Function clipRejoin

external/.d3.js:10537–10609

(segments, compareIntersection, startInside, interpolate, stream)

// into its visible line segments, and rejoins the segments by interpolating
// along the clip edge.
function clipRejoin(segments, compareIntersection, startInside, interpolate, stream) {
  var subject = [],
      clip = [],
      i,
      n;

  segments.forEach(function(segment) {
    if ((n = segment.length - 1) <= 0) return;
    var n, p0 = segment[0], p1 = segment[n], x;

    if (pointEqual(p0, p1)) {
      if (!p0[2] && !p1[2]) {
        stream.lineStart();
        for (i = 0; i < n; ++i) stream.point((p0 = segment[i])[0], p0[1]);
        stream.lineEnd();
        return;
      }
      // handle degenerate cases by moving the point
      p1[0] += 2 * epsilon$1;
    }

    subject.push(x = new Intersection(p0, segment, null, true));
    clip.push(x.o = new Intersection(p0, null, x, false));
    subject.push(x = new Intersection(p1, segment, null, false));
    clip.push(x.o = new Intersection(p1, null, x, true));
  });

  if (!subject.length) return;

  clip.sort(compareIntersection);
  link$1(subject);
  link$1(clip);

  for (i = 0, n = clip.length; i < n; ++i) {
    clip[i].e = startInside = !startInside;
  }

  var start = subject[0],
      points,
      point;

  while (1) {
    // Find first unvisited intersection.
    var current = start,
        isSubject = true;
    while (current.v) if ((current = current.n) === start) return;
    points = current.z;
    stream.lineStart();
    do {
      current.v = current.o.v = true;
      if (current.e) {
        if (isSubject) {
          for (i = 0, n = points.length; i < n; ++i) stream.point((point = points[i])[0], point[1]);
        } else {
          interpolate(current.x, current.n.x, 1, stream);
        }
        current = current.n;
      } else {