/*
Copyright (c) 2012 Sony Pictures Imageworks Inc., et al.
and
All Rights Reserved.

Redistribution and use in source and binary forms, with or without
modification, are permitted provided that the following conditions are
met:
* Redistributions of source code must retain the above copyright
  notice, this list of conditions and the following disclaimer.
* 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.
* Neither the name of Sony Pictures Imageworks nor the names of its
  contributors may be used to endorse or promote products derived from
  this software without specific prior written permission.
THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND 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 COPYRIGHT
OWNER OR 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) ARISING IN ANY WAY OUT OF THE USE
OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
*/


// Extend Imath matrix classes to include 2x2, as analogous as possible
// to Imath::Matrix33 and Imath::Matrix44.
// 
// The original Imath classes bear the "new BSD" license (same as
// ours above) and this copyright:
// Copyright (c) 2002, Industrial Light & Magic, a division of
// Lucas Digital Ltd. LLC.  All rights reserved.


#pragma once


#include <OpenEXR/ImathMatrix.h>

namespace Imathx {   // "extended" Imath

enum Uninitialized {UNINITIALIZED};


template <class T> class Matrix22
{
  public:

    //-------------------
    // Access to elements
    //-------------------

    T           x[2][2];

    T *         operator [] (int i);
    const T *   operator [] (int i) const;


    //-------------
    // Constructors
    //-------------

    Matrix22 (Uninitialized) {}

    Matrix22 ();
                                // 1 0
                                // 0 1

    Matrix22 (T a);
                                // a a
                                // a a

    Matrix22 (const T a[2][2]);
                                // a[0][0] a[0][1]
                                // a[1][0] a[1][1]

    Matrix22 (T a, T b, T c, T d);
                                // a b
                                // c d


    //--------------------------------
    // Copy constructor and assignment
    //--------------------------------

    Matrix22 (const Matrix22 &v);
    template <class S> explicit Matrix22 (const Matrix22<S> &v);

    const Matrix22 &    operator = (const Matrix22 &v);
    const Matrix22 &    operator = (T a);


    //----------------------
    // Compatibility with Sb
    //----------------------
    
    T *                 getValue ();
    const T *           getValue () const;

    template <class S>
    void                getValue (Matrix22<S> &v) const;
    template <class S>
    Matrix22 &          setValue (const Matrix22<S> &v);

    template <class S>
    Matrix22 &          setTheMatrix (const Matrix22<S> &v);


    //---------
    // Identity
    //---------

    void                makeIdentity();


    //---------
    // Equality
    //---------

    bool                operator == (const Matrix22 &v) const;
    bool                operator != (const Matrix22 &v) const;

    //-----------------------------------------------------------------------
    // Compare two matrices and test if they are "approximately equal":
    //
    // equalWithAbsError (m, e)
    //
    //      Returns true if the coefficients of this and m are the same with
    //      an absolute error of no more than e, i.e., for all i, j
    //
    //      abs (this[i][j] - m[i][j]) <= e
    //
    // equalWithRelError (m, e)
    //
    //      Returns true if the coefficients of this and m are the same with
    //      a relative error of no more than e, i.e., for all i, j
    //
    //      abs (this[i] - v[i][j]) <= e * abs (this[i][j])
    //-----------------------------------------------------------------------

    bool                equalWithAbsError (const Matrix22<T> &v, T e) const;
    bool                equalWithRelError (const Matrix22<T> &v, T e) const;


    //------------------------
    // Component-wise addition
    //------------------------

    const Matrix22 &    operator += (const Matrix22 &v);
    const Matrix22 &    operator += (T a);
    Matrix22            operator + (const Matrix22 &v) const;


    //---------------------------
    // Component-wise subtraction
    //---------------------------

    const Matrix22 &    operator -= (const Matrix22 &v);
    const Matrix22 &    operator -= (T a);
    Matrix22            operator - (const Matrix22 &v) const;


    //------------------------------------
    // Component-wise multiplication by -1
    //------------------------------------

    Matrix22            operator - () const;
    const Matrix22 &    negate ();


    //------------------------------
    // Component-wise multiplication
    //------------------------------

    const Matrix22 &    operator *= (T a);
    Matrix22            operator * (T a) const;


