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/* Copyright (C) 1999, 2000, 2002 Free Software Foundation |
/* Point2D.java -- generic point in 2-D space |
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Copyright (C) 1999, 2000, 2002 Free Software Foundation |
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This file is part of GNU Classpath. |
This file is part of GNU Classpath. |
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package java.awt.geom; |
package java.awt.geom; |
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/** |
/** |
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* This class implements a generic point in 2D Cartesian space. The storage |
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* representation is left up to the subclass. Point includes two useful |
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* nested classes, for float and double storage respectively. |
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* |
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* @author Per Bothner <bothner@cygnus.com> |
* @author Per Bothner <bothner@cygnus.com> |
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* @date February 8, 1999. |
* @author Eric Blake <ebb9@email.byu.edu> |
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* @since 1.2 |
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* @status updated to 1.4 |
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*/ |
*/ |
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/* Written using "Java Class Libraries", 2nd edition, plus online |
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* API docs for JDK 1.2 beta from http://www.javasoft.com. |
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* Status: Believed complete and correct, except that neither toString |
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* nor hashCode have been compared with JDK output. |
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*/ |
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public abstract class Point2D implements Cloneable |
public abstract class Point2D implements Cloneable |
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{ |
{ |
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public abstract double getX(); |
/** |
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public abstract double getY(); |
* The default constructor. |
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* |
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public abstract void setLocation (double x, double y); |
* @see Point |
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* @see Point2D.Float |
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protected Point2D () |
* @see Point2D.Double |
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*/ |
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protected Point2D() |
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{ |
{ |
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} |
} |
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public void setLocation (Point2D pt) { setLocation(pt.getX(), pt.getY()); } |
/** |
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* Get the X coordinate, in double precision. |
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static public double distanceSq (double X1, double Y1, double X2, double Y2) |
* |
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{ |
* @return the x coordinate |
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X2 -= X1; |
*/ |
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Y2 -= Y1; |
public abstract double getX(); |
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return X2*X2 + Y2*Y2; |
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} |
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static public double distance (double X1, double Y1, double X2, double Y2) |
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{ |
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return Math.sqrt(distance(X1, Y1, X2, Y2)); |
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} |
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public double distanceSq (double PX, double PY) |
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{ |
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return distanceSq (getX(), PX, getY(), PY); |
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} |
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public double distance (double PX, double PY) |
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{ |
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return distance (getX(), PX, getY(), PY); |
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} |
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public double distanceSq (Point2D pt) |
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{ |
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return distanceSq (getX(), pt.getX(), getY(), pt.getY()); |
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} |
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public double distance (Point2D pt) |
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{ |
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return distance (getX(), pt.getX(), getY(), pt.getY()); |
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} |
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public int hashCode() { return (int) getX() ^ (int) getY(); } |
/** |
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* Get the Y coordinate, in double precision. |
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* |
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* @return the y coordinate |
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*/ |
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public abstract double getY(); |
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/** |
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* Set the location of this point to the new coordinates. There may be a |
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* loss of precision. |
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* |
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* @param x the new x coordinate |
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* @param y the new y coordinate |
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*/ |
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public abstract void setLocation(double x, double y); |
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/** |
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* Set the location of this point to the new coordinates. There may be a |
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* loss of precision. |
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* |
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* @param p the point to copy |
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* @throws NullPointerException if p is null |
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*/ |
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public void setLocation(Point2D p) |
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{ |
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setLocation(p.getX(), p.getY()); |
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} |
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/** |
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* Return the square of the distance between two points. |
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* |
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* @param x1 the x coordinate of point 1 |
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* @param y1 the y coordinate of point 1 |
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* @param x2 the x coordinate of point 2 |
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* @param y2 the y coordinate of point 2 |
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* @return (x2 - x1)^2 + (y2 - y1)^2 |
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*/ |
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public static double distanceSq(double x1, double y1, double x2, double y2) |
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{ |
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x2 -= x1; |
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y2 -= y1; |
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return x2 * x2 + y2 * y2; |
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} |
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/** |
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* Return the distance between two points. |
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* |
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* @param x1 the x coordinate of point 1 |
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* @param y1 the y coordinate of point 1 |
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* @param x2 the x coordinate of point 2 |
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* @param y2 the y coordinate of point 2 |
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* @return the distance from (x1,y1) to (x2,y2) |
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*/ |
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static public double distance(double x1, double y1, double x2, double y2) |
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{ |
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return Math.sqrt(distance(x1, y1, x2, y2)); |
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} |
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/** |
