terraformer

<!doctype html> <html> <head> <meta charset="utf-8"> <meta content="IE=edge,chrome=1" http-equiv="X-UA-Compatible"> <title>Terraformer</title> <link href="/assets/css/terraformer-02847305.css" media="screen" rel="stylesheet" type="text/css" /> </head> <body class="core core_index" id="wrap"> <nav> <ul> <li> <a href="/" class="">Terraformer</a> </li> <li> <a href="https://github.com/search?q=%40Esri+terraformer" class="">GitHub</a> </li> <li> <a href="/install" class="">Install</a> </li> <li> <a href="/" data-direction="active-top" class="toggle" id="close-drawer">Docs</a> </li> </ul> </nav> <div class="drawer" id="drawer"> <div class="doctoc drawer-nav drawer-top"> <div class="container"> <ul> <h3>Terraformer Documentation</h3> <li><a href="/getting-started/">Getting Started</a></li> <li><a href="/core/">Terraformer Core</a></li> <li class="indent"><a href="/core/#terraformerprimitive">Primitives</a></li> <li class="indent"><a href="/core/#terraformertools">Tools</a></li> <li><a href="/geostore/">GeoStores</a></li> <li class="indent"><a href="/geostore/data-stores/">DataStores</a></li> <li class="indent"><a href="/geostore/spatial-indexes/">Spatial Indexes</a></li> <li><a href="/arcgis-parser/">ArcGIS Parser</a></li> <li><a href="/wkt-parser/">WKT Parser</a></li> <li><a href="/glossary/">Glossary</a></li> </ul> </div> </div> </div> <main class="docs main-content" id="main-content"> <h1>Terraformer Core</h1> <div class='semantic-toc'><ol><li><a href='#terraformerprimitive'>Terraformer.Primitive</a><ol><li><a href='#constructor'>Constructor</a></li><li><a href='#methods'>Methods</a></li></ol></li><li><a href='#terraformerpoint'>Terraformer.Point</a><ol><li><a href='#constructor-1'>Constructor</a></li></ol></li><li><a href='#terraformermultipoint'>Terraformer.MultiPoint</a><ol><li><a href='#constructor-2'>Constructor</a></li><li><a href='#methods-1'>Methods</a></li></ol></li><li><a href='#terraformerlinestring'>Terraformer.LineString</a><ol><li><a href='#constructor-3'>Constructor</a></li><li><a href='#methods-2'>Methods</a></li></ol></li><li><a href='#terraformermultilinestring'>Terraformer.MultiLineString</a><ol><li><a href='#constructor-4'>Constructor</a></li><li><a href='#methods-3'>Methods</a></li></ol></li><li><a href='#terraformerpolygon'>Terraformer.Polygon</a><ol><li><a href='#constructor-5'>Constructor</a></li><li><a href='#methods-4'>Methods</a></li></ol></li><li><a href='#terraformermultipolygon'>Terraformer.MultiPolygon</a><ol><li><a href='#constructor-6'>Constructor</a></li><li><a href='#methods-5'>Methods</a></li></ol></li><li><a href='#terraformerfeature'>Terraformer.Feature</a><ol><li><a href='#constructor-7'>Constructor</a></li></ol></li><li><a href='#terraformerfeaturecollection'>Terraformer.FeatureCollection</a><ol><li><a href='#constructor-8'>Constructor</a></li><li><a href='#methods-6'>Methods</a></li></ol></li><li><a href='#terraformergeometrycollection'>Terraformer.GeometryCollection</a><ol><li><a href='#constructor-9'>Constructor</a></li><li><a href='#methods-7'>Methods</a></li></ol></li><li><a href='#terraformercircle'>Terraformer.Circle</a><ol><li><a href='#constructor-10'>Constructor</a></li><li><a href='#methods-8'>Methods</a></li></ol></li><li><a href='#terraformertools'>Terraformer.Tools</a><ol><li><a href='#spatial-reference-conversions'>Spatial Reference Conversions</a></li><li><a href='#calculations'>Calculations</a></li><li><a href='#comparisons'>Comparisons</a></div> <h2> <a id='terraformerprimitive' class='section-link'></a> <a href='#terraformerprimitive' class='header-link'>Link</a> Terraformer.Primitive <a href='#' class='back-to-top-link'>Back to Top</a> </h2> Terraformer Primitives are JavaScript objects that map directly to their GeoJSON