Replace MAGNUM_TARGET_{HEADLESS,DESKTOP_GLES} with MAGNUM_TARGET_EGL.

These two options were mutually exclusive, and both were doing the same
thing -- switching to EGL on desktop GL, or switching away from EGL on
GLES. That made all logic vastly more complicated than it should be, and
unfortunately it took me half a decade to realize that. The new logic is
significantly simpler everywhere.

As usual, the old options are still recognized by CMake on a deprecated
build (with a warning), and are still exposed both as CMake variables
and a preprocessor define. But the logic for them was quite complicated,
so I don't guarantee all cases are covered.

I also tried to clean up the dependent CMake options to allow building
GLX and WGL apps on GLES independently of whether EGL is used, but it's
quite a mess due to the limitations of CMake < 3.22. Build directories
that have the options switched randomly over a long time might start
misbehaving, but the initial build should work well.

CMakeLists.txt

@@ -146,27 +146,17 @@ if(NOT DEFINED _MAGNUM_ACCEPT_DEPRECATED_UNPREFIXED_OPTIONS)
     endforeach()
 endif()
 
-# If targeting iOS, Android, Emscripten or Windows RT, set explicit OpenGL ES
-# support
-if(NOT CORRADE_TARGET_IOS AND NOT CORRADE_TARGET_ANDROID AND NOT CORRADE_TARGET_EMSCRIPTEN AND NOT CORRADE_TARGET_WINDOWS_RT)
-    option(MAGNUM_TARGET_GLES "Build for OpenGL ES / WebGL" OFF)
-else()
-    set(MAGNUM_TARGET_GLES ON)
-endif()
-
-cmake_dependent_option(MAGNUM_TARGET_GLES2 "Build for OpenGL ES 2 / WebGL 1.0" ON "MAGNUM_TARGET_GLES" OFF)
-cmake_dependent_option(MAGNUM_TARGET_DESKTOP_GLES "Build for OpenGL ES on desktop" OFF "MAGNUM_TARGET_GLES" OFF)
-
 # Magnum GL Info (currently only using GLX/CGL/EGL on *nix, WGL/EGL on Windows
 # and EGL on Emscripten)
 if(CORRADE_TARGET_UNIX OR CORRADE_TARGET_WINDOWS OR CORRADE_TARGET_EMSCRIPTEN)
     option(MAGNUM_WITH_GL_INFO "Build magnum-gl-info utility" OFF)
 endif()
 
-# Desktop-only utilities
+# Desktop-only utilities. Not guaranteed to build on GLES, but showing the
+# option everywhere for simplicity.
 if(CORRADE_TARGET_UNIX OR CORRADE_TARGET_WINDOWS)
-    cmake_dependent_option(MAGNUM_WITH_FONTCONVERTER "Build magnum-fontconverter utility" OFF "NOT MAGNUM_TARGET_GLES" OFF)
-    cmake_dependent_option(MAGNUM_WITH_DISTANCEFIELDCONVERTER "Build magnum-distancefieldconverter utility" OFF "NOT MAGNUM_TARGET_GLES" OFF)
+    option(MAGNUM_WITH_FONTCONVERTER "Build magnum-fontconverter utility" OFF)
+    option(MAGNUM_WITH_DISTANCEFIELDCONVERTER "Build magnum-distancefieldconverter utility" OFF)
 endif()
 
 # API-independent utilities
@@ -208,12 +198,31 @@ cmake_dependent_option(MAGNUM_WITH_TRADE "Build Trade library" ON "NOT MAGNUM_WI
 cmake_dependent_option(MAGNUM_WITH_GL "Build GL library" ON "NOT MAGNUM_WITH_SHADERS;NOT MAGNUM_WITH_GL_INFO;NOT MAGNUM_WITH_ANDROIDAPPLICATION;NOT MAGNUM_WITH_WINDOWLESSIOSAPPLICATION;NOT MAGNUM_WITH_WINDOWLESSCGLAPPLICATION;NOT MAGNUM_WITH_WINDOWLESSGLXAPPLICATION;NOT MAGNUM_WITH_CGLCONTEXT;NOT MAGNUM_WITH_GLXAPPLICATION;NOT MAGNUM_WITH_GLXCONTEXT;NOT MAGNUM_WITH_XEGLAPPLICATION;NOT MAGNUM_WITH_WINDOWLESSWGLAPPLICATION;NOT MAGNUM_WITH_WGLCONTEXT;NOT MAGNUM_WITH_DISTANCEFIELDCONVERTER" ON)
 option(MAGNUM_WITH_PRIMITIVES "Build Primitives library" ON)
 
-cmake_dependent_option(MAGNUM_TARGET_HEADLESS "Build command-line utilities for use on a headless machines" OFF "MAGNUM_WITH_GL" OFF)
 cmake_dependent_option(MAGNUM_TARGET_GL "Build libraries with OpenGL interoperability" ON "MAGNUM_WITH_GL" OFF)
 
-# EGL context and windowless EGL application, available everywhere
-cmake_dependent_option(MAGNUM_WITH_WINDOWLESSEGLAPPLICATION "Build WindowlessEglApplication library" OFF "NOT MAGNUM_TARGET_GLES OR MAGNUM_TARGET_DESKTOP_GLES OR NOT MAGNUM_WITH_GL_INFO;NOT MAGNUM_TARGET_HEADLESS" ON)
-option(MAGNUM_WITH_EGLCONTEXT "Build EglContext library" OFF)
+# If targeting iOS, Android, Emscripten or Windows RT, implicitly enable GLES.
+# Otherwise default to desktop GL.
+if(CORRADE_TARGET_IOS OR CORRADE_TARGET_ANDROID OR CORRADE_TARGET_EMSCRIPTEN OR CORRADE_TARGET_WINDOWS_RT)
+    set(MAGNUM_TARGET_GLES ON)
+elseif(MAGNUM_WITH_GL)
+    cmake_dependent_option(MAGNUM_TARGET_GLES "Build for OpenGL ES / WebGL" OFF "MAGNUM_WITH_GL" OFF)
+endif()
+
+# If targeting Android, Emscripten or Windows RT, implicitly enable EGL.
+# Otherwise enable EGL by default only if targeting GLES and not on iOS (where
+# it's EAGL instead)
+if(CORRADE_TARGET_ANDROID OR CORRADE_TARGET_EMSCRIPTEN OR CORRADE_TARGET_WINDOWS_RT)
+    set(MAGNUM_TARGET_EGL ON)
+else()
+    if(MAGNUM_TARGET_GLES AND NOT CORRADE_TARGET_IOS)
+        set(_MAGNUM_TARGET_EGL_DEFAULT ON)
+    else()
+        set(_MAGNUM_TARGET_EGL_DEFAULT OFF)
+    endif()
+    cmake_dependent_option(MAGNUM_TARGET_EGL "Build for EGL instead of EAGL / CGL / GLX / WGL" ${_MAGNUM_TARGET_EGL_DEFAULT} "MAGNUM_WITH_GL" OFF)
+endif()
+
+cmake_dependent_option(MAGNUM_TARGET_GLES2 "Build for OpenGL ES 2 / WebGL 1.0" ON "MAGNUM_TARGET_GLES" OFF)
 
 # Vulkan, everywhere except Emscripten
 if(NOT CORRADE_TARGET_EMSCRIPTEN)
@@ -221,6 +230,18 @@ if(NOT CORRADE_TARGET_EMSCRIPTEN)
     cmake_dependent_option(MAGNUM_TARGET_VK "Build libraries with Vulkan interoperability" ON "MAGNUM_WITH_VK" OFF)
 endif()
 
+# EGL context and windowless EGL application, available everywhere. If
+# targeting EGL and not on Windows, it's implied by the CLI tools, otherwise
+# it's independent.
+if(MAGNUM_TARGET_EGL AND NOT CORRADE_TARGET_WINDOWS)
+    cmake_dependent_option(MAGNUM_WITH_WINDOWLESSEGLAPPLICATION "Build WindowlessEglApplication library" OFF "NOT MAGNUM_WITH_GL_INFO;NOT MAGNUM_WITH_DISTANCEFIELDCONVERTER;NOT MAGNUM_WITH_FONTCONVERTER" ON)
+else()
+    # TODO when CMake 3.22 can be relied on, clean this up to use a proper
+    # condition instead
+    cmake_dependent_option(MAGNUM_WITH_WINDWLESSEGLAPPLICATION "Build WindowlessEglApplication library" OFF "ON" OFF)
+endif()
+option(MAGNUM_WITH_EGLCONTEXT "Build EglContext library" OFF)
+
 # Android-specific application libraries
 if(CORRADE_TARGET_ANDROID)
     option(MAGNUM_WITH_ANDROIDAPPLICATION "Build AndroidApplication library" OFF)
@@ -234,25 +255,42 @@ elseif(CORRADE_TARGET_IOS)
     option(MAGNUM_WITH_WINDOWLESSIOSAPPLICATION "Build WindowlessIosApplication library" OFF)
 
 # macOS-specific application libraries
-elseif(CORRADE_TARGET_APPLE AND NOT MAGNUM_TARGET_GLES)
-    cmake_dependent_option(MAGNUM_WITH_WINDOWLESSCGLAPPLICATION "Build WindowlessCglApplication library" OFF "NOT MAGNUM_WITH_GL_INFO;NOT MAGNUM_WITH_FONTCONVERTER;NOT MAGNUM_WITH_DISTANCEFIELDCONVERTER" ON)
+elseif(CORRADE_TARGET_APPLE AND NOT MAGNUM_TARGET_EGL)
+    # WindowlessCglApplication implied by the CLI tools unless targeting EGL
+    if(NOT MAGNUM_TARGET_EGL)
+        cmake_dependent_option(MAGNUM_WITH_WINDOWLESSCGLAPPLICATION "Build WindowlessCglApplication library" OFF "NOT MAGNUM_WITH_GL_INFO;NOT MAGNUM_WITH_FONTCONVERTER;NOT MAGNUM_WITH_DISTANCEFIELDCONVERTER" ON)
+    else()
+        # TODO when CMake 3.22 can be relied on, clean this up to use a proper
+        # condition instead
+        cmake_dependent_option(MAGNUM_WITH_WINDOWLESSCGLAPPLICATION "Build WindowlessCglApplication library" OFF "ON" OFF)
+    endif()
     option(MAGNUM_WITH_CGLCONTEXT "Build CglContext library" OFF)
 