    //-----------------------------------
    // Matrix-times-matrix multiplication
    //-----------------------------------

    const Matrix22 &    operator *= (const Matrix22 &v);
    Matrix22            operator * (const Matrix22 &v) const;


    //-----------------------------------------------------------------
    // Vector-times-matrix multiplication; see also the "operator *"
    // functions defined below.
    //
    // m.multVecMatrix(src,dst) implements a homogeneous transformation
    // by computing Vec3 (src.x, src.y, 1) * m and dividing by the
    // result's third element.
    //
    // m.multDirMatrix(src,dst) multiplies src by the upper left 2x2
    // submatrix, ignoring the rest of matrix m.
    //-----------------------------------------------------------------

    template <class S>
    void                multMatrix(const Imath::Vec2<S> &src, Imath::Vec2<S> &dst) const;



    //------------------------
    // Component-wise division
    //------------------------

    const Matrix22 &    operator /= (T a);
    Matrix22            operator / (T a) const;


    //------------------
    // Transposed matrix
    //------------------

    const Matrix22 &    transpose ();
    Matrix22            transposed () const;


    //------------------------------------------------------------
    // Inverse matrix: If singExc is false, inverting a singular
    // matrix produces an identity matrix.  If singExc is true,
    // inverting a singular matrix throws a SingMatrixExc.
    //
    // inverse() and invert() invert matrices using determinants.
    // 
    //------------------------------------------------------------

    const Matrix22 &    invert (bool singExc = false)
                        throw (Iex::MathExc);

    Matrix22<T>         inverse (bool singExc = false) const
                        throw (Iex::MathExc);


    //-----------------------------------------
    // Set matrix to rotation by r (in radians)
    //-----------------------------------------

    template <class S>
    const Matrix22 &    setRotation (S r);


    //-----------------------------
    // Rotate the given matrix by r
    //-----------------------------

    template <class S>
    const Matrix22 &    rotate (S r);


    //--------------------------------------------
    // Set matrix to scale by given uniform factor
    //--------------------------------------------

    const Matrix22 &    setScale (T s);


    //------------------------------------
    // Set matrix to scale by given vector
    //------------------------------------

    template <class S>
    const Matrix22 &    setScale (const Imath::Vec2<S> &s);


    //----------------------
    // Scale the matrix by s
    //----------------------

    template <class S>
    const Matrix22 &    scale (const Imath::Vec2<S> &s);


    //-------------------------------------------------
    // Limitations of type T (see also class limits<T>)
    //-------------------------------------------------

    static T            baseTypeMin()           {return Imath::limits<T>::min();}
    static T            baseTypeMax()           {return Imath::limits<T>::max();}
    static T            baseTypeSmallest()      {return Imath::limits<T>::smallest();}
    static T            baseTypeEpsilon()       {return Imath::limits<T>::epsilon();}

  private:

    template <typename R, typename S>
    struct isSameType
    {
        enum {value = 0};
    };

    template <typename R>
    struct isSameType<R, R>
    {
        enum {value = 1};
    };
};



//--------------
// Stream output
//--------------

template <class T>
std::ostream &  operator << (std::ostream & s, const Matrix22<T> &m); 


//---------------------------------------------
// Vector-times-matrix multiplication operators
//---------------------------------------------

template <class S, class T>
Imath::Vec2<S> operator * (const Matrix22<T> &m, const Imath::Vec2<S> &v)
{
    Imath::Vec2<S> tmp;
    m.multMatrix (v, tmp);
    return tmp;
}



//-------------------------
// Typedefs for convenience
//-------------------------

typedef Matrix22 <float>  M22f;
typedef Matrix22 <double> M22d;


