src/GUI/MainWindow.cpp

@@ -0,0 +1,220 @@
+#include <backends/imgui_impl_sdl2.h>
+#include <backends/imgui_impl_sdlrenderer2.h>
+#include <iostream>
+#include "MainWindow.hpp"
+#include "gui_exceptions.hpp"
+#include "../common/ougge_format.hpp"
+#include "../common/math.hpp"
+
+namespace ougge::gui {
+
+f32 MainWindow::getDPI(){
+    i32 w=0, h=0;
+    SDL_GetRendererOutputSize(sdl_renderer, &w, &h);
+    i32 sim_w=0, sim_h=0;
+    SDL_GetWindowSize(sdl_window, &sim_w, &sim_h);
+    f32 wdpi=(f32)w / sim_w;
+    f32 hdpi=(f32)h / sim_h;
+    f32 dpi=SDL_sqrtf(wdpi*wdpi + hdpi*hdpi);
+    return dpi;
+}
+
+void MainWindow::open(const std::string& window_title, resources::ResourceManager& resourceManager){
+    SDL_TRY(SDL_Init(SDL_INIT_EVERYTHING));
+    SDL_version v;
+    SDL_GetVersion(&v);
+    std::cout<<ougge_format("SDL version: %u.%u.%u\n", v.major, v.minor, v.patch);
+    
+    // From 2.0.18: Enable native IME.
+#ifdef SDL_HINT_IME_SHOW_UI
+    SDL_SetHint(SDL_HINT_IME_SHOW_UI, "1");
+#endif
+    
+    SDL_WindowFlags window_flags = (SDL_WindowFlags)(
+        SDL_WINDOW_RESIZABLE | SDL_WINDOW_ALLOW_HIGHDPI
+    );
+    sdl_window = SDL_CreateWindow(window_title.c_str(),
+        SDL_WINDOWPOS_CENTERED, SDL_WINDOWPOS_CENTERED,
+        1280, 720, window_flags);
+    if(sdl_window == nullptr)
+        throw SDLException();
+    
+    SDL_RendererFlags renderer_flags = (SDL_RendererFlags)(
+        SDL_RENDERER_ACCELERATED | SDL_RENDERER_PRESENTVSYNC
+    );
+    sdl_renderer = SDL_CreateRenderer(sdl_window, -1, renderer_flags);
+    if(sdl_renderer == nullptr)
+        throw SDLException();
+    
+    SDL_RendererInfo info;
+    SDL_GetRendererInfo(sdl_renderer, &info);
+    std::cout<<"Current SDL_Renderer driver: "<<info.name<<std::endl;
+
+    // Setup Dear ImGui context
+    IMGUI_CHECKVERSION();
+    ImGui::CreateContext();
+    ImGuiIO& io = ImGui::GetIO();
+    io.ConfigFlags |= ImGuiConfigFlags_NavEnableKeyboard; // Enable Keyboard Controls   
+    io.ConfigFlags |= ImGuiConfigFlags_NavEnableGamepad;  // Enable Gamepad Controls
+    io.ConfigFlags |= ImGuiConfigFlags_DockingEnable;     // Enable Docking
+    io.ConfigDockingTransparentPayload = true;
+    io.ConfigInputTextCursorBlink = false;
+    // io.ConfigViewportsNoTaskBarIcon = true;
+    io.ConfigWindowsMoveFromTitleBarOnly = true;
+
+    // Setup Platform/Renderer backends
+    if(!ImGui_ImplSDL2_InitForSDLRenderer(sdl_window, sdl_renderer))
+        throw SDLException();
+    if(!ImGui_ImplSDLRenderer2_Init(sdl_renderer))
+        throw SDLException();
+
+    // Setup Dear ImGui style
+    ImGui::StyleColorsDark();
+    
+    resources::ResourceFactory* font_res = resourceManager.tryGetResource(default_font_path);
+    if(font_res == nullptr)
+        throw UsefulException("can't find default font resource");
+    f32 dpi = getDPI();
+    io.FontDefault = resources::ImFont_LoadFromResource(font_res, default_font_size, dpi);
+}
+
+void MainWindow::close(){
+    ImGui_ImplSDLRenderer2_Shutdown();
+    ImGui_ImplSDL2_Shutdown();
+    ImGui::DestroyContext();
+    SDL_DestroyRenderer(sdl_renderer);
+    SDL_DestroyWindow(sdl_window);
+    SDL_Quit();
+}
+
+void MainWindow::pollEvents(bool* loopRunning){
+    SDL_Event event;
+    while (SDL_PollEvent(&event)) {
+        ImGui_ImplSDL2_ProcessEvent(&event);
+        switch(event.type){
+            case SDL_QUIT: {
+                *loopRunning = false;
+                break;
+            }
+            case SDL_WINDOWEVENT: {
+                if(event.window.event == SDL_WINDOWEVENT_CLOSE 
+                    && event.window.windowID == SDL_GetWindowID(sdl_window))
+                {
+                    *loopRunning = false;
+                }
+                break;
+            }
+        }
+    }
+}
+
+
+void MainWindow::beginFrame(){
