Vulkan: fix guest storage image and render-state handling (#332)

src/SharpEmu.Libs/VideoOut/GuestDepthExtentResolver.cs

@@ -0,0 +1,67 @@
+// Copyright (C) 2026 SharpEmu Emulator Project
+// SPDX-License-Identifier: GPL-2.0-or-later
+
+using SharpEmu.Libs.Gpu;
+
+namespace SharpEmu.Libs.VideoOut;
+
+internal enum GuestDepthExtentResolutionKind
+{
+    Exact,
+    TextureAlias,
+    StaleOneByOne,
+    Mismatch,
+}
+
+internal readonly record struct GuestDepthExtentResolution(
+    GuestDepthExtentResolutionKind Kind,
+    uint Width,
+    uint Height)
+{
+    public bool IsUsable => Kind != GuestDepthExtentResolutionKind.Mismatch;
+}
+
+internal static class GuestDepthExtentResolver
+{
+    public static GuestDepthExtentResolution Resolve(
+        GuestDepthTarget depth,
+        uint colorWidth,
+        uint colorHeight,
+        IReadOnlyList<GuestDrawTexture> textures)
+    {
+        if (depth.Width >= colorWidth && depth.Height >= colorHeight)
+        {
+            return new GuestDepthExtentResolution(
+                GuestDepthExtentResolutionKind.Exact,
+                depth.Width,
+                depth.Height);
+        }
+
+        var matchingTexture = textures.FirstOrDefault(texture =>
+            (texture.Address == depth.Address ||
+             texture.Address == depth.ReadAddress ||
+             texture.Address == depth.WriteAddress) &&
+            texture.Width >= colorWidth &&
+            texture.Height >= colorHeight);
+        if (matchingTexture is not null)
+        {
+            return new GuestDepthExtentResolution(
+                GuestDepthExtentResolutionKind.TextureAlias,
+                matchingTexture.Width,
+                matchingTexture.Height);
+        }
+
+        if (depth.Width == 1 && depth.Height == 1)
+        {
+            return new GuestDepthExtentResolution(
+                GuestDepthExtentResolutionKind.StaleOneByOne,
+                colorWidth,
+                colorHeight);
+        }
+
+        return new GuestDepthExtentResolution(
+            GuestDepthExtentResolutionKind.Mismatch,
+            depth.Width,
+            depth.Height);
+    }
+}