/*
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) 2015-2019 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
along with this program. If not, see <http://www.gnu.org/licenses/>.
*/
-#include <algorithm>
#include <cassert>
#include "bitboard.h"
-#include "bitcount.h"
#include "endgame.h"
#include "movegen.h"
// Table used to drive the king towards the edge of the board
// in KX vs K and KQ vs KR endgames.
- const int PushToEdges[SQUARE_NB] = {
+ constexpr int PushToEdges[SQUARE_NB] = {
100, 90, 80, 70, 70, 80, 90, 100,
90, 70, 60, 50, 50, 60, 70, 90,
80, 60, 40, 30, 30, 40, 60, 80,
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
// right color in KBN vs K endgames.
- const int PushToCorners[SQUARE_NB] = {
- 200, 190, 180, 170, 160, 150, 140, 130,
- 190, 180, 170, 160, 150, 140, 130, 140,
- 180, 170, 155, 140, 140, 125, 140, 150,
- 170, 160, 140, 120, 110, 140, 150, 160,
- 160, 150, 140, 110, 120, 140, 160, 170,
- 150, 140, 125, 140, 140, 155, 170, 180,
- 140, 130, 140, 150, 160, 170, 180, 190,
- 130, 140, 150, 160, 170, 180, 190, 200
+ constexpr int PushToCorners[SQUARE_NB] = {
+ 6400, 6080, 5760, 5440, 5120, 4800, 4480, 4160,
+ 6080, 5760, 5440, 5120, 4800, 4480, 4160, 4480,
+ 5760, 5440, 4960, 4480, 4480, 4000, 4480, 4800,
+ 5440, 5120, 4480, 3840, 3520, 4480, 4800, 5120,
+ 5120, 4800, 4480, 3520, 3840, 4480, 5120, 5440,
+ 4800, 4480, 4000, 4480, 4480, 4960, 5440, 5760,
+ 4480, 4160, 4480, 4800, 5120, 5440, 5760, 6080,
+ 4160, 4480, 4800, 5120, 5440, 5760, 6080, 6400
};
// Tables used to drive a piece towards or away from another piece
- const int PushClose[8] = { 0, 0, 100, 80, 60, 40, 20, 10 };
- const int PushAway [8] = { 0, 5, 20, 40, 60, 80, 90, 100 };
+ constexpr int PushClose[8] = { 0, 0, 100, 80, 60, 40, 20, 10 };
+ constexpr int PushAway [8] = { 0, 5, 20, 40, 60, 80, 90, 100 };
+
+ // Pawn Rank based scaling factors used in KRPPKRP endgame
+ constexpr 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)
- sq = ~sq;
-
- return sq;
+ return strongSide == WHITE ? sq : ~sq;
}
- // 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);
- assert(code[0] == 'K');
-
- string sides[] = { code.substr(code.find('K', 1)), // Weak
- code.substr(0, code.find('K', 1)) }; // Strong
-
- std::transform(sides[c].begin(), sides[c].end(), sides[c].begin(), tolower);
-
- 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();
- }
-
- template<typename M>
- void delete_endgame(const typename M::value_type& p) { delete p.second; }
-
} // namespace
-/// Endgames members definitions
+namespace Endgames {
-Endgames::Endgames() {
+ std::pair<Map<Value>, Map<ScaleFactor>> maps;
- add<KPK>("KPK");
- add<KNNK>("KNNK");
- add<KBNK>("KBNK");
- add<KRKP>("KRKP");
- add<KRKB>("KRKB");
- add<KRKN>("KRKN");
- add<KQKP>("KQKP");
- add<KQKR>("KQKR");
+ void init() {
- add<KNPK>("KNPK");
- add<KNPKB>("KNPKB");
- add<KRPKR>("KRPKR");
- add<KRPKB>("KRPKB");
- add<KBPKB>("KBPKB");
- add<KBPKN>("KBPKN");
- add<KBPPKB>("KBPPKB");
- 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>
-void Endgames::add(const string& code) {
+ add<KPK>("KPK");
+ add<KNNK>("KNNK");
+ add<KBNK>("KBNK");
+ add<KRKP>("KRKP");
+ add<KRKB>("KRKB");
+ add<KRKN>("KRKN");
+ add<KQKP>("KQKP");
+ add<KQKR>("KQKR");
+ add<KNNKP>("KNNKP");
- map((Endgame<E>*)0)[key(code, WHITE)] = new Endgame<E>(WHITE);
- map((Endgame<E>*)0)[key(code, BLACK)] = new Endgame<E>(BLACK);
+ add<KNPK>("KNPK");
+ add<KNPKB>("KNPKB");
+ add<KRPKR>("KRPKR");
+ add<KRPKB>("KRPKB");
+ add<KBPKB>("KBPKB");
+ add<KBPKN>("KBPKN");
+ add<KBPPKB>("KBPPKB");
+ add<KRPPKRP>("KRPPKRP");
+ }
}
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.pieces(strongSide, BISHOP) & ~DarkSquares)
+ && (pos.pieces(strongSide, BISHOP) & DarkSquares)))
+ result = std::min(result + VALUE_KNOWN_WIN, VALUE_MATE_IN_MAX_PLY - 1);
return strongSide == pos.side_to_move() ? result : -result;
}
/// 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.
