/*
Stockfish, a UCI chess playing engine derived from Glaurung 2.1
Copyright (C) 2004-2008 Tord Romstad (Glaurung author)
- Copyright (C) 2008-2012 Marco Costalba, Joona Kiiski, Tord Romstad
+ Copyright (C) 2008-2013 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
along with this program. If not, see <http://www.gnu.org/licenses/>.
*/
+#include <algorithm> // For std::min
#include <cassert>
#include <cstring>
-#include <algorithm>
#include "material.h"
const int NoPawnsSF[4] = { 6, 12, 32 };
// 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 QuadraticCoefficientsSameColor[][8] = {
- { 7, 7, 7, 7, 7, 7 }, { 39, 2, 7, 7, 7, 7 }, { 35, 271, -4, 7, 7, 7 },
- { 7, 25, 4, 7, 7, 7 }, { -27, -2, 46, 100, 56, 7 }, { 58, 29, 83, 148, -3, -25 } };
-
- const int QuadraticCoefficientsOppositeColor[][8] = {
- { 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 } };
+ const Value RedundantQueen = Value(320);
+ const Value RedundantRook = Value(554);
+
+ // pair pawn knight bishop rook queen
+ const int LinearCoefficients[6] = { 1617, -162, -1172, -190, 105, 26 };
+
+ const int QuadraticCoefficientsSameColor[][PIECE_TYPE_NB] = {
+ // pair pawn knight bishop rook queen
+ { 7 }, // Bishop pair
+ { 39, 2 }, // Pawn
+ { 35, 271, -4 }, // Knight
+ { 7, 105, 4, 7 }, // Bishop
+ { -27, -2, 46, 100, 56 }, // Rook
+ { 58, 29, 83, 148, -3, -25 } // Queen
+ };
+
+ const int QuadraticCoefficientsOppositeColor[][PIECE_TYPE_NB] = {
+ // THEIR PIECES
+ // pair pawn knight bishop rook queen
+ { 41 }, // Bishop pair
+ { 37, 41 }, // Pawn
+ { 10, 62, 41 }, // Knight OUR PIECES
+ { 57, 64, 39, 41 }, // Bishop
+ { 50, 40, 23, -22, 41 }, // Rook
+ { 106, 101, 3, 151, 171, 41 } // Queen
+ };
// Endgame evaluation and scaling functions accessed direcly and not through
// the function maps because correspond to more then one material hash key.
// 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_ZERO
- && pos.piece_count(Them, PAWN) == 0
- && pos.non_pawn_material(Us) >= RookValueMidgame;
+ return !pos.count<PAWN>(Them)
+ && pos.non_pawn_material(Them) == VALUE_ZERO
+ && pos.non_pawn_material(Us) >= RookValueMg;
}
template<Color Us> bool is_KBPsKs(const Position& pos) {
- return pos.non_pawn_material(Us) == BishopValueMidgame
- && pos.piece_count(Us, BISHOP) == 1
- && pos.piece_count(Us, PAWN) >= 1;
+ return pos.non_pawn_material(Us) == BishopValueMg
+ && pos.count<BISHOP>(Us) == 1
+ && pos.count<PAWN >(Us) >= 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;
+ return !pos.count<PAWN>(Us)
+ && pos.non_pawn_material(Us) == QueenValueMg
+ && pos.count<QUEEN>(Us) == 1
+ && pos.count<ROOK>(Them) == 1
+ && pos.count<PAWN>(Them) >= 1;
+ }
+
+ /// imbalance() calculates imbalance comparing piece count of each
+ /// piece type for both colors.
+
+ template<Color Us>
+ int imbalance(const int pieceCount[][PIECE_TYPE_NB]) {
+
+ const Color Them = (Us == WHITE ? BLACK : WHITE);
+
+ int pt1, pt2, pc, v;
+ int value = 0;
+
+ // Redundancy of major pieces, formula based on Kaufman's paper
+ // "The Evaluation of Material Imbalances in Chess"
+ if (pieceCount[Us][ROOK] > 0)
+ value -= RedundantRook * (pieceCount[Us][ROOK] - 1)
+ + RedundantQueen * pieceCount[Us][QUEEN];
+
+ // Second-degree polynomial material imbalance by Tord Romstad
+ for (pt1 = NO_PIECE_TYPE; pt1 <= QUEEN; pt1++)
+ {
+ pc = pieceCount[Us][pt1];
+ if (!pc)
+ continue;
+
+ v = LinearCoefficients[pt1];
+
+ for (pt2 = NO_PIECE_TYPE; pt2 <= pt1; pt2++)
+ v += QuadraticCoefficientsSameColor[pt1][pt2] * pieceCount[Us][pt2]
+ + QuadraticCoefficientsOppositeColor[pt1][pt2] * pieceCount[Them][pt2];
+
+ value += pc * v;
+ }
+ return value;
}
} // namespace
+namespace Material {
-/// MaterialInfoTable::material_info() takes a position object as input,
-/// computes or looks up a MaterialInfo object, and returns a pointer to it.
