MGLRasterSource


@interface MGLRasterSource : MGLTileSource

MGLRasterSource is a map content source that supplies raster image tiles to be shown on the map. The location of and metadata about the tiles are defined either by an option dictionary or by an external file that conforms to the TileJSON specification. A raster source is added to an MGLStyle object along with one or more MGLRasterStyleLayer objects. Use a raster style layer to control the appearance of content supplied by the raster source.

Each raster source defined by the style JSON file is represented at runtime by an MGLRasterSource object that you can use to initialize new style layers. You can also add and remove sources dynamically using methods such as -[MGLStyle addSource:] and -[MGLStyle sourceWithIdentifier:].

Example

let source = MGLRasterSource(identifier: clouds, tileURLTemplates: [https://example.com/raster-tiles/{z}/{x}/{y}.png], options: [
    .minimumZoomLevel: 9,
    .maximumZoomLevel: 16,
    .tileSize: 512,
    .attributionInfos: [
        MGLAttributionInfo(title: NSAttributedString(string: © Mapbox), url: URL(string: http://mapbox.com))
    ]
])
mapView.style?.addSource(source)

Initializing a Source


                    
                    
                    -initWithIdentifier:configurationURL:

Returns a raster source initialized with an identifier and configuration URL.

After initializing and configuring the source, add it to a map view’s style using the -[MGLStyle addSource:] method.

The URL may be a full HTTP or HTTPS URL or, for tile sets hosted by Mapbox, a Mapbox URL indicating a map identifier (mapbox://<mapid>). The URL should point to a JSON file that conforms to the TileJSON specification.

If a Mapbox URL is specified, this source uses a tile size of 256. For all other tile sets, the default value is 512. (See the MGLTileSourceOptionTileSize documentation for more information about tile sizes.) If you need to use a tile size other than the default, use the -initWithIdentifier:configurationURL:tileSize: method.

Declaration

Objective-C

- (nonnull instancetype)initWithIdentifier:(nonnull NSString *)identifier
                          configurationURL:(nonnull NSURL *)configurationURL;

Swift

convenience init(identifier: String, configurationURL: URL)

Parameters

`identifier`	A string that uniquely identifies the source in the style to which it is added.
`configurationURL`	A URL to a TileJSON configuration file describing the source’s contents and other metadata.

Return Value

An initialized raster source.

View Source on GitHub


                    
                    
                    -initWithIdentifier:configurationURL:tileSize:

Returns a raster source initialized with an identifier, configuration URL, and tile size.

After initializing and configuring the source, add it to a map view’s style using the -[MGLStyle addSource:] method.

Declaration

Objective-C

- (nonnull instancetype)initWithIdentifier:(nonnull NSString *)identifier
                          configurationURL:(nonnull NSURL *)configurationURL
                                  tileSize:(CGFloat)tileSize;

Swift

init(identifier: String, configurationURL: URL, tileSize: CGFloat)

Parameters

`identifier`	A string that uniquely identifies the source in the style to which it is added.
`configurationURL`	A URL to a TileJSON configuration file describing the source’s contents and other metadata.
`tileSize`	The width and height (measured in points) of each tiled image in the raster source. See the `MGLTileSourceOptionTileSize` documentation for details.

Return Value

An initialized raster source.

View Source on GitHub


                    
                    
                    -initWithIdentifier:tileURLTemplates:options:

Returns a raster source initialized an identifier, tile URL templates, and options.

After initializing and configuring the source, add it to a map view’s style using the -[MGLStyle addSource:] method.

Tile URL templates

Tile URL templates are strings that specify the URLs of the tile images to load. Each template resembles an absolute URL, but with any number of placeholder strings that the source evaluates based on the tile it needs to load. For example:

http://www.example.com/tiles/{z}/{x}/{y}.pbf could be evaluated as http://www.example.com/tiles/14/6/9.pbf.
http://www.example.com/tiles/{z}/{x}/{y}{ratio}.png could be evaluated as http://www.example.com/tiles/14/6/9@2x.png.

Tile sources support the following placeholder strings in tile URL templates, all of which are optional:

Placeholder string	Description
`{x}`	The index of the tile along the map’s x axis according to Spherical Mercator projection. If the value is 0, the tile’s left edge corresponds to the 180th meridian west. If the value is 2^z−1, the tile’s right edge corresponds to the 180th meridian east.
`{y}`	The index of the tile along the map’s y axis according to Spherical Mercator projection. If the value is 0, the tile’s tile edge corresponds to arctan(sinh(π)), or approximately 85.0511 degrees north. If the value is 2^z−1, the tile’s bottom edge corresponds to −arctan(sinh(π)), or approximately 85.0511 degrees south. The y axis is inverted if the `options` parameter contains `MGLTileSourceOptionTileCoordinateSystem` with a value of `MGLTileCoordinateSystemTMS`.
`{z}`	The tile’s zoom level. At zoom level 0, each tile covers the entire world map; at zoom level 1, it covers ¼ of the world; at zoom level 2, ¹⁄₁₆ of the world, and so on. For tiles loaded by a `MGLRasterSource` object, whether the tile zoom level matches the map’s current zoom level depends on the value of the source’s tile size as specified in the `MGLTileSourceOptionTileSize` key of the `options` parameter.
`{bbox-epsg-3857}`	The tile’s bounding box, expressed as a comma-separated list of the tile’s western, southern, eastern, and northern extents according to Spherical Mercator (EPSG:3857) projection. The bounding box is typically used with map services conforming to the Web Map Service protocol.
`{quadkey}`	A quadkey indicating both the tile’s location and its zoom level. The quadkey is typically used with Bing Maps.
`{ratio}`	A suffix indicating the resolution of the tile image. The suffix is the empty string for standard resolution displays and `@2x` for Retina displays, including displays for which `NSScreen.backingScaleFactor` or `UIScreen.scale` is 3.
`{prefix}`	Two hexadecimal digits chosen such that each visible tile has a different prefix. The prefix is typically used for domain sharding.

For more information about the {x}, {y}, and {z} placeholder strings, consult the OpenStreetMap Wiki.

Declaration

Objective-C

- (nonnull instancetype)
initWithIdentifier:(nonnull NSString *)identifier
  tileURLTemplates:(nonnull NSArray<NSString *> *)tileURLTemplates
           options:(nullable NSDictionary<MGLTileSourceOption, id> *)options;

Swift

init(identifier: String, tileURLTemplates: [String], options: [MGLTileSourceOption : Any]? = nil)

Parameters

`identifier`	A string that uniquely identifies the source in the style to which it is added.
`tileURLTemplates`	An array of tile URL template strings. Only the first string is used; any additional strings are ignored.
`options`	A dictionary containing configuration options. See `MGLTileSourceOption` for available keys and values. Pass in `nil` to use the default values.

Return Value

An initialized tile source.

View Source on GitHub