Path: utzoo!utgpu!watmath!clyde!att!rutgers!cmcl2!nrl-cmf!ukma!uflorida!mailrus!ncar!boulder!sunybcs!lively
From: lively@sunybcs.uucp (Richard S. Lively)
Newsgroups: comp.graphics
Subject: Color lookup tables
Message-ID: <3048@cs.Buffalo.EDU>
Date: 2 Dec 88 20:23:17 GMT
Sender: nobody@cs.Buffalo.EDU
Reply-To: lively@sunybcs.UUCP (Richard S. Lively)
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Organization: SUNY/Buffalo Computer Science
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Suppose that you are using a multiple window environment on a
color workstation.  You are using a single window which requires the
use of 150 entries in the color lookup table and now you want to open
another window which requires another 150 entries in the lookup table
(potentially there will be no similar colors in the separate windows).
However, there are not enough available slots in the lookup table to support
that many entries.  How can you maintain color integrity in both windows?

When I asked how different windowing environments handle this, I received
the following responses:

           SunView     -     any window except active window is black
           X           -     does not allow creation of the second window
           Mac II      -     separate lookup table for each window (but
                             not exactly perfect)

Are these answers correct?  If so, what design decisions prompted these
choices?  Is there any reason that each window can't have a separate
lookup table which can become active or inactive dynamically in the
middle of a scan line?