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/registry.hpp | 1222 +++++++++++++++++++++++++++++++++ 1 file changed, 1222 insertions(+) create mode 100644 deps/include/entt/entity/registry.hpp (limited to 'deps/include/entt/entity/registry.hpp') diff --git a/deps/include/entt/entity/registry.hpp b/deps/include/entt/entity/registry.hpp new file mode 100644 index 0000000..c7be616 --- /dev/null +++ b/deps/include/entt/entity/registry.hpp @@ -0,0 +1,1222 @@ +#ifndef ENTT_ENTITY_REGISTRY_HPP +#define ENTT_ENTITY_REGISTRY_HPP + +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include "../config/config.h" +#include "../container/dense_map.hpp" +#include "../core/algorithm.hpp" +#include "../core/any.hpp" +#include "../core/fwd.hpp" +#include "../core/iterator.hpp" +#include "../core/memory.hpp" +#include "../core/type_info.hpp" +#include "../core/type_traits.hpp" +#include "../core/utility.hpp" +#include "entity.hpp" +#include "fwd.hpp" +#include "group.hpp" +#include "mixin.hpp" +#include "sparse_set.hpp" +#include "storage.hpp" +#include "view.hpp" + +namespace entt { + +/*! @cond TURN_OFF_DOXYGEN */ +namespace internal { + +template +class registry_storage_iterator final { + template + friend class registry_storage_iterator; + + using mapped_type = std::remove_reference_t()->second)>; + +public: + using value_type = std::pair &>; + using pointer = input_iterator_pointer; + using reference = value_type; + using difference_type = std::ptrdiff_t; + using iterator_category = std::input_iterator_tag; + using iterator_concept = std::random_access_iterator_tag; + + constexpr registry_storage_iterator() noexcept + : it{} {} + + constexpr registry_storage_iterator(It iter) noexcept + : it{iter} {} + + template && std::is_constructible_v>> + constexpr registry_storage_iterator(const registry_storage_iterator &other) noexcept + : registry_storage_iterator{other.it} {} + + constexpr registry_storage_iterator &operator++() noexcept { + return ++it, *this; + } + + constexpr registry_storage_iterator operator++(int) noexcept { + registry_storage_iterator orig = *this; + return ++(*this), orig; + } + + constexpr registry_storage_iterator &operator--() noexcept { + return --it, *this; + } + + constexpr registry_storage_iterator operator--(int) noexcept { + registry_storage_iterator orig = *this; + return operator--(), orig; + } + + constexpr registry_storage_iterator &operator+=(const difference_type value) noexcept { + it += value; + return *this; + } + + constexpr registry_storage_iterator operator+(const difference_type value) const noexcept { + registry_storage_iterator copy = *this; + return (copy += value); + } + + constexpr registry_storage_iterator &operator-=(const difference_type value) noexcept { + return (*this += -value); + } + + constexpr registry_storage_iterator operator-(const difference_type value) const noexcept { + return (*this + -value); + } + + [[nodiscard]] constexpr reference operator[](const difference_type value) const noexcept { + return {it[value].first, *it[value].second}; + } + + [[nodiscard]] constexpr reference operator*() const noexcept { + return operator[](0); + } + + [[nodiscard]] constexpr pointer operator->() const noexcept { + return operator*(); + } + + template + friend constexpr std::ptrdiff_t operator-(const registry_storage_iterator &, const registry_storage_iterator &) noexcept; + + template + friend constexpr bool operator==(const registry_storage_iterator &, const registry_storage_iterator &) noexcept; + + template + friend constexpr bool operator<(const registry_storage_iterator &, const registry_storage_iterator &) noexcept; + +private: + It it; +}; + +template +[[nodiscard]] constexpr std::ptrdiff_t operator-(const registry_storage_iterator &lhs, const registry_storage_iterator &rhs) noexcept { + return lhs.it - rhs.it; +} + +template +[[nodiscard]] constexpr bool operator==(const registry_storage_iterator &lhs, const registry_storage_iterator &rhs) noexcept { + return lhs.it == rhs.it; +} + +template +[[nodiscard]] constexpr bool operator!=(const registry_storage_iterator &lhs, const registry_storage_iterator &rhs) noexcept { + return !(lhs == rhs); +} + +template +[[nodiscard]] constexpr bool operator<(const registry_storage_iterator &lhs, const registry_storage_iterator &rhs) noexcept { + return lhs.it < rhs.it; +} + +template +[[nodiscard]] constexpr bool operator>(const registry_storage_iterator &lhs, const registry_storage_iterator &rhs) noexcept { + return rhs < lhs; +} + +template +[[nodiscard]] constexpr bool operator<=(const registry_storage_iterator &lhs, const registry_storage_iterator &rhs) noexcept { + return !