along with this program. If not, see <http://www.gnu.org/licenses/>.
*/
-
-////
-//// Includes
-////
-
#include <cassert>
#include "bitcount.h"
#include "endgame.h"
+#include "pawns.h"
+using std::string;
-////
-//// Local definitions
-////
+extern uint32_t probe_kpk_bitbase(Square wksq, Square wpsq, Square bksq, Color stm);
namespace {
// Table used to drive the defending king towards the edge of the board
// in KX vs K and KQ vs KR endgames.
- const uint8_t MateTable[64] = {
+ const int MateTable[64] = {
100, 90, 80, 70, 70, 80, 90, 100,
90, 70, 60, 50, 50, 60, 70, 90,
80, 60, 40, 30, 30, 40, 60, 80,
// Table used to drive the defending king towards a corner square of the
// right color in KBN vs K endgames.
- const uint8_t KBNKMateTable[64] = {
+ const int KBNKMateTable[64] = {
200, 190, 180, 170, 160, 150, 140, 130,
190, 180, 170, 160, 150, 140, 130, 140,
180, 170, 155, 140, 140, 125, 140, 150,
// and knight in KR vs KN endgames.
const int KRKNKingKnightDistancePenalty[8] = { 0, 0, 4, 10, 20, 32, 48, 70 };
- // Bitbase for KP vs K
- uint8_t KPKBitbase[24576];
+ // Build corresponding key code for the opposite color: "KBPKN" -> "KNKBP"
+ const string swap_colors(const string& keyCode) {
- // Various inline functions for accessing the above arrays
- inline Value mate_table(Square s) {
- return Value(MateTable[s]);
+ size_t idx = keyCode.find('K', 1);
+ return keyCode.substr(idx) + keyCode.substr(0, idx);
}
- inline Value kbnk_mate_table(Square s) {
- return Value(KBNKMateTable[s]);
- }
+ // Get the material key of a position out of the given endgame key code
+ // like "KBPKN". The trick here is to first build up a FEN string and then
+ // let a Position object to do the work for us. Note that the FEN string
+ // could correspond to an illegal position.
+ Key mat_key(const string& keyCode) {
- inline Value distance_bonus(int d) {
- return Value(DistanceBonus[d]);
- }
+ assert(keyCode.length() > 0 && keyCode.length() < 8);
+ assert(keyCode[0] == 'K');
- inline Value krkn_king_knight_distance_penalty(int d) {
- return Value(KRKNKingKnightDistancePenalty[d]);
+ string fen;
+ size_t i = 0;
+
+ // First add white and then black pieces
+ do fen += keyCode[i]; while (keyCode[++i] != 'K');
+ do fen += char(tolower(keyCode[i])); while (++i < keyCode.length());
+
+ // Add file padding and remaining empty ranks
+ fen += string(1, '0' + int(8 - keyCode.length())) + "/8/8/8/8/8/8/8 w - - 0 10";
+
+ // Build a Position out of the fen string and get its material key
+ return Position(fen, false, 0).get_material_key();
}
- // Function for probing the KP vs K bitbase
- int probe_kpk(Square wksq, Square wpsq, Square bksq, Color stm);
+ typedef EndgameBase<Value> EF;
+ typedef EndgameBase<ScaleFactor> SF;
+
+} // namespace
+
+
+/// Endgames member definitions
+
+template<> const Endgames::EFMap& Endgames::get<EF>() const { return maps.first; }
+template<> const Endgames::SFMap& Endgames::get<SF>() const { return maps.second; }
+
+Endgames::Endgames() {
+
+ add<Endgame<Value, KNNK> >("KNNK");
+ add<Endgame<Value, KPK> >("KPK");
+ add<Endgame<Value, KBNK> >("KBNK");
+ add<Endgame<Value, KRKP> >("KRKP");
+ add<Endgame<Value, KRKB> >("KRKB");
+ add<Endgame<Value, KRKN> >("KRKN");
+ add<Endgame<Value, KQKR> >("KQKR");
+ add<Endgame<Value, KBBKN> >("KBBKN");
+
+ add<Endgame<ScaleFactor, KNPK> >("KNPK");
+ add<Endgame<ScaleFactor, KRPKR> >("KRPKR");
+ add<Endgame<ScaleFactor, KBPKB> >("KBPKB");
+ add<Endgame<ScaleFactor, KBPPKB> >("KBPPKB");
+ add<Endgame<ScaleFactor, KBPKN> >("KBPKN");
+ add<Endgame<ScaleFactor, KRPPKRP> >("KRPPKRP");
+}
+
+Endgames::~Endgames() {
+
+ for (EFMap::const_iterator it = get<EF>().begin(); it != get<EF>().end(); ++it)
+ delete it->second;
+ for (SFMap::const_iterator it = get<SF>().begin(); it != get<SF>().end(); ++it)
+ delete it->second;
}
+template<class T>
+void Endgames::add(const string& keyCode) {
-////
-//// Functions
-////
+ typedef typename T::Base F;
+ typedef std::map<Key, F*> M;
+
+ const_cast<M&>(get<F>()).insert(std::pair<Key, F*>(mat_key(keyCode), new T(WHITE)));
+ const_cast<M&>(get<F>()).insert(std::pair<Key, F*>(mat_key(swap_colors(keyCode)), new T(BLACK)));
+}
-/// init_bitbases() is called during program initialization, and simply loads
-/// bitbases from disk into memory. At the moment, there is only the bitbase
-/// for KP vs K, but we may decide to add other bitbases later.
