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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
    20  import java.util.Comparator;
    21
    22  import org.apache.commons.geometry.core.GeometryTestUtils;
    23  import org.apache.commons.geometry.euclidean.threed.Vector3D;
    24  import org.apache.commons.geometry.spherical.SphericalTestUtils;
    25  import org.apache.commons.numbers.angle.Angle;
    26  import org.apache.commons.numbers.core.Precision;
    27  import org.junit.jupiter.api.Assertions;
    28  import org.junit.jupiter.api.Test;
    29
    30
    31  class Point2STest {
    32
    33      private static final double TEST_EPS = 1e-10;
    34
    35      @Test
    36      void testProperties() {
    37          for (int k = -2; k < 3; ++k) {
    38              // arrange
    39              final Point2S p = Point2S.of(1.0 + k * Angle.TWO_PI, 1.4);
    40
    41              // act/assert
    42              Assertions.assertEquals(1.0, p.getAzimuth(), TEST_EPS);
    43              Assertions.assertEquals(1.4, p.getPolar(), TEST_EPS);
    44
    45              Assertions.assertEquals(Math.cos(1.0) * Math.sin(1.4), p.getVector().getX(), TEST_EPS);
    46              Assertions.assertEquals(Math.sin(1.0) * Math.sin(1.4), p.getVector().getY(), TEST_EPS);
    47              Assertions.assertEquals(Math.cos(1.4), p.getVector().getZ(), TEST_EPS);
    48
    49              Assertions.assertFalse(p.isNaN());
    50          }
    51      }
    52
    53      @Test
    54      void testAzimuthPolarComparator() {
    55          // arrange
    56          final Comparator<Point2S> comp = Point2S.POLAR_AZIMUTH_ASCENDING_ORDER;
    57
    58          // act/assert
    59          Assertions.assertEquals(0, comp.compare(Point2S.of(1, 2), Point2S.of(1, 2)));
    60          Assertions.assertEquals(1, comp.compare(Point2S.of(1, 2), Point2S.of(2, 1)));
    61          Assertions.assertEquals(-1, comp.compare(Point2S.of(2, 1), Point2S.of(1, 2)));
    62
    63          Assertions.assertEquals(-1, comp.compare(Point2S.of(1, 2), Point2S.of(1, 3)));
    64          Assertions.assertEquals(1, comp.compare(Point2S.of(1, 3), Point2S.of(1, 2)));
    65
    66          Assertions.assertEquals(1, comp.compare(null, Point2S.of(1, 2)));
    67          Assertions.assertEquals(-1, comp.compare(Point2S.of(1, 2), null));
    68          Assertions.assertEquals(0, comp.compare(null, null));
    69      }
    70
    71      @Test
    72      void testFrom_vector() {
    73          // arrange
    74          final double quarterPi = 0.25 * Math.PI;
    75
    76          // act/assert
    77          checkPoint(Point2S.from(Vector3D.of(1, 1, 0)), quarterPi, Angle.PI_OVER_TWO);
    78          checkPoint(Point2S.from(Vector3D.of(1, 0, 1)), 0, quarterPi);
    79          checkPoint(Point2S.from(Vector3D.of(0, 1, 1)), Angle.PI_OVER_TWO, quarterPi);
    80
    81          checkPoint(Point2S.from(Vector3D.of(1, -1, 0)), Angle.TWO_PI - quarterPi, Angle.PI_OVER_TWO);
    82          checkPoint(Point2S.from(Vector3D.of(-1, 0, -1)), Math.PI, Math.PI - quarterPi);
    83          checkPoint(Point2S.from(Vector3D.of(0, -1, -1)), Angle.TWO_PI - Angle.PI_OVER_TWO, Math.PI - quarterPi);
    84      }
    85
    86      @Test
    87      void testNaN() {
    88          // act/assert
    89          Assertions.assertTrue(Point2S.NaN.isNaN());
    90          Assertions.assertEquals(Point2S.NaN, Point2S.of(Double.NaN, 1.0));
    91          Assertions.assertNotEquals(Point2S.of(1.0, 1.3), Point2S.NaN);
    92          Assertions.assertNull(Point2S.NaN.getVector());
    93
    94          Assertions.assertEquals(Point2S.NaN.hashCode(), Point2S.of(Double.NaN, Double.NaN).hashCode());
    95      }
    96
    97      @Test
    98      void testInfinite() {
    99          // act/assert
    100         Assertions.assertTrue(Point2S.of(0, Double.POSITIVE_INFINITY).isInfinite());
    101         Assertions.assertTrue(Point2S.of(Double.POSITIVE_INFINITY, 0).isInfinite());
    102
