I cannot get Dissolve do compile

[JohanDore]

Hi All,

As always, I want to start by thanking you for your work on Boost Geometry. It's been incredibly helpful to us.

We still use Dissolve to fix erroneous polygons that are drawn manually or received from third parties. We encounter various errors, and Dissolve has been a great function for us over the years.

If there are any alternatives, I would be happy to learn how to avoid using Dissolve. But if not, please help get Dissolve to compile again? It worked in 1.85 but with 1.88 I've been trying for the past few hours without any progress, so I probably can't make it work in finite time

Thanks a lot.

Best regards,

Johan

[barendgehrels]

hi @JohanDore ,

Thanks for reporting this issue!

Last spring I have done a big improvement in handling all intersection/union/difference code. I had also dissolve in mind - it should be easier now - but did not yet get to that part yet.

But I will do now, I hope to be able to work on it this and next Month - and it would actually be great to finally have it in the normal branch as well.

Best regards, Barend

[JohanDore]

Hi @barendgehrels,

Oh that is great to hear. Let me know if there is anything I can do to help

Best regards

Johan

[barendgehrels]

hi @JohanDore

First step is there #1411 . See comments there. It compiles again - but it works not yet for all cases. (It works for some cases though)

However, if you want to target 1.88 then most of the changes would do for you. What is not working yet is the adaptation to the new underlying Graph algorithm. Hope to continue that next week.

[JohanDore]

Oh thanks a lot @barendgehrels. It's always a pleasure working with you:-)
I can confirm that it compiles under 1.88, however quite a few of my dissolve unitest still fails, e.g:

polygon<DPointXY> Poly;
read_wkt("POLYGON((0 0, 0 4, 4 4, 4 0, 1 0, 1 3, 3 3, 3 0))", Poly);
correct(Poly);

DMultiPolygon Dissolved;
boost::geometry::dissolve(Poly, Dissolved);

BOOST_CHECK(is_valid(Dissolved));
BOOST_CHECK_EQUAL(Dissolved.size(), 1);
BOOST_CHECK_EQUAL(Dissolved[0].outer().size(), 5); 	//It should have 5 points
BOOST_CHECK_EQUAL(Dissolved[0].inners().size(), 0);
BOOST_CHECK_CLOSE(area(Dissolved), 16.0, 0.0001);

worked under 1.85.

So maybe I better await you next iterations