Update ImGui to 1.75.

8 files changed, 1208 insertions, 691 deletions

diff --git a/imgui/LICENSE.txt b/imgui/LICENSE.txt
index 3b439aa4..d8763995 100644
--- a/imgui/LICENSE.txt
+++ b/imgui/LICENSE.txt
@@ -1,6 +1,6 @@
 The MIT License (MIT)
 
-Copyright (c) 2014-2019 Omar Cornut
+Copyright (c) 2014-2020 Omar Cornut
 
 Permission is hereby granted, free of charge, to any person obtaining a copy
 of this software and associated documentation files (the "Software"), to deal
diff --git a/imgui/imconfig.h b/imgui/imconfig.h
index 279acdb6..f56972d0 100644
--- a/imgui/imconfig.h
+++ b/imgui/imconfig.h
@@ -14,6 +14,7 @@
 #pragma once
 
 //---- Define assertion handler. Defaults to calling assert().
+// If your macro uses multiple statements, make sure is enclosed in a 'do { .. } while (0)' block so it can be used as a single statement.
 //#define IM_ASSERT(_EXPR)  MyAssert(_EXPR)
 //#define IM_ASSERT(_EXPR)  ((void)(_EXPR))     // Disable asserts
 
@@ -22,13 +23,14 @@
 //#define IMGUI_API __declspec( dllexport )
 //#define IMGUI_API __declspec( dllimport )
 
-//---- Don't define obsolete functions/enums names. Consider enabling from time to time after updating to avoid using soon-to-be obsolete function/names.
+//---- Don't define obsolete functions/enums/behaviors. Consider enabling from time to time after updating to avoid using soon-to-be obsolete function/names.
 //#define IMGUI_DISABLE_OBSOLETE_FUNCTIONS
 
-//---- Don't implement demo windows functionality (ShowDemoWindow()/ShowStyleEditor()/ShowUserGuide() methods will be empty)
-// It is very strongly recommended to NOT disable the demo windows during development. Please read the comments in imgui_demo.cpp.
-//#define IMGUI_DISABLE_DEMO_WINDOWS
-//#define IMGUI_DISABLE_METRICS_WINDOW
+//---- Disable all of Dear ImGui or don't implement standard windows. 
+// It is very strongly recommended to NOT disable the demo windows during development. Please read comments in imgui_demo.cpp.
+//#define IMGUI_DISABLE                                     // Disable everything: all headers and source files will be empty. 
+//#define IMGUI_DISABLE_DEMO_WINDOWS                        // Disable demo windows: ShowDemoWindow()/ShowStyleEditor() will be empty. Not recommended. 
+//#define IMGUI_DISABLE_METRICS_WINDOW                      // Disable debug/metrics window: ShowMetricsWindow() will be empty.
 
 //---- Don't implement some functions to reduce linkage requirements.
 //#define IMGUI_DISABLE_WIN32_DEFAULT_CLIPBOARD_FUNCTIONS   // [Win32] Don't implement default clipboard handler. Won't use and link with OpenClipboard/GetClipboardData/CloseClipboard etc.
@@ -53,6 +55,10 @@
 //#define IMGUI_DISABLE_STB_TRUETYPE_IMPLEMENTATION
 //#define IMGUI_DISABLE_STB_RECT_PACK_IMPLEMENTATION
 
+//---- Unless IMGUI_DISABLE_DEFAULT_FORMAT_FUNCTIONS is defined, use the much faster STB sprintf library implementation of vsnprintf instead of the one from the default C library.
+// Note that stb_sprintf.h is meant to be provided by the user and available in the include path at compile time. Also, the compatibility checks of the arguments and formats done by clang and GCC will be disabled in order to support the extra formats provided by STB sprintf.
+// #define IMGUI_USE_STB_SPRINTF
+
 //---- Define constructor and implicit cast operators to convert back<>forth between your math types and ImVec2/ImVec4.
 // This will be inlined as part of ImVec2 and ImVec4 class declarations.
 /*
@@ -77,14 +83,19 @@
 //typedef void (*MyImDrawCallback)(const ImDrawList* draw_list, const ImDrawCmd* cmd, void* my_renderer_user_data);
 //#define ImDrawCallback MyImDrawCallback
 
-//---- Debug Tools
-// Use 'Metrics->Tools->Item Picker' to pick widgets with the mouse and break into them for easy debugging.
+//---- Debug Tools: Macro to break in Debugger
+// (use 'Metrics->Tools->Item Picker' to pick widgets with the mouse and break into them for easy debugging.)
 //#define IM_DEBUG_BREAK  IM_ASSERT(0)
 //#define IM_DEBUG_BREAK  __debugbreak()
-// Have the Item Picker break in the ItemAdd() function instead of ItemHoverable() - which is earlier in the code, will catch a few extra items, allow picking items other than Hovered one.
+
+//---- Debug Tools: Have the Item Picker break in the ItemAdd() function instead of ItemHoverable(),
+// (which comes earlier in the code, will catch a few extra items, allow picking items other than Hovered one.)
 // This adds a small runtime cost which is why it is not enabled by default.
 //#define IMGUI_DEBUG_TOOL_ITEM_PICKER_EX
 
+//---- Debug Tools: Enable slower asserts
+//#define IMGUI_DEBUG_PARANOID
+
 //---- Tip: You can add extra functions within the ImGui:: namespace, here or in your own headers files.
 /*
 namespace ImGui
diff --git a/imgui/imgui.cpp b/imgui/imgui.cpp
index c2b489ad..1b78dd83 100644
--- a/imgui/imgui.cpp
+++ b/imgui/imgui.cpp
@@ -1,18 +1,25 @@
-// dear imgui, v1.74
+// dear imgui, v1.75
 // (main code and documentation)
 
-// Call and read ImGui::ShowDemoWindow() in imgui_demo.cpp for demo code.
-// Newcomers, read 'Programmer guide' below for notes on how to setup Dear ImGui in your codebase.
-// Get latest version at https://github.com/ocornut/imgui
-// Releases change-log at https://github.com/ocornut/imgui/releases
-// Technical Support for Getting Started https://github.com/ocornut/imgui/wiki
-// Gallery (please post your screenshots/video there!): https://github.com/ocornut/imgui/issues/2847
+// Help:
+// - Read FAQ at http://dearimgui.org/faq
+// - Newcomers, read 'Programmer guide' below for notes on how to setup Dear ImGui in your codebase.
+// - Call and read ImGui::ShowDemoWindow() in imgui_demo.cpp for demo code. All applications in examples/ are doing that.
+
+// Resources:
+// - FAQ                   http://dearimgui.org/faq
+// - Homepage & latest     https://github.com/ocornut/imgui
+// - Releases & changelog  https://github.com/ocornut/imgui/releases
+// - Gallery               https://github.com/ocornut/imgui/issues/2847 (please post your screenshots/video there!)
+// - Glossary              https://github.com/ocornut/imgui/wiki/Glossary
+// - Wiki                  https://github.com/ocornut/imgui/wiki
+// - Issues & support      https://github.com/ocornut/imgui/issues
 
 // Developed by Omar Cornut and every direct or indirect contributors to the GitHub.
 // See LICENSE.txt for copyright and licensing details (standard MIT License).
 // This library is free but I need your support to sustain development and maintenance.
-// Businesses: you can support continued maintenance and development via support contracts or sponsoring, see docs/README.
-// Individuals: you can support continued maintenance and development via donations or Patreon https://www.patreon.com/imgui.
+// Businesses: you can support continued development via invoiced technical support, maintenance and sponsoring contracts. Please reach out to "contact AT dearimgui.org".
+// Individuals: you can support continued development via donations. See docs/README or web page.
 
 // It is recommended that you don't modify imgui.cpp! It will become difficult for you to update the library.
 // Note that 'ImGui::' being a namespace, you can add functions into the namespace from your own source files, without
@@ -45,7 +52,8 @@ CODE
 // [SECTION] FORWARD DECLARATIONS
 // [SECTION] CONTEXT AND MEMORY ALLOCATORS
 // [SECTION] MAIN USER FACING STRUCTURES (ImGuiStyle, ImGuiIO)
-// [SECTION] MISC HELPERS/UTILITIES (Geomtry, String, Format, Hash, File functions)
+// [SECTION] MISC HELPERS/UTILITIES (Geometry functions)
+// [SECTION] MISC HELPERS/UTILITIES (String, Format, Hash functions)
 // [SECTION] MISC HELPERS/UTILITIES (File functions)
 // [SECTION] MISC HELPERS/UTILITIES (ImText* functions)
 // [SECTION] MISC HELPERS/UTILITIES (Color functions)
@@ -154,8 +162,9 @@ CODE
  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.
+ - In the majority of cases you should be able to use unmodified back-ends files available in the examples/ folder.
  - 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).
+   It is recommended you build and statically link the .cpp files as part of your project and NOT as shared library (DLL).
  - You can later customize the imconfig.h file to tweak some compile-time behavior, such as integrating Dear ImGui types with your own maths types.
  - When using Dear ImGui, your programming IDE is your friend: follow the declaration of variables, functions and types to find comments about them.
  - Dear ImGui never touches or knows about your GPU state. The only function that knows about GPU is the draw function that you provide.
@@ -175,7 +184,7 @@ CODE
      // TODO: Fill optional fields of the io structure later.
      // TODO: Load TTF/OTF fonts if you don't want to use the default font.
 
-     // Initialize helper Platform and Renderer bindings (here we are using imgui_impl_win32 and imgui_impl_dx11)
+     // Initialize helper Platform and Renderer bindings (here we are using imgui_impl_win32.cpp and imgui_impl_dx11.cpp)
      ImGui_ImplWin32_Init(hwnd);
      ImGui_ImplDX11_Init(g_pd3dDevice, g_pd3dDeviceContext);
 
@@ -310,9 +319,18 @@ CODE
  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!
+ - 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
  - The initial focus was to support game controllers, but keyboard is becoming increasingly and decently usable.
+ - Keyboard:
+    - Set io.ConfigFlags |= ImGuiConfigFlags_NavEnableKeyboard to enable.
+      NewFrame() will automatically fill io.NavInputs[] based on your io.KeysDown[] + io.KeyMap[] arrays.
+    - When keyboard navigation is active (io.NavActive + ImGuiConfigFlags_NavEnableKeyboard), the io.WantCaptureKeyboard flag
+      will be set. For more advanced uses, you may want to read from:
+       - io.NavActive: true when a window is focused and it doesn't have the ImGuiWindowFlags_NoNavInputs flag set.
+       - io.NavVisible: true when the navigation cursor is visible (and usually goes false when mouse is used).
+       - or query focus information with e.g. IsWindowFocused(ImGuiFocusedFlags_AnyWindow), IsItemFocused() etc. functions.
+      Please reach out if you think the game vs navigation input sharing could be improved.
  - Gamepad:
     - Set io.ConfigFlags |= ImGuiConfigFlags_NavEnableGamepad to enable.
     - Backend: Set io.BackendFlags |= ImGuiBackendFlags_HasGamepad + fill the io.NavInputs[] fields before calling NewFrame().
@@ -324,15 +342,6 @@ CODE
     - You can download PNG/PSD files depicting the gamepad controls for common controllers at: http://goo.gl/9LgVZW.
     - If you need to share inputs between your game and the imgui parts, the easiest approach is to go all-or-nothing, with a buttons combo
       to toggle the target. Please reach out if you think the game vs navigation input sharing could be improved.
- - Keyboard:
-    - Set io.ConfigFlags |= ImGuiConfigFlags_NavEnableKeyboard to enable.
-      NewFrame() will automatically fill io.NavInputs[] based on your io.KeysDown[] + io.KeyMap[] arrays.
-    - When keyboard navigation is active (io.NavActive + ImGuiConfigFlags_NavEnableKeyboard), the io.WantCaptureKeyboard flag
-      will be set. For more advanced uses, you may want to read from:
-       - io.NavActive: true when a window is focused and it doesn't have the ImGuiWindowFlags_NoNavInputs flag set.
-       - io.NavVisible: true when the navigation cursor is visible (and usually goes false when mouse is used).
-       - or query focus information with e.g. IsWindowFocused(ImGuiFocusedFlags_AnyWindow), IsItemFocused() etc. functions.
-      Please reach out if you think the game vs navigation input sharing could be improved.
  - Mouse:
     - PS4 users: Consider emulating a mouse cursor with DualShock4 touch pad or a spare analog stick as a mouse-emulation fallback.
     - Consoles/Tablet/Phone users: Consider using a Synergy 1.x server (on your PC) + uSynergy.c (on your console/tablet/phone app) to share your PC mouse/keyboard.
@@ -353,10 +362,30 @@ 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.
 
+ - 2020/01/22 (1.75) - ImDrawList::AddCircle()/AddCircleFilled() functions don't accept negative radius any more.
+ - 2019/12/17 (1.75) - made Columns() limited to 64 columns by asserting above that limit. While the current code technically supports it, future code may not so we're putting the restriction ahead.
+ - 2019/12/13 (1.75) - [imgui_internal.h] changed ImRect() default constructor initializes all fields to 0.0f instead of (FLT_MAX,FLT_MAX,-FLT_MAX,-FLT_MAX). If you used ImRect::Add() to create bounding boxes by adding multiple points into it, you may need to fix your initial value.
+ - 2019/12/08 (1.75) - removed redirecting functions/enums that were marked obsolete in 1.53 (December 2017):
+                       - ShowTestWindow()                    -> use ShowDemoWindow()
+                       - IsRootWindowFocused()               -> use IsWindowFocused(ImGuiFocusedFlags_RootWindow)
+                       - IsRootWindowOrAnyChildFocused()     -> use IsWindowFocused(ImGuiFocusedFlags_RootAndChildWindows)
+                       - SetNextWindowContentWidth(w)        -> use SetNextWindowContentSize(ImVec2(w, 0.0f)
+                       - GetItemsLineHeightWithSpacing()     -> use GetFrameHeightWithSpacing()
+                       - ImGuiCol_ChildWindowBg              -> use ImGuiCol_ChildBg
+                       - ImGuiStyleVar_ChildWindowRounding   -> use ImGuiStyleVar_ChildRounding
+                       - ImGuiTreeNodeFlags_AllowOverlapMode -> use ImGuiTreeNodeFlags_AllowItemOverlap
+                       - IMGUI_DISABLE_TEST_WINDOWS          -> use IMGUI_DISABLE_DEMO_WINDOWS
+ - 2019/12/08 (1.75) - obsoleted calling ImDrawList::PrimReserve() with a negative count (which was the vaguely documented and rarely if ever used). Instead we added an explicit PrimUnreserve() API.
+ - 2019/12/06 (1.75) - removed implicit default parameter to IsMouseDragging(int button = 0) to be consistent with other mouse functions (none of the other functions have it).
  - 2019/11/21 (1.74) - ImFontAtlas::AddCustomRectRegular() now requires an ID larger than 0x110000 (instead of 0x10000) to conform with supporting Unicode planes 1-16 in a future update. ID below 0x110000 will now assert.
  - 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.
+ - 2019/10/22 (1.74) - removed redirecting functions/enums that were marked obsolete in 1.52 (October 2017):
+                       - Begin() [old 5 args version]        -> use Begin() [3 args], use SetNextWindowSize() SetNextWindowBgAlpha() if needed
+                       - IsRootWindowOrAnyChildHovered()     -> use IsWindowHovered(ImGuiHoveredFlags_RootAndChildWindows)
+                       - AlignFirstTextHeightToWidgets()     -> use AlignTextToFramePadding()
+                       - SetNextWindowPosCenter()            -> use SetNextWindowPos() with a pivot of (0.5f, 0.5f)
+                       - ImFont::Glyph                       -> use ImFontGlyph
  - 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.
                        The function was triggering on: 0.0 and (delay+rate*N) where (N>=1). Fixed formula responds to (N>=0). Effectively it made io.KeyRepeatRate behave like it was set to (io.KeyRepeatRate + io.KeyRepeatDelay).
@@ -475,7 +504,7 @@ CODE
  - 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, 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: 
+                       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().
@@ -535,14 +564,13 @@ CODE
  - 2015/02/01 (1.31) - removed IO.MemReallocFn (unused)
  - 2015/01/19 (1.30) - renamed ImGuiStorage::GetIntPtr()/GetFloatPtr() to GetIntRef()/GetIntRef() because Ptr was conflicting with actual pointer storage functions.
  - 2015/01/11 (1.30) - big font/image API change! now loads TTF file. allow for multiple fonts. no need for a PNG loader.
-              (1.30) - removed GetDefaultFontData(). uses io.Fonts->GetTextureData*() API to retrieve uncompressed pixels.
-                       font init:  { const void* png_data; unsigned int png_size; ImGui::GetDefaultFontData(NULL, NULL, &png_data, &png_size); <..Upload texture to GPU..>; }
-                       became:     { unsigned char* pixels; int width, height; io.Fonts->GetTexDataAsRGBA32(&pixels, &width, &height); <..Upload texture to GPU>; io.Fonts->TexId = YourTextureIdentifier; }
-                       you now have more flexibility to load multiple TTF fonts and manage the texture buffer for internal needs.
-                       it is now recommended that you sample the font texture with bilinear interpolation.
-              (1.30) - added texture identifier in ImDrawCmd passed to your render function (we can now render images). make sure to set io.Fonts->TexID.
-              (1.30) - removed IO.PixelCenterOffset (unnecessary, can be handled in user projection matrix)
-              (1.30) - removed ImGui::IsItemFocused() in favor of ImGui::IsItemActive() which handles all widgets
+ - 2015/01/11 (1.30) - removed GetDefaultFontData(). uses io.Fonts->GetTextureData*() API to retrieve uncompressed pixels.
+                       - old:  const void* png_data; unsigned int png_size; ImGui::GetDefaultFontData(NULL, NULL, &png_data, &png_size); [..Upload texture to GPU..];
+                       - new:  unsigned char* pixels; int width, height; io.Fonts->GetTexDataAsRGBA32(&pixels, &width, &height); [..Upload texture to GPU..]; io.Fonts->TexId = YourTexIdentifier;
+                       you now have more flexibility to load multiple TTF fonts and manage the texture buffer for internal needs. It is now recommended that you sample the font texture with bilinear interpolation.
+ - 2015/01/11 (1.30) - added texture identifier in ImDrawCmd passed to your render function (we can now render images). make sure to set io.Fonts->TexID.
+ - 2015/01/11 (1.30) - removed IO.PixelCenterOffset (unnecessary, can be handled in user projection matrix)
+ - 2015/01/11 (1.30) - removed ImGui::IsItemFocused() in favor of ImGui::IsItemActive() which handles all widgets
  - 2014/12/10 (1.18) - removed SetNewWindowDefaultPos() in favor of new generic API SetNextWindowPos(pos, ImGuiSetCondition_FirstUseEver)
  - 2014/11/28 (1.17) - moved IO.Font*** options to inside the IO.Font-> structure (FontYOffset, FontTexUvForWhite, FontBaseScale, FontFallbackGlyph)
  - 2014/11/26 (1.17) - reworked syntax of IMGUI_ONCE_UPON_A_FRAME helper macro to increase compiler compatibility
@@ -571,42 +599,26 @@ CODE
     - See demo code in imgui_demo.cpp and particularly the ImGui::ShowDemoWindow() function.
     - The demo covers most features of Dear ImGui, so you can read the code and see its output.
     - See documentation and comments at the top of imgui.cpp + effectively imgui.h.
-    - Dozens of standalone example applications using e.g. OpenGL/DirectX are provided in the examples/
-      folder to explain how to integrate Dear ImGui with your own engine/application.
+    - Dozens of standalone example applications using e.g. OpenGL/DirectX are provided in the
+      examples/ folder to explain how to integrate Dear ImGui with your own engine/application.
+    - The Wiki (https://github.com/ocornut/imgui/wiki) has many resources and links.
+    - The Glossary (https://github.com/ocornut/imgui/wiki/Glossary) page also may be useful.
     - Your programming IDE is your friend, find the type or function declaration to find comments
       associated to it.
 
+ Q: What is this library called?
  Q: Which version should I get?
- Q: Why the names "Dear ImGui" vs "ImGui"?
- >> See https://www.dearimgui.org/faq
-
- Q&A: Concerns
- =============
-
- Q: Who uses Dear ImGui?
- Q: Can you create elaborate/serious tools with Dear ImGui?
- Q: Can you reskin the look of Dear ImGui?
- Q: Why using C++ (as opposed to C)?
+ >> This library is called "Dear ImGui", please don't call it "ImGui" :)
  >> See https://www.dearimgui.org/faq
 
  Q&A: Integration
  ================
 
  Q: How can I tell whether to dispatch mouse/keyboard to Dear ImGui or to my application?
- A: You can read the 'io.WantCaptureMouse', 'io.WantCaptureKeyboard' and 'io.WantTextInput' flags from the ImGuiIO structure (e.g. if (ImGui::GetIO().WantCaptureMouse) { ... } )
-    - When 'io.WantCaptureMouse' is set, imgui wants to use your mouse state, and you may want to discard/hide the inputs from the rest of your application.
-    - When 'io.WantCaptureKeyboard' is set, imgui wants to use your keyboard state, and you may want to discard/hide the inputs from the rest of your application.
-    - When 'io.WantTextInput' is set to may want to notify your OS to popup an on-screen keyboard, if available (e.g. on a mobile phone, or console OS).
-    Note: you should always pass your mouse/keyboard inputs to imgui, even when the io.WantCaptureXXX flag are set false.
-     This is because imgui needs to detect that you clicked in the void to unfocus its own windows.
-    Note: The 'io.WantCaptureMouse' is more accurate that any attempt to "check if the mouse is hovering a window" (don't do that!).
-     It handle mouse dragging correctly (both dragging that started over your application or over an imgui window) and handle e.g. modal windows blocking inputs.
-     Those flags are updated by ImGui::NewFrame(). Preferably read the flags after calling NewFrame() if you can afford it, but reading them before is also
-     perfectly fine, as the bool toggle fairly rarely. If you have on a touch device, you might find use for an early call to UpdateHoveredWindowAndCaptureFlags().
-    Note: Text input widget releases focus on "Return KeyDown", so the subsequent "Return KeyUp" event that your application receive will typically
-     have 'io.WantCaptureKeyboard=false'. Depending on your application logic it may or not be inconvenient. You might want to track which key-downs
-     were targeted for Dear ImGui, e.g. with an array of bool, and filter out the corresponding key-ups.)
+ A: You should read the 'io.WantCaptureMouse', 'io.WantCaptureKeyboard' and 'io.WantTextInput' flags!
+ >> See https://www.dearimgui.org/faq for fully detailed answer. You really want to read this.
 
+ Q. How can I enable keyboard controls?
  Q: How can I use this without a mouse, without a keyboard or without a screen? (gamepad, input share, remote display)
  Q: I integrated Dear ImGui in my engine and the text or lines are blurry..
  Q: I integrated Dear ImGui in my engine and some elements are clipping or disappearing when I move windows around..
@@ -748,15 +760,26 @@ CODE
  Q: How can I display and input non-Latin characters such as Chinese, Japanese, Korean, Cyrillic?
  >> See https://www.dearimgui.org/faq and docs/FONTS.txt
 
+ Q&A: Concerns
+ =============
+
+ Q: Who uses Dear ImGui?
+ Q: Can you create elaborate/serious tools with Dear ImGui?
+ Q: Can you reskin the look of Dear ImGui?
+ Q: Why using C++ (as opposed to C)?
+ >> See https://www.dearimgui.org/faq
+
  Q&A: Community
  ==============
 
  Q: How can I help?
- A: - If you are experienced with Dear ImGui and C++, look at the github issues, look at the Wiki, read docs/TODO.txt
+ A: - Businesses: please reach out to "contact AT dearimgui.org" if you work in a place using Dear ImGui!
+      We can discuss ways for your company to fund development via invoiced technical support, maintenance or sponsoring contacts.
+      This is among the most useful thing you can do for Dear ImGui. With increased funding we can hire more people working on this project.
+    - Individuals: you can support continued development via PayPal donations. See README.
+    - If you are experienced with Dear ImGui and C++, look at the github issues, look at the Wiki, read docs/TODO.txt
       and see how you want to help and can help!
-    - Businesses: convince your company to fund development via support contracts/sponsoring! This is among the most useful thing you can do for dear imgui.
-    - Individuals: you can also become a Patron (http://www.patreon.com/imgui) or donate on PayPal! See README.
-    - Disclose your usage of dear imgui via a dev blog post, a tweet, a screenshot, a mention somewhere etc.
+    - Disclose your usage of Dear ImGui via a dev blog post, a tweet, a screenshot, a mention somewhere etc.
       You may post screenshot or links in the gallery threads (github.com/ocornut/imgui/issues/2847). Visuals are ideal as they inspire other programmers.
       But even without visuals, disclosing your use of dear imgui help the library grow credibility, and help other teams and programmers with taking decisions.
     - If you have issues or if you need to hack into the library, even if you don't expect any support it is useful that you share your issues (on github or privately).
@@ -768,6 +791,8 @@ CODE
 #endif
 
 #include "imgui.h"
+#ifndef IMGUI_DISABLE
+
 #ifndef IMGUI_DEFINE_MATH_OPERATORS
 #define IMGUI_DEFINE_MATH_OPERATORS
 #endif
@@ -784,12 +809,15 @@ CODE
 // Debug options
 #define IMGUI_DEBUG_NAV_SCORING     0   // Display navigation scoring preview when hovering items. Display last moving direction matches when holding CTRL
 #define IMGUI_DEBUG_NAV_RECTS       0   // Display the reference navigation rectangle for each window
-#define IMGUI_DEBUG_INI_SETTINGS    0   // Save additional comments in .ini file
+#define IMGUI_DEBUG_INI_SETTINGS    0   // Save additional comments in .ini file (particularly helps for Docking, but makes saving slower)
 
 // Visual Studio warnings
 #ifdef _MSC_VER
 #pragma warning (disable: 4127)     // condition expression is constant
 #pragma warning (disable: 4996)     // 'This function or variable may be unsafe': strcpy, strdup, sprintf, vsnprintf, sscanf, fopen
+#if defined(_MSC_VER) && _MSC_VER >= 1922 // MSVC 2019 16.2 or later
+#pragma warning (disable: 5054)     // operator '|': deprecated between enumerations of different types
+#endif
 #endif
 
 // Clang/GCC warnings with -Weverything
@@ -857,8 +885,6 @@ static void             ImeSetInputScreenPosFn_DefaultImpl(int x, int y);
 
 namespace ImGui
 {
-static bool             BeginChildEx(const char* name, ImGuiID id, const ImVec2& size_arg, bool border, ImGuiWindowFlags flags);
-
 // Navigation
 static void             NavUpdate();
 static void             NavUpdateWindowing();
@@ -959,12 +985,13 @@ ImGuiStyle::ImGuiStyle()
     ColorButtonPosition     = ImGuiDir_Right;   // Side of the color button in the ColorEdit4 widget (left/right). Defaults to ImGuiDir_Right.
     ButtonTextAlign         = ImVec2(0.5f,0.5f);// Alignment of button text when button is larger than text.
     SelectableTextAlign     = ImVec2(0.0f,0.0f);// Alignment of selectable text when button is larger than text.
-    DisplayWindowPadding    = ImVec2(19,19);    // Window position are clamped to be visible within the display area by at least this amount. Only applies to regular windows.
+    DisplayWindowPadding    = ImVec2(19,19);    // Window position are clamped to be visible within the display area or monitors by at least this amount. Only applies to regular windows.
     DisplaySafeAreaPadding  = ImVec2(3,3);      // If you cannot see the edge of your screen (e.g. on a TV) increase the safe area padding. Covers popups/tooltips as well regular windows.
     MouseCursorScale        = 1.0f;             // Scale software rendered mouse cursor (when io.MouseDrawCursor is enabled). May be removed later.
     AntiAliasedLines        = true;             // Enable anti-aliasing on lines/borders. Disable if you are really short on CPU/GPU.
     AntiAliasedFill         = true;             // Enable anti-aliasing on filled shapes (rounded rectangles, circles, etc.)
     CurveTessellationTol    = 1.25f;            // Tessellation tolerance when using PathBezierCurveTo() without a specific number of segments. Decrease for highly tessellated curves (higher quality, more polygons), increase to reduce quality.
+    CircleSegmentMaxError   = 1.60f;            // Maximum error (in pixels) allowed when using AddCircle()/AddCircleFilled() or drawing rounded corner rectangles with no explicit segment count specified. Decrease for higher quality but more geometry.
 
     // Default theme
     ImGui::StyleColorsDark(this);
@@ -1000,6 +1027,7 @@ ImGuiIO::ImGuiIO()
 {
     // Most fields are initialized with zero
     memset(this, 0, sizeof(*this));
+    IM_ASSERT(IM_ARRAYSIZE(ImGuiIO::MouseDown) == ImGuiMouseButton_COUNT && IM_ARRAYSIZE(ImGuiIO::MouseClicked) == ImGuiMouseButton_COUNT); // Our pre-C++11 IM_STATIC_ASSERT() macros triggers warning on modern compilers so we don't use it here.
 
     // Settings
     ConfigFlags = ImGuiConfigFlags_None;
@@ -1083,9 +1111,77 @@ void ImGuiIO::ClearInputCharacters()
 }
 
 //-----------------------------------------------------------------------------
-// [SECTION] MISC HELPERS/UTILITIES (Geometry, String, Format, Hash, File functions)
+// [SECTION] MISC HELPERS/UTILITIES (Geometry functions)
 //-----------------------------------------------------------------------------
 
+ImVec2 ImBezierClosestPoint(const ImVec2& p1, const ImVec2& p2, const ImVec2& p3, const ImVec2& p4, const ImVec2& p, int num_segments)
+{
+    IM_ASSERT(num_segments > 0); // Use ImBezierClosestPointCasteljau()
+    ImVec2 p_last = p1;
+    ImVec2 p_closest;
+    float p_closest_dist2 = FLT_MAX;
+    float t_step = 1.0f / (float)num_segments;
+    for (int i_step = 1; i_step <= num_segments; i_step++)
+    {
+        ImVec2 p_current = ImBezierCalc(p1, p2, p3, p4, t_step * i_step);
+        ImVec2 p_line = ImLineClosestPoint(p_last, p_current, p);
+        float dist2 = ImLengthSqr(p - p_line);
+        if (dist2 < p_closest_dist2)
+        {
+            p_closest = p_line;
+            p_closest_dist2 = dist2;
+        }
+        p_last = p_current;
+    }
+    return p_closest;
+}
+
+// Closely mimics PathBezierToCasteljau() in imgui_draw.cpp
+static void BezierClosestPointCasteljauStep(const ImVec2& p, ImVec2& p_closest, ImVec2& p_last, float& p_closest_dist2, float x1, float y1, float x2, float y2, float x3, float y3, float x4, float y4, float tess_tol, int level)
+{
+    float dx = x4 - x1;
+    float dy = y4 - y1;
+    float d2 = ((x2 - x4) * dy - (y2 - y4) * dx);
+    float d3 = ((x3 - x4) * dy - (y3 - y4) * dx);
+    d2 = (d2 >= 0) ? d2 : -d2;
+    d3 = (d3 >= 0) ? d3 : -d3;
+    if ((d2+d3) * (d2+d3) < tess_tol * (dx*dx + dy*dy))
+    {
+        ImVec2 p_current(x4, y4);
+        ImVec2 p_line = ImLineClosestPoint(p_last, p_current, p);
+        float dist2 = ImLengthSqr(p - p_line);
+        if (dist2 < p_closest_dist2)
+        {
+            p_closest = p_line;
+            p_closest_dist2 = dist2;
+        }
+        p_last = p_current;
+    }
+    else if (level < 10)
+    {
+        float x12 = (x1+x2)*0.5f,       y12 = (y1+y2)*0.5f;
+        float x23 = (x2+x3)*0.5f,       y23 = (y2+y3)*0.5f;
+        float x34 = (x3+x4)*0.5f,       y34 = (y3+y4)*0.5f;
+        float x123 = (x12+x23)*0.5f,    y123 = (y12+y23)*0.5f;
+        float x234 = (x23+x34)*0.5f,    y234 = (y23+y34)*0.5f;
+        float x1234 = (x123+x234)*0.5f, y1234 = (y123+y234)*0.5f;
+        BezierClosestPointCasteljauStep(p, p_closest, p_last, p_closest_dist2, x1, y1, x12, y12, x123, y123, x1234, y1234, tess_tol, level + 1);
+        BezierClosestPointCasteljauStep(p, p_closest, p_last, p_closest_dist2, x1234, y1234, x234, y234, x34, y34, x4, y4, tess_tol, level + 1);
+    }
+}
+
+// tess_tol is generally the same value you would find in ImGui::GetStyle().CurveTessellationTol
+// Because those ImXXX functions are lower-level than ImGui:: we cannot access this value automatically.
+ImVec2 ImBezierClosestPointCasteljau(const ImVec2& p1, const ImVec2& p2, const ImVec2& p3, const ImVec2& p4, const ImVec2& p, float tess_tol)
+{
+    IM_ASSERT(tess_tol > 0.0f);
+    ImVec2 p_last = p1;
+    ImVec2 p_closest;
+    float p_closest_dist2 = FLT_MAX;
+    BezierClosestPointCasteljauStep(p, p_closest, p_last, p_closest_dist2, p1.x, p1.y, p2.x, p2.y, p3.x, p3.y, p4.x, p4.y, tess_tol, 0);
+    return p_closest;
+}
+
 ImVec2 ImLineClosestPoint(const ImVec2& a, const ImVec2& b, const ImVec2& p)
 {
     ImVec2 ap = p - a;
@@ -1134,6 +1230,10 @@ ImVec2 ImTriangleClosestPoint(const ImVec2& a, const ImVec2& b, const ImVec2& c,
     return proj_ca;
 }
 
+//-----------------------------------------------------------------------------
+// [SECTION] MISC HELPERS/UTILITIES (String, Format, Hash functions)
+//-----------------------------------------------------------------------------
+
 // Consider using _stricmp/_strnicmp under Windows or strcasecmp/strncasecmp. We don't actually use either ImStricmp/ImStrnicmp in the codebase any more.
 int ImStricmp(const char* str1, const char* str2)
 {
@@ -1258,10 +1358,9 @@ const char* ImStrSkipBlank(const char* str)
 #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 
+// 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 "stb_sprintf.h"
@@ -1384,7 +1483,7 @@ ImU32 ImHashStr(const char* data_p, size_t data_size, ImU32 seed)
 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. 
+    // 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;
@@ -1704,38 +1803,6 @@ void ImGui::ColorConvertHSVtoRGB(float h, float s, float v, float& out_r, float&
     }
 }
 
-ImU32 ImGui::GetColorU32(ImGuiCol idx, float alpha_mul)
-{
-    ImGuiStyle& style = GImGui->Style;
-    ImVec4 c = style.Colors[idx];
-    c.w *= style.Alpha * alpha_mul;
-    return ColorConvertFloat4ToU32(c);
-}
-
-ImU32 ImGui::GetColorU32(const ImVec4& col)
-{
-    ImGuiStyle& style = GImGui->Style;
-    ImVec4 c = col;
-    c.w *= style.Alpha;
-    return ColorConvertFloat4ToU32(c);
-}
-
-const ImVec4& ImGui::GetStyleColorVec4(ImGuiCol idx)
-{
-    ImGuiStyle& style = GImGui->Style;
-    return style.Colors[idx];
-}
-
-ImU32 ImGui::GetColorU32(ImU32 col)
-{
-    float style_alpha = GImGui->Style.Alpha;
-    if (style_alpha >= 1.0f)
-        return col;
-    ImU32 a = (col & IM_COL32_A_MASK) >> IM_COL32_A_SHIFT;
-    a = (ImU32)(a * style_alpha); // We don't need to clamp 0..255 because Style.Alpha is in 0..1 range.
-    return (col & ~IM_COL32_A_MASK) | (a << IM_COL32_A_SHIFT);
-}
-
 //-----------------------------------------------------------------------------
 // [SECTION] ImGuiStorage
 // Helper: Key->value storage
@@ -2193,10 +2260,42 @@ bool ImGuiListClipper::Step()
 
 //-----------------------------------------------------------------------------
 // [SECTION] RENDER HELPERS
-// Those (internal) functions are currently quite a legacy mess - their signature and behavior will change.
+// Some of those (internal) functions are currently quite a legacy mess - their signature and behavior will change.
 // Also see imgui_draw.cpp for some more which have been reworked to not rely on ImGui:: state.
 //-----------------------------------------------------------------------------
 
+ImU32 ImGui::GetColorU32(ImGuiCol idx, float alpha_mul)
+{
+    ImGuiStyle& style = GImGui->Style;
+    ImVec4 c = style.Colors[idx];
+    c.w *= style.Alpha * alpha_mul;
+    return ColorConvertFloat4ToU32(c);
+}
+
+ImU32 ImGui::GetColorU32(const ImVec4& col)
+{
+    ImGuiStyle& style = GImGui->Style;
+    ImVec4 c = col;
+    c.w *= style.Alpha;
+    return ColorConvertFloat4ToU32(c);
+}
+
+const ImVec4& ImGui::GetStyleColorVec4(ImGuiCol idx)
+{
+    ImGuiStyle& style = GImGui->Style;
+    return style.Colors[idx];
+}
+
+ImU32 ImGui::GetColorU32(ImU32 col)
+{
+    ImGuiStyle& style = GImGui->Style;
+    if (style.Alpha >= 1.0f)
+        return col;
+    ImU32 a = (col & IM_COL32_A_MASK) >> IM_COL32_A_SHIFT;
+    a = (ImU32)(a * style.Alpha); // We don't need to clamp 0..255 because Style.Alpha is in 0..1 range.
+    return (col & ~IM_COL32_A_MASK) | (a << IM_COL32_A_SHIFT);
+}
+
 const char* ImGui::FindRenderedTextEnd(const char* text, const char* text_end)
 {
     const char* text_display_end = text;
@@ -2524,6 +2623,7 @@ ImGuiWindow::ImGuiWindow(ImGuiContext* context, const char* name)
     SkipItems = false;
     Appearing = false;
     Hidden = false;
+    IsFallbackWindow = false;
     HasCloseButton = false;
     ResizeBorderHeld = -1;
     BeginCount = 0;
@@ -2659,25 +2759,6 @@ void ImGui::GcAwakeTransientWindowBuffers(ImGuiWindow* window)
     window->MemoryDrawListIdxCapacity = window->MemoryDrawListVtxCapacity = 0;
 }
 
