mcpe/source/Base/Random.hpp
2023-07-30 22:41:09 +03:00

54 lines
1.8 KiB
C++

/********************************************************************
Minecraft: Pocket Edition - Decompilation Project
Copyright (C) 2023 iProgramInCpp
The following code is licensed under the BSD 1 clause license.
SPDX-License-Identifier: BSD-1-Clause
********************************************************************/
#pragma once
#include <cstdint>
// This appears to be VERY similar to https://github.com/SethRobinson/proton/blob/master/shared/util/CRandom.h#L10
// It turns out, RTsoft, Mojang, and the author of Game Coding Complete used the same reference implementation of
// the Mersenne Twister:
// http://www.math.sci.hiroshima-u.ac.jp/m-mat/MT/MT2002/CODES/mt19937ar.c
//A random generator based on the Mersenne Twister originally developed by Takuji Nishimura and Makoto Matsumoto.
// From the book GameCoding Complete by Mike McShaffry
/* Period parameters */
#define CMATH_N 624
#define CMATH_M 397
#define CMATH_MATRIX_A 0x9908b0df /* constant vector a */
#define CMATH_UPPER_MASK 0x80000000 /* most significant w-r bits */
#define CMATH_LOWER_MASK 0x7fffffff /* least significant r bits */
/* Tempering parameters */
#define CMATH_TEMPERING_MASK_B 0x9d2c5680
#define CMATH_TEMPERING_MASK_C 0xefc60000
#define CMATH_TEMPERING_SHIFT_U(y) (y >> 11)
#define CMATH_TEMPERING_SHIFT_S(y) (y << 7)
#define CMATH_TEMPERING_SHIFT_T(y) (y << 15)
#define CMATH_TEMPERING_SHIFT_L(y) (y >> 18)
int getTimeMs();
class Random
{
unsigned int rseed;
unsigned long mt[CMATH_N]; // the array for the state vector
int mti; // mti==N+1 means mt[N] is not initialized
public:
Random(long seed = getTimeMs());
void setSeed(long seed);
void init_genrand(unsigned long);
int nextInt(int max);
unsigned genrand_int32();
float nextFloat();
double genrand_real2();
long nextLong();
int nextInt();
};