Created working windows build in GLFW and OpenGL3

.gitignore

@@ -441,6 +441,9 @@ FodyWeavers.xsd
 *.a
 *.lib
 
+#Ignore glfw compiled libraries
+!glfw3.lib
+
 # Executables
 *.exe
 *.out

ImGui-Example.vcxproj

@@ -76,10 +76,14 @@
       <SDLCheck>true</SDLCheck>
       <PreprocessorDefinitions>WIN32;_DEBUG;_CONSOLE;%(PreprocessorDefinitions)</PreprocessorDefinitions>
       <ConformanceMode>true</ConformanceMode>
+      <AdditionalIncludeDirectories>$(SolutionDir)includes;$(SolutionDir)includes\imgui;$(SolutionDir)includes\imgui\backends</AdditionalIncludeDirectories>
+      <AdditionalUsingDirectories>%(AdditionalUsingDirectories)</AdditionalUsingDirectories>
     </ClCompile>
     <Link>
       <SubSystem>Console</SubSystem>
       <GenerateDebugInformation>true</GenerateDebugInformation>
+      <AdditionalLibraryDirectories>$(SolutionDir)dependencies\GLFW;%(AdditionalLibraryDirectories)</AdditionalLibraryDirectories>
+      <AdditionalDependencies>glfw3.lib;OpenGL32.lib;%(AdditionalDependencies)</AdditionalDependencies>
     </Link>
   </ItemDefinitionGroup>
   <ItemDefinitionGroup Condition="'$(Configuration)|$(Platform)'=='Release|Win32'">
@@ -90,12 +94,16 @@
       <SDLCheck>true</SDLCheck>
       <PreprocessorDefinitions>WIN32;NDEBUG;_CONSOLE;%(PreprocessorDefinitions)</PreprocessorDefinitions>
       <ConformanceMode>true</ConformanceMode>
+      <AdditionalIncludeDirectories>$(SolutionDir)includes;$(SolutionDir)includes\imgui;$(SolutionDir)includes\imgui\backends</AdditionalIncludeDirectories>
+      <AdditionalUsingDirectories>%(AdditionalUsingDirectories)</AdditionalUsingDirectories>
     </ClCompile>
     <Link>
       <SubSystem>Console</SubSystem>
       <EnableCOMDATFolding>true</EnableCOMDATFolding>
       <OptimizeReferences>true</OptimizeReferences>
       <GenerateDebugInformation>true</GenerateDebugInformation>
+      <AdditionalLibraryDirectories>$(SolutionDir)dependencies\GLFW;%(AdditionalLibraryDirectories)</AdditionalLibraryDirectories>
+      <AdditionalDependencies>glfw3.lib;OpenGL32.lib;%(AdditionalDependencies)</AdditionalDependencies>
     </Link>
   </ItemDefinitionGroup>
   <ItemDefinitionGroup Condition="'$(Configuration)|$(Platform)'=='Debug|x64'">
@@ -105,11 +113,13 @@
       <PreprocessorDefinitions>_DEBUG;_CONSOLE;%(PreprocessorDefinitions)</PreprocessorDefinitions>
       <ConformanceMode>true</ConformanceMode>
       <AdditionalUsingDirectories>%(AdditionalUsingDirectories)</AdditionalUsingDirectories>
-      <AdditionalIncludeDirectories>$(SolutionDir)includes\imgui; $(SolutionDir)includes\imgui\backends</AdditionalIncludeDirectories>
+      <AdditionalIncludeDirectories>$(SolutionDir)includes;$(SolutionDir)includes\imgui;$(SolutionDir)includes\imgui\backends</AdditionalIncludeDirectories>
     </ClCompile>
     <Link>
       <SubSystem>Console</SubSystem>
       <GenerateDebugInformation>true</GenerateDebugInformation>
+      <AdditionalLibraryDirectories>$(SolutionDir)dependencies\GLFW;%(AdditionalLibraryDirectories)</AdditionalLibraryDirectories>
+      <AdditionalDependencies>glfw3.lib;OpenGL32.lib;%(AdditionalDependencies)</AdditionalDependencies>
     </Link>
   </ItemDefinitionGroup>
   <ItemDefinitionGroup Condition="'$(Configuration)|$(Platform)'=='Release|x64'">
@@ -120,17 +130,21 @@
       <SDLCheck>true</SDLCheck>
       <PreprocessorDefinitions>NDEBUG;_CONSOLE;%(PreprocessorDefinitions)</PreprocessorDefinitions>
       <ConformanceMode>true</ConformanceMode>
+      <AdditionalIncludeDirectories>$(SolutionDir)includes;$(SolutionDir)includes\imgui;$(SolutionDir)includes\imgui\backends</AdditionalIncludeDirectories>
+      <AdditionalUsingDirectories>%(AdditionalUsingDirectories)</AdditionalUsingDirectories>
     </ClCompile>
     <Link>
       <SubSystem>Console</SubSystem>
       <EnableCOMDATFolding>true</EnableCOMDATFolding>
       <OptimizeReferences>true</OptimizeReferences>
       <GenerateDebugInformation>true</GenerateDebugInformation>
+      <AdditionalLibraryDirectories>$(SolutionDir)dependencies\GLFW;%(AdditionalLibraryDirectories)</AdditionalLibraryDirectories>
+      <AdditionalDependencies>glfw3.lib;OpenGL32.lib;%(AdditionalDependencies)</AdditionalDependencies>
     </Link>
   </ItemDefinitionGroup>
   <ItemGroup>
     <ClCompile Include="includes\imgui\backends\imgui_impl_glfw.cpp" />
-    <ClCompile Include="includes\imgui\backends\imgui_impl_vulkan.cpp" />
+    <ClCompile Include="includes\imgui\backends\imgui_impl_opengl3.cpp" />
     <ClCompile Include="includes\imgui\imgui.cpp" />
     <ClCompile Include="includes\imgui\imgui_demo.cpp" />
     <ClCompile Include="includes\imgui\imgui_draw.cpp" />
@@ -139,8 +153,11 @@
     <ClCompile Include="src\main.cpp" />
   </ItemGroup>
   <ItemGroup>
+    <ClInclude Include="includes\GLFW\glfw3.h" />
+    <ClInclude Include="includes\GLFW\glfw3native.h" />
     <ClInclude Include="includes\imgui\backends\imgui_impl_glfw.h" />
-    <ClInclude Include="includes\imgui\backends\imgui_impl_vulkan.h" />
+    <ClInclude Include="includes\imgui\backends\imgui_impl_opengl3.h" />
+    <ClInclude Include="includes\imgui\backends\imgui_impl_opengl3_loader.h" />
     <ClInclude Include="includes\imgui\imconfig.h" />
     <ClInclude Include="includes\imgui\imgui.h" />
     <ClInclude Include="includes\imgui\imgui_internal.h" />
@@ -153,6 +170,9 @@
     <None Include="LICENSE" />
     <None Include="README.md" />
   </ItemGroup>
+  <ItemGroup>
+    <Library Include="dependencies\GLFW\glfw3.lib" />
+  </ItemGroup>
   <Import Project="$(VCTargetsPath)\Microsoft.Cpp.targets" />
   <ImportGroup Label="ExtensionTargets">
   </ImportGroup>

ImGui-Example.vcxproj.filters

@@ -18,9 +18,6 @@
     <ClCompile Include="includes\imgui\backends\imgui_impl_glfw.cpp">
       <Filter>Source Files</Filter>
     </ClCompile>
-    <ClCompile Include="includes\imgui\backends\imgui_impl_vulkan.cpp">
-      <Filter>Source Files</Filter>
-    </ClCompile>
     <ClCompile Include="includes\imgui\imgui.cpp">
       <Filter>Source Files</Filter>
     </ClCompile>
@@ -36,6 +33,9 @@
     <ClCompile Include="includes\imgui\imgui_widgets.cpp">
       <Filter>Source Files</Filter>
     </ClCompile>
+    <ClCompile Include="includes\imgui\backends\imgui_impl_opengl3.cpp">
+      <Filter>Source Files</Filter>
+    </ClCompile>
     <ClCompile Include="src\main.cpp">
       <Filter>Source Files</Filter>
     </ClCompile>
@@ -44,9 +44,6 @@
     <ClInclude Include="includes\imgui\backends\imgui_impl_glfw.h">
       <Filter>Header Files</Filter>
     </ClInclude>
-    <ClInclude Include="includes\imgui\backends\imgui_impl_vulkan.h">
-      <Filter>Header Files</Filter>
-    </ClInclude>
     <ClInclude Include="includes\imgui\imconfig.h">
       <Filter>Header Files</Filter>
     </ClInclude>
@@ -65,10 +62,25 @@
     <ClInclude Include="includes\imgui\imstb_truetype.h">
       <Filter>Header Files</Filter>
     </ClInclude>
+    <ClInclude Include="includes\GLFW\glfw3.h">
+      <Filter>Header Files</Filter>
+    </ClInclude>
+    <ClInclude Include="includes\GLFW\glfw3native.h">
+      <Filter>Header Files</Filter>
+    </ClInclude>
+    <ClInclude Include="includes\imgui\backends\imgui_impl_opengl3.h">
+      <Filter>Header Files</Filter>
+    </ClInclude>
+    <ClInclude Include="includes\imgui\backends\imgui_impl_opengl3_loader.h">
+      <Filter>Header Files</Filter>
+    </ClInclude>
   </ItemGroup>
   <ItemGroup>
     <None Include=".gitignore" />
     <None Include="LICENSE" />
     <None Include="README.md" />
   </ItemGroup>
+  <ItemGroup>
+    <Library Include="dependencies\GLFW\glfw3.lib" />
+  </ItemGroup>
 </Project>

README.md

@@ -1,3 +1,5 @@
 # ImGui-Example
 
-Repository for getting a working implementation of ImGui using GLFW
+Repository for getting a working implementation of ImGui using GLFW and OpenGL
+
+This uses libraries from GLFW and OpenGL. Please make sure you refer to relevant licences for further information.

imgui.ini

@@ -0,0 +1,22 @@
+[Window][Debug##Default]
+Pos=60,60
+Size=400,400
+Collapsed=0
+
+[Window][Dear ImGui Demo]
+Pos=479,19
+Size=550,680
+Collapsed=0
+
+[Window][Hello, world!]
+Pos=594,166
+Size=411,178
+Collapsed=0
+
+[Window][Another Window]
+Pos=762,95
+Size=493,210
+Collapsed=0
+
+[Docking][Data]
+

includes/GLFW/glfw3native.h

@@ -0,0 +1,628 @@
+/*************************************************************************
+ * GLFW 3.3 - www.glfw.org
+ * A library for OpenGL, window and input
+ *------------------------------------------------------------------------
+ * Copyright (c) 2002-2006 Marcus Geelnard
+ * Copyright (c) 2006-2018 Camilla Löwy <elmindreda@glfw.org>
+ *
+ * This software is provided 'as-is', without any express or implied
+ * warranty. In no event will the authors be held liable for any damages
+ * arising from the use of this software.
+ *
+ * Permission is granted to anyone to use this software for any purpose,
+ * including commercial applications, and to alter it and redistribute it
+ * freely, subject to the following restrictions:
+ *
+ * 1. The origin of this software must not be misrepresented; you must not
+ *    claim that you wrote the original software. If you use this software
+ *    in a product, an acknowledgment in the product documentation would
+ *    be appreciated but is not required.
+ *
+ * 2. Altered source versions must be plainly marked as such, and must not
+ *    be misrepresented as being the original software.
+ *
+ * 3. This notice may not be removed or altered from any source
+ *    distribution.
+ *
+ *************************************************************************/
+
+#ifndef _glfw3_native_h_
+#define _glfw3_native_h_
+
+#ifdef __cplusplus
+extern "C" {
+#endif
+
+
+/*************************************************************************
+ * Doxygen documentation
+ *************************************************************************/
+
+/*! @file glfw3native.h
+ *  @brief The header of the native access functions.
+ *
+ *  This is the header file of the native access functions.  See @ref native for
+ *  more information.
+ */
+/*! @defgroup native Native access
+ *  @brief Functions related to accessing native handles.
+ *
+ *  **By using the native access functions you assert that you know what you're
+ *  doing and how to fix problems caused by using them.  If you don't, you
+ *  shouldn't be using them.**
+ *
+ *  Before the inclusion of @ref glfw3native.h, you may define zero or more
+ *  window system API macro and zero or more context creation API macros.
+ *
+ *  The chosen backends must match those the library was compiled for.  Failure
+ *  to do this will cause a link-time error.
+ *
+ *  The available window API macros are:
+ *  * `GLFW_EXPOSE_NATIVE_WIN32`
+ *  * `GLFW_EXPOSE_NATIVE_COCOA`
+ *  * `GLFW_EXPOSE_NATIVE_X11`
+ *  * `GLFW_EXPOSE_NATIVE_WAYLAND`
+ *
+ *  The available context API macros are:
+ *  * `GLFW_EXPOSE_NATIVE_WGL`
+ *  * `GLFW_EXPOSE_NATIVE_NSGL`
+ *  * `GLFW_EXPOSE_NATIVE_GLX`
+ *  * `GLFW_EXPOSE_NATIVE_EGL`
+ *  * `GLFW_EXPOSE_NATIVE_OSMESA`
+ *
+ *  These macros select which of the native access functions that are declared
+ *  and which platform-specific headers to include.  It is then up your (by
+ *  definition platform-specific) code to handle which of these should be
+ *  defined.
+ *
+ *  If you do not want the platform-specific headers to be included, define
+ *  `GLFW_NATIVE_INCLUDE_NONE` before including the @ref glfw3native.h header.
+ *
+ *  @code
+ *  #define GLFW_EXPOSE_NATIVE_WIN32
+ *  #define GLFW_EXPOSE_NATIVE_WGL
+ *  #define GLFW_NATIVE_INCLUDE_NONE
+ *  #include <GLFW/glfw3native.h>
+ *  @endcode
+ */
+
+
+/*************************************************************************
+ * System headers and types
+ *************************************************************************/
+
+#if !defined(GLFW_NATIVE_INCLUDE_NONE)
+
+ #if defined(GLFW_EXPOSE_NATIVE_WIN32) || defined(GLFW_EXPOSE_NATIVE_WGL)
+  /* This is a workaround for the fact that glfw3.h needs to export APIENTRY (for
+   * example to allow applications to correctly declare a GL_KHR_debug callback)
+   * but windows.h assumes no one will define APIENTRY before it does
+   */
+  #if defined(GLFW_APIENTRY_DEFINED)
+   #undef APIENTRY
+   #undef GLFW_APIENTRY_DEFINED
+  #endif
+  #include <windows.h>
+ #elif defined(GLFW_EXPOSE_NATIVE_COCOA) || defined(GLFW_EXPOSE_NATIVE_NSGL)
+  #if defined(__OBJC__)
+   #import <Cocoa/Cocoa.h>
+  #else
+   #include <ApplicationServices/ApplicationServices.h>
+   #include <objc/objc.h>
+  #endif
+ #elif defined(GLFW_EXPOSE_NATIVE_X11) || defined(GLFW_EXPOSE_NATIVE_GLX)
+  #include <X11/Xlib.h>
+  #include <X11/extensions/Xrandr.h>
+ #elif defined(GLFW_EXPOSE_NATIVE_WAYLAND)
+  #include <wayland-client.h>
+ #endif
+
+ #if defined(GLFW_EXPOSE_NATIVE_WGL)
+  /* WGL is declared by windows.h */
+ #endif
+ #if defined(GLFW_EXPOSE_NATIVE_NSGL)
+  /* NSGL is declared by Cocoa.h */
+ #endif
+ #if defined(GLFW_EXPOSE_NATIVE_GLX)
+  /* This is a workaround for the fact that glfw3.h defines GLAPIENTRY because by
+   * default it also acts as an OpenGL header
+   * However, glx.h will include gl.h, which will define it unconditionally
+   */
+  #if defined(GLFW_GLAPIENTRY_DEFINED)
+   #undef GLAPIENTRY
+   #undef GLFW_GLAPIENTRY_DEFINED
+  #endif
+  #include <GL/glx.h>
+ #endif
+ #if defined(GLFW_EXPOSE_NATIVE_EGL)
+  #include <EGL/egl.h>
+ #endif
+ #if defined(GLFW_EXPOSE_NATIVE_OSMESA)
+  /* This is a workaround for the fact that glfw3.h defines GLAPIENTRY because by
+   * default it also acts as an OpenGL header
+   * However, osmesa.h will include gl.h, which will define it unconditionally
+   */
+  #if defined(GLFW_GLAPIENTRY_DEFINED)
+   #undef GLAPIENTRY
+   #undef GLFW_GLAPIENTRY_DEFINED
+  #endif
+  #include <GL/osmesa.h>
+ #endif
+
+#endif /*GLFW_NATIVE_INCLUDE_NONE*/
+
+
+/*************************************************************************
+ * Functions
+ *************************************************************************/
+
+#if defined(GLFW_EXPOSE_NATIVE_WIN32)
+/*! @brief Returns the adapter device name of the specified monitor.
+ *
+ *  @return The UTF-8 encoded adapter device name (for example `\\.\DISPLAY1`)
+ *  of the specified monitor, or `NULL` if an [error](@ref error_handling)
+ *  occurred.
+ *
+ *  @errors Possible errors include @ref GLFW_NOT_INITIALIZED.
+ *
+ *  @thread_safety This function may be called from any thread.  Access is not
+ *  synchronized.
+ *
+ *  @since Added in version 3.1.
+ *
+ *  @ingroup native
+ */
+GLFWAPI const char* glfwGetWin32Adapter(GLFWmonitor* monitor);
+
+/*! @brief Returns the display device name of the specified monitor.
+ *
+ *  @return The UTF-8 encoded display device name (for example
+ *  `\\.\DISPLAY1\Monitor0`) of the specified monitor, or `NULL` if an
+ *  [error](@ref error_handling) occurred.
+ *
+ *  @errors Possible errors include @ref GLFW_NOT_INITIALIZED.
+ *
+ *  @thread_safety This function may be called from any thread.  Access is not
+ *  synchronized.
+ *
+ *  @since Added in version 3.1.
+ *
+ *  @ingroup native
+ */
+GLFWAPI const char* glfwGetWin32Monitor(GLFWmonitor* monitor);
+
+/*! @brief Returns the `HWND` of the specified window.
+ *
+ *  @return The `HWND` of the specified window, or `NULL` if an
+ *  [error](@ref error_handling) occurred.
+ *
+ *  @errors Possible errors include @ref GLFW_NOT_INITIALIZED.
+ *
+ *  @remark The `HDC` associated with the window can be queried with the
+ *  [GetDC](https://docs.microsoft.com/en-us/windows/win32/api/winuser/nf-winuser-getdc)
+ *  function.
+ *  @code
+ *  HDC dc = GetDC(glfwGetWin32Window(window));
+ *  @endcode
+ *  This DC is private and does not need to be released.
+ *
+ *  @thread_safety This function may be called from any thread.  Access is not
+ *  synchronized.
+ *
+ *  @since Added in version 3.0.
+ *
+ *  @ingroup native
+ */
+GLFWAPI HWND glfwGetWin32Window(GLFWwindow* window);
+#endif
+
+#if defined(GLFW_EXPOSE_NATIVE_WGL)
+/*! @brief Returns the `HGLRC` of the specified window.
+ *
+ *  @return The `HGLRC` of the specified window, or `NULL` if an
+ *  [error](@ref error_handling) occurred.
+ *
+ *  @errors Possible errors include @ref GLFW_NO_WINDOW_CONTEXT and @ref
+ *  GLFW_NOT_INITIALIZED.
+ *
+ *  @remark The `HDC` associated with the window can be queried with the
+ *  [GetDC](https://docs.microsoft.com/en-us/windows/win32/api/winuser/nf-winuser-getdc)
+ *  function.
+ *  @code
+ *  HDC dc = GetDC(glfwGetWin32Window(window));
+ *  @endcode
+ *  This DC is private and does not need to be released.
+ *
+ *  @thread_safety This function may be called from any thread.  Access is not
+ *  synchronized.
+ *
+ *  @since Added in version 3.0.
+ *
+ *  @ingroup native
+ */
+GLFWAPI HGLRC glfwGetWGLContext(GLFWwindow* window);
+#endif
+
+#if defined(GLFW_EXPOSE_NATIVE_COCOA)
+/*! @brief Returns the `CGDirectDisplayID` of the specified monitor.
+ *
+ *  @return The `CGDirectDisplayID` of the specified monitor, or
+ *  `kCGNullDirectDisplay` if an [error](@ref error_handling) occurred.
+ *
+ *  @errors Possible errors include @ref GLFW_NOT_INITIALIZED.
+ *
+ *  @thread_safety This function may be called from any thread.  Access is not
+ *  synchronized.
+ *
+ *  @since Added in version 3.1.
+ *
+ *  @ingroup native
+ */
+GLFWAPI CGDirectDisplayID glfwGetCocoaMonitor(GLFWmonitor* monitor);
+
+/*! @brief Returns the `NSWindow` of the specified window.
+ *
+ *  @return The `NSWindow` of the specified window, or `nil` if an
+ *  [error](@ref error_handling) occurred.
+ *
+ *  @errors Possible errors include @ref GLFW_NOT_INITIALIZED.
+ *
+ *  @thread_safety This function may be called from any thread.  Access is not
+ *  synchronized.
+ *
+ *  @since Added in version 3.0.
+ *
+ *  @ingroup native
+ */
+GLFWAPI id glfwGetCocoaWindow(GLFWwindow* window);
+#endif
+
+#if defined(GLFW_EXPOSE_NATIVE_NSGL)
+/*! @brief Returns the `NSOpenGLContext` of the specified window.
+ *
+ *  @return The `NSOpenGLContext` of the specified window, or `nil` if an
+ *  [error](@ref error_handling) occurred.
+ *
+ *  @errors Possible errors include @ref GLFW_NO_WINDOW_CONTEXT and @ref
+ *  GLFW_NOT_INITIALIZED.
+ *
+ *  @thread_safety This function may be called from any thread.  Access is not
+ *  synchronized.
+ *
+ *  @since Added in version 3.0.
+ *
+ *  @ingroup native
+ */
+GLFWAPI id glfwGetNSGLContext(GLFWwindow* window);
+#endif
+
+#if defined(GLFW_EXPOSE_NATIVE_X11)
+/*! @brief Returns the `Display` used by GLFW.
+ *
+ *  @return The `Display` used by GLFW, or `NULL` if an
+ *  [error](@ref error_handling) occurred.
+ *
+ *  @errors Possible errors include @ref GLFW_NOT_INITIALIZED.
+ *
+ *  @thread_safety This function may be called from any thread.  Access is not
+ *  synchronized.
+ *
+ *  @since Added in version 3.0.
+ *
+ *  @ingroup native
+ */
+GLFWAPI Display* glfwGetX11Display(void);
+
+/*! @brief Returns the `RRCrtc` of the specified monitor.
+ *
+ *  @return The `RRCrtc` of the specified monitor, or `None` if an
+ *  [error](@ref error_handling) occurred.
+ *
+ *  @errors Possible errors include @ref GLFW_NOT_INITIALIZED.
+ *
+ *  @thread_safety This function may be called from any thread.  Access is not
+ *  synchronized.
+ *
+ *  @since Added in version 3.1.
+ *
+ *  @ingroup native
+ */
+GLFWAPI RRCrtc glfwGetX11Adapter(GLFWmonitor* monitor);
+
+/*! @brief Returns the `RROutput` of the specified monitor.
+ *
+ *  @return The `RROutput` of the specified monitor, or `None` if an
+ *  [error](@ref error_handling) occurred.
+ *
+ *  @errors Possible errors include @ref GLFW_NOT_INITIALIZED.
+ *
+ *  @thread_safety This function may be called from any thread.  Access is not
+ *  synchronized.
+ *
+ *  @since Added in version 3.1.
+ *
+ *  @ingroup native
+ */
+GLFWAPI RROutput glfwGetX11Monitor(GLFWmonitor* monitor);
+
+/*! @brief Returns the `Window` of the specified window.
+ *
+ *  @return The `Window` of the specified window, or `None` if an
+ *  [error](@ref error_handling) occurred.
+ *
+ *  @errors Possible errors include @ref GLFW_NOT_INITIALIZED.
+ *
+ *  @thread_safety This function may be called from any thread.  Access is not
+ *  synchronized.
+ *
+ *  @since Added in version 3.0.
+ *
+ *  @ingroup native
+ */
+GLFWAPI Window glfwGetX11Window(GLFWwindow* window);
+
+/*! @brief Sets the current primary selection to the specified string.
+ *
+ *  @param[in] string A UTF-8 encoded string.
+ *
+ *  @errors Possible errors include @ref GLFW_NOT_INITIALIZED and @ref
+ *  GLFW_PLATFORM_ERROR.
+ *
+ *  @pointer_lifetime The specified string is copied before this function
+ *  returns.
+ *
+ *  @thread_safety This function must only be called from the main thread.
+ *
+ *  @sa @ref clipboard
+ *  @sa glfwGetX11SelectionString
+ *  @sa glfwSetClipboardString
+ *
+ *  @since Added in version 3.3.
+ *
+ *  @ingroup native
+ */
+GLFWAPI void glfwSetX11SelectionString(const char* string);
+
+/*! @brief Returns the contents of the current primary selection as a string.
+ *
+ *  If the selection is empty or if its contents cannot be converted, `NULL`
+ *  is returned and a @ref GLFW_FORMAT_UNAVAILABLE error is generated.
+ *
+ *  @return The contents of the selection as a UTF-8 encoded string, or `NULL`
+ *  if an [error](@ref error_handling) occurred.
+ *
+ *  @errors Possible errors include @ref GLFW_NOT_INITIALIZED and @ref
+ *  GLFW_PLATFORM_ERROR.
+ *
+ *  @pointer_lifetime The returned string is allocated and freed by GLFW. You
+ *  should not free it yourself. It is valid until the next call to @ref
+ *  glfwGetX11SelectionString or @ref glfwSetX11SelectionString, or until the
+ *  library is terminated.
+ *
+ *  @thread_safety This function must only be called from the main thread.
+ *
+ *  @sa @ref clipboard
+ *  @sa glfwSetX11SelectionString
+ *  @sa glfwGetClipboardString
+ *
+ *  @since Added in version 3.3.
+ *
+ *  @ingroup native
+ */
+GLFWAPI const char* glfwGetX11SelectionString(void);
+#endif
+
+#if defined(GLFW_EXPOSE_NATIVE_GLX)
+/*! @brief Returns the `GLXContext` of the specified window.
+ *
+ *  @return The `GLXContext` of the specified window, or `NULL` if an
+ *  [error](@ref error_handling) occurred.
+ *
+ *  @errors Possible errors include @ref GLFW_NO_WINDOW_CONTEXT and @ref
+ *  GLFW_NOT_INITIALIZED.
+ *
+ *  @thread_safety This function may be called from any thread.  Access is not
+ *  synchronized.
+ *
+ *  @since Added in version 3.0.
+ *
+ *  @ingroup native
+ */
+GLFWAPI GLXContext glfwGetGLXContext(GLFWwindow* window);
+
+/*! @brief Returns the `GLXWindow` of the specified window.
+ *
+ *  @return The `GLXWindow` of the specified window, or `None` if an
+ *  [error](@ref error_handling) occurred.
+ *
+ *  @errors Possible errors include @ref GLFW_NO_WINDOW_CONTEXT and @ref
+ *  GLFW_NOT_INITIALIZED.
+ *
+ *  @thread_safety This function may be called from any thread.  Access is not
+ *  synchronized.
+ *
+ *  @since Added in version 3.2.
+ *
+ *  @ingroup native
+ */
+GLFWAPI GLXWindow glfwGetGLXWindow(GLFWwindow* window);
+#endif
+
+#if defined(GLFW_EXPOSE_NATIVE_WAYLAND)
+/*! @brief Returns the `struct wl_display*` used by GLFW.
+ *
+ *  @return The `struct wl_display*` used by GLFW, or `NULL` if an
+ *  [error](@ref error_handling) occurred.
+ *
+ *  @errors Possible errors include @ref GLFW_NOT_INITIALIZED.
+ *
+ *  @thread_safety This function may be called from any thread.  Access is not
+ *  synchronized.
+ *
+ *  @since Added in version 3.2.
+ *
+ *  @ingroup native
+ */
+GLFWAPI struct wl_display* glfwGetWaylandDisplay(void);
+
+/*! @brief Returns the `struct wl_output*` of the specified monitor.
+ *
+ *  @return The `struct wl_output*` of the specified monitor, or `NULL` if an
+ *  [error](@ref error_handling) occurred.
+ *
+ *  @errors Possible errors include @ref GLFW_NOT_INITIALIZED.
+ *
+ *  @thread_safety This function may be called from any thread.  Access is not
+ *  synchronized.
+ *
+ *  @since Added in version 3.2.
+ *
+ *  @ingroup native
+ */
+GLFWAPI struct wl_output* glfwGetWaylandMonitor(GLFWmonitor* monitor);
+
+/*! @brief Returns the main `struct wl_surface*` of the specified window.
+ *
+ *  @return The main `struct wl_surface*` of the specified window, or `NULL` if
+ *  an [error](@ref error_handling) occurred.
+ *
+ *  @errors Possible errors include @ref GLFW_NOT_INITIALIZED.
+ *
+ *  @thread_safety This function may be called from any thread.  Access is not
+ *  synchronized.
+ *
+ *  @since Added in version 3.2.
+ *
+ *  @ingroup native
+ */
+GLFWAPI struct wl_surface* glfwGetWaylandWindow(GLFWwindow* window);
+#endif
+
+#if defined(GLFW_EXPOSE_NATIVE_EGL)
+/*! @brief Returns the `EGLDisplay` used by GLFW.
+ *
+ *  @return The `EGLDisplay` used by GLFW, or `EGL_NO_DISPLAY` if an
+ *  [error](@ref error_handling) occurred.
+ *
+ *  @errors Possible errors include @ref GLFW_NOT_INITIALIZED.
+ *
+ *  @remark Because EGL is initialized on demand, this function will return
+ *  `EGL_NO_DISPLAY` until the first context has been created via EGL.
+ *
+ *  @thread_safety This function may be called from any thread.  Access is not
+ *  synchronized.
+ *
+ *  @since Added in version 3.0.
+ *
+ *  @ingroup native
+ */
+GLFWAPI EGLDisplay glfwGetEGLDisplay(void);
+
+/*! @brief Returns the `EGLContext` of the specified window.
+ *
+ *  @return The `EGLContext` of the specified window, or `EGL_NO_CONTEXT` if an
+ *  [error](@ref error_handling) occurred.
+ *
+ *  @errors Possible errors include @ref GLFW_NO_WINDOW_CONTEXT and @ref
+ *  GLFW_NOT_INITIALIZED.
+ *
+ *  @thread_safety This function may be called from any thread.  Access is not
+ *  synchronized.
+ *
+ *  @since Added in version 3.0.
+ *
+ *  @ingroup native
+ */
+GLFWAPI EGLContext glfwGetEGLContext(GLFWwindow* window);
+
+/*! @brief Returns the `EGLSurface` of the specified window.
+ *
+ *  @return The `EGLSurface` of the specified window, or `EGL_NO_SURFACE` if an
+ *  [error](@ref error_handling) occurred.
+ *
+ *  @errors Possible errors include @ref GLFW_NO_WINDOW_CONTEXT and @ref
+ *  GLFW_NOT_INITIALIZED.
+ *
+ *  @thread_safety This function may be called from any thread.  Access is not
+ *  synchronized.
+ *
+ *  @since Added in version 3.0.
+ *
+ *  @ingroup native
+ */
+GLFWAPI EGLSurface glfwGetEGLSurface(GLFWwindow* window);
+#endif
+
+#if defined(GLFW_EXPOSE_NATIVE_OSMESA)
+/*! @brief Retrieves the color buffer associated with the specified window.
+ *
+ *  @param[in] window The window whose color buffer to retrieve.
+ *  @param[out] width Where to store the width of the color buffer, or `NULL`.
+ *  @param[out] height Where to store the height of the color buffer, or `NULL`.
+ *  @param[out] format Where to store the OSMesa pixel format of the color
+ *  buffer, or `NULL`.
+ *  @param[out] buffer Where to store the address of the color buffer, or
+ *  `NULL`.
+ *  @return `GLFW_TRUE` if successful, or `GLFW_FALSE` if an
+ *  [error](@ref error_handling) occurred.
+ *
+ *  @errors Possible errors include @ref GLFW_NO_WINDOW_CONTEXT and @ref
+ *  GLFW_NOT_INITIALIZED.
+ *
+ *  @thread_safety This function may be called from any thread.  Access is not
+ *  synchronized.
+ *
+ *  @since Added in version 3.3.
+ *
+ *  @ingroup native
+ */
+GLFWAPI int glfwGetOSMesaColorBuffer(GLFWwindow* window, int* width, int* height, int* format, void** buffer);
+
+/*! @brief Retrieves the depth buffer associated with the specified window.
+ *
+ *  @param[in] window The window whose depth buffer to retrieve.
+ *  @param[out] width Where to store the width of the depth buffer, or `NULL`.
+ *  @param[out] height Where to store the height of the depth buffer, or `NULL`.
+ *  @param[out] bytesPerValue Where to store the number of bytes per depth
+ *  buffer element, or `NULL`.
+ *  @param[out] buffer Where to store the address of the depth buffer, or
+ *  `NULL`.
+ *  @return `GLFW_TRUE` if successful, or `GLFW_FALSE` if an
+ *  [error](@ref error_handling) occurred.
+ *
+ *  @errors Possible errors include @ref GLFW_NO_WINDOW_CONTEXT and @ref
+ *  GLFW_NOT_INITIALIZED.
+ *
+ *  @thread_safety This function may be called from any thread.  Access is not
+ *  synchronized.
+ *
+ *  @since Added in version 3.3.
+ *
+ *  @ingroup native
+ */
+GLFWAPI int glfwGetOSMesaDepthBuffer(GLFWwindow* window, int* width, int* height, int* bytesPerValue, void** buffer);
+
+/*! @brief Returns the `OSMesaContext` of the specified window.
+ *
+ *  @return The `OSMesaContext` of the specified window, or `NULL` if an
+ *  [error](@ref error_handling) occurred.
+ *
+ *  @errors Possible errors include @ref GLFW_NO_WINDOW_CONTEXT and @ref
+ *  GLFW_NOT_INITIALIZED.
+ *
+ *  @thread_safety This function may be called from any thread.  Access is not
+ *  synchronized.
+ *
+ *  @since Added in version 3.3.
+ *
+ *  @ingroup native
+ */
+GLFWAPI OSMesaContext glfwGetOSMesaContext(GLFWwindow* window);
+#endif
+
+#ifdef __cplusplus
+}
+#endif
+
+#endif /* _glfw3_native_h_ */
+

includes/imgui/backends/imgui_impl_glfw.cpp

@@ -1,13 +1,17 @@
 // dear imgui: Platform Backend for GLFW
 // This needs to be used along with a Renderer (e.g. OpenGL3, Vulkan, WebGPU..)
 // (Info: GLFW is a cross-platform general purpose library for handling windows, inputs, OpenGL/Vulkan graphics context creation, etc.)
-// (Requires: GLFW 3.1+)
+// (Requires: GLFW 3.1+. Prefer GLFW 3.3+ for full feature support.)
 
 // Implemented features:
 //  [X] Platform: Clipboard support.
 //  [X] Platform: Keyboard support. Since 1.87 we are using the io.AddKeyEvent() function. Pass ImGuiKey values to all key functions e.g. ImGui::IsKeyPressed(ImGuiKey_Space). [Legacy GLFW_KEY_* values will also be supported unless IMGUI_DISABLE_OBSOLETE_KEYIO is set]
 //  [X] Platform: Gamepad support. Enable with 'io.ConfigFlags |= ImGuiConfigFlags_NavEnableGamepad'.
 //  [X] Platform: Mouse cursor shape and visibility. Disable with 'io.ConfigFlags |= ImGuiConfigFlags_NoMouseCursorChange' (note: the resizing cursors requires GLFW 3.4+).
+//  [X] Platform: Multi-viewport support (multiple windows). Enable with 'io.ConfigFlags |= ImGuiConfigFlags_ViewportsEnable'.
+
+// Issues:
+//  [ ] Platform: Multi-viewport support: ParentViewportID not honored, and so io.ConfigViewportsNoDefaultParent has no effect (minor).
 
 // You can use unmodified imgui_impl_* files in your project. See examples/ folder for examples of using this.
 // Prefer including the entire imgui/ repository into your project (either as a copy or as a submodule), and only build the backends you need.
@@ -16,6 +20,7 @@
 
 // CHANGELOG
 // (minor and older changes stripped away, please see git history for details)
+//  2022-XX-XX: Platform: Added support for multiple windows via the ImGuiPlatformIO interface.
 //  2022-10-18: Perform a dummy glfwGetError() read to cancel missing mouse cursors errors. Using GLFW_VERSION_COMBINED directly. (#5785)
 //  2022-10-11: Using 'nullptr' instead of 'NULL' as per our switch to C++11.
 //  2022-09-26: Inputs: Renamed ImGuiKey_ModXXX introduced in 1.87 to ImGuiMod_XXX (old names still supported).
@@ -67,19 +72,38 @@
 
 // GLFW
 #include <GLFW/glfw3.h>
+
 #ifdef _WIN32
 #undef APIENTRY
 #define GLFW_EXPOSE_NATIVE_WIN32
-#include <GLFW/glfw3native.h>   // for glfwGetWin32Window
+#include <GLFW/glfw3native.h>   // for glfwGetWin32Window()
+#endif
+#ifdef __APPLE__
+#define GLFW_EXPOSE_NATIVE_COCOA
+#include <GLFW/glfw3native.h>   // for glfwGetCocoaWindow()
 #endif
 
 // We gather version tests as define in order to easily see which features are version-dependent.
 #define GLFW_VERSION_COMBINED           (GLFW_VERSION_MAJOR * 1000 + GLFW_VERSION_MINOR * 100 + GLFW_VERSION_REVISION)
+#define GLFW_HAS_WINDOW_TOPMOST         (GLFW_VERSION_COMBINED >= 3200) // 3.2+ GLFW_FLOATING
+#define GLFW_HAS_WINDOW_HOVERED         (GLFW_VERSION_COMBINED >= 3300) // 3.3+ GLFW_HOVERED
+#define GLFW_HAS_WINDOW_ALPHA           (GLFW_VERSION_COMBINED >= 3300) // 3.3+ glfwSetWindowOpacity
+#define GLFW_HAS_PER_MONITOR_DPI        (GLFW_VERSION_COMBINED >= 3300) // 3.3+ glfwGetMonitorContentScale
+#define GLFW_HAS_VULKAN                 (GLFW_VERSION_COMBINED >= 3200) // 3.2+ glfwCreateWindowSurface
+#define GLFW_HAS_FOCUS_WINDOW           (GLFW_VERSION_COMBINED >= 3200) // 3.2+ glfwFocusWindow
+#define GLFW_HAS_FOCUS_ON_SHOW          (GLFW_VERSION_COMBINED >= 3300) // 3.3+ GLFW_FOCUS_ON_SHOW
+#define GLFW_HAS_MONITOR_WORK_AREA      (GLFW_VERSION_COMBINED >= 3300) // 3.3+ glfwGetMonitorWorkarea
+#define GLFW_HAS_OSX_WINDOW_POS_FIX     (GLFW_VERSION_COMBINED >= 3301) // 3.3.1+ Fixed: Resizing window repositions it on MacOS #1553
 #ifdef GLFW_RESIZE_NESW_CURSOR          // Let's be nice to people who pulled GLFW between 2019-04-16 (3.4 define) and 2019-11-29 (cursors defines) // FIXME: Remove when GLFW 3.4 is released?
 #define GLFW_HAS_NEW_CURSORS            (GLFW_VERSION_COMBINED >= 3400) // 3.4+ GLFW_RESIZE_ALL_CURSOR, GLFW_RESIZE_NESW_CURSOR, GLFW_RESIZE_NWSE_CURSOR, GLFW_NOT_ALLOWED_CURSOR
 #else
 #define GLFW_HAS_NEW_CURSORS            (0)
 #endif
+#ifdef GLFW_MOUSE_PASSTHROUGH           // Let's be nice to people who pulled GLFW between 2019-04-16 (3.4 define) and 2020-07-17 (passthrough)
+#define GLFW_HAS_MOUSE_PASSTHROUGH      (GLFW_VERSION_COMBINED >= 3400) // 3.4+ GLFW_MOUSE_PASSTHROUGH
+#else
+#define GLFW_HAS_MOUSE_PASSTHROUGH      (0)
+#endif
 #define GLFW_HAS_GAMEPAD_API            (GLFW_VERSION_COMBINED >= 3300) // 3.3+ glfwGetGamepadState() new api
 #define GLFW_HAS_GETKEYNAME             (GLFW_VERSION_COMBINED >= 3200) // 3.2+ glfwGetKeyName()
 
@@ -99,7 +123,12 @@ struct ImGui_ImplGlfw_Data
     GLFWwindow*             MouseWindow;
     GLFWcursor*             MouseCursors[ImGuiMouseCursor_COUNT];
     ImVec2                  LastValidMousePos;
+    GLFWwindow*             KeyOwnerWindows[GLFW_KEY_LAST];
     bool                    InstalledCallbacks;
+    bool                    WantUpdateMonitors;
+#ifdef _WIN32
+    WNDPROC                 GlfwWndProc;
+#endif
 
     // Chain GLFW callbacks: our callbacks will call the user's previously installed callbacks, if any.
     GLFWwindowfocusfun      PrevUserCallbackWindowFocus;
@@ -126,6 +155,11 @@ static ImGui_ImplGlfw_Data* ImGui_ImplGlfw_GetBackendData()
     return ImGui::GetCurrentContext() ? (ImGui_ImplGlfw_Data*)ImGui::GetIO().BackendPlatformUserData : nullptr;
 }
 
+// Forward Declarations
+static void ImGui_ImplGlfw_UpdateMonitors();
+static void ImGui_ImplGlfw_InitPlatformInterface();
+static void ImGui_ImplGlfw_ShutdownPlatformInterface();
+
 // Functions
 static const char* ImGui_ImplGlfw_GetClipboardText(void* user_data)
 {
@@ -337,6 +371,9 @@ void ImGui_ImplGlfw_KeyCallback(GLFWwindow* window, int keycode, int scancode, i
         mods = (action == GLFW_PRESS) ? (mods | keycode_to_mod) : (mods & ~keycode_to_mod);
     ImGui_ImplGlfw_UpdateKeyModifiers(mods);
 
+    if (keycode >= 0 && keycode < IM_ARRAYSIZE(bd->KeyOwnerWindows))
+        bd->KeyOwnerWindows[keycode] = (action == GLFW_PRESS) ? window : nullptr;
+
     keycode = ImGui_ImplGlfw_TranslateUntranslatedKey(keycode, scancode);
 
     ImGuiIO& io = ImGui::GetIO();
@@ -364,6 +401,13 @@ void ImGui_ImplGlfw_CursorPosCallback(GLFWwindow* window, double x, double y)
         return;
 
     ImGuiIO& io = ImGui::GetIO();
+    if (io.ConfigFlags & ImGuiConfigFlags_ViewportsEnable)
+    {
+        int window_x, window_y;
+        glfwGetWindowPos(window, &window_x, &window_y);
+        x += window_x;
+        y += window_y;
+    }
     io.AddMousePosEvent((float)x, (float)y);
     bd->LastValidMousePos = ImVec2((float)x, (float)y);
 }
@@ -404,7 +448,8 @@ void ImGui_ImplGlfw_CharCallback(GLFWwindow* window, unsigned int c)
 
 void ImGui_ImplGlfw_MonitorCallback(GLFWmonitor*, int)
 {
-	// Unused in 'master' branch but 'docking' branch will use this, so we declare it ahead of it so if you have to install callbacks you can install this one too.
+    ImGui_ImplGlfw_Data* bd = ImGui_ImplGlfw_GetBackendData();
+    bd->WantUpdateMonitors = true;
 }
 
 void ImGui_ImplGlfw_InstallCallbacks(GLFWwindow* window)
@@ -461,19 +506,19 @@ static bool ImGui_ImplGlfw_Init(GLFWwindow* window, bool install_callbacks, Glfw
     io.BackendPlatformName = "imgui_impl_glfw";
     io.BackendFlags |= ImGuiBackendFlags_HasMouseCursors;         // We can honor GetMouseCursor() values (optional)
     io.BackendFlags |= ImGuiBackendFlags_HasSetMousePos;          // We can honor io.WantSetMousePos requests (optional, rarely used)
+    io.BackendFlags |= ImGuiBackendFlags_PlatformHasViewports;    // We can create multi-viewports on the Platform side (optional)
+#if GLFW_HAS_MOUSE_PASSTHROUGH || (GLFW_HAS_WINDOW_HOVERED && defined(_WIN32))
+    io.BackendFlags |= ImGuiBackendFlags_HasMouseHoveredViewport; // We can call io.AddMouseViewportEvent() with correct data (optional)
+#endif
 
     bd->Window = window;
     bd->Time = 0.0;
+    bd->WantUpdateMonitors = true;
 
     io.SetClipboardTextFn = ImGui_ImplGlfw_SetClipboardText;
     io.GetClipboardTextFn = ImGui_ImplGlfw_GetClipboardText;
     io.ClipboardUserData = bd->Window;
 
-    // Set platform dependent data in viewport
-#if defined(_WIN32)
-    ImGui::GetMainViewport()->PlatformHandleRaw = (void*)glfwGetWin32Window(bd->Window);
-#endif
-
     // Create mouse cursors
     // (By design, on X11 cursors are user configurable and some cursors may be missing. When a cursor doesn't exist,
     // GLFW will emit an error which will often be printed by the app, so we temporarily disable error reporting.
@@ -504,6 +549,21 @@ static bool ImGui_ImplGlfw_Init(GLFWwindow* window, bool install_callbacks, Glfw
     if (install_callbacks)
         ImGui_ImplGlfw_InstallCallbacks(window);
 
+    // Update monitors the first time (note: monitor callback are broken in GLFW 3.2 and earlier, see github.com/glfw/glfw/issues/784)
+    ImGui_ImplGlfw_UpdateMonitors();
+    glfwSetMonitorCallback(ImGui_ImplGlfw_MonitorCallback);
+
+    // Our mouse update function expect PlatformHandle to be filled for the main viewport
+    ImGuiViewport* main_viewport = ImGui::GetMainViewport();
+    main_viewport->PlatformHandle = (void*)bd->Window;
+#ifdef _WIN32
+    main_viewport->PlatformHandleRaw = glfwGetWin32Window(bd->Window);
+#elif defined(__APPLE__)
+    main_viewport->PlatformHandleRaw = (void*)glfwGetCocoaWindow(bd->Window);
+#endif
+    if (io.ConfigFlags & ImGuiConfigFlags_ViewportsEnable)
+        ImGui_ImplGlfw_InitPlatformInterface();
+
     bd->ClientApi = client_api;
     return true;
 }
@@ -529,6 +589,8 @@ void ImGui_ImplGlfw_Shutdown()
     IM_ASSERT(bd != nullptr && "No platform backend to shutdown, or already shutdown?");
     ImGuiIO& io = ImGui::GetIO();
 
+    ImGui_ImplGlfw_ShutdownPlatformInterface();
+
     if (bd->InstalledCallbacks)
         ImGui_ImplGlfw_RestoreCallbacks(bd->Window);
 
@@ -544,6 +606,7 @@ static void ImGui_ImplGlfw_UpdateMouseData()
 {
     ImGui_ImplGlfw_Data* bd = ImGui_ImplGlfw_GetBackendData();
     ImGuiIO& io = ImGui::GetIO();
+    ImGuiPlatformIO& platform_io = ImGui::GetPlatformIO();
 
     if (glfwGetInputMode(bd->Window, GLFW_CURSOR) == GLFW_CURSOR_DISABLED)
     {
@@ -551,26 +614,68 @@ static void ImGui_ImplGlfw_UpdateMouseData()
         return;
     }
 
-#ifdef __EMSCRIPTEN__
+    ImGuiID mouse_viewport_id = 0;
-    const bool is_app_focused = true;
+    const ImVec2 mouse_pos_prev = io.MousePos;
-#else
+    for (int n = 0; n < platform_io.Viewports.Size; n++)
-    const bool is_app_focused = glfwGetWindowAttrib(bd->Window, GLFW_FOCUSED) != 0;
-#endif
-    if (is_app_focused)
     {
-        // (Optional) Set OS mouse position from Dear ImGui if requested (rarely used, only when ImGuiConfigFlags_NavEnableSetMousePos is enabled by user)
+        ImGuiViewport* viewport = platform_io.Viewports[n];
-        if (io.WantSetMousePos)
+        GLFWwindow* window = (GLFWwindow*)viewport->PlatformHandle;
-            glfwSetCursorPos(bd->Window, (double)io.MousePos.x, (double)io.MousePos.y);
 
-        // (Optional) Fallback to provide mouse position when focused (ImGui_ImplGlfw_CursorPosCallback already provides this when hovered or captured)
+#ifdef __EMSCRIPTEN__
-        if (is_app_focused && bd->MouseWindow == nullptr)
+        const bool is_window_focused = true;
+#else
+        const bool is_window_focused = glfwGetWindowAttrib(window, GLFW_FOCUSED) != 0;
+#endif
+        if (is_window_focused)
         {
-            double mouse_x, mouse_y;
+            // (Optional) Set OS mouse position from Dear ImGui if requested (rarely used, only when ImGuiConfigFlags_NavEnableSetMousePos is enabled by user)
-            glfwGetCursorPos(bd->Window, &mouse_x, &mouse_y);
+            // When multi-viewports are enabled, all Dear ImGui positions are same as OS positions.
-            io.AddMousePosEvent((float)mouse_x, (float)mouse_y);
+            if (io.WantSetMousePos)
-            bd->LastValidMousePos = ImVec2((float)mouse_x, (float)mouse_y);
+                glfwSetCursorPos(window, (double)(mouse_pos_prev.x - viewport->Pos.x), (double)(mouse_pos_prev.y - viewport->Pos.y));
+
+            // (Optional) Fallback to provide mouse position when focused (ImGui_ImplGlfw_CursorPosCallback already provides this when hovered or captured)
+            if (bd->MouseWindow == nullptr)
+            {
+                double mouse_x, mouse_y;
+                glfwGetCursorPos(window, &mouse_x, &mouse_y);
+                if (io.ConfigFlags & ImGuiConfigFlags_ViewportsEnable)
+                {
+                    // Single viewport mode: mouse position in client window coordinates (io.MousePos is (0,0) when the mouse is on the upper-left corner of the app window)
+                    // Multi-viewport mode: mouse position in OS absolute coordinates (io.MousePos is (0,0) when the mouse is on the upper-left of the primary monitor)
+                    int window_x, window_y;
+                    glfwGetWindowPos(window, &window_x, &window_y);
+                    mouse_x += window_x;
+                    mouse_y += window_y;
+                }
+                bd->LastValidMousePos = ImVec2((float)mouse_x, (float)mouse_y);
+                io.AddMousePosEvent((float)mouse_x, (float)mouse_y);
+            }
         }
+
+        // (Optional) When using multiple viewports: call io.AddMouseViewportEvent() with the viewport the OS mouse cursor is hovering.
+        // If ImGuiBackendFlags_HasMouseHoveredViewport is not set by the backend, Dear imGui will ignore this field and infer the information using its flawed heuristic.
+        // - [X] GLFW >= 3.3 backend ON WINDOWS ONLY does correctly ignore viewports with the _NoInputs flag.
+        // - [!] GLFW <= 3.2 backend CANNOT correctly ignore viewports with the _NoInputs flag, and CANNOT reported Hovered Viewport because of mouse capture.
+        //       Some backend are not able to handle that correctly. If a backend report an hovered viewport that has the _NoInputs flag (e.g. when dragging a window
+        //       for docking, the viewport has the _NoInputs flag in order to allow us to find the viewport under), then Dear ImGui is forced to ignore the value reported
+        //       by the backend, and use its flawed heuristic to guess the viewport behind.
+        // - [X] GLFW backend correctly reports this regardless of another viewport behind focused and dragged from (we need this to find a useful drag and drop target).
+        // FIXME: This is currently only correct on Win32. See what we do below with the WM_NCHITTEST, missing an equivalent for other systems.
+        // See https://github.com/glfw/glfw/issues/1236 if you want to help in making this a GLFW feature.
+#if GLFW_HAS_MOUSE_PASSTHROUGH || (GLFW_HAS_WINDOW_HOVERED && defined(_WIN32))
+        const bool window_no_input = (viewport->Flags & ImGuiViewportFlags_NoInputs) != 0;
+#if GLFW_HAS_MOUSE_PASSTHROUGH
+        glfwSetWindowAttrib(window, GLFW_MOUSE_PASSTHROUGH, window_no_input);
+#endif
+        if (glfwGetWindowAttrib(window, GLFW_HOVERED) && !window_no_input)
+            mouse_viewport_id = viewport->ID;
+#else
+        // We cannot use bd->MouseWindow maintained from CursorEnter/Leave callbacks, because it is locked to the window capturing mouse.
+#endif
     }
+
+    if (io.BackendFlags & ImGuiBackendFlags_HasMouseHoveredViewport)
+        io.AddMouseViewportEvent(mouse_viewport_id);
 }
 
 static void ImGui_ImplGlfw_UpdateMouseCursor()
@@ -581,17 +686,22 @@ static void ImGui_ImplGlfw_UpdateMouseCursor()
         return;
 
