Updated ImGui.

3rdparty/dear-imgui/imgui.cpp

@@ -29,12 +29,12 @@ DOCUMENTATION
 - MISSION STATEMENT
 - END-USER GUIDE
 - PROGRAMMER GUIDE
-  - Read first.
-  - How to update to a newer version of Dear ImGui.
-  - Getting started with integrating Dear ImGui in your code/engine.
-  - This is how a simple application may look like (2 variations).
-  - This is how a simple rendering function may look like.
-  - Using gamepad/keyboard navigation controls.
+  - READ FIRST
+  - HOW TO UPDATE TO A NEWER VERSION OF DEAR IMGUI
+  - GETTING STARTED WITH INTEGRATING DEAR IMGUI IN YOUR CODE/ENGINE
+  - HOW A SIMPLE APPLICATION MAY LOOK LIKE (2 variations)
+  - HOW A SIMPLE RENDERING FUNCTION MAY LOOK LIKE
+  - USING GAMEPAD/KEYBOARD NAVIGATION CONTROLS
 - API BREAKING CHANGES (read me when you update!)
 - FREQUENTLY ASKED QUESTIONS (FAQ)
   - Read all answers online: https://www.dearimgui.org/faq, or in docs/FAQ.md (with a Markdown viewer)
@@ -46,6 +46,7 @@ CODE
 // [SECTION] CONTEXT AND MEMORY ALLOCATORS
 // [SECTION] MAIN USER FACING STRUCTURES (ImGuiStyle, ImGuiIO)
 // [SECTION] MISC HELPERS/UTILITIES (Maths, String, Format, Hash, File functions)
+// [SECTION] MISC HELPERS/UTILITIES (File functions)
 // [SECTION] MISC HELPERS/UTILITIES (ImText* functions)
 // [SECTION] MISC HELPERS/UTILITIES (Color functions)
 // [SECTION] ImGuiStorage
@@ -118,8 +119,8 @@ CODE
  PROGRAMMER GUIDE
  ================
 
- READ FIRST:
-
+ READ FIRST
+ ----------
  - Remember to read the FAQ (https://www.dearimgui.org/faq)
  - Your code creates the UI, if your code doesn't run the UI is gone! The UI can be highly dynamic, there are no construction
    or destruction steps, less superfluous data retention on your side, less state duplication, less state synchronization, less bugs.
@@ -140,8 +141,8 @@ CODE
    However, imgui_internal.h can optionally export math operators for ImVec2/ImVec4, which we use in this codebase.
  - C++: pay attention that ImVector<> manipulates plain-old-data and does not honor construction/destruction (avoid using it in your code!).
 
- HOW TO UPDATE TO A NEWER VERSION OF DEAR IMGUI:
-
+ HOW TO UPDATE TO A NEWER VERSION OF DEAR IMGUI
+ ----------------------------------------------
  - Overwrite all the sources files except for imconfig.h (if you have made modification to your copy of imconfig.h)
  - Or maintain your own branch where you have imconfig.h modified.
  - Read the "API BREAKING CHANGES" section (below). This is where we list occasional API breaking changes.
@@ -150,8 +151,8 @@ CODE
    likely be a comment about it. Please report any issue to the GitHub page!
  - Try to keep your copy of dear imgui reasonably up to date.
 
- GETTING STARTED WITH INTEGRATING DEAR IMGUI IN YOUR CODE/ENGINE:
-
+ GETTING STARTED WITH INTEGRATING DEAR IMGUI IN YOUR CODE/ENGINE
+ ---------------------------------------------------------------
  - Run and study the examples and demo in imgui_demo.cpp to get acquainted with the library.
  - Add the Dear ImGui source files to your projects or using your preferred build system.
    It is recommended you build and statically link the .cpp files as part of your project and not as shared library (DLL).
@@ -163,7 +164,8 @@ CODE
  - Refer to the bindings and demo applications in the examples/ folder for instruction on how to setup your code.
  - If you are running over a standard OS with a common graphics API, you should be able to use unmodified imgui_impl_*** files from the examples/ folder.
 
- HOW A SIMPLE APPLICATION MAY LOOK LIKE:
+ HOW A SIMPLE APPLICATION MAY LOOK LIKE
+ --------------------------------------
  EXHIBIT 1: USING THE EXAMPLE BINDINGS (imgui_impl_XXX.cpp files from the examples/ folder).
 
