Re: Math/Theory Questions about PostScript-style drawing
Re: Math/Theory Questions about PostScript-style drawing
- Subject: Re: Math/Theory Questions about PostScript-style drawing
- From: chamlin <email@hidden>
- Date: Mon, 17 Sep 2001 18:09:01 -0400
On Monday, September 17, 2001, at 05:44 PM, David W. Halliday wrote:
Matthew Cox wrote:
...
The transformations are all carried out on the coordinates of each
and
every point. Therefore, if you wish to rotate an object, for instance,
around some particular point (in the object, such as it's "center", for
instance) then you create a transformation matrix that translates the
origin
to the desired point, rotates about that origin, and then translates
back to
the initial origin.
Of course, this can all be reduced to a single transformation
matrix.
I hope this clears such things up. (Incidentally, this is far more
general than PostScript-style drawing---it is a general method for
handling
the group of all linear transformations, including translation, allowed
in 2
dimensional space, and can be easily generalized to higher dimensions.)
Is this really more general than PS-style drawing? The matrices and
equations he gives are more-or-less exactly reproduced in the PS
Language Reference (Red Book). What are you describing that can't
be done in PS?
Regards,
Chris Hamlin