Single header, 100 line implementation of 32bit PCG random number generator.
Advantages
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Blazing fast generation of uint32 and 32bit floats in [0,1)
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Each rng class instance only takes 128bits of memory (two uint64)
Disadvantages
Doesn't conform to full C++11 rng engine requirements. It's a very simple rng that produces output fast.
Constructor
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Based on nanosecond clock and thread id
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Should guarantee different rng values in most usecases
- You can also manually seed by providing two uint64_t
- The first being the seed, second the sequence id
Generating rng values
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next() generates a uniformly distributed uint32_t
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next_bounded(uint32_t) generates a bounded uint32_t (exclusive)
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next_float() generates a float in [0,1)
Requires C++11 for default seeding. Specifically <thread> and <chrono>.
#include "pcg.h"
int main() {
// Create new instance of RNG
// Default seed is different for all threads and nanosecond-time based
pcg::pcg32 rng;
for (int i = 0; i < 99; ++i) {
std::cout << rng.next() << std::endl;
std::cout << rng.next_float() << std::endl;
std::cout << rng.next_bounded(101) << std::endl;
}
return 0;
}