Merge af6e36f250 into 8e15281d34

This adds the glfwGetGLXFBConfig function for querying the GLXFBConfig
the GLXWindow of a window.

This commit is a squashed and modified version of PR #1925 by knokko.
The following changes were made by elmindreda:

The function signature was changed to handle GLXFBConfig being an opaque
value in core GLX.  The function error checks were fixed and updated.
The struct member name was changed.  The struct member clearing on
context destruction was removed.  All documentation snippets were
updated.

Closes #1925

CONTRIBUTORS.md

@@ -23,6 +23,7 @@ video tutorials.
  - Denis Bernard
  - BiBi
  - Doug Binks
+ - bitb4ker
  - blanco
  - Waris Boonyasiriwat
  - Kyle Brenneman
@@ -123,6 +124,7 @@ video tutorials.
  - Josh Kilmer
  - Byunghoon Kim
  - Cameron King
+ - knokko
  - Peter Knut
  - Christoph Kubisch
  - Yuri Kunde Schlesner

README.md

@@ -9,34 +9,28 @@ GLFW is an Open Source, multi-platform library for OpenGL, OpenGL ES and Vulkan
 application development.  It provides a simple, platform-independent API for
 creating windows, contexts and surfaces, reading input, handling events, etc.
 
-GLFW natively supports Windows, macOS and Linux and other Unix-like systems.  On
-Linux both Wayland and X11 are supported.
+GLFW is written primarily in C99, with parts of macOS support being written in
+Objective-C.
+
+GLFW supports Windows, macOS and Linux, and also works on many other Unix-like
+systems.  On Linux both Wayland and X11 are supported.
 
 GLFW is licensed under the [zlib/libpng
 license](https://www.glfw.org/license.html).
 
 You can [download](https://www.glfw.org/download.html) the latest stable release
-as source or Windows binaries.  Each release starting with 3.0 also has
-a corresponding [annotated tag](https://github.com/glfw/glfw/releases) with
-source and binary archives.
+as source or Windows and macOS binaries.  There are [release
+tags](https://github.com/glfw/glfw/releases) with source and binary archives
+attached for every version since 3.0.
 
 The [documentation](https://www.glfw.org/docs/latest/) is available online and is
-included in all source and binary archives.  See the [release
-notes](https://www.glfw.org/docs/latest/news.html) for new features, caveats and
-deprecations in the latest release.  For more details see the [version
-history](https://www.glfw.org/changelog.html).
-
-The `master` branch is the stable integration branch and _should_ always compile
-and run on all supported platforms, although details of newly added features may
-change until they have been included in a release.  New features and many bug
-fixes live in [other branches](https://github.com/glfw/glfw/branches/all) until
-they are stable enough to merge.
-
-If you are new to GLFW, you may find the
-[tutorial](https://www.glfw.org/docs/latest/quick.html) for GLFW 3 useful.  If
-you have used GLFW 2 in the past, there is a [transition
-guide](https://www.glfw.org/docs/latest/moving.html) for moving to the GLFW
-3 API.
+also included in source and binary archives, except those generated
+automatically by Github.  The documentation contains guides, a tutorial and the
+API reference.  The [release
+notes](https://www.glfw.org/docs/latest/news.html) list the new features,
+caveats and deprecations in the latest release.  The [version
+history](https://www.glfw.org/changelog.html) lists every user-visible change
+for every release.
 
 GLFW exists because of the contributions of [many people](CONTRIBUTORS.md)
 around the world, whether by reporting bugs, providing community support, adding
@@ -44,57 +38,37 @@ features, reviewing or testing code, debugging, proofreading docs, suggesting
 features or fixing bugs.
 
 
-## Compiling GLFW
-
-GLFW is written primarily in C99, with parts of macOS support being written in
-Objective-C.  GLFW itself requires only the headers and libraries for your OS
-and window system.  It does not need any additional headers for context creation
-APIs (WGL, GLX, EGL, NSGL, OSMesa) or rendering APIs (OpenGL, OpenGL ES, Vulkan)
-to enable support for them.
-
-GLFW supports compilation on Windows with Visual C++ (2013 and later) and
-MinGW-w64, on macOS with Clang and on Linux and other Unix-like systems with GCC
-and Clang.  It will likely compile in other environments as well, but this is
-not regularly tested.
-
-There are [pre-compiled binaries](https://www.glfw.org/download.html) available
-for all supported compilers on Windows and macOS.
-
-See the [compilation guide](https://www.glfw.org/docs/latest/compile.html) for
-more information about how to compile GLFW yourself.
-
-
-## Using GLFW
-
-See the [documentation](https://www.glfw.org/docs/latest/) for tutorials, guides
-and the API reference.
-
-
-## Contributing to GLFW
-
-See the [contribution
-guide](https://github.com/glfw/glfw/blob/master/docs/CONTRIBUTING.md) for
-more information.
-
-
 ## System requirements
 
-GLFW supports Windows 7 and later and macOS 10.11 and later.  Linux and other
-Unix-like systems running the X Window System are supported even without
-a desktop environment or modern extensions, although some features require
-a running window or clipboard manager.  The OSMesa backend requires Mesa 6.3.
+GLFW supports Windows 7 and later and macOS 10.11 and later.  On GNOME Wayland,
+window decorations will be very basic unless the
+[libdecor](https://gitlab.freedesktop.org/libdecor/libdecor) package is
+installed.  Linux and other Unix-like systems running X11 are supported even
+without a desktop environment or modern extensions, although some features
+require a clipboard manager or a modern window manager.
 
 See the [compatibility guide](https://www.glfw.org/docs/latest/compat.html)
-in the documentation for more information.
+for more detailed information.
 
 
-## Dependencies
+## Compiling GLFW
 
-GLFW itself needs only CMake 3.16 or later and the headers and libraries for your
-OS and window system.
+GLFW supports compilation with Visual C++ (2013 and later), GCC and Clang.  Both
+Clang-CL and MinGW-w64 are supported.  Other C99 compilers will likely also
+work, but this is not regularly tested.
+
+There are [pre-compiled binaries](https://www.glfw.org/download.html)
+available for Windows and macOS.
+
+GLFW itself needs only CMake and the headers and libraries for your operating
+system and window system.  No other SDKs are required.
+
+See the [compilation guide](https://www.glfw.org/docs/latest/compile.html) for
+more information about compiling GLFW and the exact dependencies required for
+each window system.
 
 The examples and test programs depend on a number of tiny libraries.  These are
-located in the `deps/` directory.
+bundled in the `deps/` directory.  The repository has no submodules.
 
  - [getopt\_port](https://github.com/kimgr/getopt_port/) for examples
    with command-line options
@@ -107,8 +81,33 @@ located in the `deps/` directory.
  - [Nuklear](https://github.com/Immediate-Mode-UI/Nuklear) for test and example UI
  - [stb\_image\_write](https://github.com/nothings/stb) for writing images to disk
 
-The documentation is generated with [Doxygen](https://doxygen.org/) if CMake can
-find that tool.
+The documentation is generated with [Doxygen](https://doxygen.org/) when the
+library is built, provided CMake could find a sufficiently new version of it
+during configuration.
+
+
+## Using GLFW
+
+See the [HTML documentation](https://www.glfw.org/docs/latest/) for a tutorial,
+guides and the API reference.
+
+
+## Contributing to GLFW
+
+See the [contribution
+guide](https://github.com/glfw/glfw/blob/master/docs/CONTRIBUTING.md) for
+more information.
+
+The `master` branch is the stable integration branch and _should_ always compile
+and run on all supported platforms.  Details of a newly added feature,
+including the public API, may change until it has been included in a release.
+
+The `latest` branch is equivalent to the [highest numbered](https://semver.org/)
+release, although it may not always point to the same commit as the tag for that
+release.
+
+The `ci` branch is used to trigger continuous integration jobs for code under
+testing and should never be relied on for any purpose.
 
 
 ## Reporting bugs
@@ -121,8 +120,13 @@ information on what to include when reporting a bug.
 
 ## Changelog since 3.4
 
+ - Added OpenGL and OpenGL ES user contexts for multiple window contexts via
+         `GLFWusercontext`, `glfwCreateUserContext`, `glfwDestroyUserContext`,
+         `glfwMakeUserContextCurrent`, `glfwGetCurrentUserContext` (#1687,#1870)
  - Added `GLFW_UNLIMITED_MOUSE_BUTTONS` input mode that allows mouse buttons beyond
    the limit of the mouse button tokens to be reported (#2423)
+ - Added `glfwGetEGLConfig` function to query the `EGLConfig` of a window (#2045)
+ - Added `glfwGetGLXFBConfig` function to query the `GLXFBConfig` of a window (#1925)
  - Updated minimum CMake version to 3.16 (#2541)
  - Removed support for building with original MinGW (#2540)
  - [Win32] Removed support for Windows XP and Vista (#2505)
@@ -149,7 +153,6 @@ information on what to include when reporting a bug.
  - [EGL] Allowed native access on Wayland with `GLFW_CONTEXT_CREATION_API` set to
    `GLFW_NATIVE_CONTEXT_API` (#2518)
 
-
 ## Contact
 
 On [glfw.org](https://www.glfw.org/) you can find the latest version of GLFW, as

docs/CMakeLists.txt

@@ -1,4 +1,8 @@
 
+# Because of bugs and limitations in its Markdown support, only fairly recent
+# versions of Doxygen can produce acceptable output
+set(MINIMUM_DOXYGEN_VERSION 1.9.8)
+
 # NOTE: The order of this list determines the order of items in the Guides
 #       (i.e. Pages) list in the generated documentation
 set(source_files
@@ -32,10 +36,10 @@ foreach(file IN LISTS source_files)
 endforeach()
 
 set(DOXYGEN_SKIP_DOT TRUE)
-find_package(Doxygen)
+find_package(Doxygen ${MINIMUM_DOXYGEN_VERSION} QUIET)
 
-if (NOT DOXYGEN_FOUND OR DOXYGEN_VERSION VERSION_LESS "1.9.8")
-    message(STATUS "Documentation generation requires Doxygen 1.9.8 or later")
+if (NOT DOXYGEN_FOUND)
+    message(STATUS "Documentation generation requires Doxygen ${MINIMUM_DOXYGEN_VERSION} or later")
 else()
     configure_file(Doxyfile.in Doxyfile @ONLY)
     add_custom_command(OUTPUT "html/index.html"
@@ -46,7 +50,7 @@ else()
                        COMMENT "Generating HTML documentation"
                        VERBATIM)
 
-    add_custom_target(docs ALL SOURCES "html/index.html")
+    add_custom_target(docs ALL SOURCES ${source_files} DEPENDS "html/index.html")
     set_target_properties(docs PROPERTIES FOLDER "GLFW3")
 
     if (GLFW_INSTALL)

docs/Doxyfile.in

@@ -278,13 +278,7 @@ ALIASES                = "thread_safety=@par Thread safety^^" \
                          "analysis=@par Analysis^^" \
                          "reentrancy=@par Reentrancy^^" \
                          "errors=@par Errors^^" \
-                         "callback_signature=@par Callback signature^^" \
-                         "glfw3=__GLFW 3:__" \
-                         "x11=__X11:__" \
-                         "wayland=__Wayland:__" \
-                         "win32=__Windows:__" \
-                         "macos=__macOS:__" \
-                         "linux=__Linux:__"
+                         "callback_signature=@par Callback signature^^"
 
 # Set the OPTIMIZE_OUTPUT_FOR_C tag to YES if your project consists of C sources
 # only. Doxygen will then generate output that is more tailored for C. For

docs/compat.md

@@ -50,10 +50,11 @@ compositing window manager to un-redirect full screen GLFW windows.  If the
 running window manager uses compositing but does not support this property then
 additional copying may be performed for each buffer swap of full screen windows.
 
-GLFW uses the [clipboard manager protocol][ClipboardManager] to push a clipboard
-string (i.e. selection) owned by a GLFW window about to be destroyed to the
-clipboard manager.  If there is no running clipboard manager, the clipboard
-string will be unavailable once the window has been destroyed.
+GLFW uses the [clipboard manager protocol][ClipboardManager] to keep the
+clipboard string availble for the user after the libary has been terminated.  If
+there is no running clipboard manager and the clipboard contents has been set
+with @ref glfwSetClipboardString, the clipboard will be emptied when the library
+is terminated.
 
 [clipboardManager]: https://www.freedesktop.org/wiki/ClipboardManager/
 

docs/context.md

@@ -91,6 +91,28 @@ You can disable context creation by setting the
 Windows without contexts should not be passed to @ref glfwMakeContextCurrent or
 @ref glfwSwapBuffers.  Doing this generates a @ref GLFW_NO_WINDOW_CONTEXT error.
 
+@subsection context_user User contexts for multi context windows
+
+GLFW supports multiple OpenGL or OpenGL ES contexts per window. Providing
+a window with an existing OpenGL or OpenGL ES context has been created further
+user contexts can be created using @ref glfwCreateUserContext with the same
+API sharing the window context objects.
+
+@code
+GLFWusercontext* usercontext = glfwCreateUserContext(window);
+
+/* make the user context current */
+glfwMakeUserContextCurrent(usercontext);
+
+/* make the window context current */
+glfwMakeContextCurrent(window);
+
+/* destroy the user context */
+glfwDestroyUserContext(usercontext);
+
+@endcode
+
+User contexts See also the test program `usercontext`.
 
 ## Current context {#context_current}
 
@@ -121,6 +143,26 @@ error.
  - @ref glfwExtensionSupported
  - @ref glfwGetProcAddress
 
+@subsection context_current_user Current user context
+
+When using [user contexts](@ref context_user) the user context can be
+made current using @ref glfwMakeUserContextCurrent.
+
+@code
+glfwMakeUserContextCurrent(usercontext);
+@endcode
+
+This makes the any window context non-current on the calling thread, such that
+a call to @ref glfwGetCurrentContext will return `NULL`.
+
+The current user context is returned by @ref glfwGetCurrentUserContext.
+
+@code
+GLFWusercontext* usercontext = glfwGetCurrentUserContext();
+@endcode
+
+This will return the current user context or `NULL` if either the main window context
+or no context is current.
 
 ## Buffer swapping {#context_swap}
 

docs/intro.md

@@ -63,7 +63,7 @@ before the application exits.  Modern systems are very good at freeing resources
 allocated by programs that exit, but GLFW sometimes has to change global system
 settings and these might not be restored without termination.
 
-@macos When the library is initialized the main menu and dock icon are created.
+__macOS:__ When the library is initialized the main menu and dock icon are created.
 These are not desirable for a command-line only program.  The creation of the
 main menu and dock icon can be disabled with the @ref GLFW_COCOA_MENUBAR init
 hint.

docs/monitor.md

@@ -255,7 +255,7 @@ hardware gamma correction, which today is typically an approximation of sRGB
 gamma.  This means that setting a perfectly linear ramp, or gamma 1.0, will
 produce the default (usually sRGB-like) behavior.
 
-@note @wayland An application cannot read or modify the monitor gamma ramp.  The
-@ref glfwGetGammaRamp, @ref glfwSetGammaRamp and @ref glfwSetGamma functions
+@note __Wayland:__ An application cannot read or modify the monitor gamma ramp.
+The @ref glfwGetGammaRamp, @ref glfwSetGammaRamp and @ref glfwSetGamma functions
 emit @ref GLFW_FEATURE_UNAVAILABLE.
 

docs/news.md

@@ -5,6 +5,15 @@
 
 ## New features {#features}
 
+### Multiple window contexts {#multiple_window_contexts}
+
+GLFW now provides the ability to create multiple OpenGL and OpenGL ES
+contexts for a given window. Called user contexts, a [GLFWusercontext](@ref context_user)
+can be created using @ref glfwCreateUserContext,
+destroyed using @ref glfwDestroyUserContext, and managed with
+@ref glfwMakeUserContextCurrent and @ref glfwGetCurrentUserContext.
+For more information see the [user context](@ref context_user) documentation.
+
 ### Unlimited mouse buttons {#unlimited_mouse_buttons}
 
 GLFW now has an input mode which allows an unlimited number of mouse buttons to
@@ -14,6 +23,19 @@ values over 8. For compatibility with older versions, the
 @ref GLFW_UNLIMITED_MOUSE_BUTTONS input mode needs to be set to make use of
 this.
 
