Refactor SGSky handling and ownership - sink into Renderer, remove global variable 'the sky', and hence clean up main loop and subsystem creation a little more.

src/Environment/environment_mgr.cxx

@@ -31,6 +31,7 @@
 #include <simgear/structure/event_mgr.hxx>
 
 #include <Main/main.hxx>
+#include <Main/renderer.hxx>
 #include <Main/fg_props.hxx>
 #include <FDM/flight.hxx>
 
@@ -45,9 +46,6 @@
 #include "Airports/simple.hxx"
 #include "gravity.hxx"
 
-class SGSky;
-extern SGSky *thesky;
-
 class FG3DCloudsListener : public SGPropertyChangeListener {
 public:
   FG3DCloudsListener( FGClouds * fgClouds );
@@ -91,7 +89,8 @@ FGEnvironmentMgr::FGEnvironmentMgr () :
   _altitude_n(fgGetNode("/position/altitude-ft", true)),
   _longitude_n(fgGetNode( "/position/longitude-deg", true )),
   _latitude_n( fgGetNode( "/position/latitude-deg", true )),
-  _3dCloudsEnableListener(new FG3DCloudsListener(fgClouds) )
+  _3dCloudsEnableListener(new FG3DCloudsListener(fgClouds) ),
+  _sky(globals->get_renderer()->getSky())
 {
   set_subsystem("controller", Environment::LayerInterpolateController::createInstance( fgGetNode("/environment/config", true ) ));
   set_subsystem("realwx", Environment::RealWxController::createInstance( fgGetNode("/environment/realwx", true ) ), 1.0 );
@@ -171,7 +170,7 @@ FGEnvironmentMgr::bind ()
 
   _tiedProperties.setRoot( fgGetNode( "/environment", true ) );
 
-  _tiedProperties.Tie( "effective-visibility-m", thesky,
+  _tiedProperties.Tie( "effective-visibility-m", _sky,
           &SGSky::get_visibility );
 
   _tiedProperties.Tie("rebuild-layers", fgClouds,
@@ -220,15 +219,15 @@ FGEnvironmentMgr::bind ()
 
   _tiedProperties.setRoot( fgGetNode("/sim/rendering", true ) );
 
-  _tiedProperties.Tie( "clouds3d-density", thesky,
+  _tiedProperties.Tie( "clouds3d-density", _sky,
           &SGSky::get_3dCloudDensity,
           &SGSky::set_3dCloudDensity);
 
-  _tiedProperties.Tie("clouds3d-vis-range", thesky,
+  _tiedProperties.Tie("clouds3d-vis-range", _sky,
           &SGSky::get_3dCloudVisRange,
           &SGSky::set_3dCloudVisRange);
 
-  _tiedProperties.Tie("clouds3d-wrap", thesky,
+  _tiedProperties.Tie("clouds3d-wrap", _sky,
           &SGSky::get_3dCloudWrap,
           &SGSky::set_3dCloudWrap);
 
@@ -325,19 +324,19 @@ FGEnvironmentMgr::getEnvironment(const SGGeod& aPos) const
 double
 FGEnvironmentMgr::get_cloud_layer_span_m (int index) const
 {
-  return thesky->get_cloud_layer(index)->getSpan_m();
+  return _sky->get_cloud_layer(index)->getSpan_m();
 }
 
 void
 FGEnvironmentMgr::set_cloud_layer_span_m (int index, double span_m)
 {
-  thesky->get_cloud_layer(index)->setSpan_m(span_m);
+  _sky->get_cloud_layer(index)->setSpan_m(span_m);
 }
 
 double
 FGEnvironmentMgr::get_cloud_layer_elevation_ft (int index) const
 {
-  return thesky->get_cloud_layer(index)->getElevation_m() * SG_METER_TO_FEET;
+  return _sky->get_cloud_layer(index)->getElevation_m() * SG_METER_TO_FEET;
 }
 
 void
@@ -346,88 +345,88 @@ FGEnvironmentMgr::set_cloud_layer_elevation_ft (int index, double elevation_ft)
   FGEnvironment env = *_environment;
   env.set_elevation_ft(elevation_ft);
 
-  thesky->get_cloud_layer(index)
+  _sky->get_cloud_layer(index)
     ->setElevation_m(elevation_ft * SG_FEET_TO_METER);
 
