John Woo’s unparalleled directing career is best known for blazing barrels, shadow selves and slow-motion “heroic bloodshed.” To celebrate the Hong Kong legend’s 75th birthday, we talk Woo’s full arc with University of Houston film scholar Karen Fang. Then, we focus on a sweet spot in Woo’s oeuvre, when he maxed out his Hong Kong street operas with “Hard Boiled“(1992) and transitioned to inimitable American shoot-em-ups “Hard Target” and “Face/Off.”