X-Git-Url: https://git.sesse.net/?p=stockfish;a=blobdiff_plain;f=src%2Fendgame.cpp;h=04469e87b4ea3f23d09d22852bd7b152370904d4;hp=4ee515ade71cab5c856f3f6c547d1fd959a8820f;hb=b96dd754ede60b8463606cf38eac3eab400a123d;hpb=c0d3010438e9cec2d40dec9e92695b58514497bb diff --git a/src/endgame.cpp b/src/endgame.cpp index 4ee515ad..04469e87 100644 --- a/src/endgame.cpp +++ b/src/endgame.cpp @@ -1,7 +1,8 @@ /* Stockfish, a UCI chess playing engine derived from Glaurung 2.1 Copyright (C) 2004-2008 Tord Romstad (Glaurung author) - Copyright (C) 2008-2014 Marco Costalba, Joona Kiiski, Tord Romstad + Copyright (C) 2008-2015 Marco Costalba, Joona Kiiski, Tord Romstad + Copyright (C) 2015-2016 Marco Costalba, Joona Kiiski, Gary Linscott, Tord Romstad Stockfish is free software: you can redistribute it and/or modify it under the terms of the GNU General Public License as published by @@ -21,7 +22,6 @@ #include #include "bitboard.h" -#include "bitcount.h" #include "endgame.h" #include "movegen.h" @@ -39,7 +39,7 @@ namespace { 70, 50, 30, 20, 20, 30, 50, 70, 80, 60, 40, 30, 30, 40, 60, 80, 90, 70, 60, 50, 50, 60, 70, 90, - 100, 90, 80, 70, 70, 80, 90, 100, + 100, 90, 80, 70, 70, 80, 90, 100 }; // Table used to drive the king towards a corner square of the @@ -59,9 +59,12 @@ namespace { const int PushClose[8] = { 0, 0, 100, 80, 60, 40, 20, 10 }; const int PushAway [8] = { 0, 5, 20, 40, 60, 80, 90, 100 }; + // Pawn Rank based scaling factors used in KRPPKRP endgame + const int KRPPKRPScaleFactors[RANK_NB] = { 0, 9, 10, 14, 21, 44, 0, 0 }; + #ifndef NDEBUG - bool verify_material(const Position& pos, Color c, Value npm, int num_pawns) { - return pos.non_pawn_material(c) == npm && pos.count(c) == num_pawns; + bool verify_material(const Position& pos, Color c, Value npm, int pawnsCnt) { + return pos.non_pawn_material(c) == npm && pos.count(c) == pawnsCnt; } #endif @@ -71,7 +74,7 @@ namespace { assert(pos.count(strongSide) == 1); - if (file_of(pos.list(strongSide)[0]) >= FILE_E) + if (file_of(pos.square(strongSide)) >= FILE_E) sq = Square(sq ^ 7); // Mirror SQ_H1 -> SQ_A1 if (strongSide == BLACK) @@ -96,12 +99,10 @@ namespace { string fen = sides[0] + char(8 - sides[0].length() + '0') + "/8/8/8/8/8/8/" + sides[1] + char(8 - sides[1].length() + '0') + " w - - 0 10"; - return Position(fen, false, NULL).material_key(); + StateInfo st; + return Position().set(fen, false, &st, nullptr).material_key(); } - template - void delete_endgame(const typename M::value_type& p) { delete p.second; } - } // namespace @@ -128,17 +129,11 @@ Endgames::Endgames() { add("KRPPKRP"); } -Endgames::~Endgames() { - for_each(m1.begin(), m1.end(), delete_endgame); - for_each(m2.begin(), m2.end(), delete_endgame); -} - -template +template void Endgames::add(const string& code) { - - map((Endgame*)0)[key(code, WHITE)] = new Endgame(WHITE); - map((Endgame*)0)[key(code, BLACK)] = new Endgame(BLACK); + map()[key(code, WHITE)] = std::unique_ptr>(new Endgame(WHITE)); + map()[key(code, BLACK)] = std::unique_ptr>(new Endgame(BLACK)); } @@ -156,19 +151,20 @@ Value Endgame::operator()(const Position& pos) const { if (pos.side_to_move() == weakSide && !MoveList(pos).size()) return VALUE_DRAW; - Square winnerKSq = pos.king_square(strongSide); - Square loserKSq = pos.king_square(weakSide); + Square winnerKSq = pos.square(strongSide); + Square loserKSq = pos.square(weakSide); Value