MercatorTile

Spherical mercator tile and coordinate utilities for C++.

The tools provides ul function that return the upper left corner longitudes and latitudes, a bounds function return the bounding longitudes and latitudes, a xy function that return the spherical mercator x and y coordinates, a tile function that returns the tile containing a given point. And lots of other usful functions.

You can check out the Utility Functions or examples.

How to use

#include "MercatorTile.h"
using namespace mercatortile;

LngLat ul_result = ul(Tile{3425, 1549, 12});
cout<<"lng: "<<ul_result.lng<<" lat:"<<ul_result.lat<<"\n"<<endl;

Tile tile = mercatortile::tile(120.32, 43.5, 10);

Tile ttile = tile(lng, lat, 4);
cout<<ttile.x<<" "<<ttile.y<<" "<<ttile.z<<endl;

Data Structures

• struct Tile {x,y,z} defines an XYZ web mercator tile. x for column number, y for row number, z for zoom level.

• struct LngLat {lng, lat} defines a longitude and latitude pair.

• struct XY {x, y} defines a x and y pair of web mercator.

• struct Bbox {west, sourth, east, north} defines a web mercator bounding box.

• struct LngLatBbox {left, bottom, right, top} defines a geographic bounding box, value should be longitude and latitude.

Utility Functions

• ul(const Tile &tile) -> LngLat: get the upper left longitude and latitude of a tile.

• bounds(const Tile &tile) -> LngLatBbox: get the lonlat bounding box of a tile.

• xy(const double &lng, const double &lat)->XY: convert longtitude and latitude to web mercator x, y.

• lonlat(const double &x, const double &y) -> LngLat: convert web mercator x, y to longtitude and latitude.

• xy_bounds(const Tile &tile) -> Bbox: get the web mercator bounding box of a tile.

• tile(const double &lng, const double &lat, const int &zoom) -> Tile: get the tile containing a longitude and latitude.

• parent(const Tile &tile) -> Tile: get the parent tile of a tile.

• parent(const Tile &tile, const int &zoom) -> TIle: get the parent tile of a tile.

• children(const Tile &tile) -> std::vector<Tile>: get the children of a tile.

• children(const Tile &tile, const int &zoom) -> std::vector<Tile>: get the children of a tile.

• tiles(const LngLatBbox &bbox, const int &zoom) -> std::vector<Tile>: get the tiles intersecting a geographic bounding box.

• quadkey(const Tile &tile) -> std::string: get the quadkey of a tile.

• quadkey_to_tile(const std::string &qk) -> Tile: get the tile corresponding to a quadkey.

Install

mkdir build && cd build
cmake ..
make
make install

Reference

• https://github.com/mapbox/mercantile