code: private void computeMatrixTopoGraphClusters_(int geometry_a, int geometry_b) {
  		boolean bRelationKnown = false;
  
  		int id_a = m_topo_graph.getGeometryID(geometry_a);
  		int id_b = m_topo_graph.getGeometryID(geometry_b);
  
  		for (int cluster = m_topo_graph.getFirstCluster(); cluster != -1; cluster = m_topo_graph
  				.getNextCluster(cluster)) {
  			// Invoke relational predicates
  			switch (m_predicates_cluster) {
  			case Predicates.AreaPointPredicates:
  				bRelationKnown = areaPointPredicates_(cluster, id_a, id_b);
  				break;
  			case Predicates.LinePointPredicates:
  				bRelationKnown = linePointPredicates_(cluster, id_a, id_b);
  				break;
  			case Predicates.PointPointPredicates:
  				bRelationKnown = pointPointPredicates_(cluster, id_a, id_b);
  				break;
  			default:
  				throw GeometryException.GeometryInternalError();
  			}
  
  			if (bRelationKnown)
  				break;
  		}
  
  		if (!bRelationKnown)
  			setRemainingPredicatesToFalse_();
  	}
docs: Line/Point, and Point/Point relations