added imgui and sdl

src/gui/gui.h

@@ -0,0 +1,15 @@
+#pragma once
+
+#if __cplusplus
+extern "C" {
+#endif
+
+#include "../../kerep/src/base/base.h"
+
+Maybe main_window_open();
+Maybe main_window_loop_start();
+Maybe main_window_close();
+
+#if __cplusplus
+}
+#endif

src/gui/gui_internal.hpp

@@ -0,0 +1,8 @@
+#pragma once
+
+#include "gui.h"
+#include "SDL2/SDL.h"
+#include "SDL2/SDL_opengl.h"
+#include "../../imgui/imgui.h"
+#include "../../imgui/backends/imgui_impl_sdl2.h"
+#include "../../imgui/backends/imgui_impl_opengl3.h"

src/gui/main_window.cpp

@@ -0,0 +1,157 @@
+#include "gui_internal.hpp"
+
+const char* window_title="GraphC";
+bool loop_running=false;
+SDL_Window* sdl_window;
+SDL_GLContext gl_context;
+
+#define SDL_ERROR_SAFETHROW() { \
+    const char* sdl_error=SDL_GetError(); \
+    throw_msg(cptr_concat("SDL Error: ", sdl_error)); \
+    SDL_ClearError(); \
+}
+#define SDL_TRY_ZERO(FUNC_CALL) if(FUNC_CALL != 0) SDL_ERROR_SAFETHROW();
+
+Maybe main_window_open(){
+    SDL_TRY_ZERO(SDL_Init(SDL_INIT_VIDEO));
+    // GL 3.0 + GLSL 130
+    const char* glsl_version = "#version 130";
+    SDL_TRY_ZERO( SDL_GL_SetAttribute(SDL_GL_CONTEXT_FLAGS, 0));
+    SDL_TRY_ZERO( SDL_GL_SetAttribute(SDL_GL_CONTEXT_PROFILE_MASK, SDL_GL_CONTEXT_PROFILE_CORE));
+    SDL_TRY_ZERO( SDL_GL_SetAttribute(SDL_GL_CONTEXT_MAJOR_VERSION, 3));
+    SDL_TRY_ZERO( SDL_GL_SetAttribute(SDL_GL_CONTEXT_MINOR_VERSION, 0));
+
+    // From 2.0.18: Enable native IME.
+#ifdef SDL_HINT_IME_SHOW_UI
+    SDL_SetHint(SDL_HINT_IME_SHOW_UI, "1");
+#endif
+    
+    // Create window with graphics context
+    SDL_TRY_ZERO( SDL_GL_SetAttribute(SDL_GL_DOUBLEBUFFER, 1));
+    SDL_TRY_ZERO( SDL_GL_SetAttribute(SDL_GL_DEPTH_SIZE, 24));
+    SDL_TRY_ZERO( SDL_GL_SetAttribute(SDL_GL_STENCIL_SIZE, 8));
+    SDL_WindowFlags window_flags = (SDL_WindowFlags)(SDL_WINDOW_OPENGL|SDL_WINDOW_RESIZABLE|SDL_WINDOW_ALLOW_HIGHDPI);
+    sdl_window = SDL_CreateWindow(window_title,
+        SDL_WINDOWPOS_CENTERED, SDL_WINDOWPOS_CENTERED,
+        1280, 720, window_flags);
+    gl_context = SDL_GL_CreateContext(sdl_window);
+    SDL_TRY_ZERO( SDL_GL_MakeCurrent(sdl_window, gl_context));
+    SDL_TRY_ZERO( SDL_GL_SetSwapInterval(1)); // Enable vsync
+
+    // Setup Dear ImGui context
+    IMGUI_CHECKVERSION();
+    ImGui::CreateContext();
+    ImGuiIO& io = ImGui::GetIO(); (void)io;
+    io.ConfigFlags |= ImGuiConfigFlags_NavEnableKeyboard;
+    
+    // Setup Dear ImGui style
+    ImGui::StyleColorsDark();
+
+    // Setup Platform/Renderer backends
+    if(ImGui_ImplSDL2_InitForOpenGL(sdl_window, gl_context) != true)
+        SDL_ERROR_SAFETHROW();
+    if(ImGui_ImplOpenGL3_Init(glsl_version) != true)
+        SDL_ERROR_SAFETHROW();
+
+    return MaybeNull;
+}
+
+Maybe main_window_loop_start(){
+    if(loop_running)
+        safethrow_msg("loop is already running",;);
+    loop_running=true;
+
+    // Our state
+    bool show_demo_window = true;
+    bool show_another_window = false;
+    ImVec4 clear_color = ImVec4(0.45f, 0.55f, 0.60f, 1.00f);
+
+    // main loop
+    while(loop_running){
+        // Poll and handle events (inputs, window resize, etc.)
+        // You can read the io.WantCaptureMouse, io.WantCaptureKeyboard flags to tell if dear imgui wants to use your inputs.
+        // - When io.WantCaptureMouse is true, do not dispatch mouse input data to your main application, or clear/overwrite your copy of the mouse data.
+        // - When io.WantCaptureKeyboard is true, do not dispatch keyboard input data to your main application, or clear/overwrite your copy of the keyboard data.
