- From: Doug Schepers <schepers@w3.org>
- Date: Wed, 17 Jun 2009 00:44:00 -0400
- To: Chris Lilley <chris@w3.org>
- CC: Patrick Ion <ion@ams.org>, W3C SVG Public Working Group <public-svg-wg@w3.org>
Hi, folks- Raph Levien's Spiro work might be relevant to this topic, particularly with SVG fonts. Some of this is implemented in Inkscape, which might make it a natural inclusion. http://www.levien.com/spiro/ http://www.levien.com/phd/phd.html Regards- -Doug Chris Lilley wrote (on 6/11/09 11:34 AM): > Hello Patrick, > > I hope this mail finds you well. I'm mailing you with a copy to the > SVG public list, because we would like your help on a mathematical > problem we are having. > > A couple of years ago, at TPAC, we were discussing a class of curves > with the property of passing through a set of points (or near, for > some definition of near), and differing from the curves that SVG > already has (cubic and quadratic Beziers) or might have (non-uniform > rational b-spline curves) in that no off-curve control points are > used to define the curve, only the on-curve knots. > > I suppose these are piecewise curves with some fairing or smoothness > property where the pieces join. > > Does this ring any bells? I can't even recall the name for that class > of curves, sorry. > > We have a couple of use cases for such curves, now; one is for > graphing/charting applications where it is desired to run a smooth > (for some definition of smooth) curve through a set of 2D points > rather than joining them by a polyline. > > The second is to run a curve through a set of 3D points (where the 3D > space is a colour space) to produce colour gradients from a list of > colours, without perceptual discontinuities. Current gradients > effectively connect colours by polylines, so there is a perceptual > discontinuity at each colour stop. > > tracker, this relates to ACTION-2584 >
Received on Wednesday, 17 June 2009 04:44:09 UTC