Xref:	news2.mv.net comp.os.msdos.djgpp:4466
From:	Shawn Hargreaves <slh100 AT york DOT ac DOT uk>
Newsgroups:	comp.os.msdos.djgpp
Subject:	Re: Are near pointers worth it?
Date:	Sun, 2 Jun 1996 09:25:44 +0100
Organization:	The University of York, UK
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Message-ID:	<Pine.SGI.3.91.960602091339.1316A-100000@sgi16.york.ac.uk>
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In-Reply-To:	<833639372.28391.0@gememail.demon.co.uk>
To:	djgpp AT delorie DOT com
DJ-Gateway:	from newsgroup comp.os.msdos.djgpp

On Sat, 1 Jun 1996, Owen wrote:

> I have managed to get graphics to work in DJGPP by doing all the work
> on an off screen buffer, and the copying the whole thing to VGA memory
> in one go. So I only have to set the selector once, and the use a rep
> movsb command. I have also made this work with SVGA graphics, VESA 1.2
> and VESA 2 linear frame buffers. If I were to use near pointers would
> it make it any faster?

I think not. I got about a 5% speedup of my putpixel() function from 
using near pointers, and that is the absolute worst case becuase it 
involves a segment load per pixel. If you are just setting the selector 
once for any more significant drawing tasks, the overhead is so small as 
to be totally insignificant.



/*
 *	Shawn Hargreaves.        Why is 'phonetic' spelt with a ph?
 *	Check out Allegro and FED on http://www.york.ac.uk/~slh100/
 */

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