2024-10-31 01:08:01 +10:00

267 lines
8.1 KiB
C++

#ifndef ENTT_ENTITY_FWD_HPP
#define ENTT_ENTITY_FWD_HPP
#include <cstdint>
#include <memory>
#include <type_traits>
#include "../core/fwd.hpp"
#include "../core/type_traits.hpp"
namespace entt {
/*! @brief Default entity identifier. */
enum class entity : id_type {};
/*! @brief Storage deletion policy. */
enum class deletion_policy : std::uint8_t {
/*! @brief Swap-and-pop deletion policy. */
swap_and_pop = 0u,
/*! @brief In-place deletion policy. */
in_place = 1u,
/*! @brief Swap-only deletion policy. */
swap_only = 2u
};
template<typename Entity = entity, typename = std::allocator<Entity>>
class basic_sparse_set;
template<typename Type, typename = entity, typename = std::allocator<Type>, typename = void>
class basic_storage;
template<typename, typename>
class basic_sigh_mixin;
template<typename Entity = entity, typename = std::allocator<Entity>>
class basic_registry;
template<typename, typename, typename = void>
class basic_view;
template<typename Type, typename = std::allocator<Type *>>
class basic_runtime_view;
template<typename, typename, typename>
class basic_group;
template<typename, typename Mask = std::uint32_t, typename = std::allocator<Mask>>
class basic_observer;
template<typename>
class basic_organizer;
template<typename, typename...>
struct basic_handle;
template<typename>
class basic_snapshot;
template<typename>
class basic_snapshot_loader;
template<typename>
class basic_continuous_loader;
/*! @brief Alias declaration for the most common use case. */
using sparse_set = basic_sparse_set<>;
/**
* @brief Alias declaration for the most common use case.
* @tparam Type Type of objects assigned to the entities.
*/
template<typename Type>
using storage = basic_storage<Type>;
/**
* @brief Alias declaration for the most common use case.
* @tparam Type Underlying storage type.
*/
template<typename Type>
using sigh_mixin = basic_sigh_mixin<Type, basic_registry<typename Type::entity_type, typename Type::base_type::allocator_type>>;
/*! @brief Alias declaration for the most common use case. */
using registry = basic_registry<>;
/*! @brief Alias declaration for the most common use case. */
using observer = basic_observer<registry>;
/*! @brief Alias declaration for the most common use case. */
using organizer = basic_organizer<registry>;
/*! @brief Alias declaration for the most common use case. */
using handle = basic_handle<registry>;
/*! @brief Alias declaration for the most common use case. */
using const_handle = basic_handle<const registry>;
/**
* @brief Alias declaration for the most common use case.
* @tparam Args Other template parameters.
*/
template<typename... Args>
using handle_view = basic_handle<registry, Args...>;
/**
* @brief Alias declaration for the most common use case.
* @tparam Args Other template parameters.
*/
template<typename... Args>
using const_handle_view = basic_handle<const registry, Args...>;
/*! @brief Alias declaration for the most common use case. */
using snapshot = basic_snapshot<registry>;
/*! @brief Alias declaration for the most common use case. */
using snapshot_loader = basic_snapshot_loader<registry>;
/*! @brief Alias declaration for the most common use case. */
using continuous_loader = basic_continuous_loader<registry>;
/*! @brief Alias declaration for the most common use case. */
using runtime_view = basic_runtime_view<sparse_set>;
/*! @brief Alias declaration for the most common use case. */
using const_runtime_view = basic_runtime_view<const sparse_set>;
/**
* @brief Alias for exclusion lists.
* @tparam Type List of types.
*/
template<typename... Type>
struct exclude_t final: type_list<Type...> {
/*! @brief Default constructor. */
explicit constexpr exclude_t() {}
};
/**
* @brief Variable template for exclusion lists.
* @tparam Type List of types.
*/
template<typename... Type>
inline constexpr exclude_t<Type...> exclude{};
/**
* @brief Alias for lists of observed components.
* @tparam Type List of types.
