The JDD_GETDEVCAPS message is sent to get joystick device capability information.
Parameters
LPARAM lParam1
Specifies a pointer to a JOYCAPS structure, which is described in the Win32 SDK. The driver fills this structure with the capabilities of the device.
LPARAM lParam2
Specifies the size of the structure pointed to by lParam1 in bytes.
Return Value
If JDD_GETDEVCAPS succeeds, it returns MMSYSERR_NOERROR. Otherwise, it returns JOYERR_PARMS.
Comments
Compare the structure size value passed to lParam2 with the size of the JOYCAPS structure with which the driver was compiled. If lParam2 is larger than the expected structure size, fill the remaining with zeros.
If lParam2 is zero, return MMSYSERR_NOERROR without writing anything to the location specified by lParam1.