From cc6b1a8b39eb6f6c9bb583ca5000f4c008ec8848 Mon Sep 17 00:00:00 2001
From: Amer Koleci <amerkoleci@gmail.com>
Date: Mon, 5 Sep 2022 09:37:11 +0200
Subject: [PATCH] WIP: Some test for string marshalling (based on TerraFX)

---
 src/Vortice.Win32/Graphics/Dxgi.Manual.cs |  57 +++++++
 src/Vortice.Win32/NetStandard.cs          |  23 +++
 src/Vortice.Win32/StringUtilities.cs      | 176 ++++++++++++++++++++++
 src/Vortice.Win32/UnsafeUtilities.cs      | 171 +++++++++++++++++++++
 src/samples/01-ClearScreen/Program.cs     |  26 +++-
 5 files changed, 451 insertions(+), 2 deletions(-)
 create mode 100644 src/Vortice.Win32/StringUtilities.cs
 create mode 100644 src/Vortice.Win32/UnsafeUtilities.cs

diff --git a/src/Vortice.Win32/Graphics/Dxgi.Manual.cs b/src/Vortice.Win32/Graphics/Dxgi.Manual.cs
index 6fd69ed..c03ad1b 100644
--- a/src/Vortice.Win32/Graphics/Dxgi.Manual.cs
+++ b/src/Vortice.Win32/Graphics/Dxgi.Manual.cs
@@ -2,9 +2,66 @@
 // Licensed under the MIT License (MIT). See LICENSE in the repository root for more information.
 
 using static Win32.Graphics.Dxgi.Apis;
+using static Win32.StringUtilities;
 
 namespace Win32.Graphics.Dxgi;
 
+public unsafe partial struct AdapterDescription
+{
+    /// <include file='../Generated/DXGI.xml' path='doc/member[@name="DXGI_ADAPTER_DESC::Description"]/*' />
+    public readonly string DescriptionStr
+    {
+        get
+        {
+            fixed (ushort* ptr = Description)
+            {
+                return GetString(ptr, 128) ?? string.Empty;
+            }
+        }
+    }
+}
+
+public unsafe partial struct AdapterDescription1
+{
+    /// <include file='../Generated/DXGI.xml' path='doc/member[@name="DXGI_ADAPTER_DESC1::Description"]/*' />
+    public readonly string DescriptionStr
+    {
+        get
+        {
+            fixed (ushort* ptr = Description)
+            {
+                return GetString(ptr, 128) ?? string.Empty;
+            }
+        }
+    }
+}
+
+public unsafe partial struct AdapterDescription2
+{
+    public readonly ReadOnlySpan<ushort> DescriptionSpan
+    {
+        get
+        {
+            fixed (ushort* ptr = Description)
+            {
+                return GetUtf16Span(ptr, 128);
+            }
+        }
+    }
+
+    /// <include file='../Generated/DXGI.xml' path='doc/member[@name="DXGI_ADAPTER_DESC2::Description"]/*' />
+    public readonly string DescriptionStr
+    {
+        get
+        {
+            fixed (ushort* ptr = Description)
+            {
+                return GetString(ptr, 128) ?? string.Empty;
+            }
+        }
+    }
+}
+
 public unsafe partial struct IDXGIFactory5
 {
     public TFeature CheckFeatureSupport<TFeature>(Feature feature)
diff --git a/src/Vortice.Win32/NetStandard.cs b/src/Vortice.Win32/NetStandard.cs
index e3a0272..e005052 100644
--- a/src/Vortice.Win32/NetStandard.cs
+++ b/src/Vortice.Win32/NetStandard.cs
@@ -23,6 +23,17 @@ internal static class MemoryMarshal
         return ref global::System.Runtime.InteropServices.MemoryMarshal.GetReference(span);
     }
 
+    /// <summary>
+    /// Returns a reference to the 0th element of <paramref name="array"/>. If the array is empty, returns a reference
+    /// to where the 0th element would have been stored. Such a reference may be used for pinning but must never be dereferenced.
