I am writing a wrapper class for raw input and I don't understand the RIDI_PREPARSEDDATA option of the function GetRawInputDeviceInfo(). I am testing with my keyboard as the device and I always seem to get back an empty buffer when using this option. (RIDI_DEVICENAME and RIDI_DEVICEINFO work's fine)
I wasn't able to find good documentation for this option
For those just stumbling onto this now, RIDI_PREPARSEDDATA refers to the same preparsed
data used by HidP_GetCaps, HidD_GetPreparsedData, and other related functions. You can use preparsed data
to, for example, figure out the format of the raw input data for a game controller.