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* Return the square of the distance from this point to the given one. |
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* |
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* @param x the x coordinate of the other point |
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* @param y the y coordinate of the other point |
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* @return the square of the distance |
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*/ |
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public double distanceSq(double x, double y) |
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{ |
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return distanceSq(getX(), x, getY(), y); |
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} |
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/** |
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* Return the square of the distance from this point to the given one. |
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* |
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* @param p the other point |
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* @return the square of the distance |
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* @throws NullPointerException if p is null |
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*/ |
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public double distanceSq(Point2D p) |
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{ |
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return distanceSq(getX(), p.getX(), getY(), p.getY()); |
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} |
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/** |
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* Return the distance from this point to the given one. |
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* |
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* @param x the x coordinate of the other point |
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* @param y the y coordinate of the other point |
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* @return the distance |
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*/ |
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public double distance(double x, double y) |
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{ |
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return distance(getX(), x, getY(), y); |
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} |
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/** |
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* Return the distance from this point to the given one. |
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* |
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* @param p the other point |
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* @return the distance |
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* @throws NullPointerException if p is null |
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*/ |
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public double distance(Point2D p) |
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{ |
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return distance(getX(), p.getX(), getY(), p.getY()); |
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} |
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/** |
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* Create a new point of the same run-time type with the same contents as |
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* this one. |
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* |
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* @return the clone |
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*/ |
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public Object clone() |
public Object clone() |
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{ |
{ |
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try |
try |
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{ |
{ |
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return super.clone (); |
return super.clone(); |
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} |
} |
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catch (CloneNotSupportedException _) {return null;} |
catch (CloneNotSupportedException e) |
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} |
{ |
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throw (Error) new InternalError().initCause(e); // Impossible |
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public boolean equals (Object o) |
} |
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} |
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/** |
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* Return the hashcode for this point. The formula is not documented, but |
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* appears to be the same as: |
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* <pre> |
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* long l = Double.doubleToLongBits(getY()); |
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* l = l * 31 ^ Double.doubleToLongBits(getX()); |
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* return (int) ((l >> 32) ^ l); |
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* </pre> |
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* |
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* @return the hashcode |
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*/ |
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public int hashCode() |
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{ |
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// Talk about a fun time reverse engineering this one! |
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long l = java.lang.Double.doubleToLongBits(getY()); |
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l = l * 31 ^ java.lang.Double.doubleToLongBits(getX()); |
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return (int) ((l >> 32) ^ l); |
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} |
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/** |
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* Compares to points for equality. This returns true if they have the |
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* same coordinates. |
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* |
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* @param o the point to compare |
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* @return true if it is equal |
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*/ |
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public boolean equals(Object o) |
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{ |
{ |
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if (! (o instanceof Point2D)) |
if (! (o instanceof Point2D)) |
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return false; |
return false; |
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Point2D p = (Point2D) o; |
Point2D p = (Point2D) o; |
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return getX () == p.getX () && getY () == p.getY (); |
return getX() == p.getX() && getY() == p.getY(); |
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} |
} |
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/** |
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* This class defines a point in <code>double</code> precision. |
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* |
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* @author Eric Blake <ebb9@email.byu.edu> |
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* @since 1.2 |
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* @status updated to 1.4 |
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*/ |
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public static class Double extends Point2D |
public static class Double extends Point2D |
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{ |
{ |
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/** The X coordinate. */ |
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public double x; |
public double x; |
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/** The Y coordinate. */ |
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public double y; |
public double y; |
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public Double () |
/** |
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* Create a new point at (0,0). |
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*/ |
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public Double() |
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{ |
{ |
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x = 0; |
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y = 0; |
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} |
} |
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public Double (double x, double y) |
/** |
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* Create a new point at (x,y). |
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* |
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* @param x the x coordinate |
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* @param y the y coordinate |
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*/ |
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public Double(double x, double y) |
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{ |
{ |
