text: #include "pch.h"
  
  // dear imgui: Platform Binding for GLFW
  // This needs to be used along with a Renderer (e.g. OpenGL3, Vulkan..)
  // (Info: GLFW is a cross-platform general purpose library for handling windows, inputs, OpenGL/Vulkan graphics context creation, etc.)
  // (Requires: GLFW 3.1+)
  
  // Implemented features:
  //  [X] Platform: Clipboard support.
  //  [X] Platform: Gamepad support. Enable with 'io.ConfigFlags |= ImGuiConfigFlags_NavEnableGamepad'.
  //  [x] Platform: Mouse cursor shape and visibility. Disable with 'io.ConfigFlags |= ImGuiConfigFlags_NoMouseCursorChange'. FIXME: 3 cursors types are missing from GLFW.
  //  [X] Platform: Keyboard arrays indexed using GLFW_KEY_* codes, e.g. ImGui::IsKeyPressed(GLFW_KEY_SPACE).
  
  // You can copy and use unmodified imgui_impl_* files in your project. See main.cpp for an example of using this.
  // If you are new to dear imgui, read examples/README.txt and read the documentation at the top of imgui.cpp.
  // https://github.com/ocornut/imgui
  
  // CHANGELOG
  // (minor and older changes stripped away, please see git history for details)
  //  2019-07-21: Inputs: Added mapping for ImGuiKey_KeyPadEnter.
  //  2019-05-11: Inputs: Don't filter value from character callback before calling AddInputCharacter().
  //  2019-03-12: Misc: Preserve DisplayFramebufferScale when main window is minimized.
  //  2018-11-30: Misc: Setting up io.BackendPlatformName so it can be displayed in the About Window.
  //  2018-11-07: Inputs: When installing our GLFW callbacks, we save user's previously installed ones - if any - and chain call them.
  //  2018-08-01: Inputs: Workaround for Emscripten which doesn't seem to handle focus related calls.
  //  2018-06-29: Inputs: Added support for the ImGuiMouseCursor_Hand cursor.
  //  2018-06-08: Misc: Extracted imgui_impl_glfw.cpp/.h away from the old combined GLFW+OpenGL/Vulkan examples.
  //  2018-03-20: Misc: Setup io.BackendFlags ImGuiBackendFlags_HasMouseCursors flag + honor ImGuiConfigFlags_NoMouseCursorChange flag.
  //  2018-02-20: Inputs: Added support for mouse cursors (ImGui::GetMouseCursor() value, passed to glfwSetCursor()).
  //  2018-02-06: Misc: Removed call to ImGui::Shutdown() which is not available from 1.60 WIP, user needs to call CreateContext/DestroyContext themselves.
  //  2018-02-06: Inputs: Added mapping for ImGuiKey_Space.
  //  2018-01-25: Inputs: Added gamepad support if ImGuiConfigFlags_NavEnableGamepad is set.
  //  2018-01-25: Inputs: Honoring the io.WantSetMousePos by repositioning the mouse (when using navigation and ImGuiConfigFlags_NavMoveMouse is set).
  //  2018-01-20: Inputs: Added Horizontal Mouse Wheel support.
  //  2018-01-18: Inputs: Added mapping for ImGuiKey_Insert.
  //  2017-08-25: Inputs: MousePos set to -FLT_MAX,-FLT_MAX when mouse is unavailable/missing (instead of -1,-1).
  //  2016-10-15: Misc: Added a void* user_data parameter to Clipboard function handlers.
  
  #include "imgui.h"
  #include "imgui_impl_glfw.h"
  
  // GLFW
  #include <GLFW/glfw3.h>
  #ifdef _WIN32
  #undef APIENTRY
  #define GLFW_EXPOSE_NATIVE_WIN32
  #include <GLFW/glfw3native.h>   // for glfwGetWin32Window
  #endif
  #define GLFW_HAS_WINDOW_TOPMOST       (GLFW_VERSION_MAJOR * 1000 + GLFW_VERSION_MINOR * 100 >= 3200) // 3.2+ GLFW_FLOATING
  #define GLFW_HAS_WINDOW_HOVERED       (GLFW_VERSION_MAJOR * 1000 + GLFW_VERSION_MINOR * 100 >= 3300) // 3.3+ GLFW_HOVERED
  #define GLFW_HAS_WINDOW_ALPHA         (GLFW_VERSION_MAJOR * 1000 + GLFW_VERSION_MINOR * 100 >= 3300) // 3.3+ glfwSetWindowOpacity
  #define GLFW_HAS_PER_MONITOR_DPI      (GLFW_VERSION_MAJOR * 1000 + GLFW_VERSION_MINOR * 100 >= 3300) // 3.3+ glfwGetMonitorContentScale
  #define GLFW_HAS_VULKAN               (GLFW_VERSION_MAJOR * 1000 + GLFW_VERSION_MINOR * 100 >= 3200) // 3.2+ glfwCreateWindowSurface
  
