Files
openlayers/test/spec/ol/proj/epsg3857.test.js
Tim Schaub 7f47883c48 Transformed
2017-12-12 06:53:18 -07:00

81 lines
2.6 KiB
JavaScript

import _ol_proj_ from '../../../../src/ol/proj.js';
import _ol_proj_EPSG3857_ from '../../../../src/ol/proj/EPSG3857.js';
describe('ol.proj.EPSG3857', function() {
afterEach(function() {
_ol_proj_.clearAllProjections();
_ol_proj_.addCommon();
});
describe('fromEPSG4326()', function() {
it('transforms from geographic to Web Mercator', function() {
var forward = _ol_proj_EPSG3857_.fromEPSG4326;
var edge = _ol_proj_EPSG3857_.HALF_SIZE;
var tolerance = 1e-5;
var cases = [{
g: [0, 0],
m: [0, 0]
}, {
g: [-180, -90],
m: [-edge, -edge]
}, {
g: [180, 90],
m: [edge, edge]
}, {
g: [-111.0429, 45.6770],
m: [-12361239.084208, 5728738.469095]
}];
for (var i = 0, ii = cases.length; i < ii; ++i) {
var point = cases[i].g;
var transformed = forward(point);
expect(transformed[0]).to.roughlyEqual(cases[i].m[0], tolerance);
expect(transformed[1]).to.roughlyEqual(cases[i].m[1], tolerance);
}
});
});
describe('getPointResolution', function() {
it('returns the correct point scale at the equator', function() {
// @see http://msdn.microsoft.com/en-us/library/aa940990.aspx
var epsg3857 = _ol_proj_.get('EPSG:3857');
var resolution = 19.11;
var point = [0, 0];
expect(_ol_proj_.getPointResolution(epsg3857, resolution, point)).
to.roughlyEqual(19.11, 1e-1);
});
it('returns the correct point scale at the latitude of Toronto',
function() {
// @see http://msdn.microsoft.com/en-us/library/aa940990.aspx
var epsg3857 = _ol_proj_.get('EPSG:3857');
var epsg4326 = _ol_proj_.get('EPSG:4326');
var resolution = 19.11;
var point = _ol_proj_.transform([0, 43.65], epsg4326, epsg3857);
expect(_ol_proj_.getPointResolution(epsg3857, resolution, point)).
to.roughlyEqual(19.11 * Math.cos(Math.PI * 43.65 / 180), 1e-9);
});
it('returns the correct point scale at various latitudes', function() {
// @see http://msdn.microsoft.com/en-us/library/aa940990.aspx
var epsg3857 = _ol_proj_.get('EPSG:3857');
var epsg4326 = _ol_proj_.get('EPSG:4326');
var resolution = 19.11;
var latitude;
for (latitude = 0; latitude <= 85; ++latitude) {
var point = _ol_proj_.transform([0, latitude], epsg4326, epsg3857);
expect(_ol_proj_.getPointResolution(epsg3857, resolution, point)).
to.roughlyEqual(19.11 * Math.cos(Math.PI * latitude / 180), 1e-9);
}
});
});
});