draw (Gruff::SideStackedBar)

    # File lib/gruff/side_stacked_bar.rb, line 14
      def draw
        @has_left_labels = true
        get_maximum_by_stack
        super

        return unless @has_data

        # Setup spacing.
        #
        # Columns sit stacked.
        spacing_factor = 0.9

        @bar_width = @graph_height / @column_count.to_f
        @d = @d.stroke_opacity 0.0
        height = Array.new(@column_count, 0)
        length = Array.new(@column_count, @graph_left)

        @norm_data.each_with_index do |data_row, row_index|
          @d = @d.fill data_row[DATA_COLOR_INDEX]

          data_row[DATA_VALUES_INDEX].each_with_index do |data_point, point_index|

              ## using the original calcs from the stacked bar chart to get the difference between
              ## part of the bart chart we wish to stack.
              temp1 = @graph_left + (@graph_width -
                                        data_point * @graph_width -
                                        height[point_index]) + 1
              temp2 = @graph_left + @graph_width - height[point_index] - 1
              difference = temp2 - temp1

              left_x = length[point_index] #+ 1
                  left_y = @graph_top + (@bar_width * point_index)
              right_x = left_x + difference
                  right_y = left_y + @bar_width * spacing_factor
              length[point_index] += difference
            height[point_index] += (data_point * @graph_width - 2)

            @d = @d.rectangle(left_x, left_y, right_x, right_y)

            # Calculate center based on bar_width and current row
            label_center = @graph_top + (@bar_width * point_index) + (@bar_width * spacing_factor / 2.0)
            draw_label(label_center, point_index)
          end

        end

        @d.draw(@base_image)
      end