couterparts. Converting a GeoJSON object into a Terraformer Primitive will allow you use convenience methods like <code>point.within(polygon)</code>. Every <code>Primitive</code> inherits from the <code>Terraformer.Primitive</code> base class, thus all other Primitives share the <code>Terraformer.Primitive</code> methods. There is a Primitive for every type of GeoJSON object, plus a <code>Circle</code> Primitive which represents a circle as a polygon. <h3> <a id='constructor' class='section-link'></a> <a href='#constructor' class='header-link'>Link</a> Constructor <a href='#' class='back-to-top-link'>Back to Top</a> </h3> You create a new <code>Terraformer.Primitive</code> object by passing it a valid <a href="/glossary/#geojson">GeoJSON Object</a>. This will return a <code>Terraformer.Primitive</code> with the same type as your GeoJSON object. <pre class="highlight javascript"><code>var point = new Terraformer.Primitive({ type:"Point", coordinates:[1,2] }); point instanceof Terraformer.Point; //-> true point instanceof Terraformer.Primitive; //-> true point.within(polygon) //-> true or false </code></pre> <h3> <a id='methods' class='section-link'></a> <a href='#methods' class='header-link'>Link</a> Methods <a href='#' class='back-to-top-link'>Back to Top</a> </h3> <table><thead> <tr> <th>Method</th> <th>Returns</th> <th>Description</th> </tr> </thead><tbody> <tr> <td><code>toMercator()</code></td> <td><code>this</code></td> <td>Converts this GeoJSON object’s coordinates to the <a href="http://spatialreference.org/ref/sr-org/6928/">web mercator spatial reference</a>.</td> </tr> <tr> <td><code>toGeographic()</code></td> <td><code>this</code></td> <td>Converts this GeoJSON object’s coordinates to <a href="http://spatialreference.org/ref/epsg/4326/">geographic coordinates</a>.</td> </tr> <tr> <td><code>envelope()</code></td> <td><a href="/glossary/#envelope"><code>Envelope</code></a></td> <td>Returns an object with <code>x</code>, <code>y</code>, <code>w</code> and <code>h</code> suitable for passing to most indexes.</td> </tr> <tr> <td><code>bbox()</code></td> <td><a href="/glossary/#bbox"><code>BBox</code></a></td> <td>Returns the <a href="/glossary/#bbox">GeoJSON Bounding Box</a> for this primitive.</td> </tr> <tr> <td><code>convexHull()</code></td> <td><a href="#polygon"><code>Polygon</code></a> or <code>null</code></td> <td>Returns the convex hull of this primitive as a <a href="#polygon"><code>Polygon</code></a>. Will return <code>null</code> if the convex hull cannot be calculated or a valid Polygon cannot be created.</td> </tr> <tr> <td><code>contains(<a href="/glossary/#geometry"><Geometry></a> geometry)</code></td> <td><code>Boolean</code></td> <td>Returns <code>true</code> if the passed <a href="/glossary/#geometry"><code>GeoJSON Geometry</code></a> object is completely contained inside this primitive.</td> </tr> <tr> <td><code>within(<a href="/glossary/#geometry"><Geometry></a> geometry)</code></td> <td><code>Boolean</code></td> <td>Returns <code>true</code> if the passed <a href="/glossary/#geometry"><code>GeoJSON Geometry</code></a> object is completely within this primitive.</td> </tr> <tr> <td><code>intersects(<a href="/glossary/#geometry"><Geometry></a> geometry)</code></td> <td><code>Boolean</code></td> <td>Returns <code>true</code> if the passed <a href="/glossary/#geometry"><code>GeoJSON Geometry</code></a> intersects this primitive.