-  thesky->get_cloud_layer(index)
+  _sky->get_cloud_layer(index)
     ->setSpeed(env.get_wind_speed_kt() * 0.5151);	// 1 kt = 0.5151 m/s
 
-  thesky->get_cloud_layer(index)
+  _sky->get_cloud_layer(index)
     ->setDirection(env.get_wind_from_heading_deg());
 }
 
 double
 FGEnvironmentMgr::get_cloud_layer_thickness_ft (int index) const
 {
-  return thesky->get_cloud_layer(index)->getThickness_m() * SG_METER_TO_FEET;
+  return _sky->get_cloud_layer(index)->getThickness_m() * SG_METER_TO_FEET;
 }
 
 void
 FGEnvironmentMgr::set_cloud_layer_thickness_ft (int index, double thickness_ft)
 {
-  thesky->get_cloud_layer(index)
+  _sky->get_cloud_layer(index)
     ->setThickness_m(thickness_ft * SG_FEET_TO_METER);
 }
 
 double
 FGEnvironmentMgr::get_cloud_layer_transition_ft (int index) const
 {
-  return thesky->get_cloud_layer(index)->getTransition_m() * SG_METER_TO_FEET;
+  return _sky->get_cloud_layer(index)->getTransition_m() * SG_METER_TO_FEET;
 }
 
 void
 FGEnvironmentMgr::set_cloud_layer_transition_ft (int index,
 						 double transition_ft)
 {
-  thesky->get_cloud_layer(index)
+  _sky->get_cloud_layer(index)
     ->setTransition_m(transition_ft * SG_FEET_TO_METER);
 }
 
 const char *
 FGEnvironmentMgr::get_cloud_layer_coverage (int index) const
 {
-  return thesky->get_cloud_layer(index)->getCoverageString().c_str();
+  return _sky->get_cloud_layer(index)->getCoverageString().c_str();
 }
 
 void
 FGEnvironmentMgr::set_cloud_layer_coverage (int index,
                                             const char * coverage_name)
 {
-  if( thesky->get_cloud_layer(index)->getCoverageString() == coverage_name )
+  if( _sky->get_cloud_layer(index)->getCoverageString() == coverage_name )
     return;
 
-  thesky->get_cloud_layer(index)->setCoverageString(coverage_name);
+  _sky->get_cloud_layer(index)->setCoverageString(coverage_name);
   _cloudLayersDirty = true;
 }
 
 int
 FGEnvironmentMgr::get_cloud_layer_coverage_type (int index) const
 {
-  return thesky->get_cloud_layer(index)->getCoverage();
+  return _sky->get_cloud_layer(index)->getCoverage();
 }
 
 double
 FGEnvironmentMgr::get_cloud_layer_visibility_m (int index) const
 {
-    return thesky->get_cloud_layer(index)->getVisibility_m();
+    return _sky->get_cloud_layer(index)->getVisibility_m();
 }
 
 void
 FGEnvironmentMgr::set_cloud_layer_visibility_m (int index, double visibility_m)
 {
-    thesky->get_cloud_layer(index)->setVisibility_m(visibility_m);
+    _sky->get_cloud_layer(index)->setVisibility_m(visibility_m);
 }
 
 double
 FGEnvironmentMgr::get_cloud_layer_maxalpha (int index ) const
 {
-    return thesky->get_cloud_layer(index)->getMaxAlpha();
+    return _sky->get_cloud_layer(index)->getMaxAlpha();
 }
 
 void
 FGEnvironmentMgr::set_cloud_layer_maxalpha (int index, double maxalpha)
 {
-    thesky->get_cloud_layer(index)->setMaxAlpha(maxalpha);
+    _sky->get_cloud_layer(index)->setMaxAlpha(maxalpha);
 }
 
 void
@@ -438,10 +437,10 @@ FGEnvironmentMgr::set_cloud_layer_coverage_type (int index, int type )
     return;
   }
 
-  if( static_cast<SGCloudLayer::Coverage>(type) == thesky->get_cloud_layer(index)->getCoverage() )
+  if( static_cast<SGCloudLayer::Coverage>(type) == _sky->get_cloud_layer(index)->getCoverage() )
     return;
 
