@polygonjs/polygonjs/dist/src/core/LineUtils.js

node-based WebGL 3D engine https://polygonjs.com

"use strict";
import { Vector3 } from "three";
const _u = new Vector3();
const _v = new Vector3();
const _w = new Vector3();
const EPS = 1e-4;
export function closestPointsBetweenLines(line1, line2, target) {
  _u.copy(line1.end).sub(line1.start);
  _v.copy(line2.end).sub(line2.start);
  _w.copy(line1.start).sub(line2.start);
  const a = _u.dot(_u);
  const b = _u.dot(_v);
  const c = _v.dot(_v);
  const d = _u.dot(_w);
  const e = _v.dot(_w);
  const D = a * c - b * b;
  let sc;
  let tc;
  if (D < EPS) {
    sc = 0;
    tc = b > c ? d / b : e / c;
  } else {
    sc = (b * e - c * d) / D;
    tc = (a * e - b * d) / D;
  }
  target.pointOnLine1.addVectors(line1.start, _u.multiplyScalar(sc));
  target.pointOnLine2.addVectors(line2.start, _v.multiplyScalar(tc));
}