There is no requirement for the bar to be straight , just that it is technically is supposed to pass midway between the shoulder and elbow.
A lot of the cars I build are for older racers who need the swing out feature .
There are a lot of different kits out there to do it , I prefer to use the clevis style that Applied Racing Technology sells, no slop in them .
Simple to use and you can "clock" them to allow for any swing angle .
If you only have a roll bar ,I'd recommend a gusset or brace to the rocker sill of some sort on the floor end to prevent the bar from flexing up and down when opened .
I use these clevis' and install limit stops on them , they open and close as good as a door.
https://www.appliedracing.com/roll-b...-bar-kits.html
https://www.appliedracing.com/roll-b...vis-mount.html