Package com.github.tommyettinger.random

Class Xoshiro160RoadroxoRandom

java.lang.Object
java.util.Random
com.github.tommyettinger.random.EnhancedRandom
com.github.tommyettinger.random.Xoshiro160RoadroxoRandom
All Implemented Interfaces:
Externalizable, Serializable, RandomGenerator
public class Xoshiro160RoadroxoRandom extends EnhancedRandom
A random number generator that is optimized for performance on 32-bit machines and with Google Web Toolkit, this uses no multiplication and is similar to the published xoshiro128 algorithm, but has an extra 32-bit state that acts like a counter. Unlike any variations on xoshiro128 with four states, this is actually 1-dimensionally equidistributed - existing generators like xoshiro128++ produce the result 0 less frequently (by a tiny difference, but that is enough to mean it isn't equal). This produces all 32-bit results equally frequently with nextInt(). It is also almost 1-dimensionally equidistributed with nextLong(); of the Math.pow(2, 64) possible results for nextLong(), all but Math.pow(2, 32) results are returned Math.pow(2, 128) times, and the remaining Math.pow(2, 32) results are returned Math.pow(2, 128) - 1 times. Note that the pow() call is pseudocode; real Java code would consider Math.pow(2, 128) and Math.pow(2, 128) - 1 equal. It is important to emphasize that nextLong() is not actually equidistributed, just very close to that, in the same way that xoshiro128++ is not actually equidistributed, just very close to it. This is also very close to 2D-equidistributed for 32-bit outputs, with (2 to the 32) output pairs occurring once less often than the remaining (2 to the 64) minus (2 to the 32) pairs. Each output will occur either (2 to the 128) or ((2 to the 128) minus 1) times.
An unusual property of this generator is that the state changes in exactly the same way and by the same distance regardless of whether nextInt() or nextLong() is called (and the same for the reverse-direction methods previousInt() and previousLong()). The result is calculated differently for 64-bit output than 32-bit output. For nextInt(), stateA, stateB, and stateE are combined by rotating some, adding a pair of states, and XORing the two halves. For nextLong(), all states are combined by forming two 32-bit outputs (using the same or similar 32-bit math as for nextInt()) and combining them into one 64-bit value only at the end.
The actual speed of this is going to vary wildly depending on the platform being benchmarked. On GWT, which is the main place where the performance of a random number generator might actually be a bottleneck in a game, this performs very well. On desktop platforms, it is faster at generating int values than long, which is to be expected for a 32-bit generator, but not as fast as some other generators, like ChopRandom. However, this guarantees a larger minimum period than ChopRandom can possibly provide as a maximum period.
Xoshiro160RoadroxoRandom has a guaranteed period of pow(2, 160) - pow(2, 32). The only disallowed states have each of stateA, stateB, stateC, and stateD equal to 0; stateE is unconstrained. It starts returning fully-decorrrelated results even given very-correlated initial states after about 10 calls to nextInt() or nextLong(). This passes 64TB of PractRand with no anomalies, both for nextInt() and the different algorithm for nextLong().
This implements all optional methods in EnhancedRandom except EnhancedRandom.skip(long). It also implements leap() to allow jumping ahead by the equivalent of at least 2 to the 64 calls to nextInt(). Methods that can use only nextInt(), without needing nextLong() to produce equal-quality results, do so.
Based on this public-domain code by Vigna and Blackman.
See Also:

  • Field Details

    • stateA

      protected int stateA
      The first state; can be any int.

    • stateB

      protected int stateB
      The second state; can be any int.

    • stateC

      protected int stateC
      The third state; can be any int.

    • stateD

      protected int stateD
      The fourth state; can be any int.

    • stateE

      protected int stateE
      The fifth state; can be any int.

  • Constructor Details

    • Xoshiro160RoadroxoRandom

      public Xoshiro160RoadroxoRandom()
      Creates a new Xoshiro160RoadroxoRandom with a random state.

