// gmaps.polygon.containsLatLng.js
// Create polygon method for collision detection
GPolygon.prototype.containsLatLng = function(latLng) {
    // Do simple calculation so we don't do more CPU-intensive calcs for obvious misses
    var bounds = this.getBounds();

    if (!bounds.containsLatLng(latLng)) {
        return false;
    }

    var numPoints = this.getVertexCount();
    var inPoly = false;
    var i;
    var j = numPoints - 1;

    for (var i = 0; i < numPoints; i++) {
        var vertex1 = this.getVertex(i);
        var vertex2 = this.getVertex(j);

        if (vertex1.lng() < latLng.lng() && vertex2.lng() >= latLng.lng() || vertex2.lng() < latLng.lng() && vertex1.lng() >= latLng.lng()) {
            if (vertex1.lat() + (latLng.lng() - vertex1.lng()) / (vertex2.lng() - vertex1.lng()) * (vertex2.lat() - vertex1.lat()) < latLng.lat()) {
                inPoly = !inPoly;
            }
        }

        j = i;
    }

    return inPoly;
};