*/
template<typename... Type>
struct get_t final: type_list<Type...> {
/*! @brief Default constructor. */
explicit constexpr get_t() {}
};
/**
* @brief Variable template for lists of observed components.
* @tparam Type List of types.
*/
template<typename... Type>
inline constexpr get_t<Type...> get{};
/**
* @brief Alias for lists of owned components.
* @tparam Type List of types.
*/
template<typename... Type>
struct owned_t final: type_list<Type...> {
/*! @brief Default constructor. */
explicit constexpr owned_t() {}
};
/**
* @brief Variable template for lists of owned components.
* @tparam Type List of types.
*/
template<typename... Type>
inline constexpr owned_t<Type...> owned{};
/**
* @brief Applies a given _function_ to a get list and generate a new list.
* @tparam Type Types provided by the get list.
* @tparam Op Unary operation as template class with a type member named `type`.
*/
template<typename... Type, template<typename...> class Op>
struct type_list_transform<get_t<Type...>, Op> {
/*! @brief Resulting get list after applying the transform function. */
using type = get_t<typename Op<Type>::type...>;
};
/**
* @brief Applies a given _function_ to an exclude list and generate a new list.
* @tparam Type Types provided by the exclude list.
* @tparam Op Unary operation as template class with a type member named `type`.
*/
template<typename... Type, template<typename...> class Op>
struct type_list_transform<exclude_t<Type...>, Op> {
/*! @brief Resulting exclude list after applying the transform function. */
using type = exclude_t<typename Op<Type>::type...>;
};
/**
* @brief Applies a given _function_ to an owned list and generate a new list.
* @tparam Type Types provided by the owned list.
* @tparam Op Unary operation as template class with a type member named `type`.
*/
template<typename... Type, template<typename...> class Op>
struct type_list_transform<owned_t<Type...>, Op> {
/*! @brief Resulting owned list after applying the transform function. */
using type = owned_t<typename Op<Type>::type...>;
};
/**
* @brief Provides a common way to define storage types.
* @tparam Type Storage value type.
* @tparam Entity A valid entity type.
* @tparam Allocator Type of allocator used to manage memory and elements.
*/
template<typename Type, typename Entity = entity, typename Allocator = std::allocator<Type>, typename = void>
struct storage_type {
/*! @brief Type-to-storage conversion result. */
using type = sigh_mixin<basic_storage<Type, Entity, Allocator>>;
};
/**
* @brief Helper type.
* @tparam Args Arguments to forward.
*/
template<typename... Args>
using storage_type_t = typename storage_type<Args...>::type;
/**
* Type-to-storage conversion utility that preserves constness.
* @tparam Type Storage value type, eventually const.
* @tparam Entity A valid entity type.
* @tparam Allocator Type of allocator used to manage memory and elements.
*/
template<typename Type, typename Entity = entity, typename Allocator = std::allocator<std::remove_const_t<Type>>>
struct storage_for {
/*! @brief Type-to-storage conversion result. */
using type = constness_as_t<storage_type_t<std::remove_const_t<Type>, Entity, Allocator>, Type>;
};
/**
* @brief Helper type.
* @tparam Args Arguments to forward.
*/
template<typename... Args>
using storage_for_t = typename storage_for<Args...>::type;
/**
* @brief Alias declaration for the most common use case.
* @tparam Get Types of storage iterated by the view.
* @tparam Exclude Types of storage used to filter the view.
*/
template<typename Get, typename Exclude = exclude_t<>>
using view = basic_view<type_list_transform_t<Get, storage_for>, type_list_transform_t<Exclude, storage_for>>;
/**
* @brief Alias declaration for the most common use case.
* @tparam Owned Types of storage _owned_ by the group.
* @tparam Get Types of storage _observed_ by the group.
* @tparam Exclude Types of storage used to filter the group.
*/
template<typename Owned, typename Get, typename Exclude>
using group = basic_group<type_list_transform_t<Owned, storage_for>, type_list_transform_t<Get, storage_for>, type_list_transform_t<Exclude, storage_for>>;
} // namespace entt
#endif