(lhs > rhs); +} + +template +[[nodiscard]] constexpr bool operator>=(const registry_storage_iterator &lhs, const registry_storage_iterator &rhs) noexcept { + return !(lhs < rhs); +} + +template +class registry_context { + using alloc_traits = std::allocator_traits; + using allocator_type = typename alloc_traits::template rebind_alloc>>; + +public: + explicit registry_context(const allocator_type &allocator) + : ctx{allocator} {} + + template + Type &emplace_as(const id_type id, Args &&...args) { + return any_cast(ctx.try_emplace(id, std::in_place_type, std::forward(args)...).first->second); + } + + template + Type &emplace(Args &&...args) { + return emplace_as(type_id().hash(), std::forward(args)...); + } + + template + Type &insert_or_assign(const id_type id, Type &&value) { + return any_cast> &>(ctx.insert_or_assign(id, std::forward(value)).first->second); + } + + template + Type &insert_or_assign(Type &&value) { + return insert_or_assign(type_id().hash(), std::forward(value)); + } + + template + bool erase(const id_type id = type_id().hash()) { + const auto it = ctx.find(id); + return it != ctx.end() && it->second.type() == type_id() ? (ctx.erase(it), true) : false; + } + + template + [[nodiscard]] const Type &get(const id_type id = type_id().hash()) const { + return any_cast(ctx.at(id)); + } + + template + [[nodiscard]] Type &get(const id_type id = type_id().hash()) { + return any_cast(ctx.at(id)); + } + + template + [[nodiscard]] const Type *find(const id_type id = type_id().hash()) const { + const auto it = ctx.find(id); + return it != ctx.cend() ? any_cast(&it->second) : nullptr; + } + + template + [[nodiscard]] Type *find(const id_type id = type_id().hash()) { + const auto it = ctx.find(id); + return it != ctx.end() ? any_cast(&it->second) : nullptr; + } + + template + [[nodiscard]] bool contains(const id_type id = type_id().hash()) const { + const auto it = ctx.find(id); + return it != ctx.cend() && it->second.type() == type_id(); + } + +private: + dense_map, identity, std::equal_to<>, allocator_type> ctx; +}; + +} // namespace internal +/*! @endcond */ + +/** + * @brief Fast and reliable entity-component system. + * @tparam Entity A valid entity type. + * @tparam Allocator Type of allocator used to manage memory and elements. + */ +template +class basic_registry { + using base_type = basic_sparse_set; + using alloc_traits = std::allocator_traits; + static_assert(std::is_same_v, "Invalid value type"); + // std::shared_ptr because of its type erased allocator which is useful here + using pool_container_type = dense_map, identity, std::equal_to<>, typename alloc_traits::template rebind_alloc>>>; + using group_container_type = dense_map, identity, std::equal_to<>, typename alloc_traits::template rebind_alloc>>>; + using traits_type = entt_traits; + + template + [[nodiscard]] auto &assure([[maybe_unused]] const id_type id = type_hash::value()) { + static_assert(std::is_same_v>, "Non-decayed types not allowed"); + + if constexpr(std::is_same_v) { + ENTT_ASSERT(id == type_hash::value(), "User entity storage not allowed"); + return entities; + } else { + using storage_type = storage_for_type; + + if(auto it = pools.find(id); it == pools.cend()) { + using alloc_type = typename storage_type::allocator_type; + typename pool_container_type::mapped_type cpool{}; + + if constexpr(std::is_void_v && !std::is_constructible_v) { + // std::allocator has no cross constructors (waiting for C++20) + cpool = std::allocate_shared(get_allocator(), alloc_type{}); + } else { + cpool = std::allocate_shared(get_allocator(), get_allocator()); + } + + pools.emplace(id, cpool); + cpool->bind(forward_as_any(*this)); + + return static_cast(*cpool); + } else { + ENTT_ASSERT(it->second->type() == type_id(), "Unexpected type"); + return static_cast(*it->second); + } + } + } + + template + [[nodiscard]] const auto *assure([[maybe_unused]] const id_type id = type_hash::value()) const { + static_assert(std::is_same_v>, "Non-decayed types not allowed"); + + if constexpr(std::is_same_v) { + ENTT_ASSERT(id == type_hash::value(), "User entity storage not allowed"); + return &entities; + } else { + if(const auto it = pools.find(id); it != pools.cend()) { + ENTT_ASSERT(it->second->type() == type_id(), "Unexpected type"); + return static_cast *>(it->second.get()); + } + + return static_cast *>(nullptr); + } + } + + void rebind() { + entities.bind(forward_as_any(*this)); + + for(auto &&curr: pools) { + curr.second->bind(forward_as_any(*this)); + } + } + +public: + /*! @brief Allocator type. */ + using allocator_type = Allocator; + /*! @brief Underlying entity identifier. */ + using entity_type = typename traits_type::value_type; + /*! @brief Underlying version type. */ + using version_type = typename traits_type::version_type; + /*! @brief