Function verticesFromBoostRing

src/utilities/geometry/Intersection.cpp:480–509

convert a boost ring to vertices

// convert a boost ring to vertices
std::vector<Point3d> verticesFromBoostRing(const BoostRing& ring, std::vector<Point3d>& allPoints, double tol) {
  std::vector<Point3d> result;

  // add point for each vertex except final vertex
  for (unsigned i = 0; i < ring.size() - 1; ++i) {
    const Point3d point3d(ring[i].x(), ring[i].y(), 0.0);

    // try to combine points within tolerance
    Point3d resultPoint = getCombinedPoint(point3d, allPoints, tol);

    // don't keep repeated vertices
    if ((i > 0) && (result.back() == resultPoint)) {
      continue;
    }
    result.emplace_back(std::move(resultPoint));
  }

  result = removeCollinearLegacy(result);

  // don't keep repeated vertices
  if (result.front() == result.back()) {
    result.pop_back();
  }

  if (result.size() < 3) {
    return {};
  }

  return result;
}

// struct used to sort polygons in descending order by area
struct BoostPolygonAreaGreater