C# maths, collision detection, xna

Question

Im doing collision detection in a game. All the surfaces are orthagonal so I only need to determine which face of an obstacle my moving object has collided with. I have the rectangle defining the intersection of the two objects and the vector representing the moving objects speed and direction of movement.

I reckon I need to translate the intersection rectangle along my moving objects vector until the intersection becomes a line, then I'll know which face was collided with 1st.

I have no idea how to do this mathematically of programatically however

Answer 1

Actually I may have figured it out...

• Find the point on the intersection rectangle that isnt on the objects rectangle

• draw a line from there in the vectors direction

• whatever side it intersects with is the side that collided 1st