Unsigned integer type. */ + using size_type = std::size_t; + /*! @brief Common type among all storage types. */ + using common_type = base_type; + /*! @brief Context type. */ + using context = internal::registry_context; + /*! @brief Iterable registry type. */ + using iterable = iterable_adaptor>; + /*! @brief Constant iterable registry type. */ + using const_iterable = iterable_adaptor>; + + /** + * @copybrief storage_for + * @tparam Type Storage value type, eventually const. + */ + template + using storage_for_type = typename storage_for>>::type; + + /*! @brief Default constructor. */ + basic_registry() + : basic_registry{allocator_type{}} {} + + /** + * @brief Constructs an empty registry with a given allocator. + * @param allocator The allocator to use. + */ + explicit basic_registry(const allocator_type &allocator) + : basic_registry{0u, allocator} {} + + /** + * @brief Allocates enough memory upon construction to store `count` pools. + * @param count The number of pools to allocate memory for. + * @param allocator The allocator to use. + */ + basic_registry(const size_type count, const allocator_type &allocator = allocator_type{}) + : vars{allocator}, + pools{allocator}, + groups{allocator}, + entities{allocator} { + pools.reserve(count); + rebind(); + } + + /*! @brief Default copy constructor, deleted on purpose. */ + basic_registry(const basic_registry &) = delete; + + /** + * @brief Move constructor. + * @param other The instance to move from. + */ + basic_registry(basic_registry &&other) noexcept + : vars{std::move(other.vars)}, + pools{std::move(other.pools)}, + groups{std::move(other.groups)}, + entities{std::move(other.entities)} { + rebind(); + } + + /*! @brief Default destructor. */ + ~basic_registry() noexcept = default; + + /** + * @brief Default copy assignment operator, deleted on purpose. + * @return This mixin. + */ + basic_registry &operator=(const basic_registry &) = delete; + + /** + * @brief Move assignment operator. + * @param other The instance to move from. + * @return This registry. + */ + basic_registry &operator=(basic_registry &&other) noexcept { + vars = std::move(other.vars); + pools = std::move(other.pools); + groups = std::move(other.groups); + entities = std::move(other.entities); + + rebind(); + + return *this; + } + + /** + * @brief Exchanges the contents with those of a given registry. + * @param other Registry to exchange the content with. + */ + void swap(basic_registry &other) { + using std::swap; + + swap(vars, other.vars); + swap(pools, other.pools); + swap(groups, other.groups); + swap(entities, other.entities); + + rebind(); + other.rebind(); + } + + /** + * @brief Returns the associated allocator. + * @return The associated allocator. + */ + [[nodiscard]] constexpr allocator_type get_allocator() const noexcept { + return entities.get_allocator(); + } + + /** + * @brief Returns an iterable object to use to _visit_ a registry. + * + * The iterable object returns a pair that contains the name and a reference + * to the current storage. + * + * @return An iterable object to use to _visit_ the registry. + */ + [[nodiscard]] iterable storage() noexcept { + return iterable{pools.begin(), pools.end()}; + } + + /*! @copydoc storage */ + [[nodiscard]] const_iterable storage() const noexcept { + return const_iterable{pools.cbegin(), pools.cend()}; + } + + /** + * @brief Finds the storage associated with a given name, if any. + * @param id Name used to map the storage within the registry. + * @return A pointer to the storage if it exists, a null pointer otherwise. + */ + [[nodiscard]] common_type *storage(const id_type id) { + return const_cast(std::as_const(*this).storage(id)); + } + + /** + * @brief Finds the storage associated with a given name, if any. + * @param id Name used to map the storage within the registry. + * @return A pointer to the storage if it exists, a null pointer otherwise. + */ + [[nodiscard]] const common_type *storage(const id_type id) const { + const auto it = pools.find(id); + return it == pools.cend() ? nullptr : it->second.get(); + } + + /** + * @brief Returns the storage for a given element type. + * @tparam Type Type of element of which to return the storage. + * @param id Optional name used to map the storage within the registry. + * @return The storage for the given element type. + */ + template + storage_for_type &storage(const id_type id = type_hash::value()) { + return assure(id); + } + + /** + * @brief Returns the storage for a given element type, if any. + * @tparam Type Type of element of which to return the storage. + * @param id Optional name used to map the storage within the registry. + * @return The storage for the given element type. + */ + template + [[nodiscard]] const