Groups > comp.lang.java.programmer > #19103

Re: BafflinTransform

From	markspace <-@.>
Newsgroups	comp.lang.java.programmer
Subject	Re: BafflinTransform
Date	2012-10-04 11:44 -0700
Organization	A noiseless patient Spider
Message-ID	<k4kldp$g1q$1@dont-email.me> (permalink)
References	<a1dd4f88-2a80-4af5-8716-d356d9fb3852@googlegroups.com> <k4hmjn$c5t$1@dont-email.me> <e69f5245-a51f-4547-9837-22f23ca838f2@googlegroups.com> <fder68l1c0etqevoaigdb3f09l4rp222l1@4ax.com> <nospam-E2F47C.13581304102012@news.aioe.org>

Show all headers | View raw

On 10/4/2012 10:58 AM, John B. Matthews wrote:

 > In article <fder68l1c0etqevoaigdb3f09l4rp222l1@4ax.com>,
>>
>>       Matrix multiplication is NOT commutative.
>>
>>

> Absolutely correct, as well as pithy. Conceptually, it may help
> to think of a series of (post-) concatenated transformations as
> having been applied in a last-specified-first-applied order.

Another rule of thumb is that scaling and rotating tend to occur around 
the origin, not the translation point.  So if you scale or rotate an 
already-translated AffinceTransform, you might get unintended results.

The method I'm used to from 3D graphics is to translate any objects back 
to the origin, scale and rotate, then translate them back to their 
original/intended point in space.  It's a literal three step process; 
you can't put all that together in one matrix.

Given that AffineTransforms are 2D transforms, some results might be 
different than the 3D equivalents.  Like I said, some math might be 
involved here.

Thread

BafflinTransform bob smith <bob@coolfone.comze.com> - 2012-10-03 07:58 -0700
  Re: BafflinTransform markspace <-@.> - 2012-10-03 08:45 -0700
    Re: BafflinTransform Lew <lewbloch@gmail.com> - 2012-10-03 10:41 -0700
      Re: BafflinTransform Gene Wirchenko <genew@ocis.net> - 2012-10-03 10:51 -0700
      Re: BafflinTransform Arne Vajhøj <arne@vajhoej.dk> - 2012-10-03 21:36 -0400
        Re: BafflinTransform Gene Wirchenko <genew@ocis.net> - 2012-10-03 21:49 -0700
        Re: BafflinTransform Jeff Higgins <jeff@invalid.invalid> - 2012-10-04 03:26 -0400
          Re: BafflinTransform Gene Wirchenko <genew@ocis.net> - 2012-10-04 09:30 -0700
          Re: BafflinTransform Arne Vajhøj <arne@vajhoej.dk> - 2012-10-04 17:38 -0400
            Re: BafflinTransform Jeff Higgins <jeff@invalid.invalid> - 2012-10-05 03:00 -0400
              Re: BafflinTransform Arne Vajhøj <arne@vajhoej.dk> - 2012-10-05 22:02 -0400
        Re: BafflinTransform Lew <lewbloch@gmail.com> - 2012-10-04 12:05 -0700
    Re: BafflinTransform bob smith <bob@coolfone.comze.com> - 2012-10-04 07:22 -0700
      Re: BafflinTransform Gene Wirchenko <genew@ocis.net> - 2012-10-04 09:35 -0700
        Re: BafflinTransform "John B. Matthews" <nospam@nospam.invalid> - 2012-10-04 13:58 -0400
          Re: BafflinTransform markspace <-@.> - 2012-10-04 11:44 -0700
            Re: BafflinTransform "John B. Matthews" <nospam@nospam.invalid> - 2012-10-04 21:23 -0400
              Re: BafflinTransform markspace <-@.> - 2012-10-04 19:27 -0700
                Re: BafflinTransform Peter Duniho <NpOeStPeAdM@NnOwSlPiAnMk.com> - 2012-10-04 19:55 -0700
                Re: BafflinTransform Eric Sosman <esosman@ieee-dot-org.invalid> - 2012-10-04 23:33 -0400
            Re: BafflinTransform Gene Wirchenko <genew@ocis.net> - 2012-10-05 09:04 -0700
              Re: BafflinTransform markspace <-@.> - 2012-10-05 09:34 -0700
                Re: BafflinTransform Gene Wirchenko <genew@ocis.net> - 2012-10-05 12:58 -0700
                Re: BafflinTransform markspace <-@.> - 2012-10-05 17:15 -0700
          Re: BafflinTransform Gene Wirchenko <genew@ocis.net> - 2012-10-04 13:51 -0700
  Re: BafflinTransform Jeff Higgins <jeff@invalid.invalid> - 2012-10-03 15:15 -0400
    Re: BafflinTransform Lew <lewbloch@gmail.com> - 2012-10-03 12:49 -0700
  Re: BafflinTransform Roedy Green <see_website@mindprod.com.invalid> - 2012-10-03 16:01 -0700

csiph-web