+
+### EGLConfig native access function {#eglconfig}
+
+GLFW now provides the @ref glfwGetEGLConfig native access function for querying
+the `EGLConfig` of a window that has a `EGLSurface`.
+
+
+### GLXFBConfig native access function {#glxfbconfig}
+
+GLFW now provides the @ref glfwGetGLXFBConfig native access function for
+querying the `GLXFBConfig` of a window that has a `GLXWindow`.
+
+
 ## Caveats {#caveats}
 
 ## Deprecations {#deprecations}
@@ -39,6 +61,10 @@ actively maintained and available on many platforms.
 
 ### New functions {#new_functions}
 
+ - @ref glfwGetEGLConfig
+ - @ref glfwGetGLXFBConfig
+
+
 ### New types {#new_types}
 
 ### New constants {#new_constants}

docs/vulkan.md

@@ -35,7 +35,7 @@ By default, GLFW will load the Vulkan loader dynamically at runtime via its stan
 `vulkan-1.dll` on Windows, `libvulkan.so.1` on Linux and other Unix-like systems and
 `libvulkan.1.dylib` on macOS.
 
-@macos GLFW will also look up and search the `Frameworks` subdirectory of your
+__macOS:__ GLFW will also look up and search the `Frameworks` subdirectory of your
 application bundle.
 
 If your code is using a Vulkan loader with a different name or in a non-standard location
@@ -47,7 +47,7 @@ entry point retrieval.  This prevents GLFW from dynamically loading the Vulkan l
 glfwInitVulkanLoader(vkGetInstanceProcAddr);
 ```
 
-@macos To make your application be redistributable you will need to set up the application
+__macOS:__ To make your application be redistributable you will need to set up the application
 bundle according to the LunarG SDK documentation.  This is explained in more detail in the
 [SDK documentation for macOS](https://vulkan.lunarg.com/doc/sdk/latest/mac/getting_started.html).
 
@@ -186,7 +186,7 @@ check whether any extensions you wish to enable are already in the returned
 array, as it is an error to specify an extension more than once in the
 `VkInstanceCreateInfo` struct.
 
-@macos MoltenVK is (as of July 2022) not yet a fully conformant implementation
+__macOS:__ MoltenVK is (as of July 2022) not yet a fully conformant implementation
 of Vulkan.  As of Vulkan SDK 1.3.216.0, this means you must also enable the
 `VK_KHR_portability_enumeration` instance extension and set the
 `VK_INSTANCE_CREATE_ENUMERATE_PORTABILITY_BIT_KHR` bit in the instance creation

docs/window.md

@@ -363,10 +363,10 @@ which API was used to create the current context may fail if you change this
 hint.  This can be resolved by having it load functions via @ref
 glfwGetProcAddress.
 
-@note @wayland The EGL API _is_ the native context creation API, so this hint
+@note __Wayland:__ The EGL API _is_ the native context creation API, so this hint
 will have no effect.
 
-@note @x11 On some Linux systems, creating contexts via both the native and EGL
+@note __X11:__ On some Linux systems, creating contexts via both the native and EGL
 APIs in a single process will cause the application to segfault.  Stick to one
 API or the other on Linux for now.
 
@@ -400,7 +400,7 @@ requested.  Additionally, OpenGL ES 1.x cannot be returned if 2.0 or later was
 requested, and vice versa.  This is because OpenGL ES 3.x is backward compatible
 with 2.0, but OpenGL ES 2.0 is not backward compatible with 1.x.
 
-@note @macos The OS only supports core profile contexts for OpenGL versions 3.2
+@note __macOS:__ The OS only supports core profile contexts for OpenGL versions 3.2
 and later.  Before creating an OpenGL context of version 3.2 or later you must
 set the [GLFW_OPENGL_PROFILE](@ref GLFW_OPENGL_PROFILE_hint) hint accordingly.
 OpenGL 3.0 and 3.1 contexts are not supported at all on macOS.
@@ -893,7 +893,7 @@ int xpos, ypos;
 glfwGetWindowPos(window, &xpos, &ypos);
 ```
 
