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