I tried the quaternion solution posted by Alvaro, related to point rotation around vector and it works (tried some debug values).
However, if you take a look at the attached picture (it's updated), I need to rotate point B around the X local axis of point A (or general axis, as Alvaro calls it).
What I tried to do, is to Normalize vector A, and calculate the cross product of such normalized vector with (0,1,0). That way, I get the perpendicular vector to those; however this vector is normalized, and a rotation of point B around it will be done relative to origin (0,0,0), and not point A.
So how'd I account for that?
