def draw
get_maximum_by_stack
super
return unless @has_data
spacing_factor = 0.9
@bar_width = @graph_width / @column_count.to_f
@d = @d.stroke_opacity 0.0
height = Array.new(@column_count, 0)
@norm_data.each_with_index do |data_row, row_index|
@d = @d.fill data_row[DATA_COLOR_INDEX]
data_row[1].each_with_index do |data_point, point_index|
left_x = @graph_left + (@bar_width * point_index)
left_y = @graph_top + (@graph_height -
data_point * @graph_height -
height[point_index]) + 1
right_x = left_x + @bar_width * spacing_factor
right_y = @graph_top + @graph_height - height[point_index] - 1
height[point_index] += (data_point * @graph_height - 2)
@d = @d.rectangle(left_x, left_y, right_x, right_y)
label_center = @graph_left + (@bar_width * point_index) + (@bar_width * spacing_factor / 2.0)
draw_label(label_center, point_index)
end
end
@d.draw(@base_image)
end