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64 lines
1.7 KiB
C++
64 lines
1.7 KiB
C++
#ifndef AXIO_CRANDOM_H
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#define AXIO_CRANDOM_H
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#include <cstdint>
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#include <ctime>
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/** CRandom - LCG random number generator implementation */
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class CRandom
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{
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/** Current random seed */
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uint32_t mSeed;
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public:
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/** Constructor with the seed default-initialized to the current time */
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explicit CRandom(uint32_t InSeed = (uint32_t) time(NULL))
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: mSeed(InSeed)
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{}
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CRandom(const CRandom&) noexcept = default;
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CRandom(CRandom&&) noexcept = default;
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CRandom& operator=(const CRandom&) noexcept = default;
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CRandom& operator=(CRandom&&) noexcept = default;
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/** Advance the generator and retrieve a new random number */
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int32_t Int32();
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/** Generate a random 16-bit int */
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int16_t Int16();
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/** Generate a random 64-bit int */
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int64_t Int64();
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/** Generate a random float between 0 and 1 */
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float Float();
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/** Generate a random number within the given range */
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int32_t Range(int32_t Min, int32_t Max);
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float Range(float Min, float Max);
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/** Get/set current seed */
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inline uint32_t GetSeed() const { return mSeed; }
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inline void SetSeed(uint32_t NewSeed) { mSeed = NewSeed; }
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/** We track a single "active" CRandom instance globally. This is essentially
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* a drop-in replacement for rand() but with the option of being able to
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* use a deterministic RNG for certain scenarios by changing the global random.
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*/
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static CRandom& GlobalRandom();
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};
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/** CGlobalRandomContext - Push a CRandom instance as the global random */
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class CGlobalRandomContext
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{
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/** The previous global CRandom instance */
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CRandom mPrevRandom;
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public:
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explicit CGlobalRandomContext(const CRandom& InRandom);
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~CGlobalRandomContext();
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};
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#endif // AXIO_CRANDOM_H
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