Added support for TextureCubeMap into osgUtil::RenderToTextureStage.

include/osg/TextureCubeMap

@@ -17,7 +17,16 @@
 #include <osg/Texture>
 
 #ifndef GL_TEXTURE_CUBE_MAP
-#define GL_TEXTURE_CUBE_MAP 0x8513
+    #define GL_TEXTURE_CUBE_MAP             0x8513
+    #define GL_TEXTURE_BINDING_CUBE_MAP     0x8514
+    #define GL_TEXTURE_CUBE_MAP_POSITIVE_X  0x8515
+    #define GL_TEXTURE_CUBE_MAP_NEGATIVE_X  0x8516
+    #define GL_TEXTURE_CUBE_MAP_POSITIVE_Y  0x8517
+    #define GL_TEXTURE_CUBE_MAP_NEGATIVE_Y  0x8518
+    #define GL_TEXTURE_CUBE_MAP_POSITIVE_Z  0x8519
+    #define GL_TEXTURE_CUBE_MAP_NEGATIVE_Z  0x851A
+    #define GL_PROXY_TEXTURE_CUBE_MAP       0x851B
+    #define GL_MAX_CUBE_MAP_TEXTURE_SIZE    0x851C
 #endif
 
 namespace osg {
@@ -110,6 +119,16 @@ class OSG_EXPORT TextureCubeMap : public Texture
         /** Get the number of mip map levels the the texture has been created with. */
         unsigned int getNumMipmapLevels() const { return _numMipmapLevels; }        
 
+        /** Copies a two-dimensional texture subimage, as per
+          * glCopyTexSubImage2D. Updates a portion of an existing OpenGL
+          * texture object from the current OpenGL background framebuffer
+          * contents at position \a x, \a y with width \a width and height
+          * \a height. Loads framebuffer data into the texture using offsets
+          * \a xoffset and \a yoffset. \a width and \a height must be powers
+          * of two. */
+        void copyTexSubImageCubeMap(State& state, int face, int xoffset, int yoffset, int x, int y, int width, int height );
+
+
         /** On first apply (unless already compiled), create the mipmapped
           * texture and bind it. Subsequent apply will simple bind to texture.
         */