X-Git-Url: https://git.sesse.net/?p=stockfish;a=blobdiff_plain;f=src%2Fendgame.cpp;h=f8f4c802d118441c09a5da4e405867605695a336;hp=1be384410b4d4a59091528826880a3f80f668b83;hb=13524bea9b7a64dd2881880b2272f3ccd494c262;hpb=9b1d5bd5343540db412c50ae2944246e3f25d18b diff --git a/src/endgame.cpp b/src/endgame.cpp index 1be38441..f8f4c802 100644 --- a/src/endgame.cpp +++ b/src/endgame.cpp @@ -17,27 +17,21 @@ along with this program. If not, see . */ - -//// -//// Includes -//// - #include -#include "bitbase.h" #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, @@ -50,7 +44,7 @@ namespace { // 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, @@ -69,62 +63,114 @@ namespace { // 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 EF; + typedef EndgameBase SF; + +} // namespace + +/// Endgames member definitions + +template<> const Endgames::EFMap& Endgames::get() const { return maps.first; } +template<> const Endgames::SFMap& Endgames::get() const { return maps.second; } + +Endgames::Endgames() { + + add >("KNNK"); + add >("KPK"); + add >("KBNK"); + add >("KRKP"); + add >("KRKB"); + add >("KRKN"); + add >("KQKR"); + add >("KBBKN"); + + add >("KNPK"); + add >("KRPKR"); + add >("KBPKB"); + add >("KBPPKB"); + add >("KBPKN"); + add >("KRPPKRP"); } +Endgames::~Endgames() { + + for (EFMap::const_iterator it = get().begin(); it != get().end(); ++it) + delete it->second; + + for (SFMap::const_iterator it = get().begin(); it != get().end(); ++it) + delete it->second; +} -//// -//// Functions -//// +template +void Endgames::add(const string& keyCode) { -/// 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. + typedef typename T::Base F; + typedef std::map M; -void init_bitbases() { - generate_kpk_bitbase(KPKBitbase); + const_cast(get()).insert(std::pair(mat_key(keyCode), new T(WHITE))); + const_cast(get()).insert(std::pair(mat_key(swap_colors(keyCode)), new T(BLACK))); } +template +T* Endgames::get(Key key) const { + + typename std::map::const_iterator it = get().find(key); + return it != get().end() ? it->second : NULL; +} + +// Explicit template instantiations +template EF* Endgames::get(Key key) const; +template SF* Endgames::get(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::apply(const Position& pos) const { +Value Endgame::apply(const Position& pos) const { - assert(pos.non_pawn_material(weakerSide) == Value(0)); - assert(pos.piece_count(weakerSide, PAWN) == Value(0)); + 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); 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) @@ -139,10 +185,10 @@ Value EvaluationFunction::apply(const Position& pos) const { /// 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::apply(const Position& pos) const { +Value Endgame::apply(const Position& pos) const { - assert(pos.non_pawn_material(weakerSide) == Value(0)); - assert(pos.piece_count(weakerSide, PAWN) == Value(0)); + assert(pos.non_pawn_material(weakerSide) == VALUE_ZERO); + assert(pos.piece_count(weakerSide, PAWN) == VALUE_ZERO); assert(pos.non_pawn_material(strongerSide) == KnightValueMidgame + BishopValueMidgame); assert(pos.piece_count(strongerSide, BISHOP) == 1); assert(pos.piece_count(strongerSide, KNIGHT) == 1); @@ -150,17 +196,20 @@ Value EvaluationFunction::apply(const Position& pos) const { 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]; - if (same_color_squares(bishopSquare, SQ_A1)) + // 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 (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; } @@ -168,10 +217,10 @@ Value EvaluationFunction::apply(const Position& pos) const { /// KP vs K. This endgame is evaluated with the help of a bitbase. template<> -Value EvaluationFunction::apply(const Position& pos) const { +Value Endgame::apply(const Position& pos) const { - assert(pos.non_pawn_material(strongerSide) == Value(0)); - assert(pos.non_pawn_material(weakerSide) == Value(0)); + assert(pos.non_pawn_material(strongerSide) == VALUE_ZERO); + assert(pos.non_pawn_material(weakerSide) == VALUE_ZERO); assert(pos.piece_count(strongerSide, PAWN) == 1); assert(pos.piece_count(weakerSide, PAWN) == 0); @@ -182,14 +231,14 @@ Value EvaluationFunction::apply(const Position& pos) const { { 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()); } @@ -200,7 +249,7 @@ Value EvaluationFunction::apply(const Position& pos) const { 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 @@ -216,7 +265,7 @@ Value EvaluationFunction::apply(const Position& pos) const { /// far advanced with support of the king, while the attacking king is far /// away. template<> -Value EvaluationFunction::apply(const Position& pos) const { +Value Endgame::apply(const Position& pos) const { assert(pos.non_pawn_material(strongerSide) == RookValueMidgame); assert(pos.piece_count(strongerSide, PAWN) == 