/*
Stockfish, a UCI chess playing engine derived from Glaurung 2.1
Copyright (C) 2004-2008 Tord Romstad (Glaurung author)
- Copyright (C) 2008-2013 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
#include <cassert>
#include "bitboard.h"
-#include "bitcount.h"
#include "endgame.h"
#include "movegen.h"
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
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<PAWN>(c) == num_pawns;
+ bool verify_material(const Position& pos, Color c, Value npm, int pawnsCnt) {
+ return pos.non_pawn_material(c) == npm && pos.count<PAWN>(c) == pawnsCnt;
}
#endif
assert(pos.count<PAWN>(strongSide) == 1);
- if (file_of(pos.list<PAWN>(strongSide)[0]) >= FILE_E)
+ if (file_of(pos.square<PAWN>(strongSide)) >= FILE_E)
sq = Square(sq ^ 7); // Mirror SQ_H1 -> SQ_A1
if (strongSide == BLACK)
return sq;
}
- // Get the material key of a Position out of the given endgame key code
- // like "KBPKN". The trick here is to first forge an ad-hoc 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.
+ // Get the material key of Position out of the given endgame key code
+ // like "KBPKN". The trick here is to first forge an ad-hoc FEN string
+ // and then let a Position object do the work for us.
Key key(const string& code, Color c) {
assert(code.length() > 0 && code.length() < 8);
std::transform(sides[c].begin(), sides[c].end(), sides[c].begin(), tolower);
- string fen = sides[0] + char('0' + int(8 - code.length()))
- + sides[1] + "/8/8/8/8/8/8/8 w - - 0 10";
+ 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<typename M>
- void delete_endgame(const typename M::value_type& p) { delete p.second; }
-
} // namespace
add<KRKN>("KRKN");
add<KQKP>("KQKP");
add<KQKR>("KQKR");
- add<KBBKN>("KBBKN");
add<KNPK>("KNPK");
add<KNPKB>("KNPKB");
add<KRPPKRP>("KRPPKRP");
}
-Endgames::~Endgames() {
-
- for_each(m1.begin(), m1.end(), delete_endgame<M1>);
- for_each(m2.begin(), m2.end(), delete_endgame<M2>);
-}
-template<EndgameType E>
+template<EndgameType E, typename T>
void Endgames::add(const string& code) {
-
- map((Endgame<E>*)0)[key(code, WHITE)] = new Endgame<E>(WHITE);
- map((Endgame<E>*)0)[key(code, BLACK)] = new Endgame<E>(BLACK);
+ map<T>()[key(code, WHITE)] = std::unique_ptr<EndgameBase<T>>(new Endgame<E>(WHITE));
+ map<T>()[key(code, BLACK)] = std::unique_ptr<EndgameBase<T>>(new Endgame<E>(BLACK));
}
if (pos.side_to_move() == weakSide && !MoveList<LEGAL>(pos).size())
return VALUE_DRAW;
- Square winnerKSq = pos.king_square(strongSide);
- Square loserKSq = pos.king_square(weakSide);
+ Square winnerKSq = pos.square<KING>(strongSide);
+ Square loserKSq = pos.square<KING>(weakSide);
Value result = pos.non_pawn_material(strongSide)
+ pos.count<PAWN>(strongSide) * PawnValueEg
+ PushToEdges[loserKSq]
- + PushClose[square_distance(winnerKSq, loserKSq)];
+ + PushClose[distance(winnerKSq, loserKSq)];
if ( pos.count<QUEEN>(strongSide)
|| pos.count<ROOK>(strongSide)
- || pos.bishop_pair(strongSide))
- result += VALUE_KNOWN_WIN;
+ ||(pos.count<BISHOP>(strongSide) && pos.count<KNIGHT>(strongSide))
+ ||(pos.count<BISHOP>(strongSide) > 1 && opposite_colors(pos.squares<BISHOP>(strongSide)[0],
+ pos.squares<BISHOP>(strongSide)[1])))
+ result = std::min(result + VALUE_KNOWN_WIN, VALUE_MATE_IN_MAX_PLY - 1);
return strongSide == pos.side_to_move() ? result : -result;
}
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<BISHOP>(strongSide)[0];
+ Square winnerKSq = pos.square<KING>(strongSide);
+ Square loserKSq = pos.square<KING>(weakSide);
+ Square bishopSq = pos.square<BISHOP>(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
+ // 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
// to drive the enemy toward corners A8 or H1.
