so2.h

// -*- c++ -*-

// Copyright (C) 2005,2009 Tom Drummond (twd20@cam.ac.uk),
// Ed Rosten (er258@cam.ac.uk), Gerhard Reitmayr (gr281@cam.ac.uk)

//All rights reserved.
//
//Redistribution and use in source and binary forms, with or without
//modification, are permitted provided that the following conditions
//are met:
//1. Redistributions of source code must retain the above copyright
//    notice, this list of conditions and the following disclaimer.
//2. Redistributions in binary form must reproduce the above copyright
//   notice, this list of conditions and the following disclaimer in the
//   documentation and/or other materials provided with the distribution.
//
//THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND OTHER CONTRIBUTORS ``AS IS''
//AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
//IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
//ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR OTHER CONTRIBUTORS BE
//LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
//CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
//SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
//INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
//CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
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#ifndef TOON_INCLUDE_SO2_H
#define TOON_INCLUDE_SO2_H

#include <TooN/TooN.h>
#include <TooN/helpers.h>

namespace TooN {

template <typename Precision> class SO2;
template <typename Precision> class SE2;
template <typename Precision> class SIM2;

template<typename Precision> inline std::istream & operator>>(std::istream &, SO2<Precision> & );
template<typename Precision> inline std::istream & operator>>(std::istream &, SE2<Precision> & );
template<typename Precision> inline std::istream & operator>>(std::istream &, SIM2<Precision> & );

template<typename Precision = DefaultPrecision>
class SO2 {
    friend std::istream& operator>> <Precision>(std::istream&, SO2& );
    friend std::istream& operator>> <Precision>(std::istream&, SE2<Precision>& );
    friend std::istream& operator>> <Precision>(std::istream&, SIM2<Precision>& );

public:
    SO2(const Operator<Internal::Identity<Internal::One> >&)
    :my_matrix(Identity)
    {}
    
    SO2() : my_matrix(Identity) {} 
    
    SO2(const Matrix<2,2,Precision>& rhs) {  
        *this = rhs; 
        coerce();
    }

    explicit SO2(const Precision l) { *this = exp(l); }
  
    template <int R, int C, typename P, typename A> 
    SO2& operator=(const Matrix<R,C,P,A>& rhs){
        my_matrix = rhs;
        coerce();
        return *this;
    }

    void coerce(){
        my_matrix[0] = unit(my_matrix[0]);
        my_matrix[1] -= my_matrix[0] * (my_matrix[0]*my_matrix[1]);
        my_matrix[1] = unit(my_matrix[1]);
    }

    inline static SO2 exp(const Precision & d){
        SO2<Precision> result;
        result.my_matrix[0][0] = result.my_matrix[1][1] = cos(d);
        result.my_matrix[1][0] = sin(d);
        result.my_matrix[0][1] = -result.my_matrix[1][0];
        return result;
    }

    Precision ln() const { return atan2(my_matrix[1][0], my_matrix[0][0]); }

    SO2 inverse() const { return SO2(*this, Invert()); }

    template <typename P>
    SO2& operator *=(const SO2<P>& rhs){
        my_matrix=my_matrix*rhs.get_matrix();
        return *this;
    }

    template <typename P>
    SO2<typename Internal::MultiplyType<Precision, P>::type> operator *(const SO2<P>& rhs) const { 
        return SO2<typename Internal::MultiplyType<Precision, P>::type>(*this,rhs); 
    }

    const Matrix<2,2,Precision>& get_matrix() const {return my_matrix;}

    static Matrix<2,2,Precision> generator() {
        Matrix<2,2,Precision> result;
        result[0] = makeVector(0,-1);
        result[1] = makeVector(1,0);
        return result;
    }

private:
    struct Invert {};
    inline SO2(const SO2& so2, const Invert&) : my_matrix(so2.my_matrix.T()) {}
    template <typename PA, typename PB>
    inline SO2(const SO2<PA>& a, const SO2<PB>& b) : my_matrix(a.get_matrix()*b.get_matrix()) {}

    Matrix<2,2,Precision> my_matrix;
};

template <typename Precision>
inline std::ostream& operator<< (std::ostream& os, const SO2<Precision> & rhs){
    return os << rhs.get_matrix();
}

template <typename Precision>
inline std::istream& operator>>(std::istream& is, SO2<Precision>& rhs){
    is >> rhs.my_matrix;
    rhs.coerce();
    return is;
}

template<int D, typename P1, typename PV, typename Accessor>
inline Vector<2, typename Internal::MultiplyType<P1, PV>::type> operator*(const SO2<P1> & lhs, const Vector<D, PV, Accessor> & rhs){
    return lhs.get_matrix() * rhs;
}

template<int D, typename P1, typename PV, typename Accessor>
inline Vector<2, typename Internal::MultiplyType<PV,P1>::type> operator*(const Vector<D, PV, Accessor>& lhs, const SO2<P1> & rhs){
    return lhs * rhs.get_matrix();
}

template <int R, int C, typename P1, typename P2, typename Accessor> 
inline Matrix<2,C,typename Internal::MultiplyType<P1,P2>::type> operator*(const SO2<P1> & lhs, const Matrix<R,C,P2,Accessor>& rhs){
    return lhs.get_matrix() * rhs;
}

template <int R, int C, typename P1, typename P2, typename Accessor>
inline Matrix<R,2,typename Internal::MultiplyType<P1,P2>::type> operator*(const Matrix<R,C,P1,Accessor>& lhs, const SO2<P2>& rhs){
    return lhs * rhs.get_matrix();
}

}

#endif