@Test
public void divideByScalarReturnsNewPointWithEachCoordinateDividedByTheScalarValueSpecified()
throws Exception {
Point point = new Triple(8, 6, 12).divide(2);
assertPointEquals(new Triple(4, 3, 6), point);
}
@Test
public void divideByScalarLeavesStateOfThisObjectUnchanged() throws Exception {
Point point = new Triple(10, 20, 30);
point.divide(5);
assertPointEquals(new Triple(10, 20, 30), point);
}
@Test
public void addReturnsDifferenceOfTheTwoInvolvedPoints() throws Exception {
Point point = new Triple(1, 2, 3).add((Point) new Triple(4, 5, 6));
assertPointEquals(new Triple(5, 7, 9), point);
}
@Test
public void subtractRetunsDifferenceOfTheTwoInvolvedPoints() throws Exception {
Point point = new Triple(1, 2, 3).subtract(new Triple(4, 5, 6));
assertPointEquals(new Triple(-3, -3, -3), point);
}
@Test
public void addDoesNotChangeStateOfTheParameterPoint() throws Exception {
Point point = new Triple(1, 2, 3);
new Triple(4, 5, 6).add(point);
assertPointEquals(new Triple(1, 2, 3), point);
}
@Test
public void addDoesNotChangeStateOfThisPoint() throws Exception {
Point point = new Triple(1, 2, 3);
point.add(new Triple(4, 5, 6));
assertPointEquals(new Triple(1, 2, 3), point);
}