There are many types of gamepads currently on the market for both PCs and Macs. Some resemble game controllers made for popular console gaming systems, such as Xbox, PlayStation, and Nintendo, while others have their own unique design and capabilities. Figure 1 shows a typical gamepad. These gamepads are designed to put a lot of control options within easy reach.

Figure 1 identifies several common groupings of gamepad controls. A D-pad is a control often used to allow players to indicate direction (hence, the D in the name). It is fairly flat and designed for thumb use. The analog sticks serve as mini joysticks on the controller and allow fast and accurate positional control. For example, some games may use them to allow the player to look around a 3D world or aim a weapon. In a controller designed for an Xbox (and other popular consoles), the analog sticks can also be pushed down, providing two additional action buttons. The action buttons provide the user a way to specify...