result = pos.non_pawn_material(strongSide) + pos.count(strongSide) * PawnValueEg + PushToEdges[loserKSq] - + PushClose[square_distance(winnerKSq, loserKSq)]; + + PushClose[distance(winnerKSq, loserKSq)]; if ( pos.count(strongSide) || pos.count(strongSide) ||(pos.count(strongSide) && pos.count(strongSide)) - || pos.bishop_pair(strongSide)) - result += VALUE_KNOWN_WIN; + ||(pos.count(strongSide) > 1 && opposite_colors(pos.squares(strongSide)[0], + pos.squares(strongSide)[1]))) + result = std::min(result + VALUE_KNOWN_WIN, VALUE_MATE_IN_MAX_PLY - 1); return strongSide == pos.side_to_move() ? result : -result; } @@ -182,9 +178,9 @@ Value Endgame::operator()(const Position& pos) const { assert(verify_material(pos, strongSide, KnightValueMg + BishopValueMg, 0)); assert(verify_material(pos, weakSide, VALUE_ZERO, 0)); - Square winnerKSq = pos.king_square(strongSide); - Square loserKSq = pos.king_square(weakSide); - Square bishopSq = pos.list(strongSide)[0]; + Square winnerKSq = pos.square(strongSide); + Square loserKSq = pos.square(weakSide); + Square bishopSq = pos.square(strongSide); // kbnk_mate_table() tries to drive toward corners A1 or H8. If we have a // bishop that cannot reach the above squares, we flip the kings in order @@ -196,7 +192,7 @@ Value Endgame::operator()(const Position& pos) const { } Value result = VALUE_KNOWN_WIN - + PushClose[square_distance(winnerKSq, loserKSq)] + + PushClose[distance(winnerKSq, loserKSq)] + PushToCorners[loserKSq]; return strongSide == pos.side_to_move() ? result : -result; @@ -211,13 +207,13 @@ Value Endgame::operator()(const Position& pos) const { assert(verify_material(pos, weakSide, VALUE_ZERO, 0)); // Assume strongSide is white and the pawn is on files A-D - Square wksq = normalize(pos, strongSide, pos.king_square(strongSide)); - Square bksq = normalize(pos, strongSide, pos.king_square(weakSide)); - Square psq = normalize(pos, strongSide, pos.list(strongSide)[0]); + Square wksq = normalize(pos, strongSide, pos.square(strongSide)); + Square bksq = normalize(pos, strongSide, pos.square(weakSide)); + Square psq = normalize(pos, strongSide, pos.square(strongSide)); Color us = strongSide == pos.side_to_move() ? WHITE : BLACK; - if (!Bitbases::probe_kpk(wksq, psq, bksq, us)) + if (!Bitbases::probe(wksq, psq, bksq, us)) return VALUE_DRAW; Value result = VALUE_KNOWN_WIN + PawnValueEg + Value(rank_of(psq)); @@ -236,36 +232,36 @@ Value Endgame::operator()(const Position& pos) const { assert(verify_material(pos, strongSide, RookValueMg, 0)); assert(verify_material(pos, weakSide, VALUE_ZERO, 1)); - Square wksq = relative_square(strongSide, pos.king_square(strongSide)); - Square bksq = relative_square(strongSide, pos.king_square(weakSide)); - Square rsq = relative_square(strongSide, pos.list(strongSide)[0]); - Square psq = relative_square(strongSide, pos.list(weakSide)[0]); + Square wksq = relative_square(strongSide, pos.square(strongSide)); + Square bksq = relative_square(strongSide, pos.square(weakSide)); + Square rsq = relative_square(strongSide, pos.square(strongSide)); + Square psq = relative_square(strongSide, pos.square(weakSide)); Square queeningSq = make_square(file_of(psq), RANK_1); Value result; // If the stronger side's king is in front of the pawn, it's a win if (wksq < psq && file_of(wksq) == file_of(psq)) - result = RookValueEg - square_distance(wksq, psq); + result = RookValueEg - distance(wksq, psq); // If the weaker side's king is too far from the pawn and the rook, // it's a win. - else if ( square_distance(bksq, psq) >= 3 + (pos.side_to_move() == weakSide) - && square_distance(bksq, rsq) >= 3) - result = RookValueEg - square_distance(wksq, psq); + else if ( distance(bksq, psq) >= 3 + (pos.side_to_move() == weakSide) + && distance(bksq, rsq) >= 3) + result = RookValueEg - distance(wksq, psq); // If the pawn is far advanced and supported by the defending king, // the position is drawish else if ( rank_of(bksq) <= RANK_3 - && square_distance(bksq, psq) == 1 + && distance(bksq, psq) == 1 && rank_of(wksq) >= RANK_4 - && square_distance(wksq, psq) > 2 + (pos.side_to_move() == strongSide)) - result = Value(80) - 8 * square_distance(wksq, psq); + && distance(wksq, psq) > 2 + (pos.side_to_move() == strongSide)) + result = Value(80) - 8 * distance(wksq, psq); else - result = Value(200) - 8 * ( square_distance(wksq, psq + DELTA_S) - - square_distance(bksq, psq + DELTA_S) - - square_distance(psq, queeningSq)); + result = Value(200) - 8 * ( distance(wksq, psq + DELTA_S) + - distance(bksq, psq + DELTA_S) + - distance(psq, queeningSq)); return strongSide == pos.side_to_move() ? result : -result; } @@ -279,7 +275,7 @@ Value Endgame::operator()(const Position& pos) const { assert(verify_material(pos, strongSide, RookValueMg, 0)); assert(verify_material(pos, weakSide, BishopValueMg, 0)); - Value result = Value(PushToEdges[pos.king_square(weakSide)]); + Value result = Value(PushToEdges[pos.square(weakSide)]); return strongSide == pos.side_to_move() ? result : -result; } @@ -292,9 +288,9 @@ Value Endgame::operator()(const Position& pos) const { assert(verify_material(pos, strongSide, RookValueMg, 0)); assert(verify_material(pos, weakSide, KnightValueMg, 0)); - Square bksq = pos.king_square(weakSide); - Square bnsq = pos.list(weakSide)[0]; - Value result = Value(PushToEdges[bksq] + PushAway[square_distance(bksq, bnsq)]); + Square bksq = pos.square(weakSide); + Square bnsq = pos.square(weakSide); + Value result = Value(PushToEdges[bksq] + PushAway[distance(bksq, bnsq)]); return strongSide == pos.side_to_move() ? result : -result; } @@ -309,14 +305,14 @@ Value Endgame::operator()(const Position& pos) const { assert(verify_material(pos, strongSide, QueenValueMg, 0)); assert(verify_material(pos, weakSide, VALUE_ZERO, 1)); - Square winnerKSq = pos.king_square(strongSide); - Square loserKSq = pos.king_square(weakSide); - Square pawnSq = pos.list(weakSide)[0]; + Square winnerKSq = pos.square(strongSide); + Square loserKSq = pos.square(weakSide); + Square pawnSq = pos.square(weakSide); - Value result = Value(PushClose[square_distance(winnerKSq, loserKSq)]); + Value result = Value(PushClose[distance(winnerKSq, loserKSq)]); if ( relative_rank(weakSide, pawnSq) != RANK_7 - || square_distance(loserKSq, pawnSq) != 1 + || distance(loserKSq, pawnSq) != 1 || !