The cast of director Barry Levinson’s Whitey Bulger biopic is taking shape. Joining Johnny Depp, who’s on board to play the notorious gangster in the movie based on Dick Lehr and Gerald O’Neill’s book, “Black Mass: The True Story of an Unholy Alliance Between the FBI and the Irish Mob,” is Joel Edgerton . Deadline.com reports that the Australian actor who costars in director Baz Luhrmann’s “The Great Gatsby” has signed on to play crooked FBI agent John Connolly. We’re told filming is set to begin in August. Producer Brian Oliver has promised a project that paints “a vivid portrait of Boston’s underbelly and its corrupt political machine, as well as exposing the worst scandal in FBI history. It’s also an examination of loyalty to family, Irish heritage, and South Boston.”. . . Meanwhile, actor Casey Affleck, who’s set to play Billy Bulger in a Whitey Bulger movie being worked on by Casey’s brother Ben, was at the Cannes Film Festival over the weekend with his new movie, “Ain’t Them Bodies Saints,” costarring Rooney Mara . . . Sudbury’s own Chris Evans is mulling the lead in an adaptation of Stephen King’s “The Ten O’Clock People.” The “Captain America” star would replace Justin Long, who, according to Deadline.com, pulled out because of a scheduling conflict.