+/// defending king towards a corner square that our bishop attacks.
template<>
Value Endgame<KBNK>::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<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
- // to drive the enemy toward corners A8 or H1.
- if (opposite_colors(bishopSq, SQ_A1))
- {
- winnerKSq = ~winnerKSq;
- loserKSq = ~loserKSq;
- }
+ // If our Bishop does not attack A1/H8, we flip the enemy king square
+ // to drive to opposite corners (A8/H1).
Value result = VALUE_KNOWN_WIN
- + PushClose[square_distance(winnerKSq, loserKSq)]
- + PushToCorners[loserKSq];
+ + PushClose[distance(winnerKSq, loserKSq)]
+ + PushToCorners[opposite_colors(bishopSq, SQ_A1) ? ~loserKSq : loserKSq];
+ assert(abs(result) < VALUE_MATE_IN_MAX_PLY);
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 = 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);
+ if (forward_file_bb(WHITE, 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 + SOUTH)
+ - distance(bksq, psq + SOUTH)
+ - distance(psq, queeningSq));
return strongSide == pos.side_to_move() ? result : -result;
}
-/// KR vs KB. This is very simple, and always returns drawish scores. The
+/// 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 Endgame<KRKB>::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<KING>(weakSide)]);
return strongSide == pos.side_to_move() ? result : -result;
}
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;
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)];
+ + PushClose[distance(winnerKSq, loserKSq)];
+
+ return strongSide == pos.side_to_move() ? result : -result;
+}
+
+
+/// KNN vs KP. Simply push the opposing king to the corner
+template<>
+Value Endgame<KNNKP>::operator()(const Position& pos) const {
+
+ assert(verify_material(pos, strongSide, 2 * KnightValueMg, 0));
+ assert(verify_material(pos, weakSide, VALUE_ZERO, 1));
+
+ Value result = 2 * KnightValueEg
+ - PawnValueEg
+ + PushToEdges[pos.square<KING>(weakSide)];
return strongSide == pos.side_to_move() ? result : -result;
}
// 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, make_square(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 weakPawnSq = frontmost_sq(strongSide, 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,
// the bishop cannot attack it or they only have one pawn left
&& (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
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)
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);
// 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
// the pawn's path, it's probably a draw.
{
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);
+ Direction push = pawn_push(strongSide);
// If the pawn is on the 5th rank and the pawn (currently) is on
// the same color square as the bishop then there is a chance of
// 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);
}
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, 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)))
+ if ( !(pawns & ~forward_ranks_bb(weakSide, ksq))
&& !((pawns & ~FileABB) && (pawns & ~FileHBB))
- && file_distance(ksq, psq) <= 1)
+ && distance<File>(ksq, lsb(pawns)) <= 1)
return SCALE_FACTOR_DRAW;
return SCALE_FACTOR_NONE;
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)
// Case 2: Opposite colored bishops
if (opposite_colors(strongBishopSq, weakBishopSq))
- {
- // We assume that the position is drawn in the following three situations:
- //
- // a. The pawn is on rank 5 or further back.
- // b. The defending king is somewhere in the pawn's path.
- // c. The defending bishop attacks some square along the pawn's path,
- // and is at least three squares away from the pawn.
- //
- // These rules are probably not perfect, but in practice they work
- // reasonably well.
-
- if (relative_rank(strongSide, pawnSq) <= RANK_5)
- return SCALE_FACTOR_DRAW;
- else
- {
- Bitboard path = forward_bb(strongSide, pawnSq);
-
- if (path & pos.pieces(weakSide, KING))
- return SCALE_FACTOR_DRAW;
+ return SCALE_FACTOR_DRAW;
- if ( (pos.attacks_from<BISHOP>(weakBishopSq) & path)
- && square_distance(weakBishopSq, pawnSq) >= 3)
- return SCALE_FACTOR_DRAW;
- }
- }
return SCALE_FACTOR_NONE;
}
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];
- Rank r1 = rank_of(psq1);
- Rank r2 = rank_of(psq2);
+ Square ksq = pos.square<KING>(weakSide);
+ Square psq1 = pos.squares<PAWN>(strongSide)[0];
+ Square psq2 = pos.squares<PAWN>(strongSide)[1];
Square blockSq1, blockSq2;
if (relative_rank(strongSide, psq1) > relative_rank(strongSide, 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<Rank>(psq1, psq2) >= 2))
return SCALE_FACTOR_DRAW;
else if ( ksq == blockSq2
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)
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;
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);
+ assert(verify_material(pos, strongSide, KnightValueMg, 1));
+ assert(verify_material(pos, weakSide, BishopValueMg, 0));
+
+ 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));
+ if (forward_file_bb(strongSide, pawnSq) & pos.attacks_from<BISHOP>(bishopSq))
+ return ScaleFactor(distance(weakKingSq, pawnSq));
return SCALE_FACTOR_NONE;
}
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