      // Application init: create a dear imgui context, setup some options, load fonts
@@ -199,8 +201,7 @@ CODE
      ImGui_ImplWin32_Shutdown();
      ImGui::DestroyContext();
 
- HOW A SIMPLE APPLICATION MAY LOOK LIKE:
- EXHIBIT 2: IMPLEMENTING CUSTOM BINDING / CUSTOM ENGINE.
+ EXHIBIT 2: IMPLEMENTING CUSTOM BINDING / CUSTOM ENGINE
 
      // Application init: create a dear imgui context, setup some options, load fonts
      ImGui::CreateContext();
@@ -254,8 +255,8 @@ CODE
      // Shutdown
      ImGui::DestroyContext();
 
- HOW A SIMPLE RENDERING FUNCTION MAY LOOK LIKE:
-
+ HOW A SIMPLE RENDERING FUNCTION MAY LOOK LIKE
+ ---------------------------------------------
     void void MyImGuiRenderFunction(ImDrawData* draw_data)
     {
        // TODO: Setup render state: alpha-blending enabled, no face culling, no depth testing, scissor enabled
@@ -307,7 +308,7 @@ CODE
  - Refer to the FAQ for more information. Amusingly, it is called a FAQ because people frequently run into the same issues!
 
  USING GAMEPAD/KEYBOARD NAVIGATION CONTROLS
-
+ ------------------------------------------
  - The gamepad/keyboard navigation is fairly functional and keeps being improved.
  - Gamepad support is particularly useful to use dear imgui on a console system (e.g. PS4, Switch, XB1) without a mouse!
  - You can ask questions and report issues at https://github.com/ocornut/imgui/issues/787
@@ -352,6 +353,8 @@ CODE
  When you are not sure about a old symbol or function name, try using the Search/Find function of your IDE to look for comments or references in all imgui files.
  You can read releases logs https://github.com/ocornut/imgui/releases for more details.
 
