Runtime selection of platform (or window system)

.github/workflows/build.yml

@@ -31,8 +31,8 @@ jobs:
             - name: Build shared library
               run: cmake --build build-shared --parallel
 
-    build-linux-wayland-clang:
-        name: Wayland (Linux, Clang)
+    build-linux-full-clang:
+        name: X11+Wayland (Linux, Clang)
         runs-on: ubuntu-latest
         env:
             CC: clang
@@ -42,38 +42,15 @@ jobs:
             - name: Install dependencies
               run: |
                   sudo apt update
-                  sudo apt install wayland-protocols libwayland-dev libxkbcommon-dev
+                  sudo apt install libxrandr-dev libxinerama-dev libxcursor-dev libxi-dev libxext-dev wayland-protocols libwayland-dev libxkbcommon-dev
 
             - name: Configure static library
-              run: cmake -S . -B build-static -D GLFW_USE_WAYLAND=ON
+              run: cmake -S . -B build-static -D GLFW_BUILD_WAYLAND=ON
             - name: Build static library
               run: cmake --build build-static --parallel
 
             - name: Configure shared library
-              run: cmake -S . -B build-shared -D GLFW_USE_WAYLAND=ON -D BUILD_SHARED_LIBS=ON
-            - name: Build shared library
-              run: cmake --build build-shared --parallel
-
-    build-linux-null-clang:
-        name: Null (Linux, Clang)
-        runs-on: ubuntu-latest
-        env:
-            CC: clang
-            CFLAGS: -Werror
-        steps:
-            - uses: actions/checkout@v2
-            - name: Install dependencies
-              run: |
-                  sudo apt update
-                  sudo apt install libosmesa6-dev
-
-            - name: Configure static library
-              run: cmake -S . -B build-static -D GLFW_USE_OSMESA=ON
-            - name: Build static library
-              run: cmake --build build-static --parallel
-
-            - name: Configure shared library
-              run: cmake -S . -B build-shared -D GLFW_USE_OSMESA=ON -D BUILD_SHARED_LIBS=ON
+              run: cmake -S . -B build-shared -D GLFW_BUILD_WAYLAND=ON -D BUILD_SHARED_LIBS=ON
             - name: Build shared library
               run: cmake --build build-shared --parallel
 

CMakeLists.txt

@@ -32,12 +32,13 @@ option(GLFW_VULKAN_STATIC "Assume the Vulkan loader is linked with the applicati
 include(GNUInstallDirs)
 include(CMakeDependentOption)
 
-cmake_dependent_option(GLFW_USE_OSMESA "Use OSMesa for offscreen context creation" OFF
-                       "UNIX" OFF)
+cmake_dependent_option(GLFW_BUILD_WIN32 "Build support for Win32" ON "WIN32" OFF)
+cmake_dependent_option(GLFW_BUILD_COCOA "Build support for Cocoa" ON "APPLE" OFF)
+cmake_dependent_option(GLFW_BUILD_X11 "Build support for X11" ON "UNIX;NOT APPLE" OFF)
+cmake_dependent_option(GLFW_BUILD_WAYLAND "Build support for Wayland" OFF "UNIX;NOT APPLE" OFF)
+
 cmake_dependent_option(GLFW_USE_HYBRID_HPG "Force use of high-performance GPU on hybrid systems" OFF
                        "WIN32" OFF)
-cmake_dependent_option(GLFW_USE_WAYLAND "Use Wayland for window creation" OFF
-                       "UNIX;NOT APPLE" OFF)
 cmake_dependent_option(USE_MSVC_RUNTIME_LIBRARY_DLL "Use MSVC runtime library DLL" ON
                        "MSVC" OFF)
 
@@ -54,22 +55,6 @@ else()
     set(GLFW_BUILD_SHARED_LIBRARY ${BUILD_SHARED_LIBS})
 endif()
 
-if (UNIX AND GLFW_BUILD_SHARED_LIBRARY)
-    # On Unix-like systems, shared libraries can use the soname system.
-    set(GLFW_LIB_NAME glfw)
-else()
-    set(GLFW_LIB_NAME glfw3)
-endif()
-
-if (GLFW_VULKAN_STATIC)
-    if (GLFW_BUILD_SHARED_LIBRARY)
-        # If you absolutely must do this, remove this line and add the Vulkan
-        # loader static library via the CMAKE_SHARED_LINKER_FLAGS
-        message(FATAL_ERROR "You are trying to link the Vulkan loader static library into the GLFW shared library")
-    endif()
-    set(_GLFW_VULKAN_STATIC 1)
-endif()
-
 list(APPEND CMAKE_MODULE_PATH "${GLFW_SOURCE_DIR}/CMake/modules")
 
 find_package(Threads REQUIRED)
@@ -79,6 +64,22 @@ if (GLFW_BUILD_DOCS)
     find_package(Doxygen)
 endif()
 
