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From: etaylor@wilkins.iaims.bcm.tmc.edu (Eric Taylor)
Newsgroups: comp.windows.x
Subject: Re: X window
Message-ID: <2961@gazette.bcm.tmc.edu>
Date: 29 Nov 90 21:19:24 GMT
References: <169@nys138.nysnet.nysnet>
Sender: usenet@bcm.tmc.edu
Reply-To: etaylor@wilkins.iaims.bcm.tmc.edu (Eric Taylor)
Organization: Baylor College of Medicine, Houston, Tx
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Nntp-Posting-Host: wilkins.iaims.bcm.tmc.edu


You have already posted this note.

There are many problems with your code segment :

	Problem #1 :
		XReadBitmapFile does not read TIFF.

	Problem #2 :
		In exposeHandler, you begin setting the fields
		pointed to by image, but that pointer is UNITIALIZED.
		You should not use a pointer in this example.  Use
		the whole structure (change XImage *image to XImage image
			and change image-> to image.)  Also, your function
		block is not there.  Bus Error is the likely result.

	Problem #3 :
		You should construct your XImage ahead of time.
		You should not do it every time your widget is exposed.

	Problem #4 :
		You are cramming a pointer to a pixmap into the image->data
		field.  This is wrong, wrong, wrong.   A Pixmap is
		completely different from image data.

		Use XGetImage to get an image from a pixmap.

		You don't really, have to mess with XImages at all if you
		already have a bitmap.  Use XCopyArea or XCopyPlane instead.


If you have a tiff file already,  convert it to a ppm file and
use xloadimage.  If you have xtiff, you could display the image
using that.
--
					Eric Taylor
					Baylor College of Medicine
					etaylor@wilkins.bmc.tmc.edu
					(713) 798-3776