EntityPredicate.hpp

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//
//  CeresEngine - A game development framework
//
//  Created by Rogiel Sulzbach.
//  Copyright (c) 2018-2022 Rogiel Sulzbach. All rights reserved.
//
 
#pragma once
 
#include "Component.hpp"
#include "Entity.hpp"
 
#include "CeresEngine/Macros.hpp"
 
#include "CeresEngine/Foundation/Predicate.hpp"
 
#include <utility>
 
namespace CeresEngine {
 
    template<CComponent... Cs> struct ComponentPredicate : Predicate<ComponentPredicate<Cs...>> {
        inline bool operator()(const Entity& entity) const noexcept { return entity.has<Cs...>(); }
    };
 
    template<CComponent... Cs> struct ComponentPredicate<ComponentSet<Cs...>> : ComponentPredicate<Cs...> {};
 
    template<CComponent... Cs> [[nodiscard]] inline constexpr auto withComponent() noexcept { return ComponentPredicate<Cs...>(); }
 
    template<typename CS> [[nodiscard]] inline constexpr auto withComponents() noexcept { return CS::template Apply<ComponentPredicate>(); }
 
    template<CComponent... Cs, typename Predicate> [[nodiscard]] inline constexpr auto withComponent(Predicate&& subpredicate) noexcept {
        return withComponent<Cs...>() &&
            predicate([subpredicate = std::forward<Predicate>(subpredicate)](Entity entity) noexcept { return subpredicate(entity.get<Cs>()...); });
    }
 
    struct ParentPredicate : public Predicate<ParentPredicate> {
        const Entity parent;
 
        explicit inline ParentPredicate(const Entity parent) : parent(parent) {}
 
        inline bool operator()(const Entity& entity) const noexcept { return entity.getParent() == parent; }
    };
 
    [[nodiscard]] inline ParentPredicate withParent(const Entity& parent) noexcept { return ParentPredicate{parent}; }
 
    struct NamePredicate : public Predicate<ParentPredicate> {
        const String name;
 
        explicit inline NamePredicate(String name) : name(std::move(name)) {}
 
        inline bool operator()(const Entity& entity) const noexcept { return entity.getName() == name; }
    };
 
    [[nodiscard]] inline NamePredicate withName(String name) { return NamePredicate{std::move(name)}; }
 
} // namespace CeresEngine