-void ImGui::SetNavID(ImGuiID id, int nav_layer)
-{
-    ImGuiContext& g = *GImGui;
-    IM_ASSERT(g.NavWindow);
-    IM_ASSERT(nav_layer == 0 || nav_layer == 1);
-    g.NavId = id;
-    g.NavWindow->NavLastIds[nav_layer] = id;
-}
-
-void ImGui::SetNavIDWithRectRel(ImGuiID id, int nav_layer, const ImRect& rect_rel)
-{
-    ImGuiContext& g = *GImGui;
-    SetNavID(id, nav_layer);
-    g.NavWindow->NavRectRel[nav_layer] = rect_rel;
-    g.NavMousePosDirty = true;
-    g.NavDisableHighlight = false;
-    g.NavDisableMouseHover = true;
-}
-
 void ImGui::SetActiveID(ImGuiID id, ImGuiWindow* window)
 {
     ImGuiContext& g = *GImGui;
@@ -2710,29 +2791,6 @@ void ImGui::SetActiveID(ImGuiID id, ImGuiWindow* window)
     g.ActiveIdUsingKeyInputMask = 0x00;
 }
 
-// FIXME-NAV: The existence of SetNavID/SetNavIDWithRectRel/SetFocusID is incredibly messy and confusing and needs some explanation or refactoring.
-void ImGui::SetFocusID(ImGuiID id, ImGuiWindow* window)
-{
-    ImGuiContext& g = *GImGui;
-    IM_ASSERT(id != 0);
-
-    // Assume that SetFocusID() is called in the context where its NavLayer is the current layer, which is the case everywhere we call it.
-    const ImGuiNavLayer nav_layer = window->DC.NavLayerCurrent;
-    if (g.NavWindow != window)
-        g.NavInitRequest = false;
-    g.NavId = id;
-    g.NavWindow = window;
-    g.NavLayer = nav_layer;
-    window->NavLastIds[nav_layer] = id;
-    if (window->DC.LastItemId == id)
-        window->NavRectRel[nav_layer] = ImRect(window->DC.LastItemRect.Min - window->Pos, window->DC.LastItemRect.Max - window->Pos);
-
-    if (g.ActiveIdSource == ImGuiInputSource_Nav)
-        g.NavDisableMouseHover = true;
-    else
-        g.NavDisableHighlight = true;
-}
-
 void ImGui::ClearActiveID()
 {
     SetActiveID(0, NULL);
@@ -2791,7 +2849,6 @@ static inline bool IsWindowContentHoverable(ImGuiWindow* window, ImGuiHoveredFla
                 if ((focused_root_window->Flags & ImGuiWindowFlags_Popup) && !(flags & ImGuiHoveredFlags_AllowWhenBlockedByPopup))
                     return false;
             }
-
     return true;
 }
 
@@ -2861,10 +2918,10 @@ bool ImGui::ItemAdd(const ImRect& bb, ImGuiID id, const ImRect* nav_bb_arg)
 
         // [DEBUG] Item Picker tool, when enabling the "extended" version we perform the check in ItemAdd()
 #ifdef IMGUI_DEBUG_TOOL_ITEM_PICKER_EX
-        if (id == g.DebugItemPickerBreakID)
+        if (id == g.DebugItemPickerBreakId)
         {
             IM_DEBUG_BREAK();
-            g.DebugItemPickerBreakID = 0;
+            g.DebugItemPickerBreakId = 0;
         }
 #endif
     }
@@ -2963,7 +3020,7 @@ bool ImGui::ItemHoverable(const ImRect& bb, ImGuiID id)
     // #define IMGUI_DEBUG_TOOL_ITEM_PICKER_EX in imconfig.h if you want this check to also be performed in ItemAdd().
     if (g.DebugItemPickerActive && g.HoveredIdPreviousFrame == id)
         GetForegroundDrawList()->AddRect(bb.Min, bb.Max, IM_COL32(255, 255, 0, 255));
-    if (g.DebugItemPickerBreakID == id)
+    if (g.DebugItemPickerBreakId == id)
         IM_DEBUG_BREAK();
 
     return true;
@@ -2987,24 +3044,24 @@ bool ImGui::FocusableItemRegister(ImGuiWindow* window, ImGuiID id)
 
     // Increment counters
     const bool is_tab_stop = (window->DC.ItemFlags & (ImGuiItemFlags_NoTabStop | ImGuiItemFlags_Disabled)) == 0;
-    window->DC.FocusCounterAll++;
+    window->DC.FocusCounterRegular++;
     if (is_tab_stop)
-        window->DC.FocusCounterTab++;
+        window->DC.FocusCounterTabStop++;
 
     // Process TAB/Shift-TAB to tab *OUT* of the currently focused item.
     // (Note that we can always TAB out of a widget that doesn't allow tabbing in)
     if (g.ActiveId == id && g.FocusTabPressed && !IsActiveIdUsingKey(ImGuiKey_Tab) && g.FocusRequestNextWindow == NULL)
     {
         g.FocusRequestNextWindow = window;
-        g.FocusRequestNextCounterTab = window->DC.FocusCounterTab + (g.IO.KeyShift ? (is_tab_stop ? -1 : 0) : +1); // Modulo on index will be applied at the end of frame once we've got the total counter of items.
+        g.FocusRequestNextCounterTabStop = window->DC.FocusCounterTabStop + (g.IO.KeyShift ? (is_tab_stop ? -1 : 0) : +1); // Modulo on index will be applied at the end of frame once we've got the total counter of items.
     }
 
     // Handle focus requests
     if (g.FocusRequestCurrWindow == window)
     {
-        if (window->DC.FocusCounterAll == g.FocusRequestCurrCounterAll)
+        if (window->DC.FocusCounterRegular == g.FocusRequestCurrCounterRegular)
             return true;
-        if (is_tab_stop && window->DC.FocusCounterTab == g.FocusRequestCurrCounterTab)
+        if (is_tab_stop && window->DC.FocusCounterTabStop == g.FocusRequestCurrCounterTabStop)
         {
             g.NavJustTabbedId = id;
             return true;
@@ -3020,8 +3077,8 @@ bool ImGui::FocusableItemRegister(ImGuiWindow* window, ImGuiID id)
 
 void ImGui::FocusableItemUnregister(ImGuiWindow* window)
 {
-    window->DC.FocusCounterAll--;
-    window->DC.FocusCounterTab--;
+    window->DC.FocusCounterRegular--;
+    window->DC.FocusCounterTabStop--;
 }
 
 float ImGui::CalcWrapWidthForPos(const ImVec2& pos, float wrap_pos_x)
@@ -3235,10 +3292,10 @@ void ImGui::UpdateMouseMovingWindowNewFrame()
     }
 }
 
-// Initiate moving window, handle left-click and right-click focus
+// Initiate moving window when clicking on empty space or title bar.
+// Handle left-click and right-click focus.
 void ImGui::UpdateMouseMovingWindowEndFrame()
 {
-    // Initiate moving window
     ImGuiContext& g = *GImGui;
     if (g.ActiveId != 0 || g.HoveredId != 0)
         return;
@@ -3507,6 +3564,7 @@ static void NewFrameSanityChecks()
     IM_ASSERT(g.IO.Fonts->Fonts.Size > 0                                && "Font Atlas not built. Did you call io.Fonts->GetTexDataAsRGBA32() / GetTexDataAsAlpha8() ?");
     IM_ASSERT(g.IO.Fonts->Fonts[0]->IsLoaded()                          && "Font Atlas not built. Did you call io.Fonts->GetTexDataAsRGBA32() / GetTexDataAsAlpha8() ?");
     IM_ASSERT(g.Style.CurveTessellationTol > 0.0f                       && "Invalid style setting!");
+    IM_ASSERT(g.Style.CircleSegmentMaxError > 0.0f                      && "Invalid style setting!");
     IM_ASSERT(g.Style.Alpha >= 0.0f && g.Style.Alpha <= 1.0f            && "Invalid style setting. Alpha cannot be negative (allows us to avoid a few clamps in color computations)!");
     IM_ASSERT(g.Style.WindowMinSize.x >= 1.0f && g.Style.WindowMinSize.y >= 1.0f && "Invalid style setting.");
     IM_ASSERT(g.Style.WindowMenuButtonPosition == ImGuiDir_None || g.Style.WindowMenuButtonPosition == ImGuiDir_Left || g.Style.WindowMenuButtonPosition == ImGuiDir_Right);
@@ -3569,6 +3627,7 @@ void ImGui::NewFrame()
     IM_ASSERT(g.Font->IsLoaded());
     g.DrawListSharedData.ClipRectFullscreen = ImVec4(0.0f, 0.0f, g.IO.DisplaySize.x, g.IO.DisplaySize.y);
     g.DrawListSharedData.CurveTessellationTol = g.Style.CurveTessellationTol;
+    g.DrawListSharedData.SetCircleSegmentMaxError(g.Style.CircleSegmentMaxError);
     g.DrawListSharedData.InitialFlags = ImDrawListFlags_None;
     if (g.Style.AntiAliasedLines)
         g.DrawListSharedData.InitialFlags |= ImDrawListFlags_AntiAliasedLines;
@@ -3674,26 +3733,26 @@ void ImGui::NewFrame()
         // Note that SetKeyboardFocusHere() sets the Next fields mid-frame. To be consistent we also
         // manipulate the Next fields even, even though they will be turned into Curr fields by the code below.
         g.FocusRequestNextWindow = g.NavWindow;
-        g.FocusRequestNextCounterAll = INT_MAX;
+        g.FocusRequestNextCounterRegular = INT_MAX;
         if (g.NavId != 0 && g.NavIdTabCounter != INT_MAX)
-            g.FocusRequestNextCounterTab = g.NavIdTabCounter + 1 + (g.IO.KeyShift ? -1 : 1);
+            g.FocusRequestNextCounterTabStop = g.NavIdTabCounter + 1 + (g.IO.KeyShift ? -1 : 1);
         else
-            g.FocusRequestNextCounterTab = g.IO.KeyShift ? -1 : 0;
+            g.FocusRequestNextCounterTabStop = g.IO.KeyShift ? -1 : 0;
     }
 
     // Turn queued focus request into current one
     g.FocusRequestCurrWindow = NULL;
-    g.FocusRequestCurrCounterAll = g.FocusRequestCurrCounterTab = INT_MAX;
+    g.FocusRequestCurrCounterRegular = g.FocusRequestCurrCounterTabStop = INT_MAX;
     if (g.FocusRequestNextWindow != NULL)
     {
         ImGuiWindow* window = g.FocusRequestNextWindow;
         g.FocusRequestCurrWindow = window;
-        if (g.FocusRequestNextCounterAll != INT_MAX && window->DC.FocusCounterAll != -1)
-            g.FocusRequestCurrCounterAll = ImModPositive(g.FocusRequestNextCounterAll, window->DC.FocusCounterAll + 1);
-        if (g.FocusRequestNextCounterTab != INT_MAX && window->DC.FocusCounterTab != -1)
-            g.FocusRequestCurrCounterTab = ImModPositive(g.FocusRequestNextCounterTab, window->DC.FocusCounterTab + 1);
+        if (g.FocusRequestNextCounterRegular != INT_MAX && window->DC.FocusCounterRegular != -1)
+            g.FocusRequestCurrCounterRegular = ImModPositive(g.FocusRequestNextCounterRegular, window->DC.FocusCounterRegular + 1);
+        if (g.FocusRequestNextCounterTabStop != INT_MAX && window->DC.FocusCounterTabStop != -1)
+            g.FocusRequestCurrCounterTabStop = ImModPositive(g.FocusRequestNextCounterTabStop, window->DC.FocusCounterTabStop + 1);
         g.FocusRequestNextWindow = NULL;
-        g.FocusRequestNextCounterAll = g.FocusRequestNextCounterTab = INT_MAX;
+        g.FocusRequestNextCounterRegular = g.FocusRequestNextCounterTabStop = INT_MAX;
     }
 
     g.NavIdTabCounter = INT_MAX;
@@ -3709,7 +3768,7 @@ void ImGui::NewFrame()
         window->Active = false;
         window->WriteAccessed = false;
 
-        // Garbage collect (this is totally functional but we may need decide if the side-effects are desirable)
+        // Garbage collect transient buffers of recently unused windows
         if (!window->WasActive && !window->MemoryCompacted && window->LastTimeActive < memory_compact_start_time)
             GcCompactTransientWindowBuffers(window);
     }
@@ -3730,9 +3789,10 @@ void ImGui::NewFrame()
     // Create implicit/fallback window - which we will only render it if the user has added something to it.
     // We don't use "Debug" to avoid colliding with user trying to create a "Debug" window with custom flags.
     // This fallback is particularly important as it avoid ImGui:: calls from crashing.
+    g.WithinFrameScopeWithImplicitWindow = true;
     SetNextWindowSize(ImVec2(400,400), ImGuiCond_FirstUseEver);
     Begin("Debug##Default");
-    g.WithinFrameScopeWithImplicitWindow = true;
+    IM_ASSERT(g.CurrentWindow->IsFallbackWindow == true);
 
 #ifdef IMGUI_ENABLE_TEST_ENGINE
     ImGuiTestEngineHook_PostNewFrame(&g);
@@ -3743,7 +3803,7 @@ void ImGui::NewFrame()
 void ImGui::UpdateDebugToolItemPicker()
 {
     ImGuiContext& g = *GImGui;
-    g.DebugItemPickerBreakID = 0;
+    g.DebugItemPickerBreakId = 0;
     if (g.DebugItemPickerActive)
     {
         const ImGuiID hovered_id = g.HoveredIdPreviousFrame;
@@ -3752,7 +3812,7 @@ void ImGui::UpdateDebugToolItemPicker()
             g.DebugItemPickerActive = false;
         if (ImGui::IsMouseClicked(0) && hovered_id)
         {
-            g.DebugItemPickerBreakID = hovered_id;
+            g.DebugItemPickerBreakId = hovered_id;
             g.DebugItemPickerActive = false;
         }
         ImGui::SetNextWindowBgAlpha(0.60f);
@@ -3780,6 +3840,22 @@ void ImGui::Initialize(ImGuiContext* context)
         g.SettingsHandlers.push_back(ini_handler);
     }
 
+#ifdef IMGUI_HAS_TABLE
+    // Add .ini handle for ImGuiTable type
+    {
+        ImGuiSettingsHandler ini_handler;
+        ini_handler.TypeName = "Table";
+        ini_handler.TypeHash = ImHashStr("Table");
+        ini_handler.ReadOpenFn = TableSettingsHandler_ReadOpen;
+        ini_handler.ReadLineFn = TableSettingsHandler_ReadLine;
+        ini_handler.WriteAllFn = TableSettingsHandler_WriteAll;
+        g.SettingsHandlers.push_back(ini_handler);
+    }
+#endif // #ifdef IMGUI_HAS_TABLE
+
+#ifdef IMGUI_HAS_DOCK
+#endif // #ifdef IMGUI_HAS_DOCK
+
     g.Initialized = true;
 }
 
@@ -3813,7 +3889,7 @@ void ImGui::Shutdown(ImGuiContext* context)
         IM_DELETE(g.Windows[i]);
     g.Windows.clear();
     g.WindowsFocusOrder.clear();
-    g.WindowsSortBuffer.clear();
+    g.WindowsTempSortBuffer.clear();
     g.CurrentWindow = NULL;
     g.CurrentWindowStack.clear();
     g.WindowsById.Clear();
@@ -3941,10 +4017,8 @@ static void AddWindowToDrawData(ImVector<ImDrawList*>* out_render_list, ImGuiWin
 static void AddRootWindowToDrawData(ImGuiWindow* window)
 {
     ImGuiContext& g = *GImGui;
-    if (window->Flags & ImGuiWindowFlags_Tooltip)
-        AddWindowToDrawData(&g.DrawDataBuilder.Layers[1], window);
-    else
-        AddWindowToDrawData(&g.DrawDataBuilder.Layers[0], window);
+    int layer = (window->Flags & ImGuiWindowFlags_Tooltip) ? 1 : 0;
+    AddWindowToDrawData(&g.DrawDataBuilder.Layers[layer], window);
 }
 
 void ImDrawDataBuilder::FlattenIntoSingleLayer()
@@ -4051,19 +4125,19 @@ void ImGui::EndFrame()
 
     // Sort the window list so that all child windows are after their parent
     // We cannot do that on FocusWindow() because childs may not exist yet
-    g.WindowsSortBuffer.resize(0);
-    g.WindowsSortBuffer.reserve(g.Windows.Size);
+    g.WindowsTempSortBuffer.resize(0);
+    g.WindowsTempSortBuffer.reserve(g.Windows.Size);
     for (int i = 0; i != g.Windows.Size; i++)
     {
         ImGuiWindow* window = g.Windows[i];
         if (window->Active && (window->Flags & ImGuiWindowFlags_ChildWindow))       // if a child is active its parent will add it
             continue;
-        AddWindowToSortBuffer(&g.WindowsSortBuffer, window);
+        AddWindowToSortBuffer(&g.WindowsTempSortBuffer, window);
     }
 
     // This usually assert if there is a mismatch between the ImGuiWindowFlags_ChildWindow / ParentWindow values and DC.ChildWindows[] in parents, aka we've done something wrong.
-    IM_ASSERT(g.Windows.Size == g.WindowsSortBuffer.Size);
-    g.Windows.swap(g.WindowsSortBuffer);
+    IM_ASSERT(g.Windows.Size == g.WindowsTempSortBuffer.Size);
+    g.Windows.swap(g.WindowsTempSortBuffer);
     g.IO.MetricsActiveWindows = g.WindowsActiveCount;
 
     // Unlock font atlas
@@ -4083,16 +4157,17 @@ void ImGui::Render()
     if (g.FrameCountEnded != g.FrameCount)
         EndFrame();
     g.FrameCountRendered = g.FrameCount;
-
-    // Gather ImDrawList to render (for each active window)
-    g.IO.MetricsRenderVertices = g.IO.MetricsRenderIndices = g.IO.MetricsRenderWindows = 0;
+    g.IO.MetricsRenderWindows = 0;
     g.DrawDataBuilder.Clear();
+    
+    // Add background ImDrawList
     if (!g.BackgroundDrawList.VtxBuffer.empty())
         AddDrawListToDrawData(&g.DrawDataBuilder.Layers[0], &g.BackgroundDrawList);
 
+    // Add ImDrawList to render
     ImGuiWindow* windows_to_render_top_most[2];
     windows_to_render_top_most[0] = (g.NavWindowingTarget && !(g.NavWindowingTarget->Flags & ImGuiWindowFlags_NoBringToFrontOnFocus)) ? g.NavWindowingTarget->RootWindow : NULL;
-    windows_to_render_top_most[1] = g.NavWindowingTarget ? g.NavWindowingList : NULL;
+    windows_to_render_top_most[1] = (g.NavWindowingTarget ? g.NavWindowingList : NULL);
     for (int n = 0; n != g.Windows.Size; n++)
     {
         ImGuiWindow* window = g.Windows[n];
@@ -4108,6 +4183,7 @@ void ImGui::Render()
     if (g.IO.MouseDrawCursor)
         RenderMouseCursor(&g.ForegroundDrawList, g.IO.MousePos, g.Style.MouseCursorScale, g.MouseCursor, IM_COL32_WHITE, IM_COL32_BLACK, IM_COL32(0, 0, 0, 48));
 
+    // Add foreground ImDrawList
     if (!g.ForegroundDrawList.VtxBuffer.empty())
         AddDrawListToDrawData(&g.DrawDataBuilder.Layers[0], &g.ForegroundDrawList);
 
@@ -4216,7 +4292,8 @@ int ImGui::GetKeyIndex(ImGuiKey imgui_key)
     return g.IO.KeyMap[imgui_key];
 }
 
-// Note that imgui doesn't know the semantic of each entry of io.KeysDown[]. Use your own indices/enums according to how your back-end/engine stored them into io.KeysDown[]!
+// Note that dear imgui doesn't know the semantic of each entry of io.KeysDown[]!
+// Use your own indices/enums according to how your back-end/engine stored them into io.KeysDown[]!
 bool ImGui::IsKeyDown(int user_key_index)
 {
     if (user_key_index < 0)
@@ -4276,23 +4353,14 @@ bool ImGui::IsKeyReleased(int user_key_index)
     return g.IO.KeysDownDurationPrev[user_key_index] >= 0.0f && !g.IO.KeysDown[user_key_index];
 }
 
-bool ImGui::IsMouseDown(int button)
+bool ImGui::IsMouseDown(ImGuiMouseButton button)
 {
     ImGuiContext& g = *GImGui;
     IM_ASSERT(button >= 0 && button < IM_ARRAYSIZE(g.IO.MouseDown));
     return g.IO.MouseDown[button];
 }
 
-bool ImGui::IsAnyMouseDown()
-{
-    ImGuiContext& g = *GImGui;
-    for (int n = 0; n < IM_ARRAYSIZE(g.IO.MouseDown); n++)
-        if (g.IO.MouseDown[n])
-            return true;
-    return false;
-}
-
-bool ImGui::IsMouseClicked(int button, bool repeat)
+bool ImGui::IsMouseClicked(ImGuiMouseButton button, bool repeat)
 {
     ImGuiContext& g = *GImGui;
     IM_ASSERT(button >= 0 && button < IM_ARRAYSIZE(g.IO.MouseDown));
@@ -4307,18 +4375,17 @@ bool ImGui::IsMouseClicked(int button, bool repeat)
         if (amount > 0)
             return true;
     }
-
     return false;
 }
 
-bool ImGui::IsMouseReleased(int button)
+bool ImGui::IsMouseReleased(ImGuiMouseButton button)
 {
     ImGuiContext& g = *GImGui;
     IM_ASSERT(button >= 0 && button < IM_ARRAYSIZE(g.IO.MouseDown));
     return g.IO.MouseReleased[button];
 }
 
-bool ImGui::IsMouseDoubleClicked(int button)
+bool ImGui::IsMouseDoubleClicked(ImGuiMouseButton button)
 {
     ImGuiContext& g = *GImGui;
     IM_ASSERT(button >= 0 && button < IM_ARRAYSIZE(g.IO.MouseDown));
@@ -4326,7 +4393,7 @@ bool ImGui::IsMouseDoubleClicked(int button)
 }
 
 // [Internal] This doesn't test if the button is pressed
-bool ImGui::IsMouseDragPastThreshold(int button, float lock_threshold)
+bool ImGui::IsMouseDragPastThreshold(ImGuiMouseButton button, float lock_threshold)
 {
     ImGuiContext& g = *GImGui;
     IM_ASSERT(button >= 0 && button < IM_ARRAYSIZE(g.IO.MouseDown));
@@ -4335,7 +4402,7 @@ bool ImGui::IsMouseDragPastThreshold(int button, float lock_threshold)
     return g.IO.MouseDragMaxDistanceSqr[button] >= lock_threshold * lock_threshold;
 }
 
-bool ImGui::IsMouseDragging(int button, float lock_threshold)
+bool ImGui::IsMouseDragging(ImGuiMouseButton button, float lock_threshold)
 {
     ImGuiContext& g = *GImGui;
     IM_ASSERT(button >= 0 && button < IM_ARRAYSIZE(g.IO.MouseDown));
@@ -4346,7 +4413,8 @@ bool ImGui::IsMouseDragging(int button, float lock_threshold)
 
 ImVec2 ImGui::GetMousePos()
 {
-    return GImGui->IO.MousePos;
+    ImGuiContext& g = *GImGui;
+    return g.IO.MousePos;
 }
 
 // NB: prefer to call right after BeginPopup(). At the time Selectable/MenuItem is activated, the popup is already closed!
@@ -4369,10 +4437,19 @@ bool ImGui::IsMousePosValid(const ImVec2* mouse_pos)
     return p.x >= MOUSE_INVALID && p.y >= MOUSE_INVALID;
 }
 
+bool ImGui::IsAnyMouseDown()
+{
+    ImGuiContext& g = *GImGui;
+    for (int n = 0; n < IM_ARRAYSIZE(g.IO.MouseDown); n++)
+        if (g.IO.MouseDown[n])
+            return true;
+    return false;
+}
+
 // Return the delta from the initial clicking position while the mouse button is clicked or was just released.
 // This is locked and return 0.0f until the mouse moves past a distance threshold at least once.
 // NB: This is only valid if IsMousePosValid(). Back-ends in theory should always keep mouse position valid when dragging even outside the client window.
-ImVec2 ImGui::GetMouseDragDelta(int button, float lock_threshold)
+ImVec2 ImGui::GetMouseDragDelta(ImGuiMouseButton button, float lock_threshold)
 {
     ImGuiContext& g = *GImGui;
     IM_ASSERT(button >= 0 && button < IM_ARRAYSIZE(g.IO.MouseDown));
@@ -4385,7 +4462,7 @@ ImVec2 ImGui::GetMouseDragDelta(int button, float lock_threshold)
     return ImVec2(0.0f, 0.0f);
 }
 
-void ImGui::ResetMouseDragDelta(int button)
+void ImGui::ResetMouseDragDelta(ImGuiMouseButton button)
 {
     ImGuiContext& g = *GImGui;
     IM_ASSERT(button >= 0 && button < IM_ARRAYSIZE(g.IO.MouseDown));
@@ -4461,7 +4538,7 @@ bool ImGui::IsItemFocused()
     return true;
 }
 
-bool ImGui::IsItemClicked(int mouse_button)
+bool ImGui::IsItemClicked(ImGuiMouseButton mouse_button)
 {
     return IsMouseClicked(mouse_button) && IsItemHovered(ImGuiHoveredFlags_None);
 }
@@ -4542,7 +4619,7 @@ static ImRect GetViewportRect()
     return ImRect(0.0f, 0.0f, g.IO.DisplaySize.x, g.IO.DisplaySize.y);
 }
 
-static bool ImGui::BeginChildEx(const char* name, ImGuiID id, const ImVec2& size_arg, bool border, ImGuiWindowFlags flags)
+bool ImGui::BeginChildEx(const char* name, ImGuiID id, const ImVec2& size_arg, bool border, ImGuiWindowFlags flags)
 {
     ImGuiContext& g = *GImGui;
     ImGuiWindow* parent_window = g.CurrentWindow;
@@ -4611,7 +4688,7 @@ void ImGui::EndChild()
     ImGuiWindow* window = g.CurrentWindow;
 
     IM_ASSERT(g.WithinEndChild == false);
-    IM_ASSERT(window->Flags & ImGuiWindowFlags_ChildWindow);   // Mismatched BeginChild()/EndChild() callss
+    IM_ASSERT(window->Flags & ImGuiWindowFlags_ChildWindow);   // Mismatched BeginChild()/EndChild() calls
 
     g.WithinEndChild = true;
     if (window->BeginCount > 1)
@@ -4763,8 +4840,9 @@ static ImVec2 CalcWindowSizeAfterConstraint(ImGuiWindow* window, ImVec2 new_size
     // Minimum size
     if (!(window->Flags & (ImGuiWindowFlags_ChildWindow | ImGuiWindowFlags_AlwaysAutoResize)))
     {
+        ImGuiWindow* window_for_height = window;
         new_size = ImMax(new_size, g.Style.WindowMinSize);
-        new_size.y = ImMax(new_size.y, window->TitleBarHeight() + window->MenuBarHeight() + ImMax(0.0f, g.Style.WindowRounding - 1.0f)); // Reduce artifacts with very small windows
+        new_size.y = ImMax(new_size.y, window_for_height->TitleBarHeight() + window_for_height->MenuBarHeight() + ImMax(0.0f, g.Style.WindowRounding - 1.0f)); // Reduce artifacts with very small windows
     }
     return new_size;
 }
@@ -4971,6 +5049,10 @@ static bool ImGui::UpdateManualResize(ImGuiWindow* window, const ImVec2& size_au
     }
     PopID();
 
+    // Restore nav layer
+    window->DC.NavLayerCurrent = ImGuiNavLayer_Main;
+    window->DC.NavLayerCurrentMask = (1 << ImGuiNavLayer_Main);
+
     // Navigation resize (keyboard/gamepad)
     if (g.NavWindowingTarget && g.NavWindowingTarget->RootWindow == window)
     {
@@ -5003,10 +5085,6 @@ static bool ImGui::UpdateManualResize(ImGuiWindow* window, const ImVec2& size_au
         MarkIniSettingsDirty(window);
     }
 
-    // Resize nav layer
-    window->DC.NavLayerCurrent = ImGuiNavLayer_Main;
-    window->DC.NavLayerCurrentMask = (1 << ImGuiNavLayer_Main);
-
     window->Size = window->SizeFull;
     return ret_auto_fit;
 }
@@ -5055,6 +5133,8 @@ static void ImGui::RenderWindowOuterBorders(ImGuiWindow* window)
     }
 }
 
+// Draw background and borders
+// Draw and handle scrollbars
 void ImGui::RenderWindowDecorations(ImGuiWindow* window, const ImRect& title_bar_rect, bool title_bar_is_highlight, int resize_grip_count, const ImU32 resize_grip_col[4], float resize_grip_draw_size)
 {
     ImGuiContext& g = *GImGui;
@@ -5083,10 +5163,14 @@ void ImGui::RenderWindowDecorations(ImGuiWindow* window, const ImRect& title_bar
         if (!(flags & ImGuiWindowFlags_NoBackground))
         {
             ImU32 bg_col = GetColorU32(GetWindowBgColorIdxFromFlags(flags));
+            bool override_alpha = false;
             float alpha = 1.0f;
             if (g.NextWindowData.Flags & ImGuiNextWindowDataFlags_HasBgAlpha)
+            {
                 alpha = g.NextWindowData.BgAlphaVal;
-            if (alpha != 1.0f)
+                override_alpha = true;
+            }
+            if (override_alpha)
                 bg_col = (bg_col & ~IM_COL32_A_MASK) | (IM_F32_TO_INT8_SAT(alpha) << IM_COL32_A_SHIFT);
             window->DrawList->AddRectFilled(window->Pos + ImVec2(0, window->TitleBarHeight()), window->Pos + window->Size, bg_col, window_rounding, (flags & ImGuiWindowFlags_NoTitleBar) ? ImDrawCornerFlags_All : ImDrawCornerFlags_Bot);
         }
@@ -5266,6 +5350,7 @@ bool ImGui::Begin(const char* name, bool* p_open, ImGuiWindowFlags flags)
 
     const int current_frame = g.FrameCount;
     const bool first_begin_of_the_frame = (window->LastFrameActive != current_frame);
+    window->IsFallbackWindow = (g.CurrentWindowStack.Size == 0 && g.WithinFrameScopeWithImplicitWindow);
 
     // Update the Appearing flag
     bool window_just_activated_by_user = (window->LastFrameActive < current_frame - 1);   // Not using !WasActive because the implicit "Debug" window would always toggle off->on
@@ -5319,6 +5404,10 @@ bool ImGui::Begin(const char* name, bool* p_open, ImGuiWindowFlags flags)
     if (window_just_appearing_after_hidden_for_resize && !(flags & ImGuiWindowFlags_ChildWindow))
         window->NavLastIds[0] = 0;
 
+    // Update ->RootWindow and others pointers (before any possible call to FocusWindow)
+    if (first_begin_of_the_frame)
+        UpdateWindowParentAndRootLinks(window, flags, parent_window);
+
     // Process SetNextWindow***() calls
     bool window_pos_set_by_api = false;
     bool window_size_x_set_by_api = false, window_size_y_set_by_api = false;
@@ -5360,8 +5449,6 @@ bool ImGui::Begin(const char* name, bool* p_open, ImGuiWindowFlags flags)
     {
         // Initialize
         const bool window_is_child_tooltip = (flags & ImGuiWindowFlags_ChildWindow) && (flags & ImGuiWindowFlags_Tooltip); // FIXME-WIP: Undocumented behavior of Child+Tooltip for pinned tooltip (#1345)
-        UpdateWindowParentAndRootLinks(window, flags, parent_window);
-
         window->Active = true;
         window->HasCloseButton = (p_open != NULL);
         window->ClipRect = ImVec4(-FLT_MAX,-FLT_MAX,+FLT_MAX,+FLT_MAX);
@@ -5411,6 +5498,7 @@ bool ImGui::Begin(const char* name, bool* p_open, ImGuiWindowFlags flags)
             }
         }
 
+        // SELECT VIEWPORT
         // FIXME-VIEWPORT: In the docking/viewport branch, this is the point where we select the current viewport (which may affect the style)
         SetCurrentWindow(window);
 
@@ -5423,8 +5511,6 @@ bool ImGui::Begin(const char* name, bool* p_open, ImGuiWindowFlags flags)
         window->WindowPadding = style.WindowPadding;
         if ((flags & ImGuiWindowFlags_ChildWindow) && !(flags & (ImGuiWindowFlags_AlwaysUseWindowPadding | ImGuiWindowFlags_Popup)) && window->WindowBorderSize == 0.0f)
             window->WindowPadding = ImVec2(0.0f, (flags & ImGuiWindowFlags_MenuBar) ? style.WindowPadding.y : 0.0f);
-        window->DC.MenuBarOffset.x = ImMax(ImMax(window->WindowPadding.x, style.ItemSpacing.x), g.NextWindowData.MenuBarOffsetMinVal.x);
-        window->DC.MenuBarOffset.y = g.NextWindowData.MenuBarOffsetMinVal.y;
 
         // Collapse window by double-clicking on title bar
         // At this point we don't have a clipping rectangle setup yet, so we can use the title bar area for hit detection and drawing
@@ -5523,14 +5609,13 @@ bool ImGui::Begin(const char* name, bool* p_open, ImGuiWindowFlags flags)
             window->Pos = FindBestWindowPosForPopup(window);
 
         // Clamp position/size so window stays visible within its viewport or monitor
-
         // Ignore zero-sized display explicitly to avoid losing positions if a window manager reports zero-sized window when initializing or minimizing.
         ImRect viewport_rect(GetViewportRect());
         if (!window_pos_set_by_api && !(flags & ImGuiWindowFlags_ChildWindow) && window->AutoFitFramesX <= 0 && window->AutoFitFramesY <= 0)
         {
-            if (g.IO.DisplaySize.x > 0.0f && g.IO.DisplaySize.y > 0.0f) // Ignore zero-sized display explicitly to avoid losing positions if a window manager reports zero-sized window when initializing or minimizing.
+            ImVec2 clamp_padding = ImMax(style.DisplayWindowPadding, style.DisplaySafeAreaPadding);
+            if (viewport_rect.GetWidth() > 0 && viewport_rect.GetHeight() > 0.0f)
             {
-                ImVec2 clamp_padding = ImMax(style.DisplayWindowPadding, style.DisplaySafeAreaPadding);
                 ClampWindowRect(window, viewport_rect, clamp_padding);
             }
         }
@@ -5667,20 +5752,22 @@ bool ImGui::Begin(const char* name, bool* p_open, ImGuiWindowFlags flags)
         // We disable this when the parent window has zero vertices, which is a common pattern leading to laying out multiple overlapping child.
         // We also disabled this when we have dimming overlay behind this specific one child.
         // FIXME: More code may rely on explicit sorting of overlapping child window and would need to disable this somehow. Please get in contact if you are affected.
-        bool render_decorations_in_parent = false;
-        if ((flags & ImGuiWindowFlags_ChildWindow) && !(flags & ImGuiWindowFlags_Popup) && !window_is_child_tooltip)
-            if (window->DrawList->CmdBuffer.back().ElemCount == 0 && parent_window->DrawList->VtxBuffer.Size > 0)
-                render_decorations_in_parent = true;
-        if (render_decorations_in_parent)
-            window->DrawList = parent_window->DrawList;
-
-        // Handle title bar, scrollbar, resize grips and resize borders
-        const ImGuiWindow* window_to_highlight = g.NavWindowingTarget ? g.NavWindowingTarget : g.NavWindow;
-        const bool title_bar_is_highlight = want_focus || (window_to_highlight && window->RootWindowForTitleBarHighlight == window_to_highlight->RootWindowForTitleBarHighlight);
-        RenderWindowDecorations(window, title_bar_rect, title_bar_is_highlight, resize_grip_count, resize_grip_col, resize_grip_draw_size);
-
-        if (render_decorations_in_parent)
-            window->DrawList = &window->DrawListInst;
+        {
+            bool render_decorations_in_parent = false;
+            if ((flags & ImGuiWindowFlags_ChildWindow) && !(flags & ImGuiWindowFlags_Popup) && !window_is_child_tooltip)
+                if (window->DrawList->CmdBuffer.back().ElemCount == 0 && parent_window->DrawList->VtxBuffer.Size > 0)
+                    render_decorations_in_parent = true;
+            if (render_decorations_in_parent)
+                window->DrawList = parent_window->DrawList;
+
+            // Handle title bar, scrollbar, resize grips and resize borders
+            const ImGuiWindow* window_to_highlight = g.NavWindowingTarget ? g.NavWindowingTarget : g.NavWindow;
+            const bool title_bar_is_highlight = want_focus || (window_to_highlight && window->RootWindowForTitleBarHighlight == window_to_highlight->RootWindowForTitleBarHighlight);
+            RenderWindowDecorations(window, title_bar_rect, title_bar_is_highlight, resize_grip_count, resize_grip_col, resize_grip_draw_size);
+
+            if (render_decorations_in_parent)
+                window->DrawList = &window->DrawListInst;
+        }
 