-extern void generate_kpk_bitbase(uint8_t bitbase[]);
+template<class T>
+T* Endgames::get(Key key) const {
-void init_bitbases() {
- generate_kpk_bitbase(KPKBitbase);
+ typename std::map<Key, T*>::const_iterator it = get<T>().find(key);
+ return it != get<T>().end() ? it->second : NULL;
}
+// Explicit template instantiations
+template EF* Endgames::get<EF>(Key key) const;
+template SF* Endgames::get<SF>(Key key) const;
+
/// Mate with KX vs K. This function is used to evaluate positions with
/// King and plenty of material vs a lone king. It simply gives the
/// attacking side a bonus for driving the defending king towards the edge
/// of the board, and for keeping the distance between the two kings small.
template<>
-Value EvaluationFunction<KXK>::apply(const Position& pos) const {
+Value Endgame<Value, KXK>::apply(const Position& pos) const {
assert(pos.non_pawn_material(weakerSide) == VALUE_ZERO);
assert(pos.piece_count(weakerSide, PAWN) == VALUE_ZERO);
Value result = pos.non_pawn_material(strongerSide)
+ pos.piece_count(strongerSide, PAWN) * PawnValueEndgame
- + mate_table(loserKSq)
- + distance_bonus(square_distance(winnerKSq, loserKSq));
+ + MateTable[loserKSq]
+ + DistanceBonus[square_distance(winnerKSq, loserKSq)];
if ( pos.piece_count(strongerSide, QUEEN)
|| pos.piece_count(strongerSide, ROOK)
/// Mate with KBN vs K. This is similar to KX vs K, but we have to drive the
/// defending king towards a corner square of the right color.
template<>
-Value EvaluationFunction<KBNK>::apply(const Position& pos) const {
+Value Endgame<Value, KBNK>::apply(const Position& pos) const {
assert(pos.non_pawn_material(weakerSide) == VALUE_ZERO);
assert(pos.piece_count(weakerSide, PAWN) == VALUE_ZERO);
Square winnerKSq = pos.king_square(strongerSide);
Square loserKSq = pos.king_square(weakerSide);
- Square bishopSquare = pos.piece_list(strongerSide, BISHOP, 0);
+ Square bishopSquare = pos.piece_list(strongerSide, BISHOP)[0];
// kbnk_mate_table() tries to drive toward corners A1 or H8,
// if we have a bishop that cannot reach the above squares we
// mirror the kings so to drive enemy toward corners A8 or H1.
