Question

I am drawing a list of zip code areas in google maps and I am trying to write a label with the zip code over the area. I can do this just fine, except that I am using the centriod of the area to position the label, but some areas are shaped irregularly and the centroid falls outside the area itself. Here is an example of what I mean:

Watch zip code 81151, how it shows up on top of the area for zip code 81123 rather than on top of his own area.

Does anyone know of a better algorithm to correctly position the zip code on top of an irregular area, rather than using the area’s centroid?

Answer 1

You can use the google.maps.geometry.poly.containsLocation and google.maps.geometry.spherical.interpolate functions.

for example. get a boundary point and the center point of the polygon and use the function ‘google.maps.geometry.spherical.interpolate ({centerpoint}, {bundaypoint}, {distance})‘
then you verify that the resulting point is in the area of ​​the polygon with
‘google.maps.geometry.poly.containsLocation ({resultPoint}, {polygonObject})‘ function.

GetBounds function:

if (!google.maps.Polygon.prototype.getBounds) {
            google.maps.Polygon.prototype.getBounds = function (latLng) {
                var bounds = new google.maps.LatLngBounds();
                var paths = this.getPaths();
                var path;
                for (var p = 0; p < paths.getLength() ; p++) {
                    path = paths.getAt(p);
                    for (var i = 0; i < path.getLength() ; i++) {
                        bounds.extend(path.getAt(i));
                    }
                }
                return bounds;
            }
        }