|
|
- #ifndef ENTT_ENTITY_ORGANIZER_HPP
- #define ENTT_ENTITY_ORGANIZER_HPP
-
- #include <algorithm>
- #include <cstddef>
- #include <type_traits>
- #include <utility>
- #include <vector>
- #include "../container/dense_map.hpp"
- #include "../core/type_info.hpp"
- #include "../core/type_traits.hpp"
- #include "../core/utility.hpp"
- #include "fwd.hpp"
- #include "helper.hpp"
-
- namespace entt {
-
- /**
- * @cond TURN_OFF_DOXYGEN
- * Internal details not to be documented.
- */
-
- namespace internal {
-
- template<typename>
- struct is_view: std::false_type {};
-
- template<typename Entity, typename... Component, typename... Exclude>
- struct is_view<basic_view<Entity, get_t<Component...>, exclude_t<Exclude...>>>: std::true_type {};
-
- template<typename Type>
- inline constexpr bool is_view_v = is_view<Type>::value;
-
- template<typename Type, typename Override>
- struct unpack_type {
- using ro = std::conditional_t<
- type_list_contains_v<Override, std::add_const_t<Type>> || (std::is_const_v<Type> && !type_list_contains_v<Override, std::remove_const_t<Type>>),
- type_list<std::remove_const_t<Type>>,
- type_list<>>;
-
- using rw = std::conditional_t<
- type_list_contains_v<Override, std::remove_const_t<Type>> || (!std::is_const_v<Type> && !type_list_contains_v<Override, std::add_const_t<Type>>),
- type_list<Type>,
- type_list<>>;
- };
-
- template<typename Entity, typename... Override>
- struct unpack_type<basic_registry<Entity>, type_list<Override...>> {
- using ro = type_list<>;
- using rw = type_list<>;
- };
-
- template<typename Entity, typename... Override>
- struct unpack_type<const basic_registry<Entity>, type_list<Override...>>
- : unpack_type<basic_registry<Entity>, type_list<Override...>> {};
-
- template<typename Entity, typename... Component, typename... Exclude, typename... Override>
- struct unpack_type<basic_view<Entity, get_t<Component...>, exclude_t<Exclude...>>, type_list<Override...>> {
- using ro = type_list_cat_t<type_list<Exclude...>, typename unpack_type<Component, type_list<Override...>>::ro...>;
- using rw = type_list_cat_t<typename unpack_type<Component, type_list<Override...>>::rw...>;
- };
-
- template<typename Entity, typename... Component, typename... Exclude, typename... Override>
- struct unpack_type<const basic_view<Entity, get_t<Component...>, exclude_t<Exclude...>>, type_list<Override...>>
- : unpack_type<basic_view<Entity, get_t<Component...>, exclude_t<Exclude...>>, type_list<Override...>> {};
-
- template<typename, typename>
- struct resource_traits;
-
- template<typename... Args, typename... Req>
- struct resource_traits<type_list<Args...>, type_list<Req...>> {
- using args = type_list<std::remove_const_t<Args>...>;
- using ro = type_list_cat_t<typename unpack_type<Args, type_list<Req...>>::ro..., typename unpack_type<Req, type_list<>>::ro...>;
- using rw = type_list_cat_t<typename unpack_type<Args, type_list<Req...>>::rw..., typename unpack_type<Req, type_list<>>::rw...>;
- };
-
- template<typename... Req, typename Ret, typename... Args>
- resource_traits<type_list<std::remove_reference_t<Args>...>, type_list<Req...>> free_function_to_resource_traits(Ret (*)(Args...));
-
- template<typename... Req, typename Ret, typename Type, typename... Args>
- resource_traits<type_list<std::remove_reference_t<Args>...>, type_list<Req...>> constrained_function_to_resource_traits(Ret (*)(Type &, Args...));
-
- template<typename... Req, typename Ret, typename Class, typename... Args>
- resource_traits<type_list<std::remove_reference_t<Args>...>, type_list<Req...>> constrained_function_to_resource_traits(Ret (Class::*)(Args...));
-
- template<typename... Req, typename Ret, typename Class, typename... Args>
- resource_traits<type_list<std::remove_reference_t<Args>...>, type_list<Req...>> constrained_function_to_resource_traits(Ret (Class::*)(Args...) const);
-
- } // namespace internal
-
- /**
- * Internal details not to be documented.
- * @endcond
- */
-
- /**
- * @brief Utility class for creating a static task graph.
