[heoullxx] Analog input devices that click

Create a knob, a user-interface accessory, which can be programmed to click at arbitrary points, signifying crossing a threshold.  In general, force feedback.  The dial could be programmed to be discrete, or the clicks could simply be markers allowing any analog setting.  This would be an improvement over the Griffin PowerMate or early Evans Sutherland graphics computers.

Also for a linear slider; I think it already exists, demonstrated in Oskar Van Deventer's slider maze.

Also for a two-dimensional slider.  Force feedback could be very complicated, for example navigating a 2D maze.

Original motivation was an input device for a virtual Rubik's cube, but I suspect pure keyboard input is superior.  Maybe a wheel for rotating around the twist axis in 3D.