storage_for_type *storage(const id_type id = type_hash::value()) const { + return assure(id); + } + + /** + * @brief Checks if an identifier refers to a valid entity. + * @param entt An identifier, either valid or not. + * @return True if the identifier is valid, false otherwise. + */ + [[nodiscard]] bool valid(const entity_type entt) const { + return static_cast(entities.find(entt).index()) < entities.free_list(); + } + + /** + * @brief Returns the actual version for an identifier. + * @param entt A valid identifier. + * @return The version for the given identifier if valid, the tombstone + * version otherwise. + */ + [[nodiscard]] version_type current(const entity_type entt) const { + return entities.current(entt); + } + + /** + * @brief Creates a new entity or recycles a destroyed one. + * @return A valid identifier. + */ + [[nodiscard]] entity_type create() { + return entities.emplace(); + } + + /** + * @copybrief create + * + * If the requested entity isn't in use, the suggested identifier is used. + * Otherwise, a new identifier is generated. + * + * @param hint Required identifier. + * @return A valid identifier. + */ + [[nodiscard]] entity_type create(const entity_type hint) { + return entities.emplace(hint); + } + + /** + * @brief Assigns each element in a range an identifier. + * + * @sa create + * + * @tparam It Type of forward iterator. + * @param first An iterator to the first element of the range to generate. + * @param last An iterator past the last element of the range to generate. + */ + template + void create(It first, It last) { + entities.insert(std::move(first), std::move(last)); + } + + /** + * @brief Destroys an entity and releases its identifier. + * + * @warning + * Adding or removing elements to an entity that is being destroyed can + * result in undefined behavior. + * + * @param entt A valid identifier. + * @return The version of the recycled entity. + */ + version_type destroy(const entity_type entt) { + for(size_type pos = pools.size(); pos; --pos) { + pools.begin()[pos - 1u].second->remove(entt); + } + + entities.erase(entt); + return entities.current(entt); + } + + /** + * @brief Destroys an entity and releases its identifier. + * + * The suggested version or the valid version closest to the suggested one + * is used instead of the implicitly generated version. + * + * @sa destroy + * + * @param entt A valid identifier. + * @param version A desired version upon destruction. + * @return The version actually assigned to the entity. + */ + version_type destroy(const entity_type entt, const version_type version) { + destroy(entt); + const auto elem = traits_type::construct(traits_type::to_entity(entt), version); + return entities.bump((elem == tombstone) ? traits_type::next(elem) : elem); + } + + /** + * @brief Destroys all entities in a range and releases their identifiers. + * + * @sa destroy + * + * @tparam It Type of input iterator. + * @param first An iterator to the first element of the range of entities. + * @param last An iterator past the last element of the range of entities. + */ + template + void destroy(It first, It last) { + const auto to = entities.sort_as(first, last); + const auto from = entities.cend() - entities.free_list(); + + for(auto &&curr: pools) { + curr.second->remove(from, to); + } + + entities.erase(from, to); + } + + /** + * @brief Assigns the given element to an entity. + * + * The element must have a proper constructor or be of aggregate type. + * + * @warning + * Attempting to assign an element to an entity that already owns it results + * in undefined behavior. + * + * @tparam Type Type of element to create. + * @tparam Args Types of arguments to use to construct the element. + * @param entt A valid identifier. + * @param args Parameters to use to initialize the element. + * @return A reference to the newly created element. + */ + template + decltype(auto) emplace(const entity_type entt, Args &&...args) { + ENTT_ASSERT(valid(entt), "Invalid entity"); + return assure().emplace(entt, std::forward(args)...); + } + + /** + * @brief Assigns each entity in a range the given element. + * + * @sa emplace + * + * @tparam Type Type of element to create. + * @tparam It Type of input iterator. + * @param first An iterator to the first element of the range of entities. + * @param last An iterator past the last element of the range of entities. + * @param value An instance of the element to assign. + */ + template + void insert(It first, It last, const Type &value = {}) { + ENTT_ASSERT(std::all_of(first, last, [this](const auto entt) { return valid(entt); }), "Invalid entity"); + assure().insert(std::move(first), std::move(last), value); + } + + /** + * @brief Assigns each entity