Function newell

src/ifcgeom/kernels/cgal/CgalConversionResult.cpp:34–45

namespace {
	template <typename Facet>
	CGAL::Direction_3<Kernel_> newell(Facet& face) {
		typename Kernel_::FT a(0), b(0), c(0);
		CGAL::Polyhedron_3<Kernel_>::Halfedge_around_facet_const_circulator current_halfedge = face.facet_begin();
		do {
			auto& curr = current_halfedge->vertex()->point();
			auto& next = current_halfedge->next()->vertex()->point();
			a += (curr.y() - next.y()) * (curr.z() + next.z());
			b += (curr.z() - next.z()) * (curr.x() + next.x());
			c += (curr.x() - next.x()) * (curr.y() + next.y());
		} while (++current_halfedge != face.facet_begin());
		return CGAL::Direction_3<Kernel_>(a, b, c);
	}

	struct Plane_equation {
		template <typename Facet>