138 lines
4.9 KiB
C++
138 lines
4.9 KiB
C++
/*
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==============================================================================
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This file is part of the JUCE library.
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Copyright (c) 2017 - ROLI Ltd.
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JUCE is an open source library subject to commercial or open-source
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licensing.
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The code included in this file is provided under the terms of the ISC license
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http://www.isc.org/downloads/software-support-policy/isc-license. Permission
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To use, copy, modify, and/or distribute this software for any purpose with or
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without fee is hereby granted provided that the above copyright notice and
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this permission notice appear in all copies.
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JUCE IS PROVIDED "AS IS" WITHOUT ANY WARRANTY, AND ALL WARRANTIES, WHETHER
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EXPRESSED OR IMPLIED, INCLUDING MERCHANTABILITY AND FITNESS FOR PURPOSE, ARE
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DISCLAIMED.
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==============================================================================
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*/
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namespace juce
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{
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//==============================================================================
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/**
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A random number generator.
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You can create a Random object and use it to generate a sequence of random numbers.
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@tags{Core}
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*/
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class JUCE_API Random final
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{
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public:
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//==============================================================================
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/** Creates a Random object based on a seed value.
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For a given seed value, the subsequent numbers generated by this object
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will be predictable, so a good idea is to set this value based
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on the time, e.g.
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new Random (Time::currentTimeMillis())
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*/
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explicit Random (int64 seedValue) noexcept;
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/** Creates a Random object using a random seed value.
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Internally, this calls setSeedRandomly() to randomise the seed.
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*/
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Random();
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/** Destructor. */
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~Random() noexcept;
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/** Returns the next random 32 bit integer.
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@returns a random integer from the full range 0x80000000 to 0x7fffffff
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*/
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int nextInt() noexcept;
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/** Returns the next random number, limited to a given range.
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The maxValue parameter may not be negative, or zero.
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@returns a random integer between 0 (inclusive) and maxValue (exclusive).
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*/
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int nextInt (int maxValue) noexcept;
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/** Returns the next random number, limited to a given range.
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@returns a random integer between the range start (inclusive) and its end (exclusive).
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*/
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int nextInt (Range<int> range) noexcept;
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/** Returns the next 64-bit random number.
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@returns a random integer from the full range 0x8000000000000000 to 0x7fffffffffffffff
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*/
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int64 nextInt64() noexcept;
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/** Returns the next random floating-point number.
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@returns a random value in the range 0 (inclusive) to 1.0 (exclusive)
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*/
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float nextFloat() noexcept;
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/** Returns the next random floating-point number.
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@returns a random value in the range 0 (inclusive) to 1.0 (exclusive)
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*/
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double nextDouble() noexcept;
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/** Returns the next random boolean value. */
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bool nextBool() noexcept;
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/** Returns a BigInteger containing a random number.
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@returns a random value in the range 0 to (maximumValue - 1).
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*/
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BigInteger nextLargeNumber (const BigInteger& maximumValue);
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/** Fills a block of memory with random values. */
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void fillBitsRandomly (void* bufferToFill, size_t sizeInBytes);
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/** Sets a range of bits in a BigInteger to random values. */
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void fillBitsRandomly (BigInteger& arrayToChange, int startBit, int numBits);
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//==============================================================================
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/** Resets this Random object to a given seed value. */
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void setSeed (int64 newSeed) noexcept;
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/** Returns the RNG's current seed. */
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int64 getSeed() const noexcept { return seed; }
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/** Merges this object's seed with another value.
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This sets the seed to be a value created by combining the current seed and this
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new value.
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*/
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void combineSeed (int64 seedValue) noexcept;
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/** Reseeds this generator using a value generated from various semi-random system
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properties like the current time, etc.
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Because this function convolves the time with the last seed value, calling
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it repeatedly will increase the randomness of the final result.
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*/
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void setSeedRandomly();
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/** The overhead of creating a new Random object is fairly small, but if you want to avoid
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it, you can call this method to get a global shared Random object.
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It's not thread-safe though, so threads should use their own Random object, otherwise
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you run the risk of your random numbers becoming.. erm.. randomly corrupted..
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*/
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static Random& getSystemRandom() noexcept;
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private:
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//==============================================================================
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int64 seed;
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JUCE_LEAK_DETECTOR (Random)
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};
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} // namespace juce
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