XInputGetCapabilities

XInputGetCapabilities is an API function used in the XInput library, a component of the X.Org Foundation's X11 GUI system. It allows developers to retrieve information about the capabilities of a device, specifically a human interface device (HID) such as a gamepad, joystick, or keyboard.

The XInputGetCapabilities function takes three parameters: an integer device identifier, an integer usage type, and a pointer to a mask of capabilities. The function returns the address of a capabilities bitmask, allowing the caller to retrieve information about the device's capabilities.

The usage type parameter identifies the type of HID being queried. Common usage types include XInputattery, Gamepad, and Keyboard. The capabilities bitmask returned by the function indicates whether the device supports features such as absolute or relative axes, hats, and buttons, as well as the number of axes, hats, and buttons available.

Developers can use the information retrieved by XInputGetCapabilities to adapt their applications to the capabilities of the HID being used. For example, if a gamebuypress requires a controller with a specific number of buttons or axis, the application can check the device's capabilities to ensure compatibility.

XInputGetCapabilities is a low-level API function that can be used in conjunction with other XInput functions, such as XInputOpenDevice and XInputReadAnalog, to create complex HID input handling. However, its use is primarily intended for low-level device handling and driver implementation.