DirectInput

DirectInput is a legacy input API that was part of Microsoft DirectX. It provides a uniform interface for handling input from a range of devices, including keyboards, mice, joysticks, gamepads, steering wheels, and other human interface devices. DirectInput was designed to offer applications low-level access to device data and to support features such as multiple simultaneous devices and force feedback. It supports both polled input and buffered input, the latter delivering a queue of events that can be processed by the application.

The API exposes devices and their data through COM-based interfaces, most notably IDirectInput and IDirectInputDevice. Applications enumerate available devices, acquire them, and read their state via functions such as GetDeviceState for current state or GetDeviceData for buffered events. DirectInput supports various device types (keyboard, mouse, joystick, gamepad) and allows configuration of cooperative levels (exclusive or nonexclusive, foreground or background) to control how a device is shared with other processes. It also provides data formats, axes, button counts, and, on compatible devices, force feedback support.

In modern Windows development, DirectInput has largely been superseded by other input APIs. XInput is preferred for Xbox-compatible controllers, while Raw Input and Windows.Gaming.Input handle keyboard, mouse, and other HID devices. DirectInput remains available for backward compatibility with older games and devices that rely on its interface or force feedback features, but it is generally not the recommended path for new projects.