Point.java

public class Point {

  private double x;
  private double y;
  private double z;
  public final double MIN = .00001;

  public Point(double x, double y, double z) {
    this.x = x;
    this.y = y;
    this.z = z;
  }

  public Point(Point p) {
    this.x = p.getX();
    this.y = p.getY();
    this.z = p.getZ();
  }

  public Point getUnitVector(Point dir) {
    double dist = getDistance(dir);
    Point diff = new Point(0, 0, 0);
    if (dist <= MIN)
      return new Point(0, 0, 0);
    diff = dir.subtract(this);

    return diff.divide(dist);
  }

  public Point multiply(double mult) {
    return new Point(x * mult, y * mult, z * mult);
  }

  public Point bounce(Point normal) {
    double bx = (normal.x * (2.0 * (normal.x)) - this.x);
    double by = (normal.y * (2.0 * (normal.y)) - this.y);
    double bz = (normal.z * (2.0 * (normal.z)) - this.z);

    return new Point(bx, by, bz);
  }

  public void addTo(Point p) {
    this.x = this.x + p.x;
    this.y = this.y + p.y;
    this.z = this.z + p.z;
  }

  public Point divide(double divisor) {
    double a = x / divisor;
    double b = y / divisor;
    double c = z / divisor;

    return new Point(a, b, c);
  }

  public double getDistance(Point point) {
    Point diff = subtract(point);

    return Math.sqrt(diff.dotProduct(diff));
  }

  public void print() {
    System.out.println(x + ", " + y + ", " + z);
  }

  public double getX() {
    return x;
  }

  public double getY() {
    return y;
  }

  public double getZ() {
    return z;
  }

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

  public Point subtract(Point point) {
    double tx = x - point.x;
    double ty = y - point.y;
    double tz = z - point.z;

    return new Point(tx, ty, tz);
  }

  public double dotProduct(Point point) {
    double tx = x * point.x;
    double ty = y * point.y;
    double tz = z * point.z;
    return tx + ty + tz;
  }

  public static void main(String[] args) {// this main was used in a lab, and is
                                          // not to be used for the raytracer
                                          // assignment
    Point p1 = new Point(.2, .4, 0);
    Point p2 = new Point(3.9, 1.9, 4);
    Point p3 = p1.subtract(p2);
    p3.print();
    Point p4 = p2.subtract(p1);
    p4.print();
    double product1 = p1.dotProduct(p2);
    double product2 = p2.dotProduct(p3);
    System.out.println(product1);
    System.out.println(product2);
  }
}