GreatCircle is an iOS framework that provides a set of extensions to the CLLocation class.
The CLLocation class provides only one method:
- (CLLocationDistance)distanceFromLocation:(const CLLocation *)location
For calculating the distance between two GPS locations. Because of this, iOS developers must "roll their own" to solve more complex GPS location calculation problems.
GreatCircle - which is based on the amazing work of Chris Veness, the owner
of the Geodesy functions project - provides a comprehensive set of extension methods to the CLLocation class that
make working with GPS locations and performing calculations on then simple and easy.
(For a more general introduction, see: Movable Type Scripts Latitude / Longitude Calculations Reference)
Thus far, I have worked on porting the spherical-earth model, which provides simple formulae covering the accuracy requirements of most use cases.
GreatCircle can be used via Carthage dependency manager or as a CocoaPod.
There are excellent Instructions available on the Carthage site, which are summarized below.
github "softwarenerd/GreatCircle"
carthage update
On your application targets’ “General” settings tab, in the “Linked Frameworks and Libraries” section, drag and drop GreatCircle.framework the Carthage/Build/iOS folder on disk.
On your application targets’ “Build Phases” settings tab, click the “+” icon and choose “New Run Script Phase”. Create a Run Script in which you specify your shell (ex: bin/sh), add the following contents to the script area below the shell:
/usr/local/bin/carthage copy-frameworksand add the paths to the frameworks you want to use under “Input Files”, e.g.:
$(SRCROOT)/Carthage/Build/iOS/GreatCircle.framework
Add GreatCircle to your podfile:
target 'MyApp' do
use_frameworks!
pod 'GreatCircle', '~> 1.0'
end
And install it using:
pod install
If this is the first time you've used a CocoaPod in your project, you will need to switch from your ProjectName.xcodeproj file to the ProjectName.xcworkspace that was created by the pod install command.
Import the GreatCircle framework into your source file(s) as needed.
Extension Methods
-crossTrackDistanceToStartLocation:endLocation:
Returns the cross track distance (in meters) of this location relative to the specified start location and end location.
-crossTrackLocationToStartLocation:endLocation:
Returns a location representing the cross track point of this location relative to the specified start location and end location.
-distanceToOtherLocation:
Returns the distance (in meters) between this location and the other location.
-finalBearingToOtherLocation:
Returns the final bearing (in degrees) between this location and the other location. The final bearing is the initial bearing from
the other location to this location reversed 180°. The final bearing will differ from the initial bearing by varying degrees according
to distance and latitude.
-initialBearingToOtherLocation:
Returns the initial bearing (in degrees) between this location and the other location.
+intersectionOfLocation:andBearing:withLocation:andBearing:
Returns a location representing the point of intersection of two paths, each specified by a location and bearing. Returns nil if
the two paths do not cross.
-isEqualToOtherLocation:
Compares this location to the other location for equality.
-locationWithBearing:distance:
Returns a location representing the point that lies at the specified bearing and distance from this location.
-midpointToOtherLocation:
Returns a location representing the midpoint between this location and the other location.
GreatCircle is a work in progress and your contributions are most welcome. Feel free to fork the repo and submit PR's.
GreatCircle is released under the MIT License.