sim.util
Class Double2D
java.lang.Object
sim.util.Double2D
- All Implemented Interfaces:
- java.io.Serializable
- public final class Double2D
- extends java.lang.Object
- implements java.io.Serializable
Double2D is more or less the same class as java.awt.geom.Point2D.Double, 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 Point2D? Because Point2D is broken with respect to hash tables. You use Point2D as a key in a hash table at your own peril. Try this: hash an object by a Point2D as key. Then change the x value of the original Point2D. Ta-da! The object is lost in the hash table.
One day in the far future, Double3D 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.
Double2D.equals(...) can compare by value against other Int2Ds and Double2Ds.
- See Also:
- Serialized Form
Field Summary |
double |
x
|
double |
y
|
Constructor Summary |
Double2D()
|
Double2D(double x,
double y)
|
Double2D(Int2D p)
|
Double2D(java.awt.Point p)
|
Double2D(java.awt.geom.Point2D.Double p)
|
Double2D(java.awt.geom.Point2D.Float p)
|
Double2D(java.awt.geom.Point2D p)
Only included for completeness' sakes, in case a new Point2D subclass is created in the future. |
Methods inherited from class java.lang.Object |
clone, finalize, getClass, notify, notifyAll, wait, wait, wait |
x
public final double x
y
public final double y
Double2D
public Double2D()
Double2D
public Double2D(Int2D p)
Double2D
public Double2D(java.awt.Point p)
Double2D
public Double2D(java.awt.geom.Point2D.Double p)
Double2D
public Double2D(java.awt.geom.Point2D.Float p)
Double2D
public Double2D(java.awt.geom.Point2D p)
- Only included for completeness' sakes, in case a new Point2D subclass is created in the future.
Double2D
public Double2D(double x,
double y)
getX
public final double getX()
getY
public final double getY()
toString
public java.lang.String toString()
toCoordinates
public java.lang.String toCoordinates()
hashCode
public final int hashCode()
equals
public final boolean equals(java.lang.Object obj)