Posted by gouessej on Nov 11, 2012; 9:44pm
URL: https://forum.jogamp.org/Newt-Mouse-Event-tp4026853p4026868.html

If GET_WHEEL_DELTA_WPARAM(wParam) is lower than 120, zero is used as a wheel rotation (the result of the division is truncated). It can occur, especially on finer-resolution freely-rotating wheels without notch.