namespace {
- int generate_white_pawn_captures(const Position &pos, MoveStack *mlist);
- int generate_black_pawn_captures(const Position &pos, MoveStack *mlist);
- int generate_white_pawn_noncaptures(const Position &pos, MoveStack *mlist);
- int generate_black_pawn_noncaptures(const Position &pos, MoveStack *mlist);
- int generate_knight_moves(const Position &pos, MoveStack *mlist,
- Color side, Bitboard target);
- int generate_bishop_moves(const Position &pos, MoveStack *mlist,
- Color side, Bitboard target);
- int generate_rook_moves(const Position &pos, MoveStack *mlist,
- Color side, Bitboard target);
- int generate_queen_moves(const Position &pos, MoveStack *mlist,
- Color side, Bitboard target);
- int generate_king_moves(const Position &pos, MoveStack *mlist,
- Square from, Bitboard target);
- int generate_castle_moves(const Position &pos, MoveStack *mlist, Color us);
+ int generate_white_pawn_captures(const Position&, MoveStack*);
+ int generate_black_pawn_captures(const Position&, MoveStack*);
+ int generate_white_pawn_noncaptures(const Position&, MoveStack*);
+ int generate_black_pawn_noncaptures(const Position&, MoveStack*);
+ int generate_knight_moves(const Position&, MoveStack*, Color side, Bitboard t);
+ int generate_bishop_moves(const Position&, MoveStack*, Color side, Bitboard t);
+ int generate_rook_moves(const Position&, MoveStack*, Color side, Bitboard t);
+ int generate_queen_moves(const Position&, MoveStack*, Color side, Bitboard t);
+ int generate_king_moves(const Position&, MoveStack*, Square from, Bitboard t);
+ int generate_castle_moves(const Position&, MoveStack*, Color us);
}
/// generate_captures generates() all pseudo-legal captures and queen
/// promotions. The return value is the number of moves generated.
-int generate_captures(const Position &pos, MoveStack *mlist) {
- Color us = pos.side_to_move();
- Bitboard target = pos.pieces_of_color(opposite_color(us));
- int n = 0;
+int generate_captures(const Position& pos, MoveStack* mlist) {
assert(pos.is_ok());
assert(!pos.is_check());
- if(us == WHITE)
- n += generate_white_pawn_captures(pos, mlist);
+ Color us = pos.side_to_move();
+ Bitboard target = pos.pieces_of_color(opposite_color(us));
+ int n;
+
+ if (us == WHITE)
+ n = generate_white_pawn_captures(pos, mlist);
else
- n += generate_black_pawn_captures(pos, mlist);
+ n = generate_black_pawn_captures(pos, mlist);
+
n += generate_knight_moves(pos, mlist+n, us, target);
n += generate_bishop_moves(pos, mlist+n, us, target);
n += generate_rook_moves(pos, mlist+n, us, target);
n += generate_queen_moves(pos, mlist+n, us, target);
n += generate_king_moves(pos, mlist+n, pos.king_square(us), target);
-
return n;
}
/// generate_noncaptures() generates all pseudo-legal non-captures and
/// underpromotions. The return value is the number of moves generated.
-int generate_noncaptures(const Position &pos, MoveStack *mlist) {
- Color us = pos.side_to_move();
- Bitboard target = pos.empty_squares();
- int n = 0;
+int generate_noncaptures(const Position& pos, MoveStack *mlist) {
assert(pos.is_ok());
assert(!pos.is_check());
- if(us == WHITE)
- n += generate_white_pawn_noncaptures(pos, mlist);
+ Color us = pos.side_to_move();
+ Bitboard target = pos.empty_squares();
+ int n;
+
+ if (us == WHITE)
+ n = generate_white_pawn_noncaptures(pos, mlist);
else
- n += generate_black_pawn_noncaptures(pos, mlist);
+ n = generate_black_pawn_noncaptures(pos, mlist);
+
n += generate_knight_moves(pos, mlist+n, us, target);
n += generate_bishop_moves(pos, mlist+n, us, target);
n += generate_rook_moves(pos, mlist+n, us, target);
n += generate_queen_moves(pos, mlist+n, us, target);
n += generate_king_moves(pos, mlist+n, pos.king_square(us), target);
n += generate_castle_moves(pos, mlist+n, us);
-
return n;
}
/// checks, except castling moves (will add this later). It returns the
/// number of generated moves.