    103         Assertions.assertTrue(Point2S.of(Double.NEGATIVE_INFINITY, Double.POSITIVE_INFINITY).isInfinite());
    104
    105         Assertions.assertFalse(Point2S.of(0, 0).isInfinite());
    106         Assertions.assertFalse(Point2S.of(1, 1).isInfinite());
    107         Assertions.assertFalse(Point2S.NaN.isInfinite());
    108     }
    109
    110     @Test
    111     void testFinite() {
    112         // act/assert
    113         Assertions.assertTrue(Point2S.of(0, 0).isFinite());
    114         Assertions.assertTrue(Point2S.of(1, 1).isFinite());
    115
    116         Assertions.assertFalse(Point2S.of(0, Double.POSITIVE_INFINITY).isFinite());
    117         Assertions.assertFalse(Point2S.of(Double.POSITIVE_INFINITY, 0).isFinite());
    118         Assertions.assertFalse(Point2S.of(Double.NEGATIVE_INFINITY, Double.POSITIVE_INFINITY).isFinite());
    119
    120         Assertions.assertFalse(Point2S.NaN.isFinite());
    121     }
    122
    123     @Test
    124     void testDistance() {
    125         // arrange
    126         final Point2S a = Point2S.of(1.0, 0.5 * Math.PI);
    127         final Point2S b = Point2S.of(a.getAzimuth() + 0.5 * Math.PI, a.getPolar());
    128
    129         // act/assert
    130         Assertions.assertEquals(0.5 * Math.PI, a.distance(b), 1.0e-10);
    131         Assertions.assertEquals(Math.PI, a.distance(a.antipodal()), 1.0e-10);
    132         Assertions.assertEquals(0.5 * Math.PI, Point2S.MINUS_I.distance(Point2S.MINUS_K), 1.0e-10);
    133         Assertions.assertEquals(0.0, Point2S.of(1.0, 0).distance(Point2S.of(2.0, 0)), 1.0e-10);
    134     }
    135
    136     @Test
    137     void testSlerp_alongEquator() {
    138         // arrange
    139         final Point2S p1 = Point2S.PLUS_I;
    140         final Point2S p2 = Point2S.PLUS_J;
    141
    142         // act/assert
    143         SphericalTestUtils.assertPointsEq(p1, p1.slerp(p2, 0), TEST_EPS);
    144         SphericalTestUtils.assertPointsEq(Point2S.of(0.25 * Angle.PI_OVER_TWO, Angle.PI_OVER_TWO), p1.slerp(p2, 0.25), TEST_EPS);
    145         SphericalTestUtils.assertPointsEq(Point2S.of(0.5 * Angle.PI_OVER_TWO, Angle.PI_OVER_TWO), p1.slerp(p2, 0.5), TEST_EPS);
    146         SphericalTestUtils.assertPointsEq(Point2S.of(0.75 * Angle.PI_OVER_TWO, Angle.PI_OVER_TWO), p1.slerp(p2, 0.75), TEST_EPS);
    147         SphericalTestUtils.assertPointsEq(p2, p1.slerp(p2, 1), TEST_EPS);
    148
    149         SphericalTestUtils.assertPointsEq(p2, p2.slerp(p1, 0), TEST_EPS);
    150         SphericalTestUtils.assertPointsEq(Point2S.of(0.75 * Angle.PI_OVER_TWO, Angle.PI_OVER_TWO), p2.slerp(p1, 0.25), TEST_EPS);
    151         SphericalTestUtils.assertPointsEq(Point2S.of(0.5 * Angle.PI_OVER_TWO, Angle.PI_OVER_TWO), p2.slerp(p1, 0.5), TEST_EPS);
    152         SphericalTestUtils.assertPointsEq(Point2S.of(0.25 * Angle.PI_OVER_TWO, Angle.PI_OVER_TWO), p2.slerp(p1, 0.75), TEST_EPS);
    153         SphericalTestUtils.assertPointsEq(p1, p2.slerp(p1, 1), TEST_EPS);
    154
    155         SphericalTestUtils.assertPointsEq(Point2S.MINUS_I, p1.slerp(p2, 2), TEST_EPS);
    156         SphericalTestUtils.assertPointsEq(Point2S.MINUS_J, p1.slerp(p2, -1), TEST_EPS);
    157     }
    158
    159     @Test
    160     void testSlerp_alongMeridian() {
    161         // arrange
    162         final Point2S p1 = Point2S.PLUS_J;
    163         final Point2S p2 = Point2S.PLUS_K;
    164
    165         // act/assert
    166         SphericalTestUtils.assertPointsEq(p1, p1.slerp(p2, 0), TEST_EPS);
    167         SphericalTestUtils.assertPointsEq(Point2S.of(Angle.PI_OVER_TWO, 0.75 * Angle.PI_OVER_TWO), p1.slerp(p2, 0.25), TEST_EPS);
    168         SphericalTestUtils.assertPointsEq(Point2S.of(Angle.PI_OVER_TWO, 0.5 * Angle.PI_OVER_TWO), p1.slerp(p2, 0.5), TEST_EPS);
    169         SphericalTestUtils.assertPointsEq(Point2S.of(Angle.PI_OVER_TWO, 0.25 * Angle.PI_OVER_TWO), p1.slerp(p2, 0.75), TEST_EPS);
    170         SphericalTestUtils.assertPointsEq(p2, p1.slerp(p2, 1), TEST_EPS);
    171