+#--------------------------------------------------------------------
+# Report backend selection
+#--------------------------------------------------------------------
+if (GLFW_BUILD_WIN32)
+    message(STATUS "Including Win32 support")
+endif()
+if (GLFW_BUILD_COCOA)
+    message(STATUS "Including Cocoa support")
+endif()
+if (GLFW_BUILD_WAYLAND)
+    message(STATUS "Including Wayland support")
+endif()
+if (GLFW_BUILD_X11)
+    message(STATUS "Including X11 support")
+endif()
+
 #--------------------------------------------------------------------
 # Apply Microsoft C runtime library option
 # This is here because it also applies to tests and examples
@@ -104,169 +105,6 @@ if (MSVC AND NOT USE_MSVC_RUNTIME_LIBRARY_DLL)
     endif()
 endif()
 
-#--------------------------------------------------------------------
-# Detect and select backend APIs
-#--------------------------------------------------------------------
-if (GLFW_USE_WAYLAND)
-    set(_GLFW_WAYLAND 1)
-    message(STATUS "Using Wayland for window creation")
-elseif (GLFW_USE_OSMESA)
-    set(_GLFW_OSMESA 1)
-    message(STATUS "Using OSMesa for headless context creation")
-elseif (WIN32)
-    set(_GLFW_WIN32 1)
-    message(STATUS "Using Win32 for window creation")
-elseif (APPLE)
-    set(_GLFW_COCOA 1)
-    message(STATUS "Using Cocoa for window creation")
-elseif (UNIX)
-    set(_GLFW_X11 1)
-    message(STATUS "Using X11 for window creation")
-else()
-    message(FATAL_ERROR "No supported platform was detected")
-endif()
-
-#--------------------------------------------------------------------
-# Find and add Unix math and time libraries
-#--------------------------------------------------------------------
-if (UNIX AND NOT APPLE)
-    find_library(RT_LIBRARY rt)
-    mark_as_advanced(RT_LIBRARY)
-    if (RT_LIBRARY)
-        list(APPEND glfw_LIBRARIES "${RT_LIBRARY}")
-        list(APPEND glfw_PKG_LIBS "-lrt")
-    endif()
-
-    find_library(MATH_LIBRARY m)
-    mark_as_advanced(MATH_LIBRARY)
-    if (MATH_LIBRARY)
-        list(APPEND glfw_LIBRARIES "${MATH_LIBRARY}")
-        list(APPEND glfw_PKG_LIBS "-lm")
-    endif()
-
-    if (CMAKE_DL_LIBS)
-        list(APPEND glfw_LIBRARIES "${CMAKE_DL_LIBS}")
-        list(APPEND glfw_PKG_LIBS "-l${CMAKE_DL_LIBS}")
-    endif()
-endif()
-
-#--------------------------------------------------------------------
-# Use Win32 for window creation
-#--------------------------------------------------------------------
-if (_GLFW_WIN32)
-
-    list(APPEND glfw_PKG_LIBS "-lgdi32")
-
-    if (GLFW_USE_HYBRID_HPG)
-        set(_GLFW_USE_HYBRID_HPG 1)
-    endif()
-endif()
-
-#--------------------------------------------------------------------
-# Use X11 for window creation
-#--------------------------------------------------------------------
-if (_GLFW_X11)
-
-    find_package(X11 REQUIRED)
-
-    # Set up library and include paths
-    list(APPEND glfw_INCLUDE_DIRS "${X11_X11_INCLUDE_PATH}")
-
-    # Check for XRandR (modern resolution switching and gamma control)
-    if (NOT X11_Xrandr_INCLUDE_PATH)
-        message(FATAL_ERROR "RandR headers not found; install libxrandr development package")
-    endif()
-
-    # Check for Xinerama (legacy multi-monitor support)
-    if (NOT X11_Xinerama_INCLUDE_PATH)
-        message(FATAL_ERROR "Xinerama headers not found; install libxinerama development package")
-    endif()
-
-    # Check for Xkb (X keyboard extension)
-    if (NOT X11_Xkb_INCLUDE_PATH)
-        message(FATAL_ERROR "XKB headers not found; install X11 development package")
-    endif()
-
-    # Check for Xcursor (cursor creation from RGBA images)
-    if (NOT X11_Xcursor_INCLUDE_PATH)
-        message(FATAL_ERROR "Xcursor headers not found; install libxcursor development package")
-    endif()
-
-    # Check for XInput (modern HID input)
-    if (NOT X11_Xi_INCLUDE_PATH)
-        message(FATAL_ERROR "XInput headers not found; install libxi development package")
-    endif()
-
-    # Check for X Shape (custom window input shape)
-    if (NOT X11_Xshape_INCLUDE_PATH)
-        message(FATAL_ERROR "X Shape headers not found; install libxext development package")
-    endif()
-endif()
-
-#--------------------------------------------------------------------
-# Use Wayland for window creation
-#--------------------------------------------------------------------
-if (_GLFW_WAYLAND)
-
-    include(FindPkgConfig)
-    pkg_check_modules(Wayland REQUIRED
-        wayland-client>=0.2.7
-        wayland-cursor>=0.2.7
-        wayland-egl>=0.2.7
-        xkbcommon)
-
-    list(APPEND glfw_INCLUDE_DIRS "${Wayland_INCLUDE_DIRS}")
-
-    include(CheckIncludeFiles)
-    include(CheckFunctionExists)
-    check_include_files(xkbcommon/xkbcommon-compose.h HAVE_XKBCOMMON_COMPOSE_H)
-    check_function_exists(memfd_create HAVE_MEMFD_CREATE)
-
-    if (NOT CMAKE_SYSTEM_NAME STREQUAL "Linux")
-        find_package(EpollShim)
-        if (EPOLLSHIM_FOUND)
-            list(APPEND glfw_INCLUDE_DIRS "${EPOLLSHIM_INCLUDE_DIRS}")
-            list(APPEND glfw_LIBRARIES "${EPOLLSHIM_LIBRARIES}")
-        endif()
-    endif()
-endif()
-
-#--------------------------------------------------------------------
-# Use Cocoa for window creation and NSOpenGL for context creation
-#--------------------------------------------------------------------
-if (_GLFW_COCOA)
-
-    list(APPEND glfw_LIBRARIES
-        "-framework Cocoa"
-        "-framework IOKit"
-        "-framework CoreFoundation")
-
-    set(glfw_PKG_DEPS "")
-    set(glfw_PKG_LIBS "-framework Cocoa -framework IOKit -framework CoreFoundation")
-endif()
-
-#--------------------------------------------------------------------
-# Add the Vulkan loader as a dependency if necessary
-#--------------------------------------------------------------------
-if (GLFW_VULKAN_STATIC)
-    list(APPEND glfw_PKG_DEPS "vulkan")
-endif()
-
-#--------------------------------------------------------------------
-# Export GLFW library dependencies
-#--------------------------------------------------------------------
-foreach(arg ${glfw_PKG_DEPS})
-    string(APPEND deps " ${arg}")
-endforeach()
-foreach(arg ${glfw_PKG_LIBS})
-    string(APPEND libs " ${arg}")
-endforeach()
-
-set(GLFW_PKG_CONFIG_REQUIRES_PRIVATE "${deps}" CACHE INTERNAL
-    "GLFW pkg-config Requires.private")
-set(GLFW_PKG_CONFIG_LIBS_PRIVATE "${libs}" CACHE INTERNAL
-    "GLFW pkg-config Libs.private")
-
 #--------------------------------------------------------------------
 # Create generated files
 #--------------------------------------------------------------------
@@ -283,8 +121,6 @@ write_basic_package_version_file(src/glfw3ConfigVersion.cmake
                                  VERSION ${GLFW_VERSION}
                                  COMPATIBILITY SameMajorVersion)
 
