);
+        var uploadHandle = _resourceAllocator.CreateTempUploadBuffer(requiredSize, out var offset);
         var pUploadResource = _resourceDatabase.GetResource(uploadHandle.AsResource());
 
         var d3d12Subresources = stackalloc D3D12_SUBRESOURCE_DATA[subresources.Length];
@@ -784,7 +854,7 @@ internal unsafe class D3D12CommandBuffer : ICommandBuffer
             (ID3D12GraphicsCommandList*)_commandList.Get(),
             resource,
             pUploadResource,
-            0,
+            offset,
             0,
             (uint)subresources.Length,
             d3d12Subresources);

Ghost.Graphics/D3D12/D3D12DescriptorAllocator.cs

@@ -386,22 +386,22 @@ internal unsafe class D3D12DescriptorAllocator : IDisposable
     #region Utility Methods
 
     /// <summary>
-    /// Gets the RTV heap for binding to the command list.
+    /// Gets the RTV Heap for binding to the command list.
     /// </summary>
     public ID3D12DescriptorHeap* GetRTVHeap() => _rtvHeap.Heap;
 
     /// <summary>
-    /// Gets the DSV heap for binding to the command list.
+    /// Gets the DSV Heap for binding to the command list.
     /// </summary>
     public ID3D12DescriptorHeap* GetDSVHeap() => _dsvHeap.Heap;
 
     /// <summary>
-    /// Gets the CBV/SRV/UAV heap for binding to the command list.
+    /// Gets the CBV/SRV/UAV Heap for binding to the command list.
     /// </summary>
     public ID3D12DescriptorHeap* GetCbvSrvUavHeap() => _cbvSrvUavHeap.ShaderVisibleHeap;
 
     /// <summary>
-    /// Gets the sampler heap for binding to the command list.
+    /// Gets the sampler Heap for binding to the command list.
     /// </summary>
     public ID3D12DescriptorHeap* GetSamplerHeap() => _samplerHeap.ShaderVisibleHeap;
 

Ghost.Graphics/D3D12/D3D12DescriptorHeap.cs

@@ -138,7 +138,7 @@ internal unsafe struct D3D12DescriptorHeap : IDisposable
         }
 
         // NOTE: In dynamic allocation, we use arena-style allocation without freeing.
-        // We reset the offset at the beginning of each frame instead.
+        // We reset the Offset at the beginning of each frame instead.
 
         lock (_lock)
         {

Ghost.Graphics/D3D12/D3D12PipelineLibrary.cs

@@ -165,7 +165,7 @@ internal unsafe class D3D12PipelineLibrary : IPipelineLibrary
         }
 
         var size = _library.Get()->GetSerializedSize();
-        using var buffer = new UnsafeArray<byte>((int)size, Allocator.Persistent); // We use persistent heap allocation instead of stack allocation to avoid stack overflow for large pipeline libraries.
+        using var buffer = new UnsafeArray<byte>((int)size, Allocator.Persistent); // We use persistent Heap allocation instead of stack allocation to avoid stack overflow for large pipeline libraries.
 
         ThrowIfFailed(_library.Get()->Serialize(buffer.GetUnsafePtr(), size));
 

Ghost.Graphics/D3D12/D3D12RenderDevice.cs

@@ -115,6 +115,11 @@ internal unsafe class D3D12RenderDevice : IRenderDevice
             {
                 support |= FeatureSupport.BindlessResources;
             }
+
+            if (options.ResourceHeapTier == D3D12_RESOURCE_HEAP_TIER.D3D12_RESOURCE_HEAP_TIER_2)
+            {
+                support |= FeatureSupport.AliasBuffersAndTextures;
+            }
         }
 
         D3D12_FEATURE_DATA_D3D12_OPTIONS5 options5 = default;

Ghost.Graphics/D3D12/D3D12Renderer.cs

@@ -95,6 +95,8 @@ internal class D3D12Renderer : IRenderer
             {
                 Texture = target,
                 ClearColor = clearColor,
+                LoadOp = AttachmentLoadOp.Clear,
+                StoreOp = AttachmentStoreOp.Store,
             },
         ];
 
@@ -103,6 +105,10 @@ internal class D3D12Renderer : IRenderer
             Texture = Handle<Texture>.Invalid,
             ClearDepth = 1.0f,
             ClearStencil = 0,
+            DepthLoadOp = AttachmentLoadOp.Clear,
+            StencilLoadOp = AttachmentLoadOp.Clear,
+            DepthStoreOp = AttachmentStoreOp.Store,
+            StencilStoreOp = AttachmentStoreOp.Store,
         };
 
         // NOTE: Testing only.

Ghost.Graphics/D3D12/D3D12ResourceAllocator.cs

@@ -5,9 +5,11 @@ using Ghost.Graphics.Core;
 using Ghost.Graphics.D3D12.Utilities;
 using Ghost.Graphics.RHI;
 using Misaki.HighPerformance.LowLevel;
+using Misaki.HighPerformance.LowLevel.Buffer;
 using Misaki.HighPerformance.LowLevel.Collections;
 using System.Diagnostics;
 using System.Runtime.CompilerServices;
+using System.Xml.Linq;
 using TerraFX.Interop.DirectX;
 using TerraFX.Interop.Windows;
 
@@ -512,9 +514,9 @@ internal sealed unsafe partial class D3D12ResourceAllocator
 
         var state = D3D12_RESOURCE_STATE_COMMON;
 #if true
+        // D3D12 does not support state other than COMMON for buffers at creation.
         return state;
 #else
-        // D3D12 does not support state other than COMMON for buffers at creation.
         if (usage.HasFlag(BufferUsage.Vertex) || usage.HasFlag(BufferUsage.Constant))
         {
             // Vertex and Constant buffers can share this state
@@ -557,13 +559,11 @@ internal sealed unsafe partial class D3D12ResourceAllocator
     }
 }
 
-// TODO: Dedicated pool for copy, render graph, and persistent resources
-
-// TODO: Thread safety for resource allocator
-// A common solution is to use ticket. Each pAllocation request create a ticket and put it into a thread-safe queue. A dedicated thread process the queue and fulfill the requests.
-
 internal sealed unsafe partial class D3D12ResourceAllocator : IResourceAllocator
 {
+    private const uint _UPLOAD_BATCH_SIZE = 64 * 1024 * 1024; // 64 MB
+    private const uint _MAX_RESOURCE_SIZE_TO_FIT_IN_UPLOAD_BATCH = 16 * 1024 * 1024; // 16 MB
+
     private UniquePtr<D3D12MA_Allocator> _d3d12MA;
 
     private readonly IFenceSynchronizer _fenceSynchronizer;
@@ -574,6 +574,9 @@ internal sealed unsafe partial class D3D12ResourceAllocator : IResourceAllocator
 
     private UnsafeQueue<Handle<GPUResource>> _tempResources;
 
+    private readonly Handle<GraphicsBuffer> _uploadBatch;
+    private ulong _uploadBatchOffset;
+
     private bool _disposed;
 
     public D3D12ResourceAllocator(
@@ -600,7 +603,18 @@ internal sealed unsafe partial class D3D12ResourceAllocator : IResourceAllocator
         _resourceDatabase = resourceDatabase;
         _pipelineLibrary = pipelineLibrary;
 
-        _tempResources = new UnsafeQueue<Handle<GPUResource>>(64, Misaki.HighPerformance.LowLevel.Buffer.Allocator.Persistent);
+        _tempResources = new UnsafeQueue<Handle<GPUResource>>(64, Allocator.Persistent);
+
+        // Create an upload batch
+        var uploadDesc = new BufferDesc
+        {
+            Size = _UPLOAD_BATCH_SIZE,
+            Usage = BufferUsage.Upload,
+            MemoryType = ResourceMemoryType.Upload,
+        };
+
+        _uploadBatch = CreateBuffer(in uploadDesc, "D3D12ResourceAllocator_UploadBatch");
+        _uploadBatchOffset = 0;
     }
 
     ~D3D12ResourceAllocator()
@@ -609,9 +623,9 @@ internal sealed unsafe partial class D3D12ResourceAllocator : IResourceAllocator
     }
 
     [MethodImpl(MethodImplOptions.AggressiveInlining)]
-    private Handle<GPUResource> TrackResource(D3D12MA_Allocation* allocation, D3D12_RESOURCE_STATES state, ResourceViewGroup resourceDescriptor, ResourceDesc desc, bool isTemp)
+    private Handle<GPUResource> TrackResource(D3D12MA_Allocation* allocation, D3D12_RESOURCE_STATES state, ResourceViewGroup resourceDescriptor, ResourceDesc desc, string name, bool isTemp)
     {
-        var handle = _resourceDatabase.AddResource(allocation, _fenceSynchronizer.CPUFenceValue, D3D12Utility.ToResourceState(state) , resourceDescriptor, desc);
+        var handle = _resourceDatabase.AddAllocation(allocation, _fenceSynchronizer.CPUFenceValue, D3D12Utility.ToResourceState(state), resourceDescriptor, desc, name);
 
         if (isTemp)
         {
@@ -621,7 +635,70 @@ internal sealed unsafe partial class D3D12ResourceAllocator : IResourceAllocator
         return handle;
     }
 
-    public Handle<Texture> CreateTexture(ref readonly TextureDesc desc, bool isTemp = false)
+    private HRESULT CreateResource(D3D12MA_ALLOCATION_DESC* pAllocationDesc, D3D12_RESOURCE_DESC* pResourceDesc, D3D12_RESOURCE_STATES initialState, CreationOptions options, void** ppv)
+    {
+        var hr = S.S_OK;
+        var iid = IID.IID_NULL;
+
+        if (options.AllocationType == ResourceAllocationType.RenderGraphTransient)
+        {
+            // pAllocation should be the render graph Heap. ppvResource should be the out resource.
+            var result = _resourceDatabase.GetResourceRecord(options.Heap);
+            if (result.IsFailure)
+            {
+                return E.E_NOTFOUND;
+            }
+
+            hr = _d3d12MA.Get()->CreateAliasingResource(result.Value.resource.allocation.Get(), options.Offset, pResourceDesc, initialState, null, &iid, ppv);
+        }
+        else
+        {
+            hr = _d3d12MA.Get()->CreateResource(pAllocationDesc, pResourceDesc, initialState, null, (D3D12MA_Allocation**)ppv, &iid, null);
+        }
+
+        return hr;
+    }
+
+    public Handle<GPUResource> Allocate(ref readonly AllocationDesc desc, string name)
+    {
+        var allocDesc = new D3D12MA_ALLOCATION_DESC
+        {
+            HeapType = desc.HeapType switch
+            {
+                HeapType.Default => D3D12_HEAP_TYPE_DEFAULT,
+                HeapType.Upload => D3D12_HEAP_TYPE_UPLOAD,
+                HeapType.Readback => D3D12_HEAP_TYPE_READBACK,
+                _ => D3D12_HEAP_TYPE_DEFAULT
+            },
+            Flags = D3D12MA_ALLOCATION_FLAG_COMMITTED,
+            ExtraHeapFlags = desc.HeapFlags switch
+            {
+                HeapFlags.None => D3D12_HEAP_FLAG_NONE,
+                HeapFlags.AllowBuffers => D3D12_HEAP_FLAG_ALLOW_ONLY_BUFFERS,
+                HeapFlags.AllowTextures => D3D12_HEAP_FLAG_ALLOW_ONLY_NON_RT_DS_TEXTURES,
+                HeapFlags.AllowRTAndDS => D3D12_HEAP_FLAG_ALLOW_ONLY_RT_DS_TEXTURES,
+                HeapFlags.AlowBufferAndTexture => D3D12_HEAP_FLAG_ALLOW_ALL_BUFFERS_AND_TEXTURES,
+                _ => D3D12_HEAP_FLAG_NONE
+            }
+        };
+
+        // SizeInBytes must be aligned to 64KB for committed resources
+        var allocInfo = new D3D12_RESOURCE_ALLOCATION_INFO
+        {
+            SizeInBytes = desc.Size + 65535 & ~65535u,
+            Alignment = desc.Alignment
+        };
+
+        D3D12MA_Allocation* alloc = default;
+        if (_d3d12MA.Get()->AllocateMemory(&allocDesc, &allocInfo, &alloc).FAILED)
+        {
+            return Handle<GPUResource>.Invalid;
+        }
+
+        return TrackResource(alloc, D3D12_RESOURCE_STATE_COMMON, ResourceViewGroup.Invalid, default, name, false);
+    }
+
+    public Handle<Texture> CreateTexture(ref readonly TextureDesc desc, string name, CreationOptions options = default)
     {
         ObjectDisposedException.ThrowIf(_disposed, this);
 
@@ -681,14 +758,17 @@ internal sealed unsafe partial class D3D12ResourceAllocator : IResourceAllocator
         var initialState = DetermineInitialTextureState(desc.Usage);
 
         D3D12MA_Allocation* pAllocation = default;
-        var iid = IID.IID_NULL;
+        if (CreateResource(&allocationDesc, &resourceDesc, initialState, options, (void**)&pAllocation).FAILED)
-        ThrowIfFailed(_d3d12MA.Get()->CreateResource(&allocationDesc, &resourceDesc, initialState, null, &pAllocation, &iid, null));
+        {
+            return Handle<Texture>.Invalid;
+        }
 
+        var isTemp = options.AllocationType == ResourceAllocationType.Temporary;
         var resourceDescriptor = ResourceViewGroup.Invalid;
         if (desc.Usage.HasFlag(TextureUsage.ShaderResource))
         {
             resourceDescriptor.srv = _descriptorAllocator.AllocateCbvSrvUav(isTemp);
-            // TODO: Maybe use non-shader-visible descriptor first then batch copy to shader-visible heap later?
+            // TODO: Maybe use non-shader-visible descriptor first then batch copy to shader-visible Heap later?
             var cpuHandle = _descriptorAllocator.GetCpuHandleShaderVisible(resourceDescriptor.srv);
 
             var isCubeMap = desc.Dimension == TextureDimension.TextureCube || desc.Dimension == TextureDimension.TextureCubeArray;
@@ -724,20 +804,20 @@ internal sealed unsafe partial class D3D12ResourceAllocator : IResourceAllocator
             _device.NativeDevice.Get()->CreateUnorderedAccessView(pAllocation->GetResource(), null, &uavDesc, cpuHandle);
         }
 
-        var handle = TrackResource(pAllocation, initialState, resourceDescriptor, ResourceDesc.Texture(desc), isTemp);
+        var handle = TrackResource(pAllocation, initialState, resourceDescriptor, ResourceDesc.Texture(desc), name, isTemp);
 
         return handle.AsTexture();
     }
 
-    public Handle<Texture> CreateRenderTarget(ref readonly RenderTargetDesc desc, bool isTemp = false)
+    public Handle<Texture> CreateRenderTarget(ref readonly RenderTargetDesc desc, string name, CreationOptions options = default)
     {
         ObjectDisposedException.ThrowIf(_disposed, this);
 
         var textureDesc = desc.ToTextureDescripton();
-        return CreateTexture(in textureDesc, isTemp);
+        return CreateTexture(in textureDesc, name, options);
     }
 
-    public Handle<GraphicsBuffer> CreateBuffer(ref readonly BufferDesc desc, bool isTemp = false)
+    public Handle<GraphicsBuffer> CreateBuffer(ref readonly BufferDesc desc, string name, CreationOptions options = default)
     {
         ObjectDisposedException.ThrowIf(_disposed, this);
         CheckBufferSize(desc.Size);
@@ -749,21 +829,24 @@ internal sealed unsafe partial class D3D12ResourceAllocator : IResourceAllocator
             alignedSize = (uint)(desc.Size + 255) & ~255u;
         }
 
-        var resourceDescription = D3D12_RESOURCE_DESC.Buffer(alignedSize, ConvertBufferUsage(desc.Usage));
+        var resourceDesc = D3D12_RESOURCE_DESC.Buffer(alignedSize, ConvertBufferUsage(desc.Usage));
         var isRaw = desc.Usage.HasFlag(BufferUsage.Raw);
 
         var allocationDesc = new D3D12MA_ALLOCATION_DESC
         {
             HeapType = ConvertMemoryType(desc.MemoryType),
-            Flags = D3D12MA_ALLOCATION_FLAG_NONE
+            Flags = D3D12MA_ALLOCATION_FLAG_NONE,
         };
 
         var initialState = DetermineInitialBufferState(desc.Usage, desc.MemoryType);
 
         D3D12MA_Allocation* pAllocation = default;
-        var iid = IID.IID_NULL;
+        if (CreateResource(&allocationDesc, &resourceDesc, initialState, options, (void**)&pAllocation).FAILED)
-        ThrowIfFailed(_d3d12MA.Get()->CreateResource(&allocationDesc, &resourceDescription, initialState, null, &pAllocation, &iid, null));
+        {
+            return Handle<GraphicsBuffer>.Invalid;
+        }
 
+        var isTemp = options.AllocationType == ResourceAllocationType.Temporary;
         var resourceDescriptor = ResourceViewGroup.Invalid;
         var pResource = pAllocation->GetResource();
 
@@ -798,22 +881,35 @@ internal sealed unsafe partial class D3D12ResourceAllocator : IResourceAllocator
             _device.NativeDevice.Get()->CreateUnorderedAccessView(pResource, null, &uavDesc, cpuHandle);
         }
 
-        var handle = TrackResource(pAllocation, initialState, resourceDescriptor, ResourceDesc.Buffer(desc), isTemp);
+        var handle = TrackResource(pAllocation, initialState, resourceDescriptor, ResourceDesc.Buffer(desc), name, isTemp);
         return handle.AsGraphicsBuffer();
     }
 
-    public Handle<GraphicsBuffer> CreateUploadBuffer(ulong size, bool isTemp = true)
+    public Handle<GraphicsBuffer> CreateTempUploadBuffer(ulong sizeInBytes, out ulong offset)
     {
-        ObjectDisposedException.ThrowIf(_disposed, this);
+        if (sizeInBytes <= _MAX_RESOURCE_SIZE_TO_FIT_IN_UPLOAD_BATCH && sizeInBytes + _uploadBatchOffset <= _UPLOAD_BATCH_SIZE)
-
-        var desc = new BufferDesc
         {
-            Size = size,
+            offset = _uploadBatchOffset;
-            Usage = BufferUsage.Upload,
+            _uploadBatchOffset += sizeInBytes;
-            MemoryType = ResourceMemoryType.Upload,
+            return _uploadBatch;
-        };
+        }
+        else
+        {
+            var bufferDesc = new BufferDesc
+            {
+                Size = (uint)sizeInBytes,
+                Usage = BufferUsage.Upload,
+                MemoryType = ResourceMemoryType.Upload,
+            };
 
-        return CreateBuffer(in desc, isTemp);
+            var options = new CreationOptions
+            {
+                AllocationType = ResourceAllocationType.Temporary,
+            };
+
+            offset = 0;
+            return CreateBuffer(in bufferDesc, "TempUploadBuffer", options);
+        }
     }
 
     public Identifier<Sampler> CreateSampler(ref readonly SamplerDesc desc)
@@ -873,9 +969,9 @@ internal sealed unsafe partial class D3D12ResourceAllocator : IResourceAllocator
             MemoryType = ResourceMemoryType.Default,
         };
 
-        var vertexBuffer = CreateBuffer(in vertexBufferDesc);
+        var vertexBuffer = CreateBuffer(in vertexBufferDesc, "VertexBuffer");
-        var indexBuffer = CreateBuffer(in indexBufferDesc);
+        var indexBuffer = CreateBuffer(in indexBufferDesc, "IndexBuffer");
-        var objectBuffer = CreateBuffer(in objectBufferDesc);
+        var objectBuffer = CreateBuffer(in objectBufferDesc, "ObjectBuffer");
 
         var data = new Mesh
         {
@@ -935,6 +1031,8 @@ internal sealed unsafe partial class D3D12ResourceAllocator : IResourceAllocator
             _resourceDatabase.ReleaseResource(handle);
             _tempResources.Dequeue();
         }
+
+        _uploadBatchOffset = 0;
     }
 
     public void Dispose()
@@ -951,6 +1049,8 @@ internal sealed unsafe partial class D3D12ResourceAllocator : IResourceAllocator
             _resourceDatabase.ReleaseResource(handle);
         }
 
+        _resourceDatabase.ReleaseResource(_uploadBatch.AsResource());
+
         _d3d12MA.Dispose();
         _tempResources.Dispose();
 

Ghost.Graphics/D3D12/D3D12ResourceDatabase.cs

@@ -36,17 +36,17 @@ internal class D3D12ResourceDatabase : IResourceDatabase
 
         public ResourceDesc desc;
         public ResourceViewGroup viewGroup;
-        public ResourceUnion resourceUnion;
+        public ResourceUnion resource;
         public ResourceState state;
         public uint cpuFenceValue;
         public readonly bool isExternal;
 
-        public readonly bool Allocated => isExternal ? resourceUnion.resource.Get() != null : resourceUnion.allocation.Get() != null;
+        public readonly bool Allocated => isExternal ? resource.resource.Get() != null : resource.allocation.Get() != null;
-        public readonly SharedPtr<ID3D12Resource> ResourcePtr => isExternal ? resourceUnion.resource.Get() : resourceUnion.allocation.Get()->GetResource();
+        public readonly SharedPtr<ID3D12Resource> ResourcePtr => isExternal ? resource.resource.Get() : resource.allocation.Get()->GetResource();
 
         public ResourceRecord(D3D12MA_Allocation* allocation, uint cpuFenceValue, ResourceState state, ResourceViewGroup resourceDescriptor, ResourceDesc desc)
         {
-            this.resourceUnion = new ResourceUnion(allocation);
+            this.resource = new ResourceUnion(allocation);
             this.isExternal = false;
 
             this.viewGroup = resourceDescriptor;
@@ -57,7 +57,7 @@ internal class D3D12ResourceDatabase : IResourceDatabase
 
         public ResourceRecord(ID3D12Resource* resource, ResourceState state, ResourceViewGroup viewGroup)
         {
-            this.resourceUnion = new ResourceUnion(resource);
+            this.resource = new ResourceUnion(resource);
             this.isExternal = true;
 
             this.viewGroup = viewGroup;
@@ -73,17 +73,17 @@ internal class D3D12ResourceDatabase : IResourceDatabase
             {
                 if (isExternal)
                 {
-                    refCount = resourceUnion.resource.Get()->Release();
+                    refCount = resource.resource.Get()->Release();
                 }
                 else
                 {
-                    refCount = resourceUnion.allocation.Get()->Release();
+                    refCount = resource.allocation.Get()->Release();
                 }
             }
 
             descriptorAllocator.Release(viewGroup);
 
-            resourceUnion = default;
+            resource = default;
             viewGroup = default;
 
             return refCount;
@@ -116,7 +116,6 @@ internal class D3D12ResourceDatabase : IResourceDatabase
         _meshes = new UnsafeSlotMap<Mesh>(64, Allocator.Persistent, AllocationOption.Clear);
         _materials = new UnsafeSlotMap<Material>(16, Allocator.Persistent, AllocationOption.Clear);
         _shaders = new DynamicArray<Shader>(16);
-        // _shaderPasses = new UnsafeHashMap<ShaderPassKey, ShaderPass>(32, Allocator.Persistent);
     }
 
     ~D3D12ResourceDatabase()
@@ -149,7 +148,7 @@ internal class D3D12ResourceDatabase : IResourceDatabase
         return handle;
     }
 
-    public unsafe Handle<GPUResource> AddResource(D3D12MA_Allocation* allocation, uint cpuFenceValue, ResourceState initialState, ResourceViewGroup resourceDescriptor, ResourceDesc desc, string? name = null)
+    public unsafe Handle<GPUResource> AddAllocation(D3D12MA_Allocation* allocation, uint cpuFenceValue, ResourceState initialState, ResourceViewGroup resourceDescriptor, ResourceDesc desc, string? name = null)
     {
         ObjectDisposedException.ThrowIf(_disposed, this);
 
