From:	"A. Sinan Unur" <asu1 AT c-o-r-n-e-l-l DOT edu>
Newsgroups:	comp.os.msdos.djgpp
Subject:	Re: Problem using a struct
Date:	8 Jan 2003 19:30:18 GMT
Organization:	Cornell University
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"Joel Saunders" <jbs30000 AT aol DOT com> wrote in
news:bcd4cba120fadbd18cb606881c88ae87 DOT 62691 AT mygate DOT mailgate DOT org: 

> I made a post about this yesterday, but it never showed up, so I'll
> try again, and hope it posts this time.
> For a basic bmp loader I made, the struct to hold the bmp header
> doesn't work.  I used __attribute__((__packed__)) after each item, but
> it's no good.  I gave the file for the program, a C extention, instead
> of a cpp extention, so I know that probably makes some difference.
> Here's the header...
> struct BMP_Header {
>         unsigned int BM __attribute__((__packed__));
>         unsigned long File_Size __attribute__((__packed__));

<snip>

> Here's what I had to use instead of the header:

> unsigned char image[54];
> #define image_BM ((int *)&image[0])[0]
> #define image_File_Size ((long *)&image[2])[0]

sizeof int on djgpp is 4, not 2.

-- 
A. Sinan Unur
asu1 AT c-o-r-n-e-l-l DOT edu
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