/*
Stockfish, a UCI chess playing engine derived from Glaurung 2.1
Copyright (C) 2004-2020 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 .
*/
//Definition of input features HalfKP of NNUE evaluation function
#include "half_kp.h"
#include "index_list.h"
namespace Eval::NNUE::Features {
// Find the index of the feature quantity from the king position and PieceSquare
template
inline IndexType HalfKP::MakeIndex(Square sq_k, PieceSquare p) {
return static_cast(PS_END) * static_cast(sq_k) + p;
}
// Get pieces information
template
inline void HalfKP::GetPieces(
const Position& pos, Color perspective,
PieceSquare** pieces, Square* sq_target_k) {
*pieces = (perspective == BLACK) ?
pos.eval_list()->piece_list_fb() :
pos.eval_list()->piece_list_fw();
const PieceId target = (AssociatedKing == Side::kFriend) ?
static_cast(PIECE_ID_KING + perspective) :
static_cast(PIECE_ID_KING + ~perspective);
*sq_target_k = static_cast(((*pieces)[target] - PS_W_KING) % SQUARE_NB);
}
// Get a list of indices for active features
template
void HalfKP::AppendActiveIndices(
const Position& pos, Color perspective, IndexList* active) {
// Do nothing if array size is small to avoid compiler warning
if (RawFeatures::kMaxActiveDimensions < kMaxActiveDimensions) return;
PieceSquare* pieces;
Square sq_target_k;
GetPieces(pos, perspective, &pieces, &sq_target_k);
for (PieceId i = PIECE_ID_ZERO; i < PIECE_ID_KING; ++i) {
if (pieces[i] != PS_NONE) {
active->push_back(MakeIndex(sq_target_k, pieces[i]));
}
}
}
// Get a list of indices for recently changed features
template
void HalfKP::AppendChangedIndices(
const Position& pos, Color perspective,
IndexList* removed, IndexList* added) {
PieceSquare* pieces;
Square sq_target_k;
GetPieces(pos, perspective, &pieces, &sq_target_k);
const auto& dp = pos.state()->dirtyPiece;
for (int i = 0; i < dp.dirty_num; ++i) {
if (dp.pieceId[i] >= PIECE_ID_KING) continue;
const auto old_p = static_cast(
dp.old_piece[i].from[perspective]);
if (old_p != PS_NONE) {
removed->push_back(MakeIndex(sq_target_k, old_p));
}
const auto new_p = static_cast(
dp.new_piece[i].from[perspective]);
if (new_p != PS_NONE) {
added->push_back(MakeIndex(sq_target_k, new_p));
}
}
}
template class HalfKP;
} // namespace Eval::NNUE::Features