/*

 * Copyright (c) 1997, 2006, Oracle and/or its affiliates. All rights reserved.

 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.

 *

 * This code is free software; you can redistribute it and/or modify it

 * under the terms of the GNU General Public License version 2 only, as

 * published by the Free Software Foundation.  Oracle designates this

 * particular file as subject to the "Classpath" exception as provided

 * by Oracle in the LICENSE file that accompanied this code.

 *

 * This code 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

 * version 2 for more details (a copy is included in the LICENSE file that

 * accompanied this code).

 *

 * You should have received a copy of the GNU General Public License version

 * 2 along with this work; if not, write to the Free Software Foundation,

 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.

 *

 * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA

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 */

package java.awt.geom;

import java.io.Serializable;

/**

 * The <code>Point2D</code> class defines a point representing a location

 * in {@code (x,y)} coordinate space.

 * <p>

 * This class is only the abstract superclass for all objects that

 * store a 2D coordinate.

 * The actual storage representation of the coordinates is left to

 * the subclass.

 *

 * @author      Jim Graham

 * @since 1.2

 */

public abstract class Point2D implements Cloneable {

    /**

     * The <code>Float</code> class defines a point specified in float

     * precision.

     * @since 1.2

     */

    public static class Float extends Point2D implements Serializable {

        /**

         * The X coordinate of this <code>Point2D</code>.

         * @since 1.2

         * @serial

         */

        public float x;

        /**

         * The Y coordinate of this <code>Point2D</code>.

         * @since 1.2

         * @serial

         */

        public float y;

        /**

         * Constructs and initializes a <code>Point2D</code> with

         * coordinates (0, 0).

         * @since 1.2

         */

        public Float() {

        }

        /**

         * Constructs and initializes a <code>Point2D</code> with

         * the specified coordinates.

         *

         * @param x the X coordinate of the newly

         *          constructed <code>Point2D</code>

         * @param y the Y coordinate of the newly

         *          constructed <code>Point2D</code>

         * @since 1.2

         */

        public Float(float x, float y) {

            this.x = x;

            this.y = y;

        }

        /**

         * {@inheritDoc}

         * @since 1.2

         */

        public double getX() {

            return (double) x;

        }

        /**

         * {@inheritDoc}

         * @since 1.2

         */

        public double getY() {

            return (double) y;

        }

        /**

         * {@inheritDoc}

         * @since 1.2

         */

        public void setLocation(double x, double y) {

            this.x = (float) x;

            this.y = (float) y;

        }

        /**

         * Sets the location of this <code>Point2D</code> to the

         * specified <code>float</code> coordinates.

         *

         * @param x the new X coordinate of this {@code Point2D}

         * @param y the new Y coordinate of this {@code Point2D}

         * @since 1.2

         */

        public void setLocation(float x, float y) {

            this.x = x;

            this.y = y;

        }

        /**

         * Returns a <code>String</code> that represents the value

         * of this <code>Point2D</code>.

         * @return a string representation of this <code>Point2D</code>.

         * @since 1.2

         */

        public String toString() {

            return "Point2D.Float["+x+", "+y+"]";

        }

        /*

         * JDK 1.6 serialVersionUID

         */

        private static final long serialVersionUID = -2870572449815403710L;

    }

    /**

     * The <code>Double</code> class defines a point specified in

     * <code>double</code> precision.

     * @since 1.2

     */

    public static class Double extends Point2D implements Serializable {

        /**

         * The X coordinate of this <code>Point2D</code>.

         * @since 1.2

         * @serial

         */

        public double x;

        /**

         * The Y coordinate of this <code>Point2D</code>.

         * @since 1.2

         * @serial

         */

        public double y;

        /**

         * Constructs and initializes a <code>Point2D</code> with

         * coordinates (0, 0).

         * @since 1.2

         */

        public Double() {

        }

        /**

         * Constructs and initializes a <code>Point2D</code> with the

         * specified coordinates.

         *

         * @param x the X coordinate of the newly

         *          constructed <code>Point2D</code>

         * @param y the Y coordinate of the newly

         *          constructed <code>Point2D</code>

         * @since 1.2

         */

        public Double(double x, double y) {

            this.x = x;

            this.y = y;

        }

        /**

         * {@inheritDoc}

         * @since 1.2

         */

        public double getX() {

            return x;

        }

        /**

         * {@inheritDoc}

         * @since 1.2

         */

        public double getY() {

            return y;

        }

        /**

         * {@inheritDoc}

         * @since 1.2

         */

        public void setLocation(double x, double y) {

            this.x = x;

            this.y = y;

        }

        /**

         * Returns a <code>String</code> that represents the value

         * of this <code>Point2D</code>.

         * @return a string representation of this <code>Point2D</code>.

         * @since 1.2

         */

        public String toString() {

            return "Point2D.Double["+x+", "+y+"]";

        }

        /*

         * JDK 1.6 serialVersionUID

         */

        private static final long serialVersionUID = 6150783262733311327L;

    }

    /**

     * This is an abstract class that cannot be instantiated directly.

     * Type-specific implementation subclasses are available for

     * instantiation and provide a number of formats for storing

     * the information necessary to satisfy the various accessor

     * methods below.

     *

     * @see java.awt.geom.Point2D.Float

     * @see java.awt.geom.Point2D.Double

     * @see java.awt.Point

     * @since 1.2

     */

    protected Point2D() {

    }

    /**

     * Returns the X coordinate of this <code>Point2D</code> in

     * <code>double</code> precision.

     * @return the X coordinate of this <code>Point2D</code>.