+    // Start the Dear ImGui frame
+    ImGui_ImplSDLRenderer2_NewFrame();
+    ImGui_ImplSDL2_NewFrame();
+    ImGui::NewFrame();
+
+    ImGuiIO& io = ImGui::GetIO();
+    SDL_RenderSetScale(sdl_renderer, io.DisplayFramebufferScale.x, io.DisplayFramebufferScale.y);
+    SDL_SetRenderDrawColor(sdl_renderer, 
+        (u8)(clear_color.x * 255),
+        (u8)(clear_color.y * 255),
+        (u8)(clear_color.z * 255),
+        (u8)(clear_color.w * 255));
+    SDL_RenderClear(sdl_renderer);
+
+    draw_bg_window();
+    draw_debug_window();
+}
+
+void MainWindow::endFrame(){
+    ImGui::Render();
+    ImGui_ImplSDLRenderer2_RenderDrawData(ImGui::GetDrawData(), sdl_renderer);
+    // Swap buffers
+    SDL_RenderPresent(sdl_renderer);
+}
+
+void MainWindow::draw_bg_window(){
+    const ImGuiDockNodeFlags dockspace_flags =
+            ImGuiDockNodeFlags_PassthruCentralNode;
+    const ImGuiWindowFlags window_flags =
+        ImGuiWindowFlags_MenuBar |
+        ImGuiWindowFlags_NoDocking |
+        ImGuiWindowFlags_NoScrollbar |
+        ImGuiWindowFlags_NoScrollWithMouse |
+        ImGuiWindowFlags_NoBringToFrontOnFocus |
+        ImGuiWindowFlags_NoFocusOnAppearing |
+        ImGuiWindowFlags_NoMove |
+        ImGuiWindowFlags_NoResize |
+        ImGuiWindowFlags_NoCollapse |
+        ImGuiWindowFlags_NoTitleBar |
+        ImGuiWindowFlags_NoBackground;
+    // not dockable window that always bound to viewport
+    ImGuiViewport* viewport = ImGui::GetWindowViewport();
+    ImGui::SetNextWindowPos(viewport->Pos, ImGuiCond_Always);
+    ImGui::SetNextWindowSize(viewport->Size, ImGuiCond_Always);
+    ImGui::PushStyleVar(ImGuiStyleVar_WindowRounding, 0.0f);
+    ImGui::PushStyleVar(ImGuiStyleVar_WindowBorderSize, 0.0f);
+	ImGui::PushStyleVar(ImGuiStyleVar_WindowPadding, ImVec2(0.0f, 0.0f));
+    ImGui::Begin("bg_window", nullptr, window_flags);
+    ImGui::PopStyleVar(3);
+
+    // DockSpace
+    ImGuiID dockspace_id = ImGui::GetID("bg_dockspace");
+    ImGui::DockSpace(dockspace_id, ImVec2(0.0f, 0.0f), dockspace_flags);
+    
+    // MenuBar
+    if(ImGui::BeginMainMenuBar()){
+        if(ImGui::BeginMenu("test")){
+            if(ImGui::MenuItem("throw exception")){
+                ImGui::EndMenu();
+                ImGui::EndMainMenuBar();
+                ImGui::End();
+                throw UsefulException("example exception");
+            }
+            if(ImGui::MenuItem("throw const char*")){
+                ImGui::EndMenu();
+                ImGui::EndMainMenuBar();
+                ImGui::End();
+                throw "cptr";
+            }
+            if(ImGui::MenuItem("throw std::string")){
+                ImGui::EndMenu();
+                ImGui::EndMainMenuBar();
+                ImGui::End();
+                throw std::string("str");
+            }
+            if(ImGui::MenuItem("throw unknown")){
+                ImGui::EndMenu();
+                ImGui::EndMainMenuBar();
+                ImGui::End();
+                throw 111;
+            }
+            ImGui::EndMenu();
+        }
+        ImGui::EndMainMenuBar();
+    }
+
+    ImGui::End();
+}
+
+void MainWindow::draw_debug_window(){
+    ImGuiIO& io = ImGui::GetIO();
+    if(ImGui::Begin("Debug Options", &show_debug_window)){
+        ImGui::ColorEdit3("clear_color", (float*)&clear_color);
+        ImGui::InputInt("fps_max", &fps_max);
+        ImGui::Text("Application average %.3f ms/frame (%.2f FPS)", 1000.0f / io.Framerate, io.Framerate);
+        ImGui::Checkbox("Demo Window", &show_demo_window);
+        ImGui::Checkbox("Metrics/Debug Window", &show_metrics_window);
+        ImGui::End();
+    }
+
+    if (show_demo_window)
+        ImGui::ShowDemoWindow(&show_demo_window);
+
+    if (show_metrics_window)
+        ImGui::ShowMetricsWindow(&show_metrics_window);
+}
+
+}

