refactor: move pass and renderer to engine

example/damaged_helmet/main.cpp

@@ -1,38 +1,12 @@
-#include <memory>
-
-#include <GLFW/glfw3.h>
-#include <glad/gl.h>
-#include <glm/glm.hpp>
-#include <glm/gtc/matrix_transform.hpp>
-#include <glm/gtc/type_ptr.hpp>
-
 #include "paimon/app/application.h"
-#include "paimon/app/panel/editor_layer.h"
-#include "paimon/app/panel/interaction_layer.h"
 #include "paimon/core/log_system.h"
 
-#include "renderer.h"
-
 using namespace paimon;
 
-class HelmetApp : public Application {
-public:
-  HelmetApp() : Application() {
-    // Setup editor layer first
-    auto* editorLayer = pushLayer(std::make_unique<EditorLayer>());
-
-    // Setup interaction layer for camera control
-    auto* interactionLayer = pushLayer(std::make_unique<InteractionLayer>());
-
-    // Setup renderer with the scene and viewport
-    auto *renderer = pushLayer(std::make_unique<Renderer>());
-  }
-};
-
 int main() {
   LogSystem::init();
 
-  HelmetApp app;
+  Application app;
   app.run();
 
   return 0;

source/paimon/app/application.cpp

@@ -1,5 +1,7 @@
 #include "paimon/app/application.h"
 
+#include "paimon/app/panel/editor_layer.h"
+#include "paimon/app/panel/interaction_layer.h"
 #include "paimon/config.h"
 
 namespace paimon {
@@ -17,7 +19,13 @@ Application::Application(const ApplicationConfig& config) {
 
   m_shaderManager.load(PAIMON_SHADER_DIR);
 
-  m_imguiLayer = pushLayer(std::make_unique<ImGuiLayer>("ImGuiLayer"));
+  m_imguiLayer = pushLayer(std::make_unique<ImGuiLayer>());
+
+  pushLayer(std::make_unique<EditorLayer>());
+
+  pushLayer(std::make_unique<InteractionLayer>());
+
+  m_renderer = pushLayer(std::make_unique<Renderer>());
 }
 
 void Application::onEvent(Event& event) {

source/paimon/app/application.h

@@ -9,6 +9,7 @@
 #include "paimon/app/window.h"
 #include "paimon/core/ecs/scene.h"
 #include "paimon/platform/context.h"
+#include "paimon/rendering/renderer.h"
 #include "paimon/rendering/shader_manager.h"
 
 namespace paimon {
@@ -20,13 +21,13 @@ struct ApplicationConfig {
 
 class Application {
 public:
-  static Application& getInstance() { return *s_instance; }
+  static Application &getInstance() { return *s_instance; }
 
-  Application(const ApplicationConfig& config = {});
+  Application(const ApplicationConfig &config = {});
   virtual ~Application() = default;
 
-  Application(const Application&) = delete;
-  Application& operator=(const Application&) = delete;
+  Application(const Application &) = delete;
+  Application &operator=(const Application &) = delete;
 
   template <class T>
     requires std::is_base_of<Layer, T>::value
@@ -36,21 +37,28 @@ class Application {
     return static_cast<T *>(m_layers.back().get());
   }
 
-  void onEvent(Event& event);
+  void onEvent(Event &event);
 
   void run();
 
-  Window* getWindow() const { return m_window.get(); }
+  Window *getWindow() const { return m_window.get(); }
 
-  ShaderManager& getShaderManager() { return m_shaderManager; }
-  const ShaderManager& getShaderManager() const { return m_shaderManager; }
+  ShaderManager &getShaderManager() { return m_shaderManager; }
+  const ShaderManager &getShaderManager() const { return m_shaderManager; }
 
   // Scene management
-  ecs::Scene& getScene() { return *m_scene; }
-  const ecs::Scene& getScene() const { return *m_scene; }
+  ecs::Scene &getScene() { return *m_scene; }
+  const ecs::Scene &getScene() const { return *m_scene; }
+
+  void setScene(std::unique_ptr<ecs::Scene> scene) {
+    m_scene = std::move(scene);
+  }
+
+  Renderer& getRenderer() { return *m_renderer; }
+  const Renderer& getRenderer() const { return *m_renderer; }
 
 private:
-  static Application* s_instance;
+  static Application *s_instance;
 
   std::unique_ptr<Window> m_window;
 
