ADD: Introduce Scenes

CMakeLists.txt

@@ -101,6 +101,8 @@ add_library(Engine STATIC
         engine/src/utils/openglWrapper/shader/Uniform.h
         engine/src/utils/openglWrapper/shader/UniformValue.cpp
         engine/src/utils/openglWrapper/shader/UniformValue.h
+        engine/src/layer/Scene.cpp
+        engine/src/layer/Scene.h
 )
 target_include_directories(Engine PUBLIC engine/src)
 target_link_libraries(Engine PUBLIC OpenGL::GL glfw glad glm::glm imgui)
@@ -140,6 +142,10 @@ add_executable(ColorRace
         engine/src/layer/Layer.h
         game/src/GameLayer.cpp
         game/src/GameLayer.h
+        engine/src/layer/SceneManager.cpp
+        engine/src/layer/SceneManager.h
+        game/src/GameScene.cpp
+        game/src/GameScene.h
 
 )
 

engine/src/layer/Scene.cpp

@@ -0,0 +1,26 @@
+//
+// Created by sebastian on 30.07.26.
+//
+
+#include "Scene.h"
+
+#include <iostream>
+#include <ostream>
+
+void engine::Scene::onUpdate() {
+    for (const auto& layer : m_layers) {
+        layer->onUpdate();
+    }
+}
+
+void engine::Scene::onRender() {
+    for (const auto& layer : m_layers) {
+        layer->onRender();
+    }
+}
+
+void engine::Scene::addLayer(std::unique_ptr<Layer> layer) {
+    layer->onAttach();
+    m_layers.push_back(std::move(layer));
+
+}

engine/src/layer/Scene.h

@@ -0,0 +1,38 @@
+//
+// Created by sebastian on 30.07.26.
+//
+
+#ifndef COLORRACE_SCENE_H
+#define COLORRACE_SCENE_H
+#include <memory>
+#include <vector>
+
+#include "Layer.h"
+#include "renderer/entities/Camera.h"
+
+
+namespace engine {
+    class Scene {
+    public:
+        explicit Scene()  {}
+        virtual ~Scene() = default;
+        virtual void onEnter() {}
+        virtual void onExit() {
+            for (const auto& layer : m_layers) {
+                layer->onDetach();
+            }
+        }
+
+        void onUpdate();
+        void onRender();
+    protected:
+        std::vector<std::unique_ptr<Layer>> m_layers;
+
+        void addLayer(std::unique_ptr<Layer> layer);
+
+        engine::EntityRegistry entityRegistry;
+    };
+}
+
+
+#endif //COLORRACE_SCENE_H

engine/src/layer/SceneManager.cpp

@@ -0,0 +1,51 @@
+//
+// Created by sebastian on 30.07.26.
+//
+
+#include "SceneManager.h"
+
+#include <iostream>
+#include <ostream>
+
+void engine::SceneManager::switchTo(std::unique_ptr<Scene> scene, std::function<void()> onSceneLoaded) {
+    onSceneLoaded = std::move(onSceneLoaded);
+    nextScene = std::move(scene);
+
+    //Todo: Integrate Asset Loader
+}
+
+void engine::SceneManager::update()  {
+    if (nextScene) {
+        //Todo: AssetLoader should process AssetQueue
+
+        if (getTransitionProgress() == 1.0) { // Todo: Replace with AssetLoader.getProgress.done()
+            if (currentScene) {
+                currentScene->onExit();
+            }
+
+            currentScene = std::move(nextScene);
+            nextScene = nullptr;
+            currentScene->onEnter();
+
+            // Todo: Stop AssetLoader
+            if (onSceneLoaded) {
+                onSceneLoaded();
+                onSceneLoaded = nullptr;
+            }
+        }
+    }
+
+    if (currentScene) {
+        currentScene->onUpdate();
+    }
+}
+
+void engine::SceneManager::render() const {
+    if (currentScene) {
+        currentScene->onRender();
+    }
+}
+
+float engine::SceneManager::getTransitionProgress() const {
+    return 1.0f;
+}

engine/src/layer/SceneManager.h

@@ -0,0 +1,31 @@
+//
+// Created by sebastian on 30.07.26.
+//
+
+#ifndef COLORRACE_SCENEMANAGER_H
+#define COLORRACE_SCENEMANAGER_H
+#include <memory>
+
+#include "Scene.h"
+
+
+namespace engine {
+    class SceneManager {
+    public:
+        SceneManager() = default;
+        void switchTo(std::unique_ptr<Scene> scene, std::function<void()> onSceneLoaded = nullptr);
+        void update();
+        void render() const;
+        ~SceneManager() = default;
+
+        [[nodiscard]] float getTransitionProgress() const;
+    private:
+        std::unique_ptr<Scene> currentScene;
+        std::unique_ptr<Scene> nextScene;
+        bool isTransitioning = false;
+        std::function<void()> onSceneLoaded;
+    };
+
+
+}
+#endif //COLORRACE_SCENEMANAGER_H

engine/src/renderer/RenderQueue.h

@@ -4,7 +4,9 @@
 
 #ifndef COLORRACE_RENDERQUEUE_H
 #define COLORRACE_RENDERQUEUE_H
+#include <iostream>
 #include <memory>
+#include <ostream>
 