in a range the given elements. + * + * @sa emplace + * + * @tparam Type Type of element to create. + * @tparam EIt Type of input iterator. + * @tparam CIt Type of input iterator. + * @param first An iterator to the first element of the range of entities. + * @param last An iterator past the last element of the range of entities. + * @param from An iterator to the first element of the range of elements. + */ + template::value_type, Type>>> + void insert(EIt first, EIt last, CIt from) { + ENTT_ASSERT(std::all_of(first, last, [this](const auto entt) { return valid(entt); }), "Invalid entity"); + assure().insert(first, last, from); + } + + /** + * @brief Assigns or replaces the given element for an entity. + * + * @sa emplace + * @sa replace + * + * @tparam Type Type of element to assign or replace. + * @tparam Args Types of arguments to use to construct the element. + * @param entt A valid identifier. + * @param args Parameters to use to initialize the element. + * @return A reference to the newly created element. + */ + template + decltype(auto) emplace_or_replace(const entity_type entt, Args &&...args) { + if(auto &cpool = assure(); cpool.contains(entt)) { + return cpool.patch(entt, [&args...](auto &...curr) { ((curr = Type{std::forward(args)...}), ...); }); + } else { + ENTT_ASSERT(valid(entt), "Invalid entity"); + return cpool.emplace(entt, std::forward(args)...); + } + } + + /** + * @brief Patches the given element for an entity. + * + * The signature of the function should be equivalent to the following: + * + * @code{.cpp} + * void(Type &); + * @endcode + * + * @warning + * Attempting to patch an element of an entity that doesn't own it results + * in undefined behavior. + * + * @tparam Type Type of element to patch. + * @tparam Func Types of the function objects to invoke. + * @param entt A valid identifier. + * @param func Valid function objects. + * @return A reference to the patched element. + */ + template + decltype(auto) patch(const entity_type entt, Func &&...func) { + return assure().patch(entt, std::forward(func)...); + } + + /** + * @brief Replaces the given element for an entity. + * + * The element must have a proper constructor or be of aggregate type. + * + * @warning + * Attempting to replace an element of an entity that doesn't own it results + * in undefined behavior. + * + * @tparam Type Type of element to replace. + * @tparam Args Types of arguments to use to construct the element. + * @param entt A valid identifier. + * @param args Parameters to use to initialize the element. + * @return A reference to the element being replaced. + */ + template + decltype(auto) replace(const entity_type entt, Args &&...args) { + return patch(entt, [&args...](auto &...curr) { ((curr = Type{std::forward(args)...}), ...); }); + } + + /** + * @brief Removes the given elements from an entity. + * @tparam Type Type of element to remove. + * @tparam Other Other types of elements to remove. + * @param entt A valid identifier. + * @return The number of elements actually removed. + */ + template + size_type remove(const entity_type entt) { + return (assure().remove(entt) + ... + assure().remove(entt)); + } + + /** + * @brief Removes the given elements from all the entities in a range. + * + * @sa remove + * + * @tparam Type Type of element to remove. + * @tparam Other Other types of elements to remove. + * @tparam It Type of input iterator. + * @param first An iterator to the first element of the range of entities. + * @param last An iterator past the last element of the range of entities. + * @return The number of elements actually removed. + */ + template + size_type remove(It first, It last) { + size_type count{}; + + if constexpr(std::is_same_v) { + std::array cpools{static_cast(&assure()), static_cast(&assure())...}; + + for(auto from = cpools.begin(), to = cpools.end(); from != to; ++from) { + if constexpr(sizeof...(Other) != 0u) { + if((*from)->data() == first.data()) { + std::swap((*from), cpools.back()); + } + } + + count += (*from)->remove(first, last); + } + + } else { + for(auto cpools = std::forward_as_tuple(assure(), assure()...); first != last; ++first) { + count += std::apply([entt = *first](auto &...curr) { return (curr.remove(entt) + ... + 0u); }, cpools); + } + } + + return count; + } + + /** + * @brief Erases the given elements from an entity. + * + * @warning + * Attempting to erase an element from an entity that doesn't own it results + * in undefined behavior. + * + * @tparam Type Types of elements to erase. + * @tparam Other Other types of elements to erase. + * @param entt A valid identifier. + */ + template + void erase(const entity_type entt) { + (assure().erase(entt), (assure().erase(entt), ...)); + } + + /** + * @brief Erases the given elements from all the entities in a range. + * + * @sa erase + * + * @tparam Type Types of elements to erase. + * @tparam Other Other types of elements to erase. + * @tparam It Type of input iterator. + * @param first An iterator to the first element of the range of entities. + * @param last An iterator past the last element of the range of entities. + */ + template + void erase(It first, It last) { + if constexpr(std::is_same_v) { + std::array cpools{static_cast(&assure()), static_cast(&assure())...