123 lines
3.9 KiB
JavaScript
123 lines
3.9 KiB
JavaScript
//>>built
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define("dojox/geo/openlayers/GreatCircle", ["dojo/_base/lang",
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"dojox/geo/openlayers/GeometryFeature",
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"dojox/geo/openlayers/Point",
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"dojox/geo/openlayers/LineString"], function(lang, GeometryFeature, Point, lineString){
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lang.getObject("geo.openlayers", true, dojox);
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dojox.geo.openlayers.GreatCircle = {
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toPointArray : function(p1, p2, increment){
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// summary:
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// Create a geodetic line as an array of OpenLayers.Point.
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// descritpion:
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// Create a geodetic line as an array of OpenLayers.Point between the point p1
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// and the point p2. Result is a polyline approximation for which a new point is
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// calculated every <em>increment</em> degrees.
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// p1: Point
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// The first point of the geodetic line. x and y fields are longitude and
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// latitude in decimal degrees.
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// p2: Point
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// The second point of the geodetic line. x and y fields are longitude and
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// latitude in decimal degrees.
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// increment: Float
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// The value at which a new point is computed.
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var startLon = p1.x;
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var endLon = p2.x;
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var sl = Math.min(startLon, endLon);
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var el = Math.max(startLon, endLon);
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var d2r = this.DEG2RAD;
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var lat1 = p1.y * d2r;
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var lon1 = p1.x * d2r;
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var lat2 = p2.y * d2r;
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var lon2 = p2.x * d2r;
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if (Math.abs(lon1 - lon2) <= this.TOLERANCE) {
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var l = Math.min(lon1, lon2);
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lon2 = l + Math.PI;
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}
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if (Math.abs(lon2 - lon1) == Math.PI) {
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if (lat1 + lat2 == 0.0) {
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lat2 += Math.PI / 180000000;
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}
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}
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var lon = sl * d2r;
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var elon = el * d2r;
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var incr = increment * d2r;
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var wp = [];
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var k = 0;
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var r2d = this.RAD2DEG;
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while (lon <= elon) {
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lat = Math.atan((Math.sin(lat1) * Math.cos(lat2) * Math.sin(lon - lon2) - Math.sin(lat2) * Math.cos(lat1)
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* Math.sin(lon - lon1))
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/ (Math.cos(lat1) * Math.cos(lat2) * Math.sin(lon1 - lon2)));
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var p = {
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x : lon * r2d,
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y : lat * r2d
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};
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wp[k++] = p;
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if (lon < elon && (lon + incr) >= elon)
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lon = elon;
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else
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lon = lon + incr;
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}
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return wp;
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},
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toLineString : function(p1, p2, increment){
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// summary:
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// Create a geodetic line as an array of OpenLayers.Geometry.LineString.
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// descritpion:
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// Create a geodetic line as a OpenLayers.Geometry.LineString between the point p1
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// and the point p2. Result is a polyline approximation for which a new point is
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// calculated every <em>increment</em> degrees.
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// p1: Point
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// The first point of the geodetic line. x and y fields are longitude and
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// latitude in decimal degrees.
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// p2: Point
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// The second point of the geodetic line. x and y fields are longitude and
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// latitude in decimal degrees.
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// increment: Float
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// The value at which a new point is computed.
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var wp = this.toPointArray(p1, p2, increment);
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var ls = new OpenLayers.Geometry.LineString(wp);
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return ls;
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},
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toGeometryFeature : function(p1, p2, increment){
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// summary:
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// Create a geodetic line as an array of dojox.geo.openlayers.GeometryFeature.
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// description:
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// Create a geodetic line as a dojox.geo.openlayers.GeometryFeature between the point p1
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// ant the point p2. Result is a polyline approximation for which a new point is
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// calculated every <em>increment</em> degrees.
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// p1: Point
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// The first point of the geodetic line. x and y fields are longitude and
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// latitude in decimal degrees.
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// p2: Point
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// The second point of the geodetic line. x and y fields are longitude and
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// latitude in decimal degrees.
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// increment: Float
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// The value at which a new point is computed.
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// returns: GeometryFeature
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// The geodetic line as a GeometryFeature
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var ls = this.toLineString(p1, p2, increment);
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return new GeometryFeature(ls);
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},
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DEG2RAD : Math.PI / 180,
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RAD2DEG : 180 / Math.PI,
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TOLERANCE : 0.00001
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};
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return dojox.geo.openlayers.GreatCircle;
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});
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