-int generate_checks(const Position &pos, MoveStack *mlist, Bitboard dc) {
+int generate_checks(const Position& pos, MoveStack* mlist, Bitboard dc) {
+
+ assert(pos.is_ok());
+ assert(!pos.is_check());
+
Color us, them;
Square ksq, from, to;
Bitboard empty, checkSqs, b1, b2, b3;
int n = 0;
- assert(pos.is_ok());
- assert(!pos.is_check());
-
us = pos.side_to_move();
them = opposite_color(us);
// Pawn moves. This is somewhat messy, and we use separate code for white
// and black, because we can't shift by negative numbers in C/C++. :-(
- if(us == WHITE) {
+ if (us == WHITE)
+ {
// Pawn moves which give discovered check. This is possible only if the
// pawn is not on the same file as the enemy king, because we don't
// generate captures.
/// function is very ugly, and needs cleaning up some time later. FIXME
int generate_evasions(const Position &pos, MoveStack *mlist) {
+
+ assert(pos.is_ok());
+ assert(pos.is_check());
+
Color us, them;
Bitboard checkers = pos.checkers();
Bitboard pinned, b1, b2;
Square ksq, from, to;
int n = 0;
- assert(pos.is_ok());
- assert(pos.is_check());
-
us = pos.side_to_move();
them = opposite_color(us);
b1 = pos.pawn_attacks(them, checksq) & pos.pawns(us) & ~pinned;
while(b1) {
from = pop_1st_bit(&b1);
- if(pawn_rank(us, checksq) == RANK_8) {
+ if(relative_rank(us, checksq) == RANK_8) {
mlist[n++].move = make_promotion_move(from, checksq, QUEEN);
mlist[n++].move = make_promotion_move(from, checksq, ROOK);
mlist[n++].move = make_promotion_move(from, checksq, BISHOP);
/// very hard to write an efficient legal move generator, but for the moment
/// we don't need it.
-int generate_legal_moves(const Position &pos, MoveStack *mlist) {
+int generate_legal_moves(const Position& pos, MoveStack* mlist) {
+
assert(pos.is_ok());
- if(pos.is_check())
- return generate_evasions(pos, mlist);
- else {
- int i, n;
- Bitboard pinned = pos.pinned_pieces(pos.side_to_move());
+ if (pos.is_check())
+ return generate_evasions(pos, mlist);
- // Generate pseudo-legal moves:
- n = generate_captures(pos, mlist);
- n += generate_noncaptures(pos, mlist + n);
+ // Generate pseudo-legal moves:
+ int n = generate_captures(pos, mlist);
+ n += generate_noncaptures(pos, mlist + n);
- // Remove illegal moves from the list:
- for(i = 0; i < n; i++) {
- if(!pos.move_is_legal(mlist[i].move, pinned))
- mlist[i--].move = mlist[--n].move;
- }
+ Bitboard pinned = pos.pinned_pieces(pos.side_to_move());
- return n;
- }
+ // Remove illegal moves from the list:
+ for (int i = 0; i < n; i++)
+ if (!pos.move_is_legal(mlist[i].move, pinned))
+ mlist[i--].move = mlist[--n].move;
+
+ return n;
}
/// only be used when the side to move is not in check.
Move generate_move_if_legal(const Position &pos, Move m, Bitboard pinned) {
- Color us, them;
- Square from, to;
- Piece pc;
assert(pos.is_ok());
assert(!pos.is_check());
assert(move_is_ok(m));
- us = pos.side_to_move();
- them = opposite_color(us);
- from = move_from(m);
- pc = pos.piece_on(from);
+ Color us = pos.side_to_move();
+ Color them = opposite_color(us);
+ Square from = move_from(m);
+ Piece pc = pos.piece_on(from);
// If the from square is not occupied by a piece belonging to the side to
// move, the move is obviously not legal.