}; + + for(auto from = cpools.begin(), to = cpools.end(); from != to; ++from) { + if constexpr(sizeof...(Other) != 0u) { + if((*from)->data() == first.data()) { + std::swap(*from, cpools.back()); + } + } + + (*from)->erase(first, last); + } + } else { + for(auto cpools = std::forward_as_tuple(assure(), assure()...); first != last; ++first) { + std::apply([entt = *first](auto &...curr) { (curr.erase(entt), ...); }, cpools); + } + } + } + + /** + * @brief Erases elements satisfying specific criteria from an entity. + * + * The function type is equivalent to: + * + * @code{.cpp} + * void(const id_type, typename basic_registry::common_type &); + * @endcode + * + * Only storage where the entity exists are passed to the function. + * + * @tparam Func Type of the function object to invoke. + * @param entt A valid identifier. + * @param func A valid function object. + */ + template + void erase_if(const entity_type entt, Func func) { + for(auto [id, cpool]: storage()) { + if(cpool.contains(entt) && func(id, std::as_const(cpool))) { + cpool.erase(entt); + } + } + } + + /** + * @brief Removes all tombstones from a registry or only the pools for the + * given elements. + * @tparam Type Types of elements for which to clear all tombstones. + */ + template + void compact() { + if constexpr(sizeof...(Type) == 0u) { + for(auto &&curr: pools) { + curr.second->compact(); + } + } else { + (assure().compact(), ...); + } + } + + /** + * @brief Check if an entity is part of all the given storage. + * @tparam Type Type of storage to check for. + * @param entt A valid identifier. + * @return True if the entity is part of all the storage, false otherwise. + */ + template + [[nodiscard]] bool all_of([[maybe_unused]] const entity_type entt) const { + if constexpr(sizeof...(Type) == 1u) { + auto *cpool = assure...>(); + return cpool && cpool->contains(entt); + } else { + return (all_of(entt) && ...); + } + } + + /** + * @brief Check if an entity is part of at least one given storage. + * @tparam Type Type of storage to check for. + * @param entt A valid identifier. + * @return True if the entity is part of at least one storage, false + * otherwise. + */ + template + [[nodiscard]] bool any_of([[maybe_unused]] const entity_type entt) const { + return (all_of(entt) || ...); + } + + /** + * @brief Returns references to the given elements for an entity. + * + * @warning + * Attempting to get an element from an entity that doesn't own it results + * in undefined behavior. + * + * @tparam Type Types of elements to get. + * @param entt A valid identifier. + * @return References to the elements owned by the entity. + */ + template + [[nodiscard]] decltype(auto) get([[maybe_unused]] const entity_type entt) const { + if constexpr(sizeof...(Type) == 1u) { + return (assure>()->get(entt), ...); + } else { + return std::forward_as_tuple(get(entt)...); + } + } + + /*! @copydoc get */ + template + [[nodiscard]] decltype(auto) get([[maybe_unused]] const entity_type entt) { + if constexpr(sizeof...(Type) == 1u) { + return (static_cast &>(assure>()).get(entt), ...); + } else { + return std::forward_as_tuple(get(entt)...); + } + } + + /** + * @brief Returns a reference to the given element for an entity. + * + * In case the entity doesn't own the element, the parameters provided are + * used to construct it. + * + * @sa get + * @sa emplace + * + * @tparam Type Type of element to get. + * @tparam Args Types of arguments to use to construct the element. + * @param entt A valid identifier. + * @param args Parameters to use to initialize the element. + * @return Reference to the element owned by the entity. + */ + template + [[nodiscard]] decltype(auto) get_or_emplace(const entity_type entt, Args &&...args) { + if(auto &cpool = assure(); cpool.contains(entt)) { + return cpool.get(entt); + } else { + ENTT_ASSERT(valid(entt), "Invalid entity"); + return cpool.emplace(entt, std::forward(args)...); + } + } + + /** + * @brief Returns pointers to the given elements for an entity. + * + * @note + * The registry retains ownership of the pointed-to elements. + * + * @tparam Type Types of elements to get. + * @param entt A valid identifier. + * @return Pointers to the elements owned by the entity. + */ + template + [[nodiscard]] auto try_get([[maybe_unused]] const entity_type entt) const { + if constexpr(sizeof...