Path: utzoo!mnetor!uunet!lll-winken!lll-lcc!lll-tis!mordor!sri-spam!ames!nrl-cmf!cmcl2!husc6!bbn!uwmcsd1!ig!agate!ucbvax!ATHENA.MIT.EDU!newman
From: newman@ATHENA.MIT.EDU
Newsgroups: comp.windows.x
Subject: Re: XCreateBitmapFromData() bug/feature question
Message-ID: <8802042313.AA08403@LEO.MIT.EDU>
Date: 4 Feb 88 23:13:28 GMT
Sender: daemon@ucbvax.BERKELEY.EDU
Organization: The Internet
Lines: 21

You are having byte-order difficulties because you are passing
XCreateBitmapFromData() an array of 'short', when it wants an array of
'char'.  To make your application run portably, you need to convert
your X10-format bitmap files to X11 format.

As you know, X10 bitmap files declared the "_bits" variable as an array
of "short", which is normally 16 bits.  That was fine then, because
X10's XBitmapBitsPut() routine expected 16-bit data too, and the server
took care of any needed byte-swapping if the client and server had
different byte orders.

In X11, however, bitmap files declare the _bits array as an array of
'char'.  This means the data is now in 8-bit format, and is independent
of the client machine's byte order.   That is the format that
XCreateBitmapFromData() wants to see; it assumes that bitmap_unit=8
(NOT that bytes_order=LSBFirst).

To convert an X10 bitmap file to X11 format, use the "bm-convert"
utility to convert your favorite X10-format bitmap file to X11 format. 
 You should find "bm-convert" in the util/ subdirectory of your X11 distribution.

/Ron Newman