Files
GhostEngine/Ghost.Graphics/RenderGraphModule/RenderGraph.cs
2026-01-22 12:33:23 +09:00

1477 lines
51 KiB
C#

using Ghost.Core;
using Ghost.Graphics.Core;
using Ghost.Graphics.RHI;
using Misaki.HighPerformance.LowLevel.Buffer;
using Misaki.HighPerformance.LowLevel.Collections;
using System.IO.Hashing;
using TerraFX.Interop.Windows;
namespace Ghost.Graphics.RenderGraphModule;
/// <summary>
/// Main render graph class that manages resource allocation and pass execution.
/// </summary>
public sealed class RenderGraph : IDisposable
{
private readonly IGraphicsEngine _graphicsEngine;
private readonly RenderGraphObjectPool _objectPool;
private readonly RenderGraphResourceRegistry _resources;
private readonly List<RenderGraphPassBase> _passes;
private readonly List<RenderGraphPassBase> _compiledPasses;
private readonly List<NativeRenderPass> _nativePasses;
private readonly RenderGraphBuilder _builder;
private readonly ResourceAliasingManager _aliasingManager;
private readonly Dictionary<int, ResourceState> _resourceStates;
private readonly List<ResourceBarrier> _barriers;
private readonly RenderGraphCompilationCache _compilationCache;
private readonly RenderGraphContext _context;
private bool _compiled;
private Handle<GPUResource> _resourceHeap;
private ViewState _currentViewState;
public RenderGraphBlackboard Blackboard
{
get;
}
public RenderGraph(IGraphicsEngine graphicsEngine)
{
_graphicsEngine = graphicsEngine;
_objectPool = new RenderGraphObjectPool();
_resources = new RenderGraphResourceRegistry(_objectPool);
_passes = new List<RenderGraphPassBase>(32);
_compiledPasses = new List<RenderGraphPassBase>(32);
_nativePasses = new List<NativeRenderPass>(32);
_builder = new RenderGraphBuilder();
_aliasingManager = new ResourceAliasingManager(_objectPool);
_resourceStates = new Dictionary<int, ResourceState>(64);
_barriers = new List<ResourceBarrier>(128);
_compilationCache = new RenderGraphCompilationCache();
_resourceHeap = Handle<GPUResource>.Invalid;
_context = new RenderGraphContext(
_graphicsEngine.ResourceDatabase,
_graphicsEngine.PipelineLibrary,
_graphicsEngine.ShaderCompiler,
_resources
);
Blackboard = new RenderGraphBlackboard();
}
/// <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();
// Return native passes to pool
for (var i = 0; i < _nativePasses.Count; i++)
{
_objectPool.Return(_nativePasses[i]);
}
_nativePasses.Clear();
_compiled = false;
}
/// <summary>
/// Imports an external texture into the render graph.
/// </summary>
/// <param name="texture">The external texture handle.</param>
/// <returns>The identifier of the imported render graph texture. Invalid if import fails.</returns>
public Identifier<RGTexture> ImportTexture(Handle<Texture> texture, string name)
{
var r = _graphicsEngine.ResourceDatabase.GetResourceDescription(texture.AsResource());
if (r.IsFailure)
{
return Identifier<RGTexture>.Invalid;
}
var desc = r.Value;
return _resources.ImportTexture(in desc._desc.textureDescription, texture, name);
}
/// <summary>
/// Imports an external buffer into the render graph.
