10 float x, y, z, w; // w + xi + yj + zk
12 static Quaternion identity;
14 Quaternion() : x(0), y(0), z(0), w(1) {}
15 Quaternion(float x_, float y_, float z_, float w_) : x(x_), y(y_), z(z_), w(w_) {}
16 Quaternion(const Vector3 &v, float s) : x(v.x), y(v.y), z(v.z), w(s) {}
21 Matrix4x4 calc_matrix() const;
24 inline Quaternion operator -(const Quaternion &q);
25 inline Quaternion operator +(const Quaternion &a, const Quaternion &b);
26 inline Quaternion operator -(const Quaternion &a, const Quaternion &b);
27 inline Quaternion operator *(const Quaternion &a, const Quaternion &b);
29 inline Quaternion &operator +=(Quaternion &a, const Quaternion &b);
30 inline Quaternion &operator -=(Quaternion &a, const Quaternion &b);
31 inline Quaternion &operator *=(Quaternion &a, const Quaternion &b);
33 inline Quaternion conjugate(const Quaternion &q);
35 inline float length(const Quaternion &q);
36 inline float length_sq(const Quaternion &q);
38 inline Quaternion normalize(const Quaternion &q);
39 inline Quaternion inverse(const Quaternion &q);
41 Quaternion slerp(const Quaternion &a, const Quaternion &b, float t);
42 inline Quaternion lerp(const Quaternion &a, const Quaternion &b, float t);
48 #endif // QUATERNION_H_