  // Data
  enum GlfwClientApi
  {
      GlfwClientApi_Unknown,
      GlfwClientApi_OpenGL,
      GlfwClientApi_Vulkan
  };
  static GLFWwindow*          g_Window = NULL;    // Main window
  static GlfwClientApi        g_ClientApi = GlfwClientApi_Unknown;
  static double               g_Time = 0.0;
  static bool                 g_MouseJustPressed[5] = { false, false, false, false, false };
  static GLFWcursor*          g_MouseCursors[ImGuiMouseCursor_COUNT] = { 0 };
  
  // Chain GLFW callbacks: our callbacks will call the user's previously installed callbacks, if any.
  static GLFWmousebuttonfun   g_PrevUserCallbackMousebutton = NULL;
  static GLFWscrollfun        g_PrevUserCallbackScroll = NULL;
  static GLFWkeyfun           g_PrevUserCallbackKey = NULL;
  static GLFWcharfun          g_PrevUserCallbackChar = NULL;
  
  static const char* ImGui_ImplGlfw_GetClipboardText(void* user_data)
  {
      return glfwGetClipboardString((GLFWwindow*)user_data);
  }
  
  static void ImGui_ImplGlfw_SetClipboardText(void* user_data, const char* text)
  {
      glfwSetClipboardString((GLFWwindow*)user_data, text);
  }
  
  void ImGui_ImplGlfw_MouseButtonCallback(GLFWwindow* window, int button, int action, int mods)
  {
      if (g_PrevUserCallbackMousebutton != NULL)
          g_PrevUserCallbackMousebutton(window, button, action, mods);
  
      if (action == GLFW_PRESS && button >= 0 && button < IM_ARRAYSIZE(g_MouseJustPressed))
          g_MouseJustPressed[button] = true;
  }
  
  void ImGui_ImplGlfw_ScrollCallback(GLFWwindow* window, double xoffset, double yoffset)
  {
      if (g_PrevUserCallbackScroll != NULL)
          g_PrevUserCallbackScroll(window, xoffset, yoffset);
  
      ImGuiIO& io = ImGui::GetIO();
      io.MouseWheelH += (float)xoffset;
      io.MouseWheel += (float)yoffset;
  }
  
  void ImGui_ImplGlfw_KeyCallback(GLFWwindow* window, int key, int scancode, int action, int mods)
  {
      if (g_PrevUserCallbackKey != NULL)
          g_PrevUserCallbackKey(window, key, scancode, action, mods);
  
      ImGuiIO& io = ImGui::GetIO();
      if (action == GLFW_PRESS)
          io.KeysDown[key] = true;
      if (action == GLFW_RELEASE)
          io.KeysDown[key] = false;
  
      // Modifiers are not reliable across systems
      io.KeyCtrl = io.KeysDown[GLFW_KEY_LEFT_CONTROL] || io.KeysDown[GLFW_KEY_RIGHT_CONTROL];
      io.KeyShift = io.KeysDown[GLFW_KEY_LEFT_SHIFT] || io.KeysDown[GLFW_KEY_RIGHT_SHIFT];
      io.KeyAlt = io.KeysDown[GLFW_KEY_LEFT_ALT] || io.KeysDown[GLFW_KEY_RIGHT_ALT];
      io.KeySuper = io.KeysDown[GLFW_KEY_LEFT_SUPER] || io.KeysDown[GLFW_KEY_RIGHT_SUPER];
  }
  
  void ImGui_ImplGlfw_CharCallback(GLFWwindow* window, unsigned int c)
  {
      if (g_PrevUserCallbackChar != NULL)
          g_PrevUserCallbackChar(window, c);
  
      ImGuiIO& io = ImGui::GetIO();
      io.AddInputCharacter(c);
  }
  
  static bool ImGui_ImplGlfw_Init(GLFWwindow* window, bool install_callbacks, GlfwClientApi client_api)
  {
      g_Window = window;
      g_Time = 0.0;
  
