https://stackoverflow.com/a/1448478/1130520

Current offset relative to the active reference-point origin (updated after drag).

* Called when the event filter detects a keyboard event. * * This function prompts the joystick to update its axis, button and POV values * based o

* Polls the keyboard events and if required, reports a change in the axis * values of the virtual joystick device. */

* Polls the keyboard events and if required, reports a change in the button * values of the virtual joystick device. */

* Polls the keyboard events and if required, reports a change in the POV/hat * values of the virtual joystick device. */