diff options
Diffstat (limited to 'Eigen/src/Geometry/Quaternion.h')
| -rw-r--r-- | Eigen/src/Geometry/Quaternion.h | 31 |
1 files changed, 23 insertions, 8 deletions
diff --git a/Eigen/src/Geometry/Quaternion.h b/Eigen/src/Geometry/Quaternion.h index 97add91d9..b82f37e7d 100644 --- a/Eigen/src/Geometry/Quaternion.h +++ b/Eigen/src/Geometry/Quaternion.h @@ -163,6 +163,15 @@ public: */ inline Scalar norm() const { return m_coeffs.norm(); } + /** \returns the dot product of \c *this and \a other + * Geometrically speaking, the dot product of two unit quaternions + * corresponds to the cosine of half the angle between the two rotations. + * \sa angularDistance() + */ + inline Scalar dot(const Quaternion& other) const { return m_coeffs.dot(other.m_coeffs); } + + inline Scalar angularDistance(const Quaternion& other) const; + Matrix3 toRotationMatrix(void) const; template<typename Derived1, typename Derived2> @@ -357,22 +366,28 @@ inline Quaternion<Scalar> Quaternion<Scalar>::conjugate() const return Quaternion(this->w(),-this->x(),-this->y(),-this->z()); } +/** \returns the angle (in radian) between two rotations + * \sa dot() + */ +template <typename Scalar> +inline Scalar Quaternion<Scalar>::angularDistance(const Quaternion& other) const +{ + double d = ei_abs(this->dot(other)); + if (d>=1.0) + return 0; + return 2.0 * std::acos(d); +} + /** \returns the spherical linear interpolation between the two quaternions * \c *this and \a other at the parameter \a t */ template <typename Scalar> Quaternion<Scalar> Quaternion<Scalar>::slerp(Scalar t, const Quaternion& other) const { - // FIXME options for this function would be: - // 1 - Quaternion& fromSlerp(Scalar t, const Quaternion& q0, const Quaternion& q1); - // which set *this from the s-lerp and returns *this - // 2 - Quaternion slerp(Scalar t, const Quaternion& other) const - // which returns the s-lerp between this and other - // ?? static const Scalar one = Scalar(1) - precision<Scalar>(); - Scalar d = m_coeffs.dot(other.m_coeffs); + Scalar d = this->dot(other); Scalar absD = ei_abs(d); - if (d>=one) + if (absD>=one) return *this; // theta is the angle between the 2 quaternions |