    172         SphericalTestUtils.assertPointsEq(p2, p2.slerp(p1, 0), TEST_EPS);
    173         SphericalTestUtils.assertPointsEq(Point2S.of(Angle.PI_OVER_TWO, 0.25 * Angle.PI_OVER_TWO), p2.slerp(p1, 0.25), TEST_EPS);
    174         SphericalTestUtils.assertPointsEq(Point2S.of(Angle.PI_OVER_TWO, 0.5 * Angle.PI_OVER_TWO), p2.slerp(p1, 0.5), TEST_EPS);
    175         SphericalTestUtils.assertPointsEq(Point2S.of(Angle.PI_OVER_TWO, 0.75 * Angle.PI_OVER_TWO), p2.slerp(p1, 0.75), TEST_EPS);
    176         SphericalTestUtils.assertPointsEq(p1, p2.slerp(p1, 1), TEST_EPS);
    177
    178         SphericalTestUtils.assertPointsEq(Point2S.MINUS_J, p1.slerp(p2, 2), TEST_EPS);
    179         SphericalTestUtils.assertPointsEq(Point2S.MINUS_K, p1.slerp(p2, -1), TEST_EPS);
    180     }
    181
    182     @Test
    183     void testSlerp_samePoint() {
    184         // arrange
    185         final Point2S p1 = Point2S.PLUS_I;
    186
    187         // act/assert
    188         SphericalTestUtils.assertPointsEq(p1, p1.slerp(p1, 0), TEST_EPS);
    189         SphericalTestUtils.assertPointsEq(p1, p1.slerp(p1, 0.5), TEST_EPS);
    190         SphericalTestUtils.assertPointsEq(p1, p1.slerp(p1, 1), TEST_EPS);
    191     }
    192
    193     @Test
    194     void testSlerp_antipodal() {
    195         // arrange
    196         final Point2S p1 = Point2S.PLUS_I;
    197         final Point2S p2 = Point2S.MINUS_I;
    198
    199         // act/assert
    200         SphericalTestUtils.assertPointsEq(p1, p1.slerp(p1, 0), TEST_EPS);
    201         SphericalTestUtils.assertPointsEq(p1, p1.slerp(p1, 1), TEST_EPS);
    202
    203         final Point2S pt = p1.slerp(p2, 0.5);
    204         Assertions.assertEquals(p1.distance(pt), p2.distance(pt), TEST_EPS);
    205     }
    206
    207     @Test
    208     void testAntipodal() {
    209         for (double az = -6 * Math.PI; az <= 6 * Math.PI; az += 0.1) {
    210             for (double p = 0; p <= Math.PI; p += 0.1) {
    211                 // arrange
    212                 final Point2S pt = Point2S.of(az, p);
    213
    214                 // act
    215                 final Point2S result = pt.antipodal();
    216
    217                 // assert
    218                 Assertions.assertEquals(Math.PI, pt.distance(result), TEST_EPS);
    219
    220                 // check that the azimuth and polar components of the point are correct by creating a
    221                 // new point and checking the distance
    222                 Assertions.assertEquals(Math.PI,
    223                         Point2S.of(result.getAzimuth(), result.getPolar()).distance(pt), TEST_EPS);
    224
    225                 // check that the vectors point in opposite directions
    226                 Assertions.assertEquals(-1, pt.getVector().dot(result.getVector()), TEST_EPS);
    227             }
    228         }
    229     }
    230
    231     @Test
    232     void testAntipodal_numericalStability() {
    233         // arrange
    234         final double eps = 1e-16;
    235         final Point2S pt = Point2S.of(1, 2);
    236
    237         // act
    238         final Point2S result = pt.antipodal().antipodal();
    239
    240         // assert
    241         Assertions.assertEquals(1.0, result.getAzimuth(), eps);
    242         Assertions.assertEquals(2.0, result.getPolar(), eps);
    243     }
    244
    245     @Test
    246     void testDimension() {
    247         // arrange
    248         final Point2S pt = Point2S.of(1, 2);
    249
    250         // act/assert
    251         Assertions.assertEquals(2, pt.getDimension());
    252     }
    253
    254     @Test
    255     void testEq() {
    256         // arrange
    257         final Precision.DoubleEquivalence smallEps = Precision.doubleEquivalenceOfEpsilon(1e-5);
    258         final Precision.DoubleEquivalence largeEps = Precision.doubleEquivalenceOfEpsilon(5e-1);
    259
    260         final Point2S a = Point2S.of(1.0, 2.0);
    261         final Point2S b = Point2S.of(1.0, 2.01);
