polygons
Write rooms in the xml-file as polygons containing one line
For example:
<room id="0" caption="botleneck" zpos="0.000000">
<subroom id="0" closed="0" class="subroom">
<polygon caption="line1">
<vertex px="65.000000" py="104.000000" />
<vertex px="62.000000" py="104.000000" />
</polygon>
<polygon caption="line2">
<vertex px="62.000000" py="102.400" />
<vertex px="62.000000" py="104.000000" />
</polygon>
</subroom>