src/GUI/MainWindow.hpp

@@ -0,0 +1,47 @@
+#pragma once
+
+#include <SDL.h>
+#include <imgui.h>
+#include "../common/std.hpp"
+#include "../common/time.hpp"
+#include "../resources/resources.hpp"
+#include "../resources/fonts.hpp"
+
+/// converts hex color to float vector
+#define RGBAHexToF(R8,G8,B8,A8) ImVec4(((u8)35)/255.0f, ((u8)35)/255.0f, ((u8)50)/255.0f, ((u8)255)/255.0f)
+/// converts float vector to hex color
+#define RGBAFToHex(VEC4) {(u8)(VEC4.x*255), (u8)(VEC4.y*255), (u8)(VEC4.z*255), (u8)(VEC4.w*255)}
+
+namespace ougge::gui {
+
+#define default_font_path "fonts/DroidSans.ttf"
+
+class MainWindow {
+public:
+    i32 fps_max = 60;
+    f32 default_font_size = 14.0f;
+    ImVec4 clear_color = RGBAHexToF(35,35,50,255);
+    SDL_Window* sdl_window = nullptr;
+    SDL_Renderer* sdl_renderer = nullptr;
+
+private:
+    bool show_debug_window = true;
+    bool show_demo_window = false;
+    bool show_metrics_window = false;
+
+public:
+    void open(const std::string& window_title, resources::ResourceManager& resourceManager);
+    void close();
+
+    /// process io events happened since previous frame
+    void pollEvents(bool* loopRunning);
+    void beginFrame();
+    void endFrame();
+
+    f32 getDPI();
+private:
+    void draw_debug_window();
+    void draw_bg_window();
+};
+
+}

src/Game/GameObject.cpp

@@ -0,0 +1,30 @@
+#include "GameObject.hpp"
+
+namespace ougge::game {
+
+std::ostream& operator<<(std::ostream& s, Transform& t){
+    s<<"{ position: {x: "<<t.position.x<<", y: "<<t.position.y;
+    s<<"}, rotation: "<<t.rotation;
+    s<<", scale {x: "<<t.scale.x<<", y: "<<t.scale.y<<"} }";
+    return s;
+}
+
+GameObject::GameObject(Mono::Object managed_obj)
+    : object_handle(managed_obj) 
+{}
+
+GameObject::GameObject(GameObject &&o) :
+    object_handle(std::move(o.object_handle)),
+    parent(o.parent),
+    transform(o.transform)
+{
+}
+
+GameObject& GameObject::operator=(GameObject &&o){
+    object_handle = std::move(o.object_handle);
+    parent = o.parent;
+    transform = o.transform;
+    return *this;
+}
+
+}

src/Game/GameObject.hpp

@@ -0,0 +1,45 @@
+#pragma once
+
+#include <map>
+#include <iostream>
+#include "../common/math.hpp"
+#include "../common/UsefulException.hpp"
+#include "../mono/mono.hpp"
+
+namespace ougge::game {
+
+class GameObject;
+
+struct Transform {
+    Vec2 scale = { 1, 1 };
+    Vec2 position = { 0, 0 };
+    angle_t rotation = 0;
+};
+
+std::ostream& operator<<(std::ostream& s, Transform& t);
+
+
+class GameObject {
+    Mono::ObjectHandle object_handle;
+    GameObject* parent;
+    Transform transform;
+
+public:
+    /// @warning Do not use this to create objects.
+    /// This constructor creates null values for GameObject arrays
+    /// GameObject* array = new GameObject[10];
+    /// array[0] = GameObject(initialized_mono_object_ptr)
+    GameObject() = default;
+    GameObject(Mono::Object managed_obj);
+    GameObject(const GameObject& o) = delete;
+    GameObject(GameObject&& o);
+    
+    GameObject& operator=(GameObject&& o);
+
+    inline Mono::ObjectHandle& getObjectHandle() { return object_handle; }
+    inline GameObject* getParent() { return parent; }
+    inline void setParent(GameObject* p) { parent = p; }
+    inline Transform& getTransform() { return transform; }
+};
+
+}