- if (!same_color_squares(bishopSquare, SQ_A1))
+ if (opposite_color_squares(bishopSquare, SQ_A1))
{
winnerKSq = flop_square(winnerKSq);
loserKSq = flop_square(loserKSq);
}
Value result = VALUE_KNOWN_WIN
- + distance_bonus(square_distance(winnerKSq, loserKSq))
- + kbnk_mate_table(loserKSq);
+ + DistanceBonus[square_distance(winnerKSq, loserKSq)]
+ + KBNKMateTable[loserKSq];
return strongerSide == pos.side_to_move() ? result : -result;
}
/// KP vs K. This endgame is evaluated with the help of a bitbase.
template<>
-Value EvaluationFunction<KPK>::apply(const Position& pos) const {
+Value Endgame<Value, KPK>::apply(const Position& pos) const {
assert(pos.non_pawn_material(strongerSide) == VALUE_ZERO);
assert(pos.non_pawn_material(weakerSide) == VALUE_ZERO);
{
wksq = pos.king_square(WHITE);
bksq = pos.king_square(BLACK);
- wpsq = pos.piece_list(WHITE, PAWN, 0);
+ wpsq = pos.piece_list(WHITE, PAWN)[0];
stm = pos.side_to_move();
}
else
{
wksq = flip_square(pos.king_square(BLACK));
bksq = flip_square(pos.king_square(WHITE));
- wpsq = flip_square(pos.piece_list(BLACK, PAWN, 0));
+ wpsq = flip_square(pos.piece_list(BLACK, PAWN)[0]);
stm = opposite_color(pos.side_to_move());
}
wpsq = flop_square(wpsq);
}
- if (!probe_kpk(wksq, wpsq, bksq, stm))
+ if (!probe_kpk_bitbase(wksq, wpsq, bksq, stm))
return VALUE_DRAW;
Value result = VALUE_KNOWN_WIN
/// far advanced with support of the king, while the attacking king is far
/// away.
template<>
-Value EvaluationFunction<KRKP>::apply(const Position& pos) const {
+Value Endgame<Value, KRKP>::apply(const Position& pos) const {
assert(pos.non_pawn_material(strongerSide) == RookValueMidgame);
assert(pos.piece_count(strongerSide, PAWN) == 0);
int tempo = (pos.side_to_move() == strongerSide);
wksq = pos.king_square(strongerSide);
- wrsq = pos.piece_list(strongerSide, ROOK, 0);
+ wrsq = pos.piece_list(strongerSide, ROOK)[0];
bksq = pos.king_square(weakerSide);
- bpsq = pos.piece_list(weakerSide, PAWN, 0);
+ bpsq = pos.piece_list(weakerSide, PAWN)[0];
if (strongerSide == BLACK)
{
/// KR vs KB. This is very simple, and always returns drawish scores. The
/// score is slightly bigger when the defending king is close to the edge.
template<>
-Value EvaluationFunction<KRKB>::apply(const Position& pos) const {
+Value Endgame<Value, KRKB>::apply(const Position& pos) const {
assert(pos.non_pawn_material(strongerSide) == RookValueMidgame);
assert(pos.piece_count(strongerSide, PAWN) == 0);
assert(pos.piece_count(weakerSide, PAWN) == 0);
assert(pos.piece_count(weakerSide, BISHOP) == 1);
- Value result = mate_table(pos.king_square(weakerSide));
+ Value result = Value(MateTable[pos.king_square(weakerSide)]);
return strongerSide == pos.side_to_move() ? result : -result;
}
/// KR vs KN. The attacking side has slightly better winning chances than
/// in KR vs KB, particularly if the king and the knight are far apart.
template<>
-Value EvaluationFunction<KRKN>::apply(const Position& pos) const {
+Value Endgame<Value, KRKN>::apply(const Position& pos) const {
assert(pos.non_pawn_material(strongerSide) == RookValueMidgame);
assert(pos.piece_count(strongerSide, PAWN) == 0);
assert(pos.piece_count(weakerSide, KNIGHT) == 1);
Square defendingKSq = pos.king_square(weakerSide);
- Square nSq = pos.piece_list(weakerSide, KNIGHT, 0);
+ Square nSq = pos.piece_list(weakerSide, KNIGHT)[0];
int d = square_distance(defendingKSq, nSq);
Value result = Value(10)
- + mate_table(defendingKSq)
- + krkn_king_knight_distance_penalty(d);
+ + MateTable[defendingKSq]
+ + KRKNKingKnightDistancePenalty[d];
return strongerSide == pos.side_to_move() ? result : -result;
}
/// for the defending side in the search, this is usually sufficient to be
/// able to win KQ vs KR.
