boolean vector effects (Was: Re: [Inkscape-user] Equivalent to Illustrator's Gradient Mesh?)

On Tue, 2007-05-22 at 05:36 +0200, Chris Lilley wrote:
> M> by way of contrast, the boolean
> M> operations required by SVG vector effects represent a _much_ higher
> M> implementation burden than triangulation would.
> 
> Although Inkscape still seems to implement most of them, while
> calculating the resulting geometry itself rather than writing out the
> vector effect. but that should be a separate thread.

The thing is, the code we brought in to implement that is pretty
problematic -- the author vanished on us, the licensing status is a
little fuzzy, and the code quality is so poor as to be nearly
unmaintainable.  I couldn't recommend that anyone else use it, and the
only reason we haven't replaced it ourselves is that there simply aren't
any other computational geometry libraries with the required features
(and numerical stability!) available under a liberal enough license.
Unfortunately writing a robust implementation of those operations
requires a great deal of very specialized domain knowledge.

Until we see other open source implementations of vector effects (and
until there's a finalized standard, which realistically probably depends
on that), I don't think I can sell implementing vector effects to the
other developers.  We've discussed approaches using <switch> to deal
with user agents that don't implement them, but the consensus was that
such approaches would introduce too much complexity to the UI code for
working with paths.

-mental