Add parent GPU option

app/App.xaml.cs

@@ -29,6 +29,14 @@ namespace ParsecVDisplay
                 var modes = Display.ParseModes(e.Args[1]);
                 ParsecVDD.SetCustomDisplayModes(modes);
 
+                if (e.Args.Length >= 3)
+                {
+                    if (Enum.TryParse<ParsecVDD.ParentGPU>(e.Args[2], true, out var kind))
+                    {
+                        ParsecVDD.SetParentGPU(kind);
+                    }
+                }
+
                 Shutdown();
                 return;
             }

app/Components/CustomPage.xaml

@@ -77,6 +77,14 @@
                 <Label>Hz</Label>
             </StackPanel>
         </StackPanel>
+        <StackPanel Orientation="Horizontal" HorizontalAlignment="Left" VerticalAlignment="Bottom" Margin="25,0,0,25">
+            <TextBlock Text="Parent GPU:" FontSize="14" FontWeight="SemiBold" Foreground="White" VerticalAlignment="Center" />
+            <ComboBox x:Name="xParentGPU" Width="80" FontSize="14" SelectedIndex="0" BorderBrush="Transparent" Background="Transparent" Margin="10,0,0,0">
+                <ComboBoxItem Content="Auto" />
+                <ComboBoxItem Content="AMD" />
+                <ComboBoxItem Content="NVIDIA" />
+            </ComboBox>
+        </StackPanel>
         <StackPanel HorizontalAlignment="Right" VerticalAlignment="Bottom" Orientation="Horizontal" Margin="0,0,25,25">
             <local:Button Click="ApplyChanges" Width="120" Height="36" Foreground="White">
                 <local:Button.Children>

app/Components/CustomPage.xaml.cs

@@ -14,6 +14,12 @@ namespace ParsecVDisplay.Components
         public CustomPage()
         {
             InitializeComponent();
+
+            xParentGPU.Items.Clear();
+            foreach (var item in Enum.GetValues(typeof(ParsecVDD.ParentGPU)))
+            {
+                xParentGPU.Items.Add(item.ToString());
+            }
         }
 
         private void ApplyChanges(object sender, EventArgs e)
@@ -44,15 +50,19 @@ namespace ParsecVDisplay.Components
                 }
             }
 
-            if (modes.Count > 0)
+            ParsecVDD.ParentGPU parentGPU;
+            bool validParentGPU = Enum.TryParse(xParentGPU.SelectedValue.ToString(), true, out parentGPU);
+
+            if (modes.Count > 0 && validParentGPU)
             {
                 if (Helper.IsAdmin())
                 {
                     ParsecVDD.SetCustomDisplayModes(modes);
+                    ParsecVDD.SetParentGPU(parentGPU);
                 }
                 else
                 {
-                    var args = $"-custom \"{Display.DumpModes(modes)}\"";
+                    var args = $"-custom \"{Display.DumpModes(modes)}\" \"{parentGPU}\"";
                     if (Helper.RunAdminTask(args) == false)
                     {
                         MessageBox.Show("Could not set custom resolutions, access denied!",
@@ -77,6 +87,9 @@ namespace ParsecVDisplay.Components
                 TextBoxes[i + 1].Text = $"{modes[j].Height}";
                 TextBoxes[i + 2].Text = $"{modes[j].Hz}";
             }
+
+            var parentGPU = ParsecVDD.GetParentGPU();
+            xParentGPU.SelectedValue = parentGPU.ToString();
         }
 
         private void Page_Unloaded(object sender, RoutedEventArgs e)

app/ParsecVDD.cs

@@ -269,6 +269,54 @@ namespace ParsecVDisplay
             }
         }
 
+        public enum ParentGPU
+        {
+            Auto = 0,
+            NVIDIA = 0x10DE,
+            AMD = 0x1002,
+        }
+
+        public static ParentGPU GetParentGPU()
+        {
+            using (var parameters = Registry.LocalMachine.OpenSubKey(
+                "SOFTWARE\\Microsoft\\Windows NT\\CurrentVersion\\WUDF\\Services\\ParsecVDA\\Parameters",
+                RegistryKeyPermissionCheck.ReadSubTree))
+            {
+                if (parameters != null)
+                {
+                    object value = parameters.GetValue("PreferredRenderAdapterVendorId");
+                    if (value != null)
+                    {
+                        return (ParentGPU)Convert.ToInt32(value);
+                    }
+                }
+            }
+
+            return ParentGPU.Auto;
+        }
+
+        // Requires admin perm
+        public static void SetParentGPU(ParentGPU kind)
+        {
+            using (var parameters = Registry.LocalMachine.OpenSubKey(
+                "SOFTWARE\\Microsoft\\Windows NT\\CurrentVersion\\WUDF\\Services\\ParsecVDA\\Parameters",
+                RegistryKeyPermissionCheck.ReadWriteSubTree))
+            {
+                if (parameters != null)
+                {
+                    if (kind == ParentGPU.Auto)
+                    {
+                        parameters.DeleteValue("PreferredRenderAdapterVendorId", false);
+                    }
+                    else
+                    {
+                        parameters.SetValue("PreferredRenderAdapterVendorId",
+                            (uint)kind, RegistryValueKind.DWord);
+                    }
+                }
+            }
+        }
+
         static unsafe class Native
         {
             [DllImport("kernel32.dll")]

app/Properties/AssemblyInfo.cs

@@ -7,11 +7,11 @@ using System.Windows;
 // General Information about an assembly is controlled through the following
 // set of attributes. Change these attribute values to modify the information
 // associated with an assembly.
-[assembly: AssemblyTitle("ParsecVDisplay")]
+[assembly: AssemblyTitle(ParsecVDisplay.App.NAME)]
 [assembly: AssemblyDescription("")]
 [assembly: AssemblyConfiguration("")]
 [assembly: AssemblyCompany("")]
-[assembly: AssemblyProduct("ParsecVDisplay")]
+[assembly: AssemblyProduct(ParsecVDisplay.App.NAME)]
 [assembly: AssemblyCopyright("Copyright ©  2024")]
 [assembly: AssemblyTrademark("")]
 [assembly: AssemblyCulture("")]