-/// If the material configuration is not already present in the table, it
-/// is stored there, so we don't have to recompute everything when the
-/// same material configuration occurs again.
+/// Material::probe() takes a position object as input, looks up a MaterialEntry
+/// object, and returns a pointer to it. If the material configuration is not
+/// already present in the table, it is computed and stored there, so we don't
+/// have to recompute everything when the same material configuration occurs again.
-MaterialInfo* MaterialInfoTable::material_info(const Position& pos) const {
+Entry* probe(const Position& pos, Table& entries, Endgames& endgames) {
Key key = pos.material_key();
- MaterialInfo* mi = probe(key);
+ Entry* e = entries[key];
- // If mi->key matches the position's material hash key, it means that we
+ // If e->key matches the position's material hash key, it means that we
// have analysed this material configuration before, and we can simply
// return the information we found the last time instead of recomputing it.
- if (mi->key == key)
- return mi;
+ if (e->key == key)
+ return e;
- // Initialize MaterialInfo entry
- memset(mi, 0, sizeof(MaterialInfo));
- mi->key = key;
- mi->factor[WHITE] = mi->factor[BLACK] = (uint8_t)SCALE_FACTOR_NORMAL;
-
- // Store game phase
- mi->gamePhase = MaterialInfoTable::game_phase(pos);
+ std::memset(e, 0, sizeof(Entry));
+ e->key = key;
+ e->factor[WHITE] = e->factor[BLACK] = (uint8_t)SCALE_FACTOR_NORMAL;
+ e->gamePhase = game_phase(pos);
// Let's look if we have a specialized evaluation function for this
// particular material configuration. First we look for a fixed
// configuration one, then a generic one if previous search failed.
- if ((mi->evaluationFunction = funcs->get<Value>(key)) != NULL)
- return mi;
+ if (endgames.probe(key, e->evaluationFunction))
+ return e;
if (is_KXK<WHITE>(pos))
{
- mi->evaluationFunction = &EvaluateKXK[WHITE];
- return mi;
+ e->evaluationFunction = &EvaluateKXK[WHITE];
+ return e;
}
if (is_KXK<BLACK>(pos))
{
- mi->evaluationFunction = &EvaluateKXK[BLACK];
- return mi;
+ e->evaluationFunction = &EvaluateKXK[BLACK];
+ return e;
+ }
+
+ // Draw by insufficient material (trivial draws like KK, KBK and KNK)
+ if ( !pos.pieces(PAWN)
+ && pos.non_pawn_material(WHITE) + pos.non_pawn_material(BLACK) <= BishopValueMg)
+ {
+ e->evaluationFunction = &EvaluateKmmKm[pos.side_to_move()];
+ return e;
}
+ // Minor piece endgame with at least one minor piece per side and
+ // no pawns. Note that the case KmmK is already handled by KXK.
if (!pos.pieces(PAWN) && !pos.pieces(ROOK) && !pos.pieces(QUEEN))
{
- // Minor piece endgame with at least one minor piece per side and
- // no pawns. Note that the case KmmK is already handled by KXK.
- assert((pos.pieces(KNIGHT, WHITE) | pos.pieces(BISHOP, WHITE)));
- assert((pos.pieces(KNIGHT, BLACK) | pos.pieces(BISHOP, BLACK)));
+ assert((pos.pieces(WHITE, KNIGHT) | pos.pieces(WHITE, BISHOP)));
+ assert((pos.pieces(BLACK, KNIGHT) | pos.pieces(BLACK, BISHOP)));
- if ( pos.piece_count(WHITE, BISHOP) + pos.piece_count(WHITE, KNIGHT) <= 2
- && pos.piece_count(BLACK, BISHOP) + pos.piece_count(BLACK, KNIGHT) <= 2)
+ if ( pos.count<BISHOP>(WHITE) + pos.count<KNIGHT>(WHITE) <= 2
+ && pos.count<BISHOP>(BLACK) + pos.count<KNIGHT>(BLACK) <= 2)
{
- mi->evaluationFunction = &EvaluateKmmKm[pos.side_to_move()];
- return mi;
+ e->evaluationFunction = &EvaluateKmmKm[pos.side_to_move()];
+ return e;
}
}
// scaling functions and we need to decide which one to use.
