using std::cout;
using std::endl;
-static inline bool isZero(char c) { return c == '0'; }
-struct PieceLetters : public std::map<char, Piece> {
+////
+//// Position's static data definitions
+////
+
+Key Position::zobrist[2][8][64];
+Key Position::zobEp[64];
+Key Position::zobCastle[16];
+Key Position::zobSideToMove;
+Key Position::zobExclusion;
+
+Score Position::PieceSquareTable[16][64];
+
+// Material values arrays, indexed by Piece
+const Value Position::PieceValueMidgame[17] = {
+ VALUE_ZERO,
+ PawnValueMidgame, KnightValueMidgame, BishopValueMidgame,
+ RookValueMidgame, QueenValueMidgame, VALUE_ZERO,
+ VALUE_ZERO, VALUE_ZERO,
+ PawnValueMidgame, KnightValueMidgame, BishopValueMidgame,
+ RookValueMidgame, QueenValueMidgame
+};
+
+const Value Position::PieceValueEndgame[17] = {
+ VALUE_ZERO,
+ PawnValueEndgame, KnightValueEndgame, BishopValueEndgame,
+ RookValueEndgame, QueenValueEndgame, VALUE_ZERO,
+ VALUE_ZERO, VALUE_ZERO,
+ PawnValueEndgame, KnightValueEndgame, BishopValueEndgame,
+ RookValueEndgame, QueenValueEndgame
+};
+
+// Material values array used by SEE, indexed by PieceType
+const Value Position::seeValues[] = {
+ VALUE_ZERO,
+ PawnValueMidgame, KnightValueMidgame, BishopValueMidgame,
+ RookValueMidgame, QueenValueMidgame, QueenValueMidgame*10
+};
+
+
+namespace {
+
+ // Bonus for having the side to move (modified by Joona Kiiski)
+ const Score TempoValue = make_score(48, 22);
+
+ bool isZero(char c) { return c == '0'; }
+
+ struct PieceLetters : public std::map<char, Piece> {
PieceLetters() {
operator[]('B') = WB; operator[]('b') = BB;
operator[]('N') = WN; operator[]('n') = BN;
operator[]('P') = WP; operator[]('p') = BP;
- operator[](' ') = PIECE_NONE; operator[]('.') = PIECE_NONE_DARK_SQ;
+ operator[](' ') = PIECE_NONE;
+ operator[]('.') = PIECE_NONE_DARK_SQ;
}
char from_piece(Piece p) const {
- std::map<char, Piece>::const_iterator it;
- for (it = begin(); it != end(); ++it)
- if (it->second == p)
- return it->first;
+ std::map<char, Piece>::const_iterator it;
+ for (it = begin(); it != end(); ++it)
+ if (it->second == p)
+ return it->first;
- assert(false);
- return 0;
+ assert(false);
+ return 0;
}
-};
-
-
-////
-//// Constants and variables
-////
-
-/// Bonus for having the side to move (modified by Joona Kiiski)
-
-static const Score TempoValue = make_score(48, 22);
-
-
-Key Position::zobrist[2][8][64];
-Key Position::zobEp[64];
-Key Position::zobCastle[16];
-Key Position::zobSideToMove;
-Key Position::zobExclusion;
-
-Score Position::PieceSquareTable[16][64];
-
-static PieceLetters pieceLetters;
+ };
-// Material values used by SEE, indexed by PieceType
-const Value Position::seeValues[] = {
- VALUE_ZERO, PawnValueMidgame, KnightValueMidgame, BishopValueMidgame,
- RookValueMidgame, QueenValueMidgame, QueenValueMidgame*10
-};
+ PieceLetters pieceLetters;
+}
-/// Constructors
+/// CheckInfo c'tor
CheckInfo::CheckInfo(const Position& pos) {
for (Square sq = sqH; sq >= sqA; sq--)
if (piece_on(sq) == rook)
{
- allow_oo(c);
+ do_allow_oo(c);
initialKRFile = square_file(sq);
break;
}
for (Square sq = sqA; sq <= sqH; sq++)
if (piece_on(sq) == rook)
{
- allow_ooo(c);
+ do_allow_ooo(c);
initialQRFile = square_file(sq);
break;
}
File rookFile = File(token - 'A') + FILE_A;
if (rookFile < initialKFile)
{
- allow_ooo(c);
+ do_allow_ooo(c);
initialQRFile = rookFile;
}
else
{
- allow_oo(c);
+ do_allow_oo(c);
initialKRFile = rookFile;
}
}
switch (p)
{
- case WP: return attacks_from<PAWN>(s, WHITE);
- case BP: return attacks_from<PAWN>(s, BLACK);
- case WN: case BN: return attacks_from<KNIGHT>(s);
case WB: case BB: return attacks_from<BISHOP>(s);
case WR: case BR: return attacks_from<ROOK>(s);
