def test_trackball__identity():
origin_original = Point3(0., 1., 6.8)
trackball = Trackball(origin_original, Point3(0., 1., 0.))
origin_new = trackball.drag(Point2(0, 0))
_assert_vectors_eq(origin_original, origin_new)
def test_transform__identity():
z_axis = Point3(0., 0., 6.8)
up = Point3(0, 1, 0)
transform = Transform.to_world(z_axis, up)
z_axis_new = transform.transform_direction(Point3(0, 0, 1))
_assert_vectors_eq(z_axis.normalized(), z_axis_new)
def spherical_to_cartesian(phi, theta):
y = math.cos(theta)
x = math.sin(theta) * math.cos(phi)
z = math.sin(theta) * math.sin(phi)
return Point3(x, y, z)
def drag(self, point):
velocity = 0.1
delta = (point - self.anchor) * velocity
radians = delta / 180. * math.pi
cartesian = coordinates.spherical_to_cartesian(math.pi / 2 - radians.x,
math.pi / 2 + radians.y)
transform = Transform.to_world((self.origin - self.target),
Point3(0, 1, 0))
new_origin_direction = transform.transform_direction(cartesian)
return self.target + new_origin_direction * self.radius
def transform_direction(self, direction):
x = np.array([direction.x, direction.y, direction.z, 0.])
result = self.data.dot(x)
return Point3(*self.data.dot(x)[:3])
def test_cartesian_zero():
cartesian = coordinates.spherical_to_cartesian(math.pi / 2, math.pi / 2)
_assert_vectors_eq(cartesian, Point3(0, 0, 1))