-  thesky->get_cloud_layer(index)->setCoverage(static_cast<SGCloudLayer::Coverage>(type));
+  _sky->get_cloud_layer(index)->setCoverage(static_cast<SGCloudLayer::Coverage>(type));
   _cloudLayersDirty = true;
 }
 

src/Environment/environment_mgr.hxx

@@ -38,6 +38,7 @@ class FGMetarCtrl;
 class FGMetarFetcher;
 class FGClouds;
 class FGPrecipitationMgr;
+class SGSky;
 
 /**
  * Manage environment information.
@@ -102,6 +103,8 @@ private:
   SGPropertyNode_ptr _latitude_n;
   simgear::TiedPropertyList _tiedProperties;
   SGPropertyChangeListener * _3dCloudsEnableListener;
+  SGSky* _sky;
+    
 };
 
 #endif // _ENVIRONMENT_MGR_HXX

src/Environment/ephemeris.cxx

@@ -32,6 +32,10 @@ Ephemeris::Ephemeris() :
   _impl(NULL),
   _latProp(NULL)
 {
+    SGPath ephem_data_path(globals->get_fg_root());
+    ephem_data_path.append("Astro");
+    _impl = new SGEphemeris(ephem_data_path.c_str());
+    globals->set_ephem(_impl);
 }
 
 Ephemeris::~Ephemeris()
@@ -41,15 +45,6 @@ Ephemeris::~Ephemeris()
 
 void Ephemeris::init()
 {
-  if (_impl) {
-    return;
-  }
-  
-  SGPath ephem_data_path(globals->get_fg_root());
-  ephem_data_path.append("Astro");
-  _impl = new SGEphemeris(ephem_data_path.c_str());
-  globals->set_ephem(_impl);
-  
   _latProp = fgGetNode("/position/latitude-deg", true);
   update(0.0);
 }

src/Environment/fgclouds.cxx

@@ -38,13 +38,12 @@
 #include <simgear/props/props_io.hxx>
 
 #include <Main/globals.hxx>
+#include <Main/renderer.hxx>
 #include <Airports/simple.hxx>
 #include <Main/util.hxx>
 
 #include "fgclouds.hxx"
 
-extern SGSky *thesky;
-
 static bool do_delete_3Dcloud (const SGPropertyNode *arg);
 static bool do_move_3Dcloud (const SGPropertyNode *arg);
 static bool do_add_3Dcloud (const SGPropertyNode *arg);
@@ -182,6 +181,8 @@ void FGClouds::buildLayer(int iLayer, const string& name, double coverage) {
 	int CloudVarietyCount = 0;
 	double totalCount = 0.0;
 
+    SGSky* thesky = globals->get_renderer()->getSky();
+    
 	SGPropertyNode *cloud_def_root = fgGetNode("/environment/cloudlayers/clouds", false);
 	SGPropertyNode *box_def_root   = fgGetNode("/environment/cloudlayers/boxes", false);
 	SGPropertyNode *layer_def_root = fgGetNode("/environment/cloudlayers/layers", false);
@@ -274,6 +275,7 @@ void FGClouds::buildCloudLayers(void) {
 	double cumulus_base = 122.0 * (temperature_degc - dewpoint_degc);
 	double stratus_base = 100.0 * (100.0 - rel_humidity) * SG_FEET_TO_METER;
 
+    SGSky* thesky = globals->get_renderer()->getSky();
 	for(int iLayer = 0 ; iLayer < thesky->get_cloud_layer_count(); iLayer++) {
 		SGPropertyNode *cloud_root = fgGetNode("/environment/clouds/layer", iLayer, true);
 
@@ -366,7 +368,7 @@ bool FGClouds::get_3dClouds() const
 	 float x   = arg->getFloatValue("x-offset-m",  0.0f);
 	 float y   = arg->getFloatValue("y-offset-m",  0.0f);
 
-
+   SGSky* thesky = globals->get_renderer()->getSky();
    SGCloudField *layer = thesky->get_cloud_layer(l)->get_layer3D();
    SGNewCloud cld = SGNewCloud(texture_root, arg);
 	 bool success = layer->addCloud(lon, lat, alt, x, y, index, cld.genCloud());
@@ -392,6 +394,7 @@ bool FGClouds::get_3dClouds() const
    int l = arg->getIntValue("layer", 0);
    int i = arg->getIntValue("index", 0);
 
