Rename `first_example` to `snake`. Also create entity & component system

examples/CMakeLists.txt

@@ -1,2 +1,2 @@
 # Add examples as a subdirectory
-add_subdirectory(first)
+add_subdirectory(snake)

examples/first/CMakeLists.txt

@@ -1,15 +0,0 @@
-cmake_minimum_required (VERSION 3.6)
-project(first_example)
-
-add_executable(first_example src/main.cpp)
-
-# Link headers and source files.
-file(GLOB_RECURSE source_list src/*.cpp)
-target_sources(first_example PRIVATE ${source_list})
-target_include_directories(first_example PUBLIC include)
-
-# Link simpleengine
-target_link_libraries(first_example PUBLIC simpleengine)
-
-# Set standard to C++17
-set_target_properties(first_example PROPERTIES CXX_STANDARD 17 CXX_EXTENSIONS OFF)

examples/first/src/main.cpp

@@ -1,78 +0,0 @@
-//
-// Created by SeanOMik on 7/2/2020.
-// Github: https://github.com/SeanOMik
-// Email: seanomik@gmail.com
-//
-
-#include <iostream>
-
-#include <simpleengine/game.h>
-#include <simpleengine/event.h>
-#include <simpleengine/entity.h>
-
-class PlayerEntity : public simpleengine::Entity {
-private:
-    sf::RectangleShape shape;
-    float movement_speed;
-public:
-    PlayerEntity() {
-        shape = sf::RectangleShape(sf::Vector2f(50, 50));
-        shape.setFillColor(sf::Color::White);
-
-        movement_speed = 250;
-    }
-
-    void Move(const float& delta_time, const float& x, const float& y) override {
-        shape.move(x * movement_speed * delta_time, y * movement_speed * delta_time);
-    }
-
-    void Update(const float& delta_time) override {
-        if (sf::Keyboard::isKeyPressed(sf::Keyboard::A)) {
-            Move(delta_time, -1, 0);
-        }
-
-        if (sf::Keyboard::isKeyPressed(sf::Keyboard::W)) {
-            Move(delta_time, 0, -1);
-        }
-
-        if (sf::Keyboard::isKeyPressed(sf::Keyboard::D)) {
-            Move(delta_time, 1, 0);
-        }
-
-        if (sf::Keyboard::isKeyPressed(sf::Keyboard::S)) {
-            Move(delta_time, 0, 1);
-        }
-    }
-
-    void Render(sf::RenderTarget* target = nullptr) override {
-        target->draw(shape);
-    }
-};
-
-class PlayerEvent : public simpleengine::Event {
-private:
-    PlayerEntity entity;
-public:
-    explicit PlayerEvent(sf::RenderWindow* window = nullptr) : simpleengine::Event(window) {}
-
-    void CheckForQuit() override {
-        if (sf::Keyboard::isKeyPressed(sf::Keyboard::Escape)) {
-            quit = true;
-        }
-    }
-
-    void Update(const float& delta_time) override {
-        entity.Update(delta_time);
-    }
-
-    void Render(sf::RenderTarget* target = nullptr) override {
-        entity.Render(target);
-    }
-};
-
-int main(int argc, char *argv[]) {
-    simpleengine::Game game(500, 500, "First Example");
-    game.AddEvent(new PlayerEvent());
-
-    return game.Run();
-}

examples/snake/CMakeLists.txt

@@ -0,0 +1,15 @@
+cmake_minimum_required (VERSION 3.6)
+project(Snake)
+
+add_executable(snake src/main.cpp)
+
+# Link headers and source files.
+file(GLOB_RECURSE source_list src/*.cpp)
+target_sources(snake PRIVATE ${source_list})
+target_include_directories(snake PUBLIC include)
+
+# Link simpleengine
+target_link_libraries(snake PUBLIC simpleengine)
+
+# Set standard to C++17
+set_target_properties(snake PROPERTIES CXX_STANDARD 17 CXX_EXTENSIONS OFF)