//---------------------------
// Implementation of Matrix22
//---------------------------

template <class T>
inline T *
Matrix22<T>::operator [] (int i)
{
    return x[i];
}

template <class T>
inline const T *
Matrix22<T>::operator [] (int i) const
{
    return x[i];
}

template <class T>
inline
Matrix22<T>::Matrix22 ()
{
    x[0][0] = 1;
    x[0][1] = 0;
    x[1][0] = 0;
    x[1][1] = 1;
}

template <class T>
inline
Matrix22<T>::Matrix22 (T a)
{
    x[0][0] = a;
    x[0][1] = a;
    x[1][0] = a;
    x[1][1] = a;
}

template <class T>
inline
Matrix22<T>::Matrix22 (const T a[2][2]) 
{
    memcpy (x, a, sizeof (x));
}

template <class T>
inline
Matrix22<T>::Matrix22 (T a, T b, T c, T d)
{
    x[0][0] = a;
    x[0][1] = b;
    x[1][0] = c;
    x[1][1] = d;
}

template <class T>
inline
Matrix22<T>::Matrix22 (const Matrix22 &v)
{
    memcpy (x, v.x, sizeof (x));
}

template <class T>
template <class S>
inline
Matrix22<T>::Matrix22 (const Matrix22<S> &v)
{
    x[0][0] = T (v.x[0][0]);
    x[0][1] = T (v.x[0][1]);
    x[1][0] = T (v.x[1][0]);
    x[1][1] = T (v.x[1][1]);
}

template <class T>
inline const Matrix22<T> &
Matrix22<T>::operator = (const Matrix22 &v)
{
    memcpy (x, v.x, sizeof (x));
    return *this;
}

template <class T>
inline const Matrix22<T> &
Matrix22<T>::operator = (T a)
{
    x[0][0] = a;
    x[0][1] = a;
    x[1][0] = a;
    x[1][1] = a;
    return *this;
}

template <class T>
inline T *
Matrix22<T>::getValue ()
{
    return (T *) &x[0][0];
}

template <class T>
inline const T *
Matrix22<T>::getValue () const
{
    return (const T *) &x[0][0];
}

template <class T>
template <class S>
inline void
Matrix22<T>::getValue (Matrix22<S> &v) const
{
    if (isSameType<S,T>::value)
    {
        memcpy (v.x, x, sizeof (x));
    }
    else
    {
        v.x[0][0] = x[0][0];
        v.x[0][1] = x[0][1];
        v.x[1][0] = x[1][0];
        v.x[1][1] = x[1][1];
    }
}

template <class T>
template <class S>
inline Matrix22<T> &
Matrix22<T>::setValue (const Matrix22<S> &v)
{
    if (isSameType<S,T>::value)
    {
        memcpy (x, v.x, sizeof (x));
    }
    else
    {
        x[0][0] = v.x[0][0];
        x[0][1] = v.x[0][1];
        x[1][0] = v.x[1][0];
        x[1][1] = v.x[1][1];
    }

    return *this;
}

template <class T>
template <class S>
inline Matrix22<T> &
Matrix22<T>::setTheMatrix (const Matrix22<S> &v)
{
    if (isSameType<S,T>::value)
    {
        memcpy (x, v.x, sizeof (x));
    }
    else
    {
        x[0][0] = v.x[0][0];
        x[0][1] = v.x[0][1];
        x[1][0] = v.x[1][0];
        x[1][1] = v.x[1][1];
    }

    return *this;
}

template <class T>
inline void
Matrix22<T>::makeIdentity()
{
    x[0][0] = 1;
    x[0][1] = 0;
    x[1][0] = 0;
    x[1][1] = 1;
}

template <class T>
bool
Matrix22<T>::operator == (const Matrix22 &v) const
{
    return x[0][0] == v.x[0][0] &&
           x[0][1] == v.x[0][1] &&
           x[1][0] == v.x[1][0] &&
           x[1][1] == v.x[1][1];
}

template <class T>
bool
Matrix22<T>::operator != (const Matrix22 &v) const
{
    return x[0][0] != v.x[0][0] ||
           x[0][1] != v.x[0][1] ||
           x[1][0] != v.x[1][0] ||
           x[1][1] != v.x[1][1];
}

template <class T>
bool
Matrix22<T>::equalWithAbsError (const Matrix22<T> &m, T e) const
{
    for (int i = 0; i < 2; i++)
        for (int j = 0; j < 2; j++)
            if (!Imath::equalWithAbsError ((*this)[i][j], m[i][j], e))
                return false;

