From Thomas Hogarth and Stephan Huber, "attached you'll find part one of iphone-support. It includes

* support for NPOT-textures on IOS
* support for FBOs (only renderToTexture for now) on IOS (should work
for other OpenGL ES 1/2 targets, too)
* FileUtils-support for IOS"

include/osg/GL

@@ -20,7 +20,7 @@
 #if defined(OSG_GLES1_AVAILABLE)
 
     #ifdef __APPLE__
-        //if its apple include the target defines so we can check for iphone
+        //if its apple include the target defines so we can check for IOS
         #include "TargetConditionals.h"
         #include <OpenGLES/ES1/gl.h>
     #else
@@ -30,7 +30,7 @@
 #elif defined(OSG_GLES2_AVAILABLE)
 
     #ifdef __APPLE__
-        //if its apple include the target defines so we can check for iphone
+        //if its apple include the target defines so we can check for IOS
         #include "TargetConditionals.h"
         #include <OpenGLES/ES2/gl.h>
     #else

include/osg/GraphicsContext

@@ -460,6 +460,11 @@ class OSG_EXPORT GraphicsContext : public Object
 
         /** Get the the const list of cameras associated with this graphics context.*/
         const Cameras& getCameras() const { return _cameras; }
+        
+        /** set the default FBO-id, this id will be used when the rendering-backend is finished with RTT FBOs */
+        void setDefaultFboId(GLuint i) { _defaultFboId = i; }
+        
+        GLuint getDefaultFboId() const { return _defaultFboId; }
 
     public:
 
@@ -510,6 +515,8 @@ class OSG_EXPORT GraphicsContext : public Object
         ref_ptr<SwapCallback>               _swapCallback;
         
         Timer_t                             _lastClearTick;
+        
+        GLuint                              _defaultFboId;
 };