public Fix64 GetYAngle()
{
//Fix64 r31 = -(Fix64)2 * (x * z - w * y);
//Fix64 r32 = w * w - x * x - y * y + z * z;
//return Fix64.Atan2(r31, r32);
Fix64 sinp = (Fix64)2 * (w * y - z * x);
//if (Fix64.Abs(sinp) >= Fix64.one)
//{
// Fix64 sign = Fix64.Sign(sinp);
// return sign * Fix64.halfPi;
//}
return(Fix64.Asin(sinp));
}
//https://www.euclideanspace.com/maths/geometry/rotations/conversions/quaternionToEuler/
public Fix64Vec3 EulerAngles1()
{
Fix64 sqw = w * w;
Fix64 sqx = x * x;
Fix64 sqy = y * y;
Fix64 sqz = z * z;
Fix64 unit = sqx + sqy + sqz + sqw; // if normalised is one, otherwise is correction factor
Fix64 test = x * y + z * w;
Fix64 _x = Fix64.zero;
Fix64 _y = Fix64.zero;
Fix64 _z = Fix64.zero;
Fix64 cutoff = Fix64.FromDivision(499, 1000) * unit;
_z = Fix64.Atan2((Fix64)2 * y * w - (Fix64)2 * x * z, sqx - sqy - sqz + sqw);
_y = Fix64.Asin((Fix64)2 * test / unit);
_x = Fix64.Atan2((Fix64)2 * x * w - (Fix64)2 * y * z, -sqx + sqy - sqz + sqw);
//if (test >= cutoff)
//{ // singularity at north pole
// _z = (Fix64)2 * Fix64.Atan2(x, w);
// _y = Fix64.halfPi;
// _x = Fix64.zero;
//}
//else if (test < -cutoff)
//{ // singularity at south pole
// _z = -(Fix64)2 * Fix64.Atan2(x, w);
// _y = -Fix64.halfPi;
// _x = Fix64.zero;
//}
//else
//{
// _z = Fix64.Atan2((Fix64)2 * y * w - (Fix64)2 * x * z, sqx - sqy - sqz + sqw);
// _y = Fix64.Asin((Fix64)2 * test / unit);
// _x = Fix64.Atan2((Fix64)2 * x * w - (Fix64)2 * y * z, -sqx + sqy - sqz + sqw);
//}
Fix64 xDegree = Fix64.RadToDeg(_x);
Fix64 yDegree = Fix64.RadToDeg(_y);
Fix64 zDegree = Fix64.RadToDeg(_z);
return(new Fix64Vec3(xDegree, zDegree, yDegree));
}
