Path: utzoo!utgpu!news-server.csri.toronto.edu!bonnie.concordia.ca!thunder.mcrcim.mcgill.edu!snorkelwacker.mit.edu!bu.edu!rpi!zaphod.mps.ohio-state.edu!swrinde!cs.utexas.edu!uunet!comp.vuw.ac.nz!actrix!templar!jbickers
From: jbickers@templar.actrix.gen.nz (John Bickers)
Newsgroups: comp.sys.amiga.graphics
Subject: Re: Colorburst and Animation
Message-ID: <1562.tnews@templar.actrix.gen.nz>
Date: 21 Mar 91 23:48:54 GMT
References: <13948@life.ai.mit.edu> <JLANGE.91Mar14151051@ap1seq.oracle.com> <1991Mar15.193235.2926@cs.mcgill.ca> <979@cbmger.UUCP>
Organization: TAP, NZAmigaUG.
Lines: 43

Quoted from <979@cbmger.UUCP> by peterk@cbmger.UUCP (Peter Kittel GERMANY):
> In article <1991Mar15.193235.2926@cs.mcgill.ca> tinyguy@cs.mcgill.ca (Yeo-Hoon BAE) writes:

> > Is it really necessary to use all 24 bits?
> > From quick calculation, 18 bits are more than enough to
> > display 640x400 screen with every pixel having different

    In no time at all people will want to have 1K x 1K displays, if not
    larger. I know I see little value in splashing out $$ on a 24-bit
    board if it has significantly less resolution than that.

> > colors. So why not have 24 bit palettes and use 18 bits
> > or less for the lower resolutions?
> 
> Indeed, 24-bit palettes were nice to have, BUT: Do you know one
> existing chip that can hold that palette data (or color lookup
> table)? Remember, you want 2^24 entries in your palette with
> 18 bits each, this is, well, let's calculate, 48 Megabytes.

    It'd be 1 << 18 entries, with 24 bits each, wouldn't it? If you're
    going to have 24-bit pixels anyhow, then having an 18-bit palette
    seems a bit ridiculous.

> (I love such speculations:) And the reason to use palettes is to
> have such nice effects like color cycling easily available. Now

    Is there a scheme where a 24-bit board could use a (very small)
    palette for these sorts of effects, or some table of colors
    that can be used to fiddle with the palette easily, even if its
    some sort of restricted mode?

    Like a table of 48-bit entries, where the 1st 24 bits are the
    color to fake (yeah, like an alias table!), and the other half of
    the entry contains the color to replace the 1st half with when
    displaying.

    This table could have some sort of queueing scheme set up so that
    aliases could be replaced when the table got full.

> Best regards, Dr. Peter Kittel  // E-Mail to  \\  Only my personal opinions... 
--
*** John Bickers, TAP, NZAmigaUG.        jbickers@templar.actrix.gen.nz ***
***         "Patterns multiplying, re-direct our view" - Devo.          ***