-@note @wayland An applications cannot know the positions of its windows or
+@note __Wayland:__ An applications cannot know the positions of its windows or
 whether one has been moved.  The @ref GLFW_POSITION_X and @ref GLFW_POSITION_Y
 window hints are ignored.  The @ref glfwGetWindowPos and @ref glfwSetWindowPos
 functions emit @ref GLFW_FEATURE_UNAVAILABLE.  The window position callback will
@@ -1044,7 +1044,7 @@ You can also get the current iconification state with @ref glfwGetWindowAttrib.
 int iconified = glfwGetWindowAttrib(window, GLFW_ICONIFIED);
 ```
 
-@note @wayland An application cannot know if any of its windows have been
+@note __Wayland:__ An application cannot know if any of its windows have been
 iconified or restore one from iconification.  The @ref glfwRestoreWindow
 function can only restore windows from maximization and the iconify callback
 will not be called.  The [GLFW_ICONIFIED](@ref GLFW_ICONIFIED_attrib) attribute

include/GLFW/glfw3.h

@@ -1228,13 +1228,13 @@ extern "C" {
  *  The top-left to bottom-right diagonal resize/move shape.  This is usually
  *  a diagonal double-headed arrow.
  *
- *  @note @macos This shape is provided by a private system API and may fail
+ *  @note __macOS:__ This shape is provided by a private system API and may fail
  *  with @ref GLFW_CURSOR_UNAVAILABLE in the future.
  *
- *  @note @wayland This shape is provided by a newer standard not supported by
+ *  @note __Wayland:__ This shape is provided by a newer standard not supported by
  *  all cursor themes.
  *
- *  @note @x11 This shape is provided by a newer standard not supported by all
+ *  @note __X11:__ This shape is provided by a newer standard not supported by all
  *  cursor themes.
  */
 #define GLFW_RESIZE_NWSE_CURSOR     0x00036007
@@ -1243,13 +1243,13 @@ extern "C" {
  *  The top-right to bottom-left diagonal resize/move shape.  This is usually
  *  a diagonal double-headed arrow.
  *
- *  @note @macos This shape is provided by a private system API and may fail
+ *  @note __macOS:__ This shape is provided by a private system API and may fail
  *  with @ref GLFW_CURSOR_UNAVAILABLE in the future.
  *
- *  @note @wayland This shape is provided by a newer standard not supported by
+ *  @note __Wayland:__ This shape is provided by a newer standard not supported by
  *  all cursor themes.
  *
- *  @note @x11 This shape is provided by a newer standard not supported by all
+ *  @note __X11:__ This shape is provided by a newer standard not supported by all
  *  cursor themes.
  */
 #define GLFW_RESIZE_NESW_CURSOR     0x00036008
@@ -1264,10 +1264,10 @@ extern "C" {
  *  The operation-not-allowed shape.  This is usually a circle with a diagonal
  *  line through it.
  *
- *  @note @wayland This shape is provided by a newer standard not supported by
+ *  @note __Wayland:__ This shape is provided by a newer standard not supported by
  *  all cursor themes.
  *
- *  @note @x11 This shape is provided by a newer standard not supported by all
+ *  @note __X11:__ This shape is provided by a newer standard not supported by all
  *  cursor themes.
  */
 #define GLFW_NOT_ALLOWED_CURSOR     0x0003600A
@@ -1403,6 +1403,18 @@ typedef struct GLFWmonitor GLFWmonitor;
  */
 typedef struct GLFWwindow GLFWwindow;
 
+/*! @brief Opaque user OpenGL & OpenGL ES context object.
+ *
+ *  Opaque user OpenGL OpenGL ES context object.
+ *
+ *  @see @ref context_user
+ *
+ *  @since Added in version 3.4.
+ *
+ *  @ingroup window
+ */
+typedef struct GLFWusercontext GLFWusercontext;
+
 /*! @brief Opaque cursor object.
  *
  *  Opaque cursor object.
@@ -1629,7 +1641,7 @@ typedef void (* GLFWwindowposfun)(GLFWwindow* window, int xpos, int ypos);
  *  @sa @ref glfwSetWindowSizeCallback
  *
  *  @since Added in version 1.0.
- *  @glfw3 Added window handle parameter.
+ *  __GLFW 3:__ Added window handle parameter.
  *
  *  @ingroup window
  */
@@ -1649,7 +1661,7 @@ typedef void (* GLFWwindowsizefun)(GLFWwindow* window, int width, int height);
  *  @sa @ref glfwSetWindowCloseCallback
  *
  *  @since Added in version 2.5.
- *  @glfw3 Added window handle parameter.
+ *  __GLFW 3:__ Added window handle parameter.
  *
  *  @ingroup window
  */
@@ -1669,7 +1681,7 @@ typedef void (* GLFWwindowclosefun)(GLFWwindow* window);
  *  @sa @ref glfwSetWindowRefreshCallback
  *
  *  @since Added in version 2.5.
- *  @glfw3 Added window handle parameter.
+ *  __GLFW 3:__ Added window handle parameter.
  *
  *  @ingroup window
  */
@@ -1800,7 +1812,7 @@ typedef void (* GLFWwindowcontentscalefun)(GLFWwindow* window, float xscale, flo
  *  @sa @ref glfwSetMouseButtonCallback
  *
  *  @since Added in version 1.0.
- *  @glfw3 Added window handle and modifier mask parameters.
+ *  __GLFW 3:__ Added window handle and modifier mask parameters.
  *
  *  @ingroup input
  */
@@ -1891,7 +1903,7 @@ typedef void (* GLFWscrollfun)(GLFWwindow* window, double xoffset, double yoffse
  *  @sa @ref glfwSetKeyCallback
  *
  *  @since Added in version 1.0.
- *  @glfw3 Added window handle, scancode and modifier mask parameters.
+ *  __GLFW 3:__ Added window handle, scancode and modifier mask parameters.
  *
  *  @ingroup input
  */
@@ -1912,7 +1924,7 @@ typedef void (* GLFWkeyfun)(GLFWwindow* window, int key, int scancode, int actio
  *  @sa @ref glfwSetCharCallback
  *
  *  @since Added in version 2.4.
- *  @glfw3 Added window handle parameter.
+ *  __GLFW 3:__ Added window handle parameter.
  *
  *  @ingroup input
  */
@@ -2020,7 +2032,7 @@ typedef void (* GLFWjoystickfun)(int jid, int event);
  *  @sa @ref glfwGetVideoModes
  *
  *  @since Added in version 1.0.
- *  @glfw3 Added refresh rate member.
+ *  __GLFW 3:__ Added refresh rate member.
  *
  *  @ingroup monitor
  */
@@ -2083,7 +2095,7 @@ typedef struct GLFWgammaramp
  *  @sa @ref window_icon
  *
  *  @since Added in version 2.1.
- *  @glfw3 Removed format and bytes-per-pixel members.
+ *  __GLFW 3:__ Removed format and bytes-per-pixel members.
  *
  *  @ingroup window
  */
@@ -2183,12 +2195,12 @@ typedef struct GLFWallocator
  *  @errors Possible errors include @ref GLFW_PLATFORM_UNAVAILABLE and @ref
  *  GLFW_PLATFORM_ERROR.
  *
- *  @remark @macos This function will change the current directory of the
+ *  @remark __macOS:__ This function will change the current directory of the
  *  application to the `Contents/Resources` subdirectory of the application's
  *  bundle, if present.  This can be disabled with the @ref
  *  GLFW_COCOA_CHDIR_RESOURCES init hint.
  *
- *  @remark @macos This function will create the main menu and dock icon for the
+ *  @remark __macOS:__ This function will create the main menu and dock icon for the
  *  application.  If GLFW finds a `MainMenu.nib` it is loaded and assumed to
  *  contain a menu bar.  Otherwise a minimal menu bar is created manually with
  *  common commands like Hide, Quit and About.  The About entry opens a minimal
@@ -2203,7 +2215,7 @@ typedef struct GLFWallocator
  *  to something other than `wayland` or `x11`, the regular detection mechanism
  *  will be used instead.
  *
- *  @remark @x11 This function will set the `LC_CTYPE` category of the
+ *  @remark __X11:__ This function will set the `LC_CTYPE` category of the
  *  application locale according to the current environment if that category is
  *  still "C".  This is because the "C" locale breaks Unicode text input.
  *
@@ -2679,7 +2691,7 @@ GLFWAPI void glfwGetMonitorWorkarea(GLFWmonitor* monitor, int* xpos, int* ypos,
  *
  *  @errors Possible errors include @ref GLFW_NOT_INITIALIZED.
  *
- *  @remark @win32 On Windows 8 and earlier the physical size is calculated from
+ *  @remark __Win32:__ On Windows 8 and earlier the physical size is calculated from
  *  the current resolution and system DPI instead of querying the monitor EDID data.
  *
  *  @thread_safety This function must only be called from the main thread.
@@ -2713,7 +2725,7 @@ GLFWAPI void glfwGetMonitorPhysicalSize(GLFWmonitor* monitor, int* widthMM, int*
  *  @errors Possible errors include @ref GLFW_NOT_INITIALIZED and @ref
  *  GLFW_PLATFORM_ERROR.
  *
- *  @remark @wayland Fractional scaling information is not yet available for
+ *  @remark __Wayland:__ Fractional scaling information is not yet available for
  *  monitors, so this function only returns integer content scales.
  *
  *  @thread_safety This function must only be called from the main thread.
@@ -2861,7 +2873,7 @@ GLFWAPI GLFWmonitorfun glfwSetMonitorCallback(GLFWmonitorfun callback);
  *  @sa @ref glfwGetVideoMode
  *
  *  @since Added in version 1.0.
- *  @glfw3 Changed to return an array of modes for a specific monitor.
+ *  __GLFW 3:__ Changed to return an array of modes for a specific monitor.
  *
  *  @ingroup monitor
  */
@@ -2915,7 +2927,7 @@ GLFWAPI const GLFWvidmode* glfwGetVideoMode(GLFWmonitor* monitor);
  *  @errors Possible errors include @ref GLFW_NOT_INITIALIZED, @ref GLFW_INVALID_VALUE,
  *  @ref GLFW_PLATFORM_ERROR and @ref GLFW_FEATURE_UNAVAILABLE (see remarks).
  *
- *  @remark @wayland Monitor gamma is a privileged protocol, so this function
+ *  @remark __Wayland:__ Monitor gamma is a privileged protocol, so this function
  *  cannot be implemented and emits @ref GLFW_FEATURE_UNAVAILABLE.
  *
  *  @thread_safety This function must only be called from the main thread.
@@ -2939,7 +2951,7 @@ GLFWAPI void glfwSetGamma(GLFWmonitor* monitor, float gamma);
  *  @errors Possible errors include @ref GLFW_NOT_INITIALIZED, @ref GLFW_PLATFORM_ERROR
  *  and @ref GLFW_FEATURE_UNAVAILABLE (see remarks).
  *
- *  @remark @wayland Monitor gamma is a privileged protocol, so this function
+ *  @remark __Wayland:__ Monitor gamma is a privileged protocol, so this function
  *  cannot be implemented and emits @ref GLFW_FEATURE_UNAVAILABLE while
  *  returning `NULL`.
  *
@@ -2981,9 +2993,9 @@ GLFWAPI const GLFWgammaramp* glfwGetGammaRamp(GLFWmonitor* monitor);
  *  @remark The size of the specified gamma ramp should match the size of the
  *  current ramp for that monitor.
  *
- *  @remark @win32 The gamma ramp size must be 256.
+ *  @remark __Win32:__ The gamma ramp size must be 256.
  *
- *  @remark @wayland Monitor gamma is a privileged protocol, so this function
+ *  @remark __Wayland:__ Monitor gamma is a privileged protocol, so this function
  *  cannot be implemented and emits @ref GLFW_FEATURE_UNAVAILABLE.
  *
  *  @pointer_lifetime The specified gamma ramp is copied before this function
@@ -3159,32 +3171,32 @@ GLFWAPI void glfwWindowHintString(int hint, const char* value);
  *  GLFW_VERSION_UNAVAILABLE, @ref GLFW_FORMAT_UNAVAILABLE, @ref
  *  GLFW_NO_WINDOW_CONTEXT and @ref GLFW_PLATFORM_ERROR.
  *
- *  @remark @win32 Window creation will fail if the Microsoft GDI software
+ *  @remark __Win32:__ Window creation will fail if the Microsoft GDI software
  *  OpenGL implementation is the only one available.
  *
- *  @remark @win32 If the executable has an icon resource named `GLFW_ICON,` it
+ *  @remark __Win32:__ If the executable has an icon resource named `GLFW_ICON,` it
  *  will be set as the initial icon for the window.  If no such icon is present,
  *  the `IDI_APPLICATION` icon will be used instead.  To set a different icon,
  *  see @ref glfwSetWindowIcon.
  *
- *  @remark @win32 The context to share resources with must not be current on
+ *  @remark __Win32:__ The context to share resources with must not be current on
  *  any other thread.
  *
- *  @remark @macos The OS only supports core profile contexts for OpenGL
+ *  @remark __macOS:__ The OS only supports core profile contexts for OpenGL
  *  versions 3.2 and later.  Before creating an OpenGL context of version 3.2 or
  *  later you must set the [GLFW_OPENGL_PROFILE](@ref GLFW_OPENGL_PROFILE_hint)
  *  hint accordingly.  OpenGL 3.0 and 3.1 contexts are not supported at all
  *  on macOS.
  *
- *  @remark @macos The GLFW window has no icon, as it is not a document
+ *  @remark __macOS:__ The GLFW window has no icon, as it is not a document
  *  window, but the dock icon will be the same as the application bundle's icon.
  *  For more information on bundles, see the
  *  [Bundle Programming Guide][bundle-guide] in the Mac Developer Library.
  *
  *  [bundle-guide]: https://developer.apple.com/library/mac/documentation/CoreFoundation/Conceptual/CFBundles/
  *
- *  @remark @macos The window frame will not be rendered at full resolution on
- *  Retina displays unless the
+ *  @remark __macOS:__  The window frame will not be rendered at full resolution
+ *  on Retina displays unless the
  *  [GLFW_SCALE_FRAMEBUFFER](@ref GLFW_SCALE_FRAMEBUFFER_hint)
  *  hint is `GLFW_TRUE` and the `NSHighResolutionCapable` key is enabled in the
  *  application bundle's `Info.plist`.  For more information, see
@@ -3195,11 +3207,11 @@ GLFWAPI void glfwWindowHintString(int hint, const char* value);
  *
  *  [hidpi-guide]: https://developer.apple.com/library/mac/documentation/GraphicsAnimation/Conceptual/HighResolutionOSX/Explained/Explained.html
  *
- *  @remark @macos When activating frame autosaving with
+ *  @remark __macOS:__ When activating frame autosaving with
  *  [GLFW_COCOA_FRAME_NAME](@ref GLFW_COCOA_FRAME_NAME_hint), the specified
  *  window size and position may be overridden by previously saved values.
  *
- *  @remark @wayland GLFW uses [libdecor][] where available to create its window
+ *  @remark __Wayland:__ GLFW uses [libdecor][] where available to create its window
  *  decorations.  This in turn uses server-side XDG decorations where available
  *  and provides high quality client-side decorations on compositors like GNOME.
  *  If both XDG decorations and libdecor are unavailable, GLFW falls back to
@@ -3208,15 +3220,15 @@ GLFWAPI void glfwWindowHintString(int hint, const char* value);
  *
  *  [libdecor]: https://gitlab.freedesktop.org/libdecor/libdecor
  *
- *  @remark @x11 Some window managers will not respect the placement of
+ *  @remark __X11:__ Some window managers will not respect the placement of
  *  initially hidden windows.
  *
- *  @remark @x11 Due to the asynchronous nature of X11, it may take a moment for
+ *  @remark __X11:__ Due to the asynchronous nature of X11, it may take a moment for
  *  a window to reach its requested state.  This means you may not be able to
  *  query the final size, position or other attributes directly after window
  *  creation.
  *
- *  @remark @x11 The class part of the `WM_CLASS` window property will by
+ *  @remark __X11:__ The class part of the `WM_CLASS` window property will by
  *  default be set to the window title passed to this function.  The instance
  *  part will use the contents of the `RESOURCE_NAME` environment variable, if
  *  present and not empty, or fall back to the window title.  Set the
@@ -3349,7 +3361,7 @@ GLFWAPI const char* glfwGetWindowTitle(GLFWwindow* window);
  *  @errors Possible errors include @ref GLFW_NOT_INITIALIZED and @ref
  *  GLFW_PLATFORM_ERROR.
  *
- *  @remark @macos The window title will not be updated until the next time you
+ *  @remark __macOS:__ The window title will not be updated until the next time you
  *  process events.
  *
  *  @thread_safety This function must only be called from the main thread.
@@ -3358,7 +3370,7 @@ GLFWAPI const char* glfwGetWindowTitle(GLFWwindow* window);
  *  @sa @ref glfwGetWindowTitle
  *
  *  @since Added in version 1.0.
- *  @glfw3 Added window handle parameter.
+ *  __GLFW 3:__ Added window handle parameter.
  *
  *  @ingroup window
  */
@@ -3392,14 +3404,14 @@ GLFWAPI void glfwSetWindowTitle(GLFWwindow* window, const char* title);
  *  @pointer_lifetime The specified image data is copied before this function
  *  returns.
  *
- *  @remark @macos Regular windows do not have icons on macOS.  This function
+ *  @remark __macOS:__ Regular windows do not have icons on macOS.  This function
  *  will emit @ref GLFW_FEATURE_UNAVAILABLE.  The dock icon will be the same as
  *  the application bundle's icon.  For more information on bundles, see the
