92 lines
2.0 KiB
C++
92 lines
2.0 KiB
C++
#include "Rand.hpp"
|
|
#include "core/Core.hpp"
|
|
|
|
std::unique_ptr<std::mt19937> Rand::generator;
|
|
|
|
int32_t Rand::rand(int32_t startInclusive, int32_t endExclusive) {
|
|
std::uniform_int_distribution<int32_t> dist(startInclusive, endExclusive - 1);
|
|
return dist(*Rand::generator);
|
|
}
|
|
|
|
int32_t Rand::rand(int32_t endExclusive) {
|
|
return Rand::rand(0, endExclusive);
|
|
}
|
|
|
|
int32_t Rand::rand() {
|
|
return Rand::rand(0, INT32_MAX);
|
|
}
|
|
|
|
int32_t Rand::randWeighted(const std::vector<int32_t>& weights) {
|
|
std::discrete_distribution<int32_t> dist(weights.begin(), weights.end());
|
|
return dist(*Rand::generator);
|
|
}
|
|
|
|
float Rand::randFloat(float startInclusive, float endExclusive) {
|
|
std::uniform_real_distribution<float> dist(startInclusive, endExclusive);
|
|
return dist(*Rand::generator);
|
|
}
|
|
|
|
float Rand::randFloat(float endExclusive) {
|
|
return Rand::randFloat(0.0f, endExclusive);
|
|
}
|
|
|
|
float Rand::randFloat() {
|
|
return Rand::randFloat(0.0f, 1.0f);
|
|
}
|
|
|
|
#define RANDBYTES 8
|
|
|
|
/*
|
|
* Cryptographically secure RNG. Borrowed from bcrypt_gensalt().
|
|
*/
|
|
uint64_t Rand::cryptoRand() {
|
|
uint8_t buf[RANDBYTES];
|
|
|
|
#ifdef _WIN32
|
|
HCRYPTPROV p;
|
|
|
|
// Acquire a crypt context for generating random bytes.
|
|
if (CryptAcquireContext(&p, NULL, NULL, PROV_RSA_FULL, CRYPT_VERIFYCONTEXT) == FALSE) {
|
|
goto fail;
|
|
}
|
|
|
|
if (CryptGenRandom(p, RANDBYTES, (BYTE*)buf) == FALSE) {
|
|
goto fail;
|
|
}
|
|
|
|
if (CryptReleaseContext(p, 0) == FALSE) {
|
|
goto fail;
|
|
}
|
|
#else
|
|
int fd;
|
|
|
|
// Get random bytes on Unix/Linux.
|
|
fd = open("/dev/urandom", O_RDONLY);
|
|
if (fd < 0) {
|
|
perror("open");
|
|
goto fail;
|
|
}
|
|
|
|
if (read(fd, buf, RANDBYTES) < RANDBYTES) {
|
|
perror("read");
|
|
close(fd);
|
|
goto fail;
|
|
}
|
|
|
|
close(fd);
|
|
#endif
|
|
|
|
return *(uint64_t*)buf;
|
|
|
|
fail:
|
|
std::cout << "[FATAL] Failed to generate cryptographic random number" << std::endl;
|
|
terminate(0);
|
|
|
|
/* not reached */
|
|
return 0;
|
|
}
|
|
|
|
void Rand::init(uint64_t seed) {
|
|
Rand::generator = std::make_unique<std::mt19937>(std::mt19937(seed));
|
|
}
|