Can't use more than 1 glut at once

I wrote a simple terrain generator, with an airplane to fly over it. Using GLUT, I can’t
get the plane to fly and roll using two keys
simultaneously. I have to stop flying to roll
and vice a versa. Any suggestions?
Is this called multithreading?

no, you dont have to stop flying (assumed to be forward) to roll …

lets assume you push ‘f’ to go forward
and ‘r’ to roll

the behavior should be that when you push ‘f’
instead of moving forward you should increment the forward velocity…

that is instead of incrementing the forward position you increment the velocity

so will go forward (assuming the velocity is > 0 ) even if you don’t hit ‘f’

you can do the same for the roll…