fix for the d3.js radial tree bug (when there is only 1 child on the root)

d3-radial-tree-bug

importScripts('../vendor/d3/d3.layout.redux.js')

@onmessage = (msg) ->
  tree = msg.data

  # the layout has a weird effect
  if tree.children.length is 1
    for n in tree.children[0].children
      tree.children.push ghost: yes, children: []

  d3_layout = d3.layout.tree()

  d3_layout.separation (a, b) ->
    (if a.parent is b.parent then 1 else 3) / a.depth

  nodes = d3_layout.nodes tree

  newNodes = for n in nodes
    continue if n.ghost
    angle = n.x * Math.PI * 2
    n.x = 2000 * n.y * Math.cos angle
    n.y = 2000 * n.y * Math.sin angle
    n
       
  nodes = newNodes

   # sort elements by id
  nodes.sort (a,b) -> a.id - b.id

  postMessage nodes