         // Draw navigation selection/windowing rectangle border
         if (g.NavWindowingTargetAnim == window)
@@ -5732,27 +5819,35 @@ bool ImGui::Begin(const char* name, bool* p_open, ImGuiWindowFlags flags)
         window->DC.CursorMaxPos = window->DC.CursorStartPos;
         window->DC.CurrLineSize = window->DC.PrevLineSize = ImVec2(0.0f, 0.0f);
         window->DC.CurrLineTextBaseOffset = window->DC.PrevLineTextBaseOffset = 0.0f;
-        window->DC.NavHideHighlightOneFrame = false;
-        window->DC.NavHasScroll = (window->ScrollMax.y > 0.0f);
+
+        window->DC.NavLayerCurrent = ImGuiNavLayer_Main;
+        window->DC.NavLayerCurrentMask = (1 << ImGuiNavLayer_Main);
         window->DC.NavLayerActiveMask = window->DC.NavLayerActiveMaskNext;
         window->DC.NavLayerActiveMaskNext = 0x00;
+        window->DC.NavFocusScopeIdCurrent = 0;
+        window->DC.NavHideHighlightOneFrame = false;
+        window->DC.NavHasScroll = (window->ScrollMax.y > 0.0f);
+
         window->DC.MenuBarAppending = false;
+        window->DC.MenuBarOffset.x = ImMax(ImMax(window->WindowPadding.x, style.ItemSpacing.x), g.NextWindowData.MenuBarOffsetMinVal.x);
+        window->DC.MenuBarOffset.y = g.NextWindowData.MenuBarOffsetMinVal.y;
+        window->DC.MenuColumns.Update(3, style.ItemSpacing.x, window_just_activated_by_user);
+        window->DC.TreeDepth = 0;
+        window->DC.TreeJumpToParentOnPopMask = 0x00;
         window->DC.ChildWindows.resize(0);
+        window->DC.StateStorage = &window->StateStorage;
+        window->DC.CurrentColumns = NULL;
         window->DC.LayoutType = ImGuiLayoutType_Vertical;
         window->DC.ParentLayoutType = parent_window ? parent_window->DC.LayoutType : ImGuiLayoutType_Vertical;
-        window->DC.FocusCounterAll = window->DC.FocusCounterTab = -1;
+        window->DC.FocusCounterRegular = window->DC.FocusCounterTabStop = -1;
+
         window->DC.ItemFlags = parent_window ? parent_window->DC.ItemFlags : ImGuiItemFlags_Default_;
         window->DC.ItemWidth = window->ItemWidthDefault;
         window->DC.TextWrapPos = -1.0f; // disabled
         window->DC.ItemFlagsStack.resize(0);
         window->DC.ItemWidthStack.resize(0);
         window->DC.TextWrapPosStack.resize(0);
-        window->DC.CurrentColumns = NULL;
-        window->DC.TreeDepth = 0;
-        window->DC.TreeMayJumpToParentOnPopMask = 0x00;
-        window->DC.StateStorage = &window->StateStorage;
         window->DC.GroupStack.resize(0);
-        window->MenuColumns.Update(3, style.ItemSpacing.x, window_just_activated_by_user);
 
         if ((flags & ImGuiWindowFlags_ChildWindow) && (window->DC.ItemFlags != parent_window->DC.ItemFlags))
         {
@@ -5932,6 +6027,7 @@ void ImGui::FocusWindow(ImGuiWindow* window)
             g.NavMousePosDirty = true;
         g.NavInitRequest = false;
         g.NavId = window ? window->NavLastIds[0] : 0; // Restore NavId
+        g.NavFocusScopeId = 0;
         g.NavIdIsAlive = false;
         g.NavLayer = ImGuiNavLayer_Main;
         //IMGUI_DEBUG_LOG("FocusWindow(\"%s\")\n", window ? window->Name : NULL);
@@ -5945,18 +6041,19 @@ void ImGui::FocusWindow(ImGuiWindow* window)
         return;
 
     // Move the root window to the top of the pile
-    if (window->RootWindow)
-        window = window->RootWindow;
+    IM_ASSERT(window->RootWindow != NULL);
+    ImGuiWindow* focus_front_window = window->RootWindow; // NB: In docking branch this is window->RootWindowDockStop
+    ImGuiWindow* display_front_window = window->RootWindow;
 
     // Steal focus on active widgets
-    if (window->Flags & ImGuiWindowFlags_Popup) // FIXME: This statement should be unnecessary. Need further testing before removing it..
-        if (g.ActiveId != 0 && g.ActiveIdWindow && g.ActiveIdWindow->RootWindow != window)
+    if (focus_front_window->Flags & ImGuiWindowFlags_Popup) // FIXME: This statement may be unnecessary? Need further testing before removing it..
+        if (g.ActiveId != 0 && g.ActiveIdWindow && g.ActiveIdWindow->RootWindow != focus_front_window)
             ClearActiveID();
 
     // Bring to front
-    BringWindowToFocusFront(window);
-    if (!(window->Flags & ImGuiWindowFlags_NoBringToFrontOnFocus))
-        BringWindowToDisplayFront(window);
+    BringWindowToFocusFront(focus_front_window);
+    if (((window->Flags | display_front_window->Flags) & ImGuiWindowFlags_NoBringToFrontOnFocus) == 0)
+        BringWindowToDisplayFront(display_front_window);
 }
 
 void ImGui::FocusTopMostWindowUnderOne(ImGuiWindow* under_this_window, ImGuiWindow* ignore_window)
@@ -6788,14 +6885,30 @@ void ImGui::ActivateItem(ImGuiID id)
     g.NavNextActivateId = id;
 }
 
+void ImGui::PushFocusScope(ImGuiID id)
+{
+    ImGuiContext& g = *GImGui;
+    ImGuiWindow* window = g.CurrentWindow;
+    window->IDStack.push_back(window->DC.NavFocusScopeIdCurrent);
+    window->DC.NavFocusScopeIdCurrent = id;
+}
+
+void ImGui::PopFocusScope()
+{
+    ImGuiContext& g = *GImGui;
+    ImGuiWindow* window = g.CurrentWindow;
+    window->DC.NavFocusScopeIdCurrent = window->IDStack.back();
+    window->IDStack.pop_back();
+}
+
 void ImGui::SetKeyboardFocusHere(int offset)
 {
     IM_ASSERT(offset >= -1);    // -1 is allowed but not below
     ImGuiContext& g = *GImGui;
     ImGuiWindow* window = g.CurrentWindow;
     g.FocusRequestNextWindow = window;
-    g.FocusRequestNextCounterAll = window->DC.FocusCounterAll + 1 + offset;
-    g.FocusRequestNextCounterTab = INT_MAX;
+    g.FocusRequestNextCounterRegular = window->DC.FocusCounterRegular + 1 + offset;
+    g.FocusRequestNextCounterTabStop = INT_MAX;
 }
 
 void ImGui::SetItemDefaultFocus()
@@ -7244,7 +7357,13 @@ void ImGui::SetScrollHereY(float center_y_ratio)
 
 void ImGui::BeginTooltip()
 {
+    BeginTooltipEx(ImGuiWindowFlags_None, ImGuiTooltipFlags_None);
+}
+
+void ImGui::BeginTooltipEx(ImGuiWindowFlags extra_flags, ImGuiTooltipFlags tooltip_flags)
+{
     ImGuiContext& g = *GImGui;
+
     if (g.DragDropWithinSourceOrTarget)
     {
         // The default tooltip position is a little offset to give space to see the context menu (it's also clamped within the current viewport/monitor)
@@ -7255,21 +7374,12 @@ void ImGui::BeginTooltip()
         SetNextWindowPos(tooltip_pos);
         SetNextWindowBgAlpha(g.Style.Colors[ImGuiCol_PopupBg].w * 0.60f);
         //PushStyleVar(ImGuiStyleVar_Alpha, g.Style.Alpha * 0.60f); // This would be nice but e.g ColorButton with checkboard has issue with transparent colors :(
-        BeginTooltipEx(0, true);
-    }
-    else
-    {
-        BeginTooltipEx(0, false);
+        tooltip_flags |= ImGuiTooltipFlags_OverridePreviousTooltip;
     }
-}
 
-// Not exposed publicly as BeginTooltip() because bool parameters are evil. Let's see if other needs arise first.
-void ImGui::BeginTooltipEx(ImGuiWindowFlags extra_flags, bool override_previous_tooltip)
-{
-    ImGuiContext& g = *GImGui;
     char window_name[16];
     ImFormatString(window_name, IM_ARRAYSIZE(window_name), "##Tooltip_%02d", g.TooltipOverrideCount);
-    if (override_previous_tooltip)
+    if (tooltip_flags & ImGuiTooltipFlags_OverridePreviousTooltip)
         if (ImGuiWindow* window = FindWindowByName(window_name))
             if (window->Active)
             {
@@ -7290,11 +7400,7 @@ void ImGui::EndTooltip()
 
 void ImGui::SetTooltipV(const char* fmt, va_list args)
 {
-    ImGuiContext& g = *GImGui;
-    if (g.DragDropWithinSourceOrTarget)
-        BeginTooltip();
-    else
-        BeginTooltipEx(0, true);
+    BeginTooltipEx(0, ImGuiTooltipFlags_OverridePreviousTooltip);
     TextV(fmt, args);
     EndTooltip();
 }
@@ -7478,7 +7584,7 @@ void ImGui::CloseCurrentPopup()
         window->DC.NavHideHighlightOneFrame = true;
 }
 
-bool ImGui::BeginPopupEx(ImGuiID id, ImGuiWindowFlags extra_flags)
+bool ImGui::BeginPopupEx(ImGuiID id, ImGuiWindowFlags flags)
 {
     ImGuiContext& g = *GImGui;
     if (!IsPopupOpen(id))
@@ -7488,12 +7594,13 @@ bool ImGui::BeginPopupEx(ImGuiID id, ImGuiWindowFlags extra_flags)
     }
 
     char name[20];
-    if (extra_flags & ImGuiWindowFlags_ChildMenu)
+    if (flags & ImGuiWindowFlags_ChildMenu)
         ImFormatString(name, IM_ARRAYSIZE(name), "##Menu_%02d", g.BeginPopupStack.Size); // Recycle windows based on depth
     else
         ImFormatString(name, IM_ARRAYSIZE(name), "##Popup_%08x", id); // Not recycling, so we can close/open during the same frame
 
-    bool is_open = Begin(name, NULL, extra_flags | ImGuiWindowFlags_Popup);
+    flags |= ImGuiWindowFlags_Popup;
+    bool is_open = Begin(name, NULL, flags);
     if (!is_open) // NB: Begin can return false when the popup is completely clipped (e.g. zero size display)
         EndPopup();
 
@@ -7560,7 +7667,7 @@ void ImGui::EndPopup()
     g.WithinEndChild = false;
 }
 
-bool ImGui::OpenPopupOnItemClick(const char* str_id, int mouse_button)
+bool ImGui::OpenPopupOnItemClick(const char* str_id, ImGuiMouseButton mouse_button)
 {
     ImGuiWindow* window = GImGui->CurrentWindow;
     if (IsMouseReleased(mouse_button) && IsItemHovered(ImGuiHoveredFlags_AllowWhenBlockedByPopup))
@@ -7576,7 +7683,7 @@ bool ImGui::OpenPopupOnItemClick(const char* str_id, int mouse_button)
 // This is a helper to handle the simplest case of associating one named popup to one given widget.
 // You may want to handle this on user side if you have specific needs (e.g. tweaking IsItemHovered() parameters).
 // You can pass a NULL str_id to use the identifier of the last item.
-bool ImGui::BeginPopupContextItem(const char* str_id, int mouse_button)
+bool ImGui::BeginPopupContextItem(const char* str_id, ImGuiMouseButton mouse_button)
 {
     ImGuiWindow* window = GImGui->CurrentWindow;
     if (window->SkipItems)
@@ -7588,7 +7695,7 @@ bool ImGui::BeginPopupContextItem(const char* str_id, int mouse_button)
     return BeginPopupEx(id, ImGuiWindowFlags_AlwaysAutoResize|ImGuiWindowFlags_NoTitleBar|ImGuiWindowFlags_NoSavedSettings);
 }
 
-bool ImGui::BeginPopupContextWindow(const char* str_id, int mouse_button, bool also_over_items)
+bool ImGui::BeginPopupContextWindow(const char* str_id, ImGuiMouseButton mouse_button, bool also_over_items)
 {
     if (!str_id)
         str_id = "window_context";
@@ -7599,7 +7706,7 @@ bool ImGui::BeginPopupContextWindow(const char* str_id, int mouse_button, bool a
     return BeginPopupEx(id, ImGuiWindowFlags_AlwaysAutoResize|ImGuiWindowFlags_NoTitleBar|ImGuiWindowFlags_NoSavedSettings);
 }
 
-bool ImGui::BeginPopupContextVoid(const char* str_id, int mouse_button)
+bool ImGui::BeginPopupContextVoid(const char* str_id, ImGuiMouseButton mouse_button)
 {
     if (!str_id)
         str_id = "void_context";
@@ -7721,6 +7828,52 @@ ImVec2 ImGui::FindBestWindowPosForPopup(ImGuiWindow* window)
 // [SECTION] KEYBOARD/GAMEPAD NAVIGATION
 //-----------------------------------------------------------------------------
 
+// FIXME-NAV: The existence of SetNavID vs SetNavIDWithRectRel vs SetFocusID is incredibly messy and confusing,
+// and needs some explanation or serious refactoring.
+void ImGui::SetNavID(ImGuiID id, int nav_layer, ImGuiID focus_scope_id)
+{
+    ImGuiContext& g = *GImGui;
+    IM_ASSERT(g.NavWindow);
+    IM_ASSERT(nav_layer == 0 || nav_layer == 1);
+    g.NavId = id;
+    g.NavFocusScopeId = focus_scope_id;
+    g.NavWindow->NavLastIds[nav_layer] = id;
+}
+
+void ImGui::SetNavIDWithRectRel(ImGuiID id, int nav_layer, ImGuiID focus_scope_id, const ImRect& rect_rel)
+{
+    ImGuiContext& g = *GImGui;
+    SetNavID(id, nav_layer, focus_scope_id);
+    g.NavWindow->NavRectRel[nav_layer] = rect_rel;
+    g.NavMousePosDirty = true;
+    g.NavDisableHighlight = false;
+    g.NavDisableMouseHover = true;
+}
+
+void ImGui::SetFocusID(ImGuiID id, ImGuiWindow* window)
+{
+    ImGuiContext& g = *GImGui;
+    IM_ASSERT(id != 0);
+
+    // Assume that SetFocusID() is called in the context where its window->DC.NavLayerCurrent and window->DC.NavFocusScopeIdCurrent are valid.
+    // Note that window may be != g.CurrentWindow (e.g. SetFocusID call in InputTextEx for multi-line text)
+    const ImGuiNavLayer nav_layer = window->DC.NavLayerCurrent;
+    if (g.NavWindow != window)
+        g.NavInitRequest = false;
+    g.NavWindow = window;
+    g.NavId = id;
+    g.NavLayer = nav_layer;
+    g.NavFocusScopeId = window->DC.NavFocusScopeIdCurrent;
+    window->NavLastIds[nav_layer] = id;
+    if (window->DC.LastItemId == id)
+        window->NavRectRel[nav_layer] = ImRect(window->DC.LastItemRect.Min - window->Pos, window->DC.LastItemRect.Max - window->Pos);
+
+    if (g.ActiveIdSource == ImGuiInputSource_Nav)
+        g.NavDisableMouseHover = true;
+    else
+        g.NavDisableHighlight = true;
+}
+
 ImGuiDir ImGetDirQuadrantFromDelta(float dx, float dy)
 {
     if (ImFabs(dx) > ImFabs(dy))
@@ -7924,21 +8077,22 @@ static void ImGui::NavProcessItem(ImGuiWindow* window, const ImRect& nav_bb, con
 #endif
         if (new_best)
         {
-            result->ID = id;
-            result->SelectScopeId = g.MultiSelectScopeId;
             result->Window = window;
+            result->ID = id;
+            result->FocusScopeId = window->DC.NavFocusScopeIdCurrent;
             result->RectRel = nav_bb_rel;
         }
 
+        // Features like PageUp/PageDown need to maintain a separate score for the visible set of items.
         const float VISIBLE_RATIO = 0.70f;
         if ((g.NavMoveRequestFlags & ImGuiNavMoveFlags_AlsoScoreVisibleSet) && window->ClipRect.Overlaps(nav_bb))
             if (ImClamp(nav_bb.Max.y, window->ClipRect.Min.y, window->ClipRect.Max.y) - ImClamp(nav_bb.Min.y, window->ClipRect.Min.y, window->ClipRect.Max.y) >= (nav_bb.Max.y - nav_bb.Min.y) * VISIBLE_RATIO)
                 if (NavScoreItem(&g.NavMoveResultLocalVisibleSet, nav_bb))
                 {
                     result = &g.NavMoveResultLocalVisibleSet;
-                    result->ID = id;
-                    result->SelectScopeId = g.MultiSelectScopeId;
                     result->Window = window;
+                    result->ID = id;
+                    result->FocusScopeId = window->DC.NavFocusScopeIdCurrent;
                     result->RectRel = nav_bb_rel;
                 }
     }
@@ -7948,8 +8102,9 @@ static void ImGui::NavProcessItem(ImGuiWindow* window, const ImRect& nav_bb, con
     {
         g.NavWindow = window;                                           // Always refresh g.NavWindow, because some operations such as FocusItem() don't have a window.
         g.NavLayer = window->DC.NavLayerCurrent;
+        g.NavFocusScopeId = window->DC.NavFocusScopeIdCurrent;
         g.NavIdIsAlive = true;
-        g.NavIdTabCounter = window->DC.FocusCounterTab;
+        g.NavIdTabCounter = window->DC.FocusCounterTabStop;
         window->NavRectRel[window->DC.NavLayerCurrent] = nav_bb_rel;    // Store item bounding box (relative to window position)
     }
 }
@@ -8038,10 +8193,11 @@ static void NavRestoreLayer(ImGuiNavLayer layer)
     g.NavLayer = layer;
     if (layer == 0)
         g.NavWindow = ImGui::NavRestoreLastChildNavWindow(g.NavWindow);
-    if (layer == 0 && g.NavWindow->NavLastIds[0] != 0)
-        ImGui::SetNavIDWithRectRel(g.NavWindow->NavLastIds[0], layer, g.NavWindow->NavRectRel[0]);
+    ImGuiWindow* window = g.NavWindow;
+    if (layer == 0 && window->NavLastIds[0] != 0)
+        ImGui::SetNavIDWithRectRel(window->NavLastIds[0], layer, 0, window->NavRectRel[0]);
     else
-        ImGui::NavInitWindow(g.NavWindow, true);
+        ImGui::NavInitWindow(window, true);
 }
 
 static inline void ImGui::NavUpdateAnyRequestFlag()
@@ -8064,7 +8220,7 @@ void ImGui::NavInitWindow(ImGuiWindow* window, bool force_reinit)
     //IMGUI_DEBUG_LOG("[Nav] NavInitWindow() init_for_nav=%d, window=\"%s\", layer=%d\n", init_for_nav, window->Name, g.NavLayer);
     if (init_for_nav)
     {
-        SetNavID(0, g.NavLayer);
+        SetNavID(0, g.NavLayer, 0);
         g.NavInitRequest = true;
         g.NavInitRequestFromMove = false;
         g.NavInitResultId = 0;
@@ -8074,6 +8230,7 @@ void ImGui::NavInitWindow(ImGuiWindow* window, bool force_reinit)
     else
     {
         g.NavId = window->NavLastIds[0];
+        g.NavFocusScopeId = 0;
     }
 }
 
@@ -8143,7 +8300,8 @@ static void ImGui::NavUpdate()
     if (g.NavScoringCount > 0) IMGUI_DEBUG_LOG("NavScoringCount %d for '%s' layer %d (Init:%d, Move:%d)\n", g.FrameCount, g.NavScoringCount, g.NavWindow ? g.NavWindow->Name : "NULL", g.NavLayer, g.NavInitRequest || g.NavInitResultId != 0, g.NavMoveRequest);
 #endif
 
-    // Set input source as Gamepad when buttons are pressed before we map Keyboard (some features differs when used with Gamepad vs Keyboard)
+    // Set input source as Gamepad when buttons are pressed (as some features differs when used with Gamepad vs Keyboard)
+    // (do it before we map Keyboard input!)
     bool nav_keyboard_active = (g.IO.ConfigFlags & ImGuiConfigFlags_NavEnableKeyboard) != 0;
     bool nav_gamepad_active = (g.IO.ConfigFlags & ImGuiConfigFlags_NavEnableGamepad) != 0 && (g.IO.BackendFlags & ImGuiBackendFlags_HasGamepad) != 0;
     if (nav_gamepad_active)
@@ -8180,9 +8338,9 @@ static void ImGui::NavUpdate()
         // Apply result from previous navigation init request (will typically select the first item, unless SetItemDefaultFocus() has been called)
         //IMGUI_DEBUG_LOG("[Nav] Apply NavInitRequest result: 0x%08X Layer %d in \"%s\"\n", g.NavInitResultId, g.NavLayer, g.NavWindow->Name);
         if (g.NavInitRequestFromMove)
-            SetNavIDWithRectRel(g.NavInitResultId, g.NavLayer, g.NavInitResultRectRel);
+            SetNavIDWithRectRel(g.NavInitResultId, g.NavLayer, 0, g.NavInitResultRectRel);
         else
-            SetNavID(g.NavInitResultId, g.NavLayer);
+            SetNavID(g.NavInitResultId, g.NavLayer, 0);
         g.NavWindow->NavRectRel[g.NavLayer] = g.NavInitResultRectRel;
     }
     g.NavInitRequest = false;
@@ -8249,8 +8407,9 @@ static void ImGui::NavUpdate()
             ImGuiWindow* parent_window = g.NavWindow->ParentWindow;
             IM_ASSERT(child_window->ChildId != 0);
             FocusWindow(parent_window);
-            SetNavID(child_window->ChildId, 0);
-            g.NavIdIsAlive = false;
+            SetNavID(child_window->ChildId, 0, 0);
+            // Reassigning with same value, we're being explicit here.
+            g.NavIdIsAlive = false;     // -V1048
             if (g.NavDisableMouseHover)
                 g.NavMousePosDirty = true;
         }
@@ -8270,7 +8429,7 @@ static void ImGui::NavUpdate()
             // Clear NavLastId for popups but keep it for regular child window so we can leave one and come back where we were
             if (g.NavWindow && ((g.NavWindow->Flags & ImGuiWindowFlags_Popup) || !(g.NavWindow->Flags & ImGuiWindowFlags_ChildWindow)))
                 g.NavWindow->NavLastIds[0] = 0;
-            g.NavId = 0;
+            g.NavId = g.NavFocusScopeId = 0;
         }
     }
 
@@ -8340,7 +8499,8 @@ static void ImGui::NavUpdate()
     {
         //IMGUI_DEBUG_LOG("[Nav] NavInitRequest from move, window \"%s\", layer=%d\n", g.NavWindow->Name, g.NavLayer);
         g.NavInitRequest = g.NavInitRequestFromMove = true;
-        g.NavInitResultId = 0;
+        // Reassigning with same value, we're being explicit here.
+        g.NavInitResultId = 0;     // -V1048
         g.NavDisableHighlight = false;
     }
     NavUpdateAnyRequestFlag();
@@ -8389,7 +8549,7 @@ static void ImGui::NavUpdate()
             float pad = window->CalcFontSize() * 0.5f;
             window_rect_rel.Expand(ImVec2(-ImMin(window_rect_rel.GetWidth(), pad), -ImMin(window_rect_rel.GetHeight(), pad))); // Terrible approximation for the intent of starting navigation from first fully visible item
             window->NavRectRel[g.NavLayer].ClipWith(window_rect_rel);
-            g.NavId = 0;
+            g.NavId = g.NavFocusScopeId = 0;
         }
         g.NavMoveFromClampedRefRect = false;
     }
@@ -8469,9 +8629,10 @@ static void ImGui::NavUpdateMoveResult()
     {
         // Don't set NavJustMovedToId if just landed on the same spot (which may happen with ImGuiNavMoveFlags_AllowCurrentNavId)
         g.NavJustMovedToId = result->ID;
-        g.NavJustMovedToMultiSelectScopeId = result->SelectScopeId;
+        g.NavJustMovedToFocusScopeId = result->FocusScopeId;
+
     }
-    SetNavIDWithRectRel(result->ID, g.NavLayer, result->RectRel);
+    SetNavIDWithRectRel(result->ID, g.NavLayer, result->FocusScopeId, result->RectRel);
     g.NavMoveFromClampedRefRect = false;
 }
 
@@ -8611,7 +8772,7 @@ static void ImGui::NavUpdateWindowing()
     if (start_windowing_with_gamepad || start_windowing_with_keyboard)
         if (ImGuiWindow* window = g.NavWindow ? g.NavWindow : FindWindowNavFocusable(g.WindowsFocusOrder.Size - 1, -INT_MAX, -1))
         {
-            g.NavWindowingTarget = g.NavWindowingTargetAnim = window;
+            g.NavWindowingTarget = g.NavWindowingTargetAnim = window->RootWindow; // FIXME-DOCK: Will need to use RootWindowDockStop
             g.NavWindowingTimer = g.NavWindowingHighlightAlpha = 0.0f;
             g.NavWindowingToggleLayer = start_windowing_with_keyboard ? false : true;
             g.NavInputSource = start_windowing_with_keyboard ? ImGuiInputSource_NavKeyboard : ImGuiInputSource_NavGamepad;
@@ -8793,7 +8954,7 @@ bool ImGui::BeginDragDropSource(ImGuiDragDropFlags flags)
     bool source_drag_active = false;
     ImGuiID source_id = 0;
     ImGuiID source_parent_id = 0;
-    int mouse_button = 0;
+    ImGuiMouseButton mouse_button = ImGuiMouseButton_Left;
     if (!(flags & ImGuiDragDropFlags_SourceExtern))
     {
         source_id = window->DC.LastItemId;
@@ -9709,12 +9870,18 @@ void ImGui::ShowMetricsWindow(bool* p_open)
         return;
     }
 
-    // State
+    // Debugging enums
     enum { WRT_OuterRect, WRT_OuterRectClipped, WRT_InnerRect, WRT_InnerClipRect, WRT_WorkRect, WRT_Content, WRT_ContentRegionRect, WRT_Count }; // Windows Rect Type
     const char* wrt_rects_names[WRT_Count] = { "OuterRect", "OuterRectClipped", "InnerRect", "InnerClipRect", "WorkRect", "Content", "ContentRegionRect" };
+    enum { TRT_OuterRect, TRT_WorkRect, TRT_HostClipRect, TRT_InnerClipRect, TRT_BackgroundClipRect, TRT_ColumnsRect, TRT_ColumnsClipRect, TRT_ColumnsContentHeadersUsed, TRT_ColumnsContentHeadersDesired, TRT_ColumnsContentRowsFrozen, TRT_ColumnsContentRowsUnfrozen, TRT_Count }; // Tables Rect Type
+    const char* trt_rects_names[TRT_Count] = { "OuterRect", "WorkRect", "HostClipRect", "InnerClipRect", "BackgroundClipRect", "ColumnsRect", "ColumnsClipRect", "ColumnsContentHeadersUsed", "ColumnsContentHeadersDesired", "ColumnsContentRowsFrozen", "ColumnsContentRowsUnfrozen" };
+
+    // State
     static bool show_windows_rects = false;
     static int  show_windows_rect_type = WRT_WorkRect;
     static bool show_windows_begin_order = false;
+    static bool show_tables_rects = false;
+    static int  show_tables_rect_type = TRT_WorkRect;
     static bool show_drawcmd_details = true;
 
     // Basic info
@@ -9728,11 +9895,12 @@ void ImGui::ShowMetricsWindow(bool* p_open)
     ImGui::Separator();
 
     // Helper functions to display common structures:
-    // - NodeDrawList
-    // - NodeColumns
-    // - NodeWindow
-    // - NodeWindows
-    // - NodeTabBar
+    // - NodeDrawList()
+    // - NodeColumns()
+    // - NodeWindow()
+    // - NodeWindows()
+    // - NodeTabBar()
+    // - NodeStorage()
     struct Funcs
     {
         static ImRect GetWindowRect(ImGuiWindow* window, int rect_type)
@@ -9788,7 +9956,7 @@ void ImGui::ShowMetricsWindow(bool* p_open)
                 if (show_drawcmd_details && fg_draw_list && ImGui::IsItemHovered())
                 {
                     ImRect clip_rect = pcmd->ClipRect;
-                    ImRect vtxs_rect;
+                    ImRect vtxs_rect(FLT_MAX, FLT_MAX, -FLT_MAX, -FLT_MAX);
                     for (unsigned int i = elem_offset; i < elem_offset + (int)pcmd->ElemCount; i++)
                         vtxs_rect.Add(draw_list->VtxBuffer[idx_buffer ? idx_buffer[i] : i].pos);
                     fg_draw_list->AddRect(ImFloor(clip_rect.Min), ImFloor(clip_rect.Max), IM_COL32(255,0,255,255));
@@ -9872,7 +10040,11 @@ void ImGui::ShowMetricsWindow(bool* p_open)
             if (!ImGui::TreeNode(label, "%s (%d)", label, windows.Size))
                 return;
             for (int i = 0; i < windows.Size; i++)
+            {
+                ImGui::PushID(windows[i]);
                 Funcs::NodeWindow(windows[i], "Window");
+                ImGui::PopID();
+            }
             ImGui::TreePop();
         }
 
@@ -9883,7 +10055,7 @@ void ImGui::ShowMetricsWindow(bool* p_open)
                 ImGui::BulletText("%s: NULL", label);
                 return;
             }
-            bool open = ImGui::TreeNode(window, "%s '%s', %d @ 0x%p", label, window->Name, (window->Active || window->WasActive), window);
+            bool open = ImGui::TreeNode(label, "%s '%s', %d @ 0x%p", label, window->Name, (window->Active || window->WasActive), window);
             if (ImGui::IsItemHovered() && window->WasActive)
                 ImGui::GetForegroundDrawList()->AddRect(window->Pos, window->Pos + window->Size, IM_COL32(255, 255, 0, 255));
             if (!open)
@@ -9923,7 +10095,7 @@ void ImGui::ShowMetricsWindow(bool* p_open)
             char buf[256];
             char* p = buf;
             const char* buf_end = buf + IM_ARRAYSIZE(buf);
-            ImFormatString(p, buf_end - p, "TabBar (%d tabs)%s", tab_bar->Tabs.Size, (tab_bar->PrevFrameVisible < ImGui::GetFrameCount() - 2) ? " *Inactive*" : "");
+            p += ImFormatString(p, buf_end - p, "TabBar (%d tabs)%s", tab_bar->Tabs.Size, (tab_bar->PrevFrameVisible < ImGui::GetFrameCount() - 2) ? " *Inactive*" : "");
             if (ImGui::TreeNode(tab_bar, "%s", buf))
             {
                 for (int tab_n = 0; tab_n < tab_bar->Tabs.Size; tab_n++)
@@ -9953,6 +10125,7 @@ void ImGui::ShowMetricsWindow(bool* p_open)
     };
 
     Funcs::NodeWindows(g.Windows, "Windows");
+    //Funcs::NodeWindows(g.WindowsFocusOrder, "WindowsFocusOrder");
     if (ImGui::TreeNode("DrawLists", "Active DrawLists (%d)", g.DrawDataBuilder.Layers[0].Size))
     {
         for (int i = 0; i < g.DrawDataBuilder.Layers[0].Size; i++)
@@ -9960,6 +10133,7 @@ void ImGui::ShowMetricsWindow(bool* p_open)
         ImGui::TreePop();
     }
 
+    // Details for Popups
     if (ImGui::TreeNode("Popups", "Popups (%d)", g.OpenPopupStack.Size))
     {
         for (int i = 0; i < g.OpenPopupStack.Size; i++)
@@ -9970,6 +10144,7 @@ void ImGui::ShowMetricsWindow(bool* p_open)
         ImGui::TreePop();
     }
 
+    // Details for TabBars
     if (ImGui::TreeNode("TabBars", "Tab Bars (%d)", g.TabBars.GetSize()))
     {
         for (int n = 0; n < g.TabBars.GetSize(); n++)
@@ -9977,20 +10152,28 @@ void ImGui::ShowMetricsWindow(bool* p_open)
         ImGui::TreePop();
     }
 
-#if 0
-    if (ImGui::TreeNode("Docking"))
+    // Details for Tables
+    IM_UNUSED(trt_rects_names);
+    IM_UNUSED(show_tables_rects);
+    IM_UNUSED(show_tables_rect_type);
+#ifdef IMGUI_HAS_TABLE
+    if (ImGui::TreeNode("Tables", "Tables (%d)", g.Tables.GetSize()))
     {
+        for (int n = 0; n < g.Tables.GetSize(); n++)
+            Funcs::NodeTable(g.Tables.GetByIndex(n));
         ImGui::TreePop();
     }
-#endif
+#endif // #define IMGUI_HAS_TABLE
 
-#if 0
-    if (ImGui::TreeNode("Tables", "Tables (%d)", g.Tables.GetSize()))
+    // Details for Docking
+#ifdef IMGUI_HAS_DOCK
+    if (ImGui::TreeNode("Docking"))
     {
         ImGui::TreePop();
     }
-#endif
+#endif // #define IMGUI_HAS_DOCK
 
+    // Misc Details
     if (ImGui::TreeNode("Internal state"))
     {
         const char* input_source_names[] = { "None", "Mouse", "Nav", "NavKeyboard", "NavGamepad" }; IM_ASSERT(IM_ARRAYSIZE(input_source_names) == ImGuiInputSource_COUNT);
@@ -10011,6 +10194,7 @@ void ImGui::ShowMetricsWindow(bool* p_open)
         ImGui::TreePop();
     }
 
+    // Tools
     if (ImGui::TreeNode("Tools"))
     {
         // The Item Picker tool is super useful to visually select an item and break into the call-stack of where it was submitted.
@@ -10023,7 +10207,7 @@ void ImGui::ShowMetricsWindow(bool* p_open)
         ImGui::Checkbox("Show windows rectangles", &show_windows_rects);
         ImGui::SameLine();
         ImGui::SetNextItemWidth(ImGui::GetFontSize() * 12);
-        show_windows_rects |= ImGui::Combo("##show_windows_rect_type", &show_windows_rect_type, wrt_rects_names, WRT_Count);
+        show_windows_rects |= ImGui::Combo("##show_windows_rect_type", &show_windows_rect_type, wrt_rects_names, WRT_Count, WRT_Count);
         if (show_windows_rects && g.NavWindow)
         {
             ImGui::BulletText("'%s':", g.NavWindow->Name);
@@ -10039,7 +10223,7 @@ void ImGui::ShowMetricsWindow(bool* p_open)
         ImGui::TreePop();
     }
 
-    // Tool: Display windows Rectangles and Begin Order
+    // Overlay: Display windows Rectangles and Begin Order
     if (show_windows_rects || show_windows_begin_order)
     {
         for (int n = 0; n < g.Windows.Size; n++)
@@ -10063,6 +10247,25 @@ void ImGui::ShowMetricsWindow(bool* p_open)
             }
         }
     }
+
+#ifdef IMGUI_HAS_TABLE
+    // Overlay: Display Tables Rectangles
+    if (show_tables_rects)
+    {
+        for (int table_n = 0; table_n < g.Tables.GetSize(); table_n++)
+        {
+            ImGuiTable* table = g.Tables.GetByIndex(table_n);
+        }
+    }
+#endif // #define IMGUI_HAS_TABLE
+
+#ifdef IMGUI_HAS_DOCK
+    // Overlay: Display Docking info
+    if (show_docking_nodes && g.IO.KeyCtrl)
+    {
+    }
+#endif // #define IMGUI_HAS_DOCK
+
     ImGui::End();
 }
 
@@ -10081,3 +10284,5 @@ void ImGui::ShowMetricsWindow(bool*) { }
 #endif
 
 //-----------------------------------------------------------------------------
+
+#endif // #ifndef IMGUI_DISABLE
diff --git a/imgui/imgui.h b/imgui/imgui.h
index 9fcdaeaa..c2bbb7f7 100644
--- a/imgui/imgui.h
+++ b/imgui/imgui.h
@@ -1,10 +1,20 @@
-// dear imgui, v1.74
+// dear imgui, v1.75
 // (headers)
 
