@Override
    public void onMouseMotionEvent(MouseMotionEvent evt) {
        // Only forward the event if there's actual motion involved.
        if (inputManager.isCursorVisible() && (evt.getDX() != 0
                || evt.getDY() != 0
                || evt.getDeltaWheel() != 0)) {
            inputQueue.add(evt);
        }
    }
@param height The height of the viewport. Used to convert
bottom-left origin to upper-left origin.
jme3-niftygui/src/main/java/com/jme3/niftygui/InputSystemJme.java