Refactor IID logic into marshaller type

src/ComputeSharp.UI/ComputeSharp.UI.projitems

@@ -17,7 +17,7 @@
     <Compile Include="$(MSBuildThisFileDirectory)Extensions\IDXGIAdapterExtensions.cs" />
     <Compile Include="$(MSBuildThisFileDirectory)Extensions\SemaphoreSlimExtensions.cs" />
     <Compile Include="$(MSBuildThisFileDirectory)Helpers\DynamicResolutionManager.cs" />
-    <Compile Include="$(MSBuildThisFileDirectory)Helpers\SwapChainManager.IID.cs" />
+    <Compile Include="$(MSBuildThisFileDirectory)Helpers\SwapChainPanelNativeMarshaller.cs" />
     <Compile Include="$(MSBuildThisFileDirectory)Helpers\SwapChainManager.cs" />
     <Compile Include="$(MSBuildThisFileDirectory)Helpers\SwapChainManager.Rendering.cs" />
     <Compile Include="$(MSBuildThisFileDirectory)IFrameRequestQueue.cs" />

src/ComputeSharp.UI/Helpers/SwapChainManager.cs

@@ -20,7 +20,6 @@
 using Windows.System;
 using Windows.UI.Xaml.Controls;
 #endif
-using WinRT;
 
 #if WINDOWS_UWP
 namespace ComputeSharp.Uwp.Helpers;
@@ -233,7 +232,7 @@ public SwapChainManager(TOwner owner, GraphicsDevice device)
         // IDXGISwapChain reference just created and set that as the swap chain panel to use.
         fixed (ISwapChainPanelNative** swapChainPanelNative = this.swapChainPanelNative)
         {
-            ((IWinRTObject)owner).NativeObject.TryAs(*IID_ISwapChainPanelNative, out *(nint*)swapChainPanelNative).Assert();
+            SwapChainPanelNativeMarshaller.GetNativeObject(owner, swapChainPanelNative);
         }
 
         // Get the underlying ID3D12Device in use

src/ComputeSharp.UI/Helpers/SwapChainPanelNativeMarshaller.cs

@@ -0,0 +1,68 @@
+using System;
+using System.Runtime.CompilerServices;
+using ComputeSharp.Core.Extensions;
+using ComputeSharp.Win32;
+#if !WINDOWS_UWP
+using Microsoft.UI.Xaml.Controls;
+#endif
+using System.Runtime.InteropServices;
+#if WINDOWS_UWP
+using Windows.UI.Xaml.Controls;
+#endif
+using WinRT;
+
+#if WINDOWS_UWP
+namespace ComputeSharp.Uwp.Helpers;
+#else
+namespace ComputeSharp.WinUI.Helpers;
+#endif
+
+/// <summary>
+/// A helper type to handle marshalling <see cref="SwapChainPanel"/> objects for native interop.
+/// </summary>
+internal static unsafe class SwapChainPanelNativeMarshaller
+{
+    /// <summary>
+    /// Retrieves the underlying <see cref="ISwapChainPanelNative"/> object for an input <see cref="SwapChainPanel"/> instance.
+    /// </summary>
+    /// <param name="managedObject">The input <see cref="SwapChainPanel"/> instance to unwrap.</param>
+    /// <param name="nativeObject">A pointer to the resulting <see cref="ISwapChainPanelNative"/> object to retrieve.</param>
+    public static void GetNativeObject(SwapChainPanel managedObject, ISwapChainPanelNative** nativeObject)
+    {
+#if WINDOWS_UWP
+        ReadOnlySpan<byte> data =
+        [
+            0xD2, 0x19, 0x2F, 0xF9,
+            0xDE, 0x3A,
+            0xA6, 0x45,
+            0xA2,
+            0x0C,
+            0xF6,
+            0xF1,
+            0xEA,
+            0x90,
+            0x55,
+            0x4B
+        ];
+#else
+        ReadOnlySpan<byte> data =
+        [
+            0xB8, 0xD0, 0xAA, 0x63,
+            0x24, 0x7C,
+            0xFF, 0x40,
+            0x85,
+            0xA8,
+            0x64,
+            0x0D,
+            0x94,
+            0x4C,
+            0xC3,
+            0x25
+        ];
+#endif
+        // Unwrap and get the 'ISwapChainPanelNative' interface with the right IID depending on the UI framework
+        ((IWinRTObject)managedObject).NativeObject.TryAs(
+            iid: Unsafe.As<byte, Guid>(ref MemoryMarshal.GetReference(data)),
+            ppv: out *(nint*)nativeObject).Assert();
+    }
+}