From:	Gary Preston <gary AT prestons DOT demon DOT co DOT uk>
Newsgroups:	comp.os.msdos.djgpp
Subject:	Pixel speed
Date:	Mon, 12 May 1997 19:44:49 +0100
Organization:	None
Distribution:	world
Message-ID:	<VvSYuBAhU2dzEw8S@prestons.demon.co.uk>
NNTP-Posting-Host:	prestons.demon.co.uk
MIME-Version:	1.0
Lines:	19
To:	djgpp AT delorie DOT com
DJ-Gateway:	from newsgroup comp.os.msdos.djgpp

 Hi,
 I've read the djgppgfx guide on a web page, can't remember the name but
it basically had many ways of using the video mem in 32bit protected
mode. I used to draw pixels with the dosmemput( &colour, ....... );
type of call until I saw the :-
#define putpixel(x,y,c) _farpokeb(.....);
after testing the two calls on my machine it took 18 seconds to plot
90000000 pixels in the same pos ( for loop ) with _farpoke but a
staggering 60s with dosmemput. Now the numbers themselves are not very
useful since this is dependent on my code for the rest of the stuff and
my machine but by just changing this line the _farpokeb hack appears
to be 3x as fast ( roughly ).
  Why is this? How does farpokeb work? is there an even quicker method?

Thanks
-- 
Gary Preston

Turnpike evaluation. For information, see http://www.turnpike.com/

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