Allow creating texture aliases on texture pool

src/Ryujinx.Graphics.Gpu/Image/FormatTable.cs

@@ -711,5 +711,120 @@ namespace Ryujinx.Graphics.Gpu.Image
 
             return result;
         }
+
+        /// <summary>
+        /// Gets the bytes per pixel for a image compatible format.
+        /// </summary>
+        /// <param name="format">Format</param>
+        /// <returns>Bytes per pixel, or zero if the format is not a image compatible format</returns>
+        public static int GetImageFormatBytesPerPixel(Format format)
+        {
+            switch (format)
+            {
+                case Format.R8Unorm:
+                case Format.R8Snorm:
+                case Format.R8Uint:
+                case Format.R8Sint:
+                    return 1;
+                case Format.R16Float:
+                case Format.R16Unorm:
+                case Format.R16Snorm:
+                case Format.R16Uint:
+                case Format.R16Sint:
+                case Format.R8G8Unorm:
+                case Format.R8G8Snorm:
+                case Format.R8G8Uint:
+                case Format.R8G8Sint:
+                    return 2;
+                case Format.R32Float:
+                case Format.R32Uint:
+                case Format.R32Sint:
+                case Format.R16G16Float:
+                case Format.R16G16Unorm:
+                case Format.R16G16Snorm:
+                case Format.R16G16Uint:
+                case Format.R16G16Sint:
+                case Format.R8G8B8A8Unorm:
+                case Format.R8G8B8A8Snorm:
+                case Format.R8G8B8A8Uint:
+                case Format.R8G8B8A8Sint:
+                case Format.R10G10B10A2Unorm:
+                case Format.R10G10B10A2Uint:
+                case Format.R11G11B10Float:
+                    return 4;
+                case Format.R32G32Float:
+                case Format.R32G32Uint:
+                case Format.R32G32Sint:
+                case Format.R16G16B16A16Float:
+                case Format.R16G16B16A16Unorm:
+                case Format.R16G16B16A16Snorm:
+                case Format.R16G16B16A16Uint:
+                case Format.R16G16B16A16Sint:
+                    return 8;
+                case Format.R32G32B32A32Float:
+                case Format.R32G32B32A32Uint:
+                case Format.R32G32B32A32Sint:
+                    return 16;
+            }
+
+            return 0;
+        }
+
+        /// <summary>
+        /// Gets the amount of components (RGBA) for a image compatible format.
+        /// </summary>
+        /// <param name="format">Format</param>
+        /// <returns>Number of components (from 1 to 4), or zero if the format is not a image compatible format</returns>
+        public static int GetImageFormatComponents(Format format)
+        {
+            switch (format)
+            {
+                case Format.R8Unorm:
+                case Format.R8Snorm:
+                case Format.R8Uint:
+                case Format.R8Sint:
+                case Format.R16Float:
+                case Format.R16Unorm:
+                case Format.R16Snorm:
+                case Format.R16Uint:
+                case Format.R16Sint:
+                case Format.R32Float:
+                case Format.R32Uint:
+                case Format.R32Sint:
+                    return 1;
+                case Format.R8G8Unorm:
+                case Format.R8G8Snorm:
+                case Format.R8G8Uint:
+                case Format.R8G8Sint:
+                case Format.R16G16Float:
+                case Format.R16G16Unorm:
+                case Format.R16G16Snorm:
+                case Format.R16G16Uint:
+                case Format.R16G16Sint:
+                case Format.R32G32Float:
+                case Format.R32G32Uint:
+                case Format.R32G32Sint:
+                    return 2;
+                case Format.R11G11B10Float:
+                    return 3;
+                case Format.R8G8B8A8Unorm:
+                case Format.R8G8B8A8Snorm:
+                case Format.R8G8B8A8Uint:
+                case Format.R8G8B8A8Sint:
+                case Format.R10G10B10A2Unorm:
+                case Format.R10G10B10A2Uint:
+                case Format.R16G16B16A16Float:
+                case Format.R16G16B16A16Unorm:
+                case Format.R16G16B16A16Snorm:
+                case Format.R16G16B16A16Uint:
+                case Format.R16G16B16A16Sint:
+                case Format.R32G32B32A32Float:
+                case Format.R32G32B32A32Uint:
+                case Format.R32G32B32A32Sint:
+                    return 4;
+            }
+
+            return 0;
+        }
     }
 }

src/Ryujinx.Graphics.Gpu/Image/TextureBindingsManager.cs

@@ -629,7 +629,7 @@ namespace Ryujinx.Graphics.Gpu.Image
                         cachedTexture.SignalModified();
                     }
 
-                    Format format = bindingInfo.Format == 0 ? cachedTexture.Format : bindingInfo.Format;
+                    Format format = cachedTexture.Format; // bindingInfo.Format == 0 ? cachedTexture.Format : bindingInfo.Format;
 
                     if (state.ImageFormat != format ||
                         ((usageFlags & TextureUsageFlags.NeedsScaleValue) != 0 &&
@@ -648,7 +648,7 @@ namespace Ryujinx.Graphics.Gpu.Image
 
                 state.TextureHandle = textureId;
 
