From: pmartz@dsd.es.com (Paul Martz)
Subject: Re: Animation with XPutImage()?
Nntp-Posting-Host: bambam
Reply-To: pmartz@dsd.es.com (Paul Martz)
Organization: Evans & Sutherland Computer Corp., Salt Lake City, UT
Lines: 28

In article <1993Apr21.154620.16330@infodev.cam.ac.uk>, dcr@mail.ast.cam.ac.uk (Derek C. Richardson) writes:
> Hi, I'm new to this group so please bear with me!
> 
> Two years ago I wrote a Sunview application for fast animation
> of raster files. With Sunview becoming rapidly obselete, I've
> finally decided to rewrite everything from scratch in XView.
> I put together a quick test, and I've found that XPutImage()
> is considerably slower (factor of 2 on average?) than the
> Sunview command pw_rop() which moves image data from memory
> pixrects to a canvas. This was on a Sparc IPX. It seems that:
> (1) the X protocol communication is slowing things down; or
> (2) XPutImage is inefficient...or both!

Using XPutImage, your source is maintained by the client and the
destination is maintained by the server, thus you incur the overhead
of transporting through whatever client-server communications
mechanism you are using.

Is it possible for you to maintain your source images in pixmaps?
These are maintained by the server, so copying them into a window is
much cheaper.

Also make sure you are not sending any unnecessary XSyncs, or running
in XSynchonize mode.
-- 

   -paul	pmartz@dsd.es.com
		Evans & Sutherland
