squidpony.squidmath

Class RNG.CustomRandom

java.lang.Object

java.util.Random

squidpony.squidmath.RNG.CustomRandom

All Implemented Interfaces:

java.io.Serializable

Enclosing class:

RNG

public static class RNG.CustomRandom
extends java.util.Random

A subclass of java.util.Random that uses a RandomnessSource supplied by the user instead of the default.

See Also:

Serialized Form

Constructor Summary

Constructors

Constructor and Description
CustomRandom() Creates a new random number generator.
CustomRandom(RandomnessSource randomnessSource) Creates a new random number generator.

Method Summary

Modifier and Type	Method and Description
protected int	next(int bits) Generates the next pseudorandom number.
long	nextLong() Returns the next pseudorandom, uniformly distributed long value from this random number generator's sequence.

Methods inherited from class java.util.Random

doubles, doubles, doubles, doubles, ints, ints, ints, ints, longs, longs, longs, longs, nextBoolean, nextBytes, nextDouble, nextFloat, nextGaussian, nextInt, nextInt, setSeed

Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Constructor Detail

CustomRandom

public CustomRandom()

Creates a new random number generator. This constructor uses a DiverRNG with a random seed.

CustomRandom

public CustomRandom(RandomnessSource randomnessSource)

Creates a new random number generator. This constructor uses the seed of the given RandomnessSource if it has been seeded.

Parameters:

randomnessSource - a way to get random bits, supplied by RNG

Method Detail

next

protected int next(int bits)

Generates the next pseudorandom number. Subclasses should override this, as this is used by all other methods.

The general contract of next is that it returns an int value and if the argument bits is between 1 and 32 (inclusive), then that many low-order bits of the returned value will be (approximately) independently chosen bit values, each of which is (approximately) equally likely to be 0 or 1. The method next is implemented by class Random by atomically updating the seed to

 (seed * 0x5DEECE66DL + 0xBL) & ((1L << 48) - 1)

and returning

 (int)(seed >>> (48 - bits)).

This is a linear congruential pseudorandom number generator, as defined by D. H. Lehmer and described by Donald E. Knuth in The Art of Computer Programming, Volume 3: Seminumerical Algorithms, section 3.2.1.

Overrides:

next in class java.util.Random

Parameters:

bits - random bits

Returns:

the next pseudorandom value from this random number generator's sequence

Since:

1.1

nextLong

public long nextLong()

Returns the next pseudorandom, uniformly distributed long value from this random number generator's sequence. The general contract of nextLong is that one long value is pseudorandomly generated and returned.

Overrides:

nextLong in class java.util.Random

Returns:

the next pseudorandom, uniformly distributed long value from this random number generator's sequence