+    /// </summary>
+    /// <exception cref="NullReferenceException"><paramref name="array"/> is <see langword="null"/>.</exception>
+    [MethodImpl(MethodImplOptions.AggressiveInlining)]
+    public static ref T GetArrayDataReference<T>(T[] array)
+    {
+        return ref global::System.Runtime.InteropServices.MemoryMarshal.GetReference(array.AsSpan());
+    }
+
     /// <summary>
     /// Creates a new <see cref="Span{T}"/> from a given reference.
     /// </summary>
@@ -34,6 +45,18 @@ internal static class MemoryMarshal
     {
         return new(Unsafe.AsPointer(ref value), length);
     }
+
+    /// <summary>
+    /// Creates a new <see cref="ReadOnlySpan{T}"/> from a given reference.
+    /// </summary>
+    /// <typeparam name="T">The type of reference to wrap.</typeparam>
+    /// <param name="value">The target reference.</param>
+    /// <param name="length">The length of the <see cref="Span{T}"/> to create.</param>
+    /// <returns>A new <see cref="Span{T}"/> wrapping <paramref name="value"/>.</returns>
+    public static unsafe ReadOnlySpan<T> CreateReadOnlySpan<T>(ref T value, int length)
+    {
+        return new(Unsafe.AsPointer(ref value), length);
+    }
 }
 
 #endif
diff --git a/src/Vortice.Win32/StringUtilities.cs b/src/Vortice.Win32/StringUtilities.cs
new file mode 100644
index 0000000..9a1ac1a
--- /dev/null
+++ b/src/Vortice.Win32/StringUtilities.cs
@@ -0,0 +1,176 @@
+// Copyright © Amer Koleci and Contributors.
+// Licensed under the MIT License (MIT). See LICENSE in the repository root for more information.
+// Copyright © Tanner Gooding and Contributors. Licensed under the MIT License (MIT). See License.md in the repository root for more information.
+
+using System.Runtime.CompilerServices;
+using System.Text;
+using static Win32.UnsafeUtilities;
+
+namespace Win32;
+
+/// <summary>
+/// Provides a set of methods to supplement for <see cref="string" />.
+/// </summary>
+public static unsafe class StringUtilities
+{
+    public static string? GetString(sbyte* pointer, int maxLength = -1)
+    {
+        return GetUtf8Span(pointer, maxLength).GetString();
+    }
+
+    public static string? GetString(ushort* pointer, int maxLength = -1)
+    {
+        return GetUtf16Span(pointer, maxLength).GetString();
+    }
+
+    /// <summary>Gets a null-terminated sequence of UTF8 characters for a string.</summary>
+    /// <param name="source">The string for which to get the null-terminated UTF8 character sequence.</param>
+    /// <returns>A null-terminated UTF8 character sequence created from <paramref name="source" />.</returns>
+    [MethodImpl(MethodImplOptions.AggressiveInlining)]
+    public static ReadOnlySpan<sbyte> GetUtf8Span(this string? source)
+    {
+        ReadOnlySpan<byte> result;
+
+        if (source is not null)
+        {
+            int maxLength = Encoding.UTF8.GetMaxByteCount(source.Length);
+#if NET6_0_OR_GREATER
+            var bytes = new byte[maxLength + 1];
+            var length = Encoding.UTF8.GetBytes(source, bytes);
+            result = bytes.AsSpan(0, length);
+#else
+            byte* bytes = stackalloc byte[maxLength + 1];
+            fixed (char* namePtr = source)
+            {
+                Encoding.UTF8.GetBytes(namePtr, source.Length, bytes, maxLength);
+            }
+            bytes[maxLength] = 0;
+            result = new(bytes, source.Length);
+#endif
+        }
