The result type is std::list<polygon_type>, polygon_set_concept I think, where polygon_type I defined is polygon_concept.

This small program shows the visual result of 2 polygons clipping, and the resultant ploygons are represented as blue outlines(contours).

The input ploygons are taken from Boost.Polygon's unit test, so I would expect the result to be correct at least in this case.

But when doing "union", Boost.Polygon shows me the wierd result, [1], seems like all distinct polygons are merged into one contour, while the correct one should be [2]
Screen shots:
[1]http://tinyurl.com/27fwxfn
[2]http://tinyurl.com/26w3qj6

I'm not sure what's wrong here.


Thanks