diff --git a/src/UsefulException.cpp b/src/UsefulException.cpp
new file mode 100644
index 0000000..ad1446d
--- /dev/null
+++ b/src/UsefulException.cpp
@@ -0,0 +1,19 @@
+#include "UsefulException.hpp"
+#include <sstream>
+
+namespace GraphC {
+
+UsefulException_::UsefulException_(std::string _message, std::string _file, std::string _func, int _line_n)
+    : message(_message), file(_file), function(_func), line_n(_line_n)
+{
+    std::stringstream ss;
+    ss<<message<<'\n';
+    ss<<file<<':'<<_line_n<<" in "<<function;
+    complete_text = ss.str();
+}
+
+const char* UsefulException_::what() {
+    return complete_text.c_str();
+}
+
+}
diff --git a/src/UsefulException.hpp b/src/UsefulException.hpp
new file mode 100644
index 0000000..c823d35
--- /dev/null
+++ b/src/UsefulException.hpp
@@ -0,0 +1,23 @@
+#pragma once
+
+#include <stdexcept>
+#include <string>
+
+namespace GraphC {
+
+#define UsefulException(MSG) UsefulException_(MSG, __FILE__, __func__, __LINE__)
+
+class UsefulException_ : public std::exception {
+    std::string message;
+    std::string file;
+    std::string function;
+    int line_n;
+    std::string complete_text;
+
+public:
+    UsefulException_(std::string msg, std::string _file, std::string _func, int line_n);
+
+    const char* what();
+};
+
+}
diff --git a/src/gui/NodeEditor.cpp b/src/gui/NodeEditor.cpp
index 1e0890b..e544f65 100644
--- a/src/gui/NodeEditor.cpp
+++ b/src/gui/NodeEditor.cpp
@@ -1,4 +1,4 @@
-#include "gui_internal.hpp"
+#include "gui.hpp"
 #include <algorithm>
 #include "NodeEditor.hpp"
 
@@ -92,7 +92,6 @@ void NodeEditor::draw(){
         id_t out_attr_id;
         if (ImNodes::IsLinkCreated(&in_attr_id, &out_attr_id))
         {
-            kprintf("new link id: %i\n", next_id);
             NodeAttributeLink link(next_id++, in_attr_id, out_attr_id);
             links.push_back(link);
         }
@@ -101,15 +100,12 @@ void NodeEditor::draw(){
         id_t link_id;
         if (ImNodes::IsLinkDestroyed(&link_id))
         {
-            kprintf("link destroyed %i\n", link_id);
             auto iter = std::find_if(links.begin(), links.end(), 
                 [link_id](const NodeAttributeLink& link) -> bool {
-                    kprintf("destroyed link found\n");
                     return link.id == link_id;
                 });
             assert(iter != links.end());
             links.erase(iter);
-            kprintf("destroyed link erased\n");
         }
 
