Fix view compatibility for compressed textures with different logical sizes

It has been confirmed that Divinity: Original Sin 2 may describe the same or overlapping guest GPU memory using BCn-compressed textures with different logical dimensions, such as 104×104 and 102×102.

BCn formats store texture data in blocks, with each BC block covering 4×4 texels. After rounding the dimensions up to complete blocks, both 104×104 and 102×102 textures require a 26×26 grid of BC blocks. As a result, they have the same block footprint at the base mip level. Ryujinx originally determined size compatibility in TextureCompatibility.ViewSizeMatches() primarily from this block footprint, which could cause these textures to be classified as Full view-compatible and allowed to share the same Vulkan VkImage directly.

However, because the two textures have different logical dimensions, their mip chains are also different. For example, at mip level 3, a 104×104 texture is reduced to 13×13, while a 102×102 texture is reduced to 12×12. If a 104×104 child texture view shares the backing image of a 102×102 parent texture, a subsequent full mip upload may attempt to write 13×13 compressed data into a Vulkan image subresource whose actual dimensions are only 12×12.

This produces a compressed buffer-to-image copy that does not match the geometry of the backing image. After the invalid command is submitted to the GPU, the Vulkan driver may asynchronously report VK_ERROR_DEVICE_LOST during command buffer submission, waiting, or presentation. In Ryujinx, this eventually appears as: VulkanException: Unexpected API error "ErrorDeviceLost".

The fix adds a logical-dimension check to TextureCompatibility.ViewSizeMatches(). If either the parent or child uses a compressed texture format, and the actual width or height of the corresponding parent mip does not match the logical width or height of the child, the relationship is no longer classified as Full view-compatible. Instead, it is downgraded to CopyOnly.

CopyOnly indicates that the two textures may still describe the same or overlapping guest memory and that their contents must remain synchronized, but they cannot directly share a single fixed-size Vulkan image. Ryujinx instead allows each texture to retain a host texture matching its own logical dimensions and synchronizes their contents through the existing copy-dependency mechanism.

As a result, the 13×13 mip of the 104×104 texture is uploaded to an actual 13×13 destination mip, while the 12×12 mip of the 102×102 texture is uploaded to an actual 12×12 destination mip.

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

@@ -381,12 +381,15 @@ namespace Ryujinx.Graphics.Gpu.Image
             }
 
             // Some APIs align the width for copy and render target textures,
-            // so the width may not match in this case for different uses of the same texture.
+            // so the width may not match for different uses of the same texture.
             // To account for this, we compare the aligned width here.
-            // We expect height to always match exactly, if the texture is the same.
+            // However, matching block footprints are not sufficient for compressed textures;
+            // their logical dimensions must also match.
             if (alignedWidthMatches && lhsSize.Height == rhsSize.Height)
             {
-                return (exact && lhsSize.Width != rhsSize.Width) || lhsSize.Width < rhsSize.Width
+                return ((lhs.FormatInfo.IsCompressed || rhs.FormatInfo.IsCompressed) &&
+                        (Math.Max(1, lhs.Width >> level) != rhs.Width || Math.Max(1, lhs.Height >> level) != rhs.Height)) ||
+                       (exact && lhsSize.Width != rhsSize.Width) || lhsSize.Width < rhsSize.Width
                     ? TextureViewCompatibility.CopyOnly
                     : result;
             }

src/Ryujinx.Graphics.OpenGL/Framebuffer.cs

@@ -20,6 +20,27 @@ namespace Ryujinx.Graphics.OpenGL
         private int _colorsCount;
         private bool _dualSourceBlend;
 
+        public bool HasAttachments
+        {
+            get
+            {
+                if (_depthStencil != null)
+                {
+                    return true;
+                }
+
+                for (int index = 0; index < _colors.Length; index++)
+                {
+                    if (_colors[index] != null)
+                    {
+                        return true;
+                    }
+                }
+
+                return false;
+            }
+        }
+
         public Framebuffer()
         {
             Handle = GL.GenFramebuffer();
@@ -34,6 +55,12 @@ namespace Ryujinx.Graphics.OpenGL
             return Handle;
         }
 