 #include "glm/glm.hpp"
 #include "model/RawModel.h"

game/src/ColorRaceApp.cpp

@@ -12,9 +12,9 @@
 
 
 void ColorRaceApp::onUpdate(float deltaTime) {
-    gameLayer->onUpdate();
+    sceneManager->update();
 }
 
 void ColorRaceApp::onRender() {
-    gameLayer->onRender();
+    sceneManager->render();
 }

game/src/ColorRaceApp.h

@@ -5,10 +5,12 @@
 #ifndef COLORRACE_COLORRACEAPP_H
 #define COLORRACE_COLORRACEAPP_H
 #include "GameLayer.h"
+#include "GameScene.h"
 #include "core/Application.h"
 #include "ecs/EntityRegistry.h"
 #include "ecs/standardComponents/MeshComponent.h"
 #include "ecs/standardComponents/TransformComponent.h"
+#include "layer/SceneManager.h"
 #include "renderer/MeshRenderer.h"
 #include "renderer/entities/Camera.h"
 #include "renderer/primitives/CubeFactory.h"
@@ -31,13 +33,11 @@ public:
         config.debugContext = true;
         return config;
     }
-    ColorRaceApp() : Application(makeConfig()) {
-
-        gameLayer = std::make_unique<GameLayer>();
-        gameLayer->onAttach();
+    ColorRaceApp() : Application(makeConfig()), sceneManager(std::make_unique<engine::SceneManager>()) {
+        sceneManager->switchTo(std::make_unique<GameScene>());
     }
 private:
-    std::unique_ptr<GameLayer> gameLayer;
+    std::unique_ptr<engine::SceneManager> sceneManager;
 protected:
     void onUpdate(float deltaTime) override;
     void onRender() override;

game/src/GameLayer.cpp

@@ -4,6 +4,9 @@
 
 #include "GameLayer.h"
 
+#include <iostream>
+#include <ostream>
+
 #include "ecs/standardComponents/MeshComponent.h"
 #include "ecs/standardComponents/TransformComponent.h"
 #include "renderer/MeshRenderer.h"
@@ -14,11 +17,6 @@ void GameLayer::onAttach() {
     m_renderState.depthTesting = false;
     m_renderState.backfaceCulling = false;
 
-    m_camera = std::make_unique<engine::Camera>();
-    m_camera->setPosition({0.0f, 0.0f, 5.0f});
-    m_camera->setYaw(0.0f);
-    m_camera->setPitch(0.0f);
-
     m_renderer = std::make_unique<engine::MeshRenderer>();
 
     Entity entity = m_entityRegistry.createEntity();
@@ -45,7 +43,5 @@ void GameLayer::onRender() {
 
     MeshRenderSystem meshRenderSystem;
     meshRenderSystem.update(m_entityRegistry, m_renderQueue);
-
-    MeshRenderer renderer;
-    renderer.render(m_renderQueue, *m_camera);
+    m_renderer->render(m_renderQueue, *m_camera);
 }

game/src/GameLayer.h

@@ -4,6 +4,8 @@
 
 #ifndef COLORRACE_GAMELAYER_H
 #define COLORRACE_GAMELAYER_H
+#include <utility>
+
 #include "ecs/EntityRegistry.h"
 #include "layer/Layer.h"
 #include "renderer/MeshRenderer.h"
@@ -13,6 +15,8 @@
 
 class GameLayer: public engine::Layer {
 public:
+    GameLayer(engine::EntityRegistry& entityRegistry, std::shared_ptr<engine::Camera> cam)
+        : m_entityRegistry(entityRegistry), m_camera(std::move(cam)), m_renderer(std::make_unique<engine::MeshRenderer>()) {}
     void onAttach() override;
     void onDetach() override;
     void onUpdate() override;
@@ -20,9 +24,9 @@ public:
 private:
     engine::GLRenderState m_renderState;
     engine::RenderQueue m_renderQueue;
-    engine::EntityRegistry m_entityRegistry;
+    engine::EntityRegistry& m_entityRegistry;
+    std::shared_ptr<engine::Camera> m_camera;
     std::unique_ptr<engine::MeshRenderer> m_renderer;
-    std::unique_ptr<engine::Camera> m_camera;
 };
 
 #endif //COLORRACE_GAMELAYER_H

game/src/GameScene.cpp

@@ -0,0 +1,21 @@
+//
+// Created by sebastian on 30.07.26.
+//
+
+#include "GameScene.h"
+
+#include "GameLayer.h"
+
+GameScene::GameScene() : Scene(), m_camera(std::make_unique<engine::Camera>()) {}
+
+void GameScene::onEnter() {
+    addLayer(std::make_unique<GameLayer>(entityRegistry, m_camera));
+
+    m_camera->setPosition({0.0f, 0.0f, 5.0f});
+    m_camera->setYaw(0.0f);
+    m_camera->setPitch(0.0f);
+}
+
+void GameScene::onExit() {
+    Scene::onExit();
+}

game/src/GameScene.h

@@ -0,0 +1,21 @@
+//
+// Created by sebastian on 30.07.26.
+//
+
+#ifndef COLORRACE_GAMESCENE_H
+#define COLORRACE_GAMESCENE_H
+#include "layer/Scene.h"
+
+
+class GameScene : public engine::Scene {
+public:
+    GameScene();
+    void onEnter() override;
+    void onExit() override;
+private:
+    std::shared_ptr<engine::Camera> m_camera;
+
+};
+
+
+#endif //COLORRACE_GAMESCENE_H