def draw_line_markers
return if @hide_line_markers
@d = @d.stroke_antialias false
@d = @d.stroke(@marker_color)
@d = @d.stroke_width 1
number_of_lines = 5
increment = significant(@maximum_value.to_f / number_of_lines)
(0..number_of_lines).each do |index|
line_diff = (@graph_right - @graph_left) / number_of_lines
x = @graph_right - (line_diff * index) - 1
@d = @d.line(x, @graph_bottom, x, @graph_bottom + 0.5 * LABEL_MARGIN)
diff = index - number_of_lines
marker_label = diff.abs * increment
unless @hide_line_numbers
@d.fill = @font_color
@d.font = @font if @font
@d.stroke = 'transparent'
@d.pointsize = scale_fontsize(@marker_font_size)
@d.gravity = CenterGravity
@d = @d.annotate_scaled( @base_image,
0, 0,
x, @graph_bottom + (LABEL_MARGIN * 2.0),
marker_label.to_s, @scale)
end
@d = @d.stroke_antialias true
end
end