Moving a CLLocation by x meters

Question

I have a CLLocation defined, and I'd like to move that point x meters to the east and y meters to the south. How may I achieve that?

Answer 1

Slight adjustment to @CocoaChris answer: now a category on CLLocation, and using the built-in units.

#import <CoreLocation/CoreLocation.h>


@interface CLLocation (Movement)

- (CLLocation *)locationByMovingDistance:(double)distanceMeters withBearing:(CLLocationDirection)bearingDegrees;

@end


@implementation CLLocation (Movement)

- (CLLocation *)locationByMovingDistance:(double)distanceMeters withBearing:(CLLocationDirection)bearingDegrees
{
    const double distanceRadians = distanceMeters / (6372797.6); // earth radius in meters
    const double bearingRadians = bearingDegrees * M_PI / 180;

    float lat1 = self.coordinate.latitude * M_PI / 180;
    float lon1 = self.coordinate.longitude * M_PI / 180;

    float lat2 = asin(sin(lat1) * cos(distanceRadians) + cos(lat1) * sin(distanceRadians) * cos(bearingRadians));
    float lon2 = lon1 + atan2(sin(bearingRadians) * sin(distanceRadians) * cos(lat1),
                              cos(distanceRadians) - sin(lat1) * sin(lat2) );

    return [[CLLocation alloc] initWithLatitude:lat2 * 180 / M_PI
                                      longitude:lon2 * 180 / M_PI];
}

@end