KdTreeTest.java

/*
 * Copyright (c) 2016 Martin Davis.
 *
 * All rights reserved. This program and the accompanying materials
 * are made available under the terms of the Eclipse Public License v1.0
 * and Eclipse Distribution License v. 1.0 which accompanies this distribution.
 * The Eclipse Public License is available at http://www.eclipse.org/legal/epl-v10.html
 * and the Eclipse Distribution License is available at
 *
 * http://www.eclipse.org/org/documents/edl-v10.php.
 */

package org.locationtech.jts.index.kdtree;

import java.util.Arrays;
import java.util.List;

import org.locationtech.jts.geom.Coordinate;
import org.locationtech.jts.geom.CoordinateArrays;
import org.locationtech.jts.geom.Envelope;

import junit.framework.TestCase;
import junit.textui.TestRunner;
import test.jts.util.IOUtil;

public class KdTreeTest extends TestCase {
  public static void main(String args[]) {
    TestRunner.run(KdTreeTest.class);
  }

  public KdTreeTest(String name) {
    super(name);
  }

  public void testSinglePoint() {
    KdTree index = new KdTree(.001);

    KdNode node1 = index.insert(new Coordinate(1, 1));
    KdNode node2 = index.insert(new Coordinate(1, 1));

    assertTrue("Inserting 2 identical points should create one node",
        node1 == node2);

    Envelope queryEnv = new Envelope(0, 10, 0, 10);

    List result = index.query(queryEnv);
    assertTrue(result.size() == 1);

    KdNode node = (KdNode) result.get(0);
    assertTrue(node.getCount() == 2);
    assertTrue(node.isRepeated());
  }

  public void testMultiplePoint() {
    testQuery("MULTIPOINT ( (1 1), (2 2) )", 0,
        new Envelope(0, 10, 0, 10), 
        "MULTIPOINT ( (1 1), (2 2) )");
  }

  public void testSubset() {
    testQuery("MULTIPOINT ( (1 1), (2 2), (3 3), (4 4) )", 
        0, 
        new Envelope(1.5, 3.4, 1.5, 3.5),
        "MULTIPOINT ( (2 2), (3 3) )");
  }

  public void testToleranceFailure() {
    testQuery("MULTIPOINT ( (0 0), (-.1 1), (.1 1) )", 
        1, 
        new Envelope(-9, 9, -9, 9),
        "MULTIPOINT ( (0 0), (-.1 1) )");
  }
  
  public void testTolerance2() {
    testQuery("MULTIPOINT ((10 60), (20 60), (30 60), (30 63))", 
        9, 
        new Envelope(0,99, 0, 99),
        "MULTIPOINT ((10 60), (20 60), (30 60))");
  }
  
  public void testTolerance2_perturbedY() {
    testQuery("MULTIPOINT ((10 60), (20 61), (30 60), (30 63))", 
        9, 
        new Envelope(0,99, 0, 99),
        "MULTIPOINT ((10 60), (20 61), (30 60))");
  }
  
  public void testSnapToNearest() {
    testQueryRepeated("MULTIPOINT ( (10 60), (20 60), (16 60))", 
        5, 
        new Envelope(0,99, 0, 99),
        "MULTIPOINT ( (10 60), (20 60), (20 60))");
  }
  
  private void testQuery(String wktInput, double tolerance,
      Envelope queryEnv, String wktExpected) {
    KdTree index = build(wktInput, tolerance);
    testQuery(
        index,
        queryEnv, false,
        IOUtil.read(wktExpected).getCoordinates());
  }

  private void testQueryRepeated(String wktInput, double tolerance,
      Envelope queryEnv, String wktExpected) {
    KdTree index = build(wktInput, tolerance);
    testQuery(
        index,
        queryEnv, true,
        IOUtil.read(wktExpected).getCoordinates());
  }

  private void testQuery(KdTree index,
      Envelope queryEnv, Coordinate[] expectedCoord) {
    Coordinate[] result = KdTree.toCoordinates(index.query(queryEnv));

    Arrays.sort(result);
    Arrays.sort(expectedCoord);
    
    assertTrue("Result count = " + result.length + ", expected count = " + expectedCoord.length,
        result.length == expectedCoord.length);
    
    boolean isMatch = CoordinateArrays.equals(result, expectedCoord);
    assertTrue("Expected result coordinates not found", isMatch);
  }

  private void testQuery(KdTree index,
      Envelope queryEnv, boolean includeRepeated, Coordinate[] expectedCoord) {
    Coordinate[] result = KdTree.toCoordinates(index.query(queryEnv), includeRepeated);

    Arrays.sort(result);
    Arrays.sort(expectedCoord);
    
    assertTrue("Result count = " + result.length + ", expected count = " + expectedCoord.length,
        result.length == expectedCoord.length);
    
    boolean isMatch = CoordinateArrays.equals(result, expectedCoord);
    assertTrue("Expected result coordinates not found", isMatch);
  }

  private KdTree build(String wktInput, double tolerance) {
    final KdTree index = new KdTree(tolerance);
    Coordinate[] coords = IOUtil.read(wktInput).getCoordinates();
    for (int i = 0; i < coords.length; i++) {
      index.insert(coords[i]);
    }
    return index;
  }

}