Add unit system into dev branch

src/core/CMakeLists.txt

@@ -5,6 +5,7 @@ file(GLOB_RECURSE CORE_SRC
   "./application/*.cpp"
   "./graphic/*.cpp"
   # "./input/*.cpp"
+  "./scene/*.cpp"
   "./resource/*cpp"
   "./utils/*.cpp"
   "./*.cpp"

src/core/application.cpp

@@ -3,7 +3,7 @@
 #include <SDL3/SDL_init.h>
 #include <SDL3/SDL_log.h>
 
-gkit::Application::Application() noexcept  {
+gkit::Application::Application() noexcept : root(), windows() {
     SDL_InitFlags flags = SDL_INIT_AUDIO |
                           SDL_INIT_EVENTS |
                           SDL_INIT_GAMEPAD |
@@ -18,4 +18,24 @@ gkit::Application::Application() noexcept  {
 
 gkit::Application::~Application() noexcept {
     SDL_Quit();
-}
+}
+
+
+auto gkit::Application::set_root(std::unique_ptr<scene::Unit>&& root_ptr) noexcept -> void {
+    if (root_ptr == nullptr) return;
+    this->root = std::move(root_ptr);
+}
+
+
+auto gkit::Application::run() -> void {
+    this->root->ready_handler();
+    this->running.store(true);
+    while (this->running.load()) {
+        this->root->process_handler();
+    }
+}
+
+
+auto gkit::Application::stop() -> void {
+    this->running.store(false);
+}

src/core/graphic/window.cpp

@@ -4,17 +4,18 @@
 #include <SDL3/SDL_log.h>
 #include <SDL3/SDL_video.h>
 
-gkit::Window::Window(std::string title, int width, int height) noexcept 
-    : window_ptr(SDL_CreateWindow(title.c_str(), width, height, SDL_WINDOW_RESIZABLE), SDL_DestroyWindow)
+gkit::graphic::Window::Window(std::string title, int width, int height) noexcept 
+    : gkit::scene::Unit()
+    , window_ptr(SDL_CreateWindow(title.c_str(), width, height, SDL_WINDOW_RESIZABLE), SDL_DestroyWindow)
     , renderer_ptr(SDL_CreateRenderer(this->window_ptr.get(), nullptr), SDL_DestroyRenderer) {
 
     if (!SDL_InitSubSystem(SDL_INIT_VIDEO)) {
         SDL_Log("SDL_INIT_VIDEO initialize failed, error: %s", SDL_GetError());
     }
 }
 
-gkit::Window::Window(std::string title, int width, int height, std::vector<SDL_WindowFlags> flags) noexcept 
-    : gkit::Window::Window(title, width, height) {
+gkit::graphic::Window::Window(std::string title, int width, int height, std::vector<SDL_WindowFlags> flags) noexcept 
+    : gkit::graphic::Window::Window(title, width, height) {
     SDL_WindowFlags win_flags = 0x00ul;
     for (auto flag : flags) {
         win_flags |= flag;
@@ -23,10 +24,10 @@ gkit::Window::Window(std::string title, int width, int height, std::vector<SDL_W
     this->window_ptr.reset(SDL_CreateWindow(title.c_str(), width, height, win_flags));
 }
 
-void gkit::Window::hide() noexcept {
+void gkit::graphic::Window::hide() noexcept {
     SDL_HideWindow(this->window_ptr.get());
 }
 
-void gkit::Window::show() noexcept {
+void gkit::graphic::Window::show() noexcept {
     SDL_ShowWindow(this->window_ptr.get());
 }

src/core/include/application.hpp

@@ -1,13 +1,29 @@
 #pragma once
 
+#include "graphic/window.hpp"
+#include "scene/unit.hpp"
+#include <atomic>
+#include <memory>
+#include <vector>
+
 namespace gkit {
 
     class Application {
     public:
         explicit Application() noexcept;
         virtual ~Application() noexcept;
 
+    public:
+        auto run() -> void;
+        auto stop() -> void;
+
+        auto set_root(std::unique_ptr<scene::Unit>&& root_ptr) noexcept -> void;
+
+    private:
+        std::unique_ptr<scene::Unit> root;
+        std::vector<std::unique_ptr<gkit::graphic::Window>> windows;
 
+        std::atomic<bool> running = false;
     }; // class Application
 
 } // namespace gkit

src/core/include/gkit.hpp

@@ -6,6 +6,10 @@
 // Graphic
 #include <graphic/window.hpp>
 
+// Scene
+#include <scene/unit.hpp>
+#include <scene/object.hpp>
+
 // Resource
 #include <resource/resource.hpp>
 #include <resource/texture.hpp>

src/core/include/graphic/window.hpp

@@ -1,15 +1,16 @@
 #pragma once
 
+#include "scene/unit.hpp"
 #include <SDL3/SDL.h>
 #include <SDL3/SDL_render.h>
 #include <SDL3/SDL_video.h>
 #include <string>
 #include <memory>
 #include <vector>
 
-namespace gkit {
+namespace gkit::graphic {
 
-    class Window {
+    class Window : gkit::scene::Unit{
     public:
         Window(std::string title, int width, int height) noexcept;
         Window(std::string title, int width, int height, std::vector<SDL_WindowFlags> flags) noexcept;

src/core/include/scene/object.hpp

@@ -0,0 +1,13 @@
+#pragma once
+
+#include "unit.hpp"
+namespace gkit::scene {
+    /**
+     * @brief This is the basic unit of game composition
+     */
+    class Object : protected gkit::scene::Unit {
+    public:
+        Object() = default;
+        virtual ~Object();
+    };
+}