- *
- * This class offers minimal support (but sufficient in many cases) for creating
- * an execution graph from functions and their requirements on resources.<br/>
- * Note that the resulting tasks aren't executed in any case. This isn't the
- * goal of the tool. Instead, they are returned to the user in the form of a
- * graph that allows for safe execution.
- *
- * @tparam Entity A valid entity type (see entt_traits for more details).
- */
- template<typename Entity>
- class basic_organizer final {
- using callback_type = void(const void *, basic_registry<Entity> &);
- using prepare_type = void(basic_registry<Entity> &);
- using dependency_type = std::size_t(const bool, const type_info **, const std::size_t);
-
- struct vertex_data final {
- std::size_t ro_count{};
- std::size_t rw_count{};
- const char *name{};
- const void *payload{};
- callback_type *callback{};
- dependency_type *dependency;
- prepare_type *prepare{};
- const type_info *info{};
- };
-
- template<typename Type>
- [[nodiscard]] static decltype(auto) extract(basic_registry<Entity> ®) {
- if constexpr(std::is_same_v<Type, basic_registry<Entity>>) {
- return reg;
- } else if constexpr(internal::is_view_v<Type>) {
- return as_view{reg};
- } else {
- return reg.ctx().template emplace<std::remove_reference_t<Type>>();
- }
- }
-
- template<typename... Args>
- [[nodiscard]] static auto to_args(basic_registry<Entity> ®, type_list<Args...>) {
- return std::tuple<decltype(extract<Args>(reg))...>(extract<Args>(reg)...);
- }
-
- template<typename... Type>
- static std::size_t fill_dependencies(type_list<Type...>, [[maybe_unused]] const type_info **buffer, [[maybe_unused]] const std::size_t count) {
- if constexpr(sizeof...(Type) == 0u) {
- return {};
- } else {
- const type_info *info[sizeof...(Type)]{&type_id<Type>()...};
- const auto length = (std::min)(count, sizeof...(Type));
- std::copy_n(info, length, buffer);
- return length;
- }
- }
-
- template<typename... RO, typename... RW>
- void track_dependencies(std::size_t index, const bool requires_registry, type_list<RO...>, type_list<RW...>) {
- dependencies[type_hash<basic_registry<Entity>>::value()].emplace_back(index, requires_registry || (sizeof...(RO) + sizeof...(RW) == 0u));
- (dependencies[type_hash<RO>::value()].emplace_back(index, false), ...);
- (dependencies[type_hash<RW>::value()].emplace_back(index, true), ...);
- }
-
- [[nodiscard]] std::vector<bool> adjacency_matrix() {
- const auto length = vertices.size();
- std::vector<bool> edges(length * length, false);
-
- // creates the adjacency matrix
- for(const auto &deps: dependencies) {
- const auto last = deps.second.cend();
- auto it = deps.second.cbegin();
-
- while(it != last) {
- if(it->second) {
- // rw item
- if(auto curr = it++; it != last) {
- if(it->second) {
- edges[curr->first * length + it->first] = true;
- } else {
- if(const auto next = std::find_if(it, last, [](const auto &elem) { return elem.second; }); next != last) {
- for(; it != next; ++it) {
- edges[curr->first * length + it->first] = true;
- edges[it->first * length + next->first] = true;
- }
- } else {
- for(; it != next; ++it) {
- edges[curr->first * length + it->first] = true;
- }
- }
- }
- }
- } else {
- // ro item, possibly only on first iteration
- if(const auto next = std::find_if(it, last, [](const auto &elem) { return elem.second; }); next != last) {
- for(; it != next; ++it) {
- edges[it->first * length + next->first] = true;
- }
- } else {
- it = last;
- }
- }
- }
- }
-
- // computes the transitive closure
- for(std::size_t vk{}; vk < length; ++vk) {
- for(std::size_t vi{}; vi < length; ++vi) {
- for(std::size_t vj{}; vj < length; ++vj) {
- edges[vi * length + vj] = edges[vi * length + vj] || (edges[vi * length + vk] && edges[vk * length + vj]);
- }
- }
- }
-
- // applies the transitive reduction
- for(std::size_t vert{}; vert < length; ++vert) {
- edges[vert * length + vert] = false;
- }
-
- for(std::size_t vj{}; vj < length; ++vj) {
- for(std::size_t vi{}; vi < length; ++vi) {
- if(edges[vi * length + vj]) {
- for(std::size_t vk{}; vk < length; ++vk) {
- if(edges[vj * length + vk]) {
- edges[vi * length + vk] = false;
- }
- }
- }
- }
- }
-
- return edges;
- }
-
- public:
- /*! @brief Underlying entity identifier. */
- using entity_type = Entity;
- /*! @brief Unsigned integer type. */
- using size_type = std::size_t;
- /*! @brief Raw task function type. */
- using function_type = callback_type;
-
- /*! @brief Vertex type of a task graph defined as an adjacency list. */
- struct vertex {
- /**
- * @brief Constructs a vertex of the task graph.