    • Xoshiro160RoadroxoRandom

      public Xoshiro160RoadroxoRandom(long seed)
      Creates a new Xoshiro160RoadroxoRandom with the given seed; all long values are permitted. The seed will be passed to setSeed(long) to attempt to adequately distribute the seed randomly.
      Parameters:
      seed - any long value

    • Xoshiro160RoadroxoRandom

      public Xoshiro160RoadroxoRandom(int stateA, int stateB, int stateC, int stateD, int stateE)
      Creates a new Xoshiro160RoadroxoRandom with the given four states; all int values are permitted. These states will be used verbatim, unless the first 4 states are each 0 -- if those are all 0, then stateD is replaced with 1. Note that stateE can have any int value without constraining the other states.
      Parameters:
      stateA - any int value
      stateB - any int value
      stateC - any int value
      stateD - any int value
      stateE - any int value

  • Method Details

    • getTag

      public String getTag()
      Description copied from class: EnhancedRandom
      Gets the tag used to identify this type of EnhancedRandom, as a String. This tag should be unique, and for uniformity purposes, all tags used in this library are 4 characters long. User-defined tags should have a different length.
      Specified by:
      getTag in class EnhancedRandom
      Returns:
      a unique String identifier for this type of EnhancedRandom; usually 4 chars long.

    • mainlyGeneratesInt

      public boolean mainlyGeneratesInt()
      This generator mainly generates int values.
      Overrides:
      mainlyGeneratesInt in class EnhancedRandom
      Returns:
      true
      See Also:

    • getMinimumPeriod

      public BigInteger getMinimumPeriod()
      (2 to the 160) - (2 to the 64).
      Overrides:
      getMinimumPeriod in class EnhancedRandom
      Returns:
      (2 to the 160) - (2 to the 64)

    • getStateCount

      public int getStateCount()
      This generator has 5 int states, so this returns 5.
      Overrides:
      getStateCount in class EnhancedRandom
      Returns:
      5 (five)

    • getSelectedState

      public long getSelectedState(int selection)
      Gets the state determined by selection, as-is. The value for selection should be between 0 and 5, inclusive; if it is any other value this gets state E as if 4 was given.
      Overrides:
      getSelectedState in class EnhancedRandom
      Parameters:
      selection - used to select which state variable to get; generally 0, 1, 2, 3, or 4
      Returns:
      the value of the selected state, which is an int that will be promoted to long

    • setSelectedState

      public void setSelectedState(int selection, long value)
      Sets one of the states, determined by selection, to the lower 32 bits of value, as-is. Selections 0, 1, 2, 3, and 4 refer to states A, B, C, D, and E and if the selection is anything else, this treats it as 4 and sets stateE. This always casts value to an int before using it. If the first four states would be 0 as a result of this call, it instead sets the fourth part of the state (stateD) to 1.
      Overrides:
      setSelectedState in class EnhancedRandom
      Parameters:
      selection - used to select which state variable to set; generally 0, 1, 2, 3, or 4
      value - the exact value to use for the selected state, if valid

    • setSeed

      public void setSeed(long seed)
      This initializes all 5 states of the generator to random values based on the given seed. (2 to the 64) possible initial generator states can be produced here. This is not capable of setting the full state to the only invalid value (all zeros).
      Specified by:
      setSeed in class EnhancedRandom
      Parameters:
      seed - the initial seed; may be any long

    • setSeed

      public void setSeed(int seed)
      This initializes all 4 states of the generator to random values based on the given seed. (2 to the 32) possible initial generator states can be produced here.
      Parameters:
      seed - the initial seed; may be any int

    • getStateA

      public long getStateA()

    • setStateA

      public void setStateA(long stateA)
      Sets the first part of the state by casting the parameter to an int.
      Parameters:
      stateA - can be any long, but will be cast to an int before use

    • getStateB

      public long getStateB()

    • setStateB

      public void setStateB(long stateB)
      Sets the second part of the state by casting the parameter to an int.
      Parameters:
      stateB - can be any long, but will be cast to an int before use