+   SGSky* thesky = globals->get_renderer()->getSky();
    SGCloudField *layer = thesky->get_cloud_layer(l)->get_layer3D();
 	 return layer->deleteCloud(i);
  }
@@ -410,6 +413,7 @@ bool FGClouds::get_3dClouds() const
  {
    int l = arg->getIntValue("layer", 0);
    int i = arg->getIntValue("index", 0);
+      SGSky* thesky = globals->get_renderer()->getSky();
      
 	 float lon = arg->getFloatValue("lon-deg", 0.0f);
 	 float lat = arg->getFloatValue("lat-deg", 0.0f);

src/Environment/precipitation_mgr.cxx

@@ -39,13 +39,11 @@
 
 #include <Main/fg_props.hxx>
 #include <Main/globals.hxx>
+#include <Main/renderer.hxx>
 #include <Scenery/scenery.hxx>
 
 #include "precipitation_mgr.hxx"
 
-extern SGSky *thesky;
-
-
 /** 
  * @brief FGPrecipitation Manager constructor 
  *
@@ -141,6 +139,8 @@ float FGPrecipitationMgr::getPrecipitationAtAltitudeMax(void)
     max = SGCloudLayer::SG_MAX_CLOUD_COVERAGES;
     result = 0;
 
+     SGSky* thesky = globals->get_renderer()->getSky();
+    
     // To avoid messing up
     if (thesky == NULL)
         return result;

src/Main/fg_init.cxx

@@ -106,7 +106,7 @@
 #include <Traffic/TrafficMgr.hxx>
 #include <MultiPlayer/multiplaymgr.hxx>
 #include <FDM/fdm_shell.hxx>
-
+#include <Environment/ephemeris.hxx>
 #include <Environment/environment_mgr.hxx>
 
 #include "fg_init.hxx"
@@ -1176,12 +1176,6 @@ bool fgInitGeneral() {
 // gear, its initialization call should located in this routine.
 // Returns non-zero if a problem encountered.
 bool fgInitSubsystems() {
-    // static const SGPropertyNode *longitude
-    //     = fgGetNode("/sim/presets/longitude-deg");
-    // static const SGPropertyNode *latitude
-    //     = fgGetNode("/sim/presets/latitude-deg");
-    // static const SGPropertyNode *altitude
-    //     = fgGetNode("/sim/presets/altitude-ft");
 
     SG_LOG( SG_GENERAL, SG_INFO, "Initialize Subsystems");
     SG_LOG( SG_GENERAL, SG_INFO, "========== ==========");
@@ -1239,6 +1233,7 @@ bool fgInitSubsystems() {
 
     // Initialize the weather modeling subsystem
     globals->add_subsystem("environment", new FGEnvironmentMgr);
+    globals->add_subsystem("ephemeris", new Ephemeris);
     
     ////////////////////////////////////////////////////////////////////
     // Initialize the aircraft systems and instrumentation (before the
@@ -1287,9 +1282,7 @@ bool fgInitSubsystems() {
     // sub system infrastructure.
     ////////////////////////////////////////////////////////////////////
 
-    SG_LOG(SG_GENERAL, SG_INFO, "  ATC Manager");
+    globals->add_subsystem("Old ATC", new FGATCMgr, SGSubsystemMgr::INIT);
-    globals->set_ATC_mgr(new FGATCMgr);
-    globals->get_ATC_mgr()->init(); 
 
     ////////////////////////////////////////////////////////////////////
    // Initialize the ATC subsystem

src/Main/globals.cxx

@@ -161,9 +161,6 @@ FGGlobals::FGGlobals() :
 // Destructor
 FGGlobals::~FGGlobals() 
 {    
-    delete renderer;
-    renderer = NULL;
-    
 // The AIModels manager performs a number of actions upon
     // Shutdown that implicitly assume that other subsystems
     // are still operational (Due to the dynamic allocation and
@@ -180,6 +177,9 @@ FGGlobals::~FGGlobals()
     subsystem_mgr->unbind();
     delete subsystem_mgr;
     
