Hello! I've had a similar idea for a year, but in mine, the arc is suspended instead of being fixed on the deck. The fixture should allow for pivot, and front and back movement.
As code is concerned, i am spending a lot of time learning the theory behind f.lux to incorporate it into the controller as that program really really helped my sleep. Something cheaper than this: https://www.kickstarter.com/projects/rph8/visual-caffeine-our-revolutionary-lamp-keeps-you-e
I do not own a 3d printer (yet) so I am building a pvc pipe based prototype, very ugly , unlike your beautiful bridge;-)