Counter-clockwise orientation of points

Hi!! I’ve got a problem. I’ve to approximate a generic surface (I took a sphere as example, but my program has to work with other functions) with polygons originated by the intersection between this surface and the edges of cube small as I want (in fact, I decide how much the edge is long). In other words, I take the surface and the edges of a generic cube: when intersecated, the surface and the edges originate some points (I’m supposing from 3 to 6-or 0 if there is no intersection-but it doesn’t matter); I can suppose they’re planar. Now, I’ve to originate the polygon with GL_POLYGON; the problem is that it works with verteces in counter-clockwise sense.

My question is: how can I give a counter-clockwise orientation to these points?

thanks a lot for your help!!!