Re: [Lib2geom-devel] Method for "fuse two paths at a common point"

[Johan E. <jbc...@sw...>]

On 5-9-2012 17:21, mathog wrote:
>
> Geom::Piecewise<Geom::D2<Geom::SBasis> > P1; // N points assigned
> Geom::Piecewise<Geom::D2<Geom::SBasis> > P2; // M points assigned
>
> where P1's last point is the same as P2's first.  The slopes
> on both sides of that common point are correct too because P1 and P2
> are
> subpaths of a common path.  What is (pseudocode)
>
>     P1.fuse(P2);
>
> to leave P1 with N+M-1 points and the segments beginning/ending on the
> common point fused?
>
> Presumably it isn't:
>
>      P1.concat(P2);
>
> because, as I think I understand it, concat would leave two copies of
> the common point and
> would not fuse the draw operation through it.

The Piecewise class does not store points, only path segments 
(D2<SBasis> in this case). Segments are completely independent from each 
other (discontinuities are allowed, for example). So concat does what 
you wish; it only places P2 after P1, without modifying/adjusting the 
result.

Regards,
   Johan