+ - 2019/11/19 (1.74) - renamed IMGUI_DISABLE_FORMAT_STRING_FUNCTIONS to IMGUI_DISABLE_DEFAULT_FORMAT_FUNCTIONS for consistency.
+ - 2019/11/19 (1.74) - renamed IMGUI_DISABLE_MATH_FUNCTIONS to IMGUI_DISABLE_DEFAULT_MATH_FUNCTIONS for consistency.
  - 2019/10/22 (1.74) - removed redirecting functions/enums that were marked obsolete in 1.52 (October 2017): Begin() (5 arguments signature), IsRootWindowOrAnyChildHovered(), AlignFirstTextHeightToWidgets(), SetNextWindowPosCenter(), ImFont::Glyph. See docs/Changelog.txt or grep this log for details and new names, or see how they were implemented until 1.73.
  - 2019/10/14 (1.74) - inputs: Fixed a miscalculation in the keyboard/mouse "typematic" repeat delay/rate calculation, used by keys and e.g. repeating mouse buttons as well as the GetKeyPressedAmount() function.
                        if you were using a non-default value for io.KeyRepeatRate (previous default was 0.250), you can add +io.KeyRepeatDelay to it to compensate for the fix.
@@ -470,14 +473,9 @@ CODE
  - 2016/09/25 (1.50) - style.WindowTitleAlign is now a ImVec2 (ImGuiAlign enum was removed). set to (0.5f,0.5f) for horizontal+vertical centering, (0.0f,0.0f) for upper-left, etc.
  - 2016/07/30 (1.50) - SameLine(x) with x>0.0f is now relative to left of column/group if any, and not always to left of window. This was sort of always the intent and hopefully breakage should be minimal.
  - 2016/05/12 (1.49) - title bar (using ImGuiCol_TitleBg/ImGuiCol_TitleBgActive colors) isn't rendered over a window background (ImGuiCol_WindowBg color) anymore.
-                       If your TitleBg/TitleBgActive alpha was 1.0f or you are using the default theme it will not affect you.
-                       If your TitleBg/TitleBgActive alpha was <1.0f you need to tweak your custom theme to readjust for the fact that we don't draw a WindowBg background behind the title bar.
-                       This helper function will convert an old TitleBg/TitleBgActive color into a new one with the same visual output, given the OLD color and the OLD WindowBg color.
-                           ImVec4 ConvertTitleBgCol(const ImVec4& win_bg_col, const ImVec4& title_bg_col)
-                           {
-                               float new_a = 1.0f - ((1.0f - win_bg_col.w) * (1.0f - title_bg_col.w)), k = title_bg_col.w / new_a;
-                               return ImVec4((win_bg_col.x * win_bg_col.w + title_bg_col.x) * k, (win_bg_col.y * win_bg_col.w + title_bg_col.y) * k, (win_bg_col.z * win_bg_col.w + title_bg_col.z) * k, new_a);
-                           }
+                       If your TitleBg/TitleBgActive alpha was 1.0f or you are using the default theme it will not affect you, otherwise if <1.0f you need tweak your custom theme to readjust for the fact that we don't draw a WindowBg background behind the title bar.
+                       This helper function will convert an old TitleBg/TitleBgActive color into a new one with the same visual output, given the OLD color and the OLD WindowBg color: 
+                       ImVec4 ConvertTitleBgCol(const ImVec4& win_bg_col, const ImVec4& title_bg_col) { float new_a = 1.0f - ((1.0f - win_bg_col.w) * (1.0f - title_bg_col.w)), k = title_bg_col.w / new_a; return ImVec4((win_bg_col.x * win_bg_col.w + title_bg_col.x) * k, (win_bg_col.y * win_bg_col.w + title_bg_col.y) * k, (win_bg_col.z * win_bg_col.w + title_bg_col.z) * k, new_a); }
                        If this is confusing, pick the RGB value from title bar from an old screenshot and apply this as TitleBg/TitleBgActive. Or you may just create TitleBgActive from a tweaked TitleBg color.
  - 2016/05/07 (1.49) - removed confusing set of GetInternalState(), GetInternalStateSize(), SetInternalState() functions. Now using CreateContext(), DestroyContext(), GetCurrentContext(), SetCurrentContext().
  - 2016/05/02 (1.49) - renamed SetNextTreeNodeOpened() to SetNextTreeNodeOpen(), no redirection.
@@ -1258,12 +1256,16 @@ const char* ImStrSkipBlank(const char* str)
 // A) MSVC version appears to return -1 on overflow, whereas glibc appears to return total count (which may be >= buf_size).
 // Ideally we would test for only one of those limits at runtime depending on the behavior the vsnprintf(), but trying to deduct it at compile time sounds like a pandora can of worm.
 // B) When buf==NULL vsnprintf() will return the output size.
-#ifndef IMGUI_DISABLE_FORMAT_STRING_FUNCTIONS
+#ifndef IMGUI_DISABLE_DEFAULT_FORMAT_FUNCTIONS
 
+// We support stb_sprintf which is much faster (see: https://github.com/nothings/stb/blob/master/stb_sprintf.h)
+// You may set IMGUI_USE_STB_SPRINTF to use our default wrapper, or set IMGUI_DISABLE_DEFAULT_FORMAT_FUNCTIONS 
+// and setup the wrapper yourself. (FIXME-OPT: Some of our high-level operations such as ImGuiTextBuffer::appendfv() are 
+// designed using two-passes worst case, which probably could be improved using the stbsp_vsprintfcb() function.)
 //#define IMGUI_USE_STB_SPRINTF
 #ifdef IMGUI_USE_STB_SPRINTF
 #define STB_SPRINTF_IMPLEMENTATION
-#include "imstb_sprintf.h"
+#include "stb_sprintf.h"
 #endif
 
 #if defined(_MSC_VER) && !defined(vsnprintf)
@@ -1302,7 +1304,7 @@ int ImFormatStringV(char* buf, size_t buf_size, const char* fmt, va_list args)
     buf[w] = 0;
     return w;
 }
-#endif // #ifdef IMGUI_DISABLE_FORMAT_STRING_FUNCTIONS
+#endif // #ifdef IMGUI_DISABLE_DEFAULT_FORMAT_FUNCTIONS
 
 // CRC32 needs a 1KB lookup table (not cache friendly)
 // Although the code to generate the table is simple and shorter than the table itself, using a const table allows us to easily:
@@ -1374,10 +1376,16 @@ ImU32 ImHashStr(const char* data_p, size_t data_size, ImU32 seed)
     return ~crc;
 }
 
