def draw_bars
@bar_spacing ||= 0.9
@bar_width = @graph_width / (@column_count * @data.length).to_f
padding = (@bar_width * (1 - @bar_spacing)) / 2
@d = @d.stroke_opacity 0.0
conversion = Gruff::BarConversion.new()
conversion.graph_height = @graph_height
conversion.graph_top = @graph_top
if @minimum_value >= 0 then
conversion.mode = 1
else
if @maximum_value <= 0 then
conversion.mode = 2
else
conversion.mode = 3
conversion.spread = @spread
conversion.minimum_value = @minimum_value
conversion.zero = -@minimum_value/@spread
end
end
@norm_data.each_with_index do |data_row, row_index|
data_row[DATA_VALUES_INDEX].each_with_index do |data_point, point_index|
left_x = @graph_left + (@bar_width * (row_index + point_index + ((@data.length - 1) * point_index))) + padding
right_x = left_x + @bar_width * @bar_spacing
conv = []
conversion.getLeftYRightYscaled( data_point, conv )
@d = @d.fill data_row[DATA_COLOR_INDEX]
@d = @d.rectangle(left_x, conv[0], right_x, conv[1])
label_center = @graph_left +
(@data.length * @bar_width * point_index) +
(@data.length * @bar_width / 2.0)
draw_label(label_center - (@center_labels_over_point ? @bar_width / 2.0 : 0.0), point_index)
end
end
draw_label(@graph_right, @column_count) if @center_labels_over_point
@d.draw(@base_image)
end