/// <summary>
/// Vector equality check
/// </summary>
/// <param name="obj">object to check against</param>
/// <returns>true if the object is a vector and the components match</returns>
public override bool Equals(object obj)
{
return(obj switch {
Quat other => this.X == other.X && this.Y == other.Y && this.Z == other.Z && this.W == other.W,
_ => base.Equals(obj)
});
/// <summary>
/// Linearly interpolate between two quaternions
/// </summary>
/// <param name="a">first quaternion</param>
/// <param name="b">second quaternion</param>
/// <param name="t">interpolation factor</param>
/// <returns>interpolated quaternion</returns>
public static Quat Lerp(Quat a, Quat b, double t)
{
return((1 - t) * a + t * b);
}
/// <summary>
/// Dot product of two quaternion vectors
/// </summary>
/// <param name="a">first quaternion</param>
/// <param name="b">second quaternion</param>
/// <returns>vector dot product</returns>
public static double Dot(Quat a, Quat b)
{
return(a.X * b.X + a.Y * b.Y + a.Z * b.Z + a.W * b.W);
}
/// <summary>
/// Angle between two quaternions
/// </summary>
/// <param name="a">first quaternion</param>
/// <param name="b">second quaternion</param>
/// <returns>angle</returns>
public static double Angle(Quat a, Quat b)
{
var d = Dot(a, b);
return(Math.Acos(Math.Min(Math.Abs(d), 1) * 2));
}
/// <summary>
/// Copy an existing quaternion
/// </summary>
/// <param name="other">quaternion to copy</param>
public Quat(Quat other) : this(other.X, other.Y, other.Z, other.W)
{
}