examples/snake/src/main.cpp

@@ -0,0 +1,113 @@
+//
+// Created by SeanOMik on 7/2/2020.
+// Github: https://github.com/SeanOMik
+// Email: seanomik@gmail.com
+//
+
+#include <iostream>
+
+#include <simpleengine/game.h>
+#include <simpleengine/event.h>
+#include <simpleengine/entity.h>
+#include <simpleengine/components/movement/movement_component.h>
+#include <simpleengine/events/entity_event.h>
+
+class SnakeMovementComponent : public simpleengine::Component {
+public:
+    explicit SnakeMovementComponent(simpleengine::Entity* owning_entity, float movement_speed) : simpleengine::Component(owning_entity), movement_speed(movement_speed) {
+
+    }
+
+    void Update(const float &delta_time) override {
+        if (sf::Keyboard::isKeyPressed(sf::Keyboard::A)) {
+            movement_direction.x = -1;
+            movement_direction.y = 0;
+        }
+
+        if (sf::Keyboard::isKeyPressed(sf::Keyboard::W)) {
+            movement_direction.x = 0;
+            movement_direction.y = -1;
+        }
+
+        if (sf::Keyboard::isKeyPressed(sf::Keyboard::D)) {
+            movement_direction.x = 1;
+            movement_direction.y = 0;
+        }
+
+        if (sf::Keyboard::isKeyPressed(sf::Keyboard::S)) {
+            movement_direction.x = 0;
+            movement_direction.y = 1;
+        }
+
+        owning_entity->Move(delta_time, movement_direction.x, movement_direction.y);
+    }
+private:
+    float movement_speed;
+    sf::Vector2f movement_direction;
+};
+
+class SnakePlayerEntity : public simpleengine::Entity {
+private:
+    sf::RectangleShape shape;
+    float movement_speed = 100;
+    sf::Vector2u window_size;
+    sf::Vector2f loc;
+public:
+    explicit SnakePlayerEntity(sf::Vector2u window_size) : window_size(window_size) {
+        shape = sf::RectangleShape(sf::Vector2f(15, 15));
+        shape.setFillColor(sf::Color::White);
+
+        this->AddComponent(new SnakeMovementComponent(this, movement_speed));
+        loc = sf::Vector2f(0, 0);
+    }
+
+    void Move(const float& delta_time, const float& x, const float& y) override {
+        shape.move(x * movement_speed * delta_time, y * movement_speed * delta_time);
+    }
+
+    void Update(const float& delta_time) override {
+        UpdateComponents(delta_time);
+
+        if (loc.x >= window_size.x) {
+            DestroyEntity();
+        }
+
+        if (loc.y >= window_size.y) {
+            DestroyEntity();
+        }
+    }
+
+    void Render(sf::RenderTarget* target = nullptr) override {
+        target->draw(shape);
+    }
+};
+
+/*class PlayerEvent : public simpleengine::Event {
+private:
+    SnakePlayerEntity snake_player;
+public:
+    explicit PlayerEvent(sf::RenderWindow* window) : simpleengine::Event(window),
+        snake_player(SnakePlayerEntity(window->getSize())) {
+    }
+
+    void CheckForQuit() override {
+        if (sf::Keyboard::isKeyPressed(sf::Keyboard::Escape)) {
+            quit = true;
+        }
+    }
+
+    void Update(const float& delta_time) override {
+        snake_player.Update(delta_time);
+    }
+
+    void Render(sf::RenderTarget* target = nullptr) override {
+        snake_player.Render(target);
+    }
+};*/
+
+int main(int argc, char *argv[]) {
+    simpleengine::Game game(500, 500, "First Example");
+    game.AddEvent(new simpleengine::EntityEvent(game.GetWindow(), new SnakePlayerEntity(game.GetWindow()->getSize())));
+
+    return game.Run();
+}

include/simpleengine/component.h

@@ -0,0 +1,26 @@
+//
+// Created by SeanOMik on 7/2/2020.
+// Github: https://github.com/SeanOMik
+// Email: seanomik@gmail.com
+//
+
+#ifndef SIMPLEENGINE_COMPONENT_H
+#define SIMPLEENGINE_COMPONENT_H
+
+#include <SFML/Graphics.hpp>
+
+namespace simpleengine {
+    class Entity;
+    class Component {
+    public:
+        explicit Component(Entity* owning_entity = nullptr) : owning_entity(owning_entity) {}
+        virtual ~Component() = default;
+
+        virtual void Update(const float& delta_time) = 0;
+        virtual void Render(sf::RenderTarget* target = nullptr) {}; // Most components won't need to be rendered.
+    protected:
+        Entity* owning_entity;
+    };
+}
+
+#endif //SIMPLEENGINE_COMPONENT_H

include/simpleengine/components/movement/movement_component.h

@@ -0,0 +1,27 @@
+//
+// Created by SeanOMik on 7/2/2020.
+// Github: https://github.com/SeanOMik
+// Email: seanomik@gmail.com
+//
+
+#ifndef SIMPLEENGINE_MOVEMENT_COMPONENT_H
+#define SIMPLEENGINE_MOVEMENT_COMPONENT_H
+
+#include "../../component.h"
+
+#include <SFML/Graphics.hpp>
+
+namespace simpleengine {
+    class Entity;
+
+    class MovementComponent : public Component {
+    public:
+        explicit MovementComponent(Entity* owning_entity, float movement_speed);
+
+        void Update(const float &delta_time) override;
+    private:
+        float movement_speed;
+    };
+}
+
+#endif //SIMPLEENGINE_MOVEMENT_COMPONENT_H

