Error in Visual Studio 2010 with NX8.5

[WilsonBlr]

Visual Studio 2010 behaves in a weird manner.
I have a function to extract control points from a surface in which i use UF_MODL_ask_bsurf(). Sometimes VS executes past the code line and prints the control points on console. Some other times it stops at UF_MODL_ask_bsurf(). I cant figure out why? Anybody had this problem before ?

The function was running properly till yesterday. Now I see that it is crashing at UF_MODL_ask_bsurf() again. Is there something with the environment that needs to be set to get this working properly? .
This is an external NX application.

This is the error
====================================================
Failed to handle error condition correctly - exiting
General Fault Exception
====================================================
====================
Fatal error detected
====================


Below is the full code.

vector<MyPoints> MyLibrary::getNURBSSurfaceControlPoints(int surfTag)
{
	double *ptr;

	cout<< "In sub function : " << endl;

	UF_MODL_bsurface_p_t t_struc_info;
	
	UF_CALL(UF_MODL_ask_bsurf(surfTag, t_struc_info));


	cout<< " ---- output ---- " << endl;

	cout << " Is rational ?? : " << t_struc_info->is_rational << endl;
	cout << " Num poles u : " << t_struc_info->num_poles_u << endl;
	cout << " Num poles v : " << t_struc_info->num_poles_v << endl;
	cout << " Order u : " << t_struc_info->order_u << endl;
	cout << " Order v : " << t_struc_info->order_v << endl;  


	int d_num_poles_u = t_struc_info->num_poles_u;
	int d_num_poles_v = t_struc_info->num_poles_v;
	int d_order_u = t_struc_info->order_u;
	int d_order_v = t_struc_info->order_v;

	cout.flush();

	cout << d_num_poles_u << "  " << d_num_poles_v << endl;

	double (*Values)[4] = t_struc_info->poles;
	double* Xvalues;
	double* Yvalues;
	double* Zvalues;
	double* Wvalues;

	Xvalues = t_struc_info->poles[0];
	Yvalues = t_struc_info->poles[1];
	Zvalues = t_struc_info->poles[2];
	Wvalues = t_struc_info->poles[3];
	
	vector<MyPoints> PolesArray;
	for (int i = 0; i<d_num_poles_u*d_num_poles_v; i++)
	{
		//cout <<"Point No: "<<i <<" ";
		//cout << "X: " << Values[i][0] << " " ;
		//cout << "Y: " << Values[i][1] << " " ;
		//cout << "Z: " << Values[i][2] << " " ;
		//cout << "W: " << Values[i][3] << "  "<<endl ;



		MyPoints Pt; 
		 
		Pt.X = Values[i][0];
		Pt.Y = Values[i][1];
		Pt.Z = Values[i][2];		
		PolesArray.push_back(Pt);
	}
	return PolesArray;
}

 

[Bleaker]

Documentation is your friend. The NX Open C API provides both the answer to your question ("The user should allocate a UF_MODL_bsurface_t structure and pass in a pointer to this structure") and a working example:

UF_MODL_bsurface_t bsurf;
UF_CALL(UF_MODL_ask_bsurf( bsurf_obj_id, &bsurf ));
// ...
UF_CALL(UF_MODL_free_bsurf_data(&bsurf));

Basically, you must allocate/free space for the bsurface data yourself for this function.

 

[WilsonBlr]

Hey thanks a ton Bleaker.
That is what I needed. I was using the pointer without allocating memory.

But surprisingly the program executed a few times before and I was able to print the control points, I guess the function UF_MODL_ask_bsurf was also allocating memory internally. Not sure.

Regards
Wilson

 

[Bleaker]

Yes, the way I understand it, the function takes the pointer and happily allocates memory and writes its data to wherever it is pointing. By passing it an uninitialized pointer you're basically uttering a prayer to the Gods of Chaos. If they are merciful, you hit an unallocated space in the heap and get away with a successful execution and a memory leak. Otherwise... well, let's just thank the Creators for protected mode.