Add Silk.NET.Input handling and hit-testing

UIX.RenderApi.OpenGL/Engine/GLInputSystem.cs

@@ -1,13 +1,22 @@
+using Microsoft.Iris.Input;
+
 namespace Microsoft.Iris.Render.OpenGL
 {
     /// <summary>
-    /// Holds the current raw-input callback sink. The window (see <see cref="GLRenderWindow"/>)
-    /// translates Silk.NET input events and dispatches them here.
+    /// Holds the current raw-input callback sink and mouse-capture site. The input
+    /// translator (see <see cref="GLInputTranslator"/>) reads <see cref="Callbacks"/>
+    /// each event and dispatches translated Silk.NET input to it.
     /// </summary>
     public sealed class GLInputSystem : IInputSystem
     {
         public IRawInputCallbacks? Callbacks { get; private set; }
 
+        /// <summary>
+        /// The visual that has grabbed the mouse via <see cref="IRenderWindow.SetCapture"/>,
+        /// or null. When set, mouse events are routed to it regardless of hit-testing.
+        /// </summary>
+        public IRawInputSite? CaptureSite { get; set; }
+
         public void RegisterRawInputCallbacks(IRawInputCallbacks handlers) => Callbacks = handlers;
 
         public void UnregisterRawInputCallbacks() => Callbacks = null;

