Merge remote-tracking branch 'origin/master' into max/POC-ECS-memory-efficient

1 files changed, 55 insertions, 0 deletions

diff --git a/mwe/ecs-homemade/inc/ComponentManager.h b/mwe/ecs-homemade/inc/ComponentManager.h
new file mode 100644
index 0000000..d368516
--- /dev/null
+++ b/mwe/ecs-homemade/inc/ComponentManager.h
@@ -0,0 +1,55 @@
+#pragma once
+
+#include "Components.h"
+#include <cstdint>
+#include <memory>
+#include <typeindex>
+#include <unordered_map>
+#include <utility>
+#include <vector>
+
+class ComponentManager {
+public:
+	static ComponentManager & GetInstance(); //Singleton
+
+	ComponentManager(const ComponentManager &) = delete; //Singleton
+	ComponentManager(ComponentManager &&) = delete; //Singleton
+	ComponentManager & operator=(const ComponentManager &) = delete; //Singleton
+	ComponentManager & operator=(ComponentManager &&) = delete; //Singleton
+
+	template <typename T, typename... Args>
+	void AddComponent(std::uint32_t id,
+					  Args &&... args); //Add a component of a specific type
+	template <typename T>
+	void DeleteComponentsById(
+		std::uint32_t id); //Deletes all components of a specific type and id
+	template <typename T>
+	void DeleteComponents(); //Deletes all components of a specific type
+	void DeleteAllComponentsOfId(
+		std::uint32_t id); //Deletes all components of a specific id
+	void DeleteAllComponents(); //Deletes all components
+
+	template <typename T>
+	std::vector<std::reference_wrapper<T>> GetComponentsByID(std::uint32_t id)
+		const; //Get a vector<> of all components at specific type and id
+	template <typename T>
+	std::vector<std::reference_wrapper<T>> GetComponentsByType()
+		const; //Get a vector<> of all components of a specific type
+
+private:
+	static ComponentManager mInstance; //Singleton
+
+	ComponentManager(); //Singleton
+
+	/*
+	 * The std::unordered_map<std::type_index, std::vector<std::vector<std::unique_ptr<Component>>>> below might seem a bit strange, let me explain this structure:
+	 * The std::unordered_map<> has a key and value. The key is a std::type_index and the value is a std::vector. So, a new std::vector will be created for each new std::type_index.
+	 * The first std::vector<> stores another vector<>. This first vector<> is to bind the entity's id to a component.
+	 * The second std::vector<> stores unique_ptrs. Each component can be gathered via an unique_ptr. This second vector<> allows multiple components of the same std::type_index for one entity (id).
+	 */
+	std::unordered_map<std::type_index,
+					   std::vector<std::vector<std::unique_ptr<Component>>>>
+		mComponents;
+};
+
+#include "ComponentManager.hpp"