      // Setup back-end capabilities flags
      ImGuiIO& io = ImGui::GetIO();
      io.BackendFlags |= ImGuiBackendFlags_HasMouseCursors;         // We can honor GetMouseCursor() values (optional)
      io.BackendFlags |= ImGuiBackendFlags_HasSetMousePos;          // We can honor io.WantSetMousePos requests (optional, rarely used)
      io.BackendPlatformName = "imgui_impl_glfw";
  
      // Keyboard mapping. ImGui will use those indices to peek into the io.KeysDown[] array.
      io.KeyMap[ImGuiKey_Tab] = GLFW_KEY_TAB;
      io.KeyMap[ImGuiKey_LeftArrow] = GLFW_KEY_LEFT;
      io.KeyMap[ImGuiKey_RightArrow] = GLFW_KEY_RIGHT;
      io.KeyMap[ImGuiKey_UpArrow] = GLFW_KEY_UP;
      io.KeyMap[ImGuiKey_DownArrow] = GLFW_KEY_DOWN;
      io.KeyMap[ImGuiKey_PageUp] = GLFW_KEY_PAGE_UP;
      io.KeyMap[ImGuiKey_PageDown] = GLFW_KEY_PAGE_DOWN;
      io.KeyMap[ImGuiKey_Home] = GLFW_KEY_HOME;
      io.KeyMap[ImGuiKey_End] = GLFW_KEY_END;
      io.KeyMap[ImGuiKey_Insert] = GLFW_KEY_INSERT;
      io.KeyMap[ImGuiKey_Delete] = GLFW_KEY_DELETE;
      io.KeyMap[ImGuiKey_Backspace] = GLFW_KEY_BACKSPACE;
      io.KeyMap[ImGuiKey_Space] = GLFW_KEY_SPACE;
      io.KeyMap[ImGuiKey_Enter] = GLFW_KEY_ENTER;
      io.KeyMap[ImGuiKey_Escape] = GLFW_KEY_ESCAPE;
      io.KeyMap[ImGuiKey_KeyPadEnter] = GLFW_KEY_KP_ENTER;
      io.KeyMap[ImGuiKey_A] = GLFW_KEY_A;
      io.KeyMap[ImGuiKey_C] = GLFW_KEY_C;
      io.KeyMap[ImGuiKey_V] = GLFW_KEY_V;
      io.KeyMap[ImGuiKey_X] = GLFW_KEY_X;
      io.KeyMap[ImGuiKey_Y] = GLFW_KEY_Y;
      io.KeyMap[ImGuiKey_Z] = GLFW_KEY_Z;
  
      io.SetClipboardTextFn = ImGui_ImplGlfw_SetClipboardText;
      io.GetClipboardTextFn = ImGui_ImplGlfw_GetClipboardText;
      io.ClipboardUserData = g_Window;
  #if defined(_WIN32)
      io.ImeWindowHandle = (void*)glfwGetWin32Window(g_Window);
  #endif
  
      g_MouseCursors[ImGuiMouseCursor_Arrow] = glfwCreateStandardCursor(GLFW_ARROW_CURSOR);
      g_MouseCursors[ImGuiMouseCursor_TextInput] = glfwCreateStandardCursor(GLFW_IBEAM_CURSOR);
      g_MouseCursors[ImGuiMouseCursor_ResizeAll] = glfwCreateStandardCursor(GLFW_ARROW_CURSOR);   // FIXME: GLFW doesn't have this.
      g_MouseCursors[ImGuiMouseCursor_ResizeNS] = glfwCreateStandardCursor(GLFW_VRESIZE_CURSOR);
      g_MouseCursors[ImGuiMouseCursor_ResizeEW] = glfwCreateStandardCursor(GLFW_HRESIZE_CURSOR);
      g_MouseCursors[ImGuiMouseCursor_ResizeNESW] = glfwCreateStandardCursor(GLFW_ARROW_CURSOR);  // FIXME: GLFW doesn't have this.
      g_MouseCursors[ImGuiMouseCursor_ResizeNWSE] = glfwCreateStandardCursor(GLFW_ARROW_CURSOR);  // FIXME: GLFW doesn't have this.
      g_MouseCursors[ImGuiMouseCursor_Hand] = glfwCreateStandardCursor(GLFW_HAND_CURSOR);
  