    • getStateC

      public long getStateC()

    • setStateC

      public void setStateC(long stateC)
      Sets the third part of the state by casting the parameter to an int.
      Parameters:
      stateC - can be any long, but will be cast to an int before use

    • getStateD

      public long getStateD()

    • setStateD

      public void setStateD(long stateD)
      Sets the fourth part of the state by casting the parameter to an int. If all four states would be 0 as a result of this call, it instead sets the fourth part of the state to 1.
      Parameters:
      stateD - can be any long, but will be cast to an int before use

    • getStateE

      public long getStateE()

    • setStateE

      public void setStateE(long stateE)
      Sets the fifth part of the state by casting the parameter to an int.
      Parameters:
      stateE - can be any long, but will be cast to an int before use

    • setState

      public void setState(long stateA, long stateB, long stateC, long stateD, long stateE)
      Sets the state completely to the given five state variables, casting each to an int. This is the same as calling setStateA(long), setStateB(long), setStateC(long), setStateD(long), and setStateE(long) as a group. If the first four states would all be 0 as a result of this call, it instead sets the fourth part of the state to 1.
      Overrides:
      setState in class EnhancedRandom
      Parameters:
      stateA - the first state; can be any long, but will be cast to an int before use
      stateB - the second state; can be any long, but will be cast to an int before use
      stateC - the third state; can be any long, but will be cast to an int before use
      stateD - the fourth state; can be any long, but will be cast to an int before use
      stateE - the fifth state; can be any long, but will be cast to an int before use

    • nextLong

      public long nextLong()
      Description copied from class: EnhancedRandom
      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.
      The only methods that need to be implemented by this interface are this and EnhancedRandom.copy(), though other methods can be implemented as appropriate for generators that, for instance, natively produce ints rather than longs.
      Specified by:
      nextLong in interface RandomGenerator
      Specified by:
      nextLong in class EnhancedRandom
      Returns:
      the next pseudorandom, uniformly distributed long value from this random number generator's sequence

    • previousLong

      public long previousLong()
      Description copied from class: EnhancedRandom
      Optional; moves the state to its previous value and returns the previous long that would have been produced by EnhancedRandom.nextLong(). This can be equivalent to calling EnhancedRandom.skip(long) with -1L, but not always; many generators can't efficiently skip long distances, but can step back by one value.
      Generators that natively generate int results typically produce long values by generating an int for the high 32 bits and an int for the low 32 bits. When producing the previous long, the order the high and low bits are generated, such as by EnhancedRandom.previousInt(), should be reversed. Generators that natively produce long values usually don't need to implement EnhancedRandom.previousInt(), but those that produce int usually should implement it, and may optionally call previousInt() twice in this method.
      If you know how to implement the reverse of a particular random number generator, it is recommended you do so here, rather than rely on skip(). This isn't always easy, but should always be possible for any decent PRNG (some historical PRNGs, such as the Middle-Square PRNG, cannot be reversed at all). If a generator cannot be reversed because multiple initial states can transition to the same subsequent state, it is known to have statistical problems that are not necessarily present in a generator that matches one initial state to one subsequent state.
      The public implementation calls EnhancedRandom.skip(long) with -1L, and if skip() has not been implemented differently, then it will throw an UnsupportedOperationException.
      Overrides:
      previousLong in class EnhancedRandom
      Returns:
      the previous number this would have produced with EnhancedRandom.nextLong()

