Message-ID:	<000601bd93ce$155240a0$c34d08c3@arthur>
From:	"Arthur" <arfa AT clara DOT net>
To:	"DJGPP Mailing List" <djgpp AT delorie DOT com>
Subject:	Re: a tile engine question
Date:	Tue, 9 Jun 1998 17:44:27 +0100
MIME-Version:	1.0

> I've got a basic smooth-scroll tile engine that works, but I wanted to get
> some ideas from you guys about what the most effecient means of redrawing
> the screen is.....as of now, everytime the view is to shift, everything is
> redrawn to a new buffer and then blitted to the screen.....it's not too
bad
> but pretty bad....does anyone have any better ideas??

I know you all hate me ranting on about how good my old Atari ST is, but
there was a very fast elegant way on the ST.

You have your standard screen memory reserved by the system. The address of
this screen is pointed to by a dword in low memory. Now the clever bit: by
changing this pointer, you can change the area of memory the computer thinks
is the screen. Now you can have two or three screen buffers, which you can
swap to the screen in one ASM instruction.

Is there any way you can do this on th PC, or more specifically DJGPP?

James Arthur
jaa AT arfa DOT clara DOT net

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