</td> </tr> </tbody></table> <h2> <a id='terraformerpoint' class='section-link'></a> <a href='#terraformerpoint' class='header-link'>Link</a> Terraformer.Point <a href='#' class='back-to-top-link'>Back to Top</a> </h2> A JavaScript object representing a <a href="/glossary/#point">GeoJSON Point</a>. <h3> <a id='constructor-1' class='section-link'></a> <a href='#constructor-1' class='header-link'>Link</a> Constructor <a href='#' class='back-to-top-link'>Back to Top</a> </h3> <code>Terraformer.Point</code> can be created by passing a <a href="/glossary/#coordinate">GeoJSON Coordinate Pair</a> like <code>[longitude, latitude]</code>, with plain <code>x,y</code>, or a valid <a href="/glossary/#point">GeoJSON Point</a>. <pre class="highlight javascript"><code>var point1 = new Terraformer.Point({ type:"Point", coordinates:[1,2] }); var point2 = new Terraformer.Point(1,2); var point3 = new Terraformer.Point([1,2]); </code></pre> <h2> <a id='terraformermultipoint' class='section-link'></a> <a href='#terraformermultipoint' class='header-link'>Link</a> Terraformer.MultiPoint <a href='#' class='back-to-top-link'>Back to Top</a> </h2> A JavaScript object representing a <a href="/glossary/#multipoint">GeoJSON MultiPoint</a>. <h3> <a id='constructor-2' class='section-link'></a> <a href='#constructor-2' class='header-link'>Link</a> Constructor <a href='#' class='back-to-top-link'>Back to Top</a> </h3> <code>Terraformer.MultiPoint</code> can be created by passing in a valid <a href="/glossary/#multipoint">GeoJSON MultiPoint</a>, or an array of <a href="/glossary/#coordinates">GeoJSON Coordinates</a>. <pre class="highlight javascript"><code>var multipoint1 = new Terraformer.MultiPoint({ type:"MultiPoint", coordinates:[ [1,2],[2,1] ] }); var multipoint2 = new Terraformer.MultiPoint([ [1,2],[2,1] ]); </code></pre> <h3> <a id='methods-1' class='section-link'></a> <a href='#methods-1' class='header-link'>Link</a> Methods <a href='#' class='back-to-top-link'>Back to Top</a> </h3> <table><thead> <tr> <th>Method</th> <th>Returns</th> <th>Description</th> </tr> </thead><tbody> <tr> <td><code>forEach(<Function> function)</code></td> <td><code>null</code></td> <td>Iterates over each point. Equivalent to <code>multipoint.coordinates.forEach(function)</code>. The function will be called with <code>point</code>, <code>index</code> and <code>coordinates</code>.</td> </tr> <tr> <td><code>get(<Integer> index)</code></td> <td><a href="/glossary/#point-primitive"><code>Point</code></a></td> <td>Returns a <a href="/glossary/#point-primitive"><code>Terraformer.Point</code></a> for the point at <code>index</code> in the coordinate array.</td> </tr> <tr> <td><code>addPoint(<a href="/glossary/#coordinate"><Coordinate></a> coordinate)</code></td> <td><code>this</code></td> <td>Adds a new coordinate to the end of the coordinate array. Equivalent to <code>multipoint.coordinates.push([3,4])</code>.</td> </tr> <tr> <td><code>insertPoint(<a href="/glossary/#coordinate"><Coordinate></a> coordinate, <Integer> index)</code></td> <td><code>this</code></td> <td>Inserts the passed point at the passed index. Equivalent to <code>multipoint.coordinates.splice(index, 0, point)</code></td> </tr> <tr> <td><code>removePoint(<Integer> index or <a href="/glossary/#coordinate"><Coordinate></a> coordinate)</code></td> <td><code>this</code></td> <td>Removes the point at <code>index</code> or the passed Coordinate depending on the type of object passed in.</td> </tr> </tbody></table> <h2> <a id='terraformerlinestring' class='section-link'></a> <a href='#terraformerlinestring' class='header-link'>Link</a> Terraformer.LineString <a href='#' class='back-to-top-link'>Back to Top</a> </h2> A JavaScript object representing a <a href="/glossary/#linestring">GeoJSON LineString</a>. <h3> <a id='constructor-3' class='section-link'></a> <a href='#constructor-3' class='header-link'>Link</a> Constructor <a href='#' class='back-to-top-link'>Back to Top</a> </h3> <code>Terraformer.LineString</code> can be created by passing in a valid <a href="/glossary/#linestring">GeoJSON LineString</a>, or an array