#include "pcg.h"
// Random number generator.// Based on:// *Really* minimal PCG32 code / (c) 2014 M.E. O'Neill / pcg-random.org// Licensed under Apache License 2.0 (NO WARRANTY, etc. see website)
uint64_t state = 0x853c49e6748fea9bULL;uint64_t inc = 0xda3e39cb94b95bdbULL;
// Update seed of generator.void pcg_seed(uint64_t seed) { state = seed;}
// Generate random integer.uint32_t pcg_rand() { uint64_t oldstate = state; // Advance internal state state = oldstate * 6364136223846793005ULL + (inc|1); // Calculate output function (XSH RR), uses old state for max ILP uint32_t xorshifted = ((oldstate >> 18u) ^ oldstate) >> 27u; uint32_t rot = oldstate >> 59u; return (xorshifted >> rot) | (xorshifted << ((-rot) & 31));}
// Fill out buffer with size random bytes.void pcg_bytes(char* out, int size) { // TODO: We can be more efficient by using all 4 // pieces of the random number returned. for (int i = 0; i < size; i ++) { out[i] = (char)pcg_rand(); }}