Xref:	news2.mv.net comp.os.msdos.djgpp:4709
From:	lehmann AT mathematik DOT th-darmstadt DOT de (Alexander Lehmann)
Newsgroups:	comp.os.msdos.djgpp
Subject:	Re: bmp file format
Date:	7 Jun 1996 14:56:35 GMT
Organization:	Technische Hochschule Darmstadt
Lines:	26
Message-ID:	<4p9fv3$e60@rs18.hrz.th-darmstadt.de>
References:	<9606071033 DOT AA21600 AT slater DOT chemie DOT uni-bremen DOT de>
NNTP-Posting-Host:	fb0410.mathematik.th-darmstadt.de
To:	djgpp AT delorie DOT com
DJ-Gateway:	from newsgroup comp.os.msdos.djgpp

Mathias Koch (mkoch AT chemie DOT uni-bremen DOT de) wrote:
: I want to write a part of the graphic screen into a .bmp file. I
: changed the variable formats, I have found in a script, from 'DWORD'
: to 'unsigned long' and from 'WORD' to 'unsigned short', which should
: have the same length in bytes.

: I found, that the bytes within the variables are disordered in the
: file and no graphic program can read my bmp files!

: Can anyone help me, to fix this problem?

Common reasons for this are different structure packing conventions
and different endianess. Since BMP uses little endian and so does
djgpp, I would guess that some members of your struct get aligned to
multiples of 4. A way to fix this is to write the individual structure
elements with separate fwrite commands (or even better use an endian
independent variant)


bye, Alexander

--
Alexander Lehmann,                                  |  "On the Internet,
alex AT hal DOT rhein-main DOT de  (plain, MIME, NeXT)         |   nobody knows
lehmann AT mathematik DOT th-darmstadt DOT de (plain)          |   you're a dog."
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