global-mercator

Global Mercator

A set of tools geospatial tools to help with TMS, Google (XYZ) Tiles.

This library is insipered by GDAL2Tiles, Google Summer of Code 2007 & 2008

Installation

Using npm:

$ npm install --save global-mercator

In Node.js:

                     
import * as mercator from 'global-mercator'

                         
import { latLngToMeters } from 'global-mercator'

latLngToMeters

Converts {LatLng} coordinates to {Meters} coordinates.

Parameters

• lat number
• lng number
• zoom [number]

Examples

latLngToMeters({lat: 37, lng: 126})
//= Meters { mx: 14026255.83995247, my: 4439106.787250587 }

Returns Meters

metersToLatLng

Converts {Meters} coordinates to {LatLng} coordinates.

Parameters

• mx number
• my number
• zoom [number]

Examples

metersToLatLng({ mx: 14026255, my: 4439106 })
//= LatLng { lat: 36.99999435205559, lng: 125.99999245457859 }

Returns LatLng

metersToPixels

Converts {Meters} coordinates to {Pixels}.

Parameters

• mx number
• my number
• zoom number

Examples

metersToPixels({ mx: 14026255, my: 4439106, zoom: 13 })
//= Pixels { px: 1782579.1560447346, py: 1280877.3387406059, zoom: 13 }

Returns Pixels

latLngToTile

Converts {LatLng} coordinates to TMS {Tile}.

Parameters

• lat number
• lng number
• zoom number

Examples

latLngToTile({lat: 37, lng: 126, zoom: 13 })
//= Tile { tx: 6963, ty: 5003, zoom: 13 }

Returns Tile TMS Tile

latLngToGoogle

Converts {LatLng} coordinates to {Google} (XYZ) Tile.

Parameters

• lat number
• lng number

Examples

latLngToGoogle({lat: 37, lng: 126, zoom: 13 })
//= Google { x: 6963, y: 3188, zoom: 13 }

Returns Google Google Tile

metersToTile

Converts {Meters} coordinates to TMS {Tile}.

Parameters

• mx number
• my number

Examples

metersToTile({ mx: 14026255, my: 4439106, zoom: 13 })
//= Tile { tx: 6963, ty: 5003, zoom: 13 }

Returns Tile TMS Tile

pixelsToMeters

Converts {Pixels} coordinates to {Meters} coordinates.

Parameters

• px number
• py number
• zoom number

Examples

pixelsToMeters({ px: 1782579, py: 1280877, zoom: 13 })
//= Meters { mx: 14026252.018101055, my: 4439099.526918683, zoom: 13 }

Returns Meters

pixelsToTile

Converts {Pixels} coordinates to TMS {Tile}.

Parameters

• px number
• py number
• zoom number

Examples

pixelsToTile({ px: 1782579, py: 1280877, zoom: 13 })
//= Tile { tx: 6963, ty: 5003, zoom: 13 }

Returns Tile TMS Tile

tileBounds

Converts TMS {Tile} to bounds in {Meters} coordinates.

Parameters

• tx number
• ty number
• zoom number

Examples

tileBounds({ tx: 6963, ty: 5003, zoom: 13 })
//= [ 14025277.445990417, 4437016.617897913, 14030169.415800672, 4441908.587708164 ]

Returns Array<number> {bbox} extent in [minX, minY, maxX, maxY] order

tileLatLngBounds

Converts TMS {Tile} to bounds in {LatLng} coordinates.

Parameters

• tx number
• ty number
• zoom number

Examples

tileLatLngBounds({ tx: 6963, ty: 5003, zoom: 13 })
//= [ 125.99121093749999, 36.98500309285596, 126.03515625, 37.020098201368135 ]

Returns Array<number> {bbox} extent in [minX, minY, maxX, maxY] order

googleBounds

Converts {Google} (XYZ) Tile to bounds in {Meters} coordinates.

Parameters

• x number
• y number
• zoom number

Examples

googleBounds({ x: 6963, y: 3188, zoom: 13 })
//= [ 14025277.445990417, 4437016.617897913, 14030169.415800672, 4441908.587708164 ]

Returns Array<number> {bbox} extent in [minX, minY, maxX, maxY] order

googleLatLngBounds

Converts {Google} (XYZ) Tile to bounds in {LatLng} coordinates.

