1 /* 2 Stockfish, a UCI chess playing engine derived from Glaurung 2.1 3 Copyright (C) 2004-2021 The Stockfish developers (see AUTHORS file) 4 5 Stockfish is free software: you can redistribute it and/or modify 6 it under the terms of the GNU General Public License as published by 7 the Free Software Foundation, either version 3 of the License, or 8 (at your option) any later version. 9 10 Stockfish is distributed in the hope that it will be useful, 11 but WITHOUT ANY WARRANTY; without even the implied warranty of 12 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the 13 GNU General Public License for more details. 14 15 You should have received a copy of the GNU General Public License 16 along with this program. If not, see <http://www.gnu.org/licenses/>. 17 */ 18 19 //Definition of input features HalfKAv2 of NNUE evaluation function 20 21 #include "half_ka_v2.h" 22 23 #include "../../position.h" 24 25 namespace Stockfish::Eval::NNUE::Features { 26 27 // Orient a square according to perspective (rotates by 180 for black) orient(Color perspective,Square s)28 inline Square HalfKAv2::orient(Color perspective, Square s) { 29 return Square(int(s) ^ (bool(perspective) * 56)); 30 } 31 32 // Index of a feature for a given king position and another piece on some square make_index(Color perspective,Square s,Piece pc,Square ksq)33 inline IndexType HalfKAv2::make_index(Color perspective, Square s, Piece pc, Square ksq) { 34 return IndexType(orient(perspective, s) + PieceSquareIndex[perspective][pc] + PS_NB * ksq); 35 } 36 37 // Get a list of indices for active features append_active_indices(const Position & pos,Color perspective,ValueListInserter<IndexType> active)38 void HalfKAv2::append_active_indices( 39 const Position& pos, 40 Color perspective, 41 ValueListInserter<IndexType> active 42 ) { 43 Square ksq = orient(perspective, pos.square<KING>(perspective)); 44 Bitboard bb = pos.pieces(); 45 while (bb) 46 { 47 Square s = pop_lsb(bb); 48 active.push_back(make_index(perspective, s, pos.piece_on(s), ksq)); 49 } 50 } 51 52 53 // append_changed_indices() : get a list of indices for recently changed features 54 append_changed_indices(Square ksq,StateInfo * st,Color perspective,ValueListInserter<IndexType> removed,ValueListInserter<IndexType> added)55 void HalfKAv2::append_changed_indices( 56 Square ksq, 57 StateInfo* st, 58 Color perspective, 59 ValueListInserter<IndexType> removed, 60 ValueListInserter<IndexType> added 61 ) { 62 const auto& dp = st->dirtyPiece; 63 Square oriented_ksq = orient(perspective, ksq); 64 for (int i = 0; i < dp.dirty_num; ++i) { 65 Piece pc = dp.piece[i]; 66 if (dp.from[i] != SQ_NONE) 67 removed.push_back(make_index(perspective, dp.from[i], pc, oriented_ksq)); 68 if (dp.to[i] != SQ_NONE) 69 added.push_back(make_index(perspective, dp.to[i], pc, oriented_ksq)); 70 } 71 } 72 update_cost(StateInfo * st)73 int HalfKAv2::update_cost(StateInfo* st) { 74 return st->dirtyPiece.dirty_num; 75 } 76 refresh_cost(const Position & pos)77 int HalfKAv2::refresh_cost(const Position& pos) { 78 return pos.count<ALL_PIECES>(); 79 } 80 requires_refresh(StateInfo * st,Color perspective)81 bool HalfKAv2::requires_refresh(StateInfo* st, Color perspective) { 82 return st->dirtyPiece.piece[0] == make_piece(perspective, KING); 83 } 84 85 } // namespace Stockfish::Eval::NNUE::Features 86