feat: event emitter

engine/include/engine/api.h

@@ -12,6 +12,7 @@
 extern IApplication* CreateApplication();
 
 int main() {
-    Engine::Run(std::unique_ptr<IApplication>(CreateApplication()));
+    auto engine = Engine::GetInstance();
+    engine->Run(std::unique_ptr<IApplication>(CreateApplication()));
     return 0;
 }

engine/include/engine/app/app.h

@@ -2,7 +2,7 @@
 #define APPLICATION_H_
 
 #include "engine/scene/scene.h"
-#include "engine/window/event.h"
+#include "engine/window/event.hpp"
 #include "engine/export.h"
 
 class ENGINE_API IApplication {

engine/include/engine/renderer/core.h

@@ -13,15 +13,22 @@
 #include "engine/app/app.h"
 #include "engine/export.h"
 
-class ENGINE_API Engine {
+class ENGINE_API Engine : public EventHandler {
 public:
-    static void Run(std::unique_ptr<IApplication> app);
+    static Engine* GetInstance();    
+
+    void Run(std::unique_ptr<IApplication> app);
 private:
-    static std::unique_ptr<IApplication> s_app;
-    static std::shared_ptr<Window> s_window;
-    static std::unique_ptr<Renderer> s_renderer;
-    static std::shared_ptr<Scene> s_scene;
-    static bool s_running;
+    Engine() {}
+    static Engine* s_instance;
+
+    void OnEvent(const Event& event) override;
+private:
+    std::unique_ptr<IApplication> m_app;
+    std::shared_ptr<Window> m_window;
+    std::unique_ptr<Renderer> m_renderer;
+    std::shared_ptr<Scene> m_scene;
+    bool m_running;
 };
 
 

engine/include/engine/window/event.h

@@ -1,81 +0,0 @@
-#ifndef EVENT_H_
-#define EVENT_H_
-
-#include <functional>
-#include <algorithm>
-#include <typeindex>
-#include <unordered_map>
-#include <vector>
-
-enum class EventType {
-    WINDOW_RESIZE,
-    WINDOW_CLOSE,
-};
-
-class Event {
-public:
-    enum EventCategory {
-        WINDOW,
-        // KEYBOARD ...
-    };
-
-    Event(EventCategory category) : m_category(category) {}
-    virtual ~Event() {}
-
-    Event(const Event& event) = default;
-
-    inline const EventCategory GetCategory() const { return m_category; }
-
-    inline const virtual EventType GetType() const = 0;
-private:
-    EventCategory m_category;
-};
-
-class EventDispatcher {
-    using Type = std::type_index;
-    using RawFn = std::function<void(const void*)>;
-
-    struct Slot { std::size_t id; RawFn fn; };
-
-    std::unordered_map<Type, std::vector<Slot>> subs_;
-    std::size_t next_id_ = 1;
-
-public:
-    struct Handle {
-        std::type_index type{typeid(void)};
-        std::size_t id{0};
-        explicit operator bool() const { return id != 0; }
-    };
-
-    template<class E, class F>
-    Handle Subscribe(F&& f) {
-        auto& vec = subs_[Type(typeid(E))];
-        Handle h{ Type(typeid(E)), next_id_++ };
-        // Wrap strongly typed callback into type-erased RawFn
-        RawFn wrapper = [fn = std::function<void(const E&)>(std::forward<F>(f))](const void* p){
-            fn(*static_cast<const E*>(p));
-        };
-        vec.push_back(Slot{h.id, std::move(wrapper)});
-        return h;
-    }
-
-    // Unsubscribe with handle
-    void Unsubscribe(const Handle& h) {
-        auto it = subs_.find(h.type);
-        if (it == subs_.end()) return;
-        auto& vec = it->second;
-        vec.erase(std::remove_if(vec.begin(), vec.end(),
-                  [&](const Slot& s){ return s.id == h.id; }),
-                  vec.end());
-    }
-
-    // Publish immediately
-    template<class E>
-    void Dispatch(const E& e) const {
-        auto it = subs_.find(Type(typeid(E)));
-        if (it == subs_.end()) return;
-        for (auto& slot : it->second) slot.fn(&e);
-    }
-};
-
-#endif // EVENT_H_

