Point2D class defines a point representing a location
* in (x, y) coordinate space.
*
* 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.
*
* @version 1.18, 12/19/03
* @author Jim Graham
*/
public abstract class Point2D implements Cloneable {
/**
* The Float class defines a point specified in float
* precision.
*/
public static class Float extends Point2D {
/**
* The X coordinate of this Point2D.
* @since 1.2
*/
public float x;
/**
* The Y coordinate of this Point2D.
* @since 1.2
*/
public float y;
/**
* Constructs and initializes a Point2D with
* coordinates (0, 0).
* @since 1.2
*/
public Float() {
}
/**
* Constructs and initializes a Point2D with
* the specified coordinates.
* @param x, y the coordinates to which to set the newly
* constructed Point2D
* @since 1.2
*/
public Float(float x, float y) {
this.x = x;
this.y = y;
}
/**
* Returns the X coordinate of this Point2D in
* double precision.
* @return the X coordinate of this Point2D.
* @since 1.2
*/
public double getX() {
return (double) x;
}
/**
* Returns the Y coordinate of this Point2D in
* double precision.
* @return the Y coordinate of this Point2D.
* @since 1.2
*/
public double getY() {
return (double) y;
}
/**
* Sets the location of this Point2D to the
* specified double coordinates.
* @param x, y the coordinates to which to set this
* Point2D
* @since 1.2
*/
public void setLocation(double x, double y) {
this.x = (float) x;
this.y = (float) y;
}
/**
* Sets the location of this Point2D to the
* specified float coordinates.
* @param x, y the coordinates to which to set this
* Point2D
* @since 1.2
*/
public void setLocation(float x, float y) {
this.x = x;
this.y = y;
}
/**
* Returns a String that represents the value
* of this Point2D.
* @return a string representation of this Point2D.
* @since 1.2
*/
public String toString() {
return "Point2D.Float["+x+", "+y+"]";
}
}
/**
* The Double class defines a point specified in
* double precision.
*/
public static class Double extends Point2D {
/**
* The X coordinate of this Point2D.
* @since 1.2
*/
public double x;
/**
* The Y coordinate of this Point2D.
* @since 1.2
*/
public double y;
/**
* Constructs and initializes a Point2D with
* coordinates (0, 0).
* @since 1.2
*/
public Double() {
}
/**
* Constructs and initializes a Point2D with the
* specified coordinates.
* @param x, y the coordinates to which to set the newly
* constructed Point2D
* @since 1.2
*/
public Double(double x, double y) {
this.x = x;
this.y = y;
}
/**
* Returns the X coordinate of this Point2D
* in double precision.
* @return the X coordinate of this Point2D.
* @since 1.2
*/
public double getX() {
return x;
}
/**
* Returns the Y coordinate of this Point2D in
* double precision.
* @return the Y coordinate of this Point2D.
* @since 1.2
*/
public double getY() {
return y;
}
/**
* Sets the location of this Point2D to the
* specified double coordinates.
* @param x, y the coordinates to which to set this
* Point2D
* @since 1.2
*/
public void setLocation(double x, double y) {
this.x = x;
this.y = y;
}
/**
* Returns a String that represents the value
* of this Point2D.
* @return a string representation of this Point2D.
* @since 1.2
*/
public String toString() {
return "Point2D.Double["+x+", "+y+"]";
}
}
/**
* 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
*/
protected Point2D() {
}
/**
* Returns the X coordinate of this Point2D in
* double precision.
* @return the X coordinate of this Point2D.
* @since 1.2
*/
public abstract double getX();
/**
* Returns the Y coordinate of this Point2D in
* double precision.
* @return the Y coordinate of this Point2D.
* @since 1.2
*/
public abstract double getY();
/**
* Sets the location of this Point2D to the
* specified double coordinates.
* @param x, y the coordinates of this Point2D
* @since 1.2
*/
public abstract void setLocation(double x, double y);
/**
* Sets the location of this Point2D to the same
* coordinates as the specified Point2D object.
* @param p the specified Point2D the which to set
* this Point2D
* @since 1.2
*/
public void setLocation(Point2D p) {
setLocation(p.getX(), p.getY());
}
/**
* Returns the square of the distance between two points.
* @param X1, Y1 the coordinates of the first point
* @param X2, Y2 the coordinates of the second point
* @return the square of the distance between the two
* sets of specified coordinates.
*/
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, Y1 the coordinates of the first point
* @param X2, Y2 the coordinates of the second point
* @return the distance between the two sets of specified
* coordinates.
*/
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
* Point2D to a specified point.
* @param PX, PY the coordinates of the other point
* @return the square of the distance between this
* Point2D and the specified point.
*/
public double distanceSq(double PX, double PY) {
PX -= getX();
PY -= getY();
return (PX * PX + PY * PY);
}
/**
* Returns the square of the distance from this
* Point2D to a specified Point2D.
* @param pt the specified Point2D
* @return the square of the distance between this
* Point2D to a specified Point2D.
*/
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 Point2D to
* a specified point.
* @param PX, PY the coordinates of the specified
* Point2D
* @return the distance between this Point2D
* and a specified point.
*/
public double distance(double PX, double PY) {
PX -= getX();
PY -= getY();
return Math.sqrt(PX * PX + PY * PY);
}
/**
* Returns the distance from this Point2D to a
* specified Point2D.
* @param pt the specified Point2D
* @return the distance between this Point2D and
* the specified Point2D.
*/
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
throw new InternalError();
}
}
/**
* Returns the hashcode for this Point2D.
* @return a hash code for this Point2D.
*/
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
* Point2D are equal if the values of their
* x and y member fields, representing
* their position in the coordinate space, are the same.
* @param obj an object to be compared with this Point2D
* @return true if the object to be compared is
* an instance of Point2D and has
* the same values; false 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);
}
}