Its only relevant use case has been to use the software renderer on hardware not capable of OpenGL 3.3, but a large chunk of that can now be serviced with GLES.
In addition it has ceased further development and has not received any of the recent 2D render features which further reduces its viability.
* Remove threading from the drawers
* Fix some r_scene_multithreaded related bugs
* Fix some r_scene_multithreaded crashes
* Fix fullbright shade bug
* Fix truecolor drawer crash
* Add debug code for showing the render slices
* Fix texture loading race condition and improve performance by only locking the load mutex if data hasn't already been updated for this frame
Co-authored-by: Magnus Norddahl <dpjudas@users.noreply.github.com>