     ImGui::End();
diff --git a/src/gui/bg_window.cpp b/src/gui/bg_window.cpp
deleted file mode 100644
index cee674d..0000000
--- a/src/gui/bg_window.cpp
+++ /dev/null
@@ -1,36 +0,0 @@
-#include "gui_internal.hpp"
-
-void 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
-    //TODO
-
-    ImGui::End();
-}
diff --git a/src/gui/debug_ui.cpp b/src/gui/debug_ui.cpp
deleted file mode 100644
index e0ddd8d..0000000
--- a/src/gui/debug_ui.cpp
+++ /dev/null
@@ -1,20 +0,0 @@
-#include "gui_internal.hpp"
-
-bool show_demo_window = false;
-bool show_metrics_window = false;
-
-void draw_debug_window(ImGuiIO& io, bool* main_loop_wait_for_input){
-    ImGui::Begin("Debug Options");
-    ImGui::ColorEdit3("clear_color", (float*)&clear_color);
-    ImGui::Checkbox("main_loop_wait_for_input", main_loop_wait_for_input);
-    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);
-}
diff --git a/src/gui/exceptions.cpp b/src/gui/exceptions.cpp
new file mode 100644
index 0000000..d30f79a
--- /dev/null
+++ b/src/gui/exceptions.cpp
@@ -0,0 +1,12 @@
+#include "exceptions.hpp"
+#include "../../dependencies/SDL2/include/SDL.h"
+
+namespace GraphC::gui {
+
+SDLException_::SDLException_(std::string _file, std::string _func, int _line_n)
+    : UsefulException_(SDL_GetError(), _file, _func, _line_n)
+{
+    SDL_ClearError();
+}
+
+}
\ No newline at end of file
diff --git a/src/gui/exceptions.hpp b/src/gui/exceptions.hpp
new file mode 100644
index 0000000..e085841
--- /dev/null
+++ b/src/gui/exceptions.hpp
@@ -0,0 +1,17 @@
+#pragma once
+
+#include "../UsefulException.hpp"
+
+namespace GraphC::gui {
+
+#define SDLException() SDLException_(__FILE__, __func__, __LINE__)
+
+class SDLException_ : UsefulException_ {
+public:
+    SDLException_(std::string _file, std::string _func, int line_n);
+};
+
+#define SDL_TRY_ZERO(FUNC_CALL) if(FUNC_CALL != 0) throw SDLException();
+#define SDL_TRY_ONE(FUNC_CALL) if(FUNC_CALL != 1) throw SDLException();
+
+}
\ No newline at end of file
diff --git a/src/gui/fonts.cpp b/src/gui/fonts.cpp
index c1144e0..671fb00 100644
--- a/src/gui/fonts.cpp
+++ b/src/gui/fonts.cpp
@@ -1,15 +1,19 @@
-#include "gui_internal.hpp"
+#include "gui.hpp"
 
-ImFont* ImFont_LoadFromFile(const char* file_path, f32 font_size){
+namespace GraphC::gui::fonts {
+
+ImFont* ImFont_LoadFromFile(const char* file_path, f32 font_size, f32 dpi){
     ImGuiIO& io = ImGui::GetIO();
-    font_size *= getMainWindowDPI();
+    font_size *= dpi;
     return io.Fonts->AddFontFromFileTTF(file_path, font_size);
 }
 
-ImFont* _ImFont_LoadEmbedded(const void* data, int data_size, const char* font_name, f32 font_size){
+ImFont* _ImFont_LoadEmbedded(const void* data, int data_size, const char* font_name, f32 font_size, f32 dpi){
     ImGuiIO& io = ImGui::GetIO();
-    font_size *= getMainWindowDPI();
+    font_size *= dpi;
     ImFontConfig font_cfg = ImFontConfig();
     sprintf_s(font_cfg.Name, IM_ARRAYSIZE(font_cfg.Name), "%s, %.0fpx", font_name, font_size);
     return io.Fonts->AddFontFromMemoryCompressedTTF(data, data_size, font_size, &font_cfg);
 }
+
+}
diff --git a/src/gui/fonts.hpp b/src/gui/fonts.hpp
new file mode 100644
index 0000000..6c42678
--- /dev/null
+++ b/src/gui/fonts.hpp
@@ -0,0 +1,23 @@
+#pragma once
+
+#include "../../dependencies/imgui/imgui.h"
+#include "../generated/fonts_embedded.h"
+
+namespace GraphC::gui::fonts {
+
+#define __CAT3(A,B,C) A##B##C
+#define embedded_font_data(FONT) __CAT3(font_,FONT,_compressed_data)
+#define embedded_font_data_size(FONT) __CAT3(font_,FONT,_compressed_size)
+#define embedded_font_name(FONT) #FONT
+
+
+ImFont* ImFont_LoadFromFile(const char* file_path, f32 font_size, f32 dpi);
+
+#define ImFont_LoadEmbedded(FONT, FONT_SIZE, DPI) _ImFont_LoadEmbedded( \
+    embedded_font_data(FONT), \
+    embedded_font_data_size(FONT), \
+    embedded_font_name(FONT), \
+    FONT_SIZE, DPI)
+ImFont* _ImFont_LoadEmbedded(const void* data, int data_size, const char* font_name, f32 font_size, f32 dpi);
+
+}
diff --git a/src/gui/main_window.cpp b/src/gui/gui.cpp
similarity index 65%
rename from src/gui/main_window.cpp
rename to src/gui/gui.cpp
index 14ac066..546f69b 100644
--- a/src/gui/main_window.cpp
+++ b/src/gui/gui.cpp
@@ -1,17 +1,10 @@
-#include "gui_internal.hpp"
-#include "NodeEditor.hpp"
-using namespace GraphC::gui;
+#include "gui.hpp"
+#include "../../dependencies/imgui/backends/imgui_impl_sdl2.h"
+#include "../../dependencies/imgui/backends/imgui_impl_opengl3.h"
 