      // Chain GLFW callbacks: our callbacks will call the user's previously installed callbacks, if any.
      g_PrevUserCallbackMousebutton = NULL;
      g_PrevUserCallbackScroll = NULL;
      g_PrevUserCallbackKey = NULL;
      g_PrevUserCallbackChar = NULL;
      if (install_callbacks)
      {
          g_PrevUserCallbackMousebutton = glfwSetMouseButtonCallback(window, ImGui_ImplGlfw_MouseButtonCallback);
          g_PrevUserCallbackScroll = glfwSetScrollCallback(window, ImGui_ImplGlfw_ScrollCallback);
          g_PrevUserCallbackKey = glfwSetKeyCallback(window, ImGui_ImplGlfw_KeyCallback);
          g_PrevUserCallbackChar = glfwSetCharCallback(window, ImGui_ImplGlfw_CharCallback);
      }
  
      g_ClientApi = client_api;
      return true;
  }
  
  bool ImGui_ImplGlfw_InitForOpenGL(GLFWwindow* window, bool install_callbacks)
  {
      return ImGui_ImplGlfw_Init(window, install_callbacks, GlfwClientApi_OpenGL);
  }
  
  bool ImGui_ImplGlfw_InitForVulkan(GLFWwindow* window, bool install_callbacks)
  {
      return ImGui_ImplGlfw_Init(window, install_callbacks, GlfwClientApi_Vulkan);
  }
  
  void ImGui_ImplGlfw_Shutdown()
  {
      for (ImGuiMouseCursor cursor_n = 0; cursor_n < ImGuiMouseCursor_COUNT; cursor_n++)
      {
          glfwDestroyCursor(g_MouseCursors[cursor_n]);
          g_MouseCursors[cursor_n] = NULL;
      }
      g_ClientApi = GlfwClientApi_Unknown;
  }
  
  static void ImGui_ImplGlfw_UpdateMousePosAndButtons()
  {
      // Update buttons
      ImGuiIO& io = ImGui::GetIO();
      for (int i = 0; i < IM_ARRAYSIZE(io.MouseDown); i++)
      {
          // If a mouse press event came, always pass it as "mouse held this frame", so we don't miss click-release events that are shorter than 1 frame.
          io.MouseDown[i] = g_MouseJustPressed[i] || glfwGetMouseButton(g_Window, i) != 0;
          g_MouseJustPressed[i] = false;
      }
  
      // Update mouse position
      const ImVec2 mouse_pos_backup = io.MousePos;
      io.MousePos = ImVec2(-FLT_MAX, -FLT_MAX);
  #ifdef __EMSCRIPTEN__
      const bool focused = true; // Emscripten
  #else
      const bool focused = glfwGetWindowAttrib(g_Window, GLFW_FOCUSED) != 0;
  #endif
      if (focused)
      {
          if (io.WantSetMousePos)
          {
              glfwSetCursorPos(g_Window, (double)mouse_pos_backup.x, (double)mouse_pos_backup.y);
          }
          else
          {
              double mouse_x, mouse_y;
              glfwGetCursorPos(g_Window, &mouse_x, &mouse_y);
              io.MousePos = ImVec2((float)mouse_x, (float)mouse_y);
          }
      }
  }
  
  static void ImGui_ImplGlfw_UpdateMouseCursor()
  {
      ImGuiIO& io = ImGui::GetIO();
      if ((io.ConfigFlags & ImGuiConfigFlags_NoMouseCursorChange) || glfwGetInputMode(g_Window, GLFW_CURSOR) == GLFW_CURSOR_DISABLED)
          return;
  
      ImGuiMouseCursor imgui_cursor = ImGui::GetMouseCursor();
      if (imgui_cursor == ImGuiMouseCursor_None || io.MouseDrawCursor)
      {
          // Hide OS mouse cursor if imgui is drawing it or if it wants no cursor
          glfwSetInputMode(g_Window, GLFW_CURSOR, GLFW_CURSOR_HIDDEN);
      }
      else
      {
          // Show OS mouse cursor
          // FIXME-PLATFORM: Unfocused windows seems to fail changing the mouse cursor with GLFW 3.2, but 3.3 works here.
          glfwSetCursor(g_Window, g_MouseCursors[imgui_cursor] ? g_MouseCursors[imgui_cursor] : g_MouseCursors[ImGuiMouseCursor_Arrow]);
          glfwSetInputMode(g_Window, GLFW_CURSOR, GLFW_CURSOR_NORMAL);
      }
  }
  
  static void ImGui_ImplGlfw_UpdateGamepads()
  {
      ImGuiIO& io = ImGui::GetIO();
      memset(io.NavInputs, 0, sizeof(io.NavInputs));
      if ((io.ConfigFlags & ImGuiConfigFlags_NavEnableGamepad) == 0)
          return;
  
