Re: Thoughts about variable-width strokes in SVG2

I think, you can provide all options, 
if you align with the corresponding functionality of animateMotion.
If one has a corresponding set of attributes and lists, one can
get all the functionalities.
This allows as well to use cubic Bezier curves and a smooth
change of the width. 
The Catmull-Rom method seems to have the problem, that
the derivatives typically do not approximate intended paths
very good, therefore one needs a lot of points (large document
size) to approximate with good quality. 
This is ok for fast approaches, but advanced authors should
have the option to provide control points as well.

Asymmetrical stroke-width can be relevant as well, negative
width is not completely useless.  If an author
sets it to a negative value - is it a problem for implementation?
If not, then one can interprete it simply as a width to the other
side, this would allow a simple method to get a zero width 
somewhere within the segment without the need to specifiy
this as a point of the path or knowing exactly the path fragment
length.

The asymmetry itself is not really a problem,  because one
can or should align it according to the pace of path data,
respectively the directionality of the path data as used 
for some other features as well, therefore it is already defined,
what the direction is and therefore it is known, what it means
to be on the left or the right of a path.


Olaf

Received on Tuesday, 7 May 2013 08:37:23 UTC