* calculates intersections and adds the information to the
* {@link MapElement}s
*/
private static void calculateIntersectionsInMapData(MapData mapData) {
MapDataIndex index = new MapIntersectionGrid(mapData.getDataBoundary());
for (MapElement e1 : mapData.getMapElements()) {
/* collect all nearby elements */
Collection<? extends Iterable<MapElement>> leaves
= index.insertAndProbe(e1);
Iterable<MapElement> nearbyElements;
if (leaves.size() == 1) {
nearbyElements = leaves.iterator().next();