+        public void SetDefaultSize(int width, int height)
+        {
+            GL.FramebufferParameter(FramebufferTarget.Framebuffer, FramebufferDefaultParameter.FramebufferDefaultWidth, Math.Max(1, width));
+            GL.FramebufferParameter(FramebufferTarget.Framebuffer, FramebufferDefaultParameter.FramebufferDefaultHeight, Math.Max(1, height));
+        }
+
         [MethodImpl(MethodImplOptions.AggressiveInlining)]
         public void AttachColor(int index, TextureView color)
         {
@@ -105,13 +132,20 @@ namespace Ryujinx.Graphics.OpenGL
             _colorsCount = colorsCount;
         }
 
-        private static void SetDrawBuffersImpl(int colorsCount)
+        private void SetDrawBuffersImpl(int colorsCount)
         {
             DrawBuffersEnum[] drawBuffers = new DrawBuffersEnum[colorsCount];
 
             for (int index = 0; index < colorsCount; index++)
             {
-                drawBuffers[index] = DrawBuffersEnum.ColorAttachment0 + index;
+                if (_colors[index] != null)
+                {
+                    drawBuffers[index] = DrawBuffersEnum.ColorAttachment0 + index;
+                }
+                else
+                {
+                    drawBuffers[index] = DrawBuffersEnum.None;
+                }
             }
 
             GL.DrawBuffers(colorsCount, drawBuffers);

src/Ryujinx.Graphics.OpenGL/Pipeline.cs

@@ -1537,6 +1537,11 @@ namespace Ryujinx.Graphics.OpenGL
         {
             DrawCount++;
 
+            if (!_framebuffer.HasAttachments && _viewportArray.Length >= 4)
+            {
+                _framebuffer.SetDefaultSize((int)_viewportArray[2], (int)_viewportArray[3]);
+            }
+
             _unit0Texture?.Bind(0);
         }
 

src/Ryujinx.Graphics.Shader/Translation/Optimizations/BindlessElimination.cs

@@ -70,19 +70,7 @@ namespace Ryujinx.Graphics.Shader.Translation.Optimizations
 
             Operand bindlessHandle = texOp.GetSource(0);
 
-            if (bindlessHandle.AsgOp is PhiNode phi)
-            {
-                for (int srcIndex = 0; srcIndex < phi.SourcesCount; srcIndex++)
-                {
-                    Operand phiSource = phi.GetSource(srcIndex);
-
-                    if (phiSource.AsgOp is not PhiNode && !IsBindlessAccessAllowed(phiSource))
-                    {
-                        return false;
-                    }
-                }
-            }
-            else if (!IsBindlessAccessAllowed(bindlessHandle))
+            if (!IsBindlessAccessAllowed(bindlessHandle))
             {
                 return false;
             }
@@ -100,7 +88,10 @@ namespace Ryujinx.Graphics.Shader.Translation.Optimizations
 
             texOp.SetSource(0, textureIndex);
 
-            bool hasSampler = !texOp.Inst.IsImage();
+            // Buffer textures use a TIC/BufferView only and never consume a sampler.
+            // Avoiding a sampler descriptor array here is especially important for bindless
+            // texture buffers, where the array can span the entire sampler pool for no benefit.
+            bool hasSampler = !texOp.Inst.IsImage() && texOp.Type != SamplerType.TextureBuffer;
 
             SetBindingPair textureSetAndBinding = resourceManager.GetTextureOrImageBinding(
                 texOp.Inst,
@@ -143,26 +134,112 @@ namespace Ryujinx.Graphics.Shader.Translation.Optimizations
 
         private static bool IsBindlessAccessAllowed(Operand bindlessHandle)
         {
-            if (bindlessHandle.Type == OperandType.ConstantBuffer)
-            {
-                // Bindless access with handles from constant buffer is allowed.
+            // Walk only SSA merges and integer operations that can transparently construct
+            // or select a packed texture/sampler handle. Do not walk arbitrary operations:
+            // finding an unrelated resource load elsewhere in the SSA graph must not enable
+            // descriptor-array access for this handle.
+            const int MaxVisitedOperands = 256;
+            const int MaxDepth = 64;
 
