Hi, I'm trying to do a comparision with DirectInput GUID e.g GUID_XAxis, GUID_YAxis from a value I get from GetProperty
eg
DIPROPRANGE propRange;
DIJoystick->GetProperty (DIPROP_RANGE, &propRange.diph);
// This will crash
if (GUID_XAxis == MAKEDIPROP (propRange.diph.dwObj))
;
How should I be comparing the GUID from GetProperty?
I'm not familiar with this part of DirectInput, but some issues to fix first: You have to fill in propRange before you pass it to GetProperty, or else it will fail, and you have to check whether GetProperty fails or not.
I omitted the error checking and other parts for readability, the whole that crashes is this
BOOL CALLBACK EnumAxesCallback (const DIDEVICEOBJECTINSTANCE* instance, VOID* context)
{
DIPROPRANGE propRange;
propRange.diph.dwSize = sizeof (DIPROPRANGE);
propRange.diph.dwHeaderSize = sizeof (DIPROPHEADER);
propRange.diph.dwHow = DIPH_BYID;
propRange.diph.dwObj = instance->dwType;
propRange.lMin = -1000;
propRange.lMax = +1000;
// ok
if (FAILED (DIJoystick->SetProperty (DIPROP_RANGE, &propRange.diph)))
return DIENUM_STOP;
// ok
if (FAILED (DIJoystick->GetProperty (DIPROP_RANGE, &propRange.diph)))
return DIENUM_STOP;
// crash if I try to compare GUID
if (GUID_XAxis == MAKEDIPROP (propRange.diph.dwObj))
;
MAKEDIPROP treats the parameter as a pointer to a GUID. dwObj isn't one.
instance has guidType however, so this should work:
if ( GUID_XAxis == MAKEDIPROP( &instance->guidType ) )
Hmm, not so sure it works. none of the ID match in enum callback, I plugged in a xbox360 controller
struct GUIDName
{
GUID Guid;
string GuidString;
};
GUIDName guidNames [] =
{
{ GUID_XAxis, "GUID_XAxis" }
,{ GUID_YAxis, "GUID_YAxis" }
,{ GUID_ZAxis, "GUID_ZAxis" }
,{ GUID_RxAxis, "GUID_RxAxis" }
,{ GUID_RyAxis, "GUID_RyAxis" }
,{ GUID_RzAxis, "GUID_RzAxis" }
,{ GUID_Slider, "GUID_Slider" }
,{ GUID_Button, "GUID_Button" }
,{ GUID_Key, "GUID_Key" }
,{ GUID_POV, "GUID_POV" }
,{ GUID_SysMouse, "GUID_SysMouse" }
,{ GUID_SysKeyboard, "GUID_SysKeyboard" }
,{ GUID_Joystick, "GUID_Joystick" }
,{ GUID_SysMouseEm, "GUID_SysMouseEm" }
,{ GUID_SysMouseEm2, "GUID_SysMouseEm2" }
,{ GUID_SysKeyboardEm, "GUID_SysKeyboardEm" }
,{ GUID_SysKeyboardEm2, "GUID_SysKeyboardEm2" }
};
for (int i = 0; i < sizeof (guidNames)/sizeof (guidNames [0]); ++i)
{
if (guidNames [i].Guid == MAKEDIPROP (&propRange.diph.dwObj))
cout << "---------------------------------------" << guidNames [i].GuidString << endl;
}
You're still using MAKEDIPROP on a non-GUID. A DIPROPRANGE struct simply does not have a GUID as member.
Since you're assumedly inside your EnumObjects callback, the GUID is in your instance object:
for (int i = 0; i < sizeof (guidNames)/sizeof (guidNames [0]); ++i)
{
if (guidNames [i].Guid == instance->guidType )
cout << "---------------------------------------" << guidNames [i].GuidString << endl;
}
I'm not in the the EnumObjects callback function, I'm shimming GetProperty function, what takes in &propRange.diph
So I try to access it from the DWORD variable propRange.diph.dwObj which is assigned to instance->guidType from caller.
