FPS counter in games

[Schmagz]

Would it be possible to add a FPS counter in one of the corners of the screen when booting a game from OPL?

Quake 2 apprently has a code for a FPS counter "PS2_DrawFPSCounter" but I have no idea if that could be used in OPL - I have about zero programming knowledge :)
https://github.com/glampert/quake2-for-ps2/blob/master/src/ps2/ref_ps2.c