     ImGuiMouseCursor imgui_cursor = ImGui::GetMouseCursor();
-    if (imgui_cursor == ImGuiMouseCursor_None || io.MouseDrawCursor)
+    ImGuiPlatformIO& platform_io = ImGui::GetPlatformIO();
+    for (int n = 0; n < platform_io.Viewports.Size; n++)
     {
-        // Hide OS mouse cursor if imgui is drawing it or if it wants no cursor
+        GLFWwindow* window = (GLFWwindow*)platform_io.Viewports[n]->PlatformHandle;
-        glfwSetInputMode(bd->Window, GLFW_CURSOR, GLFW_CURSOR_HIDDEN);
+        if (imgui_cursor == ImGuiMouseCursor_None || io.MouseDrawCursor)
-    }
+        {
-    else
+            // Hide OS mouse cursor if imgui is drawing it or if it wants no cursor
-    {
+            glfwSetInputMode(window, GLFW_CURSOR, GLFW_CURSOR_HIDDEN);
-        // Show OS mouse cursor
+        }
-        // FIXME-PLATFORM: Unfocused windows seems to fail changing the mouse cursor with GLFW 3.2, but 3.3 works here.
+        else
-        glfwSetCursor(bd->Window, bd->MouseCursors[imgui_cursor] ? bd->MouseCursors[imgui_cursor] : bd->MouseCursors[ImGuiMouseCursor_Arrow]);
+        {
-        glfwSetInputMode(bd->Window, GLFW_CURSOR, GLFW_CURSOR_NORMAL);
+            // Show OS mouse cursor
+            // FIXME-PLATFORM: Unfocused windows seems to fail changing the mouse cursor with GLFW 3.2, but 3.3 works here.
+            glfwSetCursor(window, bd->MouseCursors[imgui_cursor] ? bd->MouseCursors[imgui_cursor] : bd->MouseCursors[ImGuiMouseCursor_Arrow]);
+            glfwSetInputMode(window, GLFW_CURSOR, GLFW_CURSOR_NORMAL);
+        }
     }
 }
 
@@ -648,6 +758,41 @@ static void ImGui_ImplGlfw_UpdateGamepads()
     #undef MAP_ANALOG
 }
 
+static void ImGui_ImplGlfw_UpdateMonitors()
+{
+    ImGui_ImplGlfw_Data* bd = ImGui_ImplGlfw_GetBackendData();
+    ImGuiPlatformIO& platform_io = ImGui::GetPlatformIO();
+    int monitors_count = 0;
+    GLFWmonitor** glfw_monitors = glfwGetMonitors(&monitors_count);
+    platform_io.Monitors.resize(0);
+    for (int n = 0; n < monitors_count; n++)
+    {
+        ImGuiPlatformMonitor monitor;
+        int x, y;
+        glfwGetMonitorPos(glfw_monitors[n], &x, &y);
+        const GLFWvidmode* vid_mode = glfwGetVideoMode(glfw_monitors[n]);
+        monitor.MainPos = monitor.WorkPos = ImVec2((float)x, (float)y);
+        monitor.MainSize = monitor.WorkSize = ImVec2((float)vid_mode->width, (float)vid_mode->height);
+#if GLFW_HAS_MONITOR_WORK_AREA
+        int w, h;
+        glfwGetMonitorWorkarea(glfw_monitors[n], &x, &y, &w, &h);
+        if (w > 0 && h > 0) // Workaround a small GLFW issue reporting zero on monitor changes: https://github.com/glfw/glfw/pull/1761
+        {
+            monitor.WorkPos = ImVec2((float)x, (float)y);
+            monitor.WorkSize = ImVec2((float)w, (float)h);
+        }
+#endif
+#if GLFW_HAS_PER_MONITOR_DPI
+        // Warning: the validity of monitor DPI information on Windows depends on the application DPI awareness settings, which generally needs to be set in the manifest or at runtime.
+        float x_scale, y_scale;
+        glfwGetMonitorContentScale(glfw_monitors[n], &x_scale, &y_scale);
+        monitor.DpiScale = x_scale;
+#endif
+        platform_io.Monitors.push_back(monitor);
+    }
+    bd->WantUpdateMonitors = false;
+}
+
 void ImGui_ImplGlfw_NewFrame()
 {
     ImGuiIO& io = ImGui::GetIO();
@@ -662,6 +807,8 @@ void ImGui_ImplGlfw_NewFrame()
     io.DisplaySize = ImVec2((float)w, (float)h);
     if (w > 0 && h > 0)
         io.DisplayFramebufferScale = ImVec2((float)display_w / (float)w, (float)display_h / (float)h);
+    if (bd->WantUpdateMonitors)
+        ImGui_ImplGlfw_UpdateMonitors();
 
     // Setup time step
     double current_time = glfwGetTime();
@@ -675,6 +822,364 @@ void ImGui_ImplGlfw_NewFrame()
     ImGui_ImplGlfw_UpdateGamepads();
 }
 
+//--------------------------------------------------------------------------------------------------------
+// MULTI-VIEWPORT / PLATFORM INTERFACE SUPPORT
+// This is an _advanced_ and _optional_ feature, allowing the backend to create and handle multiple viewports simultaneously.
+// If you are new to dear imgui or creating a new binding for dear imgui, it is recommended that you completely ignore this section first..
+//--------------------------------------------------------------------------------------------------------
+
+// Helper structure we store in the void* RenderUserData field of each ImGuiViewport to easily retrieve our backend data.
+struct ImGui_ImplGlfw_ViewportData
+{
+    GLFWwindow* Window;
+    bool        WindowOwned;
+    int         IgnoreWindowPosEventFrame;
+    int         IgnoreWindowSizeEventFrame;
+
+    ImGui_ImplGlfw_ViewportData()  { Window = nullptr; WindowOwned = false; IgnoreWindowSizeEventFrame = IgnoreWindowPosEventFrame = -1; }
+    ~ImGui_ImplGlfw_ViewportData() { IM_ASSERT(Window == nullptr); }
+};
+
+static void ImGui_ImplGlfw_WindowCloseCallback(GLFWwindow* window)
+{
+    if (ImGuiViewport* viewport = ImGui::FindViewportByPlatformHandle(window))
+        viewport->PlatformRequestClose = true;
+}
+
+// GLFW may dispatch window pos/size events after calling glfwSetWindowPos()/glfwSetWindowSize().
+// However: depending on the platform the callback may be invoked at different time:
+// - on Windows it appears to be called within the glfwSetWindowPos()/glfwSetWindowSize() call
+// - on Linux it is queued and invoked during glfwPollEvents()
+// Because the event doesn't always fire on glfwSetWindowXXX() we use a frame counter tag to only
+// ignore recent glfwSetWindowXXX() calls.
+static void ImGui_ImplGlfw_WindowPosCallback(GLFWwindow* window, int, int)
+{
+    if (ImGuiViewport* viewport = ImGui::FindViewportByPlatformHandle(window))
+    {
+        if (ImGui_ImplGlfw_ViewportData* vd = (ImGui_ImplGlfw_ViewportData*)viewport->PlatformUserData)
+        {
+            bool ignore_event = (ImGui::GetFrameCount() <= vd->IgnoreWindowPosEventFrame + 1);
+            //data->IgnoreWindowPosEventFrame = -1;
+            if (ignore_event)
+                return;
+        }
+        viewport->PlatformRequestMove = true;
+    }
+}
+
+static void ImGui_ImplGlfw_WindowSizeCallback(GLFWwindow* window, int, int)
+{
+    if (ImGuiViewport* viewport = ImGui::FindViewportByPlatformHandle(window))
+    {
+        if (ImGui_ImplGlfw_ViewportData* vd = (ImGui_ImplGlfw_ViewportData*)viewport->PlatformUserData)
+        {
+            bool ignore_event = (ImGui::GetFrameCount() <= vd->IgnoreWindowSizeEventFrame + 1);
+            //data->IgnoreWindowSizeEventFrame = -1;
+            if (ignore_event)
+                return;
+        }
+        viewport->PlatformRequestResize = true;
+    }
+}
+
+static void ImGui_ImplGlfw_CreateWindow(ImGuiViewport* viewport)
+{
+    ImGui_ImplGlfw_Data* bd = ImGui_ImplGlfw_GetBackendData();
+    ImGui_ImplGlfw_ViewportData* vd = IM_NEW(ImGui_ImplGlfw_ViewportData)();
+    viewport->PlatformUserData = vd;
+
+    // GLFW 3.2 unfortunately always set focus on glfwCreateWindow() if GLFW_VISIBLE is set, regardless of GLFW_FOCUSED
+    // With GLFW 3.3, the hint GLFW_FOCUS_ON_SHOW fixes this problem
+    glfwWindowHint(GLFW_VISIBLE, false);
+    glfwWindowHint(GLFW_FOCUSED, false);
+#if GLFW_HAS_FOCUS_ON_SHOW
+    glfwWindowHint(GLFW_FOCUS_ON_SHOW, false);
+ #endif
+    glfwWindowHint(GLFW_DECORATED, (viewport->Flags & ImGuiViewportFlags_NoDecoration) ? false : true);
+#if GLFW_HAS_WINDOW_TOPMOST
+    glfwWindowHint(GLFW_FLOATING, (viewport->Flags & ImGuiViewportFlags_TopMost) ? true : false);
+#endif
+    GLFWwindow* share_window = (bd->ClientApi == GlfwClientApi_OpenGL) ? bd->Window : nullptr;
+    vd->Window = glfwCreateWindow((int)viewport->Size.x, (int)viewport->Size.y, "No Title Yet", nullptr, share_window);
+    vd->WindowOwned = true;
+    viewport->PlatformHandle = (void*)vd->Window;
+#ifdef _WIN32
+    viewport->PlatformHandleRaw = glfwGetWin32Window(vd->Window);
+#elif defined(__APPLE__)
+    viewport->PlatformHandleRaw = (void*)glfwGetCocoaWindow(vd->Window);
+#endif
+    glfwSetWindowPos(vd->Window, (int)viewport->Pos.x, (int)viewport->Pos.y);
+
+    // Install GLFW callbacks for secondary viewports
+    glfwSetWindowFocusCallback(vd->Window, ImGui_ImplGlfw_WindowFocusCallback);
+    glfwSetCursorEnterCallback(vd->Window, ImGui_ImplGlfw_CursorEnterCallback);
+    glfwSetCursorPosCallback(vd->Window, ImGui_ImplGlfw_CursorPosCallback);
+    glfwSetMouseButtonCallback(vd->Window, ImGui_ImplGlfw_MouseButtonCallback);
+    glfwSetScrollCallback(vd->Window, ImGui_ImplGlfw_ScrollCallback);
+    glfwSetKeyCallback(vd->Window, ImGui_ImplGlfw_KeyCallback);
+    glfwSetCharCallback(vd->Window, ImGui_ImplGlfw_CharCallback);
+    glfwSetWindowCloseCallback(vd->Window, ImGui_ImplGlfw_WindowCloseCallback);
+    glfwSetWindowPosCallback(vd->Window, ImGui_ImplGlfw_WindowPosCallback);
+    glfwSetWindowSizeCallback(vd->Window, ImGui_ImplGlfw_WindowSizeCallback);
+    if (bd->ClientApi == GlfwClientApi_OpenGL)
+    {
+        glfwMakeContextCurrent(vd->Window);
+        glfwSwapInterval(0);
+    }
+}
+
+static void ImGui_ImplGlfw_DestroyWindow(ImGuiViewport* viewport)
+{
+    ImGui_ImplGlfw_Data* bd = ImGui_ImplGlfw_GetBackendData();
+    if (ImGui_ImplGlfw_ViewportData* vd = (ImGui_ImplGlfw_ViewportData*)viewport->PlatformUserData)
+    {
+        if (vd->WindowOwned)
+        {
+#if !GLFW_HAS_MOUSE_PASSTHROUGH && GLFW_HAS_WINDOW_HOVERED && defined(_WIN32)
+            HWND hwnd = (HWND)viewport->PlatformHandleRaw;
+            ::RemovePropA(hwnd, "IMGUI_VIEWPORT");
+#endif
+
+            // Release any keys that were pressed in the window being destroyed and are still held down,
+            // because we will not receive any release events after window is destroyed.
+            for (int i = 0; i < IM_ARRAYSIZE(bd->KeyOwnerWindows); i++)
+                if (bd->KeyOwnerWindows[i] == vd->Window)
+                    ImGui_ImplGlfw_KeyCallback(vd->Window, i, 0, GLFW_RELEASE, 0); // Later params are only used for main viewport, on which this function is never called.
+
+            glfwDestroyWindow(vd->Window);
+        }
+        vd->Window = nullptr;
+        IM_DELETE(vd);
+    }
+    viewport->PlatformUserData = viewport->PlatformHandle = nullptr;
+}
+
+// We have submitted https://github.com/glfw/glfw/pull/1568 to allow GLFW to support "transparent inputs".
+// In the meanwhile we implement custom per-platform workarounds here (FIXME-VIEWPORT: Implement same work-around for Linux/OSX!)
+#if !GLFW_HAS_MOUSE_PASSTHROUGH && GLFW_HAS_WINDOW_HOVERED && defined(_WIN32)
+static LRESULT CALLBACK WndProcNoInputs(HWND hWnd, UINT msg, WPARAM wParam, LPARAM lParam)
+{
+    ImGui_ImplGlfw_Data* bd = ImGui_ImplGlfw_GetBackendData();
+    if (msg == WM_NCHITTEST)
+    {
+        // Let mouse pass-through the window. This will allow the backend to call io.AddMouseViewportEvent() properly (which is OPTIONAL).
+        // The ImGuiViewportFlags_NoInputs flag is set while dragging a viewport, as want to detect the window behind the one we are dragging.
+        // If you cannot easily access those viewport flags from your windowing/event code: you may manually synchronize its state e.g. in
+        // your main loop after calling UpdatePlatformWindows(). Iterate all viewports/platform windows and pass the flag to your windowing system.
+        ImGuiViewport* viewport = (ImGuiViewport*)::GetPropA(hWnd, "IMGUI_VIEWPORT");
+        if (viewport->Flags & ImGuiViewportFlags_NoInputs)
+            return HTTRANSPARENT;
+    }
+    return ::CallWindowProc(bd->GlfwWndProc, hWnd, msg, wParam, lParam);
+}
+#endif
+
+static void ImGui_ImplGlfw_ShowWindow(ImGuiViewport* viewport)
+{
+    ImGui_ImplGlfw_ViewportData* vd = (ImGui_ImplGlfw_ViewportData*)viewport->PlatformUserData;
+
+#if defined(_WIN32)
+    // GLFW hack: Hide icon from task bar
+    HWND hwnd = (HWND)viewport->PlatformHandleRaw;
+    if (viewport->Flags & ImGuiViewportFlags_NoTaskBarIcon)
+    {
+        LONG ex_style = ::GetWindowLong(hwnd, GWL_EXSTYLE);
+        ex_style &= ~WS_EX_APPWINDOW;
+        ex_style |= WS_EX_TOOLWINDOW;
+        ::SetWindowLong(hwnd, GWL_EXSTYLE, ex_style);
+    }
+
+    // GLFW hack: install hook for WM_NCHITTEST message handler
+#if !GLFW_HAS_MOUSE_PASSTHROUGH && GLFW_HAS_WINDOW_HOVERED && defined(_WIN32)
+    ImGui_ImplGlfw_Data* bd = ImGui_ImplGlfw_GetBackendData();
+    ::SetPropA(hwnd, "IMGUI_VIEWPORT", viewport);
+    if (bd->GlfwWndProc == nullptr)
+        bd->GlfwWndProc = (WNDPROC)::GetWindowLongPtr(hwnd, GWLP_WNDPROC);
+    ::SetWindowLongPtr(hwnd, GWLP_WNDPROC, (LONG_PTR)WndProcNoInputs);
+#endif
+
+#if !GLFW_HAS_FOCUS_ON_SHOW
+    // GLFW hack: GLFW 3.2 has a bug where glfwShowWindow() also activates/focus the window.
+    // The fix was pushed to GLFW repository on 2018/01/09 and should be included in GLFW 3.3 via a GLFW_FOCUS_ON_SHOW window attribute.
+    // See https://github.com/glfw/glfw/issues/1189
+    // FIXME-VIEWPORT: Implement same work-around for Linux/OSX in the meanwhile.
+    if (viewport->Flags & ImGuiViewportFlags_NoFocusOnAppearing)
+    {
+        ::ShowWindow(hwnd, SW_SHOWNA);
+        return;
+    }
+#endif
+#endif
+
+    glfwShowWindow(vd->Window);
+}
+
+static ImVec2 ImGui_ImplGlfw_GetWindowPos(ImGuiViewport* viewport)
+{
+    ImGui_ImplGlfw_ViewportData* vd = (ImGui_ImplGlfw_ViewportData*)viewport->PlatformUserData;
+    int x = 0, y = 0;
+    glfwGetWindowPos(vd->Window, &x, &y);
+    return ImVec2((float)x, (float)y);
+}
+
+static void ImGui_ImplGlfw_SetWindowPos(ImGuiViewport* viewport, ImVec2 pos)
+{
+    ImGui_ImplGlfw_ViewportData* vd = (ImGui_ImplGlfw_ViewportData*)viewport->PlatformUserData;
+    vd->IgnoreWindowPosEventFrame = ImGui::GetFrameCount();
+    glfwSetWindowPos(vd->Window, (int)pos.x, (int)pos.y);
+}
+
+static ImVec2 ImGui_ImplGlfw_GetWindowSize(ImGuiViewport* viewport)
+{
+    ImGui_ImplGlfw_ViewportData* vd = (ImGui_ImplGlfw_ViewportData*)viewport->PlatformUserData;
+    int w = 0, h = 0;
+    glfwGetWindowSize(vd->Window, &w, &h);
+    return ImVec2((float)w, (float)h);
+}
+
+static void ImGui_ImplGlfw_SetWindowSize(ImGuiViewport* viewport, ImVec2 size)
+{
+    ImGui_ImplGlfw_ViewportData* vd = (ImGui_ImplGlfw_ViewportData*)viewport->PlatformUserData;
+#if __APPLE__ && !GLFW_HAS_OSX_WINDOW_POS_FIX
+    // Native OS windows are positioned from the bottom-left corner on macOS, whereas on other platforms they are
+    // positioned from the upper-left corner. GLFW makes an effort to convert macOS style coordinates, however it
+    // doesn't handle it when changing size. We are manually moving the window in order for changes of size to be based
+    // on the upper-left corner.
+    int x, y, width, height;
+    glfwGetWindowPos(vd->Window, &x, &y);
+    glfwGetWindowSize(vd->Window, &width, &height);
+    glfwSetWindowPos(vd->Window, x, y - height + size.y);
+#endif
+    vd->IgnoreWindowSizeEventFrame = ImGui::GetFrameCount();
+    glfwSetWindowSize(vd->Window, (int)size.x, (int)size.y);
+}
+
+static void ImGui_ImplGlfw_SetWindowTitle(ImGuiViewport* viewport, const char* title)
+{
+    ImGui_ImplGlfw_ViewportData* vd = (ImGui_ImplGlfw_ViewportData*)viewport->PlatformUserData;
+    glfwSetWindowTitle(vd->Window, title);
+}
+
+static void ImGui_ImplGlfw_SetWindowFocus(ImGuiViewport* viewport)
+{
+#if GLFW_HAS_FOCUS_WINDOW
+    ImGui_ImplGlfw_ViewportData* vd = (ImGui_ImplGlfw_ViewportData*)viewport->PlatformUserData;
+    glfwFocusWindow(vd->Window);
+#else
+    // FIXME: What are the effect of not having this function? At the moment imgui doesn't actually call SetWindowFocus - we set that up ahead, will answer that question later.
+    (void)viewport;
+#endif
+}
+
+static bool ImGui_ImplGlfw_GetWindowFocus(ImGuiViewport* viewport)
+{
+    ImGui_ImplGlfw_ViewportData* vd = (ImGui_ImplGlfw_ViewportData*)viewport->PlatformUserData;
+    return glfwGetWindowAttrib(vd->Window, GLFW_FOCUSED) != 0;
+}
+
+static bool ImGui_ImplGlfw_GetWindowMinimized(ImGuiViewport* viewport)
+{
+    ImGui_ImplGlfw_ViewportData* vd = (ImGui_ImplGlfw_ViewportData*)viewport->PlatformUserData;
+    return glfwGetWindowAttrib(vd->Window, GLFW_ICONIFIED) != 0;
+}
+
+#if GLFW_HAS_WINDOW_ALPHA
+static void ImGui_ImplGlfw_SetWindowAlpha(ImGuiViewport* viewport, float alpha)
+{
+    ImGui_ImplGlfw_ViewportData* vd = (ImGui_ImplGlfw_ViewportData*)viewport->PlatformUserData;
+    glfwSetWindowOpacity(vd->Window, alpha);
+}
+#endif
+
+static void ImGui_ImplGlfw_RenderWindow(ImGuiViewport* viewport, void*)
+{
+    ImGui_ImplGlfw_Data* bd = ImGui_ImplGlfw_GetBackendData();
+    ImGui_ImplGlfw_ViewportData* vd = (ImGui_ImplGlfw_ViewportData*)viewport->PlatformUserData;
+    if (bd->ClientApi == GlfwClientApi_OpenGL)
+        glfwMakeContextCurrent(vd->Window);
+}
+
+static void ImGui_ImplGlfw_SwapBuffers(ImGuiViewport* viewport, void*)
+{
+    ImGui_ImplGlfw_Data* bd = ImGui_ImplGlfw_GetBackendData();
+    ImGui_ImplGlfw_ViewportData* vd = (ImGui_ImplGlfw_ViewportData*)viewport->PlatformUserData;
+    if (bd->ClientApi == GlfwClientApi_OpenGL)
+    {
+        glfwMakeContextCurrent(vd->Window);
+        glfwSwapBuffers(vd->Window);
+    }
+}
+
+//--------------------------------------------------------------------------------------------------------
+// Vulkan support (the Vulkan renderer needs to call a platform-side support function to create the surface)
+//--------------------------------------------------------------------------------------------------------
+
+// Avoid including <vulkan.h> so we can build without it
+#if GLFW_HAS_VULKAN
+#ifndef VULKAN_H_
+#define VK_DEFINE_HANDLE(object) typedef struct object##_T* object;
+#if defined(__LP64__) || defined(_WIN64) || defined(__x86_64__) || defined(_M_X64) || defined(__ia64) || defined (_M_IA64) || defined(__aarch64__) || defined(__powerpc64__)
+#define VK_DEFINE_NON_DISPATCHABLE_HANDLE(object) typedef struct object##_T *object;
+#else
+#define VK_DEFINE_NON_DISPATCHABLE_HANDLE(object) typedef uint64_t object;
+#endif
+VK_DEFINE_HANDLE(VkInstance)
+VK_DEFINE_NON_DISPATCHABLE_HANDLE(VkSurfaceKHR)
+struct VkAllocationCallbacks;
+enum VkResult { VK_RESULT_MAX_ENUM = 0x7FFFFFFF };
+#endif // VULKAN_H_
+extern "C" { extern GLFWAPI VkResult glfwCreateWindowSurface(VkInstance instance, GLFWwindow* window, const VkAllocationCallbacks* allocator, VkSurfaceKHR* surface); }
+static int ImGui_ImplGlfw_CreateVkSurface(ImGuiViewport* viewport, ImU64 vk_instance, const void* vk_allocator, ImU64* out_vk_surface)
+{
+    ImGui_ImplGlfw_Data* bd = ImGui_ImplGlfw_GetBackendData();
+    ImGui_ImplGlfw_ViewportData* vd = (ImGui_ImplGlfw_ViewportData*)viewport->PlatformUserData;
+    IM_UNUSED(bd);
+    IM_ASSERT(bd->ClientApi == GlfwClientApi_Vulkan);
+    VkResult err = glfwCreateWindowSurface((VkInstance)vk_instance, vd->Window, (const VkAllocationCallbacks*)vk_allocator, (VkSurfaceKHR*)out_vk_surface);
+    return (int)err;
+}
+#endif // GLFW_HAS_VULKAN
+
+static void ImGui_ImplGlfw_InitPlatformInterface()
+{
+    // Register platform interface (will be coupled with a renderer interface)
+    ImGui_ImplGlfw_Data* bd = ImGui_ImplGlfw_GetBackendData();
+    ImGuiPlatformIO& platform_io = ImGui::GetPlatformIO();
+    platform_io.Platform_CreateWindow = ImGui_ImplGlfw_CreateWindow;
+    platform_io.Platform_DestroyWindow = ImGui_ImplGlfw_DestroyWindow;
+    platform_io.Platform_ShowWindow = ImGui_ImplGlfw_ShowWindow;
+    platform_io.Platform_SetWindowPos = ImGui_ImplGlfw_SetWindowPos;
+    platform_io.Platform_GetWindowPos = ImGui_ImplGlfw_GetWindowPos;
+    platform_io.Platform_SetWindowSize = ImGui_ImplGlfw_SetWindowSize;
+    platform_io.Platform_GetWindowSize = ImGui_ImplGlfw_GetWindowSize;
+    platform_io.Platform_SetWindowFocus = ImGui_ImplGlfw_SetWindowFocus;
+    platform_io.Platform_GetWindowFocus = ImGui_ImplGlfw_GetWindowFocus;
+    platform_io.Platform_GetWindowMinimized = ImGui_ImplGlfw_GetWindowMinimized;
+    platform_io.Platform_SetWindowTitle = ImGui_ImplGlfw_SetWindowTitle;
+    platform_io.Platform_RenderWindow = ImGui_ImplGlfw_RenderWindow;
+    platform_io.Platform_SwapBuffers = ImGui_ImplGlfw_SwapBuffers;
+#if GLFW_HAS_WINDOW_ALPHA
+    platform_io.Platform_SetWindowAlpha = ImGui_ImplGlfw_SetWindowAlpha;
+#endif
+#if GLFW_HAS_VULKAN
+    platform_io.Platform_CreateVkSurface = ImGui_ImplGlfw_CreateVkSurface;
+#endif
+
+    // Register main window handle (which is owned by the main application, not by us)
+    // This is mostly for simplicity and consistency, so that our code (e.g. mouse handling etc.) can use same logic for main and secondary viewports.
+    ImGuiViewport* main_viewport = ImGui::GetMainViewport();
+    ImGui_ImplGlfw_ViewportData* vd = IM_NEW(ImGui_ImplGlfw_ViewportData)();
+    vd->Window = bd->Window;
+    vd->WindowOwned = false;
+    main_viewport->PlatformUserData = vd;
+    main_viewport->PlatformHandle = (void*)bd->Window;
+}
+
+static void ImGui_ImplGlfw_ShutdownPlatformInterface()
+{
+    ImGui::DestroyPlatformWindows();
+}
+
 #if defined(__clang__)
 #pragma clang diagnostic pop
 #endif

includes/imgui/backends/imgui_impl_glfw.h

@@ -1,12 +1,17 @@
 // dear imgui: Platform Backend for GLFW
 // This needs to be used along with a Renderer (e.g. OpenGL3, Vulkan, WebGPU..)
 // (Info: GLFW is a cross-platform general purpose library for handling windows, inputs, OpenGL/Vulkan graphics context creation, etc.)
+// (Requires: GLFW 3.1+. Prefer GLFW 3.3+ for full feature support.)
 
 // Implemented features:
 //  [X] Platform: Clipboard support.
 //  [X] Platform: Keyboard support. Since 1.87 we are using the io.AddKeyEvent() function. Pass ImGuiKey values to all key functions e.g. ImGui::IsKeyPressed(ImGuiKey_Space). [Legacy GLFW_KEY_* values will also be supported unless IMGUI_DISABLE_OBSOLETE_KEYIO is set]
 //  [X] Platform: Gamepad support. Enable with 'io.ConfigFlags |= ImGuiConfigFlags_NavEnableGamepad'.
-//  [X] Platform: Mouse cursor shape and visibility. Disable with 'io.ConfigFlags |= ImGuiConfigFlags_NoMouseCursorChange' (note: the resizing cursors requires GLFW 3.4+).
+//  [x] Platform: Mouse cursor shape and visibility. Disable with 'io.ConfigFlags |= ImGuiConfigFlags_NoMouseCursorChange' (note: the resizing cursors requires GLFW 3.4+).
+//  [X] Platform: Multi-viewport support (multiple windows). Enable with 'io.ConfigFlags |= ImGuiConfigFlags_ViewportsEnable'.
+
+// Issues:
+//  [ ] Platform: Multi-viewport support: ParentViewportID not honored, and so io.ConfigViewportsNoDefaultParent has no effect (minor).
 
 // You can use unmodified imgui_impl_* files in your project. See examples/ folder for examples of using this.
 // Prefer including the entire imgui/ repository into your project (either as a copy or as a submodule), and only build the backends you need.