  *  [Bundle Programming Guide][bundle-guide] in the Mac Developer Library.
  *
  *  [bundle-guide]: https://developer.apple.com/library/mac/documentation/CoreFoundation/Conceptual/CFBundles/
  *
- *  @remark @wayland There is no existing protocol to change an icon, the
+ *  @remark __Wayland:__ There is no existing protocol to change an icon, the
  *  window will thus inherit the one defined in the application's desktop file.
  *  This function will emit @ref GLFW_FEATURE_UNAVAILABLE.
  *
@@ -3430,7 +3442,7 @@ GLFWAPI void glfwSetWindowIcon(GLFWwindow* window, int count, const GLFWimage* i
  *  @errors Possible errors include @ref GLFW_NOT_INITIALIZED, @ref
  *  GLFW_PLATFORM_ERROR and @ref GLFW_FEATURE_UNAVAILABLE (see remarks).
  *
- *  @remark @wayland Window positions are not currently part of any common
+ *  @remark __Wayland:__ Window positions are not currently part of any common
  *  Wayland protocol, so this function cannot be implemented and will emit @ref
  *  GLFW_FEATURE_UNAVAILABLE.
  *
@@ -3464,7 +3476,7 @@ GLFWAPI void glfwGetWindowPos(GLFWwindow* window, int* xpos, int* ypos);
  *  @errors Possible errors include @ref GLFW_NOT_INITIALIZED, @ref
  *  GLFW_PLATFORM_ERROR and @ref GLFW_FEATURE_UNAVAILABLE (see remarks).
  *
- *  @remark @wayland Window positions are not currently part of any common
+ *  @remark __Wayland:__ Window positions are not currently part of any common
  *  Wayland protocol, so this function cannot be implemented and will emit @ref
  *  GLFW_FEATURE_UNAVAILABLE.
  *
@@ -3474,7 +3486,7 @@ GLFWAPI void glfwGetWindowPos(GLFWwindow* window, int* xpos, int* ypos);
  *  @sa @ref glfwGetWindowPos
  *
  *  @since Added in version 1.0.
- *  @glfw3 Added window handle parameter.
+ *  __GLFW 3:__ Added window handle parameter.
  *
  *  @ingroup window
  */
@@ -3504,7 +3516,7 @@ GLFWAPI void glfwSetWindowPos(GLFWwindow* window, int xpos, int ypos);
  *  @sa @ref glfwSetWindowSize
  *
  *  @since Added in version 1.0.
- *  @glfw3 Added window handle parameter.
+ *  __GLFW 3:__ Added window handle parameter.
  *
  *  @ingroup window
  */
@@ -3539,7 +3551,7 @@ GLFWAPI void glfwGetWindowSize(GLFWwindow* window, int* width, int* height);
  *  @remark If you set size limits and an aspect ratio that conflict, the
  *  results are undefined.
  *
- *  @remark @wayland The size limits will not be applied until the window is
+ *  @remark __Wayland:__ The size limits will not be applied until the window is
  *  actually resized, either by the user or by the compositor.
  *
  *  @thread_safety This function must only be called from the main thread.
@@ -3582,7 +3594,7 @@ GLFWAPI void glfwSetWindowSizeLimits(GLFWwindow* window, int minwidth, int minhe
  *  @remark If you set size limits and an aspect ratio that conflict, the
  *  results are undefined.
  *
- *  @remark @wayland The aspect ratio will not be applied until the window is
+ *  @remark __Wayland:__ The aspect ratio will not be applied until the window is
  *  actually resized, either by the user or by the compositor.
  *
  *  @thread_safety This function must only be called from the main thread.
@@ -3628,7 +3640,7 @@ GLFWAPI void glfwSetWindowAspectRatio(GLFWwindow* window, int numer, int denom);
  *  @sa @ref glfwSetWindowMonitor
  *
  *  @since Added in version 1.0.
- *  @glfw3 Added window handle parameter.
+ *  __GLFW 3:__ Added window handle parameter.
  *
  *  @ingroup window
  */
@@ -3778,7 +3790,7 @@ GLFWAPI float glfwGetWindowOpacity(GLFWwindow* window);
  *  @errors Possible errors include @ref GLFW_NOT_INITIALIZED, @ref
  *  GLFW_PLATFORM_ERROR and @ref GLFW_FEATURE_UNAVAILABLE (see remarks).
  *
- *  @remark @wayland There is no way to set an opacity factor for a window.
+ *  @remark __Wayland:__ There is no way to set an opacity factor for a window.
  *  This function will emit @ref GLFW_FEATURE_UNAVAILABLE.
  *
  *  @thread_safety This function must only be called from the main thread.
@@ -3814,7 +3826,7 @@ GLFWAPI void glfwSetWindowOpacity(GLFWwindow* window, float opacity);
  *  @sa @ref glfwMaximizeWindow
  *
  *  @since Added in version 2.1.
- *  @glfw3 Added window handle parameter.
+ *  __GLFW 3:__ Added window handle parameter.
  *
  *  @ingroup window
  */
@@ -3834,9 +3846,9 @@ GLFWAPI void glfwIconifyWindow(GLFWwindow* window);
  *  @errors Possible errors include @ref GLFW_NOT_INITIALIZED and @ref
  *  GLFW_PLATFORM_ERROR.
  *
- *  @remark @wayland Restoring a window from maximization is not currently part
- *  of any common Wayland protocol, so this function can only restore windows
- *  from maximization.
+ *  @remark __Wayland:__ Restoring a window from maximization is not currently
+ *  part of any common Wayland protocol, so this function can only restore
+ *  windows from maximization.
  *
  *  @thread_safety This function must only be called from the main thread.
  *
@@ -3845,7 +3857,7 @@ GLFWAPI void glfwIconifyWindow(GLFWwindow* window);
  *  @sa @ref glfwMaximizeWindow
  *
  *  @since Added in version 2.1.
- *  @glfw3 Added window handle parameter.
+ *  __GLFW 3:__ Added window handle parameter.
  *
  *  @ingroup window
  */
@@ -3892,7 +3904,7 @@ GLFWAPI void glfwMaximizeWindow(GLFWwindow* window);
  *  @errors Possible errors include @ref GLFW_NOT_INITIALIZED and @ref
  *  GLFW_PLATFORM_ERROR.
  *
- *  @remark @wayland Because Wayland wants every frame of the desktop to be
+ *  @remark __Wayland:__ Because Wayland wants every frame of the desktop to be
  *  complete, this function does not immediately make the window visible.
  *  Instead it will become visible the next time the window framebuffer is
  *  updated after this call.
@@ -3955,7 +3967,7 @@ GLFWAPI void glfwHideWindow(GLFWwindow* window);
  *  @errors Possible errors include @ref GLFW_NOT_INITIALIZED and @ref
  *  GLFW_PLATFORM_ERROR.
  *
- *  @remark @wayland The compositor will likely ignore focus requests unless
+ *  @remark __Wayland:__ The compositor will likely ignore focus requests unless
  *  another window created by the same application already has input focus.
  *
  *  @thread_safety This function must only be called from the main thread.
@@ -3983,7 +3995,7 @@ GLFWAPI void glfwFocusWindow(GLFWwindow* window);
  *  @errors Possible errors include @ref GLFW_NOT_INITIALIZED and @ref
  *  GLFW_PLATFORM_ERROR.
  *
- *  @remark @macos Attention is requested to the application as a whole, not the
+ *  @remark __macOS:__ Attention is requested to the application as a whole, not the
  *  specific window.
  *
  *  @thread_safety This function must only be called from the main thread.
@@ -4058,7 +4070,7 @@ GLFWAPI GLFWmonitor* glfwGetWindowMonitor(GLFWwindow* window);
  *  affected by any resizing or mode switching, although you may need to update
  *  your viewport if the framebuffer size has changed.
  *
- *  @remark @wayland Window positions are not currently part of any common
+ *  @remark __Wayland:__ Window positions are not currently part of any common
  *  Wayland protocol.  The window position arguments are ignored.
  *
  *  @thread_safety This function must only be called from the main thread.
@@ -4096,7 +4108,7 @@ GLFWAPI void glfwSetWindowMonitor(GLFWwindow* window, GLFWmonitor* monitor, int
  *  errors.  However, this function should not fail as long as it is passed
  *  valid arguments and the library has been [initialized](@ref intro_init).
  *
- *  @remark @wayland Checking whether a window is iconified is not currently
+ *  @remark __Wayland:__ Checking whether a window is iconified is not currently
  *  part of any common Wayland protocol, so the @ref GLFW_ICONIFIED attribute
  *  cannot be implemented and is always `GLFW_FALSE`.
  *
@@ -4140,7 +4152,7 @@ GLFWAPI int glfwGetWindowAttrib(GLFWwindow* window, int attrib);
  *  @remark Calling @ref glfwGetWindowAttrib will always return the latest
  *  value, even if that value is ignored by the current mode of the window.
  *
- *  @remark @wayland The [GLFW_FLOATING](@ref GLFW_FLOATING_attrib) window attribute is
+ *  @remark __Wayland:__ The [GLFW_FLOATING](@ref GLFW_FLOATING_attrib) window attribute is
  *  not supported.  Setting this will emit @ref GLFW_FEATURE_UNAVAILABLE.
  *
  *  @thread_safety This function must only be called from the main thread.
@@ -4220,7 +4232,7 @@ GLFWAPI void* glfwGetWindowUserPointer(GLFWwindow* window);
  *
  *  @errors Possible errors include @ref GLFW_NOT_INITIALIZED.
  *
- *  @remark @wayland This callback will not be called.  The Wayland protocol
+ *  @remark __Wayland:__ This callback will not be called.  The Wayland protocol
  *  provides no way to be notified of when a window is moved.
  *
  *  @thread_safety This function must only be called from the main thread.
@@ -4259,7 +4271,7 @@ GLFWAPI GLFWwindowposfun glfwSetWindowPosCallback(GLFWwindow* window, GLFWwindow
  *  @sa @ref window_size
  *
  *  @since Added in version 1.0.
- *  @glfw3 Added window handle parameter and return value.
+ *  __GLFW 3:__ Added window handle parameter and return value.
  *
  *  @ingroup window
  */
@@ -4291,7 +4303,7 @@ GLFWAPI GLFWwindowsizefun glfwSetWindowSizeCallback(GLFWwindow* window, GLFWwind
  *
  *  @errors Possible errors include @ref GLFW_NOT_INITIALIZED.
  *
- *  @remark @macos Selecting Quit from the application menu will trigger the
+ *  @remark __macOS:__ Selecting Quit from the application menu will trigger the
  *  close callback for all windows.
  *
  *  @thread_safety This function must only be called from the main thread.
@@ -4299,7 +4311,7 @@ GLFWAPI GLFWwindowsizefun glfwSetWindowSizeCallback(GLFWwindow* window, GLFWwind
  *  @sa @ref window_close
  *
  *  @since Added in version 2.5.
- *  @glfw3 Added window handle parameter and return value.
+ *  __GLFW 3:__ Added window handle parameter and return value.
  *
  *  @ingroup window
  */
@@ -4335,7 +4347,7 @@ GLFWAPI GLFWwindowclosefun glfwSetWindowCloseCallback(GLFWwindow* window, GLFWwi
  *  @sa @ref window_refresh
  *
  *  @since Added in version 2.5.
- *  @glfw3 Added window handle parameter and return value.
+ *  __GLFW 3:__ Added window handle parameter and return value.
  *
  *  @ingroup window
  */
@@ -4396,7 +4408,7 @@ GLFWAPI GLFWwindowfocusfun glfwSetWindowFocusCallback(GLFWwindow* window, GLFWwi
  *
  *  @errors Possible errors include @ref GLFW_NOT_INITIALIZED.
  *
- *  @remark @wayland This callback will not be called.  The Wayland protocol
+ *  @remark __Wayland:__ This callback will not be called.  The Wayland protocol
  *  provides no way to be notified of when a window is iconified, and no way to
  *  check whether a window is currently iconified.
  *
@@ -4905,7 +4917,7 @@ GLFWAPI int glfwGetKeyScancode(int key);
  *  @sa @ref input_key
  *
  *  @since Added in version 1.0.
- *  @glfw3 Added window handle parameter.
+ *  __GLFW 3:__ Added window handle parameter.
  *
  *  @ingroup input
  */
@@ -4937,7 +4949,7 @@ GLFWAPI int glfwGetKey(GLFWwindow* window, int key);
  *  @sa @ref input_mouse_button
  *
  *  @since Added in version 1.0.
- *  @glfw3 Added window handle parameter.
+ *  __GLFW 3:__ Added window handle parameter.
  *
  *  @ingroup input
  */
@@ -5007,7 +5019,7 @@ GLFWAPI void glfwGetCursorPos(GLFWwindow* window, double* xpos, double* ypos);
  *  @errors Possible errors include @ref GLFW_NOT_INITIALIZED, @ref
  *  GLFW_PLATFORM_ERROR and @ref GLFW_FEATURE_UNAVAILABLE (see remarks).
  *
- *  @remark @wayland This function will only work when the cursor mode is
+ *  @remark __Wayland:__ This function will only work when the cursor mode is
  *  `GLFW_CURSOR_DISABLED`, otherwise it will emit @ref GLFW_FEATURE_UNAVAILABLE.
  *
  *  @thread_safety This function must only be called from the main thread.
@@ -5205,7 +5217,7 @@ GLFWAPI void glfwSetCursor(GLFWwindow* window, GLFWcursor* cursor);
  *  @sa @ref input_key
  *
  *  @since Added in version 1.0.
- *  @glfw3 Added window handle parameter and return value.
+ *  __GLFW 3:__ Added window handle parameter and return value.
  *
  *  @ingroup input
  */
@@ -5248,7 +5260,7 @@ GLFWAPI GLFWkeyfun glfwSetKeyCallback(GLFWwindow* window, GLFWkeyfun callback);
  *  @sa @ref input_char
  *
  *  @since Added in version 2.4.
- *  @glfw3 Added window handle parameter and return value.
+ *  __GLFW 3:__ Added window handle parameter and return value.
  *
  *  @ingroup input
  */
@@ -5332,7 +5344,7 @@ GLFWAPI GLFWcharmodsfun glfwSetCharModsCallback(GLFWwindow* window, GLFWcharmods
  *  @sa @ref input_mouse_button
  *
  *  @since Added in version 1.0.
- *  @glfw3 Added window handle parameter and return value.
+ *  __GLFW 3:__ Added window handle parameter and return value.
  *
  *  @ingroup input
  */
@@ -5562,7 +5574,7 @@ GLFWAPI const float* glfwGetJoystickAxes(int jid, int* count);
  *  @sa @ref joystick_button
  *
  *  @since Added in version 2.2.
- *  @glfw3 Changed to return a dynamic array.
+ *  __GLFW 3:__ Changed to return a dynamic array.
  *
  *  @ingroup input
  */
@@ -5926,7 +5938,7 @@ GLFWAPI int glfwGetGamepadState(int jid, GLFWgamepadstate* state);
  *  @errors Possible errors include @ref GLFW_NOT_INITIALIZED and @ref
  *  GLFW_PLATFORM_ERROR.
  *
- *  @remark @win32 The clipboard on Windows has a single global lock for reading and
+ *  @remark __Win32:__ The clipboard on Windows has a single global lock for reading and
  *  writing.  GLFW tries to acquire it a few times, which is almost always enough.  If it
  *  cannot acquire the lock then this function emits @ref GLFW_PLATFORM_ERROR and returns.
  *  It is safe to try this multiple times.
@@ -5959,7 +5971,7 @@ GLFWAPI void glfwSetClipboardString(GLFWwindow* window, const char* string);
  *  @errors Possible errors include @ref GLFW_NOT_INITIALIZED, @ref
  *  GLFW_FORMAT_UNAVAILABLE and @ref GLFW_PLATFORM_ERROR.
  *
- *  @remark @win32 The clipboard on Windows has a single global lock for reading and
+ *  @remark __Win32:__ The clipboard on Windows has a single global lock for reading and
  *  writing.  GLFW tries to acquire it a few times, which is almost always enough.  If it
  *  cannot acquire the lock then this function emits @ref GLFW_PLATFORM_ERROR and returns.
  *  It is safe to try this multiple times.
@@ -6093,6 +6105,9 @@ GLFWAPI uint64_t glfwGetTimerFrequency(void);
  *  thread can have only a single current context at a time.  Making a context
  *  current detaches any previously current context on the calling thread.
  *
+ *  Making a context of a window current on a given thread will detach
+ *  any user context which is current on that thread and visa versa.
+ *
  *  When moving a context between threads, you must detach it (make it
  *  non-current) on the old thread before making it current on the new one.
  *
@@ -6120,6 +6135,9 @@ GLFWAPI uint64_t glfwGetTimerFrequency(void);
  *
  *  @sa @ref context_current
  *  @sa @ref glfwGetCurrentContext
+ *  @sa @ref context_current_user
+ *  @sa @ref glfwMakeUserContextCurrent
+ *  @sa @ref glfwGetCurrentUserContext
  *
  *  @since Added in version 3.0.
  *
@@ -6176,7 +6194,7 @@ GLFWAPI GLFWwindow* glfwGetCurrentContext(void);
  *  @sa @ref glfwSwapInterval
  *
  *  @since Added in version 1.0.
- *  @glfw3 Added window handle parameter.
+ *  __GLFW 3:__ Added window handle parameter.
  *
  *  @ingroup window
  */
@@ -6308,6 +6326,147 @@ GLFWAPI int glfwExtensionSupported(const char* extension);
  */
 GLFWAPI GLFWglproc glfwGetProcAddress(const char* procname);
 
+/*! @brief Create a new OpenGL or OpenGL ES user context for a window
+ *
+ *  This function creates a new OpenGL or OpenGL ES user context for a
+ *  window, which can be used to call OpenGL or OpenGL ES functions on
+ *  another thread. For a valid user context the window must be created
+ *  with a [GLFW_CLIENT_API](@ref GLFW_CLIENT_API_hint) other than
+ *  `GLFW_NO_API`.
+ *
+ *  User context creation uses the window context and framebuffer related
+ *  hints to ensure a valid context is created for that window, these hints
+ *  should be the same at the time of user context creation as when the
+ *  window was created.
+ *