EndgameBase<ScaleFactor>* sf;
- if ((sf = funcs->get<ScaleFactor>(key)) != NULL)
+ if (endgames.probe(key, sf))
{
- mi->scalingFunction[sf->color()] = sf;
- return mi;
+ e->scalingFunction[sf->color()] = sf;
+ return e;
}
// 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 (is_KBPsKs<WHITE>(pos))
- mi->scalingFunction[WHITE] = &ScaleKBPsK[WHITE];
+ e->scalingFunction[WHITE] = &ScaleKBPsK[WHITE];
if (is_KBPsKs<BLACK>(pos))
- mi->scalingFunction[BLACK] = &ScaleKBPsK[BLACK];
+ e->scalingFunction[BLACK] = &ScaleKBPsK[BLACK];
if (is_KQKRPs<WHITE>(pos))
- mi->scalingFunction[WHITE] = &ScaleKQKRPs[WHITE];
+ e->scalingFunction[WHITE] = &ScaleKQKRPs[WHITE];
else if (is_KQKRPs<BLACK>(pos))
- mi->scalingFunction[BLACK] = &ScaleKQKRPs[BLACK];
+ e->scalingFunction[BLACK] = &ScaleKQKRPs[BLACK];
Value npm_w = pos.non_pawn_material(WHITE);
Value npm_b = pos.non_pawn_material(BLACK);
if (npm_w + npm_b == VALUE_ZERO)
{
- if (pos.piece_count(BLACK, PAWN) == 0)
+ if (!pos.count<PAWN>(BLACK))
{
- assert(pos.piece_count(WHITE, PAWN) >= 2);
- mi->scalingFunction[WHITE] = &ScaleKPsK[WHITE];
+ assert(pos.count<PAWN>(WHITE) >= 2);
+ e->scalingFunction[WHITE] = &ScaleKPsK[WHITE];
}
- else if (pos.piece_count(WHITE, PAWN) == 0)
+ else if (!pos.count<PAWN>(WHITE))
{
- assert(pos.piece_count(BLACK, PAWN) >= 2);
- mi->scalingFunction[BLACK] = &ScaleKPsK[BLACK];
+ assert(pos.count<PAWN>(BLACK) >= 2);
+ e->scalingFunction[BLACK] = &ScaleKPsK[BLACK];
}
- else if (pos.piece_count(WHITE, PAWN) == 1 && pos.piece_count(BLACK, PAWN) == 1)
+ else if (pos.count<PAWN>(WHITE) == 1 && pos.count<PAWN>(BLACK) == 1)
{
// This is a special case because we set scaling functions
// for both colors instead of only one.
- mi->scalingFunction[WHITE] = &ScaleKPKP[WHITE];
- mi->scalingFunction[BLACK] = &ScaleKPKP[BLACK];
+ e->scalingFunction[WHITE] = &ScaleKPKP[WHITE];
+ e->scalingFunction[BLACK] = &ScaleKPKP[BLACK];
}
}
// No pawns makes it difficult to win, even with a material advantage
- if (pos.piece_count(WHITE, PAWN) == 0 && npm_w - npm_b <= BishopValueMidgame)
+ if (!pos.count<PAWN>(WHITE) && npm_w - npm_b <= BishopValueMg)
{
- mi->factor[WHITE] = (uint8_t)
- (npm_w == npm_b || npm_w < RookValueMidgame ? 0 : NoPawnsSF[std::min(pos.piece_count(WHITE, BISHOP), 2)]);
+ e->factor[WHITE] = (uint8_t)
+ (npm_w == npm_b || npm_w < RookValueMg ? 0 : NoPawnsSF[std::min(pos.count<BISHOP>(WHITE), 2)]);
}
- if (pos.piece_count(BLACK, PAWN) == 0 && npm_b - npm_w <= BishopValueMidgame)
+ if (!pos.count<PAWN>(BLACK) && npm_b - npm_w <= BishopValueMg)
{
- mi->factor[BLACK] = (uint8_t)
- (npm_w == npm_b || npm_b < RookValueMidgame ? 0 : NoPawnsSF[std::min(pos.piece_count(BLACK, BISHOP), 2)]);
+ e->factor[BLACK] = (uint8_t)
+ (npm_w == npm_b || npm_b < RookValueMg ? 0 : NoPawnsSF[std::min(pos.count<BISHOP>(BLACK), 2)]);
}
// Compute the space weight
- if (npm_w + npm_b >= 2 * QueenValueMidgame + 4 * RookValueMidgame + 2 * KnightValueMidgame)
+ if (npm_w + npm_b >= 2 * QueenValueMg + 4 * RookValueMg + 2 * KnightValueMg)
{
- int minorPieceCount = pos.piece_count(WHITE, KNIGHT) + pos.piece_count(WHITE, BISHOP)
- + pos.piece_count(BLACK, KNIGHT) + pos.piece_count(BLACK, BISHOP);
+ int minorPieceCount = pos.count<KNIGHT>(WHITE) + pos.count<BISHOP>(WHITE)
+ + pos.count<KNIGHT>(BLACK) + pos.count<BISHOP>(BLACK);
- mi->spaceWeight = minorPieceCount * minorPieceCount;
+ e->spaceWeight = make_score(minorPieceCount * minorPieceCount, 0);
}
// Evaluate the material imbalance. We use PIECE_TYPE_NONE as a place holder
// for the bishop pair "extended piece", this allow us to be more flexible
// in defining bishop pair bonuses.
