本源码实现了一个在3D编程中很重要的四元数的类。在写这个类前提还包括对三维空间中向量类，以及4*4矩阵的运算。四元数对于三维模型的旋转能够很好的计算。-The source to achieve a 3D programming in a very important class Quaternion. At the time of writing the premise of this class also includes three-dimensional vector space cat