From: "Damian Yerrick" <web DOT poison AT pineight DOT 8m DOT com>
Newsgroups: comp.os.msdos.djgpp
References: <Pine DOT SUN DOT 3 DOT 91 DOT 991021170208 DOT 4001C-100000 AT is> <380EF520 DOT C2FAE759 AT connect DOT ab DOT ca>
Subject: Re: Plague of the slow 'blit' routine :)
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NNTP-Posting-Date: Sat, 23 Oct 1999 19:53:38 GMT
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Date: Sat, 23 Oct 1999 19:53:38 GMT
To: djgpp AT delorie DOT com
DJ-Gateway: from newsgroup comp.os.msdos.djgpp
Reply-To: djgpp AT delorie DOT com

Tom Fjellstrom <tomcf AT connect DOT ab DOT ca> wrote:
> Thank you Eli,
>
> But I can't be completely sure if the 'bitmap' i'm blitting
> to or from is in video memory. If I could then it would
> make sense to call the dosmemput or farptr functions
> only for those 'bitmaps'. I may be wrong but I don't think
> 'regular' memory can (or should?) be accessed with
> dosmemput or those farptr functions. The only way I have
> thought of determining that a bitmap is in video memory
> is too add a variable to the bitmap struct when creating
> it to indicate whether or not it is in video memory. If that
> is the only safe way of doing it I guess i'll have to.

That's the way it was done in Allegro.
http://www.talula.demon.co.uk/allegro/

--
Damian Yerrick
CM 398, Rose-Hulman Institute of Technology
5500 Wabash Ave | Terre Haute, IN 47803
http://come.to/yerrick <- redpinocchio
http://yerricde.tripod.com/ <- pinocchio's brother