 # X11 + GLX/EGL-specific application libraries
 elseif(CORRADE_TARGET_UNIX)
     option(MAGNUM_WITH_GLXAPPLICATION "Build GlxApplication library" OFF)
-    if(NOT MAGNUM_TARGET_GLES OR MAGNUM_TARGET_DESKTOP_GLES)
+    # WindowlessGlxApplication implied by the CLI tools unless targeting EGL
+    if(NOT MAGNUM_TARGET_EGL)
         cmake_dependent_option(MAGNUM_WITH_WINDOWLESSGLXAPPLICATION "Build WindowlessGlxApplication library" OFF "NOT MAGNUM_WITH_GL_INFO;NOT MAGNUM_WITH_FONTCONVERTER;NOT MAGNUM_WITH_DISTANCEFIELDCONVERTER" ON)
-        option(MAGNUM_WITH_GLXCONTEXT "Build GlxContext library" OFF)
+    else()
+        # TODO when CMake 3.22 can be relied on, clean this up to use a proper
+        # condition instead
+        cmake_dependent_option(MAGNUM_WITH_WINDOWLESSGLXAPPLICATION "Build WindowlessGlxApplication library" OFF "ON" OFF)
     endif()
+    option(MAGNUM_WITH_GLXCONTEXT "Build GlxContext library" OFF)
     option(MAGNUM_WITH_XEGLAPPLICATION "Build XEglApplication library" OFF)
 
 # Windows-specific application libraries
 elseif(CORRADE_TARGET_WINDOWS)
-    if(NOT MAGNUM_TARGET_GLES OR MAGNUM_TARGET_DESKTOP_GLES)
+    # WindowlessWglApplication implied by the CLI tools unless targeting EGL
+    if(NOT MAGNUM_TARGET_EGL)
         cmake_dependent_option(MAGNUM_WITH_WINDOWLESSWGLAPPLICATION "Build WindowlessWglApplication library" OFF "NOT MAGNUM_WITH_GL_INFO;NOT MAGNUM_WITH_FONTCONVERTER;NOT MAGNUM_WITH_DISTANCEFIELDCONVERTER" ON)
-        option(MAGNUM_WITH_WGLCONTEXT "Build WglContext library" OFF)
+    else()
+        # TODO when CMake 3.22 can be relied on, clean this up to use a proper
+        # condition instead
+        cmake_dependent_option(MAGNUM_WITH_WINDOWLESSWGLAPPLICATION "Build WindowlessWglApplication library" OFF "ON" OFF)
     endif()
+    option(MAGNUM_WITH_WGLCONTEXT "Build WglContext library" OFF)
 endif()
 
 # Platform-independent (almost) application libraries
@@ -265,18 +303,6 @@ endif()
 
 option(MAGNUM_BUILD_DEPRECATED "Include deprecated API in the build" ON)
 
-# BUILD_MULTITHREADED got moved to Corrade itself. In case we're building with
-# deprecated features enabled, print a warning in case it's set but Corrade
-# reports a different value. We can't print a warning in case it's set because
-# that would cause false positives when both Corrade and Magnum are subprojects
-# (and thus this option is visible to both). Otherwise it's silent --- for
-# non-deprecated builds CMake will at most warn about "variable being unused".
-if(MAGNUM_BUILD_DEPRECATED)
-    if(DEFINED BUILD_MULTITHREADED AND ((NOT CORRADE_BUILD_MULTITHREADED AND BUILD_MULTITHREADED) OR (CORRADE_BUILD_MULTITHREADED AND NOT BUILD_MULTITHREADED)))
-        message(DEPRECATION "BUILD_MULTITHREADED (set to ${BUILD_MULTITHREADED}) is now ignored — you need to set it when building Corrade instead (there it's ${CORRADE_BUILD_MULTITHREADED} now)")
-    endif()
-endif()
-
 set(MAGNUM_DEPLOY_PREFIX "."
     CACHE STRING "Prefix where to put final application executables")
 
@@ -386,6 +412,9 @@ if(_MAGNUM_ACCEPT_DEPRECATED_UNPREFIXED_OPTIONS AND MAGNUM_BUILD_DEPRECATED)
                 set(WITH_WINDOWLESSCGLAPPLICATION ON)
             endif()
         elseif(CORRADE_TARGET_UNIX)
+            # Checking the old deprecated options here, checking
+            # MAGNUM_TARGET_EGL wouldn't make sense as that's an option the
+            # old code definitely won't use.
             if((NOT TARGET_GLES AND NOT TARGET_HEADLESS) OR TARGET_DESKTOP_GLES)
                 if(NOT DEFINED WITH_WINDOWLESSGLXAPPLICATION)
                     set(WITH_WINDOWLESSGLXAPPLICATION ON)
@@ -454,6 +483,45 @@ if(_MAGNUM_ACCEPT_DEPRECATED_UNPREFIXED_OPTIONS AND MAGNUM_BUILD_DEPRECATED)
     endif()
 endif()
 
+# Handle other deprecated options. For non-deprecated builds CMake will at most
+# warn about "variable being unused". Done after the MAGNUM_ prefix backwards
+# compatibility above to pick up also the old names, i.e. TARGET_HEADLESS ->
+# MAGNUM_TARGET_EGL.
+if(MAGNUM_BUILD_DEPRECATED)
+    # BUILD_MULTITHREADED got moved to Corrade itself. Print a warning in case
+    # it's set but Corrade reports a different value. We can't print a warning
+    # in case it's set because that would cause false positives when both
+    # Corrade and Magnum are subprojects (and thus this option is visible to
+    # both).
+    if(DEFINED BUILD_MULTITHREADED AND ((NOT CORRADE_BUILD_MULTITHREADED AND BUILD_MULTITHREADED) OR (CORRADE_BUILD_MULTITHREADED AND NOT BUILD_MULTITHREADED)))
+        message(DEPRECATION "BUILD_MULTITHREADED (set to ${BUILD_MULTITHREADED}) is now ignored — you need to set it when building Corrade instead (there it's ${CORRADE_BUILD_MULTITHREADED} now)")
+    endif()
+
+    # The following two options were desktop-only, so don't handle any
+    # backwards compatibility on mobile / web platforms
+    if(NOT CORRADE_TARGET_IOS AND NOT CORRADE_TARGET_ANDROID AND NOT CORRADE_TARGET_EMSCRIPTEN AND NOT CORRADE_TARGET_WINDOWS_RT)
+        # MAGNUM_TARGET_HEADLESS is now MAGNUM_TARGET_EGL. Print a warning in
+        # case we're on desktop GL (where it was meant to be used) and the two
+        # are set to a different value, and sync them.
+        if(NOT MAGNUM_TARGET_GLES AND DEFINED MAGNUM_TARGET_HEADLESS AND ((NOT MAGNUM_TARGET_EGL AND MAGNUM_TARGET_HEADLESS) OR (MAGNUM_TARGET_EGL AND NOT MAGNUM_TARGET_HEADLESS)))
+            message(DEPRECATION "MAGNUM_TARGET_HEADLESS is deprecated, use MAGNUM_TARGET_EGL instead")
+            set(MAGNUM_TARGET_EGL ${MAGNUM_TARGET_HEADLESS})
+        endif()
+
+        # MAGNUM_TARGET_DESKTOP_GLES is now an inverse of MAGNUM_TARGET_EGL.
+        # Print a warning in case we're on GLES (where it was meant to be used)
+        # and the two are set to a different value, and sync them.
+        if(MAGNUM_TARGET_GLES AND DEFINED MAGNUM_TARGET_DESKTOP_GLES AND ((MAGNUM_TARGET_EGL AND MAGNUM_TARGET_DESKTOP_GLES) OR (NOT MAGNUM_TARGET_EGL AND NOT MAGNUM_TARGET_DESKTOP_GLES)))
+            message(DEPRECATION "MAGNUM_TARGET_DESKTOP_GLES is deprecated, use MAGNUM_TARGET_EGL instead")
+            if(MAGNUM_TARGET_DESKTOP_GLES)
+                set(MAGNUM_TARGET_EGL OFF)
+            else()
+                set(MAGNUM_TARGET_EGL ON)
+            endif()
+        endif()
+    endif()
+endif()
+
 # Dynamic linking is meaningless on Emscripten and too inconvenient on Android
 if(CORRADE_TARGET_EMSCRIPTEN OR CORRADE_TARGET_ANDROID)
     set(MAGNUM_BUILD_STATIC ON)
@@ -465,7 +533,7 @@ endif()
 
