IDirectInputDevice

IDirectInputDevice is a COM interface within the DirectInput portion of Microsoft DirectX. It represents a single input device, such as a keyboard, mouse, joystick, gamepad, or other HID device. An application obtains an IDirectInputDevice instance from an IDirectInput object, typically by calling CreateDevice with the device’s GUID or by enumerating devices and selecting one.

The interface provides the means to configure the device, control its lifecycle, and retrieve input data. Key responsibilities include acquiring and unacquiring the device, defining how data is returned, and selecting how the device shares access with other applications. Data can be retrieved as an immediate device state (a snapshot of current inputs) or as buffered events, depending on the device and chosen data format. The data format is set with a format descriptor via SetDataFormat, which determines the structure of data returned by GetDeviceState and GetDeviceData. Cooperative level, set by SetCooperativeLevel, controls whether the device is used in exclusive or shared mode and whether input is processed in the foreground or background.

Additional capabilities are queried and configured through methods such as GetCapabilities, GetProperty, and SetProperty. The interface is complemented by other DirectInput components, and in newer Windows APIs, DirectInput devices may be managed by IDirectInputDevice8 or by newer input systems. DirectInput, including IDirectInputDevice, is considered legacy for many modern input scenarios, with alternatives like XInput and Windows.Gaming.Input often recommended for contemporary game devices.