Newsgroups: comp.os.msdos.djgpp
From: samantha <jazz AT ceasars DOT co DOT za>
Subject: Re: Allegro Problems
Message-ID: <34131262.4A18@ceasars.co.za>
Date: Sun, 07 Sep 1997 13:45:22 -0700
References: <3411E944 DOT 52E6 AT voyageur DOT ca> <34124D0A DOT D8B AT drao DOT nrc DOT ca>
Reply-To: jazz AT ceasars DOT co DOT za
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> J.E. wrote:
>
> Hello.  I just downloaded Allegro v2.2, but I am having some serious
> problems with the screen scrolling function.  I wrote this code to test
> the scrolling (something new to me):
>

Why try to do hardware scroll? I am working on something that does
scrolling in full 640x480 SVGA under Allegro. I wanted to use hardware
scroll too (sounded faster) but then checked out the Alleg docs and
realised that some cards won't go for it. So I used a simple system of
two Allegro bitmaps, one the bitmap that is to be scolled (much larger
than my physical screen) with another bitmap (the window) that gets
blitted to screen to simulate a hardware scroll over the much larger
virtual bitmap. It is very fast ( I use a Pent 150 under W95, running
DJGPP in a DOS box). If you want, mail me at acebear AT sb DOT puk DOT ac DOT za and I
can let you have my source for this. otherwise, post here, but I can't
guarantee that I will be able to answer.

Hope this helped!

Rylan