UIX.RenderApi.OpenGL/Engine/GLInputTranslator.cs

@@ -0,0 +1,326 @@
+using System;
+using System.Collections.Generic;
+using Microsoft.Iris.Input;
+using Silk.NET.Input;
+using SilkKey = Silk.NET.Input.Key;
+using SilkMouseButton = Silk.NET.Input.MouseButton;
+
+namespace Microsoft.Iris.Render.OpenGL
+{
+    /// <summary>
+    /// Translates Silk.NET.Input keyboard/mouse events into the render API's raw-input
+    /// protocol (<see cref="IRawInputCallbacks"/>). Message identifiers match what the
+    /// UIX <c>InputManager</c> expects: keyboard uses the <see cref="KeyboardMessageId"/>
+    /// ordinals, mouse uses Win32 <c>WM_*</c> codes.
+    /// </summary>
+    public sealed class GLInputTranslator : IDisposable
+    {
+        // Win32 mouse messages (the values MouseDevice.OnRawInput switches on).
+        private const uint WM_MOUSEMOVE = 0x0200;
+        private const uint WM_LBUTTONDOWN = 0x0201, WM_LBUTTONUP = 0x0202, WM_LBUTTONDBLCLK = 0x0203;
+        private const uint WM_RBUTTONDOWN = 0x0204, WM_RBUTTONUP = 0x0205, WM_RBUTTONDBLCLK = 0x0206;
+        private const uint WM_MBUTTONDOWN = 0x0207, WM_MBUTTONUP = 0x0208, WM_MBUTTONDBLCLK = 0x0209;
+        private const uint WM_MOUSEWHEEL = 0x020A;
+        private const uint WM_XBUTTONDOWN = 0x020B, WM_XBUTTONUP = 0x020C, WM_XBUTTONDBLCLK = 0x020D;
+
+        private readonly IInputContext m_context;
+        private readonly GLInputSystem m_input;
+        private readonly GLRenderWindow m_window;
+
+        // Per-key repeat counters so RawKeyboardData._repCount reflects auto-repeat,
+        // which the InputManager uses for key coalescing.
+        private readonly Dictionary<SilkKey, uint> m_repeat = new Dictionary<SilkKey, uint>();
+
+        public GLInputTranslator(IInputContext context, GLInputSystem input, GLRenderWindow window)
+        {
+            m_context = context;
+            m_input = input;
+            m_window = window;
+
+            foreach (IKeyboard keyboard in context.Keyboards)
+                Hook(keyboard);
+            foreach (IMouse mouse in context.Mice)
+                Hook(mouse);
+
+            context.ConnectionChanged += OnConnectionChanged;
+        }
+
+        private void OnConnectionChanged(IInputDevice device, bool connected)
+        {
+            if (!connected)
+                return;
+            if (device is IKeyboard keyboard)
+                Hook(keyboard);
+            else if (device is IMouse mouse)
+                Hook(mouse);
+        }
+
+        private void Hook(IKeyboard keyboard)
+        {
+            keyboard.KeyDown += OnKeyDown;
+            keyboard.KeyUp += OnKeyUp;
+            keyboard.KeyChar += OnKeyChar;
+        }
+
+        private void Hook(IMouse mouse)
+        {
+            mouse.MouseMove += OnMouseMove;
+            mouse.MouseDown += OnMouseDown;
+            mouse.MouseUp += OnMouseUp;
+            mouse.Scroll += OnScroll;
+            mouse.DoubleClick += OnDoubleClick;
+        }
+
+        // ---- Keyboard ------------------------------------------------------------
+        private void OnKeyDown(IKeyboard keyboard, SilkKey key, int scanCode)
+        {
+            IRawInputCallbacks? cb = m_input.Callbacks;
+            if (cb == null)
+                return;
+
+            uint repeat = m_repeat.TryGetValue(key, out uint prev) ? prev + 1 : 1;
+            m_repeat[key] = repeat;
+
+            bool system = IsAltDown();
+            uint message = (uint)(system ? KeyboardMessageId.SysDown : KeyboardMessageId.Down);
+            var data = new RawKeyboardData(MapKey(key), scanCode, repeat, 0, InputDeviceType.Keyboard);
+            cb.HandleRawKeyboardInput(message, ComputeModifiers(), ref data);
+        }
+
+        private void OnKeyUp(IKeyboard keyboard, SilkKey key, int scanCode)
+        {
+            m_repeat.Remove(key);
+
+            IRawInputCallbacks? cb = m_input.Callbacks;
+            if (cb == null)
+                return;
+
+            bool system = IsAltDown();
+            uint message = (uint)(system ? KeyboardMessageId.SysUp : KeyboardMessageId.Up);
+            var data = new RawKeyboardData(MapKey(key), scanCode, 1, 0, InputDeviceType.Keyboard);
+            cb.HandleRawKeyboardInput(message, ComputeModifiers(), ref data);
+        }
+
+        private void OnKeyChar(IKeyboard keyboard, char character)
+        {
+            IRawInputCallbacks? cb = m_input.Callbacks;
+            if (cb == null)
+                return;
+
+            bool system = IsAltDown();
+            uint message = (uint)(system ? KeyboardMessageId.SysChar : KeyboardMessageId.Char);
+            // Character messages carry the char in _virtualKey (see KeyboardDevice.OnRawKeyCharacter).
