d3-octree/src/visitAfter.js

Three-dimensional recursive spatial subdivision.

import Octant from "./octant.js";

export default function(callback) {
  var octs = [], next = [], q;
  if (this._root) octs.push(new Octant(this._root, this._x0, this._y0, this._z0, this._x1, this._y1, this._z1));
  while (q = octs.pop()) {
    var node = q.node;
    if (node.length) {
      var child, x0 = q.x0, y0 = q.y0, z0 = q.z0, x1 = q.x1, y1 = q.y1, z1 = q.z1, xm = (x0 + x1) / 2, ym = (y0 + y1) / 2, zm = (z0 + z1) / 2;
      if (child = node[0]) octs.push(new Octant(child, x0, y0, z0, xm, ym, zm));
      if (child = node[1]) octs.push(new Octant(child, xm, y0, z0, x1, ym, zm));
      if (child = node[2]) octs.push(new Octant(child, x0, ym, z0, xm, y1, zm));
      if (child = node[3]) octs.push(new Octant(child, xm, ym, z0, x1, y1, zm));
      if (child = node[4]) octs.push(new Octant(child, x0, y0, zm, xm, ym, z1));
      if (child = node[5]) octs.push(new Octant(child, xm, y0, zm, x1, ym, z1));
      if (child = node[6]) octs.push(new Octant(child, x0, ym, zm, xm, y1, z1));
      if (child = node[7]) octs.push(new Octant(child, xm, ym, zm, x1, y1, z1));
    }
    next.push(q);
  }
  while (q = next.pop()) {
    callback(q.node, q.x0, q.y0, q.z0, q.x1, q.y1, q.z1);
  }
  return this;
}