PolygonHoleJoinerTest.java

/*
 * Copyright (c) 2022 Martin Davis.
 *
 * All rights reserved. This program and the accompanying materials
 * are made available under the terms of the Eclipse Public License 2.0
 * and Eclipse Distribution License v. 1.0 which accompanies this distribution.
 * The Eclipse Public License is available at http://www.eclipse.org/legal/epl-v20.html
 * and the Eclipse Distribution License is available at
 *
 * http://www.eclipse.org/org/documents/edl-v10.php.
 */
package org.locationtech.jts.triangulate.polygon;

import org.locationtech.jts.geom.Geometry;
import org.locationtech.jts.geom.Polygon;

import junit.textui.TestRunner;
import test.jts.GeometryTestCase;

public class PolygonHoleJoinerTest extends GeometryTestCase {
  public static void main(String args[]) {
    TestRunner.run(PolygonHoleJoinerTest.class);
  }
  
  public PolygonHoleJoinerTest(String name) {
    super(name);
  }
  
  /**
   * A failing case for hole joining with two holes that touch at leftmost vertex
   * Fails due to PolygonHoleJoiner joining holes with same leftmost vertex
   * so that the result linework self-crosses.
   * Note that input is normalized.
   */
  public void testTouchingHoles() {
    checkJoin(
  "POLYGON ((0 0, 0 9, 9 9, 9 0, 0 0), (1 4, 5 1, 5 4, 1 4), (1 4, 5 5, 6 8, 1 4))",
  "POLYGON ((0 0, 0 9, 1 4, 5 1, 5 4, 1 4, 5 5, 6 8, 1 4, 0 9, 9 9, 9 0, 0 0))"
        );
  }
  
  public void testHolesTouchEdgeVertical() {
    checkJoin(
  "POLYGON ((1 9, 9 9, 9 0, 1 0, 1 9), (1 4, 5 1, 5 4, 1 4), (1 5, 5 5, 6 8, 1 5))",
  "POLYGON ((1 9, 9 9, 9 0, 1 0, 1 4, 5 1, 5 4, 1 4, 1 5, 5 5, 6 8, 1 5, 1 9))"
        );
  }
  
  public void testHoleTouchesEdgeVertical() {
    checkJoin(
  "POLYGON ((1 9, 9 9, 9 0, 1 0, 1 9), (1 5, 5 5, 6 8, 1 5))",
  "POLYGON ((1 0, 1 5, 5 5, 6 8, 1 5, 1 9, 9 9, 9 0, 1 0))"
        );
  }
  
  /**
   * Hole ring is CW, to test ring orientation handling.
   */
  public void testHoleTouchesEdgeWithCloserVertex() {
    checkJoin(
  "POLYGON ((1 9, 9 9, 5 6, 9 6, 19 1, 9 1, 1 9), (8 5, 9 3, 5 5, 8 5))",
  "POLYGON ((1 9, 9 9, 5 6, 9 6, 19 1, 9 1, 5 5, 9 3, 8 5, 5 5, 1 9))"
        );
  }
  
  public void testHoleTouchesEdge() {
    checkJoin(
  "POLYGON ((5 5, 9 5, 9 0, 0 0, 5 5), (3 3, 6 1, 5 3, 3 3))",
  "POLYGON ((5 5, 9 5, 9 0, 0 0, 3 3, 6 1, 5 3, 3 3, 5 5))"
        );
  }
  
  public void testHoleTouchesVertex() {
    checkJoin(
  "POLYGON ((70 10, 0 0, 7 47, 20 90, 70 60, 70 10), (10 40, 30 50, 7 47, 10 40))",
  "POLYGON ((70 10, 0 0, 7 47, 10 40, 30 50, 7 47, 20 90, 70 60, 70 10))"
        );
  }
  
  public void testHolesManyVertical() {
    checkJoin(
  "POLYGON ((10 90, 90 90, 90 10, 10 10, 50 20, 10 30, 50 50, 10 70, 53 80, 10 90), (60 70, 60 60, 50 60, 50 70, 60 70), (55 55, 55 50, 50 50, 50 55, 55 55), (61 45, 61 40, 50 40, 50 45, 61 45), (60 30, 50 30, 50 35, 60 35, 60 30), (50 15, 50 18, 60 18, 60 15, 50 15), (60 85, 50 85, 55 80, 50 75, 60 75, 60 85))",
  "POLYGON ((10 10, 50 15, 60 15, 60 18, 50 18, 50 15, 10 10, 50 20, 50 30, 60 30, 60 35, 50 35, 50 40, 61 40, 61 45, 50 45, 50 40, 50 35, 50 30, 50 20, 10 30, 50 50, 55 50, 55 55, 50 55, 50 60, 60 60, 60 70, 50 70, 50 75, 60 75, 60 85, 50 85, 55 80, 50 75, 50 70, 50 60, 50 55, 50 50, 10 70, 53 80, 10 90, 90 90, 90 10, 10 10))"
        );
  }
  
  /**
   * A failing case revealing that joining a hole by a zero-length cut
   * was introducing duplicate vertices.
   */
  public void testZeroLenCutDuplicateVertices() {
    checkJoin(
  "POLYGON ((70 10, 0 0, 7 47, 16 94, 70 60, 70 10), (10 40, 30 49, 7 47, 10 40), (13 59, 13 54, 26 53, 13 59))",
  "POLYGON ((0 0, 7 47, 10 40, 30 49, 7 47, 13 54, 26 53, 13 59, 13 54, 7 47, 16 94, 70 60, 70 10, 0 0))"
        );
  }
  
  /**
   * Revealed a bug due to original use of tolerance for coordinate comparison (now removed)
   */
  public void testBugHoleJoinCrosses() {
    checkJoin(
  "POLYGON ((27.182 58.2714, 27.182 58.27, 27.1804 58.27, 27.1804 58.2714, 27.182 58.2714), (27.18097 58.2701, 27.18091 58.27009, 27.18086 58.27007, 27.18086 58.27004, 27.18097 58.2701), (27.18079 58.27099, 27.18074 58.27029, 27.18075 58.27024, 27.18079 58.27019, 27.18151 58.27021, 27.18085 58.27104, 27.18079 58.27099))",
  "POLYGON ((27.1804 58.27, 27.1804 58.2714, 27.18074 58.27029, 27.18075 58.27024, 27.18079 58.27019, 27.18086 58.27004, 27.18097 58.2701, 27.18091 58.27009, 27.18086 58.27007, 27.18086 58.27004, 27.18079 58.27019, 27.18151 58.27021, 27.18085 58.27104, 27.18079 58.27099, 27.18074 58.27029, 27.1804 58.2714, 27.182 58.2714, 27.182 58.27, 27.1804 58.27))"
        );
  }
  
  private void checkJoin(String wkt, String wktExpected) {
    Polygon geom = (Polygon) read(wkt);
    Geometry actual = PolygonHoleJoiner.joinAsPolygon(geom);
    if (wktExpected == null) {
      System.out.println("Result: " + actual);
      return;
    }
    Geometry expected = read(wktExpected);
    checkEqual(expected, actual);
  }
}