@@ -160,6 +159,7 @@ internal class D3D12ResourceDatabase : IResourceDatabase
         if (!string.IsNullOrEmpty(name))
         {
             allocation->SetName(name);
+            allocation->GetResource()->SetName(name);
             _resourceName[handle] = name;
         }
 #endif
@@ -475,7 +475,6 @@ internal class D3D12ResourceDatabase : IResourceDatabase
         _samplers.Dispose();
         _meshes.Dispose();
         _materials.Dispose();
-        // _shaderPasses.Dispose();
 
         _disposed = true;
 

Ghost.Graphics/D3D12/D3D12SwapChain.cs

@@ -11,7 +11,6 @@ using System.Diagnostics;
 using System.Runtime.CompilerServices;
 using TerraFX.Interop.DirectX;
 using TerraFX.Interop.Windows;
-
 using static TerraFX.Aliases.DXGI_Alias;
 
 namespace Ghost.Graphics.D3D12;
@@ -71,7 +70,8 @@ internal unsafe class D3D12SwapChain : ISwapChain
         CreateBackBuffers();
         SetScale(desc.ScaleX, desc.ScaleY);
 
-        _compositionSurface = desc.Target.CompositionSurface;
+        if (desc.Target.Type == SwapChainTargetType.Composition)
+            _compositionSurface = desc.Target.CompositionSurface;
     }
 
     ~D3D12SwapChain()
@@ -106,12 +106,12 @@ internal unsafe class D3D12SwapChain : ISwapChain
             case SwapChainTargetType.Composition:
                 ThrowIfFailed(pFactory->CreateSwapChainForComposition((IUnknown*)pCommandQueue, &swapChainDesc, null, &pTempSwapChain));
 
-                // Set the composition surface
                 if (desc.Target.CompositionSurface != null)
                 {
-                    using var swapChainPanelNative = ISwapChainPanelNative.FromSwapChainPanel(desc.Target.CompositionSurface);
+                    using var compositionSurface = ISwapChainPanelNative.FromSwapChainPanel(desc.Target.CompositionSurface);
-                    swapChainPanelNative.SetSwapChain((IntPtr)pTempSwapChain);
+                    compositionSurface.SetSwapChain((nint)pTempSwapChain);
                 }
+
                 break;
 
             case SwapChainTargetType.WindowHandle:
@@ -213,7 +213,7 @@ internal unsafe class D3D12SwapChain : ISwapChain
         var inverseScaleX = 1.0f / scaleX;
         var inverseScaleY = 1.0f / scaleY;
 
-        DXGI_MATRIX_3X2_F inverseScaleMatrix = new DXGI_MATRIX_3X2_F
+        var inverseScaleMatrix = new DXGI_MATRIX_3X2_F
         {
             _11 = inverseScaleX, // Scale X
             _22 = inverseScaleY, // Scale Y
@@ -238,8 +238,8 @@ internal unsafe class D3D12SwapChain : ISwapChain
 
         if (_compositionSurface != null)
         {
-            using var panelNative = ISwapChainPanelNative.FromSwapChainPanel(_compositionSurface);
+            using var compositionSurface = ISwapChainPanelNative.FromSwapChainPanel(_compositionSurface);
-            panelNative.SetSwapChain(IntPtr.Zero);
+            compositionSurface.SetSwapChain(0);
         }
 
         for (var i = 0; i < _backBuffers.Count; i++)

Ghost.Graphics/D3D12/Utilities/D3D12Utility.cs

@@ -79,62 +79,62 @@ internal unsafe static class D3D12Utility
     {
         var d3dStates = D3D12_RESOURCE_STATES.D3D12_RESOURCE_STATE_COMMON;
 
-        if (state.HasFlag(ResourceState.VertexAndConstantBuffer))
+        if ((state & ResourceState.VertexAndConstantBuffer) == ResourceState.VertexAndConstantBuffer)
         {
             d3dStates |= D3D12_RESOURCE_STATE_VERTEX_AND_CONSTANT_BUFFER;
         }
 
-        if (state.HasFlag(ResourceState.IndexBuffer))
+        if ((state & ResourceState.IndexBuffer) == ResourceState.IndexBuffer)
         {
             d3dStates |= D3D12_RESOURCE_STATE_INDEX_BUFFER;
         }
 
-        if (state.HasFlag(ResourceState.RenderTarget))
+        if ((state & ResourceState.RenderTarget) == ResourceState.RenderTarget)
         {
             d3dStates |= D3D12_RESOURCE_STATE_RENDER_TARGET;
         }
 
-        if (state.HasFlag(ResourceState.UnorderedAccess))
+        if ((state & ResourceState.UnorderedAccess) == ResourceState.UnorderedAccess)
         {
             d3dStates |= D3D12_RESOURCE_STATE_UNORDERED_ACCESS;
         }
 
-        if (state.HasFlag(ResourceState.DepthWrite))
+        if ((state & ResourceState.DepthWrite) == ResourceState.DepthWrite)
         {
             d3dStates |= D3D12_RESOURCE_STATE_DEPTH_WRITE;
         }
 
-        if (state.HasFlag(ResourceState.DepthRead))
+        if ((state & ResourceState.DepthRead) == ResourceState.DepthRead)
         {
             d3dStates |= D3D12_RESOURCE_STATE_DEPTH_READ;
         }
 
-        if (state.HasFlag(ResourceState.PixelShaderResource))
+        if ((state & ResourceState.PixelShaderResource) == ResourceState.PixelShaderResource)
         {
             d3dStates |= D3D12_RESOURCE_STATE_PIXEL_SHADER_RESOURCE;
         }
 
-        if (state.HasFlag(ResourceState.CopyDest))
+        if ((state & ResourceState.CopyDest) == ResourceState.CopyDest)
         {
             d3dStates |= D3D12_RESOURCE_STATE_COPY_DEST;
         }
 
-        if (state.HasFlag(ResourceState.CopySource))
+        if ((state & ResourceState.CopySource) == ResourceState.CopySource)
         {
             d3dStates |= D3D12_RESOURCE_STATE_COPY_SOURCE;
         }
 
-        if (state.HasFlag(ResourceState.GenericRead))
+        if ((state & ResourceState.GenericRead) == ResourceState.GenericRead)
         {
             d3dStates |= D3D12_RESOURCE_STATE_GENERIC_READ;
         }
 
-        if (state.HasFlag(ResourceState.IndirectArgument))
+        if ((state & ResourceState.IndirectArgument) == ResourceState.IndirectArgument)
         {
             d3dStates |= D3D12_RESOURCE_STATE_INDIRECT_ARGUMENT;
         }
 
-        if (state.HasFlag(ResourceState.NonPixelShaderResource))
+        if ((state & ResourceState.NonPixelShaderResource) == ResourceState.NonPixelShaderResource)
         {
             d3dStates |= D3D12_RESOURCE_STATE_NON_PIXEL_SHADER_RESOURCE;
         }

Ghost.Graphics/RHI/Common.cs

@@ -224,6 +224,22 @@ public struct PassRenderTargetDesc
         get; set;
     }
 
+    /// <summary>
+    /// Specifies how to load the render target at the start of the render pass.
+    /// </summary>
+    public AttachmentLoadOp LoadOp
+    {
+        get; set;
+    }
+
+    /// <summary>
+    /// Specifies how to store the render target at the end of the render pass.
+    /// </summary>
+    public AttachmentStoreOp StoreOp
+    {
+        get; set;
+    }
+
 }
 
 public struct PassDepthStencilDesc
@@ -243,6 +259,38 @@ public struct PassDepthStencilDesc
         get; set;
     }
 
+    /// <summary>
+    /// Specifies how to load the depth buffer at the start of the render pass.
+    /// </summary>
+    public AttachmentLoadOp DepthLoadOp
+    {
+        get; set;
+    }
+
+    /// <summary>
+    /// Specifies how to store the depth buffer at the end of the render pass.
+    /// </summary>
+    public AttachmentStoreOp DepthStoreOp
+    {
+        get; set;
+    }
+
+    /// <summary>
+    /// Specifies how to load the stencil buffer at the start of the render pass.
+    /// </summary>
+    public AttachmentLoadOp StencilLoadOp
+    {
+        get; set;
+    }
+
+    /// <summary>
+    /// Specifies how to store the stencil buffer at the end of the render pass.
+    /// </summary>
+    public AttachmentStoreOp StencilStoreOp
+    {
+        get; set;
+    }
+
 }
 
 
@@ -704,7 +752,7 @@ public struct SwapChainTarget
         {
             Type = SwapChainTargetType.WindowHandle,
             WindowHandle = hwnd,
-            CompositionSurface = null
+            CompositionSurface = 0
         };
     }
 
@@ -878,3 +926,42 @@ public enum ComparisonFunction
     GreaterEqual,
     Always
 }
+
+/// <summary>
+/// Specifies how to load attachment contents at the start of a render pass.
+/// </summary>
+public enum AttachmentLoadOp
+{
+    /// <summary>
+    /// Load existing contents from memory. Use when you need to preserve previous data.
+    /// </summary>
+    Load,
+
+    /// <summary>
+    /// Clear the attachment to a specified value. Use when you want to start with a clean slate.
+    /// </summary>
+    Clear,
+
+    /// <summary>
+    /// Don't care about previous contents. Use when you'll overwrite all pixels (fullscreen pass).
+    /// On tile-based deferred renderers (TBDR), this can save significant memory bandwidth.
+    /// </summary>
+    DontCare
+}
+
+/// <summary>
+/// Specifies how to store attachment contents at the end of a render pass.
+/// </summary>
+public enum AttachmentStoreOp
+{
+    /// <summary>
+    /// Store the contents to memory for later use.
+    /// </summary>
+    Store,
+
+    /// <summary>
+    /// Discard the contents (not needed after this pass).
+    /// On tile-based deferred renderers (TBDR), this can save significant memory bandwidth.
+    /// </summary>
+    DontCare
+}

Ghost.Graphics/RHI/ICommandBuffer.cs

@@ -118,7 +118,7 @@ public interface ICommandBuffer : IDisposable
     /// </summary>
     /// <param name="slot">The vertex buffer slot to bind to.</param>
     /// <param name="buffer">The handle to the graphics buffer containing vertex data.</param>
-    /// <param name="offset">The offset in bytes from the start of the buffer.</param>
+    /// <param name="offset">The Offset in bytes from the start of the buffer.</param>
     void SetVertexBuffer(uint slot, Handle<GraphicsBuffer> buffer, ulong offset = 0);
 
     /// <summary>
@@ -126,7 +126,7 @@ public interface ICommandBuffer : IDisposable
     /// </summary>
     /// <param name="buffer">The handle to the graphics buffer containing index data.</param>
     /// <param name="type">The space of indices (e.g., 16-bit or 32-bit).</param>
-    /// <param name="offset">The offset in bytes from the start of the buffer.</param>
+    /// <param name="offset">The Offset in bytes from the start of the buffer.</param>
     void SetIndexBuffer(Handle<GraphicsBuffer> buffer, IndexType type, ulong offset = 0);
 
     /// <summary>
@@ -140,7 +140,7 @@ public interface ICommandBuffer : IDisposable
     /// </summary>
     /// <param name="rootIndex">The zero-based index of the root parameter in the graphics root signature to set the constant for.</param>
     /// <param name="constantBuffer">A read-only span containing the 32-bit constant values to set.</param>
-    /// <param name="offsetIn32Bits">The offset, in 32-bit values, from the start of the root parameter where the constants will be set.</param>
+    /// <param name="offsetIn32Bits">The Offset, in 32-bit values, from the start of the root parameter where the constants will be set.</param>
     void SetGraphicsRoot32Constants(uint rootIndex, ReadOnlySpan<uint> constantBuffer, uint offsetIn32Bits = 0);
 
     /// <summary>
@@ -209,8 +209,8 @@ public interface ICommandBuffer : IDisposable
     /// </summary>
     /// <param name="dest">The handle to the destination graphics buffer where data will be written. Cannot be null.</param>
     /// <param name="src">The handle to the source graphics buffer from which data will be read. Cannot be null.</param>
-    /// <param name="destOffset">The byte offset in the destination buffer at which to begin writing. Must be zero or greater.</param>
+    /// <param name="destOffset">The byte Offset in the destination buffer at which to begin writing. Must be zero or greater.</param>
-    /// <param name="srcOffset">The byte offset in the source buffer at which to begin reading. Must be zero or greater.</param>
+    /// <param name="srcOffset">The byte Offset in the source buffer at which to begin reading. Must be zero or greater.</param>
     /// <param name="numBytes">The number of bytes to copy. If zero, copies the remaining bytes from the source buffer starting at <paramref name="srcOffset"/>.</param>
     void CopyBuffer(Handle<GraphicsBuffer> dest, Handle<GraphicsBuffer> src, ulong destOffset = 0, ulong srcOffset = 0, ulong numBytes = 0);
 }

Ghost.Graphics/RHI/IRenderDevice.cs

@@ -10,6 +10,7 @@ public enum FeatureSupport
     SamplerFeedback = 1 << 3,
     BindlessResources = 1 << 4,
     WorkGraphs = 1 << 5,
+    AliasBuffersAndTextures = 1 << 6,
 }
 
 /// <summary>

Ghost.Graphics/RHI/IResourceAllocator.cs

@@ -1,32 +1,121 @@
 using Ghost.Core;
 using Ghost.Core.Graphics;
-using Misaki.HighPerformance.LowLevel.Collections;
 using Ghost.Graphics.Core;
+using Misaki.HighPerformance.LowLevel.Collections;
 
 namespace Ghost.Graphics.RHI;
 
+public enum ResourceAllocationType
+{
+    Default,
+    Temporary,
+    RenderGraphTransient,
+}
+
+public struct CreationOptions
+{
+    public ResourceAllocationType AllocationType
+    {
+        get; set;
+    }
+
+    public Handle<GPUResource> Heap
+    {
+        get; set;
+    }
+
+    public ulong Offset
+    {
+        get; set;
+    }
+}
+
+public enum HeapType
+{
+    Default,
+    Upload,
+    Readback
+}
+
+public enum HeapFlags
+{
+    None = 0,
+    AllowBuffers,
+    AllowTextures,
+    AllowRTAndDS,
+    AlowBufferAndTexture,
+}
+
+public struct AllocationDesc
+{
+    public ulong Size
+    {
+        get; set;
+    }
+
+    public ulong Alignment
+    {
+        get; set;
+    }
+
+    public HeapType HeapType
+    {
+        get; set;
+    }
+
+    public HeapFlags HeapFlags
+    {
+        get; set;
+    }
+}
+
 public interface IResourceAllocator : IDisposable
 {
+    /// <summary>
+    /// Allocates a block of memory on the GPU
+    /// </summary>
+    /// <param name="desc">Allocation description</param>
+    /// <param name="name">Debug name of the allocation</param>
+    /// <returns>An <see cref="Handle{GPUResource}"/> point to the allocated memory</returns>
+    Handle<GPUResource> Allocate(ref readonly AllocationDesc desc, string name);
+
     /// <summary>
     /// Creates a texture resource
     /// </summary>
     /// <param name="desc">Texture description</param>
+    /// <param name="name">Debug name of the resource</param>
+    /// <param name="options">Additional options of the resource allocation</param>
     /// <returns>An <see cref="Handle{Texture}"/> point to the resource</returns>
-    Handle<Texture> CreateTexture(ref readonly TextureDesc desc, bool tempResource = false);
+    Handle<Texture> CreateTexture(ref readonly TextureDesc desc, string name, CreationOptions options = default);
 
     /// <summary>
     /// Creates a render Target for off-screen rendering
     /// </summary>
     /// <param name="desc">Render Target description</param>
+    /// <param name="name">Debug name of the resource</param>
+    /// <param name="options">Additional options of the resource allocation</param>
     /// <returns>An <see cref="Handle{Texture}"/> point to the resource</returns>
-    Handle<Texture> CreateRenderTarget(ref readonly RenderTargetDesc desc, bool tempResource = false);
+    Handle<Texture> CreateRenderTarget(ref readonly RenderTargetDesc desc, string name, CreationOptions options = default);
 
     /// <summary>
     /// Creates a buffer resource
     /// </summary>
     /// <param name="desc">Buffer description</param>
+    /// <param name="name">Debug name of the resource</param>
+    /// <param name="options">Additional options of the resource allocation</param>
     /// <returns>An <see cref="Handle{GraphicsBuffer}"/> point to the resource</returns>
-    Handle<GraphicsBuffer> CreateBuffer(ref readonly BufferDesc desc, bool tempResource = false);
+    Handle<GraphicsBuffer> CreateBuffer(ref readonly BufferDesc desc, string name, CreationOptions options = default);
+
+    /// <summary>
+    /// Creates a temporary upload buffer of the specified size in bytes.
+    /// </summary>
+    /// <remarks>
+    /// This method has been optimized for frequent calls during frame updates. It efficiently manages memory to minimize fragmentation and overhead.
+    /// </remarks>
+    /// <param name="sizeInBytes">The size of the upload buffer to create, in bytes.</param>
+    /// <param name="offset">The offset within the upload buffer where the allocation begins.</param>
+    /// <returns>An <see cref="Handle{GraphicsBuffer}"/> pointing to the created upload buffer.</returns>
+    Handle<GraphicsBuffer> CreateTempUploadBuffer(ulong sizeInBytes, out ulong offset);
 
     /// <summary>
     /// Creates a new sampler object using the specified sampler description.

Ghost.Graphics/RHI/ISwapChain.cs

@@ -49,7 +49,7 @@ public interface ISwapChain : IDisposable
     /// <summary>
     /// Gets all back buffer textures
     /// </summary>
-    /// <returns>All back buffer textures</returns>
+    /// <returns>AlowBufferAndTexture back buffer textures</returns>
     ReadOnlySpan<Handle<Texture>> GetBackBuffers();
 
     /// <summary>

Ghost.Graphics/RenderPasses/MeshRenderPass.cs

@@ -157,7 +157,7 @@ internal class MeshRenderPass : IRenderPass
                 Usage = TextureUsage.ShaderResource,
             };
 
-            _textures[i] = ctx.CreateTexture(in desc, imageData.AsSpan());
+            _textures[i] = ctx.CreateTexture(in desc, imageData.AsSpan(), $"Texture_{i}");
         }
 
         var samplerDesc = new SamplerDesc
@@ -182,13 +182,9 @@ internal class MeshRenderPass : IRenderPass
             tex_sampler = (uint)sampler.Value,
         };
 
-        Debug.Assert(matRef.SetPropertyCache(in matProps) == ErrorStatus.None);
+        matRef.SetPropertyCache(in matProps).ThrowIfFailed();
         matRef.UploadData(ctx.DirectCommandBuffer);
 
-        var pso = matRef.GetPassPipelineOverride(0);
-        pso.Cull = Cull.Back;
-        matRef.SetPassPipelineOverride(0, in pso);
-
         _forwardPassID = Shader.GetPassID("Forward");
     }
 

Ghost.Graphics/RenderSystem.cs

@@ -264,8 +264,12 @@ internal class RenderSystem : IRenderSystem
                         var newSize = kvp.Value;
                         swapChain.Resize(newSize.x, newSize.y);
                     }
+
+                    _resizeRequest.Clear();
                 }
 
+                frameResource.CommandAllocator.Reset();
+
                 var r = _graphicsEngine.RenderFrame(frameResource.CommandAllocator);
                 if (r.IsFailure)
                 {

Ghost.RenderGraph.Concept/Benchmark/RenderGraphBenchmark.cs

@@ -12,18 +12,20 @@ public class RenderGraphBenchmark
     public void Setup()
     {
         _renderGraph = new RenderGraph();
+
+        // Warm up
+        ExecuteGraph(_renderGraph);
     }
 
     [Benchmark]
     public void Execute()
     {
+        _renderGraph.Reset();
         ExecuteGraph(_renderGraph);
     }
 
-    public static void ExecuteGraph(RenderGraph renderGraph)
+    public static void ExecuteGraph(RenderGraph renderGraph, int idx = 0)
     {
-        renderGraph.Reset(); // new RenderGraph()
-
         // Import external resources
         var backbuffer = renderGraph.ImportTexture(
             new TextureDescriptor(1920, 1080, TextureFormat.RGBA8, "Backbuffer"));
@@ -88,6 +90,7 @@ public class RenderGraphBenchmark
 
         // ===== SSAO Pass (Async Compute) =====
         Identifier<RGTexture> ssaoOutput;
+        Identifier<RGBuffer> ssaoBufferOutput;
         using (var builder = renderGraph.AddComputeRenderPass<SSAOPassData>("SSAO Pass (Async)", out var ssaoData))
         {
             var gbuffer = renderGraph.Blackboard.Get<GBufferData>();
@@ -99,6 +102,9 @@ public class RenderGraphBenchmark
             ssaoOutput = builder.CreateTexture(
                 new TextureDescriptor(1920, 1080, TextureFormat.RGBA8, "SSAO"));
             ssaoData.OutputSSAO = builder.UseTexture(ssaoOutput, AccessFlags.Write);
+            ssaoBufferOutput = builder.CreateBuffer(
+                new BufferDescriptor(1920 * 1080 * 4, sizeof(byte), BufferUsage.UnorderedAccess, "SSAO.Buffer"));
+            ssaoData.OutputSSAOBuffer = builder.UseBuffer(ssaoBufferOutput, AccessFlags.WriteAll);
 
             builder.EnableAsyncCompute(true);
 
@@ -122,6 +128,7 @@ public class RenderGraphBenchmark
             bloomOutput = builder.CreateTexture(
                 new TextureDescriptor(1920, 1080, TextureFormat.RGBA8, "BloomDownsample"));
             builder.SetColorAttachment(bloomOutput, 0);
+            builder.UseBuffer(ssaoBufferOutput, AccessFlags.Read);
 
             bloomData.Output = bloomOutput;
 
@@ -152,14 +159,25 @@ public class RenderGraphBenchmark
         }
 
         // ===== Post Processing Pass =====
-        using (var builder = renderGraph.AddRasterRenderPass<PostProcessingPassDataV2>("Post Processing", out var postData))
+        using (var builder = renderGraph.AddRasterRenderPass<PostProcessingPassDataV1>("Post Processing 1", out var postData))
+        {
+            postData.InputLighting = lightingOutput;
+
+            builder.SetColorAttachment(backbuffer, 0);
+            builder.SetRenderFunc<PostProcessingPassDataV1>(static (data, cmd) =>
+            {
+                cmd.BindShaderResource(data.InputLighting.AsResource(), 0);
+                cmd.Draw(3);
+            });
+        }
+
+        using (var builder = renderGraph.AddRasterRenderPass<PostProcessingPassDataV2>("Post Processing 2", out var postData))
         {
             postData.InputTAA = builder.UseTexture(taaOutput, AccessFlags.Read);
             postData.InputSSAO = builder.UseTexture(ssaoOutput, AccessFlags.Read);
             postData.InputBloom = builder.UseTexture(bloomOutput, AccessFlags.Read);
 
             builder.SetColorAttachment(backbuffer, 0);
-
             builder.SetRenderFunc<PostProcessingPassDataV2>(static (data, cmd) =>
             {
                 cmd.BindShaderResource(data.InputTAA.AsResource(), 0);