of <a href="/glossary/#coordinates">GeoJSON Coordinates</a> like <code>[longitude, latitude]</code>. <pre class="highlight javascript"><code>var linestring = new Terraformer.LineString({ type:"LineString", coordinates:[ [1,2],[2,1] ] }); var linestring = new Terraformer.LineString([ [1,2],[2,1] ]); </code></pre> <h3> <a id='methods-2' class='section-link'></a> <a href='#methods-2' class='header-link'>Link</a> Methods <a href='#' class='back-to-top-link'>Back to Top</a> </h3> <table><thead> <tr> <th>Method</th> <th>Returns</th> <th>Description</th> </tr> </thead><tbody> <tr> <td><code>addVertex(<a href="/glossary/#coordinate"><Coordinate></a> coordinate)</code></td> <td><code>this</code></td> <td>Adds a new coordinate to the end of the coordinate array. Equivalent to <code>linestring.coordinates.push([3,4])</code>.</td> </tr> <tr> <td><code>insertVertex(<a href="/glossary/#coordinate"><Coordinate></a> coordinate, <Integer> index)</code></td> <td><code>this</code></td> <td>Inserts the passed coordinate at the passed index. Equivalent to <code>linestring.coordinates.splice(index, 0, point)</code></td> </tr> <tr> <td><code>removeVertex(<Integer> index)</code></td> <td><code>this</code></td> <td>Removes the coordinate at <code>index</code>. Equivalent to calling <code>linestring.coordinates.splice(remove, 1)</code></td> </tr> </tbody></table> <h2> <a id='terraformermultilinestring' class='section-link'></a> <a href='#terraformermultilinestring' class='header-link'>Link</a> Terraformer.MultiLineString <a href='#' class='back-to-top-link'>Back to Top</a> </h2> A JavaScript object representing a <a href="/glossary/#multilinestring">GeoJSON MultiLineString</a>. <h3> <a id='constructor-4' class='section-link'></a> <a href='#constructor-4' class='header-link'>Link</a> Constructor <a href='#' class='back-to-top-link'>Back to Top</a> </h3> <code>Terraformer.LineString</code> can be created by passing in a valid <a href="/glossary/#multilinestring">GeoJSON MultiLineString</a>, or a <a href="/glossary/#multilinestring">GeoJSON MultiLineString</a> coordinate array. <pre class="highlight javascript"><code>var multilinestring = new Terraformer.MultiLineString({ type:"LineString", coordinates:[ [1,2],[2,1] ] }); var multilinestring = new Terraformer.MultiLineString([ [[1,1],[2,2],[3,4]], [[0,1],[0,2],[0,3]] ]); </code></pre> <h3> <a id='methods-3' class='section-link'></a> <a href='#methods-3' class='header-link'>Link</a> Methods <a href='#' class='back-to-top-link'>Back to Top</a> </h3> <table><thead> <tr> <th>Method</th> <th>Returns</th> <th>Description</th> </tr> </thead><tbody> <tr> <td><code>forEach(<Function> function)</code></td> <td><code>null</code></td> <td>Iterates over each LineString. Equivalent to <code>multilinestring.coordinates.forEach(function)</code>. The function will be called with <code>linestring</code>, <code>index</code> and <code>coordinates</code>.</td> </tr> <tr> <td><code>get(<Integer> index)</code></td> <td><a href="#linestring"><code>LineString</code></a></td> <td>Returns a <a href="#linestring"><code>Terraformer.LineString</code></a> for the LineString at <code>index</code> in the coordinates array.</td> </tr> </tbody></table> <h2> <a id='terraformerpolygon' class='section-link'></a> <a href='#terraformerpolygon' class='header-link'>Link</a> Terraformer.Polygon <a href='#' class='back-to-top-link'>Back to Top</a> </h2> A JavaScript object representing a <a href="/glossary/#polygon">GeoJSON Polygon</a>. <h3> <a id='constructor-5' class='section-link'></a> <a href='#constructor-5' class='header-link'>Link</a> Constructor <a href='#' class='back-to-top-link'>Back to Top</a> </h3> <code>Terraformer.Polygon</code> can be created by passing in a valid <a href="/glossary/#polygon">GeoJSON