- const int pieceCount[2][8] = {
- { pos.piece_count(WHITE, BISHOP) > 1, pos.piece_count(WHITE, PAWN), pos.piece_count(WHITE, KNIGHT),
- pos.piece_count(WHITE, BISHOP) , pos.piece_count(WHITE, ROOK), pos.piece_count(WHITE, QUEEN) },
- { 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) } };
-
- mi->value = (int16_t)((imbalance<WHITE>(pieceCount) - imbalance<BLACK>(pieceCount)) / 16);
- return mi;
-}
-
-
-/// MaterialInfoTable::imbalance() calculates imbalance comparing piece count of each
-/// piece type for both colors.
-
-template<Color Us>
-int MaterialInfoTable::imbalance(const int pieceCount[][8]) {
-
- const Color Them = (Us == WHITE ? BLACK : WHITE);
-
- int pt1, pt2, pc, v;
- int value = 0;
-
- // Redundancy of major pieces, formula based on Kaufman's paper
- // "The Evaluation of Material Imbalances in Chess"
- if (pieceCount[Us][ROOK] > 0)
- value -= RedundantRookPenalty * (pieceCount[Us][ROOK] - 1)
- + RedundantQueenPenalty * pieceCount[Us][QUEEN];
-
- // Second-degree polynomial material imbalance by Tord Romstad
- for (pt1 = NO_PIECE_TYPE; pt1 <= QUEEN; pt1++)
- {
- pc = pieceCount[Us][pt1];
- if (!pc)
- continue;
-
- v = LinearCoefficients[pt1];
-
- for (pt2 = NO_PIECE_TYPE; pt2 <= pt1; pt2++)
- v += QuadraticCoefficientsSameColor[pt1][pt2] * pieceCount[Us][pt2]
- + QuadraticCoefficientsOppositeColor[pt1][pt2] * pieceCount[Them][pt2];
-
- value += pc * v;
- }
- return value;
+ const int pieceCount[COLOR_NB][PIECE_TYPE_NB] = {
+ { pos.count<BISHOP>(WHITE) > 1, pos.count<PAWN>(WHITE), pos.count<KNIGHT>(WHITE),
+ pos.count<BISHOP>(WHITE) , pos.count<ROOK>(WHITE), pos.count<QUEEN >(WHITE) },
+ { pos.count<BISHOP>(BLACK) > 1, pos.count<PAWN>(BLACK), pos.count<KNIGHT>(BLACK),
+ pos.count<BISHOP>(BLACK) , pos.count<ROOK>(BLACK), pos.count<QUEEN >(BLACK) } };
+
+ e->value = (int16_t)((imbalance<WHITE>(pieceCount) - imbalance<BLACK>(pieceCount)) / 16);
+ return e;
}
-/// MaterialInfoTable::game_phase() calculates the phase given the current
+/// Material::game_phase() calculates the phase given the current
/// position. Because the phase is strictly a function of the material, it
-/// is stored in MaterialInfo.
+/// is stored in MaterialEntry.
-Phase MaterialInfoTable::game_phase(const Position& pos) {
+Phase game_phase(const Position& pos) {
Value npm = pos.non_pawn_material(WHITE) + pos.non_pawn_material(BLACK);
: npm <= EndgameLimit ? PHASE_ENDGAME
: Phase(((npm - EndgameLimit) * 128) / (MidgameLimit - EndgameLimit));
}
+
+} // namespace Material
projects / stockfish / blobdiff