glIsRenderbuffer — determine if a name corresponds to a renderbuffer object
| GLboolean glIsRenderbuffer( | GLuint renderbuffer ); | 
            glIsRenderbuffer returns GL_TRUE if renderbuffer is currently the name of a renderbuffer
            object. If renderbuffer is zero, or if renderbuffer is not the name of a renderbuffer object, or if an error
            occurs, glIsRenderbuffer returns GL_FALSE. If renderbuffer is a name returned by
            glGenRenderbuffers, by that has not yet been bound through a call to
            glBindRenderbuffer or glFramebufferRenderbuffer,
            then the name is not a renderbuffer object and glIsRenderbuffer returns GL_FALSE.
        
Copyright © 2010 Khronos Group. This material may be distributed subject to the terms and conditions set forth in the Open Publication License, v 1.0, 8 June 1999. http://opencontent.org/openpub/.