/* * 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.overlay; import java.util.*; import com.vividsolutions.jts.geom.*; import com.vividsolutions.jts.algorithm.*; import com.vividsolutions.jts.geomgraph.*; /** * A ring of {@link DirectedEdge}s which may contain nodes of degree > 2. * A <tt>MaximalEdgeRing</tt> may represent two different spatial entities: * <ul> * <li>a single polygon possibly containing inversions (if the ring is oriented CW) * <li>a single hole possibly containing exversions (if the ring is oriented CCW) * </ul> * If the MaximalEdgeRing represents a polygon, * the interior of the polygon is strongly connected. * <p> * These are the form of rings used to define polygons under some spatial data models. * However, under the OGC SFS model, {@link MinimalEdgeRing}s are required. * A MaximalEdgeRing can be converted to a list of MinimalEdgeRings using the * {@link #buildMinimalRings() } method. * * @version 1.7 * @see com.vividsolutions.jts.operation.overlay.MinimalEdgeRing */ public class MaximalEdgeRing extends EdgeRing { public MaximalEdgeRing(DirectedEdge start, GeometryFactory geometryFactory) { super(start, geometryFactory); } public DirectedEdge getNext(DirectedEdge de) { return de.getNext(); } public void setEdgeRing(DirectedEdge de, EdgeRing er) { de.setEdgeRing(er); } /** * For all nodes in this EdgeRing, * link the DirectedEdges at the node to form minimalEdgeRings */ public void linkDirectedEdgesForMinimalEdgeRings() { DirectedEdge de = startDe; do { Node node = de.getNode(); ((DirectedEdgeStar) node.getEdges()).linkMinimalDirectedEdges(this); de = de.getNext(); } while (de != startDe); } public List buildMinimalRings() { List minEdgeRings = new ArrayList(); DirectedEdge de = startDe; do { if (de.getMinEdgeRing() == null) { EdgeRing minEr = new MinimalEdgeRing(de, geometryFactory); minEdgeRings.add(minEr); } de = de.getNext(); } while (de != startDe); return minEdgeRings; } }