-FILE* ImFileOpen(const char* filename, const char* mode)
+//-----------------------------------------------------------------------------
+// [SECTION] MISC HELPERS/UTILITIES (File functions)
+//-----------------------------------------------------------------------------
+
+// Default file functions
+#ifndef IMGUI_DISABLE_DEFAULT_FILE_FUNCTIONS
+ImFileHandle ImFileOpen(const char* filename, const char* mode)
 {
 #if defined(_WIN32) && !defined(IMGUI_DISABLE_WIN32_FUNCTIONS) && !defined(__CYGWIN__) && !defined(__GNUC__)
-    // We need a fopen() wrapper because MSVC/Windows fopen doesn't handle UTF-8 filenames. Converting both strings from UTF-8 to wchar format (using a single allocation, because we can)
+    // We need a fopen() wrapper because MSVC/Windows fopen doesn't handle UTF-8 filenames. 
     const int filename_wsize = ImTextCountCharsFromUtf8(filename, NULL) + 1;
     const int mode_wsize = ImTextCountCharsFromUtf8(mode, NULL) + 1;
     ImVector<ImWchar> buf;
@@ -1389,43 +1397,47 @@ FILE* ImFileOpen(const char* filename, const char* mode)
     return fopen(filename, mode);
 #endif
 }
+int     ImFileClose(ImFileHandle f)     { return fclose(f); }
+size_t  ImFileGetSize(ImFileHandle f)   { long off = 0, sz = 0; return ((off = ftell(f)) != -1 && !fseek(f, 0, SEEK_END) && (sz = ftell(f)) != -1 && !fseek(f, off, SEEK_SET)) ? (size_t)sz : (size_t)-1; }
+size_t  ImFileRead(void* data, size_t sz, size_t count, ImFileHandle f)         { return fread(data, sz, count, f); }
+size_t  ImFileWrite(const void* data, size_t sz, size_t count, ImFileHandle f)  { return fwrite(data, sz, count, f); }
+#endif // #ifndef IMGUI_DISABLE_DEFAULT_FILE_FUNCTIONS
 
-// Load file content into memory
+// Helper: Load file content into memory
 // Memory allocated with IM_ALLOC(), must be freed by user using IM_FREE() == ImGui::MemFree()
-void* ImFileLoadToMemory(const char* filename, const char* file_open_mode, size_t* out_file_size, int padding_bytes)
+void*   ImFileLoadToMemory(const char* filename, const char* mode, size_t* out_file_size, int padding_bytes)
 {
-    IM_ASSERT(filename && file_open_mode);
+    IM_ASSERT(filename && mode);
     if (out_file_size)
         *out_file_size = 0;
 
-    FILE* f;
-    if ((f = ImFileOpen(filename, file_open_mode)) == NULL)
+    ImFileHandle f;
+    if ((f = ImFileOpen(filename, mode)) == NULL)
         return NULL;
 
-    long file_size_signed;
-    if (fseek(f, 0, SEEK_END) || (file_size_signed = ftell(f)) == -1 || fseek(f, 0, SEEK_SET))
+    size_t file_size = ImFileGetSize(f);
+    if (file_size == (size_t)-1)
     {
-        fclose(f);
+        ImFileClose(f);
         return NULL;
     }
 
-    size_t file_size = (size_t)file_size_signed;
     void* file_data = IM_ALLOC(file_size + padding_bytes);
     if (file_data == NULL)
     {
-        fclose(f);
+        ImFileClose(f);
         return NULL;
     }
-    if (fread(file_data, 1, file_size, f) != file_size)
+    if (ImFileRead(file_data, 1, file_size, f) != file_size)
     {
-        fclose(f);
+        ImFileClose(f);
         IM_FREE(file_data);
         return NULL;
     }
     if (padding_bytes > 0)
         memset((void*)(((char*)file_data) + file_size), 0, (size_t)padding_bytes);
 
-    fclose(f);
+    ImFileClose(f);
     if (out_file_size)
         *out_file_size = file_size;
 
@@ -3827,9 +3839,12 @@ void ImGui::Shutdown(ImGuiContext* context)
     g.SettingsWindows.clear();
     g.SettingsHandlers.clear();
 