+        else
+        {
+            result = null;
+        }
+
+        return result.As<byte, sbyte>();
+    }
+
+    /// <summary>Gets a span for a null-terminated UTF8 character sequence.</summary>
+    /// <param name="source">The pointer to a null-terminated UTF8 character sequence.</param>
+    /// <param name="maxLength">The maxmimum length of <paramref name="source" /> or <c>-1</c> if the maximum length is unknown.</param>
+    /// <returns>A span that starts at <paramref name="source" /> and extends to <paramref name="maxLength" /> or the first null character, whichever comes first.</returns>
+    [MethodImpl(MethodImplOptions.AggressiveInlining)]
+    public static ReadOnlySpan<sbyte> GetUtf8Span(sbyte* source, int maxLength = -1)
+        => (source != null) ? GetUtf8Span(in source[0], maxLength) : null;
+
+    /// <summary>Gets a span for a null-terminated UTF8 character sequence.</summary>
+    /// <param name="source">The reference to a null-terminated UTF8 character sequence.</param>
+    /// <param name="maxLength">The maxmimum length of <paramref name="source" /> or <c>-1</c> if the maximum length is unknown.</param>
+    /// <returns>A span that starts at <paramref name="source" /> and extends to <paramref name="maxLength" /> or the first null character, whichever comes first.</returns>
+    [MethodImpl(MethodImplOptions.AggressiveInlining)]
+    public static ReadOnlySpan<sbyte> GetUtf8Span(in sbyte source, int maxLength = -1)
+    {
+        ReadOnlySpan<sbyte> result;
+
+        if (!IsNullRef(in source))
+        {
+            if (maxLength < 0)
+            {
+                maxLength = int.MaxValue;
+            }
+
+            result = CreateReadOnlySpan(in source, maxLength);
+            var length = result.IndexOf((sbyte)'\0');
+
+            if (length != -1)
+            {
+                result = result.Slice(0, length);
+            }
+        }
+        else
+        {
+            result = null;
+        }
+
+        return result;
+    }
+
+    /// <summary>Gets a null-terminated sequence of UTF16 characters for a string.</summary>
+    /// <param name="source">The string for which to get the null-terminated UTF16 character sequence.</param>
+    /// <returns>A null-terminated UTF16 character sequence created from <paramref name="source" />.</returns>
+    [MethodImpl(MethodImplOptions.AggressiveInlining)]
+    public static ReadOnlySpan<ushort> GetUtf16Span(this string? source) => source.AsSpan().As<char, ushort>();
+
+    /// <summary>Marshals a null-terminated UTF16 string to a <see cref="ReadOnlySpan{UInt16}" />.</summary>
+    /// <param name="source">The pointer to a null-terminated UTF16 string.</param>
+    /// <param name="maxLength">The maxmimum length of <paramref name="source" /> or <c>-1</c> if the maximum length is unknown.</param>
+    /// <returns>A <see cref="ReadOnlySpan{UInt16}" /> that starts at <paramref name="source" /> and extends to <paramref name="maxLength" /> or the first null character, whichever comes first.</returns>
+    [MethodImpl(MethodImplOptions.AggressiveInlining)]
+    public static ReadOnlySpan<ushort> GetUtf16Span(ushort* source, int maxLength = -1)
+        => (source != null) ? GetUtf16Span(in source[0], maxLength) : null;
+
+    /// <summary>Marshals a null-terminated UTF16 string to a <see cref="ReadOnlySpan{UInt16}" />.</summary>
