public void QuaternionNegateTest()
{
Quaternion a = new Quaternion(1.0f, 2.0f, 3.0f, 4.0f);
Quaternion expected = new Quaternion(-1.0f, -2.0f, -3.0f, -4.0f);
Quaternion actual;
actual = Quaternion.Negate(a);
Assert.Equal(expected, actual);
}
public void QuaternionLerpTest3()
{
Vector3 axis = Vector3.Normalize(new Vector3(1.0f, 2.0f, 3.0f));
Quaternion a = Quaternion.CreateFromAxisAngle(axis, MathHelper.ToRadians(10.0f));
Quaternion b = Quaternion.Negate(a);
Single t = 1.0f;
Quaternion actual = Quaternion.Lerp(a, b, t);
// Note that in quaternion world, Q == -Q. In the case of quaternions dot product is zero,
// one of the quaternion will be flipped to compute the shortest distance. When t = 1, we
// expect the result to be the same as quaternion b but flipped.
Assert.True(actual == a, $"Quaternion.Lerp did not return the expected value: expected {a} actual {actual}");
}