+    delete renderer;
+    renderer = NULL;
+    
     delete time_params;
     delete mag;
     delete matlib;

src/Main/main.cxx

@@ -67,7 +67,6 @@
 #include <ATCDCL/ATCmgr.hxx>
 #include <Time/TimeManager.hxx>
 #include <Environment/environment_mgr.hxx>
-#include <Environment/ephemeris.hxx>
 #include <GUI/gui.h>
 #include <GUI/new_gui.hxx>
 #include <MultiPlayer/multiplaymgr.hxx>
@@ -104,21 +103,8 @@ extern int _bootstrap_OSInit;
 
 // What should we do when we have nothing else to do?  Let's get ready
 // for the next move and update the display?
-static void fgMainLoop( void ) {
+static void fgMainLoop( void )
-    
+{
-    static SGConstPropertyNode_ptr longitude
-        = fgGetNode("/position/longitude-deg");
-    static SGConstPropertyNode_ptr latitude
-        = fgGetNode("/position/latitude-deg");
-    static SGConstPropertyNode_ptr altitude
-        = fgGetNode("/position/altitude-ft");
-    static SGConstPropertyNode_ptr vn_fps
-        = fgGetNode("/velocities/speed-north-fps");
-    static SGConstPropertyNode_ptr ve_fps
-        = fgGetNode("/velocities/speed-east-fps");
-    static SGConstPropertyNode_ptr vd_fps
-        = fgGetNode("/velocities/speed-down-fps");
-      
     static SGPropertyNode_ptr frame_signal
         = fgGetNode("/sim/signals/frame", true);
 
@@ -145,16 +131,9 @@ static void fgMainLoop( void ) {
     timeMgr->computeTimeDeltas(sim_dt, real_dt);
 
     // update magvar model
-    globals->get_mag()->update( longitude->getDoubleValue()
+    globals->get_mag()->update( globals->get_aircraft_position(),
-                                * SGD_DEGREES_TO_RADIANS,
-                                latitude->getDoubleValue()
-                                * SGD_DEGREES_TO_RADIANS,
-                                altitude->getDoubleValue() * SG_FEET_TO_METER,
                                 globals->get_time_params()->getJD() );
 
-    // Run ATC subsystem
-    globals->get_ATC_mgr()->update(sim_dt);
-    
     globals->get_subsystem_mgr()->update(sim_dt);
 
     // Update the sound manager last so it can use the CPU while the GPU
@@ -410,37 +389,6 @@ static void fgIdleFunction ( void ) {
 
     } else if ( idle_state == 6 ) {
         idle_state++;
-        // Initialize the sky
-
-        Ephemeris* eph = new Ephemeris;
-        globals->add_subsystem("ephemeris", eph);
-        eph->init(); // FIXME - remove this once SGSky code below is also a subsystem
-        eph->bind();
-
-        // TODO: move to environment mgr
-        thesky = new SGSky;
-        SGPath texture_path(globals->get_fg_root());
-        texture_path.append("Textures");
-        texture_path.append("Sky");
-        for (int i = 0; i < FGEnvironmentMgr::MAX_CLOUD_LAYERS; i++) {
-            SGCloudLayer * layer = new SGCloudLayer(texture_path.str());
-            thesky->add_cloud_layer(layer);
-        }
-
-        SGPath sky_tex_path( globals->get_fg_root() );
-        sky_tex_path.append( "Textures" );
-        sky_tex_path.append( "Sky" );
-        thesky->texture_path( sky_tex_path.str() );
-
-        // The sun and moon diameters are scaled down numbers of the
-        // actual diameters. This was needed to fit both the sun and the
-        // moon within the distance to the far clip plane.
-        // Moon diameter:    3,476 kilometers
-        // Sun diameter: 1,390,000 kilometers
-        thesky->build( 80000.0, 80000.0,
-                       463.3, 361.8,
-                       *globals->get_ephem(),
-                       fgGetNode("/environment", true));
         
         // Initialize MagVar model
         SGMagVar *magvar = new SGMagVar();
@@ -462,11 +410,6 @@ static void fgIdleFunction ( void ) {
         fgSetDouble("/instrumentation/heading-indicator/offset-deg", -var);
         fgSetDouble("/instrumentation/heading-indicator-fg/offset-deg", -var);
 
