/*
Stockfish, a UCI chess playing engine derived from Glaurung 2.1
Copyright (C) 2004-2008 Tord Romstad (Glaurung author)
- Copyright (C) 2008-2009 Marco Costalba
+ Copyright (C) 2008-2010 Marco Costalba, Joona Kiiski, 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
// Polynomial material balance parameters
const Value RedundantQueenPenalty = Value(320);
const Value RedundantRookPenalty = Value(554);
- const int LinearCoefficients[6] = { 1617, -162, -1172, -190, 105, 26 };
+
+ const int LinearCoefficients[6] = { 1617, -162, -1172, -190, 105, 26 };
const int QuadraticCoefficientsSameColor[][6] = {
{ 7, 7, 7, 7, 7, 7 }, { 39, 2, 7, 7, 7, 7 }, { 35, 271, -4, 7, 7, 7 },
typedef EndgameEvaluationFunctionBase EF;
typedef EndgameScalingFunctionBase SF;
+
+ // Helper templates used to detect a given material distribution
+ template<Color Us> bool is_KXK(const Position& pos) {
+ const Color Them = (Us == WHITE ? BLACK : WHITE);
+ return pos.non_pawn_material(Them) == Value(0)
+ && pos.piece_count(Them, PAWN) == 0
+ && pos.non_pawn_material(Us) >= RookValueMidgame;
+ }
+
+ template<Color Us> bool is_KBPsK(const Position& pos) {
+ return pos.non_pawn_material(Us) == BishopValueMidgame
+ && pos.piece_count(Us, BISHOP) == 1
+ && pos.piece_count(Us, PAWN) >= 1;
+ }
+
+ template<Color Us> bool is_KQKRPs(const Position& pos) {
+ const Color Them = (Us == WHITE ? BLACK : WHITE);
+ return pos.piece_count(Us, PAWN) == 0
+ && pos.non_pawn_material(Us) == QueenValueMidgame
+ && pos.piece_count(Us, QUEEN) == 1
+ && pos.piece_count(Them, ROOK) == 1
+ && pos.piece_count(Them, PAWN) >= 1;
+ }
}
}
-/// MaterialInfoTable::game_phase() calculate the phase given the current
+/// MaterialInfoTable::game_phase() calculates the phase given the current
/// position. Because the phase is strictly a function of the material, it
/// is stored in MaterialInfo.
mi->clear();
mi->key = key;
- // Calculate game phase
+ // Store game phase
mi->gamePhase = MaterialInfoTable::game_phase(pos);
// Let's look if we have a specialized evaluation function for this
if ((mi->evaluationFunction = funcs->get<EF>(key)) != NULL)
return mi;
- else if ( pos.non_pawn_material(BLACK) == Value(0)
- && pos.piece_count(BLACK, PAWN) == 0
- && pos.non_pawn_material(WHITE) >= RookValueMidgame)
+ else if (is_KXK<WHITE>(pos) || is_KXK<BLACK>(pos))
{
- mi->evaluationFunction = &EvaluateKXK;
+ mi->evaluationFunction = is_KXK<WHITE>(pos) ? &EvaluateKXK : &EvaluateKKX;
return mi;
}
- else if ( pos.non_pawn_material(WHITE) == Value(0)
- && pos.piece_count(WHITE, PAWN) == 0
- && pos.non_pawn_material(BLACK) >= RookValueMidgame)
- {
- mi->evaluationFunction = &EvaluateKKX;
- return mi;
- }
- else if ( pos.pieces(PAWN) == EmptyBoardBB
- && pos.pieces(ROOK) == EmptyBoardBB
+ else if ( pos.pieces(PAWN) == EmptyBoardBB
+ && pos.pieces(ROOK) == EmptyBoardBB
&& pos.pieces(QUEEN) == EmptyBoardBB)
{
// Minor piece endgame with at least one minor piece per side and
// Generic scaling functions that refer to more then one material
// distribution. Should be probed after the specialized ones.
// Note that these ones don't return after setting the function.