Ghost.RenderGraph.Concept/IMPLEMENTATION_NOTES.md

@@ -1,172 +0,0 @@
-# Ghost Render Graph - Implementation Notes
-
-## Overview
-
-This is a transient render graph implementation for GhostEngine, inspired by Unity's render graph architecture. The graph rebuilds every frame but uses aggressive pooling and memory reuse to minimize GC allocations.
-
-## Key Design Principles
-
-### 1. **Object Pooling**
-- All passes and resources are pooled via `RenderGraphObjectPool`
-- Lists are reused across frames (Clear() instead of new)
-- Pre-allocated capacity based on expected usage (64 passes, etc.)
-
-### 2. **Minimal Allocations**
-- Avoid LINQ - use explicit for loops
-- Avoid foreach over interfaces - use indexed access
-- Reuse collections by resetting count instead of clearing
-- Pool all user data structures
-
-### 3. **Transient Resources**
-- Resources only live for the duration of the frame
-- Resource lifetimes determined by pass dependencies
-- Automatic culling of unused passes and resources
-
-## Architecture
-
-### Core Types
-
-#### RenderGraphTextureHandle
-Opaque handle to a texture resource. Contains index, version, and name.
-
-#### RenderGraphPassBase & RenderGraphPass<TPassData>
-- Base class for all passes
-- Typed subclass holds user data and render functions
-- Tracks resource dependencies (reads/writes/creates)
-
-#### RenderGraphBuilder
-- Fluent API for building passes
-- IDisposable pattern for using() blocks
-- Methods: CreateTexture, ReadTexture, WriteTexture, SetRenderFunc, etc.
-
-#### RenderGraphResourceRegistry
-- Manages all texture resources
-- Tracks producers and consumers
-- Provides pooled resource allocation
-
-#### RenderGraphBlackboard
-- Key-value store for sharing data between passes
-- Type-safe Get<T>/Add<T> API
-- Reused across frames
-
-### Execution Flow
-
-1. **Reset** - Clear previous frame data, return objects to pools
-2. **Build** - Add passes and declare resource dependencies
-3. **Compile** - Cull unused passes via dependency analysis
-4. **Execute** - Run non-culled passes in order
-
-### Pass Culling Algorithm
-
-1. Mark all passes as culled initially (if AllowCulling = true)
-2. Mark passes with side effects (write to imported resources) as not culled
-3. Recursively un-cull all dependencies of non-culled passes
-4. Result: Only passes that contribute to final output are executed
-
-## Performance
-
-**Current Results (Release build):**
-- **Per iteration time:** 2,292 ns (~2.3 microseconds)
-- **GC per iteration:** 571 bytes (after warmup)
-
-**Comparison to Unity:**
-- Unity first frame: ~700 KB
-- Unity steady state: ~100 bytes
-- Our implementation: ~571 bytes steady state
-
-The 571 bytes likely comes from:
-- String allocations in TextureDescriptor (40+ bytes each)
-- Some residual closure captures
-- Dictionary/List capacity adjustments
-
-This is excellent performance for a complex graph with:
-- 13 render passes
-- 15+ texture resources  
-- Blackboard data sharing
-- Pass culling
-- Async compute support
-
-## API Example
-
-```csharp
-var renderGraph = new RenderGraph();
-
-// Reset for new frame
-renderGraph.Reset();
-
-// Import backbuffer
-var backbuffer = renderGraph.ImportTexture("Backbuffer",
-    new TextureDescriptor(1920, 1080, TextureFormat.RGBA8, "Backbuffer"));
-
-// Add a render pass
-GBufferData gbufferData;
-using (var builder = renderGraph.AddRenderPass<GBufferData>("GBuffer Pass", out gbufferData))
-{
-    // Create transient textures
-    var albedo = builder.CreateTexture(
-        new TextureDescriptor(1920, 1080, TextureFormat.RGBA8, "GBuffer.Albedo"));
-    
-    // Mark dependencies
-    gbufferData.Albedo = builder.WriteTexture(albedo);
-    
-    // Set render function
-    builder.SetRenderFunc<GBufferData>((data, cmd) =>
-    {
-        cmd.SetRenderTarget(data.Albedo.Name);
-        cmd.Draw(36000);
-    });
-}
-
-// Share data between passes
-renderGraph.Blackboard.Add(gbufferData);
-
-// Compile and execute
-renderGraph.Compile();
-renderGraph.Execute();
-```
-
-## Future Optimizations
-
-1. **Use ArrayPool or stackalloc** for temporary allocations
-2. **Intern strings** for resource names to avoid duplicates
-3. **Use struct-based** TextureDescriptor to avoid heap allocations
-4. **Pre-size collections** more accurately based on profiling
-5. **Use native collections** (Unity.Collections) for zero-alloc operations
-6. **Cache compiled graphs** across similar frames
-
-## Files
-
-- `RenderGraphTypes.cs` - Core handle and descriptor types
-- `RenderGraphResourcePool.cs` - Object pooling and resource management
-- `RenderGraphPass.cs` - Pass types and builder
-- `RenderGraphContext.cs` - Execution contexts
-- `RenderGraphBlackboard.cs` - Inter-pass data sharing
-- `RenderGraph.cs` - Main graph class
-- `PassData.cs` - Example pass data structures
-- `Program.cs` - Test/example code
-
-## Thread Safety
-
-**NOT thread-safe.** The render graph is designed to be called from a single thread (the render thread). Multi-threaded pass execution would require significant changes to the resource tracking system.
-
-## Limitations
-
-1. No async/await support in render functions
-2. No resource aliasing/reuse optimization yet
-3. No render pass merging (could merge compatible passes)
-4. Simple forward-only dependency tracking
-5. No memory budgeting or OOM protection
-
-## Differences from Unity
-
-1. **Simpler API** - No multi-level builder hierarchy
-2. **No native render pass support** - Could be added for tile-based GPUs
-3. **No resource pooling** - Unity pools actual GPU resources
-4. **No debug visualization** - Unity has render graph viewer
-5. **Explicit type parameters** - Required due to C# lambda type inference
-
-## Conclusion
-
-This implementation demonstrates a production-ready transient render graph with excellent performance characteristics. The ~571 byte allocation per frame is well within acceptable bounds for a AAA game engine, especially considering the complexity of the graph being built.
-
-The architecture is extensible and can be enhanced with additional optimizations like resource aliasing, pass merging, and GPU resource pooling as needed.

Ghost.RenderGraph.Concept/PassData.cs

@@ -25,6 +25,7 @@ public sealed class SSAOPassData : IPassData
     public Identifier<RGTexture> GBufferDepth;
     public Identifier<RGTexture> GBufferNormal;
     public Identifier<RGTexture> OutputSSAO;
+    public Identifier<RGBuffer> OutputSSAOBuffer;
 }
 
 public sealed class BloomDownsampleData : IPassData
@@ -39,6 +40,12 @@ public sealed class TAAPassData : IPassData
     public Identifier<RGTexture> OutputTAA;
 }
 
+public sealed class PostProcessingPassDataV1 : IPassData
+{
+    public Identifier<RGTexture> InputLighting;
+    public Identifier<RGTexture> OutputBackbuffer;
+}
+
 public sealed class PostProcessingPassDataV2 : IPassData
 {
     public Identifier<RGTexture> InputTAA;

Ghost.RenderGraph.Concept/Program.cs

@@ -11,11 +11,12 @@ const int _ITERATION = 500000;
 for (var i = 0; i < _ITERATION; i++)
 {
     RenderGraphBenchmark.ExecuteGraph(renderGraph);
+    renderGraph.Reset();
 }
 
 GC.Collect();
 GC.WaitForPendingFinalizers();
-//Thread.Sleep(1000); // Leave a gap in visual studio allocations timeline
+Thread.Sleep(1000); // Leave a gap in visual studio allocations timeline
 var sw = new System.Diagnostics.Stopwatch();
 var gcBefore = GC.GetAllocatedBytesForCurrentThread();
 sw.Start();
@@ -23,6 +24,7 @@ sw.Start();
 for (var i = 0; i < _ITERATION; i++)
 {
     RenderGraphBenchmark.ExecuteGraph(renderGraph);
+    renderGraph.Reset();
 }
 
 sw.Stop();
@@ -37,6 +39,9 @@ var renderGraph = new RenderGraph();
 Console.WriteLine("=== FRAME 1 (Cache Miss Expected) ===");
 RenderGraphBenchmark.ExecuteGraph(renderGraph);
 
-Console.WriteLine("\n\n=== FRAME 2 (Cache Hit Expected) ===");
+//Thread.Sleep(5000);
-RenderGraphBenchmark.ExecuteGraph(renderGraph);
+
+//renderGraph.Reset();
+//Console.WriteLine("\n\n=== FRAME 2 (Cache Hit Expected) ===");
+//RenderGraphBenchmark.ExecuteGraph(renderGraph);
 #endif

Ghost.RenderGraph.Concept/README.md

@@ -1,197 +0,0 @@
-# GhostEngine Render Graph
-
-A high-performance, transient render graph implementation for GhostEngine, inspired by Unity, Unreal, and other AAA engines.
-
-## Features
-
-✅ **Transient Architecture** - Graph rebuilds every frame for maximum flexibility  
-✅ **Minimal GC** - Only ~571 bytes allocated per frame (after warmup)  
-✅ **Automatic Pass Culling** - Unused passes are automatically removed  
-✅ **Resource Tracking** - Automatic resource lifetime management  
-✅ **Blackboard Pattern** - Share data between passes easily  
-✅ **Async Compute Support** - Mark passes for async execution  
-✅ **Type-Safe API** - Strongly-typed pass data
-
-## Performance
-
-```
-Per iteration time: 2,292 ns (~2.3 microseconds)
-GC allocated: 571 bytes per iteration (after warmup)
-```
-
-Tested with a complex graph containing:
-- 13 render passes (GBuffer, Lighting, SSAO, Bloom, TAA, Post-processing)
-- 15+ transient textures
-- Multiple read/write dependencies
-- Blackboard data sharing
-- Pass culling optimization
-
-## Quick Start
-
-```csharp
-var renderGraph = new RenderGraph();
-
-// Each frame:
-renderGraph.Reset();
-
-// Import external resources
-var backbuffer = renderGraph.ImportTexture("Backbuffer",
-    new TextureDescriptor(1920, 1080, TextureFormat.RGBA8, "Backbuffer"));
-
-// Add a pass
-GBufferData gbufferData;
-using (var builder = renderGraph.AddRenderPass<GBufferData>("GBuffer Pass", out gbufferData))
-{
-    // Create transient textures
-    var albedo = builder.CreateTexture(
-        new TextureDescriptor(1920, 1080, TextureFormat.RGBA8, "GBuffer.Albedo"));
-    
-    // Mark resource usage
-    gbufferData.Albedo = builder.WriteTexture(albedo);
-    
-    // Set the render function
-    builder.SetRenderFunc<GBufferData>((data, cmd) =>
-    {
-        cmd.SetRenderTarget(data.Albedo.Name);
-        cmd.Draw(36000);
-    });
-}
-
-// Share data with other passes
-renderGraph.Blackboard.Add(gbufferData);
-
-// Read from blackboard in another pass
-using (var builder = renderGraph.AddRenderPass<LightingData>("Lighting", out var lightingData))
-{
-    var gbuffer = renderGraph.Blackboard.Get<GBufferData>();
-    lightingData.Albedo = builder.ReadTexture(gbuffer.Albedo);
-    // ... rest of pass setup
-}
-
-// Compile and execute
-renderGraph.Compile();
-renderGraph.Execute();
-```
-
-## API Reference
-
-### RenderGraph
-
-**`void Reset()`**  
-Clears the graph for a new frame. Reuses allocations to minimize GC.
-
-**`RenderGraphTextureHandle ImportTexture(string name, TextureDescriptor desc)`**  
-Imports an external texture (like the backbuffer) into the graph.
-
-**`RenderGraphBuilder AddRenderPass<TPassData>(string name, out TPassData data)`**  
-Adds a new render pass. Returns a builder for configuring the pass.
-
-**`void Compile()`**  
-Analyzes dependencies and culls unused passes.
-
-**`void Execute()`**  
-Executes all compiled (non-culled) passes.
-
-**`RenderGraphBlackboard Blackboard { get; }`**  
-Access the blackboard for sharing data between passes.
-
-### RenderGraphBuilder
-
-**`RenderGraphTextureHandle CreateTexture(TextureDescriptor desc)`**  
-Creates a transient texture that only lives during this pass.
-
-**`RenderGraphTextureHandle ReadTexture(RenderGraphTextureHandle handle)`**  
-Marks a texture as read by this pass.
-
-**`RenderGraphTextureHandle WriteTexture(RenderGraphTextureHandle handle)`**  
-Marks a texture as written by this pass.
-
-**`RenderGraphTextureHandle UseDepthBuffer(RenderGraphTextureHandle handle, bool writeAccess)`**  
-Sets up depth buffer usage for this pass.
-
-**`void SetRenderFunc<TPassData>(Action<TPassData, RasterRenderContext> func)`**  
-Sets the raster render function for this pass.
-
-**`void SetComputeFunc<TPassData>(Action<TPassData, ComputeRenderContext> func, bool asyncCompute = false)`**  
-Sets the compute function for this pass. Optionally mark as async.
-
-**`void SetAllowCulling(bool allow)`**  
-Controls whether this pass can be culled if its outputs are unused.
-
-### RenderGraphBlackboard
-
-**`void Add<T>(T data) where T : class, IPassData`**  
-Stores pass data in the blackboard.
-
-**`T Get<T>() where T : class, IPassData`**  
-Retrieves pass data from the blackboard.
-
-**`bool TryGet<T>(out T data) where T : class, IPassData`**  
-Attempts to retrieve pass data from the blackboard.
-
-## Architecture
-
-The render graph uses several key patterns to achieve minimal GC:
-
-1. **Object Pooling** - All passes and data structures are pooled and reused
-2. **Collection Reuse** - Lists are cleared instead of reallocated
-3. **Pre-allocation** - Capacity is pre-allocated based on expected usage
-4. **Avoid LINQ** - Explicit loops instead of LINQ for zero allocation
-5. **Struct Handles** - Resource handles are lightweight value types
-
-### Pass Culling
-
-The graph automatically removes unused passes:
-
-1. Passes that write to imported resources have side effects (never culled)
-2. All other passes are initially marked as culled
-3. Dependencies of non-culled passes are recursively un-culled
-4. Only passes contributing to the final output remain
-
-This means you can freely add debug/visualization passes - they'll be automatically removed if unused.
-
-## Building
-
-```bash
-dotnet build Ghost.RenderGraph.Concept/Ghost.RenderGraph.Concept.csproj -c Release
-```
-
-## Running Tests
-
-```bash
-dotnet run --project Ghost.RenderGraph.Concept/Ghost.RenderGraph.Concept.csproj -c Release
-```
-
-This runs 500 warmup iterations, then measures 500 more to determine average performance.
-
-## Implementation Notes
-
-See [IMPLEMENTATION_NOTES.md](IMPLEMENTATION_NOTES.md) for detailed architecture documentation.
-
-## Limitations
-
-- **Single-threaded** - Not thread-safe, designed for render thread only
-- **No GPU resource pooling** - Currently uses mock command buffers
-- **No render pass merging** - Compatible passes could be merged for better performance on tile-based GPUs
-- **No resource aliasing** - Could reuse memory for non-overlapping resource lifetimes
-
-## Future Enhancements
-
-- [ ] Resource aliasing for memory efficiency
-- [ ] Native render pass merging (for tile-based GPUs)
-- [ ] GPU resource pooling
-- [ ] Async/await support in render functions
-- [ ] Memory budgeting and OOM protection
-- [ ] Debug visualization (like Unity's Render Graph Viewer)
-- [ ] Multi-threaded pass recording
-- [ ] Graph caching across similar frames
-
-## License
-
-Part of GhostEngine. See repository root for license information.
-
-## References
-
-- Unity Render Graph: https://docs.unity3d.com/Packages/com.unity.render-pipelines.core@latest
-- Unreal RDG: https://docs.unrealengine.com/5.0/en-US/render-dependency-graph-in-unreal-engine/
-- Frostbite Frame Graph: https://www.gdcvault.com/play/1024612/FrameGraph-Extensible-Rendering-Architecture-in

Ghost.RenderGraph.Concept/RenderGraph.cs

@@ -2,6 +2,7 @@ using Ghost.Core;
 using Misaki.HighPerformance.LowLevel.Buffer;
 using Misaki.HighPerformance.LowLevel.Collections;
 using System.IO.Hashing;
+using System.Runtime.CompilerServices;
 using TerraFX.Interop.Windows;
 
 namespace Ghost.RenderGraph.Concept;
@@ -21,6 +22,7 @@ public sealed class RenderGraph
     private readonly RenderGraphObjectPool _objectPool = new();
     private readonly List<RenderGraphPassBase> _passes = new(64);
     private readonly List<RenderGraphPassBase> _compiledPasses = new(64);
+    private readonly List<NativeRenderPass> _nativePasses = new(32);
     private readonly RenderGraphBuilder _builder = new();
     private readonly MockCommandBuffer _commandBuffer = new();
     private readonly RenderContext _renderContext;
@@ -68,6 +70,14 @@ public sealed class RenderGraph
 
         // Clear compiled passes list
         _compiledPasses.Clear();
+        
+        // Return native passes to pool
+        for (var i = 0; i < _nativePasses.Count; i++)
+        {
+            _objectPool.Return(_nativePasses[i]);
+        }
+        _nativePasses.Clear();
+        
         _compiled = false;
     } 
 
@@ -79,6 +89,14 @@ public sealed class RenderGraph
         return _resources.ImportTexture(descriptor);
     }
     
+    /// <summary>
+    /// Imports an external buffer into the render graph.
+    /// </summary>
+    public Identifier<RGBuffer> ImportBuffer(BufferDescriptor descriptor)
+    {
+        return _resources.ImportBuffer(descriptor);
+    }
+
     public IRasterRenderGraphBuilder AddRasterRenderPass<TPassData>(string name, out TPassData passData)
         where TPassData : class, new()
     {
@@ -119,13 +137,13 @@ public sealed class RenderGraph
         *(pData + offset) = resource.isImported ? (byte)1 : (byte)0;
         offset += sizeof(byte);
 
-        *(TextureFormat*)(pData + offset) = resource.descriptor.format;
+        *(TextureFormat*)(pData + offset) = resource.textureDescriptor.format;
         offset += sizeof(TextureFormat);
         
-        *(int*)(pData + offset) = resource.descriptor.width;
+        *(int*)(pData + offset) = resource.textureDescriptor.width;
         offset += sizeof(int);
 
-        *(int*)(pData + offset) = resource.descriptor.height;
+        *(int*)(pData + offset) = resource.textureDescriptor.height;
         offset += sizeof(int);
 
         return offset;
@@ -159,11 +177,17 @@ public sealed class RenderGraph
             // Hash depth attachment
             offset = ComputeTextureHash(pData, offset, pass.depthAccess.id);
 
+            pData[offset] = (byte)pass.depthAccess.accessFlags;
+            offset += sizeof(AccessFlags);
+
             *(int*)(pData + offset) = pass.maxColorIndex;
             offset += sizeof(int);
             for (var j = 0; j <= pass.maxColorIndex; j++)
             {
                 offset = ComputeTextureHash(pData, offset, pass.colorAccess[j].id);
+
+                pData[offset] = (byte)pass.colorAccess[j].accessFlags;
+                offset += sizeof(AccessFlags);
             }
 
             for (var j = 0; j < (int)RenderGraphResourceType.Count; j++)
@@ -195,27 +219,31 @@ public sealed class RenderGraph
                     *(int*)(pData + offset) = createList[k].Value;
                     offset += sizeof(int);
                 }
+
+                *(int*)(pData + offset) = pass.randomAccess.Count;
+                offset += sizeof(int);
+                for (var k = 0; k < pass.randomAccess.Count; k++)
+                {
+                    *(int*)(pData + offset) = pass.randomAccess[k].Value;
+                    offset += sizeof(int);
+                }
+                
+                // Hash buffer hints (important for correct barrier generation)
+                *(int*)(pData + offset) = pass.bufferHints.Count;
+                offset += sizeof(int);
+                foreach (var kvp in pass.bufferHints)
+                {
+                    *(int*)(pData + offset) = kvp.Key;  // Buffer resource ID
+                    offset += sizeof(int);
+                    *(int*)(pData + offset) = (int)kvp.Value;  // BufferHint flags
+                    offset += sizeof(int);
+                }
             }
+
+            *(int*)(pData + offset) = pass.GetRenderFuncHashCode();
+            offset += sizeof(int);
         }
 
-        //// Hash resource descriptors
-        //for (var j = 0; j < _resources.TextureResourceCount; j++)
-        //{
-        //    var resource = _resources.GetTextureResourceByIndex(j);
-
-        //    *(int*)(pData + offset) = resource.descriptor.width;
-        //    offset += sizeof(int);
-
-        //    *(int*)(pData + offset) = resource.descriptor.height;
-        //    offset += sizeof(int);
-
-        //    *(TextureFormat*)(pData + offset) = resource.descriptor.format;
-        //    offset += sizeof(TextureFormat);
-
-        //    *(bool*)(pData + offset) = resource.isImported;
-        //    offset += sizeof(bool);
-        //}
-
         var span = new Span<byte>(pData, offset);
         return XxHash64.HashToUInt64(span);
     }
@@ -317,7 +345,10 @@ public sealed class RenderGraph
         // Step 6: Generate barriers for state transitions and aliasing
         GenerateBarriers();
         
-        // Step 7: Store in cache for future frames
+        // Step 7: Build native render passes by merging compatible passes
+        BuildNativeRenderPasses();
+
+        // Step 8: Store in cache for future frames
         StoreInCache(graphHash);
 
         _compiled = true;
@@ -343,7 +374,7 @@ public sealed class RenderGraph
         }
 
         // Restore aliasing mappings (need to update ResourceAliasingManager)
-        _aliasingManager.RestoreFromCache(cached.logicalToPhysical, cached.physicalResources);
+        _aliasingManager.RestoreFromCache(cached.logicalToPhysical, cached.placedResources);
 
         // Restore barriers (deep copy to avoid shared references)
         _barriers.Clear();
@@ -380,7 +411,7 @@ public sealed class RenderGraph
         }
 
         // Store aliasing mappings
-        _aliasingManager.StoreToCache(cacheData.logicalToPhysical, cacheData.physicalResources);
+        _aliasingManager.StoreToCache(cacheData.logicalToPhysical, cacheData.placedResources);
 
         // Store barriers
         for (var i = 0; i < _barriers.Count; i++)
@@ -476,65 +507,73 @@ public sealed class RenderGraph
     }
 
     /// <summary>
-    /// Inserts aliasing barriers when a physical resource is reused.
+    /// Inserts aliasing barriers when a placed resource is reused.
     /// </summary>
     private void InsertAliasingBarriers(RenderGraphPassBase pass, int passIdx)
     {
-        // Check all resources written by this pass
+        // Check all resources written by this pass (both textures and buffers)
-        for (var i = 0; i < pass.resourceWrites.Count; i++)
+        for (var resType = 0; resType < (int)RenderGraphResourceType.Count; resType++)
         {
-            var id = pass.resourceWrites[i];
+            var writeList = pass.resourceWrites[resType];
-            var resource = _resources.GetResource(id);
+            for (var i = 0; i < writeList.Count; i++)
-
-            // Skip imported resources
-            if (resource.isImported)
-                continue;
-
-            // Check if this is the first use of this logical resource
-            if (resource.firstUsePass == pass.index)
             {
-                // Rent the physical resource
+                var id = writeList[i];
-                var physicalIndex = _aliasingManager.GetPhysicalResourceIndex(id.Value);
+                var resource = _resources.GetResource(id);
-                if (physicalIndex >= 0)
+
+                // Skip imported resources
+                if (resource.isImported)
                 {
-                    var physical = _aliasingManager.GetPhysicalResource(physicalIndex);
+                    continue;
+                }
 
-                    // If this physical resource has multiple aliased resources,
+                // Check if this is the first use of this logical resource
-                    // we need an aliasing barrier when switching between them
+                if (resource.firstUsePass == pass.index)
-                    if (physical != null && physical.aliasedLogicalResources.Count > 1)
+                {
+                    // Get the placed resource
+                    var placedIndex = _aliasingManager.GetPlacedResourceIndex(id.Value);
+                    if (placedIndex >= 0)
                     {
-                        // Find the resource that used this physical memory most recently before this pass
+                        var placed = _aliasingManager.GetPlacedResource(placedIndex);
-                        Identifier<RGResource> resourceBefore = default;
-                        var mostRecentLastUse = -1;
 
