Hello,
I
have been working for a couple of weeks on writing a DLL in Visual C++
Studio. My intention is to write an exported function in the DLL to
initialize a Logitech Force3Dpro joystick, setup a force feedback
effect and run it using DirectInput. I would like to control this force
feedback effect (in particular, the intensity of the feedback) from Labview by calling the function in the DLL.
I
followed the FFConst example in Microsoft SDK DirectInput Samples for
making an .exe file to setup and run force feedback effects. I have
been able to build the DLL successfully with an exported function that
can be accessed from Labview by "Call a function node". I tested the
function by running simple functions such as addition and
multiplication of integers, andconfirmed the fact that the DLL was
built correctly. I have also included the DirectInput code for
initializing and running the force feedback effect. I am able to
compile and build the DLL with no problems.
The Problem:
The only problem that I have at this point is with setting SetCooperativeLevel
for the DirectInput8 joystick device. I have to provide a top-level
window handle to SetCooperativeLevel so that I can give the function
exclusive access to the joystick. Since I am not making a window and am
building a DLL, I am not sure what handle I am supposed to provide it
so that the joystick can respond. I am not sure if passing a handle to
the Labview window would work because it is accessing the DLL's
function? I tried passing LabView window handle to the function and
read the X-axisposition off the joystick, but it read some junk (huge
long integer) - which lead me to believe that the problem is something
to do with initializing the joystick.
For all practical purposes, I am a complete novice at DirectInput
programming and working with Visual C++. Although, I have programmed in
C++previously. I am sorry for the long message, but I wanted to give a bit of background so that my aim is clear.
Any help, advice or direction with this problem be very much appreciated. Thank you for your time!
Cheers!
Abhishek
P.S. I apologize for posting this message in an old thread. I have been following many such threads and this one in particular seemed pretty close to the problem I am currently facing.