src/Game/GameObjectPool.cpp

@@ -0,0 +1,130 @@
+#include "GameObjectPool.hpp"
+#include <bit>
+#include <cstring>
+
+namespace ougge::game {
+
+GameObjectPool::GameObjectPool(u32 size)
+{
+    useful_assert(size % 64 == 0, "size of GameObjectPool must be a multiple of 64");
+    this->size = size; 
+    first_unused_index = 0;
+    buffer = new GameObject[size];
+    used_indices = new u64[size/64];
+    // std::memset(buffer, 0, size*sizeof(GameObject));
+    std::memset(used_indices, 0, size/8);
+}
+
+GameObjectPool::~GameObjectPool()
+{
+    delete[] buffer;
+    delete[] used_indices;
+}
+
+bool GameObjectPool::isIndexUsed(u32 index)
+{
+    return ( used_indices[index/64] & (u64(1)<<(index%64)) ) != 0;
+}
+
+u32 GameObjectPool::getNearestUnusedIndex(u32 startIndex)
+{
+    if(startIndex >= size)
+        return -1;
+    if(!isIndexUsed(startIndex))
+        return startIndex;
+    
+    u32 i = startIndex/64;
+    // mark previous bits as used
+    u64 u = used_indices[i] | ( (u64(1)<<startIndex%64) -1 );
+    while(u == u64(-1)){
+        i++;
+        if(i == size/64)
+            return -1;
+        u = used_indices[i];
+    }
+    u32 bitpos = std::countr_one(u);
+    if(bitpos == 64)
+        return -1;
+    u32 index = i*64 + bitpos;
+    return index;
+}
+
+u32 GameObjectPool::getNearestUsedIndex(u32 startIndex)
+{
+    if(startIndex >= size)
+        return -1;
+    if(isIndexUsed(startIndex))
+        return startIndex;
+    
+    u32 i = startIndex/64;
+    // mark previous bits as unused
+    u64 u = used_indices[i] & !( (u64(1)<<startIndex%64) -1 );
+    while(u == 0){
+        i++;
+        if(i == size/64)
+            return -1;
+        u = used_indices[i];
+    }
+    u32 bitpos = std::countr_zero(u);
+    if(bitpos == 64)
+        return -1;
+    u32 index = i*64 + bitpos;
+    return index;
+}
+
+GameObject& GameObjectPool::get(u32 index)
+{
+    if(index >= size)
+        throw UsefulException(ougge_format("index %i is out of size %i", index, size));
+    if(!isIndexUsed(index))
+        throw UsefulException(ougge_format("there is no object at index %i", index));
+    return buffer[index];
+}
+
+std::pair<u32, GameObject&> GameObjectPool::emplace(GameObject&& new_obj)
+{
+    u32 i = first_unused_index;
+    if(i == u32(-1))
+        throw UsefulException("can't put new GameObject to GameObjectPool because it's full");
+    
+    buffer[i] = std::move(new_obj);
+    GameObject& r = buffer[i];
+    used_indices[i/64] |= u64(1)<<(i%64); // mark index bit as used
+    first_unused_index = getNearestUnusedIndex(i+1);
+    return std::pair<u32, GameObject&>(i, r);
+}
+
+void GameObjectPool::erase(u32 index)
+{
+    if(index >= size)
+        throw UsefulException(ougge_format("index %i is out of size %i", index, size));
+    if(!isIndexUsed(index))
+        throw UsefulException(ougge_format("there is no object at index %i", index));
+    
+    buffer[index] = GameObject();
+    used_indices[index/64] &= ~(u64(1)<<(index%64)); // mark index bit as unused
+    if(index < first_unused_index)
+        first_unused_index = index;
+}
+
+GameObjectPool::iterator::iterator(GameObjectPool* pool, u32 index)
+    : pool(pool), index(index)
+{
+}
+
+std::pair<u32, GameObject&> GameObjectPool::iterator::operator*()
+{
+    if(index >= pool->size)
+        throw UsefulException("can't get value of end() iterator");
+    
+    GameObject& r = pool->buffer[index];
+    return  std::pair<u32, GameObject&>(index, r);
+}
+
+GameObjectPool::iterator& GameObjectPool::iterator::operator++()
+{
+    index = pool->getNearestUsedIndex(index+1);
+    return *this;
+}
+
+}

src/Game/GameObjectPool.hpp

@@ -0,0 +1,70 @@
+#include "GameObject.hpp"
+
+namespace ougge::game {
+
+/*
+Fixed array that stores deleted elements indices as bits in array of u64.
+Fast emplace, erase and lookup. 
+
+------------------------[construct]------------------------
+operation 'GameObjectPool::GameObjectPool()' took 1.0549 ms
+operation 'other_collections_construct' took 0.0133 ms
+-------------------------[emplace]-------------------------
+operation 'GameObjectPool::emplace' took 8.0557 ms
+operation 'vector::emplace_back' took 11.3735 ms
+operation 'set::emplace' took 80.5633 ms
+operation 'list::emplace_front' took 18.1442 ms
+operation 'forward_list::emplace_front' took 11.5467 ms
+--------------------------[erase]--------------------------
+operation 'GameObjectPool::erase' took 0.2745 ms
+operation 'vector::erase' took 15790.6 ms
+operation 'set::erase' took 1.2697 ms
+operation 'list::erase_after' took 0.93 ms
+operation 'forward_list::erase_after' took 1.1127 ms
+-------------------------[iterate]-------------------------
+operation 'GameObjectPool::iterate' took 1.1166 ms
+operation 'vector::iterate' took 0.8883 ms
+operation 'set::iterate' took 2.8011 ms
+operation 'list::iterate' took 2.0766 ms
+operation 'forward_list::iterate' took 2.0823 ms
+*/
+
+class GameObjectPool {
+    GameObject* buffer;
+    u64* used_indices;
+    u32 size;
+    u32 first_unused_index;
+
+    bool isIndexUsed(u32 index);
+    u32 getNearestUnusedIndex(u32 startIndex);
+    u32 getNearestUsedIndex(u32 startIndex);
+public:
+
+    ///@param size must be a multiple of 64
+    GameObjectPool(u32 size);
+    ~GameObjectPool();
+    GameObject& get(u32 index);
+    std::pair<u32, GameObject&> emplace(GameObject&& new_obj);
+    void erase(u32 index);
+
+    #pragma region iterator class
+    class iterator {
+        GameObjectPool* pool;
+        u32 index = 0;
+    
+    public:
+        iterator(GameObjectPool* pool, u32 index);
+        std::pair<u32, GameObject&> operator*();
+        iterator& operator++();
+        inline bool operator!=(const iterator& o) const { return index != o.index; };
+        inline bool operator==(const iterator& o) const { return index == o.index; };
+    };
+    #pragma endregion
+
+    inline iterator begin() { return iterator(this, 0); }
+    inline iterator end() { return iterator(this, -1); }
+    
+    friend class iterator;
+};
+
+}

