Split the OpenGL layer out, pt 3: new MAGNUM_TARGET_GL variable.

This will later enable conditional compilation of APIs that depend on
the GL library (for example the Text library directly producing compiled
meshes instead of just plain vertex data).

CMakeLists.txt

@@ -116,6 +116,8 @@ cmake_dependent_option(WITH_TEXTURETOOLS "Build TextureTools library" ON "NOT WI
 cmake_dependent_option(WITH_TRADE "Build Trade library" ON "NOT WITH_MESHTOOLS;NOT WITH_PRIMITIVES;NOT WITH_IMAGECONVERTER;NOT WITH_ANYIMAGEIMPORTER;NOT WITH_ANYIMAGECONVERTER;NOT WITH_ANYSCENEIMPORTER;NOT WITH_OBJIMPORTER;NOT WITH_TGAIMAGECONVERTER;NOT WITH_TGAIMPORTER" ON)
 cmake_dependent_option(WITH_GL "Build GL library" ON "NOT WITH_DEBUGTOOLS;NOT WITH_MESHTOOLS;NOT WITH_PRIMITIVES;NOT WITH_SHADERS;NOT WITH_TEXT;NOT WITH_TEXTURETOOLS;NOT WITH_TRADE;NOT WITH_MAGNUMINFO;NOT WITH_ANDROIDAPPLICATION;NOT WITH_WINDOWLESSIOSAPPLICATION;NOT WITH_CGLCONTEXT;NOT WITH_GLXAPPLICATION;NOT WITH_GLXCONTEXT;NOT WITH_XEGLAPPLICATION;NOT WITH_WINDOWLESSWGLAPPLICATION;NOT WITH_GLXCONTEXT;NOT WITH_XEGLAPPLICATION;NOT WITH_WINDOWLESSWGLAPPLICATION;NOT WITH_WGLCONTEXT;NOT WITH_WINDOWLESSWINDOWSEGLAPPLICATION;NOT WITH_GLFWAPPLICATION;NOT WITH_GLUTAPPLICATION;NOT WITH_SDL2APPLICATION;NOT WITH_DISTANCEFIELDCONVERTER;NOT WITH_FONTCONVERTER;NOT WITH_IMAGECONVERTER" ON)
 
+cmake_dependent_option(TARGET_GL "Build libraries with OpenGL interoperability" ON "WITH_GL" OFF)
+
 # Magnum AL Info
 cmake_dependent_option(WITH_AL_INFO "Build magnum-al-info utility" OFF "WITH_AUDIO" OFF)
 
@@ -217,6 +219,9 @@ else()
 endif()
 
 # Configuration variables (saved later to configure.h)
+if(TARGET_GL)
+    set(MAGNUM_TARGET_GL 1)
+endif()
 if(TARGET_GLES)
     set(MAGNUM_TARGET_GLES 1)
     if(TARGET_GLES2)

Doxyfile

@@ -2052,7 +2052,8 @@ PREDEFINED             = DOXYGEN_GENERATING_OUTPUT \
     CORRADE_DEPRECATED_FILE(message)= CORRADE_VISIBILITY_EXPORT= \
     CORRADE_VISIBILITY_LOCAL= CORRADE_VISIBILITY_IMPORT= \
     CORRADE_IGNORE_DEPRECATED_PUSH= CORRADE_IGNORE_DEPRECATED_POP= \
-    CORRADE_ENUMSET_OPERATORS(message)= MAGNUM_BUILD_DEPRECATED
+    CORRADE_ENUMSET_OPERATORS(message)= MAGNUM_BUILD_DEPRECATED \
+    MAGNUM_TARGET_GL
 
 # If the MACRO_EXPANSION and EXPAND_ONLY_PREDEF tags are set to YES then this
 # tag can be used to specify a list of macro names that should be expanded. The

doc/building.dox

@@ -383,6 +383,10 @@ By default the engine is built for desktop OpenGL. Using the `TARGET_*` CMake
 options you can target other platforms. Note that some features are
 available for desktop OpenGL only, see @ref requires-gl.
 
+-   `TARGET_GL` --- Build libraries with OpenGL interoperability enabled.
+    Enabled by default when `WITH_GL` is enabled. Disabling this will cause
+    libraries to not depend on the @ref GL library, but doesn't affect the
+    @ref GL library itself.
 -   `TARGET_GLES` --- Target OpenGL ES. Available only when `WITH_GL` is
     enabled.
 -   `TARGET_GLES2` --- Target OpenGL ES 2.0 instead of 3.0 and later. Available

doc/cmake.dox

@@ -209,6 +209,8 @@ are also available as preprocessor variables if including
     are shared libraries.
 -   `MAGNUM_BUILD_MULTITHREADED` --- Defined if compiled in a way that allows
     having multiple thread-local Magnum contexts. The default.
+-   `MAGNUM_TARGET_GL` --- Defined if compiled with OpenGL interoperability
+    enabled
 -   `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

modules/FindMagnum.cmake

@@ -120,6 +120,7 @@
 #  MAGNUM_BUILD_STATIC          - Defined if compiled as static libraries
 #  MAGNUM_BUILD_MULTITHREADED   - Defined if compiled in a way that allows
 #   having multiple thread-local Magnum contexts
+#  MAGNUM_TARGET_GL             - Defined if compiled with OpenGL interop
 #  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
@@ -248,6 +249,7 @@ set(_magnumFlags
     BUILD_DEPRECATED
     BUILD_STATIC
     BUILD_MULTITHREADED
+    TARGET_GL
     TARGET_GLES
     TARGET_GLES2
     TARGET_GLES3

src/Magnum/Magnum.h

@@ -95,6 +95,18 @@ Magnum contexts. Enabled by default.
 #define MAGNUM_BUILD_MULTITHREADED
 #undef MAGNUM_BUILD_MULTITHREADED
 
+/**
+@brief OpenGL interoperability
+
+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
+*/
+#define MAGNUM_TARGET_GL
+/* (enabled by default) */
+
 /**
 @brief OpenGL ES target
 

src/Magnum/configure.h.cmake

@@ -28,6 +28,7 @@
 #cmakedefine MAGNUM_BUILD_DEPRECATED
 #cmakedefine MAGNUM_BUILD_STATIC
 #cmakedefine MAGNUM_BUILD_MULTITHREADED
+#cmakedefine MAGNUM_TARGET_GL
 #cmakedefine MAGNUM_TARGET_GLES
 #cmakedefine MAGNUM_TARGET_GLES2
 #cmakedefine MAGNUM_TARGET_GLES3