    • previousInt

      public int previousInt()
      Description copied from class: EnhancedRandom
      Optional; moves the state to its previous value and returns the previous int that would have been produced by EnhancedRandom.nextInt(). This can be equivalent to calling EnhancedRandom.previousLong() and casting to int, but not always; generators that natively generate int results typically move the state once in nextInt() and twice in nextLong(), and should move the state back once here.
      If EnhancedRandom.nextInt() is implemented using a call to EnhancedRandom.nextLong(), the implementation in this class is almost always sufficient and correct. If nextInt() changes state differently from nextLong(), then this should be implemented, if feasible, and EnhancedRandom.previousLong() can be implemented using this method. If you know how to implement the reverse of a particular random number generator, it is recommended you do so here, rather than rely on skip(). This isn't always easy, but should always be possible for any decent PRNG (some historical PRNGs, such as the Middle-Square PRNG, cannot be reversed at all). If a generator cannot be reversed because multiple initial states can transition to the same subsequent state, it is known to have statistical problems that are not necessarily present in a generator that matches one initial state to one subsequent state.
      The public implementation calls EnhancedRandom.previousLong() and casts it to int, and if previousLong() and skip() have not been implemented differently, then it will throw an UnsupportedOperationException.
      Overrides:
      previousInt in class EnhancedRandom
      Returns:
      the previous number this would have produced with EnhancedRandom.nextInt()

    • next

      public int next(int bits)
      Description copied from class: EnhancedRandom
      Generates the next pseudorandom number with a specific maximum size in bits (not a max number). If you want to get a random number in a range, you should usually use EnhancedRandom.nextInt(int) instead. For some specific cases, this method is more efficient and less biased than EnhancedRandom.nextInt(int). For bits values between 1 and 30, this should be similar in effect to nextInt(1 << bits); though it won't typically produce the same values, they will have the correct range. If bits is 31, this can return any non-negative int; note that nextInt(1 << 31) won't behave this way because 1 << 31 is negative. If bits is 32 (or 0), this can return any int.

      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.

      Note that you can give this values for bits that are outside its expected range of 1 to 32, but the value used, as long as bits is positive, will effectively be bits % 32. As stated before, a value of 0 for bits is the same as a value of 32.

      Overrides:
      next in class EnhancedRandom
      Parameters:
      bits - the amount of random bits to request, from 1 to 32
      Returns:
      the next pseudorandom value from this random number generator's sequence

    • nextInt

      public int nextInt()
      Description copied from class: EnhancedRandom
      Returns the next pseudorandom, uniformly distributed int value from this random number generator's sequence. The general contract of nextInt is that one int value is pseudorandomly generated and returned. All 232 possible int values are produced with (approximately) equal probability.
      Specified by:
      nextInt in interface RandomGenerator
      Overrides:
      nextInt in class EnhancedRandom
      Returns:
      the next pseudorandom, uniformly distributed int value from this random number generator's sequence

    • nextInt

      public int nextInt(int bound)
      Description copied from class: EnhancedRandom
      Returns a pseudorandom, uniformly distributed int value between 0 (inclusive) and the specified value (exclusive), drawn from this random number generator's sequence. The general contract of nextInt is that one int value in the specified range is pseudorandomly generated and returned. All bound possible int values are produced with (approximately) equal probability.
      This method clamps bound to be at least 0; it never returns a negative int.
      It should be mentioned that the technique this uses has some bias, depending on bound, but it typically isn't measurable without specifically looking for it. Using the method this does allows this method to always advance the state by one step, instead of a varying and unpredictable amount with the more typical ways of rejection-sampling random numbers and only using numbers that can produce an int within the bound without bias. See M.E. O'Neill's blog about random numbers for discussion of alternative, unbiased methods.
      Specified by:
      nextInt in interface RandomGenerator
      Overrides:
      nextInt in class EnhancedRandom
      Parameters:
      bound - the upper bound (exclusive). If negative or 0, this always returns 0.
      Returns:
      the next pseudorandom, uniformly distributed int value between zero (inclusive) and bound (exclusive) from this random number generator's sequence

