private List createSubgraphs(PlanarGraph graph) {
List subgraphList = new ArrayList();
for (Iterator i = graph.getNodes().iterator(); i.hasNext(); ) {
Node node = (Node) i.next();
if (!node.isVisited()) {
BufferSubgraph subgraph = new BufferSubgraph();
subgraph.create(node);
subgraphList.add(subgraph);
}
}
/**
* Sort the subgraphs in descending order of their rightmost coordinate. This ensures that when
* the Polygons for the subgraphs are built, subgraphs for shells will have been built before
* the subgraphs for any holes they contain.
*/
Collections.sort(subgraphList, Collections.reverseOrder());
return subgraphList;
}
/**
* Completes the building of the input subgraphs by depth-labelling them, and adds them to the
* PolygonBuilder. The subgraph list must be sorted in rightmost-coordinate order.
*
* @param subgraphList the subgraphs to build
* @param polyBuilder the PolygonBuilder which will build the final polygons
*/
private void buildSubgraphs(List subgraphList, PolygonBuilder polyBuilder) {
List processedGraphs = new ArrayList();
for (Iterator i = subgraphList.iterator(); i.hasNext(); ) {
BufferSubgraph subgraph = (BufferSubgraph) i.next();
Coordinate p = subgraph.getRightmostCoordinate();
// int outsideDepth = 0;
// if (polyBuilder.containsPoint(p))
// outsideDepth = 1;
SubgraphDepthLocater locater = new SubgraphDepthLocater(processedGraphs);
int outsideDepth = locater.getDepth(p);
// try {
subgraph.computeDepth(outsideDepth);
// }
// catch (RuntimeException ex) {
// // debugging only
// //subgraph.saveDirEdges();
// throw ex;
// }
subgraph.findResultEdges();
processedGraphs.add(subgraph);
polyBuilder.add(subgraph.getDirectedEdges(), subgraph.getNodes());
}
}