Package Exports
- sphericalmercator
This package does not declare an exports field, so the exports above have been automatically detected and optimized by JSPM instead. If any package subpath is missing, it is recommended to post an issue to the original package (sphericalmercator) to support the "exports" field. If that is not possible, create a JSPM override to customize the exports field for this package.
Readme
node-sphericalmercator provides projection math for converting between
mercator meters, screen pixels (of 256x256 or configurable-size tiles), and
latitude/longitude.
Compatible with nodejs packages and in-browser.
Installation
npm install sphericalmercator
API
Some datatypes are assumed to be arrays: ll is [lon, lat], xy and px are
[x, y].
// By default, precomputes up to z30
var merc = new SphericalMercator({
size: 256
});px(ll, zoom)
Convert lon, lat to screen pixel x, y from 0, 0 origin, at a certain zoom level.
The inverse of ll
ll(px, zoom)
Convert screen pixel value to lon, lat, at a certain zoom level. The inverse
of px
bbox(x, y, zoom, tms_style, srs)
Convert tile xyz value to bbox of the form [w, s, e, n]
x{Number} x (longitude) number.y{Number} y (latitude) number.zoom{Number} zoom.tms_style{Boolean} whether to compute using tms-style. (optional, default false)srs{String} projection for resulting bbox (WGS84|900913). (optional, default WGS84)
Returns bbox array of values in form [w, s, e, n].
xyz(bbox, zoom, tms_style, srs)
Convert bbox to xyz bounds
bbox{Number} bbox in the form[w, s, e, n].zoom{Number} zoom.tms_style{Boolean} whether to compute using tms-style. (optional, default false)srs{String} projection of input bbox (WGS84|900913). (optional, default WGS84)
Returns {Object} XYZ bounds containing minX, maxX, minY, maxY properties.
convert(bbox, to)
Convert bbox from 900913 to WGS84 or vice versa
bbox{Number} bbox in the form[w, s, e, n].to{String} projection of resulting bbox (WGS84|900913). (optional, default WGS84)
Returns bbox array of values in form [w, s, e, n].
forward(ll)
Convert lon, lat values to mercator x, y
inverse(xy)
Convert mercator x, y values to lon, lat
See Also
- mercantile provides similar utilities for projection and tile math in Python