Created by: kbrenneman
This is an extension to the libGLX vendor library interface that allows a vendor to provide different dispatch tables for each GLXContext.
It adds two optional callbacks to the __GLXapiImports struct. The first allows the vendor to provide an opaque dispatch table handle for a GLXContext. The second callback is used to populate a dispatch table.
The goal is to allow a library such as Mesa to use libglvnd's dispatch layer instead of having to send every OpenGL function through two layers.