Polygon</a>, or <a href="/glossary/#polygon">GeoJSON Polygon</a> coordinate array. <pre class="highlight javascript"><code>var polygon1 = new Terraformer.Polygon({ "type": "Polygon", "coordinates": [ [ [100.0, 0.0], [101.0, 0.0], [101.0, 1.0], [100.0, 1.0], [100.0, 0.0] ], [ [100.2, 0.2], [100.8, 0.2], [100.8, 0.8], [100.2, 0.8], [100.2, 0.2] ] ] }); var polygon2 = new Terraformer.Polygon([ [ [100.0, 0.0], [101.0, 0.0], [101.0, 1.0], [100.0, 1.0], [100.0, 0.0] ], [ [100.2, 0.2], [100.8, 0.2], [100.8, 0.8], [100.2, 0.8], [100.2, 0.2] ] ]); </code></pre> <h3> <a id='methods-4' class='section-link'></a> <a href='#methods-4' class='header-link'>Link</a> Methods <a href='#' class='back-to-top-link'>Back to Top</a> </h3> <table><thead> <tr> <th>Method</th> <th>Returns</th> <th>Description</th> </tr> </thead><tbody> <tr> <td><code>addVertex(<a href="/glossary/#coordinate"><Coordinate></a> coordinate)</code></td> <td><code>this</code></td> <td>Adds a new coordinate just before the closing coordinate of the linear ring.</td> </tr> <tr> <td><code>insertVertex(<a href="/glossary/#coordinate"><Coordinate></a> coordinate, <Integer> index)</code></td> <td><code>this</code></td> <td>Inserts the passed coordinate at the passed index. Equivalent to <code>polygon.coordinates.splice(index, 0, point)</code></td> </tr> <tr> <td><code>removeVertex(<Integer> index)</code></td> <td><code>this</code></td> <td>Removes the coordinate at <code>index</code>. Equivalent to calling <code>polygon.coordinates.splice(remove, 1)</code></td> </tr> <tr> <td><code>close()</code></td> <td><code>this</code></td> <td>Ensures that the first and last vertex of the polygon are equal to each other.</td> </tr> <tr> <td><code>hasHoles()</code></td> <td>Boolean</td> <td>True if this polygon has holes.</td> </tr> <tr> <td><code>holes()</code></td> <td>Array <code><Polygon></code></td> <td>Returns an <code>Array</code> of <code>Polygon</code> objects made from each hole in this polygon.</td> </tr> </tbody></table> <h2> <a id='terraformermultipolygon' class='section-link'></a> <a href='#terraformermultipolygon' class='header-link'>Link</a> Terraformer.MultiPolygon <a href='#' class='back-to-top-link'>Back to Top</a> </h2> A JavaScript object representing a <a href="/glossary/#multipolygon">GeoJSON MultiPolygon</a>. <h3> <a id='constructor-6' class='section-link'></a> <a href='#constructor-6' class='header-link'>Link</a> Constructor <a href='#' class='back-to-top-link'>Back to Top</a> </h3> <code>Terraformer.MultiPolygon</code> can be created by passing in a valid <a href="/glossary/#multipolygon">GeoJSON MultiPolygon</a>, or an array that is a valid coordinate array for <a href="/glossary/#multipolygon">GeoJSON MultiPolygon</a>. <pre class="highlight javascript"><code>var multipolygon1 = new Terraformer.MultiPolygon({ "type": "MultiPolygon", "coordinates": [ [ [ [100.0, 0.0], [101.0, 0.0], [101.0, 1.0], [100.0, 1.0], [100.0, 0.0] ] ], [ [ [100.2, 0.2], [100.8, 0.2], [100.8, 0.8], [100.2, 0.8], [100.2, 0.2] ] ] ] }); var multipolygon2 = new Terraformer.MultiPolygon([ [ [ [100.0, 0.0], [101.0, 0.0], [101.0, 1.0], [100.0, 1.0], [100.0, 0.0] ] ], [ [ [100.2, 0.2], [100.8, 0.2], [100.8, 0.8], [100.2, 0.8], [100.2, 0.2] ] ] ]); </code></pre> <h3> <a id='methods-5' class='section-link'></a> <a href='#methods-5' class='header-link'>Link</a> Methods <a href='#' class='back-to-top-link'>Back to Top</a> </h3> <table><thead> <tr> <th>Method</th> <th>Returns</th> <th>Description</th> </tr> </thead><tbody> <tr> <td><code>forEach(<Function> function)</code></td> <td><code>null</code></td> <td>Iterates over each LineString. Equivalent to <code>multipolygon.coordinates.forEach(function)</code>. The function will be called with <code>polygon</code>, <code>index</code> and <code>coordinates</code>.