remove graphic module and fix submodule problem

.gitmodules

@@ -2,6 +2,7 @@
 	path = third_party/sdl
 	url = https://github.com/gkit-org/SDL.git
 	branch = release-3.4.x
+
 [submodule "third_party/sdl_image"]
 	path = third_party/sdl_image
 	url = https://github.com/gkit-org/SDL_image.git

src/core/CMakeLists.txt

@@ -3,8 +3,6 @@ set (CORE "gkit_core")
 ## Core Sources file ##
 file(GLOB_RECURSE CORE_SRC
   "./application/*.cpp"
-  "./graphic/*.cpp"
-  # "./input/*.cpp"
   "./scene/*.cpp"
   "./resource/*cpp"
   "./utils/*.cpp"

src/core/application.cpp

@@ -1,9 +1,10 @@
 #include "../include/application.hpp"
+#include "scene/unit.hpp"
 #include <SDL3/SDL_error.h>
 #include <SDL3/SDL_init.h>
 #include <SDL3/SDL_log.h>
 
-gkit::Application::Application() noexcept : root(), windows() {
+gkit::Application::Application() noexcept : root(), singleton_units(gkit::scene::Unit::create<scene::Unit>()) {
     SDL_InitFlags flags = SDL_INIT_AUDIO |
                           SDL_INIT_EVENTS |
                           SDL_INIT_GAMEPAD |

src/core/include/application.hpp

@@ -1,14 +1,14 @@
 #pragma once
 
-#include "graphic/window.hpp"
 #include "scene/unit.hpp"
+#include "utils/Singleton.hpp"
 #include <atomic>
 #include <memory>
 #include <vector>
 
 namespace gkit {
 
-    class Application {
+    class Application : public utils::Singleton<Application> {
     public:
         explicit Application() noexcept;
         virtual ~Application() noexcept;
@@ -21,8 +21,7 @@ namespace gkit {
 
     private:
         std::unique_ptr<scene::Unit> root;
-        std::vector<std::unique_ptr<gkit::graphic::Window>> windows;
-
+        std::unique_ptr<scene::Unit> singleton_units;
         std::atomic<bool> running = false;
     }; // class Application
 

src/core/include/gkit.hpp

@@ -3,9 +3,6 @@
 // Basic
 #include <application.hpp>
 
-// Graphic
-#include <graphic/window.hpp>
-
 // Scene
 #include <scene/unit.hpp>
 #include <scene/object.hpp>

src/core/include/resource/resource_loader.hpp

@@ -18,7 +18,8 @@ namespace gkit::resource {
         auto load(std::filesystem::path path) -> std::optional<std::shared_ptr<T>> {
             auto cached_res = get_cache(path);
             if (cached_res.has_value()) {
-                return std::static_pointer_cast<T>(cached_res);
+                auto target_res = std::dynamic_pointer_cast<T>(cached_res);
+                return target_res == nullptr ? std::nullopt : target_res;
             }
 
             auto loaded_res = std::make_shared(T());
@@ -32,9 +33,8 @@ namespace gkit::resource {
             }
         };
     private:
-        std::shared_mutex cache_rw_mutex = std::shared_mutex();
-        std::unordered_map<std::filesystem::path, std::shared_ptr<gkit::resource::Resource>> resource_cache 
-                    = std::unordered_map<std::filesystem::path, std::shared_ptr<gkit::resource::Resource>>();
+        std::shared_mutex cache_rw_mutex {};
+        std::unordered_map<std::filesystem::path, std::shared_ptr<gkit::resource::Resource>> resource_cache {};
 
         auto push_to_cache(std::shared_ptr<gkit::resource::Resource> res) -> void;
         auto get_cache(std::filesystem::path path) -> std::optional<std::shared_ptr<gkit::resource::Resource>>;

src/core/include/scene/unit.hpp

@@ -8,6 +8,7 @@
 #include <shared_mutex>
 #include <string>
 #include <type_traits>
+#include <unordered_map>
 #include <vector>
 #include <memory>
 
