Function tree

docs/tests/v2/es6/js/sanddance.js:121953–121980

(root)

      nodeSize = null;

  function tree(root) {
    var t = treeRoot(root); // Compute the layout using Buchheim et al.’s algorithm.

    t.eachAfter(firstWalk), t.parent.m = -t.z;
    t.eachBefore(secondWalk); // If a fixed node size is specified, scale x and y.

    if (nodeSize) root.eachBefore(sizeNode); // If a fixed tree size is specified, scale x and y based on the extent.
    // Compute the left-most, right-most, and depth-most nodes for extents.
    else {
        var left = root,
            right = root,
            bottom = root;
        root.eachBefore(function (node) {
          if (node.x < left.x) left = node;
          if (node.x > right.x) right = node;
          if (node.depth > bottom.depth) bottom = node;
        });
        var s = left === right ? 1 : separation(left, right) / 2,
            tx = s - left.x,
            kx = dx / (right.x + s + tx),
            ky = dy / (bottom.depth || 1);
        root.eachBefore(function (node) {
          node.x = (node.x + tx) * kx;
          node.y = node.depth * ky;
        });
      }
    return root;
  } // Computes a preliminary x-coordinate for v. Before that, FIRST WALK is
  // applied recursively to the children of v, as well as the function
  // APPORTION. After spacing out the children by calling EXECUTE SHIFTS, the
  // node v is placed to the midpoint of its outermost children.