case WQ: case BQ: return attacks_from<QUEEN>(s);
- case WK: case BK: return attacks_from<KING>(s);
- default: break;
+ default: return StepAttackBB[p][s];
+ }
+}
+
+Bitboard Position::attacks_from(Piece p, Square s, Bitboard occ) {
+
+ assert(square_is_ok(s));
+
+ switch (p)
+ {
+ case WB: case BB: return bishop_attacks_bb(s, occ);
+ case WR: case BR: return rook_attacks_bb(s, occ);
+ case WQ: case BQ: return bishop_attacks_bb(s, occ) | rook_attacks_bb(s, occ);
+ default: return StepAttackBB[p][s];
}
- return false;
}
if (move_is_castle(m))
return true;
- Color us = side_to_move();
- Square from = move_from(m);
-
- assert(color_of_piece_on(from) == us);
- assert(piece_on(king_square(us)) == piece_of_color_and_type(us, KING));
-
// En passant captures are a tricky special case. Because they are
// rather uncommon, we do it simply by testing whether the king is attacked
// after the move is made
if (move_is_ep(m))
{
+ Color us = side_to_move();
Color them = opposite_color(us);
+ Square from = move_from(m);
Square to = move_to(m);
Square capsq = make_square(square_file(to), square_rank(from));
- Bitboard b = occupied_squares();
Square ksq = king_square(us);
+ Bitboard b = occupied_squares();
assert(to == ep_square());
assert(piece_on(from) == piece_of_color_and_type(us, PAWN));
&& !(bishop_attacks_bb(ksq, b) & pieces(BISHOP, QUEEN, them));
}
+ Color us = side_to_move();
+ Square from = move_from(m);
+
+ assert(color_of_piece_on(from) == us);
+ assert(piece_on(king_square(us)) == piece_of_color_and_type(us, KING));
+
// If the moving piece is a king, check whether the destination
// square is attacked by the opponent.
if (type_of_piece_on(from) == KING)
int Position::see(Square from, Square to) const {
- Bitboard occ, attackers, stmAttackers, b;
+ Bitboard occupied, attackers, stmAttackers, b;
int swapList[32], slIndex = 1;
PieceType capturedType, pt;
Color stm;
if (capturedType == KING)
return seeValues[capturedType];
- occ = occupied_squares();
+ occupied = occupied_squares();
// Handle en passant moves
if (st->epSquare == to && type_of_piece_on(from) == PAWN)
{
- Square capQq = (side_to_move() == WHITE) ? (to - DELTA_N) : (to - DELTA_S);
+ Square capQq = (side_to_move() == WHITE ? to - DELTA_N : to - DELTA_S);
assert(capturedType == PIECE_TYPE_NONE);
assert(type_of_piece_on(capQq) == PAWN);
// Remove the captured pawn
- clear_bit(&occ, capQq);
+ clear_bit(&occupied, capQq);
capturedType = PAWN;
}
// Find all attackers to the destination square, with the moving piece
// removed, but possibly an X-ray attacker added behind it.
- clear_bit(&occ, from);
- attackers = (rook_attacks_bb(to, occ) & pieces(ROOK, QUEEN))
- | (bishop_attacks_bb(to, occ) & pieces(BISHOP, QUEEN))
- | (attacks_from<KNIGHT>(to) & pieces(KNIGHT))
- | (attacks_from<KING>(to) & pieces(KING))
- | (attacks_from<PAWN>(to, WHITE) & pieces(PAWN, BLACK))
- | (attacks_from<PAWN>(to, BLACK) & pieces(PAWN, WHITE));
+ clear_bit(&occupied, from);
+ attackers = (rook_attacks_bb(to, occupied) & pieces(ROOK, QUEEN))
+ | (bishop_attacks_bb(to, occupied)& pieces(BISHOP, QUEEN))
+ | (attacks_from<KNIGHT>(to) & pieces(KNIGHT))
+ | (attacks_from<KING>(to) & pieces(KING))
+ | (attacks_from<PAWN>(to, WHITE) & pieces(PAWN, BLACK))
+ | (attacks_from<PAWN>(to, BLACK) & pieces(PAWN, WHITE));
// If the opponent has no attackers we are finished
stm = opposite_color(color_of_piece_on(from));
for (pt = PAWN; !(stmAttackers & pieces(pt)); pt++)
assert(pt < KING);
- // Remove the attacker we just found from the 'attackers' bitboard,
+ // Remove the attacker we just found from the 'occupied' bitboard,
// and scan for new X-ray attacks behind the attacker.
