rock spawning issues

see line 100
// the issue with this atm is that everytime the world is drawn (like
every game tick),
    // drawRock is called again. since drawRock uses random numbers for
positions of rocks,
    // every time it's called, the rocks move around. i want the rocks
to stay static over time
    // ideally i could create the random numbers elsewhere and use
another function
    // to get them into drawRock, but haven't been able to do that yet.
probably overkill too