engine/include/engine/window/event.hpp

@@ -0,0 +1,74 @@
+#ifndef EVENT_H_
+#define EVENT_H_
+
+#include <functional>
+#include <algorithm>
+#include <typeindex>
+#include <unordered_map>
+#include <vector>
+
+enum class EventType {
+    WINDOW_RESIZE,
+    WINDOW_CLOSE,
+};
+
+class Event {
+public:
+    enum EventCategory {
+        WINDOW,
+        // KEYBOARD ...
+    };
+
+    Event(EventCategory category) : m_category(category) {}
+    virtual ~Event() {}
+
+    Event(const Event& event) = default;
+
+    inline const EventCategory GetCategory() const { return m_category; }
+
+    inline const virtual EventType GetType() const = 0;
+private:
+    EventCategory m_category;
+};
+
+class EventHandler {
+public:
+    EventHandler() = default;
+
+    virtual void OnEvent(const Event& event) = 0;
+};
+
+class EventEmitter {
+public:
+    struct Handle {
+        std::size_t id{0};
+        explicit operator bool() const { return id != 0; }
+    };
+
+    EventEmitter() = default;
+
+    Handle Subscribe2(EventHandler* handler) {
+        auto slot = Slot{ m_next_id++, handler };
+        m_subs.push_back(slot);
+        return Handle{ slot.id };
+    }
+
+    void Unsubscribe2(const Handle& h) {
+        m_subs.erase(std::remove_if(m_subs.begin(), m_subs.end(),
+                  [&](const Slot& s){ return s.id == h.id; }),
+                  m_subs.end());
+    }    
+protected:
+    void EmitEvent(const Event& event) {
+        for (auto &sub : m_subs) {
+            sub.handler->OnEvent(event);
+        }
+    }
+
+private:
+    struct Slot { std::size_t id; EventHandler* handler; };
+    std::vector<Slot> m_subs;
+    std::size_t m_next_id = 1;
+};
+
+#endif // EVENT_H_

engine/include/engine/window/events/window_events.h

@@ -1,7 +1,7 @@
 #ifndef WINDOW_EVENTS_H_
 #define WINDOW_EVENTS_H_
 
-#include "engine/window/event.h"
+#include "engine/window/event.hpp"
 
 class WindowEvent : public Event {
 public:

engine/include/engine/window/window.h

@@ -3,7 +3,7 @@
 #include <SDL3/SDL.h>
 #include <memory>
 
-#include "engine/window/event.h"
+#include "engine/window/event.hpp"
 
 #define ENGINE_GL_MAJOR_VERSION 4
 #define ENGINE_GL_MINOR_VERSION 6
@@ -13,7 +13,7 @@
 #define DEFAULT_WIDTH 1024
 #define DEFAULT_HEIGHT 768
 
-class Window : public EventDispatcher {
+class Window : public EventEmitter {
     friend class Engine;
 private:
     Window();

engine/src/renderer/core.cpp

@@ -2,48 +2,67 @@
 
 #include "engine/renderer/core.h"
 
-#include "engine/window/event.h"
+#include "engine/window/event.hpp"
 #include "engine/renderer/wavefront.h"
 
-std::unique_ptr<IApplication> Engine::s_app = nullptr;
-std::shared_ptr<Window> Engine::s_window = nullptr;
-std::unique_ptr<Renderer> Engine::s_renderer = nullptr;
-std::shared_ptr<Scene> Engine::s_scene = nullptr;
-bool Engine::s_running = false;
+Engine* Engine::s_instance = nullptr;
 
 void Engine::Run(std::unique_ptr<IApplication> app) {
-    s_scene = std::make_shared<Scene>();
-    s_renderer = std::make_unique<Renderer>(s_scene);
-    s_window = Window::GetInstance();
-    s_app = std::move(app);
-    s_running = true;
+    m_scene = std::make_shared<Scene>();
+    m_renderer = std::make_unique<Renderer>(m_scene);
+    m_window = Window::GetInstance();
+    m_app = std::move(app);
+    m_running = true;
 