+            var data = new RawKeyboardData((Keys)character, 0, 1, 0, InputDeviceType.Keyboard);
+            cb.HandleRawKeyboardInput(message, ComputeModifiers(), ref data);
+        }
+
+        // ---- Mouse ---------------------------------------------------------------
+        private void OnMouseMove(IMouse mouse, System.Numerics.Vector2 position)
+            => DispatchMouse(mouse, WM_MOUSEMOVE, MouseButtons.None, 0);
+
+        private void OnMouseDown(IMouse mouse, SilkMouseButton button)
+        {
+            (uint message, MouseButtons iris) = button switch
+            {
+                SilkMouseButton.Left => (WM_LBUTTONDOWN, MouseButtons.Left),
+                SilkMouseButton.Right => (WM_RBUTTONDOWN, MouseButtons.Right),
+                SilkMouseButton.Middle => (WM_MBUTTONDOWN, MouseButtons.Middle),
+                SilkMouseButton.Button4 => (WM_XBUTTONDOWN, MouseButtons.XButton1),
+                SilkMouseButton.Button5 => (WM_XBUTTONDOWN, MouseButtons.XButton2),
+                _ => (0u, MouseButtons.None),
+            };
+            if (message != 0)
+                DispatchMouse(mouse, message, iris, 0);
+        }
+
+        private void OnMouseUp(IMouse mouse, SilkMouseButton button)
+        {
+            (uint message, MouseButtons iris) = button switch
+            {
+                SilkMouseButton.Left => (WM_LBUTTONUP, MouseButtons.Left),
+                SilkMouseButton.Right => (WM_RBUTTONUP, MouseButtons.Right),
+                SilkMouseButton.Middle => (WM_MBUTTONUP, MouseButtons.Middle),
+                SilkMouseButton.Button4 => (WM_XBUTTONUP, MouseButtons.XButton1),
+                SilkMouseButton.Button5 => (WM_XBUTTONUP, MouseButtons.XButton2),
+                _ => (0u, MouseButtons.None),
+            };
+            if (message != 0)
+                DispatchMouse(mouse, message, iris, 0);
+        }
+
+        private void OnDoubleClick(IMouse mouse, SilkMouseButton button, System.Numerics.Vector2 position)
+        {
+            (uint message, MouseButtons iris) = button switch
+            {
+                SilkMouseButton.Left => (WM_LBUTTONDBLCLK, MouseButtons.Left),
+                SilkMouseButton.Right => (WM_RBUTTONDBLCLK, MouseButtons.Right),
+                SilkMouseButton.Middle => (WM_MBUTTONDBLCLK, MouseButtons.Middle),
+                SilkMouseButton.Button4 => (WM_XBUTTONDBLCLK, MouseButtons.XButton1),
+                SilkMouseButton.Button5 => (WM_XBUTTONDBLCLK, MouseButtons.XButton2),
+                _ => (0u, MouseButtons.None),
+            };
+            if (message != 0)
+                DispatchMouse(mouse, message, iris, 0, doubleClick: true);
+        }
+
+        private void OnScroll(IMouse mouse, ScrollWheel wheel)
+            => DispatchMouse(mouse, WM_MOUSEWHEEL, MouseButtons.None, (int)(wheel.Y * 120f));
+
+        private void DispatchMouse(IMouse mouse, uint message, MouseButtons button, int wheelDelta, bool doubleClick = false)
+        {
+            IRawInputCallbacks? cb = m_input.Callbacks;
+            if (cb == null)
+                return;
+
+            System.Numerics.Vector2 pos = mouse.Position;
+            int clientX = (int)pos.X;
+            int clientY = (int)pos.Y;
+
+            IVisual? natural = m_window.HitTest(new Silk.NET.Maths.Vector2D<float>(pos.X, pos.Y));
+            IVisual? capture = m_input.CaptureSite as IVisual ?? natural;
+
+            var data = new RawMouseData(
+                visCapture: capture!,
+                visNatural: natural!,
+                positionX: clientX,
+                positionY: clientY,
+                naturalX: clientX,
+                naturalY: clientY,
+                physicalX: clientX,
+                physicalY: clientY,
+                screenX: clientX + m_window.Left,
+                screenY: clientY + m_window.Top,
+                button: button,
+                wheelDelta: wheelDelta);
+
+            InputModifiers modifiers = ComputeModifiers(mouse);
+            if (doubleClick)
+                modifiers |= InputModifiers.DoubleClick;
+
+            cb.HandleRawMouseInput(message, modifiers, ref data);
+        }
+
+        // ---- Modifiers -----------------------------------------------------------
+        private bool IsAltDown()
+        {
+            foreach (IKeyboard k in m_context.Keyboards)
+            {
+                if (k.IsKeyPressed(SilkKey.AltLeft) || k.IsKeyPressed(SilkKey.AltRight))
+                    return true;
+            }
+            return false;
+        }
+
+        private InputModifiers ComputeModifiers(IMouse? mouse = null)
+        {
+            InputModifiers m = InputModifiers.None;
+            foreach (IKeyboard k in m_context.Keyboards)
+            {
