Surface-less Context

“It is possible to use a GL context without a default framebuffer, in which case a framebuffer object must be used to perform all rendering. This is useful for applications needing to perform offscreen rendering.”
Can anyone please explain how to implement this?

It is from the surface-less context, i am not able to figure out how to use GL context without default FBO.

That’s merely an extension which allows the default framebuffer in OpenGL ES 2.0 to be undefined. How you actually create a context with an undefined default framebuffer is up to your specific context creation system. The extension simply explains the behavior of such a context.

Thanks for your reply.
Can you please show me en example how to create context without default FBO?

It’s not part of OpenGL ES; it’s platform-dependent. So it depends on the particular platform you’re using. You’ll have to look it up on a per-platform basis.