[boost] Boost.Polygon issues

Subject: [boost] Boost.Polygon issues
From: Barend Gehrels (barend_at_[hidden])
Date: 2011-03-05 09:03:29

Hi Luke,

You asked me on the GGL mailing list ( http://bit.ly/hCwdJx ) to verify 
tests using Boost.Polygon to check Boost.Geometry's behaviour at some 
points.

I cannot reach that point. I ported a test that I already had (recursive 
polygons) to Boost.Polygon. I'm using the Polygon Set Concept with 
integer coordinates. Actually all input is in the 90/45 degree range.

If I run the program, it often gives me the wrong results, even in the 
simpler cases. And often it just crashes, in the line 1748 of file 
polygon_arbitrary_formation.hpp (called from the area function)

I extracted two (wrong but not crashing) cases. Source code here: 
http://bit.ly/fCYRWL

Summary of second case:
area p: 45000
area q: 55000
area intersection: 0
area union: 60000

The last one, area of union, should be 100000, if the intersection is 
zero, the union contains everything and its area therefore should sum to 
100000

Regards, Barend