- if(color_of_piece(pc) != us )
- return MOVE_NONE;
+ if (color_of_piece(pc) != us)
+ return MOVE_NONE;
- to = move_to(m);
+ Square to = move_to(m);
- // En passant moves:
- if(move_is_ep(m)) {
+ // En passant moves
+ if (move_is_ep(m))
+ {
+ // The piece must be a pawn and destination square must be the
+ // en passant square.
+ if ( type_of_piece(pc) != PAWN
+ || to != pos.ep_square())
+ return MOVE_NONE;
- // The piece must be a pawn:
- if(type_of_piece(pc) != PAWN)
- return MOVE_NONE;
+ assert(pos.square_is_empty(to));
+ assert(pos.piece_on(to - pawn_push(us)) == pawn_of_color(them));
- // The destination square must be the en passant square:
- if(to != pos.ep_square())
- return MOVE_NONE;
+ // The move is pseudo-legal. If it is legal, return it.
+ return (pos.move_is_legal(m) ? m : MOVE_NONE);
+ }
- assert(pos.square_is_empty(to));
- assert(pos.piece_on(to - pawn_push(us)) == pawn_of_color(them));
+ // Castling moves
+ if (move_is_short_castle(m))
+ {
+ // The piece must be a king and side to move must still have
+ // the right to castle kingside.
+ if ( type_of_piece(pc) != KING
+ ||!pos.can_castle_kingside(us))
+ return MOVE_NONE;
- // The move is pseudo-legal. If it is legal, return it.
- if(pos.move_is_legal(m))
- return m;
- else
- return MOVE_NONE;
+ assert(from == pos.king_square(us));
+ assert(to == pos.initial_kr_square(us));
+ assert(pos.piece_on(to) == rook_of_color(us));
+
+ Square g1 = relative_square(us, SQ_G1);
+ Square f1 = relative_square(us, SQ_F1);
+ Square s;
+ bool illegal = false;
+
+ // Check if any of the squares between king and rook
+ // is occupied or under attack.
+ for (s = Min(from, g1); s <= Max(from, g1); s++)
+ if ( (s != from && s != to && !pos.square_is_empty(s))
+ || pos.square_is_attacked(s, them))
+ illegal = true;
+
+ // Check if any of the squares between king and rook
+ // is occupied.
+ for (s = Min(to, f1); s <= Max(to, f1); s++)
+ if (s != from && s != to && !pos.square_is_empty(s))
+ illegal = true;
+
+ return (!illegal ? m : MOVE_NONE);
}
- // Castling moves:
- else if(move_is_short_castle(m)) {
+ if (move_is_long_castle(m))
+ {
+ // The piece must be a king and side to move must still have
+ // the right to castle kingside.
+ if ( type_of_piece(pc) != KING
+ ||!pos.can_castle_queenside(us))
+ return MOVE_NONE;
- // The piece must be a king:
- if(type_of_piece(pc) != KING)
- return MOVE_NONE;
+ assert(from == pos.king_square(us));
+ assert(to == pos.initial_qr_square(us));
+ assert(pos.piece_on(to) == rook_of_color(us));
- // The side to move must still have the right to castle kingside:
- if(!pos.can_castle_kingside(us))
- return MOVE_NONE;
+ Square c1 = relative_square(us, SQ_C1);
+ Square d1 = relative_square(us, SQ_D1);
+ Square s;
+ bool illegal = false;
- assert(from == pos.king_square(us));
- assert(to == pos.initial_kr_square(us));
- assert(pos.piece_on(to) == rook_of_color(us));
-
- Square g1 = relative_square(us, SQ_G1);
- Square f1 = relative_square(us, SQ_F1);
- Square s;
- bool illegal = false;
-
- for(s = Min(from, g1); s <= Max(from, g1); s++)
- if((s != from && s != to && !pos.square_is_empty(s)) ||
- pos.square_is_attacked(s, them))
- illegal = true;
- for(s = Min(to, f1); s <= Max(to, f1); s++)
- if(s != from && s != to && !pos.square_is_empty(s))
- illegal = true;
-
- if(!illegal)
- return m;
- else
- return MOVE_NONE;
- }
- else if(move_is_long_castle(m)) {