-#define default_font_name font_DroidSans
-const f32 default_font_size=14.0f;
-ImVec4 clear_color = RGBAHexToF(35,35,50,255);
-bool loop_running=false;
-SDL_Window* sdl_window;
-SDL_GLContext gl_context;
-bool main_loop_wait_for_input=true;
-NodeEditor node_editor("new editor");
+namespace GraphC::gui {
 
-f32 getMainWindowDPI(){
+f32 GUI::getDPI(){
     int w=0, h=0;
     SDL_GL_GetDrawableSize(sdl_window, &w, &h);
     int sim_w=0, sim_h=0;
@@ -22,7 +15,7 @@ f32 getMainWindowDPI(){
     return dpi;
 }
 
-Maybe main_window_open(const char* window_title){
+void GUI::init(const char* window_title){
     SDL_TRY_ZERO(SDL_Init(SDL_INIT_VIDEO));
     SDL_version v;
     SDL_GetVersion(&v);
@@ -69,53 +62,53 @@ Maybe main_window_open(const char* window_title){
 
     // Setup Platform/Renderer backends
     if(ImGui_ImplSDL2_InitForOpenGL(sdl_window, gl_context) != true)
-        SDL_ERROR_SAFETHROW();
+        throw SDLException();
     if(ImGui_ImplOpenGL3_Init(glsl_version) != true)
-        SDL_ERROR_SAFETHROW();
+        throw SDLException();
 
     // Setup Dear ImGui style
     ImGui::StyleColorsDark();
-    io.FontDefault=ImFont_LoadEmbedded(default_font_name, default_font_size);
-    ImFont_LoadEmbedded(font_Cousine_Regular, default_font_size);
+    f32 dpi = getDPI();
+    io.FontDefault=fonts:: ImFont_LoadEmbedded(default_font, default_font_size, dpi);
+    fonts:: ImFont_LoadEmbedded(font_Cousine_Regular, default_font_size, dpi);
 
     ImNodes::CreateContext();
     ImNodes::StyleColorsDark();
     ImNodes::PushAttributeFlag(ImNodesAttributeFlags_EnableLinkDetachWithDragClick);
     node_editor=NodeEditor("node editor");
-    return MaybeNull;
+    node_editor.show();
 }
 
 // Wait, poll and handle events (inputs, window resize, etc.)
-Maybe poll_events(u16& frame_updates_requested, bool wait){
+void GUI::poll_events(u16& frame_updates_requested, bool wait){
     SDL_Event event;
     if(wait){
         // waits for first event in cpu-efficient way
         SDL_TRY_ONE(SDL_WaitEvent(&event)); 
     }
-    // doesnt wait for event
+    // dont wait for event
     else if(!SDL_PollEvent(&event))
-        return MaybeNull;
+        return;
     
     do {
         if(ImGui_ImplSDL2_ProcessEvent(&event))
             frame_updates_requested=2;
         switch(event.type){
             case SDL_QUIT: {
-                try_cpp(main_window_close(),_9914,;);
+                close();
                 break;
             }
             case SDL_WINDOWEVENT: {
                 if(event.window.event == SDL_WINDOWEVENT_CLOSE && event.window.windowID == SDL_GetWindowID(sdl_window)){
-                    try_cpp(main_window_close(),_9915,;);
+                    close();
                 }
                 break;
             }
         }
     } while (SDL_PollEvent(&event)); // if there are more events, handles them
-    return MaybeNull;
 }
 
-Maybe draw_frame(){
+void GUI::draw_frame(){
     // Start the Dear ImGui frame
     ImGui_ImplOpenGL3_NewFrame();
     ImGui_ImplSDL2_NewFrame();
@@ -125,7 +118,6 @@ Maybe draw_frame(){
     // Draw UI
     draw_bg_window();
     draw_debug_window(io, &main_loop_wait_for_input);
-    node_editor.show();
     node_editor.draw();
 