    • nextSignedInt

      public int nextSignedInt(int outerBound)
      Description copied from class: EnhancedRandom
      Returns a pseudorandom, uniformly distributed int value between an inner bound of 0 (inclusive) and the specified outerBound (exclusive). This is meant for cases where the outer bound may be negative, especially if the bound is unknown or may be user-specified. A negative outer bound is used as the lower bound; a positive outer bound is used as the upper bound. An outer bound of -1, 0, or 1 will always return 0, keeping the bound exclusive (except for outer bound 0). This method is slightly slower than EnhancedRandom.nextInt(int).
      Overrides:
      nextSignedInt in class EnhancedRandom
      Parameters:
      outerBound - the outer exclusive bound; may be any int value, allowing negative
      Returns:
      a pseudorandom int between 0 (inclusive) and outerBound (exclusive)
      See Also:

    • nextUnsignedInt

      public int nextUnsignedInt(int bound)
      Description copied from class: EnhancedRandom
      Returns a pseudorandom, uniformly distributed int value between 0 (inclusive) and the specified value (exclusive), drawn from this random number generator's sequence. The general contract of nextInt is that one int value in the specified range is pseudorandomly generated and returned. All bound possible int values are produced with (approximately) equal probability.
      This method treats the outer bound as unsigned, so if a negative int is passed as bound, it will be treated as positive and larger than Integer.MAX_VALUE. That means this can produce results that are positive or negative, but when you mask the result and the bound with 0xFFFFFFFFL (to treat them as unsigned), the result will always be between 0L (inclusive) and the masked bound (exclusive).
      This is primarily useful as a building block for other methods in this class.
      Overrides:
      nextUnsignedInt in class EnhancedRandom
      Parameters:
      bound - the upper bound (exclusive); treated as unsigned
      Returns:
      the next pseudorandom, uniformly distributed int value between zero (inclusive) and bound (exclusive), treated as unsigned, from this random number generator's sequence

    • nextBytes

      public void nextBytes(byte[] bytes)
      Description copied from class: EnhancedRandom
      Generates random bytes and places them into a user-supplied byte array. The number of random bytes produced is equal to the length of the byte array.
      Specified by:
      nextBytes in interface RandomGenerator
      Overrides:
      nextBytes in class EnhancedRandom
      Parameters:
      bytes - the byte array to fill with random bytes

    • nextInt

      public int nextInt(int innerBound, int outerBound)
      Description copied from class: EnhancedRandom
      Returns a pseudorandom, uniformly distributed int value between the specified innerBound (inclusive) and the specified outerBound (exclusive). If outerBound is less than or equal to innerBound, this always returns innerBound.
      For any case where outerBound might be valid but less than innerBound, you can use EnhancedRandom.nextSignedInt(int, int). If outerBound is less than innerBound here, this simply returns innerBound.
      Specified by:
      nextInt in interface RandomGenerator
      Overrides:
      nextInt in class EnhancedRandom
      Parameters:
      innerBound - the inclusive inner bound; may be any int, allowing negative
      outerBound - the exclusive outer bound; must be greater than innerBound (otherwise this returns innerBound)
      Returns:
      a pseudorandom int between innerBound (inclusive) and outerBound (exclusive)
      See Also:

    • nextSignedInt

      public int nextSignedInt(int innerBound, int outerBound)
      Description copied from class: EnhancedRandom
      Returns a pseudorandom, uniformly distributed int value between the specified innerBound (inclusive) and the specified outerBound (exclusive). This is meant for cases where either bound may be negative, especially if the bounds are unknown or may be user-specified.
      Overrides:
      nextSignedInt in class EnhancedRandom
      Parameters:
      innerBound - the inclusive inner bound; may be any int, allowing negative
      outerBound - the exclusive outer bound; may be any int, allowing negative
      Returns:
      a pseudorandom int between innerBound (inclusive) and outerBound (exclusive)
      See Also:

