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Re: Simple argument question

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On Saturday, December 17, 2011 8:46:01 AM UTC+8, Bint wrote:
> 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

The size of  a double  is platform dependent. 

Is the compiler smart enough to figure out the  correct value of 
points + j*3 ? 

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Simple argument question Bint <bint@ign.com> - 2011-12-16 18:46 -0600
  Re: Simple argument question "Paul" <pchrist<nospam>or@yahoo.co.uk> - 2011-12-17 01:13 +0000
    Re: Simple argument question Bint <bint@ign.com> - 2011-12-17 12:06 -0600
      Re: Simple argument question "Paul" <pchrist<nospam>or@yahoo.co.uk> - 2011-12-17 18:45 +0000
        Re: Simple argument question "Paul" <pchrist<nospam>or@yahoo.co.uk> - 2011-12-17 23:16 +0000
          Re: Simple argument question jt@toerring.de (Jens Thoms Toerring) - 2011-12-18 22:07 +0000
            Re: Simple argument question "Paul" <pchrist<nospam>or@yahoo.co.uk> - 2011-12-18 22:34 +0000
  Re: Simple argument question 88888 Dihedral <dihedral88888@googlemail.com> - 2011-12-17 00:13 -0800
    Re: Simple argument question Juha Nieminen <nospam@thanks.invalid> - 2011-12-17 08:16 +0000
      Re: Simple argument question 88888 Dihedral <dihedral88888@googlemail.com> - 2011-12-17 00:51 -0800
        Re: Simple argument question Juha Nieminen <nospam@thanks.invalid> - 2011-12-17 10:23 +0000
  Re: Simple argument question Goran <goran.pusic@gmail.com> - 2011-12-17 23:08 -0800
    Re: Simple argument question Heck <heckja_in@ordertostymieharvestersverizon.net> - 2012-01-05 09:59 -0500
  Re: Simple argument question Krice <paulkp@mbnet.fi> - 2011-12-18 00:46 -0800
    Re: Simple argument question jt@toerring.de (Jens Thoms Toerring) - 2011-12-18 22:14 +0000
      Re: Simple argument question Jorgen Grahn <grahn+nntp@snipabacken.se> - 2011-12-19 12:01 +0000
        Re: Simple argument question Tobias Müller <troplin@bluewin.ch> - 2011-12-19 17:17 +0000
          Re: Simple argument question Jorgen Grahn <grahn+nntp@snipabacken.se> - 2011-12-20 00:33 +0000
  Re: Simple argument question Jorgen Grahn <grahn+nntp@snipabacken.se> - 2011-12-18 17:03 +0000
    Re: Simple argument question 88888 Dihedral <dihedral88888@googlemail.com> - 2011-12-18 10:04 -0800

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