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From: jmunkki@hila.hut.fi (Juri Munkki)
Newsgroups: comp.sys.mac.programmer
Subject: Re: Rotating PICTs or BitMaps by arbitrary angle
Message-ID: <1990Nov3.205726.29319@santra.uucp>
Date: 3 Nov 90 20:57:26 GMT
References: <1990Nov3.122649.12277@cs.uoregon.edu>
Sender: news@santra.uucp (Cnews - USENET news system)
Reply-To: jmunkki@hila.hut.fi (Juri Munkki)
Organization: Helsinki University of Technology, FINLAND
Lines: 30

In article <1990Nov3.122649.12277@cs.uoregon.edu> mkelly@cs.uoregon.edu (Michael A. Kelly) writes:
>
>Hello peoples.  Has anyone figured out a fast way to rotate a PICT or
>BitMap by an arbitrary angle?  I can figure out how to do it slowly, but
>I need to rotate a small (e.g. 40x40) PICT (or BitMap) at least one revolution
>per second.
>
>Source code, pseudocode, idle speculation welcome.

Take a look at UMPG (Usenet Macintosh Programmers' Guide). In this case,
you will find a complete program that will rotate either a bitmap or a
PICT to an arbitrary angle.

Now that the version 1.0 is out, I guess this is good advice to anyone
who needs sample source code or help in Mac programming. Take a look at
the guide first, and then ask for help from this newsgroup.

The guide is available from sumex-aim.stanford.edu with anonymous ftp:
-r   292153 Oct 21 18:21 ./tech/usenet-mac-prog-guide-part1.hqx
-r   291192 Oct 21 18:21 ./tech/usenet-mac-prog-guide-part2.hqx

Another possibility for rotating bitmaps is described in Graphics Gems
by Andrew Glassner (actually edited by him). It describes a method where
you rotate a bitmap by doing three shear operations. This book is just
as vital for graphics programmers as UMPG is for Macintosh programmers.

   ____________________________________________________________________________
  / Juri Munkki	    /  Helsinki University of Technology   /  Wind  / Project /
 / jmunkki@hut.fi  /  Computing Center Macintosh Support  /  Surf  /  STORM  /
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