polygon / voronoi: points on line segments yield errors

[maik.nijhuis@…]

http://www.boost.org/doc/libs/1_57_0/libs/polygon/doc/voronoi_main.htm says: "input segments should not overlap except their endpoints"

Their is no restriction on input *points*, though, so I conclude that points may lie on line segments. However, construct_voronoi fails with the following input:

• One point, at (1, 0)
• One line segment, from (0, 0) to (2, 0)

The output has only one vertex, with invalid x and y coordinates.

Fortunately, I can easily work around the issue:

• Before calling construct_voronoi, I was already using intersect_segments for creating proper input segments. When I add the points as zero-length segments in the input for intersect_segments, intersect_segments will cut segments when there is a point at the segment.
• Since intersect_segments discards zero-length segments, I still pass the points separately, as I did before.

Could you please either update the documentation or resolve the issue otherwise?

[Andrii Sydorchuk]

Hi Maik,

Thank you for the report!

You are right, the documentation is not complete. Input geometries should not intersect except their endpoints. I updated the docs in the development branch and they should be merged in 1.58 release.

[Andrii Sydorchuk]

The change was merged to the master branch. You can either start using new documentation from the github repo: ​https://github.com/boostorg/polygon or wait for the Boost 1.58 release.