delorie.com/archives/browse.cgi   search  
Mail Archives: djgpp/1997/07/24/04:18:59

From: derek AT algonet DOT se (Christian Granström)
Newsgroups: comp.os.msdos.djgpp
Subject: Re: Timeconsuming __dpmi_int problem with pageflips!
Date: Sat, 19 Jul 1997 22:09:07 GMT
Organization: RAGE
Lines: 39
Message-ID: <33d13acb.689560@news.algonet.se>
References: <33cf809b DOT 147466 AT news DOT algonet DOT se> <33CFFA50 DOT 1015 AT hotmail DOT com>
NNTP-Posting-Host: du184-1.ppp.algonet.se
To: djgpp AT delorie DOT com
DJ-Gateway: from newsgroup comp.os.msdos.djgpp

On Sat, 19 Jul 1997 01:20:48 +0200, Asbjørn <lordcrc AT hotmail DOT com>
wrote:

>Christian Granström wrote:
>> 
>> Hi!
>> 
>> I use a linearframebuffer with near pointers. Fliping between two
>> pages in the videomem can be done by function 0x4f07 using
>> the int 0x10. It worked just fine until I started to do som heavy
>> graphics routines.I could not belive that I couldn't draw more pixels
>> on p120 in 320x240x24 so i ran gprof. Gprof shows the horrible
>> truth that one single __dpmi_int takes near 50% of the cputime.
>> 
>> This is the code that flips the pages:
>
>> Am I doing something wrong?
>
>Uhm, function 07h is Get/Set Start of Display, function 05h switches
>banks,
>as far as i know...
>
>-- 
>- Asbjørn / Lord Crc
>
>http://home.sn.no/~bheid/
>lordcrc AT hotmail DOT com


Yes thats right, and its just excelent to use it for pageflipping. You
just set the start of the display one page down or up and you got
yourselves a doublebuffer. But I still like the Amiga better :)

derek/RAGE
------------------------------------------------------------------------
      Christian Granström, Bryggerigatan 4A, 733 34 Sala, Sweden
    derek AT algonet DOT se, christiang AT pasdata DOT se, www.algonet.se/~derek
                 +46(0)22477312, +46(0)704961587
------------------------------------------------------------------------

- Raw text -


  webmaster     delorie software   privacy  
  Copyright © 2019   by DJ Delorie     Updated Jul 2019