Added osg::EarthSky node to the core osg library, and added support for it into

osgUtil::SceneView, osg::CullVisitor, osgPlugin/osg and updated the hangglide
demo to use the new earth sky node.

VisualStudio/osg/osg.dsp

@@ -134,6 +134,10 @@ SOURCE=..\..\src\osg\Drawable.cpp
 # End Source File
 # Begin Source File
 
+SOURCE=..\..\src\osg\EarthSky.cpp
+# End Source File
+# Begin Source File
+
 SOURCE=..\..\src\osg\Fog.cpp
 # End Source File
 # Begin Source File
@@ -334,6 +338,10 @@ SOURCE=..\..\Include\Osg\Drawable
 # End Source File
 # Begin Source File
 
+SOURCE=..\..\Include\Osg\EarthSky
+# End Source File
+# Begin Source File
+
 SOURCE=..\..\Include\Osg\Export
 # End Source File
 # Begin Source File

include/osg/NodeVisitor

@@ -15,6 +15,7 @@ class LOD;
 class Sequence;
 class Switch;
 class Impostor;
+class EarthSky;
 
 /** Visitor for type safe operations on osg::Node's.
     Based on GOF's Visitor pattern.*/ 
@@ -128,6 +129,7 @@ class SG_EXPORT NodeVisitor : public Referenced
         virtual void apply(Sequence& node)   { apply((Group&)node); }
         virtual void apply(LOD& node)        { apply((Group&)node); }
         virtual void apply(Impostor& node)   { apply((LOD&)node); }
+        virtual void apply(EarthSky& node)   { apply((Group&)node); }
 
     protected:
 

include/osgUtil/CullVisitor

@@ -10,6 +10,7 @@
 #include <osg/State>
 #include <osg/Camera>
 #include <osg/Impostor>
+#include <osg/EarthSky>
 #include <osg/Notify>
 
 #include <osgUtil/RenderGraph>
@@ -47,12 +48,19 @@ class OSGUTIL_EXPORT CullVisitor : public osg::NodeVisitor
         virtual void apply(osg::Transform& node);
         virtual void apply(osg::Switch& node);
         virtual void apply(osg::LOD& node);
+        virtual void apply(osg::EarthSky& node);
         virtual void apply(osg::Impostor& node);
 
-        void setCamera(const osg::Camera& camera);
 
+
+        void setCamera(const osg::Camera& camera);
         const osg::Camera* getCamera() const { return _camera.get(); }
 
+
+        void setEarthSky(const osg::EarthSky* earthSky) { _earthSky = earthSky; }
+        const osg::EarthSky* getEarthSky() const { return _earthSky.get(); }
+
+
         void setLODBias(const float bias) { _LODBias = bias; }
         const float getLODBias() const    { return _LODBias; }
         
@@ -280,6 +288,8 @@ class OSGUTIL_EXPORT CullVisitor : public osg::NodeVisitor
         
         osg::ref_ptr<const osg::Camera> _camera;
         
+        osg::ref_ptr<const osg::EarthSky> _earthSky;
+
         TransparencySortMode _tsm;
 	
         // viewport x,y,width,height respectively.

src/Demos/hangglide/hangglide.cpp

@@ -2,6 +2,7 @@
 #include <osg/Notify>
 #include <osg/Depth>
 #include <osg/StateSet>
+#include <osg/EarthSky>
 
 #include <osgDB/Registry>
 #include <osgDB/ReadFile>
@@ -131,8 +132,12 @@ int main( int argc, char **argv )
         // osg::Depth, and setting their bin numbers to less than 0,
         // to force them to draw before the rest of the scene.
   
-        group->addChild(makeSky());  // bin number -2 so drawn first.
-        group->addChild(makeBase()); // bin number -1 so draw second.
+        osg::EarthSky* earthSky = new osg::EarthSky;
+        earthSky->setRequiresClear(false); // we've got base and sky to do it.
+        earthSky->addChild(makeSky());  // bin number -2 so drawn first.
+        earthSky->addChild(makeBase()); // bin number -1 so draw second.      
+        
+        group->addChild(earthSky);
 
         // the rest of the scene drawn after the base and sky above.
         group->addChild(makeTrees()); // will drop into a transparent, depth sorted bin (1)
@@ -158,10 +163,6 @@ int main( int argc, char **argv )
 
     osgUtil::SceneView* sv = viewer.getViewportSceneView(0);
     
-    // switch off the render stages clear mask as we use the earth/sky
-    // to clear it for us, see above.
-    sv->getRenderStage()->setClearMask(0);
-
     viewer.run();
 
     return 0;

src/osg/Makefile

@@ -12,6 +12,7 @@ C++FILES = \
 	CullFace.cpp\
 	Depth.cpp \
 	Drawable.cpp\
+	EarthSky.cpp\
 	Fog.cpp\
 	FrameStamp.cpp\
 	FrontFace.cpp\
@@ -69,6 +70,7 @@ TARGET_INCLUDE_FILES = \
 	osg/CullFace\
 	osg/Depth\
 	osg/Drawable\
+	osg/EarthSky\
 	osg/Export\
 	osg/Fog\
 	osg/FrameStamp\

src/osgPlugins/osg/Makefile

@@ -9,6 +9,7 @@ C++FILES = \
         CullFace.cpp\
         Depth.cpp\
         Drawable.cpp\
+        EarthSky.cpp\
         Fog.cpp\
         FrontFace.cpp\
         Geode.cpp\

src/osgUtil/CullVisitor.cpp

@@ -3,7 +3,6 @@
 #include <osg/LOD>
 #include <osg/Billboard>
 #include <osg/LightSource>
-#include <osg/Impostor>
 #include <osg/Notify>
 #include <osg/TexEnv>
 #include <osg/AlphaFunc>
@@ -645,6 +644,23 @@ void CullVisitor::apply(LOD& node)
     _cullingModeStack.pop_back();
 }
 
+void CullVisitor::apply(osg::EarthSky& node)
+{
+    // simply override the current earth sky.
+    setEarthSky(&node);
+
+    // push the node's state.
+    StateSet* node_state = node.getStateSet();
+    if (node_state) pushStateSet(node_state);
+
+    traverse(node);
+
+    // pop the node's state off the render graph stack.    
+    if (node_state) popStateSet();
+
+}
+
+
 void CullVisitor::apply(Impostor& node)
 {
     const BoundingSphere& bs = node.getBound();

src/osgUtil/SceneView.cpp

@@ -135,6 +135,7 @@ void SceneView::cull()
     _cullVisitor->setLODBias(_lodBias);
     _cullVisitor->setCamera(*_camera);
     _cullVisitor->setViewport(_viewport.get());
+    _cullVisitor->setEarthSky(NULL); // reset earth sky on each frame.
 
     _renderStage->reset();
 
@@ -170,6 +171,24 @@ void SceneView::cull()
     _renderStage->sort();
 
 
+    const osg::EarthSky* earthSky = _cullVisitor->getEarthSky();
+    if (earthSky)
+    {
+        if (earthSky->getRequiresClear())
+        {
+            _renderStage->setClearColor(earthSky->getClearColor());
+            // really should set clear mask here, but what to? Need
+            // to consider the stencil and accumulation buffers..
+            // will defer to later.  Robert Osfield. October 2001.
+        }
+        else
+        {
+            // we have an earth sky implementation to do the work for use
+            // so we don't need to clear.
+            _renderStage->setClearMask(0);
+        }
+    }
+
     // prune out any empty RenderGraph children.
     // note, this would be not required if the _renderGraph had been
     // reset at the start of each frame (see top of this method) but