/**
 * Instanced of Point3d are points in 3 dimensional space.
 * This version of Point3d takes explicit advantage of the
 * fact that it is a subclass of Object.
 * 
 * Walker White
 * February 2, 2012
 */
public class Point3d {
  
    /* These are the three coordinates. */
    private double x; // x coordinate; no restrictions
    private double y; // y coordinate; no restrictions
    private double z; // z coordinate; no restrictions
    
    /** 
     * Constructor:  a point at the origin 
     * Precondition: None
     */
    public Point3d() {
        // Uses other constructor.
        this(0.0,0.0,0.0);
    }
    
    /** 
     * Constructor: a point with given coordinates (x0,y0,z0)
     * Precondition: None
     */
    public Point3d(double x0, double y0, double z0) {
        // primary contructor.
        x = x0;
        y = y0;
        z = z0;
    }
    
    /** Yields: this Point's x coordinate */
    public double getX() {
        return x;
    }
    
    /** Assigns value to x coordinate */
    public void setX(double value) {
        x = value;
    }
    
    /** Yields: this Point's y coordinate */
    public double getY() {
        return y;
    }

    /** Assigns value to y coordinate */
    public void setY(double value) {
        y = value;
    }
    
    /** Yields: this Point's z coordinate */
    public double getZ() {
        return z;
    }
    
    /** Assigns value to z coordinate */
    public void setZ(double value) {
        z = value;
    }

    /** 
     * Overrides toString() to give a textual representation 
     */
    public String toString() {
        return "("+x+","+y+","+z+")";
    }
    
    /** 
     * Yields: "q has the same coordinates as p"
     * Overrides equals() so that it compares
     * coordinates instead of "folder names"
     */
    public boolean equals(Point3d q) {
        return (q.x == x && q.y == y && q.z == z);
    }

}