-    s_app->OnInit(s_scene);
-    s_renderer->Init();
+    m_app->OnInit(m_scene);
+    m_renderer->Init();
 
-    s_window->Subscribe<WindowCloseEvent>([&](const WindowCloseEvent& e) {
-        s_running = false;
-        s_app->OnEvent(e);
-    });
+    // m_window->Subscribe<WindowCloseEvent>([&](const WindowCloseEvent& e) {
+        
+    //     m_app->OnEvent(e);
+    // });
 
-    s_window->Subscribe<WindowResizeEvent>([&](const WindowResizeEvent& e) {
-        s_renderer->OnWindowResized(e.GetWidth(), e.GetHeight());
-        s_app->OnEvent(e);
-    });
+    // m_window->Subscribe<WindowResizeEvent>([&](const WindowResizeEvent& e) {
+    //     m_renderer->OnWindowResized(e.GetWidth(), e.GetHeight());
+    //     m_app->OnEvent(e);
+    // });
 
-    while (s_running) {
-        s_window->ProcessEvents();
+    m_window->Subscribe2(this);
 
-        s_app->OnUpdate();
+    while (m_running) {
+        m_window->ProcessEvents();
 
-        s_renderer->Render();
+        m_app->OnUpdate();
 
-        s_window->SwapBuffers();
+        m_renderer->Render();
+
+        m_window->SwapBuffers();
     }
 
-    s_app->OnShutdown();
+    m_app->OnShutdown();
 
-    s_window->Destroy();
-    s_app.reset();
+    m_window->Destroy();
+    m_app.reset();
+}
+
+void Engine::OnEvent(const Event& event) {
+    m_app->OnEvent(event);
+    if (event.GetCategory() == Event::EventCategory::WINDOW) {
+        if (event.GetType() == EventType::WINDOW_RESIZE) {
+            auto e = static_cast<const WindowResizeEvent&>(event);
+            m_renderer->OnWindowResized(e.GetWidth(), e.GetHeight());
+        }
+        if (event.GetType() == EventType::WINDOW_CLOSE) {
+            m_running = false;
+        }
+    }
+}
+
+Engine* Engine::GetInstance() {
+    if (!s_instance) {
+        s_instance = new Engine();
+    }
+
+    return s_instance;
 }
 

engine/src/window/window.cpp

@@ -101,10 +101,12 @@ void Window::ProcessEvents() {
             case SDL_EVENT_WINDOW_CLOSE_REQUESTED:
             case SDL_EVENT_QUIT:
                 Dispatch(WindowCloseEvent());
+                EmitEvent(WindowCloseEvent{});
                 break;
             case SDL_EVENT_KEY_DOWN:
                 if (event.key.scancode == SDL_SCANCODE_ESCAPE) {
                     Dispatch(WindowCloseEvent());
+                    EmitEvent(WindowCloseEvent{});
                 }
                 if (event.key.scancode == SDL_SCANCODE_F11) {
                     bool isFullscreen = SDL_GetWindowFlags(m_handle) & SDL_WINDOW_FULLSCREEN;
@@ -122,7 +124,9 @@ void Window::ProcessEvents() {
                         0,
                         width,
                         height);
-                    Dispatch(WindowResizeEvent(static_cast<unsigned int>(m_width), static_cast<unsigned int>(m_height)));
+                    auto event = WindowResizeEvent(static_cast<unsigned int>(m_width), static_cast<unsigned int>(m_height));
+                    Dispatch(event);
+                    EmitEvent(event);
                     SDL_SetWindowRelativeMouseMode(m_handle, true);
                     SDL_Rect boundaries = {0, 0, m_width, m_height};
                     SDL_SetWindowMouseRect(m_handle, &boundaries);