Determine if a location is within defined geographical boundaries

containsLocation.js

/*
=============================================
Determine if a location is within defined geographical boundaries
Using this alogrthim
http://alienryderflex.com/polygon/
And also this post
http://stackoverflow.com/a/3036426/292927
=============================================
*/

/*
ex: 
containsLocation({lat: 31.98958743167164, lng: 35.944175720214844}
          , [{lat: 32.141897196425795, lng: 35.728912353515625},
            {lat: 32.12677940089151, lng: 36.18072509765625},
            {lat: 31.781882156411022, lng: 36.12579345703125},
            {lat: 31.804059692799363, lng: 35.66986083984375}]);
*/

function containsLocation(point, paths) {
    var j = 0;
    var oddNodes = false;
    var x = point.lng;
    var y = point.lat;

    for (var i = 0; i < paths.length; i++) {
        j++;
        if (j == paths.length) {
            j = 0;
        }
        if (((paths[i].lat < y) && (paths[j].lat >= y))
            || ((paths[j].lat < y) && (paths[i].lat >= y))) {
            if (paths[i].lng + (y - paths[i].lat)
                / (paths[j].lat - paths[i].lat)
                * (paths[j].lng - paths[i].lng) < x) {
                oddNodes = !oddNodes
            }
        }
    }
    return oddNodes;
}