+ *  Contexts share resources with the window context and with any other
+ *  user context created for that window.
+ *
+ *  @errors Possible errors include @ref GLFW_NOT_INITIALIZED,
+ *  @ref GLFW_INVALID_VALUE the window parameter is `NULL`,
+ *  @ref GLFW_NO_WINDOW_CONTEXT if the window has no OpenGL or
+ *  OpenGL US context, and @ref GLFW_PLATFORM_ERROR.
+ *
+ *  @param[in] window The Window for which the user context is to be
+ *  created.
+ *  @return The handle of the user context created, or `NULL` if an
+ *  [error](@ref error_handling) occurred.
+ *
+ *  @thread_safety This function must only be called from the main thread.
+ *
+ *  @sa @ref context_user
+ *  @sa @ref usercontext_creation
+ *  @sa @ref glfwDestroyUserContext
+ *  @sa @ref window_creation
+ *  @sa @ref glfwCreateWindow
+ *  @sa @ref glfwDestroyWindow
+ *
+ *  @since Added in version 3.4.
+ *
+ *  @ingroup context
+ */
+GLFWAPI GLFWusercontext* glfwCreateUserContext(GLFWwindow* window);
+
+/*! @brief Destroys the specified user context
+ *
+ *  This function destroys the specified user context.
+ *  User contexts should be destroyed before destroying the
+ *  window they were made with.
+ *
+ *  If the user context is current on the main thread, it is
+ *  detached before being destroyed.
+ *
+ *  @param[in] context The user context to destroy.
+ *
+ *  @errors Possible errors include @ref GLFW_NOT_INITIALIZED and @ref
+ *  GLFW_PLATFORM_ERROR.
+ *
+ *  @note The user context must not be current on any other
+ *  thread when this function is called.
+ *
+ *  @reentrancy This function must not be called from a callback.
+ *
+ *  @thread_safety This function must only be called from the main thread.
+ *
+ *  @sa @ref context_user
+ *  @sa @ref usercontext_creation
+ *  @sa @ref glfwCreateUserContext
+ *  @sa @ref window_creation
+ *  @sa @ref glfwCreateWindow
+ *  @sa @ref glfwDestroyWindow
+ *
+ *  @since Added in version 3.4.
+ *
+ *  @ingroup context
+ */
+GLFWAPI void glfwDestroyUserContext(GLFWusercontext* context);
+
+/*! @brief Makes the user context current for the calling thread.
+ *
+ *  This function makes the OpenGL or OpenGL ES context of the specified user
+ *  context current on the calling thread.  A context must only be made current on
+ *  a single thread at a time and each thread can have only a single current
+ *  context at a time.
+ *
+ *  Making a user context current on a given thread will detach the context of
+ *  any window which is current on that thread and visa versa.
+ *
+ *  When moving a context between threads, you must make it non-current on the
+ *  old thread before making it current on the new one.
+ *
+ *  By default, making a context non-current implicitly forces a pipeline flush.
+ *  On machines that support `GL_KHR_context_flush_control`, you can control
+ *  whether a context performs this flush by setting the
+ *  [GLFW_CONTEXT_RELEASE_BEHAVIOR](@ref GLFW_CONTEXT_RELEASE_BEHAVIOR_hint)
+ *  hint.
+ *
+ *  @param[in] context The user context to make current, or `NULL` to
+ *  detach the current context.
+ *
+ *  @errors Possible errors include @ref GLFW_NOT_INITIALIZED,
+ *  and @ref GLFW_PLATFORM_ERROR.
+ *
+ *  @thread_safety This function may be called from any thread.
+ *
+ *  @sa @ref context_user
+ *  @sa @ref context_current_user
+ *  @sa @ref glfwGetCurrentUserContext
+ *  @sa @ref context_current
+ *  @sa @ref glfwMakeContextCurrent
+ *  @sa @ref glfwGetCurrentContext
+ *
+ *  @since Added in version 3.4.
+ *
+ *  @ingroup context
+ */
+GLFWAPI void glfwMakeUserContextCurrent(GLFWusercontext* context);
+
+/*! @brief Returns the current OpenGL or OpenGL ES user context
+ *
+ *  This function returns the user context which is current
+ *  on the calling thread.
+ *
+ *  @return The user context current, or `NULL` if no user context
+ *  is current.
+ *
+ *  @errors Possible errors include @ref GLFW_NOT_INITIALIZED.
+ *
+ *  @thread_safety This function may be called from any thread.
+ *
+ *  @sa @ref context_user
+ *  @sa @ref context_current_user
+ *  @sa @ref glfwMakeUserContextCurrent
+ *  @sa @ref context_current
+ *  @sa @ref glfwMakeContextCurrent
+ *  @sa @ref glfwGetCurrentContext
+ *
+ *  @since Added in version 3.4.
+ *
+ *  @ingroup context
+ */
+GLFWAPI GLFWusercontext* glfwGetCurrentUserContext(void);
+
+
 /*! @brief Returns whether the Vulkan loader and an ICD have been found.
  *
  *  This function returns whether the Vulkan loader and any minimally functional
@@ -6443,7 +6602,7 @@ GLFWAPI GLFWvkproc glfwGetInstanceProcAddress(VkInstance instance, const char* p
  *  @errors Possible errors include @ref GLFW_NOT_INITIALIZED, @ref
  *  GLFW_API_UNAVAILABLE and @ref GLFW_PLATFORM_ERROR.
  *
- *  @remark @macos This function currently always returns `GLFW_TRUE`, as the
+ *  @remark __macOS:__ This function currently always returns `GLFW_TRUE`, as the
  *  `VK_MVK_macos_surface` and `VK_EXT_metal_surface` extensions do not provide
  *  a `vkGetPhysicalDevice*PresentationSupport` type function.
  *
@@ -6501,15 +6660,15 @@ GLFWAPI int glfwGetPhysicalDevicePresentationSupport(VkInstance instance, VkPhys
  *  @ref glfwVulkanSupported and @ref glfwGetRequiredInstanceExtensions should
  *  eliminate almost all occurrences of these errors.
  *
- *  @remark @macos GLFW prefers the `VK_EXT_metal_surface` extension, with the
+ *  @remark __macOS:__ GLFW prefers the `VK_EXT_metal_surface` extension, with the
  *  `VK_MVK_macos_surface` extension as a fallback.  The name of the selected
  *  extension, if any, is included in the array returned by @ref
  *  glfwGetRequiredInstanceExtensions.
  *
- *  @remark @macos This function creates and sets a `CAMetalLayer` instance for
+ *  @remark __macOS:__ This function creates and sets a `CAMetalLayer` instance for
  *  the window content view, which is required for MoltenVK to function.
  *
- *  @remark @x11 By default GLFW prefers the `VK_KHR_xcb_surface` extension,
+ *  @remark __X11:__ By default GLFW prefers the `VK_KHR_xcb_surface` extension,
  *  with the `VK_KHR_xlib_surface` extension as a fallback.  You can make
  *  `VK_KHR_xlib_surface` the preferred extension by setting the
  *  [GLFW_X11_XCB_VULKAN_SURFACE](@ref GLFW_X11_XCB_VULKAN_SURFACE_hint) init

include/GLFW/glfw3native.h

@@ -478,6 +478,29 @@ GLFWAPI GLXContext glfwGetGLXContext(GLFWwindow* window);
  *  @ingroup native
  */
 GLFWAPI GLXWindow glfwGetGLXWindow(GLFWwindow* window);
+
+/*! @brief Retrieves the `GLXFBConfig` of the specified window's `GLXWindow`.
+ *
+ *  @param[in] window The window whose `GLXWindow` to query.
+ *  @param[out] config The `GLXFBConfig` of the window `GLXWindow`, if available.
+ *  @return `GLFW_TRUE` if successful, or `GLFW_FALSE` if an
+ *  [error](@ref error_handling) occurred.
+ *
+ *  @errors Possible errors include @ref GLFW_NOT_INITIALIZED, @ref
+ *  GLFW_NO_WINDOW_CONTEXT and @ref GLFW_PLATFORM_UNAVAILABLE.
+ *
+ *  @remark `GLXFBConfig` is an opaque type.  Unlike other GLFW functions, the
+ *  @p config out parameter is not cleared on error, as core GLX does not define
+ *  any invalid value.
+ *
+ *  @thread_safety This function may be called from any thread.  Access is not
+ *  synchronized.
+ *
+ *  @since Added in version 3.5
+ *
+ *  @ingroup native
+ */
+GLFWAPI int glfwGetGLXFBConfig(GLFWwindow* window, GLXFBConfig* config);
 #endif
 
 #if defined(GLFW_EXPOSE_NATIVE_WAYLAND)
@@ -586,6 +609,29 @@ GLFWAPI EGLContext glfwGetEGLContext(GLFWwindow* window);
  *  @ingroup native
  */
 GLFWAPI EGLSurface glfwGetEGLSurface(GLFWwindow* window);
+
+/*! @brief Retrieves the `EGLConfig` of the specified window's `EGLSurface`.
+ *
+ *  @param[in] window The window whose `EGLSurface` to query.
+ *  @param[out] config The `EGLConfig` of the window `EGLSurface`, if available.
+ *  @return `GLFW_TRUE` if successful, or `GLFW_FALSE` if an
+ *  [error](@ref error_handling) occurred.
+ *
+ *  @errors Possible errors include @ref GLFW_NOT_INITIALIZED and @ref
+ *  GLFW_NO_WINDOW_CONTEXT.
+ *
+ *  @remark `EGLConfig` is an opaque type.  Unlike other GLFW functions, the @p
+ *  config out parameter is not cleared on error, as core EGL does not define
+ *  any invalid value.
+ *
+ *  @thread_safety This function may be called from any thread.  Access is not
+ *  synchronized.
+ *
+ *  @since Added in version 3.5.
+ *
+ *  @ingroup native
+ */
+GLFWAPI int glfwGetEGLConfig(GLFWwindow* window, EGLConfig* config);
 #endif
 
 #if defined(GLFW_EXPOSE_NATIVE_OSMESA)

src/cocoa_init.m

@@ -559,6 +559,7 @@ GLFWbool _glfwConnectCocoa(int platformID, _GLFWplatform* platform)
         .waitEvents = _glfwWaitEventsCocoa,
         .waitEventsTimeout = _glfwWaitEventsTimeoutCocoa,
         .postEmptyEvent = _glfwPostEmptyEventCocoa,
+        .createUserContext = _glfwCreateUserContextCocoa,
         .getEGLPlatform = _glfwGetEGLPlatformCocoa,
         .getEGLNativeDisplay = _glfwGetEGLNativeDisplayCocoa,
         .getEGLNativeWindow = _glfwGetEGLNativeWindowCocoa,

src/cocoa_platform.h

@@ -107,6 +107,7 @@ typedef VkResult (APIENTRY *PFN_vkCreateMetalSurfaceEXT)(VkInstance,const VkMeta
 
 #define GLFW_NSGL_CONTEXT_STATE         _GLFWcontextNSGL nsgl;
 #define GLFW_NSGL_LIBRARY_CONTEXT_STATE _GLFWlibraryNSGL nsgl;
+#define GLFW_NSGL_USER_CONTEXT_STATE    _GLFWusercontextNSGL nsgl;
 
 // HIToolbox.framework pointer typedefs
 #define kTISPropertyUnicodeKeyLayoutData _glfw.ns.tis.kPropertyUnicodeKeyLayoutData
@@ -134,6 +135,14 @@ typedef struct _GLFWlibraryNSGL
     CFBundleRef     framework;
 } _GLFWlibraryNSGL;
 
+// NSGL-specific per usercontext data
+//
+typedef struct _GLFWusercontextNSGL
+{
+    id                object;
+
+} _GLFWusercontextNSGL;
+
 // Cocoa-specific per-window data
 //
 typedef struct _GLFWwindowNS
@@ -300,3 +309,5 @@ GLFWbool _glfwCreateContextNSGL(_GLFWwindow* window,
                                 const _GLFWfbconfig* fbconfig);
 void _glfwDestroyContextNSGL(_GLFWwindow* window);
 
+_GLFWusercontext* _glfwCreateUserContextCocoa(_GLFWwindow* window);
+_GLFWusercontext* _glfwCreateUserContextNSGL(_GLFWwindow* window);

src/cocoa_window.m

@@ -884,7 +884,7 @@ static GLFWbool createNativeWindow(_GLFWwindow* window,
 
     [window->ns.object setContentView:window->ns.view];
     [window->ns.object makeFirstResponder:window->ns.view];
-    [window->ns.object setTitle:@(wndconfig->title)];
+    [window->ns.object setTitle:@(window->title)];
     [window->ns.object setDelegate:window->ns.delegate];
     [window->ns.object setAcceptsMouseMovedEvents:YES];
     [window->ns.object setRestorable:NO];
@@ -2021,6 +2021,25 @@ VkResult _glfwCreateWindowSurfaceCocoa(VkInstance instance,
 }
 
 
+_GLFWusercontext* _glfwCreateUserContextCocoa(_GLFWwindow* window)
+{
+    if (window->context.nsgl.object)
+    {
+        return _glfwCreateUserContextNSGL(window);
+    }
+    else if (window->context.egl.handle)
+    {
+        return _glfwCreateUserContextEGL(window);
+    }
+    else if (window->context.osmesa.handle)
+    {
+        return _glfwCreateUserContextOSMesa(window);
+    }
+
+    return NULL;
+}
+
+
 //////////////////////////////////////////////////////////////////////////
 //////                        GLFW native API                       //////
 //////////////////////////////////////////////////////////////////////////

src/context.c

@@ -619,7 +619,9 @@ GLFWAPI void glfwMakeContextCurrent(GLFWwindow* handle)
 
     _GLFWwindow* window = (_GLFWwindow*) handle;
     _GLFWwindow* previous;
+    _GLFWusercontext* previousUserContext;
 
+    previousUserContext = _glfwPlatformGetTls(&_glfw.usercontextSlot);
     previous = _glfwPlatformGetTls(&_glfw.contextSlot);
 
     if (window && window->context.client == GLFW_NO_API)
@@ -629,6 +631,12 @@ GLFWAPI void glfwMakeContextCurrent(GLFWwindow* handle)
         return;
     }
 
+    if (previousUserContext)
+    {
+        assert(previous==NULL);
+        previousUserContext->makeCurrent(NULL);
+    }
+
     if (previous)
     {
         if (!window || window->context.source != previous->context.source)
@@ -763,3 +771,65 @@ GLFWAPI GLFWglproc glfwGetProcAddress(const char* procname)
     return window->context.getProcAddress(procname);
 }
 
+GLFWAPI GLFWusercontext* glfwCreateUserContext(GLFWwindow* handle)
+{
+    _GLFWusercontext* context;
+    _GLFWwindow* window = (_GLFWwindow*)handle;
+
+    _GLFW_REQUIRE_INIT_OR_RETURN(NULL);
+
+    if (!window)
+    {
+        _glfwInputError(GLFW_INVALID_VALUE,
+                        "Cannot create a user context without a valid window handle");
+        return NULL;
+    }
+
+    if (window->context.client == GLFW_NO_API)
+    {
+        _glfwInputError(GLFW_NO_WINDOW_CONTEXT,
+                        "Cannot create a user context for a window that has no OpenGL or OpenGL ES context");
+        return NULL;
+    }
+
+    context = _glfw.platform.createUserContext(window);
+
+    return (GLFWusercontext*)context;
+}
+
+GLFWAPI void glfwDestroyUserContext(GLFWusercontext* handle)
+{
+    _GLFWusercontext* context = (_GLFWusercontext*)handle;
+    _GLFWusercontext* current = _glfwPlatformGetTls(&_glfw.usercontextSlot);
+
+    _GLFW_REQUIRE_INIT();
+
+    if (context)
+    {
+        if(current==context)
+            glfwMakeContextCurrent(NULL);
+
+        context->destroy(context);
+    }
+}
+
+GLFWAPI void glfwMakeUserContextCurrent(GLFWusercontext* handle)
+{
+    _GLFWusercontext* context = (_GLFWusercontext*)handle;
+
+    _GLFW_REQUIRE_INIT();
+
+    // Call glfwMakeContextCurrent(NULL) to both clear context TLS and set
+    // context to NULL if required by platform & context, and this
+    // handles case of calling glfwMakeUserContextCurrent(NULL)
+    glfwMakeContextCurrent(NULL);
+
+    if (context)
+        context->makeCurrent(context);
+}
+
+GLFWAPI GLFWusercontext* glfwGetCurrentUserContext(void)
+{
+    _GLFW_REQUIRE_INIT_OR_RETURN(NULL);
+    return _glfwPlatformGetTls(&_glfw.usercontextSlot);
+}

src/egl_context.c

@@ -436,6 +436,10 @@ GLFWbool _glfwInitEGL(void)
         _glfwPlatformGetModuleSymbol(_glfw.egl.handle, "eglQueryString");
     _glfw.egl.GetProcAddress = (PFN_eglGetProcAddress)
         _glfwPlatformGetModuleSymbol(_glfw.egl.handle, "eglGetProcAddress");
+    _glfw.egl.CreatePbufferSurface = (PFN_eglCreatePbufferSurface)
+        _glfwPlatformGetModuleSymbol(_glfw.egl.handle, "eglCreatePbufferSurface");
+    _glfw.egl.ChooseConfig = (PFN_eglChooseConfig)
+        _glfwPlatformGetModuleSymbol(_glfw.egl.handle, "eglChooseConfig");
 
     if (!_glfw.egl.GetConfigAttrib ||
         !_glfw.egl.GetConfigs ||
@@ -453,7 +457,9 @@ GLFWbool _glfwInitEGL(void)
         !_glfw.egl.SwapBuffers ||
         !_glfw.egl.SwapInterval ||
         !_glfw.egl.QueryString ||
-        !_glfw.egl.GetProcAddress)
+        !_glfw.egl.GetProcAddress ||
+        !_glfw.egl.CreatePbufferSurface||
+        !_glfw.egl.ChooseConfig)
     {
         _glfwInputError(GLFW_PLATFORM_ERROR,
                         "EGL: Failed to load required entry points");
@@ -569,17 +575,15 @@ void _glfwTerminateEGL(void)
     attribs[index++] = v; \
 }
 
-// Create the OpenGL or OpenGL ES context
+// Create the OpenGL or OpenGL ES context for the window eglConfig
 //
-GLFWbool _glfwCreateContextEGL(_GLFWwindow* window,
+GLFWbool _glfwCreateContextForConfigEGL(EGLConfig eglConfig,
                                         const _GLFWctxconfig* ctxconfig,
-                               const _GLFWfbconfig* fbconfig)
+                                        EGLContext* context)
 {
     EGLint attribs[40];
-    EGLConfig config;
-    EGLContext share = NULL;
-    EGLNativeWindowType native;
     int index = 0;
+    EGLContext share = NULL;
 
     if (!_glfw.egl.display)
     {
@@ -590,9 +594,6 @@ GLFWbool _glfwCreateContextEGL(_GLFWwindow* window,
     if (ctxconfig->share)
         share = ctxconfig->share->context.egl.handle;
 
-    if (!chooseEGLConfig(ctxconfig, fbconfig, &config))
-        return GLFW_FALSE;
-
     if (ctxconfig->client == GLFW_OPENGL_ES_API)
     {