src/Mono/Assembly.cpp

@@ -0,0 +1,17 @@
+#include "mono.hpp"
+
+namespace Mono {
+
+Assembly::Assembly(MonoAssembly *ptr)
+    : ptr(ptr), image(mono_assembly_get_image(ptr))
+{
+}
+
+MonoClass* Assembly::getClass(const std::string &name_space, const std::string &name){
+    auto c = mono_class_from_name(image, name_space.c_str(), name.c_str());
+    if(!c)
+        throw UsefulException(ougge_format("can't get class '%s.%s'", name_space.c_str(), name.c_str()));
+    return c;
+}
+
+}

src/Mono/Mono.cpp

@@ -0,0 +1,81 @@
+#include "mono.hpp"
+#include <mono/metadata/appdomain.h>
+
+namespace Mono {
+
+template <> MonoClass* getClass<SByte>(){ return mono_get_sbyte_class(); }
+template <> MonoClass* getClass<Byte>(){ return mono_get_byte_class(); }
+template <> MonoClass* getClass<Short>(){ return mono_get_int16_class(); }
+template <> MonoClass* getClass<UShort>(){ return mono_get_uint16_class(); }
+template <> MonoClass* getClass<Int>(){ return mono_get_int32_class(); }
+template <> MonoClass* getClass<UInt>(){ return mono_get_uint32_class(); }
+template <> MonoClass* getClass<Long>(){ return mono_get_int64_class(); }
+template <> MonoClass* getClass<ULong>(){ return mono_get_uint64_class(); }
+template <> MonoClass* getClass<Float>(){ return mono_get_single_class(); }
+template <> MonoClass* getClass<Double>(){ return mono_get_double_class(); }
+template <> MonoClass* getClass<Bool>(){ return mono_get_boolean_class(); }
+template <> MonoClass* getClass<Char>(){ return mono_get_char_class(); }
+template <> MonoClass* getClass<String>(){ return mono_get_string_class(); }
+template <> MonoClass* getClass<Object>(){ return mono_get_object_class(); }
+template <> MonoClass* getClass<Void>(){ return mono_get_void_class(); }
+
+
+void getMethodSignatureTypes(MonoMethod* mono_method,
+        MonoType** return_type,
+        std::vector<MonoType*>& argument_types)
+{
+    auto signature = mono_method_signature(mono_method);
+    void* iter = nullptr;
+    *return_type = mono_signature_get_return_type(signature);
+    MonoType* pt = nullptr;
+    while( (pt = mono_signature_get_params(signature, &iter)) ){
+        argument_types.push_back(pt);
+    }
+}
+
+MonoMethod* tryGetMonoMethod(MonoClass* target_class, const std::string& name,
+        MonoClass* return_class, MonoClass* arg_classes[], size_t arg_classes_size)
+{
+    if(target_class == nullptr)
+        throw UsefulException("target_class is nullptr");
+    
+    // iterate each method
+    void* iter = nullptr;
+    MonoMethod* m = nullptr;
+    std::vector<MonoType*> argument_types;
+    while( (m = mono_class_get_methods(target_class, &iter)) ){
+        // compare name
+        std::string m_name = mono_method_get_name(m);
+        if(m_name != name)
+            continue;
+        
+        argument_types.clear();
+        MonoType* return_type = nullptr;
+        getMethodSignatureTypes(m, &return_type, argument_types);
+        // compare argument count
+        if(argument_types.size() != arg_classes_size)
+            continue;
+        
+        // compare return type
+        if(!mono_metadata_type_equal(return_type, mono_class_get_type(return_class)))
+            continue;
+        
+        // compare argument types
+        bool argument_types_mismatch = false;
+        for(size_t i = 0; i < arg_classes_size; i++){
+            if(!mono_metadata_type_equal(argument_types[i], mono_class_get_type(arg_classes[i]))){
+                argument_types_mismatch = true;
+                break;
+            }
+        }
+        if(argument_types_mismatch)
+            continue;
+        
+        // passed all tests successfully
+        break;
+    }
+
+    return m;
+}
+
+}

