| how to pass array from dll into IDL? [message #25656] |
Thu, 05 July 2001 07:53  |
maxschautzer
Messages: 2
Registered: July 2001
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Junior Member |
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Hi ,
I need to pass a bytearray from the dll to IDL (5.2).
I am writing a wrapper for a framegrabber which uses the dll functions to aquire
the single frames(monochrome).
Then I try to pass the pointer address to idl, then this address seems not to work.
Here my example:
in dll:
IDL_LONG TestFunction(int argc, void* argv[])
{
IDL_LONG *answer;
BYTE b=255; //BYTE is UCHAR
BYTE *pb;
answer = (IDL_LONG *)argv[0];
pb=&b;
*answer = (IDL_LONG)pb;
return(0L); //Return zero if all okay
}
in IDL:
a=10L
err=Call_External('aquire.dll','TestFunction',a)
print,a
IDL>10415668
This address seems not to be the address for b in dll. I tested this with:
var = EXTPROC_DEREF(addr,BYTE=1)
print,var
IDL>94 not 255
-> EXTPROC_DEREF comes from http://www.rlkling.com/
So her are my questions: How can I access these different address spaces?
How can I test this address in IDL?
Is there any possibility to transfer whole arrays(frames)?
And if, how fast can I get these arrays(25ms)?
Thanks
Max
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| Re: how to pass array from dll into IDL? [message #25704 is a reply to message #25656] |
Tue, 10 July 2001 02:27  |
nmw
Messages: 18
Registered: January 1995
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Junior Member |
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In article <3B465516.C851CAB4@home.com>, Randall Frank <rjfrank1@home.com> writes:
> Nigel,
> Make sure you supply a free_cb function in your example.
>
> The line:
>
> array = IDL_ImportArray(1, dims, IDL_TYP_BYTE, data, NULL, NULL);
>
> should read something like:
>
> array = IDL_ImportArray(1, dims, IDL_TYP_BYTE, data,
> (IDL_ARRAY_FREE_CB)free, NULL);
>
> to avoid a memory leak in your example.
>
> FWIW.
>
Very good point!
--
-----------------------------------------------------------
Nigel Wade, System Administrator, Space Plasma Physics Group,
University of Leicester, Leicester, LE1 7RH, UK
E-mail : nmw@ion.le.ac.uk
Phone : +44 (0)116 2523568, Fax : +44 (0)116 2523555
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