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/entity.hpp | 388 ++++++++++++++++++++++++++++++++++++ 1 file changed, 388 insertions(+) create mode 100644 deps/include/entt/entity/entity.hpp (limited to 'deps/include/entt/entity/entity.hpp') diff --git a/deps/include/entt/entity/entity.hpp b/deps/include/entt/entity/entity.hpp new file mode 100644 index 0000000..f9a2454 --- /dev/null +++ b/deps/include/entt/entity/entity.hpp @@ -0,0 +1,388 @@ +#ifndef ENTT_ENTITY_ENTITY_HPP +#define ENTT_ENTITY_ENTITY_HPP + +#include +#include +#include +#include "../config/config.h" +#include "../core/bit.hpp" +#include "fwd.hpp" + +namespace entt { + +/*! @cond TURN_OFF_DOXYGEN */ +namespace internal { + +template +struct entt_traits; + +template +struct entt_traits>> + : entt_traits> { + using value_type = Type; +}; + +template +struct entt_traits>> + : entt_traits { + using value_type = Type; +}; + +template<> +struct entt_traits { + using value_type = std::uint32_t; + + using entity_type = std::uint32_t; + using version_type = std::uint16_t; + + static constexpr entity_type entity_mask = 0xFFFFF; + static constexpr entity_type version_mask = 0xFFF; +}; + +template<> +struct entt_traits { + using value_type = std::uint64_t; + + using entity_type = std::uint64_t; + using version_type = std::uint32_t; + + static constexpr entity_type entity_mask = 0xFFFFFFFF; + static constexpr entity_type version_mask = 0xFFFFFFFF; +}; + +} // namespace internal +/*! @endcond */ + +/** + * @brief Common basic entity traits implementation. + * @tparam Traits Actual entity traits to use. + */ +template +class basic_entt_traits { + static constexpr auto length = popcount(Traits::entity_mask); + + static_assert(Traits::entity_mask && ((Traits::entity_mask & (Traits::entity_mask + 1)) == 0), "Invalid entity mask"); + static_assert((Traits::version_mask & (Traits::version_mask + 1)) == 0, "Invalid version mask"); + +public: + /*! @brief Value type. */ + using value_type = typename Traits::value_type; + /*! @brief Underlying entity type. */ + using entity_type = typename Traits::entity_type; + /*! @brief Underlying version type. */ + using version_type = typename Traits::version_type; + + /*! @brief Entity mask size. */ + static constexpr entity_type entity_mask = Traits::entity_mask; + /*! @brief Version mask size */ + static constexpr entity_type version_mask = Traits::version_mask; + + /** + * @brief Converts an entity to its underlying type. + * @param value The value to convert. + * @return The integral representation of the given value. + */ + [[nodiscard]] static constexpr entity_type to_integral(const value_type value) noexcept { + return static_cast(value); + } + + /** + * @brief Returns the entity part once converted to the underlying type. + * @param value The value to convert. + * @return The integral representation of the entity part. + */ + [[nodiscard]] static constexpr entity_type to_entity(const value_type value) noexcept { + return (to_integral(value) & entity_mask); + } + + /** + * @brief Returns the version part once converted to the underlying type. + * @param value The value to convert. + * @return The integral representation of the version part. + */ + [[nodiscard]] static constexpr version_type to_version(const value_type value) noexcept { + if constexpr(Traits::version_mask == 0u) { + return version_type{}; + } else { + return (static_cast(to_integral(value) >> length) & version_mask); + } + } + + /** + * @brief Returns the successor of a given identifier. + * @param value The identifier of which to return the successor. + * @return The successor of the given identifier. + */ + [[nodiscard]] static constexpr value_type next(const value_type value) noexcept { + const auto vers = to_version(value) + 1; + return construct(to_integral(value), static_cast(vers + (vers == version_mask))); + } + + /** + * @brief Constructs an identifier from its parts. + * + * If the version part is not provided, a tombstone is returned.