template<>
-Value EvaluationFunction<KQKR>::apply(const Position& pos) const {
+Value Endgame<Value, KQKR>::apply(const Position& pos) const {
assert(pos.non_pawn_material(strongerSide) == QueenValueMidgame);
assert(pos.piece_count(strongerSide, PAWN) == 0);
Value result = QueenValueEndgame
- RookValueEndgame
- + mate_table(loserKSq)
- + distance_bonus(square_distance(winnerKSq, loserKSq));
+ + MateTable[loserKSq]
+ + DistanceBonus[square_distance(winnerKSq, loserKSq)];
return strongerSide == pos.side_to_move() ? result : -result;
}
template<>
-Value EvaluationFunction<KBBKN>::apply(const Position& pos) const {
+Value Endgame<Value, KBBKN>::apply(const Position& pos) const {
assert(pos.piece_count(strongerSide, BISHOP) == 2);
assert(pos.non_pawn_material(strongerSide) == 2*BishopValueMidgame);
Value result = BishopValueEndgame;
Square wksq = pos.king_square(strongerSide);
Square bksq = pos.king_square(weakerSide);
- Square nsq = pos.piece_list(weakerSide, KNIGHT, 0);
+ Square nsq = pos.piece_list(weakerSide, KNIGHT)[0];
// Bonus for attacking king close to defending king
- result += distance_bonus(square_distance(wksq, bksq));
+ result += Value(DistanceBonus[square_distance(wksq, bksq)]);
// Bonus for driving the defending king and knight apart
result += Value(square_distance(bksq, nsq) * 32);
/// K and two minors vs K and one or two minors or K and two knights against
/// king alone are always draw.
template<>
-Value EvaluationFunction<KmmKm>::apply(const Position&) const {
+Value Endgame<Value, KmmKm>::apply(const Position&) const {
return VALUE_DRAW;
}
template<>
-Value EvaluationFunction<KNNK>::apply(const Position&) const {
+Value Endgame<Value, KNNK>::apply(const Position&) const {
return VALUE_DRAW;
}
/// returned. If not, the return value is SCALE_FACTOR_NONE, i.e. no scaling
/// will be used.
template<>
-ScaleFactor ScalingFunction<KBPsK>::apply(const Position& pos) const {
+ScaleFactor Endgame<ScaleFactor, KBPsK>::apply(const Position& pos) const {
assert(pos.non_pawn_material(strongerSide) == BishopValueMidgame);
assert(pos.piece_count(strongerSide, BISHOP) == 1);
// be detected even when the weaker side has some pawns.
Bitboard pawns = pos.pieces(PAWN, strongerSide);
- File pawnFile = square_file(pos.piece_list(strongerSide, PAWN, 0));
+ File pawnFile = square_file(pos.piece_list(strongerSide, PAWN)[0]);
// All pawns are on a single rook file ?
if ( (pawnFile == FILE_A || pawnFile == FILE_H)
&& (pawns & ~file_bb(pawnFile)) == EmptyBoardBB)
{
- Square bishopSq = pos.piece_list(strongerSide, BISHOP, 0);
+ Square bishopSq = pos.piece_list(strongerSide, BISHOP)[0];
Square queeningSq = relative_square(strongerSide, make_square(pawnFile, RANK_8));
Square kingSq = pos.king_square(weakerSide);
- if ( !same_color_squares(queeningSq, bishopSq)
- && file_distance(square_file(kingSq), pawnFile) <= 1)
+ if ( opposite_color_squares(queeningSq, bishopSq)
+ && abs(square_file(kingSq) - pawnFile) <= 1)
{
// The bishop has the wrong color, and the defending king is on the
// file of the pawn(s) or the neighboring file. Find the rank of the
/// It tests for fortress draws with a rook on the third rank defended by
/// a pawn.