includes/imgui/backends/imgui_impl_opengl3.cpp

@@ -0,0 +1,921 @@
+// dear imgui: Renderer Backend for modern OpenGL with shaders / programmatic pipeline
+// - Desktop GL: 2.x 3.x 4.x
+// - Embedded GL: ES 2.0 (WebGL 1.0), ES 3.0 (WebGL 2.0)
+// This needs to be used along with a Platform Backend (e.g. GLFW, SDL, Win32, custom..)
+
+// Implemented features:
+//  [X] Renderer: User texture binding. Use 'GLuint' OpenGL texture identifier as void*/ImTextureID. Read the FAQ about ImTextureID!
+//  [X] Renderer: Multi-viewport support (multiple windows). Enable with 'io.ConfigFlags |= ImGuiConfigFlags_ViewportsEnable'.
+//  [x] Renderer: Large meshes support (64k+ vertices) with 16-bit indices (Desktop OpenGL only).
+
+// You can use unmodified imgui_impl_* files in your project. See examples/ folder for examples of using this.
+// Prefer including the entire imgui/ repository into your project (either as a copy or as a submodule), and only build the backends you need.
+// If you are new to Dear ImGui, read documentation from the docs/ folder + read the top of imgui.cpp.
+// Read online: https://github.com/ocornut/imgui/tree/master/docs
+
+// CHANGELOG
+// (minor and older changes stripped away, please see git history for details)
+//  2022-XX-XX: Platform: Added support for multiple windows via the ImGuiPlatformIO interface.
+//  2022-10-11: Using 'nullptr' instead of 'NULL' as per our switch to C++11.
+//  2022-09-27: OpenGL: Added ability to '#define IMGUI_IMPL_OPENGL_DEBUG'.
+//  2022-05-23: OpenGL: Reworking 2021-12-15 "Using buffer orphaning" so it only happens on Intel GPU, seems to cause problems otherwise. (#4468, #4825, #4832, #5127).
+//  2022-05-13: OpenGL: Fix state corruption on OpenGL ES 2.0 due to not preserving GL_ELEMENT_ARRAY_BUFFER_BINDING and vertex attribute states.
+//  2021-12-15: OpenGL: Using buffer orphaning + glBufferSubData(), seems to fix leaks with multi-viewports with some Intel HD drivers.
+//  2021-08-23: OpenGL: Fixed ES 3.0 shader ("#version 300 es") use normal precision floats to avoid wobbly rendering at HD resolutions.
+//  2021-08-19: OpenGL: Embed and use our own minimal GL loader (imgui_impl_opengl3_loader.h), removing requirement and support for third-party loader.
+//  2021-06-29: Reorganized backend to pull data from a single structure to facilitate usage with multiple-contexts (all g_XXXX access changed to bd->XXXX).
+//  2021-06-25: OpenGL: Use OES_vertex_array extension on Emscripten + backup/restore current state.
+//  2021-06-21: OpenGL: Destroy individual vertex/fragment shader objects right after they are linked into the main shader.
+//  2021-05-24: OpenGL: Access GL_CLIP_ORIGIN when "GL_ARB_clip_control" extension is detected, inside of just OpenGL 4.5 version.
+//  2021-05-19: OpenGL: Replaced direct access to ImDrawCmd::TextureId with a call to ImDrawCmd::GetTexID(). (will become a requirement)
+//  2021-04-06: OpenGL: Don't try to read GL_CLIP_ORIGIN unless we're OpenGL 4.5 or greater.
+//  2021-02-18: OpenGL: Change blending equation to preserve alpha in output buffer.
+//  2021-01-03: OpenGL: Backup, setup and restore GL_STENCIL_TEST state.
+//  2020-10-23: OpenGL: Backup, setup and restore GL_PRIMITIVE_RESTART state.
+//  2020-10-15: OpenGL: Use glGetString(GL_VERSION) instead of glGetIntegerv(GL_MAJOR_VERSION, ...) when the later returns zero (e.g. Desktop GL 2.x)
+//  2020-09-17: OpenGL: Fix to avoid compiling/calling glBindSampler() on ES or pre 3.3 context which have the defines set by a loader.
+//  2020-07-10: OpenGL: Added support for glad2 OpenGL loader.
+//  2020-05-08: OpenGL: Made default GLSL version 150 (instead of 130) on OSX.
+//  2020-04-21: OpenGL: Fixed handling of glClipControl(GL_UPPER_LEFT) by inverting projection matrix.
+//  2020-04-12: OpenGL: Fixed context version check mistakenly testing for 4.0+ instead of 3.2+ to enable ImGuiBackendFlags_RendererHasVtxOffset.
+//  2020-03-24: OpenGL: Added support for glbinding 2.x OpenGL loader.
+//  2020-01-07: OpenGL: Added support for glbinding 3.x OpenGL loader.
+//  2019-10-25: OpenGL: Using a combination of GL define and runtime GL version to decide whether to use glDrawElementsBaseVertex(). Fix building with pre-3.2 GL loaders.
+//  2019-09-22: OpenGL: Detect default GL loader using __has_include compiler facility.
+//  2019-09-16: OpenGL: Tweak initialization code to allow application calling ImGui_ImplOpenGL3_CreateFontsTexture() before the first NewFrame() call.
+//  2019-05-29: OpenGL: Desktop GL only: Added support for large mesh (64K+ vertices), enable ImGuiBackendFlags_RendererHasVtxOffset flag.
+//  2019-04-30: OpenGL: Added support for special ImDrawCallback_ResetRenderState callback to reset render state.
+//  2019-03-29: OpenGL: Not calling glBindBuffer more than necessary in the render loop.
+//  2019-03-15: OpenGL: Added a GL call + comments in ImGui_ImplOpenGL3_Init() to detect uninitialized GL function loaders early.
+//  2019-03-03: OpenGL: Fix support for ES 2.0 (WebGL 1.0).
+//  2019-02-20: OpenGL: Fix for OSX not supporting OpenGL 4.5, we don't try to read GL_CLIP_ORIGIN even if defined by the headers/loader.
+//  2019-02-11: OpenGL: Projecting clipping rectangles correctly using draw_data->FramebufferScale to allow multi-viewports for retina display.
+//  2019-02-01: OpenGL: Using GLSL 410 shaders for any version over 410 (e.g. 430, 450).
+//  2018-11-30: Misc: Setting up io.BackendRendererName so it can be displayed in the About Window.
+//  2018-11-13: OpenGL: Support for GL 4.5's glClipControl(GL_UPPER_LEFT) / GL_CLIP_ORIGIN.
+//  2018-08-29: OpenGL: Added support for more OpenGL loaders: glew and glad, with comments indicative that any loader can be used.
+//  2018-08-09: OpenGL: Default to OpenGL ES 3 on iOS and Android. GLSL version default to "#version 300 ES".
+//  2018-07-30: OpenGL: Support for GLSL 300 ES and 410 core. Fixes for Emscripten compilation.
+//  2018-07-10: OpenGL: Support for more GLSL versions (based on the GLSL version string). Added error output when shaders fail to compile/link.
+//  2018-06-08: Misc: Extracted imgui_impl_opengl3.cpp/.h away from the old combined GLFW/SDL+OpenGL3 examples.
+//  2018-06-08: OpenGL: Use draw_data->DisplayPos and draw_data->DisplaySize to setup projection matrix and clipping rectangle.
+//  2018-05-25: OpenGL: Removed unnecessary backup/restore of GL_ELEMENT_ARRAY_BUFFER_BINDING since this is part of the VAO state.
+//  2018-05-14: OpenGL: Making the call to glBindSampler() optional so 3.2 context won't fail if the function is a nullptr pointer.
+//  2018-03-06: OpenGL: Added const char* glsl_version parameter to ImGui_ImplOpenGL3_Init() so user can override the GLSL version e.g. "#version 150".
+//  2018-02-23: OpenGL: Create the VAO in the render function so the setup can more easily be used with multiple shared GL context.
+//  2018-02-16: Misc: Obsoleted the io.RenderDrawListsFn callback and exposed ImGui_ImplSdlGL3_RenderDrawData() in the .h file so you can call it yourself.
+//  2018-01-07: OpenGL: Changed GLSL shader version from 330 to 150.
+//  2017-09-01: OpenGL: Save and restore current bound sampler. Save and restore current polygon mode.
+//  2017-05-01: OpenGL: Fixed save and restore of current blend func state.
+//  2017-05-01: OpenGL: Fixed save and restore of current GL_ACTIVE_TEXTURE.
+//  2016-09-05: OpenGL: Fixed save and restore of current scissor rectangle.
+//  2016-07-29: OpenGL: Explicitly setting GL_UNPACK_ROW_LENGTH to reduce issues because SDL changes it. (#752)
+
+//----------------------------------------
+// OpenGL    GLSL      GLSL
+// version   version   string
+//----------------------------------------
+//  2.0       110       "#version 110"
+//  2.1       120       "#version 120"
+//  3.0       130       "#version 130"
+//  3.1       140       "#version 140"
+//  3.2       150       "#version 150"
+//  3.3       330       "#version 330 core"
+//  4.0       400       "#version 400 core"
+//  4.1       410       "#version 410 core"
+//  4.2       420       "#version 410 core"
+//  4.3       430       "#version 430 core"
+//  ES 2.0    100       "#version 100"      = WebGL 1.0
+//  ES 3.0    300       "#version 300 es"   = WebGL 2.0
+//----------------------------------------
+
+#if defined(_MSC_VER) && !defined(_CRT_SECURE_NO_WARNINGS)
+#define _CRT_SECURE_NO_WARNINGS
+#endif
+
+#include "imgui.h"
+#include "imgui_impl_opengl3.h"
+#include <stdio.h>
+#if defined(_MSC_VER) && _MSC_VER <= 1500 // MSVC 2008 or earlier
+#include <stddef.h>     // intptr_t
+#else
+#include <stdint.h>     // intptr_t
+#endif
+#if defined(__APPLE__)
+#include <TargetConditionals.h>
+#endif
+
+// Clang warnings with -Weverything
+#if defined(__clang__)
+#pragma clang diagnostic push
+#pragma clang diagnostic ignored "-Wold-style-cast"     // warning: use of old-style cast
+#pragma clang diagnostic ignored "-Wsign-conversion"    // warning: implicit conversion changes signedness
+#endif
+
+// GL includes
+#if defined(IMGUI_IMPL_OPENGL_ES2)
+#if (defined(__APPLE__) && (TARGET_OS_IOS || TARGET_OS_TV))
+#include <OpenGLES/ES2/gl.h>    // Use GL ES 2
+#else
+#include <GLES2/gl2.h>          // Use GL ES 2
+#endif
+#if defined(__EMSCRIPTEN__)
+#ifndef GL_GLEXT_PROTOTYPES
+#define GL_GLEXT_PROTOTYPES
+#endif
+#include <GLES2/gl2ext.h>
+#endif
+#elif defined(IMGUI_IMPL_OPENGL_ES3)
+#if (defined(__APPLE__) && (TARGET_OS_IOS || TARGET_OS_TV))
+#include <OpenGLES/ES3/gl.h>    // Use GL ES 3
+#else
+#include <GLES3/gl3.h>          // Use GL ES 3
+#endif
+#elif !defined(IMGUI_IMPL_OPENGL_LOADER_CUSTOM)
+// Modern desktop OpenGL doesn't have a standard portable header file to load OpenGL function pointers.
+// Helper libraries are often used for this purpose! Here we are using our own minimal custom loader based on gl3w.
+// In the rest of your app/engine, you can use another loader of your choice (gl3w, glew, glad, glbinding, glext, glLoadGen, etc.).
+// If you happen to be developing a new feature for this backend (imgui_impl_opengl3.cpp):
+// - You may need to regenerate imgui_impl_opengl3_loader.h to add new symbols. See https://github.com/dearimgui/gl3w_stripped
+// - You can temporarily use an unstripped version. See https://github.com/dearimgui/gl3w_stripped/releases
+// Changes to this backend using new APIs should be accompanied by a regenerated stripped loader version.
+#define IMGL3W_IMPL
+#include "imgui_impl_opengl3_loader.h"
+#endif
+
+// Vertex arrays are not supported on ES2/WebGL1 unless Emscripten which uses an extension
+#ifndef IMGUI_IMPL_OPENGL_ES2
+#define IMGUI_IMPL_OPENGL_USE_VERTEX_ARRAY
+#elif defined(__EMSCRIPTEN__)
+#define IMGUI_IMPL_OPENGL_USE_VERTEX_ARRAY
+#define glBindVertexArray       glBindVertexArrayOES
+#define glGenVertexArrays       glGenVertexArraysOES
+#define glDeleteVertexArrays    glDeleteVertexArraysOES
+#define GL_VERTEX_ARRAY_BINDING GL_VERTEX_ARRAY_BINDING_OES
+#endif
+
+// Desktop GL 2.0+ has glPolygonMode() which GL ES and WebGL don't have.
+#ifdef GL_POLYGON_MODE
+#define IMGUI_IMPL_HAS_POLYGON_MODE
+#endif
+
+// Desktop GL 3.2+ has glDrawElementsBaseVertex() which GL ES and WebGL don't have.
+#if !defined(IMGUI_IMPL_OPENGL_ES2) && !defined(IMGUI_IMPL_OPENGL_ES3) && defined(GL_VERSION_3_2)
+#define IMGUI_IMPL_OPENGL_MAY_HAVE_VTX_OFFSET
+#endif
+
+// Desktop GL 3.3+ has glBindSampler()
+#if !defined(IMGUI_IMPL_OPENGL_ES2) && !defined(IMGUI_IMPL_OPENGL_ES3) && defined(GL_VERSION_3_3)
+#define IMGUI_IMPL_OPENGL_MAY_HAVE_BIND_SAMPLER
+#endif
+
+// Desktop GL 3.1+ has GL_PRIMITIVE_RESTART state
+#if !defined(IMGUI_IMPL_OPENGL_ES2) && !defined(IMGUI_IMPL_OPENGL_ES3) && defined(GL_VERSION_3_1)
+#define IMGUI_IMPL_OPENGL_MAY_HAVE_PRIMITIVE_RESTART
+#endif
+
+// Desktop GL use extension detection
+#if !defined(IMGUI_IMPL_OPENGL_ES2) && !defined(IMGUI_IMPL_OPENGL_ES3)
+#define IMGUI_IMPL_OPENGL_MAY_HAVE_EXTENSIONS
+#endif
+
+// [Debugging]
+//#define IMGUI_IMPL_OPENGL_DEBUG
+#ifdef IMGUI_IMPL_OPENGL_DEBUG
+#include <stdio.h>
+#define GL_CALL(_CALL)      do { _CALL; GLenum gl_err = glGetError(); if (gl_err != 0) fprintf(stderr, "GL error 0x%x returned from '%s'.\n", gl_err, #_CALL); } while (0)  // Call with error check
+#else
+#define GL_CALL(_CALL)      _CALL   // Call without error check
+#endif
+
+// OpenGL Data
+struct ImGui_ImplOpenGL3_Data
+{
+    GLuint          GlVersion;               // Extracted at runtime using GL_MAJOR_VERSION, GL_MINOR_VERSION queries (e.g. 320 for GL 3.2)
+    char            GlslVersionString[32];   // Specified by user or detected based on compile time GL settings.
+    GLuint          FontTexture;
+    GLuint          ShaderHandle;
+    GLint           AttribLocationTex;       // Uniforms location
+    GLint           AttribLocationProjMtx;
+    GLuint          AttribLocationVtxPos;    // Vertex attributes location
+    GLuint          AttribLocationVtxUV;
+    GLuint          AttribLocationVtxColor;
+    unsigned int    VboHandle, ElementsHandle;
+    GLsizeiptr      VertexBufferSize;
+    GLsizeiptr      IndexBufferSize;
+    bool            HasClipOrigin;
+    bool            UseBufferSubData;
+
+    ImGui_ImplOpenGL3_Data() { memset((void*)this, 0, sizeof(*this)); }
+};
+
+// Backend data stored in io.BackendRendererUserData to allow support for multiple Dear ImGui contexts
+// It is STRONGLY preferred that you use docking branch with multi-viewports (== single Dear ImGui context + multiple windows) instead of multiple Dear ImGui contexts.
+static ImGui_ImplOpenGL3_Data* ImGui_ImplOpenGL3_GetBackendData()
+{
+    return ImGui::GetCurrentContext() ? (ImGui_ImplOpenGL3_Data*)ImGui::GetIO().BackendRendererUserData : nullptr;
+}
+
+// Forward Declarations
+static void ImGui_ImplOpenGL3_InitPlatformInterface();
+static void ImGui_ImplOpenGL3_ShutdownPlatformInterface();
+
+// OpenGL vertex attribute state (for ES 1.0 and ES 2.0 only)
+#ifndef IMGUI_IMPL_OPENGL_USE_VERTEX_ARRAY
+struct ImGui_ImplOpenGL3_VtxAttribState
+{
+    GLint   Enabled, Size, Type, Normalized, Stride;
+    GLvoid* Ptr;
+
+    void GetState(GLint index)
+    {
+        glGetVertexAttribiv(index, GL_VERTEX_ATTRIB_ARRAY_ENABLED, &Enabled);
+        glGetVertexAttribiv(index, GL_VERTEX_ATTRIB_ARRAY_SIZE, &Size);
+        glGetVertexAttribiv(index, GL_VERTEX_ATTRIB_ARRAY_TYPE, &Type);
+        glGetVertexAttribiv(index, GL_VERTEX_ATTRIB_ARRAY_NORMALIZED, &Normalized);
+        glGetVertexAttribiv(index, GL_VERTEX_ATTRIB_ARRAY_STRIDE, &Stride);
+        glGetVertexAttribPointerv(index, GL_VERTEX_ATTRIB_ARRAY_POINTER, &Ptr);
+    }
+    void SetState(GLint index)
+    {
+        glVertexAttribPointer(index, Size, Type, (GLboolean)Normalized, Stride, Ptr);
+        if (Enabled) glEnableVertexAttribArray(index); else glDisableVertexAttribArray(index);
+    }
+};
+#endif
+
+// Functions
+bool    ImGui_ImplOpenGL3_Init(const char* glsl_version)
+{
+    ImGuiIO& io = ImGui::GetIO();
+    IM_ASSERT(io.BackendRendererUserData == nullptr && "Already initialized a renderer backend!");
+
+    // Initialize our loader
+#if !defined(IMGUI_IMPL_OPENGL_ES2) && !defined(IMGUI_IMPL_OPENGL_ES3) && !defined(IMGUI_IMPL_OPENGL_LOADER_CUSTOM)
+    if (imgl3wInit() != 0)
+    {
+        fprintf(stderr, "Failed to initialize OpenGL loader!\n");
+        return false;
+    }
+#endif
+
+    // Setup backend capabilities flags
+    ImGui_ImplOpenGL3_Data* bd = IM_NEW(ImGui_ImplOpenGL3_Data)();
+    io.BackendRendererUserData = (void*)bd;
+    io.BackendRendererName = "imgui_impl_opengl3";
+
+    // Query for GL version (e.g. 320 for GL 3.2)
+#if !defined(IMGUI_IMPL_OPENGL_ES2)
+    GLint major = 0;
+    GLint minor = 0;
+    glGetIntegerv(GL_MAJOR_VERSION, &major);
+    glGetIntegerv(GL_MINOR_VERSION, &minor);
+    if (major == 0 && minor == 0)
+    {
+        // Query GL_VERSION in desktop GL 2.x, the string will start with "<major>.<minor>"
+        const char* gl_version = (const char*)glGetString(GL_VERSION);
+        sscanf(gl_version, "%d.%d", &major, &minor);
+    }
+    bd->GlVersion = (GLuint)(major * 100 + minor * 10);
+
+    // Query vendor to enable glBufferSubData kludge
+#ifdef _WIN32
+    if (const char* vendor = (const char*)glGetString(GL_VENDOR))
+        if (strncmp(vendor, "Intel", 5) == 0)
+            bd->UseBufferSubData = true;
+#endif
+#else
+    bd->GlVersion = 200; // GLES 2
+#endif
+
+#ifdef IMGUI_IMPL_OPENGL_DEBUG
+    printf("GL_MAJOR_VERSION = %d\nGL_MINOR_VERSION = %d\nGL_VENDOR = '%s'\nGL_RENDERER = '%s'\n", major, minor, (const char*)glGetString(GL_VENDOR), (const char*)glGetString(GL_RENDERER)); // [DEBUG]
+#endif
+
+#ifdef IMGUI_IMPL_OPENGL_MAY_HAVE_VTX_OFFSET
+    if (bd->GlVersion >= 320)
+        io.BackendFlags |= ImGuiBackendFlags_RendererHasVtxOffset;  // We can honor the ImDrawCmd::VtxOffset field, allowing for large meshes.
+#endif
+    io.BackendFlags |= ImGuiBackendFlags_RendererHasViewports;  // We can create multi-viewports on the Renderer side (optional)
+
+    // Store GLSL version string so we can refer to it later in case we recreate shaders.
+    // Note: GLSL version is NOT the same as GL version. Leave this to nullptr if unsure.
+    if (glsl_version == nullptr)
+    {
+#if defined(IMGUI_IMPL_OPENGL_ES2)
+        glsl_version = "#version 100";
+#elif defined(IMGUI_IMPL_OPENGL_ES3)
+        glsl_version = "#version 300 es";
+#elif defined(__APPLE__)
+        glsl_version = "#version 150";
+#else
+        glsl_version = "#version 130";
+#endif
+    }
+    IM_ASSERT((int)strlen(glsl_version) + 2 < IM_ARRAYSIZE(bd->GlslVersionString));
+    strcpy(bd->GlslVersionString, glsl_version);
+    strcat(bd->GlslVersionString, "\n");
+
+    // Make an arbitrary GL call (we don't actually need the result)
+    // IF YOU GET A CRASH HERE: it probably means the OpenGL function loader didn't do its job. Let us know!
+    GLint current_texture;
+    glGetIntegerv(GL_TEXTURE_BINDING_2D, &current_texture);
+
+    // Detect extensions we support
+    bd->HasClipOrigin = (bd->GlVersion >= 450);
+#ifdef IMGUI_IMPL_OPENGL_MAY_HAVE_EXTENSIONS
+    GLint num_extensions = 0;
+    glGetIntegerv(GL_NUM_EXTENSIONS, &num_extensions);
+    for (GLint i = 0; i < num_extensions; i++)
+    {
+        const char* extension = (const char*)glGetStringi(GL_EXTENSIONS, i);
+        if (extension != nullptr && strcmp(extension, "GL_ARB_clip_control") == 0)
+            bd->HasClipOrigin = true;
+    }
+#endif
+
+    if (io.ConfigFlags & ImGuiConfigFlags_ViewportsEnable)
+        ImGui_ImplOpenGL3_InitPlatformInterface();
+
+    return true;
+}
+
+void    ImGui_ImplOpenGL3_Shutdown()
+{
+    ImGui_ImplOpenGL3_Data* bd = ImGui_ImplOpenGL3_GetBackendData();
+    IM_ASSERT(bd != nullptr && "No renderer backend to shutdown, or already shutdown?");
+    ImGuiIO& io = ImGui::GetIO();
+
+    ImGui_ImplOpenGL3_ShutdownPlatformInterface();
+    ImGui_ImplOpenGL3_DestroyDeviceObjects();
+    io.BackendRendererName = nullptr;
+    io.BackendRendererUserData = nullptr;
+    IM_DELETE(bd);
+}
+
+void    ImGui_ImplOpenGL3_NewFrame()
+{
+    ImGui_ImplOpenGL3_Data* bd = ImGui_ImplOpenGL3_GetBackendData();
+    IM_ASSERT(bd != nullptr && "Did you call ImGui_ImplOpenGL3_Init()?");
+
+    if (!bd->ShaderHandle)
+        ImGui_ImplOpenGL3_CreateDeviceObjects();
+}
+
+static void ImGui_ImplOpenGL3_SetupRenderState(ImDrawData* draw_data, int fb_width, int fb_height, GLuint vertex_array_object)
+{
+    ImGui_ImplOpenGL3_Data* bd = ImGui_ImplOpenGL3_GetBackendData();
+
+    // Setup render state: alpha-blending enabled, no face culling, no depth testing, scissor enabled, polygon fill
+    glEnable(GL_BLEND);
+    glBlendEquation(GL_FUNC_ADD);
+    glBlendFuncSeparate(GL_SRC_ALPHA, GL_ONE_MINUS_SRC_ALPHA, GL_ONE, GL_ONE_MINUS_SRC_ALPHA);
+    glDisable(GL_CULL_FACE);
+    glDisable(GL_DEPTH_TEST);
+    glDisable(GL_STENCIL_TEST);
+    glEnable(GL_SCISSOR_TEST);
+#ifdef IMGUI_IMPL_OPENGL_MAY_HAVE_PRIMITIVE_RESTART
+    if (bd->GlVersion >= 310)
+        glDisable(GL_PRIMITIVE_RESTART);
+#endif
+#ifdef IMGUI_IMPL_HAS_POLYGON_MODE
+    glPolygonMode(GL_FRONT_AND_BACK, GL_FILL);
+#endif
+
+    // Support for GL 4.5 rarely used glClipControl(GL_UPPER_LEFT)
+#if defined(GL_CLIP_ORIGIN)
+    bool clip_origin_lower_left = true;
+    if (bd->HasClipOrigin)
+    {
+        GLenum current_clip_origin = 0; glGetIntegerv(GL_CLIP_ORIGIN, (GLint*)&current_clip_origin);
+        if (current_clip_origin == GL_UPPER_LEFT)
+            clip_origin_lower_left = false;
+    }
+#endif
+
+    // Setup viewport, orthographic projection matrix
+    // Our visible imgui space lies from draw_data->DisplayPos (top left) to draw_data->DisplayPos+data_data->DisplaySize (bottom right). DisplayPos is (0,0) for single viewport apps.
+    GL_CALL(glViewport(0, 0, (GLsizei)fb_width, (GLsizei)fb_height));
+    float L = draw_data->DisplayPos.x;
+    float R = draw_data->DisplayPos.x + draw_data->DisplaySize.x;
+    float T = draw_data->DisplayPos.y;
+    float B = draw_data->DisplayPos.y + draw_data->DisplaySize.y;
+#if defined(GL_CLIP_ORIGIN)
+    if (!clip_origin_lower_left) { float tmp = T; T = B; B = tmp; } // Swap top and bottom if origin is upper left
+#endif
+    const float ortho_projection[4][4] =
+    {
+        { 2.0f/(R-L),   0.0f,         0.0f,   0.0f },
+        { 0.0f,         2.0f/(T-B),   0.0f,   0.0f },
+        { 0.0f,         0.0f,        -1.0f,   0.0f },
+        { (R+L)/(L-R),  (T+B)/(B-T),  0.0f,   1.0f },
+    };
+    glUseProgram(bd->ShaderHandle);
+    glUniform1i(bd->AttribLocationTex, 0);
+    glUniformMatrix4fv(bd->AttribLocationProjMtx, 1, GL_FALSE, &ortho_projection[0][0]);
+
+#ifdef IMGUI_IMPL_OPENGL_MAY_HAVE_BIND_SAMPLER
+    if (bd->GlVersion >= 330)
+        glBindSampler(0, 0); // We use combined texture/sampler state. Applications using GL 3.3 may set that otherwise.
+#endif
+
+    (void)vertex_array_object;
+#ifdef IMGUI_IMPL_OPENGL_USE_VERTEX_ARRAY
+    glBindVertexArray(vertex_array_object);
+#endif
+
+    // Bind vertex/index buffers and setup attributes for ImDrawVert
+    GL_CALL(glBindBuffer(GL_ARRAY_BUFFER, bd->VboHandle));
+    GL_CALL(glBindBuffer(GL_ELEMENT_ARRAY_BUFFER, bd->ElementsHandle));
+    GL_CALL(glEnableVertexAttribArray(bd->AttribLocationVtxPos));
+    GL_CALL(glEnableVertexAttribArray(bd->AttribLocationVtxUV));
+    GL_CALL(glEnableVertexAttribArray(bd->AttribLocationVtxColor));
+    GL_CALL(glVertexAttribPointer(bd->AttribLocationVtxPos,   2, GL_FLOAT,         GL_FALSE, sizeof(ImDrawVert), (GLvoid*)IM_OFFSETOF(ImDrawVert, pos)));
+    GL_CALL(glVertexAttribPointer(bd->AttribLocationVtxUV,    2, GL_FLOAT,         GL_FALSE, sizeof(ImDrawVert), (GLvoid*)IM_OFFSETOF(ImDrawVert, uv)));
+    GL_CALL(glVertexAttribPointer(bd->AttribLocationVtxColor, 4, GL_UNSIGNED_BYTE, GL_TRUE, sizeof(ImDrawVert), (GLvoid*)IM_OFFSETOF(ImDrawVert, col)));
+}
+
+// OpenGL3 Render function.
+// Note that this implementation is little overcomplicated because we are saving/setting up/restoring every OpenGL state explicitly.
+// This is in order to be able to run within an OpenGL engine that doesn't do so.
+void    ImGui_ImplOpenGL3_RenderDrawData(ImDrawData* draw_data)
+{
+    // Avoid rendering when minimized, scale coordinates for retina displays (screen coordinates != framebuffer coordinates)
+    int fb_width = (int)(draw_data->DisplaySize.x * draw_data->FramebufferScale.x);
+    int fb_height = (int)(draw_data->DisplaySize.y * draw_data->FramebufferScale.y);
+    if (fb_width <= 0 || fb_height <= 0)
+        return;
+
+    ImGui_ImplOpenGL3_Data* bd = ImGui_ImplOpenGL3_GetBackendData();
+
+    // Backup GL state
+    GLenum last_active_texture; glGetIntegerv(GL_ACTIVE_TEXTURE, (GLint*)&last_active_texture);
+    glActiveTexture(GL_TEXTURE0);
+    GLuint last_program; glGetIntegerv(GL_CURRENT_PROGRAM, (GLint*)&last_program);
+    GLuint last_texture; glGetIntegerv(GL_TEXTURE_BINDING_2D, (GLint*)&last_texture);
+#ifdef IMGUI_IMPL_OPENGL_MAY_HAVE_BIND_SAMPLER
+    GLuint last_sampler; if (bd->GlVersion >= 330) { glGetIntegerv(GL_SAMPLER_BINDING, (GLint*)&last_sampler); } else { last_sampler = 0; }
+#endif
+    GLuint last_array_buffer; glGetIntegerv(GL_ARRAY_BUFFER_BINDING, (GLint*)&last_array_buffer);
+#ifndef IMGUI_IMPL_OPENGL_USE_VERTEX_ARRAY
+    // This is part of VAO on OpenGL 3.0+ and OpenGL ES 3.0+.
+    GLint last_element_array_buffer; glGetIntegerv(GL_ELEMENT_ARRAY_BUFFER_BINDING, &last_element_array_buffer);
+    ImGui_ImplOpenGL3_VtxAttribState last_vtx_attrib_state_pos; last_vtx_attrib_state_pos.GetState(bd->AttribLocationVtxPos);
+    ImGui_ImplOpenGL3_VtxAttribState last_vtx_attrib_state_uv; last_vtx_attrib_state_uv.GetState(bd->AttribLocationVtxUV);
+    ImGui_ImplOpenGL3_VtxAttribState last_vtx_attrib_state_color; last_vtx_attrib_state_color.GetState(bd->AttribLocationVtxColor);
+#endif
+#ifdef IMGUI_IMPL_OPENGL_USE_VERTEX_ARRAY
+    GLuint last_vertex_array_object; glGetIntegerv(GL_VERTEX_ARRAY_BINDING, (GLint*)&last_vertex_array_object);
+#endif
+#ifdef IMGUI_IMPL_HAS_POLYGON_MODE
+    GLint last_polygon_mode[2]; glGetIntegerv(GL_POLYGON_MODE, last_polygon_mode);
+#endif
+    GLint last_viewport[4]; glGetIntegerv(GL_VIEWPORT, last_viewport);
+    GLint last_scissor_box[4]; glGetIntegerv(GL_SCISSOR_BOX, last_scissor_box);
+    GLenum last_blend_src_rgb; glGetIntegerv(GL_BLEND_SRC_RGB, (GLint*)&last_blend_src_rgb);
+    GLenum last_blend_dst_rgb; glGetIntegerv(GL_BLEND_DST_RGB, (GLint*)&last_blend_dst_rgb);
+    GLenum last_blend_src_alpha; glGetIntegerv(GL_BLEND_SRC_ALPHA, (GLint*)&last_blend_src_alpha);
+    GLenum last_blend_dst_alpha; glGetIntegerv(GL_BLEND_DST_ALPHA, (GLint*)&last_blend_dst_alpha);
+    GLenum last_blend_equation_rgb; glGetIntegerv(GL_BLEND_EQUATION_RGB, (GLint*)&last_blend_equation_rgb);
+    GLenum last_blend_equation_alpha; glGetIntegerv(GL_BLEND_EQUATION_ALPHA, (GLint*)&last_blend_equation_alpha);
+    GLboolean last_enable_blend = glIsEnabled(GL_BLEND);
+    GLboolean last_enable_cull_face = glIsEnabled(GL_CULL_FACE);
+    GLboolean last_enable_depth_test = glIsEnabled(GL_DEPTH_TEST);
+    GLboolean last_enable_stencil_test = glIsEnabled(GL_STENCIL_TEST);
+    GLboolean last_enable_scissor_test = glIsEnabled(GL_SCISSOR_TEST);
+#ifdef IMGUI_IMPL_OPENGL_MAY_HAVE_PRIMITIVE_RESTART
+    GLboolean last_enable_primitive_restart = (bd->GlVersion >= 310) ? glIsEnabled(GL_PRIMITIVE_RESTART) : GL_FALSE;
+#endif
+
+    // Setup desired GL state
+    // Recreate the VAO every time (this is to easily allow multiple GL contexts to be rendered to. VAO are not shared among GL contexts)
+    // The renderer would actually work without any VAO bound, but then our VertexAttrib calls would overwrite the default one currently bound.
+    GLuint vertex_array_object = 0;
+#ifdef IMGUI_IMPL_OPENGL_USE_VERTEX_ARRAY
+    GL_CALL(glGenVertexArrays(1, &vertex_array_object));
+#endif
+    ImGui_ImplOpenGL3_SetupRenderState(draw_data, fb_width, fb_height, vertex_array_object);
+
+    // Will project scissor/clipping rectangles into framebuffer space
+    ImVec2 clip_off = draw_data->DisplayPos;         // (0,0) unless using multi-viewports
+    ImVec2 clip_scale = draw_data->FramebufferScale; // (1,1) unless using retina display which are often (2,2)
+
+    // Render command lists
+    for (int n = 0; n < draw_data->CmdListsCount; n++)
+    {
+        const ImDrawList* cmd_list = draw_data->CmdLists[n];
+
+        // Upload vertex/index buffers
+        // - On Intel windows drivers we got reports that regular glBufferData() led to accumulating leaks when using multi-viewports, so we started using orphaning + glBufferSubData(). (See https://github.com/ocornut/imgui/issues/4468)
+        // - On NVIDIA drivers we got reports that using orphaning + glBufferSubData() led to glitches when using multi-viewports.
+        // - OpenGL drivers are in a very sorry state in 2022, for now we are switching code path based on vendors.
+        const GLsizeiptr vtx_buffer_size = (GLsizeiptr)cmd_list->VtxBuffer.Size * (int)sizeof(ImDrawVert);
+        const GLsizeiptr idx_buffer_size = (GLsizeiptr)cmd_list->IdxBuffer.Size * (int)sizeof(ImDrawIdx);
+        if (bd->UseBufferSubData)
+        {
+            if (bd->VertexBufferSize < vtx_buffer_size)
+            {
+                bd->VertexBufferSize = vtx_buffer_size;
+                GL_CALL(glBufferData(GL_ARRAY_BUFFER, bd->VertexBufferSize, nullptr, GL_STREAM_DRAW));
+            }
+            if (bd->IndexBufferSize < idx_buffer_size)
+            {
+                bd->IndexBufferSize = idx_buffer_size;
+                GL_CALL(glBufferData(GL_ELEMENT_ARRAY_BUFFER, bd->IndexBufferSize, nullptr, GL_STREAM_DRAW));
+            }
+            GL_CALL(glBufferSubData(GL_ARRAY_BUFFER, 0, vtx_buffer_size, (const GLvoid*)cmd_list->VtxBuffer.Data));
+            GL_CALL(glBufferSubData(GL_ELEMENT_ARRAY_BUFFER, 0, idx_buffer_size, (const GLvoid*)cmd_list->IdxBuffer.Data));
+        }
+        else
+        {
+            GL_CALL(glBufferData(GL_ARRAY_BUFFER, vtx_buffer_size, (const GLvoid*)cmd_list->VtxBuffer.Data, GL_STREAM_DRAW));
+            GL_CALL(glBufferData(GL_ELEMENT_ARRAY_BUFFER, idx_buffer_size, (const GLvoid*)cmd_list->IdxBuffer.Data, GL_STREAM_DRAW));
+        }
+
+        for (int cmd_i = 0; cmd_i < cmd_list->CmdBuffer.Size; cmd_i++)
+        {
+            const ImDrawCmd* pcmd = &cmd_list->CmdBuffer[cmd_i];
+            if (pcmd->UserCallback != nullptr)
+            {
+                // User callback, registered via ImDrawList::AddCallback()
+                // (ImDrawCallback_ResetRenderState is a special callback value used by the user to request the renderer to reset render state.)
+                if (pcmd->UserCallback == ImDrawCallback_ResetRenderState)
+                    ImGui_ImplOpenGL3_SetupRenderState(draw_data, fb_width, fb_height, vertex_array_object);
+                else
+                    pcmd->UserCallback(cmd_list, pcmd);
+            }
+            else
+            {
+                // Project scissor/clipping rectangles into framebuffer space
+                ImVec2 clip_min((pcmd->ClipRect.x - clip_off.x) * clip_scale.x, (pcmd->ClipRect.y - clip_off.y) * clip_scale.y);
+                ImVec2 clip_max((pcmd->ClipRect.z - clip_off.x) * clip_scale.x, (pcmd->ClipRect.w - clip_off.y) * clip_scale.y);
+                if (clip_max.x <= clip_min.x || clip_max.y <= clip_min.y)
+                    continue;
+
+                // Apply scissor/clipping rectangle (Y is inverted in OpenGL)
+                GL_CALL(glScissor((int)clip_min.x, (int)((float)fb_height - clip_max.y), (int)(clip_max.x - clip_min.x), (int)(clip_max.y - clip_min.y)));
+
+                // Bind texture, Draw
+                GL_CALL(glBindTexture(GL_TEXTURE_2D, (GLuint)(intptr_t)pcmd->GetTexID()));
+#ifdef IMGUI_IMPL_OPENGL_MAY_HAVE_VTX_OFFSET
+                if (bd->GlVersion >= 320)
+                    GL_CALL(glDrawElementsBaseVertex(GL_TRIANGLES, (GLsizei)pcmd->ElemCount, sizeof(ImDrawIdx) == 2 ? GL_UNSIGNED_SHORT : GL_UNSIGNED_INT, (void*)(intptr_t)(pcmd->IdxOffset * sizeof(ImDrawIdx)), (GLint)pcmd->VtxOffset));
+                else
+#endif
+                GL_CALL(glDrawElements(GL_TRIANGLES, (GLsizei)pcmd->ElemCount, sizeof(ImDrawIdx) == 2 ? GL_UNSIGNED_SHORT : GL_UNSIGNED_INT, (void*)(intptr_t)(pcmd->IdxOffset * sizeof(ImDrawIdx))));
+            }
+        }
+    }
+
+    // Destroy the temporary VAO
+#ifdef IMGUI_IMPL_OPENGL_USE_VERTEX_ARRAY
+    GL_CALL(glDeleteVertexArrays(1, &vertex_array_object));
+#endif
+
+    // Restore modified GL state
+    glUseProgram(last_program);
+    glBindTexture(GL_TEXTURE_2D, last_texture);
+#ifdef IMGUI_IMPL_OPENGL_MAY_HAVE_BIND_SAMPLER
+    if (bd->GlVersion >= 330)
+        glBindSampler(0, last_sampler);
+#endif
+    glActiveTexture(last_active_texture);
+#ifdef IMGUI_IMPL_OPENGL_USE_VERTEX_ARRAY
+    glBindVertexArray(last_vertex_array_object);
+#endif
+    glBindBuffer(GL_ARRAY_BUFFER, last_array_buffer);
+#ifndef IMGUI_IMPL_OPENGL_USE_VERTEX_ARRAY
+    glBindBuffer(GL_ELEMENT_ARRAY_BUFFER, last_element_array_buffer);
+    last_vtx_attrib_state_pos.SetState(bd->AttribLocationVtxPos);
+    last_vtx_attrib_state_uv.SetState(bd->AttribLocationVtxUV);
+    last_vtx_attrib_state_color.SetState(bd->AttribLocationVtxColor);
+#endif
+    glBlendEquationSeparate(last_blend_equation_rgb, last_blend_equation_alpha);
+    glBlendFuncSeparate(last_blend_src_rgb, last_blend_dst_rgb, last_blend_src_alpha, last_blend_dst_alpha);
+    if (last_enable_blend) glEnable(GL_BLEND); else glDisable(GL_BLEND);
+    if (last_enable_cull_face) glEnable(GL_CULL_FACE); else glDisable(GL_CULL_FACE);
+    if (last_enable_depth_test) glEnable(GL_DEPTH_TEST); else glDisable(GL_DEPTH_TEST);
+    if (last_enable_stencil_test) glEnable(GL_STENCIL_TEST); else glDisable(GL_STENCIL_TEST);
+    if (last_enable_scissor_test) glEnable(GL_SCISSOR_TEST); else glDisable(GL_SCISSOR_TEST);
+#ifdef IMGUI_IMPL_OPENGL_MAY_HAVE_PRIMITIVE_RESTART
+    if (bd->GlVersion >= 310) { if (last_enable_primitive_restart) glEnable(GL_PRIMITIVE_RESTART); else glDisable(GL_PRIMITIVE_RESTART); }
+#endif
+
+#ifdef IMGUI_IMPL_HAS_POLYGON_MODE
+    glPolygonMode(GL_FRONT_AND_BACK, (GLenum)last_polygon_mode[0]);
+#endif
+    glViewport(last_viewport[0], last_viewport[1], (GLsizei)last_viewport[2], (GLsizei)last_viewport[3]);
+    glScissor(last_scissor_box[0], last_scissor_box[1], (GLsizei)last_scissor_box[2], (GLsizei)last_scissor_box[3]);
+    (void)bd; // Not all compilation paths use this
+}
+
+bool ImGui_ImplOpenGL3_CreateFontsTexture()
+{
+    ImGuiIO& io = ImGui::GetIO();
+    ImGui_ImplOpenGL3_Data* bd = ImGui_ImplOpenGL3_GetBackendData();
+
+    // Build texture atlas
+    unsigned char* pixels;
+    int width, height;
+    io.Fonts->GetTexDataAsRGBA32(&pixels, &width, &height);   // Load as RGBA 32-bit (75% of the memory is wasted, but default font is so small) because it is more likely to be compatible with user's existing shaders. If your ImTextureId represent a higher-level concept than just a GL texture id, consider calling GetTexDataAsAlpha8() instead to save on GPU memory.
+
+    // Upload texture to graphics system
+    // (Bilinear sampling is required by default. Set 'io.Fonts->Flags |= ImFontAtlasFlags_NoBakedLines' or 'style.AntiAliasedLinesUseTex = false' to allow point/nearest sampling)
+    GLint last_texture;
+    GL_CALL(glGetIntegerv(GL_TEXTURE_BINDING_2D, &last_texture));
+    GL_CALL(glGenTextures(1, &bd->FontTexture));
+    GL_CALL(glBindTexture(GL_TEXTURE_2D, bd->FontTexture));
+    GL_CALL(glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MIN_FILTER, GL_LINEAR));
+    GL_CALL(glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MAG_FILTER, GL_LINEAR));
+#ifdef GL_UNPACK_ROW_LENGTH // Not on WebGL/ES
+    GL_CALL(glPixelStorei(GL_UNPACK_ROW_LENGTH, 0));
+#endif
+    GL_CALL(glTexImage2D(GL_TEXTURE_2D, 0, GL_RGBA, width, height, 0, GL_RGBA, GL_UNSIGNED_BYTE, pixels));
+
+    // Store our identifier
+    io.Fonts->SetTexID((ImTextureID)(intptr_t)bd->FontTexture);
+
+    // Restore state
+    GL_CALL(glBindTexture(GL_TEXTURE_2D, last_texture));
+
+    return true;
+}
+
+void ImGui_ImplOpenGL3_DestroyFontsTexture()
+{
+    ImGuiIO& io = ImGui::GetIO();
+    ImGui_ImplOpenGL3_Data* bd = ImGui_ImplOpenGL3_GetBackendData();
+    if (bd->FontTexture)
+    {
+        glDeleteTextures(1, &bd->FontTexture);
+        io.Fonts->SetTexID(0);
+        bd->FontTexture = 0;
+    }
+}
+
+// If you get an error please report on github. You may try different GL context version or GLSL version. See GL<>GLSL version table at the top of this file.
+static bool CheckShader(GLuint handle, const char* desc)
+{
+    ImGui_ImplOpenGL3_Data* bd = ImGui_ImplOpenGL3_GetBackendData();
+    GLint status = 0, log_length = 0;
+    glGetShaderiv(handle, GL_COMPILE_STATUS, &status);
+    glGetShaderiv(handle, GL_INFO_LOG_LENGTH, &log_length);
+    if ((GLboolean)status == GL_FALSE)
+        fprintf(stderr, "ERROR: ImGui_ImplOpenGL3_CreateDeviceObjects: failed to compile %s! With GLSL: %s\n", desc, bd->GlslVersionString);
+    if (log_length > 1)
+    {
+        ImVector<char> buf;
+        buf.resize((int)(log_length + 1));
+        glGetShaderInfoLog(handle, log_length, nullptr, (GLchar*)buf.begin());
+        fprintf(stderr, "%s\n", buf.begin());
+    }
+    return (GLboolean)status == GL_TRUE;
+}
+
+// If you get an error please report on GitHub. You may try different GL context version or GLSL version.
+static bool CheckProgram(GLuint handle, const char* desc)
+{
+    ImGui_ImplOpenGL3_Data* bd = ImGui_ImplOpenGL3_GetBackendData();
+    GLint status = 0, log_length = 0;
+    glGetProgramiv(handle, GL_LINK_STATUS, &status);
+    glGetProgramiv(handle, GL_INFO_LOG_LENGTH, &log_length);
+    if ((GLboolean)status == GL_FALSE)
+        fprintf(stderr, "ERROR: ImGui_ImplOpenGL3_CreateDeviceObjects: failed to link %s! With GLSL %s\n", desc, bd->GlslVersionString);
+    if (log_length > 1)
+    {
+        ImVector<char> buf;
+        buf.resize((int)(log_length + 1));
+        glGetProgramInfoLog(handle, log_length, nullptr, (GLchar*)buf.begin());
+        fprintf(stderr, "%s\n", buf.begin());
+    }
+    return (GLboolean)status == GL_TRUE;
+}
+
+bool    ImGui_ImplOpenGL3_CreateDeviceObjects()
+{
+    ImGui_ImplOpenGL3_Data* bd = ImGui_ImplOpenGL3_GetBackendData();
+
+    // Backup GL state
+    GLint last_texture, last_array_buffer;
+    glGetIntegerv(GL_TEXTURE_BINDING_2D, &last_texture);
+    glGetIntegerv(GL_ARRAY_BUFFER_BINDING, &last_array_buffer);
+#ifdef IMGUI_IMPL_OPENGL_USE_VERTEX_ARRAY
+    GLint last_vertex_array;
+    glGetIntegerv(GL_VERTEX_ARRAY_BINDING, &last_vertex_array);
+#endif
+
+    // Parse GLSL version string
+    int glsl_version = 130;
+    sscanf(bd->GlslVersionString, "#version %d", &glsl_version);
+
+    const GLchar* vertex_shader_glsl_120 =
+        "uniform mat4 ProjMtx;\n"
+        "attribute vec2 Position;\n"
+        "attribute vec2 UV;\n"
+        "attribute vec4 Color;\n"
+        "varying vec2 Frag_UV;\n"
+        "varying vec4 Frag_Color;\n"
+        "void main()\n"
+        "{\n"
+        "    Frag_UV = UV;\n"
+        "    Frag_Color = Color;\n"
+        "    gl_Position = ProjMtx * vec4(Position.xy,0,1);\n"
+        "}\n";
+
+    const GLchar* vertex_shader_glsl_130 =
+        "uniform mat4 ProjMtx;\n"
+        "in vec2 Position;\n"
+        "in vec2 UV;\n"
+        "in vec4 Color;\n"
+        "out vec2 Frag_UV;\n"
+        "out vec4 Frag_Color;\n"
+        "void main()\n"
+        "{\n"
+        "    Frag_UV = UV;\n"
+        "    Frag_Color = Color;\n"
+        "    gl_Position = ProjMtx * vec4(Position.xy,0,1);\n"
+        "}\n";
+
+    const GLchar* vertex_shader_glsl_300_es =
+        "precision highp float;\n"
+        "layout (location = 0) in vec2 Position;\n"
+        "layout (location = 1) in vec2 UV;\n"
+        "layout (location = 2) in vec4 Color;\n"
+        "uniform mat4 ProjMtx;\n"
+        "out vec2 Frag_UV;\n"
+        "out vec4 Frag_Color;\n"
+        "void main()\n"
+        "{\n"
+        "    Frag_UV = UV;\n"
+        "    Frag_Color = Color;\n"
+        "    gl_Position = ProjMtx * vec4(Position.xy,0,1);\n"
+        "}\n";
+
+    const GLchar* vertex_shader_glsl_410_core =
+        "layout (location = 0) in vec2 Position;\n"
+        "layout (location = 1) in vec2 UV;\n"
+        "layout (location = 2) in vec4 Color;\n"
+        "uniform mat4 ProjMtx;\n"
+        "out vec2 Frag_UV;\n"
+        "out vec4 Frag_Color;\n"
+        "void main()\n"
+        "{\n"
+        "    Frag_UV = UV;\n"
+        "    Frag_Color = Color;\n"
+        "    gl_Position = ProjMtx * vec4(Position.xy,0,1);\n"
+        "}\n";
+
+    const GLchar* fragment_shader_glsl_120 =
+        "#ifdef GL_ES\n"
+        "    precision mediump float;\n"
+        "#endif\n"
+        "uniform sampler2D Texture;\n"
+        "varying vec2 Frag_UV;\n"
+        "varying vec4 Frag_Color;\n"
+        "void main()\n"
+        "{\n"
+        "    gl_FragColor = Frag_Color * texture2D(Texture, Frag_UV.st);\n"
+        "}\n";
+
+    const GLchar* fragment_shader_glsl_130 =
+        "uniform sampler2D Texture;\n"
+        "in vec2 Frag_UV;\n"
+        "in vec4 Frag_Color;\n"
+        "out vec4 Out_Color;\n"
+        "void main()\n"
+        "{\n"
+        "    Out_Color = Frag_Color * texture(Texture, Frag_UV.st);\n"
+        "}\n";
+
+    const GLchar* fragment_shader_glsl_300_es =
+        "precision mediump float;\n"
+        "uniform sampler2D Texture;\n"
+        "in vec2 Frag_UV;\n"
+        "in vec4 Frag_Color;\n"
+        "layout (location = 0) out vec4 Out_Color;\n"
+        "void main()\n"
+        "{\n"
+        "    Out_Color = Frag_Color * texture(Texture, Frag_UV.st);\n"
+        "}\n";
+
+    const GLchar* fragment_shader_glsl_410_core =
+        "in vec2 Frag_UV;\n"
+        "in vec4 Frag_Color;\n"
+        "uniform sampler2D Texture;\n"
+        "layout (location = 0) out vec4 Out_Color;\n"
+        "void main()\n"
+        "{\n"
+        "    Out_Color = Frag_Color * texture(Texture, Frag_UV.st);\n"
+        "}\n";
+
+    // Select shaders matching our GLSL versions
+    const GLchar* vertex_shader = nullptr;
+    const GLchar* fragment_shader = nullptr;
+    if (glsl_version < 130)
+    {
+        vertex_shader = vertex_shader_glsl_120;
+        fragment_shader = fragment_shader_glsl_120;
+    }
+    else if (glsl_version >= 410)
+    {
+        vertex_shader = vertex_shader_glsl_410_core;
+        fragment_shader = fragment_shader_glsl_410_core;
+    }
+    else if (glsl_version == 300)
+    {
+        vertex_shader = vertex_shader_glsl_300_es;
+        fragment_shader = fragment_shader_glsl_300_es;
+    }
+    else
+    {
+        vertex_shader = vertex_shader_glsl_130;
+        fragment_shader = fragment_shader_glsl_130;
+    }
+
+    // Create shaders
+    const GLchar* vertex_shader_with_version[2] = { bd->GlslVersionString, vertex_shader };
+    GLuint vert_handle = glCreateShader(GL_VERTEX_SHADER);
+    glShaderSource(vert_handle, 2, vertex_shader_with_version, nullptr);
+    glCompileShader(vert_handle);
+    CheckShader(vert_handle, "vertex shader");
+
+    const GLchar* fragment_shader_with_version[2] = { bd->GlslVersionString, fragment_shader };
+    GLuint frag_handle = glCreateShader(GL_FRAGMENT_SHADER);
+    glShaderSource(frag_handle, 2, fragment_shader_with_version, nullptr);
+    glCompileShader(frag_handle);
+    CheckShader(frag_handle, "fragment shader");
+
+    // Link
+    bd->ShaderHandle = glCreateProgram();
+    glAttachShader(bd->ShaderHandle, vert_handle);
+    glAttachShader(bd->ShaderHandle, frag_handle);
+    glLinkProgram(bd->ShaderHandle);
+    CheckProgram(bd->ShaderHandle, "shader program");
+
+    glDetachShader(bd->ShaderHandle, vert_handle);
+    glDetachShader(bd->ShaderHandle, frag_handle);
+    glDeleteShader(vert_handle);
+    glDeleteShader(frag_handle);
+
+    bd->AttribLocationTex = glGetUniformLocation(bd->ShaderHandle, "Texture");
+    bd->AttribLocationProjMtx = glGetUniformLocation(bd->ShaderHandle, "ProjMtx");
+    bd->AttribLocationVtxPos = (GLuint)glGetAttribLocation(bd->ShaderHandle, "Position");
+    bd->AttribLocationVtxUV = (GLuint)glGetAttribLocation(bd->ShaderHandle, "UV");
+    bd->AttribLocationVtxColor = (GLuint)glGetAttribLocation(bd->ShaderHandle, "Color");
+
+    // Create buffers
+    glGenBuffers(1, &bd->VboHandle);
+    glGenBuffers(1, &bd->ElementsHandle);
+
+    ImGui_ImplOpenGL3_CreateFontsTexture();
+
+    // Restore modified GL state
+    glBindTexture(GL_TEXTURE_2D, last_texture);
+    glBindBuffer(GL_ARRAY_BUFFER, last_array_buffer);
+#ifdef IMGUI_IMPL_OPENGL_USE_VERTEX_ARRAY
+    glBindVertexArray(last_vertex_array);
+#endif
+
+    return true;
+}
+
+void    ImGui_ImplOpenGL3_DestroyDeviceObjects()
+{
+    ImGui_ImplOpenGL3_Data* bd = ImGui_ImplOpenGL3_GetBackendData();
+    if (bd->VboHandle)      { glDeleteBuffers(1, &bd->VboHandle); bd->VboHandle = 0; }
+    if (bd->ElementsHandle) { glDeleteBuffers(1, &bd->ElementsHandle); bd->ElementsHandle = 0; }
+    if (bd->ShaderHandle)   { glDeleteProgram(bd->ShaderHandle); bd->ShaderHandle = 0; }
+    ImGui_ImplOpenGL3_DestroyFontsTexture();
+}
+
+//--------------------------------------------------------------------------------------------------------
+// MULTI-VIEWPORT / PLATFORM INTERFACE SUPPORT
+// This is an _advanced_ and _optional_ feature, allowing the backend to create and handle multiple viewports simultaneously.
+// If you are new to dear imgui or creating a new binding for dear imgui, it is recommended that you completely ignore this section first..
+//--------------------------------------------------------------------------------------------------------
+
+static void ImGui_ImplOpenGL3_RenderWindow(ImGuiViewport* viewport, void*)
+{
+    if (!(viewport->Flags & ImGuiViewportFlags_NoRendererClear))
+    {
+        ImVec4 clear_color = ImVec4(0.0f, 0.0f, 0.0f, 1.0f);
+        glClearColor(clear_color.x, clear_color.y, clear_color.z, clear_color.w);
+        glClear(GL_COLOR_BUFFER_BIT);
+    }
+    ImGui_ImplOpenGL3_RenderDrawData(viewport->DrawData);
+}
+
+static void ImGui_ImplOpenGL3_InitPlatformInterface()
+{
+    ImGuiPlatformIO& platform_io = ImGui::GetPlatformIO();
+    platform_io.Renderer_RenderWindow = ImGui_ImplOpenGL3_RenderWindow;
+}
+
+static void ImGui_ImplOpenGL3_ShutdownPlatformInterface()
+{
+    ImGui::DestroyPlatformWindows();
+}
+
+#if defined(__clang__)
+#pragma clang diagnostic pop
+#endif

includes/imgui/backends/imgui_impl_opengl3.h

@@ -0,0 +1,56 @@
+// dear imgui: Renderer Backend for modern OpenGL with shaders / programmatic pipeline
+// - Desktop GL: 2.x 3.x 4.x
+// - Embedded GL: ES 2.0 (WebGL 1.0), ES 3.0 (WebGL 2.0)
+// This needs to be used along with a Platform Backend (e.g. GLFW, SDL, Win32, custom..)
+
+// Implemented features:
+//  [X] Renderer: User texture binding. Use 'GLuint' OpenGL texture identifier as void*/ImTextureID. Read the FAQ about ImTextureID!
+//  [X] Renderer: Multi-viewport support (multiple windows). Enable with 'io.ConfigFlags |= ImGuiConfigFlags_ViewportsEnable'.
+//  [x] Renderer: Large meshes support (64k+ vertices) with 16-bit indices (Desktop OpenGL only).
+
+// You can use unmodified imgui_impl_* files in your project. See examples/ folder for examples of using this.
+// Prefer including the entire imgui/ repository into your project (either as a copy or as a submodule), and only build the backends you need.
+// If you are new to Dear ImGui, read documentation from the docs/ folder + read the top of imgui.cpp.
+// Read online: https://github.com/ocornut/imgui/tree/master/docs
+
+// About GLSL version:
+//  The 'glsl_version' initialization parameter should be nullptr (default) or a "#version XXX" string.
+//  On computer platform the GLSL version default to "#version 130". On OpenGL ES 3 platform it defaults to "#version 300 es"
+//  Only override if your GL version doesn't handle this GLSL version. See GLSL version table at the top of imgui_impl_opengl3.cpp.
+
+#pragma once
+#include "imgui.h"      // IMGUI_IMPL_API
+
+// Backend API
+IMGUI_IMPL_API bool     ImGui_ImplOpenGL3_Init(const char* glsl_version = nullptr);
+IMGUI_IMPL_API void     ImGui_ImplOpenGL3_Shutdown();
+IMGUI_IMPL_API void     ImGui_ImplOpenGL3_NewFrame();
+IMGUI_IMPL_API void     ImGui_ImplOpenGL3_RenderDrawData(ImDrawData* draw_data);
+
+// (Optional) Called by Init/NewFrame/Shutdown
+IMGUI_IMPL_API bool     ImGui_ImplOpenGL3_CreateFontsTexture();
+IMGUI_IMPL_API void     ImGui_ImplOpenGL3_DestroyFontsTexture();
+IMGUI_IMPL_API bool     ImGui_ImplOpenGL3_CreateDeviceObjects();
+IMGUI_IMPL_API void     ImGui_ImplOpenGL3_DestroyDeviceObjects();
+
+// Specific OpenGL ES versions
+//#define IMGUI_IMPL_OPENGL_ES2     // Auto-detected on Emscripten
+//#define IMGUI_IMPL_OPENGL_ES3     // Auto-detected on iOS/Android
+
+// You can explicitly select GLES2 or GLES3 API by using one of the '#define IMGUI_IMPL_OPENGL_LOADER_XXX' in imconfig.h or compiler command-line.
+#if !defined(IMGUI_IMPL_OPENGL_ES2) \
+ && !defined(IMGUI_IMPL_OPENGL_ES3)
+
+// Try to detect GLES on matching platforms
+#if defined(__APPLE__)
+#include <TargetConditionals.h>
+#endif
+#if (defined(__APPLE__) && (TARGET_OS_IOS || TARGET_OS_TV)) || (defined(__ANDROID__))
+#define IMGUI_IMPL_OPENGL_ES3               // iOS, Android  -> GL ES 3, "#version 300 es"
+#elif defined(__EMSCRIPTEN__) || defined(__amigaos4__)
+#define IMGUI_IMPL_OPENGL_ES2               // Emscripten    -> GL ES 2, "#version 100"
+#else
+// Otherwise imgui_impl_opengl3_loader.h will be used.
+#endif
+
+#endif

