Fixed missing simulated mouse events using a Wacom tablet

The low 16-bits of the message extra info is an event sequence number when using the Wacom tablet with Windows Ink disabled. The high bits of normal mouse motion when using touch input match the touch signature, 0xFF515700. The high bits of raw input mouse motion when using touch input do not match that signature, so we have to check for the touch bit in that case.

Fixes #12927

Author: slouken

src/video/windows/SDL_windowsevents.c

@@ -442,11 +442,6 @@ static SDL_MOUSE_EVENT_SOURCE GetMouseMessageSource(ULONG extrainfo)
             return SDL_MOUSE_EVENT_SOURCE_PEN;
         }
     }
-    /* Sometimes WM_INPUT events won't have the correct touch signature,
-      so we have to rely purely on the touch bit being set. */
-    if (SDL_TouchDevicesAvailable() && extrainfo & 0x80) {
-        return SDL_MOUSE_EVENT_SOURCE_TOUCH;
-    }
     return SDL_MOUSE_EVENT_SOURCE_MOUSE;
 }
 #endif // !defined(SDL_PLATFORM_XBOXONE) && !defined(SDL_PLATFORM_XBOXSERIES)
@@ -584,7 +579,8 @@ static void WIN_HandleRawMouseInput(Uint64 timestamp, SDL_VideoData *data, HANDL
         return;
     }
 
-    if (GetMouseMessageSource(rawmouse->ulExtraInformation) != SDL_MOUSE_EVENT_SOURCE_MOUSE) {
+    if (GetMouseMessageSource(rawmouse->ulExtraInformation) != SDL_MOUSE_EVENT_SOURCE_MOUSE ||
+        (SDL_TouchDevicesAvailable() && (rawmouse->ulExtraInformation & 0x80) == 0x80)) {
         return;
     }