- * @param vtype True if the vertex is a top-level one, false otherwise.
- * @param data The data associated with the vertex.
- * @param edges The indices of the children in the adjacency list.
- */
- vertex(const bool vtype, vertex_data data, std::vector<std::size_t> edges)
- : is_top_level{vtype},
- node{std::move(data)},
- reachable{std::move(edges)} {}
-
- /**
- * @brief Fills a buffer with the type info objects for the writable
- * resources of a vertex.
- * @param buffer A buffer pre-allocated by the user.
- * @param length The length of the user-supplied buffer.
- * @return The number of type info objects written to the buffer.
- */
- size_type ro_dependency(const type_info **buffer, const std::size_t length) const ENTT_NOEXCEPT {
- return node.dependency(false, buffer, length);
- }
-
- /**
- * @brief Fills a buffer with the type info objects for the read-only
- * resources of a vertex.
- * @param buffer A buffer pre-allocated by the user.
- * @param length The length of the user-supplied buffer.
- * @return The number of type info objects written to the buffer.
- */
- size_type rw_dependency(const type_info **buffer, const std::size_t length) const ENTT_NOEXCEPT {
- return node.dependency(true, buffer, length);
- }
-
- /**
- * @brief Returns the number of read-only resources of a vertex.
- * @return The number of read-only resources of the vertex.
- */
- size_type ro_count() const ENTT_NOEXCEPT {
- return node.ro_count;
- }
-
- /**
- * @brief Returns the number of writable resources of a vertex.
- * @return The number of writable resources of the vertex.
- */
- size_type rw_count() const ENTT_NOEXCEPT {
- return node.rw_count;
- }
-
- /**
- * @brief Checks if a vertex is also a top-level one.
- * @return True if the vertex is a top-level one, false otherwise.
- */
- bool top_level() const ENTT_NOEXCEPT {
- return is_top_level;
- }
-
- /**
- * @brief Returns a type info object associated with a vertex.
- * @return A properly initialized type info object.
- */
- const type_info &info() const ENTT_NOEXCEPT {
- return *node.info;
- }
-
- /**
- * @brief Returns a user defined name associated with a vertex, if any.
- * @return The user defined name associated with the vertex, if any.
- */
- const char *name() const ENTT_NOEXCEPT {
- return node.name;
- }
-
- /**
- * @brief Returns the function associated with a vertex.
- * @return The function associated with the vertex.
- */
- function_type *callback() const ENTT_NOEXCEPT {
- return node.callback;
- }
-
- /**
- * @brief Returns the payload associated with a vertex, if any.
- * @return The payload associated with the vertex, if any.
- */
- const void *data() const ENTT_NOEXCEPT {
- return node.payload;
- }
-
- /**
- * @brief Returns the list of nodes reachable from a given vertex.
- * @return The list of nodes reachable from the vertex.
- */
- const std::vector<std::size_t> &children() const ENTT_NOEXCEPT {
- return reachable;
- }
-
- /**
- * @brief Prepares a registry and assures that all required resources
- * are properly instantiated before using them.
- * @param reg A valid registry.
- */
- void prepare(basic_registry<entity_type> ®) const {
- node.prepare ? node.prepare(reg) : void();
- }
-
- private:
- bool is_top_level;
- vertex_data node;
- std::vector<std::size_t> reachable;
- };
-
- /**
- * @brief Adds a free function to the task list.
- * @tparam Candidate Function to add to the task list.
- * @tparam Req Additional requirements and/or override resource access mode.
- * @param name Optional name to associate with the task.
- */
- template<auto Candidate, typename... Req>
- void emplace(const char *name = nullptr) {
- using resource_type = decltype(internal::free_function_to_resource_traits<Req...>(Candidate));
- constexpr auto requires_registry = type_list_contains_v<typename resource_type::args, basic_registry<entity_type>>;
-
- callback_type *callback = +[](const void *, basic_registry<entity_type> ®) {
- std::apply(Candidate, to_args(reg, typename resource_type::args{}));
- };
-
- vertex_data vdata{
- resource_type::ro::size,
- resource_type::rw::size,
- name,
- nullptr,
- callback,
- +[](const bool rw, const type_info **buffer, const std::size_t length) { return rw ? fill_dependencies(typename resource_type::rw{}, buffer, length) : fill_dependencies(typename resource_type::ro{}, buffer, length); },
- +[](basic_registry<entity_type> ®) { void(to_args(reg, typename resource_type::args{})); },
- &type_id<std::integral_constant<decltype(Candidate), Candidate>>()};
-
- track_dependencies(vertices.size(), requires_registry, typename resource_type::ro{}, typename resource_type::rw{});
- vertices.push_back(std::move(vdata));
- }
-
- /**
- * @brief Adds a free function with payload or a member function with an
- * instance to the task list.