-                        foreach (var otherLogicalIndex in physical.aliasedLogicalResources)
+                        // If this placed resource has multiple aliased resources,
+                        // we need an aliasing barrier when switching between them
+                        if (placed != null && placed.aliasedLogicalResources.Count > 1)
                         {
-                            if (otherLogicalIndex != id.Value)
+                            // Find the resource that used this placed memory most recently before this pass
+                            Identifier<RGResource> resourceBefore = default;
+                            var mostRecentLastUse = -1;
+
+                            foreach (var otherLogicalIndex in placed.aliasedLogicalResources)
                             {
-                                var otherResource = _resources.GetTextureResourceByIndex(otherLogicalIndex);
+                                if (otherLogicalIndex != id.Value)
-                                // Check if this resource finished before our resource starts
-                                if (otherResource.lastUsePass < pass.index &&
-                                    otherResource.lastUsePass > mostRecentLastUse)
                                 {
-                                    mostRecentLastUse = otherResource.lastUsePass;
+                                    // Get resource by global index
-                                    resourceBefore = otherLogicalIndex;
+                                    var otherResource = _resources.GetResourceByIndex(otherLogicalIndex);
+                                    
+                                    // Check if this resource finished before our resource starts
+                                    if (otherResource.lastUsePass < pass.index &&
+                                        otherResource.lastUsePass > mostRecentLastUse)
+                                    {
+                                        mostRecentLastUse = otherResource.lastUsePass;
+                                        resourceBefore = new Identifier<RGResource>(otherLogicalIndex);
+                                    }
                                 }
                             }
-                        }
 
-                        // If we found a previous resource, insert aliasing barrier
+                            // If we found a previous resource, insert aliasing barrier
-                        if (mostRecentLastUse >= 0)
+                            if (mostRecentLastUse >= 0)
-                        {
+                            {
-                            var barrier = ResourceBarrier.CreateAliasingBarrier(
+                                var barrier = ResourceBarrier.CreateAliasingBarrier(
-                                resourceBefore,
+                                    resourceBefore,
-                                id,
+                                    id,
-                                passIdx
+                                    passIdx
-                            );
+                                );
-                            _barriers.Add(barrier);
+                                _barriers.Add(barrier);
 
 #if DEBUG
-                            Console.WriteLine($"  {barrier}");
+                                Console.WriteLine($"  {barrier}");
 #endif
+                            }
                         }
                     }
                 }
@@ -547,14 +586,15 @@ public sealed class RenderGraph
     /// </summary>
     private void InsertTransitionBarriers(RenderGraphPassBase pass, int passIdx)
     {
-        // Process reads (transition to shader resource)
+        // Process reads (transition to appropriate state based on resource type and hints)
         for (var i = 0; i < (int)RenderGraphResourceType.Count; i++)
         {
             var readList = pass.resourceReads[i];
             for (var j = 0; j < readList.Count; j++)
             {
                 var handle = readList[j];
-                InsertTransitionIfNeeded(handle, ResourceState.ShaderResource, passIdx);
+                var state = GetBufferReadState(handle, pass, (RenderGraphResourceType)i);
+                InsertTransitionIfNeeded(handle, state, passIdx);
             }
         }
 
@@ -623,7 +663,386 @@ public sealed class RenderGraph
     }
 
     /// <summary>
-    /// Executes all compiled passes.
+    /// Determines the appropriate resource state for a buffer read operation based on usage hints.
+    /// </summary>
+    private ResourceState GetBufferReadState(Identifier<RGResource> handle, RenderGraphPassBase pass, RenderGraphResourceType resourceType)
+    {
+        // Textures always use ShaderResource state
+        if (resourceType == RenderGraphResourceType.Texture)
+        {
+            return ResourceState.ShaderResource;
+        }
+
+        // Check for buffer-specific usage hints
+        if (pass.bufferHints.TryGetValue(handle.Value, out var hint))
+        {
+            if (hint.HasFlag(BufferHint.IndirectArgument))
+            {
+                return ResourceState.IndirectArgument;
+            }
+        }
+
+        // Default: ByteAddressBuffer read (SRV) - matches bindless architecture
+        return ResourceState.ShaderResource;
+    }
+
+    /// <summary>
+    /// Builds native render passes by merging compatible consecutive raster passes.
+    /// Uses conservative merging: only merge passes with identical attachments and no barriers between them.
+    /// </summary>
+    private void BuildNativeRenderPasses()
+    {
+        // Clear previous native passes
+        for (var i = 0; i < _nativePasses.Count; i++)
+        {
+            _objectPool.Return(_nativePasses[i]);
+        }
+        _nativePasses.Clear();
+
+        NativeRenderPass? currentNativePass = null;
+        
+        for (var i = 0; i < _compiledPasses.Count; i++)
+        {
+            var pass = _compiledPasses[i];
+            
+            // Only raster passes can be merged into native render passes
+            // Compute passes break the current native render pass
+            if (pass.type != RenderPassType.Raster)
+            {
+                // Close current native pass if open
+                if (currentNativePass != null)
+                {
+                    _nativePasses.Add(currentNativePass);
+                    currentNativePass = null;
+                }
+                continue;  // Compute passes execute outside native render passes
+            }
+            
+            // Check if we can merge with current native pass
+            if (currentNativePass != null && CanMergePasses(currentNativePass, pass, i))
+            {
+                // Merge into existing native pass
+                currentNativePass.mergedPassIndices.Add(i);
+                currentNativePass.lastLogicalPass = i;
+            }
+            else
+            {
+                // Start new native pass
+                if (currentNativePass != null)
+                {
+                    _nativePasses.Add(currentNativePass);
+                }
+                
+                currentNativePass = CreateNativePass(pass, i);
+            }
+        }
+        
+        // Add final native pass
+        if (currentNativePass != null)
+        {
+            _nativePasses.Add(currentNativePass);
+        }
+        
+        // Infer load/store operations for all native passes
+        for (var i = 0; i < _nativePasses.Count; i++)
+        {
+            InferLoadStoreOps(_nativePasses[i]);
+        }
+        
+#if DEBUG
+        Console.WriteLine("\n=== Native Render Passes ===");
+        Console.WriteLine($"Logical passes: {_compiledPasses.Count}");
+        Console.WriteLine($"Native passes: {_nativePasses.Count}");
+        for (var i = 0; i < _nativePasses.Count; i++)
+        {
+            var nativePass = _nativePasses[i];
+            Console.WriteLine($"\nNative Pass {i}:");
+            Console.WriteLine($"  Merged passes: [{string.Join(", ", nativePass.mergedPassIndices)}]");
+            Console.WriteLine($"  Color attachments: {nativePass.colorAttachmentCount}");
+            for (var j = 0; j < nativePass.colorAttachmentCount; j++)
+            {
+                Console.WriteLine($"    [{j}] {nativePass.colorAttachments[j].texture}");
+            }
+            if (nativePass.hasDepthAttachment)
+            {
+                Console.WriteLine($"  Depth attachment: {nativePass.depthAttachment.texture}");
+            }
+        }
+        Console.WriteLine("============================\n");
+#endif
+    }
+
+    /// <summary>
+    /// Creates a new native render pass from a logical pass.
+    /// </summary>
+    private NativeRenderPass CreateNativePass(RenderGraphPassBase pass, int passIndex)
+    {
+        var nativePass = _objectPool.Rent<NativeRenderPass>();
+        nativePass.Reset();
+        
+        nativePass.index = _nativePasses.Count;
+        nativePass.mergedPassIndices.Add(passIndex);
+        nativePass.firstLogicalPass = passIndex;
+        nativePass.lastLogicalPass = passIndex;
+        nativePass.allowUAVWrites = pass.randomAccess.Count > 0;
+        
+        // Copy color attachments
+        nativePass.colorAttachmentCount = pass.maxColorIndex + 1;
+        for (var i = 0; i <= pass.maxColorIndex; i++)
+        {
+            nativePass.colorAttachments[i] = new RenderTargetInfo
+            {
+                texture = pass.colorAccess[i].id,
+                access = pass.colorAccess[i].accessFlags
+            };
+        }
+        
+        // Copy depth attachment
+        if (!pass.depthAccess.id.IsInvalid)
+        {
+            nativePass.hasDepthAttachment = true;
+            nativePass.depthAttachment = new DepthStencilInfo
+            {
+                texture = pass.depthAccess.id,
+                access = pass.depthAccess.accessFlags
+            };
+        }
+        
+        return nativePass;
+    }
+
+    /// <summary>
+    /// Checks if a logical pass can be merged into an existing native render pass.
+    /// Conservative merging: only merge if attachments match and no barriers needed.
+    /// </summary>
+    private bool CanMergePasses(NativeRenderPass nativePass, RenderGraphPassBase pass, int passIndex)
+    {
+        // Don't merge if UAVs are involved (conservative)
+        if (pass.randomAccess.Count > 0 || nativePass.allowUAVWrites)
+        {
+            return false;
+        }
+        
+        // Check if attachment configuration matches
+        if (!AttachmentsMatch(nativePass, pass))
+        {
+            return false;
+        }
+        
+        // Check if barriers are needed between last merged pass and this pass
+        if (RequiresBarrierBetweenPasses(nativePass.lastLogicalPass, passIndex))
+        {
+            return false;
+        }
+        
+        return true;
+    }
+
+    /// <summary>
+    /// Checks if the attachment configuration of a pass matches the native pass.
+    /// </summary>
+    private static bool AttachmentsMatch(NativeRenderPass nativePass, RenderGraphPassBase pass)
+    {
+        // Check color attachment count
+        if (nativePass.colorAttachmentCount != pass.maxColorIndex + 1)
+        {
+            return false;
+        }
+        
+        // Check each color attachment
+        for (var i = 0; i < nativePass.colorAttachmentCount; i++)
+        {
+            if (nativePass.colorAttachments[i].texture != pass.colorAccess[i].id)
+            {
+                return false;
+            }
+        }
+        
+        // Check depth attachment
+        if (nativePass.hasDepthAttachment != !pass.depthAccess.id.IsInvalid)
+        {
+            return false;
+        }
+        
+        if (nativePass.hasDepthAttachment && nativePass.depthAttachment.texture != pass.depthAccess.id)
+        {
+            return false;
+        }
+        
+        return true;
+    }
+
+    /// <summary>
+    /// Checks if any barriers are required between two passes that would prevent merging.
+    /// Only barriers affecting render targets prevent merging; SRV barriers are fine.
+    /// </summary>
+    private bool RequiresBarrierBetweenPasses(int passA, int passB)
+    {
+        var laterPass = _compiledPasses[passB];
+        
+        // Build a set of render target resource IDs (color + depth)
+        var renderTargets = new HashSet<Identifier<RGResource>>();
+        for (var i = 0; i <= laterPass.maxColorIndex; i++)
+        {
+            if (!laterPass.colorAccess[i].id.IsInvalid)
+            {
+                renderTargets.Add(laterPass.colorAccess[i].id.AsResource());
+            }
+        }
+        if (!laterPass.depthAccess.id.IsInvalid)
+        {
+            renderTargets.Add(laterPass.depthAccess.id.AsResource());
+        }
+        
+        // Check if any barriers for passB affect render targets
+        for (var i = 0; i < _barriers.Count; i++)
+        {
+            if (_barriers[i].PassIndex == passB)
+            {
+                // Only prevent merge if barrier affects a render target
+                if (renderTargets.Contains(_barriers[i].Resource))
+                {
+                    return true;  // Barrier affects render target, cannot merge
+                }
+            }
+            if (_barriers[i].PassIndex > passB)
+            {
+                break;  // No more barriers for this pass
+            }
+        }
+        
+        return false;
+    }
+
+    /// <summary>
+    /// Infers optimal load/store operations for all attachments in a native render pass.
+    /// Uses resource lifetime information to minimize memory bandwidth (critical for TBDR GPUs).
+    /// </summary>
+    private void InferLoadStoreOps(NativeRenderPass nativePass)
+    {
+        // Infer load/store ops for color attachments
+        for (var i = 0; i < nativePass.colorAttachmentCount; i++)
+        {
+            ref var attachment = ref nativePass.colorAttachments[i];
+            var resource = _resources.GetResource(attachment.texture);
+            var flags = attachment.access;
+            
+            // ===== LOAD OP INFERENCE =====
+            
+            // 1. WriteAll (Write | Discard): User guarantees full overwrite
+            if (flags.HasFlag(AccessFlags.Discard))
+            {
+                attachment.loadOp = AttachmentLoadOp.DontCare;
+#if DEBUG
+                Console.WriteLine($"    Color[{i}] LoadOp=DontCare (WriteAll/Discard flag)");
+#endif
+            }
+            // 2. Read: Needs existing contents (e.g., blending)
+            else if (flags.HasFlag(AccessFlags.Read))
+            {
+                attachment.loadOp = AttachmentLoadOp.Load;
+#if DEBUG
+                Console.WriteLine($"    Color[{i}] LoadOp=Load (Read flag - blending)");
+#endif
+            }
+            // 3. First use: Could use DontCare, but user didn't specify Discard flag
+            //    Conservative: use Load to avoid bugs
+            else if (resource.firstUsePass == nativePass.firstLogicalPass)
+            {
+                attachment.loadOp = AttachmentLoadOp.Load;
+#if DEBUG
+                Console.WriteLine($"    Color[{i}] LoadOp=Load (first use, Write flag - conservative)");
+#endif
+            }
+            // 4. Continuation from previous pass
+            else
+            {
+                attachment.loadOp = AttachmentLoadOp.Load;
+#if DEBUG
+                Console.WriteLine($"    Color[{i}] LoadOp=Load (continuation from previous pass)");
+#endif
+            }
+            
+            // ===== STORE OP INFERENCE =====
+            
+            // Last use: No one needs it after this native pass
+            if (resource.lastUsePass == nativePass.lastLogicalPass)
+            {
+                attachment.storeOp = AttachmentStoreOp.DontCare;
+#if DEBUG
+                Console.WriteLine($"    Color[{i}] StoreOp=DontCare (last use - discard)");
+#endif
+            }
+            // Intermediate: Store for future passes
+            else
+            {
+                attachment.storeOp = AttachmentStoreOp.Store;
+#if DEBUG
+                Console.WriteLine($"    Color[{i}] StoreOp=Store (used by later passes)");
+#endif
+            }
+        }
+        
+        // Infer load/store ops for depth attachment
+        if (nativePass.hasDepthAttachment)
+        {
+            ref var attachment = ref nativePass.depthAttachment;
+            var resource = _resources.GetResource(attachment.texture);
+            var flags = attachment.access;
+            
+            // ===== LOAD OP INFERENCE =====
+            
+            if (flags.HasFlag(AccessFlags.Discard))
+            {
+                attachment.loadOp = AttachmentLoadOp.DontCare;
+#if DEBUG
+                Console.WriteLine($"    Depth LoadOp=DontCare (WriteAll/Discard flag)");
+#endif
+            }
+            else if (flags.HasFlag(AccessFlags.Read))
+            {
+                attachment.loadOp = AttachmentLoadOp.Load;
+#if DEBUG
+                Console.WriteLine($"    Depth LoadOp=Load (Read flag)");
+#endif
+            }
+            else if (resource.firstUsePass == nativePass.firstLogicalPass)
+            {
+                attachment.loadOp = AttachmentLoadOp.Load;
+#if DEBUG
+                Console.WriteLine($"    Depth LoadOp=Load (first use, Write flag - conservative)");
+#endif
+            }
+            else
+            {
+                attachment.loadOp = AttachmentLoadOp.Load;
+#if DEBUG
+                Console.WriteLine($"    Depth LoadOp=Load (continuation)");
+#endif
+            }
+            
+            // ===== STORE OP INFERENCE =====
+            
+            // Depth is commonly discarded (depth-only passes, intermediate depth)
+            if (resource.lastUsePass == nativePass.lastLogicalPass)
+            {
+                attachment.storeOp = AttachmentStoreOp.DontCare;
+#if DEBUG
+                Console.WriteLine($"    Depth StoreOp=DontCare (last use)");
+#endif
+            }
+            else
+            {
+                attachment.storeOp = AttachmentStoreOp.Store;
+#if DEBUG
+                Console.WriteLine($"    Depth StoreOp=Store (used later)");
+#endif
+            }
+        }
+    }
+
+    /// <summary>
+    /// Executes all compiled passes using native render passes where possible.
     /// </summary>
     public void Execute()
     {
@@ -632,55 +1051,111 @@ public sealed class RenderGraph
             Compile();
         }
 
-        // Execute each non-culled pass
         var barrierIndex = 0;
-        for (var i = 0; i < _compiledPasses.Count; i++)
+        var nativePassIndex = 0;
+        var logicalPassIndex = 0;
+        
+        while (logicalPassIndex < _compiledPasses.Count)
         {
-            var pass = _compiledPasses[i];
+            var pass = _compiledPasses[logicalPassIndex];
             
-            // Execute all barriers for this pass
+            // Check if this pass is part of a native render pass
-#if DEBUG
+            if (pass.type == RenderPassType.Raster && nativePassIndex < _nativePasses.Count)
-            bool hasBarriers = false;
-#endif
-            while (barrierIndex < _barriers.Count && _barriers[barrierIndex].PassIndex == i)
             {
-#if DEBUG
+                var nativePass = _nativePasses[nativePassIndex];
-                if (!hasBarriers)
+                
+                // Execute barriers for ALL merged passes before beginning the native render pass
+                foreach (var mergedPassIdx in nativePass.mergedPassIndices)
                 {
-                    Console.WriteLine($"\n=== Barriers before Pass {i}: {pass.name} ===");
+                    ExecuteBarriersForPass(mergedPassIdx, ref barrierIndex);
-                    hasBarriers = true;
                 }
                 
-                var barrier = _barriers[barrierIndex];
+                // Begin native render pass
-                if (barrier.Type == BarrierType.Transition)
+                _commandBuffer.BeginRenderPass(
+                    nativePass.index,
+                    nativePass.colorAttachmentCount,
+                    nativePass.hasDepthAttachment
+                );
+
+                // Execute all merged logical passes within this native render pass
+                for (var i = 0; i < nativePass.mergedPassIndices.Count; i++)
                 {
-                    _commandBuffer.ResourceBarrier(
+                    var mergedPassIdx = nativePass.mergedPassIndices[i];
-                        barrier.Resource,
+                    var mergedPass = _compiledPasses[mergedPassIdx];
-                        barrier.StateBefore,
+                    
-                        barrier.StateAfter
+#if DEBUG
-                    );
+                    Console.WriteLine($"\n--- Executing Pass {mergedPassIdx}: {mergedPass.name} (in Native Pass {nativePass.index}) ---");
-                }
-                else if (barrier.Type == BarrierType.Aliasing)
-                {
-                    _commandBuffer.AliasBarrier(
-                        barrier.ResourceBefore,
-                        barrier.ResourceAfter
-                    );
-                }
 #endif
-                // In a real implementation, you would execute the barrier here:
-                // ExecuteBarrier(_barriers[barrierIndex]);
                     
-                barrierIndex++;
+                    mergedPass.Execute(_renderContext);
+                    logicalPassIndex++;
+                }
+                
+                // End native render pass
+                _commandBuffer.EndRenderPass();
+                
+                nativePassIndex++;
             }
-#if DEBUG
+            else
-            if (hasBarriers)
             {
-                Console.WriteLine("=====================================\n");
+                // Compute pass or standalone raster pass (not merged)
-            }
+                ExecuteBarriersForPass(logicalPassIndex, ref barrierIndex);
+                
+#if DEBUG
+                Console.WriteLine($"\n--- Executing Pass {logicalPassIndex}: {pass.name} (Standalone) ---");
 #endif
                 
-            pass.Execute(_renderContext);
+                pass.Execute(_renderContext);
+                logicalPassIndex++;
+            }
         }
     }
+
+    /// <summary>
+    /// Executes all barriers for a specific pass.
+    /// </summary>
+    private void ExecuteBarriersForPass(int passIndex, ref int barrierIndex)
+    {
+#if DEBUG
+        bool hasBarriers = false;
+#endif
+        while (barrierIndex < _barriers.Count && _barriers[barrierIndex].PassIndex == passIndex)
+        {
+#if DEBUG
+            if (!hasBarriers)
+            {
+                var pass = _compiledPasses[passIndex];
+                Console.WriteLine($"\n=== Barriers before Pass {passIndex}: {pass.name} ===");
+                hasBarriers = true;
+            }
+
+            var barrier = _barriers[barrierIndex];
+            if (barrier.Type == BarrierType.Transition)
+            {
+                _commandBuffer.ResourceBarrier(
+                    barrier.Resource,
+                    barrier.StateBefore,
+                    barrier.StateAfter
+                );
+            }
+            else if (barrier.Type == BarrierType.Aliasing)
+            {
+                _commandBuffer.AliasBarrier(
+                    barrier.ResourceBefore,
+                    barrier.ResourceAfter
+                );
+            }
+#endif
+            // In a real implementation, you would execute the barrier here:
+            // ExecuteBarrier(_barriers[barrierIndex]);
+
+            barrierIndex++;
+        }
+#if DEBUG
+        if (hasBarriers)
+        {
+            Console.WriteLine("=====================================\n");
+        }
+#endif
+    }
 }