    262         final Point2S c = Point2S.of(1.01, 2.0);
    263         final Point2S d = Point2S.of(1.0, 2.0);
    264         final Point2S e = Point2S.of(3.0, 2.0);
    265
    266         // act/assert
    267         Assertions.assertTrue(a.eq(a, smallEps));
    268         Assertions.assertFalse(a.eq(b, smallEps));
    269         Assertions.assertFalse(a.eq(c, smallEps));
    270         Assertions.assertTrue(a.eq(d, smallEps));
    271         Assertions.assertFalse(a.eq(e, smallEps));
    272
    273         Assertions.assertTrue(a.eq(a, largeEps));
    274         Assertions.assertTrue(a.eq(b, largeEps));
    275         Assertions.assertTrue(a.eq(c, largeEps));
    276         Assertions.assertTrue(a.eq(d, largeEps));
    277         Assertions.assertFalse(a.eq(e, largeEps));
    278     }
    279
    280     @Test
    281     void testHashCode() {
    282         // arrange
    283         final Point2S a = Point2S.of(1.0, 2.0);
    284         final Point2S b = Point2S.of(1.0, 3.0);
    285         final Point2S c = Point2S.of(4.0, 2.0);
    286         final Point2S d = Point2S.of(1.0, 2.0);
    287
    288         // act
    289         final int hash = a.hashCode();
    290
    291         // assert
    292         Assertions.assertEquals(hash, a.hashCode());
    293
    294         Assertions.assertNotEquals(hash, b.hashCode());
    295         Assertions.assertNotEquals(hash, c.hashCode());
    296
    297         Assertions.assertEquals(hash, d.hashCode());
    298     }
    299
    300     @Test
    301     void testEquals() {
    302         // arrange
    303         final Point2S a = Point2S.of(1.0, 2.0);
    304         final Point2S b = Point2S.of(1.0, 3.0);
    305         final Point2S c = Point2S.of(4.0, 2.0);
    306         final Point2S d = Point2S.of(1.0, 2.0);
    307
    308         // act/assert
    309         GeometryTestUtils.assertSimpleEqualsCases(a);
    310
    311         Assertions.assertNotEquals(a, b);
    312         Assertions.assertNotEquals(a, c);
    313
    314         Assertions.assertEquals(a, d);
    315         Assertions.assertEquals(d, a);
    316     }
    317
    318     @Test
    319     void testEquals_poles() {
    320         // arrange
    321         final Point2S a = Point2S.of(1.0, 0.0);
    322         final Point2S b = Point2S.of(0.0, 0.0);
    323         final Point2S c = Point2S.of(1.0, 0.0);
    324
    325         final Point2S d = Point2S.of(-1.0, Math.PI);
    326         final Point2S e = Point2S.of(0.0, Math.PI);
    327         final Point2S f = Point2S.of(-1.0, Math.PI);
    328
    329         // act/assert
    330         Assertions.assertEquals(a, a);
    331         Assertions.assertNotEquals(a, b);
    332         Assertions.assertEquals(a, c);
    333
    334         Assertions.assertEquals(d, d);
    335         Assertions.assertNotEquals(d, e);
    336         Assertions.assertEquals(d, f);
    337     }
    338
    339     @Test
    340     void testToString() {
    341         // act/assert
    342         Assertions.assertEquals("(0.0, 0.0)", Point2S.of(0.0, 0.0).toString());
    343         Assertions.assertEquals("(1.0, 2.0)", Point2S.of(1.0, 2.0).toString());
    344     }
    345
    346     @Test
    347     void testParse() {
    348         // act/assert
    349         checkPoint(Point2S.parse("(0,0)"), 0.0, 0.0);
    350         checkPoint(Point2S.parse("(1,2)"), 1.0, 2.0);
    351     }
    352
    353     @Test
    354     void testParse_failure() {
    355         // act/assert
    356         Assertions.assertThrows(IllegalArgumentException.class, () -> Point2S.parse("abc"));
    357     }
    358
    359     private static void checkPoint(final Point2S p, final double az, final double polar) {
    360         final String msg = "Expected (" + az + "," + polar + ") but was " + p;
    361
    362         Assertions.assertEquals(az, p.getAzimuth(), TEST_EPS, msg);
    363         Assertions.assertEquals(polar, p.getPolar(), TEST_EPS, msg);
    364     }
    365 }