Wayland graphics support

CMakeLists.txt

@@ -864,6 +864,11 @@ IF(NOT (ANDROID AND OSG_FIND_3RD_PARTY_DEPS))
     ENDIF()
 ENDIF()
 
+IF(OSG_WINDOWING_SYSTEM STREQUAL "X11")
+  # optional Wayland graphics also supported..
+  FIND_PACKAGE(Wayland)
+ENDIF()
+
 ################################################################################
 # Create bin and lib directories if required
 

CMakeModules/FindWayland.cmake

@@ -0,0 +1,15 @@
+# Find Wayland development libraries & headers for wayland-egl & wayland-cursor & EGL & XKBcommon
+#
+# WAYLAND_FOUND - system has a libwayland-[egl|client|cursor] + libEGL + libxkbcommon
+# WAYLAND_INCLUDE_DIR - where to find header files
+# WAYLAND_LIBRARIES - the libraries to link against Wayland
+#
+# copyright (c) 2022 Phil Ashby <[email protected]>
+# Redistribution and use of this file is allowed according to the terms of the BSD license.
+#
+
+# Use PkgConfig to find includes and libs
+find_package(PkgConfig QUIET)
+if (PKG_CONFIG_FOUND)
+	PKG_CHECK_MODULES(WAYLAND QUIET wayland-egl wayland-cursor egl xkbcommon)
+endif ()

src/osg/GraphicsContext.cpp

@@ -75,28 +75,44 @@ GraphicsContext::WindowingSystemInterface* GraphicsContext::WindowingSystemInter
         OSG_WARN<<"Warning: GraphicsContext::WindowingSystemInterfaces::getWindowingSystemInterface() failed, no interfaces available."<<std::endl;
         return 0;
     }
+    std::string search = name;
+    if (getenv("OSG_WINDOWING_SYSTEM") != NULL)
+    {
+        search = getenv("OSG_WINDOWING_SYSTEM");
+    }
 
-    if (!name.empty())
+    if (!search.empty())
     {
         for(Interfaces::iterator itr = _interfaces.begin();
             itr != _interfaces.end();
             ++itr)
         {
-            if ((*itr)->getName()==name)
+            if ((*itr)->getName()==search)
             {
+                OSG_INFO<<"found WindowingSystemInterface : "<<search<<std::endl;
                 return itr->get();
             }
-
-            OSG_NOTICE<<"   tried interface "<<typeid(*itr).name()<<", name= "<<(*itr)->getName()<<std::endl;
         }
 
-        OSG_WARN<<"Warning: GraphicsContext::WindowingSystemInterfaces::getWindowingSystemInterface() failed, no interfaces matches name : "<<name<<std::endl;
+        OSG_WARN<<"Warning: GraphicsContext::WindowingSystemInterfaces::getWindowingSystemInterface() failed, no interfaces matches name : "<<search<<std::endl;
         return 0;
     }
     else
     {
-        // no preference provided so just take the first available interface
-        return _interfaces.front().get();
+        // no preference provided so just take the first available interface that works
+        for (Interfaces::iterator itr = _interfaces.begin();
+            itr != _interfaces.end();
+            ++itr)
+        {
+            if ((*itr)->getNumScreens() > 0)
+            {
+                OSG_INFO<<"using default WindowingSystemInterface : "<<(*itr)->getName()<<std::endl;
+                return itr->get();
+            }
+        }
+
+        OSG_WARN<<"Warning: GraphicsContext::WindowingSystemInterfaces::getWindowingSystemInterface() failed, no working interfaces"<<std::endl;
+        return 0;
     }
 }
 

src/osgViewer/CMakeLists.txt

@@ -248,6 +248,16 @@ ELSE()
 
           SET(LIB_EXTRA_LIBS ${X11_X11_LIB} ${LIB_EXTRA_LIBS})
         ENDIF(APPLE)
+
+        # Add Wayland here if available..
+        IF(WAYLAND_FOUND)
+          ADD_DEFINITIONS(-DOSGVIEWER_USE_WAYLAND)
+          SET(LIB_COMMON_FILES ${LIB_COMMON_FILES}
+            GraphicsWindowWayland.cpp
+            xdg-shell.c
+            xdg-decoration-unstable-v1.c)
+          SET(LIB_EXTRA_LIBS ${WAYLAND_LIBRARIES} ${LIB_EXTRA_LIBS})
+        ENDIF()
     ELSE()
         MESSAGE(STATUS "Windowing system not supported")
     ENDIF()