#include <s2/s2latlng.h>
#include <vector>
#include <s2/s2polyline.h>
#include <s2/s2builderutil_snap_functions.h>
#include <s2/s2builderutil_s2polyline_layer.h>
#include <s2/s2loop.h>

int main(int argc, char **argv) {
    std::vector<S2LatLng> latlngs;

    latlngs.emplace_back(S2LatLng::FromRadians(1, -1));
    latlngs.emplace_back(S2LatLng::FromRadians(1, 1));
    latlngs.emplace_back(S2LatLng::FromRadians(-1, -1));
    latlngs.emplace_back(S2LatLng::FromRadians(-1, 1));
    latlngs.emplace_back(S2LatLng::FromRadians(1, -1));

    S2Polyline inPolyline(latlngs);
    S2Polyline outPolyline;
    s2builderutil::IntLatLngSnapFunction snap(2);
    snap.set_snap_radius(S1Angle::Radians(0.01));
    S2Builder::Options options(snap);
    options.set_split_crossing_edges(true);
    options.set_simplify_edge_chains(true);
    options.set_idempotent(false);
    S2Builder builder(options);
    builder.StartLayer(absl::make_unique<s2builderutil::S2PolylineLayer>(&outPolyline));
    builder.AddPolyline(inPolyline);
    S2Error error;
    S2_CHECK(builder.Build(&error)) << error;

    std::vector<S2Point> correctedContour;
    for (int i=0; i<outPolyline.num_vertices()-1; i++)
        correctedContour.emplace_back(outPolyline.vertex(i));

    S2Loop loop(correctedContour);
    return 0;
}