-// See imgui.cpp file for documentation.
-// Call and read ImGui::ShowDemoWindow() in imgui_demo.cpp for demo code.
-// Newcomers, read 'Programmer guide' in imgui.cpp for notes on how to setup Dear ImGui in your codebase.
-// Get latest version at https://github.com/ocornut/imgui
+// Help:
+// - Read FAQ at http://dearimgui.org/faq
+// - Newcomers, read 'Programmer guide' in imgui.cpp for notes on how to setup Dear ImGui in your codebase.
+// - Call and read ImGui::ShowDemoWindow() in imgui_demo.cpp for demo code. All applications in examples/ are doing that.
+// Read imgui.cpp for more details, documentation and comments.
+
+// Resources:
+// - FAQ                   http://dearimgui.org/faq
+// - Homepage & latest     https://github.com/ocornut/imgui
+// - Releases & changelog  https://github.com/ocornut/imgui/releases
+// - Gallery               https://github.com/ocornut/imgui/issues/2847 (please post your screenshots/video there!)
+// - Glossary              https://github.com/ocornut/imgui/wiki/Glossary
+// - Wiki                  https://github.com/ocornut/imgui/wiki
+// - Issues & support      https://github.com/ocornut/imgui/issues
 
 /*
 
@@ -35,6 +45,8 @@ Index of this file:
 #include "imconfig.h"
 #endif
 
+#ifndef IMGUI_DISABLE
+
 //-----------------------------------------------------------------------------
 // Header mess
 //-----------------------------------------------------------------------------
@@ -47,8 +59,8 @@ Index of this file:
 
 // Version
 // (Integer encoded as XYYZZ for use in #if preprocessor conditionals. Work in progress versions typically starts at XYY99 then bounce up to XYY00, XYY01 etc. when release tagging happens)
-#define IMGUI_VERSION               "1.74"
-#define IMGUI_VERSION_NUM           17400
+#define IMGUI_VERSION               "1.75"
+#define IMGUI_VERSION_NUM           17500
 #define IMGUI_CHECKVERSION()        ImGui::DebugCheckVersionAndDataLayout(IMGUI_VERSION, sizeof(ImGuiIO), sizeof(ImGuiStyle), sizeof(ImVec2), sizeof(ImVec4), sizeof(ImDrawVert), sizeof(ImDrawIdx))
 
 // Define attributes of all API symbols declarations (e.g. for DLL under Windows)
@@ -66,7 +78,7 @@ Index of this file:
 #include <assert.h>
 #define IM_ASSERT(_EXPR)            assert(_EXPR)                               // You can override the default assert handler by editing imconfig.h
 #endif
-#if defined(__clang__) || defined(__GNUC__)
+#if !defined(IMGUI_USE_STB_SPRINTF) && (defined(__clang__) || defined(__GNUC__))
 #define IM_FMTARGS(FMT)             __attribute__((format(printf, FMT, FMT+1))) // To apply printf-style warnings to our functions.
 #define IM_FMTLIST(FMT)             __attribute__((format(printf, FMT, 0)))
 #else
@@ -138,6 +150,7 @@ typedef int ImGuiDataType;          // -> enum ImGuiDataType_        // Enum: A
 typedef int ImGuiDir;               // -> enum ImGuiDir_             // Enum: A cardinal direction
 typedef int ImGuiKey;               // -> enum ImGuiKey_             // Enum: A key identifier (ImGui-side enum)
 typedef int ImGuiNavInput;          // -> enum ImGuiNavInput_        // Enum: An input identifier for navigation
+typedef int ImGuiMouseButton;       // -> enum ImGuiMouseButton_     // Enum: A mouse button identifier (0=left, 1=right, 2=middle)
 typedef int ImGuiMouseCursor;       // -> enum ImGuiMouseCursor_     // Enum: A mouse cursor identifier
 typedef int ImGuiStyleVar;          // -> enum ImGuiStyleVar_        // Enum: A variable identifier for styling
 typedef int ImDrawCornerFlags;      // -> enum ImDrawCornerFlags_    // Flags: for ImDrawList::AddRect(), AddRectFilled() etc.
@@ -283,7 +296,7 @@ namespace ImGui
     IMGUI_API void          SetNextWindowContentSize(const ImVec2& size);                               // set next window content size (~ scrollable client area, which enforce the range of scrollbars). Not including window decorations (title bar, menu bar, etc.) nor WindowPadding. set an axis to 0.0f to leave it automatic. call before Begin()
     IMGUI_API void          SetNextWindowCollapsed(bool collapsed, ImGuiCond cond = 0);                 // set next window collapsed state. call before Begin()
     IMGUI_API void          SetNextWindowFocus();                                                       // set next window to be focused / top-most. call before Begin()
-    IMGUI_API void          SetNextWindowBgAlpha(float alpha);                                          // set next window background color alpha. helper to easily modify ImGuiCol_WindowBg/ChildBg/PopupBg. you may also use ImGuiWindowFlags_NoBackground.
+    IMGUI_API void          SetNextWindowBgAlpha(float alpha);                                          // set next window background color alpha. helper to easily override the Alpha component of ImGuiCol_WindowBg/ChildBg/PopupBg. you may also use ImGuiWindowFlags_NoBackground.
     IMGUI_API void          SetWindowPos(const ImVec2& pos, ImGuiCond cond = 0);                        // (not recommended) set current window position - call within Begin()/End(). prefer using SetNextWindowPos(), as this may incur tearing and side-effects.
     IMGUI_API void          SetWindowSize(const ImVec2& size, ImGuiCond cond = 0);                      // (not recommended) set current window size - call within Begin()/End(). set to ImVec2(0,0) to force an auto-fit. prefer using SetNextWindowSize(), as this may incur tearing and minor side-effects.
     IMGUI_API void          SetWindowCollapsed(bool collapsed, ImGuiCond cond = 0);                     // (not recommended) set current window collapsed state. prefer using SetNextWindowCollapsed().
@@ -433,6 +446,7 @@ namespace ImGui
     // - Adjust format string to decorate the value with a prefix, a suffix, or adapt the editing and display precision e.g. "%.3f" -> 1.234; "%5.2f secs" -> 01.23 secs; "Biscuit: %.0f" -> Biscuit: 1; etc.
     // - Speed are per-pixel of mouse movement (v_speed=0.2f: mouse needs to move by 5 pixels to increase value by 1). For gamepad/keyboard navigation, minimum speed is Max(v_speed, minimum_step_at_given_precision).
     // - Use v_min < v_max to clamp edits to given limits. Note that CTRL+Click manual input can override those limits.
+    // - Use v_max = FLT_MAX / INT_MAX etc to avoid clamping to a maximum, same with v_min = -FLT_MAX / INT_MIN to avoid clamping to a minimum.
     // - Use v_min > v_max to lock edits.
     IMGUI_API bool          DragFloat(const char* label, float* v, float v_speed = 1.0f, float v_min = 0.0f, float v_max = 0.0f, const char* format = "%.3f", float power = 1.0f);     // If v_min >= v_max we have no bound
     IMGUI_API bool          DragFloat2(const char* label, float v[2], float v_speed = 1.0f, float v_min = 0.0f, float v_max = 0.0f, const char* format = "%.3f", float power = 1.0f);
@@ -466,7 +480,7 @@ namespace ImGui
     IMGUI_API bool          VSliderScalar(const char* label, const ImVec2& size, ImGuiDataType data_type, void* p_data, const void* p_min, const void* p_max, const char* format = NULL, float power = 1.0f);
 
     // Widgets: Input with Keyboard
-    // - If you want to use InputText() with a dynamic string type such as std::string or your own, see misc/cpp/imgui_stdlib.h
+    // - If you want to use InputText() with std::string or any custom dynamic string type, see misc/cpp/imgui_stdlib.h and comments in imgui_demo.cpp.
     // - Most of the ImGuiInputTextFlags flags are only useful for InputText() and not for InputFloatX, InputIntX, InputDouble etc.
     IMGUI_API bool          InputText(const char* label, char* buf, size_t buf_size, ImGuiInputTextFlags flags = 0, ImGuiInputTextCallback callback = NULL, void* user_data = NULL);
     IMGUI_API bool          InputTextMultiline(const char* label, char* buf, size_t buf_size, const ImVec2& size = ImVec2(0,0), ImGuiInputTextFlags flags = 0, ImGuiInputTextCallback callback = NULL, void* user_data = NULL);
@@ -565,23 +579,25 @@ namespace ImGui
     // - Unless modal, they can be closed by clicking anywhere outside them, or by pressing ESCAPE.
     // - Their visibility state (~bool) is held internally by imgui instead of being held by the programmer as we are used to with regular Begin() calls.
     //   User can manipulate the visibility state by calling OpenPopup().
+    // - We default to use the right mouse (ImGuiMouseButton_Right=1) for the Popup Context functions.
     // (*) You can use IsItemHovered(ImGuiHoveredFlags_AllowWhenBlockedByPopup) to bypass it and detect hovering even when normally blocked by a popup.
     // Those three properties are connected. The library needs to hold their visibility state because it can close popups at any time.
     IMGUI_API void          OpenPopup(const char* str_id);                                      // call to mark popup as open (don't call every frame!). popups are closed when user click outside, or if CloseCurrentPopup() is called within a BeginPopup()/EndPopup() block. By default, Selectable()/MenuItem() are calling CloseCurrentPopup(). Popup identifiers are relative to the current ID-stack (so OpenPopup and BeginPopup needs to be at the same level).
     IMGUI_API bool          BeginPopup(const char* str_id, ImGuiWindowFlags flags = 0);                                             // return true if the popup is open, and you can start outputting to it. only call EndPopup() if BeginPopup() returns true!
-    IMGUI_API bool          BeginPopupContextItem(const char* str_id = NULL, int mouse_button = 1);                                 // helper to open and begin popup when clicked on last item. if you can pass a NULL str_id only if the previous item had an id. If you want to use that on a non-interactive item such as Text() you need to pass in an explicit ID here. read comments in .cpp!
-    IMGUI_API bool          BeginPopupContextWindow(const char* str_id = NULL, int mouse_button = 1, bool also_over_items = true);  // helper to open and begin popup when clicked on current window.
-    IMGUI_API bool          BeginPopupContextVoid(const char* str_id = NULL, int mouse_button = 1);                                 // helper to open and begin popup when clicked in void (where there are no imgui windows).
+    IMGUI_API bool          BeginPopupContextItem(const char* str_id = NULL, ImGuiMouseButton mouse_button = 1);                    // helper to open and begin popup when clicked on last item. if you can pass a NULL str_id only if the previous item had an id. If you want to use that on a non-interactive item such as Text() you need to pass in an explicit ID here. read comments in .cpp!
+    IMGUI_API bool          BeginPopupContextWindow(const char* str_id = NULL, ImGuiMouseButton mouse_button = 1, bool also_over_items = true);  // helper to open and begin popup when clicked on current window.
+    IMGUI_API bool          BeginPopupContextVoid(const char* str_id = NULL, ImGuiMouseButton mouse_button = 1);                    // helper to open and begin popup when clicked in void (where there are no imgui windows).
     IMGUI_API bool          BeginPopupModal(const char* name, bool* p_open = NULL, ImGuiWindowFlags flags = 0);                     // modal dialog (regular window with title bar, block interactions behind the modal window, can't close the modal window by clicking outside)
     IMGUI_API void          EndPopup();                                                                                             // only call EndPopup() if BeginPopupXXX() returns true!
-    IMGUI_API bool          OpenPopupOnItemClick(const char* str_id = NULL, int mouse_button = 1);                                  // helper to open popup when clicked on last item (note: actually triggers on the mouse _released_ event to be consistent with popup behaviors). return true when just opened.
+    IMGUI_API bool          OpenPopupOnItemClick(const char* str_id = NULL, ImGuiMouseButton mouse_button = 1);                     // helper to open popup when clicked on last item (note: actually triggers on the mouse _released_ event to be consistent with popup behaviors). return true when just opened.
     IMGUI_API bool          IsPopupOpen(const char* str_id);                                    // return true if the popup is open at the current begin-ed level of the popup stack.
     IMGUI_API void          CloseCurrentPopup();                                                // close the popup we have begin-ed into. clicking on a MenuItem or Selectable automatically close the current popup.
 
     // Columns
     // - You can also use SameLine(pos_x) to mimic simplified columns.
     // - The columns API is work-in-progress and rather lacking (columns are arguably the worst part of dear imgui at the moment!)
-    // - By end of the 2019 we will expose a new 'Table' api which will replace columns.
+    // - There is a maximum of 64 columns.
+    // - Currently working on new 'Tables' api which will replace columns (see GitHub #2957)
     IMGUI_API void          Columns(int count = 1, const char* id = NULL, bool border = true);
     IMGUI_API void          NextColumn();                                                       // next column, defaults to current row or next row if the current row is finished
     IMGUI_API int           GetColumnIndex();                                                   // get current column index
@@ -632,7 +648,7 @@ namespace ImGui
     IMGUI_API bool          IsItemHovered(ImGuiHoveredFlags flags = 0);                         // is the last item hovered? (and usable, aka not blocked by a popup, etc.). See ImGuiHoveredFlags for more options.
     IMGUI_API bool          IsItemActive();                                                     // is the last item active? (e.g. button being held, text field being edited. This will continuously return true while holding mouse button on an item. Items that don't interact will always return false)
     IMGUI_API bool          IsItemFocused();                                                    // is the last item focused for keyboard/gamepad navigation?
-    IMGUI_API bool          IsItemClicked(int mouse_button = 0);                                // is the last item clicked? (e.g. button/node just clicked on) == IsMouseClicked(mouse_button) && IsItemHovered()
+    IMGUI_API bool          IsItemClicked(ImGuiMouseButton mouse_button = 0);                   // is the last item clicked? (e.g. button/node just clicked on) == IsMouseClicked(mouse_button) && IsItemHovered()
     IMGUI_API bool          IsItemVisible();                                                    // is the last item visible? (items may be out of sight because of clipping/scrolling)
     IMGUI_API bool          IsItemEdited();                                                     // did the last item modify its underlying value this frame? or was pressed? This is generally the same as the "bool" return value of many widgets.
     IMGUI_API bool          IsItemActivated();                                                  // was the last item just made active (item was previously inactive).
@@ -669,27 +685,34 @@ namespace ImGui
     IMGUI_API void          ColorConvertRGBtoHSV(float r, float g, float b, float& out_h, float& out_s, float& out_v);
     IMGUI_API void          ColorConvertHSVtoRGB(float h, float s, float v, float& out_r, float& out_g, float& out_b);
 
-    // Inputs Utilities
+    // Inputs Utilities: Keyboard
+    // - For 'int user_key_index' you can use your own indices/enums according to how your backend/engine stored them in io.KeysDown[].
+    // - We don't know the meaning of those value. You can use GetKeyIndex() to map a ImGuiKey_ value into the user index.
     IMGUI_API int           GetKeyIndex(ImGuiKey imgui_key);                                    // map ImGuiKey_* values into user's key index. == io.KeyMap[key]
-    IMGUI_API bool          IsKeyDown(int user_key_index);                                      // is key being held. == io.KeysDown[user_key_index]. note that imgui doesn't know the semantic of each entry of io.KeysDown[]. Use your own indices/enums according to how your backend/engine stored them into io.KeysDown[]!
-    IMGUI_API bool          IsKeyPressed(int user_key_index, bool repeat = true);               // was key pressed (went from !Down to Down). if repeat=true, uses io.KeyRepeatDelay / KeyRepeatRate
-    IMGUI_API bool          IsKeyReleased(int user_key_index);                                  // was key released (went from Down to !Down)..
+    IMGUI_API bool          IsKeyDown(int user_key_index);                                      // is key being held. == io.KeysDown[user_key_index].
+    IMGUI_API bool          IsKeyPressed(int user_key_index, bool repeat = true);               // was key pressed (went from !Down to Down)? if repeat=true, uses io.KeyRepeatDelay / KeyRepeatRate
+    IMGUI_API bool          IsKeyReleased(int user_key_index);                                  // was key released (went from Down to !Down)?
     IMGUI_API int           GetKeyPressedAmount(int key_index, float repeat_delay, float rate); // uses provided repeat rate/delay. return a count, most often 0 or 1 but might be >1 if RepeatRate is small enough that DeltaTime > RepeatRate
-    IMGUI_API bool          IsMouseDown(int button);                                            // is mouse button held (0=left, 1=right, 2=middle)
-    IMGUI_API bool          IsAnyMouseDown();                                                   // is any mouse button held
-    IMGUI_API bool          IsMouseClicked(int button, bool repeat = false);                    // did mouse button clicked (went from !Down to Down) (0=left, 1=right, 2=middle)
-    IMGUI_API bool          IsMouseDoubleClicked(int button);                                   // did mouse button double-clicked. a double-click returns false in IsMouseClicked(). uses io.MouseDoubleClickTime.
-    IMGUI_API bool          IsMouseReleased(int button);                                        // did mouse button released (went from Down to !Down)
-    IMGUI_API bool          IsMouseDragging(int button = 0, float lock_threshold = -1.0f);      // is mouse dragging. if lock_threshold < -1.0f uses io.MouseDraggingThreshold
-    IMGUI_API bool          IsMouseHoveringRect(const ImVec2& r_min, const ImVec2& r_max, bool clip = true);  // is mouse hovering given bounding rect (in screen space). clipped by current clipping settings, but disregarding of other consideration of focus/window ordering/popup-block.
-    IMGUI_API bool          IsMousePosValid(const ImVec2* mouse_pos = NULL);                    // by convention we use (-FLT_MAX,-FLT_MAX) to denote that there is no mouse
+    IMGUI_API void          CaptureKeyboardFromApp(bool want_capture_keyboard_value = true);    // attention: misleading name! manually override io.WantCaptureKeyboard flag next frame (said flag is entirely left for your application to handle). e.g. force capture keyboard when your widget is being hovered. This is equivalent to setting "io.WantCaptureKeyboard = want_capture_keyboard_value"; after the next NewFrame() call.
+
+    // Inputs Utilities: Mouse
+    // - To refer to a mouse button, you may use named enums in your code e.g. ImGuiMouseButton_Left, ImGuiMouseButton_Right.
+    // - You can also use regular integer: it is forever guaranteed that 0=Left, 1=Right, 2=Middle.
+    // - Dragging operations are only reported after mouse has moved a certain distance away from the initial clicking position (see 'lock_threshold' and 'io.MouseDraggingThreshold')
+    IMGUI_API bool          IsMouseDown(ImGuiMouseButton button);                               // is mouse button held?
+    IMGUI_API bool          IsMouseClicked(ImGuiMouseButton button, bool repeat = false);       // did mouse button clicked? (went from !Down to Down)
+    IMGUI_API bool          IsMouseReleased(ImGuiMouseButton button);                           // did mouse button released? (went from Down to !Down)
+    IMGUI_API bool          IsMouseDoubleClicked(ImGuiMouseButton button);                      // did mouse button double-clicked? a double-click returns false in IsMouseClicked(). uses io.MouseDoubleClickTime.
+    IMGUI_API bool          IsMouseHoveringRect(const ImVec2& r_min, const ImVec2& r_max, bool clip = true);// is mouse hovering given bounding rect (in screen space). clipped by current clipping settings, but disregarding of other consideration of focus/window ordering/popup-block.
+    IMGUI_API bool          IsMousePosValid(const ImVec2* mouse_pos = NULL);                    // by convention we use (-FLT_MAX,-FLT_MAX) to denote that there is no mouse available
+    IMGUI_API bool          IsAnyMouseDown();                                                   // is any mouse button held?
     IMGUI_API ImVec2        GetMousePos();                                                      // shortcut to ImGui::GetIO().MousePos provided by user, to be consistent with other calls
-    IMGUI_API ImVec2        GetMousePosOnOpeningCurrentPopup();                                 // retrieve backup of mouse position at the time of opening popup we have BeginPopup() into
-    IMGUI_API ImVec2        GetMouseDragDelta(int button = 0, float lock_threshold = -1.0f);    // return the delta from the initial clicking position while the mouse button is pressed or was just released. This is locked and return 0.0f until the mouse moves past a distance threshold at least once. If lock_threshold < -1.0f uses io.MouseDraggingThreshold.
-    IMGUI_API void          ResetMouseDragDelta(int button = 0);                                //
+    IMGUI_API ImVec2        GetMousePosOnOpeningCurrentPopup();                                 // retrieve mouse position at the time of opening popup we have BeginPopup() into (helper to avoid user backing that value themselves)
+    IMGUI_API bool          IsMouseDragging(ImGuiMouseButton button, float lock_threshold = -1.0f);         // is mouse dragging? (if lock_threshold < -1.0f, uses io.MouseDraggingThreshold)
+    IMGUI_API ImVec2        GetMouseDragDelta(ImGuiMouseButton button = 0, float lock_threshold = -1.0f);   // return the delta from the initial clicking position while the mouse button is pressed or was just released. This is locked and return 0.0f until the mouse moves past a distance threshold at least once (if lock_threshold < -1.0f, uses io.MouseDraggingThreshold)
+    IMGUI_API void          ResetMouseDragDelta(ImGuiMouseButton button = 0);                   //
     IMGUI_API ImGuiMouseCursor GetMouseCursor();                                                // get desired cursor type, reset in ImGui::NewFrame(), this is updated during the frame. valid before Render(). If you use software rendering by setting io.MouseDrawCursor ImGui will render those for you
-    IMGUI_API void          SetMouseCursor(ImGuiMouseCursor type);                              // set desired cursor type
-    IMGUI_API void          CaptureKeyboardFromApp(bool want_capture_keyboard_value = true);    // attention: misleading name! manually override io.WantCaptureKeyboard flag next frame (said flag is entirely left for your application to handle). e.g. force capture keyboard when your widget is being hovered. This is equivalent to setting "io.WantCaptureKeyboard = want_capture_keyboard_value"; after the next NewFrame() call.
+    IMGUI_API void          SetMouseCursor(ImGuiMouseCursor cursor_type);                       // set desired cursor type
     IMGUI_API void          CaptureMouseFromApp(bool want_capture_mouse_value = true);          // attention: misleading name! manually override io.WantCaptureMouse flag next frame (said flag is entirely left for your application to handle). This is equivalent to setting "io.WantCaptureMouse = want_capture_mouse_value;" after the next NewFrame() call.
 
     // Clipboard Utilities (also see the LogToClipboard() function to capture or output text data to the clipboard)
@@ -754,8 +777,8 @@ enum ImGuiWindowFlags_
     ImGuiWindowFlags_ChildMenu              = 1 << 28   // Don't use! For internal use by BeginMenu()
 
     // [Obsolete]
-    //ImGuiWindowFlags_ShowBorders          = 1 << 7,   // --> Set style.FrameBorderSize=1.0f / style.WindowBorderSize=1.0f to enable borders around windows and items
-    //ImGuiWindowFlags_ResizeFromAnySide    = 1 << 17,  // --> Set io.ConfigWindowsResizeFromEdges and make sure mouse cursors are supported by back-end (io.BackendFlags & ImGuiBackendFlags_HasMouseCursors)
+    //ImGuiWindowFlags_ShowBorders          = 1 << 7,   // --> Set style.FrameBorderSize=1.0f or style.WindowBorderSize=1.0f to enable borders around items or windows.
+    //ImGuiWindowFlags_ResizeFromAnySide    = 1 << 17,  // --> Set io.ConfigWindowsResizeFromEdges=true and make sure mouse cursors are supported by back-end (io.BackendFlags & ImGuiBackendFlags_HasMouseCursors)
 };
 
 // Flags for ImGui::InputText()
@@ -806,11 +829,6 @@ enum ImGuiTreeNodeFlags_
     ImGuiTreeNodeFlags_NavLeftJumpsBackHere = 1 << 13,  // (WIP) Nav: left direction may move to this TreeNode() from any of its child (items submitted between TreeNode and TreePop)
     //ImGuiTreeNodeFlags_NoScrollOnOpen     = 1 << 14,  // FIXME: TODO: Disable automatic scroll on TreePop() if node got just open and contents is not visible
     ImGuiTreeNodeFlags_CollapsingHeader     = ImGuiTreeNodeFlags_Framed | ImGuiTreeNodeFlags_NoTreePushOnOpen | ImGuiTreeNodeFlags_NoAutoOpenOnLog
-
-    // Obsolete names (will be removed)
-#ifndef IMGUI_DISABLE_OBSOLETE_FUNCTIONS
-    , ImGuiTreeNodeFlags_AllowOverlapMode = ImGuiTreeNodeFlags_AllowItemOverlap // [renamed in 1.53]
-#endif
 };
 
 // Flags for ImGui::Selectable()
@@ -1086,9 +1104,7 @@ enum ImGuiCol_
     // Obsolete names (will be removed)
 #ifndef IMGUI_DISABLE_OBSOLETE_FUNCTIONS
     , ImGuiCol_ModalWindowDarkening = ImGuiCol_ModalWindowDimBg                      // [renamed in 1.63]
-    , ImGuiCol_ChildWindowBg = ImGuiCol_ChildBg                                      // [renamed in 1.53]
-    //ImGuiCol_CloseButton, ImGuiCol_CloseButtonActive, ImGuiCol_CloseButtonHovered, // [unused since 1.60+] the close button now uses regular button colors.
-    //ImGuiCol_ComboBg,                                                              // [unused since 1.53+] ComboBg has been merged with PopupBg, so a redirect isn't accurate.
+    //, ImGuiCol_CloseButton, ImGuiCol_CloseButtonActive, ImGuiCol_CloseButtonHovered// [unused since 1.60+] the close button now uses regular button colors.
 #endif
 };
 
@@ -1125,8 +1141,7 @@ enum ImGuiStyleVar_
 
     // Obsolete names (will be removed)
 #ifndef IMGUI_DISABLE_OBSOLETE_FUNCTIONS
-    , ImGuiStyleVar_Count_ = ImGuiStyleVar_COUNT                        // [renamed in 1.60]
-    , ImGuiStyleVar_ChildWindowRounding = ImGuiStyleVar_ChildRounding   // [renamed in 1.53]
+    , ImGuiStyleVar_Count_ = ImGuiStyleVar_COUNT                    // [renamed in 1.60]
 #endif
 };
 
@@ -1175,6 +1190,16 @@ enum ImGuiColorEditFlags_
 #endif
 };
 
+// Identify a mouse button.
+// Those values are guaranteed to be stable and we frequently use 0/1 directly. Named enums provided for convenience.
+enum ImGuiMouseButton_
+{
+    ImGuiMouseButton_Left = 0,
+    ImGuiMouseButton_Right = 1,
+    ImGuiMouseButton_Middle = 2,
+    ImGuiMouseButton_COUNT = 5
+};
+
 // Enumeration for GetMouseCursor()
 // User code may request binding to display given cursor by calling SetMouseCursor(), which is why we have some cursors that are marked unused here
 enum ImGuiMouseCursor_
@@ -1188,6 +1213,7 @@ enum ImGuiMouseCursor_
     ImGuiMouseCursor_ResizeNESW,        // When hovering over the bottom-left corner of a window
     ImGuiMouseCursor_ResizeNWSE,        // When hovering over the bottom-right corner of a window
     ImGuiMouseCursor_Hand,              // (Unused by Dear ImGui functions. Use for e.g. hyperlinks)
+    ImGuiMouseCursor_NotAllowed,        // When hovering something with disallowed interaction. Usually a crossed circle.
     ImGuiMouseCursor_COUNT
 
     // Obsolete names (will be removed)
@@ -1196,7 +1222,7 @@ enum ImGuiMouseCursor_
 #endif
 };
 
-// Enumateration for ImGui::SetWindow***(), SetNextWindow***(), SetNextItem***() functions
+// Enumeration for ImGui::SetWindow***(), SetNextWindow***(), SetNextItem***() functions
 // Represent a condition.
 // Important: Treat as a regular enum! Do NOT combine multiple values using binary operators! All the functions above treat 0 as a shortcut to ImGuiCond_Always.
 enum ImGuiCond_
@@ -1273,7 +1299,7 @@ struct ImVector
     inline int          _grow_capacity(int sz) const        { int new_capacity = Capacity ? (Capacity + Capacity/2) : 8; return new_capacity > sz ? new_capacity : sz; }
     inline void         resize(int new_size)                { if (new_size > Capacity) reserve(_grow_capacity(new_size)); Size = new_size; }
     inline void         resize(int new_size, const T& v)    { if (new_size > Capacity) reserve(_grow_capacity(new_size)); if (new_size > Size) for (int n = Size; n < new_size; n++) memcpy(&Data[n], &v, sizeof(v)); Size = new_size; }
-    inline void         shrink(int new_size)                { IM_ASSERT(new_size <= Size); Size = new_size; }
+    inline void         shrink(int new_size)                { IM_ASSERT(new_size <= Size); Size = new_size; } // Resize a vector to a smaller size, guaranteed not to cause a reallocation
     inline void         reserve(int new_capacity)           { if (new_capacity <= Capacity) return; T* new_data = (T*)IM_ALLOC((size_t)new_capacity * sizeof(T)); if (Data) { memcpy(new_data, Data, (size_t)Size * sizeof(T)); IM_FREE(Data); } Data = new_data; Capacity = new_capacity; }
 
     // NB: It is illegal to call push_back/push_front/insert with a reference pointing inside the ImVector data itself! e.g. v.push_back(v[10]) is forbidden.
@@ -1335,6 +1361,7 @@ struct ImGuiStyle
     bool        AntiAliasedLines;           // Enable anti-aliasing on lines/borders. Disable if you are really tight on CPU/GPU.
     bool        AntiAliasedFill;            // Enable anti-aliasing on filled shapes (rounded rectangles, circles, etc.)
     float       CurveTessellationTol;       // Tessellation tolerance when using PathBezierCurveTo() without a specific number of segments. Decrease for highly tessellated curves (higher quality, more polygons), increase to reduce quality.
+    float       CircleSegmentMaxError;      // Maximum error (in pixels) allowed when using AddCircle()/AddCircleFilled() or drawing rounded corner rectangles with no explicit segment count specified. Decrease for higher quality but more geometry.
     ImVec4      Colors[ImGuiCol_COUNT];
 
     IMGUI_API ImGuiStyle();
@@ -1390,9 +1417,9 @@ struct ImGuiIO
     // Optional: Platform/Renderer back-end name (informational only! will be displayed in About Window) + User data for back-end/wrappers to store their own stuff.
     const char* BackendPlatformName;            // = NULL
     const char* BackendRendererName;            // = NULL
-    void*       BackendPlatformUserData;        // = NULL
-    void*       BackendRendererUserData;        // = NULL
-    void*       BackendLanguageUserData;        // = NULL
+    void*       BackendPlatformUserData;        // = NULL           // User data for platform back-end
+    void*       BackendRendererUserData;        // = NULL           // User data for renderer back-end
+    void*       BackendLanguageUserData;        // = NULL           // User data for non C++ programming language back-end
 
     // Optional: Access OS clipboard
     // (default to use native Win32 clipboard on Windows, otherwise uses a private clipboard. Override to access OS clipboard on other architectures)
@@ -1454,7 +1481,7 @@ struct ImGuiIO
     ImVec2      MouseDelta;                     // Mouse delta. Note that this is zero if either current or previous position are invalid (-FLT_MAX,-FLT_MAX), so a disappearing/reappearing mouse won't have a huge delta.
 
     //------------------------------------------------------------------
-    // [Internal] ImGui will maintain those fields. Forward compatibility not guaranteed!
+    // [Internal] Dear ImGui will maintain those fields. Forward compatibility not guaranteed!
     //------------------------------------------------------------------
 
     ImVec2      MousePosPrev;                   // Previous mouse position (note that MouseDelta is not necessary == MousePos-MousePosPrev, in case either position is invalid)
@@ -1578,12 +1605,6 @@ namespace ImGui
     static inline bool  IsAnyWindowFocused()                  { return IsWindowFocused(ImGuiFocusedFlags_AnyWindow); }
     static inline bool  IsAnyWindowHovered()                  { return IsWindowHovered(ImGuiHoveredFlags_AnyWindow); }
     static inline ImVec2 CalcItemRectClosestPoint(const ImVec2& pos, bool on_edge = false, float outward = 0.f) { IM_UNUSED(on_edge); IM_UNUSED(outward); IM_ASSERT(0); return pos; }
-    // OBSOLETED in 1.53 (between Oct 2017 and Dec 2017)
-    static inline void  ShowTestWindow()                      { return ShowDemoWindow(); }
-    static inline bool  IsRootWindowFocused()                 { return IsWindowFocused(ImGuiFocusedFlags_RootWindow); }
-    static inline bool  IsRootWindowOrAnyChildFocused()       { return IsWindowFocused(ImGuiFocusedFlags_RootAndChildWindows); }
-    static inline void  SetNextWindowContentWidth(float w)    { SetNextWindowContentSize(ImVec2(w, 0.0f)); }
-    static inline float GetItemsLineHeightWithSpacing()       { return GetFrameHeightWithSpacing(); }
 }
 typedef ImGuiInputTextCallback      ImGuiTextEditCallback;    // OBSOLETED in 1.63 (from Aug 2018): made the names consistent
 typedef ImGuiInputTextCallbackData  ImGuiTextEditCallbackData;
@@ -1715,9 +1736,13 @@ struct ImGuiStorage
 // - Step 3: the clipper validate that we have reached the expected Y position (corresponding to element DisplayEnd), advance the cursor to the end of the list and then returns 'false' to end the loop.
 struct ImGuiListClipper
 {
-    float   StartPosY;
+    int     DisplayStart, DisplayEnd;
+    int     ItemsCount;
+
+    // [Internal]
+    int     StepNo;
     float   ItemsHeight;
-    int     ItemsCount, StepNo, DisplayStart, DisplayEnd;
+    float   StartPosY;
 
     // items_count:  Use -1 to ignore (you can call Begin later). Use INT_MAX if you don't know how many items you have (in which case the cursor won't be advanced in the final step).
     // items_height: Use -1.0f to be calculated automatically on first step. Otherwise pass in the distance between your items, typically GetTextLineHeightWithSpacing() or GetFrameHeightWithSpacing().
@@ -1918,6 +1943,9 @@ struct ImDrawList
 
     // Primitives
     // - For rectangular primitives, "p_min" and "p_max" represent the upper-left and lower-right corners.
+    // - For circle primitives, use "num_segments == 0" to automatically calculate tessellation (preferred). 
+    //   In future versions we will use textures to provide cheaper and higher-quality circles. 
+    //   Use AddNgon() and AddNgonFilled() functions if you need to guaranteed a specific number of sides.
     IMGUI_API void  AddLine(const ImVec2& p1, const ImVec2& p2, ImU32 col, float thickness = 1.0f);
     IMGUI_API void  AddRect(const ImVec2& p_min, const ImVec2& p_max, ImU32 col, float rounding = 0.0f, ImDrawCornerFlags rounding_corners = ImDrawCornerFlags_All, float thickness = 1.0f);   // a: upper-left, b: lower-right (== upper-left + size), rounding_corners_flags: 4 bits corresponding to which corner to round
     IMGUI_API void  AddRectFilled(const ImVec2& p_min, const ImVec2& p_max, ImU32 col, float rounding = 0.0f, ImDrawCornerFlags rounding_corners = ImDrawCornerFlags_All);                     // a: upper-left, b: lower-right (== upper-left + size)
@@ -1928,11 +1956,13 @@ struct ImDrawList
     IMGUI_API void  AddTriangleFilled(const ImVec2& p1, const ImVec2& p2, const ImVec2& p3, ImU32 col);
     IMGUI_API void  AddCircle(const ImVec2& center, float radius, ImU32 col, int num_segments = 12, float thickness = 1.0f);
     IMGUI_API void  AddCircleFilled(const ImVec2& center, float radius, ImU32 col, int num_segments = 12);
+    IMGUI_API void  AddNgon(const ImVec2& center, float radius, ImU32 col, int num_segments, float thickness = 1.0f);
+    IMGUI_API void  AddNgonFilled(const ImVec2& center, float radius, ImU32 col, int num_segments);
     IMGUI_API void  AddText(const ImVec2& pos, ImU32 col, const char* text_begin, const char* text_end = NULL);
     IMGUI_API void  AddText(const ImFont* font, float font_size, const ImVec2& pos, ImU32 col, const char* text_begin, const char* text_end = NULL, float wrap_width = 0.0f, const ImVec4* cpu_fine_clip_rect = NULL);
     IMGUI_API void  AddPolyline(const ImVec2* points, int num_points, ImU32 col, bool closed, float thickness);
     IMGUI_API void  AddConvexPolyFilled(const ImVec2* points, int num_points, ImU32 col); // Note: Anti-aliased filling requires points to be in clockwise order.
-    IMGUI_API void  AddBezierCurve(const ImVec2& pos0, const ImVec2& cp0, const ImVec2& cp1, const ImVec2& pos1, ImU32 col, float thickness, int num_segments = 0);
+    IMGUI_API void  AddBezierCurve(const ImVec2& p1, const ImVec2& p2, const ImVec2& p3, const ImVec2& p4, ImU32 col, float thickness, int num_segments = 0);
 
     // Image primitives
     // - Read FAQ to understand what ImTextureID is.
@@ -1950,7 +1980,7 @@ struct ImDrawList
     inline    void  PathStroke(ImU32 col, bool closed, float thickness = 1.0f)  { AddPolyline(_Path.Data, _Path.Size, col, closed, thickness); _Path.Size = 0; }
     IMGUI_API void  PathArcTo(const ImVec2& center, float radius, float a_min, float a_max, int num_segments = 10);
     IMGUI_API void  PathArcToFast(const ImVec2& center, float radius, int a_min_of_12, int a_max_of_12);                                            // Use precomputed angles for a 12 steps circle
-    IMGUI_API void  PathBezierCurveTo(const ImVec2& p1, const ImVec2& p2, const ImVec2& p3, int num_segments = 0);
+    IMGUI_API void  PathBezierCurveTo(const ImVec2& p2, const ImVec2& p3, const ImVec2& p4, int num_segments = 0);
     IMGUI_API void  PathRect(const ImVec2& rect_min, const ImVec2& rect_max, float rounding = 0.0f, ImDrawCornerFlags rounding_corners = ImDrawCornerFlags_All);
 
     // Advanced
@@ -1959,8 +1989,11 @@ struct ImDrawList
     IMGUI_API ImDrawList* CloneOutput() const;                                  // Create a clone of the CmdBuffer/IdxBuffer/VtxBuffer.
 
