Add signed ViGEmBus virtual-joystick support (Xbox 360)

Replace the test-signed RioGamepad driver as the default joystick output with a
ViGEmBus virtual Xbox 360 controller (Nefarius.ViGEm.Client) — properly signed,
so it installs with no test-signing / Secure Boot change / reboot.

The coordinator now selects ViGEm first, then the RioGamepad HID feeder, then a
no-op. The XInput layout caps joystick buttons at 11, so the editor's joystick
picker lists the named Xbox buttons (A, B, X, Y, LB, RB, Back, Start, L3, R3,
Guide); the hat maps to the D-pad and the six axes to the sticks + triggers.
Bind anything beyond 11 to the keyboard.

Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>

src/RioJoy.Core/Output/ViGEmJoystickSink.cs

@@ -0,0 +1,129 @@
+using System.Runtime.Versioning;
+using Nefarius.ViGEm.Client;
+using Nefarius.ViGEm.Client.Targets;
+using Nefarius.ViGEm.Client.Targets.Xbox360;
+using RioJoy.Core.Calibration;
+using RioJoy.Core.Mapping;
+
+namespace RioJoy.Core.Output;
+
+/// <summary>
+/// <see cref="IJoystickSink"/> backed by a <b>signed ViGEmBus</b> virtual Xbox 360
+/// controller. Properly signed — installs with no test-signing / Secure-Boot
+/// changes — at the cost of the XInput layout: 11 buttons, two sticks + two
+/// triggers, and the D-pad for the hat. RIO joystick buttons beyond
+/// <see cref="MappableButtonCount"/> are dropped (map those to the keyboard).
+/// </summary>
+[SupportedOSPlatform("windows")]
+public sealed class ViGEmJoystickSink : IJoystickSink, IDisposable
+{
+    // RIO joystick button (1-based) -> Xbox 360 button, in a natural order.
+    private static readonly Xbox360Button[] ButtonMap =
+    {
+        Xbox360Button.A, Xbox360Button.B, Xbox360Button.X, Xbox360Button.Y,
+        Xbox360Button.LeftShoulder, Xbox360Button.RightShoulder,
+        Xbox360Button.Back, Xbox360Button.Start,
+        Xbox360Button.LeftThumb, Xbox360Button.RightThumb,
+        Xbox360Button.Guide,
+    };
+
+    /// <summary>Display names for the mappable buttons, aligned with <see cref="ButtonMap"/>.</summary>
+    public static IReadOnlyList<string> ButtonNames { get; } = new[]
+    {
+        "A", "B", "X", "Y", "LB", "RB", "Back", "Start", "L3", "R3", "Guide",
+    };
+
+    /// <summary>How many RIO joystick buttons map onto the Xbox 360 pad (11).</summary>
+    public static int MappableButtonCount => ButtonMap.Length;
+
+    private readonly ViGEmClient _client;
+    private readonly IXbox360Controller _pad;
+    private readonly object _gate = new();
+
+    private ViGEmJoystickSink(ViGEmClient client, IXbox360Controller pad)
+    {
+        _client = client;
+        _pad = pad;
+    }
+
+    /// <summary>
+    /// Try to connect to ViGEmBus and create a virtual Xbox 360 controller. Returns
+    /// <see langword="false"/> if ViGEmBus is not installed, so callers can fall back
+    /// to another joystick sink.
+    /// </summary>
+    public static bool TryCreate(out ViGEmJoystickSink? sink)
+    {
+        sink = null;
+        try
+        {
+            var client = new ViGEmClient();
+            IXbox360Controller pad = client.CreateXbox360Controller();
+            pad.AutoSubmitReport = false; // submit once per logical update
+            pad.Connect();
+            sink = new ViGEmJoystickSink(client, pad);
+            return true;
+        }
+        catch
+        {
+            // VigemBusNotFoundException (driver absent) or any connect failure.
+            return false;
+        }
+    }
+
+    public void SetButton(int button, bool pressed)
+    {
+        int index = button - 1; // RIO joystick buttons are 1-based
+        if (index < 0 || index >= ButtonMap.Length)
+            return; // beyond the Xbox 360 layout — bind these to the keyboard instead
+
+        lock (_gate)
+        {
+            _pad.SetButtonState(ButtonMap[index], pressed);
+            _pad.SubmitReport();
+        }
+    }
+
+    public void SetHat(RioHat position)
+    {
+        lock (_gate)
+        {
+            _pad.SetButtonState(Xbox360Button.Up, position == RioHat.Up);
+            _pad.SetButtonState(Xbox360Button.Right, position == RioHat.Right);
+            _pad.SetButtonState(Xbox360Button.Down, position == RioHat.Down);
+            _pad.SetButtonState(Xbox360Button.Left, position == RioHat.Left);
+            _pad.SubmitReport();
+        }
+    }
+
+    public void SetAxis(JoyAxis axis, int value)
+    {
+        lock (_gate)
+        {
+            switch (axis)
+            {
+                case JoyAxis.X: _pad.SetAxisValue(Xbox360Axis.LeftThumbX, ToThumb(value)); break;
+                case JoyAxis.Y: _pad.SetAxisValue(Xbox360Axis.LeftThumbY, ToThumb(value)); break;
+                case JoyAxis.Rx: _pad.SetAxisValue(Xbox360Axis.RightThumbX, ToThumb(value)); break;
+                case JoyAxis.Ry: _pad.SetAxisValue(Xbox360Axis.RightThumbY, ToThumb(value)); break;
+                case JoyAxis.Z: _pad.SetSliderValue(Xbox360Slider.LeftTrigger, ToTrigger(value)); break;
+                case JoyAxis.Rz: _pad.SetSliderValue(Xbox360Slider.RightTrigger, ToTrigger(value)); break;
+                default: return;
+            }
+            _pad.SubmitReport();
+        }
+    }
+
+    // RIO axis 0..32766 (centre 16383) -> Xbox thumb short -32768..32767.
+    private static short ToThumb(int value) =>
+        (short)Math.Clamp((value - AxisOutputs.Center) * 2, short.MinValue, short.MaxValue);
+
+    // RIO axis 0..32766 -> Xbox trigger byte 0..255.
+    private static byte ToTrigger(int value) =>
+        (byte)Math.Clamp(value * 255 / AxisOutputs.Max, 0, 255);
+
+    public void Dispose()
+    {
+        try { _pad.Disconnect(); } catch { /* already disconnected / bus gone */ }
+        _client.Dispose();
+    }
+}

src/RioJoy.Core/RioJoy.Core.csproj

@@ -11,6 +11,7 @@
   </PropertyGroup>
 
   <ItemGroup>
+    <PackageReference Include="Nefarius.ViGEm.Client" Version="1.21.256" />
     <PackageReference Include="System.IO.Ports" Version="8.0.0" />
   </ItemGroup>