(Type) == 1u) { + const auto *cpool = assure...>(); + return (cpool && cpool->contains(entt)) ? std::addressof(cpool->get(entt)) : nullptr; + } else { + return std::make_tuple(try_get(entt)...); + } + } + + /*! @copydoc try_get */ + template + [[nodiscard]] auto try_get([[maybe_unused]] const entity_type entt) { + if constexpr(sizeof...(Type) == 1u) { + return (const_cast(std::as_const(*this).template try_get(entt)), ...); + } else { + return std::make_tuple(try_get(entt)...); + } + } + + /** + * @brief Clears a whole registry or the pools for the given elements. + * @tparam Type Types of elements to remove from their entities. + */ + template + void clear() { + if constexpr(sizeof...(Type) == 0u) { + for(size_type pos = pools.size(); pos; --pos) { + pools.begin()[pos - 1u].second->clear(); + } + + const auto elem = entities.each(); + entities.erase(elem.begin().base(), elem.end().base()); + } else { + (assure().clear(), ...); + } + } + + /** + * @brief Checks if an entity has elements assigned. + * @param entt A valid identifier. + * @return True if the entity has no elements assigned, false otherwise. + */ + [[nodiscard]] bool orphan(const entity_type entt) const { + return std::none_of(pools.cbegin(), pools.cend(), [entt](auto &&curr) { return curr.second->contains(entt); }); + } + + /** + * @brief Returns a sink object for the given element. + * + * Use this function to receive notifications whenever a new instance of the + * given element is created and assigned to an entity.
+ * The function type for a listener is equivalent to: + * + * @code{.cpp} + * void(basic_registry &, Entity); + * @endcode + * + * Listeners are invoked **after** assigning the element to the entity. + * + * @sa sink + * + * @tparam Type Type of element of which to get the sink. + * @param id Optional name used to map the storage within the registry. + * @return A temporary sink object. + */ + template + [[nodiscard]] auto on_construct(const id_type id = type_hash::value()) { + return assure(id).on_construct(); + } + + /** + * @brief Returns a sink object for the given element. + * + * Use this function to receive notifications whenever an instance of the + * given element is explicitly updated.
+ * The function type for a listener is equivalent to: + * + * @code{.cpp} + * void(basic_registry &, Entity); + * @endcode + * + * Listeners are invoked **after** updating the element. + * + * @sa sink + * + * @tparam Type Type of element of which to get the sink. + * @param id Optional name used to map the storage within the registry. + * @return A temporary sink object. + */ + template + [[nodiscard]] auto on_update(const id_type id = type_hash::value()) { + return assure(id).on_update(); + } + + /** + * @brief Returns a sink object for the given element. + * + * Use this function to receive notifications whenever an instance of the + * given element is removed from an entity and thus destroyed.
+ * The function type for a listener is equivalent to: + * + * @code{.cpp} + * void(basic_registry &, Entity); + * @endcode + * + * Listeners are invoked **before** removing the element from the entity. + * + * @sa sink + * + * @tparam Type Type of element of which to get the sink. + * @param id Optional name used to map the storage within the registry. + * @return A temporary sink object. + */ + template + [[nodiscard]] auto on_destroy(const id_type id = type_hash::value()) { + return assure(id).on_destroy(); + } + + /** + * @brief Returns a view for the given elements. + * @tparam Type Type of element used to construct the view. + * @tparam Other Other types of elements used to construct the view. + * @tparam Exclude Types of elements used to filter the view. + * @return A newly created view. + */ + template + [[nodiscard]] basic_view, storage_for_type...>, exclude_t...>> + view(exclude_t = exclude_t{}) const { + const auto cpools = std::make_tuple(assure>(), assure>()..., assure>()...); + basic_view, storage_for_type...>, exclude_t...>> elem{}; + std::apply([&elem](const auto *...curr) { ((curr ? elem.storage(*curr) : void()), ...); }, cpools); + return elem; + } + + /*! @copydoc view */ + template + [[nodiscard]] basic_view, storage_for_type...>, exclude_t...>> + view(exclude_t = exclude_t{}) { + return {assure>(), assure>()..., assure>()...}; + } + + /** + * @brief Returns a group for the given elements. + * @tparam Owned Types of storage _owned_ by the group. + * @tparam Get Types of storage _observed_ by the group, if any. + * @tparam Exclude Types of storage used to filter the group, if any. + * @return A newly created group. + */ + template + basic_group...