    return true;
}

template <class T>
bool
Matrix22<T>::equalWithRelError (const Matrix22<T> &m, T e) const
{
    for (int i = 0; i < 2; i++)
        for (int j = 0; j < 2; j++)
            if (!Imath::equalWithRelError ((*this)[i][j], m[i][j], e))
                return false;

    return true;
}

template <class T>
const Matrix22<T> &
Matrix22<T>::operator += (const Matrix22<T> &v)
{
    x[0][0] += v.x[0][0];
    x[0][1] += v.x[0][1];
    x[1][0] += v.x[1][0];
    x[1][1] += v.x[1][1];

    return *this;
}

template <class T>
const Matrix22<T> &
Matrix22<T>::operator += (T a)
{
    x[0][0] += a;
    x[0][1] += a;
    x[1][0] += a;
    x[1][1] += a;
  
    return *this;
}

template <class T>
Matrix22<T>
Matrix22<T>::operator + (const Matrix22<T> &v) const
{
    return Matrix22 (x[0][0] + v.x[0][0],
                     x[0][1] + v.x[0][1],
                     x[1][0] + v.x[1][0],
                     x[1][1] + v.x[1][1]);
}

template <class T>
const Matrix22<T> &
Matrix22<T>::operator -= (const Matrix22<T> &v)
{
    x[0][0] -= v.x[0][0];
    x[0][1] -= v.x[0][1];
    x[1][0] -= v.x[1][0];
    x[1][1] -= v.x[1][1];
  
    return *this;
}

template <class T>
const Matrix22<T> &
Matrix22<T>::operator -= (T a)
{
    x[0][0] -= a;
    x[0][1] -= a;
    x[1][0] -= a;
    x[1][1] -= a;
  
    return *this;
}

template <class T>
Matrix22<T>
Matrix22<T>::operator - (const Matrix22<T> &v) const
{
    return Matrix22 (x[0][0] - v.x[0][0],
                     x[0][1] - v.x[0][1],
                     x[1][0] - v.x[1][0],
                     x[1][1] - v.x[1][1]);
}

template <class T>
Matrix22<T>
Matrix22<T>::operator - () const
{
    return Matrix22 (-x[0][0],
                     -x[0][1],
                     -x[1][0],
                     -x[1][1]);
}

template <class T>
const Matrix22<T> &
Matrix22<T>::negate ()
{
    x[0][0] = -x[0][0];
    x[0][1] = -x[0][1];
    x[1][0] = -x[1][0];
    x[1][1] = -x[1][1];

    return *this;
}

template <class T>
const Matrix22<T> &
Matrix22<T>::operator *= (T a)
{
    x[0][0] *= a;
    x[0][1] *= a;
    x[1][0] *= a;
    x[1][1] *= a;
  
    return *this;
}

template <class T>
Matrix22<T>
Matrix22<T>::operator * (T a) const
{
    return Matrix22 (x[0][0] * a,
                     x[0][1] * a,
                     x[1][0] * a,
                     x[1][1] * a);
}

template <class T>
inline Matrix22<T>
operator * (T a, const Matrix22<T> &v)
{
    return v * a;
}

template <class T>
const Matrix22<T> &
Matrix22<T>::operator *= (const Matrix22<T> &v)
{
    Matrix22 tmp (T (0));

    for (int i = 0; i < 2; i++)
        for (int j = 0; j < 2; j++)
            for (int k = 0; k < 2; k++)
                tmp.x[i][j] += x[i][k] * v.x[k][j];

    *this = tmp;
    return *this;
}

template <class T>
Matrix22<T>
Matrix22<T>::operator * (const Matrix22<T> &v) const
{
    Matrix22 tmp (T (0));

    for (int i = 0; i < 2; i++)
        for (int j = 0; j < 2; j++)
            for (int k = 0; k < 2; k++)
                tmp.x[i][j] += x[i][k] * v.x[k][j];

    return tmp;
}

template <class T>
template <class S>
void
Matrix22<T>::multMatrix(const Imath::Vec2<S> &src, Imath::Vec2<S> &dst) const
{
    S a, b;

    a = src[0] * x[0][0] + src[1] * x[1][0];
    b = src[0] * x[0][1] + src[1] * x[1][1];

