Re: XML

[Lars Clausen <lrclause cs uiuc edu>]

On Mon, 3 Feb 2003, John Edstrom wrote:
> On Mon, Feb 03, 2003 at 09:39:58AM -0600, Lars Clausen wrote:
> > On Sun, 2 Feb 2003, John Edstrom wrote:
> > > So far my biggest concern with a dot2dia transformation is that dot
> > > uses splines and dia doesn't.  Some of dot's edges get pretty baroque
> > > in complex graphs and arcs and polylines can't do equivalently
> > > tortuous paths as well.
> >
> > Can't you use Dia's beziers?  As I understand it, there are standard
> > translations between most such things.
>
> My background is not in graphics and I didn't know that.  That would
> simplify things immensely.  Is there a list of such algorithms
> anywhere?

I have my info from _Computer_Graphics_, by Hearn and Baker.  Not the
greatest book by any means, but it does describe transformation matrices
between varies splines/beziers.

Some related sites:
http://escience.anu.edu.au/lecture/cg/Spline/printCG.en.html

Note also that Dia's "bezier" isn't really a Bezier line.  It's a string of
line segments (I believe Bezier) with 4 control points each.  The xfig
import plugin has some hacky translation from FIG style splines to Dia
beziers, but it's not exact.

-Lars

-- 
Lars Clausen (http://shasta.cs.uiuc.edu/~lrclause)| Hårdgrim of Numenor
"I do not agree with a word that you say, but I   |----------------------------
will defend to the death your right to say it."   | Where are we going, and
    --Evelyn Beatrice Hall paraphrasing Voltaire  | what's with the handbasket?