package java.awt.geom;
/**
* An abstract class for a point.
* Subclasses implement float, double and integer coordinates.
*
* @author Lawrie Griffiths
*
*/
public abstract class Point2D implements Cloneable {
/**
* A point with float coordinates.
*/
public static class Float extends Point2D {
/**
* The x coordinate of the point
*/
public float x;
/**
* The y coordinate of the point
*/
public float y;
/**
* Create a point at (0,0) with float coordinates
*/
public Float() {}
/**
* Create a point at (x,y) with float coordinates
*
* @param x the x coordinate
* @param y the y coordinate
*/
public Float(float x, float y) {
this.x = x;
this.y = y;
}
@Override
public double getX() {
return (double) x;
}
@Override
public double getY() {
return (double) y;
}
@Override
public void setLocation(double x, double y) {
this.x = (float) x;
this.y = (float) y;
}
/**
* Set the location of the point
*
* @param x the new x coordinate
* @param y the new y coordinate
*/
public void setLocation(float x, float y) {
this.x = x;
this.y = y;
}
/**
* Represent the Point2SD.Float as a String
*/
@Override
public String toString() {
return "Point2D.Float["+x+", "+y+"]";
}
}
/**
* A point with double coordinates.
*/
public static class Double extends Point2D {
/**
* The x coordinate of the point
*/
public double x;
/**
* The y coordinate of the point
*/
public double y;
/**
* Create a point at (0,0) with double coordinates
*/
public Double() {}
/**
* Create a point at (x,y) with double coordinates
*
* @param x the x coordinate
* @param y the y coordinate
*/
public Double(double x, double y) {
this.x = x;
this.y = y;
}
@Override
public double getX() {
return x;
}
@Override
public double getY() {
return y;
}
@Override
public void setLocation(double x, double y) {
this.x = x;
this.y = y;
}
/**
* Represent the Point2D.Double as a String
*/
@Override
public String toString() {
return "Point2D.Double["+x+", "+y+"]";
}
}
/**
* This is abstract class that cannot be instantiated.
* Use one of its subclasses.
*/
protected Point2D() {
}
/**
* Get the x coordinate as a double
*
* @return the x co-ordinate (as a double)
*/
public abstract double getX();
/**
* Get the y coordinate as a double
*
* @return the y coordinate (as a double)
*/
public abstract double getY();
/**
* Set the location of this Point2D using double coordinates
*
* @param x the new x coordinate
* @param y the new y coordinate
*/
public abstract void setLocation(double x, double y);
/**
* Set the location of this Point2D to the same as a specified Point2D
*
* @param p the specified Point2D
*/
public void setLocation(Point2D p) {
setLocation(p.getX(), p.getY());
}
/**
* Get the square of the distance between two points
*
* @param x1 the x coordinate of the first point
* @param y1 the y coordinate of the first point
* @param x2 the x coordinate of the second point
* @param y2 the y coordinate of the second point
* @return the square of the distance between the points as a double
*/
public static double distanceSq(double x1, double y1, double x2, double y2) {
double tx = x1 - x2;
double ty = y1 - y2;
return (tx * tx + ty * ty);
}
/**
* Get the the distance between two points
*
* @param x1 the x coordinate of the first point
* @param y1 the y coordinate of the first point
* @param x2 the x coordinate of the second point
* @param y2 the y coordinate of the second point
* @return the distance between the points as a double
*/
public static double distance(double x1, double y1, double x2, double y2) {
return Math.sqrt(distanceSq(x1,y1,x2,y2));
}
/**
* Get the square of the distance between two points
*
* @param px the first point
* @param py the second point
* @return the square of the distance between the points as a double
*/
public double distanceSq(double px, double py) {
double tx = px - getX();
double ty = py - getY();
return (tx * tx + ty * ty);
}
/**
* Get the square of the distance of this point to a given point
*
* @param pt the given point
* @return the square of the distance to the given point as a double
*/
public double distanceSq(Point2D pt) {
return distanceSq(pt.getX(), pt.getY());
}
/**
* Get the distance from this point to a given point as a double
*
* @param px the x coordinate of the given point
* @param py the y coordinate of the given point
* @return the distance to the given point as a double
*/
public double distance(double px, double py) {
return Math.sqrt(distanceSq(px,py));
}
/**
* Get the distance from this point to a given point asa double
*
* @param pt the given point
* @return the distance to the given point as a double
*/
public double distance(Point2D pt) {
return Math.sqrt(distanceSq(pt));
}
/**
* Test if this point is equal to a given object
*/
@Override
public boolean equals(Object obj) {
if (obj instanceof Point2D) {
Point2D p2d = (Point2D) obj;
return (getX() == p2d.getX()) && (getY() == p2d.getY());
}
return super.equals(obj);
}
public Object clone() {
try {
return super.clone();
} catch (CloneNotSupportedException e) {
// this shouldn't happen, since we are Cloneable
throw new RuntimeException();
}
}
}