         if (!eglBindAPI(EGL_OPENGL_ES_API))
@@ -688,10 +689,9 @@ GLFWbool _glfwCreateContextEGL(_GLFWwindow* window,
 
     SET_ATTRIB(EGL_NONE, EGL_NONE);
 
-    window->context.egl.handle = eglCreateContext(_glfw.egl.display,
-                                                  config, share, attribs);
+    *context = eglCreateContext(_glfw.egl.display, eglConfig, share, attribs);
 
-    if (window->context.egl.handle == EGL_NO_CONTEXT)
+    if (*context == EGL_NO_CONTEXT)
     {
         _glfwInputError(GLFW_VERSION_UNAVAILABLE,
                         "EGL: Failed to create context: %s",
@@ -699,9 +699,32 @@ GLFWbool _glfwCreateContextEGL(_GLFWwindow* window,
         return GLFW_FALSE;
     }
 
-    // Set up attributes for surface creation
-    index = 0;
+    return GLFW_TRUE;
+}
 
+// Create the OpenGL or OpenGL ES context
+//
+GLFWbool _glfwCreateContextEGL(_GLFWwindow* window,
+                               const _GLFWctxconfig* ctxconfig,
+                               const _GLFWfbconfig* fbconfig)
+{
+    EGLNativeWindowType native;
+    EGLint attribs[40];
+    int index = 0;
+
+    if (!chooseEGLConfig(ctxconfig, fbconfig, &window->context.egl.config))
+    {
+        _glfwInputError(GLFW_FORMAT_UNAVAILABLE,
+                        "EGL: Failed to find a suitable EGLConfig");
+        return GLFW_FALSE;
+    }
+
+    if (!_glfwCreateContextForConfigEGL(window->context.egl.config,ctxconfig,&window->context.egl.handle))
+    {
+        return GLFW_FALSE;
+    }
+
+    // Set up attributes for surface creation
     if (fbconfig->sRGB)
     {
         if (_glfw.egl.KHR_gl_colorspace)
@@ -735,18 +758,18 @@ GLFWbool _glfwCreateContextEGL(_GLFWwindow* window,
         //       implement eglCreatePlatformWindowSurfaceEXT despite reporting
         //       support for EGL_EXT_platform_base
         window->context.egl.surface =
-            eglCreateWindowSurface(_glfw.egl.display, config, native, attribs);
+            eglCreateWindowSurface(_glfw.egl.display, window->context.egl.config, native, attribs);
     }
     else if (_glfw.egl.platform == EGL_PLATFORM_SURFACELESS_MESA)
     {
         // HACK: Use a pbuffer surface as the default framebuffer
         window->context.egl.surface =
-            eglCreatePbufferSurface(_glfw.egl.display, config, attribs);
+            eglCreatePbufferSurface(_glfw.egl.display, window->context.egl.config, attribs);
     }
     else
     {
         window->context.egl.surface =
-            eglCreatePlatformWindowSurfaceEXT(_glfw.egl.display, config, native, attribs);
+            eglCreatePlatformWindowSurfaceEXT(_glfw.egl.display, window->context.egl.config, native, attribs);
     }
 
     if (window->context.egl.surface == EGL_NO_SURFACE)
@@ -757,7 +780,6 @@ GLFWbool _glfwCreateContextEGL(_GLFWwindow* window,
         return GLFW_FALSE;
     }
 
-    window->context.egl.config = config;
 
     // Load the appropriate client library
     if (!_glfw.egl.KHR_get_all_proc_addresses)
@@ -895,6 +917,109 @@ GLFWbool _glfwChooseVisualEGL(const _GLFWwndconfig* wndconfig,
 }
 #endif // _GLFW_X11
 
+static void _glfwMakeUserContextCurrentEGL(_GLFWusercontext* context)
+{
+    if (context)
+    {
+        if (!eglMakeCurrent(_glfw.egl.display,
+                            context->egl.surface,
+                            context->egl.surface,
+                            context->egl.handle))
+        {
+            _glfwInputError(GLFW_PLATFORM_ERROR,
+                            "EGL: Failed to make user context current: %s",
+                            getEGLErrorString(eglGetError()));
+            _glfwPlatformSetTls(&_glfw.usercontextSlot, NULL);
+            return;
+        }
+    }
+    else
+    {
+        if (!eglMakeCurrent(_glfw.egl.display,
+                            EGL_NO_SURFACE,
+                            EGL_NO_SURFACE,
+                            EGL_NO_CONTEXT))
+        {
+            _glfwInputError(GLFW_PLATFORM_ERROR,
+                            "EGL: Failed to clear current user context: %s",
+                            getEGLErrorString(eglGetError()));
+            return;
+        }
+    }
+    _glfwPlatformSetTls(&_glfw.usercontextSlot, context);
+}
+
+static void _glfwDestroyUserContextEGL(_GLFWusercontext* context)
+{
+    if (context->egl.surface!=EGL_NO_SURFACE)
+        eglDestroySurface(_glfw.egl.display,context->egl.surface);
+
+    eglDestroyContext(_glfw.egl.display, context->egl.handle);
+    free(context);
+}
+
+_GLFWusercontext* _glfwCreateUserContextEGL(_GLFWwindow* window)
+{
+    _GLFWusercontext* context;
+    _GLFWctxconfig ctxconfig;
+    EGLint dummyConfigAttribs[] =
+    {
+        EGL_SURFACE_TYPE, EGL_PBUFFER_BIT,
+        EGL_RED_SIZE, 1, EGL_GREEN_SIZE, 1, EGL_BLUE_SIZE, 1,
+        EGL_NONE
+    };
+    EGLint dummySurfaceAttribs[] =
+    {
+        EGL_WIDTH, 1, EGL_HEIGHT, 1,
+        EGL_NONE
+    };
+    EGLint dummySurfaceNumConfigs;
+    EGLConfig dummySurfaceConfig;
+
+    context = calloc(1, sizeof(_GLFWusercontext));
+    context->window = window;
+
+    ctxconfig = _glfw.hints.context;
+    ctxconfig.share = window;
+
+    if (!_glfwCreateContextForConfigEGL(window->context.egl.config,&ctxconfig,&context->egl.handle))
+    {
+        _glfwInputError(GLFW_PLATFORM_ERROR,
+                                "EGL: Failed to create user OpenGL context");
+        free(context);
+        return NULL;
+    }
+    if (glfwExtensionSupported("EGL_KHR_surfaceless_context"))
+        context->egl.surface = EGL_NO_SURFACE;
+    else
+    {
+        eglChooseConfig(_glfw.egl.display, dummyConfigAttribs, &dummySurfaceConfig, 1, &dummySurfaceNumConfigs);
+        if (!dummySurfaceNumConfigs)
+        {
+            eglDestroyContext(_glfw.egl.display, context->egl.handle);
+            _glfwInputError(GLFW_PLATFORM_ERROR,
+                                    "EGL: Failed to find surface config for user context: %s", getEGLErrorString(eglGetError()));
+            free(context);
+            return NULL;
+        }
+        context->egl.surface = eglCreatePbufferSurface(_glfw.egl.display, dummySurfaceConfig, dummySurfaceAttribs);
+        if (context->egl.surface == EGL_NO_SURFACE)
+        {
+            eglDestroyContext(_glfw.egl.display, context->egl.handle);
+            _glfwInputError(GLFW_PLATFORM_ERROR,
+                                    "EGL: Failed to create surface for user context: %s for %s", getEGLErrorString(eglGetError()), eglQueryString(_glfw.egl.display,0x3054));
+            free(context);
+            return NULL;
+        }
+    }
+
+    context->makeCurrent = _glfwMakeUserContextCurrentEGL;
+    context->destroy = _glfwDestroyUserContextEGL;
+
+    return context;
+}
+
+
 
 //////////////////////////////////////////////////////////////////////////
 //////                        GLFW native API                       //////
@@ -939,10 +1064,32 @@ GLFWAPI EGLSurface glfwGetEGLSurface(GLFWwindow* handle)
             window->context.source != GLFW_NATIVE_CONTEXT_API)
         {
             _glfwInputError(GLFW_NO_WINDOW_CONTEXT, NULL);
-            return EGL_NO_CONTEXT;
+            return EGL_NO_SURFACE;
         }
     }
 
     return window->context.egl.surface;
 }
 
+GLFWAPI int glfwGetEGLConfig(GLFWwindow* handle, EGLConfig* config)
+{
+    _GLFW_REQUIRE_INIT_OR_RETURN(GLFW_FALSE);
+
+    _GLFWwindow* window = (_GLFWwindow*) handle;
+    assert(window != NULL);
+    assert(config != NULL);
+
+    if (window->context.source != GLFW_EGL_CONTEXT_API)
+    {
+        if (_glfw.platform.platformID != GLFW_PLATFORM_WAYLAND ||
+            window->context.source != GLFW_NATIVE_CONTEXT_API)
+        {
+            _glfwInputError(GLFW_NO_WINDOW_CONTEXT, NULL);
+            return GLFW_FALSE;
+        }
+    }
+
+    *config = window->context.egl.config;
+    return GLFW_TRUE;
+}
+

src/glx_context.c

@@ -447,26 +447,19 @@ void _glfwTerminateGLX(void)
     attribs[index++] = v; \
 }
 
-// Create the OpenGL or OpenGL ES context
+
+// Create the OpenGL or OpenGL ES context for the window fbConfig
 //
-GLFWbool _glfwCreateContextGLX(_GLFWwindow* window,
+GLFWbool _glfwCreateContextForFBGLX(_GLFWwindow* window,
                                     const _GLFWctxconfig* ctxconfig,
-                               const _GLFWfbconfig* fbconfig)
+                                    GLXContext* context)
 {
     int attribs[40];
-    GLXFBConfig native = NULL;
     GLXContext share = NULL;
 
     if (ctxconfig->share)
         share = ctxconfig->share->context.glx.handle;
 
-    if (!chooseGLXFBConfig(fbconfig, &native))
-    {
-        _glfwInputError(GLFW_FORMAT_UNAVAILABLE,
-                        "GLX: Failed to find a suitable GLXFBConfig");
-        return GLFW_FALSE;
-    }
-
     if (ctxconfig->client == GLFW_OPENGL_ES_API)
     {
         if (!_glfw.glx.ARB_create_context ||
@@ -581,9 +574,9 @@ GLFWbool _glfwCreateContextGLX(_GLFWwindow* window,
 
         SET_ATTRIB(None, None);
 
-        window->context.glx.handle =
+        *context =
             _glfw.glx.CreateContextAttribsARB(_glfw.x11.display,
-                                              native,
+                                              window->context.glx.fbconfig,
                                               share,
                                               True,
                                               attribs);
@@ -592,40 +585,64 @@ GLFWbool _glfwCreateContextGLX(_GLFWwindow* window,
         //       implementation of GLX_ARB_create_context_profile that fail
         //       default 1.0 context creation with a GLXBadProfileARB error in
         //       violation of the extension spec
-        if (!window->context.glx.handle)
+        if (!(*context))
         {
             if (_glfw.x11.errorCode == _glfw.glx.errorBase + GLXBadProfileARB &&
                 ctxconfig->client == GLFW_OPENGL_API &&
                 ctxconfig->profile == GLFW_OPENGL_ANY_PROFILE &&
                 ctxconfig->forward == GLFW_FALSE)
             {
-                window->context.glx.handle =
-                    createLegacyContextGLX(window, native, share);
+                *context =
+                    createLegacyContextGLX(window, window->context.glx.fbconfig, share);
             }
         }
     }
     else
     {
-        window->context.glx.handle =
-            createLegacyContextGLX(window, native, share);
+        *context =
+            createLegacyContextGLX(window, window->context.glx.fbconfig, share);
     }
 
     _glfwReleaseErrorHandlerX11();
 
-    if (!window->context.glx.handle)
+    if (!(*context))
     {
         _glfwInputErrorX11(GLFW_VERSION_UNAVAILABLE, "GLX: Failed to create context");
         return GLFW_FALSE;
     }
 
+    return GLFW_TRUE;
+}
+
+// Create the OpenGL or OpenGL ES context
+//
+GLFWbool _glfwCreateContextGLX(_GLFWwindow* window,
+                               const _GLFWctxconfig* ctxconfig,
+                               const _GLFWfbconfig* fbconfig)
+{
+
+    if (!chooseGLXFBConfig(fbconfig, &window->context.glx.fbconfig))
+    {
+        _glfwInputError(GLFW_FORMAT_UNAVAILABLE,
+                        "GLX: Failed to find a suitable GLXFBConfig");
+        return GLFW_FALSE;
+    }
+
+    if(!_glfwCreateContextForFBGLX(window,ctxconfig,&window->context.glx.handle))
+    {
+        return GLFW_FALSE;
+    }
+
     window->context.glx.window =
-        glXCreateWindow(_glfw.x11.display, native, window->x11.handle, NULL);
+        glXCreateWindow(_glfw.x11.display, window->context.glx.fbconfig, window->x11.handle, NULL);
     if (!window->context.glx.window)
     {
         _glfwInputError(GLFW_PLATFORM_ERROR, "GLX: Failed to create window");
         return GLFW_FALSE;
     }
 
+    window->context.glx.fbconfig = native;
+
     window->context.makeCurrent = makeContextCurrentGLX;
     window->context.swapBuffers = swapBuffersGLX;
     window->context.swapInterval = swapIntervalGLX;
@@ -670,6 +687,60 @@ GLFWbool _glfwChooseVisualGLX(const _GLFWwndconfig* wndconfig,
     return GLFW_TRUE;
 }
 
+static void _glfwMakeUserContextCurrentGLX(_GLFWusercontext* context)
+{
+	if (context)
+	{
+		if(!glXMakeCurrent(_glfw.x11.display, context->window->context.glx.window,context->glx.handle))
+		{
+			_glfwInputError(GLFW_PLATFORM_ERROR,
+							"GLX: Failed to make user context current");
+			_glfwPlatformSetTls(&_glfw.usercontextSlot, NULL);
+			return;
+		}
+	}
+	else
+    {
+        if (!glXMakeCurrent(_glfw.x11.display, None, NULL))
+        {
+            _glfwInputError(GLFW_PLATFORM_ERROR,
+                            "GLX: Failed to clear current user context");
+            return;
+        }
+    }
+    _glfwPlatformSetTls(&_glfw.usercontextSlot, context);
+}
+
+static void _glfwDestroyUserContextGLX(_GLFWusercontext* context)
+{
+    glXDestroyContext(_glfw.x11.display, context->glx.handle);
+    free(context);
+}
+
+_GLFWusercontext* _glfwCreateUserContextGLX(_GLFWwindow* window)
+{
+    _GLFWusercontext* context;
+    _GLFWctxconfig ctxconfig;
+
+    context = calloc(1, sizeof(_GLFWusercontext));
+    context->window = window;
+
+    ctxconfig = _glfw.hints.context;
+    ctxconfig.share = window;
+
+    if(!_glfwCreateContextForFBGLX(window,&ctxconfig,&context->glx.handle))
+    {
+        _glfwInputError(GLFW_PLATFORM_ERROR,
+                                "GLX: Failed to create user OpenGL context");
+        free(context);
+        return NULL;
+    }
+
+    context->makeCurrent = _glfwMakeUserContextCurrentGLX;
+    context->destroy = _glfwDestroyUserContextGLX;
+
+    return context;
+}
 
 //////////////////////////////////////////////////////////////////////////
 //////                        GLFW native API                       //////
@@ -719,5 +790,29 @@ GLFWAPI GLXWindow glfwGetGLXWindow(GLFWwindow* handle)
     return window->context.glx.window;
 }
 
+GLFWAPI int glfwGetGLXFBConfig(GLFWwindow* handle, GLXFBConfig* config)
+{
+    _GLFW_REQUIRE_INIT_OR_RETURN(GLFW_FALSE);
+
+    if (_glfw.platform.platformID != GLFW_PLATFORM_X11)
+    {
+        _glfwInputError(GLFW_PLATFORM_UNAVAILABLE, "GLX: Platform not initialized");
+        return GLFW_FALSE;
+    }
+
+    _GLFWwindow* window = (_GLFWwindow*) handle;
+    assert(window != NULL);
+    assert(config != NULL);
+
+    if (window->context.source != GLFW_NATIVE_CONTEXT_API)
+    {
+        _glfwInputError(GLFW_NO_WINDOW_CONTEXT, NULL);
+        return GLFW_FALSE;
+    }
+
+    *config = window->context.glx.fbconfig;
+    return GLFW_TRUE;
+}
+
 #endif // _GLFW_X11
 

src/init.c

@@ -132,6 +132,7 @@ static void terminate(void)
         _glfw_free(error);
     }
 
+    _glfwPlatformDestroyTls(&_glfw.usercontextSlot);
     _glfwPlatformDestroyTls(&_glfw.contextSlot);
     _glfwPlatformDestroyTls(&_glfw.errorSlot);
     _glfwPlatformDestroyMutex(&_glfw.errorLock);
@@ -410,7 +411,8 @@ GLFWAPI int glfwInit(void)
 
     if (!_glfwPlatformCreateMutex(&_glfw.errorLock) ||
         !_glfwPlatformCreateTls(&_glfw.errorSlot) ||
-        !_glfwPlatformCreateTls(&_glfw.contextSlot))
+        !_glfwPlatformCreateTls(&_glfw.contextSlot) ||
+        !_glfwPlatformCreateTls(&_glfw.usercontextSlot))
     {
         terminate();
         return GLFW_FALSE;

src/internal.h

@@ -79,6 +79,7 @@ typedef struct _GLFWmapping     _GLFWmapping;
 typedef struct _GLFWjoystick    _GLFWjoystick;
 typedef struct _GLFWtls         _GLFWtls;
 typedef struct _GLFWmutex       _GLFWmutex;
+typedef struct _GLFWusercontext _GLFWusercontext;
 
 #define GL_VERSION 0x1f02
 #define GL_NONE 0
@@ -217,6 +218,7 @@ typedef EGLBoolean (APIENTRY * PFN_eglSwapBuffers)(EGLDisplay,EGLSurface);
 typedef EGLBoolean (APIENTRY * PFN_eglSwapInterval)(EGLDisplay,EGLint);
 typedef const char* (APIENTRY * PFN_eglQueryString)(EGLDisplay,EGLint);
 typedef GLFWglproc (APIENTRY * PFN_eglGetProcAddress)(const char*);
+typedef EGLBoolean (APIENTRY * PFN_eglChooseConfig)(EGLDisplay,EGLint const*,EGLConfig*,EGLint,EGLint*);
 #define eglGetConfigAttrib _glfw.egl.GetConfigAttrib