 # Check dependencies
 if(MAGNUM_WITH_GL)
-    if(NOT MAGNUM_TARGET_GLES OR MAGNUM_TARGET_DESKTOP_GLES)
+    if(NOT MAGNUM_TARGET_GLES OR (MAGNUM_TARGET_GLES AND NOT MAGNUM_TARGET_EGL AND NOT CORRADE_TARGET_IOS))
         # OpenGL library preference. Prefer to use GLVND, since that's the
         # better approach nowadays, but allow the users to override it from
         # outside in case it is broken for some reason (Nvidia drivers in
@@ -487,7 +555,7 @@ else()
     # consistency
     set(MAGNUM_TARGET_GLES OFF)
     set(MAGNUM_TARGET_GLES2 OFF)
-    set(MAGNUM_TARGET_DESKTOP_GLES OFF)
+    set(MAGNUM_TARGET_EGL OFF)
 endif()
 
 if(NOT MAGNUM_WITH_VK)
@@ -523,7 +591,7 @@ if(MAGNUM_BUILD_TESTS)
 endif()
 
 if(MAGNUM_WITH_OPENGLTESTER)
-    if(MAGNUM_TARGET_HEADLESS OR CORRADE_TARGET_EMSCRIPTEN OR CORRADE_TARGET_ANDROID)
+    if(MAGNUM_TARGET_EGL)
         set(MAGNUM_WITH_WINDOWLESSEGLAPPLICATION ON)
         set(OPENGLTESTER_APPLICATION MagnumWindowlessEglApplication)
     elseif(CORRADE_TARGET_IOS)
@@ -533,21 +601,11 @@ if(MAGNUM_WITH_OPENGLTESTER)
         set(MAGNUM_WITH_WINDOWLESSCGLAPPLICATION ON)
         set(OPENGLTESTER_APPLICATION MagnumWindowlessCglApplication)
     elseif(CORRADE_TARGET_UNIX)
-        if(MAGNUM_TARGET_GLES AND NOT MAGNUM_TARGET_DESKTOP_GLES)
-            set(MAGNUM_WITH_WINDOWLESSEGLAPPLICATION ON)
-            set(OPENGLTESTER_APPLICATION MagnumWindowlessEglApplication)
-        else()
-            set(MAGNUM_WITH_WINDOWLESSGLXAPPLICATION ON)
-            set(OPENGLTESTER_APPLICATION MagnumWindowlessGlxApplication)
-        endif()
+        set(MAGNUM_WITH_WINDOWLESSGLXAPPLICATION ON)
+        set(OPENGLTESTER_APPLICATION MagnumWindowlessGlxApplication)
     elseif(CORRADE_TARGET_WINDOWS)
-        if(MAGNUM_TARGET_GLES AND NOT MAGNUM_TARGET_DESKTOP_GLES)
-            set(MAGNUM_WITH_WINDOWLESSEGLAPPLICATION ON)
-            set(OPENGLTESTER_APPLICATION MagnumWindowlessEglApplication)
-        else()
-            set(MAGNUM_WITH_WINDOWLESSWGLAPPLICATION ON)
-            set(OPENGLTESTER_APPLICATION MagnumWindowlessWglApplication)
-        endif()
+        set(MAGNUM_WITH_WINDOWLESSWGLAPPLICATION ON)
+        set(OPENGLTESTER_APPLICATION MagnumWindowlessWglApplication)
     else()
         # Assuming this gets hit only if MAGNUM_BUILD_GL_TESTS are enabled
         message(FATAL_ERROR "Cannot run tests for OpenGL code on this platform. Set MAGNUM_BUILD_GL_TESTS to OFF to skip building them.")

doc/building.dox

@@ -461,15 +461,10 @@ available for desktop OpenGL only, see @ref requires-gl.
 -   `MAGNUM_TARGET_GLES2` --- Target OpenGL ES 2.0 instead of 3.0 and later.
     Available only when `MAGNUM_WITH_GL` is enabled. Currently enabled by
     default when `MAGNUM_TARGET_GLES` is set.
--   `MAGNUM_TARGET_DESKTOP_GLES` --- Target OpenGL ES on desktop, i.e. use
-    OpenGL ES emulation in desktop OpenGL drivers. Available on Linux and
-    Windows, though might not be supported by all drivers. Available only when
-    `MAGNUM_WITH_GL` is enabled.
--   `MAGNUM_TARGET_HEADLESS` --- Build command-line utilities for use on a
-    headless machine. Basically it means that EGL with no display attachment is
-    being used everywhere instead of platform-specific toolkits like CGL, GLX
-    or WGL. Supported mainly on OpenGL ES drivers. Available only when
-    `MAGNUM_WITH_GL` is enabled.
+-   `MAGNUM_TARGET_EGL` --- Target EGL instead of a platform-specific OpenGL
+    support library like CGL, EAGL, GLX or WGL. Enabled implicitly on Android,
+    Emscripten and Windows RT, enabled by default when `MAGNUM_TARGET_GLES` is
+    set unless on iOS. Available only when `MAGNUM_WITH_GL` is enabled.
 -   `MAGNUM_TARGET_VK` --- Build libraries with Vulkan interoperability
     enabled. Enabled by default when `MAGNUM_WITH_VK` is enabled. Disabling
     this will cause libraries to not depend on the @ref Vk library, but doesn't
@@ -736,6 +731,9 @@ compatibility if `MAGNUM_BUILD_DEPRECATED` isn't disabled.
     this was used to handle that case. Nowadays please use NDK r19 and newer,
     with the unified sysroot layout. Defaults to ``.``. If a relative path is
     used, it's relative to `CMAKE_INSTALL_PREFIX`.
+-   `MAGNUM_TARGET_HEADLESS` --- Alias to `MAGNUM_TARGET_EGL`.
+-   `MAGNUM_TARGET_DESKTOP_GLES` --- Inverse of `MAGNUM_TARGET_EGL` if
+    `MAGNUM_TARGET_GLES` is enabled.
 
 Various plugin interfaces search for plugins in locations and order documented
 in @ref Corrade::PluginManager::implicitPluginSearchPaths(),

doc/changelog.dox

@@ -449,9 +449,9 @@ See also:
 
 -   Added a @ref Platform::GlfwApplication::setWindowIcon() overload taking a
     @ref Corrade::Containers::ArrayView in addition to @ref std::initializer_list
--   @ref Platform::GlfwApplication now defaults to EGL on
-    @ref MAGNUM_TARGET_DESKTOP_GLES "non-desktop"
-    @ref MAGNUM_TARGET_GLES "GLES builds" (see [mosra/magnum#470](https://github.com/mosra/magnum/pull/470))
+-   @ref Platform::GlfwApplication now properly uses
+    @ref MAGNUM_TARGET_EGL "EGL" on @ref MAGNUM_TARGET_GLES "GLES builds" (see
+    [mosra/magnum#470](https://github.com/mosra/magnum/pull/470))
 -   On Emscripten, @ref Platform::EmscriptenApplication used an internal
     allocation function, which changed signature in 2.0.5 and caused runtime
     failures when `-s ASSERTIONS` was enabled. A public stable API is now used
@@ -768,6 +768,13 @@ See also:
 
 @subsection changelog-latest-deprecated Deprecated APIs
 
+-   The (mutually exclusive) @ref MAGNUM_TARGET_HEADLESS and
+    @ref MAGNUM_TARGET_DESKTOP_GLES options, CMake variables and preprocessor
+    variables are deprecated in favor of @ref MAGNUM_TARGET_EGL. It's enabled
+    by default on GLES and disabled by default on desktop GL --- disabling it
+    on GLES will force creation of a GLES context using the GLX / WGL libraries
+    (if available); enabling it on desktop GL will allow running windowless
+    applications on headless machines.
 -   All @ref building-features "CMake build options" are now prefixed with
     `MAGNUM_`. For backwards compatibility, unless @ref MAGNUM_BUILD_DEPRECATED
     is disabled and unless a prefixed option is already set during the initial
@@ -2424,7 +2431,7 @@ Released 2019-10-24, tagged as
     @ref Platform::Sdl2Application::exitEvent() "exitEvent()"
 -   On OpenGL ES builds, @ref Platform::Sdl2Application now tells SDL whether
     to use a system GL driver or a dedicated GLES driver based on whether
-    @ref MAGNUM_TARGET_DESKTOP_GLES is defined. This allows for a smoother
+    @cpp MAGNUM_TARGET_DESKTOP_GLES @ce is defined. This allows for a smoother
     experience for example when using ANGLE on Windows. See
     @ref Platform-Sdl2Application-usage-gles for more information.
 -   Replaced uses of `Pointer_stringify()` in @ref Platform::Sdl2Application

doc/cmake.dox

@@ -327,11 +327,9 @@ are also available as preprocessor variables if including
 -   `MAGNUM_TARGET_GLES` --- Defined if compiled for OpenGL ES
 -   `MAGNUM_TARGET_GLES2` --- Defined if compiled for OpenGL ES 2.0
 -   `MAGNUM_TARGET_GLES3` --- Defined if compiled for OpenGL ES 3.0
--   `MAGNUM_TARGET_DESKTOP_GLES` --- Defined if compiled with OpenGL ES
-    emulation on desktop OpenGL
 -   `MAGNUM_TARGET_WEBGL` --- Defined if compiled for WebGL
--   `MAGNUM_TARGET_HEADLESS` --- Defined if compiled for headless machines. See
-    @ref MAGNUM_TARGET_HEADLESS documentation for more information.
+-   `MAGNUM_TARGET_EGL` --- Defined if compiled for EGL instead of a
+    platform-specific OpenGL support library such as CGL, EAGL, GLX or WGL.
 -   `MAGNUM_TARGET_VK` --- Defined if compiled with Vulkan interoperability
     enabled
 
@@ -341,6 +339,10 @@ release:
 
 -   `MAGNUM_BUILD_MULTITHREADED` --- Alias to `CORRADE_BUILD_MULTITHREADED`.
     Use @ref CORRADE_BUILD_MULTITHREADED instead.
+-   `MAGNUM_TARGET_HEADLESS` --- Alias to `MAGNUM_TARGET_EGL`, unless on iOS,
+    Android, Emscripten or Windows RT. Use @ref MAGNUM_TARGET_EGL instead.
+-   `MAGNUM_TARGET_DESKTOP_GLES` --- Defined if compiled for OpenGL ES but
+    GLX / WGL is used instead of EGL. Use @ref MAGNUM_TARGET_EGL instead.
 
