value when the mouse is on the bottom side of the
screen. Note: this value is never reached, because
the maximum mouse coordinate is one pixel less than the
screen height. For example, if the screen height is 900,
lo is 0.0 and
hi is 1.0, the minimum value output is
1.0 - 1.0 * 899.0/900 = 0.001111 .
value when the mouse is on the top side of the screen
curve shape. Either zero (default) for a linear
mapping, or 1 for an exponential mapping. Note:
When using exponential mapping, make sure the
is greater than zero, otherwise NaN values will be
60 dB decay time of a lag-time smoothing. Use zero to avoid any smoothing.