/* Auteur: Nicolas JANEY         */
/* nicolas.janey@univ-fcomte.fr  */
/* Novembre 2001                 */

public class Transform3D {
  public double [][] m = new double[4][4];

  public Transform3D() {
    for ( int i = 0 ; i < 4 ; i++ )
      for ( int j = 0 ; j < 4 ; j++ )
        m[i][j] = 0.0 ;
  }

  public void toIdentite() {
    for ( int i = 0 ; i < 4 ; i++ )
      for ( int j = 0 ; j < 4 ; j++ )
        m[i][j] = ( i == j ) ? 1.0 : 0.0 ;
  }

  public void toTranslation(double dx,double dy,double dz) {
    toIdentite();
    m[0][3] = dx;
    m[1][3] = dy;
    m[2][3] = dz;
  }

  public void toRotationX(double a) {
    toIdentite();
    m[2][1] = Math.sin(a);
    m[1][2] = -m[2][1];
    m[1][1] = m[2][2] = Math.cos(a);
  }

  public void toRotationY(double a) {
    toIdentite();
    m[0][2] = Math.sin(a);
    m[2][0] = -m[0][2];
    m[0][0] = m[2][2] = Math.cos(a);
  }

  public void toRotationZ(double a) {
    toIdentite();
    m[1][0] = Math.sin(a);
    m[0][1] = -m[1][0];
    m[1][1] = m[0][0] = Math.cos(a);
  }

  public Vector3d mult(Vector3d v) {
    Vector3d r = new Vector3d();
    r.x = m[0][0]*v.x+m[0][1]*v.y+m[0][2]*v.z+m[0][3];
    r.y = m[1][0]*v.x+m[1][1]*v.y+m[1][2]*v.z+m[1][3];
    r.z = m[2][0]*v.x+m[2][1]*v.y+m[2][2]*v.z+m[2][3];
    return(r);
  }
}