Point3D.java

/*
 * Copyright 2011
 *
 *   This file is part of Mobile Shuttle Tracker.
 *
 *   Mobile Shuttle Tracker is free software: you can redistribute it and/or modify
 *   it under the terms of the GNU General Public License as published by
 *   the Free Software Foundation, either version 3 of the License, or
 *   (at your option) any later version.
 *
 *   Mobile Shuttle Tracker is distributed in the hope that it will be useful,
 *   but WITHOUT ANY WARRANTY; without even the implied warranty of
 *   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 *   GNU General Public License for more details.
 *
 *   You should have received a copy of the GNU General Public License
 *   along with Mobile Shuttle Tracker.  If not, see <http://www.gnu.org/licenses/>.
 */

package com.abstractedsheep.world;

/**
 * This class constructs a three dimensional Cartesian point.
 *
 * @author saiumesh
 */
public class Point3D {
    private double x;
    private double y;
    private double z;

    public Point3D() {
        this.x = 0;
        this.y = 0;
        this.z = 0;
    }

    /**
     * @param x - x coordinate
     * @param y - y coordinate
     * @param z - z coordinate
     */
    public Point3D(double x, double y, double z) {
        this.x = x;
        this.y = y;
        this.z = z;
    }

    /**
     * @return the x
     */
    public double getX() {
        return x;
    }

    /**
     * @param x the x to set
     */
    public void setX(double x) {
        this.x = x;
    }

    /**
     * @return the y
     */
    public double getY() {
        return y;
    }

    /**
     * @param y the y to set
     */
    public void setY(double y) {
        this.y = y;
    }

    /**
     * @return the z
     */
    public double getZ() {
        return z;
    }

    /**
     * @param z the z to set
     */
    public void setZ(double z) {
        this.z = z;
    }

    /*
      * The following four methods modify the given 3d point with another 3d point
      */
    public static Point3D add(Point3D pt, Point3D d) {
        return new Point3D(pt.getX() + d.getX(), pt.getY() + d.getY(), pt.getZ() + d.getZ());
    }

    public static Point3D subtract(Point3D pt, Point3D d) {
        return new Point3D(pt.getX() - d.getX(), pt.getY() - d.getY(), pt.getZ() - d.getZ());
    }

    public static Point3D multiply(Point3D pt, Point3D d) {
        return new Point3D(pt.getX() * d.getX(), pt.getY() * d.getY(), pt.getZ() * d.getZ());
    }

    public static Point3D divide(Point3D pt, Point3D d) {
        return new Point3D(pt.getX() / d.getX(), pt.getY() / d.getY(), pt.getZ() / d.getZ());
    }

    /*
      * The following four methods modify the given 3d with a scalar value
      */
    public static Point3D add(Point3D pt, double d) {
        return new Point3D(pt.getX() + d, pt.getY() + d, pt.getZ() + d);
    }

    public static Point3D subtract(Point3D pt, double d) {
        return new Point3D(pt.getX() - d, pt.getY() - d, pt.getZ() - d);
    }

    public static Point3D multiply(Point3D pt, double d) {
        return new Point3D(pt.getX() * d, pt.getY() * d, pt.getZ() * d);
    }

    public static Point3D divide(Point3D pt, double d) {
        return new Point3D(pt.getX() / d, pt.getY() / d, pt.getZ() / d);
    }

    public Point3D crossProduct(Point3D pt) {
        return new Point3D(
                getY() * pt.getZ() - getZ() * pt.getY(),
                getX() * pt.getZ() - pt.getX() * getZ(),
                getX() * pt.getY() - pt.getX() * getY());
    }

    public double DistanceTo(Point3D pt) {
        double dX = pt.getX() - getX();
        double dY = pt.getY() - getY();
        double dZ = pt.getZ() - getZ();

        double determinant = Math.pow(dX, 2) + Math.pow(dY, 2) + Math.pow(dZ, 2);

        return Math.sqrt(determinant);
    }

    public double getMagnitude() {
        double determinant = Math.pow(getX(), 2) + Math.pow(getY(), 2) + Math.pow(getZ(), 2);

        return Math.sqrt(determinant);
    }

    public Point3D moveTowards(Point3D pt, double d) {
        Point3D vector = Point3D.subtract(pt, this);
        vector = Point3D.divide(vector, vector.getMagnitude());

        return Point3D.add(Point3D.multiply(vector, d), this);
    }

    /* (non-Javadoc)
      * @see java.lang.Object#hashCode()
      */
    @Override
    public int hashCode() {
        return ((Double) this.x).hashCode() ^ ((Double) this.y).hashCode() ^
                ((Double) this.z).hashCode();
    }

    /* (non-Javadoc)
      * @see java.lang.Object#equals(java.lang.Object)
      */
    @Override
    public boolean equals(Object obj) {
        if (obj == null)
            return false;

        try {
            Point3D p = (Point3D) obj;
            return this.x == p.x && this.y == p.y && this.z == p.z;
        } catch (ClassCastException e) {
            return false;
        }
    }
}