static bool add_pawn_moves(list_t * list, const board_t * board, int to, bool legal, bool stop) {
int me;
int inc;
int pawn;
int from;
int piece;
ASSERT(list!=NULL);
ASSERT(board!=NULL);
ASSERT(SQUARE_IS_OK(to));
ASSERT(legal==true||legal==false);
ASSERT(stop==true||stop==false);
ASSERT(board->square[to]==Empty);
me = board->turn;
inc = PAWN_MOVE_INC(me);
pawn = PAWN_MAKE(me);
from = to - inc;
piece = board->square[from];
if (piece == pawn) { // single push
if (!legal || !is_pinned(board,from,me)) {
if (stop) return true;
add_pawn_move(list,from,to);
}
} else if (piece == Empty && PAWN_RANK(to,me) == Rank4) { // double push
from = to - (2*inc);
if (board->square[from] == pawn) {
if (!legal || !is_pinned(board,from,me)) {
if (stop) return true;
ASSERT(!SQUARE_IS_PROMOTE(to));
LIST_ADD(list,MOVE_MAKE(from,to));
}
}
}
return false;
}
static void add_captures(list_t * list, const board_t * board) {
int me, opp;
int opp_flag;
const sq_t * ptr;
int from, to;
int piece, capture;
ASSERT(list!=NULL);
ASSERT(board!=NULL);
me = board->turn;
opp = COLOUR_OPP(me);
opp_flag = COLOUR_FLAG(opp);
// piece captures
for (ptr = &board->piece[me][0]; (from=*ptr) != SquareNone; ptr++) {
piece = board->square[from];
switch (PIECE_TYPE(piece)) {
case Knight64:
to = from - 33;
if (FLAG_IS(board->square[to],opp_flag)) LIST_ADD(list,MOVE_MAKE(from,to));
to = from - 31;
if (FLAG_IS(board->square[to],opp_flag)) LIST_ADD(list,MOVE_MAKE(from,to));
to = from - 18;
if (FLAG_IS(board->square[to],opp_flag)) LIST_ADD(list,MOVE_MAKE(from,to));
to = from - 14;
if (FLAG_IS(board->square[to],opp_flag)) LIST_ADD(list,MOVE_MAKE(from,to));
to = from + 14;
if (FLAG_IS(board->square[to],opp_flag)) LIST_ADD(list,MOVE_MAKE(from,to));
to = from + 18;
if (FLAG_IS(board->square[to],opp_flag)) LIST_ADD(list,MOVE_MAKE(from,to));
to = from + 31;
if (FLAG_IS(board->square[to],opp_flag)) LIST_ADD(list,MOVE_MAKE(from,to));
to = from + 33;
if (FLAG_IS(board->square[to],opp_flag)) LIST_ADD(list,MOVE_MAKE(from,to));
break;
case Bishop64:
for (to = from-17; (capture=board->square[to]) == Empty; to -= 17)
;
if (FLAG_IS(capture,opp_flag)) LIST_ADD(list,MOVE_MAKE(from,to));
for (to = from-15; (capture=board->square[to]) == Empty; to -= 15)
;
if (FLAG_IS(capture,opp_flag)) LIST_ADD(list,MOVE_MAKE(from,to));
for (to = from+15; (capture=board->square[to]) == Empty; to += 15)
;
if (FLAG_IS(capture,opp_flag)) LIST_ADD(list,MOVE_MAKE(from,to));
for (to = from+17; (capture=board->square[to]) == Empty; to += 17)
;
if (FLAG_IS(capture,opp_flag)) LIST_ADD(list,MOVE_MAKE(from,to));
break;
case Rook64:
for (to = from-16; (capture=board->square[to]) == Empty; to -= 16)
;
if (FLAG_IS(capture,opp_flag)) LIST_ADD(list,MOVE_MAKE(from,to));
for (to = from-1; (capture=board->square[to]) == Empty; to -= 1)
;
if (FLAG_IS(capture,opp_flag)) LIST_ADD(list,MOVE_MAKE(from,to));
for (to = from+1; (capture=board->square[to]) == Empty; to += 1)