+ * If the entity part is not provided, a null identifier is returned. + * + * @param entity The entity part of the identifier. + * @param version The version part of the identifier. + * @return A properly constructed identifier. + */ + [[nodiscard]] static constexpr value_type construct(const entity_type entity, const version_type version) noexcept { + if constexpr(Traits::version_mask == 0u) { + return value_type{entity & entity_mask}; + } else { + return value_type{(entity & entity_mask) | (static_cast(version & version_mask) << length)}; + } + } + + /** + * @brief Combines two identifiers in a single one. + * + * The returned identifier is a copy of the first element except for its + * version, which is taken from the second element. + * + * @param lhs The identifier from which to take the entity part. + * @param rhs The identifier from which to take the version part. + * @return A properly constructed identifier. + */ + [[nodiscard]] static constexpr value_type combine(const entity_type lhs, const entity_type rhs) noexcept { + if constexpr(Traits::version_mask == 0u) { + return value_type{lhs & entity_mask}; + } else { + return value_type{(lhs & entity_mask) | (rhs & (version_mask << length))}; + } + } +}; + +/** + * @brief Entity traits. + * @tparam Type Type of identifier. + */ +template +struct entt_traits: basic_entt_traits> { + /*! @brief Base type. */ + using base_type = basic_entt_traits>; + /*! @brief Page size, default is `ENTT_SPARSE_PAGE`. */ + static constexpr std::size_t page_size = ENTT_SPARSE_PAGE; +}; + +/** + * @brief Converts an entity to its underlying type. + * @tparam Entity The value type. + * @param value The value to convert. + * @return The integral representation of the given value. + */ +template +[[nodiscard]] constexpr typename entt_traits::entity_type to_integral(const Entity value) noexcept { + return entt_traits::to_integral(value); +} + +/** + * @brief Returns the entity part once converted to the underlying type. + * @tparam Entity The value type. + * @param value The value to convert. + * @return The integral representation of the entity part. + */ +template +[[nodiscard]] constexpr typename entt_traits::entity_type to_entity(const Entity value) noexcept { + return entt_traits::to_entity(value); +} + +/** + * @brief Returns the version part once converted to the underlying type. + * @tparam Entity The value type. + * @param value The value to convert. + * @return The integral representation of the version part. + */ +template +[[nodiscard]] constexpr typename entt_traits::version_type to_version(const Entity value) noexcept { + return entt_traits::to_version(value); +} + +/*! @brief Null object for all identifiers. */ +struct null_t { + /** + * @brief Converts the null object to identifiers of any type. + * @tparam Entity Type of identifier. + * @return The null representation for the given type. + */ + template + [[nodiscard]] constexpr operator Entity() const noexcept { + using traits_type = entt_traits; + constexpr auto value = traits_type::construct(traits_type::entity_mask, traits_type::version_mask); + return value; + } + + /** + * @brief Compares two null objects. + * @param other A null object. + * @return True in all cases. + */ + [[nodiscard]] constexpr bool operator==([[maybe_unused]] const null_t other) const noexcept { + return true; + } + + /** + * @brief Compares two null objects. + * @param other A null object. + * @return False in all cases. + */ + [[nodiscard]] constexpr bool operator!=([[maybe_unused]] const null_t other) const noexcept { + return false; + } + + /** + * @brief Compares a null object and an identifier of any type. + * @tparam Entity Type of identifier. + * @param entity Identifier with which to compare. + * @return False if the two elements differ, true otherwise. + */ + template + [[nodiscard]] constexpr bool operator==(const Entity entity) const noexcept { + using traits_type = entt_traits; + return traits_type::to_entity(entity) == traits_type::to_entity(*this); + } + + /** + * @brief Compares a null object and an identifier of any type. + * @tparam Entity Type of identifier. + * @param entity Identifier with which to compare. + * @return True if the two elements differ, false otherwise. + */ + template + [[nodiscard]] constexpr bool operator!=(const Entity entity) const noexcept { + return !