Path: chuka.playstation.co.uk!news
From: Christoph Luerig <cpluerig@immd9.informatik.uni-erlangen.de>
Newsgroups: scee.yaroze.programming.2d_graphics
Subject: Re: tiled background
Date: Wed, 01 Apr 1998 11:21:02 +0200
Organization: PlayStation Net Yaroze (SCEE)
Lines: 51
Message-ID: <352206FD.69CAF71@immd9.informatik.uni-erlangen.de>
References: <350E9D4D.4E08@telecom.at>
NNTP-Posting-Host: faui90.informatik.uni-erlangen.de
Mime-Version: 1.0
Content-Type: text/plain; charset=us-ascii
Content-Transfer-Encoding: 7bit
X-Mailer: Mozilla 4.04C-SGI [en] (X11; I; IRIX 6.3 IP32)

Hello Harald!

I stumbled over the background problem also and there have been some
threads around here, where quite a few peoples said, to use sprites
instead.
Thats the way  I also did it. To generate the background I actually use
three ordering tables. One table is for the scene without the backgorund,
with
a high z resolution, one table is for the background with a low z
resolution, as is the ordering table for the complete scene. You could
initialize the
ordering tables as follows:

GsClearOt(0,0,&ForeGround[ActiveBuffer]);
GsClearOt(0,1,&BackGround[ActiveBuffer]);
GsClearOt(0,0,&CompleteScene[ActiveBuffer]);
The second parameter in the background initialization indicates, that the
background should appear behind the foreground.
You sort every primitive you want to draw normally into the ForeGround
Buffer.
In order to generate the background, you initialize a sprite for every
different tile in advance. These sprites are then sorted into the
Background Buffer with GsSortSprite or GsSortFastSprite, depending on the
effects you would like to achieve. If one image tile is displayed several
times in the background, you can use the same sprite structure and just
change the x,y coordinates before sorting the sprite into the Background
Buffer.
If you have generated the background and the fore ground, you compose the
result by sorting these tables into the Compelte Scene by
GsSortOt(&ForeGround[ActiveBuffer],&CompleteScene[ActiveBuffer]);
GsSortOt(&BackGround[ActiveBuffer],&CompleteScene[ActiveBuffer]);
Finally you can draw the complete scene by
GsDrawOt(&CompleteScene[ActiveBuffer]);


Harald Ploch wrote:

> Hi!
>
> How to I render a tiled background. I found out that there is a GsBG
> structure (GsMAP, GsCELL) and I initialized it, but I don't know how to
> render it. I don't want to use GsSortFixBg16(...).
>
> Please Help!!!!
>
> Thanx,
>
> Harald.

Christoph Luerig