</td> </tr> <tr> <td><code>get(<Integer> index)</code></td> <td><a href="/glossary/#polygon-primitive"><code>Polygon</code></a></td> <td>Returns a <a href="/glossary/#polygon-primitive"><code>Terraformer.Polygon</code></a> for the Polygon at <code>index</code> in the coordinate array.</td> </tr> </tbody></table> <h2> <a id='terraformerfeature' class='section-link'></a> <a href='#terraformerfeature' class='header-link'>Link</a> Terraformer.Feature <a href='#' class='back-to-top-link'>Back to Top</a> </h2> A JavaScript object representing a <a href="/glossary/#feature">GeoJSON Feature</a>. <h3> <a id='constructor-7' class='section-link'></a> <a href='#constructor-7' class='header-link'>Link</a> Constructor <a href='#' class='back-to-top-link'>Back to Top</a> </h3> <code>Terraformer.Feature</code> can be created by passing in a valid <a href="/glossary/#feature">GeoJSON Feature</a> or <a href="/glossary/#geometry">GeoJSON Geometry</a>. <pre class="highlight javascript"><code>var feature1 = new Terraformer.Feature({ "type": "Feature", "geometry": { "type": "Polygon", "coordinates": [ [ [100.0, 0.0], [101.0, 0.0], [101.0, 1.0], [100.0, 1.0], [100.0, 0.0] ], [ [100.2, 0.2], [100.8, 0.2], [100.8, 0.8], [100.2, 0.8], [100.2, 0.2] ] ] } }); var feature2 = new Terraformer.Feature({ "type": "Polygon", "coordinates": [ [ [100.0, 0.0], [101.0, 0.0], [101.0, 1.0], [100.0, 1.0], [100.0, 0.0] ], [ [100.2, 0.2], [100.8, 0.2], [100.8, 0.8], [100.2, 0.8], [100.2, 0.2] ] ] }); </code></pre> <h2> <a id='terraformerfeaturecollection' class='section-link'></a> <a href='#terraformerfeaturecollection' class='header-link'>Link</a> Terraformer.FeatureCollection <a href='#' class='back-to-top-link'>Back to Top</a> </h2> A JavaScript object representing a <a href="/glossary/#featurecollection">GeoJSON FeatureCollection</a>. <h3> <a id='constructor-8' class='section-link'></a> <a href='#constructor-8' class='header-link'>Link</a> Constructor <a href='#' class='back-to-top-link'>Back to Top</a> </h3> <code>Terraformer.FeatureCollection</code> can be created by passing a valid <a href="/glossary/#featurecollection">GeoJSON Feature Collection</a> or an array of <a href="/glossary/#feature">GeoJSON Features</a>. <pre class="highlight javascript"><code>var featurecollection1 = new Terraformer.FeatureCollection( "type": "FeatureCollection", "features": [feature1, feature2] }); var featurecollection2 = new Terraformer.FeatureCollection([feature1, feature2]); </code></pre> <h3> <a id='methods-6' class='section-link'></a> <a href='#methods-6' class='header-link'>Link</a> Methods <a href='#' class='back-to-top-link'>Back to Top</a> </h3> <table><thead> <tr> <th>Method</th> <th>Returns</th> <th>Description</th> </tr> </thead><tbody> <tr> <td><code>forEach(<Function> function)</code></td> <td><code>null</code></td> <td>Iterates over each Feature. Equivalent to <code>featurecollection.features.forEach(function)</code>. The function will be called with <code>feature</code>, <code>index</code> and <code>coordinates</code>.</td> </tr> <tr> <td><code>get(<Integer> index)</code></td> <td><a href="/glossary/#feature"><code>Feature</code></a></td> <td>Returns a <a href="/glossary/#feature"><code>Terraformer.Feature</code></a> for the Feature at <code>index</code> in the features array.