test_quat.py

from vispy.util.quaternion import Quaternion
from itertools import permutations
from scipy.spatial.transform import Rotation
from napari._vispy.utils.quaternion import (
    _old_quaterion2euler as quaternion2euler,
)
import numpy as np

print('ok')

from random import randrange, choice


def test(res, deg=False):
    q = Quaternion(*res)
    # print(q.w, q.x, q.y, q.z)
    a, b, c = quaternion2euler(q, degrees=deg)

    z, y, x = Rotation.from_quat([q.x, q.y, q.z, q.w]).as_euler(
        'xyz', degrees=deg
    )
    mod = 360 if deg else np.pi * 2
    xyz = np.mod(np.array([x, y, z]), np.pi * 2)
    abc = np.mod(np.array([a, b, c]), np.pi * 2)
    diff = np.allclose(abc, xyz)
    if not diff:
        # print(diff)
        print()
        print(res)
        print(f"   old  {x:0.3f}, {y:0.3f}, {z:0.3f}")
        print(f"   new  {a:0.3f}, {b:0.3f}, {c:0.3f}")
        print(f"   diff {a-x:0.3f}, {y-b:0.3f}, {z-c:0.3f}")


for i in range(10000):
    res = [randrange(-500, 500) / 100 for _ in range(4)]
    deg = choice([False, True])
    test(res, deg)

test([0.09, -0.78, 0.09, 0.78])
test([-0.64, -0.58, -0.64, 0.58])
test([0.85, -0.98, -0.85, -0.98])
test([-0.19, 0.15, 0.19, 0.15])  # gimbal lock