-    if (g.LogFile && g.LogFile != stdout)
+    if (g.LogFile)
     {
-        fclose(g.LogFile);
+#ifndef IMGUI_DISABLE_TTY_FUNCTIONS
+        if (g.LogFile != stdout)
+#endif
+            ImFileClose(g.LogFile);
         g.LogFile = NULL;
     }
     g.LogBuffer.clear();
@@ -5536,7 +5551,7 @@ bool ImGui::Begin(const char* name, bool* p_open, ImGuiWindowFlags flags)
         // Handle manual resize: Resize Grips, Borders, Gamepad
         int border_held = -1;
         ImU32 resize_grip_col[4] = {};
-        const int resize_grip_count = g.IO.ConfigWindowsResizeFromEdges ? 2 : 1; // 4
+        const int resize_grip_count = g.IO.ConfigWindowsResizeFromEdges ? 2 : 1; // Allow resize from lower-left if we have the mouse cursor feedback for it.
         const float resize_grip_draw_size = IM_FLOOR(ImMax(g.FontSize * 1.35f, window->WindowRounding + 1.0f + g.FontSize * 0.2f));
         if (!window->Collapsed)
             if (UpdateManualResize(window, size_auto_fit, &border_held, resize_grip_count, &resize_grip_col[0]))
@@ -9060,9 +9075,15 @@ void ImGui::LogText(const char* fmt, ...)
     va_list args;
     va_start(args, fmt);
     if (g.LogFile)
-        vfprintf(g.LogFile, fmt, args);
+    {
+        g.LogBuffer.Buf.resize(0);
+        g.LogBuffer.appendfv(fmt, args);
+        ImFileWrite(g.LogBuffer.c_str(), sizeof(char), (size_t)g.LogBuffer.size(), g.LogFile);
+    }
     else
+    {
         g.LogBuffer.appendfv(fmt, args);
+    }
     va_end(args);
 }
 
@@ -9139,8 +9160,11 @@ void ImGui::LogToTTY(int auto_open_depth)
     ImGuiContext& g = *GImGui;
     if (g.LogEnabled)
         return;
+    IM_UNUSED(auto_open_depth);
+#ifndef IMGUI_DISABLE_TTY_FUNCTIONS
     LogBegin(ImGuiLogType_TTY, auto_open_depth);
     g.LogFile = stdout;
+#endif
 }
 
 // Start logging/capturing text output to given file
@@ -9157,8 +9181,8 @@ void ImGui::LogToFile(int auto_open_depth, const char* filename)
         filename = g.IO.LogFilename;
     if (!filename || !filename[0])
         return;
-    FILE* f = ImFileOpen(filename, "ab");
-    if (f == NULL)
+    ImFileHandle f = ImFileOpen(filename, "ab");
+    if (!f)
     {
         IM_ASSERT(0);
         return;
@@ -9195,10 +9219,12 @@ void ImGui::LogFinish()
     switch (g.LogType)
     {
     case ImGuiLogType_TTY:
+#ifndef IMGUI_DISABLE_TTY_FUNCTIONS
         fflush(g.LogFile);
+#endif
         break;
     case ImGuiLogType_File:
-        fclose(g.LogFile);
+        ImFileClose(g.LogFile);
         break;
     case ImGuiLogType_Buffer:
         break;
@@ -9224,7 +9250,11 @@ void ImGui::LogButtons()
     ImGuiContext& g = *GImGui;
 
     PushID("LogButtons");
+#ifndef IMGUI_DISABLE_TTY_FUNCTIONS
     const bool log_to_tty = Button("Log To TTY"); SameLine();
+#else
+    const bool log_to_tty = false;
+#endif
     const bool log_to_file = Button("Log To File"); SameLine();
     const bool log_to_clipboard = Button("Log To Clipboard"); SameLine();
     PushAllowKeyboardFocus(false);
@@ -9356,18 +9386,12 @@ void ImGui::LoadIniSettingsFromMemory(const char* ini_data, size_t ini_size)
             line_end[-1] = 0;
             const char* name_end = line_end - 1;
             const char* type_start = line + 1;
-            char* type_end = (char*)(intptr_t)ImStrchrRange(type_start, name_end, ']');
+            char* type_end = (char*)(void*)ImStrchrRange(type_start, name_end, ']');
             const char* name_start = type_end ? ImStrchrRange(type_end + 1, name_end, '[') : NULL;
             if (!type_end || !name_start)
-            {
-                name_start = type_start; // Import legacy entries that have no type
-                type_start = "Window";
-            }
-            else
-            {
-                *type_end = 0; // Overwrite first ']'
-                name_start++;  // Skip second '['
-            }
+                continue;
+            *type_end = 0; // Overwrite first ']'
+            name_start++;  // Skip second '['
             entry_handler = FindSettingsHandler(type_start);
             entry_data = entry_handler ? entry_handler->ReadOpenFn(&g, entry_handler, name_start) : NULL;
         }
@@ -9390,11 +9414,11 @@ void ImGui::SaveIniSettingsToDisk(const char* ini_filename)
 
