From 3bf42c6ff3805a0d42bbc661794a95ff31bedc26 Mon Sep 17 00:00:00 2001 From: untodesu Date: Sat, 15 Mar 2025 16:22:09 +0500 Subject: Add whatever I was working on for the last month --- deps/include/entt/entity/snapshot.hpp | 509 ++++++++++++++++++++++++++++++++++ 1 file changed, 509 insertions(+) create mode 100644 deps/include/entt/entity/snapshot.hpp (limited to 'deps/include/entt/entity/snapshot.hpp') diff --git a/deps/include/entt/entity/snapshot.hpp b/deps/include/entt/entity/snapshot.hpp new file mode 100644 index 0000000..46ebd28 --- /dev/null +++ b/deps/include/entt/entity/snapshot.hpp @@ -0,0 +1,509 @@ +#ifndef ENTT_ENTITY_SNAPSHOT_HPP +#define ENTT_ENTITY_SNAPSHOT_HPP + +#include +#include +#include +#include +#include +#include +#include "../config/config.h" +#include "../container/dense_map.hpp" +#include "../core/type_traits.hpp" +#include "entity.hpp" +#include "fwd.hpp" +#include "view.hpp" + +namespace entt { + +/*! @cond TURN_OFF_DOXYGEN */ +namespace internal { + +template +void orphans(Registry ®istry) { + auto &storage = registry.template storage(); + + for(auto entt: storage) { + if(registry.orphan(entt)) { + storage.erase(entt); + } + } +} + +} // namespace internal +/*! @endcond */ + +/** + * @brief Utility class to create snapshots from a registry. + * + * A _snapshot_ can be either a dump of the entire registry or a narrower + * selection of elements of interest.
+ * This type can be used in both cases if provided with a correctly configured + * output archive. + * + * @tparam Registry Basic registry type. + */ +template +class basic_snapshot { + static_assert(!std::is_const_v, "Non-const registry type required"); + using traits_type = entt_traits; + +public: + /*! Basic registry type. */ + using registry_type = Registry; + /*! @brief Underlying entity identifier. */ + using entity_type = typename registry_type::entity_type; + + /** + * @brief Constructs an instance that is bound to a given registry. + * @param source A valid reference to a registry. + */ + basic_snapshot(const registry_type &source) noexcept + : reg{&source} {} + + /*! @brief Default copy constructor, deleted on purpose. */ + basic_snapshot(const basic_snapshot &) = delete; + + /*! @brief Default move constructor. */ + basic_snapshot(basic_snapshot &&) noexcept = default; + + /*! @brief Default destructor. */ + ~basic_snapshot() noexcept = default; + + /** + * @brief Default copy assignment operator, deleted on purpose. + * @return This snapshot. + */ + basic_snapshot &operator=(const basic_snapshot &) = delete; + + /** + * @brief Default move assignment operator. + * @return This snapshot. + */ + basic_snapshot &operator=(basic_snapshot &&) noexcept = default; + + /** + * @brief Serializes all elements of a type with associated identifiers. + * @tparam Type Type of elements to serialize. + * @tparam Archive Type of output archive. + * @param archive A valid reference to an output archive. + * @param id Optional name used to map the storage within the registry. + * @return An object of this type to continue creating the snapshot. + */ + template + const basic_snapshot &get(Archive &archive, const id_type id = type_hash::value()) const { + if(const auto *storage = reg->template storage(id); storage) { + const typename registry_type::common_type &base = *storage; + + archive(static_cast(storage->size())); + + if constexpr(std::is_same_v) { + archive(static_cast(storage->free_list())); + + for(auto first = base.rbegin(), last = base.rend(); first != last; ++first) { + archive(*first); + } + } else if constexpr(registry_type::template storage_for_type::storage_policy == deletion_policy::in_place) { + for(auto it = base.rbegin(), last = base.rend(); it != last; ++it) { + if(const auto entt = *it; entt == tombstone) { + archive(static_cast(null)); + } else { + archive(entt); + std::apply([&archive](auto &&...args) { (archive(std::forward(args)), ...); }, storage->get_as_tuple(entt)); + } + } + } else { + for(auto elem: storage->reach()) { + std::apply([&archive](auto &&...args) { (archive(std::forward(args)), ...); }, elem); + } + } + } else { + archive(typename traits_type::entity_type{}); + } + + return *this; + } + + /** + * @brief Serializes all elements of a type with associated identifiers for + * the entities in a range. + * @tparam Type Type of elements to serialize. + * @tparam Archive Type of output archive. + * @tparam It Type of input iterator. + * @param archive A valid reference to an output archive. + * @param first An iterator to the first element of the range to serialize. + * @param last An iterator past the last element of the range to serialize. + * @param id Optional name used to map the storage within the registry. + * @return An object of this type to continue creating the snapshot. + */ + template + const basic_snapshot &get(Archive &archive, It first, It last, const id_type id = type_hash::value()) const { + static_assert(!std::is_same_v, "Entity types not supported"); + + if(const auto *storage = reg->template storage(id); storage && !storage->empty()) { + archive(static_cast(std::distance(first, last))); + + for(; first != last; ++first) { + if(const auto entt = *first; storage->contains(entt)) { + archive(entt); + std::apply([&archive](auto &&...args) { (archive(std::forward(args)), ...); }, storage->get_as_tuple(entt)); + } else { + archive(static_cast(null)); + } + } + } else { + archive(typename traits_type::entity_type{}); + } + + return *this; + } + +private: + const registry_type *reg; +}; + +/** + * @brief Utility class to restore a snapshot as a whole. + * + * A snapshot loader requires that the destination registry be empty and loads + * all the data at once while keeping intact the identifiers that the entities + * originally had.
