can you have no cursor for a window?

[Paul Davis <pbd op net>]

is there a way to fully hide the mouse cursor in a given window?
gdk_window_set_cursor() with a NULL argument simply reverts to the
parent cursor (like XDefineCursor (win, None) == XUndefineCursor (win))

i have a window in which a visual element (a canvas item) functions as
a display of the current mouse/pointer position, but it moves with
damping compared to the actual mouse cursor. its very distracting to
have them both visible.

--p