def draw
super
return unless @has_data
@x_increment = @graph_width / (@column_count - 1).to_f
@d = @d.stroke 'transparent'
@norm_data.each do |data_row|
poly_points = Array.new
prev_x = prev_y = 0.0
@d = @d.fill data_row[DATA_COLOR_INDEX]
data_row[DATA_VALUES_INDEX].each_with_index do |data_point, index|
new_x = @graph_left + (@x_increment * index)
new_y = @graph_top + (@graph_height - data_point * @graph_height)
if prev_x > 0 and prev_y > 0 then
poly_points << new_x
poly_points << new_y
else
poly_points << @graph_left
poly_points << @graph_bottom - 1
poly_points << new_x
poly_points << new_y
end
draw_label(new_x, index)
prev_x = new_x
prev_y = new_y
end
poly_points << @graph_right
poly_points << @graph_bottom - 1
poly_points << @graph_left
poly_points << @graph_bottom - 1
@d = @d.polyline(*poly_points)
end
@d.draw(@base_image)
end