hashkeys.c

#include "hashkeys.h"

uint64_t generatePosKey(const S_BOARD *pos) {
    int sq = 0;
    uint64_t finalKey = 0;
    int piece = EMPTY;

    //pieces
    for(sq = 0; sq < BRD_SQ_NUM; sq++) {
        piece = pos->pieces[sq];
        if(piece != NO_SQ && piece != EMPTY && piece != OFFBOARD) {
            ASSERT(piece >= wP && piece<=bK);
            finalKey ^= pieceKeys[piece][sq];
        }
    }

    if(pos->side == WHITE) {
        finalKey ^= sideKey;
    }

    if(pos->enPas != NO_SQ) {
        ASSERT(pos->enPas>=0 && pos->enPas<BRD_SQ_NUM);
        finalKey ^= pieceKeys[EMPTY][pos->enPas];
    }

    ASSERT(pos->castlePerm>=0 && pos->castlePerm<=15);
    finalKey ^= castleKeys[pos->castlePerm];

    return finalKey;
}