/// </summary>
/// <param name="buffer">The external buffer handle.</param>
/// <returns>The identifier of the imported render graph buffer. Invalid if import fails.</returns>
public Identifier<RGBuffer> ImportBuffer(Handle<GraphicsBuffer> buffer, string name)
{
var r = _graphicsEngine.ResourceDatabase.GetResourceDescription(buffer.AsResource());
if (r.IsFailure)
{
return Identifier<RGBuffer>.Invalid;
}
var desc = r.Value;
return _resources.ImportBuffer(in desc._desc.bufferDescription, buffer, name);
}
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;
}
public IUnsafeRenderGraphBuilder AddUnsafeRenderPass<TPassData>(string name, out TPassData passData)
where TPassData : class, new()
{
var renderPass = _objectPool.Rent<UnsafeRenderGraphPass<TPassData>>();
renderPass.Init(_passes.Count, _objectPool.Rent<TPassData>(), name, RenderPassType.Unsafe);
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());
// Hash imported flag
*(pData + offset) = resource.isImported ? (byte)1 : (byte)0;
offset += sizeof(byte);
// For imported textures, hash the backing resource handle
if (resource.isImported)
{
*(int*)(pData + offset) = resource.backingResource.GetHashCode();
offset += sizeof(int);
return offset;
}
var desc = resource.rgTextureDesc;
// Hash format (structural)
*(TextureFormat*)(pData + offset) = desc.format;
offset += sizeof(TextureFormat);
// Hash size mode (structural)
*(RGTextureSizeMode*)(pData + offset) = desc.sizeMode;
offset += sizeof(RGTextureSizeMode);
// Hash size specification based on mode
if (desc.sizeMode == RGTextureSizeMode.Absolute)
{
// Absolute mode: hash actual dimensions
*(uint*)(pData + offset) = desc.width;
offset += sizeof(uint);
*(uint*)(pData + offset) = desc.height;
offset += sizeof(uint);
}
else
{
// Relative mode: hash scale factors (NOT resolved dimensions)
*(float*)(pData + offset) = desc.scaleX;
offset += sizeof(float);
*(float*)(pData + offset) = desc.scaleY;
offset += sizeof(float);
}
// Hash other structural properties
*(TextureDimension*)(pData + offset) = desc.dimension;
offset += sizeof(TextureDimension);
*(uint*)(pData + offset) = desc.mipLevels;
offset += sizeof(uint);
*(TextureUsage*)(pData + offset) = desc.usage;
offset += sizeof(TextureUsage);
*(bool*)(pData + offset) = desc.clearAtFirstUse;
offset += sizeof(bool);
*(bool*)(pData + offset) = desc.discardAtLastUse;
offset += sizeof(bool);
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);
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++)
{
var readList = pass.resourceReads[j];
var writeList = pass.resourceWrites[j];
var createList = pass.resourceCreates[j];
*(int*)(pData + offset) = readList.Count;
offset += sizeof(int);
for (var k = 0; k < readList.Count; k++)
{
*(int*)(pData + offset) = readList[k].Value;
offset += sizeof(int);
}
*(int*)(pData + offset) = writeList.Count;
offset += sizeof(int);
for (var k = 0; k < writeList.Count; k++)
{
*(int*)(pData + offset) = writeList[k].Value;
offset += sizeof(int);
}
*(int*)(pData + offset) = createList.Count;
offset += sizeof(int);
for (var k = 0; k < createList.Count; k++)
{
*(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);
}
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(in ViewState viewState)
{
if (_compiled)
{
return;
}
_currentViewState = viewState;
// Resolve texture sizes before computing hash
_resources.ResolveTextureSizes(in viewState);
var graphHash = ComputeGraphHash();
if (_compilationCache.TryGetCached(graphHash, out var cached))
{
// Check if view state changed
if (!cached.viewState.Equals(viewState))
{
// View state changed - re-resolve sizes and recreate GPU resources
_resources.ResolveTextureSizes(in viewState);
RecreateResourcesForNewViewState(cached, viewState);
}
else
{
// Perfect cache hit - restore everything
RestoreFromCache(cached);
}
_compiled = true;
return;
}
_compiledPasses.Clear();
// 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 resources
for (var j = 0; j < (int)RenderGraphResourceType.Count; j++)
{
var writeList = pass.resourceWrites[j];
for (var k = 0; k < writeList.Count; k++)
{
var writeHandle = writeList[k];
var resource = _resources.GetResource(writeHandle);
if (resource.isImported)
{
pass.hasSideEffects = true;
break;
}
}
}
}
// 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;
}
// 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);
}
}
// 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);
}
}
_aliasingManager.AssignPhysicalResources(_resources, _passes.Count);
AllocateResource();
GenerateBarriers();
BuildNativeRenderPasses();
StoreInCache(graphHash);
_compiled = true;
}
private void AllocateResource()
{
if (_resourceHeap.IsValid)
{
