draw (Gruff::Line)

    # File lib/gruff/line.rb, line 48
      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

          data_row[1].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 clip_value_if_greater_than(@columns / (@norm_data.first[1].size * 4), 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)
            end
            circle_radius = clip_value_if_greater_than(@columns / (@norm_data.first[1].size * 2.5), 5.0)
            @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