if (opposite_colors(bishopSq, SQ_A1))
{
}
Value result = VALUE_KNOWN_WIN
- + PushClose[square_distance(winnerKSq, loserKSq)]
+ + PushClose[distance(winnerKSq, loserKSq)]
+ PushToCorners[loserKSq];
return strongSide == pos.side_to_move() ? result : -result;
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<PAWN>(strongSide)[0]);
+ Square wksq = normalize(pos, strongSide, pos.square<KING>(strongSide));
+ Square bksq = normalize(pos, strongSide, pos.square<KING>(weakSide));
+ Square psq = normalize(pos, strongSide, pos.square<PAWN>(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));
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<ROOK>(strongSide)[0]);
- Square psq = relative_square(strongSide, pos.list<PAWN>(weakSide)[0]);
+ Square wksq = relative_square(strongSide, pos.square<KING>(strongSide));
+ Square bksq = relative_square(strongSide, pos.square<KING>(weakSide));
+ Square rsq = relative_square(strongSide, pos.square<ROOK>(strongSide));
+ Square psq = relative_square(strongSide, pos.square<PAWN>(weakSide));
- Square queeningSq = file_of(psq) | RANK_1;
+ 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 - Value(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 - Value(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 - square_distance(wksq, psq) * 8);
+ && distance(wksq, psq) > 2 + (pos.side_to_move() == strongSide))
+ result = Value(80) - 8 * distance(wksq, psq);
else
- result = Value(200)
- - Value(square_distance(wksq, psq + DELTA_S) * 8)
- + Value(square_distance(bksq, psq + DELTA_S) * 8)
- + Value(square_distance(psq, queeningSq) * 8);
+ result = Value(200) - 8 * ( distance(wksq, psq + SOUTH)
+ - distance(bksq, psq + SOUTH)
+ - distance(psq, queeningSq));
return strongSide == pos.side_to_move() ? result : -result;
}
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<KING>(weakSide)]);
return strongSide == pos.side_to_move() ? result : -result;
}
-/// KR vs KN. The attacking side has slightly better winning chances than
+/// 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 Endgame<KRKN>::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<KNIGHT>(weakSide)[0];
- Value result = Value(PushToEdges[bksq] + PushAway[square_distance(bksq, bnsq)]);
+ Square bksq = pos.square<KING>(weakSide);
+ Square bnsq = pos.square<KNIGHT>(weakSide);
+ Value result = Value(PushToEdges[bksq] + PushAway[distance(bksq, bnsq)]);
return strongSide == pos.side_to_move() ? result : -result;
}
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<PAWN>(weakSide)[0];
+ Square winnerKSq = pos.square<KING>(strongSide);
+ Square loserKSq = pos.square<KING>(weakSide);
+ Square pawnSq = pos.square<PAWN>(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;
/// KQ vs KR. This is almost identical to KX vs K: We give the attacking
/// king a bonus for having the kings close together, and for forcing the
-/// defending king towards the edge. If we also take care to avoid null move
-/// for the defending side in the search, this is usually sufficient to be
-/// able to win KQ vs KR.
+/// defending king towards the edge. If we also take care to avoid null move for
+/// the defending side in the search, this is usually sufficient to win KQ vs KR.
template<>
Value Endgame<KQKR>::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<KING>(strongSide);
+ Square loserKSq = pos.square<KING>(weakSide);
Value result = QueenValueEg
- RookValueEg
+ PushToEdges[loserKSq]
- + PushClose[square_distance(winnerKSq, loserKSq)];
-
- return strongSide == pos.side_to_move() ? result : -result;
-}
-
-
-/// KBB vs KN. This is almost always a win. We try to push enemy king to a corner
-/// and away from his knight. For a reference of this difficult endgame see:
-/// en.wikipedia.org/wiki/Chess_endgame#Effect_of_tablebases_on_endgame_theory
-
-template<>
-Value Endgame<KBBKN>::operator()(const Position& pos) const {
-
- assert(verify_material(pos, strongSide, 2 * BishopValueMg, 0));
- assert(verify_material(pos, weakSide, KnightValueMg, 0));
-
- Square winnerKSq = pos.king_square(strongSide);
- Square loserKSq = pos.king_square(weakSide);
- Square knightSq = pos.list<KNIGHT>(weakSide)[0];
-
- Value result = VALUE_KNOWN_WIN
- + PushToCorners[loserKSq]
- + PushClose[square_distance(winnerKSq, loserKSq)]
- + PushAway[square_distance(loserKSq, knightSq)];
+ + PushClose[distance(winnerKSq, loserKSq)];
return strongSide == pos.side_to_move() ? result : -result;
}
/// Some cases of trivial draws
template<> Value Endgame<KNNK>::operator()(const Position&) const { return VALUE_DRAW; }
-template<> Value Endgame<KmmKm>::operator()(const Position&) const { return VALUE_DRAW; }
-/// K, bishop and one or more pawns vs K. It checks for draws with rook pawns and
+/// KB and one or more pawns vs K. It checks for draws with rook pawns and
/// a bishop of the wrong color. If such a draw is detected, SCALE_FACTOR_DRAW
/// is returned. If not, the return value is SCALE_FACTOR_NONE, i.e. no scaling
/// will be used.