     * @since 1.2

     */

    public abstract double getX();

    /**

     * Returns the Y coordinate of this <code>Point2D</code> in

     * <code>double</code> precision.

     * @return the Y coordinate of this <code>Point2D</code>.

     * @since 1.2

     */

    public abstract double getY();

    /**

     * Sets the location of this <code>Point2D</code> to the

     * specified <code>double</code> coordinates.

     *

     * @param x the new X coordinate of this {@code Point2D}

     * @param y the new Y coordinate of this {@code Point2D}

     * @since 1.2

     */

    public abstract void setLocation(double x, double y);

    /**

     * Sets the location of this <code>Point2D</code> to the same

     * coordinates as the specified <code>Point2D</code> object.

     * @param p the specified <code>Point2D</code> to which to set

     * this <code>Point2D</code>

     * @since 1.2

     */

    public void setLocation(Point2D p) {

        setLocation(p.getX(), p.getY());

    }

    /**

     * Returns the square of the distance between two points.

     *

     * @param x1 the X coordinate of the first specified point

     * @param y1 the Y coordinate of the first specified point

     * @param x2 the X coordinate of the second specified point

     * @param y2 the Y coordinate of the second specified point

     * @return the square of the distance between the two

     * sets of specified coordinates.

     * @since 1.2

     */

    public static double distanceSq(double x1, double y1,

                                    double x2, double y2)

    {

        x1 -= x2;

        y1 -= y2;

        return (x1 * x1 + y1 * y1);

    }

    /**

     * Returns the distance between two points.

     *

     * @param x1 the X coordinate of the first specified point

     * @param y1 the Y coordinate of the first specified point

     * @param x2 the X coordinate of the second specified point

     * @param y2 the Y coordinate of the second specified point

     * @return the distance between the two sets of specified

     * coordinates.

     * @since 1.2

     */

    public static double distance(double x1, double y1,

                                  double x2, double y2)

    {

        x1 -= x2;

        y1 -= y2;

        return Math.sqrt(x1 * x1 + y1 * y1);

    }

    /**

     * Returns the square of the distance from this

     * <code>Point2D</code> to a specified point.

     *

     * @param px the X coordinate of the specified point to be measured

     *           against this <code>Point2D</code>

     * @param py the Y coordinate of the specified point to be measured

     *           against this <code>Point2D</code>

     * @return the square of the distance between this

     * <code>Point2D</code> and the specified point.

     * @since 1.2

     */

    public double distanceSq(double px, double py) {

        px -= getX();

        py -= getY();

        return (px * px + py * py);

    }

    /**

     * Returns the square of the distance from this

     * <code>Point2D</code> to a specified <code>Point2D</code>.

     *

     * @param pt the specified point to be measured

     *           against this <code>Point2D</code>

     * @return the square of the distance between this

     * <code>Point2D</code> to a specified <code>Point2D</code>.

     * @since 1.2

     */

    public double distanceSq(Point2D pt) {

        double px = pt.getX() - this.getX();

        double py = pt.getY() - this.getY();

        return (px * px + py * py);

    }

    /**

     * Returns the distance from this <code>Point2D</code> to

     * a specified point.

     *

     * @param px the X coordinate of the specified point to be measured

     *           against this <code>Point2D</code>

     * @param py the Y coordinate of the specified point to be measured

     *           against this <code>Point2D</code>

     * @return the distance between this <code>Point2D</code>

     * and a specified point.

     * @since 1.2

     */

    public double distance(double px, double py) {

        px -= getX();

        py -= getY();

        return Math.sqrt(px * px + py * py);

    }

    /**

     * Returns the distance from this <code>Point2D</code> to a

     * specified <code>Point2D</code>.

     *

     * @param pt the specified point to be measured

     *           against this <code>Point2D</code>

     * @return the distance between this <code>Point2D</code> and

     * the specified <code>Point2D</code>.

     * @since 1.2

     */

    public double distance(Point2D pt) {

        double px = pt.getX() - this.getX();

        double py = pt.getY() - this.getY();

        return Math.sqrt(px * px + py * py);

    }

    /**

     * Creates a new object of the same class and with the

     * same contents as this object.

     * @return     a clone of this instance.

     * @exception  OutOfMemoryError            if there is not enough memory.

     * @see        java.lang.Cloneable

     * @since      1.2

     */

    public Object clone() {

        try {

            return super.clone();

        } catch (CloneNotSupportedException e) {

            // this shouldn't happen, since we are Cloneable

        }

    }

    /**

     * Returns the hashcode for this <code>Point2D</code>.

     * @return      a hash code for this <code>Point2D</code>.

     */

    public int hashCode() {

        long bits = java.lang.Double.doubleToLongBits(getX());

        bits ^= java.lang.Double.doubleToLongBits(getY()) * 31;

        return (((int) bits) ^ ((int) (bits >> 32)));

    }

    /**

     * Determines whether or not two points are equal. Two instances of

     * <code>Point2D</code> are equal if the values of their

     * <code>x</code> and <code>y</code> member fields, representing

     * their position in the coordinate space, are the same.

     * @param obj an object to be compared with this <code>Point2D</code>

     * @return <code>true</code> if the object to be compared is

     *         an instance of <code>Point2D</code> and has

     *         the same values; <code>false</code> otherwise.

     * @since 1.2

     */

    public boolean equals(Object obj) {

        if (obj instanceof Point2D) {

            Point2D p2d = (Point2D) obj;

            return (getX() == p2d.getX()) && (getY() == p2d.getY());

        }

        return super.equals(obj);

    }

}