# File gtk/sample/testgtk/gammacurve.rb, line 47
  def update
    max = 127 + (@count % 2) * 128
    @curve.curve.set_range(0, max, 0, max)
    vec = []
    max.times do |i|
      vec[i] = (127 / sqrt(max)) * sqrt(i)
    end
    @curve.curve.set_vector(max, vec)
    @count += 1
  end