(self, point)
Set initial cursor window coordinates and pick constrain-axis.
Set initial cursor window coordinates and pick constrain-axis.
Set initial cursor window coordinates and pick constrain - axis .
def down(self, point):
        """Set initial cursor window coordinates and pick constrain-axis."""
        self._vdown = arcball_map_to_sphere(point, self._center, self._radius)
        self._qdown = self._qpre = self._qnow
        if self._constrain and self._axes is not None:
            self._axis = arcball_nearest_axis(self._vdown, self._axes)
            self._vdown = arcball_constrain_to_axis(self._vdown, self._axis)
        else:
            self._axis = None
def down ( self , point ) : self . _vdown = arcball_map_to_sphere ( point , self . _center , self . _radius ) self . _qdown = self . _qpre = self . _qnow if self . _constrain and self . _axes is not None : self . _axis = arcball_nearest_axis ( self . _vdown , self . _axes ) self . _vdown = arcball_constrain_to_axis ( self . _vdown , self . _axis ) else : self . _axis = None