// be detected even when the weaker side has some pawns.
Bitboard pawns = pos.pieces(strongSide, PAWN);
- File pawnFile = file_of(pos.list<PAWN>(strongSide)[0]);
+ File pawnsFile = file_of(lsb(pawns));
- // All pawns are on a single rook file ?
- if ( (pawnFile == FILE_A || pawnFile == FILE_H)
- && !(pawns & ~file_bb(pawnFile)))
+ // All pawns are on a single rook file?
+ if ( (pawnsFile == FILE_A || pawnsFile == FILE_H)
+ && !(pawns & ~file_bb(pawnsFile)))
{
- Square bishopSq = pos.list<BISHOP>(strongSide)[0];
- Square queeningSq = relative_square(strongSide, pawnFile | RANK_8);
- Square kingSq = pos.king_square(weakSide);
+ Square bishopSq = pos.square<BISHOP>(strongSide);
+ Square queeningSq = relative_square(strongSide, make_square(pawnsFile, RANK_8));
+ Square kingSq = pos.square<KING>(weakSide);
if ( opposite_colors(queeningSq, bishopSq)
- && square_distance(queeningSq, kingSq) <= 1)
+ && distance(queeningSq, kingSq) <= 1)
return SCALE_FACTOR_DRAW;
}
// If all the pawns are on the same B or G file, then it's potentially a draw
- if ( (pawnFile == FILE_B || pawnFile == FILE_G)
- && !(pos.pieces(PAWN) & ~file_bb(pawnFile))
+ if ( (pawnsFile == FILE_B || pawnsFile == FILE_G)
+ && !(pos.pieces(PAWN) & ~file_bb(pawnsFile))
&& pos.non_pawn_material(weakSide) == 0
&& pos.count<PAWN>(weakSide) >= 1)
{
// Get weakSide pawn that is closest to the home rank
Square weakPawnSq = backmost_sq(weakSide, pos.pieces(weakSide, PAWN));
- Square strongKingSq = pos.king_square(strongSide);
- Square weakKingSq = pos.king_square(weakSide);
- Square bishopSq = pos.list<BISHOP>(strongSide)[0];
+ Square strongKingSq = pos.square<KING>(strongSide);
+ Square weakKingSq = pos.square<KING>(weakSide);
+ Square bishopSq = pos.square<BISHOP>(strongSide);
- // There's potential for a draw if our pawn is blocked on the 7th rank
+ // 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<PAWN>(strongSide) == 1))
{
- int strongKingDist = square_distance(weakPawnSq, strongKingSq);
- int weakKingDist = square_distance(weakPawnSq, weakKingSq);
+ 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
}
-/// K and queen vs K, rook and one or more pawns. It tests for fortress draws with
-/// a rook on the third rank defended by a pawn.
+/// KQ vs KR and one or more pawns. It tests for fortress draws with a rook on
+/// the third rank defended by a pawn.
template<>
ScaleFactor Endgame<KQKRPs>::operator()(const Position& pos) const {
assert(pos.count<ROOK>(weakSide) == 1);
assert(pos.count<PAWN>(weakSide) >= 1);
- Square kingSq = pos.king_square(weakSide);
- Square rsq = pos.list<ROOK>(weakSide)[0];
+ Square kingSq = pos.square<KING>(weakSide);
+ Square rsq = pos.square<ROOK>(weakSide);
if ( relative_rank(weakSide, kingSq) <= RANK_2
- && relative_rank(weakSide, pos.king_square(strongSide)) >= RANK_4
+ && relative_rank(weakSide, pos.square<KING>(strongSide)) >= RANK_4
&& relative_rank(weakSide, rsq) == RANK_3
&& ( pos.pieces(weakSide, PAWN)
& pos.attacks_from<KING>(kingSq)
}
-/// K, rook and one pawn vs K and a rook. This function knows a handful of the
-/// most important classes of drawn positions, but is far from perfect. It would
-/// probably be a good idea to add more knowledge in the future.