(entity == *this); + } +}; + +/** + * @brief Compares a null object and an identifier of any type. + * @tparam Entity Type of identifier. + * @param lhs Identifier with which to compare. + * @param rhs A null object yet to be converted. + * @return False if the two elements differ, true otherwise. + */ +template +[[nodiscard]] constexpr bool operator==(const Entity lhs, const null_t rhs) noexcept { + return rhs.operator==(lhs); +} + +/** + * @brief Compares a null object and an identifier of any type. + * @tparam Entity Type of identifier. + * @param lhs Identifier with which to compare. + * @param rhs A null object yet to be converted. + * @return True if the two elements differ, false otherwise. + */ +template +[[nodiscard]] constexpr bool operator!=(const Entity lhs, const null_t rhs) noexcept { + return !(rhs == lhs); +} + +/*! @brief Tombstone object for all identifiers. */ +struct tombstone_t { + /** + * @brief Converts the tombstone object to identifiers of any type. + * @tparam Entity Type of identifier. + * @return The tombstone representation for the given type. + */ + template + [[nodiscard]] constexpr operator Entity() const noexcept { + using traits_type = entt_traits; + constexpr auto value = traits_type::construct(traits_type::entity_mask, traits_type::version_mask); + return value; + } + + /** + * @brief Compares two tombstone objects. + * @param other A tombstone object. + * @return True in all cases. + */ + [[nodiscard]] constexpr bool operator==([[maybe_unused]] const tombstone_t other) const noexcept { + return true; + } + + /** + * @brief Compares two tombstone objects. + * @param other A tombstone object. + * @return False in all cases. + */ + [[nodiscard]] constexpr bool operator!=([[maybe_unused]] const tombstone_t other) const noexcept { + return false; + } + + /** + * @brief Compares a tombstone object and an identifier of any type. + * @tparam Entity Type of identifier. + * @param entity Identifier with which to compare. + * @return False if the two elements differ, true otherwise. + */ + template + [[nodiscard]] constexpr bool operator==(const Entity entity) const noexcept { + using traits_type = entt_traits; + + if constexpr(traits_type::version_mask == 0u) { + return false; + } else { + return (traits_type::to_version(entity) == traits_type::to_version(*this)); + } + } + + /** + * @brief Compares a tombstone object and an identifier of any type. + * @tparam Entity Type of identifier. + * @param entity Identifier with which to compare. + * @return True if the two elements differ, false otherwise. + */ + template + [[nodiscard]] constexpr bool operator!=(const Entity entity) const noexcept { + return !(entity == *this); + } +}; + +/** + * @brief Compares a tombstone object and an identifier of any type. + * @tparam Entity Type of identifier. + * @param lhs Identifier with which to compare. + * @param rhs A tombstone object yet to be converted. + * @return False if the two elements differ, true otherwise. + */ +template +[[nodiscard]] constexpr bool operator==(const Entity lhs, const tombstone_t rhs) noexcept { + return rhs.operator==(lhs); +} + +/** + * @brief Compares a tombstone object and an identifier of any type. + * @tparam Entity Type of identifier. + * @param lhs Identifier with which to compare. + * @param rhs A tombstone object yet to be converted. + * @return True if the two elements differ, false otherwise. + */ +template +[[nodiscard]] constexpr bool operator!=(const Entity lhs, const tombstone_t rhs) noexcept { + return !(rhs == lhs); +} + +/** + * @brief Compile-time constant for null entities. + * + * There exist implicit conversions from this variable to identifiers of any + * allowed type. Similarly, there exist comparison operators between the null + * entity and any other identifier. + */ +inline constexpr null_t null{}; + +/** + * @brief Compile-time constant for tombstone entities. + * + * There exist implicit conversions from this variable to identifiers of any + * allowed type. Similarly, there exist comparison operators between the + * tombstone entity and any other identifier. + */ +inline constexpr tombstone_t tombstone{}; + +} // namespace entt + +#endif -- cgit