Replaces FEXConfig usage of GLFW with SDL2

Sometimes GLFW3 can just consume a full CPU core, spinning on nothing.

Fixes #906

Source/Tools/FEXConfig/Main.cpp

@@ -1,19 +1,19 @@
 #include "Common/Config.h"
-#include "Context.h"
 
 #include <imgui.h>
 #define YES_IMGUIFILESYSTEM
 #include <addons/imgui_user.h>
 #include <epoxy/gl.h>
+#include <SDL.h>
+#include <SDL_scancode.h>
 #include <memory>
-#include <GLFW/glfw3.h>
 #include <filesystem>
 #include <thread>
-#include "imgui_impl_glfw.h"
+#include "imgui_impl_sdl.h"
 #include "imgui_impl_opengl3.h"
 
 namespace {
-  static double GlobalTime{};
+  static std::chrono::time_point<std::chrono::high_resolution_clock> GlobalTime{};
 
   static bool ConfigOpen{};
   static bool ConfigChanged{};
@@ -358,10 +358,11 @@ namespace {
     ImGui::EndTabBar();
   }
 
-  void DrawUI(GLContext::Context *Context) {
+  void DrawUI() {
     ImGuiIO& io = ImGui::GetIO();
-    double current_time = glfwGetTime();
-    io.DeltaTime = GlobalTime > 0.0 ? static_cast<float>(current_time - GlobalTime) : static_cast<float>(1.0f/60.0f);
+    auto current_time = std::chrono::high_resolution_clock::now();
+    auto Diff = std::chrono::duration_cast<std::chrono::milliseconds>(current_time - GlobalTime);
+    io.DeltaTime = Diff.count() > 0 ? Diff.count() : 1.0f/60.0f;
     GlobalTime = current_time;
 
     ImGui::NewFrame();
@@ -440,7 +441,7 @@ namespace {
         FillConfigWindow();
       }
 
-      if (ImGui::IsKeyPressed(GLFW_KEY_E) && io.KeyCtrl) {
+      if (ImGui::IsKeyPressed(SDL_SCANCODE_E) && io.KeyCtrl) {
         ImGui::OpenPopup(SavedPopupAppName);
       }
 
@@ -453,7 +454,7 @@ namespace {
           ImGui::CloseCurrentPopup();
         }
 
-        if (ImGui::IsKeyPressed(GLFW_KEY_ESCAPE)) {
+        if (ImGui::IsKeyPressed(SDL_SCANCODE_ESCAPE)) {
           ImGui::CloseCurrentPopup();
         }
         ImGui::EndPopup();
@@ -480,33 +481,33 @@ namespace {
     }
 
     if (Selected.Open ||
-        (ImGui::IsKeyPressed(GLFW_KEY_O) && io.KeyCtrl && !io.KeyShift)) {
+        (ImGui::IsKeyPressed(SDL_SCANCODE_O) && io.KeyCtrl && !io.KeyShift)) {
       SelectedOpenFile = true;
     }
     if (Selected.OpenDefault ||
-        (ImGui::IsKeyPressed(GLFW_KEY_O) && io.KeyCtrl && io.KeyShift)) {
+        (ImGui::IsKeyPressed(SDL_SCANCODE_O) && io.KeyCtrl && io.KeyShift)) {
       OpenFile(FEX::Config::GetConfigFileLocation());
     }
     if (Selected.LoadDefault ||
-        (ImGui::IsKeyPressed(GLFW_KEY_D) && io.KeyCtrl && io.KeyShift)) {
+        (ImGui::IsKeyPressed(SDL_SCANCODE_D) && io.KeyCtrl && io.KeyShift)) {
       LoadDefaultSettings();
     }
 
     if (Selected.Save ||
-        (ImGui::IsKeyPressed(GLFW_KEY_S) && io.KeyCtrl && !io.KeyShift)) {
+        (ImGui::IsKeyPressed(SDL_SCANCODE_S) && io.KeyCtrl && !io.KeyShift)) {
       SaveFile(ConfigFilename);
     }
     if (Selected.SaveAs ||
-        (ImGui::IsKeyPressed(GLFW_KEY_S) && io.KeyCtrl && io.KeyShift)) {
+        (ImGui::IsKeyPressed(SDL_SCANCODE_S) && io.KeyCtrl && io.KeyShift)) {
       SelectedSaveFileAs = true;
     }
 
