Checks if the google.maps.Polygon.Path is inside the polygon, to determine if exists "holes" inside the google.maps.Polygon.

ccw.js

/**
 * Checks if the google.maps.Polygon.Path is inside the polygon.
 * 
 * @see {@link https://developers.google.com/maps/documentation/javascript/overlays#Polygons}
 * @see {@link http://gmaps-samples-v3.googlecode.com/svn/trunk/poly/pentagon.html}
 * @see {@link http://debian.fmi.uni-sofia.bg/~sergei/cgsr/docs/clockwise.htm}
 * @see {@link http://en.wikipedia.org/wiki/Curve_orientation}
 * @param {google.maps.Polygon.Path} path
 * @returns {boolean}
 */
google.maps.prototype.isCounterClokwise = function(path) {
    var j, k, z,
        p = path,
        count = 0;
   
   for (var i = 0, n = p.length; i < n; i++) {
        j = (i + 1) % n;
        k = (i + 2) % n;
        
        z  = (p[j].lat() - p[i].lat()) * (p[k].lng() - p[j].lng());
        z -= (p[j].lng() - p[i].lng()) * (p[k].lat() - p[j].lat());
        
        if (z < 0) {
            count--;
        } else if (z > 0) {
            count++;
        }
   }
   
   return (count > 0);
};