sim.util
Class Double3D
java.lang.Object
sim.util.Double3D
- All Implemented Interfaces:
- java.io.Serializable
- public final class Double3D
- extends java.lang.Object
- implements java.io.Serializable
Double3D is more or less the same class as javax.vecmath.Point3d, but it is immutable: once the x and y and z values are set, they cannot be changed (they're final). Why use this immutable class when you could just use Point3d? Because Point3d is broken with respect to hash tables. You use Point3d as a key in a hash table at your own peril. Try this: hash an object by a Point3d as key. Then change the x value of the original Point3d. Ta-da! The object is lost in the hash table. Additionally, Point3d is in a nonstandard package (javax.vecmath) that we may or may not distribute with.
One day in the far future, Double2D 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.
Double3D.equals(...) can compare by value against other Int3Ds and Double3Ds.
- See Also:
- Serialized Form
Field Summary |
double |
x
|
double |
y
|
double |
z
|
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
z
public final double z
Double3D
public Double3D()
Double3D
public Double3D(Int2D p)
- Explicitly assumes the z value is set to 0
Double3D
public Double3D(Int2D p,
double z)
Double3D
public Double3D(Int3D p)
Double3D
public Double3D(Double2D p)
- Explicitly assumes the z value is set to 0
Double3D
public Double3D(Double2D p,
double z)
Double3D
public Double3D(Double3D p)
Double3D
public Double3D(double x,
double y,
double z)
getX
public final double getX()
getY
public final double getY()
getZ
public final double getZ()
toString
public java.lang.String toString()
toCoordinates
public java.lang.String toCoordinates()
hashCode
public int hashCode()
equals
public boolean equals(java.lang.Object obj)