</td> </tr> </tbody></table> <h2> <a id='terraformergeometrycollection' class='section-link'></a> <a href='#terraformergeometrycollection' class='header-link'>Link</a> Terraformer.GeometryCollection <a href='#' class='back-to-top-link'>Back to Top</a> </h2> A JavaScript object representing a <a href="/glossary/#geometrycollection">GeoJSON Geometry Collection</a>. <h3> <a id='constructor-9' class='section-link'></a> <a href='#constructor-9' class='header-link'>Link</a> Constructor <a href='#' class='back-to-top-link'>Back to Top</a> </h3> <code>Terraformer.GeometryCollection</code> can be created by passing a valid <a href="/glossary/#geometrycollection">GeoJSON Geometry Collection</a> or an array of <a href="/glossary/#geometry">GeoJSON Geometries</a>. <pre class="highlight javascript"><code>var geometrycollection1 = new Terraformer.GeometryCollection( "type": "FeatureCollection", "features": [geometry1, geometry2] }); var geometrycollection2 = new Terraformer.GeometryCollection([geometry1, geometry2]); </code></pre> <h3> <a id='methods-7' class='section-link'></a> <a href='#methods-7' class='header-link'>Link</a> Methods <a href='#' class='back-to-top-link'>Back to Top</a> </h3> <table><thead> <tr> <th>Method</th> <th>Returns</th> <th>Description</th> </tr> </thead><tbody> <tr> <td><code>forEach(<Function> function)</code></td> <td><code>null</code></td> <td>Iterates over each LineString. Equivalent to <code>geometrycollection.coordinates.forEach(function)</code>. The function will be called with <code>geometry</code>, <code>index</code> and <code>coordinates</code>.</td> </tr> <tr> <td><code>get(<Integer> index)</code></td> <td><a href="/glossary/#feature-primitive"><code>Primitive</code></a></td> <td>Returns a <a href="/glossary/#feature-primitive"><code>Terraformer.Primitive</code></a> for the Geometry at <code>index</code> in the coordinate array.</td> </tr> </tbody></table> <h2> <a id='terraformercircle' class='section-link'></a> <a href='#terraformercircle' class='header-link'>Link</a> Terraformer.Circle <a href='#' class='back-to-top-link'>Back to Top</a> </h2> The GeoJSON spec does not provide a way to visualize circles. <code>Terraformer.Circle</code> is actual a <a href="">GeoJSON Feature</a> object that contains a Polygon representing a circle with a certain number of sides. <h3> <a id='constructor-10' class='section-link'></a> <a href='#constructor-10' class='header-link'>Link</a> Constructor <a href='#' class='back-to-top-link'>Back to Top</a> </h3> <code>Terraformer.Circle</code> is created with a <code>center</code>, <code>radius</code>, and <code>steps</code>. <table><thead> <tr> <th>Option</th> <th>Type</th> <th>Default</th> <th>Description</th> </tr> </thead><tbody> <tr> <td><code>center</code></td> <td><a href="/glossary/#coordinate"><code>Coordinate</code></a></td> <td><code>null</code></td> <td>Required A <a href="/glossary/#coordinate">GeoJSON Coordinate</a> in <code>[x,y]</code> format.</td> </tr> <tr> <td><code>radius</code></td> <td><code>Integer</code></td> <td><code>250</code></td> <td>The radius of the circle in meters.</td> </tr> <tr> <td><code>steps</code></td> <td><code>Integer</code></td> <td><code>32</code></td> <td>How many steps will be used to create the polygon that represents the circle.</td> </tr> </tbody></table> <pre class="highlight javascript"><code>circle = new Terraformer.Circle([45.65, -122.27], 500, 64); circle.contains(point); </code></pre> <h3> <a id='methods-8' class='section-link'></a> <a href='#methods-8' class='header-link'>Link</a> Methods <a href='#' class='back-to-top-link'>Back to Top</a> </h3> <table><thead> <tr> <th>Method</th> <th>Returns</th> <th>Description</th> </tr> </thead><tbody> <tr> <td><code>recalculate()</code></td> <td>this</td> <td>Recalculates the circle</td> </tr> <tr> <td><code>steps(<Integer optional> steps)</code></td> <td><code>Integer</code></td> <td>Returns the number of steps to produce the polygon representing the circle. If the <code>steps</code> parameter is passed the circle will be recalculated witht he new step count before returning.