-                return true;
+            Stack<(Operand Operand, int Depth)> work = new();
+            HashSet<Operand> visited = new();
+
+            work.Push((bindlessHandle, 0));
+
+            while (work.Count != 0 && visited.Count < MaxVisitedOperands)
+            {
+                (Operand operand, int depth) = work.Pop();
+
+                if (operand == null || depth > MaxDepth || !visited.Add(operand))
+                {
+                    continue;
+                }
+
+                if (operand.Type == OperandType.ConstantBuffer)
+                {
+                    // Constant buffers are accepted by the existing direct-handle path and
+                    // remain accepted when SSA merges or integer handle arithmetic obscure them.
+                    return true;
+                }
+
+                if (operand.AsgOp is PhiNode phi)
+                {
+                    for (int index = 0; index < phi.SourcesCount; index++)
+                    {
+                        Operand source = phi.GetSource(index);
+
+                        if (source.Type != OperandType.Undefined)
+                        {
+                            work.Push((source, depth + 1));
+                        }
+                    }
+
+                    continue;
+                }
+
+                if (operand.AsgOp is not Operation operation)
+                {
+                    continue;
+                }
+
+                Instruction inst = operation.Inst & Instruction.Mask;
+
+                if (inst == Instruction.Load)
+                {
+                    // Preserve the performance restriction. Static CBUF operands are already
+                    // accepted above; accept their dynamically indexed Load form as the same
+                    // resource class, plus the existing shader-input and storage-buffer sources.
+                    // Other loads remain traversal barriers and cannot authorize a pool array.
+                    if (operation.StorageKind == StorageKind.ConstantBuffer ||
+                        operation.StorageKind == StorageKind.Input ||
+                        operation.StorageKind == StorageKind.StorageBuffer)
+                    {
+                        return true;
+                    }
+
+                    continue;
+                }
+
+                if (!IsHandleConstructionOperation(inst))
+                {
+                    // Texture/image operations, arbitrary loads, floating-point conversions,
+                    // calls and other unrelated calculations are deliberate traversal barriers.
+                    continue;
+                }
+
+                for (int index = 0; index < operation.SourcesCount; index++)
+                {
+                    work.Push((operation.GetSource(index), depth + 1));
+                }
             }
 
-            if (bindlessHandle.AsgOp is not Operation handleOp ||
-                handleOp.Inst != Instruction.Load ||
-                (handleOp.StorageKind != StorageKind.Input && handleOp.StorageKind != StorageKind.StorageBuffer))
-            {
-                // Right now, we only allow bindless access when the handle comes from a shader input or storage buffer.
-                // This is an artificial limitation to prevent it from being used in cases where it
-                // would have a large performance impact of loading all textures in the pool.
-                // It might be removed in the future, if we can mitigate the performance impact.
+            return false;
+        }
 
-                return false;
-            }
-
-            return true;
+        private static bool IsHandleConstructionOperation(Instruction inst)
+        {
+            return inst is
+                Instruction.Add or
+                Instruction.Subtract or
+                Instruction.Multiply or
+                Instruction.MultiplyHighS32 or
+                Instruction.MultiplyHighU32 or
+                Instruction.BitwiseAnd or
+                Instruction.BitwiseExclusiveOr or
+                Instruction.BitwiseNot or
+                Instruction.BitwiseOr or
+                Instruction.BitfieldExtractS32 or
+                Instruction.BitfieldExtractU32 or
+                Instruction.BitfieldInsert or
+                Instruction.ShiftLeft or
+                Instruction.ShiftRightS32 or
+                Instruction.ShiftRightU32 or
+                Instruction.MinimumU32 or
+                Instruction.MaximumU32 or
+                Instruction.ClampU32 or
+                Instruction.ConditionalSelect or
+                Instruction.Copy or
+                Instruction.VectorExtract;
         }
 
         private static bool TryConvertBindless(BasicBlock block, ResourceManager resourceManager, IGpuAccessor gpuAccessor, TextureOperation texOp)

src/Ryujinx.Graphics.Vulkan/FramebufferParams.cs

@@ -32,6 +32,29 @@ namespace Ryujinx.Graphics.Vulkan
         public bool HasDepthStencil { get; private set; }
         public int ColorAttachmentsCount => AttachmentsCount - (HasDepthStencil ? 1 : 0);
 
