main.cpp

// Dear ImGui: standalone example application for SDL2 + OpenGL
// (SDL is a cross-platform general purpose library for handling windows, inputs, OpenGL/Vulkan/Metal graphics context creation, etc.)
// If you are new to Dear ImGui, read documentation from the docs/ folder + read the top of imgui.cpp.
// Read online: https://github.com/ocornut/imgui/tree/master/docs

#include "app.hpp"
#include "file-open.hpp"
#include "imgui-impl-opengl3.h"
#include "imgui-impl-sdl.h"
#include <functional>
#include <imgui/imgui.h>
#include <log/log.hpp>
#include <sdlpp/sdlpp.hpp>
#include <stdio.h>

// Main code
int main(int argc, const char *argv[])
{
  // 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!)

  auto sdlInit = sdl::Init{SDL_INIT_VIDEO | SDL_INIT_TIMER | SDL_INIT_GAMECONTROLLER | SDL_INIT_AUDIO};

  // Decide GL+GLSL versions
#if defined(IMGUI_IMPL_OPENGL_ES2)
  // GL ES 2.0 + GLSL 100
  const char *glsl_version = "#version 100";
  SDL_GL_SetAttribute(SDL_GL_CONTEXT_FLAGS, 0);
  SDL_GL_SetAttribute(SDL_GL_CONTEXT_PROFILE_MASK, SDL_GL_CONTEXT_PROFILE_ES);
  SDL_GL_SetAttribute(SDL_GL_CONTEXT_MAJOR_VERSION, 2);
  SDL_GL_SetAttribute(SDL_GL_CONTEXT_MINOR_VERSION, 0);
#elif defined(__APPLE__)
  // GL 3.2 Core + GLSL 150
  const char *glsl_version = "#version 150";
  SDL_GL_SetAttribute(SDL_GL_CONTEXT_FLAGS, SDL_GL_CONTEXT_FORWARD_COMPATIBLE_FLAG); // Always required on Mac
  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, 2);
#else
  // 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);
#endif

  // 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("Melonix", SDL_WINDOWPOS_CENTERED, SDL_WINDOWPOS_CENTERED, 1280, 720, window_flags);
  SDL_GLContext gl_context = SDL_GL_CreateContext(window);
  SDL_GL_MakeCurrent(window, gl_context);
  SDL_GL_SetSwapInterval(1); // Enable vsync

  // Setup Dear ImGui context
  IMGUI_CHECKVERSION();
  ImGui::CreateContext();
  ImGuiIO &io = ImGui::GetIO();
  (void)io;
  io.ConfigFlags |= ImGuiConfigFlags_NavEnableKeyboard; // Enable Keyboard Controls
  // io.ConfigFlags |= ImGuiConfigFlags_NavEnableGamepad;      // Enable Gamepad Controls
  io.ConfigFlags |= ImGuiConfigFlags_DockingEnable;   // Enable Docking
  io.ConfigFlags |= ImGuiConfigFlags_ViewportsEnable; // Enable Multi-Viewport / Platform Windows
  // io.ConfigViewportsNoAutoMerge = true;
  // io.ConfigViewportsNoTaskBarIcon = true;

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

  // When viewports are enabled we tweak WindowRounding/WindowBg so platform windows can look identical to regular ones.
  ImGuiStyle &style = ImGui::GetStyle();
  if (io.ConfigFlags & ImGuiConfigFlags_ViewportsEnable)
  {
    style.WindowRounding = 0.0f;
    style.Colors[ImGuiCol_WindowBg].w = 1.0f;
  }