     // Advanced: Channels
-    // - Use to split render into layers. By switching channels to can render out-of-order (e.g. submit foreground primitives before background primitives)
-    // - Use to minimize draw calls (e.g. if going back-and-forth between multiple non-overlapping clipping rectangles, prefer to append into separate channels then merge at the end)
+    // - Use to split render into layers. By switching channels to can render out-of-order (e.g. submit FG primitives before BG primitives)
+    // - Use to minimize draw calls (e.g. if going back-and-forth between multiple clipping rectangles, prefer to append into separate channels then merge at the end)
+    // - FIXME-OBSOLETE: This API shouldn't have been in ImDrawList in the first place!
+    //   Prefer using your own persistent copy of ImDrawListSplitter as you can stack them.
+    //   Using the ImDrawList::ChannelsXXXX you cannot stack a split over another.
     inline void     ChannelsSplit(int count)    { _Splitter.Split(this, count); }
     inline void     ChannelsMerge()             { _Splitter.Merge(this); }
     inline void     ChannelsSetCurrent(int n)   { _Splitter.SetCurrentChannel(this, n); }
@@ -1970,6 +2003,7 @@ struct ImDrawList
     IMGUI_API void  Clear();
     IMGUI_API void  ClearFreeMemory();
     IMGUI_API void  PrimReserve(int idx_count, int vtx_count);
+    IMGUI_API void  PrimUnreserve(int idx_count, int vtx_count);
     IMGUI_API void  PrimRect(const ImVec2& a, const ImVec2& b, ImU32 col);      // Axis aligned rectangle (composed of two triangles)
     IMGUI_API void  PrimRectUV(const ImVec2& a, const ImVec2& b, const ImVec2& uv_a, const ImVec2& uv_b, ImU32 col);
     IMGUI_API void  PrimQuadUV(const ImVec2& a, const ImVec2& b, const ImVec2& c, const ImVec2& d, const ImVec2& uv_a, const ImVec2& uv_b, const ImVec2& uv_c, const ImVec2& uv_d, ImU32 col);
@@ -2203,10 +2237,10 @@ struct ImFont
     short                       ConfigDataCount;    // 2     // in  // ~ 1        // Number of ImFontConfig involved in creating this font. Bigger than 1 when merging multiple font sources into one ImFont.
     ImWchar                     FallbackChar;       // 2     // in  // = '?'      // Replacement character if a glyph isn't found. Only set via SetFallbackChar()
     ImWchar                     EllipsisChar;       // 2     // out // = -1       // Character used for ellipsis rendering.
+    bool                        DirtyLookupTables;  // 1     // out //
     float                       Scale;              // 4     // in  // = 1.f      // Base font scale, multiplied by the per-window font scale which you can adjust with SetWindowFontScale()
     float                       Ascent, Descent;    // 4+4   // out //            // Ascent: distance from top to bottom of e.g. 'A' [0..FontSize]
     int                         MetricsTotalSurface;// 4     // out //            // Total surface in pixels to get an idea of the font rasterization/texture cost (not exact, we approximate the cost of padding between glyphs)
-    bool                        DirtyLookupTables;  // 1     // out //
 
     // Methods
     IMGUI_API ImFont();
@@ -2243,3 +2277,5 @@ struct ImFont
 #ifdef IMGUI_INCLUDE_IMGUI_USER_H
 #include "imgui_user.h"
 #endif
+
+#endif // #ifndef IMGUI_DISABLE
diff --git a/imgui/imgui_demo.cpp b/imgui/imgui_demo.cpp
index 7e475992..7664f1b4 100644
--- a/imgui/imgui_demo.cpp
+++ b/imgui/imgui_demo.cpp
@@ -1,17 +1,24 @@
-// dear imgui, v1.74
+// dear imgui, v1.75
 // (demo code)
 
+// Help:
+// - Read FAQ at http://dearimgui.org/faq
+// - Newcomers, read 'Programmer guide' in imgui.cpp for notes on how to setup Dear ImGui in your codebase.
+// - Call and read ImGui::ShowDemoWindow() in imgui_demo.cpp for demo code. All applications in examples/ are doing that.
+// Read imgui.cpp for more details, documentation and comments.
+// Get latest version at https://github.com/ocornut/imgui
+
 // Message to the person tempted to delete this file when integrating Dear ImGui into their code base:
 // Do NOT remove this file from your project! Think again! It is the most useful reference code that you and other coders
 // will want to refer to and call. Have the ImGui::ShowDemoWindow() function wired in an always-available debug menu of
 // your game/app! Removing this file from your project is hindering access to documentation for everyone in your team,
 // likely leading you to poorer usage of the library.
 // Everything in this file will be stripped out by the linker if you don't call ImGui::ShowDemoWindow().
-// If you want to link core Dear ImGui in your shipped builds but want an easy guarantee that the demo will not be linked,
+// If you want to link core Dear ImGui in your shipped builds but want a thorough guarantee that the demo will not be linked,
 // you can setup your imconfig.h with #define IMGUI_DISABLE_DEMO_WINDOWS and those functions will be empty.
 // In other situation, whenever you have Dear ImGui available you probably want this to be available for reference.
 // Thank you,
-// -Your beloved friend, imgui_demo.cpp (that you won't delete)
+// -Your beloved friend, imgui_demo.cpp (which you won't delete)
 
 // Message to beginner C/C++ programmers about the meaning of the 'static' keyword:
 // In this demo code, we frequently we use 'static' variables inside functions. A static variable persist across calls, so it is
@@ -21,13 +28,13 @@
 // reentrant or used in multiple threads. This might be a pattern you will want to use in your code, but most of the real data
 // you would be editing is likely going to be stored outside your functions.
 
-// The Demo code is this file is designed to be easy to copy-and-paste in into your application!
+// The Demo code in this file is designed to be easy to copy-and-paste in into your application!
 // Because of this:
 // - We never omit the ImGui:: namespace when calling functions, even though most of our code is already in the same namespace.
 // - We try to declare static variables in the local scope, as close as possible to the code using them.
-// - We never use any of the helpers/facilities used internally by dear imgui, unless it has been exposed in the public API (imgui.h).
-// - We never use maths operators on ImVec2/ImVec4. For other imgui sources files, they are provided by imgui_internal.h w/ IMGUI_DEFINE_MATH_OPERATORS,
-//   for your own sources file they are optional and require you either enable those, either provide your own via IM_VEC2_CLASS_EXTRA in imconfig.h.
+// - We never use any of the helpers/facilities used internally by Dear ImGui, unless it has been exposed in the public API (imgui.h).
+// - We never use maths operators on ImVec2/ImVec4. For other of our sources files, they are provided by imgui_internal.h w/ IMGUI_DEFINE_MATH_OPERATORS.
+//   For your own sources file they are optional and require you either enable those, either provide your own via IM_VEC2_CLASS_EXTRA in imconfig.h.
 //   Because we don't want to assume anything about your support of maths operators, we don't use them in imgui_demo.cpp.
 
 /*
@@ -58,6 +65,8 @@ Index of this file:
 #endif
 
 #include "imgui.h"
+#ifndef IMGUI_DISABLE
+
 #include <ctype.h>          // toupper
 #include <limits.h>         // INT_MIN, INT_MAX
 #include <math.h>           // sqrtf, powf, cosf, sinf, floorf, ceilf
@@ -97,7 +106,7 @@ Index of this file:
 #pragma GCC diagnostic ignored "-Wmisleading-indentation"       // [__GNUC__ >= 6] warning: this 'if' clause does not guard this statement      // GCC 6.0+ only. See #883 on GitHub.
 #endif
 
-// Play it nice with Windows users. Notepad in 2017 still doesn't display text data with Unix-style \n.
+// Play it nice with Windows users (Update: since 2018-05, Notepad finally appears to support Unix-style carriage returns!)
 #ifdef _WIN32
 #define IM_NEWLINE  "\r\n"
 #else
@@ -115,10 +124,6 @@ Index of this file:
 // [SECTION] Forward Declarations, Helpers
 //-----------------------------------------------------------------------------
 
-#if !defined(IMGUI_DISABLE_OBSOLETE_FUNCTIONS) && defined(IMGUI_DISABLE_TEST_WINDOWS) && !defined(IMGUI_DISABLE_DEMO_WINDOWS)   // Obsolete name since 1.53, TEST->DEMO
-#define IMGUI_DISABLE_DEMO_WINDOWS
-#endif
-
 #if !defined(IMGUI_DISABLE_DEMO_WINDOWS)
 
 // Forward Declarations
@@ -518,6 +523,8 @@ static void ShowDemoWindowWidgets()
         }
 
         {
+            // To wire InputText() with std::string or any other custom string type,
+            // see the "Text Input > Resize Callback" section of this demo, and the misc/cpp/imgui_stdlib.h file.
             static char str0[128] = "Hello, world!";
             ImGui::InputText("input text", str0, IM_ARRAYSIZE(str0));
             ImGui::SameLine(); HelpMarker("USER:\nHold SHIFT or use mouse to select text.\n" "CTRL+Left/Right to word jump.\n" "CTRL+A or double-click to select all.\n" "CTRL+X,CTRL+C,CTRL+V clipboard.\n" "CTRL+Z,CTRL+Y undo/redo.\n" "ESCAPE to revert.\n\nPROGRAMMER:\nYou can use the ImGuiInputTextFlags_CallbackResize facility if you need to wire InputText() to a dynamic string type. See misc/cpp/imgui_stdlib.h for an example (this is not demonstrated in imgui_demo.cpp).");
@@ -993,6 +1000,8 @@ static void ShowDemoWindowWidgets()
         ImGui::TreePop();
     }
 
+    // To wire InputText() with std::string or any other custom string type,
+    // see the "Text Input > Resize Callback" section of this demo, and the misc/cpp/imgui_stdlib.h file.
     if (ImGui::TreeNode("Text Input"))
     {
         if (ImGui::TreeNode("Multi-line Text Input"))
@@ -1012,7 +1021,7 @@ static void ShowDemoWindowWidgets()
                 "\tlock cmpxchg8b eax\n";
 
             static ImGuiInputTextFlags flags = ImGuiInputTextFlags_AllowTabInput;
-            HelpMarker("You can use the ImGuiInputTextFlags_CallbackResize facility if you need to wire InputTextMultiline() to a dynamic string type. See misc/cpp/imgui_stdlib.h for an example. (This is not demonstrated in imgui_demo.cpp)");
+            HelpMarker("You can use the ImGuiInputTextFlags_CallbackResize facility if you need to wire InputTextMultiline() to a dynamic string type. See misc/cpp/imgui_stdlib.h for an example. (This is not demonstrated in imgui_demo.cpp because we don't want to include <string> in here)");
             ImGui::CheckboxFlags("ImGuiInputTextFlags_ReadOnly", (unsigned int*)&flags, ImGuiInputTextFlags_ReadOnly);
             ImGui::CheckboxFlags("ImGuiInputTextFlags_AllowTabInput", (unsigned int*)&flags, ImGuiInputTextFlags_AllowTabInput);
             ImGui::CheckboxFlags("ImGuiInputTextFlags_CtrlEnterForNewLine", (unsigned int*)&flags, ImGuiInputTextFlags_CtrlEnterForNewLine);
@@ -1041,8 +1050,9 @@ static void ShowDemoWindowWidgets()
 
         if (ImGui::TreeNode("Resize Callback"))
         {
-            // If you have a custom string type you would typically create a ImGui::InputText() wrapper than takes your type as input.
-            // See misc/cpp/imgui_stdlib.h and .cpp for an implementation of this using std::string.
+            // To wire InputText() with std::string or any other custom string type,
+            // you can use the ImGuiInputTextFlags_CallbackResize flag + create a custom ImGui::InputText() wrapper using your prefered type.
+            // See misc/cpp/imgui_stdlib.h for an implementation of this using std::string.
             HelpMarker("Demonstrate using ImGuiInputTextFlags_CallbackResize to wire your resizable string type to InputText().\n\nSee misc/cpp/imgui_stdlib.h for an implementation of this for std::string.");
             struct Funcs
             {
@@ -1782,7 +1792,7 @@ static void ShowDemoWindowLayout()
         // Child 1: no border, enable horizontal scrollbar
         {
             ImGuiWindowFlags window_flags = ImGuiWindowFlags_HorizontalScrollbar | (disable_mouse_wheel ? ImGuiWindowFlags_NoScrollWithMouse : 0);
-            ImGui::BeginChild("Child1", ImVec2(ImGui::GetWindowContentRegionWidth() * 0.5f, 260), false, window_flags);
+            ImGui::BeginChild("ChildL", ImVec2(ImGui::GetWindowContentRegionWidth() * 0.5f, 260), false, window_flags);
             for (int i = 0; i < 100; i++)
             {
                 ImGui::Text("%04d: scrollable region", i);
@@ -1800,7 +1810,7 @@ static void ShowDemoWindowLayout()
         {
             ImGuiWindowFlags window_flags = (disable_mouse_wheel ? ImGuiWindowFlags_NoScrollWithMouse : 0) | (disable_menu ? 0 : ImGuiWindowFlags_MenuBar);
             ImGui::PushStyleVar(ImGuiStyleVar_ChildRounding, 5.0f);
-            ImGui::BeginChild("Child2", ImVec2(0, 260), true, window_flags);
+            ImGui::BeginChild("ChildR", ImVec2(0, 260), true, window_flags);
             if (!disable_menu && ImGui::BeginMenuBar())
             {
                 if (ImGui::BeginMenu("Menu"))
@@ -1833,7 +1843,7 @@ static void ShowDemoWindowLayout()
         {
             ImGui::SetCursorPosX(ImGui::GetCursorPosX() + 10);
             ImGui::PushStyleColor(ImGuiCol_ChildBg, IM_COL32(255, 0, 0, 100));
-            ImGui::BeginChild("blah", ImVec2(200, 100), true, ImGuiWindowFlags_None);
+            ImGui::BeginChild("Red", ImVec2(200, 100), true, ImGuiWindowFlags_None);
             for (int n = 0; n < 50; n++)
                 ImGui::Text("Some test %d", n);
             ImGui::EndChild();
@@ -2027,7 +2037,7 @@ static void ShowDemoWindowLayout()
             if (ImGui::BeginTabBar("MyTabBar", tab_bar_flags))
             {
                 for (int n = 0; n < IM_ARRAYSIZE(opened); n++)
-                    if (opened[n] && ImGui::BeginTabItem(names[n], &opened[n]))
+                    if (opened[n] && ImGui::BeginTabItem(names[n], &opened[n], ImGuiTabItemFlags_None))
                     {
                         ImGui::Text("This is the %s tab!", names[n]);
                         if (n & 1)
@@ -2205,10 +2215,10 @@ static void ShowDemoWindowLayout()
         ImGui::SameLine(140); enable_track |= ImGui::DragInt("##item", &track_item, 0.25f, 0, 99, "Item = %d");
 
         bool scroll_to_off = ImGui::Button("Scroll Offset");
-        ImGui::SameLine(140); scroll_to_off |= ImGui::DragFloat("##off", &scroll_to_off_px, 1.00f, 0, 9999, "+%.0f px");
+        ImGui::SameLine(140); scroll_to_off |= ImGui::DragFloat("##off", &scroll_to_off_px, 1.00f, 0, FLT_MAX, "+%.0f px");
 
         bool scroll_to_pos = ImGui::Button("Scroll To Pos");
-        ImGui::SameLine(140); scroll_to_pos |= ImGui::DragFloat("##pos", &scroll_to_pos_px, 1.00f, -10, 9999, "X/Y = %.0f px");
+        ImGui::SameLine(140); scroll_to_pos |= ImGui::DragFloat("##pos", &scroll_to_pos_px, 1.00f, -10, FLT_MAX, "X/Y = %.0f px");
         ImGui::PopItemWidth();
 
         if (scroll_to_off || scroll_to_pos)
@@ -2445,7 +2455,7 @@ static void ShowDemoWindowLayout()
         ImVec2 pos = ImGui::GetCursorScreenPos();
         ImVec4 clip_rect(pos.x, pos.y, pos.x + size.x, pos.y + size.y);
         ImGui::InvisibleButton("##dummy", size);
-        if (ImGui::IsItemActive() && ImGui::IsMouseDragging()) { offset.x += ImGui::GetIO().MouseDelta.x; offset.y += ImGui::GetIO().MouseDelta.y; }
+        if (ImGui::IsItemActive() && ImGui::IsMouseDragging(0)) { offset.x += ImGui::GetIO().MouseDelta.x; offset.y += ImGui::GetIO().MouseDelta.y; }
         ImGui::GetWindowDrawList()->AddRectFilled(pos, ImVec2(pos.x + size.x, pos.y + size.y), IM_COL32(90, 90, 120, 255));
         ImGui::GetWindowDrawList()->AddText(ImGui::GetFont(), ImGui::GetFontSize()*2.0f, ImVec2(pos.x + offset.x, pos.y + offset.y), IM_COL32(255, 255, 255, 255), "Line 1 hello\nLine 2 clip me!", NULL, 0.0f, &clip_rect);
         ImGui::TreePop();
@@ -3051,7 +3061,7 @@ static void ShowDemoWindowMisc()
 
         if (ImGui::TreeNode("Mouse cursors"))
         {
-            const char* mouse_cursors_names[] = { "Arrow", "TextInput", "Move", "ResizeNS", "ResizeEW", "ResizeNESW", "ResizeNWSE", "Hand" };
+            const char* mouse_cursors_names[] = { "Arrow", "TextInput", "ResizeAll", "ResizeNS", "ResizeEW", "ResizeNESW", "ResizeNWSE", "Hand", "NotAllowed" };
             IM_ASSERT(IM_ARRAYSIZE(mouse_cursors_names) == ImGuiMouseCursor_COUNT);
 
             ImGui::Text("Current mouse cursor = %d: %s", ImGui::GetMouseCursor(), mouse_cursors_names[ImGui::GetMouseCursor()]);
@@ -3366,9 +3376,9 @@ void ImGui::ShowStyleEditor(ImGuiStyle* ref)
             filter.Draw("Filter colors", ImGui::GetFontSize() * 16);
 
             static ImGuiColorEditFlags alpha_flags = 0;
-            ImGui::RadioButton("Opaque", &alpha_flags, 0); ImGui::SameLine();
-            ImGui::RadioButton("Alpha", &alpha_flags, ImGuiColorEditFlags_AlphaPreview); ImGui::SameLine();
-            ImGui::RadioButton("Both", &alpha_flags, ImGuiColorEditFlags_AlphaPreviewHalf); ImGui::SameLine();
+            if (ImGui::RadioButton("Opaque", alpha_flags == 0))                                     { alpha_flags = 0; } ImGui::SameLine();
+            if (ImGui::RadioButton("Alpha",  alpha_flags == ImGuiColorEditFlags_AlphaPreview))      { alpha_flags = ImGuiColorEditFlags_AlphaPreview; } ImGui::SameLine();
+            if (ImGui::RadioButton("Both",   alpha_flags == ImGuiColorEditFlags_AlphaPreviewHalf))  { alpha_flags = ImGuiColorEditFlags_AlphaPreviewHalf; } ImGui::SameLine();
             HelpMarker("In the color list:\nLeft-click on colored square to open color picker,\nRight-click to open edit options menu.");
 
             ImGui::BeginChild("##colors", ImVec2(0, 0), true, ImGuiWindowFlags_AlwaysVerticalScrollbar | ImGuiWindowFlags_AlwaysHorizontalScrollbar | ImGuiWindowFlags_NavFlattened);
@@ -3423,8 +3433,9 @@ void ImGui::ShowStyleEditor(ImGuiStyle* ref)
                     const float surface_sqrt = sqrtf((float)font->MetricsTotalSurface);
                     ImGui::Text("Texture Area: about %d px ~%dx%d px", font->MetricsTotalSurface, (int)surface_sqrt, (int)surface_sqrt);
                     for (int config_i = 0; config_i < font->ConfigDataCount; config_i++)
-                        if (const ImFontConfig* cfg = &font->ConfigData[config_i])
-                            ImGui::BulletText("Input %d: \'%s\', Oversample: (%d,%d), PixelSnapH: %d", config_i, cfg->Name, cfg->OversampleH, cfg->OversampleV, cfg->PixelSnapH);
+                        if (font->ConfigData)
+                            if (const ImFontConfig* cfg = &font->ConfigData[config_i])
+                                ImGui::BulletText("Input %d: \'%s\', Oversample: (%d,%d), PixelSnapH: %d", config_i, cfg->Name, cfg->OversampleH, cfg->OversampleV, cfg->PixelSnapH);
                     if (ImGui::TreeNode("Glyphs", "Glyphs (%d)", font->Glyphs.Size))
                     {
                         // Display all glyphs of the fonts in separate pages of 256 characters
@@ -3491,8 +3502,9 @@ void ImGui::ShowStyleEditor(ImGuiStyle* ref)
             ImGui::Checkbox("Anti-aliased lines", &style.AntiAliasedLines); ImGui::SameLine(); HelpMarker("When disabling anti-aliasing lines, you'll probably want to disable borders in your style as well.");
             ImGui::Checkbox("Anti-aliased fill", &style.AntiAliasedFill);
             ImGui::PushItemWidth(100);
-            ImGui::DragFloat("Curve Tessellation Tolerance", &style.CurveTessellationTol, 0.02f, 0.10f, FLT_MAX, "%.2f", 2.0f);
+            ImGui::DragFloat("Curve Tessellation Tolerance", &style.CurveTessellationTol, 0.02f, 0.10f, 10.0f, "%.2f");
             if (style.CurveTessellationTol < 0.10f) style.CurveTessellationTol = 0.10f;
+            ImGui::DragFloat("Circle segment Max Error", &style.CircleSegmentMaxError, 0.01f, 0.10f, 10.0f, "%.2f");
             ImGui::DragFloat("Global Alpha", &style.Alpha, 0.005f, 0.20f, 1.0f, "%.2f"); // Not exposing zero here so user doesn't "lose" the UI (zero alpha clips all widgets). But application code could have a toggle to switch between zero and non-zero.
             ImGui::PopItemWidth();
 
@@ -4444,23 +4456,34 @@ static void ShowExampleAppCustomRendering(bool* p_open)
         {
             static float sz = 36.0f;
             static float thickness = 3.0f;
+            static int ngon_sides = 6;
+            static bool circle_segments_override = false;
+            static int circle_segments_override_v = 12;
             static ImVec4 colf = ImVec4(1.0f, 1.0f, 0.4f, 1.0f);
+            ImGui::PushItemWidth(-ImGui::GetFontSize() * 10);
             ImGui::DragFloat("Size", &sz, 0.2f, 2.0f, 72.0f, "%.0f");
             ImGui::DragFloat("Thickness", &thickness, 0.05f, 1.0f, 8.0f, "%.02f");
+            ImGui::SliderInt("N-gon sides", &ngon_sides, 3, 12);
+            ImGui::Checkbox("##circlesegmentoverride", &circle_segments_override);
+            ImGui::SameLine(0.0f, ImGui::GetStyle().ItemInnerSpacing.x);
+            if (ImGui::SliderInt("Circle segments", &circle_segments_override_v, 3, 40))
+                circle_segments_override = true;
             ImGui::ColorEdit4("Color", &colf.x);
+            ImGui::PopItemWidth();
             const ImVec2 p = ImGui::GetCursorScreenPos();
             const ImU32 col = ImColor(colf);
+            const float spacing = 10.0f;
+            const ImDrawCornerFlags corners_none = 0;
+            const ImDrawCornerFlags corners_all = ImDrawCornerFlags_All;
+            const ImDrawCornerFlags corners_tl_br = ImDrawCornerFlags_TopLeft | ImDrawCornerFlags_BotRight;
+            const int circle_segments = circle_segments_override ? circle_segments_override_v : 0;
             float x = p.x + 4.0f, y = p.y + 4.0f;
-            float spacing = 10.0f;
-            ImDrawCornerFlags corners_none = 0;
-            ImDrawCornerFlags corners_all = ImDrawCornerFlags_All;
-            ImDrawCornerFlags corners_tl_br = ImDrawCornerFlags_TopLeft | ImDrawCornerFlags_BotRight;
             for (int n = 0; n < 2; n++)
             {
                 // First line uses a thickness of 1.0f, second line uses the configurable thickness
                 float th = (n == 0) ? 1.0f : thickness;
-                draw_list->AddCircle(ImVec2(x + sz*0.5f, y + sz*0.5f), sz*0.5f, col, 6, th);                x += sz + spacing;  // Hexagon
-                draw_list->AddCircle(ImVec2(x + sz*0.5f, y + sz*0.5f), sz*0.5f, col, 20, th);               x += sz + spacing;  // Circle
+                draw_list->AddNgon(ImVec2(x + sz*0.5f, y + sz*0.5f), sz*0.5f, col, ngon_sides, th);         x += sz + spacing;  // N-gon
+                draw_list->AddCircle(ImVec2(x + sz*0.5f, y + sz*0.5f), sz*0.5f, col, circle_segments, th);  x += sz + spacing;  // Circle
                 draw_list->AddRect(ImVec2(x, y), ImVec2(x + sz, y + sz), col, 0.0f,  corners_none, th);     x += sz + spacing;  // Square
                 draw_list->AddRect(ImVec2(x, y), ImVec2(x + sz, y + sz), col, 10.0f, corners_all, th);      x += sz + spacing;  // Square with all rounded corners
                 draw_list->AddRect(ImVec2(x, y), ImVec2(x + sz, y + sz), col, 10.0f, corners_tl_br, th);    x += sz + spacing;  // Square with two rounded corners
@@ -4473,8 +4496,8 @@ static void ShowExampleAppCustomRendering(bool* p_open)
                 x = p.x + 4;
                 y += sz + spacing;
             }
-            draw_list->AddCircleFilled(ImVec2(x + sz*0.5f, y + sz*0.5f), sz*0.5f, col, 6);              x += sz + spacing;  // Hexagon
-            draw_list->AddCircleFilled(ImVec2(x + sz*0.5f, y + sz*0.5f), sz*0.5f, col, 32);             x += sz + spacing;  // Circle
+            draw_list->AddNgonFilled(ImVec2(x + sz * 0.5f, y + sz * 0.5f), sz*0.5f, col, ngon_sides);   x += sz + spacing;  // N-gon
+            draw_list->AddCircleFilled(ImVec2(x + sz*0.5f, y + sz*0.5f), sz*0.5f, col, circle_segments);x += sz + spacing;  // Circle
             draw_list->AddRectFilled(ImVec2(x, y), ImVec2(x + sz, y + sz), col);                        x += sz + spacing;  // Square
             draw_list->AddRectFilled(ImVec2(x, y), ImVec2(x + sz, y + sz), col, 10.0f);                 x += sz + spacing;  // Square with all rounded corners
             draw_list->AddRectFilled(ImVec2(x, y), ImVec2(x + sz, y + sz), col, 10.0f, corners_tl_br);  x += sz + spacing;  // Square with two rounded corners
@@ -4664,7 +4687,8 @@ void ShowExampleAppDocuments(bool* p_open)
     static bool opt_reorderable = true;
     static ImGuiTabBarFlags opt_fitting_flags = ImGuiTabBarFlags_FittingPolicyDefault_;
 
-    if (!ImGui::Begin("Example: Documents", p_open, ImGuiWindowFlags_MenuBar))
+    bool window_contents_visible = ImGui::Begin("Example: Documents", p_open, ImGuiWindowFlags_MenuBar);
+    if (!window_contents_visible)
     {
         ImGui::End();
         return;
@@ -4844,3 +4868,5 @@ void ImGui::ShowUserGuide() {}
 void ImGui::ShowStyleEditor(ImGuiStyle*) {}
 
 #endif
+
+#endif // #ifndef IMGUI_DISABLE
diff --git a/imgui/imgui_draw.cpp b/imgui/imgui_draw.cpp
index 8089bbef..4bb91ccf 100644
--- a/imgui/imgui_draw.cpp
+++ b/imgui/imgui_draw.cpp
@@ -1,4 +1,4 @@
-// dear imgui, v1.74
+// dear imgui, v1.75
 // (drawing and font code)
 
 /*
@@ -27,6 +27,8 @@ Index of this file:
 #endif
 
 #include "imgui.h"
+#ifndef IMGUI_DISABLE
+
 #ifndef IMGUI_DEFINE_MATH_OPERATORS
 #define IMGUI_DEFINE_MATH_OPERATORS
 #endif
@@ -348,15 +350,30 @@ ImDrawListSharedData::ImDrawListSharedData()
     Font = NULL;
     FontSize = 0.0f;
     CurveTessellationTol = 0.0f;
+    CircleSegmentMaxError = 0.0f;
     ClipRectFullscreen = ImVec4(-8192.0f, -8192.0f, +8192.0f, +8192.0f);
     InitialFlags = ImDrawListFlags_None;
 
-    // Const data
+    // Lookup tables
     for (int i = 0; i < IM_ARRAYSIZE(CircleVtx12); i++)
     {
         const float a = ((float)i * 2 * IM_PI) / (float)IM_ARRAYSIZE(CircleVtx12);
         CircleVtx12[i] = ImVec2(ImCos(a), ImSin(a));
     }
+    memset(CircleSegmentCounts, 0, sizeof(CircleSegmentCounts)); // This will be set by SetCircleSegmentMaxError()
+}
+
+void ImDrawListSharedData::SetCircleSegmentMaxError(float max_error)
+{
+    if (CircleSegmentMaxError == max_error)
+        return;
+    CircleSegmentMaxError = max_error;
+    for (int i = 0; i < IM_ARRAYSIZE(CircleSegmentCounts); i++)
+    {
+        const float radius = i + 1.0f;
+        const int segment_count = IM_DRAWLIST_CIRCLE_AUTO_SEGMENT_CALC(radius, CircleSegmentMaxError);
+        CircleSegmentCounts[i] = (ImU8)ImMin(segment_count, 255);
+    }
 }
 
 void ImDrawList::Clear()
@@ -516,10 +533,13 @@ void ImDrawList::PopTextureID()
     UpdateTextureID();
 }
 
-// NB: this can be called with negative count for removing primitives (as long as the result does not underflow)
+// Reserve space for a number of vertices and indices.
+// You must finish filling your reserved data before calling PrimReserve() again, as it may reallocate or
+// submit the intermediate results. PrimUnreserve() can be used to release unused allocations.
 void ImDrawList::PrimReserve(int idx_count, int vtx_count)
 {
     // Large mesh support (when enabled)
+    IM_ASSERT_PARANOID(idx_count >= 0 && vtx_count >= 0);
     if (sizeof(ImDrawIdx) == 2 && (_VtxCurrentIdx + vtx_count >= (1 << 16)) && (Flags & ImDrawListFlags_AllowVtxOffset))
     {
         _VtxCurrentOffset = VtxBuffer.Size;
@@ -527,7 +547,7 @@ void ImDrawList::PrimReserve(int idx_count, int vtx_count)
         AddDrawCmd();
     }
 
-    ImDrawCmd& draw_cmd = CmdBuffer.Data[CmdBuffer.Size-1];
+    ImDrawCmd& draw_cmd = CmdBuffer.Data[CmdBuffer.Size - 1];
     draw_cmd.ElemCount += idx_count;
 
     int vtx_buffer_old_size = VtxBuffer.Size;
@@ -539,6 +559,17 @@ void ImDrawList::PrimReserve(int idx_count, int vtx_count)
     _IdxWritePtr = IdxBuffer.Data + idx_buffer_old_size;
 }
 
+// Release the a number of reserved vertices/indices from the end of the last reservation made with PrimReserve().
+void ImDrawList::PrimUnreserve(int idx_count, int vtx_count)
+{
+    IM_ASSERT_PARANOID(idx_count >= 0 && vtx_count >= 0);
+
+    ImDrawCmd& draw_cmd = CmdBuffer.Data[CmdBuffer.Size - 1];
+    draw_cmd.ElemCount -= idx_count;
+    VtxBuffer.shrink(VtxBuffer.Size - vtx_count);
+    IdxBuffer.shrink(IdxBuffer.Size - idx_count);
+}
+
 // Fully unrolled with inline call to keep our debug builds decently fast.
 void ImDrawList::PrimRect(const ImVec2& a, const ImVec2& c, ImU32 col)
 {
@@ -893,6 +924,17 @@ void ImDrawList::PathArcTo(const ImVec2& center, float radius, float a_min, floa
     }
 }
 
+ImVec2 ImBezierCalc(const ImVec2& p1, const ImVec2& p2, const ImVec2& p3, const ImVec2& p4, float t)
+{
+    float u = 1.0f - t;
+    float w1 = u*u*u;
+    float w2 = 3*u*u*t;
+    float w3 = 3*u*t*t;
+    float w4 = t*t*t;
+    return ImVec2(w1*p1.x + w2*p2.x + w3*p3.x + w4*p4.x, w1*p1.y + w2*p2.y + w3*p3.y + w4*p4.y);
+}
+
+// Closely mimics BezierClosestPointCasteljauStep() in imgui.cpp
 static void PathBezierToCasteljau(ImVector<ImVec2>* path, float x1, float y1, float x2, float y2, float x3, float y3, float x4, float y4, float tess_tol, int level)
 {
     float dx = x4 - x1;
@@ -913,7 +955,6 @@ static void PathBezierToCasteljau(ImVector<ImVec2>* path, float x1, float y1, fl
         float x123 = (x12+x23)*0.5f,    y123 = (y12+y23)*0.5f;
         float x234 = (x23+x34)*0.5f,    y234 = (y23+y34)*0.5f;
         float x1234 = (x123+x234)*0.5f, y1234 = (y123+y234)*0.5f;
-
         PathBezierToCasteljau(path, x1,y1,        x12,y12,    x123,y123,  x1234,y1234, tess_tol, level+1);
         PathBezierToCasteljau(path, x1234,y1234,  x234,y234,  x34,y34,    x4,y4,       tess_tol, level+1);
     }
@@ -924,22 +965,13 @@ void ImDrawList::PathBezierCurveTo(const ImVec2& p2, const ImVec2& p3, const ImV
     ImVec2 p1 = _Path.back();
     if (num_segments == 0)
     {
-        // Auto-tessellated
-        PathBezierToCasteljau(&_Path, p1.x, p1.y, p2.x, p2.y, p3.x, p3.y, p4.x, p4.y, _Data->CurveTessellationTol, 0);
+        PathBezierToCasteljau(&_Path, p1.x, p1.y, p2.x, p2.y, p3.x, p3.y, p4.x, p4.y, _Data->CurveTessellationTol, 0); // Auto-tessellated
     }
     else
     {
         float t_step = 1.0f / (float)num_segments;
         for (int i_step = 1; i_step <= num_segments; i_step++)
-        {
-            float t = t_step * i_step;
-            float u = 1.0f - t;
-            float w1 = u*u*u;
-            float w2 = 3*u*u*t;
-            float w3 = 3*u*t*t;
-            float w4 = t*t*t;
-            _Path.push_back(ImVec2(w1*p1.x + w2*p2.x + w3*p3.x + w4*p4.x, w1*p1.y + w2*p2.y + w3*p3.y + w4*p4.y));
-        }
+            _Path.push_back(ImBezierCalc(p1, p2, p3, p4, t_step * i_step));
     }
 }
 
@@ -1070,6 +1102,67 @@ void ImDrawList::AddTriangleFilled(const ImVec2& p1, const ImVec2& p2, const ImV
 
 void ImDrawList::AddCircle(const ImVec2& center, float radius, ImU32 col, int num_segments, float thickness)
 {
+    if ((col & IM_COL32_A_MASK) == 0 || radius <= 0.0f)
+        return;
+
+    // Obtain segment count
+    if (num_segments <= 0)
+    {
+        // Automatic segment count
+        const int radius_idx = (int)radius - 1;
+        if (radius_idx < IM_ARRAYSIZE(_Data->CircleSegmentCounts))
+            num_segments = _Data->CircleSegmentCounts[radius_idx]; // Use cached value
+        else
+            num_segments = IM_DRAWLIST_CIRCLE_AUTO_SEGMENT_CALC(radius, _Data->CircleSegmentMaxError);
+    }
+    else
+    {
+        // Explicit segment count (still clamp to avoid drawing insanely tessellated shapes)
+        num_segments = ImClamp(num_segments, 3, IM_DRAWLIST_CIRCLE_AUTO_SEGMENT_MAX);
+    }
+
+    // Because we are filling a closed shape we remove 1 from the count of segments/points
+    const float a_max = (IM_PI * 2.0f) * ((float)num_segments - 1.0f) / (float)num_segments;
+    if (num_segments == 12)
+        PathArcToFast(center, radius - 0.5f, 0, 12);
+    else
+        PathArcTo(center, radius - 0.5f, 0.0f, a_max, num_segments - 1);
+    PathStroke(col, true, thickness);
+}
+
+void ImDrawList::AddCircleFilled(const ImVec2& center, float radius, ImU32 col, int num_segments)
+{
+    if ((col & IM_COL32_A_MASK) == 0 || radius <= 0.0f)
+        return;
+
+    // Obtain segment count
+    if (num_segments <= 0)
+    {
+        // Automatic segment count
+        const int radius_idx = (int)radius - 1;
+        if (radius_idx < IM_ARRAYSIZE(_Data->CircleSegmentCounts))
+            num_segments = _Data->CircleSegmentCounts[radius_idx]; // Use cached value
+        else
+            num_segments = IM_DRAWLIST_CIRCLE_AUTO_SEGMENT_CALC(radius, _Data->CircleSegmentMaxError);
+    }
+    else
+    {
+        // Explicit segment count (still clamp to avoid drawing insanely tessellated shapes)
+        num_segments = ImClamp(num_segments, 3, IM_DRAWLIST_CIRCLE_AUTO_SEGMENT_MAX);
+    }
+
+    // Because we are filling a closed shape we remove 1 from the count of segments/points
+    const float a_max = (IM_PI * 2.0f) * ((float)num_segments - 1.0f) / (float)num_segments;
+    if (num_segments == 12)
+        PathArcToFast(center, radius, 0, 12);
+    else
+        PathArcTo(center, radius, 0.0f, a_max, num_segments - 1);
+    PathFillConvex(col);
+}
+
+// Guaranteed to honor 'num_segments'
+void ImDrawList::AddNgon(const ImVec2& center, float radius, ImU32 col, int num_segments, float thickness)
+{
     if ((col & IM_COL32_A_MASK) == 0 || num_segments <= 2)
         return;
 
