import java.util.*;
public class Point3d{
  public double v[];
  public static Point3d o = new Point3d(0,0,0);
  public static Point3d i = new Point3d(1,0,0);
  public static Point3d j = new Point3d(0,1,0);
  public static Point3d k = new Point3d(0,0,1);
  public static Point3d ijk = new Point3d(1,1,1);

  public Point3d(){
    this.v = new double[3];
  }

  public Point3d(double x, double y, double z){
    this();
    this.v[0] = x;
    this.v[1] = y;
    this.v[2] = z;
  }

  public static Point3d fromSpherical(double r,double theta,double phi){
    return new Point3d(r*Math.cos(theta)*Math.cos(phi),
		       r*Math.sin(theta)*Math.cos(phi),
		       r*Math.sin(phi));
  }
  
  public static Point3d fromCylindrical(double r,double theta,double y){
    return new Point3d(r*Math.cos(theta),
		       y,
		       r*Math.sin(theta));
  }
  
  public double x(){
    return v[0];
  }

  public double y(){
    return v[1];
  }

  public double z(){
    return v[2];
  }

  public double theta(){
    return Math.atan2(v[0],v[2]);
  }

  public double r(){
    return Math.sqrt(v[0]*v[0]+v[2]*v[2]);
  }


  public String toString(){
    String s = "v["+(float)v[0]+","+(float)v[1]+","+(float)v[2]+"]";
    return s;
  }

  public static Point3d fromString(String s) throws NumberFormatException{
    StringTokenizer st = new StringTokenizer(s,"[,]");
    try{
      st.nextToken(); //get rid of leading v
      double x = Double.valueOf(st.nextToken()).doubleValue();
      double y = Double.valueOf(st.nextToken()).doubleValue();
      double z = Double.valueOf(st.nextToken()).doubleValue();
      return new Point3d(x,y,z);
    } catch (NoSuchElementException e){
      throw new NumberFormatException();
    }
  }

  public String toVRML() {
    return (float)(x())+" "+(float)(y())+" "+(float)(z());
  }

  public Point3d add(Point3d x){
    Point3d a = new Point3d();
    for (int i=0;i<3;i++){
      a.v[i] = v[i] + x.v[i];
    }
    return a;
  }

  public Point3d subtract(Point3d x){
    Point3d a = new Point3d();
    for (int i=0;i<3;i++){
      a.v[i] = v[i] - x.v[i];
    }
    return a;
  }

  public Point3d scale(double x){
    Point3d a = new Point3d();
    for (int i=0;i<3;i++){
      a.v[i] = x*v[i];
    }
    return a;
  }

  public Point3d scale(double x, double y, double z){
    return new Point3d(x*v[0],y*v[1],z*v[2]);
  }

  public double dot(Point3d x){
    double d = 0;
    for (int i=0;i<3;i++){
      d += v[i] * x.v[i];
    }
    return d;
  }

  public Point3d normalize(){
    return scale(1/length());
  }

  public double length(){
    return Math.sqrt(dot(this));
  }



  public Point3d cross(Point3d x){
    return new Point3d(v[1]*x.v[2]-x.v[1]*v[2],
		       v[2]*x.v[0]-x.v[2]*v[0],
		       v[0]*x.v[1]-x.v[0]*v[1]);
  }

  private static Random random = new Random();

  /** Set seed of random number generator */
  public static void setSeed(long seed){
    random.setSeed(seed);
  }

  /** Random in unit cube
   */
  public static Point3d random() {
    return new Point3d(random.nextDouble(),random.nextDouble(),random.nextDouble());
  }

  /** Random Gaussian
   */
  public static Point3d randomGaussian() {
    return new Point3d(random.nextGaussian(),random.nextGaussian(),random.nextGaussian());
  }

  /** Random in unit sphere
   */
  public static Point3d randomInSphere() {
    Point3d p;
    do {
      p = random().scale(2).subtract(ijk);
    } while (p.dot(p) > 1);
    return p;
  }

  /** Random in unit circle
   */
  public static Point3d randomInCircle() {
    Point3d p;
    do {
      p = random().scale(2).subtract(ijk).scale(1,1,0);
    } while (p.dot(p) > 1);
    return p;
  }

  /** Random on unit sphere
   */
  public static Point3d randomOnSphere() {
    return randomInSphere().normalize();
  }

  /** Random on unit circle
   */
  public static Point3d randomOnCircle() {
    return randomInCircle().normalize();
  }
 
}