includes/imgui/backends/imgui_impl_opengl3_loader.h

@@ -0,0 +1,794 @@
+//-----------------------------------------------------------------------------
+// About imgui_impl_opengl3_loader.h:
+//
+// We embed our own OpenGL loader to not require user to provide their own or to have to use ours,
+// which proved to be endless problems for users.
+// Our loader is custom-generated, based on gl3w but automatically filtered to only include
+// enums/functions that we use in our imgui_impl_opengl3.cpp source file in order to be small.
+//
+// YOU SHOULD NOT NEED TO INCLUDE/USE THIS DIRECTLY. THIS IS USED BY imgui_impl_opengl3.cpp ONLY.
+// THE REST OF YOUR APP SHOULD USE A DIFFERENT GL LOADER: ANY GL LOADER OF YOUR CHOICE.
+//
+// IF YOU GET BUILD ERRORS IN THIS FILE (commonly macro redefinitions or function redefinitions):
+// IT LIKELY MEANS THAT YOU ARE BUILDING 'imgui_impl_opengl3.cpp' OR INCUDING 'imgui_impl_opengl3_loader.h'
+// IN THE SAME COMPILATION UNIT AS ONE OF YOUR FILE WHICH IS USING A THIRD-PARTY OPENGL LOADER.
+// (e.g. COULD HAPPEN IF YOU ARE DOING A UNITY/JUMBO BUILD, OR INCLUDING .CPP FILES FROM OTHERS)
+// YOU SHOULD NOT BUILD BOTH IN THE SAME COMPILATION UNIT.
+// BUT IF YOU REALLY WANT TO, you can '#define IMGUI_IMPL_OPENGL_LOADER_CUSTOM' and imgui_impl_opengl3.cpp
+// WILL NOT BE USING OUR LOADER, AND INSTEAD EXPECT ANOTHER/YOUR LOADER TO BE AVAILABLE IN THE COMPILATION UNIT.
+//
+// Regenerate with:
+//   python gl3w_gen.py --output ../imgui/backends/imgui_impl_opengl3_loader.h --ref ../imgui/backends/imgui_impl_opengl3.cpp ./extra_symbols.txt
+//
+// More info:
+//   https://github.com/dearimgui/gl3w_stripped
+//   https://github.com/ocornut/imgui/issues/4445
+//-----------------------------------------------------------------------------
+
+/*
+ * This file was generated with gl3w_gen.py, part of imgl3w
+ * (hosted at https://github.com/dearimgui/gl3w_stripped)
+ *
+ * This is free and unencumbered software released into the public domain.
+ *
+ * Anyone is free to copy, modify, publish, use, compile, sell, or
+ * distribute this software, either in source code form or as a compiled
+ * binary, for any purpose, commercial or non-commercial, and by any
+ * means.
+ *
+ * In jurisdictions that recognize copyright laws, the author or authors
+ * of this software dedicate any and all copyright interest in the
+ * software to the public domain. We make this dedication for the benefit
+ * of the public at large and to the detriment of our heirs and
+ * successors. We intend this dedication to be an overt act of
+ * relinquishment in perpetuity of all present and future rights to this
+ * software under copyright law.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
+ * EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
+ * MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.
+ * IN NO EVENT SHALL THE AUTHORS BE LIABLE FOR ANY CLAIM, DAMAGES OR
+ * OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE,
+ * ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR
+ * OTHER DEALINGS IN THE SOFTWARE.
+ */
+
+#ifndef __gl3w_h_
+#define __gl3w_h_
+
+// Adapted from KHR/khrplatform.h to avoid including entire file.
+#ifndef __khrplatform_h_
+typedef          float         khronos_float_t;
+typedef signed   char          khronos_int8_t;
+typedef unsigned char          khronos_uint8_t;
+typedef signed   short int     khronos_int16_t;
+typedef unsigned short int     khronos_uint16_t;
+#ifdef _WIN64
+typedef signed   long long int khronos_intptr_t;
+typedef signed   long long int khronos_ssize_t;
+#else
+typedef signed   long  int     khronos_intptr_t;
+typedef signed   long  int     khronos_ssize_t;
+#endif
+
+#if defined(_MSC_VER) && !defined(__clang__)
+typedef signed   __int64       khronos_int64_t;
+typedef unsigned __int64       khronos_uint64_t;
+#elif (defined(__clang__) || defined(__GNUC__)) && (__cplusplus < 201100)
+#include <stdint.h>
+typedef          int64_t       khronos_int64_t;
+typedef          uint64_t      khronos_uint64_t;
+#else
+typedef signed   long long     khronos_int64_t;
+typedef unsigned long long     khronos_uint64_t;
+#endif
+#endif  // __khrplatform_h_
+
+#ifndef __gl_glcorearb_h_
+#define __gl_glcorearb_h_ 1
+#ifdef __cplusplus
+extern "C" {
+#endif
+/*
+** Copyright 2013-2020 The Khronos Group Inc.
+** SPDX-License-Identifier: MIT
+**
+** This header is generated from the Khronos OpenGL / OpenGL ES XML
+** API Registry. The current version of the Registry, generator scripts
+** used to make the header, and the header can be found at
+**   https://github.com/KhronosGroup/OpenGL-Registry
+*/
+#if defined(_WIN32) && !defined(APIENTRY) && !defined(__CYGWIN__) && !defined(__SCITECH_SNAP__)
+#ifndef WIN32_LEAN_AND_MEAN
+#define WIN32_LEAN_AND_MEAN 1
+#endif
+#include <windows.h>
+#endif
+#ifndef APIENTRY
+#define APIENTRY
+#endif
+#ifndef APIENTRYP
+#define APIENTRYP APIENTRY *
+#endif
+#ifndef GLAPI
+#define GLAPI extern
+#endif
+/* glcorearb.h is for use with OpenGL core profile implementations.
+** It should should be placed in the same directory as gl.h and
+** included as <GL/glcorearb.h>.
+**
+** glcorearb.h includes only APIs in the latest OpenGL core profile
+** implementation together with APIs in newer ARB extensions which 
+** can be supported by the core profile. It does not, and never will
+** include functionality removed from the core profile, such as
+** fixed-function vertex and fragment processing.
+**
+** Do not #include both <GL/glcorearb.h> and either of <GL/gl.h> or
+** <GL/glext.h> in the same source file.
+*/
+/* Generated C header for:
+ * API: gl
+ * Profile: core
+ * Versions considered: .*
+ * Versions emitted: .*
+ * Default extensions included: glcore
+ * Additional extensions included: _nomatch_^
+ * Extensions removed: _nomatch_^
+ */
+#ifndef GL_VERSION_1_0
+typedef void GLvoid;
+typedef unsigned int GLenum;
+
+typedef khronos_float_t GLfloat;
+typedef int GLint;
+typedef int GLsizei;
+typedef unsigned int GLbitfield;
+typedef double GLdouble;
+typedef unsigned int GLuint;
+typedef unsigned char GLboolean;
+typedef khronos_uint8_t GLubyte;
+#define GL_COLOR_BUFFER_BIT               0x00004000
+#define GL_FALSE                          0
+#define GL_TRUE                           1
+#define GL_TRIANGLES                      0x0004
+#define GL_ONE                            1
+#define GL_SRC_ALPHA                      0x0302
+#define GL_ONE_MINUS_SRC_ALPHA            0x0303
+#define GL_FRONT_AND_BACK                 0x0408
+#define GL_POLYGON_MODE                   0x0B40
+#define GL_CULL_FACE                      0x0B44
+#define GL_DEPTH_TEST                     0x0B71
+#define GL_STENCIL_TEST                   0x0B90
+#define GL_VIEWPORT                       0x0BA2
+#define GL_BLEND                          0x0BE2
+#define GL_SCISSOR_BOX                    0x0C10
+#define GL_SCISSOR_TEST                   0x0C11
+#define GL_UNPACK_ROW_LENGTH              0x0CF2
+#define GL_PACK_ALIGNMENT                 0x0D05
+#define GL_TEXTURE_2D                     0x0DE1
+#define GL_UNSIGNED_BYTE                  0x1401
+#define GL_UNSIGNED_SHORT                 0x1403
+#define GL_UNSIGNED_INT                   0x1405
+#define GL_FLOAT                          0x1406
+#define GL_RGBA                           0x1908
+#define GL_FILL                           0x1B02
+#define GL_VENDOR                         0x1F00
+#define GL_RENDERER                       0x1F01
+#define GL_VERSION                        0x1F02
+#define GL_EXTENSIONS                     0x1F03
+#define GL_LINEAR                         0x2601
+#define GL_TEXTURE_MAG_FILTER             0x2800
+#define GL_TEXTURE_MIN_FILTER             0x2801
+typedef void (APIENTRYP PFNGLPOLYGONMODEPROC) (GLenum face, GLenum mode);
+typedef void (APIENTRYP PFNGLSCISSORPROC) (GLint x, GLint y, GLsizei width, GLsizei height);
+typedef void (APIENTRYP PFNGLTEXPARAMETERIPROC) (GLenum target, GLenum pname, GLint param);
+typedef void (APIENTRYP PFNGLTEXIMAGE2DPROC) (GLenum target, GLint level, GLint internalformat, GLsizei width, GLsizei height, GLint border, GLenum format, GLenum type, const void *pixels);
+typedef void (APIENTRYP PFNGLCLEARPROC) (GLbitfield mask);
+typedef void (APIENTRYP PFNGLCLEARCOLORPROC) (GLfloat red, GLfloat green, GLfloat blue, GLfloat alpha);
+typedef void (APIENTRYP PFNGLDISABLEPROC) (GLenum cap);
+typedef void (APIENTRYP PFNGLENABLEPROC) (GLenum cap);
+typedef void (APIENTRYP PFNGLFLUSHPROC) (void);
+typedef void (APIENTRYP PFNGLPIXELSTOREIPROC) (GLenum pname, GLint param);
+typedef void (APIENTRYP PFNGLREADPIXELSPROC) (GLint x, GLint y, GLsizei width, GLsizei height, GLenum format, GLenum type, void *pixels);
+typedef GLenum (APIENTRYP PFNGLGETERRORPROC) (void);
+typedef void (APIENTRYP PFNGLGETINTEGERVPROC) (GLenum pname, GLint *data);
+typedef const GLubyte *(APIENTRYP PFNGLGETSTRINGPROC) (GLenum name);
+typedef GLboolean (APIENTRYP PFNGLISENABLEDPROC) (GLenum cap);
+typedef void (APIENTRYP PFNGLVIEWPORTPROC) (GLint x, GLint y, GLsizei width, GLsizei height);
+#ifdef GL_GLEXT_PROTOTYPES
+GLAPI void APIENTRY glPolygonMode (GLenum face, GLenum mode);
+GLAPI void APIENTRY glScissor (GLint x, GLint y, GLsizei width, GLsizei height);
+GLAPI void APIENTRY glTexParameteri (GLenum target, GLenum pname, GLint param);
+GLAPI void APIENTRY glTexImage2D (GLenum target, GLint level, GLint internalformat, GLsizei width, GLsizei height, GLint border, GLenum format, GLenum type, const void *pixels);
+GLAPI void APIENTRY glClear (GLbitfield mask);
+GLAPI void APIENTRY glClearColor (GLfloat red, GLfloat green, GLfloat blue, GLfloat alpha);
+GLAPI void APIENTRY glDisable (GLenum cap);
+GLAPI void APIENTRY glEnable (GLenum cap);
+GLAPI void APIENTRY glFlush (void);
+GLAPI void APIENTRY glPixelStorei (GLenum pname, GLint param);
+GLAPI void APIENTRY glReadPixels (GLint x, GLint y, GLsizei width, GLsizei height, GLenum format, GLenum type, void *pixels);
+GLAPI GLenum APIENTRY glGetError (void);
+GLAPI void APIENTRY glGetIntegerv (GLenum pname, GLint *data);
+GLAPI const GLubyte *APIENTRY glGetString (GLenum name);
+GLAPI GLboolean APIENTRY glIsEnabled (GLenum cap);
+GLAPI void APIENTRY glViewport (GLint x, GLint y, GLsizei width, GLsizei height);
+#endif
+#endif /* GL_VERSION_1_0 */
+#ifndef GL_VERSION_1_1
+typedef khronos_float_t GLclampf;
+typedef double GLclampd;
+#define GL_TEXTURE_BINDING_2D             0x8069
+typedef void (APIENTRYP PFNGLDRAWELEMENTSPROC) (GLenum mode, GLsizei count, GLenum type, const void *indices);
+typedef void (APIENTRYP PFNGLBINDTEXTUREPROC) (GLenum target, GLuint texture);
+typedef void (APIENTRYP PFNGLDELETETEXTURESPROC) (GLsizei n, const GLuint *textures);
+typedef void (APIENTRYP PFNGLGENTEXTURESPROC) (GLsizei n, GLuint *textures);
+#ifdef GL_GLEXT_PROTOTYPES
+GLAPI void APIENTRY glDrawElements (GLenum mode, GLsizei count, GLenum type, const void *indices);
+GLAPI void APIENTRY glBindTexture (GLenum target, GLuint texture);
+GLAPI void APIENTRY glDeleteTextures (GLsizei n, const GLuint *textures);
+GLAPI void APIENTRY glGenTextures (GLsizei n, GLuint *textures);
+#endif
+#endif /* GL_VERSION_1_1 */
+#ifndef GL_VERSION_1_3
+#define GL_TEXTURE0                       0x84C0
+#define GL_ACTIVE_TEXTURE                 0x84E0
+typedef void (APIENTRYP PFNGLACTIVETEXTUREPROC) (GLenum texture);
+#ifdef GL_GLEXT_PROTOTYPES
+GLAPI void APIENTRY glActiveTexture (GLenum texture);
+#endif
+#endif /* GL_VERSION_1_3 */
+#ifndef GL_VERSION_1_4
+#define GL_BLEND_DST_RGB                  0x80C8
+#define GL_BLEND_SRC_RGB                  0x80C9
+#define GL_BLEND_DST_ALPHA                0x80CA
+#define GL_BLEND_SRC_ALPHA                0x80CB
+#define GL_FUNC_ADD                       0x8006
+typedef void (APIENTRYP PFNGLBLENDFUNCSEPARATEPROC) (GLenum sfactorRGB, GLenum dfactorRGB, GLenum sfactorAlpha, GLenum dfactorAlpha);
+typedef void (APIENTRYP PFNGLBLENDEQUATIONPROC) (GLenum mode);
+#ifdef GL_GLEXT_PROTOTYPES
+GLAPI void APIENTRY glBlendFuncSeparate (GLenum sfactorRGB, GLenum dfactorRGB, GLenum sfactorAlpha, GLenum dfactorAlpha);
+GLAPI void APIENTRY glBlendEquation (GLenum mode);
+#endif
+#endif /* GL_VERSION_1_4 */
+#ifndef GL_VERSION_1_5
+typedef khronos_ssize_t GLsizeiptr;
+typedef khronos_intptr_t GLintptr;
+#define GL_ARRAY_BUFFER                   0x8892
+#define GL_ELEMENT_ARRAY_BUFFER           0x8893
+#define GL_ARRAY_BUFFER_BINDING           0x8894
+#define GL_ELEMENT_ARRAY_BUFFER_BINDING   0x8895
+#define GL_STREAM_DRAW                    0x88E0
+typedef void (APIENTRYP PFNGLBINDBUFFERPROC) (GLenum target, GLuint buffer);
+typedef void (APIENTRYP PFNGLDELETEBUFFERSPROC) (GLsizei n, const GLuint *buffers);
+typedef void (APIENTRYP PFNGLGENBUFFERSPROC) (GLsizei n, GLuint *buffers);
+typedef void (APIENTRYP PFNGLBUFFERDATAPROC) (GLenum target, GLsizeiptr size, const void *data, GLenum usage);
+typedef void (APIENTRYP PFNGLBUFFERSUBDATAPROC) (GLenum target, GLintptr offset, GLsizeiptr size, const void *data);
+#ifdef GL_GLEXT_PROTOTYPES
+GLAPI void APIENTRY glBindBuffer (GLenum target, GLuint buffer);
+GLAPI void APIENTRY glDeleteBuffers (GLsizei n, const GLuint *buffers);
+GLAPI void APIENTRY glGenBuffers (GLsizei n, GLuint *buffers);
+GLAPI void APIENTRY glBufferData (GLenum target, GLsizeiptr size, const void *data, GLenum usage);
+GLAPI void APIENTRY glBufferSubData (GLenum target, GLintptr offset, GLsizeiptr size, const void *data);
+#endif
+#endif /* GL_VERSION_1_5 */
+#ifndef GL_VERSION_2_0
+typedef char GLchar;
+typedef khronos_int16_t GLshort;
+typedef khronos_int8_t GLbyte;
+typedef khronos_uint16_t GLushort;
+#define GL_BLEND_EQUATION_RGB             0x8009
+#define GL_VERTEX_ATTRIB_ARRAY_ENABLED    0x8622
+#define GL_VERTEX_ATTRIB_ARRAY_SIZE       0x8623
+#define GL_VERTEX_ATTRIB_ARRAY_STRIDE     0x8624
+#define GL_VERTEX_ATTRIB_ARRAY_TYPE       0x8625
+#define GL_VERTEX_ATTRIB_ARRAY_POINTER    0x8645
+#define GL_BLEND_EQUATION_ALPHA           0x883D
+#define GL_VERTEX_ATTRIB_ARRAY_NORMALIZED 0x886A
+#define GL_FRAGMENT_SHADER                0x8B30
+#define GL_VERTEX_SHADER                  0x8B31
+#define GL_COMPILE_STATUS                 0x8B81
+#define GL_LINK_STATUS                    0x8B82
+#define GL_INFO_LOG_LENGTH                0x8B84
+#define GL_CURRENT_PROGRAM                0x8B8D
+#define GL_UPPER_LEFT                     0x8CA2
+typedef void (APIENTRYP PFNGLBLENDEQUATIONSEPARATEPROC) (GLenum modeRGB, GLenum modeAlpha);
+typedef void (APIENTRYP PFNGLATTACHSHADERPROC) (GLuint program, GLuint shader);
+typedef void (APIENTRYP PFNGLCOMPILESHADERPROC) (GLuint shader);
+typedef GLuint (APIENTRYP PFNGLCREATEPROGRAMPROC) (void);
+typedef GLuint (APIENTRYP PFNGLCREATESHADERPROC) (GLenum type);
+typedef void (APIENTRYP PFNGLDELETEPROGRAMPROC) (GLuint program);
+typedef void (APIENTRYP PFNGLDELETESHADERPROC) (GLuint shader);
+typedef void (APIENTRYP PFNGLDETACHSHADERPROC) (GLuint program, GLuint shader);
+typedef void (APIENTRYP PFNGLDISABLEVERTEXATTRIBARRAYPROC) (GLuint index);
+typedef void (APIENTRYP PFNGLENABLEVERTEXATTRIBARRAYPROC) (GLuint index);
+typedef GLint (APIENTRYP PFNGLGETATTRIBLOCATIONPROC) (GLuint program, const GLchar *name);
+typedef void (APIENTRYP PFNGLGETPROGRAMIVPROC) (GLuint program, GLenum pname, GLint *params);
+typedef void (APIENTRYP PFNGLGETPROGRAMINFOLOGPROC) (GLuint program, GLsizei bufSize, GLsizei *length, GLchar *infoLog);
+typedef void (APIENTRYP PFNGLGETSHADERIVPROC) (GLuint shader, GLenum pname, GLint *params);
+typedef void (APIENTRYP PFNGLGETSHADERINFOLOGPROC) (GLuint shader, GLsizei bufSize, GLsizei *length, GLchar *infoLog);
+typedef GLint (APIENTRYP PFNGLGETUNIFORMLOCATIONPROC) (GLuint program, const GLchar *name);
+typedef void (APIENTRYP PFNGLGETVERTEXATTRIBIVPROC) (GLuint index, GLenum pname, GLint *params);
+typedef void (APIENTRYP PFNGLGETVERTEXATTRIBPOINTERVPROC) (GLuint index, GLenum pname, void **pointer);
+typedef void (APIENTRYP PFNGLLINKPROGRAMPROC) (GLuint program);
+typedef void (APIENTRYP PFNGLSHADERSOURCEPROC) (GLuint shader, GLsizei count, const GLchar *const*string, const GLint *length);
+typedef void (APIENTRYP PFNGLUSEPROGRAMPROC) (GLuint program);
+typedef void (APIENTRYP PFNGLUNIFORM1IPROC) (GLint location, GLint v0);
+typedef void (APIENTRYP PFNGLUNIFORMMATRIX4FVPROC) (GLint location, GLsizei count, GLboolean transpose, const GLfloat *value);
+typedef void (APIENTRYP PFNGLVERTEXATTRIBPOINTERPROC) (GLuint index, GLint size, GLenum type, GLboolean normalized, GLsizei stride, const void *pointer);
+#ifdef GL_GLEXT_PROTOTYPES
+GLAPI void APIENTRY glBlendEquationSeparate (GLenum modeRGB, GLenum modeAlpha);
+GLAPI void APIENTRY glAttachShader (GLuint program, GLuint shader);
+GLAPI void APIENTRY glCompileShader (GLuint shader);
+GLAPI GLuint APIENTRY glCreateProgram (void);
+GLAPI GLuint APIENTRY glCreateShader (GLenum type);
+GLAPI void APIENTRY glDeleteProgram (GLuint program);
+GLAPI void APIENTRY glDeleteShader (GLuint shader);
+GLAPI void APIENTRY glDetachShader (GLuint program, GLuint shader);
+GLAPI void APIENTRY glDisableVertexAttribArray (GLuint index);
+GLAPI void APIENTRY glEnableVertexAttribArray (GLuint index);
+GLAPI GLint APIENTRY glGetAttribLocation (GLuint program, const GLchar *name);
+GLAPI void APIENTRY glGetProgramiv (GLuint program, GLenum pname, GLint *params);
+GLAPI void APIENTRY glGetProgramInfoLog (GLuint program, GLsizei bufSize, GLsizei *length, GLchar *infoLog);
+GLAPI void APIENTRY glGetShaderiv (GLuint shader, GLenum pname, GLint *params);
+GLAPI void APIENTRY glGetShaderInfoLog (GLuint shader, GLsizei bufSize, GLsizei *length, GLchar *infoLog);
+GLAPI GLint APIENTRY glGetUniformLocation (GLuint program, const GLchar *name);
+GLAPI void APIENTRY glGetVertexAttribiv (GLuint index, GLenum pname, GLint *params);
+GLAPI void APIENTRY glGetVertexAttribPointerv (GLuint index, GLenum pname, void **pointer);
+GLAPI void APIENTRY glLinkProgram (GLuint program);
+GLAPI void APIENTRY glShaderSource (GLuint shader, GLsizei count, const GLchar *const*string, const GLint *length);
+GLAPI void APIENTRY glUseProgram (GLuint program);
+GLAPI void APIENTRY glUniform1i (GLint location, GLint v0);
+GLAPI void APIENTRY glUniformMatrix4fv (GLint location, GLsizei count, GLboolean transpose, const GLfloat *value);
+GLAPI void APIENTRY glVertexAttribPointer (GLuint index, GLint size, GLenum type, GLboolean normalized, GLsizei stride, const void *pointer);
+#endif
+#endif /* GL_VERSION_2_0 */
+#ifndef GL_VERSION_3_0
+typedef khronos_uint16_t GLhalf;
+#define GL_MAJOR_VERSION                  0x821B
+#define GL_MINOR_VERSION                  0x821C
+#define GL_NUM_EXTENSIONS                 0x821D
+#define GL_FRAMEBUFFER_SRGB               0x8DB9
+#define GL_VERTEX_ARRAY_BINDING           0x85B5
+typedef void (APIENTRYP PFNGLGETBOOLEANI_VPROC) (GLenum target, GLuint index, GLboolean *data);
+typedef void (APIENTRYP PFNGLGETINTEGERI_VPROC) (GLenum target, GLuint index, GLint *data);
+typedef const GLubyte *(APIENTRYP PFNGLGETSTRINGIPROC) (GLenum name, GLuint index);
+typedef void (APIENTRYP PFNGLBINDVERTEXARRAYPROC) (GLuint array);
+typedef void (APIENTRYP PFNGLDELETEVERTEXARRAYSPROC) (GLsizei n, const GLuint *arrays);
+typedef void (APIENTRYP PFNGLGENVERTEXARRAYSPROC) (GLsizei n, GLuint *arrays);
+#ifdef GL_GLEXT_PROTOTYPES
+GLAPI const GLubyte *APIENTRY glGetStringi (GLenum name, GLuint index);
+GLAPI void APIENTRY glBindVertexArray (GLuint array);
+GLAPI void APIENTRY glDeleteVertexArrays (GLsizei n, const GLuint *arrays);
+GLAPI void APIENTRY glGenVertexArrays (GLsizei n, GLuint *arrays);
+#endif
+#endif /* GL_VERSION_3_0 */
+#ifndef GL_VERSION_3_1
+#define GL_VERSION_3_1 1
+#define GL_PRIMITIVE_RESTART              0x8F9D
+#endif /* GL_VERSION_3_1 */
+#ifndef GL_VERSION_3_2
+#define GL_VERSION_3_2 1
+typedef struct __GLsync *GLsync;
+typedef khronos_uint64_t GLuint64;
+typedef khronos_int64_t GLint64;
+typedef void (APIENTRYP PFNGLDRAWELEMENTSBASEVERTEXPROC) (GLenum mode, GLsizei count, GLenum type, const void *indices, GLint basevertex);
+typedef void (APIENTRYP PFNGLGETINTEGER64I_VPROC) (GLenum target, GLuint index, GLint64 *data);
+#ifdef GL_GLEXT_PROTOTYPES
+GLAPI void APIENTRY glDrawElementsBaseVertex (GLenum mode, GLsizei count, GLenum type, const void *indices, GLint basevertex);
+#endif
+#endif /* GL_VERSION_3_2 */
+#ifndef GL_VERSION_3_3
+#define GL_VERSION_3_3 1
+#define GL_SAMPLER_BINDING                0x8919
+typedef void (APIENTRYP PFNGLBINDSAMPLERPROC) (GLuint unit, GLuint sampler);
+#ifdef GL_GLEXT_PROTOTYPES
+GLAPI void APIENTRY glBindSampler (GLuint unit, GLuint sampler);
+#endif
+#endif /* GL_VERSION_3_3 */
+#ifndef GL_VERSION_4_1
+typedef void (APIENTRYP PFNGLGETFLOATI_VPROC) (GLenum target, GLuint index, GLfloat *data);
+typedef void (APIENTRYP PFNGLGETDOUBLEI_VPROC) (GLenum target, GLuint index, GLdouble *data);
+#endif /* GL_VERSION_4_1 */
+#ifndef GL_VERSION_4_3
+typedef void (APIENTRY  *GLDEBUGPROC)(GLenum source,GLenum type,GLuint id,GLenum severity,GLsizei length,const GLchar *message,const void *userParam);
+#endif /* GL_VERSION_4_3 */
+#ifndef GL_VERSION_4_5
+#define GL_CLIP_ORIGIN                    0x935C
+typedef void (APIENTRYP PFNGLGETTRANSFORMFEEDBACKI_VPROC) (GLuint xfb, GLenum pname, GLuint index, GLint *param);
+typedef void (APIENTRYP PFNGLGETTRANSFORMFEEDBACKI64_VPROC) (GLuint xfb, GLenum pname, GLuint index, GLint64 *param);
+#endif /* GL_VERSION_4_5 */
+#ifndef GL_ARB_bindless_texture
+typedef khronos_uint64_t GLuint64EXT;
+#endif /* GL_ARB_bindless_texture */
+#ifndef GL_ARB_cl_event
+struct _cl_context;
+struct _cl_event;
+#endif /* GL_ARB_cl_event */
+#ifndef GL_ARB_clip_control
+#define GL_ARB_clip_control 1
+#endif /* GL_ARB_clip_control */
+#ifndef GL_ARB_debug_output
+typedef void (APIENTRY  *GLDEBUGPROCARB)(GLenum source,GLenum type,GLuint id,GLenum severity,GLsizei length,const GLchar *message,const void *userParam);
+#endif /* GL_ARB_debug_output */
+#ifndef GL_EXT_EGL_image_storage
+typedef void *GLeglImageOES;
+#endif /* GL_EXT_EGL_image_storage */
+#ifndef GL_EXT_direct_state_access
+typedef void (APIENTRYP PFNGLGETFLOATI_VEXTPROC) (GLenum pname, GLuint index, GLfloat *params);
+typedef void (APIENTRYP PFNGLGETDOUBLEI_VEXTPROC) (GLenum pname, GLuint index, GLdouble *params);
+typedef void (APIENTRYP PFNGLGETPOINTERI_VEXTPROC) (GLenum pname, GLuint index, void **params);
+typedef void (APIENTRYP PFNGLGETVERTEXARRAYINTEGERI_VEXTPROC) (GLuint vaobj, GLuint index, GLenum pname, GLint *param);
+typedef void (APIENTRYP PFNGLGETVERTEXARRAYPOINTERI_VEXTPROC) (GLuint vaobj, GLuint index, GLenum pname, void **param);
+#endif /* GL_EXT_direct_state_access */
+#ifndef GL_NV_draw_vulkan_image
+typedef void (APIENTRY  *GLVULKANPROCNV)(void);
+#endif /* GL_NV_draw_vulkan_image */
+#ifndef GL_NV_gpu_shader5
+typedef khronos_int64_t GLint64EXT;
+#endif /* GL_NV_gpu_shader5 */
+#ifndef GL_NV_vertex_buffer_unified_memory
+typedef void (APIENTRYP PFNGLGETINTEGERUI64I_VNVPROC) (GLenum value, GLuint index, GLuint64EXT *result);
+#endif /* GL_NV_vertex_buffer_unified_memory */
+#ifdef __cplusplus
+}
+#endif
+#endif
+
+#ifndef GL3W_API
+#define GL3W_API
+#endif
+
+#ifndef __gl_h_
+#define __gl_h_
+#endif
+
+#ifdef __cplusplus
+extern "C" {
+#endif
+
+#define GL3W_OK 0
+#define GL3W_ERROR_INIT -1
+#define GL3W_ERROR_LIBRARY_OPEN -2
+#define GL3W_ERROR_OPENGL_VERSION -3
+
+typedef void (*GL3WglProc)(void);
+typedef GL3WglProc (*GL3WGetProcAddressProc)(const char *proc);
+
+/* gl3w api */
+GL3W_API int imgl3wInit(void);
+GL3W_API int imgl3wInit2(GL3WGetProcAddressProc proc);
+GL3W_API int imgl3wIsSupported(int major, int minor);
+GL3W_API GL3WglProc imgl3wGetProcAddress(const char *proc);
+
+/* gl3w internal state */
+union GL3WProcs {
+    GL3WglProc ptr[58];
+    struct {
+        PFNGLACTIVETEXTUREPROC            ActiveTexture;
+        PFNGLATTACHSHADERPROC             AttachShader;
+        PFNGLBINDBUFFERPROC               BindBuffer;
+        PFNGLBINDSAMPLERPROC              BindSampler;
+        PFNGLBINDTEXTUREPROC              BindTexture;
+        PFNGLBINDVERTEXARRAYPROC          BindVertexArray;
+        PFNGLBLENDEQUATIONPROC            BlendEquation;
+        PFNGLBLENDEQUATIONSEPARATEPROC    BlendEquationSeparate;
+        PFNGLBLENDFUNCSEPARATEPROC        BlendFuncSeparate;
+        PFNGLBUFFERDATAPROC               BufferData;
+        PFNGLBUFFERSUBDATAPROC            BufferSubData;
+        PFNGLCLEARPROC                    Clear;
+        PFNGLCLEARCOLORPROC               ClearColor;
+        PFNGLCOMPILESHADERPROC            CompileShader;
+        PFNGLCREATEPROGRAMPROC            CreateProgram;
+        PFNGLCREATESHADERPROC             CreateShader;
+        PFNGLDELETEBUFFERSPROC            DeleteBuffers;
+        PFNGLDELETEPROGRAMPROC            DeleteProgram;
+        PFNGLDELETESHADERPROC             DeleteShader;
+        PFNGLDELETETEXTURESPROC           DeleteTextures;
+        PFNGLDELETEVERTEXARRAYSPROC       DeleteVertexArrays;
+        PFNGLDETACHSHADERPROC             DetachShader;
+        PFNGLDISABLEPROC                  Disable;
+        PFNGLDISABLEVERTEXATTRIBARRAYPROC DisableVertexAttribArray;
+        PFNGLDRAWELEMENTSPROC             DrawElements;
+        PFNGLDRAWELEMENTSBASEVERTEXPROC   DrawElementsBaseVertex;
+        PFNGLENABLEPROC                   Enable;
+        PFNGLENABLEVERTEXATTRIBARRAYPROC  EnableVertexAttribArray;
+        PFNGLFLUSHPROC                    Flush;
+        PFNGLGENBUFFERSPROC               GenBuffers;
+        PFNGLGENTEXTURESPROC              GenTextures;
+        PFNGLGENVERTEXARRAYSPROC          GenVertexArrays;
+        PFNGLGETATTRIBLOCATIONPROC        GetAttribLocation;
+        PFNGLGETERRORPROC                 GetError;
+        PFNGLGETINTEGERVPROC              GetIntegerv;
+        PFNGLGETPROGRAMINFOLOGPROC        GetProgramInfoLog;
+        PFNGLGETPROGRAMIVPROC             GetProgramiv;
+        PFNGLGETSHADERINFOLOGPROC         GetShaderInfoLog;
+        PFNGLGETSHADERIVPROC              GetShaderiv;
+        PFNGLGETSTRINGPROC                GetString;
+        PFNGLGETSTRINGIPROC               GetStringi;
+        PFNGLGETUNIFORMLOCATIONPROC       GetUniformLocation;
+        PFNGLGETVERTEXATTRIBPOINTERVPROC  GetVertexAttribPointerv;
+        PFNGLGETVERTEXATTRIBIVPROC        GetVertexAttribiv;
+        PFNGLISENABLEDPROC                IsEnabled;
+        PFNGLLINKPROGRAMPROC              LinkProgram;
+        PFNGLPIXELSTOREIPROC              PixelStorei;
+        PFNGLPOLYGONMODEPROC              PolygonMode;
+        PFNGLREADPIXELSPROC               ReadPixels;
+        PFNGLSCISSORPROC                  Scissor;
+        PFNGLSHADERSOURCEPROC             ShaderSource;
+        PFNGLTEXIMAGE2DPROC               TexImage2D;
+        PFNGLTEXPARAMETERIPROC            TexParameteri;
+        PFNGLUNIFORM1IPROC                Uniform1i;
+        PFNGLUNIFORMMATRIX4FVPROC         UniformMatrix4fv;
+        PFNGLUSEPROGRAMPROC               UseProgram;
+        PFNGLVERTEXATTRIBPOINTERPROC      VertexAttribPointer;
+        PFNGLVIEWPORTPROC                 Viewport;
+    } gl;
+};
+
+GL3W_API extern union GL3WProcs imgl3wProcs;
+
+/* OpenGL functions */
+#define glActiveTexture                   imgl3wProcs.gl.ActiveTexture
+#define glAttachShader                    imgl3wProcs.gl.AttachShader
+#define glBindBuffer                      imgl3wProcs.gl.BindBuffer
+#define glBindSampler                     imgl3wProcs.gl.BindSampler
+#define glBindTexture                     imgl3wProcs.gl.BindTexture
+#define glBindVertexArray                 imgl3wProcs.gl.BindVertexArray
+#define glBlendEquation                   imgl3wProcs.gl.BlendEquation
+#define glBlendEquationSeparate           imgl3wProcs.gl.BlendEquationSeparate
+#define glBlendFuncSeparate               imgl3wProcs.gl.BlendFuncSeparate
+#define glBufferData                      imgl3wProcs.gl.BufferData
+#define glBufferSubData                   imgl3wProcs.gl.BufferSubData
+#define glClear                           imgl3wProcs.gl.Clear
+#define glClearColor                      imgl3wProcs.gl.ClearColor
+#define glCompileShader                   imgl3wProcs.gl.CompileShader
+#define glCreateProgram                   imgl3wProcs.gl.CreateProgram
+#define glCreateShader                    imgl3wProcs.gl.CreateShader
+#define glDeleteBuffers                   imgl3wProcs.gl.DeleteBuffers
+#define glDeleteProgram                   imgl3wProcs.gl.DeleteProgram
+#define glDeleteShader                    imgl3wProcs.gl.DeleteShader
+#define glDeleteTextures                  imgl3wProcs.gl.DeleteTextures
+#define glDeleteVertexArrays              imgl3wProcs.gl.DeleteVertexArrays
+#define glDetachShader                    imgl3wProcs.gl.DetachShader
+#define glDisable                         imgl3wProcs.gl.Disable
+#define glDisableVertexAttribArray        imgl3wProcs.gl.DisableVertexAttribArray
+#define glDrawElements                    imgl3wProcs.gl.DrawElements
+#define glDrawElementsBaseVertex          imgl3wProcs.gl.DrawElementsBaseVertex
+#define glEnable                          imgl3wProcs.gl.Enable
+#define glEnableVertexAttribArray         imgl3wProcs.gl.EnableVertexAttribArray
+#define glFlush                           imgl3wProcs.gl.Flush
+#define glGenBuffers                      imgl3wProcs.gl.GenBuffers
+#define glGenTextures                     imgl3wProcs.gl.GenTextures
+#define glGenVertexArrays                 imgl3wProcs.gl.GenVertexArrays
+#define glGetAttribLocation               imgl3wProcs.gl.GetAttribLocation
+#define glGetError                        imgl3wProcs.gl.GetError
+#define glGetIntegerv                     imgl3wProcs.gl.GetIntegerv
+#define glGetProgramInfoLog               imgl3wProcs.gl.GetProgramInfoLog
+#define glGetProgramiv                    imgl3wProcs.gl.GetProgramiv
+#define glGetShaderInfoLog                imgl3wProcs.gl.GetShaderInfoLog
+#define glGetShaderiv                     imgl3wProcs.gl.GetShaderiv
+#define glGetString                       imgl3wProcs.gl.GetString
+#define glGetStringi                      imgl3wProcs.gl.GetStringi
+#define glGetUniformLocation              imgl3wProcs.gl.GetUniformLocation
+#define glGetVertexAttribPointerv         imgl3wProcs.gl.GetVertexAttribPointerv
+#define glGetVertexAttribiv               imgl3wProcs.gl.GetVertexAttribiv
+#define glIsEnabled                       imgl3wProcs.gl.IsEnabled
+#define glLinkProgram                     imgl3wProcs.gl.LinkProgram
+#define glPixelStorei                     imgl3wProcs.gl.PixelStorei
+#define glPolygonMode                     imgl3wProcs.gl.PolygonMode
+#define glReadPixels                      imgl3wProcs.gl.ReadPixels
+#define glScissor                         imgl3wProcs.gl.Scissor
+#define glShaderSource                    imgl3wProcs.gl.ShaderSource
+#define glTexImage2D                      imgl3wProcs.gl.TexImage2D
+#define glTexParameteri                   imgl3wProcs.gl.TexParameteri
+#define glUniform1i                       imgl3wProcs.gl.Uniform1i
+#define glUniformMatrix4fv                imgl3wProcs.gl.UniformMatrix4fv
+#define glUseProgram                      imgl3wProcs.gl.UseProgram
+#define glVertexAttribPointer             imgl3wProcs.gl.VertexAttribPointer
+#define glViewport                        imgl3wProcs.gl.Viewport
+
+#ifdef __cplusplus
+}
+#endif
+
+#endif
+
+#ifdef IMGL3W_IMPL
+#ifdef __cplusplus
+extern "C" {
+#endif
+
+#include <stdlib.h>
+
+#define ARRAY_SIZE(x)  (sizeof(x) / sizeof((x)[0]))
+
+#if defined(_WIN32)
+#ifndef WIN32_LEAN_AND_MEAN
+#define WIN32_LEAN_AND_MEAN 1
+#endif
+#include <windows.h>
+
+static HMODULE libgl;
+typedef PROC(__stdcall* GL3WglGetProcAddr)(LPCSTR);
+static GL3WglGetProcAddr wgl_get_proc_address;
+
+static int open_libgl(void)
+{
+    libgl = LoadLibraryA("opengl32.dll");
+    if (!libgl)
+        return GL3W_ERROR_LIBRARY_OPEN;
+    wgl_get_proc_address = (GL3WglGetProcAddr)GetProcAddress(libgl, "wglGetProcAddress");
+    return GL3W_OK;
+}
+
+static void close_libgl(void) { FreeLibrary(libgl); }
+static GL3WglProc get_proc(const char *proc)
+{
+    GL3WglProc res;
+    res = (GL3WglProc)wgl_get_proc_address(proc);
+    if (!res)
+        res = (GL3WglProc)GetProcAddress(libgl, proc);
+    return res;
+}
+#elif defined(__APPLE__)
+#include <dlfcn.h>
+
+static void *libgl;
+static int open_libgl(void)
+{
+    libgl = dlopen("/System/Library/Frameworks/OpenGL.framework/OpenGL", RTLD_LAZY | RTLD_LOCAL);
+    if (!libgl)
+        return GL3W_ERROR_LIBRARY_OPEN;
+    return GL3W_OK;
+}
+
+static void close_libgl(void) { dlclose(libgl); }
+
+static GL3WglProc get_proc(const char *proc)
+{
+    GL3WglProc res;
+    *(void **)(&res) = dlsym(libgl, proc);
+    return res;
+}
+#else
+#include <dlfcn.h>
+
+static void *libgl;
+static GL3WglProc (*glx_get_proc_address)(const GLubyte *);
+
+static int open_libgl(void)
+{
+    libgl = dlopen("libGL.so.1", RTLD_LAZY | RTLD_LOCAL);
+    if (!libgl)
+        return GL3W_ERROR_LIBRARY_OPEN;
+    *(void **)(&glx_get_proc_address) = dlsym(libgl, "glXGetProcAddressARB");
+    return GL3W_OK;
+}
+
+static void close_libgl(void) { dlclose(libgl); }
+
+static GL3WglProc get_proc(const char *proc)
+{
+    GL3WglProc res;
+    res = glx_get_proc_address((const GLubyte *)proc);
+    if (!res)
+        *(void **)(&res) = dlsym(libgl, proc);
+    return res;
+}
+#endif
+
+static struct { int major, minor; } version;
+
+static int parse_version(void)
+{
+    if (!glGetIntegerv)
+        return GL3W_ERROR_INIT;
+    glGetIntegerv(GL_MAJOR_VERSION, &version.major);
+    glGetIntegerv(GL_MINOR_VERSION, &version.minor);
+    if (version.major < 3)
+        return GL3W_ERROR_OPENGL_VERSION;
+    return GL3W_OK;
+}
+
+static void load_procs(GL3WGetProcAddressProc proc);
+
+int imgl3wInit(void)
+{
+    int res = open_libgl();
+    if (res)
+        return res;
+    atexit(close_libgl);
+    return imgl3wInit2(get_proc);
+}
+
+int imgl3wInit2(GL3WGetProcAddressProc proc)
+{
+    load_procs(proc);
+    return parse_version();
+}
+
+int imgl3wIsSupported(int major, int minor)
+{
+    if (major < 3)
+        return 0;
+    if (version.major == major)
+        return version.minor >= minor;
+    return version.major >= major;
+}
+
+GL3WglProc imgl3wGetProcAddress(const char *proc) { return get_proc(proc); }
+
+static const char *proc_names[] = {
+    "glActiveTexture",
+    "glAttachShader",
+    "glBindBuffer",
+    "glBindSampler",
+    "glBindTexture",
+    "glBindVertexArray",
+    "glBlendEquation",
+    "glBlendEquationSeparate",
+    "glBlendFuncSeparate",
+    "glBufferData",
+    "glBufferSubData",
+    "glClear",
+    "glClearColor",
+    "glCompileShader",
+    "glCreateProgram",
+    "glCreateShader",
+    "glDeleteBuffers",
+    "glDeleteProgram",
+    "glDeleteShader",
+    "glDeleteTextures",
+    "glDeleteVertexArrays",
+    "glDetachShader",
+    "glDisable",
+    "glDisableVertexAttribArray",
+    "glDrawElements",
+    "glDrawElementsBaseVertex",
+    "glEnable",
+    "glEnableVertexAttribArray",
+    "glFlush",
+    "glGenBuffers",
+    "glGenTextures",
+    "glGenVertexArrays",
+    "glGetAttribLocation",
+    "glGetError",
+    "glGetIntegerv",
+    "glGetProgramInfoLog",
+    "glGetProgramiv",
+    "glGetShaderInfoLog",
+    "glGetShaderiv",
+    "glGetString",
+    "glGetStringi",
+    "glGetUniformLocation",
+    "glGetVertexAttribPointerv",
+    "glGetVertexAttribiv",
+    "glIsEnabled",
+    "glLinkProgram",
+    "glPixelStorei",
+    "glPolygonMode",
+    "glReadPixels",
+    "glScissor",
+    "glShaderSource",
+    "glTexImage2D",
+    "glTexParameteri",
+    "glUniform1i",
+    "glUniformMatrix4fv",
+    "glUseProgram",
+    "glVertexAttribPointer",
+    "glViewport",
+};
+
+GL3W_API union GL3WProcs imgl3wProcs;
+
+static void load_procs(GL3WGetProcAddressProc proc)
+{
+    size_t i;
+    for (i = 0; i < ARRAY_SIZE(proc_names); i++)
+        imgl3wProcs.ptr[i] = proc(proc_names[i]);
+}
+
+#ifdef __cplusplus
+}
+#endif
+#endif

includes/imgui/backends/imgui_impl_vulkan.h

@@ -1,157 +0,0 @@
-// dear imgui: Renderer Backend for Vulkan
-// This needs to be used along with a Platform Backend (e.g. GLFW, SDL, Win32, custom..)
-
-// Implemented features:
-//  [X] Renderer: Support for large meshes (64k+ vertices) with 16-bit indices.
-//  [!] Renderer: User texture binding. Use 'VkDescriptorSet' as ImTextureID. Read the FAQ about ImTextureID! See https://github.com/ocornut/imgui/pull/914 for discussions.
-
-// Important: on 32-bit systems, user texture binding is only supported if your imconfig file has '#define ImTextureID ImU64'.
-// See imgui_impl_vulkan.cpp file for details.
-
-// You can use unmodified imgui_impl_* files in your project. See examples/ folder for examples of using this.
-// Prefer including the entire imgui/ repository into your project (either as a copy or as a submodule), and only build the backends you need.
-// If you are new to Dear ImGui, read documentation from the docs/ folder + read the top of imgui.cpp.
-// Read online: https://github.com/ocornut/imgui/tree/master/docs
-
-// The aim of imgui_impl_vulkan.h/.cpp is to be usable in your engine without any modification.
-// IF YOU FEEL YOU NEED TO MAKE ANY CHANGE TO THIS CODE, please share them and your feedback at https://github.com/ocornut/imgui/
-
-// Important note to the reader who wish to integrate imgui_impl_vulkan.cpp/.h in their own engine/app.
-// - Common ImGui_ImplVulkan_XXX functions and structures are used to interface with imgui_impl_vulkan.cpp/.h.
-//   You will use those if you want to use this rendering backend in your engine/app.
-// - Helper ImGui_ImplVulkanH_XXX functions and structures are only used by this example (main.cpp) and by
-//   the backend itself (imgui_impl_vulkan.cpp), but should PROBABLY NOT be used by your own engine/app code.
-// Read comments in imgui_impl_vulkan.h.
-
-#pragma once
-#include "imgui.h"      // IMGUI_IMPL_API
-
-// [Configuration] in order to use a custom Vulkan function loader:
-// (1) You'll need to disable default Vulkan function prototypes.
-//     We provide a '#define IMGUI_IMPL_VULKAN_NO_PROTOTYPES' convenience configuration flag.
-//     In order to make sure this is visible from the imgui_impl_vulkan.cpp compilation unit:
-//     - Add '#define IMGUI_IMPL_VULKAN_NO_PROTOTYPES' in your imconfig.h file
-//     - Or as a compilation flag in your build system
-//     - Or uncomment here (not recommended because you'd be modifying imgui sources!)
-//     - Do not simply add it in a .cpp file!
-// (2) Call ImGui_ImplVulkan_LoadFunctions() before ImGui_ImplVulkan_Init() with your custom function.
-// If you have no idea what this is, leave it alone!
-//#define IMGUI_IMPL_VULKAN_NO_PROTOTYPES
-
-// Vulkan includes
-#if defined(IMGUI_IMPL_VULKAN_NO_PROTOTYPES) && !defined(VK_NO_PROTOTYPES)
-#define VK_NO_PROTOTYPES
-#endif
-#include <vulkan/vulkan.h>
-
-// Initialization data, for ImGui_ImplVulkan_Init()
-// [Please zero-clear before use!]
-struct ImGui_ImplVulkan_InitInfo
-{
-    VkInstance                      Instance;
-    VkPhysicalDevice                PhysicalDevice;
-    VkDevice                        Device;
-    uint32_t                        QueueFamily;
-    VkQueue                         Queue;
-    VkPipelineCache                 PipelineCache;
-    VkDescriptorPool                DescriptorPool;
-    uint32_t                        Subpass;
-    uint32_t                        MinImageCount;          // >= 2
-    uint32_t                        ImageCount;             // >= MinImageCount
-    VkSampleCountFlagBits           MSAASamples;            // >= VK_SAMPLE_COUNT_1_BIT (0 -> default to VK_SAMPLE_COUNT_1_BIT)
-    const VkAllocationCallbacks*    Allocator;
-    void                            (*CheckVkResultFn)(VkResult err);
-};
-
-// Called by user code
-IMGUI_IMPL_API bool         ImGui_ImplVulkan_Init(ImGui_ImplVulkan_InitInfo* info, VkRenderPass render_pass);
-IMGUI_IMPL_API void         ImGui_ImplVulkan_Shutdown();
-IMGUI_IMPL_API void         ImGui_ImplVulkan_NewFrame();
-IMGUI_IMPL_API void         ImGui_ImplVulkan_RenderDrawData(ImDrawData* draw_data, VkCommandBuffer command_buffer, VkPipeline pipeline = VK_NULL_HANDLE);
-IMGUI_IMPL_API bool         ImGui_ImplVulkan_CreateFontsTexture(VkCommandBuffer command_buffer);
-IMGUI_IMPL_API void         ImGui_ImplVulkan_DestroyFontUploadObjects();
-IMGUI_IMPL_API void         ImGui_ImplVulkan_SetMinImageCount(uint32_t min_image_count); // To override MinImageCount after initialization (e.g. if swap chain is recreated)
-
-// Register a texture (VkDescriptorSet == ImTextureID)
-// FIXME: This is experimental in the sense that we are unsure how to best design/tackle this problem
-// Please post to https://github.com/ocornut/imgui/pull/914 if you have suggestions.
-IMGUI_IMPL_API VkDescriptorSet ImGui_ImplVulkan_AddTexture(VkSampler sampler, VkImageView image_view, VkImageLayout image_layout);
-IMGUI_IMPL_API void            ImGui_ImplVulkan_RemoveTexture(VkDescriptorSet descriptor_set);
-
-// Optional: load Vulkan functions with a custom function loader
-// This is only useful with IMGUI_IMPL_VULKAN_NO_PROTOTYPES / VK_NO_PROTOTYPES
-IMGUI_IMPL_API bool         ImGui_ImplVulkan_LoadFunctions(PFN_vkVoidFunction(*loader_func)(const char* function_name, void* user_data), void* user_data = nullptr);
-
-//-------------------------------------------------------------------------
-// Internal / Miscellaneous Vulkan Helpers
-// (Used by example's main.cpp. Used by multi-viewport features. PROBABLY NOT used by your own engine/app.)
-//-------------------------------------------------------------------------
-// You probably do NOT need to use or care about those functions.
-// Those functions only exist because:
-//   1) they facilitate the readability and maintenance of the multiple main.cpp examples files.
-//   2) the upcoming multi-viewport feature will need them internally.
-// Generally we avoid exposing any kind of superfluous high-level helpers in the backends,
-// but it is too much code to duplicate everywhere so we exceptionally expose them.
-//
-// Your engine/app will likely _already_ have code to setup all that stuff (swap chain, render pass, frame buffers, etc.).
-// You may read this code to learn about Vulkan, but it is recommended you use you own custom tailored code to do equivalent work.
-// (The ImGui_ImplVulkanH_XXX functions do not interact with any of the state used by the regular ImGui_ImplVulkan_XXX functions)
-//-------------------------------------------------------------------------
-
-struct ImGui_ImplVulkanH_Frame;
-struct ImGui_ImplVulkanH_Window;
-
-// Helpers
-IMGUI_IMPL_API void                 ImGui_ImplVulkanH_CreateOrResizeWindow(VkInstance instance, VkPhysicalDevice physical_device, VkDevice device, ImGui_ImplVulkanH_Window* wnd, uint32_t queue_family, const VkAllocationCallbacks* allocator, int w, int h, uint32_t min_image_count);
-IMGUI_IMPL_API void                 ImGui_ImplVulkanH_DestroyWindow(VkInstance instance, VkDevice device, ImGui_ImplVulkanH_Window* wnd, const VkAllocationCallbacks* allocator);
-IMGUI_IMPL_API VkSurfaceFormatKHR   ImGui_ImplVulkanH_SelectSurfaceFormat(VkPhysicalDevice physical_device, VkSurfaceKHR surface, const VkFormat* request_formats, int request_formats_count, VkColorSpaceKHR request_color_space);
-IMGUI_IMPL_API VkPresentModeKHR     ImGui_ImplVulkanH_SelectPresentMode(VkPhysicalDevice physical_device, VkSurfaceKHR surface, const VkPresentModeKHR* request_modes, int request_modes_count);
-IMGUI_IMPL_API int                  ImGui_ImplVulkanH_GetMinImageCountFromPresentMode(VkPresentModeKHR present_mode);
-
-// Helper structure to hold the data needed by one rendering frame
-// (Used by example's main.cpp. Used by multi-viewport features. Probably NOT used by your own engine/app.)
-// [Please zero-clear before use!]
-struct ImGui_ImplVulkanH_Frame
-{
-    VkCommandPool       CommandPool;
-    VkCommandBuffer     CommandBuffer;
-    VkFence             Fence;
-    VkImage             Backbuffer;
-    VkImageView         BackbufferView;
-    VkFramebuffer       Framebuffer;
-};
-
-struct ImGui_ImplVulkanH_FrameSemaphores
-{
-    VkSemaphore         ImageAcquiredSemaphore;
-    VkSemaphore         RenderCompleteSemaphore;
-};
-
-// Helper structure to hold the data needed by one rendering context into one OS window
-// (Used by example's main.cpp. Used by multi-viewport features. Probably NOT used by your own engine/app.)
-struct ImGui_ImplVulkanH_Window
-{
-    int                 Width;
-    int                 Height;
-    VkSwapchainKHR      Swapchain;
-    VkSurfaceKHR        Surface;
-    VkSurfaceFormatKHR  SurfaceFormat;
-    VkPresentModeKHR    PresentMode;
-    VkRenderPass        RenderPass;
-    VkPipeline          Pipeline;               // The window pipeline may uses a different VkRenderPass than the one passed in ImGui_ImplVulkan_InitInfo
-    bool                ClearEnable;
-    VkClearValue        ClearValue;
-    uint32_t            FrameIndex;             // Current frame being rendered to (0 <= FrameIndex < FrameInFlightCount)
-    uint32_t            ImageCount;             // Number of simultaneous in-flight frames (returned by vkGetSwapchainImagesKHR, usually derived from min_image_count)
-    uint32_t            SemaphoreIndex;         // Current set of swapchain wait semaphores we're using (needs to be distinct from per frame data)
-    ImGui_ImplVulkanH_Frame*            Frames;
-    ImGui_ImplVulkanH_FrameSemaphores*  FrameSemaphores;
-
-    ImGui_ImplVulkanH_Window()
-    {
-        memset((void*)this, 0, sizeof(*this));
-        PresentMode = (VkPresentModeKHR)~0;     // Ensure we get an error if user doesn't set this.
-        ClearEnable = true;
-    }
-};
-

includes/imgui/imgui.h

@@ -25,6 +25,8 @@
 #define IMGUI_VERSION               "1.89 WIP"
 #define IMGUI_VERSION_NUM           18835
 #define IMGUI_HAS_TABLE
+#define IMGUI_HAS_VIEWPORT          // Viewport WIP branch
+#define IMGUI_HAS_DOCK              // Docking WIP branch
 
 /*
 
@@ -36,12 +38,12 @@ Index of this file:
 // [SECTION] Helpers: Memory allocations macros, ImVector<>
 // [SECTION] ImGuiStyle
 // [SECTION] ImGuiIO
-// [SECTION] Misc data structures (ImGuiInputTextCallbackData, ImGuiSizeCallbackData, ImGuiPayload, ImGuiTableSortSpecs, ImGuiTableColumnSortSpecs)
+// [SECTION] Misc data structures (ImGuiInputTextCallbackData, ImGuiSizeCallbackData, ImGuiWindowClass, ImGuiPayload, ImGuiTableSortSpecs, ImGuiTableColumnSortSpecs)
 // [SECTION] Helpers (ImGuiOnceUponAFrame, ImGuiTextFilter, ImGuiTextBuffer, ImGuiStorage, ImGuiListClipper, ImColor)
 // [SECTION] Drawing API (ImDrawCallback, ImDrawCmd, ImDrawIdx, ImDrawVert, ImDrawChannel, ImDrawListSplitter, ImDrawFlags, ImDrawListFlags, ImDrawList, ImDrawData)
 // [SECTION] Font API (ImFontConfig, ImFontGlyph, ImFontGlyphRangesBuilder, ImFontAtlasFlags, ImFontAtlas, ImFont)
 // [SECTION] Viewports (ImGuiViewportFlags, ImGuiViewport)
-// [SECTION] Platform Dependent Interfaces (ImGuiPlatformImeData)
+// [SECTION] Platform Dependent Interfaces (ImGuiPlatformIO, ImGuiPlatformMonitor, ImGuiPlatformImeData)
 // [SECTION] Obsolete functions and types
 
 */
@@ -151,6 +153,8 @@ struct ImGuiKeyData;                // Storage for ImGuiIO and IsKeyDown(), IsKe
 struct ImGuiListClipper;            // Helper to manually clip large list of items
 struct ImGuiOnceUponAFrame;         // Helper for running a block of code not more than once a frame
 struct ImGuiPayload;                // User data payload for drag and drop operations
+struct ImGuiPlatformIO;             // Multi-viewport support: interface for Platform/Renderer backends + viewports to render
+struct ImGuiPlatformMonitor;        // Multi-viewport support: user-provided bounds for each connected monitor/display. Used when positioning popups and tooltips to avoid them straddling monitors
 struct ImGuiPlatformImeData;        // Platform IME data for io.SetPlatformImeDataFn() function.
 struct ImGuiSizeCallbackData;       // Callback data when using SetNextWindowSizeConstraints() (rare/advanced use)
 struct ImGuiStorage;                // Helper for key->value storage
@@ -159,7 +163,8 @@ struct ImGuiTableSortSpecs;         // Sorting specifications for a table (often
 struct ImGuiTableColumnSortSpecs;   // Sorting specification for one column of a table
 struct ImGuiTextBuffer;             // Helper to hold and append into a text buffer (~string builder)
 struct ImGuiTextFilter;             // Helper to parse and apply text filters (e.g. "aaaaa[,bbbbb][,ccccc]")
-struct ImGuiViewport;               // A Platform Window (always only one in 'master' branch), in the future may represent Platform Monitor
+struct ImGuiViewport;               // A Platform Window (always 1 unless multi-viewport are enabled. One per platform window to output to). In the future may represent Platform Monitor
+struct ImGuiWindowClass;            // Window class (rare/advanced uses: provide hints to the platform backend via altered viewport flags and parent/child info)
 
 // Enumerations
 // - We don't use strongly typed enums much because they add constraints (can't extend in private code, can't store typed in bit fields, extra casting on iteration)
@@ -189,6 +194,7 @@ typedef int ImGuiButtonFlags;       // -> enum ImGuiButtonFlags_     // Flags: f
 typedef int ImGuiColorEditFlags;    // -> enum ImGuiColorEditFlags_  // Flags: for ColorEdit4(), ColorPicker4() etc.
 typedef int ImGuiConfigFlags;       // -> enum ImGuiConfigFlags_     // Flags: for io.ConfigFlags
 typedef int ImGuiComboFlags;        // -> enum ImGuiComboFlags_      // Flags: for BeginCombo()
+typedef int ImGuiDockNodeFlags;     // -> enum ImGuiDockNodeFlags_   // Flags: for DockSpace()
 typedef int ImGuiDragDropFlags;     // -> enum ImGuiDragDropFlags_   // Flags: for BeginDragDropSource(), AcceptDragDropPayload()
 typedef int ImGuiFocusedFlags;      // -> enum ImGuiFocusedFlags_    // Flags: for IsWindowFocused()
 typedef int ImGuiHoveredFlags;      // -> enum ImGuiHoveredFlags_    // Flags: for IsItemHovered(), IsWindowHovered() etc.
@@ -349,10 +355,12 @@ namespace ImGui
     IMGUI_API bool          IsWindowFocused(ImGuiFocusedFlags flags=0); // is current window focused? or its root/child, depending on flags. see flags for options.
     IMGUI_API bool          IsWindowHovered(ImGuiHoveredFlags flags=0); // is current window hovered (and typically: not blocked by a popup/modal)? see flags for options. NB: If you are trying to check whether your mouse should be dispatched to imgui or to your app, you should use the 'io.WantCaptureMouse' boolean for that! Please read the FAQ!
     IMGUI_API ImDrawList*   GetWindowDrawList();                        // get draw list associated to the current window, to append your own drawing primitives
+    IMGUI_API float         GetWindowDpiScale();                        // get DPI scale currently associated to the current window's viewport.
     IMGUI_API ImVec2        GetWindowPos();                             // get current window position in screen space (useful if you want to do your own drawing via the DrawList API)
     IMGUI_API ImVec2        GetWindowSize();                            // get current window size
     IMGUI_API float         GetWindowWidth();                           // get current window width (shortcut for GetWindowSize().x)
     IMGUI_API float         GetWindowHeight();                          // get current window height (shortcut for GetWindowSize().y)
+    IMGUI_API ImGuiViewport*GetWindowViewport();                        // get viewport currently associated to the current window.
 
     // Window manipulation
     // - Prefer using SetNextXXX functions (before Begin) rather that SetXXX functions (after Begin).
@@ -363,6 +371,7 @@ namespace ImGui
     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 override the Alpha component of ImGuiCol_WindowBg/ChildBg/PopupBg. you may also use ImGuiWindowFlags_NoBackground.
+    IMGUI_API void          SetNextWindowViewport(ImGuiID viewport_id);                                 // set next window viewport
     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().
@@ -779,6 +788,7 @@ namespace ImGui
     IMGUI_API int           GetColumnsCount();
 
     // Tab Bars, Tabs
+    // Note: Tabs are automatically created by the docking system. Use this to create tab bars/tabs yourself without docking being involved.
     IMGUI_API bool          BeginTabBar(const char* str_id, ImGuiTabBarFlags flags = 0);        // create and append into a TabBar
     IMGUI_API void          EndTabBar();                                                        // only call EndTabBar() if BeginTabBar() returns true!
     IMGUI_API bool          BeginTabItem(const char* label, bool* p_open = NULL, ImGuiTabItemFlags flags = 0); // create a Tab. Returns true if the Tab is selected.
@@ -786,6 +796,26 @@ namespace ImGui
     IMGUI_API bool          TabItemButton(const char* label, ImGuiTabItemFlags flags = 0);      // create a Tab behaving like a button. return true when clicked. cannot be selected in the tab bar.
     IMGUI_API void          SetTabItemClosed(const char* tab_or_docked_window_label);           // notify TabBar or Docking system of a closed tab/window ahead (useful to reduce visual flicker on reorderable tab bars). For tab-bar: call after BeginTabBar() and before Tab submissions. Otherwise call with a window name.
 
+    // Docking
+    // [BETA API] Enable with io.ConfigFlags |= ImGuiConfigFlags_DockingEnable.
+    // Note: You can use most Docking facilities without calling any API. You DO NOT need to call DockSpace() to use Docking!
+    // - Drag from window title bar or their tab to dock/undock. Hold SHIFT to disable docking/undocking.
+    // - Drag from window menu button (upper-left button) to undock an entire node (all windows).
+    // - When io.ConfigDockingWithShift == true, you instead need to hold SHIFT to _enable_ docking/undocking.
+    // About dockspaces:
+    // - Use DockSpace() to create an explicit dock node _within_ an existing window. See Docking demo for details.
+    // - Use DockSpaceOverViewport() to create an explicit dock node covering the screen or a specific viewport.
+    //   This is often used with ImGuiDockNodeFlags_PassthruCentralNode.
+    // - Important: Dockspaces need to be submitted _before_ any window they can host. Submit it early in your frame!
+    // - Important: Dockspaces need to be kept alive if hidden, otherwise windows docked into it will be undocked.
+    //   e.g. if you have multiple tabs with a dockspace inside each tab: submit the non-visible dockspaces with ImGuiDockNodeFlags_KeepAliveOnly.
+    IMGUI_API ImGuiID       DockSpace(ImGuiID id, const ImVec2& size = ImVec2(0, 0), ImGuiDockNodeFlags flags = 0, const ImGuiWindowClass* window_class = NULL);
+    IMGUI_API ImGuiID       DockSpaceOverViewport(const ImGuiViewport* viewport = NULL, ImGuiDockNodeFlags flags = 0, const ImGuiWindowClass* window_class = NULL);
+    IMGUI_API void          SetNextWindowDockID(ImGuiID dock_id, ImGuiCond cond = 0);           // set next window dock id
+    IMGUI_API void          SetNextWindowClass(const ImGuiWindowClass* window_class);           // set next window class (control docking compatibility + provide hints to platform backend via custom viewport flags and platform parent/child relationship)
+    IMGUI_API ImGuiID       GetWindowDockID();
+    IMGUI_API bool          IsWindowDocked();                                                   // is current window docked into another window?
+
     // Logging/Capture
     // - All text output from the interface can be captured into tty/file/clipboard. By default, tree nodes are automatically opened during logging.
     IMGUI_API void          LogToTTY(int auto_open_depth = -1);                                 // start logging to tty (stdout)
@@ -854,8 +884,10 @@ namespace ImGui
     IMGUI_API ImGuiViewport* GetMainViewport();                                                 // return primary/default viewport. This can never be NULL.
 
     // Background/Foreground Draw Lists
-    IMGUI_API ImDrawList*   GetBackgroundDrawList();                                            // this draw list will be the first rendered one. Useful to quickly draw shapes/text behind dear imgui contents.
+    IMGUI_API ImDrawList*   GetBackgroundDrawList();                                            // get background draw list for the viewport associated to the current window. this draw list will be the first rendering one. Useful to quickly draw shapes/text behind dear imgui contents.
-    IMGUI_API ImDrawList*   GetForegroundDrawList();                                            // this draw list will be the last rendered one. Useful to quickly draw shapes/text over dear imgui contents.
+    IMGUI_API ImDrawList*   GetForegroundDrawList();                                            // get foreground draw list for the viewport associated to the current window. this draw list will be the last rendered one. Useful to quickly draw shapes/text over dear imgui contents.
+    IMGUI_API ImDrawList*   GetBackgroundDrawList(ImGuiViewport* viewport);                     // get background draw list for the given viewport. this draw list will be the first rendering one. Useful to quickly draw shapes/text behind dear imgui contents.
+    IMGUI_API ImDrawList*   GetForegroundDrawList(ImGuiViewport* viewport);                     // get foreground draw list for the given viewport. this draw list will be the last rendered one. Useful to quickly draw shapes/text over dear imgui contents.
 