@@ -170,10 +171,15 @@ namespace gkit::scene {
 
     private: // children management
         std::atomic<bool> modified = false;
-        mutable std::shared_mutex index_cache_rw_mutex;
+
+        std::unordered_map<const char*, Unit*> name_map_cache;
+        mutable std::shared_mutex name_map_cache_rw_mutex;
+
         std::vector<uint32_t> active_index_cache;
-        mutable std::shared_mutex children_rw_mutex;
+        mutable std::shared_mutex index_cache_rw_mutex;
+
         std::vector<std::unique_ptr<Unit>> children;
+        mutable std::shared_mutex children_rw_mutex;
 
         // when (active_index_cache.size() / children.size() <= overload_factor)
         // children vector will realloc(call method @ref remap_children_and_cache())

src/core/scene/unit.cpp

@@ -13,22 +13,8 @@ gkit::scene::Unit::Unit() noexcept :
     children(std::vector<std::unique_ptr<Unit>>()),
     active_index_cache(),
     children_rw_mutex() { }
-// gkit::scene::Unit::Unit(const Unit&) noexcept {}
-// gkit::scene::Unit::Unit(Unit&& other) noexcept : 
-//     name(other.name),
-//     parent(nullptr),
-//     modified(true),
-//     active_index_cache(),
-//     process_enabled(other.process_enabled.load()),
-//     ready_to_drop(other.ready_to_drop.load())
-// {
-//     for (auto&& child_ptr : other.children) {
-//         if (child_ptr == nullptr) continue; 
-//         this->children.push_back(std::move(child_ptr));
-//     }
-//     this->update_index_cache();
-// }
-// gkit::scene::Unit::Unit(std::string&& name) noexcept : gkit::scene::Unit(name) { }
+
+
 gkit::scene::Unit::Unit(std::string name) noexcept : gkit::scene::Unit() {
     this->name = name;
 }
@@ -217,11 +203,11 @@ auto gkit::scene::Unit::iterator::operator--(int) -> iterator {
 auto gkit::scene::Unit::iterator::operator==(const iterator& other) const -> bool  { return m_owner == other.m_owner && m_pos == other.m_pos; }
 auto gkit::scene::Unit::iterator::operator!=(const iterator& other) const -> bool  { return !(*this == other); }
 
-auto gkit::scene::Unit::begin() -> iterator{
+auto gkit::scene::Unit::begin() -> iterator {
     return iterator(this, 0);
 }
 
-auto gkit::scene::Unit::end() -> iterator{
+auto gkit::scene::Unit::end() -> iterator {
     return iterator(this, active_index_cache.size());
 }
 
@@ -261,13 +247,11 @@ auto gkit::scene::Unit::const_iterator::operator==(const const_iterator& other)
 auto gkit::scene::Unit::const_iterator::operator!=(const const_iterator& other) const -> bool { return !(*this == other); }
 
 auto gkit::scene::Unit::begin() const -> const_iterator {
-    const_cast<Unit*>(this);
-    return const_iterator(this, 0);
+    return const_iterator(const_cast<Unit*>(this), 0);
 }
 
 auto gkit::scene::Unit::end() const -> const_iterator {
-    const_cast<Unit*>(this);
-    return const_iterator(this, active_index_cache.size());
+    return const_iterator(const_cast<Unit*>(this), active_index_cache.size());
 }
 
 auto gkit::scene::Unit::cbegin() const -> const_iterator { return begin(); }

test/core/scene/test_unit.cpp

@@ -67,7 +67,7 @@ class RootUnit : public Unit {
 
 
 int main() {
-    gkit::Application app;
+    auto& app = gkit::Application::instance();
     auto root = Unit::create<RootUnit>("root");
     app.set_root(std::move(root));
     app.run();