Reading joystick capability

Question

I'm trying to read my joystick capability by using the winmm.dll library. Here is how I'm doing it...

from ctypes import windll, Structure, c_uint, c_ushort, c_char, c_ulong
WORD = c_ushort
UINT = c_uint
TCHAR = c_char
winmm = windll.LoadLibrary('winmm.dll')
class JOYCAPS(Structure):
   _fields_ = [
    ('wMid', WORD),
    ('wPid', WORD),
    ('szPname', TCHAR * MAXPNAMELEN),  # originally szPname[MAXPNAMELEN]
    ('wXmin', UINT),
    ('wXmax', UINT),
    ('wYmin', UINT),
    ('wYmax', UINT),
    ('wZmin', UINT),
    ('wZmax', UINT),
    ('wNumButtons', UINT),
    ('wPeriodMin', UINT),
    ('wPeriodMax', UINT),
    ('wRmin', UINT),
    ('wRmax', UINT),
    ('wUmin', UINT),
    ('wUmax', UINT),
    ('wVmin', UINT),
    ('wVmax', UINT),
    ('wCaps', UINT),
    ('wMaxAxes', UINT),
    ('wNumAxes', UINT),
    ('wMaxButtons', UINT),
    ('szRegKey', TCHAR * MAXPNAMELEN),  # originally szRegKey[MAXPNAMELEN]
    ('szOEMVxD', TCHAR * MAX_JOYSTICKOEMVXDNAME)  # originally szOEMVxD[MAX_JOYSTICKOEMVXDNAME]
   ]
joyinf = JOYCAPS()
err = winmm.joyGetDevCaps(0, pointer(joyinf), sizeof(joyinf))
if err == JOYERR_NOERROR:
    for l in [s for s in dir(joyinf) if "_" not in s]:
        print(l, getattr(joyinf, l))

When I try to do so I get an error...

function 'joyGetDevCaps' not found

After searching in the source code I found that joyGetDevCapsW is for unicode and the joyGetDevCapsA is not. I tried them both and got the same result.

When trying to read them I get an error number of 165 which is not listed in the original function MSDN site but is an error code for JOYERR_PARMS which means...

The specified joystick identifier is invalid

I'm using windows 10 and python 3.6

The code is working when using the joyGetPos and joyGetPosEx.

Thank you

Volin

After more probing I found out that joyGetDevCapsW is for unicode, and I found the MAXPNAMELEN and MAX_JOYSTICKOEMVXDNAME values. But it still doesn't work – Volin

Update your code so that the strict is correct, also try getting the win32 api error? programcreek.com/python/example/7186/win32api.GetLastError and codegists.com/snippet/python/controllerpy_wezu_python – Amalberga

Thank you I updated the code and when runnig GetLastError the return value is 126 meaning The specified module could not be found. I don't think that this is connected the the winmm.dll file because I ran a command that return correctly and I get the same error. So could be it is not updated. – Volin

Could it have something to do with 32bit/64bit process? Can you try in both 32 bit as well as 64bit python and see if something changes? – Amalberga

No tried both of them just now get the same error – Volin

Answer 1

This Gist does something similar to what you do and more: https://gist.github.com/rdb/8883307

Might be that TCHAR needs a length.

Riddance