From 792953c90bc5d37370110745ca65714fff34aa4b Mon Sep 17 00:00:00 2001
From: ParantezTech <12572227+par274@users.noreply.github.com>
Date: Fri, 2 Oct 2026 18:48:02 +0300
Subject: [PATCH] [Gpu] Track the extent of DCC metadata and answer overlap
 queries

A color target records the size of its DCC metadata, and the image cache can
tell whether a guest range overlaps registered DCC metadata.
---
 src/SharpEmu.Libs/Gpu/Buffers/IGuestImageCache.cs |  2 ++
 .../Gpu/Images/GuestImageCache.Collection.cs      |  6 ++++++
 .../Gpu/Images/GuestImageCache.Metadata.cs        | 15 +++++++++++++++
 src/SharpEmu.Libs/Gpu/Images/GuestImageCache.cs   |  5 ++++-
 src/SharpEmu.Libs/Gpu/Images/SurfaceMetadata.cs   |  1 +
 5 files changed, 28 insertions(+), 1 deletion(-)

diff --git a/src/SharpEmu.Libs/Gpu/Buffers/IGuestImageCache.cs b/src/SharpEmu.Libs/Gpu/Buffers/IGuestImageCache.cs
index 79703c9..e6b247b 100644
--- a/src/SharpEmu.Libs/Gpu/Buffers/IGuestImageCache.cs
+++ b/src/SharpEmu.Libs/Gpu/Buffers/IGuestImageCache.cs
@@ -13,6 +13,8 @@ public interface IGuestImageCache
 
     bool ClearMetadata(ulong address);
 
+    bool OverlapsDccMetadata(ulong address, ulong size);
+
     void InvalidateMemory(ulong address, ulong size);
 
     void InvalidateMemoryFromGpu(ulong address, ulong size);
diff --git a/src/SharpEmu.Libs/Gpu/Images/GuestImageCache.Collection.cs b/src/SharpEmu.Libs/Gpu/Images/GuestImageCache.Collection.cs
index 9b8e456..89c3250 100644
--- a/src/SharpEmu.Libs/Gpu/Images/GuestImageCache.Collection.cs
+++ b/src/SharpEmu.Libs/Gpu/Images/GuestImageCache.Collection.cs
@@ -257,6 +257,12 @@ public sealed partial class GuestImageCache
         metadata.ClearMask = 0;
     }
 
+    internal void RegisterDccMetadataForTest(ulong address, ulong size)
+    {
+        using var held = _lock.Hold();
+        _surfaceMetadata[address] = new SurfaceMetadata { Kind = SurfaceMetadataKind.Dcc, Size = size };
+    }
+
     internal RegionLockScope HoldLockForTest() => new(_lock);
 
     internal readonly struct RegionLockScope : IDisposable
diff --git a/src/SharpEmu.Libs/Gpu/Images/GuestImageCache.Metadata.cs b/src/SharpEmu.Libs/Gpu/Images/GuestImageCache.Metadata.cs
index 8d97137..a0424cb 100644
--- a/src/SharpEmu.Libs/Gpu/Images/GuestImageCache.Metadata.cs
+++ b/src/SharpEmu.Libs/Gpu/Images/GuestImageCache.Metadata.cs
@@ -29,6 +29,21 @@ public sealed partial class GuestImageCache
 
     public bool IsMetadataCleared(ulong address, uint slice) => IsMetadataCleared(address, slice, out _);
 
+    public bool OverlapsDccMetadata(ulong address, ulong size)
+    {
+        using var held = _lock.Hold();
+        foreach (var (start, metadata) in _surfaceMetadata)
+        {
+            if (metadata.Kind == SurfaceMetadataKind.Dcc && metadata.Size != 0 &&
+                address < start + metadata.Size && start < address + size)
+            {
+                return true;
+            }
+        }
+
+        return false;
+    }
+
     // A broad clear applies to CMask, FMask and HTile; DCC needs a validated fill value.
     public bool ClearMetadata(ulong address)
     {
diff --git a/src/SharpEmu.Libs/Gpu/Images/GuestImageCache.cs b/src/SharpEmu.Libs/Gpu/Images/GuestImageCache.cs
index 1f19615..2391fc6 100644
--- a/src/SharpEmu.Libs/Gpu/Images/GuestImageCache.cs
+++ b/src/SharpEmu.Libs/Gpu/Images/GuestImageCache.cs
@@ -321,7 +321,8 @@ public sealed unsafe partial class GuestImageCache : IGuestImageCache, IGuestIma
             var address = request.Description.Metadata.Range.Address;
             if (!_surfaceMetadata.TryGetValue(address, out var metadata))
             {
-                _surfaceMetadata.Add(address, new SurfaceMetadata { Kind = SurfaceMetadataKind.Dcc });
+                metadata = new SurfaceMetadata { Kind = SurfaceMetadataKind.Dcc };
+                _surfaceMetadata.Add(address, metadata);
             }
             else if (metadata.Kind == SurfaceMetadataKind.PendingDcc)
             {
@@ -331,6 +332,8 @@ public sealed unsafe partial class GuestImageCache : IGuestImageCache, IGuestIma
             {
                 throw SubmissionScheduler.Fatal($"A color target reuses metadata that is not DCC: address=0x{address:X16} kind={metadata.Kind}.");
             }
+
+            metadata.Size = Math.Max(metadata.Size, request.Description.DccSliceSize * request.Description.TransferLayers);
         }
 
         TakeGpuOwnership(image);
diff --git a/src/SharpEmu.Libs/Gpu/Images/SurfaceMetadata.cs b/src/SharpEmu.Libs/Gpu/Images/SurfaceMetadata.cs
index bb57433..f547685 100644
--- a/src/SharpEmu.Libs/Gpu/Images/SurfaceMetadata.cs
+++ b/src/SharpEmu.Libs/Gpu/Images/SurfaceMetadata.cs
@@ -20,4 +20,5 @@ public sealed class SurfaceMetadata
     public uint ClearMask;
     public uint FillValue = 0xffffffff;
     public ulong FillSize;
+    public ulong Size;
 }