/*
* GeoTools - The Open Source Java GIS Toolkit
* http://geotools.org
*
* (C) 2002-2008, 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.graph.linegraph;
import junit.framework.TestCase;
import org.geotools.graph.build.line.BasicLineGraphGenerator;
import org.geotools.graph.structure.Edge;
import org.geotools.graph.structure.Graph;
import org.geotools.graph.structure.GraphVisitor;
import org.geotools.graph.structure.Graphable;
import org.geotools.graph.structure.Node;
import com.vividsolutions.jts.geom.Coordinate;
import com.vividsolutions.jts.geom.LineSegment;
/**
*
*
* @source $URL$
*/
public class LineGraphGeneratorTest extends TestCase {
private BasicLineGraphGenerator m_gen;
public LineGraphGeneratorTest(String name) {
super(name);
}
protected void setUp() throws Exception {
super.setUp();
m_gen = createGenerator();
}
/**
* Build a linear graph by adding a number of line segments that join
* at endpoints.
* <BR>
* Expected: 1. Number of edges = number of lines added.
* 2. Number of nodes = number of lines + 1
*
*/
public void test_0() {
final Coordinate base = new Coordinate(0d,0d);
final int n = 100;
for (int i = 1; i <= n; i++) {
Edge e = (Edge)generator().add(
new LineSegment(
new Coordinate(base.x + (i-1), base.y + (i-1)),
new Coordinate(base.x + i, base.y + i)
)
);
e.setID(i-1);
e.getNodeA().setID(i-1);
e.getNodeB().setID(i);
}
Graph built = generator().getGraph();
//ensure correct graph structure
assertTrue(built.getEdges().size() == n);
assertTrue(built.getNodes().size() == n+1);
GraphVisitor visitor = new GraphVisitor() {
public int visit(Graphable component) {
Node node = (Node)component;
Coordinate c = (Coordinate)node.getObject();
if (node.getDegree() == 1) {
assertTrue(node.getID() == 0 || node.getID() == n);
}
else {
assertTrue(node.getDegree() == 2);
}
assertTrue(
c.x == base.x + node.getID() && c.y == base.y + node.getID()
);
return(0);
}
};
built.visitNodes(visitor);
visitor = new GraphVisitor() {
public int visit(Graphable component) {
Edge edge = (Edge)component;
LineSegment line = (LineSegment)edge.getObject();
assertTrue(line.p1.x == line.p0.x + 1 && line.p1.y == line.p0.y+1);
return(0);
}
};
built.visitEdges(visitor);
}
/**
* Build a circular graph of line segments that join at endpoints. <BR>
* <BR>
* Expected: 1. Number of edges = number of nodes = number of lines.
*/
public void test_1() {
final Coordinate base = new Coordinate(0d,0d);
final int n = 100;
for (int i = 1; i <= n; i++) {
Edge e = (Edge)generator().add(
new LineSegment(
new Coordinate(base.x + (i-1), base.y + (i-1)),
new Coordinate(base.x + i, base.y + i)
)
);
e.setID(i-1);
e.getNodeA().setID(i-1);
e.getNodeB().setID(i);
}
//complete the circle
generator().add(
new LineSegment(new Coordinate(base.x + n, base.y + n), base)
);
Graph built = generator().getGraph();
assertTrue(built.getEdges().size() == n+1);
assertTrue(built.getNodes().size() == n+1);
//all nodes should be of degree 2
assertTrue(
built.getNodesOfDegree(2).size() == built.getNodes().size()
);
}
protected BasicLineGraphGenerator createGenerator() {
return(new BasicLineGraphGenerator());
}
protected BasicLineGraphGenerator generator() {
return(m_gen);
}
}