SVN commit 1088054 by lmurray:

Revert r1082246 as it needs to be done in CompositingPrefs::detect()
to work correctly but as doing it there defeats the purpose of moving
the code to begin with there's no point in moving it.
BUG: 226049


 M  +0 -3      compositingprefs.cpp  
 M  +8 -0      main.cpp  
 M  +0 -38     scene_opengl.cpp  


--- trunk/KDE/kdebase/workspace/kwin/compositingprefs.cpp #1088053:1088054
@@ -276,8 +276,6 @@
     mRecommendCompositing = true;
 
     // Known driver specific options
-    // NOTE: GLX has already been loaded so we cannot change direct rendering mode here if the
-    //       driver uses the LIBGL_ALWAYS_INDIRECT environment variable.
     if( mXgl )
         {
         mStrictBinding = false;
@@ -288,7 +286,6 @@
         }
     else if( mDriver == "nvidia" )
         {
-        mEnableDirectRendering = true; // Driver doesn't use LIBGL_ALWAYS_INDIRECT
         mStrictBinding = false;
         }
     //else if( mDriver == "fglrx" )
--- trunk/KDE/kdebase/workspace/kwin/main.cpp #1088053:1088054
@@ -496,6 +496,10 @@
     if( KDE_signal( SIGHUP, KWin::sighandler ) == SIG_IGN )
         KDE_signal( SIGHUP, SIG_IGN );
 
+    // HACK: This is needed for AIGLX
+    if( qstrcmp( qgetenv( "KWIN_DIRECT_GL" ), "1" ) != 0 )
+        setenv( "LIBGL_ALWAYS_INDIRECT","1", true );
+
     // HACK: this is needed to work around a Qt4.4.0RC1 bug (#157659)
     setenv( "QT_SLOW_TOPLEVEL_RESIZE", "1", true );
 
@@ -504,6 +508,10 @@
     KWin::SessionSaveDoneHelper helper;
     KGlobal::locale()->insertCatalog( "kwin_effects" );
 
+    // Announce when KWIN_DIRECT_GL is set for above HACK
+    if( qstrcmp( qgetenv( "KWIN_DIRECT_GL" ), "1" ) == 0 )
+        kDebug( 1212 ) << "KWIN_DIRECT_GL set, not forcing LIBGL_ALWAYS_INDIRECT=1";
+
     fcntl( XConnectionNumber( KWin::display() ), F_SETFD, 1 );
 
     QString appname;
--- trunk/KDE/kdebase/workspace/kwin/scene_opengl.cpp #1088053:1088054
@@ -113,7 +113,6 @@
 XShmSegmentInfo SceneOpenGL::shm;
 #endif
 
-//static int firstWasDirect = -1;
 
 SceneOpenGL::SceneOpenGL( Workspace* ws )
     : Scene( ws )
@@ -125,43 +124,6 @@
         kDebug( 1212 ) << "No glx extensions available";
         return; // error
         }
-
-    // LIBGL_ALWAYS_INDIRECT:
-    //   This environment variable causes the Mesa libGL to not load any DRI driver on the client's
-    // side at all. This has the side-effect of making the library behave differently when creating
-    // indirect rendering contexts for compositing.
-    //   When a Mesa driver is using DRI1 compositing will only work in indirect rendering mode
-    // while when using DRI2 it's possible to use compositing with direct rendering. When running
-    // with direct rendering we have more OpenGL features available to us therefore it's the
-    // prefered mode to be running in.
-    //   If AIGLX is enabled when we create an indirect rendering context without this variable set
-    // the context doesn't seem to be usable for compositing for some reason. Needs more research.
-    //   In Mesa this variable is only read during the first call to glXQueryVersion() so it cannot
-    // be changed after GLX has already been used by KWin.
-    //   Fglrx also uses this variable but I have yet to research how it acts under various
-    // conditions and what the optimal usage of it by KWin would be.
-    //     -- lmurray (30th Jan, 2010)
-    // TODO: Set this variable only when explicitly running in indirect rendering mode.
-    //const int isDirect = options->glDirect ? 1 : 0;
-    //if( firstWasDirect == -1 )
-    //    firstWasDirect = isDirect;
-    //else
-    //    if( isDirect != firstWasDirect )
-    //        // Switching indirect => direct won't take effect and direct => indirect will cause
-    //        // compositing to not work at all on AIGLX systems.
-    //        kWarning( 1212 ) << "Switched direct rendering mode while KWin was running. THIS IS UNSAFE!";
-    //if( !options->glDirect )
-    //    {
-        // HACK: This is required for compositing to work on AIGLX
-        if( qstrcmp( qgetenv( "KWIN_DIRECT_GL" ), "1" ) != 0 )
-            {
-            kDebug( 1212 ) << "Forcing LIBGL_ALWAYS_INDIRECT=1";
-            setenv( "LIBGL_ALWAYS_INDIRECT", "1", true );
-            }
-        else
-            kDebug( 1212 ) << "KWIN_DIRECT_GL set, not forcing LIBGL_ALWAYS_INDIRECT=1";
-    //    }
-
     initGLX();
     // check for FBConfig support
     if( !hasGLExtension( "GLX_SGIX_fbconfig" ) || !glXGetFBConfigAttrib || !glXGetFBConfigs ||