How to fit a certain bounds consisting of NE and SW coordinates into the visible map view?

Question

I need to fit a certain bounds within a map. I get the bounds from calling the google geocoder and reading the viewport property which looks like:

{
    northeas         


        

Answer 1

If your bounds can span the 180th meridian, you have to account for that in the conversion:

- (MKMapRect) mapRectThatFitsBoundsSW:(CLLocationCoordinate2D)sw 
                                   NE:(CLLocationCoordinate2D)ne 
{
    MKMapPoint pSW = MKMapPointForCoordinate(sw);
    MKMapPoint pNE = MKMapPointForCoordinate(ne);

    double antimeridianOveflow = 
      (ne.longitude > sw.longitude) ? 0 : MKMapSizeWorld.width;    

    return MKMapRectMake(pSW.x, pNE.y, 
                        (pNE.x - pSW.x) + antimeridianOveflow, 
                        (pSW.y - pNE.y));
}

But beware those MKMapRects that span the anitmeridian, because they come from the land where the dragons live. If you want to learn about some of the dangers that lie there, have a look at MKMapRect and displaying map overlays that span 180th meridian. You have been warned!