Functions
The following functions are available globally.
-
Projects
coordinate
to the map.coordinate
must be valid.Declaration
Swift
func GMSProject(_ coordinate: CLLocationCoordinate2D) -> GMSMapPoint
Objective-C
extern GMSMapPoint GMSProject(CLLocationCoordinate2D coordinate)
-
Unprojects
point
from the map. point.x must be in [-1, 1].Declaration
Swift
func GMSUnproject(_ point: GMSMapPoint) -> CLLocationCoordinate2D
Objective-C
extern CLLocationCoordinate2D GMSUnproject(GMSMapPoint point)
-
Returns a linearly interpolated point on the segment [a, b], at the fraction
t
froma
.t
==0 corresponds toa
,t
==1 corresponds tob
.The interpolation takes place along the short path between the points potentially crossing the date line. E.g. interpolating from San Francisco to Tokyo will pass north of Hawaii and cross the date line.
Declaration
Swift
func GMSMapPointInterpolate(_ a: GMSMapPoint, _ b: GMSMapPoint, _ t: Double) -> GMSMapPoint
Objective-C
extern GMSMapPoint GMSMapPointInterpolate(GMSMapPoint a, GMSMapPoint b, double t)
-
Returns the length of the segment [a, b] in projected space.
The length is computed along the short path between the points potentially crossing the date line. E.g. the distance between the points corresponding to San Francisco and Tokyo measures the segment that passes north of Hawaii crossing the date line.
Declaration
Swift
func GMSMapPointDistance(_ a: GMSMapPoint, _ b: GMSMapPoint) -> Double
Objective-C
extern double GMSMapPointDistance(GMSMapPoint a, GMSMapPoint b)
-
Returns whether
point
lies inside of path. The path is always considered closed, regardless of whether the last point equals the first or not.Inside is defined as not containing the South Pole – the South Pole is always outside.
path
describes great circle segments ifgeodesic
is YES, and rhumb (loxodromic) segments otherwise.If
point
is exactly equal to one of the vertices, the result is YES. A point that is not equal to a vertex is on one side or the other of any path segment – it can never be “exactly on the border”.See
GMSGeometryIsLocationOnPath()
for a border test with tolerance. -
Returns whether
point
lies on or nearpath
, within the specifiedtolerance
in meters.path
is composed of great circle segments ifgeodesic
is YES, and of rhumb (loxodromic) segments ifgeodesic
is NO.See also
GMSGeometryIsLocationOnPath(point, path, geodesic)
.The tolerance, in meters, is relative to the spherical radius of the Earth. If you need to work on a sphere of different radius, you may compute the equivalent tolerance from the desired tolerance on the sphere of radius R: tolerance = toleranceR * (RadiusEarth / R), with RadiusEarth==6371009.
Declaration
Swift
func GMSGeometryIsLocationOnPathTolerance(_ point: CLLocationCoordinate2D, _ path: GMSPath, _ geodesic: Bool, _ tolerance: CLLocationDistance) -> Bool
Objective-C
extern BOOL GMSGeometryIsLocationOnPathTolerance(CLLocationCoordinate2D point, GMSPath *_Nonnull path, BOOL geodesic, CLLocationDistance tolerance)
-
Same as
GMSGeometryIsLocationOnPath(point, path, geodesic, tolerance)
, with a default tolerance of 0.1 meters. -
Returns the great circle distance between two coordinates, in meters, on Earth.
This is the shortest distance between the two coordinates on the sphere.
Both coordinates must be valid.
Declaration
Swift
func GMSGeometryDistance(_ from: CLLocationCoordinate2D, _ to: CLLocationCoordinate2D) -> CLLocationDistance
Objective-C
extern CLLocationDistance GMSGeometryDistance(CLLocationCoordinate2D from, CLLocationCoordinate2D to)
-
Returns the great circle length of
path
, in meters, on Earth.This is the sum of
GMSGeometryDistance()
over the path segments.All the coordinates of the path must be valid.
-
Returns the area of a geodesic polygon defined by
path
on Earth.The “inside” of the polygon is defined as not containing the South pole.
If
path
is not closed, it is implicitly treated as a closed path nevertheless and the result is the same.All coordinates of the path must be valid.
The polygon must be simple (not self-overlapping) and may be concave.
If any segment of the path is a pair of antipodal points, the result is undefined – because two antipodal points do not form a unique great circle segment on the sphere.
-
Returns the signed area of a geodesic polygon defined by
path
on Earth.The result has the same absolute value as
GMSGeometryArea()
; it is positive if the points of path are in counter-clockwise order, and negative otherwise.The same restrictions as on GMSGeometryArea() apply.
