Bitboard QueenPseudoAttacks[64];
uint8_t BitCount8Bit[256];
-int8_t DirectionTable[64][64];
////
namespace {
- SquareDelta get_direction(Square orig, Square dest);
- void init_direction_table();
void init_masks();
void init_attacks();
void init_between_bitboards();
int rookDeltas[4][2] = {{0,1},{0,-1},{1,0},{-1,0}};
int bishopDeltas[4][2] = {{1,1},{-1,1},{1,-1},{-1,-1}};
- init_direction_table();
init_masks();
init_attacks();
- init_between_bitboards();
init_sliding_attacks(RAttacks, RAttackIndex, RMask, RShift, RMult, rookDeltas);
init_sliding_attacks(BAttacks, BAttackIndex, BMask, BShift, BMult, bishopDeltas);
init_pseudo_attacks();
+ init_between_bitboards();
}
// understand, but they all seem to work correctly, and it should never
// be necessary to touch any of them.
- SquareDelta get_direction(Square orig, Square dest) {
-
- const SquareDelta directions[] = {
- DELTA_E, DELTA_N, DELTA_NE, DELTA_NW, DELTA_W, DELTA_S, DELTA_SW, DELTA_SE
- };
-
- for (int idx = 0; idx < 8; idx++)
- {
- Square from = orig;
- Square to = from + directions[idx];
-
- while (to != dest && square_distance(to, from) == 1 && square_is_ok(to))
- {
- from = to;
- to += directions[idx];
- }
-
- if (to == dest && square_distance(from, to) == 1)
- return directions[idx];
- }
- return DELTA_NONE;
- }
-
- void init_direction_table() {
-
- for (Square s1 = SQ_A1; s1 <= SQ_H8; s1++)
- for (Square s2 = SQ_A1; s2 <= SQ_H8; s2++)
- DirectionTable[s1][s2] = uint8_t(get_direction(s1, s2));
- }
-
void init_masks() {
SetMaskBB[SQ_NONE] = 0ULL;
Square s1, s2, s3;
SquareDelta d;
+ int f, r;
for (s1 = SQ_A1; s1 <= SQ_H8; s1++)
for (s2 = SQ_A1; s2 <= SQ_H8; s2++)
{
BetweenBB[s1][s2] = EmptyBoardBB;
- d = SquareDelta(DirectionTable[s1][s2]);
- if (d == DELTA_NONE)
- continue;
+ if (bit_is_set(QueenPseudoAttacks[s1], s2))
+ {
+ f = file_distance(s1, s2);
+ r = rank_distance(s1, s2);
+
+ d = SquareDelta(s2 - s1) / Max(f, r);
- for (s3 = s1 + d; s3 != s2; s3 += d)
- set_bit(&(BetweenBB[s1][s2]), s3);
+ for (s3 = s1 + d; s3 != s2; s3 += d)
+ set_bit(&(BetweenBB[s1][s2]), s3);
+ }
}
}