     // Rendering
@@ -149,15 +141,14 @@ Maybe draw_frame(){
 
     SDL_GL_SwapWindow(sdl_window);
 
-    return MaybeNull;
 }
 
-Maybe main_window_loop_start(){
+void GUI::startAndWait(){
     if(loop_running)
-        safethrow_msg("loop is already running",;);
+        throw UsefulException("loop is already running");
 
     // draw first frame
-    try_cpp(draw_frame(),_2175,;);
+    draw_frame();
 
     u16 frame_updates_requested=1;
     u64 prev_update_time_ms=SDL_GetTicks64();
@@ -165,20 +156,20 @@ Maybe main_window_loop_start(){
     // main loop
     while(loop_running){
         // waits for events
-        try_cpp(poll_events(frame_updates_requested, main_loop_wait_for_input),_55415,;);
+        poll_events(frame_updates_requested, main_loop_wait_for_input);
 
         if(frame_updates_requested==0)
         {
             u64 update_time_ms=SDL_GetTicks64();
-            if(update_time_ms >= prev_update_time_ms + 1000/frame_rate_min){
-                // if frame rate < frame_rate_min then requests frame draw
+            if(update_time_ms >= prev_update_time_ms + 1000/fps_min){
+                // if frame rate < fps_min then requests frame draw
                 // works only if main_loop_wait_for_input = false
                 frame_updates_requested=1;
                 prev_update_time_ms=update_time_ms;
             }
             else {
                 // skips frame rendering and waits to limit fps
-                u32 frame_delay_ms=1000/frame_rate_max;
+                u32 frame_delay_ms=1000/fps_max;
                 SDL_Delay(frame_delay_ms);
                 continue;
             }
@@ -186,24 +177,20 @@ Maybe main_window_loop_start(){
 
         // deaws requested number of frames
         while(frame_updates_requested>0) {
-            try_cpp(draw_frame(),_2175,;);
+            draw_frame();
             frame_updates_requested--;
         }   
     }
 
     // Cleanup
-    main_window_destroy();
-    return MaybeNull;
+    GUI::destroy();
 }
 
-Maybe main_window_close(){
-    if(!loop_running)
-        return MaybeNull;
+void GUI::close(){
     loop_running=false;
-    return MaybeNull;
 }
 