      // Update gamepad inputs
      #define MAP_BUTTON(NAV_NO, BUTTON_NO)       { if (buttons_count > BUTTON_NO && buttons[BUTTON_NO] == GLFW_PRESS) io.NavInputs[NAV_NO] = 1.0f; }
      #define MAP_ANALOG(NAV_NO, AXIS_NO, V0, V1) { float v = (axes_count > AXIS_NO) ? axes[AXIS_NO] : V0; v = (v - V0) / (V1 - V0); if (v > 1.0f) v = 1.0f; if (io.NavInputs[NAV_NO] < v) io.NavInputs[NAV_NO] = v; }
      int axes_count = 0, buttons_count = 0;
      const float* axes = glfwGetJoystickAxes(GLFW_JOYSTICK_1, &axes_count);
      const unsigned char* buttons = glfwGetJoystickButtons(GLFW_JOYSTICK_1, &buttons_count);
      MAP_BUTTON(ImGuiNavInput_Activate,   0);     // Cross / A
      MAP_BUTTON(ImGuiNavInput_Cancel,     1);     // Circle / B
      MAP_BUTTON(ImGuiNavInput_Menu,       2);     // Square / X
      MAP_BUTTON(ImGuiNavInput_Input,      3);     // Triangle / Y
      MAP_BUTTON(ImGuiNavInput_DpadLeft,   13);    // D-Pad Left
      MAP_BUTTON(ImGuiNavInput_DpadRight,  11);    // D-Pad Right
      MAP_BUTTON(ImGuiNavInput_DpadUp,     10);    // D-Pad Up
      MAP_BUTTON(ImGuiNavInput_DpadDown,   12);    // D-Pad Down
      MAP_BUTTON(ImGuiNavInput_FocusPrev,  4);     // L1 / LB
      MAP_BUTTON(ImGuiNavInput_FocusNext,  5);     // R1 / RB
      MAP_BUTTON(ImGuiNavInput_TweakSlow,  4);     // L1 / LB
      MAP_BUTTON(ImGuiNavInput_TweakFast,  5);     // R1 / RB
      MAP_ANALOG(ImGuiNavInput_LStickLeft, 0,  -0.3f,  -0.9f);
      MAP_ANALOG(ImGuiNavInput_LStickRight,0,  +0.3f,  +0.9f);
      MAP_ANALOG(ImGuiNavInput_LStickUp,   1,  +0.3f,  +0.9f);
      MAP_ANALOG(ImGuiNavInput_LStickDown, 1,  -0.3f,  -0.9f);
      #undef MAP_BUTTON
      #undef MAP_ANALOG
      if (axes_count > 0 && buttons_count > 0)
          io.BackendFlags |= ImGuiBackendFlags_HasGamepad;
      else
          io.BackendFlags &= ~ImGuiBackendFlags_HasGamepad;
  }
  
  void ImGui_ImplGlfw_NewFrame()
  {
      ImGuiIO& io = ImGui::GetIO();
      IM_ASSERT(io.Fonts->IsBuilt() && "Font atlas not built! It is generally built by the renderer back-end. Missing call to renderer _NewFrame() function? e.g. ImGui_ImplOpenGL3_NewFrame().");
  
      // Setup display size (every frame to accommodate for window resizing)
      int w, h;
      int display_w, display_h;
      glfwGetWindowSize(g_Window, &w, &h);
      glfwGetFramebufferSize(g_Window, &display_w, &display_h);
      io.DisplaySize = ImVec2((float)w, (float)h);
      if (w > 0 && h > 0)
          io.DisplayFramebufferScale = ImVec2((float)display_w / w, (float)display_h / h);
  
      // Setup time step
      double current_time = glfwGetTime();
      io.DeltaTime = g_Time > 0.0 ? (float)(current_time - g_Time) : (float)(1.0f/60.0f);
      g_Time = current_time;
  
      ImGui_ImplGlfw_UpdateMousePosAndButtons();
      ImGui_ImplGlfw_UpdateMouseCursor();
  
      // Update game controllers (if enabled and available)
      ImGui_ImplGlfw_UpdateGamepads();
  }
  