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

  // Load Fonts
  // - If no fonts are loaded, dear imgui will use the default font. You can also load multiple fonts and use ImGui::PushFont()/PopFont() to select
  // them.
  // - AddFontFromFileTTF() will return the ImFont* so you can store it if you need to select the font among multiple.
  // - If the file cannot be loaded, the function will return NULL. Please handle those errors in your application (e.g. use an assertion, or display
  // an error and quit).
  // - The fonts will be rasterized at a given size (w/ oversampling) and stored into a texture when calling ImFontAtlas::Build()/GetTexDataAsXXXX(),
  // which ImGui_ImplXXXX_NewFrame below will call.
  // - Read 'docs/FONTS.md' for more instructions and details.
  // - Remember that in C/C++ if you want to include a backslash \ in a string literal you need to write a double backslash \\ !
  // io.Fonts->AddFontDefault();
  // io.Fonts->AddFontFromFileTTF("../../misc/fonts/Roboto-Medium.ttf", 16.0f);
  // io.Fonts->AddFontFromFileTTF("../../misc/fonts/Cousine-Regular.ttf", 15.0f);
  // io.Fonts->AddFontFromFileTTF("../../misc/fonts/DroidSans.ttf", 16.0f);
  // io.Fonts->AddFontFromFileTTF("../../misc/fonts/ProggyTiny.ttf", 10.0f);
  // ImFont* font = io.Fonts->AddFontFromFileTTF("c:\\Windows\\Fonts\\ArialUni.ttf", 18.0f, NULL, io.Fonts->GetGlyphRangesJapanese());
  // IM_ASSERT(font != NULL);

  // Main loop
  bool done = false;
  App app;

  if (argc > 1)
    app.openFile(argv[1]);

  while (!done)
  {
    // 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))
    {
      switch (event.type)
      {
      case SDL_KEYDOWN:
        // toggle playback with the space bar
        if (event.key.keysym.sym == SDLK_SPACE)
        {
          app.togglePlay();
          continue;
        }
        // left and right arrow keys
        else if (event.key.keysym.sym == SDLK_LEFT)
        {
          app.cursorLeft();
          continue;
        }
        else if (event.key.keysym.sym == SDLK_RIGHT)
        {
          app.cursorRight();
          continue;
        }
        break;
      }
      ImGui_ImplSDL2_ProcessEvent(&event);
      if (event.type == SDL_QUIT)
        done = true;
      if (event.type == SDL_WINDOWEVENT && event.window.event == SDL_WINDOWEVENT_CLOSE && event.window.windowID == SDL_GetWindowID(window))
        done = true;

      // Redirect mouse or keyboard to the app
      if (!io.WantCaptureMouse)
      {
        switch (event.type)
        {
        case SDL_MOUSEMOTION:
          app.mouseMotion(
            // x, y
            event.motion.x,
            event.motion.y,
            // dx, dy
            event.motion.xrel,
            event.motion.yrel,
            // buttons
            event.motion.state);
          break;
        case SDL_MOUSEBUTTONDOWN:
        case SDL_MOUSEBUTTONUP: {
          app.mouseButton(
            // x, y
            event.button.x,
            event.button.y,
            // state
            event.button.state,
            // button
            event.button.button);
          break;
        }
        }
      }
    }

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

    app.draw();

    // Rendering
    ImGui::Render();

    app.glDraw();

    ImGui_ImplOpenGL3_RenderDrawData(ImGui::GetDrawData());

    // Update and Render additional Platform Windows
    // (Plat*uform functions may change the current OpenGL context, so we save/restore it to make it easier to paste this code elsewhere.
    //  For this specific demo app we could also call SDL_GL_MakeCurrent(window, gl_context) directly)
    if (io.ConfigFlags & ImGuiConfigFlags_ViewportsEnable)
    {
      SDL_Window *backup_current_window = SDL_GL_GetCurrentWindow();
      SDL_GLContext backup_current_context = SDL_GL_GetCurrentContext();
      ImGui::UpdatePlatformWindows();
      ImGui::RenderPlatformWindowsDefault();
      SDL_GL_MakeCurrent(backup_current_window, backup_current_context);
    }

    SDL_GL_SwapWindow(window);
  }

  // Cleanup
  ImGui_ImplOpenGL3_Shutdown();
  ImGui_ImplSDL2_Shutdown();
  ImGui::DestroyContext();

  SDL_GL_DeleteContext(gl_context);
  SDL_DestroyWindow(window);
  SDL_Quit();

  return 0;
}