+    /// <param name="source">The reference to a null-terminated UTF16 string.</param>
+    /// <param name="maxLength">The maxmimum length of <paramref name="source" /> or <c>-1</c> if the maximum length is unknown.</param>
+    /// <returns>A <see cref="ReadOnlySpan{UInt16}" /> that starts at <paramref name="source" /> and extends to <paramref name="maxLength" /> or the first null character, whichever comes first.</returns>
+    [MethodImpl(MethodImplOptions.AggressiveInlining)]
+    public static ReadOnlySpan<ushort> GetUtf16Span(in ushort source, int maxLength = -1)
+    {
+        ReadOnlySpan<ushort> result;
+
+        if (!IsNullRef(in source))
+        {
+            if (maxLength < 0)
+            {
+                maxLength = int.MaxValue;
+            }
+
+            result = CreateReadOnlySpan(in source, maxLength);
+            var length = result.IndexOf('\0');
+
+            if (length != -1)
+            {
+                result = result.Slice(0, length);
+            }
+        }
+        else
+        {
+            result = null;
+        }
+
+        return result;
+    }
+
+    /// <summary>Gets a string for a given span.</summary>
+    /// <param name="span">The span for which to create the string.</param>
+    /// <returns>A string created from <paramref name="span" />.</returns>
+    [MethodImpl(MethodImplOptions.AggressiveInlining)]
+    public static string? GetString(this ReadOnlySpan<ushort> span)
+    {
+        if (span.GetPointer() == null)
+            return null;
+
+#if NET6_0_OR_GREATER
+        return new string(span.As<ushort, char>());
+#else
+        return new string(span.As<ushort, char>().GetPointer(), 0, span.Length);
+#endif
+    }
+
+    /// <summary>Gets a string for a given span.</summary>
+    /// <param name="span">The span for which to create the string.</param>
+    /// <returns>A string created from <paramref name="span" />.</returns>
+    [MethodImpl(MethodImplOptions.AggressiveInlining)]
+    public static string? GetString(this ReadOnlySpan<sbyte> span)
+    {
+        if (span.GetPointer() == null)
+            return null;
+
+#if NET6_0_OR_GREATER
+        return Encoding.UTF8.GetString(span.As<sbyte, byte>());
+#else
+        return Encoding.UTF8.GetString(span.As<sbyte, byte>().GetPointer(), span.Length);
+#endif
+    }
+}
diff --git a/src/Vortice.Win32/UnsafeUtilities.cs b/src/Vortice.Win32/UnsafeUtilities.cs
new file mode 100644
index 0000000..85f40c3
--- /dev/null
+++ b/src/Vortice.Win32/UnsafeUtilities.cs
@@ -0,0 +1,171 @@
+// Copyright © Tanner Gooding and Contributors. Licensed under the MIT License (MIT). See License.md in the repository root for more information.
+// Copyright © Amer Koleci and Contributors.
+// Licensed under the MIT License (MIT). See LICENSE in the repository root for more information.
+
+using System.Diagnostics.CodeAnalysis;
+using System.Runtime.CompilerServices;
+
+#if !NET6_0_OR_GREATER
+using MemoryMarshal = Win32.MemoryMarshal;
+#endif
+
+namespace Win32;
+
+/// <summary>Provides a set of methods to supplement or replace <see cref="Unsafe" /> and <see cref="MemoryMarshal" />.</summary>
+public static unsafe class UnsafeUtilities
+{
+    /// <inheritdoc cref="Unsafe.As{T}(object)" />
+    [MethodImpl(MethodImplOptions.AggressiveInlining)]
+#if NET6_0_OR_GREATER
+    [return: NotNullIfNotNull("o")]
+#endif
+    public static T? As<T>(this object? o)
+        where T : class?
