Santosh And His LightSabers

Being the android programmer geek, Santosh is; he wanted to create a game for the newly releasing Starwars franchise. But currently he's stuck. When two light sabers strike he doesn't know where they struck each other to animate the hit. Note that the light sabers would never be co-linear since that would destroy it's core. Given two line segments representing the light saber, find if the given l