     size_t ini_data_size = 0;
     const char* ini_data = SaveIniSettingsToMemory(&ini_data_size);
-    FILE* f = ImFileOpen(ini_filename, "wt");
+    ImFileHandle f = ImFileOpen(ini_filename, "wt");
     if (!f)
         return;
-    fwrite(ini_data, sizeof(char), ini_data_size, f);
-    fclose(f);
+    ImFileWrite(ini_data, sizeof(char), ini_data_size, f);
+    ImFileClose(f);
 }
 
 // Call registered handlers (e.g. SettingsHandlerWindow_WriteAll() + custom handlers) to write their stuff into a text buffer

3rdparty/dear-imgui/imgui_demo.cpp

@@ -3106,11 +3106,17 @@ void ImGui::ShowAboutWindow(bool* p_open)
 #ifdef IMGUI_DISABLE_WIN32_FUNCTIONS
         ImGui::Text("define: IMGUI_DISABLE_WIN32_FUNCTIONS");
 #endif
-#ifdef IMGUI_DISABLE_FORMAT_STRING_FUNCTIONS
-        ImGui::Text("define: IMGUI_DISABLE_FORMAT_STRING_FUNCTIONS");
+#ifdef IMGUI_DISABLE_DEFAULT_FORMAT_FUNCTIONS
+        ImGui::Text("define: IMGUI_DISABLE_DEFAULT_FORMAT_FUNCTIONS");
 #endif
-#ifdef IMGUI_DISABLE_MATH_FUNCTIONS
-        ImGui::Text("define: IMGUI_DISABLE_MATH_FUNCTIONS");
+#ifdef IMGUI_DISABLE_DEFAULT_MATH_FUNCTIONS
+        ImGui::Text("define: IMGUI_DISABLE_DEFAULT_MATH_FUNCTIONS");
+#endif
+#ifdef IMGUI_DISABLE_DEFAULT_FILE_FUNCTIONS
+        ImGui::Text("define: IMGUI_DISABLE_DEFAULT_FILE_FUNCTIONS");
+#endif
+#ifdef IMGUI_DISABLE_FILE_FUNCTIONS
+        ImGui::Text("define: IMGUI_DISABLE_FILE_FUNCTIONS");
 #endif
 #ifdef IMGUI_DISABLE_DEFAULT_ALLOCATORS
         ImGui::Text("define: IMGUI_DISABLE_DEFAULT_ALLOCATORS");

3rdparty/dear-imgui/imgui_internal.h

@@ -31,7 +31,7 @@ Index of this file:
 #error Must include imgui.h before imgui_internal.h
 #endif
 
-#include <stdio.h>      // FILE*
+#include <stdio.h>      // FILE*, sscanf
 #include <stdlib.h>     // NULL, malloc, free, qsort, atoi, atof
 #include <math.h>       // sqrtf, fabsf, fmodf, powf, floorf, ceilf, cosf, sinf
 #include <limits.h>     // INT_MIN, INT_MAX
@@ -60,6 +60,14 @@ Index of this file:
 #pragma GCC diagnostic ignored "-Wclass-memaccess"          // [__GNUC__ >= 8] warning: 'memset/memcpy' clearing/writing an object of type 'xxxx' with no trivial copy-assignment; use assignment or value-initialization instead
 #endif
 