</td> </tr> <tr> <td><code>radius(<Integer optional> radius)</code></td> <td><code>Integer</code></td> <td>Returns the radius circle. If the <code>radius</code> parameter is passed the circle will be recalculated witht he new radius before returning.</td> </tr> <tr> <td><code>center(<a href="/glossary/#coordinate"><Coordinate optional></a> center)</code></td> <td><a href=""><code>Coordinates</code></a></td> <td>Returns the center of the circle. If the <code>center</code> parameter is passed the circle will be recalculated with the new center before returning.</td> </tr> </tbody></table> <h2> <a id='terraformertools' class='section-link'></a> <a href='#terraformertools' class='header-link'>Link</a> Terraformer.Tools <a href='#' class='back-to-top-link'>Back to Top</a> </h2> Terraformer also has numerous helper methods for working with GeoJSON and geographic data. These tools work with a mix of lower level GeoJSON constructs like <a href="/glossary/#coordinate"><code>Coordinates</code></a>, <a href="/glossary/#coordinates">Coordinate Arrays</a> and <a href="/glossary/#geojson">GeoJSON</a> objects and <a href="/glossary/#primitive">Terraformer Primitives</a> <h3> <a id='spatial-reference-conversions' class='section-link'></a> <a href='#spatial-reference-conversions' class='header-link'>Link</a> Spatial Reference Conversions <a href='#' class='back-to-top-link'>Back to Top</a> </h3> <table><thead> <tr> <th>Method</th> <th>Returns</th> <th>Description</th> </tr> </thead><tbody> <tr> <td><code>toMercator(<a href="/glossary/#geojson"><GeoJSON></a> geojson)</code></td> <td><a href="/glossary/#geojson"><code>GeoJSON</code></a></td> <td>Converts this GeoJSON object’s coordinates to the <a href="http://spatialreference.org/ref/sr-org/6928/">web mercator spatial reference</a>. This is an in-place modification of the passed object.</td> </tr> <tr> <td><code>toGeographic(<a href="/glossary/#geojson"><GeoJSON></a> geojson)</code></td> <td><a href="/glossary/#geojson"><code>GeoJSON</code></a></td> <td>Converts this GeoJSON object’s coordinates to <a href="http://spatialreference.org/ref/epsg/4326/">geographic coordinates</a>. This is an in-place modification of the passed object.</td> </tr> <tr> <td><code>applyConverter(<a href="/glossary/#geojson"><GeoJSON></a> geojson), function)</td> <td><a href="/glossary/#geojson"><code>GeoJSON</code></a></td> <td>Runs the passed <code>function</code>against every <a href=""><code>Coordinate</code></a> in the <code>geojson</code> object. Your <code>function</code> will be passed a <a href="/glossary/#coordinate"><code>Coordinate</code></a> and will be expected to return a <a href=""><code>Coordinate</code></a>.</td> </tr> <tr> <td><code>positionToMercator(<a href="/glossary/#coordinate"><Coordinate></a> coordinate)</td> <td><a href="/glossary/#coordinate"><code>Coordinate</code></a></td> <td>Converts the passed <a href="/glossary/#coordinate"><code>Coordinate</code></a> to <a href="http://spatialreference.org/ref/sr-org/6928/">web mercator spatial reference</a>.</td> </tr> <tr> <td><code>positionToGeographic(<a href="/glossary/#coordinate"><Coordinate></a> coordinate)</td> <td><a href="/glossary/#coordinate"><code>Coordinate</code></a></td> <td>Converts the passed <a href="/glossary/#coordinate"><code>Coordinate</code></a> to <a href="http://spatialreference.org/ref/epsg/4326/">geographic coordinates</a>.</td> </tr> </tbody></table> <h3> <a id='calculations' class='section-link'></a> <a href='#calculations' class='header-link'>Link</a> Calculations <a href='#' class='back-to-top-link'>Back to Top</a> </h3> <table><thead> <tr> <th>Method</th> <th>Returns</th> <th>Description</th> </tr> </thead><tbody> <tr> <td><code>calculateBounds(<a href="/glossary/#geojson"><GeoJSON></a> geojson)</code></td> <td><a href="/glossary#bbox"><code>BBox</c