 Corrade library provides also its own set of CMake macros and variables, see
 @ref corrade-cmake "its documentation" for more information.

modules/FindMagnum.cmake

@@ -136,10 +136,9 @@
 #  MAGNUM_TARGET_GLES           - Defined if compiled for OpenGL ES
 #  MAGNUM_TARGET_GLES2          - Defined if compiled for OpenGL ES 2.0
 #  MAGNUM_TARGET_GLES3          - Defined if compiled for OpenGL ES 3.0
-#  MAGNUM_TARGET_DESKTOP_GLES   - Defined if compiled with OpenGL ES
-#   emulation on desktop OpenGL
 #  MAGNUM_TARGET_WEBGL          - Defined if compiled for WebGL
-#  MAGNUM_TARGET_HEADLESS       - Defined if compiled for headless machines
+#  MAGNUM_TARGET_EGL            - Defined if compiled for EGL instead of a
+#   platform-specific OpenGL support library like CGL, EAGL, GLX or WGL
 #  MAGNUM_TARGET_VK             - Defined if compiled with Vulkan interop
 #
 # The following variables are provided for backwards compatibility purposes
@@ -148,6 +147,10 @@
 #
 #  MAGNUM_BUILD_MULTITHREADED   - Alias to CORRADE_BUILD_MULTITHREADED. Use
 #   CORRADE_BUILD_MULTITHREADED instead.
+#  MAGNUM_TARGET_HEADLESS       - Alias to MAGNUM_TARGET_EGL, unless on iOS,
+#   Android, Emscripten or Windows RT. Use MAGNUM_TARGET_EGL instead.
+#  MAGNUM_TARGET_DESKTOP_GLES`  - Defined if compiled for OpenGL ES but
+#   GLX / WGL is used instead of EGL. Use MAGNUM_TARGET_EGL instead.
 #
 # Additionally these variables are defined for internal usage:
 #
@@ -268,9 +271,8 @@ set(_magnumFlags
     TARGET_GLES
     TARGET_GLES2
     TARGET_GLES3
-    TARGET_DESKTOP_GLES
     TARGET_WEBGL
-    TARGET_HEADLESS
+    TARGET_EGL
     TARGET_VK)
 foreach(_magnumFlag ${_magnumFlags})
     list(FIND _magnumConfigure "#define MAGNUM_${_magnumFlag}" _magnum_${_magnumFlag})
@@ -279,9 +281,20 @@ foreach(_magnumFlag ${_magnumFlags})
     endif()
 endforeach()
 
-# For compatibility only, to be removed at some point
-if(MAGNUM_BUILD_DEPRECATED AND CORRADE_BUILD_MULTITHREADED)
-    set(MAGNUM_BUILD_MULTITHREADED 1)
+# For compatibility only, to be removed at some point. Refer to
+# src/Magnum/configure.h.cmake for the decision logic here.
+if(MAGNUM_BUILD_DEPRECATED)
+    if(CORRADE_BUILD_MULTITHREADED)
+        set(MAGNUM_BUILD_MULTITHREADED 1)
+    endif()
+    if(NOT CORRADE_TARGET_IOS AND NOT CORRADE_TARGET_ANDROID AND NOT CORRADE_TARGET_EMSCRIPTEN AND NOT CORRADE_TARGET_WINDOWS_RT)
+        if(NOT MAGNUM_TARGET_GLES AND MAGNUM_TARGET_EGL)
+            set(MAGNUM_TARGET_HEADLESS 1)
+        endif()
+        if(MAGNUM_TARGET_GLES AND NOT MAGNUM_TARGET_EGL)
+            set(MAGNUM_TARGET_DESKTOP_GLES 1)
+        endif()
+    endif()
 endif()
 
 # OpenGL library preference. Prefer to use GLVND, since that's the better
@@ -425,24 +438,16 @@ if(MAGNUM_TARGET_GL)
 endif()
 
 set(_MAGNUM_OpenGLTester_DEPENDENCIES GL)
-if(MAGNUM_TARGET_HEADLESS OR CORRADE_TARGET_EMSCRIPTEN OR CORRADE_TARGET_ANDROID)
+if(MAGNUM_TARGET_EGL)
     list(APPEND _MAGNUM_OpenGLTester_DEPENDENCIES WindowlessEglApplication)
 elseif(CORRADE_TARGET_IOS)
     list(APPEND _MAGNUM_OpenGLTester_DEPENDENCIES WindowlessIosApplication)
-elseif(CORRADE_TARGET_APPLE AND NOT MAGNUM_TARGET_GLES)
+elseif(CORRADE_TARGET_APPLE)
     list(APPEND _MAGNUM_OpenGLTester_DEPENDENCIES WindowlessCglApplication)
 elseif(CORRADE_TARGET_UNIX)
-    if(MAGNUM_TARGET_GLES AND NOT MAGNUM_TARGET_DESKTOP_GLES)
-        list(APPEND _MAGNUM_OpenGLTester_DEPENDENCIES WindowlessEglApplication)
-    else()
-        list(APPEND _MAGNUM_OpenGLTester_DEPENDENCIES WindowlessGlxApplication)
-    endif()
+    list(APPEND _MAGNUM_OpenGLTester_DEPENDENCIES WindowlessGlxApplication)
 elseif(CORRADE_TARGET_WINDOWS)
-    if(MAGNUM_TARGET_GLES AND NOT MAGNUM_TARGET_DESKTOP_GLES)
-        list(APPEND _MAGNUM_OpenGLTester_DEPENDENCIES WindowlessEglApplication)
-    else()
-        list(APPEND _MAGNUM_OpenGLTester_DEPENDENCIES WindowlessWglApplication)
-    endif()
+    list(APPEND _MAGNUM_OpenGLTester_DEPENDENCIES WindowlessWglApplication)
 endif()
 
 set(_MAGNUM_Primitives_DEPENDENCIES MeshTools Trade)
@@ -706,16 +711,16 @@ foreach(_component ${Magnum_FIND_COMPONENTS})
                 # OPENGL_opengl_LIBRARY because that's set even if
                 # OpenGL_GL_PREFERENCE is explicitly set to LEGACY.
                 if(MAGNUM_TARGET_GL)
-                    if(CORRADE_TARGET_UNIX AND NOT CORRADE_TARGET_APPLE AND (NOT MAGNUM_TARGET_GLES OR MAGNUM_TARGET_DESKTOP_GLES))
+                    if(MAGNUM_TARGET_EGL)
+                        find_package(EGL)
+                        set_property(TARGET Magnum::${_component} APPEND
+                            PROPERTY INTERFACE_LINK_LIBRARIES EGL::EGL)
+                    elseif(CORRADE_TARGET_UNIX AND NOT CORRADE_TARGET_APPLE)
                         find_package(OpenGL)
                         if(OPENGL_opengl_LIBRARY AND OpenGL_GL_PREFERENCE STREQUAL GLVND)
                             set_property(TARGET Magnum::${_component} APPEND
                             PROPERTY INTERFACE_LINK_LIBRARIES OpenGL::GLX)
                         endif()
-                    elseif(MAGNUM_TARGET_GLES AND NOT MAGNUM_TARGET_DESKTOP_GLES AND NOT CORRADE_TARGET_EMSCRIPTEN)
-                        find_package(EGL)
-                        set_property(TARGET Magnum::${_component} APPEND
-                            PROPERTY INTERFACE_LINK_LIBRARIES EGL::EGL)
                     endif()
                 endif()
 
@@ -745,16 +750,16 @@ foreach(_component ${Magnum_FIND_COMPONENTS})
                 # OPENGL_opengl_LIBRARY because that's set even if
                 # OpenGL_GL_PREFERENCE is explicitly set to LEGACY.
                 if(MAGNUM_TARGET_GL)
-                    if(CORRADE_TARGET_UNIX AND NOT CORRADE_TARGET_APPLE AND (NOT MAGNUM_TARGET_GLES OR MAGNUM_TARGET_DESKTOP_GLES))
+                    if(MAGNUM_TARGET_EGL)
+                        find_package(EGL)
+                        set_property(TARGET Magnum::${_component} APPEND
+                            PROPERTY INTERFACE_LINK_LIBRARIES EGL::EGL)
+                    elseif(CORRADE_TARGET_UNIX AND NOT CORRADE_TARGET_APPLE)
                         find_package(OpenGL)
                         if(OPENGL_opengl_LIBRARY AND OpenGL_GL_PREFERENCE STREQUAL GLVND)
                             set_property(TARGET Magnum::${_component} APPEND
                             PROPERTY INTERFACE_LINK_LIBRARIES OpenGL::GLX)
                         endif()
-                    elseif(MAGNUM_TARGET_GLES AND NOT MAGNUM_TARGET_DESKTOP_GLES AND NOT CORRADE_TARGET_EMSCRIPTEN)
-                        find_package(EGL)
-                        set_property(TARGET Magnum::${_component} APPEND
-                            PROPERTY INTERFACE_LINK_LIBRARIES EGL::EGL)
                     endif()
                 endif()
 
@@ -852,7 +857,7 @@ foreach(_component ${Magnum_FIND_COMPONENTS})
 
