[76] | 1 | /* Copyright (c) 2006-2010 by OpenLayers Contributors (see authors.txt for |
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| 2 | * full list of contributors). Published under the Clear BSD license. |
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| 3 | * See http://svn.openlayers.org/trunk/openlayers/license.txt for the |
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| 4 | * full text of the license. */ |
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| 5 | |
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| 6 | /** |
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| 7 | * @requires OpenLayers/Geometry/MultiPoint.js |
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| 8 | */ |
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| 9 | |
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| 10 | /** |
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| 11 | * Class: OpenLayers.Geometry.Curve |
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| 12 | * A Curve is a MultiPoint, whose points are assumed to be connected. To |
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| 13 | * this end, we provide a "getLength()" function, which iterates through |
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| 14 | * the points, summing the distances between them. |
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| 15 | * |
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| 16 | * Inherits: |
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| 17 | * - <OpenLayers.Geometry.MultiPoint> |
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| 18 | */ |
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| 19 | OpenLayers.Geometry.Curve = OpenLayers.Class(OpenLayers.Geometry.MultiPoint, { |
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| 20 | |
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| 21 | /** |
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| 22 | * Property: componentTypes |
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| 23 | * {Array(String)} An array of class names representing the types of |
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| 24 | * components that the collection can include. A null |
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| 25 | * value means the component types are not restricted. |
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| 26 | */ |
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| 27 | componentTypes: ["OpenLayers.Geometry.Point"], |
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| 28 | |
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| 29 | /** |
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| 30 | * Constructor: OpenLayers.Geometry.Curve |
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| 31 | * |
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| 32 | * Parameters: |
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| 33 | * point - {Array(<OpenLayers.Geometry.Point>)} |
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| 34 | */ |
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| 35 | initialize: function(points) { |
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| 36 | OpenLayers.Geometry.MultiPoint.prototype.initialize.apply(this, |
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| 37 | arguments); |
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| 38 | }, |
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| 39 | |
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| 40 | /** |
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| 41 | * APIMethod: getLength |
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| 42 | * |
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| 43 | * Returns: |
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| 44 | * {Float} The length of the curve |
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| 45 | */ |
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| 46 | getLength: function() { |
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| 47 | var length = 0.0; |
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| 48 | if ( this.components && (this.components.length > 1)) { |
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| 49 | for(var i=1, len=this.components.length; i<len; i++) { |
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| 50 | length += this.components[i-1].distanceTo(this.components[i]); |
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| 51 | } |
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| 52 | } |
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| 53 | return length; |
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| 54 | }, |
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| 55 | |
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| 56 | /** |
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| 57 | * APIMethod: getGeodesicLength |
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| 58 | * Calculate the approximate length of the geometry were it projected onto |
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| 59 | * the earth. |
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| 60 | * |
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| 61 | * projection - {<OpenLayers.Projection>} The spatial reference system |
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| 62 | * for the geometry coordinates. If not provided, Geographic/WGS84 is |
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| 63 | * assumed. |
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| 64 | * |
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| 65 | * Returns: |
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| 66 | * {Float} The appoximate geodesic length of the geometry in meters. |
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| 67 | */ |
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| 68 | getGeodesicLength: function(projection) { |
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| 69 | var geom = this; // so we can work with a clone if needed |
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| 70 | if(projection) { |
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| 71 | var gg = new OpenLayers.Projection("EPSG:4326"); |
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| 72 | if(!gg.equals(projection)) { |
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| 73 | geom = this.clone().transform(projection, gg); |
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| 74 | } |
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| 75 | } |
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| 76 | var length = 0.0; |
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| 77 | if(geom.components && (geom.components.length > 1)) { |
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| 78 | var p1, p2; |
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| 79 | for(var i=1, len=geom.components.length; i<len; i++) { |
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| 80 | p1 = geom.components[i-1]; |
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| 81 | p2 = geom.components[i]; |
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| 82 | // this returns km and requires lon/lat properties |
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| 83 | length += OpenLayers.Util.distVincenty( |
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| 84 | {lon: p1.x, lat: p1.y}, {lon: p2.x, lat: p2.y} |
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| 85 | ); |
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| 86 | } |
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| 87 | } |
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| 88 | // convert to m |
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| 89 | return length * 1000; |
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| 90 | }, |
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| 91 | |
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| 92 | CLASS_NAME: "OpenLayers.Geometry.Curve" |
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| 93 | }); |
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