/*
* GeoTools - The Open Source Java GIS Toolkit
* http://geotools.org
*
* (C) 2001-2006 Vivid Solutions
* (C) 2001-2008, Open Source Geospatial Foundation (OSGeo)
*
* 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;
* version 2.1 of the License.
*
* 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.
*/
package org.geotools.geometry.iso.operation.overlay;
import java.util.ArrayList;
import java.util.Iterator;
import java.util.LinkedList;
import java.util.List;
import org.geotools.geometry.iso.coordinate.LineStringImpl;
import org.geotools.geometry.iso.coordinate.PointArrayImpl;
import org.geotools.geometry.iso.primitive.CurveImpl;
import org.geotools.geometry.iso.topograph2D.DirectedEdge;
import org.geotools.geometry.iso.topograph2D.DirectedEdgeStar;
import org.geotools.geometry.iso.topograph2D.Edge;
import org.geotools.geometry.iso.topograph2D.Label;
import org.geotools.geometry.iso.topograph2D.Node;
import org.geotools.geometry.iso.topograph2D.util.CoordinateArrays;
import org.geotools.geometry.iso.util.Assert;
import org.geotools.geometry.iso.util.algorithm2D.PointLocator;
import org.opengis.geometry.coordinate.LineString;
import org.opengis.geometry.coordinate.Position;
import org.opengis.geometry.primitive.CurveSegment;
import org.opengis.geometry.primitive.OrientableCurve;
import org.opengis.referencing.crs.CoordinateReferenceSystem;
/**
* Forms JTS LineStrings out of a the graph of {@link DirectedEdge}s created by
* an {@link OverlayOp}.
*
*
*
*
* @source $URL$
*/
public class LineBuilder {
private OverlayOp op;
//private FeatGeomFactoryImpl featGeomFactory;
private CoordinateReferenceSystem crs;
//private GeometryFactoryImpl coordinateFactory;
//private PrimitiveFactoryImpl primitiveFactory;
private PointLocator ptLocator;
private List lineEdgesList = new ArrayList();
private List<OrientableCurve> resultLineList = new ArrayList<OrientableCurve>();
public LineBuilder(OverlayOp op, CoordinateReferenceSystem crs,
PointLocator ptLocator) {
this.op = op;
this.crs = crs;
//this.coordinateFactory = featGeomFactory.getGeometryFactoryImpl();
//this.primitiveFactory = featGeomFactory.getPrimitiveFactory();
this.ptLocator = ptLocator;
}
/**
* @return a list of the LineStrings in the result of the specified overlay
* operation
*/
public List<OrientableCurve> build(int opCode) {
this.findCoveredLineEdges();
this.collectLines(opCode);
// labelIsolatedLines(lineEdgesList);
this.buildLines(opCode);
return resultLineList;
}
/**
* Find and mark L edges which are "covered" by the result area (if any). L
* edges at nodes which also have A edges can be checked by checking their
* depth at that node. L edges at nodes which do not have A edges can be
* checked by doing a point-in-polygon test with the previously computed
* result areas.
*/
private void findCoveredLineEdges() {
// first set covered for all L edges at nodes which have A edges too
for (Iterator nodeit = op.getGraph().getNodes().iterator(); nodeit
.hasNext();) {
Node node = (Node) nodeit.next();
// node.print(System.out);
((DirectedEdgeStar) node.getEdges()).findCoveredLineEdges();
}
/**
* For all L edges which weren't handled by the above, use a
* point-in-poly test to determine whether they are covered
*/
for (Iterator it = op.getGraph().getEdgeEnds().iterator(); it.hasNext();) {
DirectedEdge de = (DirectedEdge) it.next();
Edge e = de.getEdge();
if (de.isLineEdge() && !e.isCoveredSet()) {
boolean isCovered = op.isCoveredByA(de.getCoordinate());
e.setCovered(isCovered);
}
}
}
private void collectLines(int opCode) {
for (Iterator it = op.getGraph().getEdgeEnds().iterator(); it.hasNext();) {
DirectedEdge de = (DirectedEdge) it.next();
collectLineEdge(de, opCode, lineEdgesList);
collectBoundaryTouchEdge(de, opCode, lineEdgesList);
}
}
/**
* Collect line edges which are in the result. Line edges are in the result
* if they are not part of an area boundary, if they are in the result of
* the overlay operation, and if they are not covered by a result area.
*
* @param de
* the directed edge to test
* @param opCode
* the overlap operation
* @param edges
* the list of included line edges
*/
private void collectLineEdge(DirectedEdge de, int opCode, List edges) {
Label label = de.getLabel();
Edge e = de.getEdge();
// include L edges which are in the result
if (de.isLineEdge()) {
if (!de.isVisited() && OverlayOp.isResultOfOp(label, opCode)
&& !e.isCovered()) {
// Debug.println("de: " + de.getLabel());
// Debug.println("edge: " + e.getLabel());
edges.add(e);
de.setVisitedEdge(true);
}
}
}
/**
* Collect edges from Area inputs which should be in the result but which
* have not been included in a result area. This happens ONLY:
* <ul>
* <li>during an intersection when the boundaries of two areas touch in a
* line segment
* <li> OR as a result of a dimensional collapse.
* </ul>
*/
private void collectBoundaryTouchEdge(DirectedEdge de, int opCode,
List edges) {
Label label = de.getLabel();
if (de.isLineEdge())
return; // only interested in area edges
if (de.isVisited())
return; // already processed
if (de.isInteriorAreaEdge())
return; // added to handle dimensional collapses
if (de.getEdge().isInResult())
return; // if the edge linework is already included, don't include
// it again
// sanity check for labelling of result edgerings
Assert.isTrue(!(de.isInResult() || de.getSym().isInResult())
|| !de.getEdge().isInResult());
// include the linework if it's in the result of the operation
if (OverlayOp.isResultOfOp(label, opCode)
&& opCode == OverlayOp.INTERSECTION) {
edges.add(de.getEdge());
de.setVisitedEdge(true);
}
}
private void buildLines(int opCode) {
for (Iterator it = this.lineEdgesList.iterator(); it.hasNext();) {
Edge e = (Edge) it.next();
Label label = e.getLabel();
List<Position> positions = CoordinateArrays.toPositionList(crs, e
.getCoordinates());
LineString line = new LineStringImpl(new PointArrayImpl( positions ), 0.0); //coordinateFactory.createLineString( positions );
LinkedList<CurveSegment> tLineStrings = new LinkedList<CurveSegment>();
tLineStrings.add((CurveSegment) line);
CurveImpl curve = new CurveImpl(crs, (List<CurveSegment>) tLineStrings); //primitiveFactory.createCurve((List<CurveSegment>) tLineStrings);
resultLineList.add(curve);
e.setInResult(true);
}
}
private void labelIsolatedLines(List edgesList) {
for (Iterator it = edgesList.iterator(); it.hasNext();) {
Edge e = (Edge) it.next();
Label label = e.getLabel();
// n.print(System.out);
if (e.isIsolated()) {
if (label.isNull(0))
labelIsolatedLine(e, 0);
else
labelIsolatedLine(e, 1);
}
}
}
/**
* Label an isolated node with its relationship to the target geometry.
*/
private void labelIsolatedLine(Edge e, int targetIndex) {
int loc = ptLocator.locate(e.getCoordinate(), op
.getArgGeometry(targetIndex));
e.getLabel().setLocation(targetIndex, loc);
}
}