/* * The JTS Topology Suite is a collection of Java classes that * implement the fundamental operations required to validate a given * geo-spatial data set to a known topological specification. * * Copyright (C) 2001 Vivid Solutions * * This library is free software; you can redistribute it and/or * modify it under the terms of the GNU Lesser General Public * License as published by the Free Software Foundation; either * version 2.1 of the License, or (at your option) any later version. * * This library is distributed in the hope that it will be useful, * but WITHOUT ANY WARRANTY; without even the implied warranty of * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU * Lesser General Public License for more details. * * You should have received a copy of the GNU Lesser General Public * License along with this library; if not, write to the Free Software * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA * * For more information, contact: * * Vivid Solutions * Suite #1A * 2328 Government Street * Victoria BC V8T 5G5 * Canada * * (250)385-6040 * www.vividsolutions.com */ package com.vividsolutions.jts.operation.linemerge; import com.vividsolutions.jts.geom.Coordinate; import com.vividsolutions.jts.geom.CoordinateArrays; import com.vividsolutions.jts.geom.LineString; import com.vividsolutions.jts.planargraph.DirectedEdge; import com.vividsolutions.jts.planargraph.Edge; import com.vividsolutions.jts.planargraph.Node; import com.vividsolutions.jts.planargraph.PlanarGraph; /** * A planar graph of edges that is analyzed to sew the edges together. The * <code>marked</code> flag on @{link com.vividsolutions.planargraph.Edge}s * and @{link com.vividsolutions.planargraph.Node}s indicates whether they have been * logically deleted from the graph. * * @version 1.7 */ public class LineMergeGraph extends PlanarGraph { /** * Adds an Edge, DirectedEdges, and Nodes for the given LineString representation * of an edge. * Empty lines or lines with all coordinates equal are not added. * * @param lineString the linestring to add to the graph */ public void addEdge(LineString lineString) { if (lineString.isEmpty()) { return; } Coordinate[] coordinates = CoordinateArrays.removeRepeatedPoints(lineString.getCoordinates()); // don't add lines with all coordinates equal if (coordinates.length <= 1) return; Coordinate startCoordinate = coordinates[0]; Coordinate endCoordinate = coordinates[coordinates.length - 1]; Node startNode = getNode(startCoordinate); Node endNode = getNode(endCoordinate); DirectedEdge directedEdge0 = new LineMergeDirectedEdge(startNode, endNode, coordinates[1], true); DirectedEdge directedEdge1 = new LineMergeDirectedEdge(endNode, startNode, coordinates[coordinates.length - 2], false); Edge edge = new LineMergeEdge(lineString); edge.setDirectedEdges(directedEdge0, directedEdge1); add(edge); } private Node getNode(Coordinate coordinate) { Node node = findNode(coordinate); if (node == null) { node = new Node(coordinate); add(node); } return node; } }