void init_attacks();
void init_between_bitboards();
void init_pseudo_attacks();
+ SquareDelta squares_delta(Square orig, Square dest);
Bitboard index_to_bitboard(int index, Bitboard mask);
Bitboard sliding_attacks(int sq, Bitboard block, int dirs, int deltas[][2],
int fmin, int fmax, int rmin, int rmax);
return result;
}
+ SquareDelta squares_delta(Square orig, Square dest) {
+
+ const SquareDelta deltas[] = { DELTA_N, DELTA_NE, DELTA_E, DELTA_SE,
+ DELTA_S, DELTA_SW, DELTA_W, DELTA_NW };
+
+ for (int idx = 0; idx < 8; idx++)
+ {
+ Square s = orig + deltas[idx];
+
+ while (square_is_ok(s) && square_distance(s, s - deltas[idx]) == 1)
+ {
+ if (s == dest)
+ return deltas[idx];
+
+ s += deltas[idx];
+ }
+ }
+ return DELTA_NONE;
+ }
+
void init_between_bitboards() {
Square s1, s2, s3;
for (s2 = SQ_A1; s2 <= SQ_H8; s2++)
{
BetweenBB[s1][s2] = EmptyBoardBB;
- d = SquareDelta(DirectionTable[s1][s2]);
-
- if (d == DELTA_NONE)
- continue;
+ d = squares_delta(s1, s2);
- for (s3 = s1 + d; s3 != s2; s3 += d)
- set_bit(&(BetweenBB[s1][s2]), s3);
+ if (d != DELTA_NONE)
+ for (s3 = s1 + d; s3 != s2; s3 += d)
+ set_bit(&(BetweenBB[s1][s2]), s3);
}
}