+// Legacy defines
+#ifdef IMGUI_DISABLE_FORMAT_STRING_FUNCTIONS                // Renamed in 1.74
+#error Use IMGUI_DISABLE_DEFAULT_FORMAT_FUNCTIONS
+#endif
+#ifdef IMGUI_DISABLE_MATH_FUNCTIONS                         // Renamed in 1.74
+#error Use IMGUI_DISABLE_DEFAULT_MATH_FUNCTIONS
+#endif
+
 //-----------------------------------------------------------------------------
 // Forward declarations
 //-----------------------------------------------------------------------------
@@ -183,8 +191,6 @@ extern IMGUI_API ImGuiContext* GImGui;  // Current implicit context pointer
 #endif
 
 // Helpers: Misc
-IMGUI_API void*         ImFileLoadToMemory(const char* filename, const char* file_open_mode, size_t* out_file_size = NULL, int padding_bytes = 0);
-IMGUI_API FILE*         ImFileOpen(const char* filename, const char* file_open_mode);
 #define ImQsort         qsort
 IMGUI_API ImU32         ImHashData(const void* data, size_t data_size, ImU32 seed = 0);
 IMGUI_API ImU32         ImHashStr(const char* data, size_t data_size = 0, ImU32 seed = 0);
@@ -252,9 +258,35 @@ static inline ImVec4 operator-(const ImVec4& lhs, const ImVec4& rhs)
 static inline ImVec4 operator*(const ImVec4& lhs, const ImVec4& rhs)            { return ImVec4(lhs.x*rhs.x, lhs.y*rhs.y, lhs.z*rhs.z, lhs.w*rhs.w); }
 #endif
 
+// Helpers: File System
+#if defined(__EMSCRIPTEN__) && !defined(IMGUI_DISABLE_FILE_FUNCTIONS)
+#define IMGUI_DISABLE_FILE_FUNCTIONS
+#endif
+#ifdef IMGUI_DISABLE_FILE_FUNCTIONS
+#define IMGUI_DISABLE_DEFAULT_FILE_FUNCTIONS
+typedef void* ImFileHandle;
+static inline ImFileHandle  ImFileOpen(const char*, const char*)                    { return NULL; }
+static inline int           ImFileClose(ImFileHandle)                               { return -1; }
+static inline size_t        ImFileGetSize(ImFileHandle)                             { return (size_t)-1; }
+static inline size_t        ImFileRead(void*, size_t, size_t, ImFileHandle)         { return 0; }
+static inline size_t        ImFileWrite(const void*, size_t, size_t, ImFileHandle)  { return 0; }
+#endif
+
+#ifndef IMGUI_DISABLE_DEFAULT_FILE_FUNCTIONS
+typedef FILE* ImFileHandle;
+IMGUI_API ImFileHandle      ImFileOpen(const char* filename, const char* mode);
+IMGUI_API int               ImFileClose(ImFileHandle file);
+IMGUI_API size_t            ImFileGetSize(ImFileHandle file);
+IMGUI_API size_t            ImFileRead(void* data, size_t size, size_t count, ImFileHandle file);
+IMGUI_API size_t            ImFileWrite(const void* data, size_t size, size_t count, ImFileHandle file);
+#else
+#define IMGUI_DISABLE_TTY_FUNCTIONS // Can't use stdout, fflush if we are not using default file functions
+#endif
+IMGUI_API void*             ImFileLoadToMemory(const char* filename, const char* mode, size_t* out_file_size = NULL, int padding_bytes = 0);
+
 // Helpers: Maths
 // - Wrapper for standard libs functions. (Note that imgui_demo.cpp does _not_ use them to keep the code easy to copy)
-#ifndef IMGUI_DISABLE_MATH_FUNCTIONS
+#ifndef IMGUI_DISABLE_DEFAULT_MATH_FUNCTIONS
 static inline float  ImFabs(float x)                                            { return fabsf(x); }
 static inline float  ImSqrt(float x)                                            { return sqrtf(x); }
 static inline float  ImPow(float x, float y)                                    { return powf(x, y); }
@@ -1095,7 +1127,7 @@ struct ImGuiContext
     // Capture/Logging
     bool                    LogEnabled;
     ImGuiLogType            LogType;
-    FILE*                   LogFile;                            // If != NULL log to stdout/ file
+    ImFileHandle            LogFile;                            // If != NULL log to stdout/ file
     ImGuiTextBuffer         LogBuffer;                          // Accumulation buffer when log to clipboard. This is pointer so our GImGui static constructor doesn't call heap allocators.
     float                   LogLinePosY;
     bool                    LogLineFirstItem;