63a9567858
This class is able to convert an encoded polyline string into a LineString embedded in a Vector Feature. See https://developers.google.com/maps/documentation/utilities/polylinealgorithm for more information.
86 lines
2.4 KiB
JavaScript
86 lines
2.4 KiB
JavaScript
/* Copyright (c) 2006-2012 by OpenLayers Contributors (see authors.txt for
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* full list of contributors). Published under the 2-clause BSD license.
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* See license.txt in the OpenLayers distribution or repository for the
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* full text of the license. */
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/**
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* @requires OpenLayers/Format.js
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* @requires OpenLayers/Feature/Vector.js
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*/
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/**
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* Class: OpenLayers.Format.EncodedPolyline
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* Class for reading and writing encoded polylines. Create a new instance
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* with the <OpenLayers.Format.EncodedPolyline> constructor.
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*
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* Inherits from:
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* - <OpenLayers.Format>
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*/
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OpenLayers.Format.EncodedPolyline = OpenLayers.Class(OpenLayers.Format, {
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/**
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* Constructor: OpenLayers.Format.EncodedPolyline
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* Create a new parser for encoded polylines
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*
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* Parameters:
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* options - {Object} An optional object whose properties will be set on
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* this instance
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*
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* Returns:
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* {<OpenLayers.Format.EncodedPolyline>} A new encoded polylines parser.
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*/
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initialize: function(options) {
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OpenLayers.Format.prototype.initialize.apply(this, [options]);
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},
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/**
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* Method: read
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* Deserialize an encoded polyline string and return a vector feature.
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*
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* Parameters:
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* encoded - {String} An encoded polyline string
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*
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* Returns:
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* {<OpenLayers.Feature.Vector>} A vector feature with a linestring.
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*/
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read: function(encoded) {
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var points = new Array();
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var lat = 0;
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var lon = 0;
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for (var i = 0; i < encoded.length;) {
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var b;
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var result = 0;
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var shift = 0;
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do {
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b = encoded.charCodeAt(i++) - 63;
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result |= (b & 0x1f) << shift;
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shift += 5;
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} while (b >= 0x20);
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lat += ((result & 1) ? ~(result >> 1) : (result >> 1));
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result = 0;
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shift = 0;
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do {
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b = encoded.charCodeAt(i++) - 63;
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result |= (b & 0x1f) << shift;
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shift += 5;
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} while (b >= 0x20);
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lon += ((result & 1) ? ~(result >> 1) : (result >> 1));
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points.push(new OpenLayers.Geometry.Point(lon * 1e-5, lat * 1e-5));
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}
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return new OpenLayers.Feature.Vector(
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new OpenLayers.Geometry.LineString(points)
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);
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},
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CLASS_NAME: "OpenLayers.Format.EncodedPolyline"
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});
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