@thi.ng/geom-poly-utils/perimeter.js

2D polygon/polyline analysis & processing utilities

import { dist } from "@thi.ng/vectors/dist";
const perimeter = (pts, num = pts.length, closed = false) => {
  if (num < 2) return 0;
  let res = 0;
  let p = pts[0];
  let q = pts[1];
  for (let i = 1; i < num; p = q, q = pts[++i]) {
    res += dist(p, q);
  }
  return closed ? res + dist(p, pts[0]) : res;
};
export {
  perimeter
};