From ab187a9fa91cc9c9b8063f6222ffe6d97dbfc5a8 Mon Sep 17 00:00:00 2001
From: Benjamin Palko <benjaminpalko@hotmail.com>
Date: Thu, 10 Oct 2024 14:00:33 -0400
Subject: [PATCH] merge component array into manager

---
 libs/ecs/componentarray.cpp   | 47 -----------------------------
 libs/ecs/componentarray.hpp   | 37 -----------------------
 libs/ecs/componentmanager.cpp | 56 ++++++++++++++++++++++++++++++++++-
 libs/ecs/componentmanager.hpp | 33 +++++++++++++++++++--
 4 files changed, 86 insertions(+), 87 deletions(-)
 delete mode 100644 libs/ecs/componentarray.cpp
 delete mode 100644 libs/ecs/componentarray.hpp

diff --git a/libs/ecs/componentarray.cpp b/libs/ecs/componentarray.cpp
deleted file mode 100644
index 3b3b45b..0000000
--- a/libs/ecs/componentarray.cpp
+++ /dev/null
@@ -1,47 +0,0 @@
-#include <cassert>
-#include "componentarray.hpp"
-
-template <typename T>
-void ComponentArray<T>::InsertData(Entity entity, T component) {
-  assert(mEntityToIndexMap.find(entity) == mEntityToIndexMap.end() &&
-         "Component added to same entity more than once.");
-
-  // Put new entry at end and update the maps
-  size_t newIndex = mSize;
-  mEntityToIndexMap[entity] = newIndex;
-  mIndexToEntityMap[newIndex] = entity;
-  mComponentArray[newIndex] = component;
-  ++mSize;
-};
-template <typename T> void ComponentArray<T>::RemoveData(Entity entity) {
-  assert(mEntityToIndexMap.find(entity) != mEntityToIndexMap.end() &&
-         "Removing non-existent component.");
-
-  // Copy element at end into deleted element's place to maintain density
-  size_t indexOfRemovedEntity = mEntityToIndexMap[entity];
-  size_t indexOfLastElement = mSize - 1;
-  mComponentArray[indexOfRemovedEntity] = mComponentArray[indexOfLastElement];
-
-  // Update map to point to moved spot
-  Entity entityOfLastElement = mIndexToEntityMap[indexOfLastElement];
-  mEntityToIndexMap[entityOfLastElement] = indexOfRemovedEntity;
-  mIndexToEntityMap[indexOfRemovedEntity] = entityOfLastElement;
-
-  mEntityToIndexMap.erase(entity);
-  mIndexToEntityMap.erase(indexOfLastElement);
-
-  --mSize;
-};
-template <typename T> T &ComponentArray<T>::GetData(Entity entity) {
-  assert(mEntityToIndexMap.find(entity) != mEntityToIndexMap.end() &&
-         "Retrieving non-existent component.");
-
-  // Return a reference to the entity's component
-  return mComponentArray[mEntityToIndexMap[entity]];
-};
-template <typename T> void ComponentArray<T>::EntityDestroyed(Entity entity) {
-  if (mEntityToIndexMap.find(entity) != mEntityToIndexMap.end()) {
-    // Remove the entity's component if it existed
-    RemoveData(entity);
-  }
-};
diff --git a/libs/ecs/componentarray.hpp b/libs/ecs/componentarray.hpp
deleted file mode 100644
index f8b10c4..0000000
--- a/libs/ecs/componentarray.hpp
+++ /dev/null
@@ -1,37 +0,0 @@
-#ifndef COMPONENTARRAY_HPP
-#define COMPONENTARRAY_HPP
-
-#include <unordered_map>
-#include <array>
-#include "entity.hpp"
-
-class IComponentArray {
-public:
-  virtual ~IComponentArray() = default;
-  virtual void EntityDestroyed(Entity entity) = 0;
-};
-
-template <typename T> class ComponentArray : public IComponentArray {
-  // The packed array of components (of generic type T),
-  // set to a specified maximum amount, matching the maximum number
-  // of entities allowed to exist simultaneously, so that each entity
-  // has a unique spot.
-  std::array<T, MAX_ENTITIES> mComponentArray;
-
-  // Map from an entity ID to an array index.
-  std::unordered_map<Entity, size_t> mEntityToIndexMap;
-
-  // Map from an array index to an entity ID.
-  std::unordered_map<size_t, Entity> mIndexToEntityMap;
-
-  // Total size of valid entries in the array.
-  size_t mSize;
-
-public:
-  void InsertData(Entity entity, T component);
-  void RemoveData(Entity entity);
-  T &GetData(Entity entity);
-  void EntityDestroyed(Entity entity) override;
-};
-
-#endif // COMPONENTARRAY_HPP
diff --git a/libs/ecs/componentmanager.cpp b/libs/ecs/componentmanager.cpp
index 24584db..352c01f 100644
--- a/libs/ecs/componentmanager.cpp
+++ b/libs/ecs/componentmanager.cpp
@@ -1,7 +1,61 @@
 #include "componentmanager.hpp"
-#include "componentarray.hpp"
+
+#include <cassert>
 #include <memory>
 