     if (Selected.SaveDefault ||
-        (ImGui::IsKeyPressed(GLFW_KEY_P) && io.KeyCtrl && io.KeyShift)) {
+        (ImGui::IsKeyPressed(SDL_SCANCODE_P) && io.KeyCtrl && io.KeyShift)) {
       SaveFile(FEX::Config::GetConfigFileLocation());
     }
     if (Selected.Close ||
-        (ImGui::IsKeyPressed(GLFW_KEY_W) && io.KeyCtrl && !io.KeyShift)) {
+        (ImGui::IsKeyPressed(SDL_SCANCODE_W) && io.KeyCtrl && !io.KeyShift)) {
       CloseConfig();
     }
 
@@ -537,8 +538,27 @@ namespace {
 int main() {
   std::string ImGUIConfig = FEX::Config::GetConfigFolder(false) + "FEXConfig_imgui.ini";
 
-  auto Context = GLContext::CreateContext();
-  Context->Create("#FEXConfig");
+  // Setup SDL
+  if (SDL_Init(SDL_INIT_VIDEO | SDL_INIT_TIMER | SDL_INIT_GAMECONTROLLER) != 0)
+  {
+      printf("Error: %s\n", SDL_GetError());
+      return -1;
+  }
+
+  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("#FEXConfig", SDL_WINDOWPOS_CENTERED, SDL_WINDOWPOS_CENTERED, 640, 640, 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();
@@ -549,39 +569,54 @@ int main() {
   io.ConfigFlags |= ImGuiConfigFlags_ViewportsEnable;         // Enable Multi-Viewport / Platform Windows
   io.IniFilename = &ImGUIConfig.at(0);
 
-  GLFWwindow *Window = static_cast<GLFWwindow*>(Context->GetWindow());
-  // Setup Platform/Renderer bindings
-  ImGui_ImplGlfw_InitForOpenGL(Window, true);
+  ImGui_ImplSDL2_InitForOpenGL(window, gl_context);
   const char* glsl_version = "#version 130";
   ImGui_ImplOpenGL3_Init(glsl_version);
 
-  while (!glfwWindowShouldClose(Window)) {
-    glfwWaitEvents();
+  GlobalTime = std::chrono::high_resolution_clock::now();
+
+  bool Done{};
+  while (!Done) {
+    SDL_Event event;
+    if (SDL_WaitEvent(nullptr))
+    {
+      while (SDL_PollEvent(&event)) {
+        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;
+      }
+    }
 
     // Start the Dear ImGui frame
     ImGui_ImplOpenGL3_NewFrame();
-    ImGui_ImplGlfw_NewFrame();
-    DrawUI(Context.get());
+    ImGui_ImplSDL2_NewFrame(window);
+    DrawUI();
 
     glClear(GL_COLOR_BUFFER_BIT);
     ImGui_ImplOpenGL3_RenderDrawData(ImGui::GetDrawData());
 
     if (io.ConfigFlags & ImGuiConfigFlags_ViewportsEnable)
     {
-      GLFWwindow* backup_current_context = glfwGetCurrentContext();
+      SDL_Window* backup_current_window = SDL_GL_GetCurrentWindow();
+      SDL_GLContext backup_current_context = SDL_GL_GetCurrentContext();
       ImGui::UpdatePlatformWindows();
       ImGui::RenderPlatformWindowsDefault();
-      glfwMakeContextCurrent(backup_current_context);
+      SDL_GL_MakeCurrent(backup_current_window, backup_current_context);
     }
 
-    Context->Swap();
+    SDL_GL_SwapWindow(window);
   }
 
   // Cleanup
   ImGui_ImplOpenGL3_Shutdown();
-  ImGui_ImplGlfw_Shutdown();
+  ImGui_ImplSDL2_Shutdown();
   ImGui::DestroyContext();
-  Context->Shutdown();
+
+  SDL_GL_DeleteContext(gl_context);
+  SDL_DestroyWindow(window);
+  SDL_Quit();
 
   return 0;
 }