0); @@ -227,9 +276,9 @@ Value EvaluationFunction::apply(const Position& pos) const { 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) { @@ -273,7 +322,7 @@ Value EvaluationFunction::apply(const Position& pos) const { /// 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::apply(const Position& pos) const { +Value Endgame::apply(const Position& pos) const { assert(pos.non_pawn_material(strongerSide) == RookValueMidgame); assert(pos.piece_count(strongerSide, PAWN) == 0); @@ -281,7 +330,7 @@ Value EvaluationFunction::apply(const Position& pos) const { 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; } @@ -289,7 +338,7 @@ Value EvaluationFunction::apply(const Position& pos) const { /// 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::apply(const Position& pos) const { +Value Endgame::apply(const Position& pos) const { assert(pos.non_pawn_material(strongerSide) == RookValueMidgame); assert(pos.piece_count(strongerSide, PAWN) == 0); @@ -298,12 +347,12 @@ Value EvaluationFunction::apply(const Position& pos) const { 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; } @@ -315,7 +364,7 @@ Value EvaluationFunction::apply(const Position& pos) const { /// for the defending side in the search, this is usually sufficient to be /// able to win KQ vs KR. template<> -Value EvaluationFunction::apply(const Position& pos) const { +Value Endgame::apply(const Position& pos) const { assert(pos.non_pawn_material(strongerSide) == QueenValueMidgame); assert(pos.piece_count(strongerSide, PAWN) == 0); @@ -327,14 +376,14 @@ Value EvaluationFunction::apply(const Position& pos) const { 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::apply(const Position& pos) const { +Value Endgame::apply(const Position& pos) const { assert(pos.piece_count(strongerSide, BISHOP) == 2); assert(pos.non_pawn_material(strongerSide) == 2*BishopValueMidgame); @@ -345,16 +394,16 @@ Value EvaluationFunction::apply(const Position& pos) const { 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); // Bonus for restricting the knight's mobility - result += Value((8 - count_1s_max_15(pos.attacks_from(nsq))) * 8); + result += Value((8 - count_1s(pos.attacks_from(nsq))) * 8); return strongerSide == pos.side_to_move() ? result : -result; } @@ -363,13 +412,13 @@ Value EvaluationFunction::apply(const Position& pos) const { /// 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::apply(const Position&) const { - return Value(0); +Value Endgame::apply(const Position&) const { + return VALUE_DRAW; } template<> -Value EvaluationFunction::apply(const Position&) const { - return Value(0); +Value Endgame::apply(const Position&) const { + return VALUE_DRAW; } /// KBPKScalingFunction scales endgames where the stronger side has king, @@ -378,7 +427,7 @@ Value EvaluationFunction::apply(const Position&) const { /// returned. If not, the return value is SCALE_FACTOR_NONE, i.e. no scaling /// will be used. template<> -ScaleFactor ScalingFunction::apply(const Position& pos) const { +ScaleFactor Endgame::apply(const Position& pos) const { assert(pos.non_pawn_material(strongerSide) == BishopValueMidgame); assert(pos.piece_count(strongerSide, BISHOP) == 1); @@ -388,18 +437,18 @@ ScaleFactor ScalingFunction::apply(const Position& pos) const { // 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 @@ -432,7 +481,7 @@ ScaleFactor ScalingFunction::apply(const Position& pos) const { /// It tests for fortress draws with a rook on the third rank defended by /// a pawn. template<> -ScaleFactor ScalingFunction::apply(const Position& pos) const { +ScaleFactor Endgame::apply(const Position& pos) const { assert(pos.non_pawn_material(strongerSide) == QueenValueMidgame); assert(pos.piece_count(strongerSide, QUEEN) == 1); @@ -443,11 +492,11 @@ ScaleFactor ScalingFunction::apply(const Position& pos) const { 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(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(rsq, strongerSide) & pos.pieces(PAWN, weakerSide)) return SCALE_FACTOR_ZERO; } @@ -463,7 +512,7 @@ ScaleFactor ScalingFunction::apply(const Position& pos) const { /// 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::apply(const Position& pos) const { +ScaleFactor Endgame::apply(const Position& pos) const { assert(pos.non_pawn_material(strongerSide) == RookValueMidgame); assert(pos.piece_count(strongerSide, PAWN) == 1); @@ -471,10 +520,10 @@ ScaleFactor ScalingFunction::apply(const Position& pos) const { 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. @@ -581,15 +630,15 @@ ScaleFactor ScalingFunction::apply(const Position& pos) const { /// single pattern: If the stronger side has no pawns and the defending king /// is actively placed, the position is drawish. template<> -ScaleFactor ScalingFunction::apply(const Position& pos) const { +ScaleFactor Endgame::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? @@ -620,11 +669,11 @@ ScaleFactor ScalingFunction::apply(const Position& pos) const { /// 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::apply(const Position& pos) const { +ScaleFactor Endgame::apply(const Position& pos) const { - assert(pos.non_pawn_material(strongerSide) == Value(0)); + assert(pos.non_pawn_material(strongerSide) == VALUE_ZERO); assert(pos.piece_count(strongerSide, PAWN) >= 2); - assert(pos.non_pawn_material(weakerSide) == Value(0)); + assert(pos.non_pawn_material(weakerSide) == VALUE_ZERO); assert(pos.piece_count(weakerSide, PAWN) == 0); Square ksq = pos.king_square(weakerSide); @@ -658,7 +707,7 @@ ScaleFactor ScalingFunction::apply(const Position& pos) const { /// it's a draw. If the two bishops have opposite color, it's almost always /// a draw. template<> -ScaleFactor ScalingFunction::apply(const Position& pos) const { +ScaleFactor Endgame::apply(const Position& pos) const { assert(pos.non_pawn_material(strongerSide) == BishopValueMidgame); assert(pos.piece_count(strongerSide, BISHOP) == 1); @@ -667,20 +716,20 @@ ScaleFactor ScalingFunction::apply(const Position& pos) const { 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: // @@ -696,11 +745,12 @@ ScaleFactor ScalingFunction::apply(const Position& pos) const { return SCALE_FACTOR_ZERO; else { - Bitboard ray = ray_bb(pawnSq, (strongerSide == WHITE)? SIGNED_DIR_N : SIGNED_DIR_S); - if (ray & pos.pieces(KING, weakerSide)) + Bitboard path = squares_in_front_of(strongerSide, pawnSq); + + if (path & pos.pieces(KING, weakerSide)) return SCALE_FACTOR_ZERO; - if ( (pos.attacks_from(weakerBishopSq) & ray) + if ( (pos.attacks_from(weakerBishopSq) & path) && square_distance(weakerBishopSq, pawnSq) >= 3) return SCALE_FACTOR_ZERO; } @@ -712,7 +762,7 @@ ScaleFactor ScalingFunction::apply(const Position& pos) const { /// KBPPKBScalingFunction scales KBPP vs KB endgames. It detects a few basic /// draws with opposite-colored bishops. template<> -ScaleFactor ScalingFunction::apply(const Position& pos) const { +ScaleFactor Endgame::apply(const Position& pos) const { assert(pos.non_pawn_material(strongerSide) == BishopValueMidgame); assert(pos.piece_count(strongerSide, BISHOP) == 1); @@ -721,16 +771,15 @@ ScaleFactor ScalingFunction::apply(const Position& pos) const { 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; @@ -753,7 +802,7 @@ ScaleFactor ScalingFunction::apply(const Position& pos) const { // 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; @@ -763,14 +812,14 @@ ScaleFactor ScalingFunction::apply(const Position& pos) const { // 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(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(blockSq1) & pos.pieces(BISHOP, weakerSide)))) return SCALE_FACTOR_ZERO; @@ -789,7 +838,7 @@ ScaleFactor ScalingFunction::apply(const Position& pos) const { /// square of the king is not of the same color as the stronger side's bishop, /// it's a draw. template<> -ScaleFactor ScalingFunction::apply(const Position& pos) const { +ScaleFactor Endgame::apply(const Position& pos) const { assert(pos.non_pawn_material(strongerSide) == BishopValueMidgame); assert(pos.piece_count(strongerSide, BISHOP) == 1); @@ -798,13 +847,13 @@ ScaleFactor ScalingFunction::apply(const Position& pos) const { 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; @@ -816,15 +865,15 @@ ScaleFactor ScalingFunction::apply(const Position& pos) const { /// 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::apply(const Position& pos) const { +ScaleFactor Endgame::apply(const Position& pos) const { assert(pos.non_pawn_material(strongerSide) == KnightValueMidgame); assert(pos.piece_count(strongerSide, KNIGHT) == 1); assert(pos.piece_count(strongerSide, PAWN) == 1); - assert(pos.non_pawn_material(weakerSide) == Value(0)); + 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) @@ -846,10 +895,10 @@ ScaleFactor ScalingFunction::apply(const Position& pos) const { /// 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::apply(const Position& pos) const { +ScaleFactor Endgame::apply(const Position& pos) const { - assert(pos.non_pawn_material(strongerSide) == Value(0)); - assert(pos.non_pawn_material(weakerSide) == Value(0)); + assert(pos.non_pawn_material(strongerSide) == VALUE_ZERO); + assert(pos.non_pawn_material(weakerSide) == VALUE_ZERO); assert(pos.piece_count(WHITE, PAWN) == 1); assert(pos.piece_count(BLACK, PAWN) == 1); @@ -860,14 +909,14 @@ ScaleFactor ScalingFunction::apply(const Position& pos) const { { 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()); } @@ -886,21 +935,5 @@ ScaleFactor ScalingFunction::apply(const Position& pos) const { // 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; }