+ * An example of use is the implementation of a save/restore utility. + * + * @tparam Registry Basic registry type. + */ +template +class basic_snapshot_loader { + static_assert(!std::is_const_v, "Non-const registry type required"); + using traits_type = entt_traits; + +public: + /*! Basic registry type. */ + using registry_type = Registry; + /*! @brief Underlying entity identifier. */ + using entity_type = typename registry_type::entity_type; + + /** + * @brief Constructs an instance that is bound to a given registry. + * @param source A valid reference to a registry. + */ + basic_snapshot_loader(registry_type &source) noexcept + : reg{&source} { + // restoring a snapshot as a whole requires a clean registry + ENTT_ASSERT(reg->template storage().free_list() == 0u, "Registry must be empty"); + } + + /*! @brief Default copy constructor, deleted on purpose. */ + basic_snapshot_loader(const basic_snapshot_loader &) = delete; + + /*! @brief Default move constructor. */ + basic_snapshot_loader(basic_snapshot_loader &&) noexcept = default; + + /*! @brief Default destructor. */ + ~basic_snapshot_loader() noexcept = default; + + /** + * @brief Default copy assignment operator, deleted on purpose. + * @return This loader. + */ + basic_snapshot_loader &operator=(const basic_snapshot_loader &) = delete; + + /** + * @brief Default move assignment operator. + * @return This loader. + */ + basic_snapshot_loader &operator=(basic_snapshot_loader &&) noexcept = default; + + /** + * @brief Restores all elements of a type with associated identifiers. + * @tparam Type Type of elements to restore. + * @tparam Archive Type of input archive. + * @param archive A valid reference to an input archive. + * @param id Optional name used to map the storage within the registry. + * @return A valid loader to continue restoring data. + */ + template + basic_snapshot_loader &get(Archive &archive, const id_type id = type_hash::value()) { + auto &storage = reg->template storage(id); + typename traits_type::entity_type length{}; + + archive(length); + + if constexpr(std::is_same_v) { + typename traits_type::entity_type count{}; + + storage.reserve(length); + archive(count); + + for(entity_type entity = null; length; --length) { + archive(entity); + storage.emplace(entity); + } + + storage.free_list(count); + } else { + auto &other = reg->template storage(); + entity_type entt{null}; + + while(length--) { + if(archive(entt); entt != null) { + const auto entity = other.contains(entt) ? entt : other.emplace(entt); + ENTT_ASSERT(entity == entt, "Entity not available for use"); + + if constexpr(std::tuple_size_v == 0u) { + storage.emplace(entity); + } else { + Type elem{}; + archive(elem); + storage.emplace(entity, std::move(elem)); + } + } + } + } + + return *this; + } + + /** + * @brief Destroys those entities that have no elements. + * + * In case all the entities were serialized but only part of the elements + * was saved, it could happen that some of the entities have no elements + * once restored.
+ * This function helps to identify and destroy those entities. + * + * @return A valid loader to continue restoring data. + */ + basic_snapshot_loader &orphans() { + internal::orphans(*reg); + return *this; + } + +private: + registry_type *reg; +}; + +/** + * @brief Utility class for _continuous loading_. + * + * A _continuous loader_ is designed to load data from a source registry to a + * (possibly) non-empty destination. The loader can accommodate in a registry + * more than one snapshot in a sort of _continuous loading_ that updates the + * destination one step at a time.
+ * Identifiers that entities originally had are not transferred to the target. + * Instead, the loader maps remote identifiers to local ones while restoring a + * snapshot.
