polar clock in Shoes

clock.rb

def helper from_edge, number
  twopi = Shoes::TWO_PI
  angle1 = twopi / 4 * 3
  angle2 = (angle1 + number * twopi) % twopi
  width = @clock.width
  radius = width - from_edge * 2

  arc width / 2, width / 2, radius, radius, angle1, angle2
end

Shoes.app title: "Polar Clock", width: 500, height: 500, resizable: false do
  # some neat little options, click on the window to toggle whether or not
  # they're shown
  #   spokes: draw spokes?
  #   c24: use 24 hours instead of 12?
  @checks = flow do
    @spokes, @c24 = check, check
  end

  @checks.toggle
  click { @checks.toggle }

  @clock = flow top: 0, left: 0, width: 500, height: 500

  animate 20 do
    @clock.clear do
      r = @clock.width / 2

      hr = @c24.checked? ? 24 : 12

      if @spokes.checked?
        nofill
        strokewidth 1

        star r, r, hr, r, 0
      end

      nofill
      strokewidth 20

      now  = Time.now
      time = now.to_f + now.utc_offset

      helper 25 * 1, time / 60 / 60 % hr / hr
      helper 25 * 2, time / 60 % 60 / 60
      helper 25 * 3, time % 60 / 60
    end
  end
end