b = stmAttackers & pieces(pt);
- occ ^= (b & (~b + 1));
- attackers |= (rook_attacks_bb(to, occ) & pieces(ROOK, QUEEN))
- | (bishop_attacks_bb(to, occ) & pieces(BISHOP, QUEEN));
+ occupied ^= (b & (~b + 1));
+ attackers |= (rook_attacks_bb(to, occupied) & pieces(ROOK, QUEEN))
+ | (bishop_attacks_bb(to, occupied) & pieces(BISHOP, QUEEN));
- attackers &= occ; // Cut out pieces we've already done
+ attackers &= occupied; // Cut out pieces we've already done
// Add the new entry to the swap list
assert(slIndex < 32);
swapList[slIndex] = -swapList[slIndex - 1] + seeValues[capturedType];
slIndex++;
- // Remember the value of the capturing piece, and change the side to move
- // before beginning the next iteration
+ // Remember the value of the capturing piece, and change the side to
+ // move before beginning the next iteration.
capturedType = pt;
stm = opposite_color(stm);
stmAttackers = attackers & pieces_of_color(stm);
- // Stop after a king capture
- if (pt == KING && stmAttackers)
+ // Stop before processing a king capture
+ if (capturedType == KING && stmAttackers)
{
assert(slIndex < 32);
swapList[slIndex++] = QueenValueMidgame*10;
} while (stmAttackers);
// Having built the swap list, we negamax through it to find the best
- // achievable score from the point of view of the side to move
+ // achievable score from the point of view of the side to move.
while (--slIndex)
swapList[slIndex-1] = Min(-swapList[slIndex], swapList[slIndex-1]);
}
/// Position::put_piece() puts a piece on the given square of the board,
-/// updating the board array, bitboards, and piece counts.
+/// updating the board array, pieces list, bitboards, and piece counts.
void Position::put_piece(Piece p, Square s) {
PieceType pt = type_of_piece(p);
board[s] = p;
- index[s] = pieceCount[c][pt];
+ index[s] = pieceCount[c][pt]++;
pieceList[c][pt][index[s]] = s;
set_bit(&(byTypeBB[pt]), s);
set_bit(&(byColorBB[c]), s);
- set_bit(&byTypeBB[0], s); // HACK: byTypeBB[0] contains all occupied squares.
-
- pieceCount[c][pt]++;
-}
-
-
-/// Position::allow_oo() gives the given side the right to castle kingside.
-/// Used when setting castling rights during parsing of FEN strings.
-
-void Position::allow_oo(Color c) {
-
- st->castleRights |= (1 + int(c));
-}
-
-
-/// Position::allow_ooo() gives the given side the right to castle queenside.
-/// Used when setting castling rights during parsing of FEN strings.
-
-void Position::allow_ooo(Color c) {
-
- st->castleRights |= (4 + 4*int(c));
+ set_bit(&(byTypeBB[0]), s); // HACK: byTypeBB[0] contains all occupied squares.
}
Key Position::compute_key() const {
- Key result = 0;
+ Key result = zobCastle[st->castleRights];
for (Square s = SQ_A1; s <= SQ_H8; s++)
if (square_is_occupied(s))
if (ep_square() != SQ_NONE)
result ^= zobEp[ep_square()];
- result ^= zobCastle[st->castleRights];
if (side_to_move() == BLACK)
result ^= zobSideToMove;
Key Position::compute_pawn_key() const {
- Key result = 0;
Bitboard b;
- Square s;
+ Key result = 0;
for (Color c = WHITE; c <= BLACK; c++)
{
b = pieces(PAWN, c);
while (b)
- {
- s = pop_1st_bit(&b);
- result ^= zobrist[c][PAWN][s];
- }
+ result ^= zobrist[c][PAWN][pop_1st_bit(&b)];
}
return result;
}
Key Position::compute_material_key() const {
+ int count;
Key result = 0;
+
for (Color c = WHITE; c <= BLACK; c++)
for (PieceType pt = PAWN; pt <= QUEEN; pt++)
{
- int count = piece_count(c, pt);
+ count = piece_count(c, pt);
for (int i = 0; i < count; i++)
result ^= zobrist[c][pt][i];
}
/// updated by do_move and undo_move when the program is running in debug mode.
Score Position::compute_value() const {
- Score result = SCORE_ZERO;
Bitboard b;
- Square s;
+ Score result = SCORE_ZERO;
for (Color c = WHITE; c <= BLACK; c++)
for (PieceType pt = PAWN; pt <= KING; pt++)
{
b = pieces(pt, c);
while (b)
- {
- s = pop_1st_bit(&b);
- assert(piece_on(s) == piece_of_color_and_type(c, pt));
- result += pst(c, pt, s);
- }
+ result += pst(c, pt, pop_1st_bit(&b));
}
result += (side_to_move() == WHITE ? TempoValue / 2 : -TempoValue / 2);
/// Position::compute_non_pawn_material() computes the total non-pawn middle
-/// game material score for the given side. Material scores are updated
+/// game material value for the given side. Material values are updated
/// incrementally during the search, this function is only used while
/// initializing a new Position object.