;
if (FLAG_IS(capture,opp_flag)) LIST_ADD(list,MOVE_MAKE(from,to));
for (to = from+16; (capture=board->square[to]) == Empty; to += 16)
;
if (FLAG_IS(capture,opp_flag)) LIST_ADD(list,MOVE_MAKE(from,to));
break;
case Queen64:
for (to = from-17; (capture=board->square[to]) == Empty; to -= 17)
;
if (FLAG_IS(capture,opp_flag)) LIST_ADD(list,MOVE_MAKE(from,to));
for (to = from-16; (capture=board->square[to]) == Empty; to -= 16)
;
if (FLAG_IS(capture,opp_flag)) LIST_ADD(list,MOVE_MAKE(from,to));
for (to = from-15; (capture=board->square[to]) == Empty; to -= 15)
;
if (FLAG_IS(capture,opp_flag)) LIST_ADD(list,MOVE_MAKE(from,to));
for (to = from-1; (capture=board->square[to]) == Empty; to -= 1)
;
if (FLAG_IS(capture,opp_flag)) LIST_ADD(list,MOVE_MAKE(from,to));
for (to = from+1; (capture=board->square[to]) == Empty; to += 1)
;
if (FLAG_IS(capture,opp_flag)) LIST_ADD(list,MOVE_MAKE(from,to));
for (to = from+15; (capture=board->square[to]) == Empty; to += 15)
;
if (FLAG_IS(capture,opp_flag)) LIST_ADD(list,MOVE_MAKE(from,to));
for (to = from+16; (capture=board->square[to]) == Empty; to += 16)
;
if (FLAG_IS(capture,opp_flag)) LIST_ADD(list,MOVE_MAKE(from,to));
for (to = from+17; (capture=board->square[to]) == Empty; to += 17)
;
if (FLAG_IS(capture,opp_flag)) LIST_ADD(list,MOVE_MAKE(from,to));
break;
case King64:
to = from - 17;
if (FLAG_IS(board->square[to],opp_flag)) LIST_ADD(list,MOVE_MAKE(from,to));
to = from - 16;
if (FLAG_IS(board->square[to],opp_flag)) LIST_ADD(list,MOVE_MAKE(from,to));
to = from - 15;
if (FLAG_IS(board->square[to],opp_flag)) LIST_ADD(list,MOVE_MAKE(from,to));
to = from - 1;
if (FLAG_IS(board->square[to],opp_flag)) LIST_ADD(list,MOVE_MAKE(from,to));
to = from + 1;
if (FLAG_IS(board->square[to],opp_flag)) LIST_ADD(list,MOVE_MAKE(from,to));
to = from + 15;
if (FLAG_IS(board->square[to],opp_flag)) LIST_ADD(list,MOVE_MAKE(from,to));
to = from + 16;
if (FLAG_IS(board->square[to],opp_flag)) LIST_ADD(list,MOVE_MAKE(from,to));
to = from + 17;
if (FLAG_IS(board->square[to],opp_flag)) LIST_ADD(list,MOVE_MAKE(from,to));
break;
default:
ASSERT(false);
break;
}
}
// pawn captures
if (COLOUR_IS_WHITE(me)) {
for (ptr = &board->pawn[me][0]; (from=*ptr) != SquareNone; ptr++) {
to = from + 15;
if (FLAG_IS(board->square[to],opp_flag)) add_pawn_move(list,from,to);
to = from + 17;
if (FLAG_IS(board->square[to],opp_flag)) add_pawn_move(list,from,to);
// promote
if (SQUARE_RANK(from) == Rank7) {
to = from + 16;
if (board->square[to] == Empty) {
add_promote(list,MOVE_MAKE(from,to));
}
}
}
} else { // black
for (ptr = &board->pawn[me][0]; (from=*ptr) != SquareNone; ptr++) {
to = from - 17;
if (FLAG_IS(board->square[to],opp_flag)) add_pawn_move(list,from,to);
to = from - 15;
if (FLAG_IS(board->square[to],opp_flag)) add_pawn_move(list,from,to);
// promote
if (SQUARE_RANK(from) == Rank2) {
to = from - 16;
if (board->square[to] == Empty) {