template<>
-ScaleFactor ScalingFunction<KQKRPs>::apply(const Position& pos) const {
+ScaleFactor Endgame<ScaleFactor, KQKRPs>::apply(const Position& pos) const {
assert(pos.non_pawn_material(strongerSide) == QueenValueMidgame);
assert(pos.piece_count(strongerSide, QUEEN) == 1);
Square kingSq = pos.king_square(weakerSide);
if ( relative_rank(weakerSide, kingSq) <= RANK_2
&& relative_rank(weakerSide, pos.king_square(strongerSide)) >= RANK_4
- && (pos.pieces(ROOK, weakerSide) & relative_rank_bb(weakerSide, RANK_3))
- && (pos.pieces(PAWN, weakerSide) & relative_rank_bb(weakerSide, RANK_2))
+ && (pos.pieces(ROOK, weakerSide) & rank_bb(relative_rank(weakerSide, RANK_3)))
+ && (pos.pieces(PAWN, weakerSide) & rank_bb(relative_rank(weakerSide, RANK_2)))
&& (pos.attacks_from<KING>(kingSq) & pos.pieces(PAWN, weakerSide)))
{
- Square rsq = pos.piece_list(weakerSide, ROOK, 0);
+ Square rsq = pos.piece_list(weakerSide, ROOK)[0];
if (pos.attacks_from<PAWN>(rsq, strongerSide) & pos.pieces(PAWN, weakerSide))
return SCALE_FACTOR_ZERO;
}
/// It would also be nice to rewrite the actual code for this function,
/// which is mostly copied from Glaurung 1.x, and not very pretty.
template<>
-ScaleFactor ScalingFunction<KRPKR>::apply(const Position& pos) const {
+ScaleFactor Endgame<ScaleFactor, KRPKR>::apply(const Position& pos) const {
assert(pos.non_pawn_material(strongerSide) == RookValueMidgame);
assert(pos.piece_count(strongerSide, PAWN) == 1);
assert(pos.piece_count(weakerSide, PAWN) == 0);
Square wksq = pos.king_square(strongerSide);
- Square wrsq = pos.piece_list(strongerSide, ROOK, 0);
- Square wpsq = pos.piece_list(strongerSide, PAWN, 0);
+ Square wrsq = pos.piece_list(strongerSide, ROOK)[0];
+ Square wpsq = pos.piece_list(strongerSide, PAWN)[0];
Square bksq = pos.king_square(weakerSide);
- Square brsq = pos.piece_list(weakerSide, ROOK, 0);
+ Square brsq = pos.piece_list(weakerSide, ROOK)[0];
// Orient the board in such a way that the stronger side is white, and the
// pawn is on the left half of the board.
/// single pattern: If the stronger side has no pawns and the defending king
/// is actively placed, the position is drawish.
template<>
-ScaleFactor ScalingFunction<KRPPKRP>::apply(const Position& pos) const {
+ScaleFactor Endgame<ScaleFactor, KRPPKRP>::apply(const Position& pos) const {
assert(pos.non_pawn_material(strongerSide) == RookValueMidgame);
assert(pos.piece_count(strongerSide, PAWN) == 2);
assert(pos.non_pawn_material(weakerSide) == RookValueMidgame);
assert(pos.piece_count(weakerSide, PAWN) == 1);
- Square wpsq1 = pos.piece_list(strongerSide, PAWN, 0);
- Square wpsq2 = pos.piece_list(strongerSide, PAWN, 1);
+ Square wpsq1 = pos.piece_list(strongerSide, PAWN)[0];
+ Square wpsq2 = pos.piece_list(strongerSide, PAWN)[1];
Square bksq = pos.king_square(weakerSide);
// Does the stronger side have a passed pawn?
/// against king. There is just a single rule here: If all pawns are on
/// the same rook file and are blocked by the defending king, it's a draw.
template<>
-ScaleFactor ScalingFunction<KPsK>::apply(const Position& pos) const {
+ScaleFactor Endgame<ScaleFactor, KPsK>::apply(const Position& pos) const {
assert(pos.non_pawn_material(strongerSide) == VALUE_ZERO);
assert(pos.piece_count(strongerSide, PAWN) >= 2);
/// it's a draw. If the two bishops have opposite color, it's almost always
/// a draw.