+/// KRP vs KR. This function knows a handful of the most important classes of
+/// drawn positions, but is far from perfect. It would probably be a good idea
+/// to add more knowledge in the future.
///
/// It would also be nice to rewrite the actual code for this function,
/// which is mostly copied from Glaurung 1.x, and isn't very pretty.
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<ROOK>(strongSide)[0]);
- Square wpsq = normalize(pos, strongSide, pos.list<PAWN>(strongSide)[0]);
- Square brsq = normalize(pos, strongSide, pos.list<ROOK>(weakSide)[0]);
+ Square wksq = normalize(pos, strongSide, pos.square<KING>(strongSide));
+ Square bksq = normalize(pos, strongSide, pos.square<KING>(weakSide));
+ Square wrsq = normalize(pos, strongSide, pos.square<ROOK>(strongSide));
+ Square wpsq = normalize(pos, strongSide, pos.square<PAWN>(strongSide));
+ Square brsq = normalize(pos, strongSide, pos.square<ROOK>(weakSide));
File f = file_of(wpsq);
Rank r = rank_of(wpsq);
- Square queeningSq = f | RANK_8;
+ Square queeningSq = make_square(f, RANK_8);
int tempo = (pos.side_to_move() == strongSide);
// 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;
// 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<File>(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
// If the defending king blocks the pawn and the attacking king is too far
// 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)
+ && bksq == wpsq + NORTH
+ && 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
&& 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 + NORTH) < distance(bksq, wpsq + NORTH) - 2 + tempo)
+ && ( distance(bksq, wrsq) + tempo >= 3
+ || ( distance(wksq, queeningSq) < distance(bksq, wrsq) + tempo
+ && (distance(wksq, wpsq + NORTH) < 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
+ // If the pawn is not far advanced and the defending king is somewhere in
// the pawn's path, it's probably a draw.
if (r <= RANK_4 && bksq > wpsq)
{
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<File>(bksq, wpsq) == 1
+ && distance(wksq, bksq) > 2)
+ return ScaleFactor(24 - 2 * distance(wksq, bksq));
}
return SCALE_FACTOR_NONE;
}
// Test for a rook pawn
if (pos.pieces(PAWN) & (FileABB | FileHBB))
{
- Square ksq = pos.king_square(weakSide);
- Square bsq = pos.list<BISHOP>(weakSide)[0];
- Square psq = pos.list<PAWN>(strongSide)[0];
+ Square ksq = pos.square<KING>(weakSide);
+ Square bsq = pos.square<BISHOP>(weakSide);
+ Square psq = pos.square<PAWN>(strongSide);
Rank rk = relative_rank(strongSide, psq);
Square push = pawn_push(strongSide);
// 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<KING>(strongSide) + 2 * push))
return ScaleFactor(24);
else
return ScaleFactor(48);
// 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<File>(bsq, psq) >= 2)
return ScaleFactor(8);
}
return SCALE_FACTOR_NONE;
}
-/// K, rook and two pawns vs K, rook and one pawn. There is only a single
-/// pattern: If the stronger side has no passed pawns and the defending king
-/// is actively placed, the position is drawish.
+/// KRPP vs KRP. There is just a single rule: if the stronger side has no passed
+/// pawns and the defending king is actively placed, the position is drawish.
template<>
ScaleFactor Endgame<KRPPKRP>::operator()(const Position& pos) const {
assert(verify_material(pos, strongSide, RookValueMg, 2));
assert(verify_material(pos, weakSide, RookValueMg, 1));
- Square wpsq1 = pos.
list<PAWN>(strongSide)[0];
- Square wpsq2 = pos.
list<PAWN>(strongSide)[1];
- Square bksq = pos.king_square(weakSide);
+ Square wpsq1 = pos.
squares<PAWN>(strongSide)[0];
+ Square wpsq2 = pos.
squares<PAWN>(strongSide)[1];
+ Square bksq = pos.square<KING>(weakSide);
// Does the stronger side have a passed pawn?
if (pos.pawn_passed(strongSide, wpsq1) || pos.pawn_passed(strongSide, wpsq2))
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<File>(bksq, wpsq1) <= 1
+ && distance<File>(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;
}
assert(pos.count<PAWN>(strongSide) >= 2);
assert(verify_material(pos, weakSide, VALUE_ZERO, 0));
- Square ksq = pos.king_square(weakSide);
+ Square ksq = pos.square<KING>(weakSide);
Bitboard pawns = pos.pieces(strongSide, PAWN);
- Square psq = pos.list<PAWN>(strongSide)[0];
- // If all pawns are ahead of the king, all pawns are on a single
- // rook file and the king is within one file of the pawns then draw.
