Justin Marshall
132 lines
3.8 KiB
C++
132 lines
3.8 KiB
C++
#pragma once
|
|
|
|
#include <cstdint>
|
|
|
|
class idRandom {
|
|
public:
|
|
static const int MAX_RAND = 0x7FFF;
|
|
|
|
int seed;
|
|
|
|
explicit idRandom(const int initialSeed = 0) : seed(initialSeed) {}
|
|
void SetSeed(const int value) { seed = value; }
|
|
int GetSeed() const { return seed; }
|
|
|
|
int RandomInt() {
|
|
seed = static_cast<int>(1103515245u * static_cast<unsigned int>(seed) + 12345u);
|
|
return (static_cast<unsigned int>(seed) >> 16) & MAX_RAND;
|
|
}
|
|
|
|
int RandomInt(const int max) {
|
|
return max == 0 ? 0 : RandomInt() % max;
|
|
}
|
|
|
|
float RandomFloat() { return RandomInt() * (1.0f / 32768.0f); }
|
|
float CRandomFloat() { return 2.0f * RandomFloat() - 1.0f; }
|
|
};
|
|
|
|
class idRandom2 {
|
|
public:
|
|
static const int MAX_RAND = 0x7FFF;
|
|
|
|
unsigned int seed;
|
|
|
|
explicit idRandom2(const unsigned int initialSeed = 0) : seed(initialSeed) {}
|
|
void SetSeed(const unsigned int value) { seed = value; }
|
|
unsigned int GetSeed() const { return seed; }
|
|
|
|
int RandomInt() {
|
|
seed = 1664525u * seed + 1013904223u;
|
|
return static_cast<int>((seed >> 10) & MAX_RAND);
|
|
}
|
|
|
|
int RandomInt(const int max) {
|
|
return max == 0 ? 0 : RandomInt() % max;
|
|
}
|
|
|
|
int RandomInt(const int min, const int max) {
|
|
return min >= max ? min : min + RandomInt(max - min + 1);
|
|
}
|
|
|
|
float RandomFloat() { return RandomInt() * (1.0f / 32768.0f); }
|
|
float CRandomFloat() { return 2.0f * RandomFloat() - 1.0f; }
|
|
|
|
float BellCurve(const int degree) {
|
|
if (degree <= 0) return 0.0f;
|
|
float sum = 0.0f;
|
|
for (int index = 0; index < degree; ++index) sum += CRandomFloat();
|
|
return sum / static_cast<float>(degree);
|
|
}
|
|
};
|
|
|
|
class idRandomMersenneCyclic {
|
|
public:
|
|
unsigned int MT[624];
|
|
};
|
|
|
|
class idRandomWELL1024 {
|
|
public:
|
|
unsigned int seedArray[32];
|
|
unsigned int state_i;
|
|
unsigned int STATE[32];
|
|
};
|
|
|
|
class idRandomMersenne {
|
|
public:
|
|
unsigned int MT[624];
|
|
unsigned int index;
|
|
|
|
explicit idRandomMersenne(const unsigned int seed = 5489u) {
|
|
SetSeed(seed);
|
|
}
|
|
|
|
void SetSeed(const unsigned int seed) {
|
|
MT[0] = seed;
|
|
for (unsigned int i = 1; i < 624; ++i) {
|
|
MT[i] = 1812433253u * (MT[i - 1] ^ (MT[i - 1] >> 30)) + i;
|
|
}
|
|
index = 624;
|
|
}
|
|
|
|
void GenerateNumbers() {
|
|
static const unsigned int mag01[2] = { 0u, 0x9908B0DFu };
|
|
for (unsigned int i = 0; i < 227; ++i) {
|
|
const unsigned int value = (MT[i] & 0x80000000u)
|
|
| (MT[i + 1] & 0x7FFFFFFEu);
|
|
MT[i] = MT[i + 397] ^ (value >> 1) ^ mag01[value & 1u];
|
|
}
|
|
for (unsigned int i = 227; i < 623; ++i) {
|
|
const unsigned int value = (MT[i] & 0x80000000u)
|
|
| (MT[i + 1] & 0x7FFFFFFEu);
|
|
MT[i] = MT[i - 227] ^ (value >> 1) ^ mag01[value & 1u];
|
|
}
|
|
const unsigned int value = (MT[623] & 0x80000000u)
|
|
| (MT[0] & 0x7FFFFFFEu);
|
|
MT[623] = MT[396] ^ (value >> 1) ^ mag01[value & 1u];
|
|
}
|
|
|
|
unsigned int RandomInt() {
|
|
if (index >= 624) {
|
|
index = 0;
|
|
GenerateNumbers();
|
|
}
|
|
unsigned int value = MT[index++];
|
|
value ^= value >> 11;
|
|
value ^= (value << 7) & 0x9D2C5680u;
|
|
value ^= (value << 15) & 0xEFC60000u;
|
|
value ^= value >> 18;
|
|
return value;
|
|
}
|
|
};
|
|
|
|
using idRandomType = idRandom2;
|
|
|
|
static_assert(sizeof(idRandom) == 4, "Recovered idRandom ABI changed");
|
|
static_assert(sizeof(idRandom2) == 4, "Recovered idRandom2 ABI changed");
|
|
static_assert(sizeof(idRandomMersenneCyclic) == 2496,
|
|
"Recovered idRandomMersenneCyclic ABI changed");
|
|
static_assert(sizeof(idRandomWELL1024) == 260,
|
|
"Recovered idRandomWELL1024 ABI changed");
|
|
static_assert(sizeof(idRandomMersenne) == 2500,
|
|
"Recovered idRandomMersenne ABI changed");
|