         # GL library
         elseif(_component STREQUAL GL)
-            if(NOT MAGNUM_TARGET_GLES OR MAGNUM_TARGET_DESKTOP_GLES)
+            if(NOT MAGNUM_TARGET_GLES OR (MAGNUM_TARGET_GLES AND NOT MAGNUM_TARGET_EGL AND NOT CORRADE_TARGET_IOS))
                 # If the GLVND library (CMake 3.11+) was found, link to the
                 # imported target. Otherwise (and also on all systems except
                 # Linux) link to the classic libGL. Can't use

package/archlinux/PKGBUILD-es2desktop

@@ -22,7 +22,7 @@ build() {
         -DCMAKE_INSTALL_PREFIX=/usr \
         -DMAGNUM_TARGET_GLES=ON \
         -DMAGNUM_TARGET_GLES2=ON \
-        -DMAGNUM_TARGET_DESKTOP_GLES=ON \
+        -DMAGNUM_TARGET_EGL=OFF \
         -DMAGNUM_WITH_AUDIO=ON \
         -DMAGNUM_WITH_GLFWAPPLICATION=ON \
         -DMAGNUM_WITH_GLXAPPLICATION=ON \

package/archlinux/PKGBUILD-es3desktop

@@ -22,7 +22,7 @@ build() {
         -DCMAKE_INSTALL_PREFIX=/usr \
         -DMAGNUM_TARGET_GLES=ON \
         -DMAGNUM_TARGET_GLES2=OFF \
-        -DMAGNUM_TARGET_DESKTOP_GLES=ON \
+        -DMAGNUM_TARGET_EGL=OFF \
         -DMAGNUM_WITH_AUDIO=ON \
         -DMAGNUM_WITH_GLFWAPPLICATION=ON \
         -DMAGNUM_WITH_GLXAPPLICATION=ON \

package/ci/appveyor-desktop-gles.bat

@@ -27,7 +27,7 @@ cmake .. ^
     -DCMAKE_PREFIX_PATH="%APPVEYOR_BUILD_FOLDER%/openal" ^
     -DMAGNUM_TARGET_GLES=ON ^
     -DMAGNUM_TARGET_GLES2=%TARGET_GLES2% ^
-    -DMAGNUM_TARGET_DESKTOP_GLES=ON ^
+    -DMAGNUM_TARGET_EGL=OFF ^
     -DMAGNUM_WITH_AUDIO=OFF ^
     -DMAGNUM_WITH_VK=OFF ^
     -DMAGNUM_WITH_SCENETOOLS=OFF ^

src/Magnum/GL/CMakeLists.txt

@@ -214,7 +214,7 @@ elseif(MAGNUM_BUILD_STATIC_PIC)
     set_target_properties(MagnumGL PROPERTIES POSITION_INDEPENDENT_CODE ON)
 endif()
 target_link_libraries(MagnumGL PUBLIC Magnum)
-if(NOT MAGNUM_TARGET_GLES OR MAGNUM_TARGET_DESKTOP_GLES)
+if(NOT MAGNUM_TARGET_GLES OR (MAGNUM_TARGET_GLES AND NOT MAGNUM_TARGET_EGL AND NOT CORRADE_TARGET_IOS))
     # If the GLVND library (CMake 3.11+) was found, link to the imported
     # target. Otherwise (and also on all systems except Linux) link to the
     # classic libGL. Can't use OpenGL_OpenGL_FOUND, because that one is set
@@ -297,7 +297,7 @@ if(MAGNUM_BUILD_TESTS)
     endif()
     target_link_libraries(MagnumGLTestLib PUBLIC
         Magnum)
-    if(NOT MAGNUM_TARGET_GLES OR MAGNUM_TARGET_DESKTOP_GLES)
+    if(NOT MAGNUM_TARGET_GLES OR (MAGNUM_TARGET_GLES AND NOT MAGNUM_TARGET_EGL AND NOT CORRADE_TARGET_IOS))
         # If the GLVND library (CMake 3.11+) was found, link to the imported
         # target. Otherwise (and also on all systems except Linux) link to the
         # classic libGL. Can't use OpenGL_OpenGL_FOUND, because that one is set
@@ -331,7 +331,7 @@ if(MAGNUM_BUILD_TESTS)
         # Windows only and elsewhere I just link the same way as with
         # MagnumOpenGLTester.
         if(CORRADE_TARGET_WINDOWS)
-            if(MAGNUM_TARGET_GLES AND NOT MAGNUM_TARGET_DESKTOP_GLES)
+            if(MAGNUM_TARGET_EGL)
                 # Otherwise it complains that EGL::EGL does not exist here
                 find_package(EGL)
             endif()

src/Magnum/GL/OpenGL.h

@@ -46,7 +46,7 @@
     #endif
 
 /* Special case for desktop GLES on Windows (still links to the old opengl32.dll) */
-#elif defined(CORRADE_TARGET_WINDOWS) && defined(MAGNUM_TARGET_DESKTOP_GLES)
+#elif defined(CORRADE_TARGET_WINDOWS) && !defined(MAGNUM_TARGET_EGL)
     #ifdef MAGNUM_TARGET_GLES2
         #include "MagnumExternal/OpenGL/GLES2/flextGLWindowsDesktop.h"
     #else

src/Magnum/GL/OpenGLTester.h

@@ -37,24 +37,16 @@
 #include "Magnum/GL/Renderer.h"
 #include "Magnum/GL/TimeQuery.h"
 
-#if defined(MAGNUM_TARGET_HEADLESS) || defined(CORRADE_TARGET_EMSCRIPTEN) || defined(CORRADE_TARGET_ANDROID)
+#ifdef MAGNUM_TARGET_EGL
 #include "Magnum/Platform/WindowlessEglApplication.h"
 #elif defined(CORRADE_TARGET_IOS)
 #include "Magnum/Platform/WindowlessIosApplication.h"
-#elif defined(CORRADE_TARGET_APPLE) && !defined(MAGNUM_TARGET_GLES)
+#elif defined(CORRADE_TARGET_APPLE)
 #include "Magnum/Platform/WindowlessCglApplication.h"
 #elif defined(CORRADE_TARGET_UNIX)
-#if defined(MAGNUM_TARGET_GLES) && !defined(MAGNUM_TARGET_DESKTOP_GLES)
-#include "Magnum/Platform/WindowlessEglApplication.h"
-#else
 #include "Magnum/Platform/WindowlessGlxApplication.h"
-#endif
 #elif defined(CORRADE_TARGET_WINDOWS)
-#if defined(MAGNUM_TARGET_GLES) && !defined(MAGNUM_TARGET_DESKTOP_GLES)
-#include "Magnum/Platform/WindowlessEglApplication.h"
-#else
 #include "Magnum/Platform/WindowlessWglApplication.h"
-#endif
 #else
 #error cannot run OpenGL tests on this platform
 #endif
@@ -98,7 +90,7 @@ See @ref building, @ref cmake and @ref testsuite for more information.
 
 Implicitly, running the test executables requires presence of a GPU with OpenGL
 drivers. In addition, on desktop, unless Magnum is built with
-`MAGNUM_TARGET_HEADLESS`, OpenGL context creation requires a graphical desktop
+@ref MAGNUM_TARGET_EGL, OpenGL context creation requires a graphical desktop
 to be running. On embedded systems (and @ref CORRADE_TARGET_IOS "iOS",
 @ref CORRADE_TARGET_ANDROID "Android" in particular) running the tests has no
 special requirements. On Emscripten the tests have to be running in a browser,

src/Magnum/Magnum.h

@@ -131,7 +131,7 @@ Defined if the engine is built with OpenGL interoperability enabled --- extra
 APIs in various libraries interacting with the @ref Magnum::GL "GL" library.
 Enabled by default in case the @ref Magnum::GL "GL" library is built.
 @see @ref MAGNUM_TARGET_GLES2, @ref MAGNUM_TARGET_GLES3,
-    @ref MAGNUM_TARGET_DESKTOP_GLES, @ref building, @ref cmake
+    @ref MAGNUM_TARGET_EGL, @ref building, @ref cmake
 */
 #define MAGNUM_TARGET_GL
 /* (enabled by default) */
@@ -141,7 +141,7 @@ Enabled by default in case the @ref Magnum::GL "GL" library is built.
 
 Defined if the engine is built for OpenGL ES 3.0 or OpenGL ES 2.0.
 @see @ref MAGNUM_TARGET_GLES2, @ref MAGNUM_TARGET_GLES3,
-    @ref MAGNUM_TARGET_DESKTOP_GLES, @ref building, @ref cmake
+    @ref MAGNUM_TARGET_EGL, @ref building, @ref cmake
 */
 #define MAGNUM_TARGET_GLES
 #undef MAGNUM_TARGET_GLES
@@ -151,7 +151,7 @@ Defined if the engine is built for OpenGL ES 3.0 or OpenGL ES 2.0.
 
 Defined if the engine is built for OpenGL ES 2.0. Implies also
 @ref MAGNUM_TARGET_GLES.
-@see @ref MAGNUM_TARGET_GLES3, @ref MAGNUM_TARGET_DESKTOP_GLES, @ref building,
+@see @ref MAGNUM_TARGET_GLES3, @ref MAGNUM_TARGET_EGL, @ref building,
     @ref cmake
 */
 #define MAGNUM_TARGET_GLES2
@@ -162,23 +162,12 @@ Defined if the engine is built for OpenGL ES 2.0. Implies also
 
 Defined if the engine is built for OpenGL ES 3.0. Implies also
 @ref MAGNUM_TARGET_GLES.
-@see @ref MAGNUM_TARGET_GLES2, @ref MAGNUM_TARGET_DESKTOP_GLES, @ref building,
+@see @ref MAGNUM_TARGET_GLES2, @ref MAGNUM_TARGET_EGL, @ref building,
     @ref cmake
 */
 #define MAGNUM_TARGET_GLES3
 #undef MAGNUM_TARGET_GLES3
 
-/**
-@brief Desktop emulation of OpenGL ES target
-
-Defined if the engine is built for OpenGL ES 3.0 or OpenGL ES 2.0 emulated
-within standard desktop OpenGL. Implies also @ref MAGNUM_TARGET_GLES.
-@see @ref MAGNUM_TARGET_GLES2, @ref MAGNUM_TARGET_GLES3, @ref building,
-    @ref cmake
-*/
-#define MAGNUM_TARGET_DESKTOP_GLES
-#undef MAGNUM_TARGET_DESKTOP_GLES
-
 /**
 @brief WebGL target
 
@@ -193,19 +182,48 @@ which you might want to be aware of. Implies also @ref MAGNUM_TARGET_GLES and
 #define MAGNUM_TARGET_WEBGL
 #undef MAGNUM_TARGET_WEBGL
 
+/**
+@brief EGL target
+@m_since_latest
+
+Defined if the engine is built for EGL instead of a platform-specific OpenGL
+support library like CGL, EAGL, GLX or WGL. When enabled,
+@relativeref{Magnum,Platform::Sdl2Application} and
+@relativeref{Magnum,Platform::GlfwApplication}
+will create the context using EGL, and command-line utilities like
+@ref magnum-gl-info "magnum-gl-info" or
+@ref magnum-distancefieldconverter "magnum-distancefieldconverter" as well as
+the @relativeref{Magnum,GL::OpenGLTester} library will use
+@relativeref{Magnum,Platform::WindowlessEglApplication}. Defined implicitly on
+@ref CORRADE_TARGET_IOS "iOS", @ref CORRADE_TARGET_ANDROID "Android",
+@ref CORRADE_TARGET_EMSCRIPTEN "Emscripten" and
+@ref CORRADE_TARGET_WINDOWS_RT "Windows RT".
+*/
+#define MAGNUM_TARGET_EGL
+#undef MAGNUM_TARGET_EGL
+
+#ifdef MAGNUM_BUILD_DEPRECATED
 /**
 @brief Headless target
+@m_deprecated_since_latest Use @ref MAGNUM_TARGET_EGL instead.
 