-                ref readonly TextureDescriptor descriptor = ref pool.GetForBinding(textureId, out Texture texture);
+                ref readonly TextureDescriptor descriptor = ref pool.GetForBinding(textureId, bindingInfo.Format, out Texture texture);
 
                 specStateMatches &= specState.MatchesImage(stage, index, descriptor);
 
@@ -660,7 +660,7 @@ namespace Ryujinx.Graphics.Gpu.Image
                     // Buffers are frequently re-created to accommodate larger data, so we need to re-bind
                     // to ensure we're not using a old buffer that was already deleted.
 
-                    Format format = bindingInfo.Format;
+                    Format format = 0; // bindingInfo.Format;
 
                     if (format == 0 && texture != null)
                     {
@@ -689,7 +689,7 @@ namespace Ryujinx.Graphics.Gpu.Image
                     {
                         state.Texture = hostTexture;
 
-                        Format format = bindingInfo.Format;
+                        Format format = 0; // bindingInfo.Format;
 
                         if (format == 0 && texture != null)
                         {

src/Ryujinx.Graphics.Gpu/Image/TexturePool.cs

@@ -75,6 +75,76 @@ namespace Ryujinx.Graphics.Gpu.Image
         private readonly ConcurrentQueue<DereferenceRequest> _dereferenceQueue = new();
         private TextureDescriptor _defaultDescriptor;
 
+        /// <summary>
+        /// List of textures that shares the same memory region, but have different formats.
+        /// </summary>
+        private class TextureAliasList
+        {
+            /// <summary>
+            /// Alias texture.
+            /// </summary>
+            /// <param name="Format">Texture format</param>
+            /// <param name="Texture">Texture</param>
+            private readonly record struct Alias(Format Format, Texture Texture);
+
+            /// <summary>
+            /// List of texture aliases.
+            /// </summary>
+            private readonly List<Alias> _aliases;
+
+            /// <summary>
+            /// Creates a new instance of the texture alias list.
+            /// </summary>
+            public TextureAliasList()
+            {
+                _aliases = new List<Alias>();
+            }
+
+            /// <summary>
+            /// Adds a new texture alias.
+            /// </summary>
+            /// <param name="format">Alias format</param>
+            /// <param name="texture">Alias texture</param>
+            public void Add(Format format, Texture texture)
+            {
+                _aliases.Add(new Alias(format, texture));
+                texture.IncrementReferenceCount();
+            }
+
+            /// <summary>
+            /// Finds a texture with the requested format, or returns null if not found.
+            /// </summary>
+            /// <param name="format">Format to find</param>
+            /// <returns>Texture with the requested format, or null if not found</returns>
+            public Texture Find(Format format)
+            {
+                foreach (var alias in _aliases)
+                {
+                    if (alias.Format == format)
+                    {
+                        return alias.Texture;
+                    }
+                }
+
+                return null;
+            }
+
+            /// <summary>
+            /// Removes all alias textures.
+            /// </summary>
+            public void Destroy()
+            {
+                foreach (var entry in _aliases)
+                {
+                    entry.Texture.DecrementReferenceCount();
+                }
+
+                _aliases.Clear();
+            }
+        }
+
+        private readonly Dictionary<Texture, TextureAliasList> _aliasLists;
+
         /// <summary>
         /// Linked list node used on the texture pool cache.
         /// </summary>
@@ -95,6 +165,7 @@ namespace Ryujinx.Graphics.Gpu.Image
         public TexturePool(GpuContext context, GpuChannel channel, ulong address, int maximumId) : base(context, channel.MemoryManager.Physical, address, maximumId)
         {
             _channel = channel;
+            _aliasLists = new Dictionary<Texture, TextureAliasList>();
         }
 
         /// <summary>
@@ -115,14 +186,13 @@ namespace Ryujinx.Graphics.Gpu.Image
 
                 if (texture == null)
                 {
-                    TextureInfo info = GetInfo(descriptor, out int layerSize);
-
                     // The dereference queue can put our texture back on the cache.
                     if ((texture = ProcessDereferenceQueue(id)) != null)
                     {
                         return ref descriptor;
                     }
 
+                    TextureInfo info = GetInfo(descriptor, out int layerSize);
                     texture = PhysicalMemory.TextureCache.FindOrCreateTexture(_channel.MemoryManager, TextureSearchFlags.ForSampler, info, layerSize);
 
                     // If this happens, then the texture address is invalid, we can't add it to the cache.
@@ -197,6 +267,44 @@ namespace Ryujinx.Graphics.Gpu.Image
             return ref GetInternal(id, out texture);
         }
 
