Thanks for all replies.
Yeah, i think i have to look at the more traditional AABB, OBB intersections techniques.
Now i am starting to read up on Minkowskis sum, that seems to be very nice way for handeling polygons of all shapes.
If i can just add and use the algorithm right it should be easy to cast a ray and get the intersection point as well.
I really got it to work with the Sphere, but it is not good in 2D scrolling game.
Now i want to use a rectangle instead. =(