+ * An example of use is the implementation of a client-server application with + * the requirement of transferring somehow parts of the representation side to + * side. + * + * @tparam Registry Basic registry type. + */ +template +class basic_continuous_loader { + static_assert(!std::is_const_v, "Non-const registry type required"); + using traits_type = entt_traits; + + void restore(typename Registry::entity_type entt) { + if(const auto entity = to_entity(entt); remloc.contains(entity) && remloc[entity].first == entt) { + if(!reg->valid(remloc[entity].second)) { + remloc[entity].second = reg->create(); + } + } else { + remloc.insert_or_assign(entity, std::make_pair(entt, reg->create())); + } + } + + template + auto update(int, Container &container) -> decltype(typename Container::mapped_type{}, void()) { + // map like container + Container other; + + for(auto &&pair: container) { + using first_type = std::remove_const_t::first_type>; + using second_type = typename std::decay_t::second_type; + + if constexpr(std::is_same_v && std::is_same_v) { + other.emplace(map(pair.first), map(pair.second)); + } else if constexpr(std::is_same_v) { + other.emplace(map(pair.first), std::move(pair.second)); + } else { + static_assert(std::is_same_v, "Neither the key nor the value are of entity type"); + other.emplace(std::move(pair.first), map(pair.second)); + } + } + + using std::swap; + swap(container, other); + } + + template + auto update(char, Container &container) -> decltype(typename Container::value_type{}, void()) { + // vector like container + static_assert(std::is_same_v, "Invalid value type"); + + for(auto &&entt: container) { + entt = map(entt); + } + } + + template + void update([[maybe_unused]] Component &instance, [[maybe_unused]] Member Other::*member) { + if constexpr(!std::is_same_v) { + return; + } else if constexpr(std::is_same_v) { + instance.*member = map(instance.*member); + } else { + // maybe a container? let's try... + update(0, instance.*member); + } + } + +public: + /*! Basic registry type. */ + using registry_type = Registry; + /*! @brief Underlying entity identifier. */ + using entity_type = typename registry_type::entity_type; + + /** + * @brief Constructs an instance that is bound to a given registry. + * @param source A valid reference to a registry. + */ + basic_continuous_loader(registry_type &source) noexcept + : remloc{source.get_allocator()}, + reg{&source} {} + + /*! @brief Default copy constructor, deleted on purpose. */ + basic_continuous_loader(const basic_continuous_loader &) = delete; + + /*! @brief Default move constructor. */ + basic_continuous_loader(basic_continuous_loader &&) noexcept = default; + + /*! @brief Default destructor. */ + ~basic_continuous_loader() noexcept = default; + + /** + * @brief Default copy assignment operator, deleted on purpose. + * @return This loader. + */ + basic_continuous_loader &operator=(const basic_continuous_loader &) = delete; + + /** + * @brief Default move assignment operator. + * @return This loader. + */ + basic_continuous_loader &operator=(basic_continuous_loader &&) noexcept = default; + + /** + * @brief Restores all elements of a type with associated identifiers. + * + * It creates local counterparts for remote elements as needed.
+ * Members are either data members of type entity_type or containers of + * entities. In both cases, a loader visits them and replaces entities with + * their local counterpart. + * + * @tparam Type Type of elements to restore. + * @tparam Archive Type of input archive. + * @param archive A valid reference to an input archive. + * @param id Optional name used to map the storage within the registry. + * @return A valid loader to continue restoring data. + */ + template + basic_continuous_loader &get(Archive &archive, const id_type id = type_hash::value()) { + auto &storage = reg->template storage(id); + typename traits_type::entity_type length{}; + entity_type entt{null}; + + archive(length); + + if constexpr(std::is_same_v) { + typename traits_type::entity_type in_use{}; + + storage.reserve(length); + archive(in_use); + + for(std::size_t pos{}; pos < in_use; ++pos) { + archive(entt); + restore(entt); + } + + for(std::size_t pos = in_use; pos < length; ++pos) { + archive(entt); + + if(const auto entity = to_entity(entt); remloc.contains(entity)) { + if(reg->valid(remloc[entity].second)) { + reg->destroy(remloc[entity].second); + } + + remloc.erase(entity); + } + } + } else { + for(auto &&ref: remloc) { + storage.remove(ref.second.second); + } + + while(length--) { + if(archive(entt); entt != null) { + restore(entt); + + if constexpr(std::tuple_size_v == 0u) { + storage.emplace(map(entt)); + } else { + Type elem{}; + archive(elem); + storage.emplace(map(entt), std::move(elem)); + } + } + } + } + + return *this; + } + + /** + * @brief Destroys those entities that have no elements. + * + * In case all the entities were serialized but only part of the elements + * was saved, it could happen that some of the entities have no elements + * once restored.
+ * This function helps to identify and destroy those entities. + * + * @return A non-const reference to this loader. + */ + basic_continuous_loader &orphans() { + internal::orphans(*reg); + return *this; + } + + /** + * @brief Tests if a loader knows about a given entity. + * @param entt A valid identifier. + * @return True if `entity` is managed by the loader, false otherwise. + */ + [[nodiscard]] bool contains(entity_type entt) const noexcept { + const auto it = remloc.find(to_entity(entt)); + return it != remloc.cend() && it->second.first == entt; + } + + /** + * @brief Returns the identifier to which an entity refers. + * @param entt A valid identifier. + * @return The local identifier if any, the null entity otherwise. + */ + [[nodiscard]] entity_type map(entity_type entt) const noexcept { + if(const auto it = remloc.find(to_entity(entt)); it != remloc.cend() && it->second.first == entt) { + return it->second.second; + } + + return null; + } + +private: + dense_map> remloc; + registry_type *reg; +}; + +} // namespace entt + +#endif -- cgit