MapKit Overlays consuming massive CPU resources

Question

I'm overlaying the contents of a third-party shapefile. Some of the polygons consist of 138,000 points, most of them of about 3,000-8,000. In total there are 125 polygons.

Is that normal? Can I in some way, reduce the granularity of the polygons? CPU consumption peaks at over 190% on iPhone 5, and it takes a few minutes before the first overlays pop up.

Answer 1

One thing you might consider is using TileMill to render the Shapefile down into raster tiles with alpha transparency. You can then use that in either MapKit or the Mapbox iOS SDK. It will be highly performant, plus you can still use interactivity going the Mapbox route. Take this map, which was made from Shapefile data in TileMill: https://a.tiles.mapbox.com/v3/newamerica.motw_poverty/page.html#6/40.086/-95.471 The same way that the mouseovers work on the web, you could use Mapbox's RMInteractiveSource API to query and show on tap or other gestures.