Function newell

src/ifcgeom/kernels/cgal/CgalKernel.cpp:567–577

namespace {
	cgal_direction_t newell(const std::vector<cgal_point_t> & loop) {
		Kernel_::FT a(0.0), b(0.0), c(0.0);
		for (size_t i = 0; i < loop.size(); ++i) {
			auto & curr = loop[i];
			auto & next = loop[(i + 1) % loop.size()];
			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());
		}
		return cgal_direction_t(a, b, c);
	}
}

namespace {