Main.cpp

#include <cstdio>
#include <filesystem>

#include <SDL.h>
#include <glad/glad.h> // Initialize with gladLoadGL()
#include <imgui.h>
#include <imgui_impl_opengl3.h>
#include <imgui_impl_sdl2.h>

#include "scope_guard.hpp"

#include "ReGenny.hpp"

// Main code
int main(int, char**) {
    // Setup SDL
    // (Some versions of SDL before <2.0.10 appears to have performance/stalling issues on a minority of Windows
    // systems, depending on whether SDL_INIT_GAMECONTROLLER is enabled or disabled.. updating to latest version of SDL
    // is recommended!)
    if (SDL_Init(SDL_INIT_VIDEO | SDL_INIT_TIMER | SDL_INIT_GAMECONTROLLER) != 0) {
        printf("Error: %s\n", SDL_GetError());
        return -1;
    }

    auto cleanup_sdl = sg::make_scope_guard([] { SDL_Quit(); });

    // GL 3.0 + GLSL 130
    const char* glsl_version = "#version 130";
    SDL_GL_SetAttribute(SDL_GL_CONTEXT_FLAGS, 0);
    SDL_GL_SetAttribute(SDL_GL_CONTEXT_PROFILE_MASK, SDL_GL_CONTEXT_PROFILE_CORE);
    SDL_GL_SetAttribute(SDL_GL_CONTEXT_MAJOR_VERSION, 3);
    SDL_GL_SetAttribute(SDL_GL_CONTEXT_MINOR_VERSION, 0);

    // Create window with graphics context
    SDL_GL_SetAttribute(SDL_GL_DOUBLEBUFFER, 1);
    SDL_GL_SetAttribute(SDL_GL_DEPTH_SIZE, 24);
    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* window =
        SDL_CreateWindow("ReGenny", SDL_WINDOWPOS_CENTERED, SDL_WINDOWPOS_CENTERED, 1280, 720, window_flags);
    SDL_GLContext gl_context = SDL_GL_CreateContext(window);
    SDL_GL_SetSwapInterval(1); // Enable vsync
    SDL_SetWindowMinimumSize(window, 300, 150);

    auto cleanup_window = sg::make_scope_guard([window, gl_context] {
        SDL_GL_DeleteContext(gl_context);
        SDL_DestroyWindow(window);
    });

    // Initialize OpenGL loader
    if (gladLoadGL() == 0) {
        fprintf(stderr, "Failed to initialize OpenGL loader!\n");
        return 1;
    }

    // Setup Dear ImGui context
    IMGUI_CHECKVERSION();
    ImGui::CreateContext();

    auto app_path_str = SDL_GetPrefPath("cursey", "ReGenny");
    std::filesystem::path app_path{app_path_str};
    SDL_free(app_path_str);

    auto imgui_ini_filename = (app_path / "imgui.ini").string();
    auto& io = ImGui::GetIO();

    io.IniFilename = imgui_ini_filename.c_str();
    io.ConfigFlags |= ImGuiConfigFlags_DockingEnable;

    // Setup Dear ImGui style
    ImGui::StyleColorsDark();
    // ImGui::StyleColorsClassic();

    // Setup Platform/Renderer backends
    ImGui_ImplSDL2_InitForOpenGL(window, gl_context);
    ImGui_ImplOpenGL3_Init(glsl_version);

    auto cleanup_imgui = sg::make_scope_guard([] {
        ImGui_ImplOpenGL3_Shutdown();
        ImGui_ImplSDL2_Shutdown();
        ImGui::DestroyContext();
    });

    // Our state
    ReGenny regenny{window};
    ImVec4 clear_color = ImVec4(0.45f, 0.55f, 0.60f, 1.00f);

    // Main loop
    bool done = false;

    while (!done) {
        auto start_time = SDL_GetPerformanceCounter();

        // 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.
        // - When io.WantCaptureKeyboard is true, do not dispatch keyboard input data to your main application.
        // Generally you may always pass all inputs to dear imgui, and hide them from your application based on those
        // two flags.
        SDL_Event e{};

        while (SDL_PollEvent(&e)) {
            ImGui_ImplSDL2_ProcessEvent(&e);
            regenny.process_event(e);

            if (e.type == SDL_QUIT) {
                done = true;
            } else if (e.type == SDL_WINDOWEVENT && e.window.event == SDL_WINDOWEVENT_CLOSE &&
                       e.window.windowID == SDL_GetWindowID(window)) {
                done = true;
            }
        }

        regenny.update();

        // Start the Dear ImGui frame
        ImGui_ImplOpenGL3_NewFrame();
        ImGui_ImplSDL2_NewFrame(window);
        ImGui::NewFrame();

        regenny.ui();
        // ImGui::ShowDemoWindow();

        // 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(window);

        auto end_time = SDL_GetPerformanceCounter();
        auto elapsed_ms = (end_time - start_time) / (float)SDL_GetPerformanceFrequency() * 1000.0f;
        constexpr auto fps_cap = 1000.0f / 60.0f;

        SDL_Delay((Uint32)std::max(fps_cap - elapsed_ms, 0.0f));
    }

    return 0;
}