-configure_file(CMake/glfw3.pc.in src/glfw3.pc @ONLY)
-
 #--------------------------------------------------------------------
 # Add subdirectories
 #--------------------------------------------------------------------

README.md

@@ -116,6 +116,9 @@ information on what to include when reporting a bug.
 
 ## Changelog
 
+ - Added `GLFW_PLATFORM` init hint for runtime platform selection
+ - Added `glfwGetPlatform` function to query what platform was selected
+ - Added `glfwPlatformSupported` function to query if a platform is supported
  - Added `glfwInitAllocator` for setting a custom memory allocator (#544,#1628,#1947)
  - Added `GLFWallocator` struct and `GLFWallocatefun`, `GLFWreallocatefun` and
    `GLFWdeallocatefun` types (#544,#1628,#1947)
@@ -140,6 +143,7 @@ information on what to include when reporting a bug.
  - Made `GLFW_DOUBLEBUFFER` a read-only window attribute
  - Updated the minimum required CMake version to 3.1
  - Disabled tests and examples by default when built as a CMake subdirectory
+ - Removed CMake generated configuration header
  - Bugfix: The CMake config-file package used an absolute path and was not
    relocatable (#1470)
  - Bugfix: Video modes with a duplicate screen area were discarded (#1555,#1556)
@@ -433,6 +437,7 @@ skills.
  - Eddie Ringle
  - Max Risuhin
  - Jorge Rodriguez
+ - Jari Ronkainen
  - Luca Rood
  - Ed Ropple
  - Aleksey Rybalkin

docs/compile.dox

@@ -341,11 +341,10 @@ a configuration macro to be defined in order to know what window system it is
 being compiled for and also has optional, platform-specific ones for various
 features.
 