-void main_window_destroy(){
+void GUI::destroy(){
     ImNodes::DestroyContext();
     ImGui_ImplOpenGL3_Shutdown();
     ImGui_ImplSDL2_Shutdown();
@@ -212,3 +199,56 @@ void main_window_destroy(){
     SDL_DestroyWindow(sdl_window);
     SDL_Quit();
 }
+
+void GUI::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
+    //TODO
+
+    ImGui::End();
+}
+
+void GUI::draw_debug_window(ImGuiIO& io, bool* main_loop_wait_for_input){
+    ImGui::Begin("Debug Options");
+    ImGui::ColorEdit3("clear_color", (float*)&clear_color);
+    ImGui::Checkbox("main_loop_wait_for_input", main_loop_wait_for_input);
+    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);
+}
+
+}
\ No newline at end of file
diff --git a/src/gui/gui.h b/src/gui/gui.h
deleted file mode 100644
index 7e0e8b6..0000000
--- a/src/gui/gui.h
+++ /dev/null
@@ -1,20 +0,0 @@
-#pragma once
-
-#if __cplusplus
-extern "C" {
-#endif
-
-#include "../../dependencies/kerep/src/base/base.h"
-
-Maybe main_window_open(const char* window_title);
-Maybe main_window_loop_start();
-Maybe main_window_close();
-
-/// 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)}
-
-#if __cplusplus
-}
-#endif
diff --git a/src/gui/gui.hpp b/src/gui/gui.hpp
new file mode 100644
index 0000000..686a66f
--- /dev/null
+++ b/src/gui/gui.hpp
@@ -0,0 +1,51 @@
+#pragma once
+
+#include "../../dependencies/kerep/src/base/base.h"
+#include "../../dependencies/SDL2/include/SDL.h"
+#include "../../dependencies/SDL2/include/SDL_opengl.h"
+#include "../../dependencies/imgui/imgui.h"
+#include "NodeEditor.hpp"
+#include "imgui_extensions.hpp"
+#include "fonts.hpp"
+#include "exceptions.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 GraphC::gui {
+
+#define default_font font_DroidSans
+
+class GUI {
+public:
+    ImVec4 clear_color = RGBAHexToF(35,35,50,255);
+    f32 default_font_size = 14.0f;
+    u8 fps_min = 30;
+    u8 fps_max = 60;
+
+private:
+    bool loop_running=false;
+    bool main_loop_wait_for_input=true;
+    bool show_demo_window = false;
+    bool show_metrics_window = false;
+    SDL_Window* sdl_window;
+    SDL_GLContext gl_context;
+    NodeEditor node_editor = NodeEditor("new editor");
+
+public:
+    void init(const char* window_title);
+    void startAndWait();
+    void close();
+    f32 getDPI();
+
+private:
+    void destroy();
+    void poll_events(u16& frame_updates_requested, bool wait);
+    void draw_frame();
+    void draw_debug_window(ImGuiIO &io, bool *main_loop_wait_for_input);
+    void draw_bg_window();
+};
+
+}
diff --git a/src/gui/gui_internal.hpp b/src/gui/gui_internal.hpp
deleted file mode 100644
index bb4f342..0000000
--- a/src/gui/gui_internal.hpp
+++ /dev/null
@@ -1,65 +0,0 @@
-#pragma once
-
-#include "gui.h"
-#include "../../dependencies/SDL2/include/SDL.h"
-#include "../../dependencies/SDL2/include/SDL_opengl.h"
-#include "../../dependencies/imgui/imgui.h"
-#include "../../dependencies/imgui/backends/imgui_impl_sdl2.h"
-#include "../../dependencies/imgui/backends/imgui_impl_opengl3.h"
-#include "../../dependencies/kerep/src/Filesystem/filesystem.h"
-
-//////////////////////////////////////
-//              Fonts               //
-//////////////////////////////////////
-#include "../generated/fonts_embedded.h"
-
-#define __CAT3(A,B,C) A##B##C
-#define embedded_font_data(FONT) __CAT3(font_,FONT,_compressed_data)
-#define embedded_font_size(FONT) __CAT3(font_,FONT,_compressed_size)
-#define embedded_font_name(FONT) #FONT
-
-f32 getMainWindowDPI();
-ImFont* ImFont_LoadFromFile(const char* file_path, f32 font_size);
-ImFont* _ImFont_LoadEmbedded(const void* data, int data_size, const char* font_name, f32 font_size);
-
-#define ImFont_LoadEmbedded(FONT, FONT_SIZE) _ImFont_LoadEmbedded( \
-    embedded_font_data(FONT), \
-    embedded_font_size(FONT), \
-    embedded_font_name(FONT), \
-    FONT_SIZE)
-
-//////////////////////////////////////
-//     Variables and constants      //
-//////////////////////////////////////
-const u8 frame_rate_min=30; // frames per second
-const u8 frame_rate_max=60; // frames per second
-extern ImVec4 clear_color; // background color for main window
-
-//////////////////////////////////////
-//           UI Functions           //
-//////////////////////////////////////
-/// @brief frees all allocated resources
-void main_window_destroy();
-void draw_debug_window(ImGuiIO& io, bool* main_loop_wait_for_input);
-void draw_bg_window();
-
-//////////////////////////////////////
-//             Macros               //
-//////////////////////////////////////
-#define SDL_ERROR_SAFETHROW() { \
-    const char* sdl_error=SDL_GetError(); \
-    safethrow_msg(cptr_concat("SDL Error: ", sdl_error),;); \
-    SDL_ClearError(); \
-}
-#define SDL_TRY_ZERO(FUNC_CALL) if(FUNC_CALL != 0) SDL_ERROR_SAFETHROW();
-#define SDL_TRY_ONE(FUNC_CALL) if(FUNC_CALL != 1) SDL_ERROR_SAFETHROW();
-
-
-//////////////////////////////////////
-//        ImGui extensions          //
-//////////////////////////////////////
-namespace ImGui {
-    void SetWindowSizeMin(f32 window_width_min, f32 window_height_min);
-}
-
-ImVec2 ImVec2Add(ImVec2 a, ImVec2 b);
diff --git a/src/gui/imgui_extensions.cpp b/src/gui/imgui_extensions.cpp
index 2b5562f..3678f65 100644
--- a/src/gui/imgui_extensions.cpp
+++ b/src/gui/imgui_extensions.cpp
@@ -1,8 +1,8 @@
-#include "gui_internal.hpp"
+#include "gui.hpp"
 
