Preparing CMakeLists.txt to accept Wayland

CMakeLists.txt

@@ -427,7 +427,14 @@ if (WIN32 OR ANDROID OR IOS OR EMSCRIPTEN)
 elseif (APPLE)
   set (USE_XLIB OFF CACHE BOOL "${USE_XLIB_DESCR}")
 else()
-  set (USE_XLIB ON  CACHE BOOL "${USE_XLIB_DESCR}")
+  find_package(Xlib QUIET)
+  if (XLIB_FOUND)
+    set (USE_XLIB ON  CACHE BOOL "${USE_XLIB_DESCR}")
+    message(STATUS "Configuring XLIB")
+  else()
+    set(USE_WAYLAND)
+    message(STATUS "Configuring WAYLAND")
+  endif()
 endif()
 
 if (WIN32)
@@ -448,12 +455,24 @@ else()
 endif()
 
 # OpenGL
-if (ANDROID OR IOS OR EMSCRIPTEN OR "${CMAKE_SYSTEM_NAME}" STREQUAL "WindowsStore")
-  set (USE_OPENGL OFF)
-  set (USE_GLES2 ON)
-else()
-  set (USE_OPENGL ON CACHE BOOL "${USE_OPENGL_DESCR}")
-  set (USE_GLES2 OFF CACHE BOOL "${USE_GLES2_DESCR}")
+# Try to find OpenGL package
+if (NOT USE_D3D)
+  find_package(OpenGL QUIET)
+  # If GLES is not found, or we enforced GLES but not OpenGL, setup OpenGL
+  if(OPENGL_FOUND AND (NOT USE_GLES2 OR USE_OPENGL) )
+    set(USE_OPENGL ON)
+    set(USE_GLES2 OFF)
+    message(STATUS "OpenGL found, using OpenGL")
+    include_directories(${OPENGL_INCLUDE_DIRS})
+    list(APPEND EXTRA_LIBS ${OPENGL_LIBRARIES})
+    set(USE_OPENGL ${USE_OPENGL} CACHE BOOL "${USE_OPENGL_DESCR}")
+  elseif( OPENGLES2_FOUND )
+    # Either we found no OpenGL, or GLES was enforced
+    set(USE_OPENGL OFF)
+    set(USE_GLES2 ON)
+    message(STATUS "OpenGL ES 2 found, using GLES2")
+    set(USE_GLES2 ${USE_GLES2} CACHE BOOL "${USE_GLES2_DESCR}")
+  endif()
 endif()
 
 # include the patched or original list of modules

src/OpenGl/OpenGl_GraphicDriver.cxx

@@ -40,7 +40,7 @@ IMPLEMENT_STANDARD_RTTIEXT(OpenGl_GraphicDriver,Graphic3d_GraphicDriver)
   #include <Aspect_NeutralWindow.hxx>
 #endif
 
-#if !defined(_WIN32) && !defined(__ANDROID__) && !defined(__QNX__) && !defined(__EMSCRIPTEN__) && (!defined(__APPLE__) || defined(HAVE_XLIB))
+#if defined(HAVE_XLIB)
   #include <X11/Xlib.h> // XOpenDisplay()
   #include <GL/glx.h>
 #endif