From: frenchc AT cadvision DOT com (frenchc)
Newsgroups: comp.os.msdos.djgpp
Subject: Re: Tile based scrolling?
Date: 20 Jan 1997 04:26:22 GMT
Organization: CADVision Development Corp.
Lines: 28
Message-ID: <5bus5e$308i@elmo.cadvision.com>
References: <5bjnrh$bu2 AT dailyplanet DOT wam DOT umd DOT edu> <01bc0405$868f0a00$20d6b5cf AT default>
NNTP-Posting-Host: ts35ip234.cadvision.com
To: djgpp AT delorie DOT com
DJ-Gateway: from newsgroup comp.os.msdos.djgpp

In article <01bc0405$868f0a00$20d6b5cf AT default>, "fayda" <iii AT io DOT com> says:

>James Jeffrey Benjamin <jamesb AT wam DOT umd DOT edu> wrote in article
><5bjnrh$bu2 AT dailyplanet DOT wam DOT umd DOT edu>...
>> I'm slowly working on a tile based engine using Allegro (mainly for
>> 640x480) and it has become prone to bugs. Anyway, what I'm doing is
>double
>> buffer with blitting (moving) the virtual screen around as I add new rows
>> of sprites. Is this faster or slower with the conventional way of just
>> rewriting every (compiled) sprite onto the screen buffer? I know my way
>> will get quite complex when I introduce parallex srolling. Sprite by
>> sprite is easier, but is it faster?

>One of the main reasons for double buffering is to reduce the "flicker"
>effect you get when you write directly to the screen. There are other ways
>of doing it, but double buffering is Usually the preferred method. If your
>program is very speed intensive, I would suggest dumping Allegro and write
>the code yourself.

Uhm... Excuse me?!? Do you know what the word means? Fast. You won't get
any faster than allegro. The problem James is having is that there is no
real purpose to doing what he is doing. Just redraw the whole screen once
again to your double buffer and dump it, don't add rows. I once wrote a
dirty rectangle tile-based engine and trust me, it was waaay a bad idea.
I did eventually get it working, but it wasn't worth it. Just dump the
whole screen, that's what I'm doing now...

- Calvin -