foreach (var res in _resources.Resources)
{
if (res.isImported)
{
continue;
}
_graphicsEngine.ResourceDatabase.ReleaseResource(res.backingResource);
}
_graphicsEngine.ResourceDatabase.ReleaseResource(_resourceHeap);
}
if (_aliasingManager.Heap.size == 0)
{
return;
}
var allocationDesc = new AllocationDesc
{
Size = _aliasingManager.Heap.size + 1024 * 1024,
Alignment = ResourceHeap.DEFAULT_ALIGNMENT,
HeapFlags = HeapFlags.AlowBufferAndTexture,
HeapType = HeapType.Default
};
_resourceHeap = _graphicsEngine.ResourceAllocator.Allocate(in allocationDesc, "RenderGraphResourceHeap");
for (var i = 0; i < _resources.Resources.Count; i++)
{
var placedIndex = _aliasingManager.GetPlacedResourceIndex(i);
var placed = _aliasingManager.GetPlacedResource(placedIndex);
if (placed == null)
{
continue;
}
var res = _resources.Resources[i];
var ops = new CreationOptions
{
AllocationType = ResourceAllocationType.Suballocation,
Heap = _resourceHeap,
Offset = placed.heapOffset,
};
if (res.type == RenderGraphResourceType.Texture)
{
var textureDesc = res.rgTextureDesc.ToTextureDesc(res.resolvedWidth, res.resolvedHeight);
res.backingResource = _graphicsEngine.ResourceAllocator.CreateTexture(in textureDesc, res.name, ops).AsResource();
}
else if (res.type == RenderGraphResourceType.Buffer)
{
res.backingResource = _graphicsEngine.ResourceAllocator.CreateBuffer(in res.bufferDesc, res.name, ops).AsResource();
}
else
{
throw new NotSupportedException();
}
_compilationCache.UpdateBackingResource(i, res.backingResource);
}
}
/// <summary>
/// Recreates GPU resources when view state changes but compilation cache is valid.
/// </summary>
private void RecreateResourcesForNewViewState(CachedCompilation cached, in ViewState newViewState)
{
// Restore compilation results (passes, barriers, aliasing)
RestoreFromCache(cached);
AllocateResource();
cached.viewState = newViewState;
}
/// <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.placedResources);
// 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;
}
for (var i = 0; i < _resources.ResourceCount; i++)
{
var res = _resources.Resources[i];
if (!res.isImported)
{
res.backingResource = cached.backingResources[i];
}
}
}
/// <summary>
/// Stores current compilation results in the cache.
/// </summary>
private void StoreInCache(ulong graphHash)
{
var cacheData = new CachedCompilation();
// Store view state
cacheData.viewState = _currentViewState;
// 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.placedResources);
// 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;
}
for (var i = 0; i < _resources.ResourceCount; i++)
{
var res = _resources.Resources[i];
cacheData.backingResources.Add(res.backingResource);
}
_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 < (int)RenderGraphResourceType.Count; i++)
{
var readList = pass.resourceReads[i];
for (var j = 0; j < readList.Count; j++)
{
UnculProducer(readList[j]);
}
}
// 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();
// 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);
}
}
/// <summary>
/// Inserts aliasing barriers when a placed resource is reused.
/// </summary>
private void InsertAliasingBarriers(RenderGraphPassBase pass, int passIdx)
{
// Check all resources written by this pass (both textures and buffers)
for (var resType = 0; resType < (int)RenderGraphResourceType.Count; resType++)
{
var writeList = pass.resourceWrites[resType];
for (var i = 0; i < writeList.Count; i++)
{
var id = writeList[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)
{
// Get the placed resource
var placedIndex = _aliasingManager.GetPlacedResourceIndex(id.Value);
if (placedIndex >= 0)
{
var placed = _aliasingManager.GetPlacedResource(placedIndex);
// If this placed resource has multiple aliased resources,
// we need an aliasing barrier when switching between them
if (placed != null && placed.aliasedLogicalResources.Count > 1)
{
// 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)
{
if (otherLogicalIndex != id.Value)
{
// Get resource by global index
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 (mostRecentLastUse >= 0)
{
BarrierDesc desc;
if (resource.type == RenderGraphResourceType.Texture)
{
desc = BarrierDesc.Texture(resource.backingResource,
BarrierSync.All, BarrierSync.None,
BarrierAccess.NoAccess, BarrierAccess.NoAccess,
BarrierLayout.Undefined, BarrierLayout.Common,
discard: true);
}
else
{
desc = BarrierDesc.Buffer(resource.backingResource,
BarrierSync.All, BarrierSync.None,
BarrierAccess.NoAccess, BarrierAccess.NoAccess);
}
var barrier = ResourceBarrier.Create(passIdx, desc, id);
_barriers.Add(barrier);
}
}
}
}
}
}
}
/// <summary>
/// Inserts transition barriers when a resource changes state.
