Path: utzoo!news-server.csri.toronto.edu!rutgers!ucsd!ucbvax!UCBVAX.BERKELEY.EDU!"Dan Karron
From: Dan Karron@UCBVAX.BERKELEY.EDU
Newsgroups: comp.sys.sgi
Subject: Interrupting long draw cycles
Message-ID: <9103112256.AA08202@karron.med.nyu.edu>
Date: 11 Mar 91 22:56:24 GMT
Sender: daemon@ucbvax.BERKELEY.EDU
Reply-To: karron@cmcl2.nyu.edu
Organization: The Internet
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I am curious about using this technique:

I want to change the viewing parameters of a drawing loop. I want
to interrupt the drawing program with a signal, say SIGUSR1. The signal
handler will then do a longjmp back to the main drawing loop with
new eye position and viewing values and start drawing.

This will entail the gl calls being interrupted and aborted at any step.

My experiments with this code have resulted in occational aborts of
the graphics subsystem and the system returning to pandora.

Is there a gracefull way to interrupt the gl subsystem to regain
control ? Can I stop a long draw cycle and start another without
dammage to the gl pipeline ?

Cheers!


Dan.
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