Path: chuka.playstation.co.uk!news
From: sceetech <ps_yaroze@interactive.sony.com>
Newsgroups: scee.yaroze.programming.2d_graphics
Subject: Re: Background Images
Date: Wed, 26 Mar 1997 09:48:16 +0000
Organization: SCEE
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Richard Haskey wrote:
> 
> Hi,
> 
>         Does anyone know where I can get source for displaying a
> 
>         background image (GsBG definition)?
> 
>         I have tried all day to display a repeated texture cell
> 
>         but have been so far been unsuccessful.
> 
>         Also, is it possible to rotate the background image using
> 
>         hardware - There is a rotate field within the GsBG structure
> 
>         but the comments describing the function GsSortFixBg16
> 
>         (which I am trying to use to display the image) say :-
> 
>         "BG rotation/scaling/reduction not possible"
> 
>         Thanks in advance,
> 
>                           Richard Haskey
> 
>         N.B. For what its worth, the screen I am using is setup as
> 
>         320 X 256 with video mode PAL.


You can't rotate or scale a GsBG, the fields in the structure are a left
over from the full libraries. GsSortFixBg16 also only works for 4 and 8
bit textures with a cell size of 16.

To be honest nobody here uses it. To display a background its much
easier to use either sprites, if you want to do scaling/rotating, or use
LoadImage and MoveImage. The down side to both methods is scrolling,
which means using 4 sprites and moving them around.

Of course you can use polygons which is possibly the fastest method.

Stuart