+ for (s = Min(from, c1); s <= Max(from, c1); s++)
+ if( (s != from && s != to && !pos.square_is_empty(s))
+ || pos.square_is_attacked(s, them))
+ illegal = true;
- // The piece must be a king:
- if(type_of_piece(pc) != KING)
- return MOVE_NONE;
+ for (s = Min(to, d1); s <= Max(to, d1); s++)
+ if(s != from && s != to && !pos.square_is_empty(s))
+ illegal = true;
- // The side to move must still have the right to castle kingside:
- if(!pos.can_castle_queenside(us))
- return MOVE_NONE;
+ if ( square_file(to) == FILE_B
+ && ( pos.piece_on(to + DELTA_W) == rook_of_color(them)
+ || pos.piece_on(to + DELTA_W) == queen_of_color(them)))
+ illegal = true;
- assert(from == pos.king_square(us));
- assert(to == pos.initial_qr_square(us));
- assert(pos.piece_on(to) == rook_of_color(us));
-
- Square c1 = relative_square(us, SQ_C1);
- Square d1 = relative_square(us, SQ_D1);
- Square s;
- bool illegal = false;
-
- for(s = Min(from, c1); s <= Max(from, c1); s++)
- if((s != from && s != to && !pos.square_is_empty(s)) ||
- pos.square_is_attacked(s, them))
- illegal = true;
- for(s = Min(to, d1); s <= Max(to, d1); s++)
- if(s != from && s != to && !pos.square_is_empty(s))
- illegal = true;
- if(square_file(to) == FILE_B &&
- (pos.piece_on(to + DELTA_W) == rook_of_color(them) ||
- pos.piece_on(to + DELTA_W) == queen_of_color(them)))
- illegal = true;
-
- if(!illegal)
- return m;
- else
- return MOVE_NONE;
+ return (!illegal ? m : MOVE_NONE);
}
// Normal moves
- else {
- // The destination square cannot be occupied by a friendly piece:
- if(pos.color_of_piece_on(to) == us)
+ // The destination square cannot be occupied by a friendly piece
+ if (pos.color_of_piece_on(to) == us)
return MOVE_NONE;
- // Proceed according to the type of the moving piece.
- switch(type_of_piece(pc)) {
-
- case PAWN:
- // Pawn moves, as usual, are somewhat messy.
- if(us == WHITE) {
- // If the destination square is on the 8th rank, the move must be a
- // promotion.
- if(square_rank(to) == RANK_8 && !move_promotion(m))
+ // Proceed according to the type of the moving piece.
+ if (type_of_piece(pc) == PAWN)
+ {
+ // If the destination square is on the 8/1th rank, the move must
+ // be a promotion.
+ if ( ( (square_rank(to) == RANK_8 && us == WHITE)
+ ||(square_rank(to) == RANK_1 && us != WHITE))
+ && !move_promotion(m))
return MOVE_NONE;
-
- // Proceed according to the square delta between the source and
- // destionation squares.
- switch(to - from) {
-
- case DELTA_NW: case DELTA_NE:
- // Capture. The destination square must be occupied by an enemy piece
- // (en passant captures was handled earlier).
- if(pos.color_of_piece_on(to) != them)
- return MOVE_NONE;
- break;
- case DELTA_N:
- // Pawn push. The destination square must be empty.
- if(!pos.square_is_empty(to))
- return MOVE_NONE;
+ // Proceed according to the square delta between the source and
+ // destionation squares.
+ switch (to - from)
+ {
+ case DELTA_NW:
+ case DELTA_NE:
+ case DELTA_SW:
+ case DELTA_SE:
+ // Capture. The destination square must be occupied by an enemy
+ // piece (en passant captures was handled earlier).
+ if (pos.color_of_piece_on(to) != them)
+ return MOVE_NONE;
break;
- case DELTA_NN:
- // Double pawn push. The destination square must be on the fourth
- // rank, and both the destination square and the square between the
- // source and destination squares must be empty.
