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Diffstat (limited to 'eigen/Eigen/src/Eigen2Support/Geometry/Rotation2D.h')
-rw-r--r-- | eigen/Eigen/src/Eigen2Support/Geometry/Rotation2D.h | 145 |
1 files changed, 145 insertions, 0 deletions
diff --git a/eigen/Eigen/src/Eigen2Support/Geometry/Rotation2D.h b/eigen/Eigen/src/Eigen2Support/Geometry/Rotation2D.h new file mode 100644 index 0000000..19b8582 --- /dev/null +++ b/eigen/Eigen/src/Eigen2Support/Geometry/Rotation2D.h @@ -0,0 +1,145 @@ +// This file is part of Eigen, a lightweight C++ template library +// for linear algebra. +// +// Copyright (C) 2008 Gael Guennebaud <g.gael@free.fr> +// +// This Source Code Form is subject to the terms of the Mozilla +// Public License v. 2.0. If a copy of the MPL was not distributed +// with this file, You can obtain one at http://mozilla.org/MPL/2.0/. + +// no include guard, we'll include this twice from All.h from Eigen2Support, and it's internal anyway + +namespace Eigen { + +/** \geometry_module \ingroup Geometry_Module + * + * \class Rotation2D + * + * \brief Represents a rotation/orientation in a 2 dimensional space. + * + * \param _Scalar the scalar type, i.e., the type of the coefficients + * + * This class is equivalent to a single scalar representing a counter clock wise rotation + * as a single angle in radian. It provides some additional features such as the automatic + * conversion from/to a 2x2 rotation matrix. Moreover this class aims to provide a similar + * interface to Quaternion in order to facilitate the writing of generic algorithms + * dealing with rotations. + * + * \sa class Quaternion, class Transform + */ +template<typename _Scalar> struct ei_traits<Rotation2D<_Scalar> > +{ + typedef _Scalar Scalar; +}; + +template<typename _Scalar> +class Rotation2D : public RotationBase<Rotation2D<_Scalar>,2> +{ + typedef RotationBase<Rotation2D<_Scalar>,2> Base; + +public: + + using Base::operator*; + + enum { Dim = 2 }; + /** the scalar type of the coefficients */ + typedef _Scalar Scalar; + typedef Matrix<Scalar,2,1> Vector2; + typedef Matrix<Scalar,2,2> Matrix2; + +protected: + + Scalar m_angle; + +public: + + /** Construct a 2D counter clock wise rotation from the angle \a a in radian. */ + inline Rotation2D(Scalar a) : m_angle(a) {} + + /** \returns the rotation angle */ + inline Scalar angle() const { return m_angle; } + + /** \returns a read-write reference to the rotation angle */ + inline Scalar& angle() { return m_angle; } + + /** \returns the inverse rotation */ + inline Rotation2D inverse() const { return -m_angle; } + + /** Concatenates two rotations */ + inline Rotation2D operator*(const Rotation2D& other) const + { return m_angle + other.m_angle; } + + /** Concatenates two rotations */ + inline Rotation2D& operator*=(const Rotation2D& other) + { return m_angle += other.m_angle; return *this; } + + /** Applies the rotation to a 2D vector */ + Vector2 operator* (const Vector2& vec) const + { return toRotationMatrix() * vec; } + + template<typename Derived> + Rotation2D& fromRotationMatrix(const MatrixBase<Derived>& m); + Matrix2 toRotationMatrix(void) const; + + /** \returns the spherical interpolation between \c *this and \a other using + * parameter \a t. It is in fact equivalent to a linear interpolation. + */ + inline Rotation2D slerp(Scalar t, const Rotation2D& other) const + { return m_angle * (1-t) + other.angle() * t; } + + /** \returns \c *this with scalar type casted to \a NewScalarType + * + * Note that if \a NewScalarType is equal to the current scalar type of \c *this + * then this function smartly returns a const reference to \c *this. + */ + template<typename NewScalarType> + inline typename internal::cast_return_type<Rotation2D,Rotation2D<NewScalarType> >::type cast() const + { return typename internal::cast_return_type<Rotation2D,Rotation2D<NewScalarType> >::type(*this); } + + /** Copy constructor with scalar type conversion */ + template<typename OtherScalarType> + inline explicit Rotation2D(const Rotation2D<OtherScalarType>& other) + { + m_angle = Scalar(other.angle()); + } + + /** \returns \c true if \c *this is approximately equal to \a other, within the precision + * determined by \a prec. + * + * \sa MatrixBase::isApprox() */ + bool isApprox(const Rotation2D& other, typename NumTraits<Scalar>::Real prec = precision<Scalar>()) const + { return ei_isApprox(m_angle,other.m_angle, prec); } +}; + +/** \ingroup Geometry_Module + * single precision 2D rotation type */ +typedef Rotation2D<float> Rotation2Df; +/** \ingroup Geometry_Module + * double precision 2D rotation type */ +typedef Rotation2D<double> Rotation2Dd; + +/** Set \c *this from a 2x2 rotation matrix \a mat. + * In other words, this function extract the rotation angle + * from the rotation matrix. + */ +template<typename Scalar> +template<typename Derived> +Rotation2D<Scalar>& Rotation2D<Scalar>::fromRotationMatrix(const MatrixBase<Derived>& mat) +{ + EIGEN_STATIC_ASSERT(Derived::RowsAtCompileTime==2 && Derived::ColsAtCompileTime==2,YOU_MADE_A_PROGRAMMING_MISTAKE) + m_angle = ei_atan2(mat.coeff(1,0), mat.coeff(0,0)); + return *this; +} + +/** Constructs and \returns an equivalent 2x2 rotation matrix. + */ +template<typename Scalar> +typename Rotation2D<Scalar>::Matrix2 +Rotation2D<Scalar>::toRotationMatrix(void) const +{ + Scalar sinA = ei_sin(m_angle); + Scalar cosA = ei_cos(m_angle); + return (Matrix2() << cosA, -sinA, sinA, cosA).finished(); +} + +} // end namespace Eigen |