def test_addition_to_tuple_assumes_adding_a_vector(self):
# tuple argument assumes a Vector,
# as point addition makes no sense
vector = (-2, 3, 1)
point = Point(3, -2, 5)
dest = point.add(vector)
# a point added to a vector results in a translated point
assert isinstance(dest, Point)
assert dest is not point
assert dest.to_tuple() == (1, 1, 6, 1)
def test_subtraction_of_a_point_from_a_vector_raises_type_error(self):
v1 = Vector(3, 2, 1)
pt = Point(5, 6, 7)
with pytest.raises(TypeError):
# subtract a point from a vector makes no sense
v1.sub(pt)
def test_subtraction_of_two_points_results_in_a_vector(self):
p1 = Point(3, 2, 1)
p2 = Point(5, 6, 7)
rv = p1.sub(p2)
assert rv.to_tuple() == (-2, -4, -6, 0)
def test_addition_invalid_type_argument_raises_type_error(self):
point = Point(-2, 3, 1)
with pytest.raises(TypeError):
point.add(7) # one can not add a scalar to a point
def test_invalid_tuple_addition_raises_value_error(self):
point = Point(-2, 3, 1)
with pytest.raises(ValueError):
point.add((1, 2, 3, 4)) # tuple that is not a Point or a Vector
def test_tuple_as_vector_addition_raises_value_error(self):
point = Point(-2, 3, 1)
with pytest.raises(ValueError):
dest = point.add((3, -2, 5, 0)) # tuple that emulates a Vector
def test_recognizes_a_point_in_a_point_object(self):
point = Point(1.0, 1.0, 1.0)
assert Point.object_is_point(point)
def test_recognizes_a_point_in_a_tuple(self):
tup = (1.0, 1.0, 1.0, 1.0)
assert Point.tuple_is_point(tup)
def test_point_as_tuple(self):
point = Point(1, 1, 1)
assert point.to_tuple() == (1.0, 1.0, 1.0, 1.0)
def test_builds_a_point_from_a_tuple(self):
point = Point.from_tuple((1, 1, 1))
assert Point.object_is_point(point)
def test_creates_a_point_from_coordinates(self):
point = Point(1, 1, 1)
assert point.w == 1.0
def test_incomplete_tuple_is_not_a_point(self):
tup = (1, 1, 1)
assert not Point.tuple_is_point(tup)
def test_vector_tuple_is_not_a_point(self):
tup = (1, 1, 1, 0)
assert not Point.tuple_is_point(tup)
def test_malformed_tuple_is_not_a_point(self):
tup = (1, 1, 1, 2)
assert not Point.tuple_is_point(tup)
def test_addition_to_point_object(self):
point = Point(3, -2, 5)
vector = Vector(-2, 3, 1)
destination = vector.add(point)
# a point added to a vector results in a translated point (w=1)
assert destination.to_tuple() == (1, 1, 6, 1)
def test_point_addition_raises_type_error(self):
p1 = Point(-2, 3, 1)
p2 = Point(3, -2, 5)
with pytest.raises(TypeError):
dest = p1.add(p2) # Adding two Points does not make sense
def test_point_addition_results_in_new_point_object(self):
starting_point = Point(3, -2, 5)
vector = Vector(-2, 3, 1)
destination = vector.add(starting_point)
assert isinstance(destination, Point)
assert destination is not starting_point
def test_subtraction_of_a_vector_from_a_point_results_in_a_point(self):
p1 = Point(3, 2, 1)
v1 = Vector(5, 6, 7)
dp = p1.sub(v1)
assert dp.to_tuple() == (-2, -4, -6, 1)