template<>
-ScaleFactor ScalingFunction<KBPKB>::apply(const Position& pos) const {
+ScaleFactor Endgame<ScaleFactor, KBPKB>::apply(const Position& pos) const {
assert(pos.non_pawn_material(strongerSide) == BishopValueMidgame);
assert(pos.piece_count(strongerSide, BISHOP) == 1);
assert(pos.piece_count(weakerSide, BISHOP) == 1);
assert(pos.piece_count(weakerSide, PAWN) == 0);
- Square pawnSq = pos.piece_list(strongerSide, PAWN, 0);
- Square strongerBishopSq = pos.piece_list(strongerSide, BISHOP, 0);
- Square weakerBishopSq = pos.piece_list(weakerSide, BISHOP, 0);
+ Square pawnSq = pos.piece_list(strongerSide, PAWN)[0];
+ Square strongerBishopSq = pos.piece_list(strongerSide, BISHOP)[0];
+ Square weakerBishopSq = pos.piece_list(weakerSide, BISHOP)[0];
Square weakerKingSq = pos.king_square(weakerSide);
// Case 1: Defending king blocks the pawn, and cannot be driven away
if ( square_file(weakerKingSq) == square_file(pawnSq)
&& relative_rank(strongerSide, pawnSq) < relative_rank(strongerSide, weakerKingSq)
- && ( !same_color_squares(weakerKingSq, strongerBishopSq)
+ && ( opposite_color_squares(weakerKingSq, strongerBishopSq)
|| relative_rank(strongerSide, weakerKingSq) <= RANK_6))
return SCALE_FACTOR_ZERO;
// Case 2: Opposite colored bishops
- if (!same_color_squares(strongerBishopSq, weakerBishopSq))
+ if (opposite_color_squares(strongerBishopSq, weakerBishopSq))
{
// We assume that the position is drawn in the following three situations:
//
/// KBPPKBScalingFunction scales KBPP vs KB endgames. It detects a few basic
/// draws with opposite-colored bishops.
template<>
-ScaleFactor ScalingFunction<KBPPKB>::apply(const Position& pos) const {
+ScaleFactor Endgame<ScaleFactor, KBPPKB>::apply(const Position& pos) const {
assert(pos.non_pawn_material(strongerSide) == BishopValueMidgame);
assert(pos.piece_count(strongerSide, BISHOP) == 1);
assert(pos.piece_count(weakerSide, BISHOP) == 1);
assert(pos.piece_count(weakerSide, PAWN) == 0);
- Square wbsq = pos.piece_list(strongerSide, BISHOP, 0);
- Square bbsq = pos.piece_list(weakerSide, BISHOP, 0);
+ Square wbsq = pos.piece_list(strongerSide, BISHOP)[0];
+ Square bbsq = pos.piece_list(weakerSide, BISHOP)[0];
- if (same_color_squares(wbsq, bbsq))
- // Not opposite-colored bishops, no scaling
+ if (!opposite_color_squares(wbsq, bbsq))
return SCALE_FACTOR_NONE;
Square ksq = pos.king_square(weakerSide);
- Square psq1 = pos.piece_list(strongerSide, PAWN, 0);
- Square psq2 = pos.piece_list(strongerSide, PAWN, 1);
+ Square psq1 = pos.piece_list(strongerSide, PAWN)[0];
+ Square psq2 = pos.piece_list(strongerSide, PAWN)[1];
Rank r1 = square_rank(psq1);
Rank r2 = square_rank(psq2);
Square blockSq1, blockSq2;
// some square in the frontmost pawn's path.
if ( square_file(ksq) == square_file(blockSq1)
&& relative_rank(strongerSide, ksq) >= relative_rank(strongerSide, blockSq1)
- && !same_color_squares(ksq, wbsq))
+ && opposite_color_squares(ksq, wbsq))
return SCALE_FACTOR_ZERO;
else
return SCALE_FACTOR_NONE;
// in front of the frontmost pawn's path, and the square diagonally behind
// this square on the file of the other pawn.
if ( ksq == blockSq1
- && !same_color_squares(ksq, wbsq)
+ && opposite_color_squares(ksq, wbsq)
&& ( bbsq == blockSq2
|| (pos.attacks_from<BISHOP>(blockSq2) & pos.pieces(BISHOP, weakerSide))
- || rank_distance(r1, r2) >= 2))
+ || abs(r1 - r2) >= 2))
return SCALE_FACTOR_ZERO;
else if ( ksq == blockSq2
- && !same_color_squares(ksq, wbsq)
+ && opposite_color_squares(ksq, wbsq)
&& ( bbsq == blockSq1
|| (pos.attacks_from<BISHOP>(blockSq1) & pos.pieces(BISHOP, weakerSide))))
return SCALE_FACTOR_ZERO;
/// square of the king is not of the same color as the stronger side's bishop,
/// it's a draw.
