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From: mil@mendel.acc.Virginia.EDU (Maria I. Lasaga)
Newsgroups: comp.sys.mac.programmer
Subject: Re: Rotating bitmaps
Message-ID: <1990Sep2.213912.14801@murdoch.acc.Virginia.EDU>
Date: 2 Sep 90 21:39:12 GMT
References: <90244.145341CXT105@psuvm.psu.edu>
Sender: news@murdoch.acc.Virginia.EDU
Organization: University of Virginia
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In article <90244.145341CXT105@psuvm.psu.edu> CXT105@psuvm.psu.edu (Christopher Tate) writes:
>What is a good, fast, accepted method for rotating bitmaps?  Going bit by
>bit seems like a terribly inefficient way to do it, but I'm having trouble
>coming up with a more "intimate" method that isn't terribly complicated.
>
>Mostly, I just want to be able to rotate text in an offscreen bitmap to
>multiples of 90 degree orientations.  I'm working in C, so I have access
>to inline assembly and all those wonderful bit operators.
>
>Also, rotating bitmaps seems like a much easier task than rotating pixmaps.
>Although I don't have to work with pixmaps for the particular project I'm
>working on now, I may have to sometime....  Info on this problem would
>also be appreciated.
>
>-------
>Christopher Tate           |    "In a fit of perverse brilliance, Carl the
>                           |     repairman mistook a room humidifier for a
>cxt105@psuvm.psu.edu       |     mid-size computer, but managed to get it
>cxt105@psuvm.bitnet        |     to connect to the network anyway."


See IEEE: CG&A, May, 1987, p.21-30, for a summary of software and
hardware solutions to orthogonal rotations of bitmap images.

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Maria I. Lasaga
Dept. of Psychology
Gilmer Hall
University of Virginia
Charlottesville, Virginia  22903                 mil@virginia.bitnet
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