/// <summary>
///
/// </summary>
/// <param name="xyz"></param>
/// <param name="w"></param>
public dvec4(dvec3 xyz, double w)
{
this.x = xyz.x;
this.y = xyz.y;
this.z = xyz.z;
this.w = w;
}
/// <summary>
///
/// </summary>
/// <param name="v"></param>
public dvec2(dvec3 v)
{
this.x = v.x;
this.y = v.y;
}