Mail Archives: djgpp/1997/10/18/16:31:37

From: mert0407 AT sable DOT ox DOT ac DOT uk (George Foot)
Newsgroups: comp.os.msdos.djgpp
Subject: Re: ALLEGRO - 256 shades of grey?? How?
Date: 18 Oct 1997 16:37:55 GMT
Organization: Oxford University, England
Lines: 23
Message-ID: <62aol3$jqo$>
References: <19971017045203 DOT 14573 DOT qmail AT hotmail DOT com>
To: djgpp AT delorie DOT com
DJ-Gateway: from newsgroup comp.os.msdos.djgpp

On Fri, 17 Oct 1997 04:52:02 GMT in comp.os.msdos.djgpp John Patton
(gimli21 AT hotmail DOT com) wrote: 

: Can't you create a palette containing 256 shades of grey and set the 
: palette with allegro's set pallete function?  I haven't tried, but I 
: believe this should work.  
: i.e., a palette consisting of values like:
: 0,0,0
: 1,1,1
: 2,2,2
: ..
: 255,255,255
: and then set it.  I believe the 6 bits per color is only applicable when 
: converting a palette value to it's equivalent DAC register value.  I may 
: not have the details right, but I believe the DAC is limited to a 6-bit 
: digital to analog conversion per color(2^6 = 64).

Yes, but Allegro uses DAC format, i.e. all colour strengths go from 0 to
63. This is why the original poster had a problem.

George Foot <mert0407 AT sable DOT ox DOT ac DOT uk>
Merton College, Oxford

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