From 50423f7ec97bbafe49dd3f7e075a52253a854938 Mon Sep 17 00:00:00 2001
From: Julian <julian.frabel@epitech.eu>
Date: Mon, 24 Jun 2019 11:45:40 +0200
Subject: [PATCH] Fixed a bug in deleteAllEntities beeing stuck with
 shouldBeKeeped entities and added a safeDelete function

---
 README.md                 |  7 +++++++
 sources/Entity.cpp        |  1 +
 sources/EntityManager.cpp | 28 +++++++++++++++++++++++-----
 sources/EntityManager.hpp | 12 ++++++++++++
 4 files changed, 43 insertions(+), 5 deletions(-)

diff --git a/README.md b/README.md
index 280d6b8..4e07093 100644
--- a/README.md
+++ b/README.md
@@ -155,6 +155,13 @@ bool deleteEntity(const internal::ID &entityID);
 ```
 > **INFO**: For this and the following functions please see the [documentation](#documentation) or the [examples](#examples) for details on how to use them.
 
+If you are in an applyToEach loop or if you are iterating on entities better use safeDeleteEntity:
+```cpp
+void safeDeleteEntity(const internal::ID &entityID);
+```
+> **INFO**: For this and the following functions please see the [documentation](#documentation) or the [examples](#examples) for details on how to use them.
+> **INFO**: You will need to call in a safe spot (like your main loop the function `applySafeDelete` to take effects of safeDelete)
+
 The function used to retrieve an entity by its identifiers are as follow:
 ```cpp
 EntityHandler getEntityByID(const internal::ID &entityID);
diff --git a/sources/Entity.cpp b/sources/Entity.cpp
index 94c6769..78b8767 100644
--- a/sources/Entity.cpp
+++ b/sources/Entity.cpp
@@ -22,6 +22,7 @@ jf::entities::Entity::~Entity()
 {
     for (auto &i : _components) {
         delete i.second;
+        i.second = nullptr;
     }
     events::EventManager::getInstance().emit<events::EntityDestroyedEvent>({this});
 }
diff --git a/sources/EntityManager.cpp b/sources/EntityManager.cpp
index b261232..0208804 100644
--- a/sources/EntityManager.cpp
+++ b/sources/EntityManager.cpp
@@ -17,7 +17,7 @@ jf::entities::EntityManager &jf::entities::EntityManager::getInstance()
 }
 
 jf::entities::EntityManager::EntityManager()
-    : _maxId(0), _entities(), _freeIDs()
+    : _maxId(0), _entities(), _freeIDs(), _toDestroyIDs()
 {
 
 }
@@ -111,8 +111,26 @@ std::vector<jf::entities::EntityHandler> jf::entities::EntityManager::getEntitie
 
 void jf::entities::EntityManager::deleteAllEntities()
 {
-    while (!_entities.empty()) {
-        if (!_entities.begin()->second->shouldBeKeeped())
-            deleteEntity(_entities.begin()->first);
+    auto entity = std::find_if(_entities.begin(), _entities.end(), [](const std::pair<internal::ID, Entity *> &pair) {
+        return !pair.second->shouldBeKeeped();
+    });
+    while (entity != _entities.end()) {
+        deleteEntity(entity->first);
+        entity = std::find_if(_entities.begin(), _entities.end(), [](const std::pair<internal::ID, Entity *> &pair) {
+            return !pair.second->shouldBeKeeped();
+        });
     }
-}
\ No newline at end of file
+}
+
+void jf::entities::EntityManager::safeDeleteEntity(const jf::internal::ID &entityID)
+{
+    _toDestroyIDs.push_back(entityID);
+}
+
+void jf::entities::EntityManager::applySafeDelete()
+{
+    for (auto &id : _toDestroyIDs) {
+        unregisterEntity(id);
+    }
+    _toDestroyIDs.clear();
+}
diff --git a/sources/EntityManager.hpp b/sources/EntityManager.hpp
index 1a32cb7..d7bf2d9 100644
--- a/sources/EntityManager.hpp
+++ b/sources/EntityManager.hpp
@@ -79,12 +79,23 @@ namespace jf {
              * @return true if the entity existed and was deleted false otherwise
              */
             bool deleteEntity(const internal::ID &entityID);
+            /*!
+             * @brief Delete an entity given it's id
+             * @param entityID The id of the entity to delete
+             * @return true if the entity existed and was deleted false otherwise
+             */
+            void safeDeleteEntity(const internal::ID &entityID);
 
             /*!
              * @brief Delete all the existing entities except the ones marked as shouldBeKeeped
              */
             void deleteAllEntities();
 
+            /*!
+             * @brief Delete entities that have been marked for safe delete.
+             */
+            void applySafeDelete();
+
             /*!
              * @brief Get an entity given an ID
              * @param entityID The id of the entity to get
@@ -150,6 +161,7 @@ namespace jf {
             uint64_t _maxId; /*!< The last biggest existing entity */
             std::unordered_map<internal::ID, Entity *> _entities; /*!< A map containing all the existing entities */
             std::queue<internal::ID> _freeIDs; /*!< Ids destroyed and not used */
+            std::vector<internal::ID> _toDestroyIDs; /*!< Ids of entities to destroy */
         };
 
         template<typename C, typename... Others>