    dst.x = a;
    dst.y = b;
}

template <class T>
const Matrix22<T> &
Matrix22<T>::operator /= (T a)
{
    x[0][0] /= a;
    x[0][1] /= a;
    x[1][0] /= a;
    x[1][1] /= a;
  
    return *this;
}

template <class T>
Matrix22<T>
Matrix22<T>::operator / (T a) const
{
    return Matrix22 (x[0][0] / a,
                     x[0][1] / a,
                     x[1][0] / a,
                     x[1][1] / a);
}

template <class T>
const Matrix22<T> &
Matrix22<T>::transpose ()
{
    Matrix22 tmp (x[0][0],
                  x[1][0],
                  x[0][1],
                  x[1][1]);
    *this = tmp;
    return *this;
}

template <class T>
Matrix22<T>
Matrix22<T>::transposed () const
{
    return Matrix22 (x[0][0],
                     x[1][0],
                     x[0][1],
                     x[1][1]);
}


template <class T>
const Matrix22<T> &
Matrix22<T>::invert (bool singExc) throw (Iex::MathExc)
{
    *this = inverse (singExc);
    return *this;
}

template <class T>
Matrix22<T>
Matrix22<T>::inverse (bool singExc) const throw (Iex::MathExc)
{
    Matrix22 s ( x[1][1],  -x[0][1],
                -x[1][0],   x[0][0]);
    T r = x[0][0] * x[1][1] - x[1][0] * x[0][1];  // determinant

    if (Imath::abs (r) >= 1)
    {
        s /= r;
    }
    else
    {
        T mr = Imath::abs (r) / Imath::limits<T>::smallest();

        for (int i = 0; i < 2; ++i)
        {
            for (int j = 0; j < 2; ++j)
            {
                if (mr > Imath::abs (s[i][j]))
                {
                    s[i][j] /= r;
                }
                else
                {
                    if (singExc)
                        throw Imath::SingMatrixExc ("Cannot invert "
                                             "singular matrix.");
                    return Matrix22();
                }
            }
        }
    }

    return s;
}

template <class T>
template <class S>
const Matrix22<T> &
Matrix22<T>::setRotation (S r)
{
    S cos_r, sin_r;

    cos_r = Imath::Math<T>::cos (r);
    sin_r = Imath::Math<T>::sin (r);

    x[0][0] =  cos_r;
    x[0][1] =  sin_r;

    x[1][0] =  -sin_r;
    x[1][1] =  cos_r;

    return *this;
}

template <class T>
template <class S>
const Matrix22<T> &
Matrix22<T>::rotate (S r)
{
    *this *= Matrix22<T>().setRotation (r);
    return *this;
}

template <class T>
const Matrix22<T> &
Matrix22<T>::setScale (T s)
{
    memset (x, 0, sizeof (x));
    x[0][0] = s;
    x[1][1] = s;

    return *this;
}

template <class T>
template <class S>
const Matrix22<T> &
Matrix22<T>::setScale (const Imath::Vec2<S> &s)
{
    memset (x, 0, sizeof (x));
    x[0][0] = s[0];
    x[1][1] = s[1];

    return *this;
}

template <class T>
template <class S>
const Matrix22<T> &
Matrix22<T>::scale (const Imath::Vec2<S> &s)
{
    x[0][0] *= s[0];
    x[0][1] *= s[0];

    x[1][0] *= s[1];
    x[1][1] *= s[1];

    return *this;
}


//--------------------------------
// Implementation of stream output
//--------------------------------

template <class T>
std::ostream &
operator << (std::ostream &s, const Matrix22<T> &m)
{
    std::ios_base::fmtflags oldFlags = s.flags();
    int width;

    if (s.flags() & std::ios_base::fixed)
    {
        s.setf (std::ios_base::showpoint);
        width = s.precision() + 5;
    }
    else
    {
        s.setf (std::ios_base::scientific);
        s.setf (std::ios_base::showpoint);
        width = s.precision() + 8;
    }

    s << "(" << std::setw (width) << m[0][0] <<
         " " << std::setw (width) << m[0][1] << "\n" <<

         " " << std::setw (width) << m[1][0] <<
         " " << std::setw (width) << m[1][1] << ")\n";

    s.flags (oldFlags);
    return s;
}

} // namespace Imathx