+    {
+        //Assert(o is null or T);
+        return Unsafe.As<T>(o);
+    }
+
+    /// <inheritdoc cref="Unsafe.As{TFrom, TTo}(ref TFrom)" />
+    [MethodImpl(MethodImplOptions.AggressiveInlining)]
+    public static ref TTo As<TFrom, TTo>(ref TFrom source)
+        => ref Unsafe.As<TFrom, TTo>(ref source);
+
+    /// <inheritdoc cref="Unsafe.As{TFrom, TTo}(ref TFrom)" />
+    [MethodImpl(MethodImplOptions.AggressiveInlining)]
+    public static Span<TTo> As<TFrom, TTo>(this Span<TFrom> span)
+        where TFrom : unmanaged
+        where TTo : unmanaged
+    {
+        //Assert(AssertionsEnabled && (SizeOf<TFrom>() == SizeOf<TTo>()));
+        return CreateSpan(ref As<TFrom, TTo>(ref span.GetReference()), span.Length);
+    }
+
+    /// <inheritdoc cref="Unsafe.As{TFrom, TTo}(ref TFrom)" />
+    [MethodImpl(MethodImplOptions.AggressiveInlining)]
+    public static ReadOnlySpan<TTo> As<TFrom, TTo>(this ReadOnlySpan<TFrom> span)
+        where TFrom : unmanaged
+        where TTo : unmanaged
+    {
+        //Assert(AssertionsEnabled && (SizeOf<TFrom>() == SizeOf<TTo>()));
+        return CreateReadOnlySpan(in AsReadOnly<TFrom, TTo>(in span.GetReference()), span.Length);
+    }
+
+    /// <summary>Reinterprets the given native integer as a reference.</summary>
+    /// <typeparam name="T">The type of the reference.</typeparam>
+    /// <param name="source">The native integer to reinterpret.</param>
+    /// <returns>A reference to a value of type <typeparamref name="T" />.</returns>
+    [MethodImpl(MethodImplOptions.AggressiveInlining)]
+    public static ref T AsRef<T>(nint source) => ref Unsafe.AsRef<T>((void*)source);
+
+    /// <summary>Reinterprets the given native unsigned integer as a reference.</summary>
+    /// <typeparam name="T">The type of the reference.</typeparam>
+    /// <param name="source">The native unsigned integer to reinterpret.</param>
+    /// <returns>A reference to a value of type <typeparamref name="T" />.</returns>
+    [MethodImpl(MethodImplOptions.AggressiveInlining)]
+    public static ref T AsRef<T>(nuint source) => ref Unsafe.AsRef<T>((void*)source);
+
+    /// <inheritdoc cref="Unsafe.AsRef{T}(in T)" />
+    [MethodImpl(MethodImplOptions.AggressiveInlining)]
+    public static ref T AsRef<T>(in T source) => ref Unsafe.AsRef(in source);
+
+    /// <inheritdoc cref="Unsafe.AsRef{T}(in T)" />
+    [MethodImpl(MethodImplOptions.AggressiveInlining)]
+    public static ref TTo AsRef<TFrom, TTo>(in TFrom source)
+    {
+        ref var mutable = ref AsRef(in source);
+        return ref As<TFrom, TTo>(ref mutable);
+    }
+
+    /// <inheritdoc cref="Unsafe.AsPointer{T}(ref T)" />
+    [MethodImpl(MethodImplOptions.AggressiveInlining)]
+    public static T* AsPointer<T>(ref T source)
+        where T : unmanaged => (T*)Unsafe.AsPointer(ref source);
+
+    /// <inheritdoc cref="Unsafe.As{TFrom, TTo}(ref TFrom)" />
+    [MethodImpl(MethodImplOptions.AggressiveInlining)]
+    public static ref readonly TTo AsReadOnly<TFrom, TTo>(in TFrom source)
+        => ref Unsafe.As<TFrom, TTo>(ref AsRef(in source));
+
+    /// <inheritdoc cref="Unsafe.AsPointer{T}(ref T)" />
+    [MethodImpl(MethodImplOptions.AggressiveInlining)]
+    public static T* AsReadOnlyPointer<T>(in T source)
+        where T : unmanaged => AsPointer(ref AsRef(in source));
+
