sage_init man page
void sage_init (void)
Initialise the Sage library. This function links up the function pointers to the extensions that are reported by glGetString(GL_EXTENSIONS) and sets the sage_ext array to 1 for existing extensions.
Note that some Open GL implementations report an extension in the GL_EXTENSIONS string but do not have the function implemented.
Simon Goodall (simon (at) simongoodall.co.uk)