73 lines
2.2 KiB
JavaScript
73 lines
2.2 KiB
JavaScript
goog.require('ol.Attribution');
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goog.require('ol.Map');
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goog.require('ol.View');
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goog.require('ol.extent');
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goog.require('ol.layer.Tile');
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goog.require('ol.proj');
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goog.require('ol.source.TileImage');
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goog.require('ol.tilegrid.TileGrid');
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var attribution = new ol.Attribution({
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html: 'Copyright:© 2013 ESRI, i-cubed, GeoEye'
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});
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var projection = ol.proj.get('EPSG:4326');
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var projectionExtent = projection.getExtent();
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// The tile size supported by the ArcGIS tile service.
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var tileSize = 512;
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// Calculate the resolutions supported by the ArcGIS tile service.
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// There are 16 resolutions, with a factor of 2 between successive
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// resolutions. The max resolution is such that the world (360°)
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// fits into two (512x512 px) tiles.
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var maxResolution = ol.extent.getWidth(projectionExtent) / (tileSize * 2);
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var resolutions = new Array(16);
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var z;
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for (z = 0; z < 16; ++z) {
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resolutions[z] = maxResolution / Math.pow(2, z);
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}
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var urlTemplate = 'http://services.arcgisonline.com/arcgis/rest/services/' +
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'ESRI_Imagery_World_2D/MapServer/tile/{z}/{y}/{x}';
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var map = new ol.Map({
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target: 'map',
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layers: [
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new ol.layer.Tile({
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/* ol.source.XYZ and ol.tilegrid.XYZ have no resolutions config */
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source: new ol.source.TileImage({
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attributions: [attribution],
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tileUrlFunction: function(tileCoord, pixelRatio, projection) {
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var z = tileCoord[0];
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var x = tileCoord[1];
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var y = -tileCoord[2] - 1;
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// wrap the world on the X axis
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var n = Math.pow(2, z + 1); // 2 tiles at z=0
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x = x % n;
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if (x * n < 0) {
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// x and n differ in sign so add n to wrap the result
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// to the correct sign
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x = x + n;
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}
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return urlTemplate.replace('{z}', z.toString())
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.replace('{y}', y.toString())
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.replace('{x}', x.toString());
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},
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projection: projection,
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tileGrid: new ol.tilegrid.TileGrid({
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origin: ol.extent.getTopLeft(projectionExtent),
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resolutions: resolutions,
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tileSize: 512
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})
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})
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})
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],
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view: new ol.View({
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center: [0, 0],
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projection: projection,
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zoom: 2,
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minZoom: 2
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})
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});
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