+                if (k.IsKeyPressed(SilkKey.ControlLeft) || k.IsKeyPressed(SilkKey.ControlRight)) m |= InputModifiers.ControlKey;
+                if (k.IsKeyPressed(SilkKey.ShiftLeft) || k.IsKeyPressed(SilkKey.ShiftRight)) m |= InputModifiers.ShiftKey;
+                if (k.IsKeyPressed(SilkKey.AltLeft) || k.IsKeyPressed(SilkKey.AltRight)) m |= InputModifiers.AltKey;
+                if (k.IsKeyPressed(SilkKey.SuperLeft) || k.IsKeyPressed(SilkKey.SuperRight)) m |= InputModifiers.WindowsKey;
+            }
+
+            mouse ??= FirstMouse();
+            if (mouse != null)
+            {
+                if (mouse.IsButtonPressed(SilkMouseButton.Left)) m |= InputModifiers.LeftMouse;
+                if (mouse.IsButtonPressed(SilkMouseButton.Right)) m |= InputModifiers.RightMouse;
+                if (mouse.IsButtonPressed(SilkMouseButton.Middle)) m |= InputModifiers.MiddleMouse;
+                if (mouse.IsButtonPressed(SilkMouseButton.Button4)) m |= InputModifiers.XMouse1;
+                if (mouse.IsButtonPressed(SilkMouseButton.Button5)) m |= InputModifiers.XMouse2;
+            }
+            return m;
+        }
+
+        private IMouse? FirstMouse()
+        {
+            foreach (IMouse mouse in m_context.Mice)
+                return mouse;
+            return null;
+        }
+
+        public void Dispose()
+        {
+            m_context.ConnectionChanged -= OnConnectionChanged;
+            foreach (IKeyboard keyboard in m_context.Keyboards)
+            {
+                keyboard.KeyDown -= OnKeyDown;
+                keyboard.KeyUp -= OnKeyUp;
+                keyboard.KeyChar -= OnKeyChar;
+            }
+            foreach (IMouse mouse in m_context.Mice)
+            {
+                mouse.MouseMove -= OnMouseMove;
+                mouse.MouseDown -= OnMouseDown;
+                mouse.MouseUp -= OnMouseUp;
+                mouse.Scroll -= OnScroll;
+                mouse.DoubleClick -= OnDoubleClick;
+            }
+            m_context.Dispose();
+        }
+
+        // ---- Key mapping (Silk.NET.Input.Key -> Win32 virtual key codes) ---------
+        private static Keys MapKey(SilkKey key) => key switch
+        {
+            >= SilkKey.A and <= SilkKey.Z => Keys.A + (key - SilkKey.A),
+            >= SilkKey.Number0 and <= SilkKey.Number9 => Keys.D0 + (key - SilkKey.Number0),
+            >= SilkKey.Keypad0 and <= SilkKey.Keypad9 => Keys.NumPad0 + (key - SilkKey.Keypad0),
+            >= SilkKey.F1 and <= SilkKey.F24 => Keys.F1 + (key - SilkKey.F1),
+
+            SilkKey.Space => Keys.Space,
+            SilkKey.Enter => Keys.Return,
+            SilkKey.KeypadEnter => Keys.Return,
+            SilkKey.Escape => Keys.Escape,
+            SilkKey.Tab => Keys.Tab,
+            SilkKey.Backspace => Keys.Back,
+            SilkKey.Insert => Keys.Insert,
+            SilkKey.Delete => Keys.Delete,
+            SilkKey.Home => Keys.Home,
+            SilkKey.End => Keys.End,
+            SilkKey.PageUp => Keys.PageUp,
+            SilkKey.PageDown => Keys.PageDown,
+            SilkKey.Left => Keys.Left,
+            SilkKey.Right => Keys.Right,
+            SilkKey.Up => Keys.Up,
+            SilkKey.Down => Keys.Down,
+
+            SilkKey.CapsLock => Keys.CapsLock,
+            SilkKey.NumLock => Keys.NumLock,
+            SilkKey.ScrollLock => Keys.Scroll,
+            SilkKey.PrintScreen => Keys.PrintScreen,
+            SilkKey.Pause => Keys.Pause,
+            SilkKey.Menu => Keys.Apps,
+
+            SilkKey.ShiftLeft => Keys.LShiftKey,
+            SilkKey.ShiftRight => Keys.RShiftKey,
+            SilkKey.ControlLeft => Keys.LControlKey,
+            SilkKey.ControlRight => Keys.RControlKey,
+            SilkKey.AltLeft => Keys.LMenu,
+            SilkKey.AltRight => Keys.RMenu,
+            SilkKey.SuperLeft => Keys.LWin,
+            SilkKey.SuperRight => Keys.RWin,
+
+            SilkKey.KeypadDivide => Keys.Divide,
+            SilkKey.KeypadMultiply => Keys.Multiply,
+            SilkKey.KeypadSubtract => Keys.Subtract,
+            SilkKey.KeypadAdd => Keys.Add,
+            SilkKey.KeypadDecimal => Keys.Decimal,
+
+            SilkKey.Semicolon => Keys.OemSemicolon,
+            SilkKey.Equal => Keys.OemPlus,
+            SilkKey.Comma => Keys.OemComma,
+            SilkKey.Minus => Keys.OemMinus,
+            SilkKey.Period => Keys.OemPeriod,
+            SilkKey.Slash => Keys.OemQuestion,
+            SilkKey.GraveAccent => Keys.OemTilde,
+            SilkKey.LeftBracket => Keys.OemOpenBrackets,
+            SilkKey.BackSlash => Keys.OemPipe,
+            SilkKey.RightBracket => Keys.OemCloseBrackets,
+            SilkKey.Apostrophe => Keys.OemQuotes,
+
+            _ => Keys.None,
+        };
+    }
+}