/// </summary>
private void InsertTransitionBarriers(RenderGraphPassBase pass, int passIdx)
{
// 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];
var state = GetBufferReadState(handle, pass, (RenderGraphResourceType)i);
InsertTransitionIfNeeded(handle, state, 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 < (int)RenderGraphResourceType.Count; i++)
{
var writeList = pass.resourceWrites[i];
for (var j = 0; j < writeList.Count; j++)
{
var id = writeList[j];
InsertTransitionIfNeeded(id, ResourceState.UnorderedAccess, passIdx);
}
}
break;
case RenderPassType.Unsafe:
for (var i = 0; i < (int)RenderGraphResourceType.Count; i++)
{
var writeList = pass.resourceWrites[i];
for (var j = 0; j < writeList.Count; j++)
{
var id = writeList[j];
InsertTransitionIfNeeded(id, ResourceState.RenderTarget, passIdx);
}
}
for (var i = 0; i < pass.randomAccess.Count; i++)
{
InsertTransitionIfNeeded(pass.randomAccess[i], 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;
var r = _graphicsEngine.ResourceDatabase.GetResourceState(_resources.GetResource(resource).backingResource);
currentState = r.IsSuccess ? r.Value : ResourceState.Common;
}
if (currentState != newState)
{
var res = _resources.GetResource(resource);
GetBarrierInfo(currentState, out var syncBefore, out var accessBefore, out var layoutBefore);
GetBarrierInfo(newState, out var syncAfter, out var accessAfter, out var layoutAfter);
BarrierDesc desc;
if (res.type == RenderGraphResourceType.Texture)
{
desc = BarrierDesc.Texture(res.backingResource,
syncBefore, syncAfter,
accessBefore, accessAfter,
layoutBefore, layoutAfter);
}
else
{
desc = BarrierDesc.Buffer(res.backingResource,
syncBefore, syncAfter,
accessBefore, accessAfter);
}
var barrier = ResourceBarrier.Create(passIdx, desc, resource);
_barriers.Add(barrier);
_resourceStates[resource.Value] = newState;
}
}
private static void GetBarrierInfo(ResourceState state, out BarrierSync sync, out BarrierAccess access, out BarrierLayout layout)
{
sync = BarrierSync.None;
access = BarrierAccess.Common;
layout = BarrierLayout.Common;
if (state == ResourceState.Common)
{
return;
}
if (state.HasFlag(ResourceState.RenderTarget))
{
sync |= BarrierSync.RenderTarget;
access |= BarrierAccess.RenderTarget;
layout = BarrierLayout.RenderTarget;
}
if (state.HasFlag(ResourceState.DepthWrite))
{
sync |= BarrierSync.DepthStencil;
access |= BarrierAccess.DepthStencilWrite;
layout = BarrierLayout.DepthStencilWrite;
}
if (state.HasFlag(ResourceState.DepthRead))
{
sync |= BarrierSync.DepthStencil;
access |= BarrierAccess.DepthStencilRead;
layout = BarrierLayout.DepthStencilRead;
}
if (state.HasFlag(ResourceState.UnorderedAccess))
{
sync |= BarrierSync.AllShading;
access |= BarrierAccess.UnorderedAccess;
layout = BarrierLayout.UnorderedAccess;
}
if (state.HasFlag(ResourceState.PixelShaderResource))
{
sync |= BarrierSync.PixelShading;
access |= BarrierAccess.ShaderResource;
layout = BarrierLayout.ShaderResource;
}
if (state.HasFlag(ResourceState.NonPixelShaderResource))
{
sync |= BarrierSync.NonPixelShading;
access |= BarrierAccess.ShaderResource;
layout = BarrierLayout.ShaderResource;
}
if (state.HasFlag(ResourceState.CopyDest))
{
sync |= BarrierSync.Copy;
access |= BarrierAccess.CopyDest;
layout = BarrierLayout.CopyDest;
}
if (state.HasFlag(ResourceState.CopySource))
{
sync |= BarrierSync.Copy;
access |= BarrierAccess.CopySource;
layout = BarrierLayout.CopySource;
}
if (state.HasFlag(ResourceState.VertexAndConstantBuffer))
{
sync |= BarrierSync.VertexShading;
access |= BarrierAccess.VertexBuffer | BarrierAccess.ConstantBuffer;
layout = BarrierLayout.Common;
}
if (state.HasFlag(ResourceState.IndexBuffer))
{
sync |= BarrierSync.IndexInput;
access |= BarrierAccess.IndexBuffer;
layout = BarrierLayout.Common;
}
if (state.HasFlag(ResourceState.IndirectArgument))
{
sync |= BarrierSync.ExecuteIndirect;
access |= BarrierAccess.IndirectArgument;
layout = BarrierLayout.GenericRead;
}
if (state.HasFlag(ResourceState.GenericRead))
{
layout = BarrierLayout.GenericRead;
}
if (state.HasFlag(ResourceState.Present))
{
sync = BarrierSync.All;
access = BarrierAccess.Common;
layout = BarrierLayout.Present;
}
}
/// <summary>
/// Determines the appropriate resource state for a buffer read operation based on usage hints.
