--- /dev/null
+/*
+ Stockfish, a UCI chess playing engine derived from Glaurung 2.1
+ Copyright (C) 2004-2021 The Stockfish developers (see AUTHORS file)
+
+ Stockfish is free software: you can redistribute it and/or modify
+ it under the terms of the GNU General Public License as published by
+ the Free Software Foundation, either version 3 of the License, or
+ (at your option) any later version.
+
+ Stockfish is distributed in the hope that it will be useful,
+ but WITHOUT ANY WARRANTY; without even the implied warranty of
+ MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+ GNU General Public License for more details.
+
+ You should have received a copy of the GNU General Public License
+ along with this program. If not, see <http://www.gnu.org/licenses/>.
+*/
+
+//Definition of input features HalfKAv2_hm of NNUE evaluation function
+
+#include "half_ka_v2_hm.h"
+
+#include "../../position.h"
+
+namespace Stockfish::Eval::NNUE::Features {
+
+ // Orient a square according to perspective (rotates by 180 for black)
+ inline Square HalfKAv2_hm::orient(Color perspective, Square s, Square ksq) {
+ return Square(int(s) ^ (bool(perspective) * SQ_A8) ^ ((file_of(ksq) < FILE_E) * SQ_H1));
+ }
+
+ // Index of a feature for a given king position and another piece on some square
+ inline IndexType HalfKAv2_hm::make_index(Color perspective, Square s, Piece pc, Square ksq) {
+ Square o_ksq = orient(perspective, ksq, ksq);
+ return IndexType(orient(perspective, s, ksq) + PieceSquareIndex[perspective][pc] + PS_NB * KingBuckets[o_ksq]);
+ }
+
+ // Get a list of indices for active features
+ void HalfKAv2_hm::append_active_indices(
+ const Position& pos,
+ Color perspective,
+ ValueListInserter<IndexType> active
+ ) {
+ Square ksq = pos.square<KING>(perspective);
+ Bitboard bb = pos.pieces();
+ while (bb)
+ {
+ Square s = pop_lsb(bb);
+ active.push_back(make_index(perspective, s, pos.piece_on(s), ksq));
+ }
+ }
+
+
+ // append_changed_indices() : get a list of indices for recently changed features
+
+ void HalfKAv2_hm::append_changed_indices(
+ Square ksq,
+ StateInfo* st,
+ Color perspective,
+ ValueListInserter<IndexType> removed,
+ ValueListInserter<IndexType> added
+ ) {
+ const auto& dp = st->dirtyPiece;
+ for (int i = 0; i < dp.dirty_num; ++i) {
+ Piece pc = dp.piece[i];
+ if (dp.from[i] != SQ_NONE)
+ removed.push_back(make_index(perspective, dp.from[i], pc, ksq));
+ if (dp.to[i] != SQ_NONE)
+ added.push_back(make_index(perspective, dp.to[i], pc, ksq));
+ }
+ }
+
+ int HalfKAv2_hm::update_cost(StateInfo* st) {
+ return st->dirtyPiece.dirty_num;
+ }
+
+ int HalfKAv2_hm::refresh_cost(const Position& pos) {
+ return pos.count<ALL_PIECES>();
+ }
+
+ bool HalfKAv2_hm::requires_refresh(StateInfo* st, Color perspective) {
+ return st->dirtyPiece.piece[0] == make_piece(perspective, KING);
+ }
+
+} // namespace Stockfish::Eval::NNUE::Features