146 lines
3.5 KiB
JavaScript
146 lines
3.5 KiB
JavaScript
goog.provide('ol.proj.EPSG3857');
|
|
|
|
goog.require('goog.array');
|
|
goog.require('goog.asserts');
|
|
goog.require('ol.math');
|
|
goog.require('ol.proj');
|
|
goog.require('ol.proj.Projection');
|
|
goog.require('ol.proj.Units');
|
|
|
|
|
|
|
|
/**
|
|
* @constructor
|
|
* @extends {ol.proj.Projection}
|
|
* @param {string} code Code.
|
|
*/
|
|
ol.proj.EPSG3857 = function(code) {
|
|
goog.base(this, {
|
|
code: code,
|
|
units: ol.proj.Units.METERS,
|
|
extent: ol.proj.EPSG3857.EXTENT,
|
|
global: true
|
|
});
|
|
};
|
|
goog.inherits(ol.proj.EPSG3857, ol.proj.Projection);
|
|
|
|
|
|
/**
|
|
* @const
|
|
* @type {number}
|
|
*/
|
|
ol.proj.EPSG3857.RADIUS = 6378137;
|
|
|
|
|
|
/**
|
|
* @const
|
|
* @type {number}
|
|
*/
|
|
ol.proj.EPSG3857.HALF_SIZE = Math.PI * ol.proj.EPSG3857.RADIUS;
|
|
|
|
|
|
/**
|
|
* @const
|
|
* @type {ol.Extent}
|
|
*/
|
|
ol.proj.EPSG3857.EXTENT = [
|
|
-ol.proj.EPSG3857.HALF_SIZE, -ol.proj.EPSG3857.HALF_SIZE,
|
|
ol.proj.EPSG3857.HALF_SIZE, ol.proj.EPSG3857.HALF_SIZE
|
|
];
|
|
|
|
|
|
/**
|
|
* Lists several projection codes with the same meaning as EPSG:3857.
|
|
*
|
|
* @type {Array.<string>}
|
|
*/
|
|
ol.proj.EPSG3857.CODES = [
|
|
'EPSG:3857',
|
|
'EPSG:102100',
|
|
'EPSG:102113',
|
|
'EPSG:900913',
|
|
'urn:ogc:def:crs:EPSG:6.18:3:3857'
|
|
];
|
|
|
|
|
|
/**
|
|
* Projections equal to EPSG:3857.
|
|
*
|
|
* @const
|
|
* @type {Array.<ol.proj.Projection>}
|
|
*/
|
|
ol.proj.EPSG3857.PROJECTIONS = goog.array.map(
|
|
ol.proj.EPSG3857.CODES,
|
|
function(code) {
|
|
return new ol.proj.EPSG3857(code);
|
|
});
|
|
|
|
|
|
/**
|
|
* Transformation from EPSG:4326 to EPSG:3857.
|
|
*
|
|
* @param {Array.<number>} input Input array of coordinate values.
|
|
* @param {Array.<number>=} opt_output Output array of coordinate values.
|
|
* @param {number=} opt_dimension Dimension (default is `2`).
|
|
* @return {Array.<number>} Output array of coordinate values.
|
|
*/
|
|
ol.proj.EPSG3857.fromEPSG4326 = function(
|
|
input, opt_output, opt_dimension) {
|
|
var length = input.length,
|
|
dimension = opt_dimension > 1 ? opt_dimension : 2,
|
|
output = opt_output;
|
|
if (!goog.isDef(output)) {
|
|
if (dimension > 2) {
|
|
// preserve values beyond second dimension
|
|
output = input.slice();
|
|
} else {
|
|
output = new Array(length);
|
|
}
|
|
}
|
|
goog.asserts.assert(output.length % dimension === 0);
|
|
for (var i = 0; i < length; i += dimension) {
|
|
output[i] = ol.proj.EPSG3857.RADIUS * Math.PI * input[i] / 180;
|
|
output[i + 1] = ol.proj.EPSG3857.RADIUS *
|
|
Math.log(Math.tan(Math.PI * (input[i + 1] + 90) / 360));
|
|
}
|
|
return output;
|
|
};
|
|
|
|
|
|
/**
|
|
* Transformation from EPSG:3857 to EPSG:4326.
|
|
*
|
|
* @param {Array.<number>} input Input array of coordinate values.
|
|
* @param {Array.<number>=} opt_output Output array of coordinate values.
|
|
* @param {number=} opt_dimension Dimension (default is `2`).
|
|
* @return {Array.<number>} Output array of coordinate values.
|
|
*/
|
|
ol.proj.EPSG3857.toEPSG4326 = function(input, opt_output, opt_dimension) {
|
|
var length = input.length,
|
|
dimension = opt_dimension > 1 ? opt_dimension : 2,
|
|
output = opt_output;
|
|
if (!goog.isDef(output)) {
|
|
if (dimension > 2) {
|
|
// preserve values beyond second dimension
|
|
output = input.slice();
|
|
} else {
|
|
output = new Array(length);
|
|
}
|
|
}
|
|
goog.asserts.assert(output.length % dimension === 0);
|
|
for (var i = 0; i < length; i += dimension) {
|
|
output[i] = 180 * input[i] / (ol.proj.EPSG3857.RADIUS * Math.PI);
|
|
output[i + 1] = 360 * Math.atan(
|
|
Math.exp(input[i + 1] / ol.proj.EPSG3857.RADIUS)) / Math.PI - 90;
|
|
}
|
|
return output;
|
|
};
|
|
|
|
|
|
/**
|
|
* @inheritDoc
|
|
*/
|
|
ol.proj.EPSG3857.prototype.getPointResolution = function(resolution, point) {
|
|
return resolution / ol.math.cosh(point[1] / ol.proj.EPSG3857.RADIUS);
|
|
};
|