((FileABB | FileCBB | FileFBB | FileHBB) & pawnSq)) result += QueenValueEg - PawnValueEg; @@ -334,13 +330,13 @@ Value Endgame::operator()(const Position& pos) const { assert(verify_material(pos, strongSide, QueenValueMg, 0)); assert(verify_material(pos, weakSide, RookValueMg, 0)); - Square winnerKSq = pos.king_square(strongSide); - Square loserKSq = pos.king_square(weakSide); + Square winnerKSq = pos.square(strongSide); + Square loserKSq = pos.square(weakSide); Value result = QueenValueEg - RookValueEg + PushToEdges[loserKSq] - + PushClose[square_distance(winnerKSq, loserKSq)]; + + PushClose[distance(winnerKSq, loserKSq)]; return strongSide == pos.side_to_move() ? result : -result; } @@ -366,25 +362,50 @@ ScaleFactor Endgame::operator()(const Position& pos) const { Bitboard pawns = pos.pieces(strongSide, PAWN); File pawnsFile = file_of(lsb(pawns)); - // All pawns are on a single rook file ? + // All pawns are on a single rook file? if ( (pawnsFile == FILE_A || pawnsFile == FILE_H) && !(pawns & ~file_bb(pawnsFile))) { - Square bishopSq = pos.list(strongSide)[0]; + Square bishopSq = pos.square(strongSide); Square queeningSq = relative_square(strongSide, make_square(pawnsFile, RANK_8)); - Square kingSq = pos.king_square(weakSide); + Square kingSq = pos.square(weakSide); - // If the bishop has the wrong color, and the defending king is on the file - // of the pawn(s) or the neighboring file, then it's potentially a draw. if ( opposite_colors(queeningSq, bishopSq) - && file_distance(kingSq, lsb(pawns)) <= 1) - { - // If the defending king has distance <= 1 to the promotion square or - // is placed somewhere in front of the frontmost pawn, it's a draw. - Rank rank = relative_rank(strongSide, (frontmost_sq(strongSide, pawns))); + && distance(queeningSq, kingSq) <= 1) + return SCALE_FACTOR_DRAW; + } - if ( square_distance(kingSq, queeningSq) <= 1 - || relative_rank(strongSide, kingSq) >= rank) + // If all the pawns are on the same B or G file, then it's potentially a draw + if ( (pawnsFile == FILE_B || pawnsFile == FILE_G) + && !(pos.pieces(PAWN) & ~file_bb(pawnsFile)) + && pos.non_pawn_material(weakSide) == 0 + && pos.count(weakSide) >= 1) + { + // Get weakSide pawn that is closest to the home rank + Square weakPawnSq = backmost_sq(weakSide, pos.pieces(weakSide, PAWN)); + + Square strongKingSq = pos.square(strongSide); + Square weakKingSq = pos.square(weakSide); + Square bishopSq = pos.square(strongSide); + + // There's potential for a draw if our pawn is blocked on the 7th rank, + // the bishop cannot attack it or they only have one pawn left + if ( relative_rank(strongSide, weakPawnSq) == RANK_7 + && (pos.pieces(strongSide, PAWN) & (weakPawnSq + pawn_push(weakSide))) + && (opposite_colors(bishopSq, weakPawnSq) || pos.count(strongSide) == 1)) + { + int strongKingDist = distance(weakPawnSq, strongKingSq); + int weakKingDist = distance(weakPawnSq, weakKingSq); + + // It's a draw if the weak king is on its back two ranks, within 2 + // squares of the blocking pawn and the strong king is not + // closer. (I think this rule only fails in practically + // unreachable positions such as 5k1K/6p1/6P1/8/8/3B4/8/8 w + // and positions where qsearch will immediately correct the + // problem such as 8/4k1p1/6P1/1K6/3B4/8/8/8 w) + if ( relative_rank(strongSide, weakKingSq) >= RANK_7 + && weakKingDist <= 2 + && weakKingDist <= strongKingDist) return SCALE_FACTOR_DRAW; } } @@ -402,11 +423,11 @@ ScaleFactor Endgame::operator()(const Position& pos) const { assert(pos.count(weakSide) == 1); assert(pos.count(weakSide) >= 1); - Square kingSq = pos.king_square(weakSide); - Square rsq = pos.list(weakSide)[0]; + Square kingSq = pos.square(weakSide); + Square rsq = pos.square(weakSide); if ( relative_rank(weakSide, kingSq) <= RANK_2 - && relative_rank(weakSide, pos.king_square(strongSide)) >= RANK_4 + && relative_rank(weakSide, pos.square(strongSide)) >= RANK_4 && relative_rank(weakSide, rsq) == RANK_3 && ( pos.pieces(weakSide, PAWN) & pos.attacks_from(kingSq) @@ -430,11 +451,11 @@ ScaleFactor Endgame::operator()(const Position& pos) const { assert(verify_material(pos, weakSide, RookValueMg, 0)); // Assume strongSide is white and the pawn is on files A-D - Square wksq = normalize(pos, strongSide, pos.king_square(strongSide)); - Square bksq = normalize(pos, strongSide, pos.king_square(weakSide)); - Square wrsq = normalize(pos, strongSide, pos.list(strongSide)[0]); - Square wpsq = normalize(pos, strongSide, pos.list(strongSide)[0]); - Square brsq = normalize(pos, strongSide, pos.list(weakSide)[0]); + Square wksq = normalize(pos, strongSide, pos.square(strongSide)); + Square bksq = normalize(pos, strongSide, pos.square(weakSide)); + Square wrsq = normalize(pos, strongSide, pos.square(strongSide)); + Square wpsq = normalize(pos, strongSide, pos.square(strongSide)); + Square brsq = normalize(pos, strongSide, pos.square(weakSide)); File f = file_of(wpsq); Rank r = rank_of(wpsq); @@ -444,7 +465,7 @@ ScaleFactor Endgame::operator()(const Position& pos) const { // If the pawn is not too far advanced and the defending king defends the // queening square, use the third-rank defence. if ( r <= RANK_5 - && square_distance(bksq, queeningSq) <= 1 + && distance(bksq, queeningSq) <= 1 && wksq <= SQ_H5 && (rank_of(brsq) == RANK_6 || (r <= RANK_3 && rank_of(wrsq) != RANK_6))) return SCALE_FACTOR_DRAW; @@ -452,15 +473,15 @@ ScaleFactor Endgame::operator()(const Position& pos) const { // The defending side saves a draw by checking from behind in case the pawn // has advanced to the 6th rank with the king behind. if ( r == RANK_6 - && square_distance(bksq, queeningSq) <= 1 + && distance(bksq, queeningSq) <= 1 && rank_of(wksq) + tempo <= RANK_6 - && (rank_of(brsq) == RANK_1 || (!tempo && abs(file_of(brsq) - f) >= 3))) + && (rank_of(brsq) == RANK_1 || (!tempo && distance(brsq, wpsq) >= 3))) return SCALE_FACTOR_DRAW; if ( r >= RANK_6 && bksq == queeningSq && rank_of(brsq) == RANK_1 - && (!tempo || square_distance(wksq, wpsq) >= 2)) + && (!tempo || distance(wksq, wpsq) >= 2)) return SCALE_FACTOR_DRAW; // White pawn on a7 and rook on a8 is a draw if black's king is on g7 or h7 @@ -476,8 +497,8 @@ ScaleFactor Endgame::operator()(const Position& pos) const { // away, it's a draw. if ( r <= RANK_5 && bksq == wpsq + DELTA_N - && square_distance(wksq, wpsq) - tempo >= 2 - && square_distance(wksq, brsq) - tempo >= 2) + && distance(wksq, wpsq) - tempo >= 2 + && distance(wksq, brsq) - tempo >= 2) return SCALE_FACTOR_DRAW; // Pawn on the 7th rank supported by the rook from behind usually wins if the @@ -487,22 +508,22 @@ ScaleFactor Endgame::operator()(const Position& pos) const { && f != FILE_A && file_of(wrsq) == f && wrsq != queeningSq - && (square_distance(wksq, queeningSq) < square_distance(bksq, queeningSq) - 2 + tempo) - && (square_distance(wksq, queeningSq) < square_distance(bksq, wrsq) + tempo)) - return ScaleFactor(SCALE_FACTOR_MAX - 2 * square_distance(wksq, queeningSq)); + && (distance(wksq, queeningSq) < distance(bksq, queeningSq) - 2 + tempo) + && (distance(wksq, queeningSq) < distance(bksq, wrsq) + tempo)) + return ScaleFactor(SCALE_FACTOR_MAX - 2 * distance(wksq, queeningSq)); // Similar to the above, but