Parameters

• x number
• y number
• zoom number

Examples

googleLatLngBounds({ x: 6963, y: 3188, zoom: 13 })
//= [ 125.99121093749999, 36.98500309285596, 126.03515625, 37.020098201368135 ]

Returns Array<number> {bbox} extent in [minX, minY, maxX, maxY] order

tileGoogle

Converts TMS {Tile} to {Google} (XYZ) Tile.

Parameters

• tx number
• ty number
• zoom number

Examples

tileGoogle({ tx: 6963, ty: 5003, zoom: 13 })
//= Google { x: 6963, y: 3188, zoom: 13 }

Returns Array<number> {bbox} extent in [minX, minY, maxX, maxY] order

googleTile

Converts {Google} (XYZ) Tile to TMS {Tile}.

Parameters

• x number
• y number
• zoom number

Examples

googleTile({ x: 6963, y: 3188, zoom: 13 })
//= Tile { tx: 6963, ty: 5003, zoom: 13 }

Returns Tile TMS Tile

googleQuadkey

Converts {Google} (XYZ) Tile to {Quadkey}.

Parameters

• x number
• y number
• zoom number

Examples

googleQuadkey({ x: 6963, y: 3188, zoom: 13 })
//= '1321102330211'

Returns string Quadkey

tileQuadkey

Converts TMS {Tile} to {QuadKey}.

Parameters

• tx number
• ty number
• zoom number

Examples

tileQuadkey({ tx: 6963, ty: 5003, zoom: 13 })
//= '1321102330211'

Returns string Quadkey

quadkeyTile

Converts {Quadkey} to TMS {Tile}.

Parameters

• quadkey string

Examples

quadkeyTile('1321102330211')
//= Tile { tx: 6963, ty: 5003, zoom: 13 }

Returns Tile TMS Tile

quadkeyGoogle

Converts {Quadkey} to {Google} (XYZ) Tile.

Parameters

• quadkey string

Examples

quadkeyGoogle('1321102330211')
//= Google { x: 6963, y: 3188, zoom: 13 }

Returns Google

bboxLatLngToMeters

Converts {bbox} from {LatLng} coordinates to {Meters} coordinates

Examples

bboxLatLngToMeters([ 125, 35, 127, 37 ])
//= [ 13914936.349159198, 4163881.1440642904, 14137575.330745745, 4439106.787250587 ]

Returns Array<number> {bbox}

validateTile

Validates TMS {Tile}.

Parameters

• tx number
• ty number
• zoom number
• init
• name [string] name used for debugging message (optional, default Tile)

Examples

validateTile({tx: 60, ty: 80, zoom: 5})
//= {tx: 60, ty: 80, zoom: 5}
validateTile({tx: 60, ty: -43, zoom: 5})
//= Error: Tile <ty> must not be less than 0

Returns Object TMS Tile

validateZoom

Validates {Zoom} level.

Parameters

• Zoom number level

Examples

validateZoom(12)
//= 12
validateZoom(-4)
//= Error: <zoom> cannot be less than 1
validateZoom(30)
//= Error: <zoom> cannot be greater than 23

Returns number Zoom level

validatePixels

Validates {Pixels} coordinates.

Parameters

• Pixels Array<number> coordinates

Examples

validatePixels([-115, 44])
//= [-115, 44]

Returns Array<number> Pixels coordinates

validateMeters

Validates {Meters} coordinates.

Parameters

• Meters Array<number> coordinates

Examples

validateMeters([-115, 44])
//= [-115, 44]

Returns Array<number> Meters coordinates

validateLatLng

Validates {LatLng} coordinates.

Parameters

• LatLng Array<number> coordinates

Examples

validateLatLng([-115, 44])
//= [-115, 44]

Returns Array<number> LatLng coordinates

validateLngLat

Validates {LngLat} coordinates.

Parameters

• LngLat Array<number> coordinates

Examples

validateLngLat([-115, 44])
//= [-115, 44]

Returns Array<number> LngLat coordinates

bounds

Validates bounds.

Parameters

• bounds Array<number>

Examples

validateBounds([ -75, 44, -74, 45 ])
//= [ -75, 44, -74, 45 ]
validateBounds([ -75, 44, -74 ])
//= Error: [bounds] must be an Array of 4 numbers

assertUndefined

Assert undefined items within object.

Parameters

• items Object
• name [string] name used for debugging message

Examples

assertUndefined({foo: 'bar'})
//= {foo: 'bar'}
assertUndefined({foo: undefined})
//= Error: <foo> is required

Returns Object items