GLXOSD is an extensible on-screen display (OSD)/overlay for OpenGL applications running on Linux with X11 which aims to provide similar functionality to MSI Afterburner/RivaTuner OSD. It can show FPS, frame timings, temperatures and more in OpenGL games and applications. It can also be used to benchmark games, much like voglperf.
nickguletskii
commented
9 years ago
https://github.com/nickguletskii/GLXOSD/blob/9a589a7950c2a94e16d520fe147d6127f49ebeb8/src/glxosd/VertexBuffer.cpp#L84