Ability to build Magnum for OpenGL ES emulated with desktop OpenGL.

CMakeLists.txt

@@ -6,6 +6,7 @@ include(CMakeDependentOption)
 
 option(TARGET_GLES "Build for OpenGL ES instead of desktop OpenGL" OFF)
 cmake_dependent_option(TARGET_GLES2 "Build for OpenGL ES 2" ON "TARGET_GLES" OFF)
+cmake_dependent_option(TARGET_DESKTOP_GLES "Build for OpenGL ES on desktop" OFF "TARGET_GLES" OFF)
 
 # Parts of the library
 option(WITH_EVERYTHING "Build everything (doesn't include *Application libraries)" ON)
@@ -46,12 +47,14 @@ endif()
 
 # Check dependencies
 find_package(Corrade REQUIRED)
-if(NOT TARGET_GLES)
+if(NOT TARGET_GLES OR TARGET_DESKTOP_GLES)
     find_package(OpenGL REQUIRED)
-    find_package(GLEW REQUIRED)
 else()
     find_package(OpenGLES2 REQUIRED)
 endif()
+if(NOT TARGET_GLES)
+    find_package(GLEW REQUIRED)
+endif()
 
 # Configuration variables (saved later to corradeConfigure.h)
 if(TARGET_GLES)
@@ -60,6 +63,9 @@ endif()
 if(TARGET_GLES2)
     set(MAGNUM_TARGET_GLES2 1)
 endif()
+if(TARGET_DESKTOP_GLES)
+    set(MAGNUM_TARGET_DESKTOP_GLES 1)
+endif()
 
 # Installation paths
 set(MAGNUM_BINARY_INSTALL_DIR ${CMAKE_INSTALL_PREFIX}/bin)

README.md

@@ -53,6 +53,9 @@ installed using these four commands:
     make
     make install
 
+See Doxygen documentation for more information about enabling or disabling
+additional features and targeting different platforms such as OpenGL ES.
+
 Building and running unit tests
 -------------------------------
 

doc/building.dox

@@ -55,9 +55,17 @@ If you want to build with another compiler (e.g. Clang), pass
 
 @subsection building-optional Enabling or disabling features
 
-By default the engine is built for desktop OpenGL. If you want to target
-OpenGL ES, set `TARGET_GLES` to `ON` or pass `-DTARGET_GLES=ON` to CMake. Note
-that some features are available for desktop OpenGL only, see @ref requires-gl.
+By default the engine is built for desktop OpenGL. Using `TARGET_*` CMake
+parameters you can target other platforms:
+
+ - `TARGET_GLES` - Target OpenGL ES.
+ - `TARGET_GLES2` - Target OpenGL ES 2.0. Currently enabled by default when
+   `TARGET_GLES` is set, as no customer OpenGL ES 3.0 platform exists yet.
+ - `TARGET_DESKTOP_GLES` - Target OpenGL ES on desktop, i.e. use OpenGL ES
+   emulation in desktop OpenGL library. Might not be supported in all drivers.
+
+Note that some features are available for desktop OpenGL only, see
+@ref requires-gl.
 
 By default the engine is built with everything except
 @ref Platform "application libraries". Using `WITH_*` CMake parameters you can

modules/FindMagnum.cmake

@@ -85,13 +85,19 @@ string(FIND "${_magnumConfigure}" "#define MAGNUM_TARGET_NACL" _TARGET_NACL)
 if(NOT _TARGET_NACL EQUAL -1)
     set(MAGNUM_TARGET_NACL 1)
 endif()
+string(FIND "${_magnumConfigure}" "#define MAGNUM_TARGET_DESKTOP_GLES" _TARGET_DESKTOP_GLES)
+if(NOT _TARGET_DESKTOP_GLES EQUAL -1)
+    set(MAGNUM_TARGET_DESKTOP_GLES 1)
+endif()
 
