wrap_in_image_map

# File lib/rdoc/diagram.rb, line 313
    def wrap_in_image_map(src, dot)
      res = %{<map id="map" name="map">\n}
      dot_map = `dot -Tismap #{src}`
      dot_map.each do |area|
        unless area =~ /^rectangle \((\d+),(\d+)\) \((\d+),(\d+)\) ([\/\w.]+)\s*(.*)/
          $stderr.puts "Unexpected output from dot:\n#{area}"
          return nil
        end
        
        xs, ys = [$1.to_i, $3.to_i], [$2.to_i, $4.to_i]
        url, area_name = $5, $6

        res <<  %{  <area shape="rect" coords="#{xs.min},#{ys.min},#{xs.max},#{ys.max}" }
        res <<  %{     href="#{url}" alt="#{area_name}" />\n}
      end
      res << "</map>\n"
#      map_file = src.sub(/.dot/, '.map')
#      system("dot -Timap #{src} -o #{map_file}")
      res << %{<img src="#{dot}" usemap="#map" border="0" alt="#{dot}">}
      return res
    end