#include "bitboard.h"
#include "bitcount.h"
-#include "direction.h"
#if defined(IS_64BIT)
Bitboard ClearMaskBB[65];
Bitboard StepAttackBB[16][64];
-Bitboard RayBB[64][8];
Bitboard BetweenBB[64][64];
Bitboard SquaresInFrontMask[2][64];
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_ray_bitboards();
void init_attacks();
void init_between_bitboards();
void init_pseudo_attacks();
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_ray_bitboards();
init_attacks();
init_between_bitboards();
init_sliding_attacks(RAttacks, RAttackIndex, RMask, RShift, RMult, rookDeltas);
// 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;
BitCount8Bit[b] = (uint8_t)count_1s<CNT32>(b);
}
- int remove_bit_8(int i) { return ((i & ~15) >> 1) | (i & 7); }
-
- void init_ray_bitboards() {
-
- int d[8] = {1, -1, 16, -16, 17, -17, 15, -15};
-
- for (int i = 0; i < 128; i = (i + 9) & ~8)
- for (int j = 0; j < 8; j++)
- {
- RayBB[remove_bit_8(i)][j] = EmptyBoardBB;
- for (int k = i + d[j]; (k & 0x88) == 0; k += d[j])
- set_bit(&(RayBB[remove_bit_8(i)][j]), Square(remove_bit_8(k)));
- }
- }
-
void init_attacks() {
const int step[16][8] = {
void init_between_bitboards() {
- const SquareDelta step[8] = { DELTA_E, DELTA_W, DELTA_N, DELTA_S,
- DELTA_NE, DELTA_SW, DELTA_NW, DELTA_SE };
+ Square s1, s2, s3;
+ SquareDelta d;
- for (Square s1 = SQ_A1; s1 <= SQ_H8; s1++)
- for (Square s2 = SQ_A1; s2 <= SQ_H8; s2++)
+ for (s1 = SQ_A1; s1 <= SQ_H8; s1++)
+ for (s2 = SQ_A1; s2 <= SQ_H8; s2++)
{
BetweenBB[s1][s2] = EmptyBoardBB;
- SignedDirection d = signed_direction_between_squares(s1, s2);
+ d = SquareDelta(DirectionTable[s1][s2]);
- if (d != SIGNED_DIR_NONE)
- {
- for (Square s3 = s1 + step[d]; s3 != s2; s3 += step[d])
- set_bit(&(BetweenBB[s1][s2]), s3);
- }
+ if (d == DELTA_NONE)
+ continue;
+
+ for (s3 = s1 + d; s3 != s2; s3 += d)
+ set_bit(&(BetweenBB[s1][s2]), s3);
}
}