* OSD message background * clear glui background * add Metal to configuration * added optional config to compile Metal build without OpenGL * fixed fill_pathname_join_delim; if out_path and dir are same, don't strlcpy, as the results are undefined.
TODOs * menu shader pipeline effects * refactor / optimize graphics rendering
* use MTKView, which handles layer and scaling changes automatically between displays
* includes rgui * shader support This is a work-in-progress and there are some bugs and visual artifacts still to be fixed.
