Path: utzoo!utgpu!attcan!uunet!super!udel!gatech!rutgers!ucsd!ucsdhub!hp-sdd!hplabs!hpl-opus!hpccc!hp-sde!hpfcdc!cunniff
From: cunniff@hpfcdc.HP.COM (Ross Cunniff)
Newsgroups: comp.sys.amiga.tech
Subject: Re: IFF form for 2D drawings (again)
Message-ID: <11640004@hpfcdc.HP.COM>
Date: 8 Aug 88 15:03:18 GMT
References: <11640003@hpfcdc.HP.COM>
Organization: HP Ft. Collins, Co.
Lines: 31

In article <2412@sugar.uu.net> peter@sugar.uu.net (Peter da Silva) writes:
>> 	3. Rectangles may still be rotated.
>I don't see why you're specifically singling out rectangles here. 

It was a (feeble) attempt at a joke.  The last time we went through
this, 50% of the discussion was about PostScript, and 50% about whether
rectangles should be rotatable...

>Of course
>rectangles should be rotatable... in fact *any* object should have a rotation
>angle as part of its definition. A rectangle should be two points and an
>angle. An ellipse should be a major and minor axis, a center point, and a
>rotation angle. And so on...

Actually, every object *is* rotatable; simply rotate the actual points
of the data.  Exceptions include text and symbols, which have explicit
rotation angles in their definitions since their data is not manipulable
in such a fashion.  My rationale for precomputing the rotation is that
it is faster to render objects whose position and rotation are precomputed
rather than rotating and traslating them on the fly (although I am
open to a convicing argument in favor of including a rotation angle
for the objects...)


>		Peter da Silva  `-_-'  peter@sugar.uu.net
>		 Have you hugged  U  your wolf today?

					Ross Cunniff
					Hewlett-Packard Colorado Language Lab
					...{ucbvax,hplabs}!hpda!cunniff
					cunniff%hpda@hplabs.ARPA