Anyone know how to clip a convex polygon against another convex polygon?

The basic algorithm goes like this:

for every edge of the clipping region

for every edge of the polygon

clip polygon against clipipng region line

I can't figure out the details of this algorithm. (i.e how to communicate the vertex data from one iteration to the next)

Don't post replies about clipping lines ( i am well aware of the mathematics behind it ).

Duetti