Added include/osg/EarthSky and src/osg/EarthSky to cvs.

Also move osg across to using radians for angular paramters by default.
By defining USE_DEGREES_INTERNALLY you can get the OSG to revert to
the old style degrees. This later feature is deprecated and only meant
for helping comptability in the interim.

include/osg/EarthSky

@@ -0,0 +1,49 @@
+#ifndef OSG_EARTHSKY
+#define OSG_EARTHSKY 1
+
+#include <osg/Group>
+#include <osg/Vec4>
+
+namespace osg {
+
+/** EarthSky is a Group node which controls the clearing of the color and depth
+  * buffers at the start of each frame.
+  * The earth sky by default is empty and simply holds the clear color of
+  * the background. However, if the uses wants to add their own clearing of
+  * the color and depth buffers then the children can be added, and the
+  * background clear turned off. The EarthSky by default has StateSet attached
+  * to it which sets the default EarthSky bin number to -1, so that all drawables
+  * below it are placed in a separate bin from the rest of the scene graph, and
+  * are rendered prior to standard opaque and transparent drawables.
+*/
+class SG_EXPORT EarthSky : public Group
+{
+    public :
+        
+        EarthSky();
+
+        META_Node(EarthSky);
+
+	/** Sets the flag which control whether a glClear is required at the beginning of each frame. */
+        inline void setRequiresClear(const bool requiresClear) { _requiresClear = requiresClear; }
+
+	/** Gets the flag which control whether a glClear is required at the beginning of each frame. */
+        inline const bool getRequiresClear() const { return _requiresClear; }
+
+	/** Sets the clear color. */
+        inline void setClearColor(const Vec4& color) { _clearColor = color; }
+
+	/** Returns the clear color. */
+        inline const Vec4& getClearColor() const { return _clearColor; }
+
+    protected :
+    
+        virtual ~EarthSky() {}
+        
+        bool _requiresClear;
+        Vec4 _clearColor;  
+};
+
+};
+
+#endif

include/osg/Types

@@ -22,6 +22,18 @@ typedef uchar ubyte;
 #define M_2_SQRTPI      1.12837916709551257390
 #define M_SQRT2         1.41421356237309504880
 #define M_SQRT1_2       0.70710678118654752440
+#else
+#include <math.h>
+#endif
+
+#define USE_DEGREES_INTERNALLY
+
+#ifdef USE_DEGREES_INTERNALLY
+inline double inDegrees(float angle) { return angle; } 
+inline double inRadians(float angle) { return angle*180.0/M_PI; }
+#else
+inline double inDegrees(float angle) { return angle*M_PI/180.0; }
+inline double inRadians(float angle) { return angle; }
 #endif
 
 };