Multiple attractor points

Hey everyone!

I would like to ask if somebody could helpt me  to figur it out , how to add extra attractor point. 

I managed to attract the curves to a  point , where the distance value is defined by image sampler. More white- more  the curves are  attracted to a point.

the thing though is, i can't really figure it out, how to add more points. So that the curves would be pulled to the closest point. Because now, i have one point, and all the curves from the field are attracted to it. 

I checked lots of tutorials and definitions, but in all of them  its about vectors and points generated by grid. meanwhile i have a field of curves.

does anybody has an idea ? 

Thank you