Hi,

Menelaos Karavelas wrote:

On 07/11/2014 12:10 πμ, Menelaos Karavelas wrote:

On 06/11/2014 11:56 μμ, Will Lucas wrote:

This would hopefully allow me to define a custom multi_polygon. As my initial attempt to just create an std::vector<dft::Contour> as a multi_polygon, resulted in a bunch of compiler complaints :D

I think this is because your vector's value type is a ring rather than a polygon.

Actually this works for me. Though since a container of Rings isn't a "proper" Geometry other functions may not work with it, e.g. bg::wkt() from your example.
My code:

#include <boost/foreach.hpp>

#include <boost/geometry.hpp>

namespace bg = boost::geometry;

typedef bg::model::point<int, 2, bg::cs::cartesian> point_type;

typedef bg::model::ring<point_type> ring_type;

typedef std::vector<ring_type> rings_container;

int main()

{

    ring_type pol1, pol2;

    bg::read_wkt("POLYGON((75 75,75 175,275 175,275 75,75 75))", pol1);

    bg::read_wkt("POLYGON((50 50,50 150,250 150,250 50,50 50))", pol2);

    rings_container rings;

    bg::intersection(pol1, pol2, rings);

    BOOST_FOREACH(ring_type const& r, rings)

        std::cout << bg::wkt(r) << std::endl;

    return 0;

}

FYI, it compiles also if the input Geometries are Polygons. I tried this:

polygon_type pol1, pol2;

bg::read_wkt("POLYGON((0 0,0 10,10 10,10 0,0 0),(4 4,6 4,6 6,4 6,4 4))", pol1);

bg::read_wkt("POLYGON((1 1,1 11,11 11,11 1,1 1))", pol2);

rings_container rings;

bg::intersection(pol1, pol2, rings);

BOOST_FOREACH(ring_type const& r, rings)

    std::cout << bg::wkt(r) << std::endl;

bg::intersection(pol2, pol1, rings);

BOOST_FOREACH(ring_type const& r, rings)

    std::cout << bg::wkt(r) << std::endl;

In this case holes aren't included in the output:

POLYGON((1 10,10 10,10 1,1 1,1 10))
POLYGON((1 10,10 10,10 1,1 1,1 10))

Is this behavior intended?