Andrew Garfield is set to star in ?Mainstream,? director Gia Coppola?s followup to her 2013 indie drama ?Palo Alto,? says TheWrap. The ?Breathe? and ?Silence? actor will co-star opposite Maya Hawke, Jason Schwartzman and Nat Wolff. Filming is expected to start by the end of the year. "Mainstream" is a modern romantic drama about a love-triangle set in an internet age. Coppola?s first film ?Palo Alto? was based on a book by James Franco and starred Franco alongside Emma Roberts and Jack Kilmer.