commons-geometry-spherical/src/test/java/org/apache/commons/geometry/spherical/twod/SubCircleTest.java

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 * this work for additional information regarding copyright ownership.
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 *      http://www.apache.org/licenses/LICENSE-2.0
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package org.apache.commons.geometry.spherical.twod;

import org.apache.commons.geometry.core.Geometry;
import org.apache.commons.geometry.core.partitioning.RegionFactory;
import org.apache.commons.geometry.core.partitioning.Side;
import org.apache.commons.geometry.core.partitioning.SubHyperplane.SplitSubHyperplane;
import org.apache.commons.geometry.core.precision.DoublePrecisionContext;
import org.apache.commons.geometry.core.precision.EpsilonDoublePrecisionContext;
import org.apache.commons.geometry.euclidean.threed.Vector3D;
import org.apache.commons.geometry.euclidean.threed.rotation.QuaternionRotation;
import org.apache.commons.geometry.spherical.oned.ArcsSet;
import org.apache.commons.geometry.spherical.oned.S1Point;
import org.junit.Assert;
import org.junit.Test;

public class SubCircleTest {

    private static final double TEST_EPS = 1e-10;

    private static final DoublePrecisionContext TEST_PRECISION =
            new EpsilonDoublePrecisionContext(TEST_EPS);

    @Test
    public void testFullCircle() {
        Circle circle = new Circle(Vector3D.Unit.PLUS_Z, TEST_PRECISION);
        SubCircle set = circle.wholeHyperplane();
        Assert.assertEquals(Geometry.TWO_PI, set.getSize(), TEST_EPS);
        Assert.assertTrue(circle == set.getHyperplane());
        Assert.assertTrue(circle != set.copySelf().getHyperplane());
    }

    @Test
    public void testSide() {

        Circle xzPlane = new Circle(Vector3D.Unit.PLUS_Y, TEST_PRECISION);

        SubCircle sc1 = create(Vector3D.Unit.PLUS_Z, Vector3D.Unit.PLUS_X, Vector3D.Unit.PLUS_Y, TEST_PRECISION, 1.0, 3.0, 5.0, 6.0);
        Assert.assertEquals(Side.BOTH, sc1.split(xzPlane).getSide());

        SubCircle sc2 = create(Vector3D.Unit.PLUS_Z, Vector3D.Unit.PLUS_X, Vector3D.Unit.PLUS_Y, TEST_PRECISION, 1.0, 3.0);
        Assert.assertEquals(Side.MINUS, sc2.split(xzPlane).getSide());

        SubCircle sc3 = create(Vector3D.Unit.PLUS_Z, Vector3D.Unit.PLUS_X, Vector3D.Unit.PLUS_Y, TEST_PRECISION, 5.0, 6.0);
        Assert.assertEquals(Side.PLUS, sc3.split(xzPlane).getSide());

        SubCircle sc4 = create(Vector3D.Unit.PLUS_Y, Vector3D.Unit.PLUS_Z, Vector3D.Unit.PLUS_X, TEST_PRECISION, 5.0, 6.0);
        Assert.assertEquals(Side.HYPER, sc4.split(xzPlane).getSide());

        SubCircle sc5 = create(Vector3D.Unit.MINUS_Y, Vector3D.Unit.PLUS_X, Vector3D.Unit.PLUS_Z, TEST_PRECISION, 5.0, 6.0);
        Assert.assertEquals(Side.HYPER, sc5.split(xzPlane).getSide());

    }

    @Test
    public void testSPlit() {

        Circle xzPlane = new Circle(Vector3D.Unit.PLUS_Y, TEST_PRECISION);

        SubCircle sc1 = create(Vector3D.Unit.PLUS_Z, Vector3D.Unit.PLUS_X, Vector3D.Unit.PLUS_Y, TEST_PRECISION, 1.0, 3.0, 5.0, 6.0);
        SplitSubHyperplane<S2Point> split1 = sc1.split(xzPlane);
        ArcsSet plus1  = (ArcsSet) ((SubCircle) split1.getPlus()).getRemainingRegion();
        ArcsSet minus1 = (ArcsSet) ((SubCircle) split1.getMinus()).getRemainingRegion();
        Assert.assertEquals(1, plus1.asList().size());
        Assert.assertEquals(5.0, plus1.asList().get(0).getInf(), TEST_EPS);
        Assert.assertEquals(6.0, plus1.asList().get(0).getSup(), TEST_EPS);
        Assert.assertEquals(1, minus1.asList().size());
        Assert.assertEquals(1.0, minus1.asList().get(0).getInf(), TEST_EPS);
        Assert.assertEquals(3.0, minus1.asList().get(0).getSup(), TEST_EPS);