UIX.RenderApi.OpenGL/Engine/GLRenderEngine.cs

@@ -1,5 +1,6 @@
 using System;
 using System.Threading;
+using Silk.NET.Input;
 using Silk.NET.Maths;
 using Silk.NET.OpenGL;
 using Silk.NET.Windowing;
@@ -23,6 +24,8 @@ namespace Microsoft.Iris.Render.OpenGL
         private GL? m_gl;
         private SceneRenderer? m_renderer;
         private GLDisplayManager? m_displayManager;
+        private IInputContext? m_inputContext;
+        private GLInputTranslator? m_inputTranslator;
 
         private GraphicsRenderingQuality m_quality;
         private SoundDeviceType m_soundType;
@@ -73,6 +76,10 @@ namespace Microsoft.Iris.Render.OpenGL
             m_displayManager = new GLDisplayManager(m_silkWindow);
             m_session.GraphicsDevice = new GLGraphicsDevice(m_gl, m_quality, RenderNow);
             m_session.SoundDevice = new GLSoundDevice(m_soundType);
+
+            m_inputContext = m_silkWindow.CreateInput();
+            m_inputTranslator = new GLInputTranslator(m_inputContext, (GLInputSystem)m_session.InputSystem, m_window);
+
             m_window.RaiseLoad();
         }
 
@@ -121,6 +128,7 @@ namespace Microsoft.Iris.Render.OpenGL
 
         public void Dispose()
         {
+            m_inputTranslator?.Dispose();
             m_renderer?.Dispose();
             m_session.Dispose();
             if (!m_silkWindow.IsClosing)

