From 17b81c83cc88898b78977760fe722484462c5ff3 Mon Sep 17 00:00:00 2001
From: SeanOMik <seanomik@gmail.com>
Date: Sun, 12 Jul 2020 23:16:59 -0500
Subject: [PATCH] Use shared_ptr for components instead of unique_ptr

---
 examples/animation/src/main.cpp | 20 ++++++++++++--------
 include/simpleengine/entity.h   | 15 ++++++++++++---
 src/entity.cpp                  | 10 +++-------
 3 files changed, 27 insertions(+), 18 deletions(-)

diff --git a/examples/animation/src/main.cpp b/examples/animation/src/main.cpp
index 6e70d1d..9f91f2b 100644
--- a/examples/animation/src/main.cpp
+++ b/examples/animation/src/main.cpp
@@ -23,6 +23,9 @@ private:
     float movement_speed = 130;
     sf::Vector2u window_size;
 
+    // Components:
+    std::shared_ptr<simpleengine::HitboxComponent> hitbox_component;
+    std::shared_ptr<simpleengine::SideScrollerMovementAnimationComponent> move_anim_component;
 public:
     explicit PlayerEntity(sf::Vector2u window_size) : Entity(sprite), window_size(window_size) {
         texture.loadFromFile("player_sheet.png");
@@ -30,17 +33,18 @@ public:
         sprite.setTexture(texture);
         sprite.setScale(.7, .7);
 
-        auto move_anim_component = std::make_unique<simpleengine::SideScrollerMovementAnimationComponent>(*this, sprite,
-                texture, movement_speed, 5, 1.1);
-        move_anim_component->SetAnimation(simpleengine::MovementAnimationType::WALK_LEFT, 8, 0, 8,
-                9, 8, 128, 128);
+        move_anim_component = std::make_shared<simpleengine::SideScrollerMovementAnimationComponent>(*this, sprite,
+            texture, movement_speed, 5, 1.1);
+        move_anim_component->SetAnimation(simpleengine::MovementAnimationType::WALK_LEFT, 8, 0, 9,
+            9, 9, 128, 128);
         move_anim_component->SetAnimation(simpleengine::MovementAnimationType::IDLE_LEFT, 20, 0, 0,
-                6, 0, 128, 128);
+            6, 0, 128, 128);
         AddComponent(std::move(move_anim_component));
+        AddComponent(move_anim_component);
 
-        AddComponent(std::make_unique<simpleengine::HitboxComponent>(*this, sprite,
-                20, 12,
-                sprite.getGlobalBounds().width - 40, sprite.getGlobalBounds().height - 15));
+        hitbox_component = std::make_shared<simpleengine::HitboxComponent>(*this, sprite,
+            20, 12, sprite.getGlobalBounds().width - 40, sprite.getGlobalBounds().height - 15);
+        AddComponent(hitbox_component);
     }
 
     ~PlayerEntity() override {
diff --git a/include/simpleengine/entity.h b/include/simpleengine/entity.h
index b496524..fdc761a 100644
--- a/include/simpleengine/entity.h
+++ b/include/simpleengine/entity.h
@@ -11,6 +11,7 @@
 
 #include <vector>
 #include <memory>
+#include <assert.h>
 
 namespace simpleengine {
     class Component;
@@ -41,7 +42,7 @@ namespace simpleengine {
 
         template<typename T>
         bool HasComponent() {
-            for (std::unique_ptr<Component>& comp : components) {
+            for (std::shared_ptr<Component>& comp : components) {
                 if (dynamic_cast<T*>(comp.get())) {
                     return true;
                 }
@@ -52,12 +53,20 @@ namespace simpleengine {
 
         void UpdateComponents(const float& delta_time);
         void RenderComponents(sf::RenderTarget* target);
-        void AddComponent(std::unique_ptr<Component> component);
+
+        template<typename T>
+        void AddComponent(std::shared_ptr<T> component) {
+            static_assert(std::is_base_of_v<Component, T>, "Component class must derive from simpleengine::Component");
+
+            // Only allow one type of the same component.
+            assert(!HasComponent<T>());
+            components.push_back(component);
+        }
 
         sf::Sprite& GetSprite();
     protected:
         sf::Sprite& sprite;
-        std::vector<std::unique_ptr<Component>> components;
+        std::vector<std::shared_ptr<Component>> components;
         bool destroying = false;
     };
 }
diff --git a/src/entity.cpp b/src/entity.cpp
index da1dcb6..bfbd068 100644
--- a/src/entity.cpp
+++ b/src/entity.cpp
@@ -32,7 +32,7 @@ void simpleengine::Entity::Update(const float &delta_time) {
 }
 
 void simpleengine::Entity::UpdateComponents(const float& delta_time) {
-    for (std::unique_ptr<Component>& component : components) {
+    for (std::shared_ptr<Component>& component : components) {
         component->Update(delta_time);
 
         if (component->IsGettingDestroyed()) {
@@ -42,17 +42,13 @@ void simpleengine::Entity::UpdateComponents(const float& delta_time) {
 }
 
 void simpleengine::Entity::RenderComponents(sf::RenderTarget* target) {
-    for (std::unique_ptr<Component>& component : components) {
+    for (std::shared_ptr<Component>& component : components) {
         component->Render(target);
     }
 }
 
-void simpleengine::Entity::AddComponent(std::unique_ptr<Component> component) {
-    components.push_back(std::move(component));
-}
-
 void simpleengine::Entity::Destroying() {
-    for (std::unique_ptr<Component>& component : components) {
+    for (std::shared_ptr<Component>& component : components) {
         component->DestroyLater();
     }
 }