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From: joe@etac632 (Joe Fulson-Woytek)
Newsgroups: comp.sys.sgi
Subject: Re:  gl question - editing large objects
Message-ID: <2912@dftsrv.gsfc.nasa.gov>
Date: 27 Jul 90 11:11:18 GMT
References: <9007251346.AA24480@acf4.NYU.EDU> <10946@odin.corp.sgi.com>
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Reply-To: joe@etac632.gsfc.nasa.gov (Joe Fulson-Woytek)
Organization: NSESCC, Goddard Space Flight Center, Greenbelt MD
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In article <10946@odin.corp.sgi.com> kurt@cashew.asd.sgi.com (Kurt Akeley) writes:
>no, it is not the case that GL objects are obsolete.  (although it was
>reasonable to conclude this, based on the lack of development attention
>that they received prior to the 3.3 release.)  in the 3.3 release
>objects have been extended to include ALL the new drawing commands,
>such as bgnpolygon(), c(), n(), v(), t(), and endpolygon().  the
>execution performance of objects is now very high, in some cases slightly
>higher than can be achieved by immediate-mode calls.
>
While this part is good news, I have a philosophical problem with the
following:
>
>in general, we continue to encourage you to program using the immediate
>mode capabilities of the GL.  immediate mode coding supports interractive
>graphics driven by changing data.  that's the way we like to do graphics.
>
This implies, to me at least, that SGI considers the use of objects as
being wrong, simply because they like to do graphics without them. This
reminds me of the SGI course I took a couple of years ago when the instructor
said noone should ever use color map mode. I don't think vendors should
tell customers that it is wrong to use a tool the vendor supplies (I can
understand a vendor saying not to use a tool someone else supplies). Another
common vendor mistake is to think that how the vendor uses their own product
is how the customer is going to use it. I would urge SGI to continue
providing a range of graphics tools and supporting them without making
judgements on how or if those tools should be used. (Recommendations for
how to use a tool are, of course, appropriate and desired).

Joe Fulson-Woytek