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this.x = x; |
this.x = x; |
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this.y = y; |
this.y = y; |
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} |
} |
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public double getX () |
/** |
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* Return the x coordinate. |
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* |
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* @return the x coordinate |
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*/ |
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public double getX() |
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{ |
{ |
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return x; |
return x; |
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} |
} |
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public double getY () |
/** |
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* Return the y coordinate. |
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* |
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* @return the y coordinate |
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*/ |
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public double getY() |
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{ |
{ |
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return y; |
return y; |
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} |
} |
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public void setLocation (double x, double y) |
/** |
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* Sets the location of this point. |
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* |
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* @param x the new x coordinate |
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* @param y the new y coordinate |
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*/ |
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public void setLocation(double x, double y) |
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{ |
{ |
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this.x = x; |
this.x = x; |
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this.y = y; |
this.y = y; |
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} |
} |
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public String toString () |
/** |
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{ |
* Returns a string representation of this object. The format is: |
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return "(" + x + ", " + y + ")"; |
* <code>"Point2D.Double[" + x + ", " + y + ']'</code>. |
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} |
* |
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} |
* @return a string representation of this object |
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*/ |
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public String toString() |
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{ |
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return "Point2D.Double[" + x + ", " + y + ']'; |
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} |
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} // class Double |
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/** |
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* This class defines a point in <code>float</code> precision. |
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* |
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* @author Eric Blake <ebb9@email.byu.edu> |
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* @since 1.2 |
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* @status updated to 1.4 |
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*/ |
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public static class Float extends Point2D |
public static class Float extends Point2D |
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{ |
{ |
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/** The X coordinate. */ |
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public float x; |
public float x; |
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/** The Y coordinate. */ |
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public float y; |
public float y; |
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public Float () |
/** |
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* Create a new point at (0,0). |
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*/ |
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public Float() |
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{ |
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x = 0; |
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y = 0; |
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} |
} |
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public Float (float x, float y) |
/** |
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* Create a new point at (x,y). |
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* |
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* @param x the x coordinate |
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* @param y the y coordinate |
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*/ |
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public Float(float x, float y) |
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{ |
{ |
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this.x = x; |
this.x = x; |
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this.y = y; |
this.y = y; |
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} |
} |
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public double getX () |
/** |
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* Return the x coordinate. |
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* |
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* @return the x coordinate |
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*/ |
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public double getX() |
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{ |
{ |
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return x; |
return x; |
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} |
} |
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public double getY () |
/** |
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* Return the y coordinate. |
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* |
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* @return the y coordinate |
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*/ |
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public double getY() |
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{ |
{ |
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return y; |
return y; |
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} |
} |
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public void setLocation (double x, double y) |
/** |
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* Sets the location of this point. |
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* |
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* @param x the new x coordinate |
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* @param y the new y coordinate |
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*/ |
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public void setLocation(double x, double y) |
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{ |
{ |
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this.x = (float) x; |
this.x = (float) x; |
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this.y = (float) y; |
this.y = (float) y; |
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} |
} |
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public void setLocation (float x, float y) |
/** |
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* Sets the location of this point. |
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* |
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* @param x the new x coordinate |
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* @param y the new y coordinate |
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*/ |
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public void setLocation(float x, float y) |
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{ |
{ |
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this.x = x; |
this.x = x; |
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this.y = y; |
this.y = y; |
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} |
} |
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public String toString () |
/** |
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* Returns a string representation of this object. The format is: |
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* <code>"Point2D.Float[" + x + ", " + y + ']'</code>. |
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* |
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* @return a string representation of this object |
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*/ |
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public String toString() |
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{ |
{ |
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return "(" + x + ", " + y + ")"; |
return "Point2D.Float[" + x + ", " + y + ']'; |
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} |
} |
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} |
} // class Float |
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} |
} // class Point2D |