Xref: news2.mv.net comp.os.msdos.djgpp:4466 From: Shawn Hargreaves 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 Lines: 23 Message-ID: NNTP-Posting-Host: sgi16.york.ac.uk Mime-Version: 1.0 Content-Type: TEXT/PLAIN; charset=US-ASCII 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/ */