eachAfter method

QuadTree<T> eachAfter(VisitCallback<T> callback)

Implementation

QuadTree<T> eachAfter(VisitCallback<T> callback) {
  List<InnerQuad<T>> quads = [];
  List<InnerQuad<T>> next = [];
  InnerQuad<T> q;
  if (_root != null) {
    quads.add(InnerQuad(_root!, _x0, _y0, _x1, _y1));
  }

  while (quads.isNotEmpty) {
    q = quads.removeLast();
    QuadNode<T>? node = q.node;
    if (node.hasChild) {
      num x0 = q.x0, y0 = q.y0, x1 = q.x1, y1 = q.y1;
      num xm = ((x0 + x1) / 2);
      num ym = ((y0 + y1) / 2);
      QuadNode<T>? child;
      if ((child = node[0]) != null) quads.add(InnerQuad(child!, x0, y0, xm, ym));
      if ((child = node[1]) != null) quads.add(InnerQuad(child!, xm, y0, x1, ym));
      if ((child = node[2]) != null) quads.add(InnerQuad(child!, x0, ym, xm, y1));
      if ((child = node[3]) != null) quads.add(InnerQuad(child!, xm, ym, x1, y1));
    }
    next.add(q);
  }

  while (next.isNotEmpty) {
    q = next.removeLast();
    callback(q.node, q.x0, q.y0, q.x1, q.y1);
  }
  return this;
}