with the pawn further back if ( f != FILE_A && file_of(wrsq) == f && wrsq < wpsq - && (square_distance(wksq, queeningSq) < square_distance(bksq, queeningSq) - 2 + tempo) - && (square_distance(wksq, wpsq + DELTA_N) < square_distance(bksq, wpsq + DELTA_N) - 2 + tempo) - && ( square_distance(bksq, wrsq) + tempo >= 3 - || ( square_distance(wksq, queeningSq) < square_distance(bksq, wrsq) + tempo - && (square_distance(wksq, wpsq + DELTA_N) < square_distance(bksq, wrsq) + tempo)))) + && (distance(wksq, queeningSq) < distance(bksq, queeningSq) - 2 + tempo) + && (distance(wksq, wpsq + DELTA_N) < distance(bksq, wpsq + DELTA_N) - 2 + tempo) + && ( distance(bksq, wrsq) + tempo >= 3 + || ( distance(wksq, queeningSq) < distance(bksq, wrsq) + tempo + && (distance(wksq, wpsq + DELTA_N) < distance(bksq, wrsq) + tempo)))) return ScaleFactor( SCALE_FACTOR_MAX - - 8 * square_distance(wpsq, queeningSq) - - 2 * square_distance(wksq, queeningSq)); + - 8 * distance(wpsq, queeningSq) + - 2 * distance(wksq, queeningSq)); // If the pawn is not far advanced and the defending king is somewhere in // the pawn's path, it's probably a draw. @@ -510,9 +531,9 @@ ScaleFactor Endgame::operator()(const Position& pos) const { { if (file_of(bksq) == file_of(wpsq)) return ScaleFactor(10); - if ( abs(file_of(bksq) - file_of(wpsq)) == 1 - && square_distance(wksq, bksq) > 2) - return ScaleFactor(24 - 2 * square_distance(wksq, bksq)); + if ( distance(bksq, wpsq) == 1 + && distance(wksq, bksq) > 2) + return ScaleFactor(24 - 2 * distance(wksq, bksq)); } return SCALE_FACTOR_NONE; } @@ -526,9 +547,9 @@ ScaleFactor Endgame::operator()(const Position& pos) const { // Test for a rook pawn if (pos.pieces(PAWN) & (FileABB | FileHBB)) { - Square ksq = pos.king_square(weakSide); - Square bsq = pos.list(weakSide)[0]; - Square psq = pos.list(strongSide)[0]; + Square ksq = pos.square(weakSide); + Square bsq = pos.square(weakSide); + Square psq = pos.square(strongSide); Rank rk = relative_rank(strongSide, psq); Square push = pawn_push(strongSide); @@ -539,9 +560,9 @@ ScaleFactor Endgame::operator()(const Position& pos) const { // corner but not trapped there. if (rk == RANK_5 && !opposite_colors(bsq, psq)) { - int d = square_distance(psq + 3 * push, ksq); + int d = distance(psq + 3 * push, ksq); - if (d <= 2 && !(d == 0 && ksq == pos.king_square(strongSide) + 2 * push)) + if (d <= 2 && !(d == 0 && ksq == pos.square(strongSide) + 2 * push)) return ScaleFactor(24); else return ScaleFactor(48); @@ -552,9 +573,9 @@ ScaleFactor Endgame::operator()(const Position& pos) const { // pawn from a reasonable distance and the defending king is near // the corner if ( rk == RANK_6 - && square_distance(psq + 2 * push, ksq) <= 1 + && distance(psq + 2 * push, ksq) <= 1 && (PseudoAttacks[BISHOP][bsq] & (psq + push)) - && file_distance(bsq, psq) >= 2) + && distance(bsq, psq) >= 2) return ScaleFactor(8); } @@ -569,9 +590,9 @@ ScaleFactor Endgame::operator()(const Position& pos) const { assert(verify_material(pos, strongSide, RookValueMg, 2)); assert(verify_material(pos, weakSide, RookValueMg, 1)); - Square wpsq1 = pos.list(strongSide)[0]; - Square wpsq2 = pos.list(strongSide)[1]; - Square bksq = pos.king_square(weakSide); + Square wpsq1 = pos.squares(strongSide)[0]; + Square wpsq2 = pos.squares(strongSide)[1]; + Square bksq = pos.square(weakSide); // Does the stronger side have a passed