@@ -1079,7 +1172,8 @@ void ImDrawList::AddCircle(const ImVec2& center, float radius, ImU32 col, int nu
     PathStroke(col, true, thickness);
 }
 
-void ImDrawList::AddCircleFilled(const ImVec2& center, float radius, ImU32 col, int num_segments)
+// Guaranteed to honor 'num_segments'
+void ImDrawList::AddNgonFilled(const ImVec2& center, float radius, ImU32 col, int num_segments)
 {
     if ((col & IM_COL32_A_MASK) == 0 || num_segments <= 2)
         return;
@@ -1090,13 +1184,14 @@ void ImDrawList::AddCircleFilled(const ImVec2& center, float radius, ImU32 col,
     PathFillConvex(col);
 }
 
-void ImDrawList::AddBezierCurve(const ImVec2& pos0, const ImVec2& cp0, const ImVec2& cp1, const ImVec2& pos1, ImU32 col, float thickness, int num_segments)
+// Cubic Bezier takes 4 controls points
+void ImDrawList::AddBezierCurve(const ImVec2& p1, const ImVec2& p2, const ImVec2& p3, const ImVec2& p4, ImU32 col, float thickness, int num_segments)
 {
     if ((col & IM_COL32_A_MASK) == 0)
         return;
 
-    PathLineTo(pos0);
-    PathBezierCurveTo(cp0, cp1, pos1, num_segments);
+    PathLineTo(p1);
+    PathBezierCurveTo(p2, p3, p4, num_segments);
     PathStroke(col, false, thickness);
 }
 
@@ -1214,7 +1309,7 @@ void ImDrawListSplitter::ClearFreeMemory()
 
 void ImDrawListSplitter::Split(ImDrawList* draw_list, int channels_count)
 {
-    IM_ASSERT(_Current == 0 && _Count <= 1);
+    IM_ASSERT(_Current == 0 && _Count <= 1 && "Nested channel splitting is not supported. Please use separate instances of ImDrawListSplitter.");
     int old_channels_count = _Channels.Size;
     if (old_channels_count < channels_count)
         _Channels.resize(channels_count);
@@ -1275,7 +1370,7 @@ void ImDrawListSplitter::Merge(ImDrawList* draw_list)
             // Merge previous channel last draw command with current channel first draw command if matching.
             last_cmd->ElemCount += ch._CmdBuffer[0].ElemCount;
             idx_offset += ch._CmdBuffer[0].ElemCount;
-            ch._CmdBuffer.erase(ch._CmdBuffer.Data);
+            ch._CmdBuffer.erase(ch._CmdBuffer.Data); // FIXME-OPT: Improve for multiple merges.
         }
         if (ch._CmdBuffer.Size > 0)
             last_cmd = &ch._CmdBuffer.back();
@@ -1673,7 +1768,7 @@ ImFont* ImFontAtlas::AddFontFromFileTTF(const char* filename, float size_pixels,
     void* data = ImFileLoadToMemory(filename, "rb", &data_size, 0);
     if (!data)
     {
-        IM_ASSERT(0); // Could not load file.
+        IM_ASSERT_USER_ERROR(0, "Could not load font file!");
         return NULL;
     }
     ImFontConfig font_cfg = font_cfg_template ? *font_cfg_template : ImFontConfig();
@@ -3365,3 +3460,5 @@ static const char* GetDefaultCompressedFontDataTTFBase85()
 {
     return proggy_clean_ttf_compressed_data_base85;
 }
+
+#endif // #ifndef IMGUI_DISABLE
diff --git a/imgui/imgui_internal.h b/imgui/imgui_internal.h
index 73880098..5de13c36 100644
--- a/imgui/imgui_internal.h
+++ b/imgui/imgui_internal.h
@@ -1,4 +1,4 @@
-// dear imgui, v1.74
+// dear imgui, v1.75
 // (internal structures/api)
 
 // You may use this file to debug, understand or extend ImGui features but we don't provide any guarantee of forward compatibility!
@@ -22,6 +22,7 @@ Index of this file:
 */
 
 #pragma once
+#ifndef IMGUI_DISABLE
 
 //-----------------------------------------------------------------------------
 // Header mess
@@ -112,6 +113,7 @@ typedef int ImGuiNextWindowDataFlags;   // -> enum ImGuiNextWindowDataFlags_// F
 typedef int ImGuiSeparatorFlags;        // -> enum ImGuiSeparatorFlags_     // Flags: for SeparatorEx()
 typedef int ImGuiSliderFlags;           // -> enum ImGuiSliderFlags_        // Flags: for SliderBehavior()
 typedef int ImGuiTextFlags;             // -> enum ImGuiTextFlags_          // Flags: for TextEx()
+typedef int ImGuiTooltipFlags;          // -> enum ImGuiTooltipFlags_       // Flags: for BeginTooltipEx()
 
 //-------------------------------------------------------------------------
 // STB libraries includes
@@ -156,17 +158,18 @@ extern IMGUI_API ImGuiContext* GImGui;  // Current implicit context pointer
 #endif
 
 // "Paranoid" Debug Asserts are meant to only be enabled during specific debugging/work, otherwise would slow down the code too much.
-#define IMGUI_DEBUG_PARANOID            0
-#if IMGUI_DEBUG_PARANOID
+// We currently don't have many of those so the effect is currently negligible, but onward intent to add more aggressive ones in the code.
+//#define IMGUI_DEBUG_PARANOID
+#ifdef IMGUI_DEBUG_PARANOID
 #define IM_ASSERT_PARANOID(_EXPR)       IM_ASSERT(_EXPR)
 #else
-#define IM_ASSERT_PARANOID(_EXPR)   
+#define IM_ASSERT_PARANOID(_EXPR)
 #endif
 
 // Error handling
 // Down the line in some frameworks/languages we would like to have a way to redirect those to the programmer and recover from more faults.
 #ifndef IM_ASSERT_USER_ERROR
-#define IM_ASSERT_USER_ERROR(_EXP,_MSG) IM_ASSERT((_EXP) && (_MSG))     // Recoverable User Error
+#define IM_ASSERT_USER_ERROR(_EXP,_MSG) IM_ASSERT((_EXP) && _MSG)   // Recoverable User Error
 #endif
 
 // Misc Macros
@@ -191,6 +194,8 @@ extern IMGUI_API ImGuiContext* GImGui;  // Current implicit context pointer
 
 //-----------------------------------------------------------------------------
 // Generic helpers
+// Note that the ImXXX helpers functions are lower-level than ImGui functions.
+// ImGui functions or the ImGui context are never called/used from other ImXXX functions.
 //-----------------------------------------------------------------------------
 // - Helpers: Misc
 // - Helpers: Bit manipulation
@@ -266,9 +271,6 @@ static inline ImVec4 operator*(const ImVec4& lhs, const ImVec4& rhs)
 #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;
@@ -294,22 +296,21 @@ IMGUI_API void*             ImFileLoadToMemory(const char* filename, const char*
 // 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_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); }
-static inline double ImPow(double x, double y)                                  { return pow(x, y); }
-static inline float  ImFmod(float x, float y)                                   { return fmodf(x, y); }
-static inline double ImFmod(double x, double y)                                 { return fmod(x, y); }
-static inline float  ImCos(float x)                                             { return cosf(x); }
-static inline float  ImSin(float x)                                             { return sinf(x); }
-static inline float  ImAcos(float x)                                            { return acosf(x); }
-static inline float  ImAtan2(float y, float x)                                  { return atan2f(y, x); }
-static inline double ImAtof(const char* s)                                      { return atof(s); }
-static inline float  ImFloorStd(float x)                                        { return floorf(x); }   // we already uses our own ImFloor() { return (float)(int)v } internally so the standard one wrapper is named differently (it's used by stb_truetype)
-static inline float  ImCeil(float x)                                            { return ceilf(x); }
+#define ImFabs(X)           fabsf(X)
+#define ImSqrt(X)           sqrtf(X)
+#define ImFmod(X, Y)        fmodf((X), (Y))
+#define ImCos(X)            cosf(X)
+#define ImSin(X)            sinf(X)
+#define ImAcos(X)           acosf(X)
+#define ImAtan2(Y, X)       atan2f((Y), (X))
+#define ImAtof(STR)         atof(STR)
+#define ImFloorStd(X)       floorf(X)           // We already uses our own ImFloor() { return (float)(int)v } internally so the standard one wrapper is named differently (it's used by e.g. stb_truetype)
+#define ImCeil(X)           ceilf(X)
+static inline float  ImPow(float x, float y)    { return powf(x, y); }          // DragBehaviorT/SliderBehaviorT uses ImPow with either float/double and need the precision
+static inline double ImPow(double x, double y)  { return pow(x, y); }
 #endif
-// - ImMin/ImMax/ImClamp/ImLerp/ImSwap are used by widgets which support for variety of types: signed/unsigned int/long long float/double
-// (Exceptionally using templates here but we could also redefine them for variety of types)
+// - ImMin/ImMax/ImClamp/ImLerp/ImSwap are used by widgets which support variety of types: signed/unsigned int/long long float/double
+// (Exceptionally using templates here but we could also redefine them for those types)
 template<typename T> static inline T ImMin(T lhs, T rhs)                        { return lhs < rhs ? lhs : rhs; }
 template<typename T> static inline T ImMax(T lhs, T rhs)                        { return lhs >= rhs ? lhs : rhs; }
 template<typename T> static inline T ImClamp(T v, T mn, T mx)                   { return (v < mn) ? mn : (v > mx) ? mx : v; }
@@ -337,6 +338,9 @@ static inline float  ImLinearSweep(float current, float target, float speed)
 static inline ImVec2 ImMul(const ImVec2& lhs, const ImVec2& rhs)                { return ImVec2(lhs.x * rhs.x, lhs.y * rhs.y); }
 
 // Helpers: Geometry
+IMGUI_API ImVec2     ImBezierCalc(const ImVec2& p1, const ImVec2& p2, const ImVec2& p3, const ImVec2& p4, float t);                                         // Cubic Bezier
+IMGUI_API ImVec2     ImBezierClosestPoint(const ImVec2& p1, const ImVec2& p2, const ImVec2& p3, const ImVec2& p4, const ImVec2& p, int num_segments);       // For curves with explicit number of segments
+IMGUI_API ImVec2     ImBezierClosestPointCasteljau(const ImVec2& p1, const ImVec2& p2, const ImVec2& p3, const ImVec2& p4, const ImVec2& p, float tess_tol);// For auto-tessellated curves you can use tess_tol = style.CurveTessellationTol
 IMGUI_API ImVec2     ImLineClosestPoint(const ImVec2& a, const ImVec2& b, const ImVec2& p);
 IMGUI_API bool       ImTriangleContainsPoint(const ImVec2& a, const ImVec2& b, const ImVec2& c, const ImVec2& p);
 IMGUI_API ImVec2     ImTriangleClosestPoint(const ImVec2& a, const ImVec2& b, const ImVec2& c, const ImVec2& p);
@@ -412,20 +416,30 @@ enum ImGuiButtonFlags_
 {
     ImGuiButtonFlags_None                   = 0,
     ImGuiButtonFlags_Repeat                 = 1 << 0,   // hold to repeat
-    ImGuiButtonFlags_PressedOnClickRelease  = 1 << 1,   // [Default] return true on click + release on same item
-    ImGuiButtonFlags_PressedOnClick         = 1 << 2,   // return true on click (default requires click+release)
-    ImGuiButtonFlags_PressedOnRelease       = 1 << 3,   // return true on release (default requires click+release)
-    ImGuiButtonFlags_PressedOnDoubleClick   = 1 << 4,   // return true on double-click (default requires click+release)
-    ImGuiButtonFlags_FlattenChildren        = 1 << 5,   // allow interactions even if a child window is overlapping
-    ImGuiButtonFlags_AllowItemOverlap       = 1 << 6,   // require previous frame HoveredId to either match id or be null before being usable, use along with SetItemAllowOverlap()
-    ImGuiButtonFlags_DontClosePopups        = 1 << 7,   // disable automatically closing parent popup on press // [UNUSED]
-    ImGuiButtonFlags_Disabled               = 1 << 8,   // disable interactions
-    ImGuiButtonFlags_AlignTextBaseLine      = 1 << 9,   // vertically align button to match text baseline - ButtonEx() only // FIXME: Should be removed and handled by SmallButton(), not possible currently because of DC.CursorPosPrevLine
-    ImGuiButtonFlags_NoKeyModifiers         = 1 << 10,  // disable mouse interaction if a key modifier is held
-    ImGuiButtonFlags_NoHoldingActiveID      = 1 << 11,  // don't set ActiveId while holding the mouse (ImGuiButtonFlags_PressedOnClick only)
-    ImGuiButtonFlags_PressedOnDragDropHold  = 1 << 12,  // press when held into while we are drag and dropping another item (used by e.g. tree nodes, collapsing headers)
-    ImGuiButtonFlags_NoNavFocus             = 1 << 13,  // don't override navigation focus when activated
-    ImGuiButtonFlags_NoHoveredOnNav         = 1 << 14   // don't report as hovered when navigated on
+    ImGuiButtonFlags_PressedOnClick         = 1 << 1,   // return true on click (mouse down event)
+    ImGuiButtonFlags_PressedOnClickRelease  = 1 << 2,   // [Default] return true on click + release on same item <-- this is what the majority of Button are using
+    ImGuiButtonFlags_PressedOnClickReleaseAnywhere = 1 << 3, // return true on click + release even if the release event is not done while hovering the item
+    ImGuiButtonFlags_PressedOnRelease       = 1 << 4,   // return true on release (default requires click+release)
+    ImGuiButtonFlags_PressedOnDoubleClick   = 1 << 5,   // return true on double-click (default requires click+release)
+    ImGuiButtonFlags_PressedOnDragDropHold  = 1 << 6,   // return true when held into while we are drag and dropping another item (used by e.g. tree nodes, collapsing headers)
+    ImGuiButtonFlags_FlattenChildren        = 1 << 7,   // allow interactions even if a child window is overlapping
+    ImGuiButtonFlags_AllowItemOverlap       = 1 << 8,   // require previous frame HoveredId to either match id or be null before being usable, use along with SetItemAllowOverlap()
+    ImGuiButtonFlags_DontClosePopups        = 1 << 9,   // disable automatically closing parent popup on press // [UNUSED]
+    ImGuiButtonFlags_Disabled               = 1 << 10,  // disable interactions
+    ImGuiButtonFlags_AlignTextBaseLine      = 1 << 11,  // vertically align button to match text baseline - ButtonEx() only // FIXME: Should be removed and handled by SmallButton(), not possible currently because of DC.CursorPosPrevLine
+    ImGuiButtonFlags_NoKeyModifiers         = 1 << 12,  // disable mouse interaction if a key modifier is held
+    ImGuiButtonFlags_NoHoldingActiveId      = 1 << 13,  // don't set ActiveId while holding the mouse (ImGuiButtonFlags_PressedOnClick only)
+    ImGuiButtonFlags_NoNavFocus             = 1 << 14,  // don't override navigation focus when activated
+    ImGuiButtonFlags_NoHoveredOnNav         = 1 << 15,  // don't report as hovered when navigated on
+    ImGuiButtonFlags_MouseButtonLeft        = 1 << 16,  // [Default] react on left mouse button 
+    ImGuiButtonFlags_MouseButtonRight       = 1 << 17,  // react on right mouse button
+    ImGuiButtonFlags_MouseButtonMiddle      = 1 << 18,  // react on center mouse button
+    
+    ImGuiButtonFlags_MouseButtonMask_       = ImGuiButtonFlags_MouseButtonLeft | ImGuiButtonFlags_MouseButtonRight | ImGuiButtonFlags_MouseButtonMiddle,
+    ImGuiButtonFlags_MouseButtonShift_      = 16,
+    ImGuiButtonFlags_MouseButtonDefault_    = ImGuiButtonFlags_MouseButtonLeft,
+    ImGuiButtonFlags_PressedOnMask_         = ImGuiButtonFlags_PressedOnClick | ImGuiButtonFlags_PressedOnClickRelease | ImGuiButtonFlags_PressedOnClickReleaseAnywhere | ImGuiButtonFlags_PressedOnRelease | ImGuiButtonFlags_PressedOnDoubleClick | ImGuiButtonFlags_PressedOnDragDropHold,
+    ImGuiButtonFlags_PressedOnDefault_      = ImGuiButtonFlags_PressedOnClickRelease
 };
 
 enum ImGuiSliderFlags_
@@ -500,7 +514,7 @@ enum ImGuiItemStatusFlags_
     ImGuiItemStatusFlags_HasDisplayRect     = 1 << 1,
     ImGuiItemStatusFlags_Edited             = 1 << 2,   // Value exposed by item was edited in the current frame (should match the bool return value of most widgets)
     ImGuiItemStatusFlags_ToggledSelection   = 1 << 3,   // Set when Selectable(), TreeNode() reports toggling a selection. We can't report "Selected" because reporting the change allows us to handle clipping with less issues.
-    ImGuiItemStatusFlags_ToggledOpen        = 1 << 4,   // Set when TreeNode() reports toggling their open state. 
+    ImGuiItemStatusFlags_ToggledOpen        = 1 << 4,   // Set when TreeNode() reports toggling their open state.
     ImGuiItemStatusFlags_HasDeactivated     = 1 << 5,   // Set if the widget/group is able to provide data for the ImGuiItemStatusFlags_Deactivated flag.
     ImGuiItemStatusFlags_Deactivated        = 1 << 6    // Only valid if ImGuiItemStatusFlags_HasDeactivated is set.
 
@@ -519,6 +533,12 @@ enum ImGuiTextFlags_
     ImGuiTextFlags_NoWidthForLargeClippedText = 1 << 0
 };
 
+enum ImGuiTooltipFlags_
+{
+    ImGuiTooltipFlags_None = 0,
+    ImGuiTooltipFlags_OverridePreviousTooltip = 1 << 0      // Override will clear/ignore previously submitted tooltip (defaults to append)
+};
+
 // FIXME: this is in development, not exposed/functional as a generic feature yet.
 // Horizontal/Vertical enums are fixed to 0/1 so they may be used to index ImVec2
 enum ImGuiLayoutType_
@@ -632,8 +652,9 @@ struct ImVec1
 struct ImVec2ih
 {
     short   x, y;
-    ImVec2ih()                   { x = y = 0; }
-    ImVec2ih(short _x, short _y) { x = _x; y = _y; }
+    ImVec2ih()                           { x = y = 0; }
+    ImVec2ih(short _x, short _y)         { x = _x; y = _y; }
+    explicit ImVec2ih(const ImVec2& rhs) { x = (short)rhs.x; y = (short)rhs.y; }
 };
 
 // 2D axis aligned bounding-box
@@ -643,7 +664,7 @@ struct IMGUI_API ImRect
     ImVec2      Min;    // Upper-left
     ImVec2      Max;    // Lower-right
 
-    ImRect()                                        : Min(FLT_MAX,FLT_MAX), Max(-FLT_MAX,-FLT_MAX)  {}
+    ImRect()                                        : Min(0.0f, 0.0f), Max(0.0f, 0.0f)              {}
     ImRect(const ImVec2& min, const ImVec2& max)    : Min(min), Max(max)                            {}
     ImRect(const ImVec4& v)                         : Min(v.x, v.y), Max(v.z, v.w)                  {}
     ImRect(float x1, float y1, float x2, float y2)  : Min(x1, y1), Max(x2, y2)                      {}
@@ -823,6 +844,7 @@ struct ImGuiColumns
     ImRect              HostClipRect;           // Backup of ClipRect at the time of BeginColumns()
     ImRect              HostWorkRect;           // Backup of WorkRect at the time of BeginColumns()
     ImVector<ImGuiColumnData> Columns;
+    ImDrawListSplitter  Splitter;
 
     ImGuiColumns()      { Clear(); }
     void Clear()
@@ -841,21 +863,29 @@ struct ImGuiColumns
     }
 };
 
+// Helper function to calculate a circle's segment count given its radius and a "maximum error" value.
+#define IM_DRAWLIST_CIRCLE_AUTO_SEGMENT_MIN                     12
+#define IM_DRAWLIST_CIRCLE_AUTO_SEGMENT_MAX                     512
+#define IM_DRAWLIST_CIRCLE_AUTO_SEGMENT_CALC(_RAD,_MAXERROR)    ImClamp((int)((IM_PI * 2.0f) / ImAcos((_RAD - _MAXERROR) / _RAD)), IM_DRAWLIST_CIRCLE_AUTO_SEGMENT_MIN, IM_DRAWLIST_CIRCLE_AUTO_SEGMENT_MAX)
+
 // Data shared between all ImDrawList instances
+// You may want to create your own instance of this if you want to use ImDrawList completely without ImGui. In that case, watch out for future changes to this structure.
 struct IMGUI_API ImDrawListSharedData
 {
     ImVec2          TexUvWhitePixel;            // UV of white pixel in the atlas
     ImFont*         Font;                       // Current/default font (optional, for simplified AddText overload)
     float           FontSize;                   // Current/default font size (optional, for simplified AddText overload)
-    float           CurveTessellationTol;
+    float           CurveTessellationTol;       // Tessellation tolerance when using PathBezierCurveTo()
+    float           CircleSegmentMaxError;      // Number of circle segments to use per pixel of radius for AddCircle() etc
     ImVec4          ClipRectFullscreen;         // Value for PushClipRectFullscreen()
     ImDrawListFlags InitialFlags;               // Initial flags at the beginning of the frame (it is possible to alter flags on a per-drawlist basis afterwards)
 
-    // Const data
-    // FIXME: Bake rounded corners fill/borders in atlas
-    ImVec2          CircleVtx12[12];
+    // [Internal] Lookup tables
+    ImVec2          CircleVtx12[12];            // FIXME: Bake rounded corners fill/borders in atlas
+    ImU8            CircleSegmentCounts[64];    // Precomputed segment count for given radius (array index + 1) before we calculate it dynamically (to avoid calculation overhead)
 
     ImDrawListSharedData();
+    void SetCircleSegmentMaxError(float max_error);
 };
 
 struct ImDrawDataBuilder
@@ -869,16 +899,16 @@ struct ImDrawDataBuilder
 
 struct ImGuiNavMoveResult
 {
-    ImGuiID       ID;           // Best candidate
-    ImGuiID       SelectScopeId;// Best candidate window current selectable group ID
-    ImGuiWindow*  Window;       // Best candidate window
-    float         DistBox;      // Best candidate box distance to current NavId
-    float         DistCenter;   // Best candidate center distance to current NavId
-    float         DistAxial;
-    ImRect        RectRel;      // Best candidate bounding box in window relative space
+    ImGuiWindow*    Window;             // Best candidate window
+    ImGuiID         ID;                 // Best candidate ID
+    ImGuiID         FocusScopeId;       // Best candidate focus scope ID
+    float           DistBox;            // Best candidate box distance to current NavId
+    float           DistCenter;         // Best candidate center distance to current NavId
+    float           DistAxial;
+    ImRect          RectRel;            // Best candidate bounding box in window relative space
 
     ImGuiNavMoveResult() { Clear(); }
-    void Clear()         { ID = SelectScopeId = 0; Window = NULL; DistBox = DistCenter = DistAxial = FLT_MAX; RectRel = ImRect(); }
+    void Clear()         { Window = NULL; ID = FocusScopeId = 0; DistBox = DistCenter = DistAxial = FLT_MAX; RectRel = ImRect(); }
 };
 
 enum ImGuiNextWindowDataFlags_
@@ -908,7 +938,7 @@ struct ImGuiNextWindowData
     ImRect                      SizeConstraintRect;
     ImGuiSizeCallback           SizeCallback;
     void*                       SizeCallbackUserData;
-    float                       BgAlphaVal;
+    float                       BgAlphaVal;             // Override background alpha
     ImVec2                      MenuBarOffsetMinVal;    // *Always on* This is not exposed publicly, so we don't clear it.
 
     ImGuiNextWindowData()       { memset(this, 0, sizeof(*this)); }
@@ -925,12 +955,13 @@ enum ImGuiNextItemDataFlags_
 struct ImGuiNextItemData
 {
     ImGuiNextItemDataFlags      Flags;
-    float                       Width;          // Set by SetNextItemWidth().
-    bool                        OpenVal;        // Set by SetNextItemOpen() function.
+    float                       Width;          // Set by SetNextItemWidth()
+    ImGuiID                     FocusScopeId;   // Set by SetNextItemMultiSelectData() (!= 0 signify value has been set, so it's an alternate version of HasSelectionData, we don't use Flags for this because they are cleared too early. This is mostly used for debugging)
     ImGuiCond                   OpenCond;
+    bool                        OpenVal;        // Set by SetNextItemOpen()
 
     ImGuiNextItemData()         { memset(this, 0, sizeof(*this)); }
-    inline void ClearFlags()    { Flags = ImGuiNextItemDataFlags_None; }
+    inline void ClearFlags()    { Flags = ImGuiNextItemDataFlags_None; } // Also cleared manually by ItemAdd()!
 };
 
 //-----------------------------------------------------------------------------
@@ -953,7 +984,7 @@ struct ImGuiPtrOrIndex
 };
 
 //-----------------------------------------------------------------------------
-// Main imgui context
+// Main Dear ImGui context
 //-----------------------------------------------------------------------------
 
 struct ImGuiContext
@@ -976,8 +1007,8 @@ struct ImGuiContext
 
     // Windows state
     ImVector<ImGuiWindow*>  Windows;                            // Windows, sorted in display order, back to front
-    ImVector<ImGuiWindow*>  WindowsFocusOrder;                  // Windows, sorted in focus order, back to front
-    ImVector<ImGuiWindow*>  WindowsSortBuffer;
+    ImVector<ImGuiWindow*>  WindowsFocusOrder;                  // Windows, sorted in focus order, back to front. (FIXME: We could only store root windows here! Need to sort out the Docking equivalent which is RootWindowDockStop and is unfortunately a little more dynamic)
+    ImVector<ImGuiWindow*>  WindowsTempSortBuffer;              // Temporary buffer used in EndFrame() to reorder windows so parents are kept before their child
     ImVector<ImGuiWindow*>  CurrentWindowStack;
     ImGuiStorage            WindowsById;                        // Map window's ImGuiID to ImGuiWindow*
     int                     WindowsActiveCount;                 // Number of unique windows submitted by frame
@@ -1009,6 +1040,7 @@ struct ImGuiContext
     ImVec2                  ActiveIdClickOffset;                // Clicked offset from upper-left corner, if applicable (currently only set by ButtonBehavior)
     ImGuiWindow*            ActiveIdWindow;
     ImGuiInputSource        ActiveIdSource;                     // Activating with mouse or nav (gamepad/keyboard)
+    int                     ActiveIdMouseButton;
     ImGuiID                 ActiveIdPreviousFrame;
     bool                    ActiveIdPreviousFrameIsAlive;
     bool                    ActiveIdPreviousFrameHasBeenEditedBefore;
@@ -1027,26 +1059,21 @@ struct ImGuiContext
     ImVector<ImGuiPopupData>OpenPopupStack;                     // Which popups are open (persistent)
     ImVector<ImGuiPopupData>BeginPopupStack;                    // Which level of BeginPopup() we are in (reset every frame)
 
-    // Navigation data (for gamepad/keyboard)
+    // Gamepad/keyboard Navigation
     ImGuiWindow*            NavWindow;                          // Focused window for navigation. Could be called 'FocusWindow'
     ImGuiID                 NavId;                              // Focused item for navigation
+    ImGuiID                 NavFocusScopeId;
     ImGuiID                 NavActivateId;                      // ~~ (g.ActiveId == 0) && IsNavInputPressed(ImGuiNavInput_Activate) ? NavId : 0, also set when calling ActivateItem()
     ImGuiID                 NavActivateDownId;                  // ~~ IsNavInputDown(ImGuiNavInput_Activate) ? NavId : 0
     ImGuiID                 NavActivatePressedId;               // ~~ IsNavInputPressed(ImGuiNavInput_Activate) ? NavId : 0
     ImGuiID                 NavInputId;                         // ~~ IsNavInputPressed(ImGuiNavInput_Input) ? NavId : 0
     ImGuiID                 NavJustTabbedId;                    // Just tabbed to this id.
     ImGuiID                 NavJustMovedToId;                   // Just navigated to this id (result of a successfully MoveRequest).
-    ImGuiID                 NavJustMovedToMultiSelectScopeId;   // Just navigated to this select scope id (result of a successfully MoveRequest).
+    ImGuiID                 NavJustMovedToFocusScopeId;         // Just navigated to this focus scope id (result of a successfully MoveRequest).
     ImGuiID                 NavNextActivateId;                  // Set by ActivateItem(), queued until next frame.
     ImGuiInputSource        NavInputSource;                     // Keyboard or Gamepad mode? THIS WILL ONLY BE None or NavGamepad or NavKeyboard.
     ImRect                  NavScoringRectScreen;               // Rectangle used for scoring, in screen space. Based of window->DC.NavRefRectRel[], modified for directional navigation scoring.
     int                     NavScoringCount;                    // Metrics for debugging
-    ImGuiWindow*            NavWindowingTarget;                 // When selecting a window (holding Menu+FocusPrev/Next, or equivalent of CTRL-TAB) this window is temporarily displayed top-most.
-    ImGuiWindow*            NavWindowingTargetAnim;             // Record of last valid NavWindowingTarget until DimBgRatio and NavWindowingHighlightAlpha becomes 0.0f
-    ImGuiWindow*            NavWindowingList;
-    float                   NavWindowingTimer;
-    float                   NavWindowingHighlightAlpha;
-    bool                    NavWindowingToggleLayer;
     ImGuiNavLayer           NavLayer;                           // Layer we are navigating on. For now the system is hard-coded for 0=main contents and 1=menu/title bar, may expose layers later.
     int                     NavIdTabCounter;                    // == NavWindow->DC.FocusIdxTabCounter at time of NavId processing
     bool                    NavIdIsAlive;                       // Nav widget has been seen this frame ~~ NavRefRectRel is valid
@@ -1068,13 +1095,21 @@ struct ImGuiContext
     ImGuiNavMoveResult      NavMoveResultLocalVisibleSet;       // Best move request candidate within NavWindow that are mostly visible (when using ImGuiNavMoveFlags_AlsoScoreVisibleSet flag)
     ImGuiNavMoveResult      NavMoveResultOther;                 // Best move request candidate within NavWindow's flattened hierarchy (when using ImGuiWindowFlags_NavFlattened flag)
 
-    // Tabbing system (older than Nav, active even if Nav is disabled. FIXME-NAV: This needs a redesign!)
+    // Navigation: Windowing (CTRL+TAB, holding Menu button + directional pads to move/resize)
+    ImGuiWindow*            NavWindowingTarget;                 // When selecting a window (holding Menu+FocusPrev/Next, or equivalent of CTRL-TAB) this window is temporarily displayed top-most.
+    ImGuiWindow*            NavWindowingTargetAnim;             // Record of last valid NavWindowingTarget until DimBgRatio and NavWindowingHighlightAlpha becomes 0.0f
+    ImGuiWindow*            NavWindowingList;
+    float                   NavWindowingTimer;
+    float                   NavWindowingHighlightAlpha;
+    bool                    NavWindowingToggleLayer;
+
+    // Legacy Focus/Tabbing system (older than Nav, active even if Nav is disabled, misnamed. FIXME-NAV: This needs a redesign!)
     ImGuiWindow*            FocusRequestCurrWindow;             //
     ImGuiWindow*            FocusRequestNextWindow;             //
-    int                     FocusRequestCurrCounterAll;         // Any item being requested for focus, stored as an index (we on layout to be stable between the frame pressing TAB and the next frame, semi-ouch)
-    int                     FocusRequestCurrCounterTab;         // Tab item being requested for focus, stored as an index
-    int                     FocusRequestNextCounterAll;         // Stored for next frame
-    int                     FocusRequestNextCounterTab;         // "
+    int                     FocusRequestCurrCounterRegular;     // Any item being requested for focus, stored as an index (we on layout to be stable between the frame pressing TAB and the next frame, semi-ouch)
+    int                     FocusRequestCurrCounterTabStop;     // Tab item being requested for focus, stored as an index
+    int                     FocusRequestNextCounterRegular;     // Stored for next frame
+    int                     FocusRequestNextCounterTabStop;     // "
     bool                    FocusTabPressed;                    //
 
     // Render
@@ -1087,19 +1122,19 @@ struct ImGuiContext
 
     // Drag and Drop
     bool                    DragDropActive;
-    bool                    DragDropWithinSourceOrTarget;
+    bool                    DragDropWithinSourceOrTarget;       // Set when within a BeginDragDropXXX/EndDragDropXXX block.
     ImGuiDragDropFlags      DragDropSourceFlags;
     int                     DragDropSourceFrameCount;
     int                     DragDropMouseButton;
     ImGuiPayload            DragDropPayload;
-    ImRect                  DragDropTargetRect;
+    ImRect                  DragDropTargetRect;                 // Store rectangle of current target candidate (we favor small targets when overlapping)
     ImGuiID                 DragDropTargetId;
     ImGuiDragDropFlags      DragDropAcceptFlags;
     float                   DragDropAcceptIdCurrRectSurface;    // Target item surface (we resolve overlapping targets by prioritizing the smaller surface)
     ImGuiID                 DragDropAcceptIdCurr;               // Target item id (set at the time of accepting the payload)
     ImGuiID                 DragDropAcceptIdPrev;               // Target item id from previous frame (we need to store this to allow for overlapping drag and drop targets)
     int                     DragDropAcceptFrameCount;           // Last time a target expressed a desire to accept the source
-    ImVector<unsigned char> DragDropPayloadBufHeap;             // We don't expose the ImVector<> directly
+    ImVector<unsigned char> DragDropPayloadBufHeap;             // We don't expose the ImVector<> directly, ImGuiPayload only holds pointer+size
     unsigned char           DragDropPayloadBufLocal[16];        // Local buffer for small payloads
 
     // Tab bars
@@ -1115,6 +1150,7 @@ struct ImGuiContext
     ImGuiID                 TempInputTextId;                    // Temporary text input when CTRL+clicking on a slider, etc.
     ImGuiColorEditFlags     ColorEditOptions;                   // Store user options for color edit widgets
     float                   ColorEditLastHue;                   // Backup of last Hue associated to LastColor[3], so we can restore Hue in lossy RGB<>HSV round trips
+    float                   ColorEditLastSat;                   // Backup of last Saturation associated to LastColor[3], so we can restore Saturation in lossy RGB<>HSV round trips
     float                   ColorEditLastColor[3];
     ImVec4                  ColorPickerRef;                     // Initial/reference color at the time of opening the color picker.
     bool                    DragCurrentAccumDirty;
@@ -1124,10 +1160,6 @@ struct ImGuiContext
     int                     TooltipOverrideCount;
     ImVector<char>          PrivateClipboard;                   // If no custom clipboard handler is defined
 
-    // Range-Select/Multi-Select
-    // [This is unused in this branch, but left here to facilitate merging/syncing multiple branches]
-    ImGuiID                 MultiSelectScopeId;
-
     // Platform support
     ImVec2                  PlatformImePos;                     // Cursor position request & last passed to the OS Input Method Editor
     ImVec2                  PlatformImeLastPos;
@@ -1152,7 +1184,7 @@ struct ImGuiContext
 
     // Debug Tools
     bool                    DebugItemPickerActive;
-    ImGuiID                 DebugItemPickerBreakID;             // Will call IM_DEBUG_BREAK() when encountering this id
+    ImGuiID                 DebugItemPickerBreakId;             // Will call IM_DEBUG_BREAK() when encountering this id
 
     // Misc
     float                   FramerateSecPerFrame[120];          // Calculate estimate of framerate for user over the last 2 seconds.
@@ -1201,6 +1233,7 @@ struct ImGuiContext
         ActiveIdClickOffset = ImVec2(-1,-1);
         ActiveIdWindow = NULL;
         ActiveIdSource = ImGuiInputSource_None;
+        ActiveIdMouseButton = 0;
         ActiveIdPreviousFrame = 0;
         ActiveIdPreviousFrameIsAlive = false;
         ActiveIdPreviousFrameHasBeenEditedBefore = false;
@@ -1209,14 +1242,11 @@ struct ImGuiContext
         LastActiveIdTimer = 0.0f;
 
