discontinuedPackage jet_cad_floor_plan has been discontinued and replaced by jet_cad_2d_plan.

simplifyRing function

List<Vector2> simplifyRing(List<Vector2> ring)

Removes exact consecutive duplicates and zero-width spikes a, b, a (spec 07 D6). Stored-value comparisons, so exact; zero area, so the tiling is unchanged. Without it the triangulator refuses a pinched outline.

Implementation

List<Vector2> simplifyRing(List<Vector2> ring) {
  final r = [...ring];
  var changed = true;
  while (changed && r.length > 3) {
    changed = false;
    for (var i = 0; i < r.length && r.length > 3; i++) {
      final prev = r[(i - 1 + r.length) % r.length];
      final next = r[(i + 1) % r.length];
      if (_same(r[i], next)) {
        r.removeAt(i);
        changed = true;
        break;
      }
      if (_same(prev, next)) {
        // a, b, a -> a: drop b and the repeated a.
        final j = (i + 1) % r.length;
        if (j > i) {
          r.removeAt(j);
          r.removeAt(i);
        } else {
          r.removeAt(i);
          r.removeAt(j);
        }
        changed = true;
        break;
      }
    }
  }
  return r;
}