F:/My Projects/LSEngine/Modules/LSMathLib/Src/Matrix/LSMMatrix2x2Base.h

#ifndef __LSM_MATRIX2X2BASE_H__
#define __LSM_MATRIX2X2BASE_H__

#include "../LSMMathLib.h"
#include "../Vector/LSMVector2Base.h"

namespace lsm {

        template <typename _tType, typename _tVector2Type>
        class CMatrix2x2Base {
                // All is public.  This class has no secrets.
        public :
                // == Various constructors.
                LSE_CALLCTOR                                                                    CMatrix2x2Base() {
                }
                LSE_CALLCTOR                                                                    CMatrix2x2Base( const CMatrix2x2Base<_tType, _tVector2Type> &_m22bOther ) :
                        _11( _m22bOther._11 ), _12( _m22bOther._12 ),
                        _21( _m22bOther._21 ), _22( _m22bOther._22 ) {
                }
                LSE_CALLCTOR                                                                    CMatrix2x2Base( const CMatrix2x2Base<_tType, _tVector2Type> &_m22bOther, LSBOOL _bTranspose ) {
                        if ( !_bTranspose ) {
                                _11 =_m22bOther._11; _12 =_m22bOther._12;
                                _21 =_m22bOther._21; _22 =_m22bOther._22;
                        }
                        else {
                                _11 =_m22bOther._11; _12 =_m22bOther._21;
                                _21 =_m22bOther._12; _22 =_m22bOther._22;
                        }
                }
                LSE_CALLCTOR                                                                    CMatrix2x2Base( const _tType * _ptArray ) {
                        _11 = _ptArray[0];
                        _12 = _ptArray[1];

                        _21 = _ptArray[2];
                        _22 = _ptArray[3];
                }


                // == Operators.
                _tType & LSE_FCALL                                                              operator () ( LSUINT32 _ui32Row, LSUINT32 _ui32Col ) {
                        return reinterpret_cast<_tType *>(this)[(_ui32Row<<1UL)+_ui32Col];
                }

                _tType LSE_FCALL                                                                operator () ( LSUINT32 _ui32Row, LSUINT32 _ui32Col ) const {
                        return reinterpret_cast<const _tType *>(this)[(_ui32Row<<1UL)+_ui32Col];
                }

                CMatrix2x2Base<_tType, _tVector2Type> LSE_FCALL operator * ( const CMatrix2x2Base<_tType, _tVector2Type> &_m22bOther ) const {
                        CMatrix2x2Base<_tType, _tVector2Type> m22bOut;
                        for ( LSINT32 I = 2; --I >= 0; ) {
                                const _tType * pfBufferIn = &reinterpret_cast<const _tType *>(this)[I<<1UL];
                                _tType * pfBufferOut = &reinterpret_cast<_tType *>(&m22bOut)[I<<1UL];
                                for ( LSINT32 J = 2; --J >= 0; ) {
                                        _tType fSum = LSM_ZERO;
                                        for ( LSINT32 K = 2; --K >= 0; ) {
                                                fSum += pfBufferIn[K] * _m22bOther( K, J );
                                        }
                                        pfBufferOut[J] = fSum;
                                }
                        }

                        return m22bOut;
                }

                _tVector2Type LSE_FCALL                                                 operator * ( const _tVector2Type &_v2bOther ) const {
                        _tVector2Type v3bRet;
                        v3bRet.x = (_11 * _v2bOther.x + _21 * _v2bOther.y);
                        v3bRet.y = (_12 * _v2bOther.x + _22 * _v2bOther.y);
                        return v3bRet;
                }

                CMatrix2x2Base<_tType, _tVector2Type> LSE_FCALL operator * ( _tType _tValue ) const {
                        CMatrix2x2Base<_tType, _tVector2Type> m22bRet;
                        m22bRet._11 = _11 * _tValue;
                        m22bRet._12 = _12 * _tValue;
                        m22bRet._21 = _21 * _tValue;
                        m22bRet._22 = _22 * _tValue;
                        return m22bRet;
                }

                CMatrix2x2Base<_tType, _tVector2Type> & LSE_FCALL
                                                                                                                operator *= ( _tType _tValue ) {
                        _11 = _11 * _tValue;
                        _12 = _12 * _tValue;
                        _21 = _21 * _tValue;
                        _22 = _22 * _tValue;
                        return (*this);
                }