         NavWindow = NULL;
-        NavId = NavActivateId = NavActivateDownId = NavActivatePressedId = NavInputId = 0;
-        NavJustTabbedId = NavJustMovedToId = NavJustMovedToMultiSelectScopeId = NavNextActivateId = 0;
+        NavId = NavFocusScopeId = NavActivateId = NavActivateDownId = NavActivatePressedId = NavInputId = 0;
+        NavJustTabbedId = NavJustMovedToId = NavJustMovedToFocusScopeId = NavNextActivateId = 0;
         NavInputSource = ImGuiInputSource_None;
         NavScoringRectScreen = ImRect();
         NavScoringCount = 0;
-        NavWindowingTarget = NavWindowingTargetAnim = NavWindowingList = NULL;
-        NavWindowingTimer = NavWindowingHighlightAlpha = 0.0f;
-        NavWindowingToggleLayer = false;
         NavLayer = ImGuiNavLayer_Main;
         NavIdTabCounter = INT_MAX;
         NavIdIsAlive = false;
@@ -1229,13 +1259,17 @@ struct ImGuiContext
         NavInitResultId = 0;
         NavMoveFromClampedRefRect = false;
         NavMoveRequest = false;
-        NavMoveRequestFlags = 0;
+        NavMoveRequestFlags = ImGuiNavMoveFlags_None;
         NavMoveRequestForward = ImGuiNavForward_None;
         NavMoveDir = NavMoveDirLast = NavMoveClipDir = ImGuiDir_None;
 
+        NavWindowingTarget = NavWindowingTargetAnim = NavWindowingList = NULL;
+        NavWindowingTimer = NavWindowingHighlightAlpha = 0.0f;
+        NavWindowingToggleLayer = false;
+
         FocusRequestCurrWindow = FocusRequestNextWindow = NULL;
-        FocusRequestCurrCounterAll = FocusRequestCurrCounterTab = INT_MAX;
-        FocusRequestNextCounterAll = FocusRequestNextCounterTab = INT_MAX;
+        FocusRequestCurrCounterRegular = FocusRequestCurrCounterTabStop = INT_MAX;
+        FocusRequestNextCounterRegular = FocusRequestNextCounterTabStop = INT_MAX;
         FocusTabPressed = false;
 
         DimBgRatio = 0.0f;
@@ -1244,11 +1278,11 @@ struct ImGuiContext
         MouseCursor = ImGuiMouseCursor_Arrow;
 
         DragDropActive = DragDropWithinSourceOrTarget = false;
-        DragDropSourceFlags = 0;
+        DragDropSourceFlags = ImGuiDragDropFlags_None;
         DragDropSourceFrameCount = -1;
         DragDropMouseButton = -1;
         DragDropTargetId = 0;
-        DragDropAcceptFlags = 0;
+        DragDropAcceptFlags = ImGuiDragDropFlags_None;
         DragDropAcceptIdCurrRectSurface = 0.0f;
         DragDropAcceptIdPrev = DragDropAcceptIdCurr = 0;
         DragDropAcceptFrameCount = -1;
@@ -1259,7 +1293,7 @@ struct ImGuiContext
         LastValidMousePos = ImVec2(0.0f, 0.0f);
         TempInputTextId = 0;
         ColorEditOptions = ImGuiColorEditFlags__OptionsDefault;
-        ColorEditLastHue = 0.0f;
+        ColorEditLastHue = ColorEditLastSat = 0.0f;
         ColorEditLastColor[0] = ColorEditLastColor[1] = ColorEditLastColor[2] = FLT_MAX;
         DragCurrentAccumDirty = false;
         DragCurrentAccum = 0.0f;
@@ -1267,8 +1301,6 @@ struct ImGuiContext
         ScrollbarClickDeltaToGrabCenter = 0.0f;
         TooltipOverrideCount = 0;
 
-        MultiSelectScopeId = 0;
-
         PlatformImePos = PlatformImeLastPos = ImVec2(FLT_MAX, FLT_MAX);
 
         SettingsLoaded = false;
@@ -1283,7 +1315,7 @@ struct ImGuiContext
         LogDepthToExpand = LogDepthToExpandDefault = 2;
 
         DebugItemPickerActive = false;
-        DebugItemPickerBreakID = 0;
+        DebugItemPickerBreakId = 0;
 
         memset(FramerateSecPerFrame, 0, sizeof(FramerateSecPerFrame));
         FramerateSecPerFrameIdx = 0;
@@ -1301,6 +1333,7 @@ struct ImGuiContext
 // FIXME: That's theory, in practice the delimitation between ImGuiWindow and ImGuiWindowTempData is quite tenuous and could be reconsidered.
 struct IMGUI_API ImGuiWindowTempData
 {
+    // Layout
     ImVec2                  CursorPos;              // Current emitting position, in absolute coordinates.
     ImVec2                  CursorPosPrevLine;
     ImVec2                  CursorStartPos;         // Initial position after Begin(), generally ~ window position + WindowPadding.
@@ -1309,27 +1342,40 @@ struct IMGUI_API ImGuiWindowTempData
     ImVec2                  PrevLineSize;
     float                   CurrLineTextBaseOffset; // Baseline offset (0.0f by default on a new line, generally == style.FramePadding.y when a framed item has been added).
     float                   PrevLineTextBaseOffset;
-    int                     TreeDepth;                      // Current tree depth.
-    ImU32                   TreeMayJumpToParentOnPopMask;   // Store a copy of !g.NavIdIsAlive for TreeDepth 0..31.. Could be turned into a ImU64 if necessary.
+    ImVec1                  Indent;                 // Indentation / start position from left of window (increased by TreePush/TreePop, etc.)
+    ImVec1                  ColumnsOffset;          // Offset to the current column (if ColumnsCurrent > 0). FIXME: This and the above should be a stack to allow use cases like Tree->Column->Tree. Need revamp columns API.
+    ImVec1                  GroupOffset;
+
+    // Last item status
     ImGuiID                 LastItemId;             // ID for last item
     ImGuiItemStatusFlags    LastItemStatusFlags;    // Status flags for last item (see ImGuiItemStatusFlags_)
     ImRect                  LastItemRect;           // Interaction rect for last item
     ImRect                  LastItemDisplayRect;    // End-user display rect for last item (only valid if LastItemStatusFlags & ImGuiItemStatusFlags_HasDisplayRect)
+
+    // Keyboard/Gamepad navigation
     ImGuiNavLayer           NavLayerCurrent;        // Current layer, 0..31 (we currently only use 0..1)
     int                     NavLayerCurrentMask;    // = (1 << NavLayerCurrent) used by ItemAdd prior to clipping.
     int                     NavLayerActiveMask;     // Which layer have been written to (result from previous frame)
     int                     NavLayerActiveMaskNext; // Which layer have been written to (buffer for current frame)
+    ImGuiID                 NavFocusScopeIdCurrent; // Current focus scope ID while appending
     bool                    NavHideHighlightOneFrame;
     bool                    NavHasScroll;           // Set when scrolling can be used (ScrollMax > 0.0f)
+
+    // Miscellaneous
     bool                    MenuBarAppending;       // FIXME: Remove this
     ImVec2                  MenuBarOffset;          // MenuBarOffset.x is sort of equivalent of a per-layer CursorPos.x, saved/restored as we switch to the menu bar. The only situation when MenuBarOffset.y is > 0 if when (SafeAreaPadding.y > FramePadding.y), often used on TVs.
+    ImGuiMenuColumns        MenuColumns;            // Simplified columns storage for menu items measurement
+    int                     TreeDepth;              // Current tree depth.
+    ImU32                   TreeJumpToParentOnPopMask; // Store a copy of !g.NavIdIsAlive for TreeDepth 0..31.. Could be turned into a ImU64 if necessary.
     ImVector<ImGuiWindow*>  ChildWindows;
     ImGuiStorage*           StateStorage;           // Current persistent per-window storage (store e.g. tree node open/close state)
+    ImGuiColumns*           CurrentColumns;         // Current columns set
     ImGuiLayoutType         LayoutType;
     ImGuiLayoutType         ParentLayoutType;       // Layout type of parent window at the time of Begin()
-    int                     FocusCounterAll;        // Counter for focus/tabbing system. Start at -1 and increase as assigned via FocusableItemRegister() (FIXME-NAV: Needs redesign)
-    int                     FocusCounterTab;        // (same, but only count widgets which you can Tab through)
+    int                     FocusCounterRegular;    // (Legacy Focus/Tabbing system) Sequential counter, start at -1 and increase as assigned via FocusableItemRegister() (FIXME-NAV: Needs redesign)
+    int                     FocusCounterTabStop;    // (Legacy Focus/Tabbing system) Same, but only count widgets which you can Tab through.
 
+    // Local parameters stacks
     // We store the current settings outside of the vectors to increase memory locality (reduce cache misses). The vectors are rarely modified. Also it allows us to not heap allocate for short-lived windows which are not using those settings.
     ImGuiItemFlags          ItemFlags;              // == ItemFlagsStack.back() [empty == ImGuiItemFlags_Default]
     float                   ItemWidth;              // == ItemWidthStack.back(). 0.0: default, >0.0: width in pixels, <0.0: align xx pixels to the right of window
@@ -1340,49 +1386,47 @@ struct IMGUI_API ImGuiWindowTempData
     ImVector<ImGuiGroupData>GroupStack;
     short                   StackSizesBackup[6];    // Store size of various stacks for asserting
 
-    ImVec1                  Indent;                 // Indentation / start position from left of window (increased by TreePush/TreePop, etc.)
-    ImVec1                  GroupOffset;
-    ImVec1                  ColumnsOffset;          // Offset to the current column (if ColumnsCurrent > 0). FIXME: This and the above should be a stack to allow use cases like Tree->Column->Tree. Need revamp columns API.
-    ImGuiColumns*           CurrentColumns;         // Current columns set
-
     ImGuiWindowTempData()
     {
         CursorPos = CursorPosPrevLine = CursorStartPos = CursorMaxPos = ImVec2(0.0f, 0.0f);
         CurrLineSize = PrevLineSize = ImVec2(0.0f, 0.0f);
         CurrLineTextBaseOffset = PrevLineTextBaseOffset = 0.0f;
-        TreeDepth = 0;
-        TreeMayJumpToParentOnPopMask = 0x00;
+        Indent = ImVec1(0.0f);
+        ColumnsOffset = ImVec1(0.0f);
+        GroupOffset = ImVec1(0.0f);
+
         LastItemId = 0;
-        LastItemStatusFlags = 0;
+        LastItemStatusFlags = ImGuiItemStatusFlags_None;
         LastItemRect = LastItemDisplayRect = ImRect();
+
         NavLayerActiveMask = NavLayerActiveMaskNext = 0x00;
         NavLayerCurrent = ImGuiNavLayer_Main;
         NavLayerCurrentMask = (1 << ImGuiNavLayer_Main);
+        NavFocusScopeIdCurrent = 0;
         NavHideHighlightOneFrame = false;
         NavHasScroll = false;
+
         MenuBarAppending = false;
         MenuBarOffset = ImVec2(0.0f, 0.0f);
+        TreeDepth = 0;
+        TreeJumpToParentOnPopMask = 0x00;
         StateStorage = NULL;
+        CurrentColumns = NULL;
         LayoutType = ParentLayoutType = ImGuiLayoutType_Vertical;
-        FocusCounterAll = FocusCounterTab = -1;
+        FocusCounterRegular = FocusCounterTabStop = -1;
 
         ItemFlags = ImGuiItemFlags_Default_;
         ItemWidth = 0.0f;
         TextWrapPos = -1.0f;
         memset(StackSizesBackup, 0, sizeof(StackSizesBackup));
-
-        Indent = ImVec1(0.0f);
-        GroupOffset = ImVec1(0.0f);
-        ColumnsOffset = ImVec1(0.0f);
-        CurrentColumns = NULL;
     }
 };
 
 // Storage for one window
 struct IMGUI_API ImGuiWindow
 {
-    char*                   Name;
-    ImGuiID                 ID;                                 // == ImHash(Name)
+    char*                   Name;                               // Window name, owned by the window.
+    ImGuiID                 ID;                                 // == ImHashStr(Name)
     ImGuiWindowFlags        Flags;                              // See enum ImGuiWindowFlags_
     ImVec2                  Pos;                                // Position (always rounded-up to nearest pixel)
     ImVec2                  Size;                               // Current size (==SizeFull or collapsed title bar size)
@@ -1409,6 +1453,7 @@ struct IMGUI_API ImGuiWindow
     bool                    SkipItems;                          // Set when items can safely be all clipped (e.g. window not visible or collapsed)
     bool                    Appearing;                          // Set during the frame where the window is appearing (or re-appearing)
     bool                    Hidden;                             // Do not display (== (HiddenFrames*** > 0))
+    bool                    IsFallbackWindow;                   // Set on the "Debug##Default" window.
     bool                    HasCloseButton;                     // Set when the window has a close button (p_open != NULL)
     signed char             ResizeBorderHeld;                   // Current border being held for resize (-1: none, otherwise 0-3)
     short                   BeginCount;                         // Number of Begin() during the current frame (generally 0 or 1, 1+ if appending via multiple Begin/End pairs)
@@ -1442,7 +1487,6 @@ struct IMGUI_API ImGuiWindow
     int                     LastFrameActive;                    // Last frame number the window was Active.
     float                   LastTimeActive;                     // Last timestamp the window was Active (using float as we don't need high precision there)
     float                   ItemWidthDefault;
-    ImGuiMenuColumns        MenuColumns;                        // Simplified columns storage for menu items
     ImGuiStorage            StateStorage;
     ImVector<ImGuiColumns>  ColumnsStorage;
     float                   FontWindowScale;                    // User scale multiplier per-window, via SetWindowFontScale()
@@ -1512,7 +1556,7 @@ enum ImGuiTabBarFlagsPrivate_
 // Extend ImGuiTabItemFlags_
 enum ImGuiTabItemFlagsPrivate_
 {
-    ImGuiTabItemFlags_NoCloseButton             = 1 << 20   // Store whether p_open is set or not, which we need to recompute ContentWidth during layout.
+    ImGuiTabItemFlags_NoCloseButton             = 1 << 20   // Track whether p_open was set or not (we'll need this info on the next frame to recompute ContentWidth during layout)
 };
 
 // Storage for one active tab item (sizeof() 26~32 bytes)
@@ -1527,7 +1571,7 @@ struct ImGuiTabItem
     float               Width;                  // Width currently displayed
     float               ContentWidth;           // Width of actual contents, stored during BeginTabItem() call
 
-    ImGuiTabItem()      { ID = 0; Flags = 0; LastFrameVisible = LastFrameSelected = -1; NameOffset = -1; Offset = Width = ContentWidth = 0.0f; }
+    ImGuiTabItem()      { ID = 0; Flags = ImGuiTabItemFlags_None; LastFrameVisible = LastFrameSelected = -1; NameOffset = -1; Offset = Width = ContentWidth = 0.0f; }
 };
 
 // Storage for a tab bar (sizeof() 92~96 bytes)
@@ -1535,7 +1579,7 @@ struct ImGuiTabBar
 {
     ImVector<ImGuiTabItem> Tabs;
     ImGuiID             ID;                     // Zero for tab-bars used by docking
-    ImGuiID             SelectedTabId;          // Selected tab
+    ImGuiID             SelectedTabId;          // Selected tab/window
     ImGuiID             NextSelectedTabId;
     ImGuiID             VisibleTabId;           // Can occasionally be != SelectedTabId (e.g. when previewing contents for CTRL+TAB preview)
     int                 CurrFrameVisible;
@@ -1574,6 +1618,7 @@ struct ImGuiTabBar
 
 namespace ImGui
 {
+    // Windows
     // We should always have a CurrentWindow in the stack (there is an implicit "Debug" window)
     // If this ever crash because g.CurrentWindow is NULL it means that either
     // - ImGui::NewFrame() has never been called, which is illegal.
@@ -1582,11 +1627,6 @@ namespace ImGui
     inline    ImGuiWindow*  GetCurrentWindow()          { ImGuiContext& g = *GImGui; g.CurrentWindow->WriteAccessed = true; return g.CurrentWindow; }
     IMGUI_API ImGuiWindow*  FindWindowByID(ImGuiID id);
     IMGUI_API ImGuiWindow*  FindWindowByName(const char* name);
-    IMGUI_API void          FocusWindow(ImGuiWindow* window);
-    IMGUI_API void          FocusTopMostWindowUnderOne(ImGuiWindow* under_this_window, ImGuiWindow* ignore_window);
-    IMGUI_API void          BringWindowToFocusFront(ImGuiWindow* window);
-    IMGUI_API void          BringWindowToDisplayFront(ImGuiWindow* window);
-    IMGUI_API void          BringWindowToDisplayBack(ImGuiWindow* window);
     IMGUI_API void          UpdateWindowParentAndRootLinks(ImGuiWindow* window, ImGuiWindowFlags flags, ImGuiWindow* parent_window);
     IMGUI_API ImVec2        CalcWindowExpectedSize(ImGuiWindow* window);
     IMGUI_API bool          IsWindowChildOf(ImGuiWindow* window, ImGuiWindow* potential_parent);
@@ -1595,12 +1635,18 @@ namespace ImGui
     IMGUI_API void          SetWindowPos(ImGuiWindow* window, const ImVec2& pos, ImGuiCond cond = 0);
     IMGUI_API void          SetWindowSize(ImGuiWindow* window, const ImVec2& size, ImGuiCond cond = 0);
     IMGUI_API void          SetWindowCollapsed(ImGuiWindow* window, bool collapsed, ImGuiCond cond = 0);
-    IMGUI_API void          GcCompactTransientWindowBuffers(ImGuiWindow* window);
-    IMGUI_API void          GcAwakeTransientWindowBuffers(ImGuiWindow* window);
 
+    // Windows: Display Order and Focus Order
+    IMGUI_API void          FocusWindow(ImGuiWindow* window);
+    IMGUI_API void          FocusTopMostWindowUnderOne(ImGuiWindow* under_this_window, ImGuiWindow* ignore_window);
+    IMGUI_API void          BringWindowToFocusFront(ImGuiWindow* window);
+    IMGUI_API void          BringWindowToDisplayFront(ImGuiWindow* window);
+    IMGUI_API void          BringWindowToDisplayBack(ImGuiWindow* window);
+    
+    // Fonts, drawing
     IMGUI_API void          SetCurrentFont(ImFont* font);
     inline ImFont*          GetDefaultFont() { ImGuiContext& g = *GImGui; return g.IO.FontDefault ? g.IO.FontDefault : g.IO.Fonts->Fonts[0]; }
-    inline ImDrawList*      GetForegroundDrawList(ImGuiWindow*) { ImGuiContext& g = *GImGui; return &g.ForegroundDrawList; } // This seemingly unnecessary wrapper simplifies compatibility between the 'master' and 'docking' branches.
+    inline ImDrawList*      GetForegroundDrawList(ImGuiWindow* window) { IM_UNUSED(window); ImGuiContext& g = *GImGui; return &g.ForegroundDrawList; } // This seemingly unnecessary wrapper simplifies compatibility between the 'master' and 'docking' branches.
 
     // Init
     IMGUI_API void          Initialize(ImGuiContext* context);
@@ -1629,6 +1675,7 @@ namespace ImGui
 
     // Basic Accessors
     inline ImGuiID          GetItemID()     { ImGuiContext& g = *GImGui; return g.CurrentWindow->DC.LastItemId; }
+    inline ImGuiItemStatusFlags GetItemStatusFlags() { ImGuiContext& g = *GImGui; return g.CurrentWindow->DC.LastItemStatusFlags; }
     inline ImGuiID          GetActiveID()   { ImGuiContext& g = *GImGui; return g.ActiveId; }
     inline ImGuiID          GetFocusID()    { ImGuiContext& g = *GImGui; return g.NavId; }
     IMGUI_API void          SetActiveID(ImGuiID id, ImGuiWindow* window);
@@ -1637,8 +1684,8 @@ namespace ImGui
     IMGUI_API ImGuiID       GetHoveredID();
     IMGUI_API void          SetHoveredID(ImGuiID id);
     IMGUI_API void          KeepAliveID(ImGuiID id);
-    IMGUI_API void          MarkItemEdited(ImGuiID id);
-    IMGUI_API void          PushOverrideID(ImGuiID id);
+    IMGUI_API void          MarkItemEdited(ImGuiID id);     // Mark data associated to given item as "edited", used by IsItemDeactivatedAfterEdit() function.
+    IMGUI_API void          PushOverrideID(ImGuiID id);     // Push given value at the top of the ID stack (whereas PushID combines old and new hashes)
 
     // Basic Helpers for widget code
     IMGUI_API void          ItemSize(const ImVec2& size, float text_baseline_y = -1.0f);
@@ -1662,12 +1709,13 @@ namespace ImGui
     IMGUI_API void          LogToBuffer(int auto_open_depth = -1);              // Start logging/capturing to internal buffer
 
     // Popups, Modals, Tooltips
+    IMGUI_API bool          BeginChildEx(const char* name, ImGuiID id, const ImVec2& size_arg, bool border, ImGuiWindowFlags flags);
     IMGUI_API void          OpenPopupEx(ImGuiID id);
     IMGUI_API void          ClosePopupToLevel(int remaining, bool restore_focus_to_window_under_popup);
     IMGUI_API void          ClosePopupsOverWindow(ImGuiWindow* ref_window, bool restore_focus_to_window_under_popup);
     IMGUI_API bool          IsPopupOpen(ImGuiID id); // Test for id within current popup stack level (currently begin-ed into); this doesn't scan the whole popup stack!
     IMGUI_API bool          BeginPopupEx(ImGuiID id, ImGuiWindowFlags extra_flags);
-    IMGUI_API void          BeginTooltipEx(ImGuiWindowFlags extra_flags, bool override_previous_tooltip = true);
+    IMGUI_API void          BeginTooltipEx(ImGuiWindowFlags extra_flags, ImGuiTooltipFlags tooltip_flags);
     IMGUI_API ImGuiWindow*  GetTopMostPopupModal();
     IMGUI_API ImVec2        FindBestWindowPosForPopup(ImGuiWindow* window);
     IMGUI_API ImVec2        FindBestWindowPosForPopupEx(const ImVec2& ref_pos, const ImVec2& size, ImGuiDir* last_dir, const ImRect& r_outer, const ImRect& r_avoid, ImGuiPopupPositionPolicy policy = ImGuiPopupPositionPolicy_Default);
@@ -1682,15 +1730,20 @@ namespace ImGui
     IMGUI_API ImVec2        GetNavInputAmount2d(ImGuiNavDirSourceFlags dir_sources, ImGuiInputReadMode mode, float slow_factor = 0.0f, float fast_factor = 0.0f);
     IMGUI_API int           CalcTypematicRepeatAmount(float t0, float t1, float repeat_delay, float repeat_rate);
     IMGUI_API void          ActivateItem(ImGuiID id);   // Remotely activate a button, checkbox, tree node etc. given its unique ID. activation is queued and processed on the next frame when the item is encountered again.
-    IMGUI_API void          SetNavID(ImGuiID id, int nav_layer);
-    IMGUI_API void          SetNavIDWithRectRel(ImGuiID id, int nav_layer, const ImRect& rect_rel);
+    IMGUI_API void          SetNavID(ImGuiID id, int nav_layer, ImGuiID focus_scope_id);
+    IMGUI_API void          SetNavIDWithRectRel(ImGuiID id, int nav_layer, ImGuiID focus_scope_id, const ImRect& rect_rel);
+
+    // Focus scope (WIP)
+    IMGUI_API void          PushFocusScope(ImGuiID id);     // Note: this is storing in same stack as IDStack, so Push/Pop mismatch will be reported there.
+    IMGUI_API void          PopFocusScope();
+    inline ImGuiID          GetFocusScopeID()               { ImGuiContext& g = *GImGui; return g.NavFocusScopeId; }
 
     // Inputs
     // FIXME: Eventually we should aim to move e.g. IsActiveIdUsingKey() into IsKeyXXX functions.
     inline bool             IsActiveIdUsingNavDir(ImGuiDir dir)                         { ImGuiContext& g = *GImGui; return (g.ActiveIdUsingNavDirMask & (1 << dir)) != 0; }
     inline bool             IsActiveIdUsingNavInput(ImGuiNavInput input)                { ImGuiContext& g = *GImGui; return (g.ActiveIdUsingNavInputMask & (1 << input)) != 0; }
     inline bool             IsActiveIdUsingKey(ImGuiKey key)                            { ImGuiContext& g = *GImGui; IM_ASSERT(key < 64); return (g.ActiveIdUsingKeyInputMask & ((ImU64)1 << key)) != 0; }
-    IMGUI_API bool          IsMouseDragPastThreshold(int button, float lock_threshold = -1.0f);
+    IMGUI_API bool          IsMouseDragPastThreshold(ImGuiMouseButton button, float lock_threshold = -1.0f);
     inline bool             IsKeyPressedMap(ImGuiKey key, bool repeat = true)           { ImGuiContext& g = *GImGui; const int key_index = g.IO.KeyMap[key]; return (key_index >= 0) ? IsKeyPressed(key_index, repeat) : false; }
     inline bool             IsNavInputDown(ImGuiNavInput n)                             { ImGuiContext& g = *GImGui; return g.IO.NavInputs[n] > 0.0f; }
     inline bool             IsNavInputTest(ImGuiNavInput n, ImGuiInputReadMode rm)      { return (GetNavInputAmount(n, rm) > 0.0f); }
@@ -1700,7 +1753,7 @@ namespace ImGui
     IMGUI_API void          ClearDragDrop();
     IMGUI_API bool          IsDragDropPayloadBeingAccepted();
 
-    // New Columns API (FIXME-WIP)
+    // Internal Columns API (this is not exposed because we will encourage transitioning to the Tables api)
     IMGUI_API void          BeginColumns(const char* str_id, int count, ImGuiColumnsFlags flags = 0); // setup number of columns. use an identifier to distinguish multiple column sets. close with EndColumns().
     IMGUI_API void          EndColumns();                                                             // close columns
     IMGUI_API void          PushColumnClipRect(int column_index);
@@ -1756,7 +1809,7 @@ namespace ImGui
     IMGUI_API bool          ButtonEx(const char* label, const ImVec2& size_arg = ImVec2(0,0), ImGuiButtonFlags flags = 0);
     IMGUI_API bool          CloseButton(ImGuiID id, const ImVec2& pos);
     IMGUI_API bool          CollapseButton(ImGuiID id, const ImVec2& pos);
-    IMGUI_API bool          ArrowButtonEx(const char* str_id, ImGuiDir dir, ImVec2 size_arg, ImGuiButtonFlags flags);
+    IMGUI_API bool          ArrowButtonEx(const char* str_id, ImGuiDir dir, ImVec2 size_arg, ImGuiButtonFlags flags = 0);
     IMGUI_API void          Scrollbar(ImGuiAxis axis);
     IMGUI_API bool          ScrollbarEx(const ImRect& bb, ImGuiID id, ImGuiAxis axis, float* p_scroll_v, float avail_v, float contents_v, ImDrawCornerFlags rounding_corners);
     IMGUI_API ImGuiID       GetWindowScrollbarID(ImGuiWindow* window, ImGuiAxis axis);
@@ -1803,6 +1856,10 @@ namespace ImGui
     IMGUI_API void          ShadeVertsLinearColorGradientKeepAlpha(ImDrawList* draw_list, int vert_start_idx, int vert_end_idx, ImVec2 gradient_p0, ImVec2 gradient_p1, ImU32 col0, ImU32 col1);
     IMGUI_API void          ShadeVertsLinearUV(ImDrawList* draw_list, int vert_start_idx, int vert_end_idx, const ImVec2& a, const ImVec2& b, const ImVec2& uv_a, const ImVec2& uv_b, bool clamp);
 
+    // Garbage collection
+    IMGUI_API void          GcCompactTransientWindowBuffers(ImGuiWindow* window);
+    IMGUI_API void          GcAwakeTransientWindowBuffers(ImGuiWindow* window);
+
     // Debug Tools
     inline void             DebugDrawItemRect(ImU32 col = IM_COL32(255,0,0,255))    { ImGuiContext& g = *GImGui; ImGuiWindow* window = g.CurrentWindow; GetForegroundDrawList(window)->AddRect(window->DC.LastItemRect.Min, window->DC.LastItemRect.Max, col); }
     inline void             DebugStartItemPicker()                                  { ImGuiContext& g = *GImGui; g.DebugItemPickerActive = true; }
@@ -1856,3 +1913,5 @@ extern void                 ImGuiTestEngineHook_Log(ImGuiContext* ctx, const cha
 #ifdef _MSC_VER
 #pragma warning (pop)
 #endif
+
+#endif // #ifndef IMGUI_DISABLE
diff --git a/imgui/imgui_widgets.cpp b/imgui/imgui_widgets.cpp
index ec6f51a9..6d2c95d9 100644
--- a/imgui/imgui_widgets.cpp
+++ b/imgui/imgui_widgets.cpp
@@ -1,4 +1,4 @@
-// dear imgui, v1.74
+// dear imgui, v1.75
 // (widgets code)
 
 /*
@@ -33,6 +33,8 @@ Index of this file:
 #endif
 
 #include "imgui.h"
+#ifndef IMGUI_DISABLE
+
 #ifndef IMGUI_DEFINE_MATH_OPERATORS
 #define IMGUI_DEFINE_MATH_OPERATORS
 #endif
@@ -47,8 +49,11 @@ Index of this file:
 
 // Visual Studio warnings
 #ifdef _MSC_VER
-#pragma warning (disable: 4127) // condition expression is constant
-#pragma warning (disable: 4996) // 'This function or variable may be unsafe': strcpy, strdup, sprintf, vsnprintf, sscanf, fopen
+#pragma warning (disable: 4127)     // condition expression is constant
+#pragma warning (disable: 4996)     // 'This function or variable may be unsafe': strcpy, strdup, sprintf, vsnprintf, sscanf, fopen
+#if defined(_MSC_VER) && _MSC_VER >= 1922 // MSVC 2019 16.2 or later
+#pragma warning (disable: 5054)     // operator '|': deprecated between enumerations of different types
+#endif
 #endif
 
 // Clang/GCC warnings with -Weverything
@@ -461,9 +466,13 @@ bool ImGui::ButtonBehavior(const ImRect& bb, ImGuiID id, bool* out_hovered, bool
         return false;
     }
 
-    // Default behavior requires click+release on same spot
-    if ((flags & (ImGuiButtonFlags_PressedOnClickRelease | ImGuiButtonFlags_PressedOnClick | ImGuiButtonFlags_PressedOnRelease | ImGuiButtonFlags_PressedOnDoubleClick)) == 0)
-        flags |= ImGuiButtonFlags_PressedOnClickRelease;
+    // Default only reacts to left mouse button
+    if ((flags & ImGuiButtonFlags_MouseButtonMask_) == 0)
+        flags |= ImGuiButtonFlags_MouseButtonDefault_;
+
+    // Default behavior requires click + release inside bounding box
+    if ((flags & ImGuiButtonFlags_PressedOnMask_) == 0)
+        flags |= ImGuiButtonFlags_PressedOnDefault_;
 
     ImGuiWindow* backup_hovered_window = g.HoveredWindow;
     const bool flatten_hovered_children = (flags & ImGuiButtonFlags_FlattenChildren) && g.HoveredRootWindow == window;
@@ -502,38 +511,55 @@ bool ImGui::ButtonBehavior(const ImRect& bb, ImGuiID id, bool* out_hovered, bool
     if (hovered && (flags & ImGuiButtonFlags_AllowItemOverlap) && (g.HoveredIdPreviousFrame != id && g.HoveredIdPreviousFrame != 0))
         hovered = false;
 
-    // Mouse
+    // Mouse handling
     if (hovered)
     {
         if (!(flags & ImGuiButtonFlags_NoKeyModifiers) || (!g.IO.KeyCtrl && !g.IO.KeyShift && !g.IO.KeyAlt))
         {
-            if ((flags & ImGuiButtonFlags_PressedOnClickRelease) && g.IO.MouseClicked[0])
-            {
-                SetActiveID(id, window);
-                if (!(flags & ImGuiButtonFlags_NoNavFocus))
-                    SetFocusID(id, window);
-                FocusWindow(window);
-            }
-            if (((flags & ImGuiButtonFlags_PressedOnClick) && g.IO.MouseClicked[0]) || ((flags & ImGuiButtonFlags_PressedOnDoubleClick) && g.IO.MouseDoubleClicked[0]))
+            // Poll buttons
+            int mouse_button_clicked = -1;
+            int mouse_button_released = -1;
+            if ((flags & ImGuiButtonFlags_MouseButtonLeft) && g.IO.MouseClicked[0])         { mouse_button_clicked = 0; }
+            else if ((flags & ImGuiButtonFlags_MouseButtonRight) && g.IO.MouseClicked[1])   { mouse_button_clicked = 1; }
+            else if ((flags & ImGuiButtonFlags_MouseButtonMiddle) && g.IO.MouseClicked[2])  { mouse_button_clicked = 2; }
+            if ((flags & ImGuiButtonFlags_MouseButtonLeft) && g.IO.MouseReleased[0])        { mouse_button_released = 0; }
+            else if ((flags & ImGuiButtonFlags_MouseButtonRight) && g.IO.MouseReleased[1])  { mouse_button_released = 1; }
+            else if ((flags & ImGuiButtonFlags_MouseButtonMiddle) && g.IO.MouseReleased[2]) { mouse_button_released = 2; }
+
+            if (mouse_button_clicked != -1 && g.ActiveId != id)
             {
-                pressed = true;
-                if (flags & ImGuiButtonFlags_NoHoldingActiveID)
-                    ClearActiveID();
-                else
-                    SetActiveID(id, window); // Hold on ID
-                FocusWindow(window);
+                if (flags & (ImGuiButtonFlags_PressedOnClickRelease | ImGuiButtonFlags_PressedOnClickReleaseAnywhere))
+                {
+                    SetActiveID(id, window);
+                    g.ActiveIdMouseButton = mouse_button_clicked;
+                    if (!(flags & ImGuiButtonFlags_NoNavFocus))
+                        SetFocusID(id, window);
+                    FocusWindow(window);
+                }
+                if ((flags & ImGuiButtonFlags_PressedOnClick) || ((flags & ImGuiButtonFlags_PressedOnDoubleClick) && g.IO.MouseDoubleClicked[mouse_button_clicked]))
+                {
+                    pressed = true;
+                    if (flags & ImGuiButtonFlags_NoHoldingActiveId)
+                        ClearActiveID();
+                    else
+                        SetActiveID(id, window); // Hold on ID
+                    g.ActiveIdMouseButton = mouse_button_clicked;
+                    FocusWindow(window);
+                }
             }
-            if ((flags & ImGuiButtonFlags_PressedOnRelease) && g.IO.MouseReleased[0])
+            if ((flags & ImGuiButtonFlags_PressedOnRelease) && mouse_button_released != -1)
             {
-                if (!((flags & ImGuiButtonFlags_Repeat) && g.IO.MouseDownDurationPrev[0] >= g.IO.KeyRepeatDelay))  // Repeat mode trumps <on release>
+                // Repeat mode trumps on release behavior
+                if (!((flags & ImGuiButtonFlags_Repeat) && g.IO.MouseDownDurationPrev[mouse_button_released] >= g.IO.KeyRepeatDelay))
                     pressed = true;
                 ClearActiveID();
             }
 
             // 'Repeat' mode acts when held regardless of _PressedOn flags (see table above).
             // Relies on repeat logic of IsMouseClicked() but we may as well do it ourselves if we end up exposing finer RepeatDelay/RepeatRate settings.
-            if ((flags & ImGuiButtonFlags_Repeat) && g.ActiveId == id && g.IO.MouseDownDuration[0] > 0.0f && IsMouseClicked(0, true))
-                pressed = true;
+            if (g.ActiveId == id && (flags & ImGuiButtonFlags_Repeat))
+                if (g.IO.MouseDownDuration[g.ActiveIdMouseButton] > 0.0f && IsMouseClicked(g.ActiveIdMouseButton, true))
+                    pressed = true;
         }
 
         if (pressed)
@@ -545,7 +571,6 @@ bool ImGui::ButtonBehavior(const ImRect& bb, ImGuiID id, bool* out_hovered, bool
     if (g.NavId == id && !g.NavDisableHighlight && g.NavDisableMouseHover && (g.ActiveId == 0 || g.ActiveId == id || g.ActiveId == window->MoveId))
         if (!(flags & ImGuiButtonFlags_NoHoveredOnNav))
             hovered = true;
-
     if (g.NavActivateDownId == id)
     {
         bool nav_activated_by_code = (g.NavActivateId == id);
@@ -565,22 +590,25 @@ bool ImGui::ButtonBehavior(const ImRect& bb, ImGuiID id, bool* out_hovered, bool
     bool held = false;
     if (g.ActiveId == id)
     {
-        if (pressed)
-            g.ActiveIdHasBeenPressedBefore = true;
         if (g.ActiveIdSource == ImGuiInputSource_Mouse)
         {
             if (g.ActiveIdIsJustActivated)
                 g.ActiveIdClickOffset = g.IO.MousePos - bb.Min;
-            if (g.IO.MouseDown[0])
+
+            const int mouse_button = g.ActiveIdMouseButton;
+            IM_ASSERT(mouse_button >= 0 && mouse_button < ImGuiMouseButton_COUNT);
+            if (g.IO.MouseDown[mouse_button])
             {
                 held = true;
             }
             else
             {
-                if (hovered && (flags & ImGuiButtonFlags_PressedOnClickRelease) && !g.DragDropActive)
+                bool release_in = hovered && (flags & ImGuiButtonFlags_PressedOnClickRelease) != 0;
+                bool release_anywhere = (flags & ImGuiButtonFlags_PressedOnClickReleaseAnywhere) != 0;
+                if ((release_in || release_anywhere) && !g.DragDropActive)
                 {
-                    bool is_double_click_release = (flags & ImGuiButtonFlags_PressedOnDoubleClick) && g.IO.MouseDownWasDoubleClick[0];
-                    bool is_repeating_already = (flags & ImGuiButtonFlags_Repeat) && g.IO.MouseDownDurationPrev[0] >= g.IO.KeyRepeatDelay; // Repeat mode trumps <on release>
+                    bool is_double_click_release = (flags & ImGuiButtonFlags_PressedOnDoubleClick) && g.IO.MouseDownWasDoubleClick[mouse_button];
+                    bool is_repeating_already = (flags & ImGuiButtonFlags_Repeat) && g.IO.MouseDownDurationPrev[mouse_button] >= g.IO.KeyRepeatDelay; // Repeat mode trumps <on release>
                     if (!is_double_click_release && !is_repeating_already)
                         pressed = true;
                 }
@@ -594,6 +622,8 @@ bool ImGui::ButtonBehavior(const ImRect& bb, ImGuiID id, bool* out_hovered, bool
             if (g.NavActivateDownId != id)
                 ClearActiveID();
         }
+        if (pressed)
+            g.ActiveIdHasBeenPressedBefore = true;
     }
 
     if (out_hovered) *out_hovered = hovered;
@@ -715,7 +745,7 @@ bool ImGui::ArrowButtonEx(const char* str_id, ImGuiDir dir, ImVec2 size, ImGuiBu
 bool ImGui::ArrowButton(const char* str_id, ImGuiDir dir)
 {
     float sz = GetFrameHeight();
-    return ArrowButtonEx(str_id, dir, ImVec2(sz, sz), 0);
+    return ArrowButtonEx(str_id, dir, ImVec2(sz, sz), ImGuiButtonFlags_None);
 }
 
