Boost Intersection not working
boost, boost-geometry, c++
Solution
My best guess is that this has to do with specifying the points in counterclockwise order when by default `polygon` expects the points to be in clockwise order. So you would need to change it as follows:
read_wkt("POLYGON((-213.57 -2.131 , -350.0 -2.842 , -350.0 37.5 , -213.57 -2.131))", triangle);
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Problem
i have a big problem with boost intersection. i would like to intersect a triangle with a quad, but i get a clip: Can somebody help me? I tried to changed the orientation of the geometry, nothing happened. the intersection work with other triangles, but not with this. ``` typedef model::polygon<model::d2::point_xy<double> > polygon std::deque<polygon> tmp; bool ok = intersection(quad, triangle, tmp) ``` The triangle: ``` -213.57 -2.13163e-14 0 -350 37.5 0 -350 -2.84217e-14 0 ``` The box: ``` BoundingBox(-300, -165, 2, 170, -0.1, 0.1) ``` UPDATE: Here my code. I use gcc 4.7.2 with boost 1.53.0 on Ubuntu 12.10 ``` #include <deque> #include <fstream> #include <boost/geometry.hpp> #include <boost/geometry/geometries/polygon.hpp> #include <boost/geometry/geometries/point_xy.hpp> #include <boost/geometry/io/wkt/wkt.hpp> #include <boost/geometry/extensions/io/svg/svg_mapper.hpp> using namespace boost::geometry; int main() { typedef model::polygon<model::d2::point_xy<double> > polygon; typedef typename model::d2::point_xy<double> point_type; polygon quad, triangle; read_wkt("POLYGON((-213.57 -2.131 , -350.0 37.5 , -350.0 -2.842 , -213.57 -2.131))", triangle); read_wkt("POLYGON((-300.0 2 , -300 170 , -165 170 , -165 2 , -300 2))", quad); std::deque<polygon> output; intersection(quad, triangle, output); std::string filename = "intersectiontest.svg"; std::ofstream svg(filename.c_str()); svg_mapper<point_type> mapper(svg, 600, 600); mapper.add(output[0]); mapper.map(output[0], "fill-opacity:0.5;fill:rgb(153,204,0);stroke:rgb(255,0,0);stroke-width:5"); } ```