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1   /*
2    * Licensed to the Apache Software Foundation (ASF) under one or more
3    * contributor license agreements.  See the NOTICE file distributed with
4    * this work for additional information regarding copyright ownership.
5    * The ASF licenses this file to You under the Apache License, Version 2.0
6    * (the "License"); you may not use this file except in compliance with
7    * the License.  You may obtain a copy of the License at
8    *
9    *      http://www.apache.org/licenses/LICENSE-2.0
10   *
11   * Unless required by applicable law or agreed to in writing, software
12   * distributed under the License is distributed on an "AS IS" BASIS,
13   * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
14   * See the License for the specific language governing permissions and
15   * limitations under the License.
16   */
17  package org.apache.commons.geometry.spherical.twod;
18  
19  import java.util.ArrayList;
20  import java.util.Arrays;
21  import java.util.Collections;
22  import java.util.List;
23  import java.util.function.Consumer;
24  
25  import org.apache.commons.geometry.spherical.SphericalTestUtils;
26  import org.apache.commons.geometry.spherical.twod.InteriorAngleGreatArcConnector.Maximize;
27  import org.apache.commons.geometry.spherical.twod.InteriorAngleGreatArcConnector.Minimize;
28  import org.apache.commons.numbers.core.Precision;
29  import org.junit.jupiter.api.Assertions;
30  import org.junit.jupiter.api.Test;
31  
32  class InteriorAngleGreatArcConnectorTest {
33  
34      private static final double TEST_EPS = 1e-10;
35  
36      private static final Precision.DoubleEquivalence TEST_PRECISION =
37              Precision.doubleEquivalenceOfEpsilon(TEST_EPS);
38  
39      @Test
40      void testConnectAll_empty() {
41          runWithMaxAndMin(connector -> {
42              // arrange
43              final List<GreatArc> arcs = new ArrayList<>();
44              connector.add(arcs);
45  
46              // act
47              final List<GreatArcPath> paths = connector.connectAll();
48  
49              // assert
50              Assertions.assertEquals(0, paths.size());
51          });
52      }
53  
54      @Test
55      void testConnectAll_singlePath() {
56          runWithMaxAndMin(connector -> {
57              // arrange
58              final List<GreatArc> arcs = Collections.singletonList(
59                      GreatCircles.arcFromPoints(Point2S.PLUS_I, Point2S.PLUS_J, TEST_PRECISION)
60              );
61              connector.add(arcs);
62  
63              // act
64              final List<GreatArcPath> paths = connector.connectAll();
65  
66              // assert
67              Assertions.assertEquals(1, paths.size());
68  
69              final GreatArcPath a = paths.get(0);
70              Assertions.assertEquals(1, a.getArcs().size());
71              assertPathPoints(a, Point2S.PLUS_I, Point2S.PLUS_J);
72          });
73      }
74  
75      @Test
76      void testConnectAll_maximize_instance() {
77          // arrange
78          final GreatArc a1 = GreatCircles.arcFromPoints(Point2S.PLUS_K, Point2S.PLUS_I, TEST_PRECISION);
79          final GreatArc a2 = GreatCircles.arcFromPoints(Point2S.PLUS_I, Point2S.PLUS_J, TEST_PRECISION);
80          final GreatArc a3 = GreatCircles.arcFromPoints(Point2S.PLUS_J, Point2S.PLUS_K, TEST_PRECISION);
81  
82          final GreatArc b1 = GreatCircles.arcFromPoints(Point2S.PLUS_K, Point2S.MINUS_I, TEST_PRECISION);
83          final GreatArc b2 = GreatCircles.arcFromPoints(Point2S.MINUS_I, Point2S.MINUS_J, TEST_PRECISION);
84          final GreatArc b3 = GreatCircles.arcFromPoints(Point2S.MINUS_J, Point2S.PLUS_K, TEST_PRECISION);
85  
86          final InteriorAngleGreatArcConnector connector = new InteriorAngleGreatArcConnector.Maximize();
87  
88          // act
89          final List<GreatArcPath> paths = connector.connectAll(Arrays.asList(b3, b1, a1, a3, b2, a2));
90  
91          // assert
92          Assertions.assertEquals(1, paths.size());
93  
94          assertPathPoints(paths.get(0),
95              Point2S.PLUS_K,
96              Point2S.MINUS_I,
97              Point2S.MINUS_J,
98              Point2S.PLUS_K,
99              Point2S.PLUS_I,
100             Point2S.PLUS_J,
101             Point2S.PLUS_K
102         );
103     }
104 
105     @Test
106     void testConnectAll_maximize_method() {
107         // arrange
108         final GreatArc a1 = GreatCircles.arcFromPoints(Point2S.PLUS_K, Point2S.PLUS_I, TEST_PRECISION);
109         final GreatArc a2 = GreatCircles.arcFromPoints(Point2S.PLUS_I, Point2S.PLUS_J, TEST_PRECISION);
110         final GreatArc a3 = GreatCircles.arcFromPoints(Point2S.PLUS_J, Point2S.PLUS_K, TEST_PRECISION);