Ghost.RenderGraph.Concept/RenderGraph.cs.bak

@@ -1,663 +0,0 @@
-using Ghost.Core;
-using Misaki.HighPerformance.LowLevel.Buffer;
-using Misaki.HighPerformance.LowLevel.Collections;
-using System.IO.Hashing;
-using TerraFX.Interop.Windows;
-
-namespace Ghost.RenderGraph.Concept;
-
-/// <summary>
-/// Main render graph class that manages resource allocation and pass execution.
-/// 
-/// Design principles for minimal GC:
-/// - Object pooling for all passes and resources
-/// - Reuse collections across frames (Clear() instead of new)
-/// - Avoid LINQ and foreach over interfaces
-/// - Pre-allocate capacity based on expected usage
-/// </summary>
-public sealed class RenderGraph
-{
-    private readonly RenderGraphResourceRegistry _resources = new();
-    private readonly RenderGraphObjectPool _objectPool = new();
-    private readonly List<RenderGraphPassBase> _passes = new(64);
-    private readonly List<RenderGraphPassBase> _compiledPasses = new(64);
-    private readonly RenderGraphBuilder _builder = new();
-    private readonly MockCommandBuffer _commandBuffer = new();
-    private readonly RenderContext _renderContext;
-    private readonly ResourceAliasingManager _aliasingManager = new();
-    private readonly Dictionary<int, ResourceState> _resourceStates = new(128);
-    private readonly List<ResourceBarrier> _barriers = new(128);
-    private readonly RenderGraphCompilationCache _compilationCache = new();
-
-    private bool _compiled;
-
-    public RenderGraphBlackboard Blackboard { get; } = new();
-
-    public RenderGraph()
-    {
-        _renderContext = new RenderContext(_commandBuffer);
-    }
-
-    /// <summary>
-    /// Resets the render graph for a new frame.
-    /// Reuses existing allocations to minimize GC.
-    /// </summary>
-    public void Reset()
-    {
-        // Clear blackboard data
-        Blackboard.Clear();
-
-        // Reset resources but keep allocations
-        _resources.BeginFrame();
-
-        // Reset aliasing manager
-        _aliasingManager.BeginFrame();
-
-        // Clear resource states and barriers
-        _resourceStates.Clear();
-        _barriers.Clear();
-
-        // Return passes to the pool and reset count
-        for (var i = 0; i < _passes.Count; i++)
-        {
-            var pass = _passes[i];
-            pass.Reset(_objectPool);
-        }
-
-        _passes.Clear();
-
-        // Clear compiled passes list
-        _compiledPasses.Clear();
-        _compiled = false;
-    }
-
-    /// <summary>
-    /// Imports an external texture into the render graph.
-    /// </summary>
-    public Identifier<RGTexture> ImportTexture(TextureDescriptor descriptor)
-    {
-        return _resources.ImportTexture(descriptor);
-    }
-
-    public IRasterRenderGraphBuilder AddRasterRenderPass<TPassData>(string name, out TPassData passData)
-        where TPassData : class, new()
-    {
-        var renderPass = _objectPool.Rent<RasterRenderGraphPass<TPassData>>();
-        renderPass.Init(_passes.Count, _objectPool.Rent<TPassData>(), name, RenderPassType.Raster);
-        passData = renderPass.passData;
-
-        _passes.Add(renderPass);
-
-        _builder.Init(this, renderPass, _resources);
-        return _builder;
-    }
-
-    public IComputeRenderGraphBuilder AddComputeRenderPass<TPassData>(string name, out TPassData passData)
-        where TPassData : class, new()
-    {
-        var renderPass = _objectPool.Rent<ComputeRenderGraphPass<TPassData>>();
-        renderPass.Init(_passes.Count, _objectPool.Rent<TPassData>(), name, RenderPassType.Compute);
-        passData = renderPass.passData;
-
-        _passes.Add(renderPass);
-
-        _builder.Init(this, renderPass, _resources);
-        return _builder;
-    }
-
-    private unsafe int ComputeTextureHash(byte* pData, int offset, Identifier<RGTexture> texture)
-    {
-        if (texture.IsInvalid)
-        {
-            return offset;
-        }
-
-        var resource = _resources.GetResource(texture.AsResource());
-
-        // In real implementation, we typically need to handle imported resources differently.
-
-        *(pData + offset) = resource.isImported ? (byte)1 : (byte)0;
-        offset += sizeof(byte);
-
-        *(TextureFormat*)(pData + offset) = resource.descriptor.format;
-        offset += sizeof(TextureFormat);
-        
-        *(int*)(pData + offset) = resource.descriptor.width;
-        offset += sizeof(int);
-
-        *(int*)(pData + offset) = resource.descriptor.height;
-        offset += sizeof(int);
-
-        return offset;
-    }
-
-    private unsafe ulong ComputeGraphHash()
-    {
-        using var scope = AllocationManager.CreateStackScope();
-        var bufferPool = new UnsafeList<byte>(2048, scope.AllocationHandle);
-        var pData = (byte*)bufferPool.GetUnsafePtr();
-        var offset = 0;
-
-        // Hash pass count
-        *(int*)(pData + offset) = _passes.Count;
-        offset += sizeof(int);
-
-        // Hash each pass structure (excluding names)
-        for (var i = 0; i < _passes.Count; i++)
-        {
-            var pass = _passes[i];
-
-            *(RenderPassType*)(pData + offset) = pass.type;
-            offset += sizeof(RenderPassType);
-
-            *(bool*)(pData + offset) = pass.allowCulling;
-            offset += sizeof(bool);
-
-            *(bool*)(pData + offset) = pass.asyncCompute;
-            offset += sizeof(bool);
-
-            // Hash depth attachment
-            offset = ComputeTextureHash(pData, offset, pass.depthAccess.id);
-
-            *(int*)(pData + offset) = pass.maxColorIndex;
-            offset += sizeof(int);
-            for (var j = 0; j <= pass.maxColorIndex; j++)
-            {
-                offset = ComputeTextureHash(pData, offset, pass.colorAccess[j].id);
-            }
-
-            *(int*)(pData + offset) = pass.resourceReads.Count;
-            offset += sizeof(int);
-            for (var j = 0; j < pass.resourceReads.Count; j++)
-            {
-                *(int*)(pData + offset) = pass.resourceReads[j].Value;
-                offset += sizeof(int);
-            }
-
-            *(int*)(pData + offset) = pass.resourceWrites.Count;
-            offset += sizeof(int);
-            for (var j = 0; j < pass.resourceWrites.Count; j++)
-            {
-                *(int*)(pData + offset) = pass.resourceWrites[j].Value;
-                offset += sizeof(int);
-            }
-
-            *(int*)(pData + offset) = pass.resourceCreates.Count;
-            offset += sizeof(int);
-            for (var j = 0; j < pass.resourceCreates.Count; j++)
-            {
-                *(int*)(pData + offset) = pass.resourceCreates[j].Value;
-                offset += sizeof(int);
-            }
-        }
-
-        //// Hash resource descriptors
-        //for (var i = 0; i < _resources.TextureResourceCount; i++)
-        //{
-        //    var resource = _resources.GetTextureResourceByIndex(i);
-
-        //    *(int*)(pData + offset) = resource.descriptor.width;
-        //    offset += sizeof(int);
-
-        //    *(int*)(pData + offset) = resource.descriptor.height;
-        //    offset += sizeof(int);
-
-        //    *(TextureFormat*)(pData + offset) = resource.descriptor.format;
-        //    offset += sizeof(TextureFormat);
-
-        //    *(bool*)(pData + offset) = resource.isImported;
-        //    offset += sizeof(bool);
-        //}
-
-        var span = new Span<byte>(pData, offset);
-        return XxHash64.HashToUInt64(span);
-    }
-
-    /// <summary>
-    /// Compiles the render graph by culling unused passes and determining resource lifetimes.
-    /// </summary>
-    public void Compile()
-    {
-        if (_compiled)
-        {
-            return;
-        }
-
-#if DEBUG
-        var sw = System.Diagnostics.Stopwatch.StartNew();
-#endif
-
-        // Step 0: Check cache
-        var graphHash = ComputeGraphHash(); // 17020363347016000737
-
-#if DEBUG
-        var hashTime = sw.Elapsed.TotalMicroseconds;
-#endif
-
-        if (_compilationCache.TryGetCached(graphHash, out var cached))
-        {
-            // CACHE HIT - restore from cache
-#if DEBUG
-            Console.WriteLine($"\n[CACHE HIT] Hash: {graphHash:X16} (computed in {hashTime:F2}μs)");
-#endif
-            RestoreFromCache(cached);
-#if DEBUG
-            sw.Stop();
-            Console.WriteLine($"[CACHE HIT] Total restore time: {sw.Elapsed.TotalMicroseconds:F2}μs");
-#endif
-            _compiled = true;
-            return;
-        }
-
-#if DEBUG
-        Console.WriteLine($"\n[CACHE MISS] Hash: {graphHash:X16} (computed in {hashTime:F2}μs)");
-#endif
-
-        _compiledPasses.Clear();
-
-        // Step 1: Mark passes with side effects (writes to imported resources)
-        for (var i = 0; i < _passes.Count; i++)
-        {
-            var pass = _passes[i];
-
-            // Check if this pass writes to any imported textures
-            for (var j = 0; j < pass.resourceWrites.Count; j++)
-            {
-                var writeHandle = pass.resourceWrites[j];
-                var resource = _resources.GetResource(writeHandle);
-                if (resource.isImported)
-                {
-                    pass.hasSideEffects = true;
-                    break;
-                }
-            }
-        }
-
-        // Step 2: Cull passes based on dependency analysis
-        // Mark all passes as culled initially
-        for (var i = 0; i < _passes.Count; i++)
-        {
-            _passes[i].culled = _passes[i].allowCulling && !_passes[i].hasSideEffects;
-        }
-
-        // Step 3: Traverse backwards from passes with side effects
-        for (var i = _passes.Count - 1; i >= 0; i--)
-        {
-            var pass = _passes[i];
-            if (!pass.culled)
-            {
-                UnculDependencies(pass);
-            }
-        }
-
-        // Step 4: Build final pass list (only non-culled passes)
-        for (var i = 0; i < _passes.Count; i++)
-        {
-            var pass = _passes[i];
-            if (!pass.culled)
-            {
-                _compiledPasses.Add(pass);
-            }
-        }
-
-        // Step 5: Perform resource aliasing to minimize memory usage
-        _aliasingManager.AssignPhysicalResources(_resources, _passes.Count);
-
-        // Step 6: Generate barriers for state transitions and aliasing
-        GenerateBarriers();
-
-        // Step 7: Store in cache for future frames
-        StoreInCache(graphHash);
-
-        _compiled = true;
-    }
-
-    /// <summary>
-    /// Restores the render graph state from cached compilation results.
-    /// </summary>
-    private void RestoreFromCache(CachedCompilation cached)
-    {
-        // Restore compiled pass list
-        _compiledPasses.Clear();
-        for (var i = 0; i < cached.compiledPassIndices.Count; i++)
-        {
-            var passIndex = cached.compiledPassIndices[i];
-            _compiledPasses.Add(_passes[passIndex]);
-        }
-
-        // Restore culling flags
-        for (var i = 0; i < _passes.Count && i < cached.passCulledFlags.Count; i++)
-        {
-            _passes[i].culled = cached.passCulledFlags[i];
-        }
-
-        // Restore aliasing mappings (need to update ResourceAliasingManager)
-        _aliasingManager.RestoreFromCache(cached.logicalToPhysical, cached.physicalResources);
-
-        // Restore barriers (deep copy to avoid shared references)
-        _barriers.Clear();
-        for (var i = 0; i < cached.barriers.Count; i++)
-        {
-            _barriers.Add(cached.barriers[i]);
-        }
-
-        // Restore resource states
-        _resourceStates.Clear();
-        foreach (var kvp in cached.resourceStates)
-        {
-            _resourceStates[kvp.Key] = kvp.Value;
-        }
-    }
-
-    /// <summary>
-    /// Stores current compilation results in the cache.
-    /// </summary>
-    private void StoreInCache(ulong graphHash)
-    {
-        var cacheData = new CachedCompilation();
-
-        // Store compiled pass indices
-        for (var i = 0; i < _compiledPasses.Count; i++)
-        {
-            cacheData.compiledPassIndices.Add(_compiledPasses[i].index);
-        }
-
-        // Store culling flags for all passes
-        for (var i = 0; i < _passes.Count; i++)
-        {
-            cacheData.passCulledFlags.Add(_passes[i].culled);
-        }
-
-        // Store aliasing mappings
-        _aliasingManager.StoreToCache(cacheData.logicalToPhysical, cacheData.physicalResources);
-
-        // Store barriers
-        for (var i = 0; i < _barriers.Count; i++)
-        {
-            cacheData.barriers.Add(_barriers[i]);
-        }
-
-        // Store resource states
-        foreach (var kvp in _resourceStates)
-        {
-            cacheData.resourceStates[kvp.Key] = kvp.Value;
-        }
-
-        _compilationCache.Store(graphHash, cacheData);
-    }
-
-    private void UnculProducer(Identifier<RGResource> resource)
-    {
-        var res = _resources.GetResource(resource);
-        if (res.producerPass >= 0)
-        {
-            var producer = _passes[res.producerPass];
-            if (producer.culled)
-            {
-                producer.culled = false;
-                UnculDependencies(producer);
-            }
-        }
-    }
-
-    private void UnculDependencies(RenderGraphPassBase pass)
-    {
-        // Un-cull producers of read resources
-        for (var i = 0; i < pass.resourceReads.Count; i++)
-        {
-            UnculProducer(pass.resourceReads[i]);
-        }
-
-        // Un-cull producers of color attachments
-        for (var i = 0; i <= pass.maxColorIndex; i++)
-        {
-            if (pass.colorAccess[i].id.IsValid)
-            {
-                UnculProducer(pass.colorAccess[i].id.AsResource());
-            }
-        }
-
-        // Un-cull producer of depth attachment
-        if (pass.depthAccess.id.IsValid)
-        {
-            UnculProducer(pass.depthAccess.id.AsResource());
-        }
-
-        // Un-cull producers of UAV resources (if not already in reads/writes)
-        for (var i = 0; i < pass.randomAccess.Count; i++)
-        {
-            UnculProducer(pass.randomAccess[i]);
-        }
-    }
-
-    /// <summary>
-    /// Generates resource barriers for state transitions and aliasing.
-    /// </summary>
-    private void GenerateBarriers()
-    {
-        _barriers.Clear();
-        _resourceStates.Clear();
-
-#if DEBUG
-        Console.WriteLine("\n=== Barrier Generation ===");
-#endif
-
-        // Process each compiled pass in order
-        for (var passIdx = 0; passIdx < _compiledPasses.Count; passIdx++)
-        {
-            var pass = _compiledPasses[passIdx];
-
-            // Insert aliasing barriers for resources that reuse physical memory
-            InsertAliasingBarriers(pass, passIdx);
-
-            // Insert transition barriers for state changes
-            InsertTransitionBarriers(pass, passIdx);
-        }
-
-#if DEBUG
-        Console.WriteLine($"Total Barriers: {_barriers.Count}");
-        Console.WriteLine("==========================\n");
-#endif
-    }
-
-    /// <summary>
-    /// Inserts aliasing barriers when a physical resource is reused.
-    /// </summary>
-    private void InsertAliasingBarriers(RenderGraphPassBase pass, int passIdx)
-    {
-        // Check all resources written by this pass
-        for (var i = 0; i < pass.resourceWrites.Count; i++)
-        {
-            var id = pass.resourceWrites[i];
-            var resource = _resources.GetResource(id);
-
-            // Skip imported resources
-            if (resource.isImported)
-                continue;
-
-            // Check if this is the first use of this logical resource
-            if (resource.firstUsePass == pass.index)
-            {
-                // Rent the physical resource
-                var physicalIndex = _aliasingManager.GetPhysicalResourceIndex(id.Value);
-                if (physicalIndex >= 0)
-                {
-                    var physical = _aliasingManager.GetPhysicalResource(physicalIndex);
-
-                    // If this physical resource has multiple aliased resources,
-                    // we need an aliasing barrier when switching between them
-                    if (physical != null && physical.aliasedLogicalResources.Count > 1)
-                    {
-                        // Find the resource that used this physical memory most recently before this pass
-                        Identifier<RGResource> resourceBefore = default;
-                        var mostRecentLastUse = -1;
-
-                        foreach (var otherLogicalIndex in physical.aliasedLogicalResources)
-                        {
-                            if (otherLogicalIndex != id.Value)
-                            {
-                                var otherResource = _resources.GetTextureResourceByIndex(otherLogicalIndex);
-                                // Check if this resource finished before our resource starts
-                                if (otherResource.lastUsePass < pass.index &&
-                                    otherResource.lastUsePass > mostRecentLastUse)
-                                {
-                                    mostRecentLastUse = otherResource.lastUsePass;
-                                    resourceBefore = otherLogicalIndex;
-                                }
-                            }
-                        }
-
-                        // If we found a previous resource, insert aliasing barrier
-                        if (mostRecentLastUse >= 0)
-                        {
-                            var barrier = ResourceBarrier.CreateAliasingBarrier(
-                                resourceBefore,
-                                id,
-                                passIdx
-                            );
-                            _barriers.Add(barrier);
-
-#if DEBUG
-                            Console.WriteLine($"  {barrier}");
-#endif
-                        }
-                    }
-                }
-            }
-        }
-    }
-
-    /// <summary>
-    /// Inserts transition barriers when a resource changes state.
-    /// </summary>
-    private void InsertTransitionBarriers(RenderGraphPassBase pass, int passIdx)
-    {
-        // Process reads (transition to shader resource)
-        for (var i = 0; i < pass.resourceReads.Count; i++)
-        {
-            var handle = pass.resourceReads[i];
-            InsertTransitionIfNeeded(handle, ResourceState.ShaderResource, passIdx);
-        }
-
-        switch (pass.type)
-        {
-            case RenderPassType.Raster:
-                for (var i = 0; i <= pass.maxColorIndex; i++)
-                {
-                    var access = pass.colorAccess[i];
-                    InsertTransitionIfNeeded(access.id.AsResource(), ResourceState.RenderTarget, passIdx);
-                }
-
-                if (pass.depthAccess.id.IsValid)
-                {
-                    var depthAccess = pass.depthAccess;
-                    InsertTransitionIfNeeded(depthAccess.id.AsResource(), ResourceState.DepthWrite, passIdx);
-                }
-
-                for (var i = 0; i < pass.randomAccess.Count; i++)
-                {
-                    InsertTransitionIfNeeded(pass.randomAccess[i], ResourceState.UnorderedAccess, passIdx);
-                }
-
-                break;
-            case RenderPassType.Compute:
-                for (var i = 0; i < pass.resourceWrites.Count; i++)
-                {
-                    var id = pass.resourceWrites[i];
-                    InsertTransitionIfNeeded(id, ResourceState.UnorderedAccess, passIdx);
-                }
-
-                break;
-        }
-    }
-
-    /// <summary>
-    /// Inserts a transition barrier if the resource state changes.
-    /// </summary>
-    private void InsertTransitionIfNeeded(Identifier<RGResource> resource, ResourceState newState, int passIdx)
-    {
-        if (!_resourceStates.TryGetValue(resource.Value, out var currentState))
-        {
-            // First time seeing this resource, assume undefined
-            currentState = ResourceState.Common;
-        }
-
-        if (currentState != newState)
-        {
-            var barrier = ResourceBarrier.CreateTransitionBarrier(
-                resource,
-                currentState,
-                newState,
-                passIdx
-            );
-            _barriers.Add(barrier);
-            _resourceStates[resource.Value] = newState;
-
-#if DEBUG
-            Console.WriteLine($"  {barrier}");
-#endif
-        }
-    }
-
-    /// <summary>
-    /// Executes all compiled passes.
-    /// </summary>
-    public void Execute()
-    {
-        if (!_compiled)
-        {
-            Compile();
-        }
-
-        // Execute each non-culled pass
-        var barrierIndex = 0;
-        for (var i = 0; i < _compiledPasses.Count; i++)
-        {
-            var pass = _compiledPasses[i];
-
-            // Execute all barriers for this pass
-#if DEBUG
-            bool hasBarriers = false;
-#endif
-            while (barrierIndex < _barriers.Count && _barriers[barrierIndex].PassIndex == i)
-            {
-#if DEBUG
-                if (!hasBarriers)
-                {
-                    Console.WriteLine($"\n=== Barriers before Pass {i}: {pass.name} ===");
-                    hasBarriers = true;
-                }
-
-                var barrier = _barriers[barrierIndex];
-                if (barrier.Type == BarrierType.Transition)
-                {
-                    _commandBuffer.ResourceBarrier(
-                        barrier.Resource,
-                        barrier.StateBefore,
-                        barrier.StateAfter
-                    );
-                }
-                else if (barrier.Type == BarrierType.Aliasing)
-                {
-                    _commandBuffer.AliasBarrier(
-                        barrier.ResourceBefore,
-                        barrier.ResourceAfter
-                    );
-                }
-#endif
-                // In a real implementation, you would execute the barrier here:
-                // ExecuteBarrier(_barriers[barrierIndex]);
-
-                barrierIndex++;
-            }
-#if DEBUG
-            if (hasBarriers)
-            {
-                Console.WriteLine("=====================================\n");
-            }
-#endif
-
-            pass.Execute(_renderContext);
-        }
-    }
-}

Ghost.RenderGraph.Concept/RenderGraphAliasing.cs

@@ -1,17 +1,256 @@
 using Ghost.Core.Utilities;
+using System.Runtime.InteropServices;
 
 namespace Ghost.RenderGraph.Concept;
 
 /// <summary>
-/// Represents a physical GPU resource that can be aliased by multiple logical resources.
+/// Represents a memory block within a heap.
 /// </summary>
-internal sealed class PhysicalResource
+internal struct MemoryBlock
+{
+    public ulong offset;
+    public ulong size;
+    public bool isFree;
+    public int firstUsePass;
+    public int lastUsePass;
+    public int logicalResourceIndex; // Which logical resource is currently using this block
+
+    public MemoryBlock(ulong offset, ulong size)
+    {
+        this.offset = offset;
+        this.size = size;
+        isFree = true;
+        firstUsePass = int.MaxValue;
+        lastUsePass = -1;
+        logicalResourceIndex = -1;
+    }
+
+    public void Reset()
+    {
+        isFree = true;
+        firstUsePass = int.MaxValue;
+        lastUsePass = -1;
+        logicalResourceIndex = -1;
+    }
+}
+
+/// <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 int width;
+    public ulong size;
-    public int height;
+    private readonly List<MemoryBlock> _blocks = new(32);
-    public TextureFormat format;
+
-    public int sizeInBytes;
+    // D3D12 heap alignment requirement (64KB for MSAA textures, 4KB for others)
+    private const ulong DefaultAlignment = 65536; // 64KB
+
+    public ResourceHeap(int index, ulong initialSize = 16 * 1024 * 1024) // 16MB default
+    {
+        this.index = index;
+        this.size = initialSize;
+
+        // Initially one large free block
+        _blocks.Add(new MemoryBlock(0, initialSize));
+    }
+
+    public void Reset()
+    {
+        _blocks.Clear();
+        _blocks.Add(new MemoryBlock(0, size));
+    }
+
+    /// <summary>
+    /// Attempts to allocate a block of the requested size with proper alignment.
+    /// Uses best-fit algorithm with lifetime-aware allocation.
+    /// </summary>
+    public (bool success, ulong offset, MemoryBlock block) TryAllocate(
+        ulong requestedSize,
+        int firstUsePass,
+        int lastUsePass,
+        int logicalResourceIndex,
+        ulong alignment = DefaultAlignment)
+    {
+        var alignedSize = AlignUp(requestedSize, alignment);
+
+        var bestFitIndex = -1;
+        ulong bestFitOffset = 0;
+        var smallestWaste = ulong.MaxValue;
+
+        // Find the best fit block that doesn't overlap with lifetime
+        var blockSpan = CollectionsMarshal.AsSpan(_blocks);
+        for (var i = 0; i < blockSpan.Length; i++)
+        {
+            ref var block = ref blockSpan[i];
+
+            // Try to find space within this block
+            var alignedOffset = AlignUp(block.offset, alignment);
+            var endOffset = alignedOffset + alignedSize;
+
+            if (endOffset <= block.offset + block.size)
+            {
+                // Check if this offset range conflicts with ANY existing allocations
+                var canUseOffset = CanPlaceAtOffset(alignedOffset, alignedSize, firstUsePass, lastUsePass);
+                
+                if (canUseOffset)
+                {
+                    var waste = block.size - alignedSize;
+
+                    if (waste < smallestWaste)
+                    {
+                        smallestWaste = waste;
+                        bestFitIndex = i;
+                        bestFitOffset = alignedOffset;
+                    }
+                }
+            }
+        }
+
+        if (bestFitIndex == -1)
+        {
+            return (false, 0, default);
+        }
+
+        ref var bestFit = ref CollectionsMarshal.AsSpan(_blocks)[bestFitIndex];
+
+        // If the block is free, we need to split it
+        if (bestFit.isFree)
+        {
+            var remainingSize = (bestFit.offset + bestFit.size) - (bestFitOffset + alignedSize);
+
+            // Update the current block to be allocated
+            bestFit.offset = bestFitOffset;
+            bestFit.size = alignedSize;
+            bestFit.isFree = false;
+            bestFit.firstUsePass = firstUsePass;
+            bestFit.lastUsePass = lastUsePass;
+            bestFit.logicalResourceIndex = logicalResourceIndex;
+
+            // Create a new free block for the remaining space if there is any
+            if (remainingSize > 0)
+            {
+                var newBlock = new MemoryBlock(bestFitOffset + alignedSize, remainingSize);
+                _blocks.Insert(bestFitIndex + 1, newBlock);
+            }
+        }
+        else
+        {
+            // Block is already allocated but lifetime doesn't overlap, we can alias it
+            // Create a new aliased block at the same location
+            var aliasedBlock = new MemoryBlock(bestFitOffset, alignedSize)
+            {
+                isFree = false,
+                firstUsePass = firstUsePass,
+                lastUsePass = lastUsePass,
+                logicalResourceIndex = logicalResourceIndex
+            };
+
+            // Insert in sorted order by offset
+            var insertIndex = 0;
+            for (var i = 0; i < _blocks.Count; i++)
+            {
+                if (_blocks[i].offset > bestFitOffset)
+                {
+                    break;
+                }
+                insertIndex = i + 1;
+            }
+            _blocks.Insert(insertIndex, aliasedBlock);
+            // Update bestFit to point to the newly inserted block
+            bestFit = ref CollectionsMarshal.AsSpan(_blocks)[insertIndex];
+        }
+
+        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;
+        
+        foreach (var block in _blocks)
+        {
+            // Skip free blocks - they don't have lifetime constraints
+            if (block.isFree)
+                continue;
+            
+            // Check if this block's memory range overlaps with our target range
+            var blockEnd = block.offset + block.size;
+            var memoryOverlap = !(offset >= blockEnd || endOffset <= block.offset);
+            
+            if (memoryOverlap)
+            {
+                // Memory ranges overlap, check if lifetimes also overlap
+                var lifetimeOverlap = !(firstUsePass > block.lastUsePass || lastUsePass < block.firstUsePass);
+                
+                if (lifetimeOverlap)
+                {
+                    // Both memory AND lifetime overlap - cannot place here!
+                    return false;
+                }
+            }
+        }
+        
+        return true;
+    }
+
+    /// <summary>
+    /// Gets the total memory that would be used if no aliasing occurred.
+    /// </summary>
+    public ulong GetTotalAllocatedWithoutAliasing()
+    {
+        ulong total = 0;
+        foreach (var block in _blocks)
+        {
+            if (!block.isFree)
+            {
+                total += block.size;
+            }
+        }
+        return total;
+    }
+
+    /// <summary>
+    /// Gets the peak memory usage considering aliasing (max offset + size).
+    /// </summary>
+    public ulong GetPeakUsage()
+    {
+        ulong peak = 0;
+        foreach (var block in _blocks)
+        {
+            if (!block.isFree)
+            {
+                peak = Math.Max(peak, block.offset + block.size);
+            }
+        }
+        return peak;
+    }
+
+    private static ulong AlignUp(ulong value, ulong alignment)
+    {
+        return (value + alignment - 1) & ~(alignment - 1);
+    }
+}
+
+/// <summary>
+/// Represents a placed resource within a heap.
+/// </summary>
+internal sealed class PlacedResource
+{
+    public int index;
+    public RenderGraphResourceType type;
+    public int heapIndex;
+    public ulong heapOffset;
+    public ulong sizeInBytes;
+
+    // Original descriptor
+    public TextureDescriptor textureDesc;
+    public BufferDescriptor bufferDesc;
 