src/Mono/Mono.hpp

@@ -0,0 +1,187 @@
+#pragma once
+
+#include "../common/std.hpp"
+#include "../common/UsefulException.hpp"
+#include "../common/ougge_format.hpp"
+#include <vector>
+#include <type_traits>
+#include <mono/metadata/class.h>
+#include <mono/metadata/assembly.h>
+#include <mono/metadata/object.h>
+
+namespace Mono {
+
+typedef i8 SByte;
+typedef u8 Byte;
+typedef i16 Short;
+typedef u16 UShort;
+typedef i32 Int;
+typedef u32 UInt;
+typedef i64 Long;
+typedef u64 ULong;
+typedef f32 Float;
+typedef f64 Double;
+typedef union { mono_bool wide_bool; } Bool; //USAGE: Bool t = {true};
+typedef char16_t Char;
+typedef MonoString* String;
+/// @warning MonoObject can be moved in memory by GC in any time and raw pointer will be invalid. 
+/// Use ObjectHandle where it is possible.
+typedef MonoObject* Object;
+typedef void Void;
+
+
+template<typename PrimitiveT>
+MonoClass* getClass(); 
+
+template<typename T>
+void* valueToVoidPtr(T& v){ return &v; }
+template<>
+inline void* valueToVoidPtr<Object>(Object& v){ return v; }
+template<>
+inline void* valueToVoidPtr<String>(String& v){ return v; }
+
+template<typename T>
+T valueFromMonoObject(MonoObject* o){
+    void* result_value_ptr = mono_object_unbox(o);
+    if(result_value_ptr == nullptr)
+        throw UsefulException("can't unbox method value");
+    return *((T*)result_value_ptr);
+}
+template<>
+inline Object valueFromMonoObject<Object>(MonoObject* o){ return o; }
+template<>
+inline String valueFromMonoObject<String>(MonoObject* o){ return (String)((void*)o); }
+
+void getMethodSignatureTypes(MonoMethod* mono_method,
+        MonoType** return_type,
+        std::vector<MonoType*>& argument_types);
+
+/// searches for method `name` in `target_class` with return type `return_class` and argument types `arg_classes`
+/// @return found method or nullptr
+MonoMethod* tryGetMonoMethod(MonoClass* target_class, const std::string& name,
+    MonoClass* return_class, MonoClass* arg_classes[], size_t arg_classes_size);
+
+
+template<typename SignatureT> class Method;
+template<typename ReturnT, typename... ArgTypes>
+class Method<ReturnT(ArgTypes...)>
+{
+    MonoMethod* method_ptr;
+
+public:
+    Method() { method_ptr = nullptr; }
+
+    /// all types must implement getClass<T>()
+    Method(MonoClass* target_class, const std::string& name){
+        static MonoClass* arg_classes[] { getClass<ArgTypes>()... };
+        static MonoClass* return_class { getClass<ReturnT>() };
+        method_ptr = tryGetMonoMethod(target_class, name, return_class, arg_classes, sizeof...(ArgTypes));
+        if(method_ptr == nullptr){
+            throw UsefulException(ougge_format("can't get method '%s' from class '%s'",
+                name.c_str(), mono_class_get_name(target_class)));
+        }
+    }
+
+    // ReturnT not is void
+    template<typename RT = ReturnT>
+    std::enable_if_t<!std::is_void<RT>::value, RT> operator()(MonoObject* class_instance, ArgTypes... args) const {
+        if(method_ptr == nullptr)
+            throw UsefulException("method_ptr is null");
+        
+        void* arg_array[] = { valueToVoidPtr(args)..., nullptr };
+        MonoObject* ex = nullptr;
+        MonoObject* result = mono_runtime_invoke(method_ptr, class_instance, arg_array, &ex);
+        if(ex){
+            //TODO:  call mono_trace_set_printerr_handler from  mono/mono/utils/mono-logger.h
+            mono_print_unhandled_exception(ex);
+            throw UsefulException("Some C# exception occured");
+        }
+        return valueFromMonoObject<ReturnT>(result);
+    };
+
+    // ReturnT is void
+    template<typename RT = ReturnT>
+    std::enable_if_t<std::is_void<RT>::value, RT> operator()(MonoObject* class_instance, ArgTypes... args) const {
+        if(method_ptr == nullptr)
+            throw UsefulException("method_ptr is null");
+        
+        void* arg_array[] = { valueToVoidPtr(args)..., nullptr };
+        MonoObject* ex = nullptr;
+        mono_runtime_invoke(method_ptr, class_instance, arg_array, &ex);
+        if(ex){
+            //TODO:  call mono_trace_set_printerr_handler from  mono/mono/utils/mono-logger.h
+            mono_print_unhandled_exception(ex);
+            throw UsefulException("Some C# exception occured");
+        }
+    };
+};
+
+
+class Assembly {
+    MonoAssembly* ptr;
+    MonoImage* image;
+
+public:
+    Assembly(MonoAssembly* ptr);
+    Assembly(const Assembly&) = delete;
+    
+    MonoClass* getClass(const std::string& name_space, const std::string& name);
+    MonoAssembly* getMonoAssembly() const { return ptr; }
+    MonoImage* getMonoImage() const { return image; }
+};
+
+
+///LINUX: `config.xml`, `mscorelib.dll`, `libmono-native.so` in `mono-libs` directory
+///
+///WINDOWS: `config.xml`, `mscorelib.dll` in `mono-libs` directory
+class RuntimeJIT {
+    MonoDomain* domain;
+public:
+    RuntimeJIT(const std::string& domain_name = "OuggeDomain");
+    RuntimeJIT(const RuntimeJIT&) = delete;
+    ~RuntimeJIT();
+    
+    inline MonoDomain* getDomain() { return domain; }
+    std::shared_ptr<Assembly> loadAssembly(const std::string& name);
+
+    inline Object createObject(MonoClass* klass) { return mono_object_new(domain, klass); }
+    inline String createString(const std::string& v) { return mono_string_new_len(domain, v.c_str(), v.size()); }
+    inline String createString(const char* v) { return mono_string_new(domain, v); }
+};
+
+/// @brief ObjectHandle can be used to store reliable reference to MonoObject.
+/// MonoObject can be moved in memory by GC in any time and raw pointer will be invalid. 
+struct ObjectHandle {
+    u32 gc_handle;
+
+    inline ObjectHandle() : gc_handle(0) {}
+
+    inline ObjectHandle(Object obj) {
+        gc_handle = mono_gchandle_new(obj, false);
+    }
+
+    /// implicitly create new ObjectHandle instead
+    inline ObjectHandle(const ObjectHandle& o) = delete;
+
+    inline ObjectHandle(ObjectHandle&& o) {
+        gc_handle = o.gc_handle;
+        o.gc_handle = 0;
+    }
+
+    inline ObjectHandle& operator=(ObjectHandle&& o) {
+        gc_handle = o.gc_handle;
+        o.gc_handle = 0;
+        return *this;
+    }
+
+    inline ~ObjectHandle() {
+        if(gc_handle)
+            mono_gchandle_free(gc_handle);
+    }
+
+    inline Object getObject() const {
+        return mono_gchandle_get_target(gc_handle);
+    }
+};
+
+}