     // Miscellaneous Utilities
     IMGUI_API bool          IsRectVisible(const ImVec2& size);                                  // test if rectangle (of given size, starting from cursor position) is visible / not clipped.
@@ -939,6 +971,16 @@ namespace ImGui
     IMGUI_API void*         MemAlloc(size_t size);
     IMGUI_API void          MemFree(void* ptr);
 
+    // (Optional) Platform/OS interface for multi-viewport support
+    // Read comments around the ImGuiPlatformIO structure for more details.
+    // Note: You may use GetWindowViewport() to get the current viewport of the current window.
+    IMGUI_API ImGuiPlatformIO&  GetPlatformIO();                                                // platform/renderer functions, for backend to setup + viewports list.
+    IMGUI_API void              UpdatePlatformWindows();                                        // call in main loop. will call CreateWindow/ResizeWindow/etc. platform functions for each secondary viewport, and DestroyWindow for each inactive viewport.
+    IMGUI_API void              RenderPlatformWindowsDefault(void* platform_render_arg = NULL, void* renderer_render_arg = NULL); // call in main loop. will call RenderWindow/SwapBuffers platform functions for each secondary viewport which doesn't have the ImGuiViewportFlags_Minimized flag set. May be reimplemented by user for custom rendering needs.
+    IMGUI_API void              DestroyPlatformWindows();                                       // call DestroyWindow platform functions for all viewports. call from backend Shutdown() if you need to close platform windows before imgui shutdown. otherwise will be called by DestroyContext().
+    IMGUI_API ImGuiViewport*    FindViewportByID(ImGuiID id);                                   // this is a helper for backends.
+    IMGUI_API ImGuiViewport*    FindViewportByPlatformHandle(void* platform_handle);            // this is a helper for backends. the type platform_handle is decided by the backend (e.g. HWND, MyWindow*, GLFWwindow* etc.)
+
 } // namespace ImGui
 
 //-----------------------------------------------------------------------------
@@ -970,6 +1012,8 @@ enum ImGuiWindowFlags_
     ImGuiWindowFlags_NoNavInputs            = 1 << 18,  // No gamepad/keyboard navigation within the window
     ImGuiWindowFlags_NoNavFocus             = 1 << 19,  // No focusing toward this window with gamepad/keyboard navigation (e.g. skipped by CTRL+TAB)
     ImGuiWindowFlags_UnsavedDocument        = 1 << 20,  // Display a dot next to the title. When used in a tab/docking context, tab is selected when clicking the X + closure is not assumed (will wait for user to stop submitting the tab). Otherwise closure is assumed when pressing the X, so if you keep submitting the tab may reappear at end of tab bar.
+    ImGuiWindowFlags_NoDocking              = 1 << 21,  // Disable docking of this window
+
     ImGuiWindowFlags_NoNav                  = ImGuiWindowFlags_NoNavInputs | ImGuiWindowFlags_NoNavFocus,
     ImGuiWindowFlags_NoDecoration           = ImGuiWindowFlags_NoTitleBar | ImGuiWindowFlags_NoResize | ImGuiWindowFlags_NoScrollbar | ImGuiWindowFlags_NoCollapse,
     ImGuiWindowFlags_NoInputs               = ImGuiWindowFlags_NoMouseInputs | ImGuiWindowFlags_NoNavInputs | ImGuiWindowFlags_NoNavFocus,
@@ -981,6 +1025,7 @@ enum ImGuiWindowFlags_
     ImGuiWindowFlags_Popup                  = 1 << 26,  // Don't use! For internal use by BeginPopup()
     ImGuiWindowFlags_Modal                  = 1 << 27,  // Don't use! For internal use by BeginPopupModal()
     ImGuiWindowFlags_ChildMenu              = 1 << 28,  // Don't use! For internal use by BeginMenu()
+    ImGuiWindowFlags_DockNodeHost           = 1 << 29,  // Don't use! For internal use by Begin()/NewFrame()
 };
 
 // Flags for ImGui::InputText()
@@ -1257,7 +1302,7 @@ enum ImGuiFocusedFlags_
     ImGuiFocusedFlags_RootWindow                    = 1 << 1,   // Test from root window (top most parent of the current hierarchy)
     ImGuiFocusedFlags_AnyWindow                     = 1 << 2,   // Return true if any window is focused. Important: If you are trying to tell how to dispatch your low-level inputs, do NOT use this. Use 'io.WantCaptureMouse' instead! Please read the FAQ!
     ImGuiFocusedFlags_NoPopupHierarchy              = 1 << 3,   // Do not consider popup hierarchy (do not treat popup emitter as parent of popup) (when used with _ChildWindows or _RootWindow)
-    //ImGuiFocusedFlags_DockHierarchy               = 1 << 4,   // Consider docking hierarchy (treat dockspace host as parent of docked window) (when used with _ChildWindows or _RootWindow)
+    ImGuiFocusedFlags_DockHierarchy                 = 1 << 4,   // Consider docking hierarchy (treat dockspace host as parent of docked window) (when used with _ChildWindows or _RootWindow)
     ImGuiFocusedFlags_RootAndChildWindows           = ImGuiFocusedFlags_RootWindow | ImGuiFocusedFlags_ChildWindows,
 };
 
@@ -1271,7 +1316,7 @@ enum ImGuiHoveredFlags_
     ImGuiHoveredFlags_RootWindow                    = 1 << 1,   // IsWindowHovered() only: Test from root window (top most parent of the current hierarchy)
     ImGuiHoveredFlags_AnyWindow                     = 1 << 2,   // IsWindowHovered() only: Return true if any window is hovered
     ImGuiHoveredFlags_NoPopupHierarchy              = 1 << 3,   // IsWindowHovered() only: Do not consider popup hierarchy (do not treat popup emitter as parent of popup) (when used with _ChildWindows or _RootWindow)
-    //ImGuiHoveredFlags_DockHierarchy               = 1 << 4,   // IsWindowHovered() only: Consider docking hierarchy (treat dockspace host as parent of docked window) (when used with _ChildWindows or _RootWindow)
+    ImGuiHoveredFlags_DockHierarchy                 = 1 << 4,   // IsWindowHovered() only: Consider docking hierarchy (treat dockspace host as parent of docked window) (when used with _ChildWindows or _RootWindow)
     ImGuiHoveredFlags_AllowWhenBlockedByPopup       = 1 << 5,   // Return true even if a popup window is normally blocking access to this item/window
     //ImGuiHoveredFlags_AllowWhenBlockedByModal     = 1 << 6,   // Return true even if a modal popup window is normally blocking access to this item/window. FIXME-TODO: Unavailable yet.
     ImGuiHoveredFlags_AllowWhenBlockedByActiveItem  = 1 << 7,   // Return true even if an active item is blocking access to this item/window. Useful for Drag and Drop patterns.
@@ -1287,6 +1332,21 @@ enum ImGuiHoveredFlags_
     ImGuiHoveredFlags_NoSharedDelay                 = 1 << 13,  // Disable shared delay system where moving from one item to the next keeps the previous timer for a short time (standard for tooltips with long delays)
 };
 
+// Flags for ImGui::DockSpace(), shared/inherited by child nodes.
+// (Some flags can be applied to individual nodes directly)
+// FIXME-DOCK: Also see ImGuiDockNodeFlagsPrivate_ which may involve using the WIP and internal DockBuilder api.
+enum ImGuiDockNodeFlags_
+{
+    ImGuiDockNodeFlags_None                         = 0,
+    ImGuiDockNodeFlags_KeepAliveOnly                = 1 << 0,   // Shared       // Don't display the dockspace node but keep it alive. Windows docked into this dockspace node won't be undocked.
+    //ImGuiDockNodeFlags_NoCentralNode              = 1 << 1,   // Shared       // Disable Central Node (the node which can stay empty)
+    ImGuiDockNodeFlags_NoDockingInCentralNode       = 1 << 2,   // Shared       // Disable docking inside the Central Node, which will be always kept empty.
+    ImGuiDockNodeFlags_PassthruCentralNode          = 1 << 3,   // Shared       // Enable passthru dockspace: 1) DockSpace() will render a ImGuiCol_WindowBg background covering everything excepted the Central Node when empty. Meaning the host window should probably use SetNextWindowBgAlpha(0.0f) prior to Begin() when using this. 2) When Central Node is empty: let inputs pass-through + won't display a DockingEmptyBg background. See demo for details.
+    ImGuiDockNodeFlags_NoSplit                      = 1 << 4,   // Shared/Local // Disable splitting the node into smaller nodes. Useful e.g. when embedding dockspaces into a main root one (the root one may have splitting disabled to reduce confusion). Note: when turned off, existing splits will be preserved.
+    ImGuiDockNodeFlags_NoResize                     = 1 << 5,   // Shared/Local // Disable resizing node using the splitter/separators. Useful with programmatically setup dockspaces.
+    ImGuiDockNodeFlags_AutoHideTabBar               = 1 << 6,   // Shared/Local // Tab bar will automatically hide when there is a single window in the dock node.
+};
+
 // Flags for ImGui::BeginDragDropSource(), ImGui::AcceptDragDropPayload()
 enum ImGuiDragDropFlags_
 {
@@ -1498,6 +1558,15 @@ enum ImGuiConfigFlags_
     ImGuiConfigFlags_NoMouse                = 1 << 4,   // Instruct imgui to clear mouse position/buttons in NewFrame(). This allows ignoring the mouse information set by the backend.
     ImGuiConfigFlags_NoMouseCursorChange    = 1 << 5,   // Instruct backend to not alter mouse cursor shape and visibility. Use if the backend cursor changes are interfering with yours and you don't want to use SetMouseCursor() to change mouse cursor. You may want to honor requests from imgui by reading GetMouseCursor() yourself instead.
 
+    // [BETA] Docking
+    ImGuiConfigFlags_DockingEnable          = 1 << 6,   // Docking enable flags.
+
+    // [BETA] Viewports
+    // When using viewports it is recommended that your default value for ImGuiCol_WindowBg is opaque (Alpha=1.0) so transition to a viewport won't be noticeable.
+    ImGuiConfigFlags_ViewportsEnable        = 1 << 10,  // Viewport enable flags (require both ImGuiBackendFlags_PlatformHasViewports + ImGuiBackendFlags_RendererHasViewports set by the respective backends)
+    ImGuiConfigFlags_DpiEnableScaleViewports= 1 << 14,  // [BETA: Don't use] FIXME-DPI: Reposition and resize imgui windows when the DpiScale of a viewport changed (mostly useful for the main viewport hosting other window). Note that resizing the main window itself is up to your application.
+    ImGuiConfigFlags_DpiEnableScaleFonts    = 1 << 15,  // [BETA: Don't use] FIXME-DPI: Request bitmap-scaled fonts to match DpiScale. This is a very low-quality workaround. The correct way to handle DPI is _currently_ to replace the atlas and/or fonts in the Platform_OnChangedViewport callback, but this is all early work in progress.
+
     // User storage (to allow your backend/engine to communicate to code that may be shared between multiple projects. Those flags are NOT used by core Dear ImGui)
     ImGuiConfigFlags_IsSRGB                 = 1 << 20,  // Application is SRGB-aware.
     ImGuiConfigFlags_IsTouchScreen          = 1 << 21,  // Application is using a touch screen instead of a mouse.
@@ -1511,6 +1580,11 @@ enum ImGuiBackendFlags_
     ImGuiBackendFlags_HasMouseCursors       = 1 << 1,   // Backend Platform supports honoring GetMouseCursor() value to change the OS cursor shape.
     ImGuiBackendFlags_HasSetMousePos        = 1 << 2,   // Backend Platform supports io.WantSetMousePos requests to reposition the OS mouse position (only used if ImGuiConfigFlags_NavEnableSetMousePos is set).
     ImGuiBackendFlags_RendererHasVtxOffset  = 1 << 3,   // Backend Renderer supports ImDrawCmd::VtxOffset. This enables output of large meshes (64K+ vertices) while still using 16-bit indices.
+
+    // [BETA] Viewports
+    ImGuiBackendFlags_PlatformHasViewports  = 1 << 10,  // Backend Platform supports multiple viewports.
+    ImGuiBackendFlags_HasMouseHoveredViewport=1 << 11,  // Backend Platform supports calling io.AddMouseViewportEvent() with the viewport under the mouse. IF POSSIBLE, ignore viewports with the ImGuiViewportFlags_NoInputs flag (Win32 backend, GLFW 3.30+ backend can do this, SDL backend cannot). If this cannot be done, Dear ImGui needs to use a flawed heuristic to find the viewport under.
+    ImGuiBackendFlags_RendererHasViewports  = 1 << 12,  // Backend Renderer supports multiple viewports.
 };
 
 // Enumeration for PushStyleColor() / PopStyleColor()
@@ -1554,6 +1628,8 @@ enum ImGuiCol_
     ImGuiCol_TabActive,
     ImGuiCol_TabUnfocused,
     ImGuiCol_TabUnfocusedActive,
+    ImGuiCol_DockingPreview,        // Preview overlay color when about to docking something
+    ImGuiCol_DockingEmptyBg,        // Background color for empty node (e.g. CentralNode with no window docked into it)
     ImGuiCol_PlotLines,
     ImGuiCol_PlotLinesHovered,
     ImGuiCol_PlotHistogram,
@@ -1863,7 +1939,7 @@ struct ImGuiStyle
     ImVec2      SelectableTextAlign;        // Alignment of selectable text. Defaults to (0.0f, 0.0f) (top-left aligned). It's generally important to keep this left-aligned if you want to lay multiple items on a same line.
     ImVec2      DisplayWindowPadding;       // Window position are clamped to be visible within the display area or monitors by at least this amount. Only applies to regular windows.
     ImVec2      DisplaySafeAreaPadding;     // If you cannot see the edges of your screen (e.g. on a TV) increase the safe area padding. Apply to popups/tooltips as well regular windows. NB: Prefer configuring your TV sets correctly!
-    float       MouseCursorScale;           // Scale software rendered mouse cursor (when io.MouseDrawCursor is enabled). May be removed later.
+    float       MouseCursorScale;           // Scale software rendered mouse cursor (when io.MouseDrawCursor is enabled). We apply per-monitor DPI scaling over this scale. May be removed later.
     bool        AntiAliasedLines;           // Enable anti-aliased lines/borders. Disable if you are really tight on CPU/GPU. Latched at the beginning of the frame (copied to ImDrawList).
     bool        AntiAliasedLinesUseTex;     // Enable anti-aliased lines/borders using textures where possible. Require backend to render with bilinear filtering (NOT point/nearest filtering). Latched at the beginning of the frame (copied to ImDrawList).
     bool        AntiAliasedFill;            // Enable anti-aliased edges around filled shapes (rounded rectangles, circles, etc.). Disable if you are really tight on CPU/GPU. Latched at the beginning of the frame (copied to ImDrawList).
@@ -1920,6 +1996,18 @@ struct ImGuiIO
     ImFont*     FontDefault;                    // = NULL           // Font to use on NewFrame(). Use NULL to uses Fonts->Fonts[0].
     ImVec2      DisplayFramebufferScale;        // = (1, 1)         // For retina display or other situations where window coordinates are different from framebuffer coordinates. This generally ends up in ImDrawData::FramebufferScale.
 
+    // Docking options (when ImGuiConfigFlags_DockingEnable is set)
+    bool        ConfigDockingNoSplit;           // = false          // Simplified docking mode: disable window splitting, so docking is limited to merging multiple windows together into tab-bars.
+    bool        ConfigDockingWithShift;         // = false          // Enable docking with holding Shift key (reduce visual noise, allows dropping in wider space)
+    bool        ConfigDockingAlwaysTabBar;      // = false          // [BETA] [FIXME: This currently creates regression with auto-sizing and general overhead] Make every single floating window display within a docking node.
+    bool        ConfigDockingTransparentPayload;// = false          // [BETA] Make window or viewport transparent when docking and only display docking boxes on the target viewport. Useful if rendering of multiple viewport cannot be synced. Best used with ConfigViewportsNoAutoMerge.
+
+    // Viewport options (when ImGuiConfigFlags_ViewportsEnable is set)
+    bool        ConfigViewportsNoAutoMerge;     // = false;         // Set to make all floating imgui windows always create their own viewport. Otherwise, they are merged into the main host viewports when overlapping it. May also set ImGuiViewportFlags_NoAutoMerge on individual viewport.
+    bool        ConfigViewportsNoTaskBarIcon;   // = false          // Disable default OS task bar icon flag for secondary viewports. When a viewport doesn't want a task bar icon, ImGuiViewportFlags_NoTaskBarIcon will be set on it.
+    bool        ConfigViewportsNoDecoration;    // = true           // Disable default OS window decoration flag for secondary viewports. When a viewport doesn't want window decorations, ImGuiViewportFlags_NoDecoration will be set on it. Enabling decoration can create subsequent issues at OS levels (e.g. minimum window size).
+    bool        ConfigViewportsNoDefaultParent; // = false          // Disable default OS parenting to main viewport for secondary viewports. By default, viewports are marked with ParentViewportId = <main_viewport>, expecting the platform backend to setup a parent/child relationship between the OS windows (some backend may ignore this). Set to true if you want the default to be 0, then all viewports will be top-level OS windows.
+
     // Miscellaneous options
     bool        MouseDrawCursor;                // = false          // Request ImGui to draw a mouse cursor for you (if you are on a platform without a mouse cursor). Cannot be easily renamed to 'io.ConfigXXX' because this is frequently used by backend implementations.
     bool        ConfigMacOSXBehaviors;          // = defined(__APPLE__) // OS X style: Text editing cursor movement using Alt instead of Ctrl, Shortcuts using Cmd/Super instead of Ctrl, Line/Text Start and End using Cmd+Arrows instead of Home/End, Double click selects by word instead of selecting whole text, Multi-selection in lists uses Cmd/Super instead of Ctrl.
@@ -1968,6 +2056,7 @@ struct ImGuiIO
     IMGUI_API void  AddMousePosEvent(float x, float y);                     // Queue a mouse position update. Use -FLT_MAX,-FLT_MAX to signify no mouse (e.g. app not focused and not hovered)
     IMGUI_API void  AddMouseButtonEvent(int button, bool down);             // Queue a mouse button change
     IMGUI_API void  AddMouseWheelEvent(float wh_x, float wh_y);             // Queue a mouse wheel update
+    IMGUI_API void  AddMouseViewportEvent(ImGuiID id);                      // Queue a mouse hovered viewport. Requires backend to set ImGuiBackendFlags_HasMouseHoveredViewport to call this (for multi-viewport support).
     IMGUI_API void  AddFocusEvent(bool focused);                            // Queue a gain/loss of focus for the application (generally based on OS/platform focus of your window)
     IMGUI_API void  AddInputCharacter(unsigned int c);                      // Queue a new character input
     IMGUI_API void  AddInputCharacterUTF16(ImWchar16 c);                    // Queue a new character input from a UTF-16 character, it can be a surrogate
@@ -2019,6 +2108,7 @@ struct ImGuiIO
     bool        MouseDown[5];                       // Mouse buttons: 0=left, 1=right, 2=middle + extras (ImGuiMouseButton_COUNT == 5). Dear ImGui mostly uses left and right buttons. Other buttons allow us to track if the mouse is being used by your application + available to user as a convenience via IsMouse** API.
     float       MouseWheel;                         // Mouse wheel Vertical: 1 unit scrolls about 5 lines text.
     float       MouseWheelH;                        // Mouse wheel Horizontal. Most users don't have a mouse with a horizontal wheel, may not be filled by all backends.
+    ImGuiID     MouseHoveredViewport;               // (Optional) Modify using io.AddMouseViewportEvent(). With multi-viewports: viewport the OS mouse is hovering. If possible _IGNORING_ viewports with the ImGuiViewportFlags_NoInputs flag is much better (few backends can handle that). Set io.BackendFlags |= ImGuiBackendFlags_HasMouseHoveredViewport if you can provide this info. If you don't imgui will infer the value using the rectangles and last focused time of the viewports it knows about (ignoring other OS windows).
     bool        KeyCtrl;                            // Keyboard modifier down: Control
     bool        KeyShift;                           // Keyboard modifier down: Shift
     bool        KeyAlt;                             // Keyboard modifier down: Alt
@@ -2040,6 +2130,7 @@ struct ImGuiIO
     bool        MouseDownOwnedUnlessPopupClose[5];  // Track if button was clicked inside a dear imgui window.
     float       MouseDownDuration[5];               // Duration the mouse button has been down (0.0f == just clicked)
     float       MouseDownDurationPrev[5];           // Previous time the mouse button has been down
+    ImVec2      MouseDragMaxDistanceAbs[5];         // Maximum distance, absolute, on each axis, of how much mouse has traveled from the clicking point
     float       MouseDragMaxDistanceSqr[5];         // Squared maximum distance of how much mouse has traveled from the clicking point (used for moving thresholds)
     float       PenPressure;                        // Touch/Pen pressure (0.0f to 1.0f, should be >0.0f only when MouseDown[0] == true). Helper storage currently unused by Dear ImGui.
     bool        AppFocusLost;                       // Only modify via AddFocusEvent()
@@ -2104,6 +2195,27 @@ struct ImGuiSizeCallbackData
     ImVec2  DesiredSize;    // Read-write.  Desired size, based on user's mouse position. Write to this field to restrain resizing.
 };
 
+// [ALPHA] Rarely used / very advanced uses only. Use with SetNextWindowClass() and DockSpace() functions.
+// Important: the content of this class is still highly WIP and likely to change and be refactored
+// before we stabilize Docking features. Please be mindful if using this.
+// Provide hints:
+// - To the platform backend via altered viewport flags (enable/disable OS decoration, OS task bar icons, etc.)
+// - To the platform backend for OS level parent/child relationships of viewport.
+// - To the docking system for various options and filtering.
+struct ImGuiWindowClass
+{
+    ImGuiID             ClassId;                    // User data. 0 = Default class (unclassed). Windows of different classes cannot be docked with each others.
+    ImGuiID             ParentViewportId;           // Hint for the platform backend. -1: use default. 0: request platform backend to not parent the platform. != 0: request platform backend to create a parent<>child relationship between the platform windows. Not conforming backends are free to e.g. parent every viewport to the main viewport or not.
+    ImGuiViewportFlags  ViewportFlagsOverrideSet;   // Viewport flags to set when a window of this class owns a viewport. This allows you to enforce OS decoration or task bar icon, override the defaults on a per-window basis.
+    ImGuiViewportFlags  ViewportFlagsOverrideClear; // Viewport flags to clear when a window of this class owns a viewport. This allows you to enforce OS decoration or task bar icon, override the defaults on a per-window basis.
+    ImGuiTabItemFlags   TabItemFlagsOverrideSet;    // [EXPERIMENTAL] TabItem flags to set when a window of this class gets submitted into a dock node tab bar. May use with ImGuiTabItemFlags_Leading or ImGuiTabItemFlags_Trailing.
+    ImGuiDockNodeFlags  DockNodeFlagsOverrideSet;   // [EXPERIMENTAL] Dock node flags to set when a window of this class is hosted by a dock node (it doesn't have to be selected!)
+    bool                DockingAlwaysTabBar;        // Set to true to enforce single floating windows of this class always having their own docking node (equivalent of setting the global io.ConfigDockingAlwaysTabBar)
+    bool                DockingAllowUnclassed;      // Set to true to allow windows of this class to be docked/merged with an unclassed window. // FIXME-DOCK: Move to DockNodeFlags override?
+
+    ImGuiWindowClass() { memset(this, 0, sizeof(*this)); ParentViewportId = (ImGuiID)-1; DockingAllowUnclassed = true; }
+};
+
 // Data payload for Drag and Drop operations: AcceptDragDropPayload(), GetDragDropPayload()
 struct ImGuiPayload
 {
@@ -2632,6 +2744,7 @@ struct ImDrawData
     ImVec2          DisplayPos;             // Top-left position of the viewport to render (== top-left of the orthogonal projection matrix to use) (== GetMainViewport()->Pos for the main viewport, == (0.0) in most single-viewport applications)
     ImVec2          DisplaySize;            // Size of the viewport to render (== GetMainViewport()->Size for the main viewport, == io.DisplaySize in most single-viewport applications)
     ImVec2          FramebufferScale;       // Amount of pixels for each unit of DisplaySize. Based on io.DisplayFramebufferScale. Generally (1,1) on normal display, (2,2) on OSX with Retina display.
+    ImGuiViewport*  OwnerViewport;          // Viewport carrying the ImDrawData instance, might be of use to the renderer (generally not).
 
     // Functions
     ImDrawData()    { Clear(); }
@@ -2902,10 +3015,20 @@ enum ImGuiViewportFlags_
     ImGuiViewportFlags_IsPlatformWindow         = 1 << 0,   // Represent a Platform Window
     ImGuiViewportFlags_IsPlatformMonitor        = 1 << 1,   // Represent a Platform Monitor (unused yet)
     ImGuiViewportFlags_OwnedByApp               = 1 << 2,   // Platform Window: is created/managed by the application (rather than a dear imgui backend)
+    ImGuiViewportFlags_NoDecoration             = 1 << 3,   // Platform Window: Disable platform decorations: title bar, borders, etc. (generally set all windows, but if ImGuiConfigFlags_ViewportsDecoration is set we only set this on popups/tooltips)
+    ImGuiViewportFlags_NoTaskBarIcon            = 1 << 4,   // Platform Window: Disable platform task bar icon (generally set on popups/tooltips, or all windows if ImGuiConfigFlags_ViewportsNoTaskBarIcon is set)
+    ImGuiViewportFlags_NoFocusOnAppearing       = 1 << 5,   // Platform Window: Don't take focus when created.
+    ImGuiViewportFlags_NoFocusOnClick           = 1 << 6,   // Platform Window: Don't take focus when clicked on.
+    ImGuiViewportFlags_NoInputs                 = 1 << 7,   // Platform Window: Make mouse pass through so we can drag this window while peaking behind it.
+    ImGuiViewportFlags_NoRendererClear          = 1 << 8,   // Platform Window: Renderer doesn't need to clear the framebuffer ahead (because we will fill it entirely).
+    ImGuiViewportFlags_TopMost                  = 1 << 9,   // Platform Window: Display on top (for tooltips only).
+    ImGuiViewportFlags_Minimized                = 1 << 10,  // Platform Window: Window is minimized, can skip render. When minimized we tend to avoid using the viewport pos/size for clipping window or testing if they are contained in the viewport.
+    ImGuiViewportFlags_NoAutoMerge              = 1 << 11,  // Platform Window: Avoid merging this window into another host window. This can only be set via ImGuiWindowClass viewport flags override (because we need to now ahead if we are going to create a viewport in the first place!).
+    ImGuiViewportFlags_CanHostOtherWindows      = 1 << 12,  // Main viewport: can host multiple imgui windows (secondary viewports are associated to a single window).
 };
 
 // - Currently represents the Platform Window created by the application which is hosting our Dear ImGui windows.
-// - In 'docking' branch with multi-viewport enabled, we extend this concept to have multiple active viewports.
+// - With multi-viewport enabled, we extend this concept to have multiple active viewports.
 // - In the future we will extend this concept further to also represent Platform Monitor and support a "no main platform window" operation mode.
 // - About Main Area vs Work Area:
 //   - Main Area = entire viewport.
@@ -2913,16 +3036,31 @@ enum ImGuiViewportFlags_
 //   - Windows are generally trying to stay within the Work Area of their host viewport.
 struct ImGuiViewport
 {
+    ImGuiID             ID;                     // Unique identifier for the viewport
     ImGuiViewportFlags  Flags;                  // See ImGuiViewportFlags_
     ImVec2              Pos;                    // Main Area: Position of the viewport (Dear ImGui coordinates are the same as OS desktop/native coordinates)
     ImVec2              Size;                   // Main Area: Size of the viewport.
     ImVec2              WorkPos;                // Work Area: Position of the viewport minus task bars, menus bars, status bars (>= Pos)
     ImVec2              WorkSize;               // Work Area: Size of the viewport minus task bars, menu bars, status bars (<= Size)
+    float               DpiScale;               // 1.0f = 96 DPI = No extra scale.
+    ImGuiID             ParentViewportId;       // (Advanced) 0: no parent. Instruct the platform backend to setup a parent/child relationship between platform windows.
+    ImDrawData*         DrawData;               // The ImDrawData corresponding to this viewport. Valid after Render() and until the next call to NewFrame().
 
     // Platform/Backend Dependent Data
-    void*               PlatformHandleRaw;      // void* to hold lower-level, platform-native window handle (under Win32 this is expected to be a HWND, unused for other platforms)
+    // Our design separate the Renderer and Platform backends to facilitate combining default backends with each others.
+    // When our create your own backend for a custom engine, it is possible that both Renderer and Platform will be handled
+    // by the same system and you may not need to use all the UserData/Handle fields.
+    // The library never uses those fields, they are merely storage to facilitate backend implementation.
+    void*               RendererUserData;       // void* to hold custom data structure for the renderer (e.g. swap chain, framebuffers etc.). generally set by your Renderer_CreateWindow function.
+    void*               PlatformUserData;       // void* to hold custom data structure for the OS / platform (e.g. windowing info, render context). generally set by your Platform_CreateWindow function.
+    void*               PlatformHandle;         // void* for FindViewportByPlatformHandle(). (e.g. suggested to use natural platform handle such as HWND, GLFWWindow*, SDL_Window*)
+    void*               PlatformHandleRaw;      // void* to hold lower-level, platform-native window handle (under Win32 this is expected to be a HWND, unused for other platforms), when using an abstraction layer like GLFW or SDL (where PlatformHandle would be a SDL_Window*)
+    bool                PlatformRequestMove;    // Platform window requested move (e.g. window was moved by the OS / host window manager, authoritative position will be OS window position)
+    bool                PlatformRequestResize;  // Platform window requested resize (e.g. window was resized by the OS / host window manager, authoritative size will be OS window size)
+    bool                PlatformRequestClose;   // Platform window requested closure (e.g. window was moved by the OS / host window manager, e.g. pressing ALT-F4)
 
     ImGuiViewport()     { memset(this, 0, sizeof(*this)); }
+    ~ImGuiViewport()    { IM_ASSERT(PlatformUserData == NULL && RendererUserData == NULL); }
 
     // Helpers
     ImVec2              GetCenter() const       { return ImVec2(Pos.x + Size.x * 0.5f, Pos.y + Size.y * 0.5f); }
@@ -2930,8 +3068,125 @@ struct ImGuiViewport
 };
 
 //-----------------------------------------------------------------------------
-// [SECTION] Platform Dependent Interfaces
+// [SECTION] Platform Dependent Interfaces (for e.g. multi-viewport support)
 //-----------------------------------------------------------------------------
+// [BETA] (Optional) This is completely optional, for advanced users!
+// If you are new to Dear ImGui and trying to integrate it into your engine, you can probably ignore this for now.
+//
+// This feature allows you to seamlessly drag Dear ImGui windows outside of your application viewport.
+// This is achieved by creating new Platform/OS windows on the fly, and rendering into them.
+// Dear ImGui manages the viewport structures, and the backend create and maintain one Platform/OS window for each of those viewports.
+//
+// See Glossary https://github.com/ocornut/imgui/wiki/Glossary for details about some of the terminology.
+// See Thread https://github.com/ocornut/imgui/issues/1542 for gifs, news and questions about this evolving feature.
+//
+// About the coordinates system:
+// - When multi-viewports are enabled, all Dear ImGui coordinates become absolute coordinates (same as OS coordinates!)
+// - So e.g. ImGui::SetNextWindowPos(ImVec2(0,0)) will position a window relative to your primary monitor!
+// - If you want to position windows relative to your main application viewport, use ImGui::GetMainViewport()->Pos as a base position.
+//
+// Steps to use multi-viewports in your application, when using a default backend from the examples/ folder:
+// - Application:  Enable feature with 'io.ConfigFlags |= ImGuiConfigFlags_ViewportsEnable'.
+// - Backend:      The backend initialization will setup all necessary ImGuiPlatformIO's functions and update monitors info every frame.
+// - Application:  In your main loop, call ImGui::UpdatePlatformWindows(), ImGui::RenderPlatformWindowsDefault() after EndFrame() or Render().
+// - Application:  Fix absolute coordinates used in ImGui::SetWindowPos() or ImGui::SetNextWindowPos() calls.
+//
+// Steps to use multi-viewports in your application, when using a custom backend:
+// - Important:    THIS IS NOT EASY TO DO and comes with many subtleties not described here!
+//                 It's also an experimental feature, so some of the requirements may evolve.
+//                 Consider using default backends if you can. Either way, carefully follow and refer to examples/ backends for details.
+// - Application:  Enable feature with 'io.ConfigFlags |= ImGuiConfigFlags_ViewportsEnable'.
+// - Backend:      Hook ImGuiPlatformIO's Platform_* and Renderer_* callbacks (see below).
+//                 Set 'io.BackendFlags |= ImGuiBackendFlags_PlatformHasViewports' and 'io.BackendFlags |= ImGuiBackendFlags_PlatformHasViewports'.
+//                 Update ImGuiPlatformIO's Monitors list every frame.
+//                 Update MousePos every frame, in absolute coordinates.
+// - Application:  In your main loop, call ImGui::UpdatePlatformWindows(), ImGui::RenderPlatformWindowsDefault() after EndFrame() or Render().
+//                 You may skip calling RenderPlatformWindowsDefault() if its API is not convenient for your needs. Read comments below.
+// - Application:  Fix absolute coordinates used in ImGui::SetWindowPos() or ImGui::SetNextWindowPos() calls.
+//
+// About ImGui::RenderPlatformWindowsDefault():
+// - This function is a mostly a _helper_ for the common-most cases, and to facilitate using default backends.
+// - You can check its simple source code to understand what it does.
+//   It basically iterates secondary viewports and call 4 functions that are setup in ImGuiPlatformIO, if available:
+//     Platform_RenderWindow(), Renderer_RenderWindow(), Platform_SwapBuffers(), Renderer_SwapBuffers()
+//   Those functions pointers exists only for the benefit of RenderPlatformWindowsDefault().
+// - If you have very specific rendering needs (e.g. flipping multiple swap-chain simultaneously, unusual sync/threading issues, etc.),
+//   you may be tempted to ignore RenderPlatformWindowsDefault() and write customized code to perform your renderingg.
+//   You may decide to setup the platform_io's *RenderWindow and *SwapBuffers pointers and call your functions through those pointers,
+//   or you may decide to never setup those pointers and call your code directly. They are a convenience, not an obligatory interface.
+//-----------------------------------------------------------------------------
+
+// (Optional) Access via ImGui::GetPlatformIO()
+struct ImGuiPlatformIO
+{
+    //------------------------------------------------------------------
+    // Input - Backend interface/functions + Monitor List
+    //------------------------------------------------------------------
+
+    // (Optional) Platform functions (e.g. Win32, GLFW, SDL2)
+    // For reference, the second column shows which function are generally calling the Platform Functions:
+    //   N = ImGui::NewFrame()                        ~ beginning of the dear imgui frame: read info from platform/OS windows (latest size/position)
+    //   F = ImGui::Begin(), ImGui::EndFrame()        ~ during the dear imgui frame
+    //   U = ImGui::UpdatePlatformWindows()           ~ after the dear imgui frame: create and update all platform/OS windows
+    //   R = ImGui::RenderPlatformWindowsDefault()    ~ render
+    //   D = ImGui::DestroyPlatformWindows()          ~ shutdown
+    // The general idea is that NewFrame() we will read the current Platform/OS state, and UpdatePlatformWindows() will write to it.
+    //
+    // The functions are designed so we can mix and match 2 imgui_impl_xxxx files, one for the Platform (~window/input handling), one for Renderer.
+    // Custom engine backends will often provide both Platform and Renderer interfaces and so may not need to use all functions.
+    // Platform functions are typically called before their Renderer counterpart, apart from Destroy which are called the other way.
+
+    // Platform function --------------------------------------------------- Called by -----
+    void    (*Platform_CreateWindow)(ImGuiViewport* vp);                    // . . U . .  // Create a new platform window for the given viewport
+    void    (*Platform_DestroyWindow)(ImGuiViewport* vp);                   // N . U . D  //
+    void    (*Platform_ShowWindow)(ImGuiViewport* vp);                      // . . U . .  // Newly created windows are initially hidden so SetWindowPos/Size/Title can be called on them before showing the window
+    void    (*Platform_SetWindowPos)(ImGuiViewport* vp, ImVec2 pos);        // . . U . .  // Set platform window position (given the upper-left corner of client area)
+    ImVec2  (*Platform_GetWindowPos)(ImGuiViewport* vp);                    // N . . . .  //
+    void    (*Platform_SetWindowSize)(ImGuiViewport* vp, ImVec2 size);      // . . U . .  // Set platform window client area size (ignoring OS decorations such as OS title bar etc.)
+    ImVec2  (*Platform_GetWindowSize)(ImGuiViewport* vp);                   // N . . . .  // Get platform window client area size
+    void    (*Platform_SetWindowFocus)(ImGuiViewport* vp);                  // N . . . .  // Move window to front and set input focus
+    bool    (*Platform_GetWindowFocus)(ImGuiViewport* vp);                  // . . U . .  //
+    bool    (*Platform_GetWindowMinimized)(ImGuiViewport* vp);              // N . . . .  // Get platform window minimized state. When minimized, we generally won't attempt to get/set size and contents will be culled more easily
+    void    (*Platform_SetWindowTitle)(ImGuiViewport* vp, const char* str); // . . U . .  // Set platform window title (given an UTF-8 string)
+    void    (*Platform_SetWindowAlpha)(ImGuiViewport* vp, float alpha);     // . . U . .  // (Optional) Setup global transparency (not per-pixel transparency)
+    void    (*Platform_UpdateWindow)(ImGuiViewport* vp);                    // . . U . .  // (Optional) Called by UpdatePlatformWindows(). Optional hook to allow the platform backend from doing general book-keeping every frame.
+    void    (*Platform_RenderWindow)(ImGuiViewport* vp, void* render_arg);  // . . . R .  // (Optional) Main rendering (platform side! This is often unused, or just setting a "current" context for OpenGL bindings). 'render_arg' is the value passed to RenderPlatformWindowsDefault().
+    void    (*Platform_SwapBuffers)(ImGuiViewport* vp, void* render_arg);   // . . . R .  // (Optional) Call Present/SwapBuffers (platform side! This is often unused!). 'render_arg' is the value passed to RenderPlatformWindowsDefault().
+    float   (*Platform_GetWindowDpiScale)(ImGuiViewport* vp);               // N . . . .  // (Optional) [BETA] FIXME-DPI: DPI handling: Return DPI scale for this viewport. 1.0f = 96 DPI.
+    void    (*Platform_OnChangedViewport)(ImGuiViewport* vp);               // . F . . .  // (Optional) [BETA] FIXME-DPI: DPI handling: Called during Begin() every time the viewport we are outputting into changes, so backend has a chance to swap fonts to adjust style.
+    int     (*Platform_CreateVkSurface)(ImGuiViewport* vp, ImU64 vk_inst, const void* vk_allocators, ImU64* out_vk_surface); // (Optional) For a Vulkan Renderer to call into Platform code (since the surface creation needs to tie them both).
+
+    // (Optional) Renderer functions (e.g. DirectX, OpenGL, Vulkan)
+    void    (*Renderer_CreateWindow)(ImGuiViewport* vp);                    // . . U . .  // Create swap chain, frame buffers etc. (called after Platform_CreateWindow)
+    void    (*Renderer_DestroyWindow)(ImGuiViewport* vp);                   // N . U . D  // Destroy swap chain, frame buffers etc. (called before Platform_DestroyWindow)
+    void    (*Renderer_SetWindowSize)(ImGuiViewport* vp, ImVec2 size);      // . . U . .  // Resize swap chain, frame buffers etc. (called after Platform_SetWindowSize)
+    void    (*Renderer_RenderWindow)(ImGuiViewport* vp, void* render_arg);  // . . . R .  // (Optional) Clear framebuffer, setup render target, then render the viewport->DrawData. 'render_arg' is the value passed to RenderPlatformWindowsDefault().
+    void    (*Renderer_SwapBuffers)(ImGuiViewport* vp, void* render_arg);   // . . . R .  // (Optional) Call Present/SwapBuffers. 'render_arg' is the value passed to RenderPlatformWindowsDefault().
+
+    // (Optional) Monitor list
+    // - Updated by: app/backend. Update every frame to dynamically support changing monitor or DPI configuration.
+    // - Used by: dear imgui to query DPI info, clamp popups/tooltips within same monitor and not have them straddle monitors.
+    ImVector<ImGuiPlatformMonitor>  Monitors;
+
+    //------------------------------------------------------------------
+    // Output - List of viewports to render into platform windows
+    //------------------------------------------------------------------
+
+    // Viewports list (the list is updated by calling ImGui::EndFrame or ImGui::Render)
+    // (in the future we will attempt to organize this feature to remove the need for a "main viewport")
+    ImVector<ImGuiViewport*>        Viewports;                              // Main viewports, followed by all secondary viewports.
+    ImGuiPlatformIO()               { memset(this, 0, sizeof(*this)); }     // Zero clear
+};
+
+// (Optional) This is required when enabling multi-viewport. Represent the bounds of each connected monitor/display and their DPI.
+// We use this information for multiple DPI support + clamping the position of popups and tooltips so they don't straddle multiple monitors.
+struct ImGuiPlatformMonitor
+{
+    ImVec2  MainPos, MainSize;      // Coordinates of the area displayed on this monitor (Min = upper left, Max = bottom right)
+    ImVec2  WorkPos, WorkSize;      // Coordinates without task bars / side bars / menu bars. Used to avoid positioning popups/tooltips inside this region. If you don't have this info, please copy the value for MainPos/MainSize.
+    float   DpiScale;               // 1.0f = 96 DPI
+    ImGuiPlatformMonitor()          { MainPos = MainSize = WorkPos = WorkSize = ImVec2(0, 0); DpiScale = 1.0f; }
+};
 
 // (Optional) Support for IME (Input Method Editor) via the io.SetPlatformImeDataFn() function.
 struct ImGuiPlatformImeData

includes/imgui/imgui_demo.cpp

@@ -74,6 +74,7 @@ Index of this file:
 // [SECTION] Example App: Fullscreen window / ShowExampleAppFullscreen()
 // [SECTION] Example App: Manipulating window titles / ShowExampleAppWindowTitles()
 // [SECTION] Example App: Custom Rendering using ImDrawList API / ShowExampleAppCustomRendering()
+// [SECTION] Example App: Docking, DockSpace / ShowExampleAppDockSpace()
 // [SECTION] Example App: Documents Handling / ShowExampleAppDocuments()
 
 */
@@ -178,6 +179,7 @@ Index of this file:
 #if !defined(IMGUI_DISABLE_DEMO_WINDOWS)
 
 // Forward Declarations
+static void ShowExampleAppDockSpace(bool* p_open);
 static void ShowExampleAppDocuments(bool* p_open);
 static void ShowExampleAppMainMenuBar();
 static void ShowExampleAppConsole(bool* p_open);
@@ -221,6 +223,16 @@ static void HelpMarker(const char* desc)
     }
 }
 
+static void ShowDockingDisabledMessage()
+{
+    ImGuiIO& io = ImGui::GetIO();
+    ImGui::Text("ERROR: Docking is not enabled! See Demo > Configuration.");
+    ImGui::Text("Set io.ConfigFlags |= ImGuiConfigFlags_DockingEnable in your code, or ");
+    ImGui::SameLine(0.0f, 0.0f);
+    if (ImGui::SmallButton("click here"))
+        io.ConfigFlags |= ImGuiConfigFlags_DockingEnable;
+}
+
 // Helper to wire demo markers located in code to an interactive browser
 typedef void (*ImGuiDemoMarkerCallback)(const char* file, int line, const char* section, void* user_data);
 extern ImGuiDemoMarkerCallback      GImGuiDemoMarkerCallback;
@@ -252,6 +264,7 @@ void ImGui::ShowDemoWindow(bool* p_open)
 
     // Examples Apps (accessible from the "Examples" menu)
     static bool show_app_main_menu_bar = false;
+    static bool show_app_dockspace = false;
     static bool show_app_documents = false;
     static bool show_app_console = false;
     static bool show_app_log = false;
@@ -266,7 +279,8 @@ void ImGui::ShowDemoWindow(bool* p_open)
     static bool show_app_custom_rendering = false;
 
     if (show_app_main_menu_bar)       ShowExampleAppMainMenuBar();
-    if (show_app_documents)           ShowExampleAppDocuments(&show_app_documents);
+    if (show_app_dockspace)           ShowExampleAppDockSpace(&show_app_dockspace);     // Process the Docking app first, as explicit DockSpace() nodes needs to be submitted early (read comments near the DockSpace function)
+    if (show_app_documents)           ShowExampleAppDocuments(&show_app_documents);     // Process the Document app next, as it may also use a DockSpace()
     if (show_app_console)             ShowExampleAppConsole(&show_app_console);
     if (show_app_log)                 ShowExampleAppLog(&show_app_log);
     if (show_app_layout)              ShowExampleAppLayout(&show_app_layout);
@@ -312,6 +326,7 @@ void ImGui::ShowDemoWindow(bool* p_open)
     static bool no_nav = false;
     static bool no_background = false;
     static bool no_bring_to_front = false;
+    static bool no_docking = false;
     static bool unsaved_document = false;
 
     ImGuiWindowFlags window_flags = 0;
@@ -324,6 +339,7 @@ void ImGui::ShowDemoWindow(bool* p_open)
     if (no_nav)             window_flags |= ImGuiWindowFlags_NoNav;
     if (no_background)      window_flags |= ImGuiWindowFlags_NoBackground;
     if (no_bring_to_front)  window_flags |= ImGuiWindowFlags_NoBringToFrontOnFocus;
+    if (no_docking)         window_flags |= ImGuiWindowFlags_NoDocking;
     if (unsaved_document)   window_flags |= ImGuiWindowFlags_UnsavedDocument;
     if (no_close)           p_open = NULL; // Don't pass our bool* to Begin
 
@@ -371,6 +387,7 @@ void ImGui::ShowDemoWindow(bool* p_open)
             ImGui::MenuItem("Fullscreen window", NULL, &show_app_fullscreen);
             ImGui::MenuItem("Manipulating window titles", NULL, &show_app_window_titles);
             ImGui::MenuItem("Custom rendering", NULL, &show_app_custom_rendering);
+            ImGui::MenuItem("Dockspace", NULL, &show_app_dockspace);
             ImGui::MenuItem("Documents", NULL, &show_app_documents);
             ImGui::EndMenu();
         }
@@ -446,6 +463,43 @@ void ImGui::ShowDemoWindow(bool* p_open)
             }
             ImGui::CheckboxFlags("io.ConfigFlags: NoMouseCursorChange", &io.ConfigFlags, ImGuiConfigFlags_NoMouseCursorChange);
             ImGui::SameLine(); HelpMarker("Instruct backend to not alter mouse cursor shape and visibility.");
+
+            ImGui::CheckboxFlags("io.ConfigFlags: DockingEnable", &io.ConfigFlags, ImGuiConfigFlags_DockingEnable);
+            ImGui::SameLine();
+            if (io.ConfigDockingWithShift)
+                HelpMarker("Drag from window title bar or their tab to dock/undock. Hold SHIFT to enable docking.\n\nDrag from window menu button (upper-left button) to undock an entire node (all windows).");
+            else
+                HelpMarker("Drag from window title bar or their tab to dock/undock. Hold SHIFT to disable docking.\n\nDrag from window menu button (upper-left button) to undock an entire node (all windows).");
+            if (io.ConfigFlags & ImGuiConfigFlags_DockingEnable)
+            {
+                ImGui::Indent();
+                ImGui::Checkbox("io.ConfigDockingNoSplit", &io.ConfigDockingNoSplit);
+                ImGui::SameLine(); HelpMarker("Simplified docking mode: disable window splitting, so docking is limited to merging multiple windows together into tab-bars.");
+                ImGui::Checkbox("io.ConfigDockingWithShift", &io.ConfigDockingWithShift);
+                ImGui::SameLine(); HelpMarker("Enable docking when holding Shift only (allow to drop in wider space, reduce visual noise)");
+                ImGui::Checkbox("io.ConfigDockingAlwaysTabBar", &io.ConfigDockingAlwaysTabBar);
+                ImGui::SameLine(); HelpMarker("Create a docking node and tab-bar on single floating windows.");
+                ImGui::Checkbox("io.ConfigDockingTransparentPayload", &io.ConfigDockingTransparentPayload);
+                ImGui::SameLine(); HelpMarker("Make window or viewport transparent when docking and only display docking boxes on the target viewport. Useful if rendering of multiple viewport cannot be synced. Best used with ConfigViewportsNoAutoMerge.");
+                ImGui::Unindent();
+            }
+
+            ImGui::CheckboxFlags("io.ConfigFlags: ViewportsEnable", &io.ConfigFlags, ImGuiConfigFlags_ViewportsEnable);
+            ImGui::SameLine(); HelpMarker("[beta] Enable beta multi-viewports support. See ImGuiPlatformIO for details.");
+            if (io.ConfigFlags & ImGuiConfigFlags_ViewportsEnable)
+            {
+                ImGui::Indent();
+                ImGui::Checkbox("io.ConfigViewportsNoAutoMerge", &io.ConfigViewportsNoAutoMerge);
+                ImGui::SameLine(); HelpMarker("Set to make all floating imgui windows always create their own viewport. Otherwise, they are merged into the main host viewports when overlapping it.");
+                ImGui::Checkbox("io.ConfigViewportsNoTaskBarIcon", &io.ConfigViewportsNoTaskBarIcon);
+                ImGui::SameLine(); HelpMarker("Toggling this at runtime is normally unsupported (most platform backends won't refresh the task bar icon state right away).");
+                ImGui::Checkbox("io.ConfigViewportsNoDecoration", &io.ConfigViewportsNoDecoration);
+                ImGui::SameLine(); HelpMarker("Toggling this at runtime is normally unsupported (most platform backends won't refresh the decoration right away).");
+                ImGui::Checkbox("io.ConfigViewportsNoDefaultParent", &io.ConfigViewportsNoDefaultParent);
+                ImGui::SameLine(); HelpMarker("Toggling this at runtime is normally unsupported (most platform backends won't refresh the parenting right away).");
+                ImGui::Unindent();
+            }
+
             ImGui::Checkbox("io.ConfigInputTrickleEventQueue", &io.ConfigInputTrickleEventQueue);
             ImGui::SameLine(); HelpMarker("Enable input queue trickling: some types of events submitted during the same frame (e.g. button down + up) will be spread over multiple frames, improving interactions with low framerates.");
             ImGui::Checkbox("io.ConfigInputTextCursorBlink", &io.ConfigInputTextCursorBlink);
@@ -474,10 +528,13 @@ void ImGui::ShowDemoWindow(bool* p_open)
             // Make a local copy to avoid modifying actual backend flags.
             // FIXME: We don't use BeginDisabled() to keep label bright, maybe we need a BeginReadonly() equivalent..
             ImGuiBackendFlags backend_flags = io.BackendFlags;
-            ImGui::CheckboxFlags("io.BackendFlags: HasGamepad",           &backend_flags, ImGuiBackendFlags_HasGamepad);
+            ImGui::CheckboxFlags("io.BackendFlags: HasGamepad",             &backend_flags, ImGuiBackendFlags_HasGamepad);
-            ImGui::CheckboxFlags("io.BackendFlags: HasMouseCursors",      &backend_flags, ImGuiBackendFlags_HasMouseCursors);
+            ImGui::CheckboxFlags("io.BackendFlags: HasMouseCursors",        &backend_flags, ImGuiBackendFlags_HasMouseCursors);
-            ImGui::CheckboxFlags("io.BackendFlags: HasSetMousePos",       &backend_flags, ImGuiBackendFlags_HasSetMousePos);
+            ImGui::CheckboxFlags("io.BackendFlags: HasSetMousePos",         &backend_flags, ImGuiBackendFlags_HasSetMousePos);
-            ImGui::CheckboxFlags("io.BackendFlags: RendererHasVtxOffset", &backend_flags, ImGuiBackendFlags_RendererHasVtxOffset);
+            ImGui::CheckboxFlags("io.BackendFlags: PlatformHasViewports",   &backend_flags, ImGuiBackendFlags_PlatformHasViewports);
+            ImGui::CheckboxFlags("io.BackendFlags: HasMouseHoveredViewport",&backend_flags, ImGuiBackendFlags_HasMouseHoveredViewport);
+            ImGui::CheckboxFlags("io.BackendFlags: RendererHasVtxOffset",   &backend_flags, ImGuiBackendFlags_RendererHasVtxOffset);
+            ImGui::CheckboxFlags("io.BackendFlags: RendererHasViewports",   &backend_flags, ImGuiBackendFlags_RendererHasViewports);
             ImGui::TreePop();
             ImGui::Separator();
         }
@@ -526,6 +583,7 @@ void ImGui::ShowDemoWindow(bool* p_open)
             ImGui::TableNextColumn(); ImGui::Checkbox("No nav", &no_nav);
             ImGui::TableNextColumn(); ImGui::Checkbox("No background", &no_background);
             ImGui::TableNextColumn(); ImGui::Checkbox("No bring to front", &no_bring_to_front);
+            ImGui::TableNextColumn(); ImGui::Checkbox("No docking", &no_docking);
             ImGui::TableNextColumn(); ImGui::Checkbox("Unsaved document", &unsaved_document);
             ImGui::EndTable();
         }
@@ -2417,18 +2475,24 @@ static void ShowDemoWindowWidgets()
             "IsWindowFocused() = %d\n"
             "IsWindowFocused(_ChildWindows) = %d\n"
             "IsWindowFocused(_ChildWindows|_NoPopupHierarchy) = %d\n"
+            "IsWindowFocused(_ChildWindows|_DockHierarchy) = %d\n"
             "IsWindowFocused(_ChildWindows|_RootWindow) = %d\n"
             "IsWindowFocused(_ChildWindows|_RootWindow|_NoPopupHierarchy) = %d\n"
+            "IsWindowFocused(_ChildWindows|_RootWindow|_DockHierarchy) = %d\n"
             "IsWindowFocused(_RootWindow) = %d\n"
             "IsWindowFocused(_RootWindow|_NoPopupHierarchy) = %d\n"
+            "IsWindowFocused(_RootWindow|_DockHierarchy) = %d\n"
             "IsWindowFocused(_AnyWindow) = %d\n",
             ImGui::IsWindowFocused(),
             ImGui::IsWindowFocused(ImGuiFocusedFlags_ChildWindows),
             ImGui::IsWindowFocused(ImGuiFocusedFlags_ChildWindows | ImGuiFocusedFlags_NoPopupHierarchy),
+            ImGui::IsWindowFocused(ImGuiFocusedFlags_ChildWindows | ImGuiFocusedFlags_DockHierarchy),
             ImGui::IsWindowFocused(ImGuiFocusedFlags_ChildWindows | ImGuiFocusedFlags_RootWindow),
             ImGui::IsWindowFocused(ImGuiFocusedFlags_ChildWindows | ImGuiFocusedFlags_RootWindow | ImGuiFocusedFlags_NoPopupHierarchy),
+            ImGui::IsWindowFocused(ImGuiFocusedFlags_ChildWindows | ImGuiFocusedFlags_RootWindow | ImGuiFocusedFlags_DockHierarchy),
             ImGui::IsWindowFocused(ImGuiFocusedFlags_RootWindow),
             ImGui::IsWindowFocused(ImGuiFocusedFlags_RootWindow | ImGuiFocusedFlags_NoPopupHierarchy),
+            ImGui::IsWindowFocused(ImGuiFocusedFlags_RootWindow | ImGuiFocusedFlags_DockHierarchy),
             ImGui::IsWindowFocused(ImGuiFocusedFlags_AnyWindow));
 