>, get_t...>, exclude_t...>> + group(get_t = get_t{}, exclude_t = exclude_t{}) { + using group_type = basic_group...>, get_t...>, exclude_t...>>; + using handler_type = typename group_type::handler; + + if(auto it = groups.find(group_type::group_id()); it != groups.cend()) { + return {*std::static_pointer_cast(it->second)}; + } + + std::shared_ptr handler{}; + + if constexpr(sizeof...(Owned) == 0u) { + handler = std::allocate_shared(get_allocator(), get_allocator(), std::forward_as_tuple(assure>()...), std::forward_as_tuple(assure>()...)); + } else { + handler = std::allocate_shared(get_allocator(), std::forward_as_tuple(assure>()..., assure>()...), std::forward_as_tuple(assure>()...)); + ENTT_ASSERT(std::all_of(groups.cbegin(), groups.cend(), [](const auto &data) { return !(data.second->owned(type_id().hash()) || ...); }), "Conflicting groups"); + } + + groups.emplace(group_type::group_id(), handler); + return {*handler}; + } + + /*! @copydoc group */ + template + [[nodiscard]] basic_group...>, get_t...>, exclude_t...>> + group_if_exists(get_t = get_t{}, exclude_t = exclude_t{}) const { + using group_type = basic_group...>, get_t...>, exclude_t...>>; + using handler_type = typename group_type::handler; + + if(auto it = groups.find(group_type::group_id()); it != groups.cend()) { + return {*std::static_pointer_cast(it->second)}; + } + + return {}; + } + + /** + * @brief Checks whether the given elements belong to any group. + * @tparam Type Types of elements in which one is interested. + * @return True if the pools of the given elements are _free_, false + * otherwise. + */ + template + [[nodiscard]] bool owned() const { + return std::any_of(groups.cbegin(), groups.cend(), [](auto &&data) { return (data.second->owned(type_id().hash()) || ...); }); + } + + /** + * @brief Sorts the elements of a given element. + * + * The comparison function object returns `true` if the first element is + * _less_ than the second one, `false` otherwise. Its signature is also + * equivalent to one of the following: + * + * @code{.cpp} + * bool(const Entity, const Entity); + * bool(const Type &, const Type &); + * @endcode + * + * Moreover, it shall induce a _strict weak ordering_ on the values.
+ * The sort function object offers an `operator()` that accepts: + * + * * An iterator to the first element of the range to sort. + * * An iterator past the last element of the range to sort. + * * A comparison function object to use to compare the elements. + * + * The comparison function object hasn't necessarily the type of the one + * passed along with the other parameters to this member function. + * + * @warning + * Pools of elements owned by a group cannot be sorted. + * + * @tparam Type Type of elements to sort. + * @tparam Compare Type of comparison function object. + * @tparam Sort Type of sort function object. + * @tparam Args Types of arguments to forward to the sort function object. + * @param compare A valid comparison function object. + * @param algo A valid sort function object. + * @param args Arguments to forward to the sort function object, if any. + */ + template + void sort(Compare compare, Sort algo = Sort{}, Args &&...args) { + ENTT_ASSERT(!owned(), "Cannot sort owned storage"); + auto &cpool = assure(); + + if constexpr(std::is_invocable_v) { + auto comp = [&cpool, compare = std::move(compare)](const auto lhs, const auto rhs) { return compare(std::as_const(cpool.get(lhs)), std::as_const(cpool.get(rhs))); }; + cpool.sort(std::move(comp), std::move(algo), std::forward(args)...); + } else { + cpool.sort(std::move(compare), std::move(algo), std::forward(args)...); + } + } + + /** + * @brief Sorts two pools of elements in the same way. + * + * Entities and elements in `To` which are part of both storage are sorted + * internally with the order they have in `From`. The others follow in no + * particular order. + * + * @warning + * Pools of elements owned by a group cannot be sorted. + * + * @tparam To Type of elements to sort. + * @tparam From Type of elements to use to sort. + */ + template + void sort() { + ENTT_ASSERT(!owned(), "Cannot sort owned storage"); + const base_type &cpool = assure(); + assure().sort_as(cpool.begin(), cpool.end()); + } + + /** + * @brief Returns the context object, that is, a general purpose container. + * @return The context object, that is, a general purpose container. + */ + [[nodiscard]] context &ctx() noexcept { + return vars; + } + + /*! @copydoc ctx */ + [[nodiscard]] const context &ctx() const noexcept { + return vars; + } + +private: + context vars; + pool_container_type pools; + group_container_type groups; + storage_for_type entities; +}; + +} // namespace entt + +#endif -- cgit