-Defined if the engine is built for use on a headless machine (without any
-graphical desktop environment). Basically it means that EGL with no display
-attachment is being used everywhere instead of platform-specific toolkits like
-CGL, GLX or WGL. Note that this might not be supported on all platforms, see
-@ref Magnum::Platform::WindowlessEglApplication "Platform::WindowlessEglApplication"
-for more information.
+Alias to @ref MAGNUM_TARGET_EGL, unless on iOS, Android, Emscripten or Windows
+RT.
 */
 #define MAGNUM_TARGET_HEADLESS
 #undef MAGNUM_TARGET_HEADLESS
 
+/**
+@brief OpenGL ES target on GLX / WGL
+@m_deprecated_since_latest Use @ref MAGNUM_TARGET_EGL instead.
+
+Defined if @ref MAGNUM_TARGET_GLES is set but @ref MAGNUM_TARGET_EGL isn't,
+unless on iOS, Android, Emscripten or Windows RT.
+*/
+#define MAGNUM_TARGET_DESKTOP_GLES
+#undef MAGNUM_TARGET_DESKTOP_GLES
+#endif
+
 /**
 @brief Vulkan interoperability
 

src/Magnum/Platform/CMakeLists.txt

@@ -98,24 +98,29 @@ install(FILES ${MagnumPlatform_HEADERS} DESTINATION ${MAGNUM_INCLUDE_INSTALL_DIR
 if(MAGNUM_TARGET_GL)
     # Decide about platform-specific context for cross-platform toolkits
     if(MAGNUM_WITH_GLFWAPPLICATION OR MAGNUM_WITH_SDL2APPLICATION)
-        if(CORRADE_TARGET_APPLE AND NOT MAGNUM_TARGET_GLES)
+        # On WebGL windowless apps don't use anything from EGL, only windowless
+        # do. On iOS it's EAGL, which isn't really EGL (and thus
+        # MAGNUM_TARGET_EGL isn't set), but we handle it inside EglContext as
+        # well. TODO make EaglContext for iOS to prepare for true EGL (such as
+        # with ANGLE or Zink)
+        if((MAGNUM_TARGET_EGL AND NOT MAGNUM_TARGET_WEBGL) OR CORRADE_TARGET_IOS)
+            set(NEED_EGLCONTEXT 1)
+            set(MagnumSomeContext_OBJECTS $<TARGET_OBJECTS:MagnumEglContextObjects>)
+            # We're linking to EGL explicitly, no need to bother with GLVND there
+        elseif(CORRADE_TARGET_APPLE)
             set(NEED_CGLCONTEXT 1)
             set(MagnumSomeContext_OBJECTS $<TARGET_OBJECTS:MagnumCglContextObjects>)
-        elseif(CORRADE_TARGET_WINDOWS AND (NOT MAGNUM_TARGET_GLES OR MAGNUM_TARGET_DESKTOP_GLES))
+        elseif(CORRADE_TARGET_WINDOWS)
             set(NEED_WGLCONTEXT 1)
             set(MagnumSomeContext_OBJECTS $<TARGET_OBJECTS:MagnumWglContextObjects>)
-        elseif(CORRADE_TARGET_UNIX AND (NOT MAGNUM_TARGET_GLES OR MAGNUM_TARGET_DESKTOP_GLES))
+        elseif(CORRADE_TARGET_UNIX)
             set(NEED_GLXCONTEXT 1)
             set(MagnumSomeContext_OBJECTS $<TARGET_OBJECTS:MagnumGlxContextObjects>)
-        elseif(MAGNUM_TARGET_GLES AND NOT CORRADE_TARGET_EMSCRIPTEN)
-            set(NEED_EGLCONTEXT 1)
-            set(MagnumSomeContext_OBJECTS $<TARGET_OBJECTS:MagnumEglContextObjects>)
-            # We're linking to EGL explicitly, no need to bother with GLVND there
         endif()
     endif()
 
     # This is needed also by [Windowless]GlxApplication
-    if((MAGNUM_WITH_GLXAPPLICATION OR MAGNUM_WITH_WINDOWLESSGLXAPPLICATION OR MAGNUM_WITH_GLFWAPPLICATION OR MAGNUM_WITH_SDL2APPLICATION) AND CORRADE_TARGET_UNIX AND (NOT MAGNUM_TARGET_GLES OR MAGNUM_TARGET_DESKTOP_GLES))
+    if((MAGNUM_WITH_GLXAPPLICATION OR MAGNUM_WITH_WINDOWLESSGLXAPPLICATION OR MAGNUM_WITH_GLFWAPPLICATION OR MAGNUM_WITH_SDL2APPLICATION) AND CORRADE_TARGET_UNIX AND NOT MAGNUM_TARGET_EGL)
         # If the GLVND library (CMake 3.11+) was found and linked to, we need
         # to link to GLX explicitly. Otherwise (and also on all systems except
         # Linux) the transitive dependency to classic GL lib from MagnumGL is
@@ -255,8 +260,8 @@ if(MAGNUM_WITH_GLFWAPPLICATION)
             ${MagnumSomeContext_LIBRARY})
     endif()
 
-    # Link also EGL library, if on ES (and not on WebGL)
-    if(MAGNUM_TARGET_GLES AND NOT MAGNUM_TARGET_DESKTOP_GLES AND NOT MAGNUM_TARGET_WEBGL)
+    # Link also EGL library, if desired (and not on WebGL)
+    if(MAGNUM_TARGET_EGL AND NOT MAGNUM_TARGET_WEBGL)
         find_package(EGL REQUIRED)
         target_link_libraries(MagnumGlfwApplication PUBLIC EGL::EGL)
     endif()
@@ -327,8 +332,8 @@ if(MAGNUM_WITH_SDL2APPLICATION)
             ${MagnumSomeContext_LIBRARY})
     endif()
 
-    # Link also EGL library, if on ES (and not on WebGL)
-    if(MAGNUM_TARGET_GLES AND NOT MAGNUM_TARGET_DESKTOP_GLES AND NOT MAGNUM_TARGET_WEBGL)
+    # Link also EGL library, if desired (and not on WebGL)
+    if(MAGNUM_TARGET_EGL AND NOT MAGNUM_TARGET_WEBGL)
         find_package(EGL REQUIRED)
         target_link_libraries(MagnumSdl2Application PUBLIC EGL::EGL)
     endif()
@@ -731,7 +736,7 @@ endif()
 if(NOT MAGNUM_TARGET_GLES)
     list(APPEND MagnumContext_SRCS ../../MagnumExternal/OpenGL/GL/flextGLPlatform.cpp)
 elseif(MAGNUM_TARGET_GLES AND MAGNUM_TARGET_GLES2)
-    if(CORRADE_TARGET_WINDOWS AND MAGNUM_TARGET_DESKTOP_GLES)
+    if(CORRADE_TARGET_WINDOWS AND NOT MAGNUM_TARGET_EGL)
         list(APPEND MagnumContext_SRCS ../../MagnumExternal/OpenGL/GLES2/flextGLPlatformWindowsDesktop.cpp)
     elseif(CORRADE_TARGET_IOS)
         list(APPEND MagnumContext_SRCS ../../MagnumExternal/OpenGL/GLES2/flextGLPlatformIOS.cpp)
@@ -739,7 +744,7 @@ elseif(MAGNUM_TARGET_GLES AND MAGNUM_TARGET_GLES2)
         list(APPEND MagnumContext_SRCS ../../MagnumExternal/OpenGL/GLES2/flextGLPlatform.cpp)
     endif()
 elseif(MAGNUM_TARGET_GLES AND NOT MAGNUM_TARGET_GLES2)
-    if(CORRADE_TARGET_WINDOWS AND MAGNUM_TARGET_DESKTOP_GLES)
+    if(CORRADE_TARGET_WINDOWS AND NOT MAGNUM_TARGET_EGL)
         list(APPEND MagnumContext_SRCS ../../MagnumExternal/OpenGL/GLES3/flextGLPlatformWindowsDesktop.cpp)
     elseif(CORRADE_TARGET_IOS)
         list(APPEND MagnumContext_SRCS ../../MagnumExternal/OpenGL/GLES3/flextGLPlatformIOS.cpp)
@@ -903,24 +908,16 @@ if(MAGNUM_WITH_GL_INFO)
 
