Path: chuka.playstation.co.uk!news
From: Developer Support <dev_support@interactive.sony.com>
Newsgroups: scee.yaroze.programming.2d_graphics
Subject: Re: Double buffering in 640*x
Date: Thu, 22 May 1997 14:17:17 +0100
Organization: Sony Computer Entertainment Europe
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Message-ID: <3384475D.6083@interactive.sony.com>
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Philippe.Lorin wrote:
> 
> Hi there. (*please* tell me if my English's not correct, for I'm French)
>  1 .- I'm wondering whether it's possible to do double buffering with a
> resolution higher than 512 pixels (x value). If I correctly understand
> the double buff mechanism, I need twice the size of one screen in VRAM.
> As the VRAM's size is 1024*512, the maximum length is 1024/2, unless I
> use a 256 pixels height (but I don't want to).
>  2 .- I've already used sprites and tiled-maps on another system (ST).
> My sprites routines didn't do clipping, I just had a working area bigger
> than the real screen, so that when a part of a sprite had to be drawn
> outside there was no problem. I'm happy that the psx hardware provides
> clipping. But it seems that I can't ask it to draw sprites with negative
> coordinates, so how can I draw something that is not entirely on the
> screen ?

You can have a 640x256 screen, but thats the largest double buffered
screen. Interlaced mode does its double buffering on screen, odd and
even lines.

It is possible to set up sprites specifying where the origin of a sprite
is, eg the centre, using (mx,my). This does mean that you have to use
GsSortSprite which isn't as fast as GsSortFastSprite.

Stuart