+        /// <summary>
+        /// Gets the texture descriptor and texture with the given ID.
+        /// </summary>
+        /// <remarks>
+        /// This method assumes that the pool has been manually synchronized before doing binding.
+        /// </remarks>
+        /// <param name="id">ID of the texture. This is effectively a zero-based index</param>
+        /// <param name="texture">The texture with the given ID</param>
+        /// <returns>The texture descriptor with the given ID</returns>
+        public ref readonly TextureDescriptor GetForBinding(int id, Format format, out Texture texture)
+        {
+            ref readonly TextureDescriptor descriptor = ref GetInternal(id, out texture);
+
+            if (texture != null && format != 0 && texture.Format != format)
+            {
+                if (!_aliasLists.TryGetValue(texture, out TextureAliasList aliasList))
+                {
+                    _aliasLists.Add(texture, aliasList = new TextureAliasList());
+                }
+
+                texture = aliasList.Find(format);
+
+                if (texture == null)
+                {
+                    TextureInfo info = GetInfo(descriptor, out int layerSize);
+                    info = ChangeFormat(info, format);
+                    texture = PhysicalMemory.TextureCache.FindOrCreateTexture(_channel.MemoryManager, TextureSearchFlags.ForSampler, info, layerSize);
+
+                    if (texture != null)
+                    {
+                        aliasList.Add(format, texture);
+                    }
+                }
+            }
+
+            return ref descriptor;
+        }
+
         /// <summary>
         /// Checks if the pool was modified, and returns the last sequence number where a modification was detected.
         /// </summary>
@@ -234,6 +342,7 @@ namespace Ryujinx.Graphics.Gpu.Image
             else
             {
                 texture.DecrementReferenceCount();
+                RemoveAliasList(texture);
             }
         }
 
@@ -327,6 +436,8 @@ namespace Ryujinx.Graphics.Gpu.Image
                 {
                     texture.DecrementReferenceCount();
                 }
+
+                RemoveAliasList(texture);
             }
 
             return null;
@@ -369,6 +480,7 @@ namespace Ryujinx.Graphics.Gpu.Image
                     if (Interlocked.Exchange(ref Items[id], null) != null)
                     {
                         texture.DecrementReferenceCount(this, id);
+                        RemoveAliasList(texture);
                     }
                 }
             }
@@ -622,6 +734,68 @@ namespace Ryujinx.Graphics.Gpu.Image
                    component == SwizzleComponent.Green;
         }
 
+        /// <summary>
+        /// Changes the format on the texture information structure, and also adjusts the width for the new format if needed.
+        /// </summary>
+        /// <param name="info">Texture information</param>
+        /// <param name="dstFormat">New format</param>
+        /// <returns>Texture information with the new format</returns>
+        private static TextureInfo ChangeFormat(in TextureInfo info, Format dstFormat)
+        {
+            int dstBpp = FormatTable.GetImageFormatBytesPerPixel(dstFormat);
+
+            if (dstBpp == 0)
+            {
+                // We don't support the format. Should never happen in practice.
+
+                return info;
+            }
+
+            FormatInfo dstFormatInfo = new FormatInfo(dstFormat, 1, 1, dstBpp, FormatTable.GetImageFormatComponents(dstFormat));
+
+            int width = info.Width;
+
+            if (info.FormatInfo.BytesPerPixel != dstBpp)
+            {
+                int stride = width * info.FormatInfo.BytesPerPixel;
+                width = stride / dstBpp;
+            }
+
+            return new TextureInfo(
+                info.GpuAddress,
+                width,
+                info.Height,
+                info.DepthOrLayers,
+                info.Levels,
+                info.SamplesInX,
+                info.SamplesInY,
+                info.Stride,
+                info.IsLinear,
+                info.GobBlocksInY,
+                info.GobBlocksInZ,
+                info.GobBlocksInTileX,
+                info.Target,
+                dstFormatInfo,
+                info.DepthStencilMode,
+                info.SwizzleR,
+                info.SwizzleG,
+                info.SwizzleB,
+                info.SwizzleA);
+        }
+
+        /// <summary>
+        /// Removes all aliases for a texture.
+        /// </summary>
+        /// <param name="texture">Texture to have the aliases removed</param>
+        private void RemoveAliasList(Texture texture)
+        {
+            if (_aliasLists.TryGetValue(texture, out TextureAliasList aliasList))
+            {
+                _aliasLists.Remove(texture);
+                aliasList.Destroy();
+            }
+        }
+
         /// <summary>
         /// Decrements the reference count of the texture.
         /// This indicates that the texture pool is not using it anymore.
@@ -629,7 +803,11 @@ namespace Ryujinx.Graphics.Gpu.Image
         /// <param name="item">The texture to be deleted</param>
         protected override void Delete(Texture item)
         {
-            item?.DecrementReferenceCount(this);
+            if (item != null)
+            {
+                item.DecrementReferenceCount(this);
+                RemoveAliasList(item);
+            }
         }
 
         public override void Dispose()