The intersection of these two polygons returns an empty result

[anders.jel@…]

This may be related to #5103.

The following program prints a zero area for the intersection of the two polygons.

#include <boost/polygon/polygon.hpp>
#include <vector>
#include <iostream>

using namespace boost::polygon;
using namespace boost::polygon::operators;

int main()
{
    typedef point_data<int64_t> point;

    std::vector<point> a;
    a.push_back(point( 50000000000,   50000000000));
    a.push_back(point( 12500000000,   50000000000));
    a.push_back(point(           0,  100000000000));
    a.push_back(point(-12500000000,   50000000000));
    a.push_back(point(-50000000000,   50000000000));
    a.push_back(point(-50000000000,  -50000000000));
    a.push_back(point(-37500000000,  -50000000000));
    a.push_back(point(-50000000000, -100000000000));
    a.push_back(point( 50000000000, -100000000000));
    a.push_back(point( 37500000000,  -50000000000));
    a.push_back(point( 50000000000,  -50000000000));
    a.push_back(point( 50000000000,   50000000000));

    polygon_data<int64_t> polygon_a;
    set_points(polygon_a, a.begin(), a.end());
    
    std::vector<point> b;
    b.push_back(point(-47702617860,   50000000000));
    b.push_back(point( 50000000000,   50000000000));
    b.push_back(point( 50000000000,  -88753775284));
    b.push_back(point(-47702617860,  -88753775284));

    polygon_data<int64_t> polygon_b;
    set_points(polygon_b, b.begin(), b.end());

    polygon_set_data<int64_t> intersection = polygon_a * polygon_b;
    std::cout << area(intersection) << std::endl; // Prints 0

    std::vector<polygon_data<int64_t> > polygons_in_intersection;
    intersection.get(polygons_in_intersection);
    std::cout << polygons_in_intersection.size() << std::endl; // Prints 0

    return 0;
}

[Lucanus Simonson]

Robust operations with 64 bit integer coordinates are not supported currently. We do not have adding support for this in our short term plans, but replacing some of the coordinate_traits for the 64 bit coordinate type with sufficiently large data types ought to work out of the box. The main problem we have with doing so is lack of such types available to us in the STL or Boost.