Moving geometry until it collides

[rehe]

Hi,

I'm writing a small software where I have to collide shapes (2D) against other shapes. With collide I mean move (to specified direction) until collision occurs.

I'm have been trying to find algorithm to do that. I found a physics engine, which did it, but not the way I would have liked to. In my problem, shape has to stop just before collision.

I have a small picture of my problem:



I hope you could help me with this problem

[aokman]

I met a similar problem in 3D space.
Someone advised me to read Brain Mirtch's PhD thesis.
Although I have no time to implement the method in the paper now, I find it a good idea.
I think you should also read it.

[rehe]

Thank you, I'll look that