+ // 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<File>(ksq, lsb(pawns)) <= 1)
return SCALE_FACTOR_DRAW;
return SCALE_FACTOR_NONE;
}
-/// K, bishop and a pawn vs K and a bishop. There are two rules: If the defending
-/// king is somewhere along the path of the pawn, and the square of the king is
-/// not of the same color as the stronger side's bishop, it's a draw. If the two
-/// bishops have opposite color, it's almost always a draw.
+/// KBP vs KB. There are two rules: if the defending king is somewhere along the
+/// path of the pawn, and the square of the king is not of the same color as the
+/// stronger side's bishop, it's a draw. If the two bishops have opposite color,
+/// it's almost always a draw.
template<>
ScaleFactor Endgame<KBPKB>::operator()(const Position& pos) const {
assert(verify_material(pos, strongSide, BishopValueMg, 1));
assert(verify_material(pos, weakSide, BishopValueMg, 0));
- Square pawnSq = pos.list<PAWN>(strongSide)[0];
- Square strongBishopSq = pos.list<BISHOP>(strongSide)[0];
- Square weakBishopSq = pos.list<BISHOP>(weakSide)[0];
- Square weakKingSq = pos.king_square(weakSide);
+ Square pawnSq = pos.square<PAWN>(strongSide);
+ Square strongBishopSq = pos.square<BISHOP>(strongSide);
+ Square weakBishopSq = pos.square<BISHOP>(weakSide);
+ Square weakKingSq = pos.square<KING>(weakSide);
// Case 1: Defending king blocks the pawn, and cannot be driven away
if ( file_of(weakKingSq) == file_of(pawnSq)
return SCALE_FACTOR_DRAW;
if ( (pos.attacks_from<BISHOP>(weakBishopSq) & path)
- && square_distance(weakBishopSq, pawnSq) >= 3)
+ && distance(weakBishopSq, pawnSq) >= 3)
return SCALE_FACTOR_DRAW;
}
}
}
-/// K, bishop and two pawns vs K and bishop. It detects a few basic draws with
-/// opposite-colored bishops.
+/// KBPP vs KB. It detects a few basic draws with opposite-colored bishops
template<>
ScaleFactor Endgame<KBPPKB>::operator()(const Position& pos) const {
assert(verify_material(pos, strongSide, BishopValueMg, 2));
assert(verify_material(pos, weakSide, BishopValueMg, 0));
- Square wbsq = pos.list<BISHOP>(strongSide)[0];
- Square bbsq = pos.list<BISHOP>(weakSide)[0];
+ Square wbsq = pos.square<BISHOP>(strongSide);
+ Square bbsq = pos.square<BISHOP>(weakSide);
if (!opposite_colors(wbsq, bbsq))
return SCALE_FACTOR_NONE;
- Square ksq = pos.king_square(weakSide);
- Square psq1 = pos.
list<PAWN>(strongSide)[0];
- Square psq2 = pos.
list<PAWN>(strongSide)[1];
+ Square ksq = pos.square<KING>(weakSide);
+ Square psq1 = pos.
squares<PAWN>(strongSide)[0];
+ Square psq2 = pos.