add_promote(list,MOVE_MAKE(from,to));
}
}
}
}
}
static void add_moves(list_t * list, const board_t * board) {
int me, opp;
int opp_flag;
const sq_t * ptr;
int from, to;
int piece, capture;
const inc_t * inc_ptr;
int inc;
ASSERT(list!=NULL);
ASSERT(board!=NULL);
me = board->turn;
opp = COLOUR_OPP(me);
opp_flag = COLOUR_FLAG(opp);
// piece moves
for (ptr = &board->piece[me][0]; (from=*ptr) != SquareNone; ptr++) {
piece = board->square[from];
inc_ptr = PIECE_INC(piece);
if (PIECE_IS_SLIDER(piece)) {
for (; (inc=*inc_ptr) != IncNone; inc_ptr++) {
for (to = from+inc; (capture=board->square[to]) == Empty; to += inc) {
LIST_ADD(list,MOVE_MAKE(from,to));
}
if (FLAG_IS(capture,opp_flag)) {
LIST_ADD(list,MOVE_MAKE(from,to));
}
}
} else {
for (; (inc=*inc_ptr) != IncNone; inc_ptr++) {
to = from + inc;
capture = board->square[to];
if (capture == Empty || FLAG_IS(capture,opp_flag)) {
LIST_ADD(list,MOVE_MAKE(from,to));
}
}
}
}
// pawn moves
inc = PAWN_MOVE_INC(me);
for (ptr = &board->pawn[me][0]; (from=*ptr) != SquareNone; ptr++) {
to = from + (inc-1);
if (FLAG_IS(board->square[to],opp_flag)) {
add_pawn_move(list,from,to);
}
to = from + (inc+1);
if (FLAG_IS(board->square[to],opp_flag)) {
add_pawn_move(list,from,to);
}
to = from + inc;
if (board->square[to] == Empty) {
add_pawn_move(list,from,to);
if (PAWN_RANK(from,me) == Rank2) {
to = from + (2*inc);
if (board->square[to] == Empty) {
ASSERT(!SQUARE_IS_PROMOTE(to));
LIST_ADD(list,MOVE_MAKE(from,to));
}
}
}
}
}
static bool add_pawn_captures(list_t * list, const board_t * board, int to, bool legal, bool stop) {
int me;
int inc;
int pawn;
int from;
ASSERT(list!=NULL);
ASSERT(board!=NULL);
ASSERT(SQUARE_IS_OK(to));
ASSERT(legal==true||legal==false);
ASSERT(stop==true||stop==false);
ASSERT(COLOUR_IS(board->square[to],COLOUR_OPP(board->turn)));
me = board->turn;
inc = PAWN_MOVE_INC(me);
pawn = PAWN_MAKE(me);
from = to - (inc-1);
if (board->square[from] == pawn) {
if (!legal || !is_pinned(board,from,me)) {
if (stop) return true;
add_pawn_move(list,from,to);
}
}
from = to - (inc+1);
if (board->square[from] == pawn) {
if (!legal || !is_pinned(board,from,me)) {
if (stop) return true;
add_pawn_move(list,from,to);
}
}
if (board->ep_square != SquareNone
&& to == SQUARE_EP_DUAL(board->ep_square)) {
ASSERT(PAWN_RANK(to,me)==Rank5);
ASSERT(PIECE_IS_PAWN(board->square[to]));
to = board->ep_square;
ASSERT(PAWN_RANK(to,me)==Rank6);
ASSERT(board->square[to]==Empty);
from = to - (inc-1);
if (board->square[from] == pawn) {
if (!legal || !is_pinned(board,from,me)) {
if (stop) return true;
ASSERT(!SQUARE_IS_PROMOTE(to));
LIST_ADD(list,MOVE_MAKE_FLAGS(from,to,MoveEnPassant));
}
}
from = to - (inc+1);
if (board->square[from] == pawn) {
if (!legal || !is_pinned(board,from,me)) {
if (stop) return true;
ASSERT(!SQUARE_IS_PROMOTE(to));
LIST_ADD(list,MOVE_MAKE_FLAGS(from,to,MoveEnPassant));
}
}
}
return false;
}
// Non-capturing checks.