    • nextLong

      public long nextLong(long bound)
      Description copied from class: EnhancedRandom
      Returns a pseudorandom, uniformly distributed long value between 0 (inclusive) and the specified value (exclusive), drawn from this random number generator's sequence. The general contract of nextLong is that one long value in the specified range is pseudorandomly generated and returned. All bound possible long values are produced with (approximately) equal probability, though there is a small amount of bias depending on the bound.
      Note that this advances the state by the same amount as a single call to EnhancedRandom.nextLong(), which allows methods like EnhancedRandom.skip(long) to function correctly, but introduces some bias when bound is very large. This will also advance the state if bound is 0 or negative, so usage with a variable bound will advance the state reliably.
      This method has some bias, particularly on larger bounds. Actually measuring bias with bounds in the trillions or greater is challenging but not impossible, so don't use this for a real-money gambling purpose. The bias isn't especially significant, though.
      Specified by:
      nextLong in interface RandomGenerator
      Overrides:
      nextLong in class EnhancedRandom
      Parameters:
      bound - the upper bound (exclusive). If negative or 0, this always returns 0.
      Returns:
      the next pseudorandom, uniformly distributed long value between zero (inclusive) and bound (exclusive) from this random number generator's sequence
      See Also:

    • nextSignedLong

      public long nextSignedLong(long outer)
      Description copied from class: EnhancedRandom
      Returns a pseudorandom, uniformly distributed long value between an inner bound of 0 (inclusive) and the specified outerBound (exclusive). This is meant for cases where the outer bound may be negative, especially if the bound is unknown or may be user-specified. A negative outer bound is used as the lower bound; a positive outer bound is used as the upper bound. An outer bound of -1, 0, or 1 will always return 0, keeping the bound exclusive (except for outer bound 0).

      Note that this advances the state by the same amount as a single call to EnhancedRandom.nextLong(), which allows methods like EnhancedRandom.skip(long) to function correctly, but introduces some bias when bound is very large. This method should be about as fast as EnhancedRandom.nextLong(long) , unlike the speed difference between EnhancedRandom.nextInt(int) and EnhancedRandom.nextSignedInt(int).

      Overrides:
      nextSignedLong in class EnhancedRandom
      Parameters:
      outer - the outer exclusive bound; may be any long value, allowing negative
      Returns:
      a pseudorandom long between 0 (inclusive) and outerBound (exclusive)
      See Also:

    • nextLong

      public long nextLong(long inner, long outer)
      Description copied from class: EnhancedRandom
      Returns a pseudorandom, uniformly distributed long value between the specified innerBound (inclusive) and the specified outerBound (exclusive). If outerBound is less than or equal to innerBound, this always returns innerBound.
      For any case where outerBound might be valid but less than innerBound, you can use EnhancedRandom.nextSignedLong(long, long).
      Specified by:
      nextLong in interface RandomGenerator
      Overrides:
      nextLong in class EnhancedRandom
      Parameters:
      inner - the inclusive inner bound; may be any long, allowing negative
      outer - the exclusive outer bound; must be greater than innerBound (otherwise this returns innerBound)
      Returns:
      a pseudorandom long between innerBound (inclusive) and outerBound (exclusive)
      See Also:

    • nextSignedLong

      public long nextSignedLong(long inner, long outer)
      Description copied from class: EnhancedRandom
      Returns a pseudorandom, uniformly distributed long value between the specified innerBound (inclusive) and the specified outerBound (exclusive). This is meant for cases where either bound may be negative, especially if the bounds are unknown or may be user-specified.
      Overrides:
      nextSignedLong in class EnhancedRandom
      Parameters:
      inner - the inclusive inner bound; may be any long, allowing negative
      outer - the exclusive outer bound; may be any long, allowing negative
      Returns:
      a pseudorandom long between innerBound (inclusive) and outerBound (exclusive)
      See Also:

    • nextBoolean

      public boolean nextBoolean()
      Description copied from class: EnhancedRandom
      Returns the next pseudorandom, uniformly distributed boolean value from this random number generator's sequence. The general contract of nextBoolean is that one boolean value is pseudorandomly generated and returned. The values true and false are produced with (approximately) equal probability.
      The public implementation simply returns a sign check on EnhancedRandom.nextLong(), returning true if the generated long is negative. This is typically the safest way to implement this method; many types of generators have less statistical quality on their lowest bit, so just returning based on the lowest bit isn't always a good idea.
      Specified by:
      nextBoolean in interface RandomGenerator
      Overrides:
      nextBoolean in class EnhancedRandom
      Returns:
      the next pseudorandom, uniformly distributed boolean value from this random number generator's sequence

    • nextFloat

      public float nextFloat()
      Description copied from class: EnhancedRandom
      Returns the next pseudorandom, uniformly distributed float value between 0.0 (inclusive) and 1.0 (exclusive) from this random number generator's sequence.

