Algorithm behind vec_rotate

Hi, I've been searching for a way to rotate a vector as vec_rotate does it. Now I'm too curious to see the algorithm behind it. Can you explain it briefly?

Maybe it helps: rotating...

I guess it's three consecutive "2d" rotations (pan rotates xy, tilt xz, and roll yz). I'm not sure in which order they are performed, though.

Have a look here: http://www.conitec.net/beta/ang_to_matrix.htm

Yes, that's the algorithm. The angle is converted to a rotation matrix, with which the vector is then multiplied.

Thank you all!