/// </summary>
private static ResourceState GetBufferReadState(Identifier<RGResource> handle, RenderGraphPassBase pass, RenderGraphResourceType resourceType)
{
// Textures always use ShaderResource state
if (resourceType == RenderGraphResourceType.Texture)
{
return ResourceState.PixelShaderResource | ResourceState.NonPixelShaderResource;
}
// 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.PixelShaderResource | ResourceState.NonPixelShaderResource;
}
/// <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/Unsafe 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]);
}
}
/// <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++)
{
var access = pass.colorAccess[i];
nativePass.colorAttachments[i] = new RenderTargetInfo
{
texture = access.id,
access = access.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. First use
if (resource.firstUsePass == nativePass.firstLogicalPass)
{
// Clear at first use
if (resource.rgTextureDesc.clearAtFirstUse)
{
attachment.loadOp = AttachmentLoadOp.Clear;
attachment.clearColor = resource.rgTextureDesc.clearColor;
}
else
{
attachment.loadOp = AttachmentLoadOp.DontCare;
}
}
// 2. Discard flag: DontCare for performance
else if (flags.HasFlag(AccessFlags.Discard))
{
attachment.loadOp = AttachmentLoadOp.DontCare;
}
// 3. Read flag: Must preserve existing contents
else if (flags.HasFlag(AccessFlags.Read))
{
attachment.loadOp = AttachmentLoadOp.Load;
}
// 4. Continuation from previous pass
else
{
attachment.loadOp = AttachmentLoadOp.Load;
}
// ===== STORE OP INFERENCE =====
// Last use: No one needs it after this native pass
if (resource.lastUsePass == nativePass.lastLogicalPass)
{
if (resource.rgTextureDesc.discardAtLastUse)
{
attachment.storeOp = AttachmentStoreOp.DontCare;
}
else
{
attachment.storeOp = AttachmentStoreOp.Store;
}
}
// Intermediate: Store for future passes
else
{
attachment.storeOp = AttachmentStoreOp.Store;
}
}
// 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 =====
// 1. First Use
if (resource.firstUsePass == nativePass.firstLogicalPass)
{
// Clear at first use
if (resource.rgTextureDesc.clearAtFirstUse)
{
attachment.loadOp = AttachmentLoadOp.Clear;
attachment.clearDepth = resource.rgTextureDesc.clearDepth;
attachment.clearStencil = resource.rgTextureDesc.clearStencil;
}
else
{
attachment.loadOp = AttachmentLoadOp.DontCare;
}
}
// 2. Discard flag: DontCare for performance
else if (flags.HasFlag(AccessFlags.Discard))
{
attachment.loadOp = AttachmentLoadOp.DontCare;
}
// 3. Read flag: Must preserve existing contents
else if (flags.HasFlag(AccessFlags.Read))
{
attachment.loadOp = AttachmentLoadOp.Load;
}
// 4. Continuation from previous pass
else
{
attachment.loadOp = AttachmentLoadOp.Load;
}
// ===== STORE OP INFERENCE =====
// Depth is commonly discarded (depth-only passes, intermediate depth)
if (resource.lastUsePass == nativePass.lastLogicalPass)
{
if (resource.rgTextureDesc.discardAtLastUse)
{
attachment.storeOp = AttachmentStoreOp.DontCare;
}
else
{
attachment.storeOp = AttachmentStoreOp.Store;
}
}
else
{
attachment.storeOp = AttachmentStoreOp.Store;
}
}
}
/// <summary>
/// Executes all compiled passes using native render passes where possible.
