import java.io.*;
import java.lang.*;

/**
  * Point stores and manipulates xyz triples representing 3 space
  * points.
  *
  * @author Anthony Steed
  * @version 1.0
  */

public class Point {

  /** 
    * Holds the X component
    */
  public double X;

  /** 
    * Holds the Y component
    */
  public double Y;

  /** 
    * Holds the Z component
    */
  public double Z;

    
  /** 
    * Create a new point and set it to zero
    */
  public Point() {
    X=0.0;Y=0.0;Z=0.0;
  }
    
  /** 
    * Create a new point with the given x,y and z values
    * @param x the x value
    * @param y the y value
    * @param z the z value
    */
  public Point(double x, double y, double z) {
    X=x; Y=y; Z=z;
  }
    
  /** 
    * Set this point to the given x,y and z values
    * @param x the x value
    * @param y the y value
    * @param z the z value
    */
  public void set(double x, double y, double z) {
    X=x; Y=y; Z=z;
  }
    
  /** 
    * Create a new point by copying an existing point
    * @param v the point to copy
    */
  public Point(Point p) {
    X=p.X;
    Y=p.Y;
    Z=p.Z;
  }
    
  /** 
    * Copy an existing point to this point
    * @param v the point to copy
    */
  public void copy(Point p) {
    X=p.X;
    Y=p.Y;
    Z=p.Z;
  }
    
  /** 
    * Add the given offset vector to this point
    * @param v the vector to add
    */
  public void add(Vector v) {
    X += v.X;
    Y += v.Y; 
    Z += v.Z;
  }

  /** 
    * Test if two points are equal
    * @param v the vector to test against
    */
  public boolean equals(Point p) {
      return ((X==p.X) && (Y==p.Y) && (Z==p.Z));
  }

  /** 
    * Static function create a new point by adding a vector to a point.
    * @param p the original point
    * @param v the vector offset
    * @return the new point
    */
  public static Point add(Point p, Vector v) {
    return new Point(p.X+v.X,p.Y+v.Y,p.Z+v.Z);
  }

  /** 
    * Static function that write addition of a point by adding a
    * vector to a given destiation point
    * @param pd the destination point
    * @param p the original point
    * @param v the vector offset
    */
  public static void add(Point pd, Point p, Vector v) {
    pd.X = p.X + v.X;
    pd.Y = p.Y + v.Y; 
    pd.Z = p.Z + v.Z;
  }

  /**
    * Read the point from the given source
    * @param is the source to read from
    * @exception java.io.IOException
    * if the light can not be read
    * @exception java.io.NumberFormatException
    * if there a number format error is encountered
    */
  public void read(SceneReader is) 
    throws IOException, NumberFormatException {
      X = is.readDouble();
      Y = is.readDouble();
      Z = is.readDouble();
  }

  /**
    * Write the point to the given destination
    * @param os  the destination to write to
    * @exception java.io.IOException
    * if the write fails.
    */
  public void write(SceneWriter os) throws IOException {
    os.writeDouble(X);
    os.writeChar(' ');
    os.writeDouble(Y);
    os.writeChar(' ');
    os.writeDouble(Z);
    os.writeChar(' ');
  }

  /** 
    * Print a human readable version of the point definition to the
    * given destination
    * @param os  the destination to write to
    * @exception java.io.IOException
    * if the write fails.
    */
  public void print(SceneWriter os) throws IOException {
    os.writeChar('[');
    os.writeDouble(X);
    os.writeChar(',');
    os.writeDouble(Y);
    os.writeChar(',');
    os.writeDouble(Z);
    os.writeChar(']');
  }

  public String toString()  {
    return "[" + X + ", " + Y + ", " + Z + "]";
  }

}