#pseudorandom hash function

#include <cstdint> #include <iostream> //http://stackoverflow.com/questions/664014/what-integer-hash-function-are-good-that-accepts-an-integer-hash-key //hash a single 32-bit integer unsigned uinthash(unsigned x) { x = ((x >> 16) ^ x) * 0x45d9f3b; x = ((x >> 16) ^ x) * 0x45d9f3b; x = ((x >> 16) ^ x); return x; } //hash a byte array into a 32-bit integer unsigned fnv_hash_1a_32(void *key, int len) { unsigned char *p = static_cast<unsigned char*>(key); unsigned h = 0x811c9dc5; for (int i = 0; i < len; i++) { h = ( h ^ p[i] ) * 0x01000193; } return h; } //2D coordinates, and a world seed uint32_t coordhash(uint32_t seed, uint32_t x, uint32_t y) { //non-comutative hash return uinthash(uinthash(x)) ^ uinthash(y) ^ seed; }