- * @tparam Candidate Function or member to add to the task list.
- * @tparam Req Additional requirements and/or override resource access mode.
- * @tparam Type Type of class or type of payload.
- * @param value_or_instance A valid object that fits the purpose.
- * @param name Optional name to associate with the task.
- */
- template<auto Candidate, typename... Req, typename Type>
- void emplace(Type &value_or_instance, const char *name = nullptr) {
- using resource_type = decltype(internal::constrained_function_to_resource_traits<Req...>(Candidate));
- constexpr auto requires_registry = type_list_contains_v<typename resource_type::args, basic_registry<entity_type>>;
-
- callback_type *callback = +[](const void *payload, basic_registry<entity_type> ®) {
- Type *curr = static_cast<Type *>(const_cast<constness_as_t<void, Type> *>(payload));
- std::apply(Candidate, std::tuple_cat(std::forward_as_tuple(*curr), to_args(reg, typename resource_type::args{})));
- };
-
- vertex_data vdata{
- resource_type::ro::size,
- resource_type::rw::size,
- name,
- &value_or_instance,
- callback,
- +[](const bool rw, const type_info **buffer, const std::size_t length) { return rw ? fill_dependencies(typename resource_type::rw{}, buffer, length) : fill_dependencies(typename resource_type::ro{}, buffer, length); },
- +[](basic_registry<entity_type> ®) { void(to_args(reg, typename resource_type::args{})); },
- &type_id<std::integral_constant<decltype(Candidate), Candidate>>()};
-
- track_dependencies(vertices.size(), requires_registry, typename resource_type::ro{}, typename resource_type::rw{});
- vertices.push_back(std::move(vdata));
- }
-
- /**
- * @brief Adds an user defined function with optional payload to the task
- * list.
- * @tparam Req Additional requirements and/or override resource access mode.
- * @param func Function to add to the task list.
- * @param payload User defined arbitrary data.
- * @param name Optional name to associate with the task.
- */
- template<typename... Req>
- void emplace(function_type *func, const void *payload = nullptr, const char *name = nullptr) {
- using resource_type = internal::resource_traits<type_list<>, type_list<Req...>>;
- track_dependencies(vertices.size(), true, typename resource_type::ro{}, typename resource_type::rw{});
-
- vertex_data vdata{
- resource_type::ro::size,
- resource_type::rw::size,
- name,
- payload,
- func,
- +[](const bool rw, const type_info **buffer, const std::size_t length) { return rw ? fill_dependencies(typename resource_type::rw{}, buffer, length) : fill_dependencies(typename resource_type::ro{}, buffer, length); },
- nullptr,
- &type_id<void>()};
-
- vertices.push_back(std::move(vdata));
- }
-
- /**
- * @brief Generates a task graph for the current content.
- * @return The adjacency list of the task graph.
- */
- std::vector<vertex> graph() {
- const auto edges = adjacency_matrix();
-
- // creates the adjacency list
- std::vector<vertex> adjacency_list{};
- adjacency_list.reserve(vertices.size());
-
- for(std::size_t col{}, length = vertices.size(); col < length; ++col) {
- std::vector<std::size_t> reachable{};
- const auto row = col * length;
- bool is_top_level = true;
-
- for(std::size_t next{}; next < length; ++next) {
- if(edges[row + next]) {
- reachable.push_back(next);
- }
- }
-
- for(std::size_t next{}; next < length && is_top_level; ++next) {
- is_top_level = !edges[next * length + col];
- }
-
- adjacency_list.emplace_back(is_top_level, vertices[col], std::move(reachable));
- }
-
- return adjacency_list;
- }
-
- /*! @brief Erases all elements from a container. */
- void clear() {
- dependencies.clear();
- vertices.clear();
- }
-
- private:
- dense_map<id_type, std::vector<std::pair<std::size_t, bool>>, identity> dependencies;
- std::vector<vertex_data> vertices;
- };
-
- } // namespace entt
-
- #endif
|