Share one guest image across sRGB/UNORM aliases (#717)

Ported from origin/fix/view-compatible-guest-images 7fb8fdf. Rendering as sRGB and ImageLoad/Store-ing as UNORM at the same guest address are the same surface accessed through different number formats. Recreating the guest image per number format ping-pongs content between two VkImages and loses the rendered pixels on every transition; the mutable-format image now accepts the counterpart identity and serves it through alias views. The commit names AvPlayer movie copies as the pattern that needs this. Adapted for this base: GetOrCreateGuestImage has since grown resolution scaling and 3D/array support, so the alias accept is folded into the current predicate (LogicalWidth/LogicalHeight/LogicalDepth/Type) rather than the old Width/Height pair, and the storage-counterpart widening is placed before the physical-dimension computation. The helper functions it relies on (GetStorageImageFormat, IsCompatibleViewFormat) already existed.
2026-08-01 15:39:47 +08:00 · 2026-07-31 11:12:09 +02:00
parent 0dd543354d
commit e1695cf87f
2 changed files with 147 additions and 2 deletions
@@ -0,0 +1,82 @@
+// Copyright (C) 2026 SharpEmu Emulator Project
+// SPDX-License-Identifier: GPL-2.0-or-later
+
+using SharpEmu.Libs.VideoOut;
+using Silk.NET.Vulkan;
+using Xunit;
+
+namespace SharpEmu.Libs.Tests.VideoOut;
+
+public sealed class VulkanGuestImageAliasTests
+{
+    [Theory]
+    [InlineData(Format.R8G8B8A8Srgb, Format.R8G8B8A8Unorm)]
+    [InlineData(Format.R8G8B8A8Unorm, Format.R8G8B8A8Srgb)]
+    public void SrgbAndUnormCounterpartsShareOneGuestImage(
+        Format existing,
+        Format requested)
+    {
+        Assert.True(
+            VulkanVideoPresenter.IsAliasableGuestImageFormat(existing, requested));
+    }
+
+    [Theory]
+    [InlineData(Format.R8G8B8A8Unorm)]
+    [InlineData(Format.R8G8B8A8Srgb)]
+    [InlineData(Format.R16G16B16A16Sfloat)]
+    public void IdenticalFormatsUseTheExactMatchPath(Format format)
+    {
+        // Equal formats are accepted by the exact-match condition; the alias
+        // helper only reports genuinely different identities.
+        Assert.False(
+            VulkanVideoPresenter.IsAliasableGuestImageFormat(format, format));
+    }
+
+    [Theory]
+    [InlineData(Format.R32Uint, Format.R8G8B8A8Unorm)]
+    [InlineData(Format.R32Sint, Format.R8G8B8A8Unorm)]
+    [InlineData(Format.R32Sfloat, Format.R8G8B8A8Unorm)]
+    [InlineData(Format.R16G16Sfloat, Format.R8G8B8A8Unorm)]
+    [InlineData(Format.A2B10G10R10UnormPack32, Format.R8G8B8A8Unorm)]
+    [InlineData(Format.B10G11R11UfloatPack32, Format.R8G8B8A8Srgb)]
+    public void SameClassNumericReinterpretationKeepsRecreatePath(
+        Format existing,
+        Format requested)
+    {
+        // These pairs are legal Vulkan view aliases (same 32-bit class), but
+        // accepting them would attach fragment shaders translated for the
+        // other numeric encoding to the existing attachment format.
+        Assert.True(
+            VulkanVideoPresenter.IsCompatibleGuestImageViewFormat(existing, requested));
+        Assert.False(
+            VulkanVideoPresenter.IsAliasableGuestImageFormat(existing, requested));
+    }
+
+    [Theory]
+    [InlineData(Format.R8Srgb, Format.R8Unorm)]
+    [InlineData(Format.BC3SrgbBlock, Format.BC3UnormBlock)]
+    public void CounterpartsOutsideTheViewClassTableAreNotAliased(
+        Format existing,
+        Format requested)
+    {
+        // sRGB/UNORM counterparts that the view-compatibility table cannot
+        // alias must keep the recreate path: the shared image could never
+        // legally serve the second identity through an alias view.
+        Assert.False(
+            VulkanVideoPresenter.IsCompatibleGuestImageViewFormat(existing, requested));
+        Assert.False(
+            VulkanVideoPresenter.IsAliasableGuestImageFormat(existing, requested));
+    }
+
+    [Fact]
+    public void AliasedPairStaysWithinOneCompatibilityClass()
+    {
+        // The alias accept creates identity views of both formats on one
+        // mutable-format image; this guards the compatibility table entries
+        // the accept relies on.
+        Assert.True(
+            VulkanVideoPresenter.IsCompatibleGuestImageViewFormat(
+                Format.R8G8B8A8Srgb,
+                Format.R8G8B8A8Unorm));
+    }
+}