         // Testing IsWindowHovered() function with its various flags.
@@ -2438,10 +2502,13 @@ static void ShowDemoWindowWidgets()
             "IsWindowHovered(_AllowWhenBlockedByActiveItem) = %d\n"
             "IsWindowHovered(_ChildWindows) = %d\n"
             "IsWindowHovered(_ChildWindows|_NoPopupHierarchy) = %d\n"
+            "IsWindowHovered(_ChildWindows|_DockHierarchy) = %d\n"
             "IsWindowHovered(_ChildWindows|_RootWindow) = %d\n"
             "IsWindowHovered(_ChildWindows|_RootWindow|_NoPopupHierarchy) = %d\n"
+            "IsWindowHovered(_ChildWindows|_RootWindow|_DockHierarchy) = %d\n"
             "IsWindowHovered(_RootWindow) = %d\n"
             "IsWindowHovered(_RootWindow|_NoPopupHierarchy) = %d\n"
+            "IsWindowHovered(_RootWindow|_DockHierarchy) = %d\n"
             "IsWindowHovered(_ChildWindows|_AllowWhenBlockedByPopup) = %d\n"
             "IsWindowHovered(_AnyWindow) = %d\n",
             ImGui::IsWindowHovered(),
@@ -2449,10 +2516,13 @@ static void ShowDemoWindowWidgets()
             ImGui::IsWindowHovered(ImGuiHoveredFlags_AllowWhenBlockedByActiveItem),
             ImGui::IsWindowHovered(ImGuiHoveredFlags_ChildWindows),
             ImGui::IsWindowHovered(ImGuiHoveredFlags_ChildWindows | ImGuiHoveredFlags_NoPopupHierarchy),
+            ImGui::IsWindowHovered(ImGuiHoveredFlags_ChildWindows | ImGuiHoveredFlags_DockHierarchy),
             ImGui::IsWindowHovered(ImGuiHoveredFlags_ChildWindows | ImGuiHoveredFlags_RootWindow),
             ImGui::IsWindowHovered(ImGuiHoveredFlags_ChildWindows | ImGuiHoveredFlags_RootWindow | ImGuiHoveredFlags_NoPopupHierarchy),
+            ImGui::IsWindowHovered(ImGuiHoveredFlags_ChildWindows | ImGuiHoveredFlags_RootWindow | ImGuiHoveredFlags_DockHierarchy),
             ImGui::IsWindowHovered(ImGuiHoveredFlags_RootWindow),
             ImGui::IsWindowHovered(ImGuiHoveredFlags_RootWindow | ImGuiHoveredFlags_NoPopupHierarchy),
+            ImGui::IsWindowHovered(ImGuiHoveredFlags_RootWindow | ImGuiHoveredFlags_DockHierarchy),
             ImGui::IsWindowHovered(ImGuiHoveredFlags_ChildWindows | ImGuiHoveredFlags_AllowWhenBlockedByPopup),
             ImGui::IsWindowHovered(ImGuiHoveredFlags_AnyWindow));
 
@@ -2464,10 +2534,13 @@ static void ShowDemoWindowWidgets()
 
         // Calling IsItemHovered() after begin returns the hovered status of the title bar.
         // This is useful in particular if you want to create a context menu associated to the title bar of a window.
+        // This will also work when docked into a Tab (the Tab replace the Title Bar and guarantee the same properties).
         static bool test_window = false;
         ImGui::Checkbox("Hovered/Active tests after Begin() for title bar testing", &test_window);
         if (test_window)
         {
+            // FIXME-DOCK: This window cannot be docked within the ImGui Demo window, this will cause a feedback loop and get them stuck.
+            // Could we fix this through an ImGuiWindowClass feature? Or an API call to tag our parent as "don't skip items"?
             ImGui::Begin("Title bar Hovered/Active tests", &test_window);
             if (ImGui::BeginPopupContextItem()) // <-- This is using IsItemHovered()
             {
@@ -6048,6 +6121,12 @@ void ImGui::ShowAboutWindow(bool* p_open)
 #endif
 #ifdef __clang_version__
         ImGui::Text("define: __clang_version__=%s", __clang_version__);
+#endif
+#ifdef IMGUI_HAS_VIEWPORT
+        ImGui::Text("define: IMGUI_HAS_VIEWPORT");
+#endif
+#ifdef IMGUI_HAS_DOCK
+        ImGui::Text("define: IMGUI_HAS_DOCK");
 #endif
         ImGui::Separator();
         ImGui::Text("io.BackendPlatformName: %s", io.BackendPlatformName ? io.BackendPlatformName : "NULL");
@@ -6059,7 +6138,19 @@ void ImGui::ShowAboutWindow(bool* p_open)
         if (io.ConfigFlags & ImGuiConfigFlags_NavNoCaptureKeyboard)     ImGui::Text(" NavNoCaptureKeyboard");
         if (io.ConfigFlags & ImGuiConfigFlags_NoMouse)                  ImGui::Text(" NoMouse");
         if (io.ConfigFlags & ImGuiConfigFlags_NoMouseCursorChange)      ImGui::Text(" NoMouseCursorChange");
+        if (io.ConfigFlags & ImGuiConfigFlags_DockingEnable)            ImGui::Text(" DockingEnable");
+        if (io.ConfigFlags & ImGuiConfigFlags_ViewportsEnable)          ImGui::Text(" ViewportsEnable");
+        if (io.ConfigFlags & ImGuiConfigFlags_DpiEnableScaleViewports)  ImGui::Text(" DpiEnableScaleViewports");
+        if (io.ConfigFlags & ImGuiConfigFlags_DpiEnableScaleFonts)      ImGui::Text(" DpiEnableScaleFonts");
         if (io.MouseDrawCursor)                                         ImGui::Text("io.MouseDrawCursor");
+        if (io.ConfigViewportsNoAutoMerge)                              ImGui::Text("io.ConfigViewportsNoAutoMerge");
+        if (io.ConfigViewportsNoTaskBarIcon)                            ImGui::Text("io.ConfigViewportsNoTaskBarIcon");
+        if (io.ConfigViewportsNoDecoration)                             ImGui::Text("io.ConfigViewportsNoDecoration");
+        if (io.ConfigViewportsNoDefaultParent)                          ImGui::Text("io.ConfigViewportsNoDefaultParent");
+        if (io.ConfigDockingNoSplit)                                    ImGui::Text("io.ConfigDockingNoSplit");
+        if (io.ConfigDockingWithShift)                                  ImGui::Text("io.ConfigDockingWithShift");
+        if (io.ConfigDockingAlwaysTabBar)                               ImGui::Text("io.ConfigDockingAlwaysTabBar");
+        if (io.ConfigDockingTransparentPayload)                         ImGui::Text("io.ConfigDockingTransparentPayload");
         if (io.ConfigMacOSXBehaviors)                                   ImGui::Text("io.ConfigMacOSXBehaviors");
         if (io.ConfigInputTextCursorBlink)                              ImGui::Text("io.ConfigInputTextCursorBlink");
         if (io.ConfigWindowsResizeFromEdges)                            ImGui::Text("io.ConfigWindowsResizeFromEdges");
@@ -6069,7 +6160,10 @@ void ImGui::ShowAboutWindow(bool* p_open)
         if (io.BackendFlags & ImGuiBackendFlags_HasGamepad)             ImGui::Text(" HasGamepad");
         if (io.BackendFlags & ImGuiBackendFlags_HasMouseCursors)        ImGui::Text(" HasMouseCursors");
         if (io.BackendFlags & ImGuiBackendFlags_HasSetMousePos)         ImGui::Text(" HasSetMousePos");
+        if (io.BackendFlags & ImGuiBackendFlags_PlatformHasViewports)   ImGui::Text(" PlatformHasViewports");
+        if (io.BackendFlags & ImGuiBackendFlags_HasMouseHoveredViewport)ImGui::Text(" HasMouseHoveredViewport");
         if (io.BackendFlags & ImGuiBackendFlags_RendererHasVtxOffset)   ImGui::Text(" RendererHasVtxOffset");
+        if (io.BackendFlags & ImGuiBackendFlags_RendererHasViewports)   ImGui::Text(" RendererHasViewports");
         ImGui::Separator();
         ImGui::Text("io.Fonts: %d fonts, Flags: 0x%08X, TexSize: %d,%d", io.Fonts->Fonts.Size, io.Fonts->Flags, io.Fonts->TexWidth, io.Fonts->TexHeight);
         ImGui::Text("io.DisplaySize: %.2f,%.2f", io.DisplaySize.x, io.DisplaySize.y);
@@ -7375,6 +7469,8 @@ static void ShowExampleAppConstrainedResize(bool* p_open)
         else
         {
             ImGui::Text("(Hold SHIFT to display a dummy viewport)");
+            if (ImGui::IsWindowDocked())
+                ImGui::Text("Warning: Sizing Constraints won't work if the window is docked!");
             if (ImGui::Button("Set 200x200")) { ImGui::SetWindowSize(ImVec2(200, 200)); } ImGui::SameLine();
             if (ImGui::Button("Set 500x500")) { ImGui::SetWindowSize(ImVec2(500, 500)); } ImGui::SameLine();
             if (ImGui::Button("Set 800x200")) { ImGui::SetWindowSize(ImVec2(800, 200)); }
@@ -7401,7 +7497,7 @@ static void ShowExampleAppSimpleOverlay(bool* p_open)
 {
     static int location = 0;
     ImGuiIO& io = ImGui::GetIO();
-    ImGuiWindowFlags window_flags = ImGuiWindowFlags_NoDecoration | ImGuiWindowFlags_AlwaysAutoResize | ImGuiWindowFlags_NoSavedSettings | ImGuiWindowFlags_NoFocusOnAppearing | ImGuiWindowFlags_NoNav;
+    ImGuiWindowFlags window_flags = ImGuiWindowFlags_NoDecoration | ImGuiWindowFlags_NoDocking | ImGuiWindowFlags_AlwaysAutoResize | ImGuiWindowFlags_NoSavedSettings | ImGuiWindowFlags_NoFocusOnAppearing | ImGuiWindowFlags_NoNav;
     if (location >= 0)
     {
         const float PAD = 10.0f;
@@ -7414,6 +7510,7 @@ static void ShowExampleAppSimpleOverlay(bool* p_open)
         window_pos_pivot.x = (location & 1) ? 1.0f : 0.0f;
         window_pos_pivot.y = (location & 2) ? 1.0f : 0.0f;
         ImGui::SetNextWindowPos(window_pos, ImGuiCond_Always, window_pos_pivot);
+        ImGui::SetNextWindowViewport(viewport->ID);
         window_flags |= ImGuiWindowFlags_NoMove;
     }
     else if (location == -2)
@@ -7761,6 +7858,131 @@ static void ShowExampleAppCustomRendering(bool* p_open)
     ImGui::End();
 }
 
+//-----------------------------------------------------------------------------
+// [SECTION] Example App: Docking, DockSpace / ShowExampleAppDockSpace()
+//-----------------------------------------------------------------------------
+
+// Demonstrate using DockSpace() to create an explicit docking node within an existing window.
+// Note: You can use most Docking facilities without calling any API. You DO NOT need to call DockSpace() to use Docking!
+// - Drag from window title bar or their tab to dock/undock. Hold SHIFT to disable docking.
+// - Drag from window menu button (upper-left button) to undock an entire node (all windows).
+// - When io.ConfigDockingWithShift == true, you instead need to hold SHIFT to _enable_ docking/undocking.
+// About dockspaces:
+// - Use DockSpace() to create an explicit dock node _within_ an existing window.
+// - Use DockSpaceOverViewport() to create an explicit dock node covering the screen or a specific viewport.
+//   This is often used with ImGuiDockNodeFlags_PassthruCentralNode.
+// - Important: Dockspaces need to be submitted _before_ any window they can host. Submit it early in your frame! (*)
+// - Important: Dockspaces need to be kept alive if hidden, otherwise windows docked into it will be undocked.
+//   e.g. if you have multiple tabs with a dockspace inside each tab: submit the non-visible dockspaces with ImGuiDockNodeFlags_KeepAliveOnly.
+// (*) because of this constraint, the implicit \"Debug\" window can not be docked into an explicit DockSpace() node,
+// because that window is submitted as part of the part of the NewFrame() call. An easy workaround is that you can create
+// your own implicit "Debug##2" window after calling DockSpace() and leave it in the window stack for anyone to use.
+void ShowExampleAppDockSpace(bool* p_open)
+{
+    // If you strip some features of, this demo is pretty much equivalent to calling DockSpaceOverViewport()!
+    // In most cases you should be able to just call DockSpaceOverViewport() and ignore all the code below!
+    // In this specific demo, we are not using DockSpaceOverViewport() because:
+    // - we allow the host window to be floating/moveable instead of filling the viewport (when opt_fullscreen == false)
+    // - we allow the host window to have padding (when opt_padding == true)
+    // - we have a local menu bar in the host window (vs. you could use BeginMainMenuBar() + DockSpaceOverViewport() in your code!)
+    // TL;DR; this demo is more complicated than what you would normally use.
+    // If we removed all the options we are showcasing, this demo would become:
+    //     void ShowExampleAppDockSpace()
+    //     {
+    //         ImGui::DockSpaceOverViewport(ImGui::GetMainViewport());
+    //     }
+
+    static bool opt_fullscreen = true;
+    static bool opt_padding = false;
+    static ImGuiDockNodeFlags dockspace_flags = ImGuiDockNodeFlags_None;
+
+    // We are using the ImGuiWindowFlags_NoDocking flag to make the parent window not dockable into,
+    // because it would be confusing to have two docking targets within each others.
+    ImGuiWindowFlags window_flags = ImGuiWindowFlags_MenuBar | ImGuiWindowFlags_NoDocking;
+    if (opt_fullscreen)
+    {
+        const ImGuiViewport* viewport = ImGui::GetMainViewport();
+        ImGui::SetNextWindowPos(viewport->WorkPos);
+        ImGui::SetNextWindowSize(viewport->WorkSize);
+        ImGui::SetNextWindowViewport(viewport->ID);
+        ImGui::PushStyleVar(ImGuiStyleVar_WindowRounding, 0.0f);
+        ImGui::PushStyleVar(ImGuiStyleVar_WindowBorderSize, 0.0f);
+        window_flags |= ImGuiWindowFlags_NoTitleBar | ImGuiWindowFlags_NoCollapse | ImGuiWindowFlags_NoResize | ImGuiWindowFlags_NoMove;
+        window_flags |= ImGuiWindowFlags_NoBringToFrontOnFocus | ImGuiWindowFlags_NoNavFocus;
+    }
+    else
+    {
+        dockspace_flags &= ~ImGuiDockNodeFlags_PassthruCentralNode;
+    }
+
+    // When using ImGuiDockNodeFlags_PassthruCentralNode, DockSpace() will render our background
+    // and handle the pass-thru hole, so we ask Begin() to not render a background.
+    if (dockspace_flags & ImGuiDockNodeFlags_PassthruCentralNode)
+        window_flags |= ImGuiWindowFlags_NoBackground;
+
+    // Important: note that we proceed even if Begin() returns false (aka window is collapsed).
+    // This is because we want to keep our DockSpace() active. If a DockSpace() is inactive,
+    // all active windows docked into it will lose their parent and become undocked.
+    // We cannot preserve the docking relationship between an active window and an inactive docking, otherwise
+    // any change of dockspace/settings would lead to windows being stuck in limbo and never being visible.
+    if (!opt_padding)
+        ImGui::PushStyleVar(ImGuiStyleVar_WindowPadding, ImVec2(0.0f, 0.0f));
+    ImGui::Begin("DockSpace Demo", p_open, window_flags);
+    if (!opt_padding)
+        ImGui::PopStyleVar();
+
+    if (opt_fullscreen)
+        ImGui::PopStyleVar(2);
+
+    // Submit the DockSpace
+    ImGuiIO& io = ImGui::GetIO();
+    if (io.ConfigFlags & ImGuiConfigFlags_DockingEnable)
+    {
+        ImGuiID dockspace_id = ImGui::GetID("MyDockSpace");
+        ImGui::DockSpace(dockspace_id, ImVec2(0.0f, 0.0f), dockspace_flags);
+    }
+    else
+    {
+        ShowDockingDisabledMessage();
+    }
+
+    if (ImGui::BeginMenuBar())
+    {
+        if (ImGui::BeginMenu("Options"))
+        {
+            // Disabling fullscreen would allow the window to be moved to the front of other windows,
+            // which we can't undo at the moment without finer window depth/z control.
+            ImGui::MenuItem("Fullscreen", NULL, &opt_fullscreen);
+            ImGui::MenuItem("Padding", NULL, &opt_padding);
+            ImGui::Separator();
+
+            if (ImGui::MenuItem("Flag: NoSplit",                "", (dockspace_flags & ImGuiDockNodeFlags_NoSplit) != 0))                 { dockspace_flags ^= ImGuiDockNodeFlags_NoSplit; }
+            if (ImGui::MenuItem("Flag: NoResize",               "", (dockspace_flags & ImGuiDockNodeFlags_NoResize) != 0))                { dockspace_flags ^= ImGuiDockNodeFlags_NoResize; }
+            if (ImGui::MenuItem("Flag: NoDockingInCentralNode", "", (dockspace_flags & ImGuiDockNodeFlags_NoDockingInCentralNode) != 0))  { dockspace_flags ^= ImGuiDockNodeFlags_NoDockingInCentralNode; }
+            if (ImGui::MenuItem("Flag: AutoHideTabBar",         "", (dockspace_flags & ImGuiDockNodeFlags_AutoHideTabBar) != 0))          { dockspace_flags ^= ImGuiDockNodeFlags_AutoHideTabBar; }
+            if (ImGui::MenuItem("Flag: PassthruCentralNode",    "", (dockspace_flags & ImGuiDockNodeFlags_PassthruCentralNode) != 0, opt_fullscreen)) { dockspace_flags ^= ImGuiDockNodeFlags_PassthruCentralNode; }
+            ImGui::Separator();
+
+            if (ImGui::MenuItem("Close", NULL, false, p_open != NULL))
+                *p_open = false;
+            ImGui::EndMenu();
+        }
+        HelpMarker(
+            "When docking is enabled, you can ALWAYS dock MOST window into another! Try it now!" "\n"
+            "- Drag from window title bar or their tab to dock/undock." "\n"
+            "- Drag from window menu button (upper-left button) to undock an entire node (all windows)." "\n"
+            "- Hold SHIFT to disable docking (if io.ConfigDockingWithShift == false, default)" "\n"
+            "- Hold SHIFT to enable docking (if io.ConfigDockingWithShift == true)" "\n"
+            "This demo app has nothing to do with enabling docking!" "\n\n"
+            "This demo app only demonstrate the use of ImGui::DockSpace() which allows you to manually create a docking node _within_ another window." "\n\n"
+            "Read comments in ShowExampleAppDockSpace() for more details.");
+
+        ImGui::EndMenuBar();
+    }
+
+    ImGui::End();
+}
+
 //-----------------------------------------------------------------------------
 // [SECTION] Example App: Documents Handling / ShowExampleAppDocuments()
 //-----------------------------------------------------------------------------
@@ -7860,11 +8082,25 @@ void ShowExampleAppDocuments(bool* p_open)
     static ExampleAppDocuments app;
 
     // Options
+    enum Target
+    {
+        Target_None,
+        Target_Tab,                 // Create documents as local tab into a local tab bar
+        Target_DockSpaceAndWindow   // Create documents as regular windows, and create an embedded dockspace
+    };
+    static Target opt_target = Target_Tab;
     static bool opt_reorderable = true;
     static ImGuiTabBarFlags opt_fitting_flags = ImGuiTabBarFlags_FittingPolicyDefault_;
 
+    // When (opt_target == Target_DockSpaceAndWindow) there is the possibily that one of our child Document window (e.g. "Eggplant")
+    // that we emit gets docked into the same spot as the parent window ("Example: Documents").
+    // This would create a problematic feedback loop because selecting the "Eggplant" tab would make the "Example: Documents" tab
+    // not visible, which in turn would stop submitting the "Eggplant" window.
+    // We avoid this problem by submitting our documents window even if our parent window is not currently visible.
+    // Another solution may be to make the "Example: Documents" window use the ImGuiWindowFlags_NoDocking.
+
     bool window_contents_visible = ImGui::Begin("Example: Documents", p_open, ImGuiWindowFlags_MenuBar);
-    if (!window_contents_visible)
+    if (!window_contents_visible && opt_target != Target_DockSpaceAndWindow)
     {
         ImGui::End();
         return;
@@ -7912,6 +8148,12 @@ void ShowExampleAppDocuments(bool* p_open)
                 doc->DoForceClose();
         ImGui::PopID();
     }
+    ImGui::PushItemWidth(ImGui::GetFontSize() * 12);
+    ImGui::Combo("Output", (int*)&opt_target, "None\0TabBar+Tabs\0DockSpace+Window\0");
+    ImGui::PopItemWidth();
+    bool redock_all = false;
+    if (opt_target == Target_Tab)                { ImGui::SameLine(); ImGui::Checkbox("Reorderable Tabs", &opt_reorderable); }
+    if (opt_target == Target_DockSpaceAndWindow) { ImGui::SameLine(); redock_all = ImGui::Button("Redock all"); }
 
     ImGui::Separator();
 
@@ -7925,7 +8167,8 @@ void ShowExampleAppDocuments(bool* p_open)
     //   hole for one-frame, both in the tab-bar and in tab-contents when closing a tab/window.
     //   The rarely used SetTabItemClosed() function is a way to notify of programmatic closure to avoid the one-frame hole.
 
-    // Submit Tab Bar and Tabs
+    // Tabs
+    if (opt_target == Target_Tab)
     {
         ImGuiTabBarFlags tab_bar_flags = (opt_fitting_flags) | (opt_reorderable ? ImGuiTabBarFlags_Reorderable : 0);
         if (ImGui::BeginTabBar("##tabs", tab_bar_flags))
@@ -7965,6 +8208,53 @@ void ShowExampleAppDocuments(bool* p_open)
             ImGui::EndTabBar();
         }
     }
+    else if (opt_target == Target_DockSpaceAndWindow)
+    {
+        if (ImGui::GetIO().ConfigFlags & ImGuiConfigFlags_DockingEnable)
+        {
+            NotifyOfDocumentsClosedElsewhere(app);
+
+            // Create a DockSpace node where any window can be docked
+            ImGuiID dockspace_id = ImGui::GetID("MyDockSpace");
+            ImGui::DockSpace(dockspace_id);
+
+            // Create Windows
+            for (int doc_n = 0; doc_n < app.Documents.Size; doc_n++)
+            {
+                MyDocument* doc = &app.Documents[doc_n];
+                if (!doc->Open)
+                    continue;
+
+                ImGui::SetNextWindowDockID(dockspace_id, redock_all ? ImGuiCond_Always : ImGuiCond_FirstUseEver);
+                ImGuiWindowFlags window_flags = (doc->Dirty ? ImGuiWindowFlags_UnsavedDocument : 0);
+                bool visible = ImGui::Begin(doc->Name, &doc->Open, window_flags);
+
+                // Cancel attempt to close when unsaved add to save queue so we can display a popup.
+                if (!doc->Open && doc->Dirty)
+                {
+                    doc->Open = true;
+                    doc->DoQueueClose();
+                }
+
+                MyDocument::DisplayContextMenu(doc);
+                if (visible)
+                    MyDocument::DisplayContents(doc);
+
+                ImGui::End();
+            }
+        }
+        else
+        {
+            ShowDockingDisabledMessage();
+        }
+    }
+
+    // Early out other contents
+    if (!window_contents_visible)
+    {
+        ImGui::End();
+        return;
+    }
 
     // Update closing queue
     static ImVector<MyDocument*> close_queue;

includes/imgui/imgui_draw.cpp

@@ -214,6 +214,8 @@ void ImGui::StyleColorsDark(ImGuiStyle* dst)
     colors[ImGuiCol_TabActive]              = ImLerp(colors[ImGuiCol_HeaderActive], colors[ImGuiCol_TitleBgActive], 0.60f);
     colors[ImGuiCol_TabUnfocused]           = ImLerp(colors[ImGuiCol_Tab],          colors[ImGuiCol_TitleBg], 0.80f);
     colors[ImGuiCol_TabUnfocusedActive]     = ImLerp(colors[ImGuiCol_TabActive],    colors[ImGuiCol_TitleBg], 0.40f);
+    colors[ImGuiCol_DockingPreview]         = colors[ImGuiCol_HeaderActive] * ImVec4(1.0f, 1.0f, 1.0f, 0.7f);
+    colors[ImGuiCol_DockingEmptyBg]         = ImVec4(0.20f, 0.20f, 0.20f, 1.00f);
     colors[ImGuiCol_PlotLines]              = ImVec4(0.61f, 0.61f, 0.61f, 1.00f);
     colors[ImGuiCol_PlotLinesHovered]       = ImVec4(1.00f, 0.43f, 0.35f, 1.00f);
     colors[ImGuiCol_PlotHistogram]          = ImVec4(0.90f, 0.70f, 0.00f, 1.00f);
@@ -274,6 +276,8 @@ void ImGui::StyleColorsClassic(ImGuiStyle* dst)
     colors[ImGuiCol_TabActive]              = ImLerp(colors[ImGuiCol_HeaderActive], colors[ImGuiCol_TitleBgActive], 0.60f);
     colors[ImGuiCol_TabUnfocused]           = ImLerp(colors[ImGuiCol_Tab],          colors[ImGuiCol_TitleBg], 0.80f);
     colors[ImGuiCol_TabUnfocusedActive]     = ImLerp(colors[ImGuiCol_TabActive],    colors[ImGuiCol_TitleBg], 0.40f);
+    colors[ImGuiCol_DockingPreview]         = colors[ImGuiCol_Header] * ImVec4(1.0f, 1.0f, 1.0f, 0.7f);
+    colors[ImGuiCol_DockingEmptyBg]         = ImVec4(0.20f, 0.20f, 0.20f, 1.00f);
     colors[ImGuiCol_PlotLines]              = ImVec4(1.00f, 1.00f, 1.00f, 1.00f);
     colors[ImGuiCol_PlotLinesHovered]       = ImVec4(0.90f, 0.70f, 0.00f, 1.00f);
     colors[ImGuiCol_PlotHistogram]          = ImVec4(0.90f, 0.70f, 0.00f, 1.00f);
@@ -335,6 +339,8 @@ void ImGui::StyleColorsLight(ImGuiStyle* dst)
     colors[ImGuiCol_TabActive]              = ImLerp(colors[ImGuiCol_HeaderActive], colors[ImGuiCol_TitleBgActive], 0.60f);
     colors[ImGuiCol_TabUnfocused]           = ImLerp(colors[ImGuiCol_Tab],          colors[ImGuiCol_TitleBg], 0.80f);
     colors[ImGuiCol_TabUnfocusedActive]     = ImLerp(colors[ImGuiCol_TabActive],    colors[ImGuiCol_TitleBg], 0.40f);
+    colors[ImGuiCol_DockingPreview]         = colors[ImGuiCol_Header] * ImVec4(1.0f, 1.0f, 1.0f, 0.7f);
+    colors[ImGuiCol_DockingEmptyBg]         = ImVec4(0.20f, 0.20f, 0.20f, 1.00f);
     colors[ImGuiCol_PlotLines]              = ImVec4(0.39f, 0.39f, 0.39f, 1.00f);
     colors[ImGuiCol_PlotLinesHovered]       = ImVec4(1.00f, 0.43f, 0.35f, 1.00f);
     colors[ImGuiCol_PlotHistogram]          = ImVec4(0.90f, 0.70f, 0.00f, 1.00f);
@@ -389,6 +395,8 @@ void ImDrawList::_ResetForNewFrame()
     IM_STATIC_ASSERT(IM_OFFSETOF(ImDrawCmd, ClipRect) == 0);
     IM_STATIC_ASSERT(IM_OFFSETOF(ImDrawCmd, TextureId) == sizeof(ImVec4));
     IM_STATIC_ASSERT(IM_OFFSETOF(ImDrawCmd, VtxOffset) == sizeof(ImVec4) + sizeof(ImTextureID));
+    if (_Splitter._Count > 1)
+        _Splitter.Merge(this);
 
     CmdBuffer.resize(0);
     IdxBuffer.resize(0);
@@ -3741,6 +3749,7 @@ void ImFont::RenderText(ImDrawList* draw_list, float size, const ImVec2& pos, Im
 // - RenderArrow()
 // - RenderBullet()
 // - RenderCheckMark()
+// - RenderArrowDockMenu()
 // - RenderArrowPointingAt()
 // - RenderRectFilledRangeH()
 // - RenderRectFilledWithHole()
@@ -3814,6 +3823,14 @@ void ImGui::RenderArrowPointingAt(ImDrawList* draw_list, ImVec2 pos, ImVec2 half
     }
 }
 
+// This is less wide than RenderArrow() and we use in dock nodes instead of the regular RenderArrow() to denote a change of functionality,
+// and because the saved space means that the left-most tab label can stay at exactly the same position as the label of a loose window.
+void ImGui::RenderArrowDockMenu(ImDrawList* draw_list, ImVec2 p_min, float sz, ImU32 col)
+{
+    draw_list->AddRectFilled(p_min + ImVec2(sz * 0.20f, sz * 0.15f), p_min + ImVec2(sz * 0.80f, sz * 0.30f), col);
+    RenderArrowPointingAt(draw_list, p_min + ImVec2(sz * 0.50f, sz * 0.85f), ImVec2(sz * 0.30f, sz * 0.40f), ImGuiDir_Down, col);
+}
+
 static inline float ImAcos01(float x)
 {
     if (x <= 0.0f) return IM_PI * 0.5f;
@@ -3899,6 +3916,17 @@ void ImGui::RenderRectFilledWithHole(ImDrawList* draw_list, const ImRect& outer,
     if (fill_R && fill_D) draw_list->AddRectFilled(ImVec2(inner.Max.x, inner.Max.y), ImVec2(outer.Max.x, outer.Max.y), col, rounding, ImDrawFlags_RoundCornersBottomRight);
 }
 
+ImDrawFlags ImGui::CalcRoundingFlagsForRectInRect(const ImRect& r_in, const ImRect& r_outer, float threshold)
+{
+    bool round_l = r_in.Min.x <= r_outer.Min.x + threshold;
+    bool round_r = r_in.Max.x >= r_outer.Max.x - threshold;
+    bool round_t = r_in.Min.y <= r_outer.Min.y + threshold;
+    bool round_b = r_in.Max.y >= r_outer.Max.y - threshold;
+    return ImDrawFlags_RoundCornersNone
+        | ((round_t && round_l) ? ImDrawFlags_RoundCornersTopLeft : 0) | ((round_t && round_r) ? ImDrawFlags_RoundCornersTopRight : 0)
+        | ((round_b && round_l) ? ImDrawFlags_RoundCornersBottomLeft : 0) | ((round_b && round_r) ? ImDrawFlags_RoundCornersBottomRight : 0);
+}
+
 // Helper for ColorPicker4()
 // NB: This is rather brittle and will show artifact when rounding this enabled if rounded corners overlap multiple cells. Caller currently responsible for avoiding that.
 // Spent a non reasonable amount of time trying to getting this right for ColorButton with rounding+anti-aliasing+ImGuiColorEditFlags_HalfAlphaPreview flag + various grid sizes and offsets, and eventually gave up... probably more reasonable to disable rounding altogether.

includes/imgui/imgui_internal.h

@@ -118,6 +118,10 @@ struct ImGuiColorMod;               // Stacked color modifier, backup of modifie
 struct ImGuiContext;                // Main Dear ImGui context
 struct ImGuiContextHook;            // Hook for extensions like ImGuiTestEngine
 struct ImGuiDataTypeInfo;           // Type information associated to a ImGuiDataType enum
+struct ImGuiDockContext;            // Docking system context
+struct ImGuiDockRequest;            // Docking system dock/undock queued request
+struct ImGuiDockNode;               // Docking system node (hold a list of Windows OR two child dock nodes)
+struct ImGuiDockNodeSettings;       // Storage for a dock node in .ini file (we preserve those even if the associated dock node isn't active during the session)
 struct ImGuiGroupData;              // Stacked storage data for BeginGroup()/EndGroup()
 struct ImGuiInputTextState;         // Internal state of the currently focused/edited text input box
 struct ImGuiLastItemData;           // Status storage for last submitted items
@@ -145,6 +149,7 @@ struct ImGuiWindowTempData;         // Temporary storage for one window (that's
 struct ImGuiWindowSettings;         // Storage for a window .ini settings (we keep one of those even if the actual window wasn't instanced during this session)
 
 // Use your programming IDE "Go to definition" facility on the names of the center columns to find the actual flags/enum lists.
+typedef int ImGuiDataAuthority;         // -> enum ImGuiDataAuthority_      // Enum: for storing the source authority (dock node vs window) of a field
 typedef int ImGuiLayoutType;            // -> enum ImGuiLayoutType_         // Enum: Horizontal or vertical
 typedef int ImGuiActivateFlags;         // -> enum ImGuiActivateFlags_      // Flags: for navigation/focus function (will be for ActivateItem() later)
 typedef int ImGuiDebugLogFlags;         // -> enum ImGuiDebugLogFlags_      // Flags: for ShowDebugLogWindow(), g.DebugLogFlags
@@ -194,6 +199,9 @@ namespace ImStb
 // [SECTION] Macros
 //-----------------------------------------------------------------------------
 
+// Internal Drag and Drop payload types. String starting with '_' are reserved for Dear ImGui.
+#define IMGUI_PAYLOAD_TYPE_WINDOW       "_IMWINDOW"     // Payload == ImGuiWindow*
+
 // Debug Printing Into TTY
 // (since IMGUI_VERSION_NUM >= 18729: IMGUI_DEBUG_LOG was reworked into IMGUI_DEBUG_PRINTF (and removed framecount from it). If you were using a #define IMGUI_DEBUG_LOG please rename)
 #ifndef IMGUI_DEBUG_PRINTF
@@ -212,6 +220,8 @@ namespace ImStb
 #define IMGUI_DEBUG_LOG_NAV(...)        do { if (g.DebugLogFlags & ImGuiDebugLogFlags_EventNav)      IMGUI_DEBUG_LOG(__VA_ARGS__); } while (0)
 #define IMGUI_DEBUG_LOG_CLIPPER(...)    do { if (g.DebugLogFlags & ImGuiDebugLogFlags_EventClipper)  IMGUI_DEBUG_LOG(__VA_ARGS__); } while (0)
 #define IMGUI_DEBUG_LOG_IO(...)         do { if (g.DebugLogFlags & ImGuiDebugLogFlags_EventIO)       IMGUI_DEBUG_LOG(__VA_ARGS__); } while (0)
+#define IMGUI_DEBUG_LOG_DOCKING(...)    do { if (g.DebugLogFlags & ImGuiDebugLogFlags_EventDocking)  IMGUI_DEBUG_LOG(__VA_ARGS__); } while (0)
+#define IMGUI_DEBUG_LOG_VIEWPORT(...)   do { if (g.DebugLogFlags & ImGuiDebugLogFlags_EventViewport) IMGUI_DEBUG_LOG(__VA_ARGS__); } while (0)
 
 // Static Asserts
 #define IM_STATIC_ASSERT(_COND)         static_assert(_COND, "")
@@ -1096,6 +1106,9 @@ enum ImGuiNextWindowDataFlags_
     ImGuiNextWindowDataFlags_HasFocus           = 1 << 5,
     ImGuiNextWindowDataFlags_HasBgAlpha         = 1 << 6,
     ImGuiNextWindowDataFlags_HasScroll          = 1 << 7,
+    ImGuiNextWindowDataFlags_HasViewport        = 1 << 8,
+    ImGuiNextWindowDataFlags_HasDock            = 1 << 9,
+    ImGuiNextWindowDataFlags_HasWindowClass     = 1 << 10,
 };
 
 // Storage for SetNexWindow** functions
@@ -1105,16 +1118,21 @@ struct ImGuiNextWindowData
     ImGuiCond                   PosCond;
     ImGuiCond                   SizeCond;
     ImGuiCond                   CollapsedCond;
+    ImGuiCond                   DockCond;
     ImVec2                      PosVal;
     ImVec2                      PosPivotVal;
     ImVec2                      SizeVal;
     ImVec2                      ContentSizeVal;
     ImVec2                      ScrollVal;
+    bool                        PosUndock;
     bool                        CollapsedVal;
     ImRect                      SizeConstraintRect;
     ImGuiSizeCallback           SizeCallback;
     void*                       SizeCallbackUserData;
     float                       BgAlphaVal;             // Override background alpha
+    ImGuiID                     ViewportId;
+    ImGuiID                     DockId;
+    ImGuiWindowClass            WindowClass;
     ImVec2                      MenuBarOffsetMinVal;    // (Always on) This is not exposed publicly, so we don't clear it and it doesn't have a corresponding flag (could we? for consistency?)
 
     ImGuiNextWindowData()       { memset(this, 0, sizeof(*this)); }
@@ -1226,6 +1244,7 @@ enum ImGuiInputEventType
     ImGuiInputEventType_MousePos,
     ImGuiInputEventType_MouseWheel,
     ImGuiInputEventType_MouseButton,
+    ImGuiInputEventType_MouseViewport,
     ImGuiInputEventType_Key,
     ImGuiInputEventType_Text,
     ImGuiInputEventType_Focus,
@@ -1248,6 +1267,7 @@ enum ImGuiInputSource
 struct ImGuiInputEventMousePos      { float PosX, PosY; };
 struct ImGuiInputEventMouseWheel    { float WheelX, WheelY; };
 struct ImGuiInputEventMouseButton   { int Button; bool Down; };
+struct ImGuiInputEventMouseViewport { ImGuiID HoveredViewportID; };
 struct ImGuiInputEventKey           { ImGuiKey Key; bool Down; float AnalogValue; };
 struct ImGuiInputEventText          { unsigned int Char; };
 struct ImGuiInputEventAppFocused    { bool Focused; };
@@ -1261,6 +1281,7 @@ struct ImGuiInputEvent
         ImGuiInputEventMousePos     MousePos;       // if Type == ImGuiInputEventType_MousePos
         ImGuiInputEventMouseWheel   MouseWheel;     // if Type == ImGuiInputEventType_MouseWheel
         ImGuiInputEventMouseButton  MouseButton;    // if Type == ImGuiInputEventType_MouseButton
+        ImGuiInputEventMouseViewport MouseViewport; // if Type == ImGuiInputEventType_MouseViewport
         ImGuiInputEventKey          Key;            // if Type == ImGuiInputEventType_Key
         ImGuiInputEventText         Text;           // if Type == ImGuiInputEventType_Text
         ImGuiInputEventAppFocused   AppFocused;     // if Type == ImGuiInputEventType_Focus
@@ -1456,8 +1477,144 @@ struct ImGuiOldColumns
 // [SECTION] Docking support
 //-----------------------------------------------------------------------------
 
+#define DOCKING_HOST_DRAW_CHANNEL_BG 0  // Dock host: background fill
+#define DOCKING_HOST_DRAW_CHANNEL_FG 1  // Dock host: decorations and contents
+
 #ifdef IMGUI_HAS_DOCK
-// <this is filled in 'docking' branch>
+
+// Extend ImGuiDockNodeFlags_
+enum ImGuiDockNodeFlagsPrivate_
+{
+    // [Internal]
+    ImGuiDockNodeFlags_DockSpace                = 1 << 10,  // Local, Saved  // A dockspace is a node that occupy space within an existing user window. Otherwise the node is floating and create its own window.
+    ImGuiDockNodeFlags_CentralNode              = 1 << 11,  // Local, Saved  // The central node has 2 main properties: stay visible when empty, only use "remaining" spaces from its neighbor.
+    ImGuiDockNodeFlags_NoTabBar                 = 1 << 12,  // Local, Saved  // Tab bar is completely unavailable. No triangle in the corner to enable it back.
+    ImGuiDockNodeFlags_HiddenTabBar             = 1 << 13,  // Local, Saved  // Tab bar is hidden, with a triangle in the corner to show it again (NB: actual tab-bar instance may be destroyed as this is only used for single-window tab bar)
+    ImGuiDockNodeFlags_NoWindowMenuButton       = 1 << 14,  // Local, Saved  // Disable window/docking menu (that one that appears instead of the collapse button)
+    ImGuiDockNodeFlags_NoCloseButton            = 1 << 15,  // Local, Saved  //
+    ImGuiDockNodeFlags_NoDocking                = 1 << 16,  // Local, Saved  // Disable any form of docking in this dockspace or individual node. (On a whole dockspace, this pretty much defeat the purpose of using a dockspace at all). Note: when turned on, existing docked nodes will be preserved.
+    ImGuiDockNodeFlags_NoDockingSplitMe         = 1 << 17,  // [EXPERIMENTAL] Prevent another window/node from splitting this node.
+    ImGuiDockNodeFlags_NoDockingSplitOther      = 1 << 18,  // [EXPERIMENTAL] Prevent this node from splitting another window/node.
+    ImGuiDockNodeFlags_NoDockingOverMe          = 1 << 19,  // [EXPERIMENTAL] Prevent another window/node to be docked over this node.
+    ImGuiDockNodeFlags_NoDockingOverOther       = 1 << 20,  // [EXPERIMENTAL] Prevent this node to be docked over another window or non-empty node.
+    ImGuiDockNodeFlags_NoDockingOverEmpty       = 1 << 21,  // [EXPERIMENTAL] Prevent this node to be docked over an empty node (e.g. DockSpace with no other windows)
+    ImGuiDockNodeFlags_NoResizeX                = 1 << 22,  // [EXPERIMENTAL]
+    ImGuiDockNodeFlags_NoResizeY                = 1 << 23,  // [EXPERIMENTAL]
+    ImGuiDockNodeFlags_SharedFlagsInheritMask_  = ~0,
+    ImGuiDockNodeFlags_NoResizeFlagsMask_       = ImGuiDockNodeFlags_NoResize | ImGuiDockNodeFlags_NoResizeX | ImGuiDockNodeFlags_NoResizeY,
+    ImGuiDockNodeFlags_LocalFlagsMask_          = ImGuiDockNodeFlags_NoSplit | ImGuiDockNodeFlags_NoResizeFlagsMask_ | ImGuiDockNodeFlags_AutoHideTabBar | ImGuiDockNodeFlags_DockSpace | ImGuiDockNodeFlags_CentralNode | ImGuiDockNodeFlags_NoTabBar | ImGuiDockNodeFlags_HiddenTabBar | ImGuiDockNodeFlags_NoWindowMenuButton | ImGuiDockNodeFlags_NoCloseButton | ImGuiDockNodeFlags_NoDocking,
+    ImGuiDockNodeFlags_LocalFlagsTransferMask_  = ImGuiDockNodeFlags_LocalFlagsMask_ & ~ImGuiDockNodeFlags_DockSpace,  // When splitting those flags are moved to the inheriting child, never duplicated
+    ImGuiDockNodeFlags_SavedFlagsMask_          = ImGuiDockNodeFlags_NoResizeFlagsMask_ | ImGuiDockNodeFlags_DockSpace | ImGuiDockNodeFlags_CentralNode | ImGuiDockNodeFlags_NoTabBar | ImGuiDockNodeFlags_HiddenTabBar | ImGuiDockNodeFlags_NoWindowMenuButton | ImGuiDockNodeFlags_NoCloseButton | ImGuiDockNodeFlags_NoDocking
+};
+
+// Store the source authority (dock node vs window) of a field
+enum ImGuiDataAuthority_
+{
+    ImGuiDataAuthority_Auto,
+    ImGuiDataAuthority_DockNode,
+    ImGuiDataAuthority_Window,
+};
+
+enum ImGuiDockNodeState
+{
+    ImGuiDockNodeState_Unknown,
+    ImGuiDockNodeState_HostWindowHiddenBecauseSingleWindow,
+    ImGuiDockNodeState_HostWindowHiddenBecauseWindowsAreResizing,
+    ImGuiDockNodeState_HostWindowVisible,
+};
+
+// sizeof() 156~192
+struct IMGUI_API ImGuiDockNode
+{
+    ImGuiID                 ID;
+    ImGuiDockNodeFlags      SharedFlags;                // (Write) Flags shared by all nodes of a same dockspace hierarchy (inherited from the root node)
+    ImGuiDockNodeFlags      LocalFlags;                 // (Write) Flags specific to this node
+    ImGuiDockNodeFlags      LocalFlagsInWindows;        // (Write) Flags specific to this node, applied from windows
+    ImGuiDockNodeFlags      MergedFlags;                // (Read)  Effective flags (== SharedFlags | LocalFlagsInNode | LocalFlagsInWindows)
+    ImGuiDockNodeState      State;
+    ImGuiDockNode*          ParentNode;
+    ImGuiDockNode*          ChildNodes[2];              // [Split node only] Child nodes (left/right or top/bottom). Consider switching to an array.
+    ImVector<ImGuiWindow*>  Windows;                    // Note: unordered list! Iterate TabBar->Tabs for user-order.
+    ImGuiTabBar*            TabBar;
+    ImVec2                  Pos;                        // Current position
+    ImVec2                  Size;                       // Current size
+    ImVec2                  SizeRef;                    // [Split node only] Last explicitly written-to size (overridden when using a splitter affecting the node), used to calculate Size.
+    ImGuiAxis               SplitAxis;                  // [Split node only] Split axis (X or Y)
+    ImGuiWindowClass        WindowClass;                // [Root node only]
+    ImU32                   LastBgColor;
+
+    ImGuiWindow*            HostWindow;
+    ImGuiWindow*            VisibleWindow;              // Generally point to window which is ID is == SelectedTabID, but when CTRL+Tabbing this can be a different window.
+    ImGuiDockNode*          CentralNode;                // [Root node only] Pointer to central node.
+    ImGuiDockNode*          OnlyNodeWithWindows;        // [Root node only] Set when there is a single visible node within the hierarchy.
+    int                     CountNodeWithWindows;       // [Root node only]
+    int                     LastFrameAlive;             // Last frame number the node was updated or kept alive explicitly with DockSpace() + ImGuiDockNodeFlags_KeepAliveOnly
+    int                     LastFrameActive;            // Last frame number the node was updated.
+    int                     LastFrameFocused;           // Last frame number the node was focused.
+    ImGuiID                 LastFocusedNodeId;          // [Root node only] Which of our child docking node (any ancestor in the hierarchy) was last focused.
+    ImGuiID                 SelectedTabId;              // [Leaf node only] Which of our tab/window is selected.
+    ImGuiID                 WantCloseTabId;             // [Leaf node only] Set when closing a specific tab/window.
+    ImGuiDataAuthority      AuthorityForPos         :3;
+    ImGuiDataAuthority      AuthorityForSize        :3;
+    ImGuiDataAuthority      AuthorityForViewport    :3;
+    bool                    IsVisible               :1; // Set to false when the node is hidden (usually disabled as it has no active window)
+    bool                    IsFocused               :1;
+    bool                    IsBgDrawnThisFrame      :1;
+    bool                    HasCloseButton          :1; // Provide space for a close button (if any of the docked window has one). Note that button may be hidden on window without one.
+    bool                    HasWindowMenuButton     :1;
+    bool                    HasCentralNodeChild     :1;
+    bool                    WantCloseAll            :1; // Set when closing all tabs at once.
+    bool                    WantLockSizeOnce        :1;
+    bool                    WantMouseMove           :1; // After a node extraction we need to transition toward moving the newly created host window
+    bool                    WantHiddenTabBarUpdate  :1;
+    bool                    WantHiddenTabBarToggle  :1;
+
+    ImGuiDockNode(ImGuiID id);
+    ~ImGuiDockNode();
+    bool                    IsRootNode() const      { return ParentNode == NULL; }
+    bool                    IsDockSpace() const     { return (MergedFlags & ImGuiDockNodeFlags_DockSpace) != 0; }
+    bool                    IsFloatingNode() const  { return ParentNode == NULL && (MergedFlags & ImGuiDockNodeFlags_DockSpace) == 0; }
+    bool                    IsCentralNode() const   { return (MergedFlags & ImGuiDockNodeFlags_CentralNode) != 0; }
+    bool                    IsHiddenTabBar() const  { return (MergedFlags & ImGuiDockNodeFlags_HiddenTabBar) != 0; } // Hidden tab bar can be shown back by clicking the small triangle
+    bool                    IsNoTabBar() const      { return (MergedFlags & ImGuiDockNodeFlags_NoTabBar) != 0; }     // Never show a tab bar
+    bool                    IsSplitNode() const     { return ChildNodes[0] != NULL; }
+    bool                    IsLeafNode() const      { return ChildNodes[0] == NULL; }
+    bool                    IsEmpty() const         { return ChildNodes[0] == NULL && Windows.Size == 0; }
+    ImRect                  Rect() const            { return ImRect(Pos.x, Pos.y, Pos.x + Size.x, Pos.y + Size.y); }
+
+    void                    SetLocalFlags(ImGuiDockNodeFlags flags) { LocalFlags = flags; UpdateMergedFlags(); }
+    void                    UpdateMergedFlags()     { MergedFlags = SharedFlags | LocalFlags | LocalFlagsInWindows; }
+};
+
+// List of colors that are stored at the time of Begin() into Docked Windows.
+// We currently store the packed colors in a simple array window->DockStyle.Colors[].
+// A better solution may involve appending into a log of colors in ImGuiContext + store offsets into those arrays in ImGuiWindow,
+// but it would be more complex as we'd need to double-buffer both as e.g. drop target may refer to window from last frame.
+enum ImGuiWindowDockStyleCol
+{
+    ImGuiWindowDockStyleCol_Text,
+    ImGuiWindowDockStyleCol_Tab,
+    ImGuiWindowDockStyleCol_TabHovered,
+    ImGuiWindowDockStyleCol_TabActive,
+    ImGuiWindowDockStyleCol_TabUnfocused,
+    ImGuiWindowDockStyleCol_TabUnfocusedActive,
+    ImGuiWindowDockStyleCol_COUNT
+};
+
+struct ImGuiWindowDockStyle
+{
+    ImU32 Colors[ImGuiWindowDockStyleCol_COUNT];
+};
+
+struct ImGuiDockContext
+{
+    ImGuiStorage                    Nodes;          // Map ID -> ImGuiDockNode*: Active nodes
+    ImVector<ImGuiDockRequest>      Requests;
+    ImVector<ImGuiDockNodeSettings> NodesSettings;
+    bool                            WantFullRebuild;
+    ImGuiDockContext()              { memset(this, 0, sizeof(*this)); }
+};
+
 #endif // #ifdef IMGUI_HAS_DOCK
 
 //-----------------------------------------------------------------------------
@@ -1468,18 +1625,31 @@ struct ImGuiOldColumns
 // Every instance of ImGuiViewport is in fact a ImGuiViewportP.
 struct ImGuiViewportP : public ImGuiViewport
 {
+    int                 Idx;
+    int                 LastFrameActive;        // Last frame number this viewport was activated by a window
+    int                 LastFrontMostStampCount;// Last stamp number from when a window hosted by this viewport was made front-most (by comparing this value between two viewport we have an implicit viewport z-order
+    ImGuiID             LastNameHash;
+    ImVec2              LastPos;
+    float               Alpha;                  // Window opacity (when dragging dockable windows/viewports we make them transparent)
+    float               LastAlpha;
+    short               PlatformMonitor;
+    bool                PlatformWindowCreated;
+    ImGuiWindow*        Window;                 // Set when the viewport is owned by a window (and ImGuiViewportFlags_CanHostOtherWindows is NOT set)
     int                 DrawListsLastFrame[2];  // Last frame number the background (0) and foreground (1) draw lists were used
     ImDrawList*         DrawLists[2];           // Convenience background (0) and foreground (1) draw lists. We use them to draw software mouser cursor when io.MouseDrawCursor is set and to draw most debug overlays.
     ImDrawData          DrawDataP;
     ImDrawDataBuilder   DrawDataBuilder;
-
+    ImVec2              LastPlatformPos;
+    ImVec2              LastPlatformSize;
+    ImVec2              LastRendererSize;
     ImVec2              WorkOffsetMin;          // Work Area: Offset from Pos to top-left corner of Work Area. Generally (0,0) or (0,+main_menu_bar_height). Work Area is Full Area but without menu-bars/status-bars (so WorkArea always fit inside Pos/Size!)
     ImVec2              WorkOffsetMax;          // Work Area: Offset from Pos+Size to bottom-right corner of Work Area. Generally (0,0) or (0,-status_bar_height).
     ImVec2              BuildWorkOffsetMin;     // Work Area: Offset being built during current frame. Generally >= 0.0f.
     ImVec2              BuildWorkOffsetMax;     // Work Area: Offset being built during current frame. Generally <= 0.0f.
 
