Mail Archives: djgpp/1997/01/06/16:44:53
DHGW39B AT prodigy DOT com (Mr. Eric Domazlicky) wrote:
>> why 32K color modes? to my knowledge all cards that support 32K
>>colors
>> also support 64K colors. SVGALIB (for Linux and DJGPP) is one library
>>that
>> does support 16bpp modes on Cirrus, S3, and other common cards.
>There's quite a few reasons not to support 64K color modes, for one I
>would bet that some card manufacturers decided to do something stupid
>like put the 6 bit for red (6 bits for green being the supposed
>standard) and they can't do anything to mess up 15-bit modes except
>support the YUV color model maybe.
Both of these special cases are compliant with VESA; a true VESA
graphics library will handle them (although I don't expect anyone
bothers to check for YUV modes in practice!)
> And sometimes you could use that
>last bit on the 15-bit modes for some kind of internal game flag and
The VESA BIOS will tell you if you're allowed to use it or not - some
cards will store the surplus bit and let you read it back, some won't.
This applies to 32 bit modes as well - 8 spare, 8 R, 8 G, 8 B.
>personally i use 15-bit because i use some lookup tables for fiquring
>intensity of colors which would get really big in 64K modes.
Only twice as big :-)
ABW
--
"Simply drag your mother in law's cellphone number from the
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(Windows for Early Warning and Defence User's manual P385)
Alaric B. Williams Internet : alaric AT abwillms DOT demon DOT co DOT uk
<A HREF="http://www.abwillms.demon.co.uk/">Hello :-)</A>
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