+        // Generally you may always pass all inputs to dear imgui, and hide them from your application based on those two flags.
+        SDL_Event event;
+        while (SDL_PollEvent(&event))
+        {
+            ImGui_ImplSDL2_ProcessEvent(&event);
+            if (event.type == SDL_QUIT)
+                loop_running = false;
+            if (event.type==SDL_WINDOWEVENT && event.window.event == SDL_WINDOWEVENT_CLOSE && event.window.windowID == SDL_GetWindowID(sdl_window))
+                loop_running = false;
+        }
+
+        // Start the Dear ImGui frame
+        ImGui_ImplOpenGL3_NewFrame();
+        ImGui_ImplSDL2_NewFrame();
+        ImGui::NewFrame();
+        
+        ImGuiIO& io = ImGui::GetIO(); (void)io;
+
+        // 1. Show the big demo window (Most of the sample code is in ImGui::ShowDemoWindow()! You can browse its code to learn more about Dear ImGui!).
+        if (show_demo_window)
+            ImGui::ShowDemoWindow(&show_demo_window);
+
+        // 2. Show a simple window that we create ourselves. We use a Begin/End pair to create a named window.
+        {
+            static float f = 0.0f;
+            static int counter = 0;
+
+            ImGui::Begin("Hello, world!");                          // Create a window called "Hello, world!" and append into it.
+
+            ImGui::Text("This is some useful text.");               // Display some text (you can use a format strings too)
+            ImGui::Checkbox("Demo Window", &show_demo_window);      // Edit bools storing our window open/close state
+            ImGui::Checkbox("Another Window", &show_another_window);
+
+            ImGui::SliderFloat("float", &f, 0.0f, 1.0f);            // Edit 1 float using a slider from 0.0f to 1.0f
+            ImGui::ColorEdit3("clear color", (float*)&clear_color); // Edit 3 floats representing a color
+
+            if (ImGui::Button("Button"))                            // Buttons return true when clicked (most widgets return true when edited/activated)
+                counter++;
+            ImGui::SameLine();
+            ImGui::Text("counter = %d", counter);
+
+            ImGui::Text("Application average %.3f ms/frame (%.1f FPS)", 1000.0f / io.Framerate, io.Framerate);
+            ImGui::End();
+        }
+
+        // 3. Show another simple window.
+        if (show_another_window)
+        {
+            ImGui::Begin("Another Window", &show_another_window);   // Pass a pointer to our bool variable (the window will have a closing button that will clear the bool when clicked)
+            ImGui::Text("Hello from another window!");
+            if (ImGui::Button("Close Me"))
+                show_another_window = false;
+            ImGui::End();
+        }
+
+        // Rendering
+        ImGui::Render();
+        glViewport(0, 0, (int)io.DisplaySize.x, (int)io.DisplaySize.y);
+        glClearColor(clear_color.x * clear_color.w, clear_color.y * clear_color.w, clear_color.z * clear_color.w, clear_color.w);
+        glClear(GL_COLOR_BUFFER_BIT);
+        ImGui_ImplOpenGL3_RenderDrawData(ImGui::GetDrawData());
+        SDL_GL_SwapWindow(sdl_window);
+    }
+
+    try_cpp(main_window_close(),_999,;);
+    return MaybeNull;
+}
+
+Maybe main_window_close(){
+    if(!loop_running)
+        return MaybeNull;
+    loop_running=false;
+    
+    // Cleanup
+    ImGui_ImplOpenGL3_Shutdown();
+    ImGui_ImplSDL2_Shutdown();
+    ImGui::DestroyContext();
+    SDL_GL_DeleteContext(gl_context);
+    SDL_DestroyWindow(sdl_window);
+    SDL_Quit();
+
+    return MaybeNull;
+}