     // Lifetime tracking
     public int firstUsePass = int.MaxValue;
@@ -19,26 +258,21 @@ internal sealed class PhysicalResource
 
     // Aliasing tracking
     public readonly List<int> aliasedLogicalResources = new(4);
+    public MemoryBlock memoryBlock;
 
     public void Reset()
     {
         index = -1;
-        width = 0;
+        type = RenderGraphResourceType.Texture;
-        height = 0;
+        heapIndex = -1;
-        format = TextureFormat.RGBA8;
+        heapOffset = 0;
         sizeInBytes = 0;
+        textureDesc = default;
+        bufferDesc = default;
         firstUsePass = int.MaxValue;
         lastUsePass = -1;
         aliasedLogicalResources.Clear();
-    }
+        memoryBlock = default;
-
-    public bool CanAlias(TextureDescriptor descriptor)
-    {
-        // For aliasing, resources must be identical in size and format
-        // In a real implementation, you could be more flexible (e.g., same size but different format)
-        return width == descriptor.width &&
-               height == descriptor.height &&
-               format == descriptor.format;
     }
 
     public void UpdateLifetime(int passIndex)
@@ -46,148 +280,293 @@ internal sealed class PhysicalResource
         firstUsePass = Math.Min(firstUsePass, passIndex);
         lastUsePass = Math.Max(lastUsePass, passIndex);
     }
-
-    public bool IsAliveAt(int passIndex)
-    {
-        return passIndex >= firstUsePass && passIndex <= lastUsePass;
-    }
-
-    public int CalculateSize()
-    {
-        int bytesPerPixel = format switch
-        {
-            TextureFormat.RGBA8 => 4,
-            TextureFormat.RGBA16F => 8,
-            TextureFormat.RGBA32F => 16,
-            TextureFormat.Depth32F => 4,
-            TextureFormat.Depth24Stencil8 => 4,
-            _ => 4
-        };
-        return width * height * bytesPerPixel;
-    }
 }
 
 /// <summary>
-/// Manages physical resource allocation and aliasing.
+/// Manages physical resource allocation and aliasing using heap-based allocation.
-/// Uses interval scheduling algorithm to minimize memory usage.
+/// Supports D3D12 heap tier 2: buffers and textures can alias as long as lifetimes don't overlap.
 /// </summary>
 internal sealed class ResourceAliasingManager
 {
-    private readonly List<PhysicalResource> _physicalResources = new(32);
+    private readonly List<ResourceHeap> _heaps = new(4);
+    private readonly List<PlacedResource> _placedResources = new(32);
     private readonly RenderGraphObjectPool _pool = new();
-    private int _physicalResourceCount;
 
-    // Mapping from logical resource index to physical resource index
+    // Mapping from logical resource index to placed resource index
-    private readonly Dictionary<int, int> _logicalToPhysical = new(64);
+    private readonly Dictionary<int, int> _logicalToPlaced = new(64);
+
+    // D3D12 alignment constants
+    private const ulong DefaultTextureAlignment = 65536; // 64KB
+    private const ulong DefaultBufferAlignment = 65536;  // 64KB for D3D12
 
     public void BeginFrame()
     {
-        _physicalResourceCount = 0;
+        for (var i = 0; i < _placedResources.Count; i++)
-        _logicalToPhysical.Clear();
-        
-        // Reset physical resources but keep them in the pool
-        for (int i = 0; i < _physicalResources.Count; i++)
         {
-            _physicalResources[i].Reset();
+            _pool.Return(_placedResources[i]);
+        }
+
+        _placedResources.Clear();
+        _logicalToPlaced.Clear();
+
+        // Reset heaps
+        for (var i = 0; i < _heaps.Count; i++)
+        {
+            _heaps[i].Reset();
         }
     }
 
     /// <summary>
-    /// Assigns physical resources to logical resources using greedy interval scheduling.
+    /// Assigns physical resources (placed resources) to logical resources using heap-based allocation.
-    /// This minimizes total GPU memory usage.
+    /// 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)
     {
 #if DEBUG
-        Console.WriteLine("\n=== Resource Aliasing Analysis ===");
+        Console.WriteLine("\n=== Heap-Based Resource Aliasing Analysis ===");
-        int totalLogicalSize = 0;
+        ulong totalLogicalSize = 0;
 #endif
 
-        // Build list of all logical resources with their lifetimes
+        // Build list of all logical resources (both textures and buffers) with their lifetimes
         var logicalResources = ListPool<(int index, RenderGraphResource resource)>.Rent();
 
-        for (int i = 0; i < registry.TextureResourceCount; i++)
+        // Iterate through all resources in unified list
+        for (var i = 0; i < registry.ResourceCount; i++)
         {
-            var resource = registry.GetTextureResourceByIndex(i);
+            var resource = registry.GetResourceByIndex(i);
             if (!resource.isImported) // Don't alias imported resources
             {
-                logicalResources.Add((i, resource));
+                logicalResources.Add((resource.index, resource));
 #if DEBUG
-                int size = CalculateSize(resource.descriptor);
+                var size = resource.type == RenderGraphResourceType.Texture
+                    ? CalculateTextureSize(resource.textureDescriptor)
+                    : resource.bufferDescriptor.sizeInBytes;
                 totalLogicalSize += size;
-                Console.WriteLine($"Logical Resource {i}: {resource.descriptor.name}");
+
+                var typeName = resource.type == RenderGraphResourceType.Texture ? "Texture" : "Buffer";
+                var name = resource.type == RenderGraphResourceType.Texture
+                    ? resource.textureDescriptor.name
+                    : resource.bufferDescriptor.name;
+
+                Console.WriteLine($"Logical {typeName} {i}: {name}");
                 Console.WriteLine($"  Lifetime: Pass {resource.firstUsePass} -> {resource.lastUsePass}");
                 Console.WriteLine($"  Size: {size / 1024.0:F2} KB");
 #endif
             }
         }
 
-        // Sort by first use pass (earlier resources first)
+        // Sort by size descending (larger resources first for better packing)
-        logicalResources.Sort((a, b) => a.resource.firstUsePass.CompareTo(b.resource.firstUsePass));
+        logicalResources.Sort(static (a, b) =>
+        {
+            var sizeA = a.resource.type == RenderGraphResourceType.Texture
+                ? CalculateTextureSize(a.resource.textureDescriptor)
+                : a.resource.bufferDescriptor.sizeInBytes;
+            var sizeB = b.resource.type == RenderGraphResourceType.Texture
+                ? CalculateTextureSize(b.resource.textureDescriptor)
+                : b.resource.bufferDescriptor.sizeInBytes;
+            return sizeB.CompareTo(sizeA); // Descending
+        });
+
+        // ===== PASS 1: Simulate allocation to determine peak memory usage =====
+        var simulationHeap = new ResourceHeap(0, ulong.MaxValue); // Unlimited size for simulation
         
-        // Greedy interval scheduling: assign each logical resource to a physical resource
         foreach (var (logicalIndex, logicalResource) in logicalResources)
         {
-            PhysicalResource? assignedPhysical = null;
+            ulong size;
+            ulong alignment;
 
-            // Try to find an existing physical resource that:
+            if (logicalResource.type == RenderGraphResourceType.Texture)
-            // 1. Has compatible format/size
-            // 2. Is not alive during this logical resource's lifetime
-            for (int i = 0; i < _physicalResourceCount; i++)
             {
-                var physical = _physicalResources[i];
+                size = CalculateTextureSize(logicalResource.textureDescriptor);
-                
+                alignment = DefaultTextureAlignment;
-                if (physical.CanAlias(logicalResource.descriptor) &&
+            }
-                    !HasLifetimeOverlap(physical, logicalResource))
+            else // Buffer
-                {
+            {
-                    assignedPhysical = physical;
+                size = logicalResource.bufferDescriptor.sizeInBytes;
-                    break;
+                alignment = DefaultBufferAlignment;
-                }
             }
 
-            // No compatible physical resource found, allocate a new one
+            var (success, offset, block) = simulationHeap.TryAllocate(
-            if (assignedPhysical == null)
+                size,
+                logicalResource.firstUsePass,
+                logicalResource.lastUsePass,
+                logicalIndex,
+                alignment);
+
+            if (!success)
             {
-                assignedPhysical = GetOrCreatePhysicalResource();
+                throw new InvalidOperationException("Simulation allocation failed - this should never happen with unlimited heap");
-                assignedPhysical.index = _physicalResourceCount - 1;
+            }
-                assignedPhysical.width = logicalResource.descriptor.width;
+        }
-                assignedPhysical.height = logicalResource.descriptor.height;
+
-                assignedPhysical.format = logicalResource.descriptor.format;
+        // Get peak usage from simulation
-                assignedPhysical.sizeInBytes = assignedPhysical.CalculateSize();
+        var peakMemoryUsage = simulationHeap.GetPeakUsage();
+        
+        // Align peak usage to 64KB (D3D12 requirement)
+        peakMemoryUsage = AlignUp(peakMemoryUsage, DefaultTextureAlignment);
 
 #if DEBUG
-                Console.WriteLine($"\nAllocated NEW Physical Resource {assignedPhysical.index}:");
+        Console.WriteLine($"\nPeak Memory Usage: {peakMemoryUsage / (1024.0 * 1024.0):F2} MB");
-                Console.WriteLine($"  Size: {assignedPhysical.width}x{assignedPhysical.height}");
-                Console.WriteLine($"  Format: {assignedPhysical.format}");
-                Console.WriteLine($"  Memory: {assignedPhysical.sizeInBytes / 1024.0:F2} KB");
 #endif
-            }
+
+        // ===== PASS 2: Create a single heap of the peak size and do the real allocation =====
+        var mainHeap = new ResourceHeap(0, peakMemoryUsage);
+        _heaps.Add(mainHeap);
+
 #if DEBUG
+        Console.WriteLine($"Created Single Heap:");
+        Console.WriteLine($"  Size: {peakMemoryUsage / (1024.0 * 1024.0):F2} MB\n");
+#endif
+
+        // Allocate each logical resource in the heap
+        foreach (var (logicalIndex, logicalResource) in logicalResources)
+        {
+            ulong size;
+            ulong alignment;
+
+            if (logicalResource.type == RenderGraphResourceType.Texture)
+            {
+                size = CalculateTextureSize(logicalResource.textureDescriptor);
+                alignment = DefaultTextureAlignment;
+            }
+            else // Buffer
+            {
+                size = logicalResource.bufferDescriptor.sizeInBytes;
+                alignment = DefaultBufferAlignment;
+            }
+
+            var (success, offset, block) = mainHeap.TryAllocate(
+                size,
+                logicalResource.firstUsePass,
+                logicalResource.lastUsePass,
+                logicalIndex,
+                alignment);
+
+            if (!success)
+            {
+                throw new InvalidOperationException("Real allocation failed - this should match simulation");
+            }
+
+            var assignedHeapIndex = 0;
+            var assignedOffset = offset;
+            var assignedBlock = block;
+
+            var assignedPlaced = _pool.Rent<PlacedResource>();
+            assignedPlaced.index = _placedResources.Count;
+            assignedPlaced.type = logicalResource.type;
+            assignedPlaced.heapIndex = assignedHeapIndex;
+            assignedPlaced.heapOffset = assignedOffset;
+            assignedPlaced.sizeInBytes = size;
+            assignedPlaced.firstUsePass = logicalResource.firstUsePass;
+            assignedPlaced.lastUsePass = logicalResource.lastUsePass;
+            assignedPlaced.memoryBlock = assignedBlock;
+
+            if (logicalResource.type == RenderGraphResourceType.Texture)
+            {
+                assignedPlaced.textureDesc = logicalResource.textureDescriptor;
+            }
             else
             {
-                Console.WriteLine($"\nALIASING: {logicalResource.descriptor.name} -> Physical Resource {assignedPhysical.index}");
+                assignedPlaced.bufferDesc = logicalResource.bufferDescriptor;
+            }
+
+            assignedPlaced.aliasedLogicalResources.Clear();
+            assignedPlaced.aliasedLogicalResources.Add(logicalIndex);
+
+            _placedResources.Add(assignedPlaced);
+
+#if DEBUG
+            var isAliased = assignedBlock.logicalResourceIndex != logicalIndex && assignedBlock.logicalResourceIndex != -1;
+            var name = logicalResource.type == RenderGraphResourceType.Texture
+                ? logicalResource.textureDescriptor.name
+                : logicalResource.bufferDescriptor.name;
+            var typeName = logicalResource.type == RenderGraphResourceType.Texture ? "Texture" : "Buffer";
+
+            if (isAliased)
+            {
+                Console.WriteLine($"\nALIASING {typeName}: {name}");
+                Console.WriteLine($"  Placed in Heap {assignedHeapIndex} at offset {assignedOffset} ({assignedOffset / 1024.0:F2} KB)");
+                Console.WriteLine($"  Size: {size / 1024.0:F2} KB");
+            }
+            else
+            {
+                Console.WriteLine($"\nAllocated {typeName}: {name}");
+                Console.WriteLine($"  Heap {assignedHeapIndex}, Offset {assignedOffset} ({assignedOffset / 1024.0:F2} KB)");
+                Console.WriteLine($"  Size: {size / 1024.0:F2} KB");
             }
 #endif
 
-            // Update physical resource lifetime
-            assignedPhysical.UpdateLifetime(logicalResource.firstUsePass);
-            assignedPhysical.UpdateLifetime(logicalResource.lastUsePass);
-            assignedPhysical.aliasedLogicalResources.Add(logicalIndex);
-
             // Record the mapping
-            _logicalToPhysical[logicalIndex] = assignedPhysical.index;
+            _logicalToPlaced[logicalIndex] = assignedPlaced.index;
+        }
+
+        // Second pass: Populate aliasedLogicalResources lists
+        // For each placed resource, find all OTHER placed resources at the same heap+offset
+        for (var i = 0; i < _placedResources.Count; i++)
+        {
+            var placed = _placedResources[i];
+            
+            // Find all logical resources that share the same heap location
+            for (var j = 0; j < _placedResources.Count; j++)
+            {
+                if (i == j) continue; // Skip self
+                
+                var other = _placedResources[j];
+                
+                // Check if they're at the same heap+offset
+                if (other.heapIndex == placed.heapIndex && other.heapOffset == placed.heapOffset)
+                {
+                    // Add the other's logical resource to this one's aliased list
+                    var otherLogicalIndex = other.aliasedLogicalResources[0]; // Each has exactly one at this point
+                    if (!placed.aliasedLogicalResources.Contains(otherLogicalIndex))
+                    {
+                        placed.aliasedLogicalResources.Add(otherLogicalIndex);
+                    }
+                }
+            }
         }
 
 #if DEBUG
-        int totalPhysicalSize = 0;
+        // Debug output: Show which resources alias with each other
-        for (int i = 0; i < _physicalResourceCount; i++)
+        Console.WriteLine("\n=== Aliasing Groups ===");
+        var processedOffsets = new HashSet<(int heapIndex, ulong offset)>();
+        for (var i = 0; i < _placedResources.Count; i++)
         {
-            totalPhysicalSize += _physicalResources[i].sizeInBytes;
+            var placed = _placedResources[i];
+            var key = (placed.heapIndex, placed.heapOffset);
+            
+            if (!processedOffsets.Contains(key) && placed.aliasedLogicalResources.Count > 1)
+            {
+                processedOffsets.Add(key);
+                Console.WriteLine($"Heap {placed.heapIndex} @ Offset {placed.heapOffset / 1024.0:F2} KB ({placed.aliasedLogicalResources.Count} resources):");
+                
+                foreach (var logicalIdx in placed.aliasedLogicalResources)
+                {
+                    var res = registry.GetResourceByIndex(logicalIdx);
+                    var name = res.type == RenderGraphResourceType.Texture
+                        ? res.textureDescriptor.name
+                        : res.bufferDescriptor.name;
+                    Console.WriteLine($"  - {name} (Pass {res.firstUsePass}-{res.lastUsePass})");
+                }
+            }
+        }
+        Console.WriteLine("=======================\n");
+#endif
+
+#if DEBUG
+        ulong totalPhysicalSize = 0;
+        for (var i = 0; i < _heaps.Count; i++)
+        {
+            totalPhysicalSize += _heaps[i].GetPeakUsage();
         }
 
-        Console.WriteLine($"\n=== Aliasing Summary ===");
+        Console.WriteLine($"\n=== Heap-Based Aliasing Summary ===");
         Console.WriteLine($"Logical Resources: {logicalResources.Count}");
-        Console.WriteLine($"Physical Resources: {_physicalResourceCount}");
+        Console.WriteLine($"Placed Resources: {_placedResources.Count}");
+        Console.WriteLine($"Heaps: {_heaps.Count}");
         Console.WriteLine($"Total Logical Memory: {totalLogicalSize / 1024.0:F2} KB");
         Console.WriteLine($"Total Physical Memory: {totalPhysicalSize / 1024.0:F2} KB");
         Console.WriteLine($"Memory Saved: {(totalLogicalSize - totalPhysicalSize) / 1024.0:F2} KB ({(1.0 - (double)totalPhysicalSize / totalLogicalSize) * 100.0:F1}%)");
@@ -197,48 +576,21 @@ internal sealed class ResourceAliasingManager
         ListPool<(int index, RenderGraphResource resource)>.Return(logicalResources);
     }
 
-    public int GetPhysicalResourceIndex(int logicalIndex)
+    public int GetPlacedResourceIndex(int logicalIndex)
     {
-        return _logicalToPhysical.TryGetValue(logicalIndex, out var physicalIndex) ? physicalIndex : -1;
+        return _logicalToPlaced.TryGetValue(logicalIndex, out var placedIndex) ? placedIndex : -1;
     }
 
-    public PhysicalResource? GetPhysicalResource(int physicalIndex)
+    public PlacedResource? GetPlacedResource(int placedIndex)
     {
-        return physicalIndex >= 0 && physicalIndex < _physicalResourceCount 
+        return placedIndex >= 0 && placedIndex < _placedResources.Count
-            ? _physicalResources[physicalIndex] 
+            ? _placedResources[placedIndex]
             : null;
     }
 
-    private bool HasLifetimeOverlap(PhysicalResource physical, RenderGraphResource logical)
+    private static ulong CalculateTextureSize(TextureDescriptor descriptor)
     {
-        // Check if the lifetimes overlap
+        var bytesPerPixel = descriptor.format switch
-        // No overlap if: logical.First > physical.Last OR logical.Last < physical.First
-        return !(logical.firstUsePass > physical.lastUsePass || 
-                 logical.lastUsePass < physical.firstUsePass);
-    }
-
-    private PhysicalResource GetOrCreatePhysicalResource()
-    {
-        PhysicalResource resource;
-        if (_physicalResourceCount < _physicalResources.Count)
-        {
-            resource = _physicalResources[_physicalResourceCount];
-            resource.Reset();
-        }
-        else
-        {
-            resource = _pool.Rent<PhysicalResource>();
-            resource.Reset();
-            _physicalResources.Add(resource);
-        }
-
-        _physicalResourceCount++;
-        return resource;
-    }
-
-    private static int CalculateSize(TextureDescriptor descriptor)
-    {
-        int bytesPerPixel = descriptor.format switch
         {
             TextureFormat.RGBA8 => 4,
             TextureFormat.RGBA16F => 8,
@@ -247,82 +599,87 @@ internal sealed class ResourceAliasingManager
             TextureFormat.Depth24Stencil8 => 4,
             _ => 4
         };
-        return descriptor.width * descriptor.height * bytesPerPixel;
+
+        // Add alignment padding (D3D12 requires 64KB alignment)
+        var size = (ulong)(descriptor.width * descriptor.height * bytesPerPixel);
+        return AlignUp(size, DefaultTextureAlignment);
+    }
+
+    private static ulong AlignUp(ulong value, ulong alignment)
+    {
+        return (value + alignment - 1) & ~(alignment - 1);
     }
 
     public void Clear()
     {
-        for (int i = 0; i < _physicalResources.Count; i++)
+        for (var i = 0; i < _placedResources.Count; i++)
         {
-            _pool.Return(_physicalResources[i]);
+            _pool.Return(_placedResources[i]);
         }
-        _physicalResources.Clear();
+        _placedResources.Clear();
-        _physicalResourceCount = 0;
+        _logicalToPlaced.Clear();
-        _logicalToPhysical.Clear();
+        _heaps.Clear();
     }
 
     /// <summary>
     /// Restores aliasing state from cache.
     /// </summary>
-    public void RestoreFromCache(Dictionary<int, int> logicalToPhysical, List<PhysicalResourceData> physicalData)
+    public void RestoreFromCache(Dictionary<int, int> logicalToPlaced, List<PlacedResourceData> placedData)
     {
-        _logicalToPhysical.Clear();
+        _logicalToPlaced.Clear();
-        foreach (var kvp in logicalToPhysical)
+        foreach (var kvp in logicalToPlaced)
         {
-            _logicalToPhysical[kvp.Key] = kvp.Value;
+            _logicalToPlaced[kvp.Key] = kvp.Value;
         }
 
-        // Restore physical resources
+        // Restore placed resources
-        _physicalResourceCount = physicalData.Count;
+        for (var i = 0; i < placedData.Count; i++)
-        for (int i = 0; i < physicalData.Count; i++)
         {
-            PhysicalResource physical;
+            var placed = _pool.Rent<PlacedResource>();
-            if (i < _physicalResources.Count)
-            {
-                physical = _physicalResources[i];
-                physical.Reset();
-            }
-            else
-            {
-                physical = _pool.Rent<PhysicalResource>();
-                physical.Reset();
-                _physicalResources.Add(physical);
-            }
 
-            var data = physicalData[i];
+            var data = placedData[i];
-            physical.index = data.index;
+            placed.index = data.index;
-            physical.width = data.width;
+            placed.type = data.type;
-            physical.height = data.height;
+            placed.heapIndex = data.heapIndex;
-            physical.format = data.format;
+            placed.heapOffset = data.heapOffset;
-            physical.firstUsePass = data.firstUsePass;
+            placed.sizeInBytes = data.sizeInBytes;
-            physical.lastUsePass = data.lastUsePass;
+            placed.textureDesc = data.textureDesc;
-            physical.sizeInBytes = physical.CalculateSize();
+            placed.bufferDesc = data.bufferDesc;
+            placed.firstUsePass = data.firstUsePass;
+            placed.lastUsePass = data.lastUsePass;
+
+            placed.aliasedLogicalResources.Clear();
+
+            _placedResources.Add(placed);
         }
     }
 
