Relay-Version: version B 2.10 5/3/83; site utzoo.UUCP
Posting-Version: version B 2.10.3 4.3bsd-beta 6/6/85; site topaz.RUTGERS.EDU
Path: utzoo!watmath!clyde!cbosgd!ihnp4!houxm!whuxl!whuxlm!akgua!gatech!seismo!caip!topaz!shulman
From: shulman@topaz.RUTGERS.EDU (Jeff Shulman)
Newsgroups: net.graphics
Subject: bitmap rotation algorithm needed
Message-ID: <4224@topaz.RUTGERS.EDU>
Date: Wed, 20-Nov-85 10:46:17 EST
Article-I.D.: topaz.4224
Posted: Wed Nov 20 10:46:17 1985
Date-Received: Sat, 23-Nov-85 03:51:13 EST
Organization: Rutgers Univ., New Brunswick, N.J.
Lines: 17

I am looking for an alogithm that would allow me to rotate N x N bitmaps in
90 degree increments.  I am already familiar with the shearing algorithm (too
slow) and the quarter masking algorithm (N is not always a power of 2.)

Ideally this algorithm should have at least the same speed as the
masking algorithm and be capable of rotating the bitmap in place (or
require minimal additional memory since there is no room for a duplicate size
bitmap.)

Thanks.

							Jeff

uucp:   ...{harvard, seismo, ut-sally, sri-iu, ihnp4!packard}!topaz!shulman
arpa:   SHULMAN@RUTGERS
CIS:    76136,667
Delphi: JEFFS