commit fc119e18b95848c33f4e6946dca18144a49605cd
parent 6356b872286c6657aef4ae4c02b9243b6510b448
Author: Dimitrije Dobrota <mail@dimitrijedobrota.com>
Date: Sat, 24 Sep 2022 18:34:28 +0200
Move generation refactoring and bug fixing
Diffstat:
2 files changed, 58 insertions(+), 90 deletions(-)
diff --git a/include/utils.h b/include/utils.h
@@ -24,6 +24,9 @@ extern const U64 notHFile;
int bit_count(U64 bitboard);
int bit_lsb_index(U64 bitboard);
+#define bitboard_for_each_bit(var, bb) \
+ for (var = bit_lsb_index(bb); bb; bit_pop(bb, var), var = bit_lsb_index(bb))
+
void bitboard_print(U64 bitboard);
// squares
diff --git a/src/engine.c b/src/engine.c
@@ -92,7 +92,7 @@ typedef U32 Move;
void Move_print(Move move) {
int promote = Move_promote(move);
- printf("%5s %5s %6s %10s %10d %10d %10d %10d\n",
+ printf("%5s %5s %5s %5s %4d %4d %4d %4d\n",
square_to_coordinates[Move_source(move)],
square_to_coordinates[Move_target(move)],
Piece_fromInex(Move_piece(move))->unicode,
@@ -118,8 +118,7 @@ void MoveList_add(MoveList_T self, Move move) {
}
void MoveList_print(MoveList_T self) {
- printf(" From To P Promote Capture Double Enpassant "
- "Castle\n");
+ printf(" From To Pi Prmt Cap Dbl Enp Cst\n");
for (int i = 0; i < self->count; i++)
Move_print(self->moves[i]);
printf("Total: %d\n", self->count);
@@ -219,122 +218,86 @@ int CBoard_square_isAttack(CBoard_T self, Square square, eColor side) {
return 0;
}
-int square_index_extractor(U64 btbrd) {
- static U64 bitboard;
+#define pawn_promotion(color, source) \
+ ((color == WHITE && source >= a7 && source <= h7) || \
+ (color == BLACK && source >= a2 && source <= h2))
- if (btbrd != no_sq)
- bitboard = btbrd;
+#define pawn_start(color, source) \
+ ((color == BLACK && source >= a7 && source <= h7) || \
+ (color == WHITE && source >= a2 && source <= h2))
- if (bitboard == C64(0))
- return no_sq;
-
- int index = bit_lsb_index(bitboard);
- bit_pop(bitboard, index);
- return index;
-}
+#define pawn_promote(source, target, index, take) \
+ for (int i = 1; i < 6; i++) { \
+ move = Move_encode(source, target, index, Piece_index(&Pieces[color][i]), \
+ 0, 0, 0, 0); \
+ MoveList_add(moves, move); \
+ }
MoveList_T CBoard_move_generate(CBoard_T self, eColor color) {
MoveList_T moves;
Move move;
- Square source, target;
- U64 bitboard, attack;
+ Square src, tgt;
U64 occupancy = self->colorBB[WHITE] | self->colorBB[BLACK];
moves = MoveList_new();
- // Generate quiet pawn moves
- {
+
+ { // pawn moves
Piece_T Piece = &Pieces[color][PAWN];
int index = Piece_index(Piece);
- bitboard = self->pieceBB[PAWN] & self->colorBB[color];
- while (bitboard) {
- // push
- {
+ U64 bitboard = self->pieceBB[PAWN] & self->colorBB[color];
+ bitboard_for_each_bit(src, bitboard) {
+ { // quiet
int add = (color == WHITE) ? +8 : -8;
- target = source = bit_lsb_index(bitboard);
- target += add;
- if (target > a1 && target < h8 && !bit_get(occupancy, target)) {
- // promote
- if ((color == WHITE && source >= a7 && source <= h7) ||
- (color == BLACK && source >= a2 && source <= h2)) {
- for (int i = 1; i < 6; i++) {
- move = Move_encode(source, target, index,
- Piece_index(&Pieces[color][i]), 0, 0, 0, 0);
- MoveList_add(moves, move);
- }
+ tgt = src + add;
+ if (tgt > a1 && tgt < h8 && !bit_get(occupancy, tgt)) {
+ if (pawn_promotion(color, src)) {
+ pawn_promote(src, tgt, index, 0);
} else {
- MoveList_add(moves,
- Move_encode(source, target, index, 0, 0, 0, 0, 0));
+ MoveList_add(moves, Move_encode(src, tgt, index, 0, 0, 0, 0, 0));
// two ahead
- target += add;
- if (((color == BLACK && source >= a7 && source <= h7) ||
- (color == WHITE && source >= a2 && source <= h2)) &&
