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C:/temp/src/j2k/Deprecated/old_18mar_diff/Vector/Matrix22.cpp

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/*
Definition for a 2 by 2 matrix:
e.g.  |1 2|
      |3 4|
*/

#ifndef __J2K__Matrix22_CPP__
#define __J2K__Matrix22_CPP__

#include <j2k/Fred/Games/Matrix22.hpp>


inline JMatrix22::JMatrix22() {
  clear();
}

inline JMatrix22::~JMatrix22() { }

inline JMatrix22::JMatrix22( const Matrix22& src ) {
  for( int i = 0; i < 4; i++ ) {
    m[i] = src.m[i];
  }       
}

inline void JMatrix22::clear() {
  for( int i = 0; i < 4; i++ ) {
    m[i] = 0.0;
  }       
}

inline void JMatrix22::print() {
  printf("| %-+7.2f %-+7.2f|\n",   m[0], m[2] );
  printf("| %-+7.2f %-+7.2f|\n\n", m[1], m[3] );
}

inline void JMatrix22::identity() {
  m[0] = 1;
  m[1] = 0;
  m[2] = 0;
  m[3] = 1;
}


JMatrix22 JMatrix22::rotz( double rad ) {
  JMatrix22 ret;
  double c = cos(rad);
  double s = sin(rad);

  ret.m[0] =  c;
  ret.m[1] = -s;
  ret.m[2] =  s;
  ret.m[3] =  c;

  return ret;
}

JMatrix22 JMatrix22::mult( const JMatrix22& mat ) {
  JMatrix22 ret;

  ret.m[0] = m[0] * mat.m[0] + m[1] * mat.m[2];
  ret.m[1] = m[0] * mat.m[1] + m[1] * mat.m[3];
  ret.m[2] = m[2] * mat.m[0] + m[3] * mat.m[2];
  ret.m[3] = m[2] * mat.m[1] + m[3] * mat.m[3];

  return ret;
}

JVector2 JMatrix22::mult( const JVector2& vect ) {
  Vector2 ret;

  ret.v[0] = m[0] * vect.v[0] + m[1] * vect.v[1];
  ret.v[1] = m[2] * vect.v[0] + m[3] * vect.v[1];

  return ret;
}

#endif

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