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
21 #ifndef NNUE_FEATURES_HALF_KP_H_INCLUDED
22 #define NNUE_FEATURES_HALF_KP_H_INCLUDED
24 #include "../../evaluate.h"
25 #include "features_common.h"
27 namespace Eval::NNUE::Features {
29 // Feature HalfKP: Combination of the position of own king
30 // and the position of pieces other than kings
31 template <Side AssociatedKing>
36 static constexpr const char* kName = "HalfKP(Friend)";
37 // Hash value embedded in the evaluation file
38 static constexpr std::uint32_t kHashValue =
39 0x5D69D5B9u ^ (AssociatedKing == Side::kFriend);
40 // Number of feature dimensions
41 static constexpr IndexType kDimensions =
42 static_cast<IndexType>(SQUARE_NB) * static_cast<IndexType>(PS_END);
43 // Maximum number of simultaneously active features
44 static constexpr IndexType kMaxActiveDimensions = 30; // Kings don't count
45 // Trigger for full calculation instead of difference calculation
46 static constexpr TriggerEvent kRefreshTrigger = TriggerEvent::kFriendKingMoved;
48 // Get a list of indices for active features
49 static void AppendActiveIndices(const Position& pos, Color perspective,
52 // Get a list of indices for recently changed features
53 static void AppendChangedIndices(const Position& pos, const DirtyPiece& dp, Color perspective,
54 IndexList* removed, IndexList* added);
57 } // namespace Eval::NNUE::Features
59 #endif // #ifndef NNUE_FEATURES_HALF_KP_H_INCLUDED