include/simpleengine/entity.h

@@ -9,8 +9,15 @@
 
 #include <SFML/Graphics.hpp>
 
+#include <stack>
+
 namespace simpleengine {
+    class Component;
+    class Game;
+    class Event;
     class Entity {
+        friend class Game;
+        friend class Event;
     public:
         Entity() = default;
         virtual ~Entity() = default;
@@ -18,6 +25,28 @@ namespace simpleengine {
         virtual void Move(const float& delta_time, const float& x, const float& y) {};
         virtual void Update(const float& delta_time) = 0;
         virtual void Render(sf::RenderTarget* target = nullptr) = 0;
+        virtual void Destroying() {}; // Called when the entity is about to be destroyed.
+
+        void DestroyEntity() {
+            destroying = true;
+        }
+
+        const bool& IsGettingDestroyed() const {
+            return destroying;
+        }
+
+        // If your event does not extend from EntityEvent, you will need to execute this yourself inside Event::Update.
+        void UpdateComponents(const float& delta_time);
+
+        void AddComponent(Component* component);
+    private:
+        // This is ran from class `Game` and `Event`. It runs the `UpdateComponents` method and then the `Update` method.
+        void UpdateEntity(const float& delta_time) {
+            UpdateComponents(delta_time);
+        }
+
+        std::vector<Component*> components;
+        bool destroying = false;
     };
 }
 

include/simpleengine/events/entity_event.h

@@ -0,0 +1,42 @@
+//
+// Created by SeanOMik on 7/3/2020.
+// Github: https://github.com/SeanOMik
+// Email: seanomik@gmail.com
+//
+
+#ifndef SIMPLEENGINE_ENTITY_EVENT_H
+#define SIMPLEENGINE_ENTITY_EVENT_H
+
+#include "../event.h"
+#include "../entity.h"
+
+namespace simpleengine {
+    class EntityEvent : public Event {
+    public:
+        explicit EntityEvent(sf::RenderWindow* window, Entity* entity) : simpleengine::Event(window), entity(entity) {
+
+        }
+
+        ~EntityEvent() override {
+            delete entity;
+        }
+
+        void CheckForQuit() override {
+            /*if (sf::Keyboard::isKeyPressed(sf::Keyboard::Escape)) {
+                quit = true;
+            }*/
+        }
+
+        void Update(const float& delta_time) override {
+            entity->Update(delta_time);
+        }
+
+        void Render(sf::RenderTarget* target = nullptr) override {
+            entity->Render(target);
+        }
+    private:
+        Entity* entity;
+    };
+}
+
+#endif //SIMPLEENGINE_ENTITY_EVENT_H

src/components/movement/movement_component.cpp

@@ -0,0 +1,31 @@
+//
+// Created by SeanOMik on 7/2/2020.
+// Github: https://github.com/SeanOMik
+// Email: seanomik@gmail.com
+//
+
+#include "components/movement/movement_component.h"
+#include "entity.h"
+
+simpleengine::MovementComponent::MovementComponent(simpleengine::Entity *owning_entity, float movement_speed) :
+    Component(owning_entity), movement_speed(movement_speed) {
+
+}
+
+void simpleengine::MovementComponent::Update(const float &delta_time) {
+    if (sf::Keyboard::isKeyPressed(sf::Keyboard::A)) {
+        owning_entity->Move(delta_time, -1, 0);
+    }
+
+    if (sf::Keyboard::isKeyPressed(sf::Keyboard::W)) {
+        owning_entity->Move(delta_time, 0, -1);
+    }
+
+    if (sf::Keyboard::isKeyPressed(sf::Keyboard::D)) {
+        owning_entity->Move(delta_time, 1, 0);
+    }
+
+    if (sf::Keyboard::isKeyPressed(sf::Keyboard::S)) {
+        owning_entity->Move(delta_time, 0, 1);
+    }
+}

src/entity.cpp

@@ -0,0 +1,18 @@
+//
+// Created by SeanOMik on 7/3/2020.
+// Github: https://github.com/SeanOMik
+// Email: seanomik@gmail.com
+//
+
+#include "entity.h"
+#include "component.h"
+
+void simpleengine::Entity::UpdateComponents(const float& delta_time) {
+    for (Component* component : components) {
+        component->Update(delta_time);
+    }
+}
+
+void simpleengine::Entity::AddComponent(simpleengine::Component *component) {
+    components.emplace_back(component);
+}