        SubCircle sc2 = create(Vector3D.Unit.PLUS_Z, Vector3D.Unit.PLUS_X, Vector3D.Unit.PLUS_Y, TEST_PRECISION, 1.0, 3.0);
        SplitSubHyperplane<S2Point> split2 = sc2.split(xzPlane);
        Assert.assertNull(split2.getPlus());
        ArcsSet minus2 = (ArcsSet) ((SubCircle) split2.getMinus()).getRemainingRegion();
        Assert.assertEquals(1, minus2.asList().size());
        Assert.assertEquals(1.0, minus2.asList().get(0).getInf(), TEST_EPS);
        Assert.assertEquals(3.0, minus2.asList().get(0).getSup(), TEST_EPS);

        SubCircle sc3 = create(Vector3D.Unit.PLUS_Z, Vector3D.Unit.PLUS_X, Vector3D.Unit.PLUS_Y, TEST_PRECISION, 5.0, 6.0);
        SplitSubHyperplane<S2Point> split3 = sc3.split(xzPlane);
        ArcsSet plus3  = (ArcsSet) ((SubCircle) split3.getPlus()).getRemainingRegion();
        Assert.assertEquals(1, plus3.asList().size());
        Assert.assertEquals(5.0, plus3.asList().get(0).getInf(), TEST_EPS);
        Assert.assertEquals(6.0, plus3.asList().get(0).getSup(), TEST_EPS);
        Assert.assertNull(split3.getMinus());

        SubCircle sc4 = create(Vector3D.Unit.PLUS_Y, Vector3D.Unit.PLUS_Z, Vector3D.Unit.PLUS_X, TEST_PRECISION, 5.0, 6.0);
        SplitSubHyperplane<S2Point> split4 = sc4.split(xzPlane);
        Assert.assertEquals(Side.HYPER, sc4.split(xzPlane).getSide());
        Assert.assertNull(split4.getPlus());
        Assert.assertNull(split4.getMinus());

        SubCircle sc5 = create(Vector3D.Unit.MINUS_Y, Vector3D.Unit.PLUS_X, Vector3D.Unit.PLUS_Z, TEST_PRECISION, 5.0, 6.0);
        SplitSubHyperplane<S2Point> split5 = sc5.split(xzPlane);
        Assert.assertEquals(Side.HYPER, sc5.split(xzPlane).getSide());
        Assert.assertNull(split5.getPlus());
        Assert.assertNull(split5.getMinus());

    }

    @Test
    public void testSideSplitConsistency() {

        double tolerance = 1.0e-6;
        DoublePrecisionContext precision = new EpsilonDoublePrecisionContext(tolerance);
        Circle hyperplane = new Circle(Vector3D.of(9.738804529764676E-5, -0.6772824575010357, -0.7357230887208355),
                precision);
        SubCircle sub = new SubCircle(new Circle(Vector3D.of(2.1793884139073498E-4, 0.9790647032675541, -0.20354915700704285),
                precision),
                                      new ArcsSet(4.7121441684170700, 4.7125386635004760, precision));
        SplitSubHyperplane<S2Point> split = sub.split(hyperplane);
        Assert.assertNotNull(split.getMinus());
        Assert.assertNull(split.getPlus());
        Assert.assertEquals(Side.MINUS, sub.split(hyperplane).getSide());

    }

    private SubCircle create(Vector3D pole, Vector3D x, Vector3D y,
                             DoublePrecisionContext precision, double ... limits) {
        RegionFactory<S1Point> factory = new RegionFactory<>();
        Circle circle = new Circle(pole, precision);
        Circle phased =
                (Circle) Circle.getTransform(QuaternionRotation.createBasisRotation(circle.getXAxis(), circle.getYAxis(), x, y)).apply(circle);
        ArcsSet set = (ArcsSet) factory.getComplement(new ArcsSet(precision));
        for (int i = 0; i < limits.length; i += 2) {
            set = (ArcsSet) factory.union(set, new ArcsSet(limits[i], limits[i + 1], precision));
        }
        return new SubCircle(phased, set);
    }

}