Path: utzoo!dptcdc!jarvis.csri.toronto.edu!mailrus!ncar!boulder!ccncsu!handel.colostate.edu!bullerj
From: bullerj@handel.colostate.edu (Jon Buller)
Newsgroups: comp.graphics
Subject: Re: Pixar's noise function
Keywords: random numbers, Byte, elephants
Message-ID: <1669@ccncsu.ColoState.EDU>
Date: 17 Apr 89 15:08:22 GMT
References: <2553@ssc-vax.UUCP> <3599@pixar.UUCP> <97699@sun.Eng.Sun.COM> <1592@ccncsu.ColoState.EDU> <43327@tut.cis.ohio-state.edu> <1648@ccncsu.ColoState.EDU> <1771@skinner.nprdc.arpa>
Sender: news@ccncsu.ColoState.EDU
Reply-To: bullerj@handel.colostate.edu.UUCP (Jon Buller)
Organization: Colorado State University, Ft. Collins CO 80523
Lines: 27

In article <1771@skinner.nprdc.arpa> malloy@nprdc.arpa (Sean Malloy) writes:
>If I understand the problem correctly, writing a floor() function is
>extremely simple:

>int floor(x)
>double x;
>{
>  if (x >= 0.0) return(trunc(x));
>           else return(trunc(x)+1);
>}

> Sean Malloy					| "The proton absorbs a photon
> Navy Personnel Research & Development Center	| and emits two morons, a
> San Diego, CA 92152-6800			| lepton, a boson, and a
> malloy@nprdc.navy.mil				| boson's mate. Why did I ever
>						| take high-energy physics?"
                                     I like this      ^^^^^^      8-)

Well, that almost works, if x = -1.0, floor = -1.0, your_func = 0.0
(you meant return(trunc(x)-1); didn't you?) in this case, your_func = -2.0,
this ---->  ^^^^^^^^    will work if x is NOT an integer, will break if it is,
and it is admittedly a simple thing to fix, but as I said before, I've been
LAZY.  I can't use the thing in a render quite yet, so I haven't bothered.

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Jon Buller                                      FROM fortune IMPORT quote;
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