UIX.RenderApi.OpenGL/Engine/GLRenderWindow.cs

@@ -13,18 +13,24 @@ namespace Microsoft.Iris.Render.OpenGL
     public sealed class GLRenderWindow : IRenderWindow
     {
         private readonly SilkWindow m_window;
+        private readonly GLRenderSession m_session;
         private readonly GLVisualContainer m_root;
         private Size m_initialClientSize = new Size(1024, 768);
 
         public GLRenderWindow(SilkWindow window, GLRenderSession session)
         {
             m_window = window;
+            m_session = session;
             m_root = new GLVisualContainer(session, null!, isRoot: true);
             m_root.RegisterUsage(this);
         }
 
         internal GLVisualContainer Root => m_root;
 
+        /// <summary>Frontmost hittable visual under a client-space point, or null.</summary>
+        internal GLVisual? HitTest(Vector2D<float> clientPoint)
+            => m_root.HitTest(new Vector2(clientPoint.X, clientPoint.Y), Matrix4X4<float>.Identity);
+
         // ---- Geometry ------------------------------------------------------------
         public int Left => m_window.Position.X;
         public int Top => m_window.Position.Y;
@@ -125,7 +131,8 @@ namespace Microsoft.Iris.Render.OpenGL
         public void SetEdgeImages(bool fActiveEdges, ShadowEdgePart[] edges) { /* TODO(stage 3): window shadow edges */ }
         public void SetWindowOptions(WindowOptions options, bool enable) { /* TODO(stage 3): map to Silk window flags */ }
         public void SetMouseIdleOptions(Size sizeMouseIdleTolerance, uint nMouseIdleDelay) { }
-        public void SetCapture(IRawInputSite captureSite, bool state) { }
+        public void SetCapture(IRawInputSite captureSite, bool state)
+            => ((GLInputSystem)m_session.InputSystem).CaptureSite = state ? captureSite : null;
         public void SetDragDropResult(uint nDragOverResult, uint nDragDropResult) { }
 
         public void ClientToScreen(ref Point point)

UIX.RenderApi.OpenGL/Scene/GLSprite.cs

@@ -57,5 +57,13 @@ namespace Microsoft.Iris.Render.OpenGL
                     renderer.DrawColoredQuad(matrix, Size.X, Size.Y, c, alpha);
             }
         }
+
+        internal override GLVisual? HitTest(Vector2 screenPoint, Matrix4X4<float> parentMatrix)
+        {
+            if (!Visible || (MouseOptions & MouseOptions.Hittable) == 0)
+                return null;
+            Matrix4X4<float> world = LocalMatrix * parentMatrix;
+            return ContainsPoint(screenPoint, world) ? this : null;
+        }
     }
 }

UIX.RenderApi.OpenGL/Scene/GLVisual.cs

@@ -116,5 +116,25 @@ namespace Microsoft.Iris.Render.OpenGL
 
         /// <summary>Draw this visual (and its subtree) with the accumulated parent transform.</summary>
         internal abstract void Render(SceneRenderer renderer, Matrix4X4<float> parentMatrix, float inheritedAlpha);
+
+        /// <summary>
+        /// Return the frontmost hittable visual under <paramref name="screenPoint"/>
+        /// (client pixel space), or null. <paramref name="parentMatrix"/> is the
+        /// accumulated transform of this visual's parent.
+        /// </summary>
+        internal abstract GLVisual? HitTest(Vector2 screenPoint, Matrix4X4<float> parentMatrix);
+
+        /// <summary>Is the client-space point inside this visual's local quad?</summary>
+        private protected bool ContainsPoint(Vector2 screenPoint, Matrix4X4<float> worldMatrix)
+        {
+            if (Size.X <= 0f || Size.Y <= 0f)
+                return false;
+            if (!Matrix4X4.Invert(worldMatrix, out Matrix4X4<float> inverse))
+                return false;
+            // Our world matrix maps local -> screen as (local * world) under the
+            // renderer's convention, so the inverse maps screen -> local the same way.
+            Vector3D<float> local = Vector3D.Transform(new Vector3D<float>(screenPoint.X, screenPoint.Y, 0f), inverse);
+            return local.X >= 0f && local.X <= Size.X && local.Y >= 0f && local.Y <= Size.Y;
+        }
     }
 }

