/*
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 },
{ 41, 41, 41, 41, 41, 41 }, { 37, 41, 41, 41, 41, 41 }, { 10, 62, 41, 41, 41, 41 },
{ 57, 64, 39, 41, 41, 41 }, { 50, 40, 23, -22, 41, 41 }, { 106, 101, 3, 151, 171, 41 } };
- // Named endgame evaluation and scaling functions, these
- // are accessed direcly and not through the function maps.
- EvaluationFunction<KmmKm> EvaluateKmmKm(WHITE);
- EvaluationFunction<KXK> EvaluateKXK(WHITE), EvaluateKKX(BLACK);
- ScalingFunction<KBPsK> ScaleKBPsK(WHITE), ScaleKKBPs(BLACK);
- ScalingFunction<KQKRPs> ScaleKQKRPs(WHITE), ScaleKRPsKQ(BLACK);
- ScalingFunction<KPsK> ScaleKPsK(WHITE), ScaleKKPs(BLACK);
- ScalingFunction<KPKP> ScaleKPKPw(WHITE), ScaleKPKPb(BLACK);
-
typedef EndgameEvaluationFunctionBase EF;
typedef EndgameScalingFunctionBase SF;
+
+ // Endgame evaluation and scaling functions accessed direcly and not through
+ // the function maps because correspond to more then one material hash key.
+ EvaluationFunction<KmmKm> EvaluateKmmKm[] = { EvaluationFunction<KmmKm>(WHITE), EvaluationFunction<KmmKm>(BLACK) };
+ EvaluationFunction<KXK> EvaluateKXK[] = { EvaluationFunction<KXK>(WHITE), EvaluationFunction<KXK>(BLACK) };
+ ScalingFunction<KBPsK> ScaleKBPsK[] = { ScalingFunction<KBPsK>(WHITE), ScalingFunction<KBPsK>(BLACK) };
+ ScalingFunction<KQKRPs> ScaleKQKRPs[] = { ScalingFunction<KQKRPs>(WHITE), ScalingFunction<KQKRPs>(BLACK) };
+ ScalingFunction<KPsK> ScaleKPsK[] = { ScalingFunction<KPsK>(WHITE), ScalingFunction<KPsK>(BLACK) };
+ ScalingFunction<KPKP> ScaleKPKP[] = { ScalingFunction<KPKP>(WHITE), ScalingFunction<KPKP>(BLACK) };
+
+ // 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)
- {
- mi->evaluationFunction = &EvaluateKXK;
- return mi;
- }
- else if ( pos.non_pawn_material(WHITE) == Value(0)
- && pos.piece_count(WHITE, PAWN) == 0
- && pos.non_pawn_material(BLACK) >= RookValueMidgame)
+ else if (is_KXK<WHITE>(pos) || is_KXK<BLACK>(pos))
{
- mi->evaluationFunction = &EvaluateKKX;
+ mi->evaluationFunction = is_KXK<WHITE>(pos) ? &EvaluateKXK[WHITE] : &EvaluateKXK[BLACK];
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
if ( pos.piece_count(WHITE, BISHOP) + pos.piece_count(WHITE, KNIGHT) <= 2
&& pos.piece_count(BLACK, BISHOP) + pos.piece_count(BLACK, KNIGHT) <= 2)
{
- mi->evaluationFunction = &EvaluateKmmKm;
+ mi->evaluationFunction = &EvaluateKmmKm[WHITE];
return mi;
}
}
// OK, we didn't find any special evaluation function for the current
// material configuration. Is there a suitable scaling function?
//
- // The code below is rather messy, and it could easily get worse later,
- // if we decide to add more special cases. We face problems when there
- // are several conflicting applicable scaling functions and we need to
- // decide which one to use.
+ // We face problems when there are several conflicting applicable
+ // scaling functions and we need to decide which one to use.
SF* sf;
if ((sf = funcs->get<SF>(key)) != NULL)
// 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)
- mi->scalingFunction[WHITE] = &ScaleKBPsK;
-
- if ( pos.non_pawn_material(BLACK) == BishopValueMidgame
- && pos.piece_count(BLACK, BISHOP) == 1
- && pos.piece_count(BLACK, PAWN) >= 1)
- 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)
- 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)
- mi->scalingFunction[BLACK] = &ScaleKRPsKQ;
+ if (is_KBPsK<WHITE>(pos))
+ mi->scalingFunction[WHITE] = &ScaleKBPsK[WHITE];
+
+ if (is_KBPsK<BLACK>(pos))
+ mi->scalingFunction[BLACK] = &ScaleKBPsK[BLACK];
+
+ if (is_KQKRPs<WHITE>(pos))
+ mi->scalingFunction[WHITE] = &ScaleKQKRPs[WHITE];
+
+ else if (is_KQKRPs<BLACK>(pos))
+ mi->scalingFunction[BLACK] = &ScaleKQKRPs[BLACK];
if (pos.non_pawn_material(WHITE) + pos.non_pawn_material(BLACK) == Value(0))
{
if (pos.piece_count(BLACK, PAWN) == 0)
{
assert(pos.piece_count(WHITE, PAWN) >= 2);
- mi->scalingFunction[WHITE] = &ScaleKPsK;
+ mi->scalingFunction[WHITE] = &ScaleKPsK[WHITE];
}
else if (pos.piece_count(WHITE, PAWN) == 0)
{
assert(pos.piece_count(BLACK, PAWN) >= 2);
- mi->scalingFunction[BLACK] = &ScaleKKPs;
+ mi->scalingFunction[BLACK] = &ScaleKPsK[BLACK];
}
else if (pos.piece_count(WHITE, PAWN) == 1 && pos.piece_count(BLACK, PAWN) == 1)
{
// This is a special case because we set scaling functions
// for both colors instead of only one.
- mi->scalingFunction[WHITE] = &ScaleKPKPw;
- mi->scalingFunction[BLACK] = &ScaleKPKPb;
+ mi->scalingFunction[WHITE] = &ScaleKPKP[WHITE];
+ mi->scalingFunction[BLACK] = &ScaleKPKP[BLACK];
}
}
{ 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() {
s << char(upcase? toupper(keyCode[i]) : tolower(keyCode[i]));
}
s << 8 - keyCode.length() << "/8/8/8/8/8/8/8 w -";
- return Position(s.str()).get_material_key();
+ return Position(s.str(), 0).get_material_key();
}
const string EndgameFunctions::swapColors(const string& keyCode) {
projects / stockfish / blobdiff