     add_executable(magnum-gl-info gl-info.cpp)
     target_link_libraries(magnum-gl-info PRIVATE MagnumGL)
-    if(MAGNUM_TARGET_HEADLESS OR CORRADE_TARGET_EMSCRIPTEN OR CORRADE_TARGET_ANDROID)
+    if(MAGNUM_TARGET_EGL)
         target_link_libraries(magnum-gl-info PRIVATE MagnumWindowlessEglApplication)
     elseif(CORRADE_TARGET_IOS)
         target_link_libraries(magnum-gl-info PRIVATE MagnumWindowlessIosApplication)
-    elseif(CORRADE_TARGET_APPLE AND NOT MAGNUM_TARGET_GLES)
+    elseif(CORRADE_TARGET_APPLE)
         target_link_libraries(magnum-gl-info PRIVATE MagnumWindowlessCglApplication)
     elseif(CORRADE_TARGET_UNIX)
-        if(MAGNUM_TARGET_GLES AND NOT MAGNUM_TARGET_DESKTOP_GLES)
-            target_link_libraries(magnum-gl-info PRIVATE MagnumWindowlessEglApplication)
-        else()
-            target_link_libraries(magnum-gl-info PRIVATE MagnumWindowlessGlxApplication)
-        endif()
+        target_link_libraries(magnum-gl-info PRIVATE MagnumWindowlessGlxApplication)
     elseif(CORRADE_TARGET_WINDOWS)
-        if(MAGNUM_TARGET_GLES AND NOT MAGNUM_TARGET_DESKTOP_GLES)
-            target_link_libraries(magnum-gl-info PRIVATE MagnumWindowlessEglApplication)
-        else()
-            target_link_libraries(magnum-gl-info PRIVATE MagnumWindowlessWglApplication)
-        endif()
+        target_link_libraries(magnum-gl-info PRIVATE MagnumWindowlessWglApplication)
     else()
         message(FATAL_ERROR "magnum-gl-info is not available on this platform. Set MAGNUM_WITH_GL_INFO to OFF to skip building it.")
     endif()

src/Magnum/Platform/GlfwApplication.cpp

@@ -457,10 +457,7 @@ bool GlfwApplication::tryCreate(const Configuration& configuration, const GLConf
         }
         #else
         glfwWindowHint(GLFW_CLIENT_API, GLFW_OPENGL_ES_API);
-        /* Force EGL on Windows and non-desktop GLES -- needed by ANGLE:
-           https://stackoverflow.com/a/58904181/4084782 . Might be useful on
-           other platforms as well (Mac?), not tested yet. */
-        #if defined(CORRADE_TARGET_WINDOWS) && !defined(MAGNUM_TARGET_DESKTOP_GLES)
+        #ifdef MAGNUM_TARGET_EGL /* Force EGL if desired */
         glfwWindowHint(GLFW_CONTEXT_CREATION_API, GLFW_EGL_CONTEXT_API);
         #endif
         #endif
@@ -487,10 +484,7 @@ bool GlfwApplication::tryCreate(const Configuration& configuration, const GLConf
         #endif
         glfwWindowHint(GLFW_CONTEXT_VERSION_MINOR, 0);
         glfwWindowHint(GLFW_CLIENT_API, GLFW_OPENGL_ES_API);
-        /* Force EGL on Windows and non-desktop GLES -- needed by ANGLE:
-           https://stackoverflow.com/a/58904181/4084782 . Might be useful on
-           other platforms as well (Mac?), not tested yet. */
-        #if defined(CORRADE_TARGET_WINDOWS) && !defined(MAGNUM_TARGET_DESKTOP_GLES)
+        #ifdef MAGNUM_TARGET_EGL /* Force EGL if desired */
         glfwWindowHint(GLFW_CONTEXT_CREATION_API, GLFW_EGL_CONTEXT_API);
         #endif
         #endif

src/Magnum/Platform/GlxApplication.h

@@ -43,8 +43,7 @@ namespace Magnum { namespace Platform {
 @m_keywords{Application}
 
 Application using pure X11 and GLX. Supports keyboard and mouse handling.
-Available on desktop OpenGL and
-@ref MAGNUM_TARGET_DESKTOP_GLES "OpenGL ES emulation on desktop" on Linux.
+Available on desktop OpenGL and OpenGL ES using GLX on Linux.
 
 @section Platform-GlxApplication-bootstrap Bootstrap application
 

src/Magnum/Platform/Sdl2Application.cpp

@@ -139,10 +139,9 @@ Sdl2Application::Sdl2Application(const Arguments& arguments, NoCreateT):
     #ifdef SDL_HINT_NO_SIGNAL_HANDLERS
     SDL_SetHint(SDL_HINT_NO_SIGNAL_HANDLERS, "1");
     #endif
-    /* Available since 2.0.6, uses dedicated OpenGL ES drivers by default and a
-       desktop GLES context only if MAGNUM_TARGET_DESKTOP_GLES is defined as
-       well. */
-    #if defined(MAGNUM_TARGET_GLES) && !defined(MAGNUM_TARGET_DESKTOP_GLES) && defined(SDL_HINT_OPENGL_ES_DRIVER)
+    /* Available since 2.0.6, uses dedicated OpenGL ES drivers if EGL is used,
+       and desktop GLES context otherwise. */
+    #if defined(MAGNUM_TARGET_GLES) && defined(MAGNUM_TARGET_EGL) && defined(SDL_HINT_OPENGL_ES_DRIVER)
     SDL_SetHint(SDL_HINT_OPENGL_ES_DRIVER, "1");
     #endif
     /* Available since 2.0.8, disables compositor bypass on X11, which causes

src/Magnum/Platform/WindowlessGlxApplication.h

@@ -344,9 +344,8 @@ CORRADE_ENUMSET_OPERATORS(WindowlessGlxContext::Configuration::Flags)
 
 @m_keywords{WindowlessApplication GLX}
 
-Application for offscreen rendering using @ref WindowlessGlxContext. This
-application library is available on desktop OpenGL and
-@ref MAGNUM_TARGET_DESKTOP_GLES "OpenGL ES emulation on desktop" on Linux.
+Application for offscreen rendering using @ref WindowlessGlxContext. Available
+on desktop OpenGL and OpenGL ES using GLX on Linux.
 
 @section Platform-WindowlessGlxApplication-bootstrap Bootstrap application
 

src/Magnum/Platform/gl-info.cpp

@@ -58,24 +58,16 @@
 #include "Magnum/GL/TransformFeedback.h"
 #endif
 
-#if defined(MAGNUM_TARGET_HEADLESS) || defined(CORRADE_TARGET_EMSCRIPTEN) || defined(CORRADE_TARGET_ANDROID)
+#ifdef MAGNUM_TARGET_EGL
 #include "Magnum/Platform/WindowlessEglApplication.h"
 #elif defined(CORRADE_TARGET_IOS)
 #include "Magnum/Platform/WindowlessIosApplication.h"
-#elif defined(CORRADE_TARGET_APPLE) && !defined(MAGNUM_TARGET_GLES)
+#elif defined(CORRADE_TARGET_APPLE)
 #include "Magnum/Platform/WindowlessCglApplication.h"
 #elif defined(CORRADE_TARGET_UNIX)
-#if defined(MAGNUM_TARGET_GLES) && !defined(MAGNUM_TARGET_DESKTOP_GLES)
-#include "Magnum/Platform/WindowlessEglApplication.h"
-#else
 #include "Magnum/Platform/WindowlessGlxApplication.h"
-#endif
 #elif defined(CORRADE_TARGET_WINDOWS)
-#if defined(MAGNUM_TARGET_GLES) && !defined(MAGNUM_TARGET_DESKTOP_GLES)
-#include "Magnum/Platform/WindowlessEglApplication.h"
-#else
 #include "Magnum/Platform/WindowlessWglApplication.h"
-#endif
 #else
 #error no windowless application available on this platform
 #endif
@@ -347,14 +339,11 @@ MagnumInfo::MagnumInfo(const Arguments& arguments): Platform::WindowlessApplicat
     #ifdef MAGNUM_TARGET_GLES2
     Debug{} << "    MAGNUM_TARGET_GLES2";
     #endif
-    #ifdef MAGNUM_TARGET_DESKTOP_GLES
-    Debug{} << "    MAGNUM_TARGET_DESKTOP_GLES";
-    #endif
     #ifdef MAGNUM_TARGET_WEBGL
     Debug{} << "    MAGNUM_TARGET_WEBGL";
     #endif
-    #ifdef MAGNUM_TARGET_HEADLESS
-    Debug{} << "    MAGNUM_TARGET_HEADLESS";
+    #ifdef MAGNUM_TARGET_EGL
+    Debug{} << "    MAGNUM_TARGET_EGL";
     #endif
     Debug{} << "Compiled CPU features:";
     Debug{} << "   " << Debug::packed << Cpu::compiledFeatures();

src/Magnum/Text/CMakeLists.txt

@@ -117,24 +117,16 @@ if(MAGNUM_WITH_FONTCONVERTER)
         Magnum
         MagnumText
         MagnumTrade)
-    if(MAGNUM_TARGET_HEADLESS)
+    if(MAGNUM_TARGET_EGL)
         target_link_libraries(magnum-fontconverter PRIVATE MagnumWindowlessEglApplication)
     elseif(CORRADE_TARGET_IOS)
         target_link_libraries(magnum-fontconverter PRIVATE MagnumWindowlessIosApplication)
-    elseif(CORRADE_TARGET_APPLE AND NOT MAGNUM_TARGET_GLES)
+    elseif(CORRADE_TARGET_APPLE)
         target_link_libraries(magnum-fontconverter PRIVATE MagnumWindowlessCglApplication)
     elseif(CORRADE_TARGET_UNIX)
-        if(MAGNUM_TARGET_GLES AND NOT MAGNUM_TARGET_DESKTOP_GLES)
-            target_link_libraries(magnum-fontconverter PRIVATE MagnumWindowlessEglApplication)
-        else()
-            target_link_libraries(magnum-fontconverter PRIVATE MagnumWindowlessGlxApplication)
-        endif()
+        target_link_libraries(magnum-fontconverter PRIVATE MagnumWindowlessGlxApplication)
     elseif(CORRADE_TARGET_WINDOWS)
-        if(MAGNUM_TARGET_GLES AND NOT MAGNUM_TARGET_DESKTOP_GLES)
-            target_link_libraries(magnum-fontconverter PRIVATE MagnumWindowlessEglApplication)
-        else()
-            target_link_libraries(magnum-fontconverter PRIVATE MagnumWindowlessWglApplication)
-        endif()
+        target_link_libraries(magnum-fontconverter PRIVATE MagnumWindowlessWglApplication)
     else()
         message(FATAL_ERROR "magnum-fontconverter is not available on this platform. Set MAGNUM_WITH_FONTCONVERTER to OFF to suppress this warning.")
     endif()

src/Magnum/Text/fontconverter.cpp

@@ -34,24 +34,16 @@
 #include "Magnum/Text/DistanceFieldGlyphCache.h"
 #include "Magnum/Trade/AbstractImageConverter.h"
 
