Pierre Lamot authored Jul 30, 2018 and Thomas Guillem committed Aug 21, 2018

This module aims to provide the same kind of functionnality as vmem but for
  opengl rendering.

  Users will have to provide different callbacks:

  * vgl-setup-cb to setup resources
  * vgl-cleanup-cb to release resources
  * vgl-resize-cb will be called when video size changes
  * vgl-swap-cb that will be called once the current frame has been rendered
  * vgl-make-current-cb to enter/leave the opengl context
  * vgl-get-proc-address-cb to provide opengl functions

  Note that users will have to ensure synchronisation on their side since
  VLC will run and render OpenGL in its own thread.

Signed-off-by: Thomas Guillem <thomas@gllm.fr>