fixed pikvm/pikvm#159: workaround for windows 98 absolute mouse bug

kvmd/plugins/hid/otg/mouse.py

@@ -42,6 +42,7 @@ from .events import make_mouse_report
 class MouseProcess(BaseDeviceProcess):
     def __init__(self, **kwargs: Any) -> None:
         self.__absolute: bool = kwargs.pop("absolute")
+        self.__absolute_win98_fix: bool = kwargs.pop("absolute_win98_fix")
         self.__horizontal_wheel: bool = kwargs.pop("horizontal_wheel")
 
         super().__init__(
@@ -143,6 +144,12 @@ class MouseProcess(BaseDeviceProcess):
             assert relative_event is None
             move_x = self.__x
             move_y = self.__y
+            if self.__absolute_win98_fix:
+                # https://github.com/pikvm/pikvm/issues/159
+                # For some reason, the correct implementation of this fix
+                # is a shift to the left, and not to the right, as in VirtualBox
+                move_x <<= 1
+                move_y <<= 1
         else:
             assert self.__x == self.__y == 0
             if relative_event is not None: