pub fn spherical_phi(v: &Vector3f) -> Float {
    let p: Float = v.y.atan2(v.x);
    if p < 0.0 as Float {
        p + 2.0 as Float * PI
    } else {
        p
    }
}
/// Conversion of a direction to spherical angles.
Conversion of a direction to spherical angles.
Conversion of a direction to spherical angles .
pub fn spherical_phi(v: &Vector3f) -> Float {
    let p: Float = v.y.atan2(v.x);
    if p < 0.0 as Float {
        p + 2.0 as Float * PI
    } else {
        p
    }
}
pub fn spherical_phi ( v : & Vector3f ) -> Float { let p : Float = v . y . atan2 ( v . x ) ; if p < 0.0 as Float { p + 2.0 as Float * PI } else { p } }
Conversion of a direction to spherical angles.
Conversion of a direction to spherical angles .
v
&Vector3f