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From: etaylor@wilkins.iaims.bcm.tmc.edu (Eric Taylor)
Newsgroups: comp.windows.x
Subject: Re: Emulating pixmap with window
Message-ID: <3071@gazette.bcm.tmc.edu>
Date: 5 Dec 90 16:36:51 GMT
References: <6233@quanta.eng.ohio-state.edu> <1990Nov27.155853.10911@smsc.sony.com> <1990Dec5.005912.13695@relay.wpd.sgi.com>
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Reply-To: etaylor@wilkins.iaims.bcm.tmc.edu (Eric Taylor)
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In article <1990Dec5.005912.13695@relay.wpd.sgi.com>, mikey@eukanuba.wpd.sgi.com (Mike Yang) writes:
|> In article <1990Nov27.155853.10911@smsc.sony.com>, dce@smsc.sony.com (David Elliott) writes:
|> |> An XImage is not a drawable, but it sure would be nice to be able to
|> |> use Xlib-like drawing routines on an XImage.  For example, it would
|> |> be nice to be able to draw lines, arcs, polygons, filled polygons,
|> |> and so forth, and to do other operations on XImages.  Does such a
|> |> library exist?  (Then again, maybe I missed something obvious...)
|> 
|> What you're describing is a pixmap.  XImage is for client-side data,
|> whereas pixmaps and windows have their contents known by the server.
|> Since XImage is for the client, it doesn't make sense to provide
|> server operations on its contents.
|> 
|> -----------------------------------------------------------------------
|>                  Mike Yang        Silicon Graphics, Inc.
|>                mikey@sgi.com           415/335-1786



NO.  Pixmaps, just don't get the job done all of the time.  First of all,  "Pixmaps
should be considered a precious resource".

Second of all, SGI's don't handle pixmaps above a certain size correctly
(I last used their X about 6 months ago).

Thirdly, sometimes you need immediate access to the data you just output.
It would be horrible if I had to use XGetImage after every drawing operation
to get at the bits.

Of course it makes sense to provide the functionality for XImages.
It doesn't have to be in libX11.a though (and shouldn't) .  Some little utility
library would be nice (HINT, HINT,HINT).
--
					Eric Taylor
					Baylor College of Medicine
					etaylor@wilkins.bcm.tmc.edu
					(713) 798-3776