On Mon, Feb 13, 2012 at 10:36 AM, Aaron Windsor wrote:

On Mon, Feb 13, 2012 at 3:59 AM, Andreas Fabri < andreas.fabri@geometryfactory.com> wrote:

...

Hello,

I am wondering about the output of the example on the page http://www.boost.org/doc/libs/**1_48_0/libs/graph/doc/planar_** face_traversal.htmlhttp://www.boost.org/doc/libs/1_48_0/libs/graph/doc/planar_face_traversal.ht...

I would expect that the vertices on the border of the outer or unbounded face got reported in reverse order.

The vertices of inner faces are reported in clockwise order which makes that for each edge shared by inner faces, we traverse it once from source to target, and once from target to source. This does not hold for edges on the outer face.

Is this intentional, or just a documentation bug?

Hi Andreas,

This may just be a documentation bug - if memory serves me correctly, I didn't necessarily run the traversal to create that output, although I think you could easily modify the example code on that page ( http://www.boost.org/doc/libs/1_48_0/libs/graph/example/planar_face_traversa...) to generate similar output.

I don't have a boost checkout handy right now to verify that it's just a documentation bug, but I'll try it out tonight and reply to this thread again.

-Aaron

Hi Andreas, This is indeed a doc bug - I changed the graph in the example code I referenced above so that it described the graph in the docs, like this: graph g(6); add_edge(0,1,g); add_edge(1,4,g); add_edge(4,3,g); add_edge(3,0,g); add_edge(4,5,g); add_edge(5,2,g); add_edge(1,2,g); add_edge(2,3,g); and the vertices came out in the correct order: Vertices on the faces: New face: 0 1 4 3 New face: 1 0 3 2 New face: 4 1 2 5 New face: 3 4 5 2 I just committed the doc fix to trunk, it should show up in the next boost release. Thanks for carefully reading the documentation and reporting this! -Aaron