//------------------------------------------------------------------------------
MoveGen *generate_checks(MoveGen *self) {
Position *p = self->p;
int color = p->color, enemy = p->color ^ 1;
int square = (int)p->king[enemy];
// Non-capturing Knight checks.
Bitmask prohibit = maskNone;
Bitmask checks = knightMoves[square];
Bitmask outposts = p->outposts[knight(color)];
while (any(outposts)) {
int from = pop(&outposts);
add_piece_move(self, from, knightMoves[from] & checks & ~p->board);
}
// Non-capturing Bishop or Queen checks.
checks = targets_for(p, square, bishop(enemy));
outposts = p->outposts[bishop(color)] | p->outposts[queen(color)];
while (any(outposts)) {
int from = pop(&outposts);
Bitmask squares = targets_for(p, from, bishop(enemy)) & checks & ~p->outposts[enemy];
while (any(squares)) {
int to = pop(&squares);
Piece piece = p->pieces[to];
if (!piece) {
// Empty square: simply move a bishop to check.
append(self, new_move(p, from, to));
} else if (color(piece) == color && any(maskDiagonal[from][square])) {
// Non-empty square occupied by friendly piece on the same
// diagonal: moving the piece away causes discovered check.
switch (kind(piece)) {
case Pawn:
// Block pawn promotions (since they are treated as
// captures) and en-passant captures.
prohibit = maskRank[0] | maskRank[7];
if (p->enpassant) {
prohibit |= bit[p->enpassant];
}
add_pawn_move(self, to, targets(p, to) & ~p->board & ~prohibit);
break;
case King:
// Make sure the king steps out of attack diaginal.
add_king_move(self, to, targets(p, to) & ~p->board & ~maskBlock[from][square]);
break;
default:
add_piece_move(self, to, targets(p, to) & ~p->board);
}
}
}
if (is_queen(p->pieces[from])) {
// Queen could move straight as a rook and check diagonally as a bishop
// or move diagonally as a bishop and check straight as a rook.
Bitmask squares = (targets_for(p, from, rook(color)) & checks) |
(targets_for(p, from, bishop(color)) & targets_for(p, square, rook(color)));
add_piece_move(self, from, squares & ~p->board);
}
}
// Non-capturing Rook or Queen checks.
checks = targets_for(p, square, rook(enemy));
outposts = p->outposts[rook(color)] | p->outposts[queen(color)];
while (any(outposts)) {
int from = pop(&outposts);
Bitmask squares = targets_for(p, from, rook(enemy)) & checks & ~p->outposts[enemy];
while (any(squares)) {
int to = pop(&squares);
Piece piece = p->pieces[to];
if (!piece) {
// Empty square: simply move a rook to check.
append(self, new_move(p, from, to));
} else if (color(piece) == color) {
if (any(maskStraight[from][square])) {
// Non-empty square occupied by friendly piece on the same
// file or rank: moving the piece away causes discovered check.
switch (kind(piece)) {
case Pawn:
// If pawn and rook share the same file then non-capturing
// discovered check is not possible since the pawn is going
// to stay on the same file no matter what.
if (col(from) == col(to)) {
continue;
}
// Block pawn promotions (since they are treated as captures)
// and en-passant captures.
prohibit = maskRank[0] | maskRank[7];
if (p->enpassant) {
prohibit |= bit[p->enpassant];
}
add_pawn_move(self, to, targets(p, to) & ~p->board & ~prohibit);
break;
case King:
// Make sure the king steps out of attack file or rank.
prohibit = maskNone;
if (row(from) == row(square)) {
prohibit = maskRank[row(from)];
} else {
prohibit = maskFile[col(square)];
}
add_king_move(self, to, targets(p, to) & ~p->board & ~prohibit);
break;
default:
add_piece_move(self, to, targets(p, to) & ~p->board);
}
}
}
}
}
// Non-capturing Pawn checks.
outposts = p->outposts[pawn(color)] & maskIsolated[col(square)];
while (any(outposts)) {
int from = pop(&outposts);
Bitmask target = maskPawn[color][square] & targets(p, from);
if (any(target)) {
append(self, new_pawn_move(p, from, pop(&target)));
}
}
return self;
}
