Rivet/Math/Matrix3.hh

0001 #ifndef RIVET_MATH_MATRIX3
0002 #define RIVET_MATH_MATRIX3
0003
0004 #include "Rivet/Math/MathConstants.hh"
0005 #include "Rivet/Math/MathUtils.hh"
0006 #include "Rivet/Math/MatrixN.hh"
0007 #include "Rivet/Math/Vector3.hh"
0008
0009 namespace Rivet {
0010
0011
0012   /// @brief Specialisation of MatrixN to aid 3 dimensional rotations.
0013   class Matrix3 : public Matrix<3> {
0014   public:
0015     Matrix3() = default;
0016
0017     Matrix3(const Matrix<3>& m3) :  Matrix<3>::Matrix(m3) { }
0018
0019     Matrix3(const Vector3& axis, const double angle) {
0020       const Vector3 normaxis = axis.unit();
0021       _matrix = RivetEigen::AngleAxis<double>(angle, normaxis._vec);
0022     }
0023
0024     Matrix3(const Vector3& from, const Vector3& to) {
0025       setAsRotation(from, to);
0026     }
0027
0028     static Matrix3 mkXRotation(const double angle) {
0029       return Matrix3(Vector3(1,0,0), angle);
0030     }
0031
0032     static Matrix3 mkYRotation(const double angle) {
0033       return Matrix3(Vector3(0,1,0), angle);
0034     }
0035
0036     static Matrix3 mkZRotation(const double angle) {
0037       return Matrix3(Vector3(0,0,1), angle);
0038     }
0039
0040     Matrix3& setAsRotation(const Vector3& from, const Vector3& to) {
0041       const double theta = angle(from, to);
0042       if (Rivet::isZero(theta)) {
0043         _matrix = EMatrix::Identity();
0044       } else {
0045         const Vector3 normaxis = cross(from, to).unit();
0046         _matrix = RivetEigen::AngleAxis<double>(theta, normaxis._vec);
0047       }
0048       return *this;
0049     }
0050
0051     static Matrix3 mkRotation(const Vector3& from, const Vector3& to) {
0052       Matrix3 rtn;
0053       rtn.setAsRotation(from, to);
0054       return rtn;
0055     }
0056
0057   };
0058
0059
0060 }
0061
0062 #endif