-
-        // airport = new ssgBranch;
-        // airport->setName( "Airport Lighting" );
-        // lighting->addKid( airport );
-
         fgSplashProgress("initializing subsystems");
 
     } else if ( idle_state == 7 ) {

src/Main/renderer.cxx

@@ -93,6 +93,7 @@
 #include <GUI/new_gui.hxx>
 #include <Instrumentation/HUD/HUD.hxx>
 #include <Environment/precipitation_mgr.hxx>
+#include <Environment/environment_mgr.hxx>
 
 #include "splash.hxx"
 #include "renderer.hxx"
@@ -374,9 +375,6 @@ public:
 
 bool FGScenerySwitchCallback::scenery_enabled = false;
 
-// Sky structures
-SGSky *thesky;
-
 static osg::ref_ptr<osg::FrameStamp> mFrameStamp = new osg::FrameStamp;
 static osg::ref_ptr<SGUpdateVisitor> mUpdateVisitor= new SGUpdateVisitor;
 
@@ -391,7 +389,8 @@ static void updateRenderer()
 }
 #endif
 
-FGRenderer::FGRenderer()
+FGRenderer::FGRenderer() :
+    _sky(NULL)
 {
 #ifdef FG_JPEG_SERVER
    jpgRenderFrame = updateRenderer;
@@ -404,6 +403,7 @@ FGRenderer::~FGRenderer()
 #ifdef FG_JPEG_SERVER
    jpgRenderFrame = NULL;
 #endif
+    delete _sky;
 }
 
 // Initialize various GL/view parameters
@@ -411,7 +411,7 @@ FGRenderer::~FGRenderer()
 // critical parts of the scene graph in addition to the splash screen.
 void
 FGRenderer::splashinit( void ) {
-    osgViewer::Viewer* viewer = globals->get_renderer()->getViewer();
+    osgViewer::Viewer* viewer = getViewer();
     mRealRoot = dynamic_cast<osg::Group*>(viewer->getSceneData());
     mRealRoot->addChild(fgCreateSplashNode());
     mFrameStamp = viewer->getFrameStamp();
@@ -454,6 +454,20 @@ FGRenderer::init( void )
 
     SGConfigureDirectionalLights( use_point_sprites, enhanced_lighting,
                                   distance_attenuation );
+    
+// create sky, but can't build until setupView, since we depend
+// on other subsystems to be inited, eg Ephemeris    
+    _sky = new SGSky;
+    
+    SGPath texture_path(globals->get_fg_root());
+    texture_path.append("Textures");
+    texture_path.append("Sky");
+    for (int i = 0; i < FGEnvironmentMgr::MAX_CLOUD_LAYERS; i++) {
+        SGCloudLayer * layer = new SGCloudLayer(texture_path.str());
+        _sky->add_cloud_layer(layer);
+    }
+    
+    _sky->texture_path( texture_path.str() );
 }
 
 void
@@ -472,6 +486,17 @@ FGRenderer::setupView( void )
     if ( fgGetBool("/sim/startup/fullscreen") )
         fgOSFullScreen();
 
+// build the sky    
+    // The sun and moon diameters are scaled down numbers of the
+    // actual diameters. This was needed to fit both the sun and the
+    // moon within the distance to the far clip plane.
+    // Moon diameter:    3,476 kilometers
+    // Sun diameter: 1,390,000 kilometers
+    _sky->build( 80000.0, 80000.0,
+                  463.3, 361.8,
+                  *globals->get_ephem(),
+                  fgGetNode("/environment", true));
+    
     viewer->getCamera()
         ->setComputeNearFarMode(osg::CullSettings::DO_NOT_COMPUTE_NEAR_FAR);
     