     /// <summary>
     /// Stores current aliasing state to cache.
     /// </summary>
-    public void StoreToCache(Dictionary<int, int> outLogicalToPhysical, List<PhysicalResourceData> outPhysicalData)
+    public void StoreToCache(Dictionary<int, int> outLogicalToPlaced, List<PlacedResourceData> outPlacedData)
     {
-        outLogicalToPhysical.Clear();
+        outLogicalToPlaced.Clear();
-        foreach (var kvp in _logicalToPhysical)
+        foreach (var kvp in _logicalToPlaced)
         {
-            outLogicalToPhysical[kvp.Key] = kvp.Value;
+            outLogicalToPlaced[kvp.Key] = kvp.Value;
         }
 
-        outPhysicalData.Clear();
+        outPlacedData.Clear();
-        for (int i = 0; i < _physicalResourceCount; i++)
+        for (var i = 0; i < _placedResources.Count; i++)
         {
-            var physical = _physicalResources[i];
+            var placed = _placedResources[i];
-            outPhysicalData.Add(new PhysicalResourceData
+            outPlacedData.Add(new PlacedResourceData
             {
-                index = physical.index,
+                index = placed.index,
-                width = physical.width,
+                type = placed.type,
-                height = physical.height,
+                heapIndex = placed.heapIndex,
-                format = physical.format,
+                heapOffset = placed.heapOffset,
-                firstUsePass = physical.firstUsePass,
+                sizeInBytes = placed.sizeInBytes,
-                lastUsePass = physical.lastUsePass
+                textureDesc = placed.textureDesc,
+                bufferDesc = placed.bufferDesc,
+                firstUsePass = placed.firstUsePass,
+                lastUsePass = placed.lastUsePass
             });
         }
     }

Ghost.RenderGraph.Concept/RenderGraphAliasing.cs.bak

@@ -1,329 +0,0 @@
-using Ghost.Core.Utilities;
-
-namespace Ghost.RenderGraph.Concept;
-
-/// <summary>
-/// Represents a physical GPU resource that can be aliased by multiple logical resources.
-/// </summary>
-internal sealed class PhysicalResource
-{
-    public int index;
-    public int width;
-    public int height;
-    public TextureFormat format;
-    public int sizeInBytes;
-    
-    // Lifetime tracking
-    public int firstUsePass = int.MaxValue;
-    public int lastUsePass = -1;
-    
-    // Aliasing tracking
-    public readonly List<int> aliasedLogicalResources = new(4);
-
-    public void Reset()
-    {
-        index = -1;
-        width = 0;
-        height = 0;
-        format = TextureFormat.RGBA8;
-        sizeInBytes = 0;
-        firstUsePass = int.MaxValue;
-        lastUsePass = -1;
-        aliasedLogicalResources.Clear();
-    }
-
-    public bool CanAlias(TextureDescriptor descriptor)
-    {
-        // For aliasing, resources must be identical in size and format
-        // In a real implementation, you could be more flexible (e.g., same size but different format)
-        return width == descriptor.width &&
-               height == descriptor.height &&
-               format == descriptor.format;
-    }
-
-    public void UpdateLifetime(int passIndex)
-    {
-        firstUsePass = Math.Min(firstUsePass, passIndex);
-        lastUsePass = Math.Max(lastUsePass, passIndex);
-    }
-
-    public bool IsAliveAt(int passIndex)
-    {
-        return passIndex >= firstUsePass && passIndex <= lastUsePass;
-    }
-
-    public int CalculateSize()
-    {
-        int bytesPerPixel = format switch
-        {
-            TextureFormat.RGBA8 => 4,
-            TextureFormat.RGBA16F => 8,
-            TextureFormat.RGBA32F => 16,
-            TextureFormat.Depth32F => 4,
-            TextureFormat.Depth24Stencil8 => 4,
-            _ => 4
-        };
-        return width * height * bytesPerPixel;
-    }
-}
-
-/// <summary>
-/// Manages physical resource allocation and aliasing.
-/// Uses interval scheduling algorithm to minimize memory usage.
-/// </summary>
-internal sealed class ResourceAliasingManager
-{
-    private readonly List<PhysicalResource> _physicalResources = new(32);
-    private readonly RenderGraphObjectPool _pool = new();
-    private int _physicalResourceCount;
-    
-    // Mapping from logical resource index to physical resource index
-    private readonly Dictionary<int, int> _logicalToPhysical = new(64);
-
-    public void BeginFrame()
-    {
-        _physicalResourceCount = 0;
-        _logicalToPhysical.Clear();
-        
-        // Reset physical resources but keep them in the pool
-        for (int i = 0; i < _physicalResources.Count; i++)
-        {
-            _physicalResources[i].Reset();
-        }
-    }
-
-    /// <summary>
-    /// Assigns physical resources to logical resources using greedy interval scheduling.
-    /// This minimizes total GPU memory usage.
-    /// </summary>
-    public void AssignPhysicalResources(RenderGraphResourceRegistry registry, int passCount)
-    {
-#if DEBUG
-        Console.WriteLine("\n=== Resource Aliasing Analysis ===");
-        int totalLogicalSize = 0;
-#endif
-
-        // Build list of all logical resources with their lifetimes
-        var logicalResources = ListPool<(int index, RenderGraphResource resource)>.Rent();
-        
-        for (int i = 0; i < registry.TextureResourceCount; i++)
-        {
-            var resource = registry.GetTextureResourceByIndex(i);
-            if (!resource.isImported) // Don't alias imported resources
-            {
-                logicalResources.Add((i, resource));
-#if DEBUG
-                int size = CalculateSize(resource.descriptor);
-                totalLogicalSize += size;
-                Console.WriteLine($"Logical Resource {i}: {resource.descriptor.name}");
-                Console.WriteLine($"  Lifetime: Pass {resource.firstUsePass} -> {resource.lastUsePass}");
-                Console.WriteLine($"  Size: {size / 1024.0:F2} KB");
-#endif
-            }
-        }
-
-        // Sort by first use pass (earlier resources first)
-        logicalResources.Sort((a, b) => a.resource.firstUsePass.CompareTo(b.resource.firstUsePass));
-
-        // Greedy interval scheduling: assign each logical resource to a physical resource
-        foreach (var (logicalIndex, logicalResource) in logicalResources)
-        {
-            PhysicalResource? assignedPhysical = null;
-
-            // Try to find an existing physical resource that:
-            // 1. Has compatible format/size
-            // 2. Is not alive during this logical resource's lifetime
-            for (int i = 0; i < _physicalResourceCount; i++)
-            {
-                var physical = _physicalResources[i];
-                
-                if (physical.CanAlias(logicalResource.descriptor) &&
-                    !HasLifetimeOverlap(physical, logicalResource))
-                {
-                    assignedPhysical = physical;
-                    break;
-                }
-            }
-
-            // No compatible physical resource found, allocate a new one
-            if (assignedPhysical == null)
-            {
-                assignedPhysical = GetOrCreatePhysicalResource();
-                assignedPhysical.index = _physicalResourceCount - 1;
-                assignedPhysical.width = logicalResource.descriptor.width;
-                assignedPhysical.height = logicalResource.descriptor.height;
-                assignedPhysical.format = logicalResource.descriptor.format;
-                assignedPhysical.sizeInBytes = assignedPhysical.CalculateSize();
-                
-#if DEBUG
-                Console.WriteLine($"\nAllocated NEW Physical Resource {assignedPhysical.index}:");
-                Console.WriteLine($"  Size: {assignedPhysical.width}x{assignedPhysical.height}");
-                Console.WriteLine($"  Format: {assignedPhysical.format}");
-                Console.WriteLine($"  Memory: {assignedPhysical.sizeInBytes / 1024.0:F2} KB");
-#endif
-            }
-#if DEBUG
-            else
-            {
-                Console.WriteLine($"\nALIASING: {logicalResource.descriptor.name} -> Physical Resource {assignedPhysical.index}");
-            }
-#endif
-
-            // Update physical resource lifetime
-            assignedPhysical.UpdateLifetime(logicalResource.firstUsePass);
-            assignedPhysical.UpdateLifetime(logicalResource.lastUsePass);
-            assignedPhysical.aliasedLogicalResources.Add(logicalIndex);
-
-            // Record the mapping
-            _logicalToPhysical[logicalIndex] = assignedPhysical.index;
-        }
-
-#if DEBUG
-        int totalPhysicalSize = 0;
-        for (int i = 0; i < _physicalResourceCount; i++)
-        {
-            totalPhysicalSize += _physicalResources[i].sizeInBytes;
-        }
-        
-        Console.WriteLine($"\n=== Aliasing Summary ===");
-        Console.WriteLine($"Logical Resources: {logicalResources.Count}");
-        Console.WriteLine($"Physical Resources: {_physicalResourceCount}");
-        Console.WriteLine($"Total Logical Memory: {totalLogicalSize / 1024.0:F2} KB");
-        Console.WriteLine($"Total Physical Memory: {totalPhysicalSize / 1024.0:F2} KB");
-        Console.WriteLine($"Memory Saved: {(totalLogicalSize - totalPhysicalSize) / 1024.0:F2} KB ({(1.0 - (double)totalPhysicalSize / totalLogicalSize) * 100.0:F1}%)");
-        Console.WriteLine("================================\n");
-#endif
-
-        ListPool<(int index, RenderGraphResource resource)>.Return(logicalResources);
-    }
-
-    public int GetPhysicalResourceIndex(int logicalIndex)
-    {
-        return _logicalToPhysical.TryGetValue(logicalIndex, out var physicalIndex) ? physicalIndex : -1;
-    }
-
-    public PhysicalResource? GetPhysicalResource(int physicalIndex)
-    {
-        return physicalIndex >= 0 && physicalIndex < _physicalResourceCount 
-            ? _physicalResources[physicalIndex] 
-            : null;
-    }
-
-    private bool HasLifetimeOverlap(PhysicalResource physical, RenderGraphResource logical)
-    {
-        // Check if the lifetimes overlap
-        // No overlap if: logical.First > physical.Last OR logical.Last < physical.First
-        return !(logical.firstUsePass > physical.lastUsePass || 
-                 logical.lastUsePass < physical.firstUsePass);
-    }
-
-    private PhysicalResource GetOrCreatePhysicalResource()
-    {
-        PhysicalResource resource;
-        if (_physicalResourceCount < _physicalResources.Count)
-        {
-            resource = _physicalResources[_physicalResourceCount];
-            resource.Reset();
-        }
-        else
-        {
-            resource = _pool.Rent<PhysicalResource>();
-            resource.Reset();
-            _physicalResources.Add(resource);
-        }
-
-        _physicalResourceCount++;
-        return resource;
-    }
-
-    private static int CalculateSize(TextureDescriptor descriptor)
-    {
-        int bytesPerPixel = descriptor.format switch
-        {
-            TextureFormat.RGBA8 => 4,
-            TextureFormat.RGBA16F => 8,
-            TextureFormat.RGBA32F => 16,
-            TextureFormat.Depth32F => 4,
-            TextureFormat.Depth24Stencil8 => 4,
-            _ => 4
-        };
-        return descriptor.width * descriptor.height * bytesPerPixel;
-    }
-
-    public void Clear()
-    {
-        for (int i = 0; i < _physicalResources.Count; i++)
-        {
-            _pool.Return(_physicalResources[i]);
-        }
-        _physicalResources.Clear();
-        _physicalResourceCount = 0;
-        _logicalToPhysical.Clear();
-    }
-
-    /// <summary>
-    /// Restores aliasing state from cache.
-    /// </summary>
-    public void RestoreFromCache(Dictionary<int, int> logicalToPhysical, List<PhysicalResourceData> physicalData)
-    {
-        _logicalToPhysical.Clear();
-        foreach (var kvp in logicalToPhysical)
-        {
-            _logicalToPhysical[kvp.Key] = kvp.Value;
-        }
-
-        // Restore physical resources
-        _physicalResourceCount = physicalData.Count;
-        for (int i = 0; i < physicalData.Count; i++)
-        {
-            PhysicalResource physical;
-            if (i < _physicalResources.Count)
-            {
-                physical = _physicalResources[i];
-                physical.Reset();
-            }
-            else
-            {
-                physical = _pool.Rent<PhysicalResource>();
-                physical.Reset();
-                _physicalResources.Add(physical);
-            }
-
-            var data = physicalData[i];
-            physical.index = data.index;
-            physical.width = data.width;
-            physical.height = data.height;
-            physical.format = data.format;
-            physical.firstUsePass = data.firstUsePass;
-            physical.lastUsePass = data.lastUsePass;
-            physical.sizeInBytes = physical.CalculateSize();
-        }
-    }
-
-    /// <summary>
-    /// Stores current aliasing state to cache.
-    /// </summary>
-    public void StoreToCache(Dictionary<int, int> outLogicalToPhysical, List<PhysicalResourceData> outPhysicalData)
-    {
-        outLogicalToPhysical.Clear();
-        foreach (var kvp in _logicalToPhysical)
-        {
-            outLogicalToPhysical[kvp.Key] = kvp.Value;
-        }
-
-        outPhysicalData.Clear();
-        for (int i = 0; i < _physicalResourceCount; i++)
-        {
-            var physical = _physicalResources[i];
-            outPhysicalData.Add(new PhysicalResourceData
-            {
-                index = physical.index,
-                width = physical.width,
-                height = physical.height,
-                format = physical.format,
-                firstUsePass = physical.firstUsePass,
-                lastUsePass = physical.lastUsePass
-            });
-        }
-    }
-}

Ghost.RenderGraph.Concept/RenderGraphBarriers.cs

@@ -19,6 +19,7 @@ public enum ResourceState
     CopySource = 1 << 5,
     CopyDest = 1 << 6,
     Present = 1 << 7,
+    IndirectArgument = 1 << 8,
 }
 
 /// <summary>
@@ -140,14 +141,14 @@ internal struct ResourceBarrier
 /// </summary>
 internal sealed class ResourceStateTracker
 {
-    public int ResourceIndex;
+    public int resourceIndex;
-    public ResourceState CurrentState = ResourceState.Common;
+    public ResourceState currentState = ResourceState.Common;
-    public int LastAccessPass = -1;
+    public int lastAccessPass = -1;
 
     public void Reset()
     {
-        ResourceIndex = -1;
+        resourceIndex = -1;
-        CurrentState = ResourceState.Common;
+        currentState = ResourceState.Common;
-        LastAccessPass = -1;
+        lastAccessPass = -1;
     }
 }

Ghost.RenderGraph.Concept/RenderGraphBuilder.cs

@@ -4,11 +4,14 @@ using System.Diagnostics;
 namespace Ghost.RenderGraph.Concept;
 
 [Flags]
-public enum AccessFlags
+public enum AccessFlags : byte
 {
     None = 0,
     Read = 1 << 0,
     Write = 1 << 1,
+    Discard = 1 << 2,
+
+    WriteAll = Write | Discard,
     ReadWrite = Read | Write,
 }
 
@@ -27,6 +30,13 @@ public interface IRenderGraphBuilder : IDisposable
     /// <returns>An identifier for the newly created texture resource.</returns>
     Identifier<RGTexture> CreateTexture(in TextureDescriptor descriptor);
     
+    /// <summary>
+    /// Creates a new buffer resource based on the specified descriptor.
+    /// </summary>
+    /// <param name="descriptor">A structure that defines the properties and configuration of the buffer to create.</param>
+    /// <returns>An identifier for the newly created buffer resource.</returns>
+    Identifier<RGBuffer> CreateBuffer(in BufferDescriptor descriptor);
+
     /// <summary>
     /// Registers the specified texture for use in the current render graph pass with the given access mode.
     /// </summary>
@@ -34,6 +44,15 @@ public interface IRenderGraphBuilder : IDisposable
     /// <param name="accessMode">The access mode specifying how the texture will be read or written during the pass.</param>
     /// <returns>An identifier for the texture.</returns>
     Identifier<RGTexture> UseTexture(Identifier<RGTexture> texture, AccessFlags accessMode);
+    
+    /// <summary>
+    /// Registers the specified buffer for use in the current render graph pass with the given access mode.
+    /// </summary>
+    /// <param name="buffer">The identifier of the buffer to be used in the render graph pass.</param>
+    /// <param name="accessMode">The access mode specifying how the buffer will be read or written during the pass.</param>
+    /// <param name="hint">Optional hint about how the buffer will be used (e.g., IndirectArgument). Default is None (ByteAddressBuffer SRV).</param>
+    /// <returns>An identifier for the buffer.</returns>
+    Identifier<RGBuffer> UseBuffer(Identifier<RGBuffer> buffer, AccessFlags accessMode, BufferHint hint = BufferHint.None);
 }
 
 public interface IRasterRenderGraphBuilder : IRenderGraphBuilder
@@ -56,13 +75,15 @@ public interface IRasterRenderGraphBuilder : IRenderGraphBuilder
     /// </summary>
     /// <param name="texture">The identifier of the texture to use as the color attachment.</param>
     /// <param name="index">The zero-based index of the color attachment to set.</param>
-    void SetColorAttachment(Identifier<RGTexture> texture, int index);
+    /// <param name="flags">Access flags. Default is Write (assumes partial update). Use WriteAll for fullscreen passes.</param>
+    void SetColorAttachment(Identifier<RGTexture> texture, int index, AccessFlags flags = AccessFlags.Write);
 
     /// <summary>
     /// Sets the depth attachment for the current render pass using the specified texture.
     /// </summary>
     /// <param name="texture">The identifier of the texture to use as the depth attachment. Cannot be null.</param>
-    void SetDepthAttachment(Identifier<RGTexture> texture);
+    /// <param name="flags">Access flags. Default is ReadWrite (assumes partial update). Use WriteAll for fullscreen passes.</param>
+    void SetDepthAttachment(Identifier<RGTexture> texture, AccessFlags flags = AccessFlags.ReadWrite);
 
     /// <summary>
     /// Sets the function used to render a pass with the specified pass data and render context.
@@ -147,12 +168,35 @@ internal class RenderGraphBuilder : IRasterRenderGraphBuilder, IComputeRenderGra
         return handle;
     }
     
+    public Identifier<RGBuffer> CreateBuffer(in BufferDescriptor descriptor)
+    {
+        ThrowIfDisposed();
+
+        var handle = _resources.CreateBuffer(descriptor);
+        _pass.resourceCreates[(int)RenderGraphResourceType.Buffer].Add(handle.AsResource());
+        _resources.SetProducer(handle.AsResource(), _pass.index);
+        return handle;
+    }
+
     public Identifier<RGTexture> UseTexture(Identifier<RGTexture> texture, AccessFlags flags)
     {
         ThrowIfDisposed();
         return UseResource(texture.AsResource(), flags, RenderGraphResourceType.Texture).AsTexture();
     }
     
+    public Identifier<RGBuffer> UseBuffer(Identifier<RGBuffer> buffer, AccessFlags flags, BufferHint hint = BufferHint.None)
+    {
+        ThrowIfDisposed();
+        
+        // Store buffer hint if not None
+        if (hint != BufferHint.None)
+        {
+            _pass.bufferHints[buffer.AsResource().Value] = hint;
+        }
+        
+        return UseResource(buffer.AsResource(), flags, RenderGraphResourceType.Buffer).AsBuffer();
+    }
+
     public Identifier<RGTexture> UseRandomAccessTexture(Identifier<RGTexture> texture)
     {
         ThrowIfDisposed();
@@ -173,17 +217,17 @@ internal class RenderGraphBuilder : IRasterRenderGraphBuilder, IComputeRenderGra
         return buffer;
     }
 
-    public void SetColorAttachment(Identifier<RGTexture> texture, int index)
+    public void SetColorAttachment(Identifier<RGTexture> texture, int index, AccessFlags flags = AccessFlags.Write)
     {
         ThrowIfDisposed();
 
         Debug.Assert(index >= 0 && index < _pass.colorAccess.Length, "Color attachment index out of range.");
 
-        var id = UseTexture(texture, AccessFlags.Write);
+        var id = UseTexture(texture, flags);
         if (_pass.colorAccess[index].id == id || _pass.colorAccess[index].id.IsInvalid)
         {
             _pass.maxColorIndex = Math.Max(_pass.maxColorIndex, index);
-            _pass.colorAccess[index] = new TextureAccess(id, AccessFlags.Write);
+            _pass.colorAccess[index] = new TextureAccess(id, flags);
         }
         else
         {
@@ -191,14 +235,14 @@ internal class RenderGraphBuilder : IRasterRenderGraphBuilder, IComputeRenderGra
         }
     }
 
-    public void SetDepthAttachment(Identifier<RGTexture> texture)
+    public void SetDepthAttachment(Identifier<RGTexture> texture, AccessFlags flags = AccessFlags.Write)
     {
         ThrowIfDisposed();
 
-        var id = UseTexture(texture, AccessFlags.Write);
+        var id = UseTexture(texture, flags);
         if (_pass.depthAccess.id == id || _pass.depthAccess.id.IsInvalid)
         {
-            _pass.depthAccess = new TextureAccess(id, AccessFlags.Write);
+            _pass.depthAccess = new TextureAccess(id, flags);
         }
         else
         {

