X-Git-Url: https://git.sesse.net/?p=stockfish;a=blobdiff_plain;f=src%2Fmaterial.cpp;h=f0ee5f682d02cada44957745849684613f3e4196;hp=b16710588bbed14f4c1a5c7e61cc027b9188cf4c;hb=6b7efa0cd14b73416c9030462f79a02bbfc7ad2c;hpb=46ffea46ea64ff070cff07ce374f3618e9b631c8 diff --git a/src/material.cpp b/src/material.cpp index b1671058..f0ee5f68 100644 --- a/src/material.cpp +++ b/src/material.cpp @@ -1,7 +1,7 @@ /* 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 @@ -37,10 +37,15 @@ using namespace std; namespace { + // Values modified by Joona Kiiski + const Value MidgameLimit = Value(15581); + const Value EndgameLimit = Value(3998); + // 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 }, @@ -129,6 +134,22 @@ MaterialInfoTable::~MaterialInfoTable() { } +/// 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. + +Phase MaterialInfoTable::game_phase(const Position& pos) { + + Value npm = pos.non_pawn_material(WHITE) + pos.non_pawn_material(BLACK); + + if (npm >= MidgameLimit) + return PHASE_MIDGAME; + else if (npm <= EndgameLimit) + return PHASE_ENDGAME; + + return Phase(((npm - EndgameLimit) * 128) / (MidgameLimit - EndgameLimit)); +} + /// MaterialInfoTable::get_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 @@ -151,6 +172,9 @@ MaterialInfo* MaterialInfoTable::get_material_info(const Position& pos) { mi->clear(); mi->key = key; + // Store game phase + mi->gamePhase = MaterialInfoTable::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. @@ -171,14 +195,14 @@ MaterialInfo* MaterialInfoTable::get_material_info(const Position& pos) { mi->evaluationFunction = &EvaluateKKX; return mi; } - else if ( pos.pawns() == EmptyBoardBB - && pos.rooks() == EmptyBoardBB - && pos.queens() == 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 // no pawns. Note that the case KmmK is already handled by KXK. - assert(pos.knights(WHITE) | pos.bishops(WHITE)); - assert(pos.knights(BLACK) | pos.bishops(BLACK)); + assert((pos.pieces(KNIGHT, WHITE) | pos.pieces(BISHOP, WHITE))); + assert((pos.pieces(KNIGHT, BLACK) | pos.pieces(BISHOP, BLACK))); if ( pos.piece_count(WHITE, BISHOP) + pos.piece_count(WHITE, KNIGHT) <= 2 && pos.piece_count(BLACK, BISHOP) + pos.piece_count(BLACK, KNIGHT) <= 2) @@ -269,8 +293,8 @@ MaterialInfo* MaterialInfoTable::get_material_info(const Position& pos) { { 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) { @@ -280,7 +304,7 @@ MaterialInfo* MaterialInfoTable::get_material_info(const Position& pos) { { if ( pos.non_pawn_material(c) == pos.non_pawn_material(opposite_color(c)) || pos.non_pawn_material(c) < RookValueMidgame) - mi->factor[c] = 0; + mi->factor[c] = SCALE_FACTOR_ZERO; else { switch (pos.piece_count(c, BISHOP)) { @@ -304,25 +328,27 @@ MaterialInfo* MaterialInfoTable::get_material_info(const Position& pos) { 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; @@ -348,7 +374,6 @@ EndgameFunctions::EndgameFunctions() { add >("KBPPKB"); add >("KBPKN"); add >("KRPPKRP"); - add >("KRPPKRP"); } EndgameFunctions::~EndgameFunctions() {