+        public bool SetVirtualSize(uint width, uint height, uint layers)
+        {
+            if (AttachmentsCount != 0)
+            {
+                return false;
+            }
+
+            width = Math.Max(1u, width);
+            height = Math.Max(1u, height);
+            layers = Math.Max(1u, layers);
+
+            if (Width == width && Height == height && Layers == layers)
+            {
+                return false;
+            }
+
+            Width = width;
+            Height = height;
+            Layers = layers;
+
+            return true;
+        }
+
         public FramebufferParams(Device device, TextureView view, uint width, uint height)
         {
             Format format = view.Info.Format;

src/Ryujinx.Graphics.Vulkan/PipelineBase.cs

@@ -843,6 +843,11 @@ namespace Ryujinx.Graphics.Vulkan
         public void SetImage(ShaderStage stage, int binding, ITexture image)
         {
             _descriptorSetUpdater.SetImage(Cbs, stage, binding, image);
+
+            if (stage == ShaderStage.Fragment && image is TextureView view)
+            {
+                FramebufferParams?.SetVirtualSize((uint)view.Width, (uint)view.Height, (uint)view.Layers);
+            }
         }
 
         public void SetImage(int binding, Auto<DisposableImageView> image)
@@ -1607,6 +1612,24 @@ namespace Ryujinx.Graphics.Vulkan
 
         private bool RecreateGraphicsPipelineIfNeeded()
         {
+            if (FramebufferParams != null &&
+                FramebufferParams.AttachmentsCount == 0 &&
+                FramebufferParams.Width == 1 &&
+                FramebufferParams.Height == 1 &&
+                DynamicState.ViewportsCount != 0)
+            {
+                // An attachmentless fragment pass can reach its first draw before the storage
+                // image descriptor is rebound. At that point the null framebuffer still has
+                // its constructor fallback of 1x1, even though the guest viewport already
+                // describes the real render area. Seed the virtual framebuffer from that
+                // viewport so the first storage-image draw is not clipped to one pixel.
+                Silk.NET.Vulkan.Viewport viewport = DynamicState.Viewports[0];
+                uint width = (uint)Math.Max(1f, Math.Abs(viewport.Width));
+                uint height = (uint)Math.Max(1f, Math.Abs(viewport.Height));
+
+                FramebufferParams.SetVirtualSize(width, height, 1);
+            }
+
             if (AutoFlush.ShouldFlushDraw(DrawCount))
             {
                 Gd.FlushAllCommands();

src/Ryujinx/AppHost.cs

@@ -45,6 +45,7 @@ using Ryujinx.UI.Common.Configuration;
 using Ryujinx.UI.Common.Helper;
 using Silk.NET.Vulkan;
 using SkiaSharp;
+using SPB.Graphics.Exceptions;
 using SPB.Graphics.Vulkan;
 using System;
 using System.Collections.Generic;
@@ -654,8 +655,22 @@ namespace Ryujinx.Ava
 
             if (RendererHost.EmbeddedWindow is EmbeddedWindowOpenGL openGlWindow)
             {
-                // Try to bind the OpenGL context before calling the shutdown event.
-                openGlWindow.MakeCurrent(false, false);
+                try
+                {
+                    // Try to bind the OpenGL context before disposing GPU resources.
+                    openGlWindow.MakeCurrent();
+                }
+                catch (ContextException e) when (_userChannelPersistence.ShouldRestart)
+                {
+                    // ExecuteProgram may detach the old native window before GPU
+                    // disposal. Allow the old context to be released with the window
+                    // and continue the requested program relaunch.
+                    Logger.Warning?.Print(
+                        LogClass.UI,
+                        $"Failed to bind OpenGL context during program relaunch: {e}");
+
+                    return;
+                }
 
                 Device.DisposeGpu();