 // Button to close a window
@@ -768,7 +798,7 @@ bool ImGui::CollapseButton(ImGuiID id, const ImVec2& pos)
     RenderArrow(window->DrawList, bb.Min + g.Style.FramePadding, text_col, window->Collapsed ? ImGuiDir_Right : ImGuiDir_Down, 1.0f);
 
     // Switch to moving the window after mouse is moved beyond the initial drag threshold
-    if (IsItemActive() && IsMouseDragging())
+    if (IsItemActive() && IsMouseDragging(0))
         StartMouseMovingWindow(window);
 
     return pressed;
@@ -1259,21 +1289,14 @@ void ImGui::SeparatorEx(ImGuiSeparatorFlags flags)
         // We don't provide our width to the layout so that it doesn't get feed back into AutoFit
         const ImRect bb(ImVec2(x1, window->DC.CursorPos.y), ImVec2(x2, window->DC.CursorPos.y + thickness_draw));
         ItemSize(ImVec2(0.0f, thickness_layout));
-        if (!ItemAdd(bb, 0))
+        const bool item_visible = ItemAdd(bb, 0);
+        if (item_visible)
         {
-            if (columns)
-            {
-                PopColumnsBackground();
-                columns->LineMinY = window->DC.CursorPos.y;
-            }
-            return;
+            // Draw
+            window->DrawList->AddLine(bb.Min, ImVec2(bb.Max.x, bb.Min.y), GetColorU32(ImGuiCol_Separator));
+            if (g.LogEnabled)
+                LogRenderedText(&bb.Min, "--------------------------------");
         }
-
-        // Draw
-        window->DrawList->AddLine(bb.Min, ImVec2(bb.Max.x, bb.Min.y), GetColorU32(ImGuiCol_Separator));
-        if (g.LogEnabled)
-            LogRenderedText(&bb.Min, "--------------------------------");
-
         if (columns)
         {
             PopColumnsBackground();
@@ -3250,8 +3273,25 @@ static bool STB_TEXTEDIT_INSERTCHARS(STB_TEXTEDIT_STRING* obj, int pos, const Im
 #define STB_TEXTEDIT_IMPLEMENTATION
 #include "imstb_textedit.h"
 
+// stb_textedit internally allows for a single undo record to do addition and deletion, but somehow, calling 
+// the stb_textedit_paste() function creates two separate records, so we perform it manually. (FIXME: Report to nothings/stb?) 
+static void stb_textedit_replace(STB_TEXTEDIT_STRING* str, STB_TexteditState* state, const STB_TEXTEDIT_CHARTYPE* text, int text_len)
+{
+    stb_text_makeundo_replace(str, state, 0, str->CurLenW, text_len);
+    ImStb::STB_TEXTEDIT_DELETECHARS(str, 0, str->CurLenW);
+    if (text_len <= 0)
+        return;
+    if (ImStb::STB_TEXTEDIT_INSERTCHARS(str, 0, text, text_len))
+    {
+        state->cursor = text_len;
+        state->has_preferred_x = 0;
+        return;
+    }
+    IM_ASSERT(0); // Failed to insert character, normally shouldn't happen because of how we currently use stb_textedit_replace()
 }
 
+} // namespace ImStb
+
 void ImGuiInputTextState::OnKeyPressed(int key)
 {
     stb_textedit_key(this, &Stb, key);
@@ -3437,14 +3477,23 @@ bool ImGui::InputTextEx(const char* label, const char* hint, char* buf, int buf_
             EndGroup();
             return false;
         }
-        if (!BeginChildFrame(id, frame_bb.GetSize()))
+
+        // We reproduce the contents of BeginChildFrame() in order to provide 'label' so our window internal data are easier to read/debug.
+        PushStyleColor(ImGuiCol_ChildBg, style.Colors[ImGuiCol_FrameBg]);
+        PushStyleVar(ImGuiStyleVar_ChildRounding, style.FrameRounding);
+        PushStyleVar(ImGuiStyleVar_ChildBorderSize, style.FrameBorderSize);
+        PushStyleVar(ImGuiStyleVar_WindowPadding, style.FramePadding);
+        bool child_visible = BeginChildEx(label, id, frame_bb.GetSize(), true, ImGuiWindowFlags_NoMove | ImGuiWindowFlags_AlwaysUseWindowPadding);
+        PopStyleVar(3);
+        PopStyleColor();
+        if (!child_visible)
         {
-            EndChildFrame();
+            EndChild();
             EndGroup();
             return false;
         }
         draw_window = g.CurrentWindow; // Child window
-        draw_window->DC.NavLayerActiveMaskNext |= draw_window->DC.NavLayerCurrentMask; // This is to ensure that EndChild() will display a navigation highlight
+        draw_window->DC.NavLayerActiveMaskNext |= draw_window->DC.NavLayerCurrentMask; // This is to ensure that EndChild() will display a navigation highlight so we can "enter" into it.
         inner_size.x -= draw_window->ScrollbarSizes.x;
     }
     else
@@ -3463,7 +3512,7 @@ bool ImGui::InputTextEx(const char* label, const char* hint, char* buf, int buf_
         state = &g.InputTextState;
 
     const bool focus_requested = FocusableItemRegister(window, id);
-    const bool focus_requested_by_code = focus_requested && (g.FocusRequestCurrWindow == window && g.FocusRequestCurrCounterAll == window->DC.FocusCounterAll);
+    const bool focus_requested_by_code = focus_requested && (g.FocusRequestCurrWindow == window && g.FocusRequestCurrCounterRegular == window->DC.FocusCounterRegular);
     const bool focus_requested_by_tab = focus_requested && !focus_requested_by_code;
 
     const bool user_clicked = hovered && io.MouseClicked[0];
@@ -3796,13 +3845,22 @@ bool ImGui::InputTextEx(const char* label, const char* hint, char* buf, int buf_
             // Restore initial value. Only return true if restoring to the initial value changes the current buffer contents.
             if (!is_readonly && strcmp(buf, state->InitialTextA.Data) != 0)
             {
+                // Push records into the undo stack so we can CTRL+Z the revert operation itself
                 apply_new_text = state->InitialTextA.Data;
                 apply_new_text_length = state->InitialTextA.Size - 1;
+                ImVector<ImWchar> w_text;
+                if (apply_new_text_length > 0)
+                {
+                    w_text.resize(ImTextCountCharsFromUtf8(apply_new_text, apply_new_text + apply_new_text_length) + 1);
+                    ImTextStrFromUtf8(w_text.Data, w_text.Size, apply_new_text, apply_new_text + apply_new_text_length);
+                }
+                stb_textedit_replace(state, &state->Stb, w_text.Data, (apply_new_text_length > 0) ? (w_text.Size - 1) : 0);
             }
         }
 
         // When using 'ImGuiInputTextFlags_EnterReturnsTrue' as a special case we reapply the live buffer back to the input buffer before clearing ActiveId, even though strictly speaking it wasn't modified on this frame.
-        // If we didn't do that, code like InputInt() with ImGuiInputTextFlags_EnterReturnsTrue would fail. Also this allows the user to use InputText() with ImGuiInputTextFlags_EnterReturnsTrue without maintaining any user-side storage.
+        // If we didn't do that, code like InputInt() with ImGuiInputTextFlags_EnterReturnsTrue would fail. 
+        // This also allows the user to use InputText() with ImGuiInputTextFlags_EnterReturnsTrue without maintaining any user-side storage (please note that if you use this property along ImGuiInputTextFlags_CallbackResize you can end up with your temporary string object unnecessarily allocating once a frame, either store your string data, either if you don't then don't use ImGuiInputTextFlags_CallbackResize).
         bool apply_edit_back_to_user_buffer = !cancel_edit || (enter_pressed && (flags & ImGuiInputTextFlags_EnterReturnsTrue) != 0);
         if (apply_edit_back_to_user_buffer)
         {
@@ -3896,8 +3954,11 @@ bool ImGui::InputTextEx(const char* label, const char* hint, char* buf, int buf_
         // Copy result to user buffer
         if (apply_new_text)
         {
+            // We cannot test for 'backup_current_text_length != apply_new_text_length' here because we have no guarantee that the size
+            // of our owned buffer matches the size of the string object held by the user, and by design we allow InputText() to be used
+            // without any storage on user's side.
             IM_ASSERT(apply_new_text_length >= 0);
-            if (backup_current_text_length != apply_new_text_length && is_resizable)
+            if (is_resizable)
             {
                 ImGuiInputTextCallbackData callback_data;
                 callback_data.EventFlag = ImGuiInputTextFlags_CallbackResize;
@@ -3912,6 +3973,7 @@ bool ImGui::InputTextEx(const char* label, const char* hint, char* buf, int buf_
                 apply_new_text_length = ImMin(callback_data.BufTextLen, buf_size - 1);
                 IM_ASSERT(apply_new_text_length <= buf_size);
             }
+            //IMGUI_DEBUG_LOG("InputText(\"%s\"): apply_new_text length %d\n", label, apply_new_text_length);
 
             // If the underlying buffer resize was denied or not carried to the next frame, apply_new_text_length+1 may be >= buf_size.
             ImStrncpy(buf, apply_new_text, ImMin(apply_new_text_length + 1, buf_size));
@@ -4130,7 +4192,7 @@ bool ImGui::InputTextEx(const char* label, const char* hint, char* buf, int buf_
     if (is_multiline)
     {
         Dummy(text_size + ImVec2(0.0f, g.FontSize)); // Always add room to scroll an extra line
-        EndChildFrame();
+        EndChild();
         EndGroup();
     }
 
@@ -4229,8 +4291,13 @@ bool ImGui::ColorEdit4(const char* label, float col[4], ImGuiColorEditFlags flag
     {
         // Hue is lost when converting from greyscale rgb (saturation=0). Restore it.
         ColorConvertRGBtoHSV(f[0], f[1], f[2], f[0], f[1], f[2]);
-        if (f[1] == 0 && memcmp(g.ColorEditLastColor, col, sizeof(float) * 3) == 0)
-            f[0] = g.ColorEditLastHue;
+        if (memcmp(g.ColorEditLastColor, col, sizeof(float) * 3) == 0)
+        {
+            if (f[1] == 0)
+                f[0] = g.ColorEditLastHue;
+            if (f[2] == 0)
+                f[1] = g.ColorEditLastSat;
+        }
     }
     int i[4] = { IM_F32_TO_INT8_UNBOUND(f[0]), IM_F32_TO_INT8_UNBOUND(f[1]), IM_F32_TO_INT8_UNBOUND(f[2]), IM_F32_TO_INT8_UNBOUND(f[3]) };
 
@@ -4269,16 +4336,15 @@ bool ImGui::ColorEdit4(const char* label, float col[4], ImGuiColorEditFlags flag
                 SameLine(0, style.ItemInnerSpacing.x);
             SetNextItemWidth((n + 1 < components) ? w_item_one : w_item_last);
 
-            // Disable Hue edit when Saturation is zero
-            const bool disable_hue_edit = (n == 0 && (flags & ImGuiColorEditFlags_DisplayHSV) && i[1] == 0);
+            // FIXME: When ImGuiColorEditFlags_HDR flag is passed HS values snap in weird ways when SV values go below 0.
             if (flags & ImGuiColorEditFlags_Float)
             {
-                value_changed |= DragFloat(ids[n], &f[n], 1.0f/255.0f, disable_hue_edit ? +FLT_MAX : 0.0f, disable_hue_edit ? -FLT_MAX : hdr ? 0.0f : 1.0f, fmt_table_float[fmt_idx][n]);
+                value_changed |= DragFloat(ids[n], &f[n], 1.0f/255.0f, 0.0f, hdr ? 0.0f : 1.0f, fmt_table_float[fmt_idx][n]);
                 value_changed_as_float |= value_changed;
             }
             else
             {
-                value_changed |= DragInt(ids[n], &i[n], 1.0f, disable_hue_edit ? INT_MAX : 0, disable_hue_edit ? INT_MIN : hdr ? 0 : 255, fmt_table_int[fmt_idx][n]);
+                value_changed |= DragInt(ids[n], &i[n], 1.0f, 0, hdr ? 0 : 255, fmt_table_int[fmt_idx][n]);
             }
             if (!(flags & ImGuiColorEditFlags_NoOptions))
                 OpenPopupOnItemClick("context");
@@ -4347,7 +4413,8 @@ bool ImGui::ColorEdit4(const char* label, float col[4], ImGuiColorEditFlags flag
 
     if (label != label_display_end && !(flags & ImGuiColorEditFlags_NoLabel))
     {
-        window->DC.CursorPos = ImVec2(pos.x + w_full + style.ItemInnerSpacing.x, pos.y + style.FramePadding.y);
+        const float text_offset_x = (flags & ImGuiColorEditFlags_NoInputs) ? w_button : w_full + style.ItemInnerSpacing.x;
+        window->DC.CursorPos = ImVec2(pos.x + text_offset_x, pos.y + style.FramePadding.y);
         TextEx(label, label_display_end);
     }
 
@@ -4360,6 +4427,7 @@ bool ImGui::ColorEdit4(const char* label, float col[4], ImGuiColorEditFlags flag
         if ((flags & ImGuiColorEditFlags_DisplayHSV) && (flags & ImGuiColorEditFlags_InputRGB))
         {
             g.ColorEditLastHue = f[0];
+            g.ColorEditLastSat = f[1];
             ColorConvertHSVtoRGB(f[0], f[1], f[2], f[0], f[1], f[2]);
             memcpy(g.ColorEditLastColor, f, sizeof(float) * 3);
         }
@@ -4542,8 +4610,13 @@ bool ImGui::ColorPicker4(const char* label, float col[4], ImGuiColorEditFlags fl
     {
         // Hue is lost when converting from greyscale rgb (saturation=0). Restore it.
         ColorConvertRGBtoHSV(R, G, B, H, S, V);
-        if (S == 0 && memcmp(g.ColorEditLastColor, col, sizeof(float) * 3) == 0)
-            H = g.ColorEditLastHue;
+        if (memcmp(g.ColorEditLastColor, col, sizeof(float) * 3) == 0)
+        {
+            if (S == 0)
+                H = g.ColorEditLastHue;
+            if (V == 0)
+                S = g.ColorEditLastSat;
+        }
     }
     else if (flags & ImGuiColorEditFlags_InputHSV)
     {
@@ -4671,6 +4744,7 @@ bool ImGui::ColorPicker4(const char* label, float col[4], ImGuiColorEditFlags fl
         {
             ColorConvertHSVtoRGB(H >= 1.0f ? H - 10 * 1e-6f : H, S > 0.0f ? S : 10*1e-6f, V > 0.0f ? V : 1e-6f, col[0], col[1], col[2]);
             g.ColorEditLastHue = H;
+            g.ColorEditLastSat = S;
             memcpy(g.ColorEditLastColor, col, sizeof(float) * 3);
         }
         else if (flags & ImGuiColorEditFlags_InputHSV)
@@ -4725,8 +4799,13 @@ bool ImGui::ColorPicker4(const char* label, float col[4], ImGuiColorEditFlags fl
             G = col[1];
             B = col[2];
             ColorConvertRGBtoHSV(R, G, B, H, S, V);
-            if (S == 0 && memcmp(g.ColorEditLastColor, col, sizeof(float) * 3) == 0) // Fix local Hue as display below will use it immediately.
-                H = g.ColorEditLastHue;
+            if (memcmp(g.ColorEditLastColor, col, sizeof(float) * 3) == 0) // Fix local Hue as display below will use it immediately.
+            {
+                if (S == 0)
+                    H = g.ColorEditLastHue;
+                if (V == 0)
+                    S = g.ColorEditLastSat;
+            }
         }
         else if (flags & ImGuiColorEditFlags_InputHSV)
         {
@@ -4945,7 +5024,7 @@ void ImGui::ColorTooltip(const char* text, const float* col, ImGuiColorEditFlags
 {
     ImGuiContext& g = *GImGui;
 
-    BeginTooltipEx(0, true);
+    BeginTooltipEx(0, ImGuiTooltipFlags_OverridePreviousTooltip);
     const char* text_end = text ? FindRenderedTextEnd(text, NULL) : text;
     if (text_end > text)
     {
@@ -5010,12 +5089,15 @@ void ImGui::ColorEditOptionsPopup(const float* col, ImGuiColorEditFlags flags)
         ImFormatString(buf, IM_ARRAYSIZE(buf), "(%d,%d,%d,%d)", cr, cg, cb, ca);
         if (Selectable(buf))
             SetClipboardText(buf);
-        if (flags & ImGuiColorEditFlags_NoAlpha)
-            ImFormatString(buf, IM_ARRAYSIZE(buf), "0x%02X%02X%02X", cr, cg, cb);
-        else
-            ImFormatString(buf, IM_ARRAYSIZE(buf), "0x%02X%02X%02X%02X", cr, cg, cb, ca);
+        ImFormatString(buf, IM_ARRAYSIZE(buf), "#%02X%02X%02X", cr, cg, cb);
         if (Selectable(buf))
             SetClipboardText(buf);
+        if (!(flags & ImGuiColorEditFlags_NoAlpha))
+        {
+            ImFormatString(buf, IM_ARRAYSIZE(buf), "#%02X%02X%02X%02X", cr, cg, cb, ca);
+            if (Selectable(buf))
+                SetClipboardText(buf);
+        }
         EndPopup();
     }
 
@@ -5254,7 +5336,7 @@ bool ImGui::TreeNodeBehavior(ImGuiID id, ImGuiTreeNodeFlags flags, const char* l
     const bool is_leaf = (flags & ImGuiTreeNodeFlags_Leaf) != 0;
     bool is_open = TreeNodeBehaviorIsOpen(id, flags);
     if (is_open && !g.NavIdIsAlive && (flags & ImGuiTreeNodeFlags_NavLeftJumpsBackHere) && !(flags & ImGuiTreeNodeFlags_NoTreePushOnOpen))
-        window->DC.TreeMayJumpToParentOnPopMask |= (1 << window->DC.TreeDepth);
+        window->DC.TreeJumpToParentOnPopMask |= (1 << window->DC.TreeDepth);
 
     bool item_add = ItemAdd(interact_bb, id);
     window->DC.LastItemStatusFlags |= ImGuiItemStatusFlags_HasDisplayRect;
@@ -5278,10 +5360,12 @@ bool ImGui::TreeNodeBehavior(ImGuiID id, ImGuiTreeNodeFlags flags, const char* l
         button_flags |= ImGuiButtonFlags_AllowItemOverlap;
     if (flags & ImGuiTreeNodeFlags_OpenOnDoubleClick)
         button_flags |= ImGuiButtonFlags_PressedOnDoubleClick | ((flags & ImGuiTreeNodeFlags_OpenOnArrow) ? ImGuiButtonFlags_PressedOnClickRelease : 0);
+    else
+        button_flags |= ImGuiButtonFlags_PressedOnClickRelease;
     if (!is_leaf)
         button_flags |= ImGuiButtonFlags_PressedOnDragDropHold;
 
-    // We allow clicking on the arrow section with keyboard modifiers held, in order to easily 
+    // We allow clicking on the arrow section with keyboard modifiers held, in order to easily
     // allow browsing a tree while preserving selection with code implementing multi-selection patterns.
     // When clicking on the rest of the tree node we always disallow keyboard modifiers.
     const float hit_padding_x = style.TouchExtraPadding.x;
@@ -5289,15 +5373,15 @@ bool ImGui::TreeNodeBehavior(ImGuiID id, ImGuiTreeNodeFlags flags, const char* l
     const float arrow_hit_x2 = (text_pos.x - text_offset_x) + (g.FontSize + padding.x * 2.0f) + hit_padding_x;
     if (window != g.HoveredWindow || !(g.IO.MousePos.x >= arrow_hit_x1 && g.IO.MousePos.x < arrow_hit_x2))
         button_flags |= ImGuiButtonFlags_NoKeyModifiers;
-    
+
     bool selected = (flags & ImGuiTreeNodeFlags_Selected) != 0;
     const bool was_selected = selected;
 
     bool hovered, held;
     bool pressed = ButtonBehavior(interact_bb, id, &hovered, &held, button_flags);
+    bool toggled = false;
     if (!is_leaf)
     {
-        bool toggled = false;
         if (pressed)
         {
             if ((flags & (ImGuiTreeNodeFlags_OpenOnArrow | ImGuiTreeNodeFlags_OpenOnDoubleClick)) == 0 || (g.NavActivateId == id))
@@ -5425,12 +5509,12 @@ void ImGui::TreePop()
 
     // Handle Left arrow to move to parent tree node (when ImGuiTreeNodeFlags_NavLeftJumpsBackHere is enabled)
     if (g.NavMoveDir == ImGuiDir_Left && g.NavWindow == window && NavMoveRequestButNoResultYet())
-        if (g.NavIdIsAlive && (window->DC.TreeMayJumpToParentOnPopMask & tree_depth_mask))
+        if (g.NavIdIsAlive && (window->DC.TreeJumpToParentOnPopMask & tree_depth_mask))
         {
-            SetNavID(window->IDStack.back(), g.NavLayer);
+            SetNavID(window->IDStack.back(), g.NavLayer, 0);
             NavMoveRequestCancel();
         }
-    window->DC.TreeMayJumpToParentOnPopMask &= tree_depth_mask - 1;
+    window->DC.TreeJumpToParentOnPopMask &= tree_depth_mask - 1;
 
     IM_ASSERT(window->IDStack.Size > 1); // There should always be 1 element in the IDStack (pushed during window creation). If this triggers you called TreePop/PopID too much.
     PopID();
@@ -5563,12 +5647,12 @@ bool ImGui::Selectable(const char* label, bool selected, ImGuiSelectableFlags fl
 
     // We use NoHoldingActiveID on menus so user can click and _hold_ on a menu then drag to browse child entries
     ImGuiButtonFlags button_flags = 0;
-    if (flags & ImGuiSelectableFlags_NoHoldingActiveID) button_flags |= ImGuiButtonFlags_NoHoldingActiveID;
-    if (flags & ImGuiSelectableFlags_PressedOnClick) button_flags |= ImGuiButtonFlags_PressedOnClick;
-    if (flags & ImGuiSelectableFlags_PressedOnRelease) button_flags |= ImGuiButtonFlags_PressedOnRelease;
-    if (flags & ImGuiSelectableFlags_Disabled) button_flags |= ImGuiButtonFlags_Disabled;
-    if (flags & ImGuiSelectableFlags_AllowDoubleClick) button_flags |= ImGuiButtonFlags_PressedOnClickRelease | ImGuiButtonFlags_PressedOnDoubleClick;
-    if (flags & ImGuiSelectableFlags_AllowItemOverlap) button_flags |= ImGuiButtonFlags_AllowItemOverlap;
+    if (flags & ImGuiSelectableFlags_NoHoldingActiveID) { button_flags |= ImGuiButtonFlags_NoHoldingActiveId; }
+    if (flags & ImGuiSelectableFlags_PressedOnClick)    { button_flags |= ImGuiButtonFlags_PressedOnClick; }
+    if (flags & ImGuiSelectableFlags_PressedOnRelease)  { button_flags |= ImGuiButtonFlags_PressedOnRelease; }
+    if (flags & ImGuiSelectableFlags_Disabled)          { button_flags |= ImGuiButtonFlags_Disabled; }
+    if (flags & ImGuiSelectableFlags_AllowDoubleClick)  { button_flags |= ImGuiButtonFlags_PressedOnClickRelease | ImGuiButtonFlags_PressedOnDoubleClick; }
+    if (flags & ImGuiSelectableFlags_AllowItemOverlap)  { button_flags |= ImGuiButtonFlags_AllowItemOverlap; }
 
     if (flags & ImGuiSelectableFlags_Disabled)
         selected = false;
@@ -5583,7 +5667,7 @@ bool ImGui::Selectable(const char* label, bool selected, ImGuiSelectableFlags fl
         if (!g.NavDisableMouseHover && g.NavWindow == window && g.NavLayer == window->DC.NavLayerCurrent)
         {
             g.NavDisableHighlight = true;
-            SetNavID(id, window->DC.NavLayerCurrent);
+            SetNavID(id, window->DC.NavLayerCurrent, window->DC.NavFocusScopeIdCurrent);
         }
     }
     if (pressed)
@@ -6027,7 +6111,7 @@ bool ImGui::BeginMenuBar()
     // We don't clip with current window clipping rectangle as it is already set to the area below. However we clip with window full rect.
     // We remove 1 worth of rounding to Max.x to that text in long menus and small windows don't tend to display over the lower-right rounded area, which looks particularly glitchy.
     ImRect bar_rect = window->MenuBarRect();
-    ImRect clip_rect(IM_ROUND(bar_rect.Min.x), IM_ROUND(bar_rect.Min.y + window->WindowBorderSize), IM_ROUND(ImMax(bar_rect.Min.x, bar_rect.Max.x - window->WindowRounding)), IM_ROUND(bar_rect.Max.y));
+    ImRect clip_rect(IM_ROUND(bar_rect.Min.x + window->WindowBorderSize), IM_ROUND(bar_rect.Min.y + window->WindowBorderSize), IM_ROUND(ImMax(bar_rect.Min.x, bar_rect.Max.x - ImMax(window->WindowRounding, window->WindowBorderSize))), IM_ROUND(bar_rect.Max.y));
     clip_rect.ClipWith(window->OuterRectClipped);
     PushClipRect(clip_rect.Min, clip_rect.Max, false);
 
@@ -6060,7 +6144,7 @@ void ImGui::EndMenuBar()
             const ImGuiNavLayer layer = ImGuiNavLayer_Menu;
             IM_ASSERT(window->DC.NavLayerActiveMaskNext & (1 << layer)); // Sanity check
             FocusWindow(window);
-            SetNavIDWithRectRel(window->NavLastIds[layer], layer, window->NavRectRel[layer]);
+            SetNavIDWithRectRel(window->NavLastIds[layer], layer, 0, window->NavRectRel[layer]);
             g.NavLayer = layer;
             g.NavDisableHighlight = true; // Hide highlight for the current frame so we don't see the intermediary selection.
             g.NavMoveRequestForward = ImGuiNavForward_ForwardQueued;
@@ -6155,11 +6239,11 @@ bool ImGui::BeginMenu(const char* label, bool enabled)
     {
         // Menu inside a menu
         popup_pos = ImVec2(pos.x, pos.y - style.WindowPadding.y);
-        float w = window->MenuColumns.DeclColumns(label_size.x, 0.0f, IM_FLOOR(g.FontSize * 1.20f)); // Feedback to next frame
+        float w = window->DC.MenuColumns.DeclColumns(label_size.x, 0.0f, IM_FLOOR(g.FontSize * 1.20f)); // Feedback to next frame
         float extra_w = ImMax(0.0f, GetContentRegionAvail().x - w);
         pressed = Selectable(label, menu_is_open, ImGuiSelectableFlags_NoHoldingActiveID | ImGuiSelectableFlags_PressedOnClick | ImGuiSelectableFlags_DontClosePopups | ImGuiSelectableFlags_DrawFillAvailWidth | (!enabled ? ImGuiSelectableFlags_Disabled : 0), ImVec2(w, 0.0f));
         ImU32 text_col = GetColorU32(enabled ? ImGuiCol_Text : ImGuiCol_TextDisabled);
-        RenderArrow(window->DrawList, pos + ImVec2(window->MenuColumns.Pos[2] + extra_w + g.FontSize * 0.30f, 0.0f), text_col, ImGuiDir_Right);
+        RenderArrow(window->DrawList, pos + ImVec2(window->DC.MenuColumns.Pos[2] + extra_w + g.FontSize * 0.30f, 0.0f), text_col, ImGuiDir_Right);
     }
 
     const bool hovered = enabled && ItemHoverable(window->DC.LastItemRect, id);
@@ -6303,17 +6387,17 @@ bool ImGui::MenuItem(const char* label, const char* shortcut, bool selected, boo
     else
     {
         ImVec2 shortcut_size = shortcut ? CalcTextSize(shortcut, NULL) : ImVec2(0.0f, 0.0f);
-        float w = window->MenuColumns.DeclColumns(label_size.x, shortcut_size.x, IM_FLOOR(g.FontSize * 1.20f)); // Feedback for next frame
+        float w = window->DC.MenuColumns.DeclColumns(label_size.x, shortcut_size.x, IM_FLOOR(g.FontSize * 1.20f)); // Feedback for next frame
         float extra_w = ImMax(0.0f, GetContentRegionAvail().x - w);
         pressed = Selectable(label, false, flags | ImGuiSelectableFlags_DrawFillAvailWidth, ImVec2(w, 0.0f));
         if (shortcut_size.x > 0.0f)
         {
             PushStyleColor(ImGuiCol_Text, g.Style.Colors[ImGuiCol_TextDisabled]);
-            RenderText(pos + ImVec2(window->MenuColumns.Pos[1] + extra_w, 0.0f), shortcut, NULL, false);
+            RenderText(pos + ImVec2(window->DC.MenuColumns.Pos[1] + extra_w, 0.0f), shortcut, NULL, false);
             PopStyleColor();
         }
         if (selected)
-            RenderCheckMark(pos + ImVec2(window->MenuColumns.Pos[2] + extra_w + g.FontSize * 0.40f, g.FontSize * 0.134f * 0.5f), GetColorU32(enabled ? ImGuiCol_Text : ImGuiCol_TextDisabled), g.FontSize  * 0.866f);
+            RenderCheckMark(pos + ImVec2(window->DC.MenuColumns.Pos[2] + extra_w + g.FontSize * 0.40f, g.FontSize * 0.134f * 0.5f), GetColorU32(enabled ? ImGuiCol_Text : ImGuiCol_TextDisabled), g.FontSize  * 0.866f);
     }
 
     IMGUI_TEST_ENGINE_ITEM_INFO(window->DC.LastItemId, label, window->DC.ItemFlags | ImGuiItemStatusFlags_Checkable | (selected ? ImGuiItemStatusFlags_Checked : 0));
@@ -6334,9 +6418,6 @@ bool ImGui::MenuItem(const char* label, const char* shortcut, bool* p_selected,
 //-------------------------------------------------------------------------
 // [SECTION] Widgets: BeginTabBar, EndTabBar, etc.
 //-------------------------------------------------------------------------
-// [BETA API] API may evolve! This code has been extracted out of the Docking branch,
-// and some of the construct which are not used in Master may be left here to facilitate merging.
-//-------------------------------------------------------------------------
 // - BeginTabBar()
 // - BeginTabBarEx() [Internal]
 // - EndTabBar()
@@ -6851,9 +6932,6 @@ static ImGuiTabItem* ImGui::TabBarTabListPopupButton(ImGuiTabBar* tab_bar)
 //-------------------------------------------------------------------------
 // [SECTION] Widgets: BeginTabItem, EndTabItem, etc.
 //-------------------------------------------------------------------------
-// [BETA API] API may evolve! This code has been extracted out of the Docking branch,
-// and some of the construct which are not used in Master may be left here to facilitate merging.
-//-------------------------------------------------------------------------
 // - BeginTabItem()
 // - EndTabItem()
 // - TabItemEx() [Internal]
@@ -6927,6 +7005,12 @@ bool    ImGui::TabItemEx(ImGuiTabBar* tab_bar, const char* label, bool* p_open,
         return false;
     }
 
+    // Store into ImGuiTabItemFlags_NoCloseButton, also honor ImGuiTabItemFlags_NoCloseButton passed by user (although not documented)
+    if (flags & ImGuiTabItemFlags_NoCloseButton)
+        p_open = NULL;
+    else if (p_open == NULL)
+        flags |= ImGuiTabItemFlags_NoCloseButton;
+
     // Calculate tab contents size
     ImVec2 size = TabItemCalcSize(label, p_open != NULL);
 
@@ -6944,9 +7028,6 @@ bool    ImGui::TabItemEx(ImGuiTabBar* tab_bar, const char* label, bool* p_open,
     tab_bar->LastTabItemIdx = (short)tab_bar->Tabs.index_from_ptr(tab);
     tab->ContentWidth = size.x;
 
-    if (p_open == NULL)
-        flags |= ImGuiTabItemFlags_NoCloseButton;
-
     const bool tab_bar_appearing = (tab_bar->PrevFrameVisible + 1 < g.FrameCount);
     const bool tab_bar_focused = (tab_bar->Flags & ImGuiTabBarFlags_IsFocused) != 0;
     const bool tab_appearing = (tab->LastFrameVisible + 1 < g.FrameCount);
@@ -7360,7 +7441,7 @@ void ImGui::PushColumnsBackground()
     ImGuiColumns* columns = window->DC.CurrentColumns;
     if (columns->Count == 1)
         return;
-    window->DrawList->ChannelsSetCurrent(0);
+    columns->Splitter.SetCurrentChannel(window->DrawList, 0);
     int cmd_size = window->DrawList->CmdBuffer.Size;
     PushClipRect(columns->HostClipRect.Min, columns->HostClipRect.Max, false);
     IM_UNUSED(cmd_size);
@@ -7373,7 +7454,7 @@ void ImGui::PopColumnsBackground()
     ImGuiColumns* columns = window->DC.CurrentColumns;
     if (columns->Count == 1)
         return;
-    window->DrawList->ChannelsSetCurrent(columns->Current + 1);
+    columns->Splitter.SetCurrentChannel(window->DrawList, columns->Current + 1);
     PopClipRect();
 }
 
@@ -7408,8 +7489,8 @@ void ImGui::BeginColumns(const char* str_id, int columns_count, ImGuiColumnsFlag
     ImGuiContext& g = *GImGui;
     ImGuiWindow* window = GetCurrentWindow();
 
-    IM_ASSERT(columns_count >= 1);
-    IM_ASSERT(window->DC.CurrentColumns == NULL); // Nested columns are currently not supported
+    IM_ASSERT(columns_count >= 1 && columns_count <= 64);   // Maximum 64 columns
+    IM_ASSERT(window->DC.CurrentColumns == NULL);           // Nested columns are currently not supported
 
     // Acquire storage for the columns set
     ImGuiID id = GetColumnsID(str_id, columns_count);
@@ -7464,8 +7545,8 @@ void ImGui::BeginColumns(const char* str_id, int columns_count, ImGuiColumnsFlag
 
     if (columns->Count > 1)
     {
-        window->DrawList->ChannelsSplit(1 + columns->Count);
-        window->DrawList->ChannelsSetCurrent(1);
+        columns->Splitter.Split(window->DrawList, 1 + columns->Count);
+        columns->Splitter.SetCurrentChannel(window->DrawList, 1);
         PushColumnClipRect(0);
     }
 
@@ -7504,14 +7585,14 @@ void ImGui::NextColumn()
         // Columns 1+ ignore IndentX (by canceling it out)
         // FIXME-COLUMNS: Unnecessary, could be locked?
         window->DC.ColumnsOffset.x = GetColumnOffset(columns->Current) - window->DC.Indent.x + column_padding;
-        window->DrawList->ChannelsSetCurrent(columns->Current + 1);
+        columns->Splitter.SetCurrentChannel(window->DrawList, columns->Current + 1);
     }
     else
     {
         // New row/line
         // Column 0 honor IndentX
         window->DC.ColumnsOffset.x = ImMax(column_padding - window->WindowPadding.x, 0.0f);
-        window->DrawList->ChannelsSetCurrent(1);
+        columns->Splitter.SetCurrentChannel(window->DrawList, 1);
         columns->Current = 0;
         columns->LineMinY = columns->LineMaxY;
     }
@@ -7541,7 +7622,7 @@ void ImGui::EndColumns()
     if (columns->Count > 1)
     {
         PopClipRect();
-        window->DrawList->ChannelsMerge();
+        columns->Splitter.Merge(window->DrawList);
     }
 
     const ImGuiColumnsFlags flags = columns->Flags;
@@ -7625,3 +7706,5 @@ void ImGui::Columns(int columns_count, const char* id, bool border)
 }
 
 //-------------------------------------------------------------------------
+
+#endif // #ifndef IMGUI_DISABLE