Value result = VALUE_ZERO;
for (PieceType pt = KNIGHT; pt <= QUEEN; pt++)
- {
- Bitboard b = pieces(pt, c);
- while (b)
- {
- assert(piece_on(first_1(b)) == piece_of_color_and_type(c, pt));
+ result += piece_count(c, pt) * PieceValueMidgame[pt];
- pop_1st_bit(&b);
- result += PieceValueMidgame[pt];
- }
- }
return result;
}
bool Position::is_mate() const {
MoveStack moves[MOVES_MAX];
- return is_check() && (generate_moves(*this, moves) == moves);
+ return is_check() && generate_moves(*this, moves) == moves;
}
// First pass the move to our opponent doing a null move
do_null_move(st1);
- // Then generate pseudo-legal moves that give check
+ // Then generate pseudo-legal moves that could give check
last = generate_non_capture_checks(*this, mlist);
last = generate_captures(*this, last);
void Position::init_zobrist() {
- RKISS RKiss;
int i,j, k;
+ RKISS rk;
for (i = 0; i < 2; i++) for (j = 0; j < 8; j++) for (k = 0; k < 64; k++)
- zobrist[i][j][k] = Key(RKiss.rand64());
+ zobrist[i][j][k] = rk.rand<Key>();
for (i = 0; i < 64; i++)
- zobEp[i] = Key(RKiss.rand64());
+ zobEp[i] = rk.rand<Key>();
for (i = 0; i < 16; i++)
- zobCastle[i] = Key(RKiss.rand64());
+ zobCastle[i] = rk.rand<Key>();
- zobSideToMove = Key(RKiss.rand64());
- zobExclusion = Key(RKiss.rand64());
+ zobSideToMove = rk.rand<Key>();
+ zobExclusion = rk.rand<Key>();
}
// Board
for (Square s = SQ_A1; s <= SQ_H8; s++)
if (!pos.square_is_empty(s))
- put_piece(Piece(int(pos.piece_on(s)) ^ 8), flip_square(s));
+ put_piece(Piece(pos.piece_on(s) ^ 8), flip_square(s));
// Side to move
sideToMove = opposite_color(pos.side_to_move());
// Castling rights
- if (pos.can_castle_kingside(WHITE)) allow_oo(BLACK);
- if (pos.can_castle_queenside(WHITE)) allow_ooo(BLACK);
- if (pos.can_castle_kingside(BLACK)) allow_oo(WHITE);
- if (pos.can_castle_queenside(BLACK)) allow_ooo(WHITE);
+ if (pos.can_castle_kingside(WHITE)) do_allow_oo(BLACK);
+ if (pos.can_castle_queenside(WHITE)) do_allow_ooo(BLACK);
+ if (pos.can_castle_kingside(BLACK)) do_allow_oo(WHITE);
+ if (pos.can_castle_queenside(BLACK)) do_allow_ooo(WHITE);
initialKFile = pos.initialKFile;
initialKRFile = pos.initialKRFile;
bool Position::is_ok(int* failedStep) const {
// What features of the position should be verified?
- static const bool debugBitboards = false;
- static const bool debugKingCount = false;
- static const bool debugKingCapture = false;
- static const bool debugCheckerCount = false;
- static const bool debugKey = false;
- static const bool debugMaterialKey = false;
- static const bool debugPawnKey = false;
- static const bool debugIncrementalEval = false;
- static const bool debugNonPawnMaterial = false;
- static const bool debugPieceCounts = false;
- static const bool debugPieceList = false;
- static const bool debugCastleSquares = false;
+ const bool debugAll = false;
+
+ const bool debugBitboards = debugAll || false;
+ const bool debugKingCount = debugAll || false;
+ const bool debugKingCapture = debugAll || false;
+ const bool debugCheckerCount = debugAll || false;
+ const bool debugKey = debugAll || false;
+ const bool debugMaterialKey = debugAll || false;
+ const bool debugPawnKey = debugAll || false;
+ const bool debugIncrementalEval = debugAll || false;
+ const bool debugNonPawnMaterial = debugAll || false;
+ const bool debugPieceCounts = debugAll || false;
+ const bool debugPieceList = debugAll || false;
+ const bool debugCastleSquares = debugAll || false;
if (failedStep) *failedStep = 1;