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From: simon@einode.UUCP (Simon Kenyon)
Newsgroups: comp.graphics
Subject: Re: Re: Y positive up or down?
Message-ID: <213@einode.UUCP>
Date: Tue, 11-Nov-86 05:33:26 EST
Article-I.D.: einode.213
Posted: Tue Nov 11 05:33:26 1986
Date-Received: Wed, 12-Nov-86 03:16:12 EST
References: <5298@brl-smoke.ARPA>
Organization: The National Software Centre, Dublin, Ireland.
Lines: 22

> 
> In article <7291@utzoo.UUCP> henry@utzoo.UUCP (Henry Spencer) writes:
>>To quote from "Hardware/Software Trade-offs for Bitmap Graphics
>>on the Blit", Pike/Locanthi/Reiser, Software-Practice&Experience Feb 1985:
>>
>>" ... All bitmaps share a single
>>coordinate space, with (0,0) in the upper left. ... "
> 
> Ah, but in the ACM TOG, Apr 1983 Rob used 1st-quadrant.  It is worth
> noting that almost all the algorithms are independent of this convention.
> (Exercise:  Find the one that isn't.)
i'm told, but i haven't had the heart to look, that where it bites you in the
bum is in scrolling. apparently, my layers implementation got that wrong, so
i assume that that is where the dependency lies.
[the mental scars of getting what i did get working
working still have not healed]
-- 
Simon Kenyon
EUnet: simon@einode.UUCP
Smail: The National Software Centre, Dublin, IRELAND
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