From:	Yamaha / XYZZ <scriven AT CS DOT ColoState DOT edu>
Newsgroups:	comp.os.msdos.djgpp
Subject:	Re: Smoothness in W95
Date:	Thu, 14 Nov 1996 11:24:50 -0700
Organization:	XYZZ Software Co.
Lines:	29
Message-ID:	<328B63F2.167E@CS.ColoState.edu>
References:	<3288e9cf DOT 68908 AT news DOT demon DOT co DOT uk>
NNTP-Posting-Host:	seurat.vis.colostate.edu
Mime-Version:	1.0
To:	djgpp AT delorie DOT com
DJ-Gateway:	from newsgroup comp.os.msdos.djgpp

lazer wrote:
> 
> Hi
>     I am writing a game in 360*240, Mode X  , With Triple Buffering
> and it is very smooth in dos, however when i run under W95 it is very
> jerky, i have same problem with every other mode I have tried under
> W95 even plain mode 13h.
> Can anyone help me out!

Have you been using hardware page flipping or vertical retrace
checking?  If so, that's what Windows is interfering with.

Windows will often use interrupts here and there in the middle of a page
flip or vertical retrace, thus destroying that frame and/or messing up
the timing.

I don't know how to get around this problem, though.  I just know the
cause.  It would probably be a bad idea to disable interrupts whenever
you want to wait for retrace, unless you don't intend it to run under
Windoze.

This problem will probably NOT show up noticably if your frame rate is
less that 20 fps.  (so make your game go slower... :)


-- Yamaha / XYZZ
mailto:scriven AT CS DOT ColoState DOT edu          
mailto:scriven AT VIS DOT ColoState DOT edu
http://www.vis.colostate.edu/~scriven/

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