(none)

[Lance M. Optican - LMO]

Subject: GL Device Error Checking

	I have a dial and button box (DBB) on
my 4D/140. When programs written with code for
the DBB are run on other SGI machines without
one, the DBB code generates lots of error
messages to the screen.  This slows the
graphics program considerably!

	Would someone please tell me how to
detect the presence/absence of a peripheral
device like the DBB?  I RTFM, but it seems
that the obvious way, checking the return
value of "void setvaluator()" is not possible!

NOTE TO SGI:  I could find no entry in the
either system or graphics library manuals
for GL errors.  A much better behavior for
missing peripherals would be a No-Op, rather
than an error message.  Most programs perform
usefully without input from special peripherals,
albeit with less flexibility!

			Thanks,
				Lance Optican

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	Lance M. Optican			   |	uunet!lsr-vax!lmo 
	National Eye Institute, NIH, Bethesda, MD  |	(301) 496-3549    
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