Benchmark graphics backends

[hecrj]

As #1 mentions, in order to avoid performance regressions, it would be great to have a way to run benchmarks and compare results when making changes.

Is criterion well-suited for graphics benchmarks?

[fivemoreminix]

I've used criterion tests before. Great because it constructs graphs using gnuplot on a navigable webpage. Not sure how well it would work for performance testing of a game engine, though. I think we could probably make some sort of "show the FPS, show the CPU usage, show the GPU usage" etc. of the running game.

Have not looked at criterion in a while though, so it could actually be the best option for all I know.