sim.util
Class Int2D

java.lang.Object
  extended bysim.util.Int2D
All Implemented Interfaces:
java.io.Serializable

public final class Int2D
extends java.lang.Object
implements java.io.Serializable

Int2D is more or less the same class as java.awt.Point, but it is immutable: once the x and y values are set, they cannot be changed (they're final). Why use this immutable class when you could just use Point? Because Point is broken with respect to hash tables. You use Point as a key in a hash table at your own peril. Try this: hash an object by a Point as key. Then change the x value of the original Point. Ta-da! The object is lost in the hash table.

One day in the far future, Int2D should also be HIGHLY efficient; since it is immutable, it can be passed by value rather than by pointer by a smart compiler. Not today, though. But it's not bad.

This class has an elaborate hash code generation that is much more random than Sun's standard generator, but takes more time. For very large numbers of objects, this is a good idea, but we may change it to a simpler version in the future.

Int2D.equals(...) can compare by value against other Int2Ds and Double2Ds.

See Also:
Serialized Form

Field Summary
 int x
           
 int y
           
 
Constructor Summary
Int2D()
           
Int2D(int x, int y)
           
Int2D(java.awt.Point p)
           
 
Method Summary
 boolean equals(java.lang.Object obj)
           
 java.awt.Point getPoint()
           
 int getX()
           
 int getY()
           
 int hashCode()
           
static int hashCodeFor(int x, int y)
           
 java.lang.String toCoordinates()
           
 java.lang.String toString()
           
 
Methods inherited from class java.lang.Object
clone, finalize, getClass, notify, notifyAll, wait, wait, wait
 

Field Detail

x

public final int x

y

public final int y
Constructor Detail

Int2D

public Int2D()

Int2D

public Int2D(java.awt.Point p)

Int2D

public Int2D(int x,
             int y)
Method Detail

getX

public final int getX()

getY

public final int getY()

getPoint

public final java.awt.Point getPoint()

toString

public java.lang.String toString()

toCoordinates

public java.lang.String toCoordinates()

hashCodeFor

public static final int hashCodeFor(int x,
                                    int y)

hashCode

public final int hashCode()

equals

public final boolean equals(java.lang.Object obj)