/// </summary>
public unsafe void Execute(ICommandBuffer cmd)
{
if (!_compiled)
{
throw new InvalidOperationException("Render graph must be compiled before execution. Call Compile(viewState) first.");
}
var barrierIndex = 0;
var nativePassIndex = 0;
var logicalPassIndex = 0;
_context.SetCommandBuffer(cmd);
var pPassRTDescs = stackalloc PassRenderTargetDesc[8];
var pRtFormats = stackalloc TextureFormat[8];
while (logicalPassIndex < _compiledPasses.Count)
{
var pass = _compiledPasses[logicalPassIndex];
// Check if this pass is part of a native render pass
if (pass.type == RenderPassType.Raster && nativePassIndex < _nativePasses.Count)
{
var nativePass = _nativePasses[nativePassIndex];
// Build barriers for ALL merged passes before beginning the native render pass
for (var i = 0; i < nativePass.mergedPassIndices.Count; i++)
{
var mergedPassIdx = nativePass.mergedPassIndices[i];
ExecuteBarriersForPass(cmd, mergedPassIdx, ref barrierIndex);
}
// Begin native render pass
for (var i = 0; i < nativePass.colorAttachmentCount; i++)
{
var attachment = nativePass.colorAttachments[i];
pPassRTDescs[i] = new PassRenderTargetDesc
{
Texture = _resources.GetResource(attachment.texture).backingResource.AsTexture(),
ClearColor = attachment.clearColor,
LoadOp = attachment.loadOp,
StoreOp = attachment.storeOp
};
}
var depthDesc = new PassDepthStencilDesc
{
Texture = nativePass.hasDepthAttachment
? _resources.GetResource(nativePass.depthAttachment.texture).backingResource.AsTexture()
: Handle<Texture>.Invalid,
ClearDepth = nativePass.depthAttachment.clearDepth,
ClearStencil = nativePass.depthAttachment.clearStencil,
DepthLoadOp = nativePass.hasDepthAttachment
? nativePass.depthAttachment.loadOp
: AttachmentLoadOp.DontCare,
DepthStoreOp = nativePass.hasDepthAttachment
? nativePass.depthAttachment.storeOp
: AttachmentStoreOp.DontCare,
StencilLoadOp = nativePass.hasDepthAttachment
? nativePass.depthAttachment.loadOp
: AttachmentLoadOp.DontCare,
StencilStoreOp = nativePass.hasDepthAttachment
? nativePass.depthAttachment.storeOp
: AttachmentStoreOp.DontCare
};
cmd.BeginRenderPass(new Span<PassRenderTargetDesc>(pPassRTDescs, nativePass.colorAttachmentCount), depthDesc);
for (var i = 0; i < nativePass.colorAttachmentCount; i++)
{
var attachment = nativePass.colorAttachments[i];
var resource = _resources.GetResource(attachment.texture);
pRtFormats[i] = resource.rgTextureDesc.format;
}
var depthFormat = nativePass.hasDepthAttachment
? _resources.GetResource(nativePass.depthAttachment.texture).rgTextureDesc.format
: TextureFormat.Unknown;
_context.SetRenderTargetFormats(new ReadOnlySpan<TextureFormat>(pRtFormats, nativePass.colorAttachmentCount), depthFormat);
// Build all merged logical passes within this native render pass
for (var i = 0; i < nativePass.mergedPassIndices.Count; i++)
{
var mergedPassIdx = nativePass.mergedPassIndices[i];
var mergedPass = _compiledPasses[mergedPassIdx];
mergedPass.Execute(_context);
logicalPassIndex++;
}
cmd.EndRenderPass();
nativePassIndex++;
}
else
{
// Compute pass or standalone raster pass (not merged) or Unsafe pass
ExecuteBarriersForPass(cmd, logicalPassIndex, ref barrierIndex);
pass.Execute(_context);
logicalPassIndex++;
}
}
}
/// <summary>
/// Executes all barriers for a specific pass.
/// </summary>
private unsafe void ExecuteBarriersForPass(ICommandBuffer cmd, int passIndex, ref int barrierIndex)
{
int start = barrierIndex;
int count = 0;
while (barrierIndex < _barriers.Count && _barriers[barrierIndex].PassIndex == passIndex)
{
count++;
barrierIndex++;
}
if (count > 0)
{
const int BatchSize = 64;
var descs = stackalloc BarrierDesc[BatchSize];
int processed = 0;
while (processed < count)
{
int batch = Math.Min(count - processed, BatchSize);
for (int i = 0; i < batch; i++)
{
descs[i] = _barriers[start + processed + i].Desc;
}
cmd.ResourceBarrier(new ReadOnlySpan<BarrierDesc>(descs, batch));
processed += batch;
}
}
}
public void Dispose()
{
_graphicsEngine.ResourceDatabase.ReleaseResource(_resourceHeap);
}
}