-#ifdef MAGNUM_TARGET_HEADLESS
+#ifdef MAGNUM_TARGET_EGL
 #include "Magnum/Platform/WindowlessEglApplication.h"
 #elif defined(CORRADE_TARGET_IOS)
 #include "Magnum/Platform/WindowlessIosApplication.h"
 #elif defined(CORRADE_TARGET_APPLE)
 #include "Magnum/Platform/WindowlessCglApplication.h"
 #elif defined(CORRADE_TARGET_UNIX)
-#if defined(MAGNUM_TARGET_GLES) && !defined(MAGNUM_TARGET_DESKTOP_GLES)
-#include "Magnum/Platform/WindowlessEglApplication.h"
-#else
 #include "Magnum/Platform/WindowlessGlxApplication.h"
-#endif
 #elif defined(CORRADE_TARGET_WINDOWS)
-#if defined(MAGNUM_TARGET_GLES) && !defined(MAGNUM_TARGET_DESKTOP_GLES)
-#include "Magnum/Platform/WindowlessEglApplication.h"
-#else
 #include "Magnum/Platform/WindowlessWglApplication.h"
-#endif
 #else
 #error no windowless application available on this platform
 #endif

src/Magnum/TextureTools/CMakeLists.txt

@@ -85,24 +85,16 @@ if(MAGNUM_WITH_DISTANCEFIELDCONVERTER)
         Magnum
         MagnumTextureTools
         MagnumTrade)
-    if(MAGNUM_TARGET_HEADLESS)
+    if(MAGNUM_TARGET_EGL)
         target_link_libraries(magnum-distancefieldconverter PRIVATE MagnumWindowlessEglApplication)
     elseif(CORRADE_TARGET_IOS)
         target_link_libraries(magnum-distancefieldconverter PRIVATE MagnumWindowlessIosApplication)
-    elseif(CORRADE_TARGET_APPLE AND NOT MAGNUM_TARGET_GLES)
+    elseif(CORRADE_TARGET_APPLE)
         target_link_libraries(magnum-distancefieldconverter PRIVATE MagnumWindowlessCglApplication)
     elseif(CORRADE_TARGET_UNIX)
-        if(MAGNUM_TARGET_GLES AND NOT MAGNUM_TARGET_DESKTOP_GLES)
-            target_link_libraries(magnum-distancefieldconverter PRIVATE MagnumWindowlessEglApplication)
-        else()
-            target_link_libraries(magnum-distancefieldconverter PRIVATE MagnumWindowlessGlxApplication)
-        endif()
+        target_link_libraries(magnum-distancefieldconverter PRIVATE MagnumWindowlessGlxApplication)
     elseif(CORRADE_TARGET_WINDOWS)
-        if(MAGNUM_TARGET_GLES AND NOT MAGNUM_TARGET_DESKTOP_GLES)
-            target_link_libraries(magnum-distancefieldconverter PRIVATE MagnumWindowlessEglApplication)
-        else()
-            target_link_libraries(magnum-distancefieldconverter PRIVATE MagnumWindowlessWglApplication)
-        endif()
+        target_link_libraries(magnum-distancefieldconverter PRIVATE MagnumWindowlessWglApplication)
     else()
         message(FATAL_ERROR "magnum-distancefieldconverter is not available on this platform. Set MAGNUM_WITH_DISTANCEFIELDCONVERTER to OFF to suppress this warning.")
     endif()

src/Magnum/TextureTools/distancefieldconverter.cpp

@@ -42,24 +42,16 @@
 #include "Magnum/Trade/AbstractImageConverter.h"
 #include "Magnum/Trade/ImageData.h"
 
-#ifdef MAGNUM_TARGET_HEADLESS
+#ifdef MAGNUM_TARGET_EGL
 #include "Magnum/Platform/WindowlessEglApplication.h"
 #elif defined(CORRADE_TARGET_IOS)
 #include "Magnum/Platform/WindowlessIosApplication.h"
-#elif defined(CORRADE_TARGET_APPLE) && !defined(MAGNUM_TARGET_GLES)
+#elif defined(CORRADE_TARGET_APPLE)
 #include "Magnum/Platform/WindowlessCglApplication.h"
 #elif defined(CORRADE_TARGET_UNIX)
-#if defined(MAGNUM_TARGET_GLES) && !defined(MAGNUM_TARGET_DESKTOP_GLES)
-#include "Magnum/Platform/WindowlessEglApplication.h"
-#else
 #include "Magnum/Platform/WindowlessGlxApplication.h"
-#endif
 #elif defined(CORRADE_TARGET_WINDOWS)
-#if defined(MAGNUM_TARGET_GLES) && !defined(MAGNUM_TARGET_DESKTOP_GLES)
-#include "Magnum/Platform/WindowlessEglApplication.h"
-#else
 #include "Magnum/Platform/WindowlessWglApplication.h"
-#endif
 #else
 #error no windowless application available on this platform
 #endif

src/Magnum/configure.h.cmake

@@ -32,16 +32,34 @@
 #cmakedefine MAGNUM_TARGET_GLES
 #cmakedefine MAGNUM_TARGET_GLES2
 #cmakedefine MAGNUM_TARGET_GLES3
-#cmakedefine MAGNUM_TARGET_DESKTOP_GLES
 #cmakedefine MAGNUM_TARGET_WEBGL
-#cmakedefine MAGNUM_TARGET_HEADLESS
+#cmakedefine MAGNUM_TARGET_EGL
 #cmakedefine MAGNUM_TARGET_VK
 
 #ifdef MAGNUM_BUILD_DEPRECATED
 #include "Corrade/configure.h"
 #ifdef CORRADE_BUILD_MULTITHREADED
-/* For compatibility only, to be removed at some point */
-#define MAGNUM_BUILD_MULTITHREADED
+/* For compatibility only, to be removed at some point. Deliberate double space
+   after the #define to avoid being unconditionally matched by older FindMagnum
+   modules. */
+#define  MAGNUM_BUILD_MULTITHREADED
+#endif
+/* The following applies only to desktop platforms */
+#if !defined(CORRADE_TARGET_IOS) && !defined(CORRADE_TARGET_ANDROID) && !defined(CORRADE_TARGET_EMSCRIPTEN) && !defined(CORRADE_TARGET_WINDOWS_RT)
+/* MAGNUM_TARGET_HEADLESS used to be an option defined on desktop GL only, not
+   on ES; MAGNUM_TARGET_EGL is defined implicitly also on all platforms that
+   use EGL exclusively. Deliberate double space after the #define to avoid
+   being unconditionally matched by older FindMagnum modules. */
+#if !defined(MAGNUM_TARGET_GLES) && defined(MAGNUM_TARGET_EGL)
+#define  MAGNUM_TARGET_HEADLESS
+#endif
+/* MAGNUM_TARGET_DESKTOP_GLES used to do the opposite of
+   MAGNUM_TARGET_HEADLESS, i.e. force GLX/WGL instead of EGL on GLES builds.
+   Deliberate double space after the #define to avoid being unconditionally
+   matched by older FindMagnum modules. */
+#if defined(MAGNUM_TARGET_GLES) && !defined(MAGNUM_TARGET_EGL)
+#define  MAGNUM_TARGET_DESKTOP_GLES
+#endif
 #endif
 #endif
 

src/MagnumExternal/OpenGL/GLES2/CMakeLists.txt

@@ -27,9 +27,9 @@
 # property that would have to be set on each target separately.
 set(CMAKE_FOLDER "MagnumExternal/OpenGL")
 
-# Desktop GLES on Windows still links to opengl32.dll so we have a special
+# Non-EGL GLES on Windows still links to opengl32.dll so we have a special
 # function loading code that queries everything above OpenGL 1.1
-if(CORRADE_TARGET_WINDOWS AND MAGNUM_TARGET_DESKTOP_GLES)
+if(CORRADE_TARGET_WINDOWS AND NOT MAGNUM_TARGET_EGL)
     set(MagnumOpenGL_HEADERS flextGLWindowsDesktop.h)
     set(MagnumOpenGL_SRCS flextGLWindowsDesktop.cpp)
 

src/MagnumExternal/OpenGL/GLES3/CMakeLists.txt

@@ -27,9 +27,9 @@
 # property that would have to be set on each target separately.
 set(CMAKE_FOLDER "MagnumExternal/OpenGL")
 
-# Desktop GLES on Windows still links to opengl32.dll so we have a special
+# Non-EGL GLES on Windows still links to opengl32.dll so we have a special
 # function loading code that queries everything above OpenGL 1.1
-if(CORRADE_TARGET_WINDOWS AND MAGNUM_TARGET_DESKTOP_GLES)
+if(CORRADE_TARGET_WINDOWS AND NOT MAGNUM_TARGET_EGL)
     set(MagnumOpenGL_HEADERS flextGLWindowsDesktop.h)
     set(MagnumOpenGL_SRCS flextGLWindowsDesktop.cpp)