-When building with CMake, the `glfw_config.h` configuration header is generated
-based on the current platform and CMake options.  The GLFW CMake environment
-defines @b GLFW_USE_CONFIG_H, which causes this header to be included by
-`internal.h`.  Without this macro, GLFW will expect the necessary configuration
-macros to be defined on the command-line.
+When building, GLFW will expect the necessary configuration macros to be defined
+on the command-line.  The GLFW CMake files set these as private compile
+definitions on the GLFW target but if you compile the GLFW sources manually you
+will need to define them yourself.
 
 The window creation API is used to create windows, handle input, monitors, gamma
 ramps and clipboard.  The options are:

docs/internal.dox

@@ -104,8 +104,7 @@ Examples: `isValidElementForJoystick`
 @section internals_config Configuration macros
 
 GLFW uses a number of configuration macros to select at compile time which
-interfaces and code paths to use.  They are defined in the glfw_config.h header file,
-which is generated from the `glfw_config.h.in` file by CMake.
+interfaces and code paths to use.  They are defined in the GLFW CMake target.
 
 Configuration macros the same style as tokens in the public interface, except
 with a leading underscore.

docs/intro.dox

@@ -30,6 +30,7 @@ successfully initialized, and only from the main thread.
 
  - @ref glfwGetVersion
  - @ref glfwGetVersionString
+ - @ref glfwPlatformSupported
  - @ref glfwGetError
  - @ref glfwSetErrorCallback
  - @ref glfwInitHint
@@ -89,6 +90,15 @@ Setting these hints requires no platform specific headers or functions.
 
 @subsubsection init_hints_shared Shared init hints
 
+@anchor GLFW_PLATFORM
+__GLFW_PLATFORM__ specifies the platform to use for windowing and input.
+Possible values are `GLFW_ANY_PLATFORM`, `GLFW_PLATFORM_WIN32`,
+`GLFW_PLATFORM_COCOA`, `GLFW_PLATFORM_X11`, `GLFW_PLATFORM_WAYLAND` and
+`GLFW_PLATFORM_NULL`.  The default value is `GLFW_ANY_PLATFORM`, which will
+choose any platform the library includes support for except for the null
+backend.
+
+
 @anchor GLFW_JOYSTICK_HAT_BUTTONS
 __GLFW_JOYSTICK_HAT_BUTTONS__ specifies whether to also expose joystick hats as
 buttons, for compatibility with earlier versions of GLFW that did not have @ref
@@ -137,6 +147,7 @@ the `VK_KHR_xlib_surface` extension.  Possible values are `GLFW_TRUE` and
 
 Initialization hint              | Default value                   | Supported values
 -------------------------------- | ------------------------------- | ----------------
+@ref GLFW_PLATFORM               | `GLFW_ANY_PLATFORM`             | `GLFW_ANY_PLATFORM`, `GLFW_PLATFORM_WIN32`, `GLFW_PLATFORM_COCOA`, `GLFW_PLATFORM_X11`, `GLFW_PLATFORM_WAYLAND` or `GLFW_PLATFORM_NULL`
 @ref GLFW_JOYSTICK_HAT_BUTTONS   | `GLFW_TRUE`                     | `GLFW_TRUE` or `GLFW_FALSE`
 @ref GLFW_ANGLE_PLATFORM_TYPE    | `GLFW_ANGLE_PLATFORM_TYPE_NONE` | `GLFW_ANGLE_PLATFORM_TYPE_NONE`, `GLFW_ANGLE_PLATFORM_TYPE_OPENGL`, `GLFW_ANGLE_PLATFORM_TYPE_OPENGLES`, `GLFW_ANGLE_PLATFORM_TYPE_D3D9`, `GLFW_ANGLE_PLATFORM_TYPE_D3D11`, `GLFW_ANGLE_PLATFORM_TYPE_VULKAN` or `GLFW_ANGLE_PLATFORM_TYPE_METAL`
 @ref GLFW_COCOA_CHDIR_RESOURCES  | `GLFW_TRUE`                     | `GLFW_TRUE` or `GLFW_FALSE`