Fix Windows Ink events being handled as touch events

osu.Framework/Platform/SDL2/SDL2Extensions.cs

@@ -1120,5 +1120,42 @@ public static string GetAndClearError()
             SDL.SDL_ClearError();
             return error;
         }
+
+        private static bool tryGetTouchDeviceIndex(long touchId, out int index)
+        {
+            int n = SDL.SDL_GetNumTouchDevices();
+
+            for (int i = 0; i < n; i++)
+            {
+                long currentTouchId = SDL.SDL_GetTouchDevice(i);
+
+                if (touchId == currentTouchId)
+                {
+                    index = i;
+                    return true;
+                }
+            }
+
+            index = -1;
+            return false;
+        }
+
+        /// <summary>
+        /// Gets the <paramref name="name"/> of the touch device for this <see cref="SDL.SDL_TouchFingerEvent"/>.
+        /// </summary>
+        /// <remarks>
+        /// On Windows, this will return <c>"touch"</c> for touchscreen events or <c>"pen"</c> for pen/tablet events.
+        /// </remarks>
+        public static bool TryGetTouchName(this SDL.SDL_TouchFingerEvent e, out string name)
+        {
+            if (tryGetTouchDeviceIndex(e.touchId, out int index))
+            {
+                name = SDL.SDL_GetTouchName(index);
+                return name != null;
+            }
+
+            name = null;
+            return false;
+        }
     }
 }

osu.Framework/Platform/SDL2Window.cs

@@ -570,7 +570,7 @@ protected virtual void HandleEvent(SDL.SDL_Event e)
                 case SDL.SDL_EventType.SDL_FINGERDOWN:
                 case SDL.SDL_EventType.SDL_FINGERUP:
                 case SDL.SDL_EventType.SDL_FINGERMOTION:
-                    handleTouchFingerEvent(e.tfinger);
+                    HandleTouchFingerEvent(e.tfinger);
                     break;
 
                 case SDL.SDL_EventType.SDL_DROPFILE:

osu.Framework/Platform/SDL2Window_Input.cs

@@ -235,13 +235,11 @@ private void handleDropEvent(SDL.SDL_DropEvent evtDrop)
             return null;
         }
 
-        private void handleTouchFingerEvent(SDL.SDL_TouchFingerEvent evtTfinger)
+        protected virtual void HandleTouchFingerEvent(SDL.SDL_TouchFingerEvent evtTfinger)
         {
-            var eventType = (SDL.SDL_EventType)evtTfinger.type;
-
             var existingSource = getTouchSource(evtTfinger.fingerId);
 
-            if (eventType == SDL.SDL_EventType.SDL_FINGERDOWN)
+            if (evtTfinger.type == SDL.SDL_EventType.SDL_FINGERDOWN)
             {
                 Debug.Assert(existingSource == null);
                 existingSource = assignNextAvailableTouchSource(evtTfinger.fingerId);
@@ -255,7 +253,7 @@ private void handleTouchFingerEvent(SDL.SDL_TouchFingerEvent evtTfinger)
 
             var touch = new Touch(existingSource.Value, new Vector2(x, y));
 
-            switch (eventType)
+            switch (evtTfinger.type)
             {
                 case SDL.SDL_EventType.SDL_FINGERDOWN:
                 case SDL.SDL_EventType.SDL_FINGERMOTION:
@@ -582,6 +580,8 @@ private void updateConfineMode()
         /// </summary>
         public event Action<Vector2>? MouseMove;
 
+        protected void TriggerMouseMove(float x, float y) => MouseMove?.Invoke(new Vector2(x, y));
+
         /// <summary>
         /// Invoked when the user moves the mouse cursor within the window (via relative / raw input).
         /// </summary>
@@ -592,11 +592,15 @@ private void updateConfineMode()
         /// </summary>
         public event Action<MouseButton>? MouseDown;
 
+        protected void TriggerMouseDown(MouseButton button) => MouseDown?.Invoke(button);
+
         /// <summary>
         /// Invoked when the user releases a mouse button.
         /// </summary>
         public event Action<MouseButton>? MouseUp;
 
+        protected void TriggerMouseUp(MouseButton button) => MouseUp?.Invoke(button);
+
         /// <summary>
         /// Invoked when the user presses a key.
         /// </summary>

osu.Framework/Platform/Windows/WindowsWindow.cs

@@ -9,6 +9,7 @@
 using osu.Framework.Platform.SDL2;
 using osu.Framework.Platform.Windows.Native;
 using osuTK;
+using osuTK.Input;
 using SDL2;
 using Icon = osu.Framework.Platform.Windows.Native.Icon;
 
@@ -223,6 +224,33 @@ private void handleImeMessage(IntPtr hWnd, uint uMsg, long lParam)
 
         #endregion
 
+        protected override void HandleTouchFingerEvent(SDL.SDL_TouchFingerEvent evtTfinger)
+        {
+            if (evtTfinger.TryGetTouchName(out string name) && name == "pen")
+            {
+                // Windows Ink tablet/pen handling
+                // InputManager expects to receive this as mouse events, to have proper `mouseSource` input priority (see InputManager.GetPendingInputs)
+                // osu! expects to get tablet events as mouse events, and touch events as touch events for touch device (TD mod) handling (see https://github.com/ppy/osu/issues/25590)
+
+                TriggerMouseMove(evtTfinger.x * ClientSize.Width, evtTfinger.y * ClientSize.Height);
+
+                switch (evtTfinger.type)
+                {
+                    case SDL.SDL_EventType.SDL_FINGERDOWN:
+                        TriggerMouseDown(MouseButton.Left);
+                        break;
+
+                    case SDL.SDL_EventType.SDL_FINGERUP:
+                        TriggerMouseUp(MouseButton.Left);
+                        break;
+                }
+
+                return;
+            }
+
+            base.HandleTouchFingerEvent(evtTfinger);
+        }
+
         public override Size Size
         {
             protected set

osu.Framework/osu.Framework.csproj

@@ -39,7 +39,7 @@
     <PackageReference Include="JetBrains.Annotations" Version="2022.3.1" />
     <PackageReference Include="ppy.osuTK.NS20" Version="1.0.211" />
     <PackageReference Include="StbiSharp" Version="1.1.0" />
-    <PackageReference Include="ppy.SDL2-CS" Version="1.0.671-alpha" />
+    <PackageReference Include="ppy.SDL2-CS" Version="1.0.693-alpha" />
     <PackageReference Include="ppy.osu.Framework.SourceGeneration" Version="2023.720.0" />
 
     <!-- DO NOT use ProjectReference for native packaging project.