Topic: Problem loading DLL written ot MSVC++

[dodimitrov]

Hi everyone,
I need to load external DLL in my lisp to do some calculations.Formulas and parameters are specific - cant implement in lisp.
The library was developed as dynamic library, written on Microsoft Visual C++.
I have detailed description of all three functions in DLL:

extern "C" __declspec(dllexport) long __stdcall
InitializeAllTheStuff(const char* par1, const char* par2)

extern "C" __declspec(dllexport) long __stdcall
DoTheCalc(int p1, int *z, double *a, double *b)

extern "C" __declspec(dllexport) long __stdcall
FreeStuff()

The last one is required after using "DoTheCalc" function

I have reviewed related topics and I'm trying something like this:

(defun C:loadmydll(/)
  (vlax-invoke 
      (vla-GetInterfaceObject
            (vlax-get-acad-object) "path\mydll.dll") 'InitializeAllTheStuff "p1" "p2")           
             
)

[squirreldip]

Is the path to your .dll a trusted location?

[MickD]

What are the errors you are receiving?
Is the dll the same file version as the CAD platform?

We will need some more information I'm afraid, you have only posted the goals of your experiment but no findings to date which would help in diagnosing your issue/s.

cheers.

[owenwengerd]

The library was developed as dynamic library, written on Microsoft Visual C++.

Lisp cannot call C functions. To use those functions from Lisp, you'll need to write either a COM wrapper that exposes them via COM or an ObjectARX wrapper that exposes them via lisp function.

[dodimitrov]

Thank's Owen!
I thought so. I’ll need help with that – not familiar to me.