template<>
-ScaleFactor ScalingFunction<KBPKN>::apply(const Position& pos) const {
+ScaleFactor Endgame<ScaleFactor, KBPKN>::apply(const Position& pos) const {
assert(pos.non_pawn_material(strongerSide) == BishopValueMidgame);
assert(pos.piece_count(strongerSide, BISHOP) == 1);
assert(pos.piece_count(weakerSide, KNIGHT) == 1);
assert(pos.piece_count(weakerSide, PAWN) == 0);
- Square pawnSq = pos.piece_list(strongerSide, PAWN, 0);
- Square strongerBishopSq = pos.piece_list(strongerSide, BISHOP, 0);
+ Square pawnSq = pos.piece_list(strongerSide, PAWN)[0];
+ Square strongerBishopSq = pos.piece_list(strongerSide, BISHOP)[0];
Square weakerKingSq = pos.king_square(weakerSide);
if ( square_file(weakerKingSq) == square_file(pawnSq)
&& relative_rank(strongerSide, pawnSq) < relative_rank(strongerSide, weakerKingSq)
- && ( !same_color_squares(weakerKingSq, strongerBishopSq)
+ && ( opposite_color_squares(weakerKingSq, strongerBishopSq)
|| relative_rank(strongerSide, weakerKingSq) <= RANK_6))
return SCALE_FACTOR_ZERO;
/// If the pawn is a rook pawn on the 7th rank and the defending king prevents
/// the pawn from advancing, the position is drawn.
template<>
-ScaleFactor ScalingFunction<KNPK>::apply(const Position& pos) const {
+ScaleFactor Endgame<ScaleFactor, KNPK>::apply(const Position& pos) const {
assert(pos.non_pawn_material(strongerSide) == KnightValueMidgame);
assert(pos.piece_count(strongerSide, KNIGHT) == 1);
assert(pos.non_pawn_material(weakerSide) == VALUE_ZERO);
assert(pos.piece_count(weakerSide, PAWN) == 0);
- Square pawnSq = pos.piece_list(strongerSide, PAWN, 0);
+ Square pawnSq = pos.piece_list(strongerSide, PAWN)[0];
Square weakerKingSq = pos.king_square(weakerSide);
if ( pawnSq == relative_square(strongerSide, SQ_A7)
/// advanced and not on a rook file; in this case it is often possible to win
/// (e.g. 8/4k3/3p4/3P4/6K1/8/8/8 w - - 0 1).
template<>
-ScaleFactor ScalingFunction<KPKP>::apply(const Position& pos) const {
+ScaleFactor Endgame<ScaleFactor, KPKP>::apply(const Position& pos) const {
assert(pos.non_pawn_material(strongerSide) == VALUE_ZERO);
assert(pos.non_pawn_material(weakerSide) == VALUE_ZERO);
{
wksq = pos.king_square(WHITE);
bksq = pos.king_square(BLACK);
- wpsq = pos.piece_list(WHITE, PAWN, 0);
+ wpsq = pos.piece_list(WHITE, PAWN)[0];
stm = pos.side_to_move();
}
else
{
wksq = flip_square(pos.king_square(BLACK));
bksq = flip_square(pos.king_square(WHITE));
- wpsq = flip_square(pos.piece_list(BLACK, PAWN, 0));
+ wpsq = flip_square(pos.piece_list(BLACK, PAWN)[0]);
stm = opposite_color(pos.side_to_move());
}
// Probe the KPK bitbase with the weakest side's pawn removed. If it's a
// draw, it's probably at least a draw even with the pawn.
- return probe_kpk(wksq, wpsq, bksq, stm) ? SCALE_FACTOR_NONE : SCALE_FACTOR_ZERO;
-}
-
-
-namespace {
-
- // Probe the KP vs K bitbase
-
- int probe_kpk(Square wksq, Square wpsq, Square bksq, Color stm) {
-
- int wp = square_file(wpsq) + 4 * (square_rank(wpsq) - 1);
- int index = int(stm) + 2 * bksq + 128 * wksq + 8192 * wp;
-
- assert(index >= 0 && index < 24576 * 8);
-
- return KPKBitbase[index / 8] & (1 << (index & 7));
- }
+ return probe_kpk_bitbase(wksq, wpsq, bksq, stm) ? SCALE_FACTOR_NONE : SCALE_FACTOR_ZERO;
}
projects / stockfish / blobdiff