public float get_motion_delta (uint point, out float delta_x, out float delta_y)
Retrieves the delta, in stage space, dependent on the current state of the PanAction.
If it is inactive, both fields will be set to 0. If it is panning by user action, the values will be equivalent to those returned by get_motion_delta. If it is interpolating with some form of kinetic scrolling, the values will be equivalent to those returned by get_interpolated_delta. This is a convenience method designed to be used in replacement "pan" signal handlers.
the touch point index, with 0 being the first touch point received by the action
return location for the X delta
return location for the Y delta