+    /// <inheritdoc cref="Unsafe.AsRef{T}(void*)" />
+    [MethodImpl(MethodImplOptions.AggressiveInlining)]
+    public static ref T AsRef<T>(void* source) => ref Unsafe.AsRef<T>(source);
+
+    /// <inheritdoc cref="MemoryMarshal.GetArrayDataReference{T}(T[])" />
+    [MethodImpl(MethodImplOptions.AggressiveInlining)]
+    public static ref T GetReference<T>(this T[] array) => ref MemoryMarshal.GetArrayDataReference(array);
+
+    /// <inheritdoc cref="MemoryMarshal.GetArrayDataReference{T}(T[])" />
+    [MethodImpl(MethodImplOptions.AggressiveInlining)]
+    public static ref T GetReference<T>(this T[] array, int index) => ref Unsafe.Add(ref array.GetReference(), index);
+
+    /// <inheritdoc cref="MemoryMarshal.GetArrayDataReference{T}(T[])" />
+    [MethodImpl(MethodImplOptions.AggressiveInlining)]
+    public static ref T GetReference<T>(this T[] array, nuint index) => ref Unsafe.Add(ref array.GetReference(), index);
+
+    /// <inheritdoc cref="MemoryMarshal.GetReference{T}(Span{T})" />
+    [MethodImpl(MethodImplOptions.AggressiveInlining)]
+    public static ref T GetReference<T>(this Span<T> span) => ref MemoryMarshal.GetReference(span);
+
+    /// <inheritdoc cref="MemoryMarshal.GetReference{T}(Span{T})" />
+    [MethodImpl(MethodImplOptions.AggressiveInlining)]
+    public static ref T GetReference<T>(this Span<T> span, int index) => ref Unsafe.Add(ref MemoryMarshal.GetReference(span), index);
+
+    /// <inheritdoc cref="MemoryMarshal.GetReference{T}(Span{T})" />
+    [MethodImpl(MethodImplOptions.AggressiveInlining)]
+    public static ref T GetReference<T>(this Span<T> span, nuint index) => ref Unsafe.Add(ref MemoryMarshal.GetReference(span), index);
+
+    /// <inheritdoc cref="MemoryMarshal.GetReference{T}(ReadOnlySpan{T})" />
+    [MethodImpl(MethodImplOptions.AggressiveInlining)]
+    public static ref readonly T GetReference<T>(this ReadOnlySpan<T> span) => ref MemoryMarshal.GetReference(span);
+
+    /// <inheritdoc cref="MemoryMarshal.GetReference{T}(ReadOnlySpan{T})" />
+    [MethodImpl(MethodImplOptions.AggressiveInlining)]
+    public static ref readonly T GetReference<T>(this ReadOnlySpan<T> span, int index) => ref Unsafe.Add(ref MemoryMarshal.GetReference(span), index);
+
+    /// <inheritdoc cref="MemoryMarshal.GetReference{T}(ReadOnlySpan{T})" />
+    [MethodImpl(MethodImplOptions.AggressiveInlining)]
+    public static ref readonly T GetReference<T>(this ReadOnlySpan<T> span, nuint index) => ref Unsafe.Add(ref MemoryMarshal.GetReference(span), index);
+
+    /// <summary>Determines if a given reference to a value of type <typeparamref name="T" /> is not a null reference.</summary>
+    /// <typeparam name="T">The type of the reference</typeparam>
+    /// <param name="source">The reference to check.</param>
+    /// <returns><c>true</c> if <paramref name="source" /> is not a null reference; otherwise, <c>false</c>.</returns>
+    [MethodImpl(MethodImplOptions.AggressiveInlining)]
+    public static bool IsNotNullRef<T>(in T source) => !IsNullRef(in source);
+
+    /// <inheritdoc cref="Unsafe.IsNullRef{T}(ref T)" />
+    [MethodImpl(MethodImplOptions.AggressiveInlining)]
+    public static bool IsNullRef<T>(in T source) => Unsafe.IsNullRef(ref AsRef(in source));
+
+    /// <inheritdoc cref="Unsafe.NullRef{T}" />
+    [MethodImpl(MethodImplOptions.AggressiveInlining)]
