I'm trying to make an interactive map of the US that can recognize what state the mouse is over when it clicks.  To do this, I need to be able to find if mouseX and mouseY are within a state.  I can figure out how to do this for any reasonable geometric shape (circle, rect, triangle, etc) but don't know how it can be done with a state.  I'm using a blank SVG map of the US and I've found two things that might help but I can't figure out how to make them work.  One is this code:

public boolean contains(float x, float y) {
    if (family == PATH) {
      boolean c = false;
      for (int i = 0, j = vertexCount-1; i < vertexCount; j = i++) {
        if (((vertices[i][Y] > y) != (vertices[j][Y] > y)) &&
            (x <
                (vertices[j][X]-vertices[i][X]) *
                (y-vertices[i][Y]) /
                (vertices[j][1]-vertices[i][Y]) +
                vertices[i][X])) {
          c = !c;
        }
      }
      return c;
    } else {
      throw new IllegalArgumentException("The contains() method is only implemented for paths.");
    }
  }

from http://code.google.com/p/processing/source/browse/tags/processing-1.2.1/core/src/processing/core/PShape.java?r=7108.

I don't understand what the family/PATH thing is talking about though and don't know how to make it read my SVG file. 

I've also found this:
http://doc.4d.com/4D-Language-Reference-12.3/SVG/SVG-Find-element-ID-by-coordinates.301-756041.en.html

which would seem to be a solution but can't find that code in any Processing library.

Does anyone have any suggestions?