- if ( pos.non_pawn_material(WHITE) == BishopValueMidgame
- && pos.piece_count(WHITE, BISHOP) == 1
- && pos.piece_count(WHITE, PAWN) >= 1)
+ if (is_KBPsK<WHITE>(pos))
mi->scalingFunction[WHITE] = &ScaleKBPsK;
- if ( pos.non_pawn_material(BLACK) == BishopValueMidgame
- && pos.piece_count(BLACK, BISHOP) == 1
- && pos.piece_count(BLACK, PAWN) >= 1)
+ if (is_KBPsK<BLACK>(pos))
mi->scalingFunction[BLACK] = &ScaleKKBPs;
- if ( pos.piece_count(WHITE, PAWN) == 0
- && pos.non_pawn_material(WHITE) == QueenValueMidgame
- && pos.piece_count(WHITE, QUEEN) == 1
- && pos.piece_count(BLACK, ROOK) == 1
- && pos.piece_count(BLACK, PAWN) >= 1)
+ if (is_KQKRPs<WHITE>(pos))
mi->scalingFunction[WHITE] = &ScaleKQKRPs;
- else if ( pos.piece_count(BLACK, PAWN) == 0
- && pos.non_pawn_material(BLACK) == QueenValueMidgame
- && pos.piece_count(BLACK, QUEEN) == 1
- && pos.piece_count(WHITE, ROOK) == 1
- && pos.piece_count(WHITE, PAWN) >= 1)
+ else if (is_KQKRPs<BLACK>(pos))
mi->scalingFunction[BLACK] = &ScaleKRPsKQ;
if (pos.non_pawn_material(WHITE) + pos.non_pawn_material(BLACK) == Value(0))
{ pos.piece_count(BLACK, BISHOP) > 1, pos.piece_count(BLACK, PAWN), pos.piece_count(BLACK, KNIGHT),
pos.piece_count(BLACK, BISHOP), pos.piece_count(BLACK, ROOK), pos.piece_count(BLACK, QUEEN) } };
Color c, them;
- int sign;
- int matValue = 0;
+ int sign, pt1, pt2, pc;
+ int v, vv, matValue = 0;
for (c = WHITE, sign = 1; c <= BLACK; c++, sign = -sign)
{
matValue -= sign * ((pieceCount[c][ROOK] - 1) * RedundantRookPenalty + pieceCount[c][QUEEN] * RedundantQueenPenalty);
them = opposite_color(c);
+ v = 0;
// Second-degree polynomial material imbalance by Tord Romstad
//
// We use NO_PIECE_TYPE as a place holder for the bishop pair "extended piece",
// this allow us to be more flexible in defining bishop pair bonuses.
- for (int pt1 = NO_PIECE_TYPE; pt1 <= QUEEN; pt1++)
+ for (pt1 = NO_PIECE_TYPE; pt1 <= QUEEN; pt1++)
{
- int c1 = sign * pieceCount[c][pt1];
- if (!c1)
+ pc = pieceCount[c][pt1];
+ if (!pc)
continue;
- matValue += c1 * LinearCoefficients[pt1];
+ vv = LinearCoefficients[pt1];
- for (int pt2 = NO_PIECE_TYPE; pt2 <= pt1; pt2++)
- {
- matValue += c1 * pieceCount[c][pt2] * QuadraticCoefficientsSameColor[pt1][pt2];
- matValue += c1 * pieceCount[them][pt2] * QuadraticCoefficientsOppositeColor[pt1][pt2];
- }
+ for (pt2 = NO_PIECE_TYPE; pt2 <= pt1; pt2++)
+ vv += pieceCount[c][pt2] * QuadraticCoefficientsSameColor[pt1][pt2]
+ + pieceCount[them][pt2] * QuadraticCoefficientsOppositeColor[pt1][pt2];
+
+ v += pc * vv;
}
+ matValue += sign * v;
}
mi->value = int16_t(matValue / 16);
return mi;
add<ScalingFunction<KBPPKB> >("KBPPKB");
add<ScalingFunction<KBPKN> >("KBPKN");
add<ScalingFunction<KRPPKRP> >("KRPPKRP");
- add<ScalingFunction<KRPPKRP> >("KRPPKRP");
}
EndgameFunctions::~EndgameFunctions() {
projects / stockfish / blobdiff