-    ImGuiViewportP()    { DrawListsLastFrame[0] = DrawListsLastFrame[1] = -1; DrawLists[0] = DrawLists[1] = NULL; }
+    ImGuiViewportP()                    { Idx = -1; LastFrameActive = DrawListsLastFrame[0] = DrawListsLastFrame[1] = LastFrontMostStampCount = -1; LastNameHash = 0; Alpha = LastAlpha = 1.0f; PlatformMonitor = -1; PlatformWindowCreated = false; Window = NULL; DrawLists[0] = DrawLists[1] = NULL; LastPlatformPos = LastPlatformSize = LastRendererSize = ImVec2(FLT_MAX, FLT_MAX); }
-    ~ImGuiViewportP()   { if (DrawLists[0]) IM_DELETE(DrawLists[0]); if (DrawLists[1]) IM_DELETE(DrawLists[1]); }
+    ~ImGuiViewportP()                   { if (DrawLists[0]) IM_DELETE(DrawLists[0]); if (DrawLists[1]) IM_DELETE(DrawLists[1]); }
+    void    ClearRequestFlags()         { PlatformRequestClose = PlatformRequestMove = PlatformRequestResize = false; }
 
     // Calculate work rect pos/size given a set of offset (we have 1 pair of offset for rect locked from last frame data, and 1 pair for currently building rect)
     ImVec2  CalcWorkRectPos(const ImVec2& off_min) const                            { return ImVec2(Pos.x + off_min.x, Pos.y + off_min.y); }
@@ -1502,12 +1672,17 @@ struct ImGuiViewportP : public ImGuiViewport
 struct ImGuiWindowSettings
 {
     ImGuiID     ID;
-    ImVec2ih    Pos;
+    ImVec2ih    Pos;            // NB: Settings position are stored RELATIVE to the viewport! Whereas runtime ones are absolute positions.
     ImVec2ih    Size;
+    ImVec2ih    ViewportPos;
+    ImGuiID     ViewportId;
+    ImGuiID     DockId;         // ID of last known DockNode (even if the DockNode is invisible because it has only 1 active window), or 0 if none.
+    ImGuiID     ClassId;        // ID of window class if specified
+    short       DockOrder;      // Order of the last time the window was visible within its DockNode. This is used to reorder windows that are reappearing on the same frame. Same value between windows that were active and windows that were none are possible.
     bool        Collapsed;
     bool        WantApply;      // Set when loaded from .ini data (to enable merging/loading .ini data into an already running context)
 
-    ImGuiWindowSettings()       { memset(this, 0, sizeof(*this)); }
+    ImGuiWindowSettings()       { memset(this, 0, sizeof(*this)); DockOrder = -1; }
     char* GetName()             { return (char*)(this + 1); }
 };
 
@@ -1540,7 +1715,9 @@ enum ImGuiDebugLogFlags_
     ImGuiDebugLogFlags_EventNav         = 1 << 3,
     ImGuiDebugLogFlags_EventClipper     = 1 << 4,
     ImGuiDebugLogFlags_EventIO          = 1 << 5,
-    ImGuiDebugLogFlags_EventMask_       = ImGuiDebugLogFlags_EventActiveId  | ImGuiDebugLogFlags_EventFocus | ImGuiDebugLogFlags_EventPopup | ImGuiDebugLogFlags_EventNav | ImGuiDebugLogFlags_EventClipper | ImGuiDebugLogFlags_EventIO,
+    ImGuiDebugLogFlags_EventDocking     = 1 << 6,
+    ImGuiDebugLogFlags_EventViewport    = 1 << 7,
+    ImGuiDebugLogFlags_EventMask_       = ImGuiDebugLogFlags_EventActiveId | ImGuiDebugLogFlags_EventFocus | ImGuiDebugLogFlags_EventPopup | ImGuiDebugLogFlags_EventNav | ImGuiDebugLogFlags_EventClipper | ImGuiDebugLogFlags_EventIO | ImGuiDebugLogFlags_EventDocking | ImGuiDebugLogFlags_EventViewport,
     ImGuiDebugLogFlags_OutputToTTY      = 1 << 10,  // Also send output to TTY
 };
 
@@ -1553,6 +1730,7 @@ struct ImGuiMetricsConfig
     bool        ShowTablesRects;
     bool        ShowDrawCmdMesh;
     bool        ShowDrawCmdBoundingBoxes;
+    bool        ShowDockingNodes;
     int         ShowWindowsRectsType;
     int         ShowTablesRectsType;
 
@@ -1561,6 +1739,7 @@ struct ImGuiMetricsConfig
         ShowDebugLog = ShowStackTool = ShowWindowsRects = ShowWindowsBeginOrder = ShowTablesRects = false;
         ShowDrawCmdMesh = true;
         ShowDrawCmdBoundingBoxes = true;
+        ShowDockingNodes = false;
         ShowWindowsRectsType = ShowTablesRectsType = -1;
     }
 };
@@ -1616,9 +1795,12 @@ struct ImGuiContext
     bool                    Initialized;
     bool                    FontAtlasOwnedByContext;            // IO.Fonts-> is owned by the ImGuiContext and will be destructed along with it.
     ImGuiIO                 IO;
+    ImGuiPlatformIO         PlatformIO;
     ImVector<ImGuiInputEvent> InputEventsQueue;                 // Input events which will be tricked/written into IO structure.
     ImVector<ImGuiInputEvent> InputEventsTrail;                 // Past input events processed in NewFrame(). This is to allow domain-specific application to access e.g mouse/pen trail.
     ImGuiStyle              Style;
+    ImGuiConfigFlags        ConfigFlagsCurrFrame;               // = g.IO.ConfigFlags at the time of NewFrame()
+    ImGuiConfigFlags        ConfigFlagsLastFrame;
     ImFont*                 Font;                               // (Shortcut) == FontStack.empty() ? IO.Font : FontStack.back()
     float                   FontSize;                           // (Shortcut) == FontBaseSize * g.CurrentWindow->FontWindowScale == window->FontSize(). Text height for current window.
     float                   FontBaseSize;                       // (Shortcut) == IO.FontGlobalScale * Font->Scale * Font->FontSize. Base text height.
@@ -1626,6 +1808,7 @@ struct ImGuiContext
     double                  Time;
     int                     FrameCount;
     int                     FrameCountEnded;
+    int                     FrameCountPlatformEnded;
     int                     FrameCountRendered;
     bool                    WithinFrameScope;                   // Set by NewFrame(), cleared by EndFrame()
     bool                    WithinFrameScopeWithImplicitWindow; // Set by NewFrame(), cleared by EndFrame() when the implicit debug window has been pushed
@@ -1645,7 +1828,7 @@ struct ImGuiContext
     ImGuiWindow*            CurrentWindow;                      // Window being drawn into
     ImGuiWindow*            HoveredWindow;                      // Window the mouse is hovering. Will typically catch mouse inputs.
     ImGuiWindow*            HoveredWindowUnderMovingWindow;     // Hovered window ignoring MovingWindow. Only set if MovingWindow is set.
-    ImGuiWindow*            MovingWindow;                       // Track the window we clicked on (in order to preserve focus). The actual window that is moved is generally MovingWindow->RootWindow.
+    ImGuiWindow*            MovingWindow;                       // Track the window we clicked on (in order to preserve focus). The actual window that is moved is generally MovingWindow->RootWindowDockTree.
     ImGuiWindow*            WheelingWindow;                     // Track the window we started mouse-wheeling on. Until a timer elapse or mouse has moved, generally keep scrolling the same window even if during the course of scrolling the mouse ends up hovering a child window.
     ImVec2                  WheelingWindowRefMousePos;
     float                   WheelingWindowReleaseTimer;
@@ -1707,7 +1890,14 @@ struct ImGuiContext
     int                     BeginMenuCount;
 
     // Viewports
-    ImVector<ImGuiViewportP*> Viewports;                        // Active viewports (Size==1 in 'master' branch). Each viewports hold their copy of ImDrawData.
+    ImVector<ImGuiViewportP*> Viewports;                        // Active viewports (always 1+, and generally 1 unless multi-viewports are enabled). Each viewports hold their copy of ImDrawData.
+    float                   CurrentDpiScale;                    // == CurrentViewport->DpiScale
+    ImGuiViewportP*         CurrentViewport;                    // We track changes of viewport (happening in Begin) so we can call Platform_OnChangedViewport()
+    ImGuiViewportP*         MouseViewport;
+    ImGuiViewportP*         MouseLastHoveredViewport;           // Last known viewport that was hovered by mouse (even if we are not hovering any viewport any more) + honoring the _NoInputs flag.
+    ImGuiID                 PlatformLastFocusedViewportId;
+    ImGuiPlatformMonitor    FallbackMonitor;                    // Virtual monitor used as fallback if backend doesn't provide monitor information.
+    int                     ViewportFrontMostStampCount;        // Every time the front-most window changes, we stamp its viewport with an incrementing counter
 
     // Gamepad/keyboard Navigation
     ImGuiWindow*            NavWindow;                          // Focused window for navigation. Could be called 'FocusedWindow'
@@ -1839,8 +2029,13 @@ struct ImGuiContext
     // Platform support
     ImGuiPlatformImeData    PlatformImeData;                    // Data updated by current frame
     ImGuiPlatformImeData    PlatformImeDataPrev;                // Previous frame data (when changing we will call io.SetPlatformImeDataFn
+    ImGuiID                 PlatformImeViewport;
     char                    PlatformLocaleDecimalPoint;         // '.' or *localeconv()->decimal_point
 
+    // Extensions
+    // FIXME: We could provide an API to register one slot in an array held in ImGuiContext?
+    ImGuiDockContext        DockContext;
+
     // Settings
     bool                    SettingsLoaded;
     float                   SettingsDirtyTimer;                 // Save .ini Settings to memory when time reaches zero
@@ -1874,6 +2069,7 @@ struct ImGuiContext
     ImGuiID                 DebugItemPickerBreakId;             // Will call IM_DEBUG_BREAK() when encountering this ID
     ImGuiMetricsConfig      DebugMetricsConfig;
     ImGuiStackTool          DebugStackTool;
+    ImGuiDockNode*          DebugHoveredDockNode;               // Hovered dock node.
 
     // Misc
     float                   FramerateSecPerFrame[60];           // Calculate estimate of framerate for user over the last 60 frames..
@@ -1888,13 +2084,14 @@ struct ImGuiContext
     ImGuiContext(ImFontAtlas* shared_font_atlas)
     {
         Initialized = false;
+        ConfigFlagsCurrFrame = ConfigFlagsLastFrame = ImGuiConfigFlags_None;
         FontAtlasOwnedByContext = shared_font_atlas ? false : true;
         Font = NULL;
         FontSize = FontBaseSize = 0.0f;
         IO.Fonts = shared_font_atlas ? shared_font_atlas : IM_NEW(ImFontAtlas)();
         Time = 0.0f;
         FrameCount = 0;
-        FrameCountEnded = FrameCountRendered = -1;
+        FrameCountEnded = FrameCountPlatformEnded = FrameCountRendered = -1;
         WithinFrameScope = WithinFrameScopeWithImplicitWindow = WithinEndChild = false;
         GcCompactAll = false;
         TestEngineHookItems = false;
@@ -1944,6 +2141,12 @@ struct ImGuiContext
         CurrentItemFlags = ImGuiItemFlags_None;
         BeginMenuCount = 0;
 
+        CurrentDpiScale = 0.0f;
+        CurrentViewport = NULL;
+        MouseViewport = MouseLastHoveredViewport = NULL;
+        PlatformLastFocusedViewportId = 0;
+        ViewportFrontMostStampCount = 0;
+
         NavWindow = NULL;
         NavId = NavFocusScopeId = NavActivateId = NavActivateDownId = NavActivatePressedId = NavActivateInputId = 0;
         NavJustMovedToId = NavJustMovedToFocusScopeId = NavNextActivateId = 0;
@@ -2015,6 +2218,7 @@ struct ImGuiContext
 
         PlatformImeData.InputPos = ImVec2(0.0f, 0.0f);
         PlatformImeDataPrev.InputPos = ImVec2(-1.0f, -1.0f); // Different to ensure initial submission
+        PlatformImeViewport = 0;
         PlatformLocaleDecimalPoint = '.';
 
         SettingsLoaded = false;
@@ -2036,6 +2240,7 @@ struct ImGuiContext
         DebugItemPickerActive = false;
         DebugItemPickerMouseButton = ImGuiMouseButton_Left;
         DebugItemPickerBreakId = 0;
+        DebugHoveredDockNode = NULL;
 
         memset(FramerateSecPerFrame, 0, sizeof(FramerateSecPerFrame));
         FramerateSecPerFrameIdx = FramerateSecPerFrameCount = 0;
@@ -2103,8 +2308,12 @@ struct IMGUI_API ImGuiWindow
 {
     char*                   Name;                               // Window name, owned by the window.
     ImGuiID                 ID;                                 // == ImHashStr(Name)
-    ImGuiWindowFlags        Flags;                              // See enum ImGuiWindowFlags_
+    ImGuiWindowFlags        Flags, FlagsPreviousFrame;          // See enum ImGuiWindowFlags_
+    ImGuiWindowClass        WindowClass;                        // Advanced users only. Set with SetNextWindowClass()
     ImGuiViewportP*         Viewport;                           // Always set in Begin(). Inactive windows may have a NULL value here if their viewport was discarded.
+    ImGuiID                 ViewportId;                         // We backup the viewport id (since the viewport may disappear or never be created if the window is inactive)
+    ImVec2                  ViewportPos;                        // We backup the viewport position (since the viewport may disappear or never be created if the window is inactive)
+    int                     ViewportAllowPlatformMonitorExtend; // Reset to -1 every frame (index is guaranteed to be valid between NewFrame..EndFrame), only used in the Appearing frame of a tooltip/popup to enforce clamping to a given monitor
     ImVec2                  Pos;                                // Position (always rounded-up to nearest pixel)
     ImVec2                  Size;                               // Current size (==SizeFull or collapsed title bar size)
     ImVec2                  SizeFull;                           // Size when non collapsed
@@ -2116,6 +2325,7 @@ struct IMGUI_API ImGuiWindow
     float                   WindowBorderSize;                   // Window border size at the time of Begin().
     int                     NameBufLen;                         // Size of buffer storing Name. May be larger than strlen(Name)!
     ImGuiID                 MoveId;                             // == window->GetID("#MOVE")
+    ImGuiID                 TabId;                              // == window->GetID("#TAB")
     ImGuiID                 ChildId;                            // ID of corresponding item in parent window (for navigation to return from child window to parent window)
     ImVec2                  Scroll;
     ImVec2                  ScrollMax;
@@ -2124,6 +2334,7 @@ struct IMGUI_API ImGuiWindow
     ImVec2                  ScrollTargetEdgeSnapDist;           // 0.0f = no snapping, >0.0f snapping threshold
     ImVec2                  ScrollbarSizes;                     // Size taken by each scrollbars on their smaller axis. Pay attention! ScrollbarSizes.x == width of the vertical scrollbar, ScrollbarSizes.y = height of the horizontal scrollbar.
     bool                    ScrollbarX, ScrollbarY;             // Are scrollbars visible?
+    bool                    ViewportOwned;
     bool                    Active;                             // Set to true on Begin(), unless Collapsed
     bool                    WasActive;
     bool                    WriteAccessed;                      // Set to true when any widget access the current window
@@ -2153,6 +2364,7 @@ struct IMGUI_API ImGuiWindow
     ImGuiCond               SetWindowPosAllowFlags : 8;         // store acceptable condition flags for SetNextWindowPos() use.
     ImGuiCond               SetWindowSizeAllowFlags : 8;        // store acceptable condition flags for SetNextWindowSize() use.
     ImGuiCond               SetWindowCollapsedAllowFlags : 8;   // store acceptable condition flags for SetNextWindowCollapsed() use.
+    ImGuiCond               SetWindowDockAllowFlags : 8;        // store acceptable condition flags for SetNextWindowDock() use.
     ImVec2                  SetWindowPosVal;                    // store window position when using a non-zero Pivot (position set needs to be processed when we know the window size)
     ImVec2                  SetWindowPosPivot;                  // store window pivot for positioning. ImVec2(0, 0) when positioning from top-left corner; ImVec2(0.5f, 0.5f) for centering; ImVec2(1, 1) for bottom right.
 
@@ -2172,11 +2384,13 @@ struct IMGUI_API ImGuiWindow
     ImVec2ih                HitTestHoleOffset;
 
     int                     LastFrameActive;                    // Last frame number the window was Active.
+    int                     LastFrameJustFocused;               // Last frame number the window was made Focused.
     float                   LastTimeActive;                     // Last timestamp the window was Active (using float as we don't need high precision there)
     float                   ItemWidthDefault;
     ImGuiStorage            StateStorage;
     ImVector<ImGuiOldColumns> ColumnsStorage;
     float                   FontWindowScale;                    // User scale multiplier per-window, via SetWindowFontScale()
+    float                   FontDpiScale;
     int                     SettingsOffset;                     // Offset into SettingsWindows[] (offsets are always valid as we only grow the array from the back)
 
     ImDrawList*             DrawList;                           // == &DrawListInst (for backward compatibility reason with code using imgui_internal.h we keep this a pointer)
@@ -2185,6 +2399,7 @@ struct IMGUI_API ImGuiWindow
     ImGuiWindow*            ParentWindowInBeginStack;
     ImGuiWindow*            RootWindow;                         // Point to ourself or first ancestor that is not a child window. Doesn't cross through popups/dock nodes.
     ImGuiWindow*            RootWindowPopupTree;                // Point to ourself or first ancestor that is not a child window. Cross through popups parent<>child.
+    ImGuiWindow*            RootWindowDockTree;                 // Point to ourself or first ancestor that is not a child window. Cross through dock nodes.
     ImGuiWindow*            RootWindowForTitleBarHighlight;     // Point to ourself or first ancestor which will display TitleBgActive color when this window is active.
     ImGuiWindow*            RootWindowForNav;                   // Point to ourself or first ancestor which doesn't have the NavFlattened flag.
 
@@ -2197,6 +2412,19 @@ struct IMGUI_API ImGuiWindow
     int                     MemoryDrawListVtxCapacity;
     bool                    MemoryCompacted;                    // Set when window extraneous data have been garbage collected
 
+    // Docking
+    bool                    DockIsActive        :1;             // When docking artifacts are actually visible. When this is set, DockNode is guaranteed to be != NULL. ~~ (DockNode != NULL) && (DockNode->Windows.Size > 1).
+    bool                    DockNodeIsVisible   :1;
+    bool                    DockTabIsVisible    :1;             // Is our window visible this frame? ~~ is the corresponding tab selected?
+    bool                    DockTabWantClose    :1;
+    short                   DockOrder;                          // Order of the last time the window was visible within its DockNode. This is used to reorder windows that are reappearing on the same frame. Same value between windows that were active and windows that were none are possible.
+    ImGuiWindowDockStyle    DockStyle;
+    ImGuiDockNode*          DockNode;                           // Which node are we docked into. Important: Prefer testing DockIsActive in many cases as this will still be set when the dock node is hidden.
+    ImGuiDockNode*          DockNodeAsHost;                     // Which node are we owning (for parent windows)
+    ImGuiID                 DockId;                             // Backup of last valid DockNode->ID, so single window remember their dock node id even when they are not bound any more
+    ImGuiItemStatusFlags    DockTabItemStatusFlags;
+    ImRect                  DockTabItemRect;
+
 public:
     ImGuiWindow(ImGuiContext* context, const char* name);
     ~ImGuiWindow();
@@ -2208,7 +2436,7 @@ public:
 
     // We don't use g.FontSize because the window may be != g.CurrentWindow.
     ImRect      Rect() const            { return ImRect(Pos.x, Pos.y, Pos.x + Size.x, Pos.y + Size.y); }
-    float       CalcFontSize() const    { ImGuiContext& g = *GImGui; float scale = g.FontBaseSize * FontWindowScale; if (ParentWindow) scale *= ParentWindow->FontWindowScale; return scale; }
+    float       CalcFontSize() const    { ImGuiContext& g = *GImGui; float scale = g.FontBaseSize * FontWindowScale * FontDpiScale; if (ParentWindow) scale *= ParentWindow->FontWindowScale; return scale; }
     float       TitleBarHeight() const  { ImGuiContext& g = *GImGui; return (Flags & ImGuiWindowFlags_NoTitleBar) ? 0.0f : CalcFontSize() + g.Style.FramePadding.y * 2.0f; }
     ImRect      TitleBarRect() const    { return ImRect(Pos, ImVec2(Pos.x + SizeFull.x, Pos.y + TitleBarHeight())); }
     float       MenuBarHeight() const   { ImGuiContext& g = *GImGui; return (Flags & ImGuiWindowFlags_MenuBar) ? DC.MenuBarOffset.y + CalcFontSize() + g.Style.FramePadding.y * 2.0f : 0.0f; }
@@ -2233,13 +2461,16 @@ enum ImGuiTabItemFlagsPrivate_
     ImGuiTabItemFlags_SectionMask_              = ImGuiTabItemFlags_Leading | ImGuiTabItemFlags_Trailing,
     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)
     ImGuiTabItemFlags_Button                    = 1 << 21,  // Used by TabItemButton, change the tab item behavior to mimic a button
+    ImGuiTabItemFlags_Unsorted                  = 1 << 22,  // [Docking] Trailing tabs with the _Unsorted flag will be sorted based on the DockOrder of their Window.
+    ImGuiTabItemFlags_Preview                   = 1 << 23,  // [Docking] Display tab shape for docking preview (height is adjusted slightly to compensate for the yet missing tab bar)
 };
 
-// Storage for one active tab item (sizeof() 40 bytes)
+// Storage for one active tab item (sizeof() 48 bytes)
 struct ImGuiTabItem
 {
     ImGuiID             ID;
     ImGuiTabItemFlags   Flags;
+    ImGuiWindow*        Window;                 // When TabItem is part of a DockNode's TabBar, we hold on to a window.
     int                 LastFrameVisible;
     int                 LastFrameSelected;      // This allows us to infer an ordered list of the last activated tabs with little maintenance
     float               Offset;                 // Position relative to beginning of tab
@@ -2293,6 +2524,8 @@ struct IMGUI_API ImGuiTabBar
     int                 GetTabOrder(const ImGuiTabItem* tab) const  { return Tabs.index_from_ptr(tab); }
     const char*         GetTabName(const ImGuiTabItem* tab) const
     {
+        if (tab->Window)
+            return tab->Window->Name;
         IM_ASSERT(tab->NameOffset != -1 && tab->NameOffset < TabsNames.Buf.Size);
         return TabsNames.Buf.Data + tab->NameOffset;
     }
@@ -2579,7 +2812,7 @@ namespace ImGui
     IMGUI_API ImGuiWindow*  FindWindowByName(const char* name);
     IMGUI_API void          UpdateWindowParentAndRootLinks(ImGuiWindow* window, ImGuiWindowFlags flags, ImGuiWindow* parent_window);
     IMGUI_API ImVec2        CalcWindowNextAutoFitSize(ImGuiWindow* window);
-    IMGUI_API bool          IsWindowChildOf(ImGuiWindow* window, ImGuiWindow* potential_parent, bool popup_hierarchy);
+    IMGUI_API bool          IsWindowChildOf(ImGuiWindow* window, ImGuiWindow* potential_parent, bool popup_hierarchy, bool dock_hierarchy);
     IMGUI_API bool          IsWindowWithinBeginStackOf(ImGuiWindow* window, ImGuiWindow* potential_parent);
     IMGUI_API bool          IsWindowAbove(ImGuiWindow* potential_above, ImGuiWindow* potential_below);
     IMGUI_API bool          IsWindowNavFocusable(ImGuiWindow* window);
@@ -2603,9 +2836,7 @@ namespace ImGui
     // 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* window) { IM_UNUSED(window); return GetForegroundDrawList(); } // This seemingly unnecessary wrapper simplifies compatibility between the 'master' and 'docking' branches.
+    inline ImDrawList*      GetForegroundDrawList(ImGuiWindow* window) { return GetForegroundDrawList(window->Viewport); }
-    IMGUI_API ImDrawList*   GetBackgroundDrawList(ImGuiViewport* viewport);                     // get background draw list for the given viewport. this draw list will be the first rendering one. Useful to quickly draw shapes/text behind dear imgui contents.
-    IMGUI_API ImDrawList*   GetForegroundDrawList(ImGuiViewport* viewport);                     // get foreground draw list for the given viewport. this draw list will be the last rendered one. Useful to quickly draw shapes/text over dear imgui contents.
 
     // Init
     IMGUI_API void          Initialize();
@@ -2615,6 +2846,7 @@ namespace ImGui
     IMGUI_API void          UpdateInputEvents(bool trickle_fast_inputs);
     IMGUI_API void          UpdateHoveredWindowAndCaptureFlags();
     IMGUI_API void          StartMouseMovingWindow(ImGuiWindow* window);
+    IMGUI_API void          StartMouseMovingWindowOrNode(ImGuiWindow* window, ImGuiDockNode* node, bool undock_floating_node);
     IMGUI_API void          UpdateMouseMovingWindowNewFrame();
     IMGUI_API void          UpdateMouseMovingWindowEndFrame();
 
@@ -2624,7 +2856,13 @@ namespace ImGui
     IMGUI_API void          CallContextHooks(ImGuiContext* context, ImGuiContextHookType type);
 
     // Viewports
+    IMGUI_API void          TranslateWindowsInViewport(ImGuiViewportP* viewport, const ImVec2& old_pos, const ImVec2& new_pos);
+    IMGUI_API void          ScaleWindowsInViewport(ImGuiViewportP* viewport, float scale);
+    IMGUI_API void          DestroyPlatformWindow(ImGuiViewportP* viewport);
     IMGUI_API void          SetWindowViewport(ImGuiWindow* window, ImGuiViewportP* viewport);
+    IMGUI_API void          SetCurrentViewport(ImGuiWindow* window, ImGuiViewportP* viewport);
+    IMGUI_API const ImGuiPlatformMonitor*   GetViewportPlatformMonitor(ImGuiViewport* viewport);
+    IMGUI_API ImGuiViewportP*               FindHoveredViewportFromPlatformWindowStack(const ImVec2& mouse_platform_pos);
 
     // Settings
     IMGUI_API void                  MarkIniSettingsDirty();
@@ -2765,6 +3003,58 @@ namespace ImGui
     inline bool             IsKeyPressedMap(ImGuiKey key, bool repeat = true)           { IM_ASSERT(IsNamedKey(key)); return IsKeyPressed(key, repeat); } // [removed in 1.87]
 #endif
 
+    // Docking
+    // (some functions are only declared in imgui.cpp, see Docking section)
+    IMGUI_API void          DockContextInitialize(ImGuiContext* ctx);
+    IMGUI_API void          DockContextShutdown(ImGuiContext* ctx);
+    IMGUI_API void          DockContextClearNodes(ImGuiContext* ctx, ImGuiID root_id, bool clear_settings_refs); // Use root_id==0 to clear all
+    IMGUI_API void          DockContextRebuildNodes(ImGuiContext* ctx);
+    IMGUI_API void          DockContextNewFrameUpdateUndocking(ImGuiContext* ctx);
+    IMGUI_API void          DockContextNewFrameUpdateDocking(ImGuiContext* ctx);
+    IMGUI_API void          DockContextEndFrame(ImGuiContext* ctx);
+    IMGUI_API ImGuiID       DockContextGenNodeID(ImGuiContext* ctx);
+    IMGUI_API void          DockContextQueueDock(ImGuiContext* ctx, ImGuiWindow* target, ImGuiDockNode* target_node, ImGuiWindow* payload, ImGuiDir split_dir, float split_ratio, bool split_outer);
+    IMGUI_API void          DockContextQueueUndockWindow(ImGuiContext* ctx, ImGuiWindow* window);
+    IMGUI_API void          DockContextQueueUndockNode(ImGuiContext* ctx, ImGuiDockNode* node);
+    IMGUI_API bool          DockContextCalcDropPosForDocking(ImGuiWindow* target, ImGuiDockNode* target_node, ImGuiWindow* payload_window, ImGuiDockNode* payload_node, ImGuiDir split_dir, bool split_outer, ImVec2* out_pos);
+    IMGUI_API ImGuiDockNode*DockContextFindNodeByID(ImGuiContext* ctx, ImGuiID id);
+    IMGUI_API bool          DockNodeBeginAmendTabBar(ImGuiDockNode* node);
+    IMGUI_API void          DockNodeEndAmendTabBar();
+    inline ImGuiDockNode*   DockNodeGetRootNode(ImGuiDockNode* node)                 { while (node->ParentNode) node = node->ParentNode; return node; }
+    inline bool             DockNodeIsInHierarchyOf(ImGuiDockNode* node, ImGuiDockNode* parent) { while (node) { if (node == parent) return true; node = node->ParentNode; } return false; }
+    inline int              DockNodeGetDepth(const ImGuiDockNode* node)              { int depth = 0; while (node->ParentNode) { node = node->ParentNode; depth++; } return depth; }
+    inline ImGuiID          DockNodeGetWindowMenuButtonId(const ImGuiDockNode* node) { return ImHashStr("#COLLAPSE", 0, node->ID); }
+    inline ImGuiDockNode*   GetWindowDockNode()                                      { ImGuiContext& g = *GImGui; return g.CurrentWindow->DockNode; }
+    IMGUI_API bool          GetWindowAlwaysWantOwnTabBar(ImGuiWindow* window);
+    IMGUI_API void          BeginDocked(ImGuiWindow* window, bool* p_open);
+    IMGUI_API void          BeginDockableDragDropSource(ImGuiWindow* window);
+    IMGUI_API void          BeginDockableDragDropTarget(ImGuiWindow* window);
+    IMGUI_API void          SetWindowDock(ImGuiWindow* window, ImGuiID dock_id, ImGuiCond cond);
+
+    // Docking - Builder function needs to be generally called before the node is used/submitted.
+    // - The DockBuilderXXX functions are designed to _eventually_ become a public API, but it is too early to expose it and guarantee stability.
+    // - Do not hold on ImGuiDockNode* pointers! They may be invalidated by any split/merge/remove operation and every frame.
+    // - To create a DockSpace() node, make sure to set the ImGuiDockNodeFlags_DockSpace flag when calling DockBuilderAddNode().
+    //   You can create dockspace nodes (attached to a window) _or_ floating nodes (carry its own window) with this API.
+    // - DockBuilderSplitNode() create 2 child nodes within 1 node. The initial node becomes a parent node.
+    // - If you intend to split the node immediately after creation using DockBuilderSplitNode(), make sure
+    //   to call DockBuilderSetNodeSize() beforehand. If you don't, the resulting split sizes may not be reliable.
+    // - Call DockBuilderFinish() after you are done.
+    IMGUI_API void          DockBuilderDockWindow(const char* window_name, ImGuiID node_id);
+    IMGUI_API ImGuiDockNode*DockBuilderGetNode(ImGuiID node_id);
+    inline ImGuiDockNode*   DockBuilderGetCentralNode(ImGuiID node_id)              { ImGuiDockNode* node = DockBuilderGetNode(node_id); if (!node) return NULL; return DockNodeGetRootNode(node)->CentralNode; }
+    IMGUI_API ImGuiID       DockBuilderAddNode(ImGuiID node_id = 0, ImGuiDockNodeFlags flags = 0);
+    IMGUI_API void          DockBuilderRemoveNode(ImGuiID node_id);                 // Remove node and all its child, undock all windows
+    IMGUI_API void          DockBuilderRemoveNodeDockedWindows(ImGuiID node_id, bool clear_settings_refs = true);
+    IMGUI_API void          DockBuilderRemoveNodeChildNodes(ImGuiID node_id);       // Remove all split/hierarchy. All remaining docked windows will be re-docked to the remaining root node (node_id).
+    IMGUI_API void          DockBuilderSetNodePos(ImGuiID node_id, ImVec2 pos);
+    IMGUI_API void          DockBuilderSetNodeSize(ImGuiID node_id, ImVec2 size);
+    IMGUI_API ImGuiID       DockBuilderSplitNode(ImGuiID node_id, ImGuiDir split_dir, float size_ratio_for_node_at_dir, ImGuiID* out_id_at_dir, ImGuiID* out_id_at_opposite_dir); // Create 2 child nodes in this parent node.
+    IMGUI_API void          DockBuilderCopyDockSpace(ImGuiID src_dockspace_id, ImGuiID dst_dockspace_id, ImVector<const char*>* in_window_remap_pairs);
+    IMGUI_API void          DockBuilderCopyNode(ImGuiID src_node_id, ImGuiID dst_node_id, ImVector<ImGuiID>* out_node_remap_pairs);
+    IMGUI_API void          DockBuilderCopyWindowSettings(const char* src_name, const char* dst_name);
+    IMGUI_API void          DockBuilderFinish(ImGuiID node_id);
+
     // [EXPERIMENTAL] Focus Scope
     // This is generally used to identify a unique input location (for e.g. a selection set)
     // There is one per window (automatically set in Begin), but:
@@ -2850,15 +3140,18 @@ namespace ImGui
     IMGUI_API ImGuiTableSettings*   TableSettingsFindByID(ImGuiID id);
 
     // Tab Bars
-    IMGUI_API bool          BeginTabBarEx(ImGuiTabBar* tab_bar, const ImRect& bb, ImGuiTabBarFlags flags);
+    IMGUI_API bool          BeginTabBarEx(ImGuiTabBar* tab_bar, const ImRect& bb, ImGuiTabBarFlags flags, ImGuiDockNode* dock_node);
     IMGUI_API ImGuiTabItem* TabBarFindTabByID(ImGuiTabBar* tab_bar, ImGuiID tab_id);
+    IMGUI_API ImGuiTabItem* TabBarFindMostRecentlySelectedTabForActiveWindow(ImGuiTabBar* tab_bar);
+    IMGUI_API void          TabBarAddTab(ImGuiTabBar* tab_bar, ImGuiTabItemFlags tab_flags, ImGuiWindow* window);
     IMGUI_API void          TabBarRemoveTab(ImGuiTabBar* tab_bar, ImGuiID tab_id);
     IMGUI_API void          TabBarCloseTab(ImGuiTabBar* tab_bar, ImGuiTabItem* tab);
     IMGUI_API void          TabBarQueueReorder(ImGuiTabBar* tab_bar, const ImGuiTabItem* tab, int offset);
     IMGUI_API void          TabBarQueueReorderFromMousePos(ImGuiTabBar* tab_bar, const ImGuiTabItem* tab, ImVec2 mouse_pos);
     IMGUI_API bool          TabBarProcessReorder(ImGuiTabBar* tab_bar);
-    IMGUI_API bool          TabItemEx(ImGuiTabBar* tab_bar, const char* label, bool* p_open, ImGuiTabItemFlags flags);
+    IMGUI_API bool          TabItemEx(ImGuiTabBar* tab_bar, const char* label, bool* p_open, ImGuiTabItemFlags flags, ImGuiWindow* docked_window);
     IMGUI_API ImVec2        TabItemCalcSize(const char* label, bool has_close_button_or_unsaved_marker);
+    IMGUI_API ImVec2        TabItemCalcSize(ImGuiWindow* window);
     IMGUI_API void          TabItemBackground(ImDrawList* draw_list, const ImRect& bb, ImGuiTabItemFlags flags, ImU32 col);
     IMGUI_API void          TabItemLabelAndCloseButton(ImDrawList* draw_list, const ImRect& bb, ImGuiTabItemFlags flags, ImVec2 frame_padding, const char* label, ImGuiID tab_id, ImGuiID close_button_id, bool is_contents_visible, bool* out_just_closed, bool* out_text_clipped);
 
@@ -2882,14 +3175,16 @@ namespace ImGui
     IMGUI_API void          RenderBullet(ImDrawList* draw_list, ImVec2 pos, ImU32 col);
     IMGUI_API void          RenderCheckMark(ImDrawList* draw_list, ImVec2 pos, ImU32 col, float sz);
     IMGUI_API void          RenderArrowPointingAt(ImDrawList* draw_list, ImVec2 pos, ImVec2 half_sz, ImGuiDir direction, ImU32 col);
+    IMGUI_API void          RenderArrowDockMenu(ImDrawList* draw_list, ImVec2 p_min, float sz, ImU32 col);
     IMGUI_API void          RenderRectFilledRangeH(ImDrawList* draw_list, const ImRect& rect, ImU32 col, float x_start_norm, float x_end_norm, float rounding);
     IMGUI_API void          RenderRectFilledWithHole(ImDrawList* draw_list, const ImRect& outer, const ImRect& inner, ImU32 col, float rounding);
+    IMGUI_API ImDrawFlags   CalcRoundingFlagsForRectInRect(const ImRect& r_in, const ImRect& r_outer, float threshold);
 
     // Widgets
     IMGUI_API void          TextEx(const char* text, const char* text_end = NULL, ImGuiTextFlags flags = 0);
     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          CollapseButton(ImGuiID id, const ImVec2& pos, ImGuiDockNode* dock_node);
     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, ImS64* p_scroll_v, ImS64 avail_v, ImS64 contents_v, ImDrawFlags flags);
@@ -2906,7 +3201,7 @@ namespace ImGui
     IMGUI_API bool          ButtonBehavior(const ImRect& bb, ImGuiID id, bool* out_hovered, bool* out_held, ImGuiButtonFlags flags = 0);
     IMGUI_API bool          DragBehavior(ImGuiID id, ImGuiDataType data_type, void* p_v, float v_speed, const void* p_min, const void* p_max, const char* format, ImGuiSliderFlags flags);
     IMGUI_API bool          SliderBehavior(const ImRect& bb, ImGuiID id, ImGuiDataType data_type, void* p_v, const void* p_min, const void* p_max, const char* format, ImGuiSliderFlags flags, ImRect* out_grab_bb);
-    IMGUI_API bool          SplitterBehavior(const ImRect& bb, ImGuiID id, ImGuiAxis axis, float* size1, float* size2, float min_size1, float min_size2, float hover_extend = 0.0f, float hover_visibility_delay = 0.0f);
+    IMGUI_API bool          SplitterBehavior(const ImRect& bb, ImGuiID id, ImGuiAxis axis, float* size1, float* size2, float min_size1, float min_size2, float hover_extend = 0.0f, float hover_visibility_delay = 0.0f, ImU32 bg_col = 0);
     IMGUI_API bool          TreeNodeBehavior(ImGuiID id, ImGuiTreeNodeFlags flags, const char* label, const char* label_end = NULL);
     IMGUI_API void          TreePushOverrideID(ImGuiID id);
     IMGUI_API void          TreeNodeSetOpen(ImGuiID id, bool open);
@@ -2970,7 +3265,8 @@ namespace ImGui
     IMGUI_API void          ShowFontAtlas(ImFontAtlas* atlas);
     IMGUI_API void          DebugHookIdInfo(ImGuiID id, ImGuiDataType data_type, const void* data_id, const void* data_id_end);
     IMGUI_API void          DebugNodeColumns(ImGuiOldColumns* columns);
-    IMGUI_API void          DebugNodeDrawList(ImGuiWindow* window, const ImDrawList* draw_list, const char* label);
+    IMGUI_API void          DebugNodeDockNode(ImGuiDockNode* node, const char* label);
+    IMGUI_API void          DebugNodeDrawList(ImGuiWindow* window, ImGuiViewportP* viewport, const ImDrawList* draw_list, const char* label);
     IMGUI_API void          DebugNodeDrawCmdShowMeshAndBoundingBox(ImDrawList* out_draw_list, const ImDrawList* draw_list, const ImDrawCmd* draw_cmd, bool show_mesh, bool show_aabb);
     IMGUI_API void          DebugNodeFont(ImFont* font);
     IMGUI_API void          DebugNodeFontGlyph(ImFont* font, const ImFontGlyph* glyph);

includes/imgui/imgui_widgets.cpp

@@ -503,7 +503,7 @@ bool ImGui::ButtonBehavior(const ImRect& bb, ImGuiID id, bool* out_hovered, bool
         flags |= ImGuiButtonFlags_PressedOnDefault_;
 
     ImGuiWindow* backup_hovered_window = g.HoveredWindow;
-    const bool flatten_hovered_children = (flags & ImGuiButtonFlags_FlattenChildren) && g.HoveredWindow && g.HoveredWindow->RootWindow == window;
+    const bool flatten_hovered_children = (flags & ImGuiButtonFlags_FlattenChildren) && g.HoveredWindow && g.HoveredWindow->RootWindowDockTree == window->RootWindowDockTree;
     if (flatten_hovered_children)
         g.HoveredWindow = window;
 
@@ -840,7 +840,8 @@ bool ImGui::CloseButton(ImGuiID id, const ImVec2& pos)
     return pressed;
 }
 
-bool ImGui::CollapseButton(ImGuiID id, const ImVec2& pos)
+// The Collapse button also functions as a Dock Menu button.
+bool ImGui::CollapseButton(ImGuiID id, const ImVec2& pos, ImGuiDockNode* dock_node)
 {
     ImGuiContext& g = *GImGui;
     ImGuiWindow* window = g.CurrentWindow;
@@ -851,15 +852,20 @@ bool ImGui::CollapseButton(ImGuiID id, const ImVec2& pos)
     bool pressed = ButtonBehavior(bb, id, &hovered, &held, ImGuiButtonFlags_None);
 
     // Render
+    //bool is_dock_menu = (window->DockNodeAsHost && !window->Collapsed);
     ImU32 bg_col = GetColorU32((held && hovered) ? ImGuiCol_ButtonActive : hovered ? ImGuiCol_ButtonHovered : ImGuiCol_Button);
     ImU32 text_col = GetColorU32(ImGuiCol_Text);
     if (hovered || held)
-        window->DrawList->AddCircleFilled(bb.GetCenter()/*+ ImVec2(0.0f, -0.5f)*/, g.FontSize * 0.5f + 1.0f, bg_col, 12);
+        window->DrawList->AddCircleFilled(bb.GetCenter() + ImVec2(0,-0.5f), g.FontSize * 0.5f + 1.0f, bg_col, 12);
-    RenderArrow(window->DrawList, bb.Min + g.Style.FramePadding, text_col, window->Collapsed ? ImGuiDir_Right : ImGuiDir_Down, 1.0f);
+
+    if (dock_node)
+        RenderArrowDockMenu(window->DrawList, bb.Min + g.Style.FramePadding, g.FontSize, text_col);
+    else
+        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(0))
-        StartMouseMovingWindow(window);
+        StartMouseMovingWindowOrNode(window, dock_node, true);
 
     return pressed;
 }
@@ -1471,7 +1477,7 @@ void ImGui::Separator()
 }
 
 // Using 'hover_visibility_delay' allows us to hide the highlight and mouse cursor for a short time, which can be convenient to reduce visual noise.
-bool ImGui::SplitterBehavior(const ImRect& bb, ImGuiID id, ImGuiAxis axis, float* size1, float* size2, float min_size1, float min_size2, float hover_extend, float hover_visibility_delay)
+bool ImGui::SplitterBehavior(const ImRect& bb, ImGuiID id, ImGuiAxis axis, float* size1, float* size2, float min_size1, float min_size2, float hover_extend, float hover_visibility_delay, ImU32 bg_col)
 {
     ImGuiContext& g = *GImGui;
     ImGuiWindow* window = g.CurrentWindow;
@@ -1519,7 +1525,9 @@ bool ImGui::SplitterBehavior(const ImRect& bb, ImGuiID id, ImGuiAxis axis, float
         }
     }
 
-    // Render
+    // Render at new position
+    if (bg_col & IM_COL32_A_MASK)
+        window->DrawList->AddRectFilled(bb_render.Min, bb_render.Max, bg_col, 0.0f);
     const ImU32 col = GetColorU32(held ? ImGuiCol_SeparatorActive : (hovered && g.HoveredIdTimer >= hover_visibility_delay) ? ImGuiCol_SeparatorHovered : ImGuiCol_Separator);
     window->DrawList->AddRectFilled(bb_render.Min, bb_render.Max, col, 0.0f);
 
@@ -4774,6 +4782,7 @@ bool ImGui::InputTextEx(const char* label, const char* hint, char* buf, int buf_
                 g.PlatformImeData.WantVisible = true;
                 g.PlatformImeData.InputPos = ImVec2(cursor_screen_pos.x - 1.0f, cursor_screen_pos.y - g.FontSize);
                 g.PlatformImeData.InputLineHeight = g.FontSize;
+                g.PlatformImeViewport = window->Viewport->ID;
             }
         }
     }
@@ -6861,10 +6870,10 @@ bool ImGui::BeginViewportSideBar(const char* name, ImGuiViewport* viewport_p, Im
     IM_ASSERT(dir != ImGuiDir_None);
 
     ImGuiWindow* bar_window = FindWindowByName(name);
+    ImGuiViewportP* viewport = (ImGuiViewportP*)(void*)(viewport_p ? viewport_p : GetMainViewport());
     if (bar_window == NULL || bar_window->BeginCount == 0)
     {
         // Calculate and set window size/position
-        ImGuiViewportP* viewport = (ImGuiViewportP*)(void*)(viewport_p ? viewport_p : GetMainViewport());
         ImRect avail_rect = viewport->GetBuildWorkRect();
         ImGuiAxis axis = (dir == ImGuiDir_Up || dir == ImGuiDir_Down) ? ImGuiAxis_Y : ImGuiAxis_X;
         ImVec2 pos = avail_rect.Min;
@@ -6882,7 +6891,8 @@ bool ImGui::BeginViewportSideBar(const char* name, ImGuiViewport* viewport_p, Im
             viewport->BuildWorkOffsetMax[axis] -= axis_size;
     }
 
-    window_flags |= ImGuiWindowFlags_NoTitleBar | ImGuiWindowFlags_NoResize | ImGuiWindowFlags_NoMove;
+    window_flags |= ImGuiWindowFlags_NoTitleBar | ImGuiWindowFlags_NoResize | ImGuiWindowFlags_NoMove | ImGuiWindowFlags_NoDocking;
+    SetNextWindowViewport(viewport->ID); // Enforce viewport so we don't create our own viewport when ImGuiConfigFlags_ViewportsNoMerge is set.
     PushStyleVar(ImGuiStyleVar_WindowRounding, 0.0f);
     PushStyleVar(ImGuiStyleVar_WindowMinSize, ImVec2(0, 0)); // Lift normal size constraint
     bool is_open = Begin(name, NULL, window_flags);
@@ -6896,6 +6906,9 @@ bool ImGui::BeginMainMenuBar()
     ImGuiContext& g = *GImGui;
     ImGuiViewportP* viewport = (ImGuiViewportP*)(void*)GetMainViewport();
 
+    // Notify of viewport change so GetFrameHeight() can be accurate in case of DPI change
+    SetCurrentViewport(NULL, viewport);
+
     // For the main menu bar, which cannot be moved, we honor g.Style.DisplaySafeAreaPadding to ensure text can be visible on a TV set.
     // FIXME: This could be generalized as an opt-in way to clamp window->DC.CursorStartPos to avoid SafeArea?
     // FIXME: Consider removing support for safe area down the line... it's messy. Nowadays consoles have support for TV calibration in OS settings.
@@ -7266,6 +7279,7 @@ bool ImGui::MenuItem(const char* label, const char* shortcut, bool* p_selected,
 // - TabBarCalcTabID() [Internal]
 // - TabBarCalcMaxTabWidth() [Internal]
 // - TabBarFindTabById() [Internal]
+// - TabBarAddTab() [Internal]
 // - TabBarRemoveTab() [Internal]
 // - TabBarCloseTab() [Internal]
 // - TabBarScrollClamp() [Internal]
@@ -7287,7 +7301,7 @@ struct ImGuiTabBarSection
 namespace ImGui
 {
     static void             TabBarLayout(ImGuiTabBar* tab_bar);
-    static ImU32            TabBarCalcTabID(ImGuiTabBar* tab_bar, const char* label);
+    static ImU32            TabBarCalcTabID(ImGuiTabBar* tab_bar, const char* label, ImGuiWindow* docked_window);
     static float            TabBarCalcMaxTabWidth();
     static float            TabBarScrollClamp(ImGuiTabBar* tab_bar, float scrolling);
     static void             TabBarScrollToTab(ImGuiTabBar* tab_bar, ImGuiID tab_id, ImGuiTabBarSection* sections);
@@ -7350,10 +7364,10 @@ bool    ImGui::BeginTabBar(const char* str_id, ImGuiTabBarFlags flags)
     ImGuiTabBar* tab_bar = g.TabBars.GetOrAddByKey(id);
     ImRect tab_bar_bb = ImRect(window->DC.CursorPos.x, window->DC.CursorPos.y, window->WorkRect.Max.x, window->DC.CursorPos.y + g.FontSize + g.Style.FramePadding.y * 2);
     tab_bar->ID = id;
-    return BeginTabBarEx(tab_bar, tab_bar_bb, flags | ImGuiTabBarFlags_IsFocused);
+    return BeginTabBarEx(tab_bar, tab_bar_bb, flags | ImGuiTabBarFlags_IsFocused, NULL);
 }
 
-bool    ImGui::BeginTabBarEx(ImGuiTabBar* tab_bar, const ImRect& tab_bar_bb, ImGuiTabBarFlags flags)
+bool    ImGui::BeginTabBarEx(ImGuiTabBar* tab_bar, const ImRect& tab_bar_bb, ImGuiTabBarFlags flags, ImGuiDockNode* dock_node)
 {
     ImGuiContext& g = *GImGui;
     ImGuiWindow* window = g.CurrentWindow;
@@ -7378,7 +7392,8 @@ bool    ImGui::BeginTabBarEx(ImGuiTabBar* tab_bar, const ImRect& tab_bar_bb, ImG
 
     // Ensure correct ordering when toggling ImGuiTabBarFlags_Reorderable flag, or when a new tab was added while being not reorderable
     if ((flags & ImGuiTabBarFlags_Reorderable) != (tab_bar->Flags & ImGuiTabBarFlags_Reorderable) || (tab_bar->TabsAddedNew && !(flags & ImGuiTabBarFlags_Reorderable)))
-        ImQsort(tab_bar->Tabs.Data, tab_bar->Tabs.Size, sizeof(ImGuiTabItem), TabItemComparerByBeginOrder);
+        if ((flags & ImGuiTabBarFlags_DockNode) == 0) // FIXME: TabBar with DockNode can now be hybrid
+            ImQsort(tab_bar->Tabs.Data, tab_bar->Tabs.Size, sizeof(ImGuiTabItem), TabItemComparerByBeginOrder);
     tab_bar->TabsAddedNew = false;
 
     // Flags
@@ -7403,6 +7418,13 @@ bool    ImGui::BeginTabBarEx(ImGuiTabBar* tab_bar, const ImRect& tab_bar_bb, ImG
     // Draw separator
     const ImU32 col = GetColorU32((flags & ImGuiTabBarFlags_IsFocused) ? ImGuiCol_TabActive : ImGuiCol_TabUnfocusedActive);
     const float y = tab_bar->BarRect.Max.y - 1.0f;
+    if (dock_node != NULL)
+    {
+        const float separator_min_x = dock_node->Pos.x + window->WindowBorderSize;
+        const float separator_max_x = dock_node->Pos.x + dock_node->Size.x - window->WindowBorderSize;
+        window->DrawList->AddLine(ImVec2(separator_min_x, y), ImVec2(separator_max_x, y), col, 1.0f);
+    }
+    else
     {
         const float separator_min_x = tab_bar->BarRect.Min.x - IM_FLOOR(window->WindowPadding.x * 0.5f);
         const float separator_max_x = tab_bar->BarRect.Max.x + IM_FLOOR(window->WindowPadding.x * 0.5f);
@@ -7631,6 +7653,7 @@ static void ImGui::TabBarLayout(ImGuiTabBar* tab_bar)
         {
             ImGuiTabItem* tab = &tab_bar->Tabs[section_tab_index + tab_n];
             tab->Offset = tab_offset;
+            tab->NameOffset = -1;
             tab_offset += tab->Width + (tab_n < section->TabCount - 1 ? g.Style.ItemInnerSpacing.x : 0.0f);
         }
         tab_bar->WidthAllTabs += ImMax(section->Width + section->Spacing, 0.0f);
@@ -7638,6 +7661,9 @@ static void ImGui::TabBarLayout(ImGuiTabBar* tab_bar)
         section_tab_index += section->TabCount;
     }
 
+    // Clear name buffers
+    tab_bar->TabsNames.Buf.resize(0);
+
     // If we have lost the selected tab, select the next most recently active one
     if (found_selected_tab_id == false)
         tab_bar->SelectedTabId = 0;
@@ -7648,6 +7674,10 @@ static void ImGui::TabBarLayout(ImGuiTabBar* tab_bar)
     tab_bar->VisibleTabId = tab_bar->SelectedTabId;
     tab_bar->VisibleTabWasSubmitted = false;
 
+    // CTRL+TAB can override visible tab temporarily
+    if (g.NavWindowingTarget != NULL && g.NavWindowingTarget->DockNode && g.NavWindowingTarget->DockNode->TabBar == tab_bar)
+        tab_bar->VisibleTabId = scroll_to_tab_id = g.NavWindowingTarget->TabId;
+
     // Update scrolling
     if (scroll_to_tab_id != 0)
         TabBarScrollToTab(tab_bar, scroll_to_tab_id, sections);
@@ -7669,10 +7699,6 @@ static void ImGui::TabBarLayout(ImGuiTabBar* tab_bar)
     tab_bar->ScrollingRectMinX = tab_bar->BarRect.Min.x + sections[0].Width + sections[0].Spacing;
     tab_bar->ScrollingRectMaxX = tab_bar->BarRect.Max.x - sections[2].Width - sections[1].Spacing;
 
-    // Clear name buffers
-    if ((tab_bar->Flags & ImGuiTabBarFlags_DockNode) == 0)
-        tab_bar->TabsNames.Buf.resize(0);
-
     // Actual layout in host window (we don't do it in BeginTabBar() so as not to waste an extra frame)
     ImGuiWindow* window = g.CurrentWindow;
     window->DC.CursorPos = tab_bar->BarRect.Min;
@@ -7680,12 +7706,14 @@ static void ImGui::TabBarLayout(ImGuiTabBar* tab_bar)
     window->DC.IdealMaxPos.x = ImMax(window->DC.IdealMaxPos.x, tab_bar->BarRect.Min.x + tab_bar->WidthAllTabsIdeal);
 }
 
-// Dockables uses Name/ID in the global namespace. Non-dockable items use the ID stack.
+// Dockable uses Name/ID in the global namespace. Non-dockable items use the ID stack.
-static ImU32   ImGui::TabBarCalcTabID(ImGuiTabBar* tab_bar, const char* label)
+static ImU32   ImGui::TabBarCalcTabID(ImGuiTabBar* tab_bar, const char* label, ImGuiWindow* docked_window)
 {
-    if (tab_bar->Flags & ImGuiTabBarFlags_DockNode)
+    if (docked_window != NULL)
     {
-        ImGuiID id = ImHashStr(label);
+        IM_UNUSED(tab_bar);
+        IM_ASSERT(tab_bar->Flags & ImGuiTabBarFlags_DockNode);
+        ImGuiID id = docked_window->TabId;
         KeepAliveID(id);
         return id;
     }
@@ -7711,6 +7739,41 @@ ImGuiTabItem* ImGui::TabBarFindTabByID(ImGuiTabBar* tab_bar, ImGuiID tab_id)
     return NULL;
 }
 
+// FIXME: See references to #2304 in TODO.txt
+ImGuiTabItem* ImGui::TabBarFindMostRecentlySelectedTabForActiveWindow(ImGuiTabBar* tab_bar)
+{
+    ImGuiTabItem* most_recently_selected_tab = NULL;
+    for (int tab_n = 0; tab_n < tab_bar->Tabs.Size; tab_n++)
+    {
+        ImGuiTabItem* tab = &tab_bar->Tabs[tab_n];
+        if (most_recently_selected_tab == NULL || most_recently_selected_tab->LastFrameSelected < tab->LastFrameSelected)
+            if (tab->Window && tab->Window->WasActive)
+                most_recently_selected_tab = tab;
+    }
+    return most_recently_selected_tab;
+}
+
+// The purpose of this call is to register tab in advance so we can control their order at the time they appear.
+// Otherwise calling this is unnecessary as tabs are appending as needed by the BeginTabItem() function.
+void ImGui::TabBarAddTab(ImGuiTabBar* tab_bar, ImGuiTabItemFlags tab_flags, ImGuiWindow* window)
+{
+    ImGuiContext& g = *GImGui;
+    IM_ASSERT(TabBarFindTabByID(tab_bar, window->TabId) == NULL);
+    IM_ASSERT(g.CurrentTabBar != tab_bar);  // Can't work while the tab bar is active as our tab doesn't have an X offset yet, in theory we could/should test something like (tab_bar->CurrFrameVisible < g.FrameCount) but we'd need to solve why triggers the commented early-out assert in BeginTabBarEx() (probably dock node going from implicit to explicit in same frame)
+
+    if (!window->HasCloseButton)
+        tab_flags |= ImGuiTabItemFlags_NoCloseButton;       // Set _NoCloseButton immediately because it will be used for first-frame width calculation.
+
+    ImGuiTabItem new_tab;
+    new_tab.ID = window->TabId;
+    new_tab.Flags = tab_flags;
+    new_tab.LastFrameVisible = tab_bar->CurrFrameVisible;   // Required so BeginTabBar() doesn't ditch the tab
+    if (new_tab.LastFrameVisible == -1)
+        new_tab.LastFrameVisible = g.FrameCount - 1;
+    new_tab.Window = window;                                // Required so tab bar layout can compute the tab width before tab submission
+    tab_bar->Tabs.push_back(new_tab);
+}
+
 // The *TabId fields be already set by the docking system _before_ the actual TabItem was created, so we clear them regardless.
 void ImGui::TabBarRemoveTab(ImGuiTabBar* tab_bar, ImGuiID tab_id)
 {
@@ -7987,9 +8050,9 @@ bool    ImGui::BeginTabItem(const char* label, bool* p_open, ImGuiTabItemFlags f
         IM_ASSERT_USER_ERROR(tab_bar, "Needs to be called between BeginTabBar() and EndTabBar()!");
         return false;
     }
-    IM_ASSERT(!(flags & ImGuiTabItemFlags_Button)); // BeginTabItem() Can't be used with button flags, use TabItemButton() instead!
+    IM_ASSERT((flags & ImGuiTabItemFlags_Button) == 0);             // BeginTabItem() Can't be used with button flags, use TabItemButton() instead!
 
