From:	Shawn Hargreaves <Shawn AT talula DOT demon DOT co DOT uk>
Newsgroups:	comp.os.msdos.djgpp
Subject:	Re: Allegro HiColor & Compatibility
Date:	Thu, 5 Feb 1998 19:09:04 +0000
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To:	djgpp AT delorie DOT com
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Rylan writes:
>My question is: How will switching to 15bit or higher color affect the
>executability of my code on various systems?

As long as you support both 15 and 16 bit modes and stick to common
resolutions like 640x480, it should be ok on everything but really
ancient systems. Be warned, though, that a scarily large number of VESA
drivers have some nasty bugs in their truecolor functions, so some
people will probably need to install UniVBE to make things work
correctly.

>Second Question: If I go HiColor (15 bit say) how will the speed of 
>Allegro Video Operations be affected?

This depends very much on the details of what functions you are using.
Running the test program should give you a pretty good idea of where and
how big the differences are.

>Thirdly: How much storage space will a 15 bit 640x480 screen (or 
>whatever applicable 15 bit resolution) require in relation to an 8 bit 
>640x480 screen, if stored uncompressed?

Twice as much. Sixteen bits per pixel times a 640x480 screen equals a
600k framebuffer, that is just basic arithmetic...


--
Shawn Hargreaves - shawn AT talula DOT demon DOT co DOT uk - http://www.talula.demon.co.uk/
"Pigs use it for a tambourine" - Frank Zappa

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