/* Auteur: Nicolas JANEY                                */
/* nicolas.janey@univ-fcomte.fr                         */
/* Octobre 2008                                         */
/* Une classe transformation geometrique rotation       */

public class Rotation3D extends TransformationGeometrique3D {

  public Rotation3D() {
    super();
  }

  public Rotation3D(double a,
                    double dx,double dy,double dz) throws ArithmeticException {
    super();
    remplissage(a,dx,dy,dz);
  }

  public Rotation3D(double a,
                    Direction3D d) throws ArithmeticException {
    super();
    remplissage(a,d.getX(),d.getY(),d.getZ());
  }

  public Rotation3D(Rotation3D rt) {
    super(rt);
  }

  private void remplissage(double a,
                           double x,double y,double z) throws ArithmeticException {
    a = a/180.0*(double) Math.PI;
    double c = Math.cos(a);
    double s = Math.sin(a);
    double d = Math.sqrt(x*x+y*y+z*z);
    if ( d == 0 ) {
      throw new ArithmeticException(); }
    x /= d;
    y /= d;
    z /= d;
    double x2 = x*x;
    double y2 = y*y;
    double z2 = z*z;
    double xs = x*s;
    double ys = y*s;
    double zs = z*s;
    double mc = 1.0 - c;
    double xymc = x*y*mc;
    double xzmc = x*z*mc;
    double yzmc = y*z*mc;
    this.c[0][0] = x2+c*(1.0-x2);
    this.c[0][1] = xymc-zs;
    this.c[0][2] = xzmc+ys;
    this.c[1][0] = xymc+zs;
    this.c[1][1] = y2+c*(1.0-y2);
    this.c[1][2] = yzmc-xs;
    this.c[2][0] = xzmc-ys;
    this.c[2][1] = yzmc+xs;
    this.c[2][2] = z2+c*(1.0-z2);
  }
}