[2005] Looking for geometric distance/intersection functions

Hello,

I'm hoping somebody could help me find a set of functions available that might help me deal with some 2D geometric calculations I need to perform.

I have a list of entity objects I've created which are an assortment of lines, arcs, and circles imported from a DXF file (AutoCad).

I need to find which of these is closest to a user defined point. In other words, a user is picking on the screen and I need to find out which entity the user had in mind with that selection point.

So basically, I need to compare the given point to each entity (lines, arcs, and circles) to find out which entity has a point on it which is closest to the selection point.

Does anybody know of a set of functions which might help with this?

Thank you,

--John