@@ -60,6 +68,7 @@ class Application {
 
   std::vector<std::unique_ptr<Layer>> m_layers;
   ImGuiLayer *m_imguiLayer;
+  Renderer *m_renderer;
 };
 
 } // namespace paimon

source/paimon/app/imgui/imgui_layer.cpp

@@ -10,8 +10,8 @@ using namespace paimon;
 
 bool ImGuiLayer::s_showDockSpace = true;
 
-ImGuiLayer::ImGuiLayer(const std::string &name)
-    : Layer(name) {}
+ImGuiLayer::ImGuiLayer()
+    : Layer("ImGuiLayer") {}
 
 void ImGuiLayer::onAttach() {
 

source/paimon/app/imgui/imgui_layer.h

@@ -6,7 +6,7 @@ namespace paimon {
 
 class ImGuiLayer : public Layer {
 public:
-  ImGuiLayer(const std::string &name);
+  ImGuiLayer();
 
   ~ImGuiLayer() = default;
 

source/paimon/app/panel/viewport_panel.cpp

@@ -14,69 +14,80 @@ ViewportPanel::ViewportPanel() = default;
 ViewportPanel::~ViewportPanel() = default;
 
 void ViewportPanel::onImGuiRender() {
+  auto &app = Application::getInstance();
+
   ImGui::PushStyleVar(ImGuiStyleVar_WindowPadding, ImVec2(0, 0));
   ImGui::Begin("Viewport");
-   
+
   // Get available content region
   ImVec2 viewportSize = ImGui::GetContentRegionAvail();
-
+
+  auto textureId =
+      app.getRenderer().getColorPass().getColorTexture()->get_name();
+
+  // Display the texture using ImGui::Image
+  // Note: OpenGL uses bottom-left origin, so flip UV coordinates
+  ImGui::Image((ImTextureID)(intptr_t)textureId, viewportSize,
+                ImVec2(0, 1), // UV top-left (flipped)
+                ImVec2(1, 0)  // UV bottom-right (flipped)
+  );
+
   // Check if viewport size changed
   glm::ivec2 newSize = glm::ivec2(viewportSize.x, viewportSize.y);
   if (newSize.x > 0 && newSize.y > 0 && newSize != m_viewportSize) {
     m_viewportSize = newSize;
-    
+
     // Dispatch viewport resize event
     ViewportResizeEvent event(newSize.x, newSize.y);
-    Application::getInstance().onEvent(event);
+    app.onEvent(event);
   }
 