 #define eglGetConfigs _glfw.egl.GetConfigs
 #define eglGetDisplay _glfw.egl.GetDisplay
@@ -234,6 +236,8 @@ typedef GLFWglproc (APIENTRY * PFN_eglGetProcAddress)(const char*);
 #define eglSwapInterval _glfw.egl.SwapInterval
 #define eglQueryString _glfw.egl.QueryString
 #define eglGetProcAddress _glfw.egl.GetProcAddress
+#define eglCreatePbufferSurface _glfw.egl.CreatePbufferSurface
+#define eglChooseConfig _glfw.egl.ChooseConfig
 
 typedef EGLDisplay (APIENTRY * PFNEGLGETPLATFORMDISPLAYEXTPROC)(EGLenum,void*,const EGLint*);
 typedef EGLSurface (APIENTRY * PFNEGLCREATEPLATFORMWINDOWSURFACEEXTPROC)(EGLDisplay,EGLConfig,void*,const EGLint*);
@@ -402,7 +406,6 @@ struct _GLFWwndconfig
     int           ypos;
     int           width;
     int           height;
-    const char*   title;
     GLFWbool      resizable;
     GLFWbool      visible;
     GLFWbool      decorated;
@@ -525,6 +528,29 @@ struct _GLFWcontext
     GLFW_PLATFORM_CONTEXT_STATE
 };
 
+
+// User Context structure
+//
+struct _GLFWusercontext
+{
+    _GLFWwindow* window;
+
+    void (*makeCurrent)(_GLFWusercontext* context);
+    void (*destroy)(_GLFWusercontext* context);
+
+    struct {
+       EGLContext       handle;
+       EGLSurface       surface;
+    } egl;
+
+    struct {
+        OSMesaContext   handle;
+    } osmesa;
+
+    // This is defined in platform.h
+    GLFW_PLATFORM_USER_CONTEXT_STATE
+};
+
 // Window and context structure
 //
 struct _GLFWwindow
@@ -751,6 +777,7 @@ struct _GLFWplatform
     void (*waitEvents)(void);
     void (*waitEventsTimeout)(double);
     void (*postEmptyEvent)(void);
+    _GLFWusercontext* (*createUserContext)(_GLFWwindow*);
     // EGL
     EGLenum (*getEGLPlatform)(EGLint**);
     EGLNativeDisplayType (*getEGLNativeDisplay)(void);
@@ -792,6 +819,7 @@ struct _GLFWlibrary
 
     _GLFWtls            errorSlot;
     _GLFWtls            contextSlot;
+    _GLFWtls            usercontextSlot;
     _GLFWmutex          errorLock;
 
     struct {
@@ -842,6 +870,7 @@ struct _GLFWlibrary
         PFN_eglSwapInterval         SwapInterval;
         PFN_eglQueryString          QueryString;
         PFN_eglGetProcAddress       GetProcAddress;
+        PFN_eglChooseConfig         ChooseConfig;
 
         PFNEGLGETPLATFORMDISPLAYEXTPROC GetPlatformDisplayEXT;
         PFNEGLCREATEPLATFORMWINDOWSURFACEEXTPROC CreatePlatformWindowSurfaceEXT;
@@ -992,6 +1021,7 @@ void _glfwTerminateEGL(void);
 GLFWbool _glfwCreateContextEGL(_GLFWwindow* window,
                                const _GLFWctxconfig* ctxconfig,
                                const _GLFWfbconfig* fbconfig);
+_GLFWusercontext* _glfwCreateUserContextEGL(_GLFWwindow* window);
 #if defined(_GLFW_X11)
 GLFWbool _glfwChooseVisualEGL(const _GLFWwndconfig* wndconfig,
                               const _GLFWctxconfig* ctxconfig,
@@ -1004,6 +1034,7 @@ void _glfwTerminateOSMesa(void);
 GLFWbool _glfwCreateContextOSMesa(_GLFWwindow* window,
                                   const _GLFWctxconfig* ctxconfig,
                                   const _GLFWfbconfig* fbconfig);
+_GLFWusercontext* _glfwCreateUserContextOSMesa(_GLFWwindow* window);
 
 GLFWbool _glfwInitVulkan(int mode);
 void _glfwTerminateVulkan(void);

src/nsgl_context.m

@@ -353,6 +353,54 @@ GLFWbool _glfwCreateContextNSGL(_GLFWwindow* window,
 }
 
 
+static void _glfwMakeUserContextCurrentNSGL(_GLFWusercontext* context)
+{
+    @autoreleasepool {
+
+    if (context)
+        [context->nsgl.object makeCurrentContext];
+    else
+        [NSOpenGLContext clearCurrentContext];
+
+    _glfwPlatformSetTls(&_glfw.usercontextSlot, context);
+
+    } // autoreleasepool
+}
+
+static void _glfwDestroyUserContextNSGL(_GLFWusercontext* context)
+{
+    @autoreleasepool {
+
+    [context->nsgl.object release];
+
+    } // autoreleasepool
+    free(context);
+}
+
+_GLFWusercontext* _glfwCreateUserContextNSGL(_GLFWwindow* window)
+{
+    _GLFWusercontext* context;
+
+    context = calloc(1, sizeof(_GLFWusercontext));
+    context->window = window;
+
+    context->nsgl.object =
+        [[NSOpenGLContext alloc] initWithFormat:window->context.nsgl.pixelFormat
+                                   shareContext:window->context.nsgl.object];
+    if (window->context.nsgl.object == nil)
+    {
+        _glfwInputError(GLFW_VERSION_UNAVAILABLE,
+                        "NSGL: Failed to create OpenGL user context");
+        free(context);
+        return NULL;
+    }
+
+    context->makeCurrent = _glfwMakeUserContextCurrentNSGL;
+    context->destroy = _glfwDestroyUserContextNSGL;
+
+    return context;
+}
+
 //////////////////////////////////////////////////////////////////////////
 //////                        GLFW native API                       //////
 //////////////////////////////////////////////////////////////////////////

src/null_init.c

@@ -105,6 +105,7 @@ GLFWbool _glfwConnectNull(int platformID, _GLFWplatform* platform)
         .waitEvents = _glfwWaitEventsNull,
         .waitEventsTimeout = _glfwWaitEventsTimeoutNull,
         .postEmptyEvent = _glfwPostEmptyEventNull,
+        .createUserContext = _glfwCreateUserContextNull,
         .getEGLPlatform = _glfwGetEGLPlatformNull,
         .getEGLNativeDisplay = _glfwGetEGLNativeDisplayNull,
         .getEGLNativeWindow = _glfwGetEGLNativeWindowNull,

src/null_platform.h

@@ -32,6 +32,7 @@
 #define GLFW_NULL_CONTEXT_STATE
 #define GLFW_NULL_CURSOR_STATE
 #define GLFW_NULL_LIBRARY_CONTEXT_STATE
+#define GLFW_NULL_USER_CONTEXT_STATE
 
 #define GLFW_NULL_SC_FIRST          GLFW_NULL_SC_SPACE
 #define GLFW_NULL_SC_SPACE          1
@@ -280,3 +281,5 @@ VkResult _glfwCreateWindowSurfaceNull(VkInstance instance, _GLFWwindow* window,
 
 void _glfwPollMonitorsNull(void);
 
+_GLFWusercontext* _glfwCreateUserContextNull(_GLFWwindow* window);
+

src/null_window.c

@@ -747,3 +747,12 @@ VkResult _glfwCreateWindowSurfaceNull(VkInstance instance,
     return err;
 }
 
+_GLFWusercontext* _glfwCreateUserContextNull(_GLFWwindow* window)
+{
+    if (window->context.osmesa.handle)
+    {
+        return _glfwCreateUserContextOSMesa(window);
+    }
+
+    return NULL;
+}

src/osmesa_context.c

@@ -194,9 +194,9 @@ void _glfwTerminateOSMesa(void)
     attribs[index++] = v; \
 }
 
-GLFWbool _glfwCreateContextOSMesa(_GLFWwindow* window,
-                                  const _GLFWctxconfig* ctxconfig,
-                                  const _GLFWfbconfig* fbconfig)
+GLFWbool _glfwCreateContextForConfigOSMesa(const _GLFWctxconfig* ctxconfig,
+                                           const _GLFWfbconfig* fbconfig,
+                                           OSMesaContext* context )
 {
     OSMesaContext share = NULL;
     const int accumBits = fbconfig->accumRedBits +
@@ -247,7 +247,7 @@ GLFWbool _glfwCreateContextOSMesa(_GLFWwindow* window,
 
         SET_ATTRIB(0, 0);
 
-        window->context.osmesa.handle =
+        *context =
             OSMesaCreateContextAttribs(attribs, share);
     }
     else
@@ -259,7 +259,7 @@ GLFWbool _glfwCreateContextOSMesa(_GLFWwindow* window,
             return GLFW_FALSE;
         }
 
-        window->context.osmesa.handle =
+        *context =
             OSMesaCreateContextExt(OSMESA_RGBA,
                                    fbconfig->depthBits,
                                    fbconfig->stencilBits,
@@ -267,13 +267,27 @@ GLFWbool _glfwCreateContextOSMesa(_GLFWwindow* window,
                                    share);
     }
 
-    if (window->context.osmesa.handle == NULL)
+    if (*context == NULL)
     {
         _glfwInputError(GLFW_VERSION_UNAVAILABLE,
                         "OSMesa: Failed to create context");
         return GLFW_FALSE;
     }
 
+    return GLFW_TRUE;
+}
+
+#undef setAttrib
+
+GLFWbool _glfwCreateContextOSMesa(_GLFWwindow* window,
+                                  const _GLFWctxconfig* ctxconfig,
+                                  const _GLFWfbconfig* fbconfig)
+{
+    if(!_glfwCreateContextForConfigOSMesa(ctxconfig,fbconfig,&window->context.osmesa.handle))
+    {
+        return GLFW_FALSE;
+    }
+
     window->context.makeCurrent = makeContextCurrentOSMesa;
     window->context.swapBuffers = swapBuffersOSMesa;
     window->context.swapInterval = swapIntervalOSMesa;
@@ -284,8 +298,62 @@ GLFWbool _glfwCreateContextOSMesa(_GLFWwindow* window,
     return GLFW_TRUE;
 }
 
-#undef SET_ATTRIB
+static void _glfwMakeUserContextCurrentOSMesa(_GLFWusercontext* context)
+{
+    if (context)
+    {
+        if (!OSMesaMakeCurrent(context->osmesa.handle,
+                                context->window->context.osmesa.buffer,
+                                GL_UNSIGNED_BYTE,
+                                context->window->context.osmesa.width, context->window->context.osmesa.height))
+        {
+            _glfwInputError(GLFW_PLATFORM_ERROR,
+                            "OSMesa: Failed to make user context current");
+            _glfwPlatformSetTls(&_glfw.usercontextSlot, NULL);
+            return;
+        }
+    }
+    _glfwPlatformSetTls(&_glfw.usercontextSlot, context);
+}
 
+static void _glfwDestroyUserContextOSMesa(_GLFWusercontext* context)
+{
+    if (context->osmesa.handle)
+    {
+        OSMesaDestroyContext(context->osmesa.handle);
+    }
+    free(context);
+}
+
+_GLFWusercontext* _glfwCreateUserContextOSMesa(_GLFWwindow* window)
+{
+    _GLFWusercontext* context;
+    _GLFWctxconfig ctxconfig;
+    _GLFWfbconfig fbconfig;
+
+    context = calloc(1, sizeof(_GLFWusercontext));
+    context->window = window;
+
+    ctxconfig = _glfw.hints.context;
+    ctxconfig.share = window;
+
+    fbconfig = _glfw.hints.framebuffer;
+
+    if(!_glfwCreateContextForConfigOSMesa(&ctxconfig,&fbconfig,&context->osmesa.handle))
+    {
+        _glfwInputError(GLFW_PLATFORM_ERROR,
+                                "OSMesa: Failed to create user OpenGL context");
+        free(context);
+        return NULL;
+    }
+
+    context->makeCurrent = _glfwMakeUserContextCurrentOSMesa;
+    context->destroy = _glfwDestroyUserContextOSMesa;
+
+    return context;
+}
+
+#undef SET_ATTRIB
 
 //////////////////////////////////////////////////////////////////////////
 //////                        GLFW native API                       //////

src/platform.h

@@ -52,6 +52,7 @@
  #define GLFW_WIN32_LIBRARY_WINDOW_STATE
  #define GLFW_WGL_CONTEXT_STATE
  #define GLFW_WGL_LIBRARY_CONTEXT_STATE
+ #define GLFW_WGL_USER_CONTEXT_STATE
 #endif
 
 #if defined(_GLFW_COCOA)
@@ -65,6 +66,7 @@
  #define GLFW_COCOA_LIBRARY_WINDOW_STATE
  #define GLFW_NSGL_CONTEXT_STATE
  #define GLFW_NSGL_LIBRARY_CONTEXT_STATE
+ #define GLFW_NSGL_USER_CONTEXT_STATE
 #endif
 
 #if defined(_GLFW_WAYLAND)
@@ -88,6 +90,7 @@
  #define GLFW_X11_LIBRARY_WINDOW_STATE
  #define GLFW_GLX_CONTEXT_STATE
  #define GLFW_GLX_LIBRARY_CONTEXT_STATE
+ #define GLFW_GLX_USER_CONTEXT_STATE
 #endif
 
 #include "null_joystick.h"
@@ -165,6 +168,11 @@
         GLFW_NSGL_LIBRARY_CONTEXT_STATE \
         GLFW_GLX_LIBRARY_CONTEXT_STATE
 
+#define GLFW_PLATFORM_USER_CONTEXT_STATE \
+        GLFW_WGL_USER_CONTEXT_STATE \
+        GLFW_NSGL_USER_CONTEXT_STATE \
+        GLFW_GLX_USER_CONTEXT_STATE
+
 #if defined(_WIN32)
  #define GLFW_BUILD_WIN32_THREAD
 #else

src/wgl_context.c

@@ -536,47 +536,17 @@ void _glfwTerminateWGL(void)
     attribs[index++] = v; \
 }
 
-// Create the OpenGL or OpenGL ES context
+// Create the OpenGL or OpenGL ES context for the given HDC
 //
-GLFWbool _glfwCreateContextWGL(_GLFWwindow* window,
-                               const _GLFWctxconfig* ctxconfig,
-                               const _GLFWfbconfig* fbconfig)
+GLFWbool _glfwCreateContextForDCWGL(HDC dc, const _GLFWctxconfig* ctxconfig, HGLRC* context)
 {
     int attribs[40];
-    int pixelFormat;
-    PIXELFORMATDESCRIPTOR pfd;
     HGLRC share = NULL;
 
+    *context = NULL;
     if (ctxconfig->share)
         share = ctxconfig->share->context.wgl.handle;
 
-    window->context.wgl.dc = GetDC(window->win32.handle);
-    if (!window->context.wgl.dc)
-    {
-        _glfwInputError(GLFW_PLATFORM_ERROR,
-                        "WGL: Failed to retrieve DC for window");
-        return GLFW_FALSE;
-    }
-
-    pixelFormat = choosePixelFormatWGL(window, ctxconfig, fbconfig);
-    if (!pixelFormat)
-        return GLFW_FALSE;
-
-    if (!DescribePixelFormat(window->context.wgl.dc,
-                             pixelFormat, sizeof(pfd), &pfd))
-    {
-        _glfwInputErrorWin32(GLFW_PLATFORM_ERROR,
-                             "WGL: Failed to retrieve PFD for selected pixel format");
-        return GLFW_FALSE;
-    }
-
-    if (!SetPixelFormat(window->context.wgl.dc, pixelFormat, &pfd))
-    {
-        _glfwInputErrorWin32(GLFW_PLATFORM_ERROR,
-                             "WGL: Failed to set selected pixel format");
-        return GLFW_FALSE;
-    }
-
     if (ctxconfig->client == GLFW_OPENGL_API)
     {
         if (ctxconfig->forward)
@@ -690,9 +660,9 @@ GLFWbool _glfwCreateContextWGL(_GLFWwindow* window,
 
         SET_ATTRIB(0, 0);
 
-        window->context.wgl.handle =
-            wglCreateContextAttribsARB(window->context.wgl.dc, share, attribs);
-        if (!window->context.wgl.handle)
+        *context =
+            wglCreateContextAttribsARB(dc, share, attribs);
+        if (!(*context))
         {
             const DWORD error = GetLastError();
 
@@ -742,8 +712,8 @@ GLFWbool _glfwCreateContextWGL(_GLFWwindow* window,
     }
     else
     {
-        window->context.wgl.handle = wglCreateContext(window->context.wgl.dc);
-        if (!window->context.wgl.handle)
+        *context = wglCreateContext(dc);
+        if (!(*context) )
         {
             _glfwInputErrorWin32(GLFW_VERSION_UNAVAILABLE,
                                  "WGL: Failed to create OpenGL context");
@@ -752,7 +722,7 @@ GLFWbool _glfwCreateContextWGL(_GLFWwindow* window,
 
         if (share)
         {
-            if (!wglShareLists(share, window->context.wgl.handle))
+            if (!wglShareLists(share, *context))
             {
                 _glfwInputErrorWin32(GLFW_PLATFORM_ERROR,
                                      "WGL: Failed to enable sharing with specified OpenGL context");
@@ -761,6 +731,50 @@ GLFWbool _glfwCreateContextWGL(_GLFWwindow* window,
         }
     }
 
+    return GLFW_TRUE;
+}
+
+// Create the OpenGL or OpenGL ES context
+//
+GLFWbool _glfwCreateContextWGL(_GLFWwindow* window,
+                               const _GLFWctxconfig* ctxconfig,
+                               const _GLFWfbconfig* fbconfig)
+{
+    int pixelFormat;
+    PIXELFORMATDESCRIPTOR pfd;
+
+    window->context.wgl.dc = GetDC(window->win32.handle);
+    if (!window->context.wgl.dc)
+    {
+        _glfwInputError(GLFW_PLATFORM_ERROR,
+                        "WGL: Failed to retrieve DC for window");
+        return GLFW_FALSE;
+    }
+
+    pixelFormat = choosePixelFormatWGL(window, ctxconfig, fbconfig);
+    if (!pixelFormat)
+        return GLFW_FALSE;
+
+    if (!DescribePixelFormat(window->context.wgl.dc,
+                             pixelFormat, sizeof(pfd), &pfd))
+    {
+        _glfwInputErrorWin32(GLFW_PLATFORM_ERROR,
+                             "WGL: Failed to retrieve PFD for selected pixel format");
+        return GLFW_FALSE;
+    }
+
+    if (!SetPixelFormat(window->context.wgl.dc, pixelFormat, &pfd))
+    {
+        _glfwInputErrorWin32(GLFW_PLATFORM_ERROR,
+                             "WGL: Failed to set selected pixel format");
+        return GLFW_FALSE;
+    }
+
+    if(!_glfwCreateContextForDCWGL( window->context.wgl.dc, ctxconfig, &window->context.wgl.handle ))
+    {
+        return GLFW_FALSE;
+    }
+
     window->context.makeCurrent = makeContextCurrentWGL;
     window->context.swapBuffers = swapBuffersWGL;
     window->context.swapInterval = swapIntervalWGL;
@@ -771,6 +785,65 @@ GLFWbool _glfwCreateContextWGL(_GLFWwindow* window,
     return GLFW_TRUE;
 }
 
+static void _glfwMakeUserContextCurrentWGL(_GLFWusercontext* context)
+{
+    if (context)
+    {
