examples/imgui_impl_glfw.cpp - third_party/imgui - Git at Google

 // 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' (note: the resizing cursors requires GLFW 3.4+).
 //  [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)
 //  2019-12-05: Inputs: Added support for new mouse cursors added in GLFW 3.4+ (resizing cursors, not allowed cursor).
 //  2019-10-18: Misc: Previously installed user callbacks are now restored on shutdown.
 //  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
 #ifdef GLFW_RESIZE_NESW_CURSOR  // let's be nice to people who pulled GLFW between 2019-04-16 (3.4 define) and 2019-11-29 (cursors defines) // FIXME: Remove when GLFW 3.4 is released?
 #define GLFW_HAS_NEW_CURSORS          (GLFW_VERSION_MAJOR * 1000 + GLFW_VERSION_MINOR * 100 >= 3400) // 3.4+ GLFW_RESIZE_ALL_CURSOR, GLFW_RESIZE_NESW_CURSOR, GLFW_RESIZE_NWSE_CURSOR, GLFW_NOT_ALLOWED_CURSOR
 #else
 #define GLFW_HAS_NEW_CURSORS          (0)
 #endif

 // 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] = {};
 static bool                 g_InstalledCallbacks = false;

 // 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_ResizeNS] = glfwCreateStandardCursor(GLFW_VRESIZE_CURSOR);
     g_MouseCursors[ImGuiMouseCursor_ResizeEW] = glfwCreateStandardCursor(GLFW_HRESIZE_CURSOR);
     g_MouseCursors[ImGuiMouseCursor_Hand] = glfwCreateStandardCursor(GLFW_HAND_CURSOR);
 #if GLFW_HAS_NEW_CURSORS
     g_MouseCursors[ImGuiMouseCursor_ResizeAll] = glfwCreateStandardCursor(GLFW_RESIZE_ALL_CURSOR);
     g_MouseCursors[ImGuiMouseCursor_ResizeNESW] = glfwCreateStandardCursor(GLFW_RESIZE_NESW_CURSOR);
     g_MouseCursors[ImGuiMouseCursor_ResizeNWSE] = glfwCreateStandardCursor(GLFW_RESIZE_NWSE_CURSOR);
     g_MouseCursors[ImGuiMouseCursor_NotAllowed] = glfwCreateStandardCursor(GLFW_NOT_ALLOWED_CURSOR);
 #else
     g_MouseCursors[ImGuiMouseCursor_ResizeAll] = glfwCreateStandardCursor(GLFW_ARROW_CURSOR);
     g_MouseCursors[ImGuiMouseCursor_ResizeNESW] = glfwCreateStandardCursor(GLFW_ARROW_CURSOR);
     g_MouseCursors[ImGuiMouseCursor_ResizeNWSE] = glfwCreateStandardCursor(GLFW_ARROW_CURSOR);
     g_MouseCursors[ImGuiMouseCursor_NotAllowed] = glfwCreateStandardCursor(GLFW_ARROW_CURSOR);
 #endif

     // 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_InstalledCallbacks = true;
         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()
 {
     if (g_InstalledCallbacks)
     {
         glfwSetMouseButtonCallback(g_Window, g_PrevUserCallbackMousebutton);
         glfwSetScrollCallback(g_Window, g_PrevUserCallbackScroll);
         glfwSetKeyCallback(g_Window, g_PrevUserCallbackKey);
         glfwSetCharCallback(g_Window, g_PrevUserCallbackChar);
         g_InstalledCallbacks = false;
     }

     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();
 }
	// 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' (note: the resizing cursors requires GLFW 3.4+).
	// [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)
	// 2019-12-05: Inputs: Added support for new mouse cursors added in GLFW 3.4+ (resizing cursors, not allowed cursor).
	// 2019-10-18: Misc: Previously installed user callbacks are now restored on shutdown.
	// 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
	#ifdef GLFW_RESIZE_NESW_CURSOR // let's be nice to people who pulled GLFW between 2019-04-16 (3.4 define) and 2019-11-29 (cursors defines) // FIXME: Remove when GLFW 3.4 is released?
	#define GLFW_HAS_NEW_CURSORS (GLFW_VERSION_MAJOR * 1000 + GLFW_VERSION_MINOR * 100 >= 3400) // 3.4+ GLFW_RESIZE_ALL_CURSOR, GLFW_RESIZE_NESW_CURSOR, GLFW_RESIZE_NWSE_CURSOR, GLFW_NOT_ALLOWED_CURSOR
	#else
	#define GLFW_HAS_NEW_CURSORS (0)
	#endif

	// 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] = {};
	static bool g_InstalledCallbacks = false;

	// 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_ResizeNS] = glfwCreateStandardCursor(GLFW_VRESIZE_CURSOR);
	g_MouseCursors[ImGuiMouseCursor_ResizeEW] = glfwCreateStandardCursor(GLFW_HRESIZE_CURSOR);
	g_MouseCursors[ImGuiMouseCursor_Hand] = glfwCreateStandardCursor(GLFW_HAND_CURSOR);
	#if GLFW_HAS_NEW_CURSORS
	g_MouseCursors[ImGuiMouseCursor_ResizeAll] = glfwCreateStandardCursor(GLFW_RESIZE_ALL_CURSOR);
	g_MouseCursors[ImGuiMouseCursor_ResizeNESW] = glfwCreateStandardCursor(GLFW_RESIZE_NESW_CURSOR);
	g_MouseCursors[ImGuiMouseCursor_ResizeNWSE] = glfwCreateStandardCursor(GLFW_RESIZE_NWSE_CURSOR);
	g_MouseCursors[ImGuiMouseCursor_NotAllowed] = glfwCreateStandardCursor(GLFW_NOT_ALLOWED_CURSOR);
	#else
	g_MouseCursors[ImGuiMouseCursor_ResizeAll] = glfwCreateStandardCursor(GLFW_ARROW_CURSOR);
	g_MouseCursors[ImGuiMouseCursor_ResizeNESW] = glfwCreateStandardCursor(GLFW_ARROW_CURSOR);
	g_MouseCursors[ImGuiMouseCursor_ResizeNWSE] = glfwCreateStandardCursor(GLFW_ARROW_CURSOR);
	g_MouseCursors[ImGuiMouseCursor_NotAllowed] = glfwCreateStandardCursor(GLFW_ARROW_CURSOR);
	#endif

	// 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_InstalledCallbacks = true;
	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()
	{
	if (g_InstalledCallbacks)
	{
	glfwSetMouseButtonCallback(g_Window, g_PrevUserCallbackMousebutton);
	glfwSetScrollCallback(g_Window, g_PrevUserCallbackScroll);
	glfwSetKeyCallback(g_Window, g_PrevUserCallbackKey);
	glfwSetCharCallback(g_Window, g_PrevUserCallbackChar);
	g_InstalledCallbacks = false;
	}

	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();
	}