It’s an American coming-of-age story told from a new, black perspective: getting laid is an issue, as always, but staying alive is the first order of business. The boys in this neighborhood won’t all make it: Doughboy (the rapper Ice Cube) is headed for a life of crime; his brother Ricky (Morris Chestnut) is on the brink of a football scholarship. Tre Styles (Cuba Gooding Jr.), smart, angry and conflicted, has the advantage of a fiercely protective father (Larry Fishburne), a loving but pontificating patriarch whose didacticism is, at times, inseparable from Singleton’s. But this first film has more than good intentions: it’s the work of a truly gifted filmmaker. The violence in “Boyz N the Hood” is neither gratuitous nor melodramatic; its aftermath is shattering. Singleton’s powerhouse movie has the impact of a stun gun.