Files
GhostEngine/Ghost.RenderGraph.Concept/RenderGraphAliasing.cs
Misaki 954e3756aa Refactor Render Graph: unified resources, benchmarking
Major overhaul of Render Graph system:
- Replaced texture handles with generic Identifier<T> for unified, type-safe resource management (textures, buffers, etc.)
- Refactored resource registry and pooling for performance and extensibility
- Added AccessFlags and TextureAccess for precise resource usage tracking
- Split passes into Raster and Compute types; introduced builder interfaces for safer pass construction
- Modernized pass setup API (SetColorAttachment, UseTexture, etc.)
- Updated command buffer and context structs to use new resource system
- Refactored barrier and aliasing logic for improved correctness
- Integrated BenchmarkDotNet for performance/memory benchmarking
- Improved blackboard type safety and removed obsolete code/extensions
- Added BenchmarkDotNet NuGet package

These changes make the Render Graph more extensible, efficient, and ready for future resource types and advanced features.
2026-01-12 23:48:56 +09:00

330 lines
11 KiB
C#

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
});
}
}
}