src/Mono/Runtime.cpp

@@ -0,0 +1,30 @@
+#include "mono.hpp"
+#include <mono/jit/jit.h>
+#include <mono/metadata/mono-config.h>
+#include <mono/metadata/appdomain.h>
+
+namespace Mono {
+
+RuntimeJIT::RuntimeJIT(const std::string& domain_name){
+    mono_set_dirs("mono-libs", "mono-libs");
+    mono_set_assemblies_path("mono-libs");
+    mono_config_parse("mono-libs/config.xml");
+
+    domain = mono_jit_init(domain_name.c_str());
+    if(!domain)
+        throw UsefulException("can't initialize mono domain");
+}
+
+RuntimeJIT::~RuntimeJIT(){
+    // TODO: fix segfault on cleanup
+    // mono_jit_cleanup(domain);
+}
+
+std::shared_ptr<Assembly> RuntimeJIT::loadAssembly(const std::string &name){
+    MonoAssembly* ptr = mono_domain_assembly_open(domain, name.c_str());
+    if(!ptr)
+        throw UsefulException(ougge_format("can't load assembly '%s'", name.c_str()));
+    return std::make_shared<Assembly>(ptr);
+}
+
+}

src/Resources/MemorySteam.cpp

@@ -0,0 +1,40 @@
+#include "MemoryStream.hpp"
+
+class MemoryStreamBuf : public std::streambuf {
+public:
+    MemoryStreamBuf(void* p, const std::size_t n);
+
+    virtual std::istream::pos_type seekoff(
+        std::istream::off_type off,
+        std::ios_base::seekdir dir,
+        std::ios_base::openmode which);
+};
+
+MemoryStreamBuf::MemoryStreamBuf(void* _p, const std::size_t n){
+    char* p=(char*)_p;
+    setg(p, p, p + n);
+    setp(p, p + n);
+}
+
+std::istream::pos_type MemoryStreamBuf::seekoff(
+    std::istream::off_type off,
+    std::ios_base::seekdir dir,
+    std::ios_base::openmode which)
+{
+    if (dir == std::ios_base::cur)
+        gbump(off);
+    else if (dir == std::ios_base::end)
+        setg(eback(), egptr() + off, egptr());
+    else if (dir == std::ios_base::beg)
+        setg(eback(), eback() + off, egptr());
+    return gptr() - eback();
+}
+
+
+MemoryStreamRead::MemoryStreamRead(const void* p, const std::size_t n)
+    : std::istream(new MemoryStreamBuf((void*)p, n))
+{}
+
+MemoryStreamRead::~MemoryStreamRead(){
+    delete rdbuf();
+}