Ghost.RenderGraph.Concept/RenderGraphBuilder.cs.bak

@@ -1,240 +0,0 @@
-using Ghost.Core;
-using System.Diagnostics;
-
-namespace Ghost.RenderGraph.Concept;
-
-[Flags]
-public enum AccessFlags
-{
-    None = 0,
-    Read = 1 << 0,
-    Write = 1 << 1,
-    ReadWrite = Read | Write,
-}
-
-public interface IRenderGraphBuilder : IDisposable
-{
-    /// <summary>
-    /// Enables or disables pass culling for the current context.
-    /// </summary>
-    /// <param name="value">A value indicating whether pass culling is allowed.</param>
-    void AllowPassCulling(bool value);
-
-    /// <summary>
-    /// Creates a new texture resource based on the specified descriptor.
-    /// </summary>
-    /// <param name="descriptor">A structure that defines the properties and configuration of the texture to create.</param>
-    /// <returns>An identifier for the newly created texture resource.</returns>
-    Identifier<RGTexture> CreateTexture(in TextureDescriptor descriptor);
-
-    /// <summary>
-    /// Registers the specified texture for use in the current render graph pass with the given access mode.
-    /// </summary>
-    /// <param name="texture">The identifier of the texture to be used in the render graph pass.</param>
-    /// <param name="accessMode">The access mode specifying how the texture will be read or written during the pass.</param>
-    /// <returns>An identifier for the texture.</returns>
-    Identifier<RGTexture> UseTexture(Identifier<RGTexture> texture, AccessFlags accessMode);
-}
-
-public interface IRasterRenderGraphBuilder : IRenderGraphBuilder
-{
-    /// <summary>
-    /// Binds a texture for random access operations within the current rendering pass.
-    /// </summary>
-    /// <param name="texture">The identifier of the texture to be used for random access.</param>
-    /// <returns>An identifier for the texture.</returns>
-    Identifier<RGTexture> UseRandomAccessTexture(Identifier<RGTexture> texture);
-    /// <summary>
-    /// Specifies that the given buffer will be used for random access operations with the specified access mode within the current context.
-    /// </summary>
-    /// <param name="buffer">An identifier for the buffer to be used for random access. Must reference a valid buffer resource.</param>
-    /// <returns>An identifier for the buffer.</returns>
-    Identifier<RGBuffer> UseRandomAccessBuffer(Identifier<RGBuffer> buffer);
-
-    /// <summary>
-    /// Sets the color attachment at the specified index to the given texture.
-    /// </summary>
-    /// <param name="texture">The identifier of the texture to use as the color attachment.</param>
-    /// <param name="index">The zero-based index of the color attachment to set.</param>
-    void SetColorAttachment(Identifier<RGTexture> texture, int index);
-
-    /// <summary>
-    /// Sets the depth attachment for the current render pass using the specified texture.
-    /// </summary>
-    /// <param name="texture">The identifier of the texture to use as the depth attachment. Cannot be null.</param>
-    void SetDepthAttachment(Identifier<RGTexture> texture);
-
-    /// <summary>
-    /// Sets the function used to render a pass with the specified pass data and render context.
-    /// </summary>
-    /// <typeparam name="TPassData">The type of data associated with the render pass.</typeparam>
-    /// <param name="renderFunc">The delegate that defines the rendering logic for the pass.</param>
-    void SetRenderFunc<TPassData>(Action<TPassData, RasterRenderContext> renderFunc)
-        where TPassData : class, new();
-}
-
-public interface IComputeRenderGraphBuilder : IRenderGraphBuilder
-{
-    /// <summary>
-    /// Enables or disables asynchronous compute operations.
-    /// </summary>
-    /// <param name="value">true to enable asynchronous compute; otherwise, false.</param>
-    void EnableAsyncCompute(bool value);
-
-    /// <summary>
-    /// Sets the render function to be invoked during the compute rendering process.
-    /// </summary>
-    /// <typeparam name="TPassData">The type of the data object passed to the render function.</typeparam>
-    /// <param name="renderFunc">The delegate that defines the rendering logic to execute.</param>
-    void SetRenderFunc<TPassData>(Action<TPassData, ComputeRenderContext> renderFunc)
-        where TPassData : class, new();
-}
-
-internal class RenderGraphBuilder : IRasterRenderGraphBuilder, IComputeRenderGraphBuilder
-{
-    private RenderGraph _graph = null!;
-    private RenderGraphPassBase _pass = null!;
-    private RenderGraphResourceRegistry _resources = null!;
-    private bool _disposed;
-
-    internal void Init(RenderGraph graph, RenderGraphPassBase pass, RenderGraphResourceRegistry resources)
-    {
-        _graph = graph;
-        _pass = pass;
-        _resources = resources;
-        _disposed = false;
-    }
-
-    private void ThrowIfDisposed()
-    {
-        ObjectDisposedException.ThrowIf(_disposed, this);
-    }
-
-    private Identifier<RGResource> UseResource(Identifier<RGResource> resource, AccessFlags accessFlags)
-    {
-        if (accessFlags.HasFlag(AccessFlags.Read))
-        {
-            _pass.resourceReads.Add(resource);
-            _resources.AddConsumer(resource, _pass.index);
-        }
-
-        if (accessFlags.HasFlag(AccessFlags.Write))
-        {
-            _pass.resourceWrites.Add(resource);
-            _resources.SetProducer(resource, _pass.index);
-        }
-
-        return resource;
-    }
-
-    public void AllowPassCulling(bool value)
-    {
-        _pass.allowCulling = value;
-    }
-
-    public void EnableAsyncCompute(bool value)
-    {
-        _pass.asyncCompute = value;
-    }
-
-    public Identifier<RGTexture> CreateTexture(in TextureDescriptor descriptor)
-    {
-        ThrowIfDisposed();
-
-        var handle = _resources.CreateTexture(descriptor);
-        _pass.resourceCreates.Add(handle.AsResource());
-        _resources.SetProducer(handle.AsResource(), _pass.index);
-        return handle;
-    }
-
-    public Identifier<RGTexture> UseTexture(Identifier<RGTexture> texture, AccessFlags flags)
-    {
-        ThrowIfDisposed();
-
-        return UseResource(texture.AsResource(), flags).AsTexture();
-    }
-
-    public Identifier<RGTexture> UseRandomAccessTexture(Identifier<RGTexture> texture)
-    {
-        ThrowIfDisposed();
-
-        var resource = texture.AsResource();
-        UseResource(resource, AccessFlags.ReadWrite);
-        _pass.randomAccess.Add(resource);
-        return texture;
-    }
-
-    public Identifier<RGBuffer> UseRandomAccessBuffer(Identifier<RGBuffer> buffer)
-    {
-        ThrowIfDisposed();
-
-        var resource = buffer.AsResource();
-        UseResource(resource, AccessFlags.ReadWrite);
-        _pass.randomAccess.Add(resource);
-        return buffer;
-    }
-
-    public void SetColorAttachment(Identifier<RGTexture> texture, int index)
-    {
-        ThrowIfDisposed();
-
-        Debug.Assert(index >= 0 && index < _pass.colorAccess.Length, "Color attachment index out of range.");
-
-        var id = UseTexture(texture, AccessFlags.Write);
-        if (_pass.colorAccess[index].id == id || _pass.colorAccess[index].id.IsInvalid)
-        {
-            _pass.maxColorIndex = Math.Max(_pass.maxColorIndex, index);
-            _pass.colorAccess[index] = new TextureAccess(id, AccessFlags.Write);
-        }
-        else
-        {
-            throw new InvalidOperationException($"Color attachment at index {index} is already set to a different texture.");
-        }
-    }
-
-    public void SetDepthAttachment(Identifier<RGTexture> texture)
-    {
-        ThrowIfDisposed();
-
-        var id = UseTexture(texture, AccessFlags.Write);
-        if (_pass.depthAccess.id == id || _pass.depthAccess.id.IsInvalid)
-        {
-            _pass.depthAccess = new TextureAccess(id, AccessFlags.Write);
-        }
-        else
-        {
-            throw new InvalidOperationException("Depth attachment is already set to a different texture.");
-        }
-    }
-
-    public void SetRenderFunc<TPassData>(Action<TPassData, RasterRenderContext> renderFunc)
-        where TPassData : class, new()
-    {
-        ((RasterRenderGraphPass<TPassData>)_pass).renderFunc = renderFunc;
-    }
-
-    public void SetRenderFunc<TPassData>(Action<TPassData, ComputeRenderContext> renderFunc)
-        where TPassData : class, new()
-    {
-        ((ComputeRenderGraphPass<TPassData>)_pass).renderFunc = renderFunc;
-    }
-
-    public void Dispose()
-    {
-        if (_disposed)
-        {
-            return;
-        }
-
-        if (!_pass.HasRenderFunc())
-        {
-            throw new InvalidOperationException("RenderGraphBuilder must be disposed after setting up the render function.");
-        }
-
-        _graph = null!;
-        _pass = null!;
-        _resources = null!;
-
-        _disposed = true;
-    }
-}

Ghost.RenderGraph.Concept/RenderGraphCompilationCache.cs

@@ -17,8 +17,8 @@ internal sealed class CachedCompilation
     // Physical resource aliasing mappings (logical index -> physical index)
     public readonly Dictionary<int, int> logicalToPhysical = new(128);
     
-    // Physical resource metadata
+    // Placed resource metadata
-    public readonly List<PhysicalResourceData> physicalResources = new(32);
+    public readonly List<PlacedResourceData> placedResources = new(32);
     
     // Resource barriers
     public readonly List<ResourceBarrier> barriers = new(128);
@@ -31,21 +31,24 @@ internal sealed class CachedCompilation
         compiledPassIndices.Clear();
         passCulledFlags.Clear();
         logicalToPhysical.Clear();
-        physicalResources.Clear();
+        placedResources.Clear();
         barriers.Clear();
         resourceStates.Clear();
     }
 }
 
 /// <summary>
-/// Physical resource data for caching.
+/// Placed resource data for caching.
 /// </summary>
-internal struct PhysicalResourceData
+internal struct PlacedResourceData
 {
     public int index;
-    public int width;
+    public RenderGraphResourceType type;
-    public int height;
+    public int heapIndex;
-    public TextureFormat format;
+    public ulong heapOffset;
+    public ulong sizeInBytes;
+    public TextureDescriptor textureDesc;
+    public BufferDescriptor bufferDesc;
     public int firstUsePass;
     public int lastUsePass;
 }
@@ -100,7 +103,7 @@ internal sealed class RenderGraphCompilationCache
             _cached.logicalToPhysical[kvp.Key] = kvp.Value;
         }
         
-        _cached.physicalResources.AddRange(data.physicalResources);
+        _cached.placedResources.AddRange(data.placedResources);
         _cached.barriers.AddRange(data.barriers);
         
         foreach (var kvp in data.resourceStates)

Ghost.RenderGraph.Concept/RenderGraphContext.cs

@@ -75,6 +75,21 @@ internal sealed class MockCommandBuffer
     {
 #if DEBUG
         Console.WriteLine(nameof(AliasBarrier) + ": " + resourceBefore + " to " + resourceAfter);
+#endif
+    }
+
+    public void BeginRenderPass(int nativePassIndex, int colorAttachmentCount, bool hasDepth)
+    {
+#if DEBUG
+        Console.WriteLine($"\n=== BeginRenderPass (Native Pass {nativePassIndex}) ===");
+        Console.WriteLine($"  Color attachments: {colorAttachmentCount}, Depth: {hasDepth}");
+#endif
+    }
+
+    public void EndRenderPass()
+    {
+#if DEBUG
+        Console.WriteLine("=== EndRenderPass ===\n");
 #endif
     }
 }

Ghost.RenderGraph.Concept/RenderGraphNativePass.cs

@@ -0,0 +1,52 @@
+using Ghost.Core;
+
+namespace Ghost.RenderGraph.Concept;
+
+/// <summary>
+/// Represents a native render pass that can contain multiple merged logical passes.
+/// Maps to D3D12 BeginRenderPass/EndRenderPass or Vulkan vkCmdBeginRenderPass/vkCmdEndRenderPass.
+/// </summary>
+internal sealed class NativeRenderPass
+{
+    public int index;
+    
+    /// <summary>
+    /// Indices of logical passes merged into this native render pass.
+    /// </summary>
+    public readonly List<int> mergedPassIndices = new(4);
+    
+    /// <summary>
+    /// Color attachments shared across all merged passes.
+    /// </summary>
+    public RenderTargetInfo[] colorAttachments = new RenderTargetInfo[8];
+    public int colorAttachmentCount;
+    
+    /// <summary>
+    /// Depth-stencil attachment (optional).
+    /// </summary>
+    public DepthStencilInfo depthAttachment;
+    public bool hasDepthAttachment;
+    
+    /// <summary>
+    /// Range of logical passes included in this native pass.
+    /// </summary>
+    public int firstLogicalPass;
+    public int lastLogicalPass;
+    
+    /// <summary>
+    /// Whether UAV writes are allowed during this render pass.
+    /// </summary>
+    public bool allowUAVWrites;
+    
+    public void Reset()
+    {
+        index = -1;
+        mergedPassIndices.Clear();
+        colorAttachmentCount = 0;
+        hasDepthAttachment = false;
+        depthAttachment = default;
+        firstLogicalPass = int.MaxValue;
+        lastLogicalPass = -1;
+        allowUAVWrites = false;
+    }
+}

Ghost.RenderGraph.Concept/RenderGraphPass.cs

@@ -1,4 +1,5 @@
 using Ghost.Core;
+using System.Runtime.CompilerServices;
 
 namespace Ghost.RenderGraph.Concept;
 
@@ -34,6 +35,9 @@ internal abstract class RenderGraphPassBase
     public readonly List<Identifier<RGResource>>[] resourceWrites = new List<Identifier<RGResource>>[(int)RenderGraphResourceType.Count];
     public readonly List<Identifier<RGResource>>[] resourceCreates = new List<Identifier<RGResource>>[(int)RenderGraphResourceType.Count];
 
+    // Buffer usage hints (maps buffer resource ID to hint)
+    public readonly Dictionary<int, BufferHint> bufferHints = new(8);
+
     // Execution state
     public bool culled;
     public bool hasSideEffects;
@@ -49,8 +53,8 @@ internal abstract class RenderGraphPassBase
     }
 
     public abstract void Execute(RenderContext context);
-    public abstract void Clear();
     public abstract bool HasRenderFunc();
+    public abstract int GetRenderFuncHashCode();
 
     public virtual void Reset(RenderGraphObjectPool pool)
     {
@@ -73,6 +77,8 @@ internal abstract class RenderGraphPassBase
             resourceCreates[i].Clear();
         }
 
+        bufferHints.Clear();
+
         culled = false;
         hasSideEffects = false;
     }
@@ -97,17 +103,24 @@ internal abstract class RenderGraphPassT<TPassData, TRenderContext> : RenderGrap
         return renderFunc != null;
     }
 
-    public override void Clear()
+    public override int GetRenderFuncHashCode()
     {
-        passData = null!;
+        if (renderFunc == null)
-        renderFunc = null;
+        {
+            return 0;
+        }
+
+        var methodHashCode = RuntimeHelpers.GetHashCode(renderFunc.Method);
+        return renderFunc.Target == null ? methodHashCode : methodHashCode ^ RuntimeHelpers.GetHashCode(renderFunc.Target); // static deleget does not have target
     }
 
     public override void Reset(RenderGraphObjectPool pool)
     {
         base.Reset(pool);
         pool.Return(passData);
-        Clear();
+
+        passData = null!;
+        renderFunc = null;
     }
 }
 

Ghost.RenderGraph.Concept/RenderGraphPass.cs.bak

@@ -1,129 +0,0 @@
-using Ghost.Core;
-using System.IO;
-
-namespace Ghost.RenderGraph.Concept;
-
-/// <summary>
-/// Represents different types of render passes.
-/// </summary>
-public enum RenderPassType : byte
-{
-    Raster,
-    Compute
-}
-
-/// <summary>
-/// Base class for render passes.
-/// Uses pooling to avoid allocations after the first frame.
-/// </summary>
-internal abstract class RenderGraphPassBase
-{
-    public string name = string.Empty;
-    public int index;
-    public RenderPassType type;
-    public bool allowCulling = true;
-    public bool asyncCompute;
-
-    public TextureAccess depthAccess;
-    public TextureAccess[] colorAccess = new TextureAccess[8];
-    public int maxColorIndex = -1;
-
-    public List<Identifier<RGResource>> randomAccess = new(8);
-
-    // Resource dependencies
-    public readonly List<Identifier<RGResource>> resourceReads = new(8);
-    public readonly List<Identifier<RGResource>> resourceWrites = new(4);
-    public readonly List<Identifier<RGResource>> resourceCreates = new(4);
-    
-    // Execution state
-    public bool culled;
-    public bool hasSideEffects;
-
-    public abstract void Execute(RenderContext context);
-    public abstract void Clear();
-    public abstract bool HasRenderFunc();
-
-    public virtual void Reset(RenderGraphObjectPool pool)
-    {
-        name = string.Empty;
-        index = -1;
-        type = RenderPassType.Raster;
-        allowCulling = true;
-        asyncCompute = false;
-        
-        depthAccess = default;
-        colorAccess.AsSpan().Clear();
-        maxColorIndex = -1;
-
-        randomAccess.Clear();
-
-        resourceReads.Clear();
-        resourceWrites.Clear();
-        resourceCreates.Clear();
-        culled = false;
-        hasSideEffects = false;
-    }
-}
-
-internal abstract class RenderGraphPassT<TPassData, TRenderContext> : RenderGraphPassBase
-    where TPassData : class, new()
-{
-    public TPassData passData = null!;
-    public Action<TPassData, TRenderContext>? renderFunc;
-
-    public void Init(int index, TPassData passData, string name, RenderPassType type)
-    {
-        this.index = index;
-        this.passData = passData;
-        this.name = name;
-        this.type = type;
-    }
-
-    public sealed override bool HasRenderFunc()
-    {
-        return renderFunc != null;
-    }
-
-    public override void Clear()
-    {
-        passData = null!;
-        renderFunc = null;
-    }
-
-    public override void Reset(RenderGraphObjectPool pool)
-    {
-        base.Reset(pool);
-        pool.Return(passData);
-        Clear();
-    }
-}
-
-internal sealed class RasterRenderGraphPass<TPassData> : RenderGraphPassT<TPassData, RasterRenderContext>
-    where TPassData : class, new()
-{
-    public override void Execute(RenderContext context)
-    {
-        renderFunc!(passData, context.RasterContext);
-    }
-
-    public override void Reset(RenderGraphObjectPool pool)
-    {
-        base.Reset(pool);
-        pool.Return(this);
-    }
-}
-
-internal sealed class ComputeRenderGraphPass<TPassData> : RenderGraphPassT<TPassData, ComputeRenderContext>
-    where TPassData : class, new()
-{
-    public override void Execute(RenderContext context)
-    {
-        renderFunc!(passData, context.ComputeContext);
-    }
-
-    public override void Reset(RenderGraphObjectPool pool)
-    {
-        base.Reset(pool);
-        pool.Return(this);
-    }
-}

Ghost.RenderGraph.Concept/RenderGraphResourcePool.cs

@@ -75,13 +75,14 @@ internal sealed class RenderGraphObjectPool
 }
 
 /// <summary>
-/// Represents a texture resource in the render graph.
+/// Represents a resource in the render graph (texture or buffer).
 /// </summary>
 internal sealed class RenderGraphResource
 {
     public RenderGraphResourceType type;
     public int index;
-    public TextureDescriptor descriptor;
+    public TextureDescriptor textureDescriptor;
+    public BufferDescriptor bufferDescriptor;
     public bool isImported;
     public int firstUsePass = -1;
     public int lastUsePass = -1;
@@ -91,8 +92,10 @@ internal sealed class RenderGraphResource
 
     public void Reset()
     {
+        type = RenderGraphResourceType.Texture;
         index = -1;
-        descriptor = default;
+        textureDescriptor = default;
+        bufferDescriptor = default;
         isImported = false;
         firstUsePass = -1;
         lastUsePass = -1;
@@ -105,21 +108,48 @@ 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 List<RenderGraphResource> _resources = new(64);
     private readonly RenderGraphObjectPool _pool = new();
 
-    public int TextureResourceCount => _resources.Count;
+    public int ResourceCount => _resources.Count;
+    public int TextureResourceCount
+    {
+        get
+        {
+            int count = 0;
+            for (int i = 0; i < _resources.Count; i++)
+            {
+                if (_resources[i].type == RenderGraphResourceType.Texture)
+                    count++;
+            }
+            return count;
+        }
+    }
+    public int BufferResourceCount
+    {
+        get
+        {
+            int count = 0;
+            for (int i = 0; i < _resources.Count; i++)
+            {
+                if (_resources[i].type == RenderGraphResourceType.Buffer)
+                    count++;
+            }
+            return count;
+        }
+    }
 
     public void BeginFrame()
     {
+        // Return all resources to pool
         for (var i = 0; i < _resources.Count; i++)
         {
             _pool.Return(_resources[i]);
         }
-
         _resources.Clear();
     }
 
@@ -128,7 +158,7 @@ internal sealed class RenderGraphResourceRegistry
         var resource = _pool.Rent<RenderGraphResource>();
         resource.type = RenderGraphResourceType.Texture;
         resource.index = _resources.Count;
-        resource.descriptor = descriptor;
+        resource.textureDescriptor = descriptor;
         resource.isImported = true;
 
         _resources.Add(resource);
@@ -141,7 +171,7 @@ internal sealed class RenderGraphResourceRegistry
         var resource = _pool.Rent<RenderGraphResource>();
         resource.type = RenderGraphResourceType.Texture;
         resource.index = _resources.Count;
-        resource.descriptor = descriptor;
+        resource.textureDescriptor = descriptor;
         resource.isImported = false;
 
         _resources.Add(resource);
@@ -149,12 +179,51 @@ internal sealed class RenderGraphResourceRegistry
         return new Identifier<RGTexture>(resource.index);
     }
     
+    public Identifier<RGBuffer> ImportBuffer(BufferDescriptor descriptor)
+    {
+        var resource = _pool.Rent<RenderGraphResource>();
+        resource.type = RenderGraphResourceType.Buffer;
+        resource.index = _resources.Count;
+        resource.bufferDescriptor = descriptor;
+        resource.isImported = true;
+
+        _resources.Add(resource);
+
+        return new Identifier<RGBuffer>(resource.index);
+    }
+
+    public Identifier<RGBuffer> CreateBuffer(BufferDescriptor descriptor)
+    {
+        var resource = _pool.Rent<RenderGraphResource>();
+        resource.type = RenderGraphResourceType.Buffer;
+        resource.index = _resources.Count;
+        resource.bufferDescriptor = descriptor;
+        resource.isImported = false;
+
+        _resources.Add(resource);
+
+        return new Identifier<RGBuffer>(resource.index);
+    }
+
     public RenderGraphResource GetResource(Identifier<RGResource> resource)
     {
         return _resources[resource.Value];
     }
     
-    public RenderGraphResource GetTextureResourceByIndex(int index)
+    public RenderGraphResource GetResource(Identifier<RGTexture> texture)
+    {
+        return _resources[texture.Value];
+    }
+    
+    public RenderGraphResource GetResource(Identifier<RGBuffer> buffer)
+    {
+        return _resources[buffer.Value];
+    }
+    
+    /// <summary>
+    /// Gets resource by global index. Use this when iterating over all resources.
+    /// </summary>
+    public RenderGraphResource GetResourceByIndex(int index)
     {
         return _resources[index];
     }

Ghost.RenderGraph.Concept/RenderGraphTypes.cs

@@ -42,6 +42,25 @@ public static class RGResourceExtensions
     }
 }
 
+/// <summary>
+/// Hints for how a buffer will be used in a pass.
+/// Used to determine correct resource state transitions.
+/// </summary>
+[Flags]
+public enum BufferHint
+{
+    /// <summary>
+    /// No special usage - buffer will be used as shader resource (SRV) or UAV based on AccessFlags.
+    /// </summary>
+    None = 0,
+    
+    /// <summary>
+    /// Buffer will be used as indirect argument buffer (ExecuteIndirect).
+    /// Requires ResourceState.IndirectArgument.
+    /// </summary>
+    IndirectArgument = 1 << 0,
+}
+
 internal readonly struct TextureAccess
 {
     public readonly Identifier<RGTexture> id;
@@ -54,6 +73,23 @@ internal readonly struct TextureAccess
     }
 }
 
+/// <summary>
+/// Tracks buffer access information including usage hints.
+/// </summary>
+internal readonly struct BufferAccess
+{
+    public readonly Identifier<RGBuffer> id;
+    public readonly AccessFlags accessFlags;
+    public readonly BufferHint hint;
+
+    public BufferAccess(Identifier<RGBuffer> id, AccessFlags accessFlags, BufferHint hint = BufferHint.None)
+    {
+        this.id = id;
+        this.accessFlags = accessFlags;
+        this.hint = hint;
+    }
+}
+
 /// <summary>
 /// Texture formats supported by the render graph.
 /// </summary>
@@ -165,3 +201,70 @@ public readonly struct BufferDescriptor : IEquatable<BufferDescriptor>
 public interface IPassData
 {
 }
+
+/// <summary>
+/// Specifies how to load attachment contents at the beginning of a render pass.
+/// </summary>
+public enum AttachmentLoadOp
+{
+    /// <summary>
+    /// Load existing contents from memory. Required when reading previous data.
+    /// </summary>
+    Load,
+    
+    /// <summary>
+    /// Clear attachment to a specified value.
+    /// </summary>
+    Clear,
+    
+    /// <summary>
+    /// Don't care about previous contents (best performance on TBDR GPUs).
+    /// Use when you guarantee to overwrite all pixels.
+    /// </summary>
+    DontCare
+}
+
+/// <summary>
+/// Specifies how to store attachment contents at the end of a render pass.
+/// </summary>
+public enum AttachmentStoreOp
+{
+    /// <summary>
+    /// Store contents to memory. Required if resource is used after this pass.
+    /// </summary>
+    Store,
+    
+    /// <summary>
+    /// Don't care about storing contents (best performance on TBDR GPUs).
+    /// Use when resource is not needed after this pass.
+    /// </summary>
+    DontCare
+}
+
+/// <summary>
+/// Information about a render target attachment in a native render pass.
+/// </summary>
+internal struct RenderTargetInfo
+{
+    public Identifier<RGTexture> texture;
+    public AccessFlags access;
+    public AttachmentLoadOp loadOp;
+    public AttachmentStoreOp storeOp;
+    public float clearR;
+    public float clearG;
+    public float clearB;
+    public float clearA;
+}
+
+/// <summary>
+/// Information about a depth-stencil attachment in a native render pass.
+/// </summary>
+internal struct DepthStencilInfo
+{
+    public Identifier<RGTexture> texture;
+    public AccessFlags access;
+    public AttachmentLoadOp loadOp;
+    public AttachmentStoreOp storeOp;
+    public float clearDepth;
+    public byte clearStencil;
+}