public class TransformationGeometrique {
  float m[][];

  public TransformationGeometrique() {
    m = new float[4][4];
    for ( int i = 0 ; i < 4 ; i++ )
      for ( int j = 0 ; j < 4 ; j++ )
        m[i][j] = 0.0F;
    for ( int i = 0 ; i < 4 ; i++ )
      m[i][i] = 1.0F;
  }

  public TransformationGeometrique(TransformationGeometrique tg) {
    m = new float[4][4];
    for ( int i = 0 ; i < 4 ; i++ )
      for ( int j = 0 ; j < 4 ; j++ )
        m[i][j] = tg.m[i][j];
  }
  
  public TransformationGeometrique composition(TransformationGeometrique tg) {
    TransformationGeometrique mp = new TransformationGeometrique();
    for ( int i = 0 ; i < 4 ; i++ )
      for ( int j = 0 ; j < 4 ; j++ ) {
        mp.m[i][j] = 0.0F;
        for ( int k = 0 ; k < 4 ; k++ )
          mp.m[i][j] += m[i][k]*tg.m[k][j]; }
    return(mp);
  }
  
  public CoordonneesHomogenes transformation(CoordonneesHomogenes p) {
    CoordonneesHomogenes ch = new CoordonneesHomogenes();
    for ( int i = 0 ; i < 4 ; i++ ) {
      ch.c[i] = 0.0F;
      for ( int k = 0 ; k < 4 ; k++ )
        ch.c[i] += m[i][k]*p.c[k]; }
    return(ch);
  }
  
  public String toString() {
    return(m[0][0]+" "+m[0][1]+" "+m[0][2]+" "+m[0][3]+"\n"+
           m[1][0]+" "+m[1][1]+" "+m[1][2]+" "+m[1][3]+"\n"+
           m[2][0]+" "+m[2][1]+" "+m[2][2]+" "+m[2][3]+"\n"+
           m[3][0]+" "+m[3][1]+" "+m[3][2]+" "+m[3][3]);
  }
}