def test_to_polygon_4_divisions(self):
circle = Circle(Point(2, 5), 10)
actual = circle.to_polygon(4)
expected = Polygon([
Point(12, 5),
Point(2, 15),
Point(-8, 5),
Point(2, -5)
])
self.assertEqual(expected, actual)
class TestCircle(unittest.TestCase):
circle = Circle(Point(10, 10), 10)
# --- PROPERTIES --- #
def test_area(self):
expected = math.pi * 100
self.assertAlmostEqual(expected, self.circle.area)
def test_circumference(self):
expected = math.pi * 20
self.assertAlmostEqual(expected, self.circle.circumference)
# --- CONTAINS --- #
def test_contains_point(self):
point = Point(11, 12)
self.assertTrue(self.circle.contains_point(point))
def test_doesnt_contain_point(self):
point = Point(100, 50)
self.assertFalse(self.circle.contains_point(point))
# --- OVERLAPS --- #
def test_overlaps(self):
other = Circle(Point(30, 30), 20)
self.assertTrue(self.circle.overlaps(other))
def test_dont_overlap(self):
other = Circle(Point(30, 30), 5)
self.assertFalse(self.circle.overlaps(other))
# --- PENETRATION --- #
def test_no_penetration(self):
other = Circle(Point(30, 30), 5)
self.assertIsNone(self.circle.penetration_vector(other))
def test_penetration(self):
other = Circle(Point(30, 30), 20)
actual = self.circle.penetration_vector(other)
pen_proj = -(math.sqrt(2) * 15 - 20)
expected = Vector(pen_proj, pen_proj)
self.assertEqual(expected, actual)
# --- TO POLYGON --- #
def test_to_polygon_4_divisions(self):
circle = Circle(Point(2, 5), 10)
actual = circle.to_polygon(4)
expected = Polygon([
Point(12, 5),
Point(2, 15),
Point(-8, 5),
Point(2, -5)
])
self.assertEqual(expected, actual)
def make_circle_from_points(a: Point, b: Point, c: Point):
"""
Creates a circle that passes through three points: `a`, `b`
and `c`.
:param a: `Point`
:param b: `Point`
:param c: `Point`
:return: `Circle`
"""
chord_one_bisec = Segment(a, b).bisector
chord_two_bisec = Segment(b, c).bisector
center = chord_one_bisec.intersection_with(chord_two_bisec)
radius = center.distance_to(a)
return Circle(center, radius)
def apply_to_circle(self, circle: Circle, divisions=30):
"""
Computes a `Polygon` result of applying this affine
transformation to the given `Circle`.
After applying a generic affine transformation to a circle,
this may not be a circle anymore. A shear transformation,
for instance, would turn the circle into some kind of
ellipse.
For this reason, this method returns a `Polygon` and not
a `Circle`.
:param circle: source `Circle`
:param divisions: point count used to turn the circle into
a polygon prior to the transformation
:return: transformed `Polygon`
"""
return self.apply_to_polygon(
circle.to_polygon(divisions)
)
def test_penetration(self):
other = Circle(Point(30, 30), 20)
actual = self.circle.penetration_vector(other)
pen_proj = -(math.sqrt(2) * 15 - 20)
expected = Vector(pen_proj, pen_proj)
self.assertEqual(expected, actual)
def test_no_penetration(self):
other = Circle(Point(30, 30), 5)
self.assertIsNone(self.circle.penetration_vector(other))
def test_dont_overlap(self):
other = Circle(Point(30, 30), 5)
self.assertFalse(self.circle.overlaps(other))
def test_overlaps(self):
other = Circle(Point(30, 30), 20)
self.assertTrue(self.circle.overlaps(other))