squares<PAWN>(strongSide)[1];
Rank r1 = rank_of(psq1);
Rank r2 = rank_of(psq2);
Square blockSq1, blockSq2;
if (relative_rank(strongSide, psq1) > relative_rank(strongSide, psq2))
{
blockSq1 = psq1 + pawn_push(strongSide);
- blockSq2 = file_of(psq2) | rank_of(psq1);
+ blockSq2 = make_square(file_of(psq2), rank_of(psq1));
}
else
{
blockSq1 = psq2 + pawn_push(strongSide);
- blockSq2 = file_of(psq1) | rank_of(psq2);
+ blockSq2 = make_square(file_of(psq1), rank_of(psq2));
}
- switch (file_distance(psq1, psq2))
+ switch (distance<File>(psq1, psq2))
{
case 0:
// Both pawns are on the same file. It's an easy draw if the defender firmly
&& opposite_colors(ksq, wbsq)
&& ( bbsq == blockSq2
|| (pos.attacks_from<BISHOP>(blockSq2) & pos.pieces(weakSide, BISHOP))
- || abs(r1 - r2) >= 2))
+ || distance(r1, r2) >= 2))
return SCALE_FACTOR_DRAW;
else if ( ksq == blockSq2
}
-/// K, bisop and a pawn vs K and knight. There is a single rule: If the defending
-/// king is somewhere along the path of the pawn, and the square of the king is
-/// not of the same color as the stronger side's bishop, it's a draw.
+/// KBP vs KN. There is a single rule: If the defending king is somewhere along
+/// the path of the pawn, and the square of the king is not of the same color as
+/// the stronger side's bishop, it's a draw.
template<>
ScaleFactor Endgame<KBPKN>::operator()(const Position& pos) const {
assert(verify_material(pos, strongSide, BishopValueMg, 1));
assert(verify_material(pos, weakSide, KnightValueMg, 0));
- Square pawnSq = pos.list<PAWN>(strongSide)[0];
- Square strongBishopSq = pos.list<BISHOP>(strongSide)[0];
- Square weakKingSq = pos.king_square(weakSide);
+ Square pawnSq = pos.square<PAWN>(strongSide);
+ Square strongBishopSq = pos.square<BISHOP>(strongSide);
+ Square weakKingSq = pos.square<KING>(weakSide);
if ( file_of(weakKingSq) == file_of(pawnSq)
&& relative_rank(strongSide, pawnSq) < relative_rank(strongSide, weakKingSq)
}
-/// K, knight and a pawn vs K. There is a single rule: If the pawn is a rook pawn
-/// on the 7th rank and the defending king prevents the pawn from advancing, the
-/// position is drawn.
+/// KNP vs K. There is a single rule: 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 Endgame<KNPK>::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<PAWN>(strongSide)[0]);
- Square weakKingSq = normalize(pos, strongSide, pos.king_square(weakSide));
+ Square pawnSq = normalize(pos, strongSide, pos.square<PAWN>(strongSide));
+ Square weakKingSq = normalize(pos, strongSide, pos.square<KING>(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;
}
-/// K, knight and a pawn vs K and bishop. If knight can block bishop from taking
-/// pawn, it's a win. Otherwise, drawn.
+/// KNP vs KB. If knight can block bishop from taking pawn, it's a win.
+/// Otherwise the position is drawn.
template<>
ScaleFactor Endgame<KNPKB>::operator()(const Position& pos) const {
- Square pawnSq = pos.list<PAWN>(strongSide)[0];
- Square bishopSq = pos.list<BISHOP>(weakSide)[0];
- Square weakKingSq = pos.king_square(weakSide);
+ Square pawnSq = pos.square<PAWN>(strongSide);
+ Square bishopSq = pos.square<BISHOP>(weakSide);
+ Square weakKingSq = pos.square<KING>(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<BISHOP>(bishopSq))
- return ScaleFactor(square_distance(weakKingSq, pawnSq));
+ return ScaleFactor(distance(weakKingSq, pawnSq));
return SCALE_FACTOR_NONE;
}
-/// K and a pawn vs K and a pawn. This is done by removing the weakest side's
-/// pawn and probing the KP vs K bitbase: If the weakest side has a draw without
-/// the pawn, she probably has at least a draw with the pawn as well. The exception
-/// is when the stronger side's pawn is far 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).
+/// KP vs KP. This is done by removing the weakest side's pawn and probing the
+/// KP vs K bitbase: If the weakest side has a draw without the pawn, it probably
+/// has at least a draw with the pawn as well. The exception is when the stronger
+/// side's pawn is far 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 Endgame<KPKP>::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<PAWN>(strongSide)[0]);
+ Square wksq = normalize(pos, strongSide, pos.square<KING>(strongSide));
+ Square bksq = normalize(pos, strongSide, pos.square<KING>(weakSide));
+ Square psq = normalize(pos, strongSide, pos.square<PAWN>(strongSide));
Color us = strongSide == pos.side_to_move() ? WHITE : BLACK;
// 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;
}
projects / stockfish / blobdiff