-  // Handle camera control input when viewport is focused and hovered
-  if (ImGui::IsWindowFocused() && ImGui::IsWindowHovered()) {
-    auto& io = ImGui::GetIO();
-    
+  // Handle camera control input when viewport is hovered
+  if (ImGui::IsWindowHovered()) {
+    auto &io = ImGui::GetIO();
+
     // Handle right mouse button (camera rotation)
     if (ImGui::IsMouseClicked(ImGuiMouseButton_Right)) {
       m_isRightButtonPressed = true;
       MouseButtonPressedEvent event(MouseCode::Right);
-      Application::getInstance().onEvent(event);
+      app.onEvent(event);
     }
     if (ImGui::IsMouseReleased(ImGuiMouseButton_Right)) {
       m_isRightButtonPressed = false;
       MouseButtonReleasedEvent event(MouseCode::Right);
-      Application::getInstance().onEvent(event);
+      app.onEvent(event);
     }
-    
+
     // Handle middle mouse button (camera panning)
     if (ImGui::IsMouseClicked(ImGuiMouseButton_Middle)) {
       m_isMiddleButtonPressed = true;
       MouseButtonPressedEvent event(MouseCode::Middle);
-      Application::getInstance().onEvent(event);
+      app.onEvent(event);
     }
     if (ImGui::IsMouseReleased(ImGuiMouseButton_Middle)) {
       m_isMiddleButtonPressed = false;
       MouseButtonReleasedEvent event(MouseCode::Middle);
-      Application::getInstance().onEvent(event);
+      app.onEvent(event);
     }
-    
+
     // Handle mouse movement (only when right or middle button is pressed)
     if (m_isRightButtonPressed || m_isMiddleButtonPressed) {
       ImVec2 mousePos = ImGui::GetMousePos();
       ImVec2 windowPos = ImGui::GetWindowPos();
-      ImVec2 relativePos = ImVec2(mousePos.x - windowPos.x, mousePos.y - windowPos.y);
-
+      ImVec2 relativePos =
+          ImVec2(mousePos.x - windowPos.x, mousePos.y - windowPos.y);
+
       MouseMovedEvent event(relativePos.x, relativePos.y);
-      Application::getInstance().onEvent(event);
+      app.onEvent(event);
     }
-    
+
     // Handle mouse scroll (camera zoom)
     if (io.MouseWheel != 0.0f) {
       MouseScrolledEvent event(0.0f, io.MouseWheel);
-      Application::getInstance().onEvent(event);
+      app.onEvent(event);
     }
   }
-
-  // Viewport content will be rendered by Renderer in its onImGuiRender
-
+
   ImGui::End();
   ImGui::PopStyleVar();
 }

example/damaged_helmet/color_pass.cpp → source/paimon/rendering/render_pass/color_pass.cpp

@@ -1,4 +1,4 @@
-#include "color_pass.h"
+#include "paimon/rendering/render_pass/color_pass.h"
 
 #include <glad/gl.h>
 

example/damaged_helmet/color_pass.h → source/paimon/rendering/render_pass/color_pass.h

@@ -2,12 +2,12 @@
 
 #include <memory>
 
+#include "paimon/core/ecs/scene.h"
 #include "paimon/opengl/buffer.h"
 #include "paimon/opengl/sampler.h"
 #include "paimon/opengl/texture.h"
 #include "paimon/rendering/graphics_pipeline.h"
 #include "paimon/rendering/render_context.h"
-#include "paimon/core/ecs/scene.h"
 
 namespace paimon {
 

example/damaged_helmet/final_pass.cpp → source/paimon/rendering/render_pass/final_pass.cpp

@@ -1,4 +1,4 @@
-#include "final_pass.h"
+#include "paimon/rendering/render_pass/final_pass.h"
 
 #include <glad/gl.h>
 

source/paimon/rendering/renderer.cpp

@@ -0,0 +1,41 @@
+#include "paimon/rendering/renderer.h"
+
+#include <imgui.h>
+
+#include "paimon/app/application.h"
+#include "paimon/app/event/application_event.h"
+
+using namespace paimon;
+
+Renderer::Renderer()
+    : Layer("Renderer"), m_renderContext(std::make_unique<RenderContext>()),
+      m_color_pass(*m_renderContext), m_final_pass(*m_renderContext) {}
+
+void Renderer::onAttach() {
+  // Initialization if needed
+}
+
+void Renderer::onUpdate() {
+  if (m_resolution.x == 0 || m_resolution.y == 0) {
+    return; // Skip rendering if resolution is zero
+  }
+
+  auto &scene = Application::getInstance().getScene();
+
+  // First Pass: Render to FBO
+  m_color_pass.draw(*m_renderContext, m_resolution, scene);
+
+  // Second Pass: Render FBO texture to screen (optional, for debugging)
+  // m_final_pass.draw(*m_renderContext, *m_color_pass.getColorTexture(),
+  // m_resolution);
+}
+
+void Renderer::onEvent(Event &event) {
+  EventDispatcher dispatcher(event);
+  dispatcher.dispatch<ViewportResizeEvent>([this](ViewportResizeEvent &e) {
+    m_resolution = glm::ivec2(e.getWidth(), e.getHeight());
+    return false;
+  });
+}
+
+void Renderer::onImGuiRender() {}