- !bit_get(occupancy, target)) {
- MoveList_add(moves,
- Move_encode(source, target, index, 0, 0, 1, 0, 0));
- }
+ if (pawn_start(color, src) && !bit_get(occupancy, tgt += add))
+ MoveList_add(moves, Move_encode(src, tgt, index, 0, 0, 1, 0, 0));
}
}
}
- // Capture
- {
- attack = Piece->attacks(source, occupancy) & self->colorBB[!color];
- while (attack) {
- target = bit_lsb_index(attack);
- bit_pop(attack, target);
- if ((color == WHITE && source >= a7 && source <= h7) ||
- (color == BLACK && source >= a2 && source <= h2)) {
- for (int i = 1; i < 6; i++) {
- move = Move_encode(source, target, index,
- Piece_index(&Pieces[color][i]), 1, 0, 0, 0);
- MoveList_add(moves, move);
- }
+ { // capture
+ U64 attack = Piece->attacks(src, occupancy) & self->colorBB[!color];
+ bitboard_for_each_bit(tgt, attack) {
+ if (pawn_promotion(color, src)) {
+ pawn_promote(src, tgt, index, 1);
} else {
- MoveList_add(moves,
- Move_encode(source, target, index, 0, 1, 0, 0, 0));
+ MoveList_add(moves, Move_encode(src, tgt, index, 0, 1, 0, 0, 0));
}
}
}
- // enpassant
- {
- if (self->enpassant != no_sq) {
- attack =
- Piece->attacks(source, occupancy) & (C64(1) << self->enpassant);
- if (attack) {
- target = bit_lsb_index(attack);
- MoveList_add(moves,
- Move_encode(source, target, index, 0, 1, 0, 1, 0));
- }
- }
+
+ { // en passant
+ U64 attack = Piece->attacks(src, occupancy);
+ if (self->enpassant != no_sq && attack & (C64(1) << self->enpassant))
+ MoveList_add(moves, Move_encode(src, bit_lsb_index(attack), index, 0,
+ 1, 0, 1, 0));
}
- bit_pop(bitboard, source);
}
+ }
- for (int piece = 1; piece <= 6; piece++) {
- bitboard = self->pieceBB[piece] & self->colorBB[color];
- Piece_T Piece = &Pieces[color][piece];
- int index = Piece_index(Piece);
- while (bitboard) {
- source = bit_lsb_index(bitboard);
- bit_pop(bitboard, source);
- attack = Piece->attacks(source, occupancy) & ~self->colorBB[color];
- while (attack) {
- target = bit_lsb_index(attack);
- if (bit_get(self->colorBB[!color], target))
- MoveList_add(moves,
- Move_encode(source, target, index, 0, 1, 0, 0, 0));
- else
- MoveList_add(moves,
- Move_encode(source, target, index, 0, 0, 0, 0, 0));
- bit_pop(attack, target);
- }
+ // All piece move
+ for (int piece = 1; piece < 6; piece++) {
+ Piece_T Piece = &Pieces[color][piece];
+ U64 bitboard = self->pieceBB[piece] & self->colorBB[color];
+ bitboard_for_each_bit(src, bitboard) {
+ U64 attack = Piece->attacks(src, occupancy) & ~self->colorBB[color];
+ bitboard_for_each_bit(tgt, attack) {
+ int take = bit_get(self->colorBB[!color], tgt);
+ MoveList_add(
+ moves, Move_encode(src, tgt, Piece_index(Piece), 0, take, 0, 0, 0));
}
}
}
// Castling
{
- if (!CBoard_square_isAttack(self, e1, BLACK)) {
+ if (color == WHITE && !CBoard_square_isAttack(self, e1, BLACK)) {
int index = Piece_index(&Pieces[WHITE][KING]);
if (self->castle & WK && !bit_get(occupancy, f1) &&
!bit_get(occupancy, g1)) {
@@ -346,7 +309,7 @@ MoveList_T CBoard_move_generate(CBoard_T self, eColor color) {
}
}
- if (!CBoard_square_isAttack(self, e1, WHITE)) {
+ if (color == BLACK && !CBoard_square_isAttack(self, e8, WHITE)) {
int index = Piece_index(&Pieces[BLACK][KING]);
if (self->castle & BK && !bit_get(occupancy, f8) &&
!bit_get(occupancy, g8)) {
@@ -426,7 +389,9 @@ int main(void) {
CBoard_T board;
MoveList_T moves;
- CBoard_print(board = CBoard_fromFEN(NULL, tricky_position));
+ CBoard_print(board = CBoard_fromFEN(NULL,
+ "r3k2r/p1ppqpb1/bn2pnp1/3PN3/1p2P3/"
+ "2N2Q1p/PPPBBPPP/R3K2R w KQkq c6 0 1 "));
MoveList_print(CBoard_move_generate(board, WHITE));
MoveList_print(CBoard_move_generate(board, BLACK));