pawn? if (pos.pawn_passed(strongSide, wpsq1) || pos.pawn_passed(strongSide, wpsq2)) @@ -579,18 +600,12 @@ ScaleFactor Endgame::operator()(const Position& pos) const { Rank r = std::max(relative_rank(strongSide, wpsq1), relative_rank(strongSide, wpsq2)); - if ( file_distance(bksq, wpsq1) <= 1 - && file_distance(bksq, wpsq2) <= 1 + if ( distance(bksq, wpsq1) <= 1 + && distance(bksq, wpsq2) <= 1 && relative_rank(strongSide, bksq) > r) { - switch (r) { - case RANK_2: return ScaleFactor(10); - case RANK_3: return ScaleFactor(10); - case RANK_4: return ScaleFactor(15); - case RANK_5: return ScaleFactor(20); - case RANK_6: return ScaleFactor(40); - default: assert(false); - } + assert(r > RANK_1 && r < RANK_7); + return ScaleFactor(KRPPKRPScaleFactors[r]); } return SCALE_FACTOR_NONE; } @@ -605,15 +620,14 @@ ScaleFactor Endgame::operator()(const Position& pos) const { assert(pos.count(strongSide) >= 2); assert(verify_material(pos, weakSide, VALUE_ZERO, 0)); - Square ksq = pos.king_square(weakSide); + Square ksq = pos.square(weakSide); Bitboard pawns = pos.pieces(strongSide, PAWN); - Square psq = pos.list(strongSide)[0]; // If all pawns are ahead of the king, on a single rook file and // the king is within one file of the pawns, it's a draw. if ( !(pawns & ~in_front_bb(weakSide, rank_of(ksq))) && !((pawns & ~FileABB) && (pawns & ~FileHBB)) - && file_distance(ksq, psq) <= 1) + && distance(ksq, lsb(pawns)) <= 1) return SCALE_FACTOR_DRAW; return SCALE_FACTOR_NONE; @@ -630,10 +644,10 @@ ScaleFactor Endgame::operator()(const Position& pos) const { assert(verify_material(pos, strongSide, BishopValueMg, 1)); assert(verify_material(pos, weakSide, BishopValueMg, 0)); - Square pawnSq = pos.list(strongSide)[0]; - Square strongBishopSq = pos.list(strongSide)[0]; - Square weakBishopSq = pos.list(weakSide)[0]; - Square weakKingSq = pos.king_square(weakSide); + Square pawnSq = pos.square(strongSide); + Square strongBishopSq = pos.square(strongSide); + Square weakBishopSq = pos.square(weakSide); + Square weakKingSq = pos.square(weakSide); // Case 1: Defending king blocks the pawn, and cannot be driven away if ( file_of(weakKingSq) == file_of(pawnSq) @@ -665,7 +679,7 @@ ScaleFactor Endgame::operator()(const Position& pos) const { return SCALE_FACTOR_DRAW; if ( (pos.attacks_from(weakBishopSq) & path) - && square_distance(weakBishopSq, pawnSq) >= 3) + && distance(weakBishopSq, pawnSq) >= 3) return SCALE_FACTOR_DRAW; } } @@ -680,15 +694,15 @@ ScaleFactor Endgame::operator()(const Position& pos) const { assert(verify_material(pos, strongSide, BishopValueMg, 2)); assert(verify_material(pos, weakSide, BishopValueMg, 0)); - Square wbsq = pos.list(strongSide)[0]; - Square bbsq = pos.list(weakSide)[0]; + Square wbsq = pos.square(strongSide); + Square bbsq = pos.square(weakSide); if (!opposite_colors(wbsq, bbsq)) return SCALE_FACTOR_NONE; - Square ksq = pos.king_square(weakSide); - Square psq1 = pos.list(strongSide)[0]; - Square psq2 = pos.list(strongSide)[1]; + Square ksq = pos.square(weakSide); + Square psq1 = pos.squares(strongSide)[0]; + Square psq2 = pos.squares(strongSide)[1]; Rank r1 = rank_of(psq1); Rank r2 = rank_of(psq2); Square blockSq1, blockSq2; @@ -704,7 +718,7 @@ ScaleFactor Endgame::operator()(const Position& pos) const { blockSq2 = make_square(file_of(psq1), rank_of(psq2)); } - switch (file_distance(psq1, psq2)) + switch (distance(psq1, psq2)) { case 0: // Both pawns are on the same file. It's an easy draw if the defender firmly @@ -724,7 +738,7 @@ ScaleFactor Endgame::operator()(const Position& pos) const { && opposite_colors(ksq, wbsq) && ( bbsq == blockSq2 || (pos.attacks_from(blockSq2) & pos.pieces(weakSide, BISHOP)) - || abs(r1 - r2) >= 2)) + || distance(r1, r2) >= 2)) return SCALE_FACTOR_DRAW; else if ( ksq == blockSq2 @@ -751,9 +765,9 @@ ScaleFactor Endgame::operator()(const Position& pos) const { assert(verify_material(pos, strongSide, BishopValueMg, 1)); assert(verify_material(pos, weakSide, KnightValueMg, 0)); - Square pawnSq = pos.list(strongSide)[0]; - Square strongBishopSq = pos.list(strongSide)[0]; - Square weakKingSq = pos.king_square(weakSide); + Square pawnSq = pos.square(strongSide); + Square strongBishopSq = pos.square(strongSide); + Square weakKingSq = pos.square(weakSide); if ( file_of(weakKingSq) == file_of(pawnSq) && relative_rank(strongSide, pawnSq) < relative_rank(strongSide, weakKingSq) @@ -774,10 +788,10 @@ ScaleFactor Endgame::operator()(const Position& pos) const { assert(verify_material(pos, weakSide, VALUE_ZERO, 0)); // Assume strongSide is white and the pawn is on files A-D - Square pawnSq = normalize(pos, strongSide, pos.list(strongSide)[0]); - Square weakKingSq = normalize(pos, strongSide, pos.king_square(weakSide)); + Square pawnSq = normalize(pos, strongSide, pos.square(strongSide)); + Square weakKingSq = normalize(pos, strongSide, pos.square(weakSide)); - if (pawnSq == SQ_A7 && square_distance(SQ_A8, weakKingSq) <= 1) + if (pawnSq == SQ_A7 && distance(SQ_A8, weakKingSq) <= 1) return SCALE_FACTOR_DRAW; return SCALE_FACTOR_NONE; @@ -789,14 +803,14 @@ ScaleFactor Endgame::operator()(const Position& pos) const { template<> ScaleFactor Endgame::operator()(const Position& pos) const { - Square pawnSq = pos.list(strongSide)[0]; - Square bishopSq = pos.list(weakSide)[0]; - Square weakKingSq = pos.king_square(weakSide); + Square pawnSq = pos.square(strongSide); + Square bishopSq = pos.square(weakSide); + Square weakKingSq = pos.square(weakSide); // King needs to get close to promoting pawn to prevent knight from blocking. // Rules for this are very tricky, so just approximate. if (forward_bb(strongSide, pawnSq) & pos.attacks_from(bishopSq)) - return ScaleFactor(square_distance(weakKingSq, pawnSq)); + return ScaleFactor(distance(weakKingSq, pawnSq)); return SCALE_FACTOR_NONE; } @@ -814,9 +828,9 @@ ScaleFactor Endgame::operator()(const Position& pos) const { assert(verify_material(pos, weakSide, VALUE_ZERO, 1)); // Assume strongSide is white and the pawn is on files A-D - Square wksq = normalize(pos, strongSide, pos.king_square(strongSide)); - Square bksq = normalize(pos, strongSide, pos.king_square(weakSide)); - Square psq = normalize(pos, strongSide, pos.list(strongSide)[0]); + Square wksq = normalize(pos, strongSide, pos.square(strongSide)); + Square bksq = normalize(pos, strongSide, pos.square(weakSide)); + Square psq = normalize(pos, strongSide, pos.square(strongSide)); Color us = strongSide == pos.side_to_move() ? WHITE : BLACK; @@ -827,5 +841,5 @@ ScaleFactor Endgame::operator()(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 Bitbases::probe_kpk(wksq, psq, bksq, us) ? SCALE_FACTOR_NONE : SCALE_FACTOR_DRAW; + return Bitbases::probe(wksq, psq, bksq, us) ? SCALE_FACTOR_NONE : SCALE_FACTOR_DRAW; }