Function pointRing

docs/app/js/sanddance-app.js:132698–132704

(lambda, phi)

            line.lineEnd();
        }
        function pointRing(lambda, phi) {
            ring.push([
                lambda,
                phi
            ]);
            ringSink.point(lambda, phi);
        }
        function ringStart() {
            ringSink.lineStart();
            ring = [];