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From: evensen@husc9.harvard.edu (Erik Evensen)
Newsgroups: comp.sys.mac.programmer
Subject: color/gamma table animation (was Re: what I want to see in future Apple computers)
Message-ID: <EVENSEN.91Jun20145544@husc9.harvard.edu>
Date: 20 Jun 91 18:55:44 GMT
References: <31504@hydra.gatech.EDU> <1991Jun18.135838.3444@potomac.ads.com>
	<EVENSEN.91Jun20083252@husc9.harvard.edu>
	<1991Jun20.172609.9795@ni.umd.edu>
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In-reply-to: zben@ni.umd.edu's message of 20 Jun 91 17:26:09 GMT

In article <1991Jun20.172609.9795@ni.umd.edu> zben@ni.umd.edu (Ben Cranston) writes:

   In article <EVENSEN.91Jun20083252@husc9.harvard.edu>
   evensen@husc9.harvard.edu (Erik Evensen) writes:

   > Well, I hate to be a stick in the mud but to set the record straight,
   > it is my understanding, after reading the Palette Manager section of
   > Inside Mac VI that direct devices (i.e., those whiz-bang 24 bit
   > colorcards) do not have CLUT's either.  To quote: "Color table
   > animation doesn't work on a direct device -- it has no color table."
   > (p. 20-11)  Now maybe there's a trick to getting a direct device to
   > act like one which has a CLUT but I haven't seen anything about it;
   > correct me if I'm wrong.  

   OK!   :-)

   I understand all mainline Apple video cards have a Gamma correction table,
   and that it is at least theoretically possible to do color table animation
   of sorts by modifying this table on the fly.  I've never done so and hope
   to never *have* to do so.

   [explanation of what a gamma table is deleted...]

Thank you for the information...

I looked up gamma table in IM VI and it is listed in the Control Panel
as part of an example for writing a control panel.  The passage refers
to "Designing Cards and Drivers for the Macintosh Family".  I get the
feeling that this is not something us lowly programmers are supposed
to muck with and is probably less portable than doing CLUT animation.
Am I missing some great programming technique here?

--Erik (evensen@husc.harvard.edu)