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NNTP-Posting-Date: Fri, 16 Dec 2011 18:46:03 -0600
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Date: Fri, 16 Dec 2011 18:46:01 -0600
Subject: Simple argument question
From: Bint <bint@ign.com>
Newsgroups: comp.lang.c++
Message-ID: <CB114269.B5F7%bint@ign.com>
Thread-Topic: Simple argument question
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Xref: x330-a1.tempe.blueboxinc.net comp.lang.c++:12603

Hi can someone answer a simple question involving arguments to functions?

I need to call a library function which expects an argument like this
Function(double pointlist[][3]);

My question is how do I make one of those if I am just wanting to malloc the
memory?  Can I use a double pointer?

Can I have something like this:
double *points = (double *)malloc(10*3*sizeof(double));

for int (j = 0; j < 10; j++) {
     *(points + j*3 + 0) = x;
     *(points + j*3 + 1) = y;
     *(points + j*3 + 2) = z;
}

And then call the function with points as the argument?  It doesn't compile
but I was wondering if I could cast it?  Or do I need something else instead
of a double pointer for my points?

Does that make sense? I am confused about how to call the function with
anything but something like:
 double array[500][3];

I don't want that because I don't know the number of points, see?

Thanks for any help!
B