-
Returns the initial heading (degrees clockwise of North) at
from
of the shortest path toto
.The returned value is in the range [0, 360).
Returns 0 if the two coordinates are the same.
Both coordinates must be valid.
To get the final heading at
to
one may use (GMSGeometryHeading(to
,from
) + 180) modulo 360.Declaration
Swift
func GMSGeometryHeading(_ from: CLLocationCoordinate2D, _ to: CLLocationCoordinate2D) -> CLLocationDirection
Objective-C
extern CLLocationDirection GMSGeometryHeading(CLLocationCoordinate2D from, CLLocationCoordinate2D to)
-
Returns the destination coordinate, when starting at
from
with initialheading
, travellingdistance
meters along a great circle arc, on Earth.The resulting longitude is in the range [-180, 180).
Both coordinates must be valid.
Declaration
Swift
func GMSGeometryOffset(_ from: CLLocationCoordinate2D, _ distance: CLLocationDistance, _ heading: CLLocationDirection) -> CLLocationCoordinate2D
Objective-C
extern CLLocationCoordinate2D GMSGeometryOffset(CLLocationCoordinate2D from, CLLocationDistance distance, CLLocationDirection heading)
-
Returns the coordinate that lies the given
fraction
of the way between thefrom
andto
coordinates on the shortest path between the two.The resulting longitude is in the range [-180, 180).
Declaration
Swift
func GMSGeometryInterpolate(_ from: CLLocationCoordinate2D, _ to: CLLocationCoordinate2D, _ fraction: Double) -> CLLocationCoordinate2D
Objective-C
extern CLLocationCoordinate2D GMSGeometryInterpolate(CLLocationCoordinate2D from, CLLocationCoordinate2D to, double fraction)
-
Returns an
NSArray
ofGMSStyleSpan
constructed by repeated application of style and length information fromstyles
andlengths
alongpath
.path
the path along which the output spans are computed.styles
anNSArray
of GMSStrokeStyle. Wraps if consumed. Can’t be empty.lengths
anNSArray
of NSNumber; each entry gives the length of the corresponding style fromstyles
. Wraps if consumed. Can’t be empty.lengthKind
the interpretation of values fromlengths
(geodesic, rhumb or projected).Example: a polyline with alternating black and white spans:
GMSMutablePath
*path;NSArray
*styles = @[[GMSStrokeStyle
solidColor:[UIColor whiteColor]], [GMSStrokeStyle
solidColor:[UIColor blackColor]]];NSArray
*lengths = @[@100000, @50000]; polyline.path = path; polyline.spans =GMSStyleSpans
(path, styles, lengths, kGMSLengthRhumb);Declaration
Swift
func GMSStyleSpans(_ path: GMSPath, _ styles: [GMSStrokeStyle], _ lengths: [NSNumber], _ lengthKind: GMSLengthKind) -> [GMSStyleSpan]
Objective-C
extern NSArray<GMSStyleSpan *> *_Nonnull GMSStyleSpans( GMSPath *_Nonnull path, NSArray<GMSStrokeStyle *> *_Nonnull styles, NSArray<NSNumber *> *_Nonnull lengths, GMSLengthKind lengthKind)
-
Similar to GMSStyleSpans(path, styles, lengths, lengthKind) but additionally takes an initial length offset that will be skipped over relative to the
lengths
array.lengthOffset
the length (e.g. in meters) that should be skipped initially fromlengths
.Declaration
Swift
func GMSStyleSpansOffset(_ path: GMSPath, _ styles: [GMSStrokeStyle], _ lengths: [NSNumber], _ lengthKind: GMSLengthKind, _ lengthOffset: Double) -> [GMSStyleSpan]
Objective-C
extern NSArray<GMSStyleSpan *> *_Nonnull GMSStyleSpansOffset( GMSPath *_Nonnull path, NSArray<GMSStrokeStyle *> *_Nonnull styles, NSArray<NSNumber *> *_Nonnull lengths, GMSLengthKind lengthKind, double lengthOffset)
-
Calculates a hash value for the given string.
Note
The current implementation uses an MD5 hash, which is sufficient for uniquifying styles.Declaration
Swift
func GMSStyleHashForString(_ string: String) -> UInt
Objective-C
extern NSUInteger GMSStyleHashForString(NSString *_Nonnull string)
Parameters
string
The string to use to calculate the hash value.
Return Value
The hash value.
-
Returns a
GMSOrientation
with the givenheading
andpitch
.@related
GMSOrientation
Declaration
Swift
func GMSOrientationMake(_ heading: CLLocationDirection, _ pitch: Double) -> GMSOrientation
Objective-C
static inline GMSOrientation GMSOrientationMake(CLLocationDirection heading, double pitch)