src/Resources/MemoryStream.hpp

@@ -0,0 +1,8 @@
+#include <iostream>
+
+class MemoryStreamRead : public std::istream {
+public:
+    MemoryStreamRead(const void* p, const std::size_t n);
+
+    virtual ~MemoryStreamRead();
+};

src/Resources/embedded_resources.h

@@ -0,0 +1,64 @@
+////////////////////////////////////////////////////////////////
+//        This file was generated by resource_embedder        //
+//  https://timerix.ddns.net:3322/Timerix/resource_embedder   //
+////////////////////////////////////////////////////////////////
+//                          USAGE:                            //
+//    Put it in a SOURCE file to define variables             //
+//  #define EMBEDDED_RESOURCE_DEFINITION                      //
+//  #define EMBEDDED_RESOURCE_POSTFIX your_postfix            //
+//  #include "../../src/Resources/embedded_resources.h"       //
+//                                                            //
+//    Put it in a HEADER file to declare external variables   //
+//  #define EMBEDDED_RESOURCE_POSTFIX your_postfix            //
+//  #include "../../src/Resources/embedded_resources.h"       //
+//                                                            //
+//    Then you can access embedded files through              //
+//  EmbeddedResource_table_your_postfix. You can get table    //
+//  content by index and put it into a hashtable or a map.    //
+////////////////////////////////////////////////////////////////
+
+#pragma once
+#if __cplusplus
+extern "C" {
+#endif
+
+#include <stdint.h>
+#include <stddef.h>
+
+typedef struct {
+    const char* path;
+    const char* data;
+    size_t size;
+} EmbeddedResource;
+
+#define RSCAT(A,B,C...) A##B##C
+#ifdef EMBEDDED_RESOURCE_POSTFIX
+    #define _EmbeddedResource_table(P) \
+        RSCAT(EmbeddedResource_table_, P)
+    #define _EmbeddedResource_table_count(P) \
+        RSCAT(EmbeddedResource_table_, P, _count)
+#else
+    #define _EmbeddedResource_table(P) \
+        EmbeddedResource_table
+    #define _EmbeddedResource_table_count(P) \
+        EmbeddedResource_table_count
+#endif
+extern const EmbeddedResource _EmbeddedResource_table(EMBEDDED_RESOURCE_POSTFIX)[];
+extern const int _EmbeddedResource_table_count(EMBEDDED_RESOURCE_POSTFIX);
+
+#ifdef EMBEDDED_RESOURCE_DEFINITION
+const EmbeddedResource _EmbeddedResource_table(EMBEDDED_RESOURCE_POSTFIX)[]={
+
+};
+
+const int _EmbeddedResource_table_count(EMBEDDED_RESOURCE_POSTFIX)=0;
+#endif // EMBEDDED_RESOURCE_DEFINITION
+
+#undef _EmbeddedResource_table
+#undef _EmbeddedResource_table_count
+#undef EMBEDDED_RESOURCE_POSTFIX
+#undef RSCAT
+
+#if __cplusplus
+}
+#endif

src/Resources/fonts.cpp

@@ -0,0 +1,29 @@
+#include "fonts.hpp"
+
+namespace ougge::resources {
+
+// select all glyphs from font
+static const ImWchar glyph_ranges[] = {
+    0x0020, 0xFFFF, 0
+};
+
+ImFont* ImFont_LoadFromFile(const std::string& file_path, f32 font_size, f32 dpi){
+    ImGuiIO& io = ImGui::GetIO();
+    font_size *= dpi;
+    return io.Fonts->AddFontFromFileTTF(file_path.c_str(), font_size, nullptr, glyph_ranges);
+}
+
+ImFont* ImFont_LoadFromResource(ResourceFactory* res, f32 font_size, f32 dpi){
+    ImGuiIO& io = ImGui::GetIO();
+    font_size *= dpi;
+    ImFontConfig font_cfg = ImFontConfig();
+    std::sprintf(font_cfg.Name, "%s %ipx", res->path.c_str(), (i32)font_size);
+    
+    char* font_data = new char[res->size]; 
+    res->openStream()->read(font_data, res->size);
+
+    return io.Fonts->AddFontFromMemoryTTF((void*)(font_data), res->size,
+        font_size, &font_cfg, glyph_ranges);
+}
+
+}

src/Resources/fonts.hpp

@@ -0,0 +1,13 @@
+#pragma once
+
+#include <imgui.h>
+#include "../common/std.hpp"
+#include "resources.hpp"
+
+namespace ougge::resources {
+
+ImFont* ImFont_LoadFromFile(const std::string& file_path, f32 font_size, f32 dpi);
+
+ImFont* ImFont_LoadFromResource(ResourceFactory* res, f32 font_size, f32 dpi);
+
+}