-if(NOT MAGNUM_TARGET_GLES)
+if(NOT MAGNUM_TARGET_GLES OR MAGNUM_TARGET_DESKTOP_GLES)
     find_package(OpenGL REQUIRED)
-    find_package(GLEW REQUIRED)
 else()
     find_package(OpenGLES2 REQUIRED)
 endif()
+if(NOT MAGNUM_TARGET_GLES)
+    find_package(GLEW REQUIRED)
+endif()
 
 # On Windows, *Application libraries need to have ${MAGNUM_LIBRARY} listed
 # in dependencies also after *Application.lib static library name to avoid
@@ -242,13 +248,13 @@ set(MAGNUM_INCLUDE_DIRS ${MAGNUM_INCLUDE_DIR}
 set(MAGNUM_LIBRARIES ${MAGNUM_LIBRARY}
     ${CORRADE_UTILITY_LIBRARY}
     ${CORRADE_PLUGINMANAGER_LIBRARY})
-if(NOT MAGNUM_TARGET_GLES)
-    set(MAGNUM_LIBRARIES ${MAGNUM_LIBRARIES}
-        ${OPENGL_gl_LIBRARY}
-        ${GLEW_LIBRARY})
+if(NOT MAGNUM_TARGET_GLES OR MAGNUM_TARGET_DESKTOP_GLES)
+    set(MAGNUM_LIBRARIES ${MAGNUM_LIBRARIES} ${OPENGL_gl_LIBRARY})
 else()
-    set(MAGNUM_LIBRARIES ${MAGNUM_LIBRARIES}
-        ${OPENGLES2_LIBRARY})
+    set(MAGNUM_LIBRARIES ${MAGNUM_LIBRARIES} ${OPENGLES2_LIBRARY})
+endif()
+if(NOT MAGNUM_TARGET_GLES)
+    set(MAGNUM_LIBRARIES ${MAGNUM_LIBRARIES} ${GLEW_LIBRARY})
 endif()
 
 # Installation dirs

src/CMakeLists.txt

@@ -119,13 +119,13 @@ add_library(Magnum SHARED
 set(Magnum_LIBS
     ${CORRADE_UTILITY_LIBRARY}
     ${CORRADE_PLUGINMANAGER_LIBRARY})
-if(NOT TARGET_GLES)
-    set(Magnum_LIBS ${Magnum_LIBS}
-        ${OPENGL_gl_LIBRARY}
-        ${GLEW_LIBRARY})
+if(NOT TARGET_GLES OR TARGET_DESKTOP_GLES)
+    set(Magnum_LIBS ${Magnum_LIBS} ${OPENGL_gl_LIBRARY})
 else()
-    set(Magnum_LIBS ${Magnum_LIBS}
-        ${OPENGLES2_LIBRARY})
+    set(Magnum_LIBS ${Magnum_LIBS} ${OPENGLES2_LIBRARY})
+endif()
+if(NOT TARGET_GLES)
+    set(Magnum_LIBS ${Magnum_LIBS} ${GLEW_LIBRARY})
 endif()
 target_link_libraries(Magnum ${Magnum_LIBS})
 

src/Platform/magnum-info.cpp

@@ -47,6 +47,9 @@ MagnumInfo::MagnumInfo(int& argc, char** argv): WindowlessGlxApplication(argc, a
         #ifdef MAGNUM_TARGET_GLES2
         d << "MAGNUM_TARGET_GLES2";
         #endif
+        #ifdef MAGNUM_TARGET_DESKTOP_GLES
+        d << "MAGNUM_TARGET_DESKTOP_GLES";
+        #endif
         #ifdef MAGNUM_TARGET_NACL
         d << "MAGNUM_TARGET_NACL";
         #endif

src/magnumConfigure.h.cmake

@@ -1,3 +1,4 @@
-#cmakedefine MAGNUM_TARGET_NACL
 #cmakedefine MAGNUM_TARGET_GLES
 #cmakedefine MAGNUM_TARGET_GLES2
+#cmakedefine MAGNUM_TARGET_DESKTOP_GLES
+#cmakedefine MAGNUM_TARGET_NACL