CRS

CRS is a coordinate reference system container, representing a Coordinate Reference System as defined by GeoJSON. It inherits from no base class, consists of type and properties, and provides several predefined common coordinate system constants.

import { CRS } from "maptalks";
// Usage example
const crs = new CRS("proj4", { proj: "+proj=longlat +datum=WGS84 +no_defs" });
console.log(crs.type); // proj4

Constructor

new CRS(type, properties)

Parameters:

• type — The CRS type string, e.g. "proj4", "epsg".
• properties — The CRS properties object, e.g. { proj: "..." }.

Static Methods

• CRS.createProj4(proj): CRS — Create a proj4-style CRS used by maptalks, e.g. CRS.createProj4("+proj=longlat +datum=WGS84 +no_defs").
• CRS.fromProjectionCode(code): CRS|null — Return the built-in CRS for an EPSG code (e.g. "EPSG:4326"), or null if invalid.

Predefined Constants

• CRS.WGS84 — The predefined WGS84 coordinate system (aka EPSG:4326).
• CRS.EPSG4326 — Alias for CRS.WGS84.
• CRS.EPSG3857 — The projected coordinate system used by Google Maps (aliases EPSG:3785, GOOGLE, EPSG:900913).
• CRS.IDENTITY — A simple Cartesian coordinate system that maps x, y directly, useful for flat-surface maps (indoor maps, game maps).
• CRS.CGCS2000 — The official coordinate system in China (aka EPSG:4490), in most cases considered the same as WGS84.
• CRS.EPSG4490 — Alias for CRS.CGCS2000.
• CRS.BD09LL — The projected coordinate system used by Baidu Map.
• CRS.GCJ02 — The encrypted coordinate system used by most online map services in China.

Events

CRS has no events.