@@ -547,15 +572,17 @@ FGRenderer::setupView( void )
     sunLight->setUpdateCallback(new FGLightSourceUpdateCallback(true));
     sunLight->setReferenceFrame(osg::LightSource::RELATIVE_RF);
     sunLight->setLocalStateSetModes(osg::StateAttribute::ON);
+    
     // Hang a StateSet above the sky subgraph in order to turn off
     // light 0
     Group* skyGroup = new Group;
     StateSet* skySS = skyGroup->getOrCreateStateSet();
     skySS->setMode(GL_LIGHT0, StateAttribute::OFF);
-    skyGroup->addChild(thesky->getPreRoot());
+    skyGroup->addChild(_sky->getPreRoot());
     sunLight->addChild(skyGroup);
     mRoot->addChild(sceneGroup);
     mRoot->addChild(sunLight);
+    
     // Clouds are added to the scene graph later
     stateSet = globals->get_scenery()->get_scene_graph()->getOrCreateStateSet();
     stateSet->setMode(GL_ALPHA_TEST, osg::StateAttribute::ON);
@@ -594,7 +621,7 @@ FGRenderer::setupView( void )
     // The clouds are attached directly to the scene graph root
     // because, in theory, they don't want the same default state set
     // as the rest of the scene. This may not be true in practice.
-    mRealRoot->addChild(thesky->getCloudRoot());
+    mRealRoot->addChild(_sky->getCloudRoot());
     mRealRoot->addChild(FGCreateRedoutNode());
     // Attach empty program to the scene root so that shader programs
     // don't leak into state sets (effects) that shouldn't have one.
@@ -644,7 +671,7 @@ FGRenderer::update( ) {
     // update fog params
     double actual_visibility;
     if (_cloud_status->getBoolValue()) {
-        actual_visibility = thesky->get_visibility();
+        actual_visibility = _sky->get_visibility();
     } else {
         actual_visibility = _visibility_m->getDoubleValue();
     }
@@ -673,10 +700,10 @@ FGRenderer::update( ) {
 
     // update fog params if visibility has changed
     double visibility_meters = _visibility_m->getDoubleValue();
-    thesky->set_visibility(visibility_meters);
+    _sky->set_visibility(visibility_meters);
 
     double altitude_m = _altitude_ft->getDoubleValue() * SG_FEET_TO_METER;
-    thesky->modify_vis( altitude_m, 0.0 /* time factor, now unused */);
+    _sky->modify_vis( altitude_m, 0.0 /* time factor, now unused */);
 
     // update the sky dome
     if ( skyblend ) {
@@ -720,8 +747,8 @@ FGRenderer::update( ) {
         scolor.moon_angle  = l->get_moon_angle();
   
         double delta_time_sec = _sim_delta_sec->getDoubleValue();
-        thesky->reposition( sstate, *globals->get_ephem(), delta_time_sec );
+        _sky->reposition( sstate, *globals->get_ephem(), delta_time_sec );
-        thesky->repaint( scolor, *globals->get_ephem() );
+        _sky->repaint( scolor, *globals->get_ephem() );
 
             //OSGFIXME
 //         shadows->setupShadows(

src/Main/renderer.hxx

@@ -35,7 +35,6 @@ class FGEventHandler;
 }
 
 class SGSky;
-extern SGSky *thesky;
 
 class FGRenderer {
 
@@ -73,6 +72,8 @@ public:
     */
     void addCamera(osg::Camera* camera, bool useSceneData);
 
+    SGSky* getSky() const { return _sky; }
+    
 protected:
     osg::ref_ptr<osgViewer::Viewer> viewer;
     osg::ref_ptr<flightgear::FGEventHandler> eventHandler;
@@ -85,6 +86,7 @@ protected:
     SGPropertyNode_ptr _panel_hotspots, _sim_delta_sec, _horizon_effect, _altitude_ft;
     SGPropertyNode_ptr _virtual_cockpit;
     SGTimeStamp _splash_time;
+    SGSky* _sky;
 };
 
 bool fgDumpSceneGraphToFile(const char* filename);

src/Time/light.cxx

@@ -290,6 +290,8 @@ void FGLight::update_sky_color () {
     _scene_ambient[3] = 1.0;
     gamma_correct_rgb( _scene_ambient.data() );
 
+    SGSky* thesky = globals->get_renderer()->getSky();
+    
     SGVec4f color = thesky->get_scene_color();
     _scene_diffuse[0] = color[0] * diffuse;
     _scene_diffuse[1] = color[1] * diffuse;
@@ -361,6 +363,7 @@ void FGLight::update_adj_fog_color () {
 
     // revert to unmodified values before using them.
     //
+    SGSky* thesky = globals->get_renderer()->getSky();
     SGVec4f color = thesky->get_scene_color();
 
     gamma_restore_rgb( _fog_color.data(), gamma );