 namespace ImGui {
 
-void SetWindowSizeMin(f32 window_width_min, f32 window_height_min){
+void SetWindowSizeMin(float window_width_min, float window_height_min){
     ImVec2 window_size=ImGui::GetWindowSize();
     ImVec2 new_size=window_size;
     bool changed=false;
@@ -18,11 +18,10 @@ void SetWindowSizeMin(f32 window_width_min, f32 window_height_min){
         ImGui::SetWindowSize(new_size);
 }
 
-} // namespace
-
-
 ImVec2 ImVec2Add(ImVec2 a, ImVec2 b) {
     a.x+=b.x;
     a.y+=b.y;
     return a;
 }
+
+}
diff --git a/src/gui/imgui_extensions.hpp b/src/gui/imgui_extensions.hpp
new file mode 100644
index 0000000..96cf2cb
--- /dev/null
+++ b/src/gui/imgui_extensions.hpp
@@ -0,0 +1,11 @@
+#pragma once
+
+#include "../../dependencies/imgui/imgui.h"
+
+namespace ImGui {
+
+void SetWindowSizeMin(float window_width_min, float window_height_min);
+
+ImVec2 ImVec2Add(ImVec2 a, ImVec2 b);
+
+}
diff --git a/src/main.c b/src/main.c
deleted file mode 100644
index 67f4445..0000000
--- a/src/main.c
+++ /dev/null
@@ -1,28 +0,0 @@
-#include "../dependencies/kerep/src/base/base.h"
-#include "gui/gui.h"
-
-void kt_initGraphCTypes(){
-
-}
-
-int main(const int argc, const char* const* argv){
-    if(setlocale(LC_CTYPE, "C.UTF-8")!=0)
-        kprintf("\e[93msetlocale failed!\n");
-
-    kt_beginInit(true);
-    kt_initKerepTypes();
-    kt_initGraphCTypes();
-    kt_endInit();
-
-    kprintf("\e[37margs:");
-    for(i32 i=0; i<argc; i++)
-        kprintf(" %s", argv[i]);
-    kprintf("\n");
-
-    tryLast(main_window_open("GraphC"),_1, ;);
-    tryLast(main_window_loop_start(),_2, ;);
-    tryLast(main_window_close(),_3, ;);
-
-    kt_free();
-    return 0;
-}
diff --git a/src/main.cpp b/src/main.cpp
new file mode 100644
index 0000000..6368b08
--- /dev/null
+++ b/src/main.cpp
@@ -0,0 +1,41 @@
+#include "gui/gui.hpp"
+#include <iostream>
+
+// SDL for some reason redefains main
+#ifdef main 
+    #undef main
+#endif
+
+int main(const int argc, const char* const* argv){
+    if(setlocale(LC_CTYPE, "C.UTF-8")!=0)
+        kprintf("\e[93msetlocale failed!\n");
+
+    kt_beginInit(true);
+    kt_initKerepTypes();
+    kt_endInit();
+
+    try {
+        GraphC::gui::GUI gui;
+        gui.init("GraphC");
+        gui.startAndWait();
+    }
+    catch(const std::exception& e){
+        std::cerr<<"Catched exception: "<<e.what()<<std::endl;
+        return -1;
+    }
+    catch(const char* msg){
+        std::cerr<<"Catched exception message: "<<msg<<std::endl;
+        return -1;
+    }
+    catch(std::string& msg){
+        std::cerr<<"Catched exception message: "<<msg<<std::endl;
+        return -1;
+    }
+    catch(...){
+        std::cerr<<"Catched unknown exception"<<std::endl;
+        return -1;
+    }
+    
+    kt_free();
+    return 0;
+}