- if(square_rank(to) != RANK_4 || !pos.square_is_empty(to) ||
- !pos.square_is_empty(from + DELTA_N))
- return MOVE_NONE;
+ case DELTA_N:
+ case DELTA_S:
+ // Pawn push. The destination square must be empty.
+ if (!pos.square_is_empty(to))
+ return MOVE_NONE;
break;
-
- default:
- return MOVE_NONE;
- }
- }
- else { // (us == BLACK)
- // If the destination square is on the 1st rank, the move must be a
- // promotion.
- if(square_rank(to) == RANK_1 && !move_promotion(m))
+
+ case DELTA_NN:
+ // Double white pawn push. The destination square must be on the fourth
+ // rank, and both the destination square and the square between the
+ // source and destination squares must be empty.
+ if ( square_rank(to) != RANK_4
+ || !pos.square_is_empty(to)
+ || !pos.square_is_empty(from + DELTA_N))
return MOVE_NONE;
-
- // Proceed according to the square delta between the source and
- // destionation squares.
- switch(to - from) {
-
- case DELTA_SW: case DELTA_SE:
- // Capture. The destination square must be occupied by an enemy piece
- // (en passant captures was handled earlier).
- if(pos.color_of_piece_on(to) != them)
- return MOVE_NONE;
break;
-
- case DELTA_S:
- // Pawn push. The destination square must be empty.
- if(!pos.square_is_empty(to))
- return MOVE_NONE;
- break;
-
- case DELTA_SS:
- // Double pawn push. The destination square must be on the fifth
- // rank, and both the destination square and the square between the
- // source and destination squares must be empty.
- if(square_rank(to) != RANK_5 || !pos.square_is_empty(to) ||
- !pos.square_is_empty(from + DELTA_S))
- return MOVE_NONE;
+
+ case DELTA_SS:
+ // Double black pawn push. The destination square must be on the fifth
+ // rank, and both the destination square and the square between the
+ // source and destination squares must be empty.
+ if ( square_rank(to) != RANK_5
+ || !pos.square_is_empty(to)
+ || !pos.square_is_empty(from + DELTA_S))
+ return MOVE_NONE;
break;
-
- default:
+
+ default:
return MOVE_NONE;
- }
}
// The move is pseudo-legal. Return it if it is legal.
- if(pos.move_is_legal(m))
- return m;
- else
- return MOVE_NONE;
- break;
-
- case KNIGHT:
- if(pos.knight_attacks_square(from, to) && pos.move_is_legal(m) &&
- !move_promotion(m))
- return m;
- else
- return MOVE_NONE;
- break;
-
- case BISHOP:
- if(pos.bishop_attacks_square(from, to) && pos.move_is_legal(m) &&
- !move_promotion(m))
- return m;
- else
- return MOVE_NONE;
- break;
-
- case ROOK:
- if(pos.rook_attacks_square(from, to) && pos.move_is_legal(m) &&
- !move_promotion(m))
- return m;
- else
- return MOVE_NONE;
- break;
-
- case QUEEN:
- if(pos.queen_attacks_square(from, to) && pos.move_is_legal(m) &&
- !move_promotion(m))
- return m;
- else
- return MOVE_NONE;
- break;
-
- case KING:
- if(pos.king_attacks_square(from, to) && pos.move_is_legal(m) &&
- !move_promotion(m))
- return m;
- else
- return MOVE_NONE;
- break;
-
- default:
- assert(false);
- }
+ return (pos.move_is_legal(m) ? m : MOVE_NONE);
}
- assert(false);
- return MOVE_NONE;
+ // Luckly we can handle all the other pieces in one go
+ return ( pos.piece_attacks_square(from, to)
+ && pos.move_is_legal(m)
+ && !move_promotion(m) ? m : MOVE_NONE);
}
return n;
}
-
+
int generate_knight_moves(const Position &pos, MoveStack *mlist,
Color side, Bitboard target) {
Square from, to;
projects / stockfish / blobdiff