UIX.RenderApi.OpenGL/Scene/GLVisualContainer.cs

@@ -81,6 +81,30 @@ namespace Microsoft.Iris.Render.OpenGL
                 child.Render(renderer, matrix, alpha);
         }
 
+        internal override GLVisual? HitTest(Vector2 screenPoint, Matrix4X4<float> parentMatrix)
+        {
+            if (!Visible)
+                return null;
+
+            Matrix4X4<float> world = LocalMatrix * parentMatrix;
+
+            // Children draw ascending by layer (back-to-front), so the frontmost hit is
+            // found by testing in reverse order.
+            m_children.Sort((a, b) => a.Layer.CompareTo(b.Layer));
+            for (int i = m_children.Count - 1; i >= 0; i--)
+            {
+                GLVisual? hit = m_children[i].HitTest(screenPoint, world);
+                if (hit != null)
+                    return hit;
+            }
+
+            // Otherwise the container itself, if it is hittable and has extent.
+            if ((MouseOptions & MouseOptions.Hittable) != 0 && ContainsPoint(screenPoint, world))
+                return this;
+
+            return null;
+        }
+
         protected override void DisposeCore() => RemoveAllChildren();
     }
 }

UIX.RenderApi.OpenGL/UIX.RenderApi.OpenGL.csproj

@@ -8,35 +8,20 @@
         <AllowUnsafeBlocks>true</AllowUnsafeBlocks>
         <Nullable>enable</Nullable>
         <ImplicitUsings>disable</ImplicitUsings>
-
-        <!-- The task requires targeting both modern .NET and .NET Framework 4.8.
-             net48 only builds on Windows in this repo (the projects we reference,
-             e.g. UIX.RenderApi, only produce their netfx output there — see the
-             MicrosoftIris Directory.Build.props and the note in ZuneDBApi/CLAUDE.md
-             that "on Linux only net8.0 TFMs build"). We mirror that so the project
-             stays buildable on both hosts. -->
-        <TargetFrameworks>net8.0</TargetFrameworks>
-        <TargetFrameworks Condition=" $([MSBuild]::IsOsPlatform('Windows')) ">net8.0;net48</TargetFrameworks>
     </PropertyGroup>
 
     <ItemGroup>
-        <!-- We only implement the interfaces defined in UIX.RenderApi; per the task we
-             must not modify that project, so this is a plain reference. -->
         <ProjectReference Include="..\UIX.RenderApi\UIX.RenderApi.csproj" />
-    </ItemGroup>
-
-    <ItemGroup>
+        
         <!-- Silk.NET provides the windowing/GL/input abstractions and OpenGL bindings.
              The meta-packages register the GLFW/SDL backends automatically. -->
-        <PackageReference Include="Silk.NET.Windowing" Version="2.21.0" />
-        <PackageReference Include="Silk.NET.Input" Version="2.21.0" />
-        <PackageReference Include="Silk.NET.OpenGL" Version="2.21.0" />
-        <PackageReference Include="Silk.NET.Maths" Version="2.21.0" />
+        <PackageReference Include="Silk.NET.Windowing" Version="2.23.0" />
+        <PackageReference Include="Silk.NET.Input" Version="2.23.0" />
+        <PackageReference Include="Silk.NET.OpenGL" Version="2.23.0" />
+        <PackageReference Include="Silk.NET.Maths" Version="2.23.0" />
     </ItemGroup>
 
     <ItemGroup Condition=" $(TargetFramework.StartsWith('net4')) ">
-        <!-- PolySharp backfills modern C# language features (init accessors,
-             nullable attributes, records, etc.) for the netfx target. -->
         <PackageReference Include="PolySharp" Version="1.16.0">
             <PrivateAssets>all</PrivateAssets>
             <IncludeAssets>runtime; build; native; contentfiles; analyzers</IncludeAssets>