+    public static ref T NullRef<T>() => ref Unsafe.NullRef<T>();
+
+    /// <inheritdoc cref="MemoryMarshal.CreateSpan{T}(ref T, int)" />
+    public static Span<T> CreateSpan<T>(ref T reference, int length) => MemoryMarshal.CreateSpan(ref reference, length);
+
+    /// <inheritdoc cref="MemoryMarshal.CreateReadOnlySpan{T}(ref T, int)" />
+    public static ReadOnlySpan<T> CreateReadOnlySpan<T>(in T reference, int length) => MemoryMarshal.CreateReadOnlySpan(ref AsRef(in reference), length);
+
+    /// <summary>Returns a pointer to the element of the span at index zero.</summary>
+    /// <typeparam name="T">The type of items in <paramref name="span" />.</typeparam>
+    /// <param name="span">The span from which the pointer is retrieved.</param>
+    /// <returns>A pointer to the item at index zero of <paramref name="span" />.</returns>
+    [MethodImpl(MethodImplOptions.AggressiveInlining)]
+    public static T* GetPointer<T>(this Span<T> span)
+        where T : unmanaged => AsPointer(ref span.GetReference());
+
+    /// <summary>Returns a pointer to the element of the span at index zero.</summary>
+    /// <typeparam name="T">The type of items in <paramref name="span" />.</typeparam>
+    /// <param name="span">The span from which the pointer is retrieved.</param>
+    /// <returns>A pointer to the item at index zero of <paramref name="span" />.</returns>
+    [MethodImpl(MethodImplOptions.AggressiveInlining)]
+    public static T* GetPointer<T>(this ReadOnlySpan<T> span)
+        where T : unmanaged => AsPointer(ref AsRef(in span.GetReference()));
+}
diff --git a/src/samples/01-ClearScreen/Program.cs b/src/samples/01-ClearScreen/Program.cs
index c2c9401..8a83346 100644
--- a/src/samples/01-ClearScreen/Program.cs
+++ b/src/samples/01-ClearScreen/Program.cs
@@ -12,6 +12,9 @@ public static unsafe class Program
 {
     public static void Main()
     {
+        string test = StringUtilities.GetString(new sbyte[] { (sbyte)'A', (sbyte)'B', (sbyte)'C' });
+        test = StringUtilities.GetString(new ushort[] { 'A', 'B', 'C' });
+
         using ComPtr<IDXGIFactory1> factory = default;
         HResult hr = CreateDXGIFactory1(__uuidof<IDXGIFactory4>(), (void**)&factory);
 
@@ -24,15 +27,34 @@ public static unsafe class Program
         }
 
         using ComPtr<IDXGIAdapter1> adapter = default;
+
+        using ComPtr<IDXGIFactory6> factory6 = default;
+        if (factory.CopyTo(&factory6).Success)
+        {
+            for (uint adapterIndex = 0;
+                factory6.Get()->EnumAdapterByGpuPreference(
+                    adapterIndex,
+                    GpuPreference.HighPerformance,
+                    __uuidof<IDXGIAdapter1>(),
+                    (void**)adapter.ReleaseAndGetAddressOf()).Success;
+                adapterIndex++)
+            {
+                AdapterDescription1 desc = default;
+                adapter.Get()->GetDesc1(&desc);
+
+                string name = desc.DescriptionStr;
+            }
+        }
+
         for (uint adapterIndex = 0;
             factory.Get()->EnumAdapters1(adapterIndex, adapter.ReleaseAndGetAddressOf()).Success;
             adapterIndex++)
         {
             AdapterDescription1 desc = default;
             adapter.Get()->GetDesc1(&desc);
+
+            string name = desc.DescriptionStr;
         }
-
-
     }
 
     [DllImport("dxgi", ExactSpelling = true)]