111 
112         final GreatArc b1 = GreatCircles.arcFromPoints(Point2S.PLUS_K, Point2S.MINUS_I, TEST_PRECISION);
113         final GreatArc b2 = GreatCircles.arcFromPoints(Point2S.MINUS_I, Point2S.MINUS_J, TEST_PRECISION);
114         final GreatArc b3 = GreatCircles.arcFromPoints(Point2S.MINUS_J, Point2S.PLUS_K, TEST_PRECISION);
115 
116         // act
117         final List<GreatArcPath> paths = InteriorAngleGreatArcConnector.connectMaximized(
118                 Arrays.asList(b3, b1, a1, a3, b2, a2));
119 
120         // assert
121         Assertions.assertEquals(1, paths.size());
122 
123         assertPathPoints(paths.get(0),
124             Point2S.PLUS_K,
125             Point2S.MINUS_I,
126             Point2S.MINUS_J,
127             Point2S.PLUS_K,
128             Point2S.PLUS_I,
129             Point2S.PLUS_J,
130             Point2S.PLUS_K
131         );
132     }
133 
134     @Test
135     void testConnectAll_minimize_instance() {
136         // arrange
137         final GreatArc a1 = GreatCircles.arcFromPoints(Point2S.PLUS_K, Point2S.PLUS_I, TEST_PRECISION);
138         final GreatArc a2 = GreatCircles.arcFromPoints(Point2S.PLUS_I, Point2S.PLUS_J, TEST_PRECISION);
139         final GreatArc a3 = GreatCircles.arcFromPoints(Point2S.PLUS_J, Point2S.PLUS_K, TEST_PRECISION);
140 
141         final GreatArc b1 = GreatCircles.arcFromPoints(Point2S.PLUS_K, Point2S.MINUS_I, TEST_PRECISION);
142         final GreatArc b2 = GreatCircles.arcFromPoints(Point2S.MINUS_I, Point2S.MINUS_J, TEST_PRECISION);
143         final GreatArc b3 = GreatCircles.arcFromPoints(Point2S.MINUS_J, Point2S.PLUS_K, TEST_PRECISION);
144 
145         final InteriorAngleGreatArcConnector connector = new InteriorAngleGreatArcConnector.Minimize();
146 
147         // act
148         final List<GreatArcPath> paths = connector.connectAll(Arrays.asList(b3, b1, a1, a3, b2, a2));
149 
150         // assert
151         Assertions.assertEquals(2, paths.size());
152 
153         assertPathPoints(paths.get(0),
154             Point2S.PLUS_K,
155             Point2S.MINUS_I,
156             Point2S.MINUS_J,
157             Point2S.PLUS_K
158         );
159 
160         assertPathPoints(paths.get(1),
161             Point2S.PLUS_K,
162             Point2S.PLUS_I,
163             Point2S.PLUS_J,
164             Point2S.PLUS_K
165         );
166     }
167 
168     @Test
169     void testConnectAll_minimize_method() {
170         // arrange
171         final GreatArc a1 = GreatCircles.arcFromPoints(Point2S.PLUS_K, Point2S.PLUS_I, TEST_PRECISION);
172         final GreatArc a2 = GreatCircles.arcFromPoints(Point2S.PLUS_I, Point2S.PLUS_J, TEST_PRECISION);
173         final GreatArc a3 = GreatCircles.arcFromPoints(Point2S.PLUS_J, Point2S.PLUS_K, TEST_PRECISION);
174 
175         final GreatArc b1 = GreatCircles.arcFromPoints(Point2S.PLUS_K, Point2S.MINUS_I, TEST_PRECISION);
176         final GreatArc b2 = GreatCircles.arcFromPoints(Point2S.MINUS_I, Point2S.MINUS_J, TEST_PRECISION);
177         final GreatArc b3 = GreatCircles.arcFromPoints(Point2S.MINUS_J, Point2S.PLUS_K, TEST_PRECISION);
178 
179         // act
180         final List<GreatArcPath> paths = InteriorAngleGreatArcConnector.connectMinimized(
181                 Arrays.asList(b3, b1, a1, a3, b2, a2));
182 
183         // assert
184         Assertions.assertEquals(2, paths.size());
185 
186         assertPathPoints(paths.get(0),
187             Point2S.PLUS_K,
188             Point2S.MINUS_I,
189             Point2S.MINUS_J,
190             Point2S.PLUS_K
191         );
192 
193         assertPathPoints(paths.get(1),
194             Point2S.PLUS_K,
195             Point2S.PLUS_I,
196             Point2S.PLUS_J,
197             Point2S.PLUS_K
198         );
199     }
200 
201     /**
202      * Run the given consumer function twice, once with a Maximize instance and once with
203      * a Minimize instance.
204      */
205     private static void runWithMaxAndMin(final Consumer<? super InteriorAngleGreatArcConnector> body) {
206         body.accept(new Maximize());
207         body.accept(new Minimize());
208     }
209 
210     private static void assertPathPoints(final GreatArcPath path, final Point2S... points) {
211         final List<Point2S> expectedPoints = Arrays.asList(points);
212         final List<Point2S> actualPoints = path.getVertices();
213 
214         final String msg = "Expected path points to equal " + expectedPoints + " but was " + actualPoints;
215         Assertions.assertEquals(expectedPoints.size(), actualPoints.size(), msg);
216 
217         for (int i = 0; i < expectedPoints.size(); ++i) {
218             SphericalTestUtils.assertPointsEq(expectedPoints.get(i), actualPoints.get(i), TEST_EPS);
219         }
220     }
221 }