# File lib/gruff/line.rb, line 52
  def draw
    super

    return unless @has_data

    # Check to see if more than one datapoint was given. NaN can result otherwise.
    @x_increment = (@column_count > 1) ? (@graph_width / (@column_count - 1).to_f) : @graph_width

    if (defined?(@norm_baseline)) then
      level = @graph_top + (@graph_height - @norm_baseline * @graph_height)
      @d = @d.push
      @d.stroke_color @baseline_color
      @d.fill_opacity 0.0
      @d.stroke_dasharray(10, 20)
      @d.stroke_width 5
      @d.line(@graph_left, level, @graph_left + @graph_width, level)
      @d = @d.pop
    end

    @norm_data.each do |data_row|
      prev_x = prev_y = nil

      @one_point = contains_one_point_only?(data_row)

      data_row[DATA_VALUES_INDEX].each_with_index do |data_point, index|
        new_x = @graph_left + (@x_increment * index)
        next if data_point.nil?

        draw_label(new_x, index)

        new_y = @graph_top + (@graph_height - data_point * @graph_height)

        # Reset each time to avoid thin-line errors
        @d = @d.stroke data_row[DATA_COLOR_INDEX]
        @d = @d.fill data_row[DATA_COLOR_INDEX]
        @d = @d.stroke_opacity 1.0
        @d = @d.stroke_width line_width ||
          clip_value_if_greater_than(@columns / (@norm_data.first[DATA_VALUES_INDEX].size * 4), 5.0)


        circle_radius = dot_radius ||
          clip_value_if_greater_than(@columns / (@norm_data.first[DATA_VALUES_INDEX].size * 2.5), 5.0)

        if !@hide_lines and !prev_x.nil? and !prev_y.nil? then
          @d = @d.line(prev_x, prev_y, new_x, new_y)
        elsif @one_point
          # Show a circle if there's just one_point
          @d = @d.circle(new_x, new_y, new_x - circle_radius, new_y)
        end
        @d = @d.circle(new_x, new_y, new_x - circle_radius, new_y) unless @hide_dots

        prev_x = new_x
        prev_y = new_y
      end

    end

    @d.draw(@base_image)
  end