                CMatrix2x2Base<_tType, _tVector2Type> & LSE_FCALL
                                                                                                                operator += ( const CMatrix2x2Base<_tType, _tVector2Type> &_m22bOther ) {
                        _11 += _m22bOther._11;
                        _12 += _m22bOther._12;
                        _21 += _m22bOther._21;
                        _22 += _m22bOther._22;
                        return (*this);
                }


                // == Functions.
                CMatrix2x2Base<_tType, _tVector2Type> & LSE_FCALL
                                                                                                                Identity() {
                        _11 = _22 = _tType( 1.0 );
                        _12 = _21 = _tType( 0.0 );
                        return (*this);
                }

                CMatrix2x2Base<_tType, _tVector2Type> & LSE_FCALL
                                                                                                                Transpose() {
                        CMathLib::Swap( _12, _21 );
                        return (*this);
                }

                LSVOID LSE_FCALL                                                                SetRow( LSUINT32 _ui32Row, const _tVector2Type &_v3bVec ) {
                        LSE_UNALIGNED _tType * pfData = &_11;
                        pfData += (_ui32Row << 1UL);
                        
                        pfData[0] = _v3bVec.x;
                        pfData[1] = _v3bVec.y;
                }

                CMatrix2x2Base<_tType, _tVector2Type> & LSE_FCALL
                                                                                                                MatrixRotation( _tType _tAngle ) {
                        LSREAL fS;
                        LSREAL fC;
                        CMathLib::SinCos( static_cast<LSREAL>(_tAngle), fS, fC );
                        _11 = fC;
                        _12 = fS;
                        _21 = -fS;
                        _22 = fC;
                        return (*this);
                }

                static CMatrix2x2Base<_tType, _tVector2Type> * LSE_FCALL
                                                                                                                MatrixMultiply( CMatrix2x2Base<_tType, _tVector2Type> &_m22bOut, const CMatrix2x2Base<_tType, _tVector2Type> &_m22bM1, const CMatrix2x2Base<_tType, _tVector2Type> &_m22bM2 ) {
                        const CMatrix2x2Base<_tType, _tVector2Type> * LSE_RESTRICT pmSrc1 = &_m22bM1;
                        const CMatrix2x2Base<_tType, _tVector2Type> * LSE_RESTRICT pmSrc2 = &_m22bM2;

                        for ( LSINT32 I = 2; --I >= 0; ) {
                                const _tType * pfBufferIn = &reinterpret_cast<const _tType *>(pmSrc1)[I<<1UL];
                                _tType * pfBufferOut = &reinterpret_cast<_tType *>(&_m22bOut)[I<<1UL];
                                for ( LSINT32 J = 2; --J >= 0; ) {
                                        _tType tSum = LSM_ZERO;
                                        for ( LSINT32 K = 2; --K >= 0; ) {
                                                tSum += pfBufferIn[K] * (*pmSrc2)( K, J );
                                        }
                                        pfBufferOut[J] = tSum;
                                }
                        }

                        return &_m22bOut;
                }

                static LSVOID LSE_FCALL                                                 MultiplyVec2ByMat2x2( const CMatrix2x2Base<_tType, _tVector2Type> &_m22bMat, const _tVector2Type &_v2bIn, _tVector2Type &_v2bOut ) {
                        const _tType * /*LSE_RESTRICT*/ pfIn = reinterpret_cast<const _tType *>(&_v2bIn);
                        _v2bOut[0] = _m22bMat._11 * pfIn[0] + _m22bMat._21 * pfIn[1];
                        _v2bOut[1] = _m22bMat._12 * pfIn[0] + _m22bMat._22 * pfIn[1];
                }

                LSVOID LSE_FCALL                                                                MultiplyVec2ByMat2x2Transpose( const CMatrix2x2Base<_tType, _tVector2Type> &_m22bMat, const _tVector2Type &_v2bIn, _tVector2Type &_v2bOut ) {
                        const _tType * /*LSE_RESTRICT*/ pfIn = reinterpret_cast<const _tType *>(&_v2bIn);
                        _v2bOut[0] = _m22bMat._11 * pfIn[0] + _m22bMat._12 * pfIn[1];
                        _v2bOut[1] = _m22bMat._21 * pfIn[0] + _m22bMat._22 * pfIn[1];
                }

                // == Members.
#pragma pack( push, 1 )
                _tType                                                                                  _11, _12;               // Vector 0.
                _tType                                                                                  _21, _22;               // Vector 1.
#pragma pack( pop )
        };

}       // namespace lsm

#endif  // __LSM_MATRIX2X2BASE_H__