hashtable.h

#ifndef HASHTABLE_H
#define HASHTABLE_H

// define constants for hash func

#define hash_flag_exact  0
#define hash_flag_alpha  1
#define hash_flag_beta   2
#define no_hash_entry    1000000 // outside alpha beta limits

// random piece keys [piece][square]
extern uint64_t piece_keys[13][64];

// random enpassant keys [square]
extern uint64_t enpassant_keys[64];

// random castling keys
extern uint64_t castle_keys[16];

// random side key
extern uint64_t side_key;

int read_hash_entry(uint64_t hash_key, int alpha, int beta, int depth);
void write_hash_entry(uint64_t hash_key, int score, int depth, int hash_flag);
void init_random_keys();
void clear_hash_table();
uint64_t generate_hash_key(Position &pos);

#endif