-    bool ret = TabItemEx(tab_bar, label, p_open, flags);
+    bool ret = TabItemEx(tab_bar, label, p_open, flags, NULL);
     if (ret && !(flags & ImGuiTabItemFlags_NoPushId))
     {
         ImGuiTabItem* tab = &tab_bar->Tabs[tab_bar->LastTabItemIdx];
@@ -8030,10 +8093,10 @@ bool    ImGui::TabItemButton(const char* label, ImGuiTabItemFlags flags)
         IM_ASSERT_USER_ERROR(tab_bar != NULL, "Needs to be called between BeginTabBar() and EndTabBar()!");
         return false;
     }
-    return TabItemEx(tab_bar, label, NULL, flags | ImGuiTabItemFlags_Button | ImGuiTabItemFlags_NoReorder);
+    return TabItemEx(tab_bar, label, NULL, flags | ImGuiTabItemFlags_Button | ImGuiTabItemFlags_NoReorder, NULL);
 }
 
-bool    ImGui::TabItemEx(ImGuiTabBar* tab_bar, const char* label, bool* p_open, ImGuiTabItemFlags flags)
+bool    ImGui::TabItemEx(ImGuiTabBar* tab_bar, const char* label, bool* p_open, ImGuiTabItemFlags flags, ImGuiWindow* docked_window)
 {
     // Layout whole tab bar if not already done
     ImGuiContext& g = *GImGui;
@@ -8048,7 +8111,7 @@ bool    ImGui::TabItemEx(ImGuiTabBar* tab_bar, const char* label, bool* p_open,
         return false;
 
     const ImGuiStyle& style = g.Style;
-    const ImGuiID id = TabBarCalcTabID(tab_bar, label);
+    const ImGuiID id = TabBarCalcTabID(tab_bar, label, docked_window);
 
     // If the user called us with *p_open == false, we early out and don't render.
     // We make a call to ItemAdd() so that attempts to use a contextual popup menu with an implicit ID won't use an older ID.
@@ -8097,10 +8160,21 @@ bool    ImGui::TabItemEx(ImGuiTabBar* tab_bar, const char* label, bool* p_open,
     const bool is_tab_button = (flags & ImGuiTabItemFlags_Button) != 0;
     tab->LastFrameVisible = g.FrameCount;
     tab->Flags = flags;
+    tab->Window = docked_window;
 
     // Append name with zero-terminator
-    tab->NameOffset = (ImS32)tab_bar->TabsNames.size();
+    // (regular tabs are permitted in a DockNode tab bar, but window tabs not permitted in a non-DockNode tab bar)
-    tab_bar->TabsNames.append(label, label + strlen(label) + 1);
+    if (tab->Window != NULL)
+    {
+        IM_ASSERT(tab_bar->Flags & ImGuiTabBarFlags_DockNode);
+        tab->NameOffset = -1;
+    }
+    else
+    {
+        IM_ASSERT(tab->Window == NULL);
+        tab->NameOffset = (ImS32)tab_bar->TabsNames.size();
+        tab_bar->TabsNames.append(label, label + strlen(label) + 1); // Append name _with_ the zero-terminator.
+    }
 
     // Update selected tab
     if (!is_tab_button)
@@ -8119,7 +8193,7 @@ bool    ImGui::TabItemEx(ImGuiTabBar* tab_bar, const char* label, bool* p_open,
         tab_bar->VisibleTabWasSubmitted = true;
 
     // On the very first frame of a tab bar we let first tab contents be visible to minimize appearing glitches
-    if (!tab_contents_visible && tab_bar->SelectedTabId == 0 && tab_bar_appearing)
+    if (!tab_contents_visible && tab_bar->SelectedTabId == 0 && tab_bar_appearing && docked_window == NULL)
         if (tab_bar->Tabs.Size == 1 && !(tab_bar->Flags & ImGuiTabBarFlags_AutoSelectNewTabs))
             tab_contents_visible = true;
 
@@ -8168,32 +8242,84 @@ bool    ImGui::TabItemEx(ImGuiTabBar* tab_bar, const char* label, bool* p_open,
 
     // Click to Select a tab
     ImGuiButtonFlags button_flags = ((is_tab_button ? ImGuiButtonFlags_PressedOnClickRelease : ImGuiButtonFlags_PressedOnClick) | ImGuiButtonFlags_AllowItemOverlap);
-    if (g.DragDropActive)
+    if (g.DragDropActive && !g.DragDropPayload.IsDataType(IMGUI_PAYLOAD_TYPE_WINDOW)) // FIXME: May be an opt-in property of the payload to disable this
         button_flags |= ImGuiButtonFlags_PressedOnDragDropHold;
     bool hovered, held;
     bool pressed = ButtonBehavior(bb, id, &hovered, &held, button_flags);
     if (pressed && !is_tab_button)
         tab_bar->NextSelectedTabId = id;
 
+    // Transfer active id window so the active id is not owned by the dock host (as StartMouseMovingWindow()
+    // will only do it on the drag). This allows FocusWindow() to be more conservative in how it clears active id.
+    if (held && docked_window && g.ActiveId == id && g.ActiveIdIsJustActivated)
+        g.ActiveIdWindow = docked_window;
+
     // Allow the close button to overlap unless we are dragging (in which case we don't want any overlapping tabs to be hovered)
     if (g.ActiveId != id)
         SetItemAllowOverlap();
 
-    // Drag and drop: re-order tabs
+    // Drag and drop a single floating window node moves it
-    if (held && !tab_appearing && IsMouseDragging(0))
+    ImGuiDockNode* node = docked_window ? docked_window->DockNode : NULL;
+    const bool single_floating_window_node = node && node->IsFloatingNode() && (node->Windows.Size == 1);
+    if (held && single_floating_window_node && IsMouseDragging(0, 0.0f))
     {
-        if (!g.DragDropActive && (tab_bar->Flags & ImGuiTabBarFlags_Reorderable))
+        // Move
+        StartMouseMovingWindow(docked_window);
+    }
+    else if (held && !tab_appearing && IsMouseDragging(0))
+    {
+        // Drag and drop: re-order tabs
+        int drag_dir = 0;
+        float drag_distance_from_edge_x = 0.0f;
+        if (!g.DragDropActive && ((tab_bar->Flags & ImGuiTabBarFlags_Reorderable) || (docked_window != NULL)))
         {
             // While moving a tab it will jump on the other side of the mouse, so we also test for MouseDelta.x
             if (g.IO.MouseDelta.x < 0.0f && g.IO.MousePos.x < bb.Min.x)
             {
+                drag_dir = -1;
+                drag_distance_from_edge_x = bb.Min.x - g.IO.MousePos.x;
                 TabBarQueueReorderFromMousePos(tab_bar, tab, g.IO.MousePos);
             }
             else if (g.IO.MouseDelta.x > 0.0f && g.IO.MousePos.x > bb.Max.x)
             {
+                drag_dir = +1;
+                drag_distance_from_edge_x = g.IO.MousePos.x - bb.Max.x;
                 TabBarQueueReorderFromMousePos(tab_bar, tab, g.IO.MousePos);
             }
         }
+
+        // Extract a Dockable window out of it's tab bar
+        if (docked_window != NULL && !(docked_window->Flags & ImGuiWindowFlags_NoMove))
+        {
+            // We use a variable threshold to distinguish dragging tabs within a tab bar and extracting them out of the tab bar
+            bool undocking_tab = (g.DragDropActive && g.DragDropPayload.SourceId == id);
+            if (!undocking_tab) //&& (!g.IO.ConfigDockingWithShift || g.IO.KeyShift)
+            {
+                float threshold_base = g.FontSize;
+                float threshold_x = (threshold_base * 2.2f);
+                float threshold_y = (threshold_base * 1.5f) + ImClamp((ImFabs(g.IO.MouseDragMaxDistanceAbs[0].x) - threshold_base * 2.0f) * 0.20f, 0.0f, threshold_base * 4.0f);
+                //GetForegroundDrawList()->AddRect(ImVec2(bb.Min.x - threshold_x, bb.Min.y - threshold_y), ImVec2(bb.Max.x + threshold_x, bb.Max.y + threshold_y), IM_COL32_WHITE); // [DEBUG]
+
+                float distance_from_edge_y = ImMax(bb.Min.y - g.IO.MousePos.y, g.IO.MousePos.y - bb.Max.y);
+                if (distance_from_edge_y >= threshold_y)
+                    undocking_tab = true;
+                if (drag_distance_from_edge_x > threshold_x)
+                    if ((drag_dir < 0 && tab_bar->GetTabOrder(tab) == 0) || (drag_dir > 0 && tab_bar->GetTabOrder(tab) == tab_bar->Tabs.Size - 1))
+                        undocking_tab = true;
+            }
+
+            if (undocking_tab)
+            {
+                // Undock
+                // FIXME: refactor to share more code with e.g. StartMouseMovingWindow
+                DockContextQueueUndockWindow(&g, docked_window);
+                g.MovingWindow = docked_window;
+                SetActiveID(g.MovingWindow->MoveId, g.MovingWindow);
+                g.ActiveIdClickOffset -= g.MovingWindow->Pos - bb.Min;
+                g.ActiveIdNoClearOnFocusLoss = true;
+                SetActiveIdUsingAllKeyboardKeys();
+            }
+        }
     }
 
 #if 0
@@ -8222,7 +8348,7 @@ bool    ImGui::TabItemEx(ImGuiTabBar* tab_bar, const char* label, bool* p_open,
         flags |= ImGuiTabItemFlags_NoCloseWithMiddleMouseButton;
 
     // Render tab label, process close button
-    const ImGuiID close_button_id = p_open ? GetIDWithSeed("#CLOSE", NULL, id) : 0;
+    const ImGuiID close_button_id = p_open ? GetIDWithSeed("#CLOSE", NULL, docked_window ? docked_window->ID : id) : 0;
     bool just_closed;
     bool text_clipped;
     TabItemLabelAndCloseButton(display_draw_list, bb, tab_just_unsaved ? (flags & ~ImGuiTabItemFlags_UnsavedDocument) : flags, tab_bar->FramePadding, label, id, close_button_id, tab_contents_visible, &just_closed, &text_clipped);
@@ -8232,6 +8358,11 @@ bool    ImGui::TabItemEx(ImGuiTabBar* tab_bar, const char* label, bool* p_open,
         TabBarCloseTab(tab_bar, tab);
     }
 
+    // Forward Hovered state so IsItemHovered() after Begin() can work (even though we are technically hovering our parent)
+    // That state is copied to window->DockTabItemStatusFlags by our caller.
+    if (docked_window && (hovered || g.HoveredId == close_button_id))
+        g.LastItemData.StatusFlags |= ImGuiItemStatusFlags_HoveredWindow;
+
     // Restore main window position so user can draw there
     if (want_clip_rect)
         PopClipRect();
@@ -8263,10 +8394,20 @@ void    ImGui::SetTabItemClosed(const char* label)
     if (is_within_manual_tab_bar)
     {
         ImGuiTabBar* tab_bar = g.CurrentTabBar;
-        ImGuiID tab_id = TabBarCalcTabID(tab_bar, label);
+        ImGuiID tab_id = TabBarCalcTabID(tab_bar, label, NULL);
         if (ImGuiTabItem* tab = TabBarFindTabByID(tab_bar, tab_id))
             tab->WantClose = true; // Will be processed by next call to TabBarLayout()
     }
+    else if (ImGuiWindow* window = FindWindowByName(label))
+    {
+        if (window->DockIsActive)
+            if (ImGuiDockNode* node = window->DockNode)
+            {
+                ImGuiID tab_id = TabBarCalcTabID(node->TabBar, label, window);
+                TabBarRemoveTab(node->TabBar, tab_id);
+                window->DockTabWantClose = true;
+            }
+    }
 }
 
 ImVec2 ImGui::TabItemCalcSize(const char* label, bool has_close_button_or_unsaved_marker)
@@ -8281,6 +8422,11 @@ ImVec2 ImGui::TabItemCalcSize(const char* label, bool has_close_button_or_unsave
     return ImVec2(ImMin(size.x, TabBarCalcMaxTabWidth()), size.y);
 }
 
+ImVec2 ImGui::TabItemCalcSize(ImGuiWindow* window)
+{
+    return TabItemCalcSize(window->Name, window->HasCloseButton || (window->Flags & ImGuiWindowFlags_UnsavedDocument));
+}
+
 void ImGui::TabItemBackground(ImDrawList* draw_list, const ImRect& bb, ImGuiTabItemFlags flags, ImU32 col)
 {
     // While rendering tabs, we trim 1 pixel off the top of our bounding box so they can fit within a regular frame height while looking "detached" from it.
@@ -8290,7 +8436,7 @@ void ImGui::TabItemBackground(ImDrawList* draw_list, const ImRect& bb, ImGuiTabI
     IM_ASSERT(width > 0.0f);
     const float rounding = ImMax(0.0f, ImMin((flags & ImGuiTabItemFlags_Button) ? g.Style.FrameRounding : g.Style.TabRounding, width * 0.5f - 1.0f));
     const float y1 = bb.Min.y + 1.0f;
-    const float y2 = bb.Max.y - 1.0f;
+    const float y2 = bb.Max.y + ((flags & ImGuiTabItemFlags_Preview) ? 0.0f : -1.0f);
     draw_list->PathLineTo(ImVec2(bb.Min.x, y2));
     draw_list->PathArcToFast(ImVec2(bb.Min.x + rounding, y1 + rounding), rounding, 6, 9);
     draw_list->PathArcToFast(ImVec2(bb.Max.x - rounding, y1 + rounding), rounding, 9, 12);

src/main.cpp

@@ -1,23 +1,17 @@
-// Dear ImGui: standalone example application for Glfw + Vulkan
+// Dear ImGui: standalone example application for GLFW + OpenGL 3, using programmable pipeline
+// (GLFW is a cross-platform general purpose library for handling windows, inputs, OpenGL/Vulkan/Metal graphics context creation, etc.)
 // If you are new to Dear ImGui, read documentation from the docs/ folder + read the top of imgui.cpp.
 // Read online: https://github.com/ocornut/imgui/tree/master/docs
 
-// Important note to the reader who wish to integrate imgui_impl_vulkan.cpp/.h in their own engine/app.
-// - Common ImGui_ImplVulkan_XXX functions and structures are used to interface with imgui_impl_vulkan.cpp/.h.
-//   You will use those if you want to use this rendering backend in your engine/app.
-// - Helper ImGui_ImplVulkanH_XXX functions and structures are only used by this example (main.cpp) and by
-//   the backend itself (imgui_impl_vulkan.cpp), but should PROBABLY NOT be used by your own engine/app code.
-// Read comments in imgui_impl_vulkan.h.
-
 #include "imgui.h"
 #include "imgui_impl_glfw.h"
-#include "imgui_impl_vulkan.h"
+#include "imgui_impl_opengl3.h"
-#include <stdio.h>          // printf, fprintf
+#include <stdio.h>
-#include <stdlib.h>         // abort
+#define GL_SILENCE_DEPRECATION
-#define GLFW_INCLUDE_NONE
+#if defined(IMGUI_IMPL_OPENGL_ES2)
-#define GLFW_INCLUDE_VULKAN
+#include <GLES2/gl2.h>
-#include <GLFW/glfw3.h>
+#endif
-#include <vulkan/vulkan.h>
+#include <GLFW/glfw3.h> // Will drag system OpenGL headers
 
 // [Win32] Our example includes a copy of glfw3.lib pre-compiled with VS2010 to maximize ease of testing and compatibility with old VS compilers.
 // To link with VS2010-era libraries, VS2015+ requires linking with legacy_stdio_definitions.lib, which we do using this pragma.
@@ -26,327 +20,6 @@
 #pragma comment(lib, "legacy_stdio_definitions")
 #endif
 
-//#define IMGUI_UNLIMITED_FRAME_RATE
-#ifdef _DEBUG
-#define IMGUI_VULKAN_DEBUG_REPORT
-#endif
-
-static VkAllocationCallbacks*   g_Allocator = NULL;
-static VkInstance               g_Instance = VK_NULL_HANDLE;
-static VkPhysicalDevice         g_PhysicalDevice = VK_NULL_HANDLE;
-static VkDevice                 g_Device = VK_NULL_HANDLE;
-static uint32_t                 g_QueueFamily = (uint32_t)-1;
-static VkQueue                  g_Queue = VK_NULL_HANDLE;
-static VkDebugReportCallbackEXT g_DebugReport = VK_NULL_HANDLE;
-static VkPipelineCache          g_PipelineCache = VK_NULL_HANDLE;
-static VkDescriptorPool         g_DescriptorPool = VK_NULL_HANDLE;
-
-static ImGui_ImplVulkanH_Window g_MainWindowData;
-static int                      g_MinImageCount = 2;
-static bool                     g_SwapChainRebuild = false;
-
-static void check_vk_result(VkResult err)
-{
-    if (err == 0)
-        return;
-    fprintf(stderr, "[vulkan] Error: VkResult = %d\n", err);
-    if (err < 0)
-        abort();
-}
-
-#ifdef IMGUI_VULKAN_DEBUG_REPORT
-static VKAPI_ATTR VkBool32 VKAPI_CALL debug_report(VkDebugReportFlagsEXT flags, VkDebugReportObjectTypeEXT objectType, uint64_t object, size_t location, int32_t messageCode, const char* pLayerPrefix, const char* pMessage, void* pUserData)
-{
-    (void)flags; (void)object; (void)location; (void)messageCode; (void)pUserData; (void)pLayerPrefix; // Unused arguments
-    fprintf(stderr, "[vulkan] Debug report from ObjectType: %i\nMessage: %s\n\n", objectType, pMessage);
-    return VK_FALSE;
-}
-#endif // IMGUI_VULKAN_DEBUG_REPORT
-
-static void SetupVulkan(const char** extensions, uint32_t extensions_count)
-{
-    VkResult err;
-
-    // Create Vulkan Instance
-    {
-        VkInstanceCreateInfo create_info = {};
-        create_info.sType = VK_STRUCTURE_TYPE_INSTANCE_CREATE_INFO;
-        create_info.enabledExtensionCount = extensions_count;
-        create_info.ppEnabledExtensionNames = extensions;
-#ifdef IMGUI_VULKAN_DEBUG_REPORT
-        // Enabling validation layers
-        const char* layers[] = { "VK_LAYER_KHRONOS_validation" };
-        create_info.enabledLayerCount = 1;
-        create_info.ppEnabledLayerNames = layers;
-
-        // Enable debug report extension (we need additional storage, so we duplicate the user array to add our new extension to it)
-        const char** extensions_ext = (const char**)malloc(sizeof(const char*) * (extensions_count + 1));
-        memcpy(extensions_ext, extensions, extensions_count * sizeof(const char*));
-        extensions_ext[extensions_count] = "VK_EXT_debug_report";
-        create_info.enabledExtensionCount = extensions_count + 1;
-        create_info.ppEnabledExtensionNames = extensions_ext;
-
-        // Create Vulkan Instance
-        err = vkCreateInstance(&create_info, g_Allocator, &g_Instance);
-        check_vk_result(err);
-        free(extensions_ext);
-
-        // Get the function pointer (required for any extensions)
-        auto vkCreateDebugReportCallbackEXT = (PFN_vkCreateDebugReportCallbackEXT)vkGetInstanceProcAddr(g_Instance, "vkCreateDebugReportCallbackEXT");
-        IM_ASSERT(vkCreateDebugReportCallbackEXT != NULL);
-
-        // Setup the debug report callback
-        VkDebugReportCallbackCreateInfoEXT debug_report_ci = {};
-        debug_report_ci.sType = VK_STRUCTURE_TYPE_DEBUG_REPORT_CALLBACK_CREATE_INFO_EXT;
-        debug_report_ci.flags = VK_DEBUG_REPORT_ERROR_BIT_EXT | VK_DEBUG_REPORT_WARNING_BIT_EXT | VK_DEBUG_REPORT_PERFORMANCE_WARNING_BIT_EXT;
-        debug_report_ci.pfnCallback = debug_report;
-        debug_report_ci.pUserData = NULL;
-        err = vkCreateDebugReportCallbackEXT(g_Instance, &debug_report_ci, g_Allocator, &g_DebugReport);
-        check_vk_result(err);
-#else
-        // Create Vulkan Instance without any debug feature
-        err = vkCreateInstance(&create_info, g_Allocator, &g_Instance);
-        check_vk_result(err);
-        IM_UNUSED(g_DebugReport);
-#endif
-    }
-
-    // Select GPU
-    {
-        uint32_t gpu_count;
-        err = vkEnumeratePhysicalDevices(g_Instance, &gpu_count, NULL);
-        check_vk_result(err);
-        IM_ASSERT(gpu_count > 0);
-
-        VkPhysicalDevice* gpus = (VkPhysicalDevice*)malloc(sizeof(VkPhysicalDevice) * gpu_count);
-        err = vkEnumeratePhysicalDevices(g_Instance, &gpu_count, gpus);
-        check_vk_result(err);
-
-        // If a number >1 of GPUs got reported, find discrete GPU if present, or use first one available. This covers
-        // most common cases (multi-gpu/integrated+dedicated graphics). Handling more complicated setups (multiple
-        // dedicated GPUs) is out of scope of this sample.
-        int use_gpu = 0;
-        for (int i = 0; i < (int)gpu_count; i++)
-        {
-            VkPhysicalDeviceProperties properties;
-            vkGetPhysicalDeviceProperties(gpus[i], &properties);
-            if (properties.deviceType == VK_PHYSICAL_DEVICE_TYPE_DISCRETE_GPU)
-            {
-                use_gpu = i;
-                break;
-            }
-        }
-
-        g_PhysicalDevice = gpus[use_gpu];
-        free(gpus);
-    }
-
-    // Select graphics queue family
-    {
-        uint32_t count;
-        vkGetPhysicalDeviceQueueFamilyProperties(g_PhysicalDevice, &count, NULL);
-        VkQueueFamilyProperties* queues = (VkQueueFamilyProperties*)malloc(sizeof(VkQueueFamilyProperties) * count);
-        vkGetPhysicalDeviceQueueFamilyProperties(g_PhysicalDevice, &count, queues);
-        for (uint32_t i = 0; i < count; i++)
-            if (queues[i].queueFlags & VK_QUEUE_GRAPHICS_BIT)
-            {
-                g_QueueFamily = i;
-                break;
-            }
-        free(queues);
-        IM_ASSERT(g_QueueFamily != (uint32_t)-1);
-    }
-
-    // Create Logical Device (with 1 queue)
-    {
-        int device_extension_count = 1;
-        const char* device_extensions[] = { "VK_KHR_swapchain" };
-        const float queue_priority[] = { 1.0f };
-        VkDeviceQueueCreateInfo queue_info[1] = {};
-        queue_info[0].sType = VK_STRUCTURE_TYPE_DEVICE_QUEUE_CREATE_INFO;
-        queue_info[0].queueFamilyIndex = g_QueueFamily;
-        queue_info[0].queueCount = 1;
-        queue_info[0].pQueuePriorities = queue_priority;
-        VkDeviceCreateInfo create_info = {};
-        create_info.sType = VK_STRUCTURE_TYPE_DEVICE_CREATE_INFO;
-        create_info.queueCreateInfoCount = sizeof(queue_info) / sizeof(queue_info[0]);
-        create_info.pQueueCreateInfos = queue_info;
-        create_info.enabledExtensionCount = device_extension_count;
-        create_info.ppEnabledExtensionNames = device_extensions;
-        err = vkCreateDevice(g_PhysicalDevice, &create_info, g_Allocator, &g_Device);
-        check_vk_result(err);
-        vkGetDeviceQueue(g_Device, g_QueueFamily, 0, &g_Queue);
-    }
-
-    // Create Descriptor Pool
-    {
-        VkDescriptorPoolSize pool_sizes[] =
-        {
-            { VK_DESCRIPTOR_TYPE_SAMPLER, 1000 },
-            { VK_DESCRIPTOR_TYPE_COMBINED_IMAGE_SAMPLER, 1000 },
-            { VK_DESCRIPTOR_TYPE_SAMPLED_IMAGE, 1000 },
-            { VK_DESCRIPTOR_TYPE_STORAGE_IMAGE, 1000 },
-            { VK_DESCRIPTOR_TYPE_UNIFORM_TEXEL_BUFFER, 1000 },
-            { VK_DESCRIPTOR_TYPE_STORAGE_TEXEL_BUFFER, 1000 },
-            { VK_DESCRIPTOR_TYPE_UNIFORM_BUFFER, 1000 },
-            { VK_DESCRIPTOR_TYPE_STORAGE_BUFFER, 1000 },
-            { VK_DESCRIPTOR_TYPE_UNIFORM_BUFFER_DYNAMIC, 1000 },
-            { VK_DESCRIPTOR_TYPE_STORAGE_BUFFER_DYNAMIC, 1000 },
-            { VK_DESCRIPTOR_TYPE_INPUT_ATTACHMENT, 1000 }
-        };
-        VkDescriptorPoolCreateInfo pool_info = {};
-        pool_info.sType = VK_STRUCTURE_TYPE_DESCRIPTOR_POOL_CREATE_INFO;
-        pool_info.flags = VK_DESCRIPTOR_POOL_CREATE_FREE_DESCRIPTOR_SET_BIT;
-        pool_info.maxSets = 1000 * IM_ARRAYSIZE(pool_sizes);
-        pool_info.poolSizeCount = (uint32_t)IM_ARRAYSIZE(pool_sizes);
-        pool_info.pPoolSizes = pool_sizes;
-        err = vkCreateDescriptorPool(g_Device, &pool_info, g_Allocator, &g_DescriptorPool);
-        check_vk_result(err);
-    }
-}
-
-// All the ImGui_ImplVulkanH_XXX structures/functions are optional helpers used by the demo.
-// Your real engine/app may not use them.
-static void SetupVulkanWindow(ImGui_ImplVulkanH_Window* wd, VkSurfaceKHR surface, int width, int height)
-{
-    wd->Surface = surface;
-
-    // Check for WSI support
-    VkBool32 res;
-    vkGetPhysicalDeviceSurfaceSupportKHR(g_PhysicalDevice, g_QueueFamily, wd->Surface, &res);
-    if (res != VK_TRUE)
-    {
-        fprintf(stderr, "Error no WSI support on physical device 0\n");
-        exit(-1);
-    }
-
-    // Select Surface Format
-    const VkFormat requestSurfaceImageFormat[] = { VK_FORMAT_B8G8R8A8_UNORM, VK_FORMAT_R8G8B8A8_UNORM, VK_FORMAT_B8G8R8_UNORM, VK_FORMAT_R8G8B8_UNORM };
-    const VkColorSpaceKHR requestSurfaceColorSpace = VK_COLORSPACE_SRGB_NONLINEAR_KHR;
-    wd->SurfaceFormat = ImGui_ImplVulkanH_SelectSurfaceFormat(g_PhysicalDevice, wd->Surface, requestSurfaceImageFormat, (size_t)IM_ARRAYSIZE(requestSurfaceImageFormat), requestSurfaceColorSpace);
-
-    // Select Present Mode
-#ifdef IMGUI_UNLIMITED_FRAME_RATE
-    VkPresentModeKHR present_modes[] = { VK_PRESENT_MODE_MAILBOX_KHR, VK_PRESENT_MODE_IMMEDIATE_KHR, VK_PRESENT_MODE_FIFO_KHR };
-#else
-    VkPresentModeKHR present_modes[] = { VK_PRESENT_MODE_FIFO_KHR };
-#endif
-    wd->PresentMode = ImGui_ImplVulkanH_SelectPresentMode(g_PhysicalDevice, wd->Surface, &present_modes[0], IM_ARRAYSIZE(present_modes));
-    //printf("[vulkan] Selected PresentMode = %d\n", wd->PresentMode);
-
-    // Create SwapChain, RenderPass, Framebuffer, etc.
-    IM_ASSERT(g_MinImageCount >= 2);
-    ImGui_ImplVulkanH_CreateOrResizeWindow(g_Instance, g_PhysicalDevice, g_Device, wd, g_QueueFamily, g_Allocator, width, height, g_MinImageCount);
-}
-
-static void CleanupVulkan()
-{
-    vkDestroyDescriptorPool(g_Device, g_DescriptorPool, g_Allocator);
-
-#ifdef IMGUI_VULKAN_DEBUG_REPORT
-    // Remove the debug report callback
-    auto vkDestroyDebugReportCallbackEXT = (PFN_vkDestroyDebugReportCallbackEXT)vkGetInstanceProcAddr(g_Instance, "vkDestroyDebugReportCallbackEXT");
-    vkDestroyDebugReportCallbackEXT(g_Instance, g_DebugReport, g_Allocator);
-#endif // IMGUI_VULKAN_DEBUG_REPORT
-
-    vkDestroyDevice(g_Device, g_Allocator);
-    vkDestroyInstance(g_Instance, g_Allocator);
-}
-
-static void CleanupVulkanWindow()
-{
-    ImGui_ImplVulkanH_DestroyWindow(g_Instance, g_Device, &g_MainWindowData, g_Allocator);
-}
-
-static void FrameRender(ImGui_ImplVulkanH_Window* wd, ImDrawData* draw_data)
-{
-    VkResult err;
-
-    VkSemaphore image_acquired_semaphore  = wd->FrameSemaphores[wd->SemaphoreIndex].ImageAcquiredSemaphore;
-    VkSemaphore render_complete_semaphore = wd->FrameSemaphores[wd->SemaphoreIndex].RenderCompleteSemaphore;
-    err = vkAcquireNextImageKHR(g_Device, wd->Swapchain, UINT64_MAX, image_acquired_semaphore, VK_NULL_HANDLE, &wd->FrameIndex);
-    if (err == VK_ERROR_OUT_OF_DATE_KHR || err == VK_SUBOPTIMAL_KHR)
-    {
-        g_SwapChainRebuild = true;
-        return;
-    }
-    check_vk_result(err);
-
-    ImGui_ImplVulkanH_Frame* fd = &wd->Frames[wd->FrameIndex];
-    {
-        err = vkWaitForFences(g_Device, 1, &fd->Fence, VK_TRUE, UINT64_MAX);    // wait indefinitely instead of periodically checking
-        check_vk_result(err);
-
-        err = vkResetFences(g_Device, 1, &fd->Fence);
-        check_vk_result(err);
-    }
-    {
-        err = vkResetCommandPool(g_Device, fd->CommandPool, 0);
-        check_vk_result(err);
-        VkCommandBufferBeginInfo info = {};
-        info.sType = VK_STRUCTURE_TYPE_COMMAND_BUFFER_BEGIN_INFO;
-        info.flags |= VK_COMMAND_BUFFER_USAGE_ONE_TIME_SUBMIT_BIT;
-        err = vkBeginCommandBuffer(fd->CommandBuffer, &info);
-        check_vk_result(err);
-    }
-    {
-        VkRenderPassBeginInfo info = {};
-        info.sType = VK_STRUCTURE_TYPE_RENDER_PASS_BEGIN_INFO;
-        info.renderPass = wd->RenderPass;
-        info.framebuffer = fd->Framebuffer;
-        info.renderArea.extent.width = wd->Width;
-        info.renderArea.extent.height = wd->Height;
-        info.clearValueCount = 1;
-        info.pClearValues = &wd->ClearValue;
-        vkCmdBeginRenderPass(fd->CommandBuffer, &info, VK_SUBPASS_CONTENTS_INLINE);
-    }
-
-    // Record dear imgui primitives into command buffer
-    ImGui_ImplVulkan_RenderDrawData(draw_data, fd->CommandBuffer);
-
-    // Submit command buffer
-    vkCmdEndRenderPass(fd->CommandBuffer);
-    {
-        VkPipelineStageFlags wait_stage = VK_PIPELINE_STAGE_COLOR_ATTACHMENT_OUTPUT_BIT;
-        VkSubmitInfo info = {};
-        info.sType = VK_STRUCTURE_TYPE_SUBMIT_INFO;
-        info.waitSemaphoreCount = 1;
-        info.pWaitSemaphores = &image_acquired_semaphore;
-        info.pWaitDstStageMask = &wait_stage;
-        info.commandBufferCount = 1;
-        info.pCommandBuffers = &fd->CommandBuffer;
-        info.signalSemaphoreCount = 1;
-        info.pSignalSemaphores = &render_complete_semaphore;
-
-        err = vkEndCommandBuffer(fd->CommandBuffer);
-        check_vk_result(err);
-        err = vkQueueSubmit(g_Queue, 1, &info, fd->Fence);
-        check_vk_result(err);
-    }
-}
-
-static void FramePresent(ImGui_ImplVulkanH_Window* wd)
-{
-    if (g_SwapChainRebuild)
-        return;
-    VkSemaphore render_complete_semaphore = wd->FrameSemaphores[wd->SemaphoreIndex].RenderCompleteSemaphore;
-    VkPresentInfoKHR info = {};
-    info.sType = VK_STRUCTURE_TYPE_PRESENT_INFO_KHR;
-    info.waitSemaphoreCount = 1;
-    info.pWaitSemaphores = &render_complete_semaphore;
-    info.swapchainCount = 1;
-    info.pSwapchains = &wd->Swapchain;
-    info.pImageIndices = &wd->FrameIndex;
-    VkResult err = vkQueuePresentKHR(g_Queue, &info);
-    if (err == VK_ERROR_OUT_OF_DATE_KHR || err == VK_SUBOPTIMAL_KHR)
-    {
-        g_SwapChainRebuild = true;
-        return;
-    }
-    check_vk_result(err);
-    wd->SemaphoreIndex = (wd->SemaphoreIndex + 1) % wd->ImageCount; // Now we can use the next set of semaphores
-}
-
 static void glfw_error_callback(int error, const char* description)
 {
     fprintf(stderr, "Glfw Error %d: %s\n", error, description);
@@ -354,63 +27,67 @@ static void glfw_error_callback(int error, const char* description)
 
 int main(int, char**)
 {
-    // Setup GLFW window
+    // Setup window
     glfwSetErrorCallback(glfw_error_callback);
     if (!glfwInit())
         return 1;
 
-    glfwWindowHint(GLFW_CLIENT_API, GLFW_NO_API);
+    // Decide GL+GLSL versions
-    GLFWwindow* window = glfwCreateWindow(1280, 720, "Dear ImGui GLFW+Vulkan example", NULL, NULL);
+#if defined(IMGUI_IMPL_OPENGL_ES2)
+    // GL ES 2.0 + GLSL 100
+    const char* glsl_version = "#version 100";
+    glfwWindowHint(GLFW_CONTEXT_VERSION_MAJOR, 2);
+    glfwWindowHint(GLFW_CONTEXT_VERSION_MINOR, 0);
+    glfwWindowHint(GLFW_CLIENT_API, GLFW_OPENGL_ES_API);
+#elif defined(__APPLE__)
+    // GL 3.2 + GLSL 150
+    const char* glsl_version = "#version 150";
+    glfwWindowHint(GLFW_CONTEXT_VERSION_MAJOR, 3);
+    glfwWindowHint(GLFW_CONTEXT_VERSION_MINOR, 2);
+    glfwWindowHint(GLFW_OPENGL_PROFILE, GLFW_OPENGL_CORE_PROFILE);  // 3.2+ only
+    glfwWindowHint(GLFW_OPENGL_FORWARD_COMPAT, GL_TRUE);            // Required on Mac
+#else
+    // GL 3.0 + GLSL 130
+    const char* glsl_version = "#version 130";
+    glfwWindowHint(GLFW_CONTEXT_VERSION_MAJOR, 3);
+    glfwWindowHint(GLFW_CONTEXT_VERSION_MINOR, 0);
+    //glfwWindowHint(GLFW_OPENGL_PROFILE, GLFW_OPENGL_CORE_PROFILE);  // 3.2+ only
+    //glfwWindowHint(GLFW_OPENGL_FORWARD_COMPAT, GL_TRUE);            // 3.0+ only
+#endif
 
-    // Setup Vulkan
+    // Create window with graphics context
-    if (!glfwVulkanSupported())
+    GLFWwindow* window = glfwCreateWindow(1280, 720, "Dear ImGui GLFW+OpenGL3 example", NULL, NULL);
-    {
+    if (window == NULL)
-        printf("GLFW: Vulkan Not Supported\n");
         return 1;
-    }
+    glfwMakeContextCurrent(window);
-    uint32_t extensions_count = 0;
+    glfwSwapInterval(1); // Enable vsync
-    const char** extensions = glfwGetRequiredInstanceExtensions(&extensions_count);
-    SetupVulkan(extensions, extensions_count);
-
-    // Create Window Surface
-    VkSurfaceKHR surface;
-    VkResult err = glfwCreateWindowSurface(g_Instance, window, g_Allocator, &surface);
-    check_vk_result(err);
-
-    // Create Framebuffers
-    int w, h;
-    glfwGetFramebufferSize(window, &w, &h);
-    ImGui_ImplVulkanH_Window* wd = &g_MainWindowData;
-    SetupVulkanWindow(wd, surface, w, h);
 
     // Setup Dear ImGui context
     IMGUI_CHECKVERSION();
     ImGui::CreateContext();
     ImGuiIO& io = ImGui::GetIO(); (void)io;
-    //io.ConfigFlags |= ImGuiConfigFlags_NavEnableKeyboard;     // Enable Keyboard Controls
+    io.ConfigFlags |= ImGuiConfigFlags_NavEnableKeyboard;       // Enable Keyboard Controls
     //io.ConfigFlags |= ImGuiConfigFlags_NavEnableGamepad;      // Enable Gamepad Controls
+    io.ConfigFlags |= ImGuiConfigFlags_DockingEnable;           // Enable Docking
+    io.ConfigFlags |= ImGuiConfigFlags_ViewportsEnable;         // Enable Multi-Viewport / Platform Windows
+    //io.ConfigViewportsNoAutoMerge = true;
+    //io.ConfigViewportsNoTaskBarIcon = true;
 
     // Setup Dear ImGui style
     ImGui::StyleColorsDark();
     //ImGui::StyleColorsLight();
 
+    // When viewports are enabled we tweak WindowRounding/WindowBg so platform windows can look identical to regular ones.
+    ImGuiStyle& style = ImGui::GetStyle();
+    if (io.ConfigFlags & ImGuiConfigFlags_ViewportsEnable)
+    {
+        style.WindowRounding = 0.0f;
+        style.Colors[ImGuiCol_WindowBg].w = 1.0f;
+    }
+
     // Setup Platform/Renderer backends
-    ImGui_ImplGlfw_InitForVulkan(window, true);
+    ImGui_ImplGlfw_InitForOpenGL(window, true);
-    ImGui_ImplVulkan_InitInfo init_info = {};
+    ImGui_ImplOpenGL3_Init(glsl_version);
-    init_info.Instance = g_Instance;
-    init_info.PhysicalDevice = g_PhysicalDevice;
-    init_info.Device = g_Device;
-    init_info.QueueFamily = g_QueueFamily;
-    init_info.Queue = g_Queue;
-    init_info.PipelineCache = g_PipelineCache;
-    init_info.DescriptorPool = g_DescriptorPool;
-    init_info.Subpass = 0;
-    init_info.MinImageCount = g_MinImageCount;
-    init_info.ImageCount = wd->ImageCount;
-    init_info.MSAASamples = VK_SAMPLE_COUNT_1_BIT;
-    init_info.Allocator = g_Allocator;
-    init_info.CheckVkResultFn = check_vk_result;
-    ImGui_ImplVulkan_Init(&init_info, wd->RenderPass);
 
     // Load Fonts
     // - If no fonts are loaded, dear imgui will use the default font. You can also load multiple fonts and use ImGui::PushFont()/PopFont() to select them.
@@ -428,40 +105,11 @@ int main(int, char**)
     //ImFont* font = io.Fonts->AddFontFromFileTTF("c:\\Windows\\Fonts\\ArialUni.ttf", 18.0f, NULL, io.Fonts->GetGlyphRangesJapanese());
     //IM_ASSERT(font != NULL);
 
-    // Upload Fonts
-    {
-        // Use any command queue
-        VkCommandPool command_pool = wd->Frames[wd->FrameIndex].CommandPool;
-        VkCommandBuffer command_buffer = wd->Frames[wd->FrameIndex].CommandBuffer;
-
-        err = vkResetCommandPool(g_Device, command_pool, 0);
-        check_vk_result(err);
-        VkCommandBufferBeginInfo begin_info = {};
-        begin_info.sType = VK_STRUCTURE_TYPE_COMMAND_BUFFER_BEGIN_INFO;
-        begin_info.flags |= VK_COMMAND_BUFFER_USAGE_ONE_TIME_SUBMIT_BIT;
-        err = vkBeginCommandBuffer(command_buffer, &begin_info);
-        check_vk_result(err);
-
-        ImGui_ImplVulkan_CreateFontsTexture(command_buffer);
-
-        VkSubmitInfo end_info = {};
-        end_info.sType = VK_STRUCTURE_TYPE_SUBMIT_INFO;
-        end_info.commandBufferCount = 1;
-        end_info.pCommandBuffers = &command_buffer;
-        err = vkEndCommandBuffer(command_buffer);
-        check_vk_result(err);
-        err = vkQueueSubmit(g_Queue, 1, &end_info, VK_NULL_HANDLE);
-        check_vk_result(err);
-
-        err = vkDeviceWaitIdle(g_Device);
-        check_vk_result(err);
-        ImGui_ImplVulkan_DestroyFontUploadObjects();
-    }
-
     // Our state
-    bool show_demo_window = true;
+    bool show_demo_window = false;
     bool show_another_window = false;
     ImVec4 clear_color = ImVec4(0.45f, 0.55f, 0.60f, 1.00f);
+    static char buf[128] = "Hello, World!";
 
     // Main loop
     while (!glfwWindowShouldClose(window))
@@ -473,22 +121,8 @@ int main(int, char**)
         // Generally you may always pass all inputs to dear imgui, and hide them from your application based on those two flags.
         glfwPollEvents();
 
-        // Resize swap chain?
-        if (g_SwapChainRebuild)
-        {
-            int width, height;
-            glfwGetFramebufferSize(window, &width, &height);
-            if (width > 0 && height > 0)
-            {
-                ImGui_ImplVulkan_SetMinImageCount(g_MinImageCount);
-                ImGui_ImplVulkanH_CreateOrResizeWindow(g_Instance, g_PhysicalDevice, g_Device, &g_MainWindowData, g_QueueFamily, g_Allocator, width, height, g_MinImageCount);
-                g_MainWindowData.FrameIndex = 0;
-                g_SwapChainRebuild = false;
-            }
-        }
-
         // Start the Dear ImGui frame
-        ImGui_ImplVulkan_NewFrame();
+        ImGui_ImplOpenGL3_NewFrame();
         ImGui_ImplGlfw_NewFrame();
         ImGui::NewFrame();
 
@@ -498,22 +132,14 @@ int main(int, char**)
 
         // 2. Show a simple window that we create ourselves. We use a Begin/End pair to create a named window.
         {
-            static float f = 0.0f;
+            
-            static int counter = 0;
+            ImGui::Begin("Hello, world!", nullptr, 1);                          // Create a window called "Hello, world!" and append into it.
-
-            ImGui::Begin("Hello, world!");                          // Create a window called "Hello, world!" and append into it.
 
             ImGui::Text("This is some useful text.");               // Display some text (you can use a format strings too)
             ImGui::Checkbox("Demo Window", &show_demo_window);      // Edit bools storing our window open/close state
             ImGui::Checkbox("Another Window", &show_another_window);
 
-            ImGui::SliderFloat("float", &f, 0.0f, 1.0f);            // Edit 1 float using a slider from 0.0f to 1.0f
+            ImGui::InputText("Text Box", buf, sizeof(buf));
-            ImGui::ColorEdit3("clear color", (float*)&clear_color); // Edit 3 floats representing a color
-
-            if (ImGui::Button("Button"))                            // Buttons return true when clicked (most widgets return true when edited/activated)
-                counter++;
-            ImGui::SameLine();
-            ImGui::Text("counter = %d", counter);
 
             ImGui::Text("Application average %.3f ms/frame (%.1f FPS)", 1000.0f / ImGui::GetIO().Framerate, ImGui::GetIO().Framerate);
             ImGui::End();
@@ -523,7 +149,7 @@ int main(int, char**)
         if (show_another_window)
         {
             ImGui::Begin("Another Window", &show_another_window);   // Pass a pointer to our bool variable (the window will have a closing button that will clear the bool when clicked)
-            ImGui::Text("Hello from another window!");
+            ImGui::Text(buf);
             if (ImGui::Button("Close Me"))
                 show_another_window = false;
             ImGui::End();
@@ -531,29 +157,32 @@ int main(int, char**)
 
         // Rendering
         ImGui::Render();
-        ImDrawData* draw_data = ImGui::GetDrawData();
+        int display_w, display_h;
-        const bool is_minimized = (draw_data->DisplaySize.x <= 0.0f || draw_data->DisplaySize.y <= 0.0f);
+        glfwGetFramebufferSize(window, &display_w, &display_h);
-        if (!is_minimized)
+        glViewport(0, 0, display_w, display_h);
+        glClearColor(clear_color.x * clear_color.w, clear_color.y * clear_color.w, clear_color.z * clear_color.w, clear_color.w);
+        glClear(GL_COLOR_BUFFER_BIT);
+        ImGui_ImplOpenGL3_RenderDrawData(ImGui::GetDrawData());
+    	
+        // Update and Render additional Platform Windows
+        // (Platform functions may change the current OpenGL context, so we save/restore it to make it easier to paste this code elsewhere.
+        //  For this specific demo app we could also call glfwMakeContextCurrent(window) directly)
+        if (io.ConfigFlags & ImGuiConfigFlags_ViewportsEnable)
         {
-            wd->ClearValue.color.float32[0] = clear_color.x * clear_color.w;
+            GLFWwindow* backup_current_context = glfwGetCurrentContext();
-            wd->ClearValue.color.float32[1] = clear_color.y * clear_color.w;
+            ImGui::UpdatePlatformWindows();
-            wd->ClearValue.color.float32[2] = clear_color.z * clear_color.w;
+            ImGui::RenderPlatformWindowsDefault();
-            wd->ClearValue.color.float32[3] = clear_color.w;
+            glfwMakeContextCurrent(backup_current_context);
-            FrameRender(wd, draw_data);
-            FramePresent(wd);
         }
+
+        glfwSwapBuffers(window);
     }
 
     // Cleanup
-    err = vkDeviceWaitIdle(g_Device);
+    ImGui_ImplOpenGL3_Shutdown();
-    check_vk_result(err);
-    ImGui_ImplVulkan_Shutdown();
     ImGui_ImplGlfw_Shutdown();
     ImGui::DestroyContext();
 
-    CleanupVulkanWindow();
-    CleanupVulkan();
-
     glfwDestroyWindow(window);
     glfwTerminate();