+        if (!wglMakeCurrent(context->window->context.wgl.dc,context->wgl.handle))
+        {
+            _glfwInputErrorWin32(GLFW_PLATFORM_ERROR,
+                                 "WGL: Failed to make user context current");
+            _glfwPlatformSetTls(&_glfw.usercontextSlot, NULL);
+            return;
+        }
+    }
+    else
+    {
+        if (!wglMakeCurrent(NULL, NULL))
+        {
+            _glfwInputErrorWin32(GLFW_PLATFORM_ERROR,
+                                 "WGL: Failed to clear current user context");
+        }
+    }
+
+    _glfwPlatformSetTls(&_glfw.usercontextSlot, context);
+}
+
+static void _glfwDestroyUserContextWGL(_GLFWusercontext* context)
+{
+    wglDeleteContext(context->wgl.handle);
+    free(context);
+}
+
+_GLFWusercontext* _glfwCreateUserContextWGL(_GLFWwindow* window)
+{
+    _GLFWusercontext* context;
+    _GLFWctxconfig ctxconfig;
+
+    context = calloc(1, sizeof(_GLFWusercontext));
+    context->window = window;
+
+    ctxconfig = _glfw.hints.context;
+    ctxconfig.share = window;
+
+    if (!_glfwCreateContextForDCWGL(window->context.wgl.dc, &ctxconfig, &context->wgl.handle))
+    {
+        _glfwInputErrorWin32(GLFW_PLATFORM_ERROR,
+                                "WGL: Failed to create user OpenGL context");
+        free(context);
+        return NULL;
+    }
+
+    context->makeCurrent = _glfwMakeUserContextCurrentWGL;
+    context->destroy = _glfwDestroyUserContextWGL;
+
+    return context;
+}
+
+
+//////////////////////////////////////////////////////////////////////////
+//////                        GLFW native API                       //////
+//////////////////////////////////////////////////////////////////////////
 #undef SET_ATTRIB
 
 GLFWAPI HGLRC glfwGetWGLContext(GLFWwindow* handle)

src/win32_init.c

@@ -664,6 +664,7 @@ GLFWbool _glfwConnectWin32(int platformID, _GLFWplatform* platform)
         .waitEvents = _glfwWaitEventsWin32,
         .waitEventsTimeout = _glfwWaitEventsTimeoutWin32,
         .postEmptyEvent = _glfwPostEmptyEventWin32,
+        .createUserContext = _glfwCreateUserContextWin32,
         .getEGLPlatform = _glfwGetEGLPlatformWin32,
         .getEGLNativeDisplay = _glfwGetEGLNativeDisplayWin32,
         .getEGLNativeWindow = _glfwGetEGLNativeWindowWin32,

src/win32_platform.h

@@ -307,6 +307,7 @@ typedef VkBool32 (APIENTRY *PFN_vkGetPhysicalDeviceWin32PresentationSupportKHR)(
 
 #define GLFW_WGL_CONTEXT_STATE          _GLFWcontextWGL     wgl;
 #define GLFW_WGL_LIBRARY_CONTEXT_STATE  _GLFWlibraryWGL     wgl;
+#define GLFW_WGL_USER_CONTEXT_STATE     _GLFWusercontextWGL wgl;
 
 
 // WGL-specific per-context data
@@ -350,6 +351,14 @@ typedef struct _GLFWlibraryWGL
     GLFWbool                            ARB_context_flush_control;
 } _GLFWlibraryWGL;
 
+// WGL-specific per-usercontext data
+//
+typedef struct _GLFWusercontextWGL
+{
+    HDC       dc;
+    HGLRC     handle;
+} _GLFWusercontextWGL;
+
 // Win32-specific per-window data
 //
 typedef struct _GLFWwindowWin32
@@ -565,3 +574,5 @@ GLFWbool _glfwCreateContextWGL(_GLFWwindow* window,
                                const _GLFWctxconfig* ctxconfig,
                                const _GLFWfbconfig* fbconfig);
 
+_GLFWusercontext* _glfwCreateUserContextWin32(_GLFWwindow* window);
+_GLFWusercontext* _glfwCreateUserContextWGL(_GLFWwindow* window);

src/win32_window.c

@@ -1377,7 +1377,7 @@ static int createNativeWindow(_GLFWwindow* window,
         frameHeight = rect.bottom - rect.top;
     }
 
-    wideTitle = _glfwCreateWideStringFromUTF8Win32(wndconfig->title);
+    wideTitle = _glfwCreateWideStringFromUTF8Win32(window->title);
     if (!wideTitle)
         return GLFW_FALSE;
 
@@ -2562,6 +2562,28 @@ VkResult _glfwCreateWindowSurfaceWin32(VkInstance instance,
     return err;
 }
 
+_GLFWusercontext* _glfwCreateUserContextWin32(_GLFWwindow* window)
+{
+    if (window->context.wgl.handle)
+    {
+        return _glfwCreateUserContextWGL(window);
+    }
+    else if (window->context.egl.handle)
+    {
+        return _glfwCreateUserContextEGL(window);
+    }
+    else if (window->context.osmesa.handle)
+    {
+        return _glfwCreateUserContextOSMesa(window);
+    }
+
+    return GLFW_FALSE;
+}
+
+//////////////////////////////////////////////////////////////////////////
+//////                        GLFW native API                       //////
+//////////////////////////////////////////////////////////////////////////
+
 GLFWAPI HWND glfwGetWin32Window(GLFWwindow* handle)
 {
     _GLFW_REQUIRE_INIT_OR_RETURN(NULL);

src/window.c

@@ -208,7 +208,6 @@ GLFWAPI GLFWwindow* glfwCreateWindow(int width, int height,
 
     wndconfig.width   = width;
     wndconfig.height  = height;
-    wndconfig.title   = title;
     ctxconfig.share   = (_GLFWwindow*) share;
 
     if (!_glfwIsValidContextConfig(&ctxconfig))

src/wl_init.c

@@ -510,6 +510,7 @@ GLFWbool _glfwConnectWayland(int platformID, _GLFWplatform* platform)
         .waitEvents = _glfwWaitEventsWayland,
         .waitEventsTimeout = _glfwWaitEventsTimeoutWayland,
         .postEmptyEvent = _glfwPostEmptyEventWayland,
+        .createUserContext = _glfwCreateUserContextWayland,
         .getEGLPlatform = _glfwGetEGLPlatformWayland,
         .getEGLNativeDisplay = _glfwGetEGLNativeDisplayWayland,
         .getEGLNativeWindow = _glfwGetEGLNativeWindowWayland,

src/wl_platform.h

@@ -690,6 +690,8 @@ void _glfwSetGammaRampWayland(_GLFWmonitor* monitor, const GLFWgammaramp* ramp);
 void _glfwAddOutputWayland(uint32_t name, uint32_t version);
 void _glfwUpdateBufferScaleFromOutputsWayland(_GLFWwindow* window);
 
+_GLFWusercontext* _glfwCreateUserContextWayland(_GLFWwindow* window);
+
 void _glfwAddSeatListenerWayland(struct wl_seat* seat);
 void _glfwAddDataDeviceListenerWayland(struct wl_data_device* device);
 

src/wl_window.c

@@ -3324,6 +3324,19 @@ VkResult _glfwCreateWindowSurfaceWayland(VkInstance instance,
     return err;
 }
 
+_GLFWusercontext* _glfwCreateUserContextWayland(_GLFWwindow* window)
+{
+    if (window->context.egl.handle)
+    {
+        return _glfwCreateUserContextEGL(window);
+    }
+    else if (window->context.osmesa.handle)
+    {
+        return _glfwCreateUserContextOSMesa(window);
+    }
+
+    return NULL;
+}
 
 //////////////////////////////////////////////////////////////////////////
 //////                        GLFW native API                       //////

src/x11_init.c

@@ -1241,6 +1241,7 @@ GLFWbool _glfwConnectX11(int platformID, _GLFWplatform* platform)
         .waitEvents = _glfwWaitEventsX11,
         .waitEventsTimeout = _glfwWaitEventsTimeoutX11,
         .postEmptyEvent = _glfwPostEmptyEventX11,
+        .createUserContext = _glfwCreateUserContextX11,
         .getEGLPlatform = _glfwGetEGLPlatformX11,
         .getEGLNativeDisplay = _glfwGetEGLNativeDisplayX11,
         .getEGLNativeWindow = _glfwGetEGLNativeWindowX11,

src/x11_platform.h

@@ -462,7 +462,7 @@ typedef VkBool32 (APIENTRY *PFN_vkGetPhysicalDeviceXcbPresentationSupportKHR)(Vk
 
 #define GLFW_GLX_CONTEXT_STATE          _GLFWcontextGLX glx;
 #define GLFW_GLX_LIBRARY_CONTEXT_STATE  _GLFWlibraryGLX glx;
-
+#define GLFW_GLX_USER_CONTEXT_STATE     _GLFWusercontextGLX glx;
 
 // GLX-specific per-context data
 //
@@ -470,6 +470,7 @@ typedef struct _GLFWcontextGLX
 {
     GLXContext      handle;
     GLXWindow       window;
+    GLXFBConfig     fbconfig;
 } _GLFWcontextGLX;
 
 // GLX-specific global data
@@ -518,6 +519,13 @@ typedef struct _GLFWlibraryGLX
     GLFWbool        ARB_context_flush_control;
 } _GLFWlibraryGLX;
 
+// GLX-specific per usercontext data
+//
+typedef struct _GLFWusercontextGLX
+{
+    GLXContext      handle;
+} _GLFWusercontextGLX;
+
 // X11-specific per-window data
 //
 typedef struct _GLFWwindowX11
@@ -1002,3 +1010,5 @@ GLFWbool _glfwChooseVisualGLX(const _GLFWwndconfig* wndconfig,
                               const _GLFWfbconfig* fbconfig,
                               Visual** visual, int* depth);
 
+_GLFWusercontext* _glfwCreateUserContextX11(_GLFWwindow* window);
+_GLFWusercontext* _glfwCreateUserContextGLX(_GLFWwindow* window);

src/x11_window.c

@@ -754,13 +754,13 @@ static GLFWbool createNativeWindow(_GLFWwindow* window,
             const char* resourceName = getenv("RESOURCE_NAME");
             if (resourceName && strlen(resourceName))
                 hint->res_name = (char*) resourceName;
-            else if (strlen(wndconfig->title))
-                hint->res_name = (char*) wndconfig->title;
+            else if (strlen(window->title))
+                hint->res_name = (char*) window->title;
             else
                 hint->res_name = (char*) "glfw-application";
 
-            if (strlen(wndconfig->title))
-                hint->res_class = (char*) wndconfig->title;
+            if (strlen(window->title))
+                hint->res_class = (char*) window->title;
             else
                 hint->res_class = (char*) "GLFW-Application";
         }
@@ -780,7 +780,7 @@ static GLFWbool createNativeWindow(_GLFWwindow* window,
     if (_glfw.x11.im)
         _glfwCreateInputContextX11(window);
 
-    _glfwSetWindowTitleX11(window, wndconfig->title);
+    _glfwSetWindowTitleX11(window, window->title);
     _glfwGetWindowPosX11(window, &window->x11.xpos, &window->x11.ypos);
     _glfwGetWindowSizeX11(window, &window->x11.width, &window->x11.height);
 
@@ -3282,6 +3282,24 @@ VkResult _glfwCreateWindowSurfaceX11(VkInstance instance,
     }
 }
 
+_GLFWusercontext* _glfwCreateUserContextX11(_GLFWwindow* window)
+{
+    if (window->context.glx.handle)
+    {
+        return _glfwCreateUserContextGLX(window);
+    }
+    else if (window->context.egl.handle)
+    {
+        return _glfwCreateUserContextEGL(window);
+    }
+    else if (window->context.osmesa.handle)
+    {
+        return _glfwCreateUserContextOSMesa(window);
+    }
+
+    return NULL;
+}
+
 
 //////////////////////////////////////////////////////////////////////////
 //////                        GLFW native API                       //////

tests/CMakeLists.txt

@@ -28,6 +28,7 @@ add_executable(iconify iconify.c ${GETOPT} ${GLAD_GL})
 add_executable(monitors monitors.c ${GETOPT} ${GLAD_GL})
 add_executable(reopen reopen.c ${GLAD_GL})
 add_executable(cursor cursor.c ${GLAD_GL})
+add_executable(usercontext usercontext.c  ${TINYCTHREAD} ${GLAD_GL})
 
 add_executable(empty WIN32 MACOSX_BUNDLE empty.c ${TINYCTHREAD} ${GLAD_GL})
 add_executable(gamma WIN32 MACOSX_BUNDLE gamma.c ${GLAD_GL})
@@ -51,7 +52,7 @@ endif()
 set(GUI_ONLY_BINARIES empty gamma icon inputlag joysticks tearing threads
     timeout title triangle-vulkan window)
 set(CONSOLE_BINARIES allocator clipboard events msaa glfwinfo iconify monitors
-    reopen cursor)
+    reopen cursor usercontext)
 
 set_target_properties(${GUI_ONLY_BINARIES} ${CONSOLE_BINARIES} PROPERTIES
                       C_STANDARD 99

tests/usercontext.c

@@ -0,0 +1,200 @@
+//========================================================================
+// User context test
+// Copyright (c) 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.
+//
+//========================================================================
+//
+// This test is intended to verify whether the OpenGL user context part of
+// the GLFW API is able to be used from multiple threads
+//
+//========================================================================
+
+#include "tinycthread.h"
+
+#define GLAD_GL_IMPLEMENTATION
+#include <glad/gl.h>
+#define GLFW_INCLUDE_NONE
+#include <GLFW/glfw3.h>
+#include <stdio.h>
+
+static void error_callback(int error, const char* description)
+{
+    fprintf(stderr, "Error: %s\n", description);
+}
+
+static int thread_main(void* data)
+{
+    GLFWusercontext* usercontext = (GLFWusercontext*)data;
+
+    /* set the user context current */
+    glfwMakeUserContextCurrent(usercontext);
+
+    if (glfwGetCurrentContext() != NULL)
+    {
+        fprintf(stderr, "Current glfw window context not NULL after glfwMakeUserContextCurrent\n");
+        glfwTerminate();
+        return -1;
+    }
+    if (glfwGetCurrentUserContext() != usercontext)
+    {
+        fprintf(stderr, "Current user context not correct after glfwMakeUserContextCurrent\n");
+        glfwTerminate();
+        return -1;
+    }
+
+    /* set the user context to NULL */
+    glfwMakeUserContextCurrent(NULL);
+    if (glfwGetCurrentUserContext() != NULL)
+    {
+        fprintf(stderr, "Current user context not NULL after glfwMakeContextCurrent\n");
+        glfwTerminate();
+        return -1;
+    }
+
+    return 0;
+}
+
+int main(void)
+{
+    GLFWwindow* window;
+    GLFWusercontext* usercontext;
+    thrd_t thread_id;
+    int result, count;
+
+    glfwSetErrorCallback(error_callback);
+
+    /* Initialize the library */
+    if (!glfwInit())
+        return -1;
+
+    /* Create a windowed mode window and its OpenGL context */
+    window = glfwCreateWindow(640, 480, "User Context", NULL, NULL);
+    if (!window)
+    {
+        glfwTerminate();
+        return -1;
+    }
+
+    /* Make the window's context current */
+    glfwMakeContextCurrent(window);
+    gladLoadGL(glfwGetProcAddress);
+
+    /* make a new context */
+    usercontext = glfwCreateUserContext(window);
+    if (!usercontext)
+    {
+        fprintf(stderr, "Failed to create user context\n");
+        glfwTerminate();
+        return -1;
+    }
+
+    /* set the user context current */
+    glfwMakeUserContextCurrent(usercontext);
+
+    if (glfwGetCurrentContext() != NULL)
+    {
+        fprintf(stderr, "Current glfw window context not NULL after glfwMakeUserContextCurrent\n");
+        glfwTerminate();
+        return -1;
+    }
+    if (glfwGetCurrentUserContext() != usercontext)
+    {
+        fprintf(stderr, "Current user context not correct after glfwMakeUserContextCurrent\n");
+        glfwTerminate();
+        return -1;
+    }
+
+    /* set the window context current */
+    glfwMakeContextCurrent(window);
+
+    if (glfwGetCurrentUserContext() != NULL)
+    {
+        fprintf(stderr, "Current user context not NULL after glfwMakeContextCurrent\n");
+        glfwTerminate();
+        return -1;
+    }
+    if (glfwGetCurrentContext() != window)
+    {
+        fprintf(stderr, "Current glfw window context not correct after glfwMakeContextCurrent\n");
+        glfwTerminate();
+        return -1;
+    }
+
+    glClearColor( 0.4f, 0.3f, 0.4f, 1.0f );
+
+    // Launch a thread which should create and use the usercontext
+    if (thrd_create(&thread_id, thread_main, usercontext ) !=
+            thrd_success)
+    {
+        fprintf(stderr, "Failed to create secondary thread\n");
+
+        glfwTerminate();
+        exit(EXIT_FAILURE);
+    }
+
+    /* Loop 60 times or until the user closes the window */
+    count = 0;
+    while (!glfwWindowShouldClose(window) && count++ < 60)
+    {
+        /* Render here */
+        glClear(GL_COLOR_BUFFER_BIT);
+
+        /* Swap front and back buffers */
+        glfwSwapBuffers(window);
+
+        /* Poll for and process events */
+        glfwPollEvents();
+    }
+
+    thrd_join(thread_id, &result);
+
+    /* One more test now the thread has joined */
+
+    /* set the user context current */
+    glfwMakeUserContextCurrent(usercontext);
+
+    if (glfwGetCurrentContext() != NULL)
+    {
+        fprintf(stderr, "Current glfw window context not NULL after glfwMakeUserContextCurrent\n");
+        glfwTerminate();
+        return -1;
+    }
+    if (glfwGetCurrentUserContext() != usercontext)
+    {
+        fprintf(stderr, "Current user context not correct after glfwMakeUserContextCurrent\n");
+        glfwTerminate();
+        return -1;
+    }
+
+    /* set the user context to NULL */
+    glfwMakeUserContextCurrent(NULL);
+    if (glfwGetCurrentUserContext() != NULL)
+    {
+        fprintf(stderr, "Current user context not NULL after glfwMakeContextCurrent\n");
+        glfwTerminate();
+        return -1;
+    }
+
+    glfwDestroyUserContext(usercontext);
+    glfwTerminate();
+    return 0;
+}