How to tell if Coordinate is in between two other coordinates

Question

I have an array of CLLocations which represent the route user calculated.

User has an option to add certain POIs to that route and I need to know the way to tell where exactly on the route that POI will be.

What I came up with is next:

I would go through my route array, and grab a pair of CLLocations and calculate a distance from my POI to both of those coordinates and save that value. I can do so for all pairs of coordinates on the route, and then see which distance is the smallest and that is how I would know if my coordinate is between two other ones.

Is there any other method of doing it but this one ?

Answer 1

This is how you can achieve this:

- (CLLocation*)closestLocationToLocation:(CLLocation*)currLocation {
    CLLocationDistance minDistance;

    CLLocation *closestLocation = nil;

    for (CLLocation *location in arrayOfLocations) {
        CLLocationDistance distance = [location distanceFromLocation:currLocation];

        if (distance <= minDistance || closestLocation == nil) {
            minDistance = distance;
            closestLocation = location;
        }
    }

    return closestLocation;
}