From: Max Williams <toastkid.williams@...>
Date: 2009-04-15T01:43:41+09:00
Subject: Re: A challenge: generate web colors for tree nodes.

OK, here's a stab which doesn't satisfy all the requirements.

It makes all unique colors for all 1123 properties, probably by a fluke. 
It does set a brightness limit but *doesn't* make all children of a 
given node have not-similar colors:

  #generate a unique color for this property
  def web_color
    hashable = "#{self.id}_#{self.parent_id}_#{self.name}"
    "#" + Digest::SHA1.hexdigest(hashable)[0..5]
  end

  #normalise color so that it's not above an overall 'brightness'
  def normalised_web_color(max_brightness=200)
    color = self.web_color
    arr = [color[1..2], color[3..4], color[5..6]].collect(&:hex)
    #we only want to normalise if *all* values are over max_brightness
    if arr.all?{|x| x > max_brightness}
      arr = arr.collect { |x| x = ((x.to_f/255)*max_brightness).to_i }
    end
    "##{arr.collect{|x| sprintf("%02x", x)}.join}"
  end

Feels kind of hacky and dirty to me...any thoughts, anyone?
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