Re: [Lib2geom-devel] Recent progress on boolops

[Nathan H. <nj...@nj...>]

On Thu, Aug 14, 2014 at 05:12:48PM +0200, Krzysztof Kosiński wrote:
... 
> Regarding the second issue, I added some unit tests that indicate that
> subdivision of one fragment (be it Bezier or SBasis) is actually
> exact, in the sense that A.at1() == B.at0(). The actual problem is the
> simultaneous subdivision of two fragments. If we have fragments A and
> B and we determine that they intersect at time values (a, b), we need
> an API that produces four Beziers A1, A2, B1, B2 such that A1.at1() ==
> A2.at0() == B1.at1() == B2.at0() exactly. This is required because
> A.valueAt(a) will almost always be slightly different from
> B.valueAt(b). More generally, given a vector of time value pairs, we
> need to create a vector of result Beziers adhering to the above
> condition.

That makes sense, nice analysis.  I suspect averaging the results of
A1(a), A2(a) for x, B for y, and setting the end points appropriately
will be good enough.

njh