/*
Stockfish, a UCI chess playing engine derived from Glaurung 2.1
- Copyright (C) 2004-2020 The Stockfish developers (see AUTHORS file)
+ 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
template <typename Derived>
class FeatureSetBase {
- public:
- // Get a list of indices for active features
- template <typename IndexListType>
- static void AppendActiveIndices(
- const Position& pos, TriggerEvent trigger, IndexListType active[2]) {
-
- for (Color perspective : { WHITE, BLACK }) {
- Derived::CollectActiveIndices(
- pos, trigger, perspective, &active[perspective]);
- }
- }
-
- // Get a list of indices for recently changed features
- template <typename PositionType, typename IndexListType>
- static void AppendChangedIndices(
- const PositionType& pos, TriggerEvent trigger,
- IndexListType removed[2], IndexListType added[2], bool reset[2]) {
-
- auto collect_for_one = [&](const DirtyPiece& dp) {
- for (Color perspective : { WHITE, BLACK }) {
- switch (trigger) {
- case TriggerEvent::kFriendKingMoved:
- reset[perspective] = dp.piece[0] == make_piece(perspective, KING);
- break;
- default:
- assert(false);
- break;
- }
- if (reset[perspective]) {
- Derived::CollectActiveIndices(
- pos, trigger, perspective, &added[perspective]);
- } else {
- Derived::CollectChangedIndices(
- pos, dp, trigger, perspective,
- &removed[perspective], &added[perspective]);
- }
- }
- };
-
- auto collect_for_two = [&](const DirtyPiece& dp1, const DirtyPiece& dp2) {
- for (Color perspective : { WHITE, BLACK }) {
- switch (trigger) {
- case TriggerEvent::kFriendKingMoved:
- reset[perspective] = dp1.piece[0] == make_piece(perspective, KING)
- || dp2.piece[0] == make_piece(perspective, KING);
- break;
- default:
- assert(false);
- break;
- }
- if (reset[perspective]) {
- Derived::CollectActiveIndices(
- pos, trigger, perspective, &added[perspective]);
- } else {
- Derived::CollectChangedIndices(
- pos, dp1, trigger, perspective,
- &removed[perspective], &added[perspective]);
- Derived::CollectChangedIndices(
- pos, dp2, trigger, perspective,
- &removed[perspective], &added[perspective]);
- }
- }
- };
-
- if (pos.state()->previous->accumulator.computed_accumulation) {
- const auto& prev_dp = pos.state()->dirtyPiece;
- if (prev_dp.dirty_num == 0) return;
- collect_for_one(prev_dp);
- } else {
- const auto& prev_dp = pos.state()->previous->dirtyPiece;
- if (prev_dp.dirty_num == 0) {
- const auto& prev2_dp = pos.state()->dirtyPiece;
- if (prev2_dp.dirty_num == 0) return;
- collect_for_one(prev2_dp);
- } else {
- const auto& prev2_dp = pos.state()->dirtyPiece;
- if (prev2_dp.dirty_num == 0) {
- collect_for_one(prev_dp);
- } else {
- collect_for_two(prev_dp, prev2_dp);
- }
- }
- }
- }
};
// Class template that represents the feature set
CompileTimeList<TriggerEvent, FeatureType::kRefreshTrigger>;
static constexpr auto kRefreshTriggers = SortedTriggerSet::kValues;
- private:
- // Get a list of indices for active features
- static void CollectActiveIndices(
- const Position& pos, const TriggerEvent trigger, const Color perspective,
- IndexList* const active) {
- if (FeatureType::kRefreshTrigger == trigger) {
- FeatureType::AppendActiveIndices(pos, perspective, active);
- }
- }
-
- // Get a list of indices for recently changed features
- static void CollectChangedIndices(
- const Position& pos, const DirtyPiece& dp, const TriggerEvent trigger, const Color perspective,
- IndexList* const removed, IndexList* const added) {
-
- if (FeatureType::kRefreshTrigger == trigger) {
- FeatureType::AppendChangedIndices(pos, dp, perspective, removed, added);
- }
- }
-
- // Make the base class and the class template that recursively uses itself a friend
- friend class FeatureSetBase<FeatureSet>;
- template <typename... FeatureTypes>
- friend class FeatureSet;
};
} // namespace Eval::NNUE::Features