2 Stockfish, a UCI chess playing engine derived from Glaurung 2.1
3 Copyright (C) 2004-2020 The Stockfish developers (see AUTHORS file)
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.
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.
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/>.
19 //Definition of input features HalfKP of NNUE evaluation function
22 #include "index_list.h"
24 namespace Eval::NNUE::Features {
26 // Find the index of the feature quantity from the king position and PieceSquare
27 template <Side AssociatedKing>
28 inline IndexType HalfKP<AssociatedKing>::MakeIndex(Square sq_k, PieceSquare p) {
29 return static_cast<IndexType>(PS_END) * static_cast<IndexType>(sq_k) + p;
32 // Get pieces information
33 template <Side AssociatedKing>
34 inline void HalfKP<AssociatedKing>::GetPieces(
35 const Position& pos, Color perspective,
36 PieceSquare** pieces, Square* sq_target_k) {
38 *pieces = (perspective == BLACK) ?
39 pos.eval_list()->piece_list_fb() :
40 pos.eval_list()->piece_list_fw();
41 const PieceId target = (AssociatedKing == Side::kFriend) ?
42 static_cast<PieceId>(PIECE_ID_KING + perspective) :
43 static_cast<PieceId>(PIECE_ID_KING + ~perspective);
44 *sq_target_k = static_cast<Square>(((*pieces)[target] - PS_W_KING) % SQUARE_NB);
47 // Get a list of indices for active features
48 template <Side AssociatedKing>
49 void HalfKP<AssociatedKing>::AppendActiveIndices(
50 const Position& pos, Color perspective, IndexList* active) {
52 // Do nothing if array size is small to avoid compiler warning
53 if (RawFeatures::kMaxActiveDimensions < kMaxActiveDimensions) return;
57 GetPieces(pos, perspective, &pieces, &sq_target_k);
58 for (PieceId i = PIECE_ID_ZERO; i < PIECE_ID_KING; ++i) {
59 if (pieces[i] != PS_NONE) {
60 active->push_back(MakeIndex(sq_target_k, pieces[i]));
65 // Get a list of indices for recently changed features
66 template <Side AssociatedKing>
67 void HalfKP<AssociatedKing>::AppendChangedIndices(
68 const Position& pos, Color perspective,
69 IndexList* removed, IndexList* added) {
73 GetPieces(pos, perspective, &pieces, &sq_target_k);
74 const auto& dp = pos.state()->dirtyPiece;
75 for (int i = 0; i < dp.dirty_num; ++i) {
76 if (dp.pieceId[i] >= PIECE_ID_KING) continue;
77 const auto old_p = static_cast<PieceSquare>(
78 dp.old_piece[i].from[perspective]);
79 if (old_p != PS_NONE) {
80 removed->push_back(MakeIndex(sq_target_k, old_p));
82 const auto new_p = static_cast<PieceSquare>(
83 dp.new_piece[i].from[perspective]);
84 if (new_p != PS_NONE) {
85 added->push_back(MakeIndex(sq_target_k, new_p));
90 template class HalfKP<Side::kFriend>;
92 } // namespace Eval::NNUE::Features