def test_body_bounds_transformed():
"""Get the bounds for a body."""
b = Body(Positionable(pos=Point3(10, 10, 10)),
shapes=[
Sphere(Point3(-1, 0, 0), 2),
Sphere(Point3(1, 0, 0), 1),
])
assert b.bounds() == Sphere(Point3(10, 10, 10), radius=3)
def test_body_bounds():
"""Get the bounds for a body."""
b = Body(Positionable(),
shapes=[
Sphere(Point3(-1, 0, 0), 2),
Sphere(Point3(1, 0, 0), 1),
])
eq_(b.bounds(), Sphere(radius=3))
def test_line_sphere_intersection5():
"""Point of intersection if we hit the sphere at an oblique angle."""
s = Sphere()
l = LineSegment(Point3(0.5, 0, -5), Vector3(0, 0, 5))
i = l.first_intersection(s)
assert i is not None
eq_(i[0], 5 - math.sqrt(0.75))
def test_line_sphere_intersection4():
"""Point of intersection if we start inside the sphere."""
s = Sphere()
l = LineSegment(Point3(), Vector3(0, 0, 2))
i = l.first_intersection(s)
assert i is not None
eq_(i, (0, Point3()))
def test_body_collision():
"""We can get a separation vector if two bodies collide."""
shapes = [Sphere(Point3(0, 0, 0), 2)]
b1 = Body(Positionable(pos=Point3(1, 0, 0)), shapes)
b2 = Body(Positionable(pos=Point3(4.75, 0, 0)), shapes)
col = b1.collide(b2)
assert col is not None
eq_(col, Vector3(0.25, 0, 0))
def test_line_sphere_intersection():
"""Get the point of first intersection between a line and a sphere.
Hit the sphere right in the centre.
"""
s = Sphere()
l = LineSegment(Point3(0, 0, -10), Vector3(0, 0, 10))
i = l.first_intersection(s)
assert i is not None
eq_(i, (9, Point3(0, 0, -1)))
def test_collision():
"""The physics engine detects colliding bodies."""
shapes = [Sphere()]
physics = Physics()
b1 = Body(Positionable(Point3(1.75, 0, 0)), shapes)
b2 = Body(Positionable(), shapes)
physics.add(b1)
physics.add(b2)
with patch.object(physics, 'handle_collision') as handle_collision:
physics.do_collisions()
handle_collision.assert_called_with(b1, b2, Vector3(-0.25, 0, 0))
def test_resolve_collision_static():
"""The physics engine resolves a collision between static bodies"""
shapes = [Sphere()]
physics = Physics()
b1 = Body(Positionable(Point3(0.5, 0, 0)), shapes)
b2 = Body(Positionable(Point3(-0.5, 0, 0)), shapes)
physics.add(b1)
physics.add(b2)
physics.do_collisions()
out = [
b1.positionable.pos, b2.positionable.pos, b1.positionable.vel,
b2.positionable.vel
]
expected = [
Point3(1, 0, 0),
Point3(-1, 0, 0),
Vector3(0, 0, 0),
Vector3(0, 0, 0)
]
eq_(out, expected)
def test_resolve_collision():
"""The physics engine resolves a collision."""
shapes = [Sphere()]
physics = Physics()
b1 = Body(Positionable(Point3(-1.75, 0, 0), vel=Vector3(1, 0, 0)), shapes)
b2 = Body(Positionable(), shapes)
physics.add(b1)
physics.add(b2)
physics.do_collisions()
out = [
b1.positionable.pos, b2.positionable.pos, b1.positionable.vel,
b2.positionable.vel
]
expected = [
Point3(-2, 0, 0),
Point3(0, 0, 0),
Vector3(0.35, 0, 0),
Vector3(0.65, 0, 0)
]
eq_(out, expected)
def test_line_sphere_intersection2():
"""Point of intersection if we're already past the sphere."""
s = Sphere()
l = LineSegment(Point3(0, 0, 1.5), Vector3(0, 0, 2))
i = l.first_intersection(s)
assert i is None
def test_sphere_contains2():
"""The a point on the surface of a sphere is within the sphere."""
assert Point3(0, 4, 0) in Sphere(Point3(0, 2, 0), radius=2)
def test_sphere_contains3():
"""A point slightly outside the sphere is not in the sphere."""
assert Point3(0, 2, 0.1) not in Sphere(radius=2)
def test_line_segment_bounds():
"""Get a bounding sphere for a line segment."""
l = LineSegment(Point3(5, 5, 5), Vector3(-10, -10, -10))
eq_(l.bounds(), Sphere(radius=math.sqrt(75)))
def test_sphere_contains():
"""The origin lies within a unit sphere."""
assert Point3(0, 0, 0) in Sphere()
def test_sphere_collide():
"""Two overlapping spheres collide."""
c = Point3(72, 27, 1)
c2 = Point3(71, 26, 0)
assert (c2 - c).magnitude() < 2
assert Sphere(c, radius=1).collides(Sphere(c2, radius=1))
def test_line_sphere_intersection3():
"""Point of intersection if we stop short of the sphere."""
s = Sphere()
l = LineSegment(Point3(0, 0, -2.5), Vector3(0, 0, 1))
i = l.first_intersection(s)
assert i is None
def test_sphere_transform():
"""We can transform a sphere."""
m = Matrix4.new_translate(0, 0, 5)
assert Sphere(radius=2).transformed(m) == Sphere(Point3(0, 0, 5), 2)
def test_sphere_collide2():
"""Non-overlapping spheres do not collide."""
c = Point3(72, 27, 1.5)
c2 = Point3(71, 26, 0)
assert (c2 - c).magnitude() > 2
assert not Sphere(c, radius=1).collides(Sphere(c2, radius=1))