      The general contract of nextFloat is that one float value, chosen (approximately) uniformly from the range 0.0f (inclusive) to 1.0f (exclusive), is pseudorandomly generated and returned. All 224 possible float values of the form m x 2-24, where m is a positive integer less than 224, are produced with (approximately) equal probability.

      The public implementation uses the upper 24 bits of EnhancedRandom.nextLong(), with an unsigned right shift and a multiply by a very small float (5.9604645E-8f or 0x1p-24f). It tends to be fast if nextLong() is fast, but alternative implementations could use 24 bits of EnhancedRandom.nextInt() (or just EnhancedRandom.next(int), giving it 24) if that generator doesn't efficiently generate 64-bit longs.

      Specified by:
      nextFloat in interface RandomGenerator
      Overrides:
      nextFloat in class EnhancedRandom
      Returns:
      the next pseudorandom, uniformly distributed float value between 0.0 and 1.0 from this random number generator's sequence

    • nextInclusiveFloat

      public float nextInclusiveFloat()
      Description copied from class: EnhancedRandom
      This is just like EnhancedRandom.nextFloat(), returning a float between 0 and 1, except that it is inclusive on both 0.0 and 1.0. It returns 1.0 rarely, 0.000000000000000005421010862427522% of the time if there is no bias in the generator, but it can happen.
      This method does not return purely-equidistant floats, because there the resolution of possible floats it can generate is higher as it approaches 0.0 . The smallest non-zero float this can return is 2.7105064E-20 (0x1.000006p-65 in hex), and the largest non-one float this can return is 0.99999994f (0x1.fffffep-1 in hex). This uses nearly identical code to EnhancedRandom.nextExclusiveFloat(), but does some really unusual operations on both the bits and the float value to be able to produce 0.0f and 1.0f . This retains the exclusive version's quality of having approximately uniform distributions for every mantissa bit, unlike most ways of generating random floating-point numbers.
      Overrides:
      nextInclusiveFloat in class EnhancedRandom
      Returns:
      a float between 0.0, inclusive, and 1.0, inclusive

    • copy

      public Xoshiro160RoadroxoRandom copy()
      Description copied from class: EnhancedRandom
      Creates a new EnhancedRandom with identical states to this one, so if the same EnhancedRandom methods are called on this object and its copy (in the same order), the same outputs will be produced. This is not guaranteed to copy the inherited state of any parent class, so if you call methods that are only implemented by a superclass (like Random) and not this one, the results may differ.
      Specified by:
      copy in class EnhancedRandom
      Returns:
      a deep copy of this EnhancedRandom.

    • leap

      public int leap()
      Jumps extremely far in the generator's sequence, to a state that would normally only be reached by calling nextInt() at least Math.pow(2, 64) times sequentially. "At least" here means a non-zero 32-bit unsigned integer multiple of Math.pow(2, 64), because this only changes states A, B, C, and D -- stateE doesn't change, even though normally calling nextInt() 2 to the 64 times would change stateE by an unpredictable amount. This can be used to create over 18 quintillion distinct substreams of this generator's sequence, each with a period of at least Math.pow(2, 64).
      Note that this returns an int, unlike most leap() functions in other classes here.
      Returns:
      the result of what nextInt() would return if it was called at the state this jumped to

    • equals

      public boolean equals(Object o)
      Overrides:
      equals in class Object

    • toString

      public String toString()
      Overrides:
      toString in class Object