Add frame rate limiting option

[dylanfrankcom]

Adding an environment variable to control frame rate would be awesome if possible!

Thanks for the project!

[netbrain]

Interesting indeed. Not sure if it can be done though. Seems zwift doesn't have a configuration option for this, so need to be handled through other means. I see some windows users has uses nvidia control panel to limit framerate, but this would only work for nvidia gpus, and unsure if the same hack would work in linux as you have the host/container split.

So unless wine itself provides a way of doing this, then i think we need to wait until zwift has this as a defined configuration option.

[glennvl]

@dylanfrankcom What is your usecase for limiting the frame rate? Zwift already has vsync to limit the fps to the monitor's refresh rate. Anyway, I've found https://gitlab.com/torkel104/libstrangle which might work.

[glennvl]

I made an attempt to implement a ZWIFT_FPS_LIMIT option using libstrangle.

• Limiting the fps for glxgears in the container works
• Limiting the fps for the windows version of glxgears launched with wine in the container works
• Limiting the fps for zwift does not work, zwift launches as usual and ignores the fps limit

For anyone interested in trying it or helping out, see: glennvl#2