+/**
+ * ComponentArray
+ **/
+
+template <typename T>
+void ComponentArray<T>::InsertData(Entity entity, T component) {
+  assert(mEntityToIndexMap.find(entity) == mEntityToIndexMap.end() &&
+         "Component added to same entity more than once.");
+
+  // Put new entry at end and update the maps
+  size_t newIndex = mSize;
+  mEntityToIndexMap[entity] = newIndex;
+  mIndexToEntityMap[newIndex] = entity;
+  mComponentArray[newIndex] = component;
+  ++mSize;
+};
+template <typename T> void ComponentArray<T>::RemoveData(Entity entity) {
+  assert(mEntityToIndexMap.find(entity) != mEntityToIndexMap.end() &&
+         "Removing non-existent component.");
+
+  // Copy element at end into deleted element's place to maintain density
+  size_t indexOfRemovedEntity = mEntityToIndexMap[entity];
+  size_t indexOfLastElement = mSize - 1;
+  mComponentArray[indexOfRemovedEntity] = mComponentArray[indexOfLastElement];
+
+  // Update map to point to moved spot
+  Entity entityOfLastElement = mIndexToEntityMap[indexOfLastElement];
+  mEntityToIndexMap[entityOfLastElement] = indexOfRemovedEntity;
+  mIndexToEntityMap[indexOfRemovedEntity] = entityOfLastElement;
+
+  mEntityToIndexMap.erase(entity);
+  mIndexToEntityMap.erase(indexOfLastElement);
+
+  --mSize;
+};
+template <typename T> T &ComponentArray<T>::GetData(Entity entity) {
+  assert(mEntityToIndexMap.find(entity) != mEntityToIndexMap.end() &&
+         "Retrieving non-existent component.");
+
+  // Return a reference to the entity's component
+  return mComponentArray[mEntityToIndexMap[entity]];
+};
+template <typename T> void ComponentArray<T>::EntityDestroyed(Entity entity) {
+  if (mEntityToIndexMap.find(entity) != mEntityToIndexMap.end()) {
+    // Remove the entity's component if it existed
+    RemoveData(entity);
+  }
+};
+
+/**
+ * ComponentManager
+ **/
+
 //  Private functions
 template <typename T>
 std::shared_ptr<ComponentArray<T>> ComponentManager::GetComponentArray() {
diff --git a/libs/ecs/componentmanager.hpp b/libs/ecs/componentmanager.hpp
index 16ab368..a61a95f 100644
--- a/libs/ecs/componentmanager.hpp
+++ b/libs/ecs/componentmanager.hpp
@@ -1,11 +1,40 @@
 #ifndef COMPONENTMANAGER_HPP
 #define COMPONENTMANAGER_HPP
 
+#include <array>
 #include <unordered_map>
 #include <memory>
-#include <cassert>
+#include "entity.hpp"
 #include "component.hpp"
-#include "componentarray.hpp"
+
+class IComponentArray {
+public:
+  virtual ~IComponentArray() = default;
+  virtual void EntityDestroyed(Entity entity) = 0;
+};
+
+template <typename T> class ComponentArray : public IComponentArray {
+  // The packed array of components (of generic type T),
+  // set to a specified maximum amount, matching the maximum number
+  // of entities allowed to exist simultaneously, so that each entity
+  // has a unique spot.
+  std::array<T, MAX_ENTITIES> mComponentArray;
+
+  // Map from an entity ID to an array index.
+  std::unordered_map<Entity, size_t> mEntityToIndexMap;
+
+  // Map from an array index to an entity ID.
+  std::unordered_map<size_t, Entity> mIndexToEntityMap;
+
+  // Total size of valid entries in the array.
+  size_t mSize;
+
+public:
+  void InsertData(Entity entity, T component);
+  void RemoveData(Entity entity);
+  T &GetData(Entity entity);
+  void EntityDestroyed(Entity entity) override;
+};
 
 class ComponentManager {
   // Map from type string pointer to a component type