The joystick represents a class of devices that report tactile movements and actions players make within a game. DirectInput provides the functionality to process the data representing these movements and actions from joysticks, as well as other related devices, such as trackballs and flight harnesses.
Currently, DirectInput is simply another name for an existing Win32 function, joyGetPosEx. This function provides extended capabilities to its predecessor, joyGetPos, and should be used for any joystick services. In future support for input devices, including virtual reality hardware, games that use joyGetPosEx will be automatically supported for joystick input services. This is not the case for joyGetPos.