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#ifndef __CGLA_ARITHSQMAT2X2FLOAT_H__
#define __CGLA_ARITHSQMAT2X2FLOAT_H__

#include "ExceptionStandard.h"
#include "ArithSqMatFloat.h"


namespace CGLA 
{

        CGLA_DERIVEEXCEPTION(Mat2x2fException);

        /** Two by two float matrix. This class is useful for various 
                        vector transformations in the plane. */
        
        template<class V, class M>
        class ArithSqMat2x2Float: public ArithSqMatFloat<V,M, 2>
        {
        public:

                /// Vector type
                typedef V VectorType;

                /// The type of a matrix element
                typedef typename V::ScalarType ScalarType;

        public:

                /// Construct a Mat2x2f from two Vec2f vectors.
                ArithSqMat2x2Float(V a, V b): 
                        ArithSqMatFloat<V, M, 2> (a,b) {}

                /// Construct a Mat2x2f from four scalars.
                ArithSqMat2x2Float(ScalarType a, ScalarType b, 
                                                                                         ScalarType c, ScalarType d): 
                        ArithSqMatFloat<V, M, 2>(V(a,b),V(c,d)) {}
  
                /// Construct the 0 matrix
                ArithSqMat2x2Float() {}

        };

        /** Compute the determinant of a Mat2x2f. This function is faster than
                        the generic determinant function for ArithSqMat */
        template<class V, class M>
        inline typename ArithSqMat2x2Float<V,M>::ScalarType 
        determinant(const ArithSqMat2x2Float<V,M> & m)
        {
                return m[0][0]*m[1][1]-m[0][1]*m[1][0];
        }

        template<class V, class M>
        const M invert(const ArithSqMat2x2Float<V,M>& m)
        {
                float det = determinant(m);
                if( !is_tiny(fabs(det)))
                        {
                                return M(m[1][1]/det, -m[0][1]/det,-m[1][0]/det, m[0][0]/det);
                        }
                throw Mat2x2fException("Cannot invert matrix");
        }


}
#endif