Roads API 最多可接受沿路线收集的 100 个 GPS 点,并返回类似的数据集,其中包含已贴合到车辆行驶的最可能道路上的点。您可以选择请求对点进行插值,从而生成一条平滑贴合道路几何形状的路径。
请求
您必须使用 HTTPS 以以下形式发送贴合到道路的请求:
https://roads.googleapis.com/v1/snapToRoads?parameters&key=YOUR_API_KEY
Required parameters
path
The path to be snapped. The path parameter accepts a list of latitude/longitude pairs. Latitude and longitude values should be separated by commas. Coordinates should be separated by the pipe character: "|". For example:
path=60.170880,24.942795|60.170879,24.942796|60.170877,24.942796
.Note: The snapping algorithm works best for points that are not too far apart. If you observe odd snapping behavior, try creating paths that have points closer together. To ensure the best snap-to-road quality, you should aim to provide paths on which consecutive pairs of points are within 300m of each other. This will also help in handling any isolated, long jumps between consecutive points caused by GPS signal loss, or noise.
Optional parameters
interpolate
Whether to interpolate a path to include all points forming the full road-geometry. When true, additional interpolated points will also be returned, resulting in a path that smoothly follows the geometry of the road, even around corners and through tunnels. Interpolated paths will most likely contain more points than the original path. Defaults to
false
.
示例
以下请求会将指定点贴合到道路几何图形。这组特定数据位于环形道路上;设置 interpolate=true
可使返回的几何图形与道路的曲率相匹配。使用 interpolate=false
时,贴合的路径仍会沿道路行进,但生成的折线不够平滑。
网址
https://roads.googleapis.com/v1/snapToRoads ?interpolate=true &path=-35.27801%2C149.12958%7C-35.28032%2C149.12907%7C-35.28099%2C149.12929%7C-35.28144%2C149.12984%7C-35.28194%2C149.13003%7C-35.28282%2C149.12956%7C-35.28302%2C149.12881%7C-35.28473%2C149.12836 &key=YOUR_API_KEY
cURL
curl -L -X GET 'https://roads.googleapis.com/v1/snapToRoads?path=-35.27801%2C149.12958%7C-35.28032%2C149.12907%7C-35.28099%2C149.12929%7C-35.28144%2C149.12984%7C-35.28194%2C149.13003%7C-35.28282%2C149.12956%7C-35.28302%2C149.12881%7C-35.28473%2C149.12836&interpolate=true&key=YOUR_API_KEY'
响应
对于每个有效请求,Roads API 都会以请求网址中指示的格式返回响应,例如以下 JSON 响应。
{ "snappedPoints": [ { "location": { "latitude": -35.27800489993019, "longitude": 149.129531998742 }, "originalIndex": 0, "placeId": "ChIJr_xl0GdNFmsRsUtUbW7qABM", }, { "location": { "latitude": -35.2784195, "longitude": 149.12946589999999 }, "placeId": "ChIJr_xl0GdNFmsRsUtUbW7qABM", }, { "location": { "latitude": -35.2784195, "longitude": 149.12946589999999 }, "placeId": "ChIJ6aXGemhNFmsRZE_zHqhmrG4", }, { "location": { "latitude": -35.2792731, "longitude": 149.12933809999998 }, "placeId": "ChIJ6aXGemhNFmsRZE_zHqhmrG4", }, { "location": { "latitude": -35.2792731, "longitude": 149.12933809999998 }, "placeId": "ChIJTcTdZ2hNFmsRXokM4mWCWfk", }, { "location": { "latitude": -35.279557, "longitude": 149.1292973 }, "placeId": "ChIJTcTdZ2hNFmsRXokM4mWCWfk", }, { "location": { "latitude": -35.279557, "longitude": 149.1292973 }, "placeId": "ChIJiUfNQmhNFmsRSsAI-1m6y1g", }, { "location": { "latitude": -35.279610999999996, "longitude": 149.1292889 }, "placeId": "ChIJiUfNQmhNFmsRSsAI-1m6y1g", }, { "location": { "latitude": -35.2796484, "longitude": 149.1292791 }, "placeId": "ChIJiUfNQmhNFmsRSsAI-1m6y1g", }, { "location": { "latitude": -35.2796484, "longitude": 149.1292791 }, "placeId": "ChIJ_RyFQ2hNFmsRoHJAbW7qABM", }, { "location": { "latitude": -35.279947299999996, "longitude": 149.1291894 }, "placeId": "ChIJ_RyFQ2hNFmsRoHJAbW7qABM", }, { "location": { "latitude": -35.279947299999996, "longitude": 149.1291894 }, "placeId": "ChIJOyypT2hNFmsRZBtscGL0htw", }, { "location": { "latitude": -35.280323564795005, "longitude": 149.1290903128365 }, "originalIndex": 1, "placeId": "ChIJOyypT2hNFmsRZBtscGL0htw", }, { "location": { "latitude": -35.2803426, "longitude": 149.12908529999999 }, "placeId": "ChIJOyypT2hNFmsRZBtscGL0htw", }, { "location": { "latitude": -35.2803426, "longitude": 149.12908529999999 }, "placeId": "ChIJr8xRTGhNFmsRzMb-rxgjspc", }, { "location": { "latitude": -35.280409899999995, "longitude": 149.1290699 }, "placeId": "ChIJr8xRTGhNFmsRzMb-rxgjspc", }, { "location": { "latitude": -35.28048179999999, "longitude": 149.129062 }, "placeId": "ChIJr8xRTGhNFmsRzMb-rxgjspc", }, { "location": { "latitude": -35.2805541, "longitude": 149.1290623 }, "placeId": "ChIJr8xRTGhNFmsRzMb-rxgjspc", }, { "location": { "latitude": -35.280626, "longitude": 149.1290712 }, "placeId": "ChIJr8xRTGhNFmsRzMb-rxgjspc", }, { "location": { "latitude": -35.280626, "longitude": 149.1290712 }, "placeId": "ChIJv5r0smlNFmsR5nunau79Fv4", }, { "location": { "latitude": -35.280695099999996, "longitude": 149.12908489999998 }, "placeId": "ChIJv5r0smlNFmsR5nunau79Fv4", }, { "location": { "latitude": -35.2807629, "longitude": 149.1291046 }, "placeId": "ChIJv5r0smlNFmsR5nunau79Fv4", }, { "location": { "latitude": -35.2808294, "longitude": 149.1291306 }, "placeId": "ChIJv5r0smlNFmsR5nunau79Fv4", }, { "location": { "latitude": -35.2809064, "longitude": 149.1291693 }, "placeId": "ChIJv5r0smlNFmsR5nunau79Fv4", }, { "location": { "latitude": -35.280968200000004, "longitude": 149.129208 }, "placeId": "ChIJv5r0smlNFmsR5nunau79Fv4", }, { "location": { "latitude": -35.28101395754623, "longitude": 149.1292430025548 }, "originalIndex": 2, "placeId": "ChIJv5r0smlNFmsR5nunau79Fv4", }, { "location": { "latitude": -35.28103840000001, "longitude": 149.1292617 }, "placeId": "ChIJv5r0smlNFmsR5nunau79Fv4", }, { "location": { "latitude": -35.2810936, "longitude": 149.1293121 }, "placeId": "ChIJv5r0smlNFmsR5nunau79Fv4", }, { "location": { "latitude": -35.2810979, "longitude": 149.1293176 }, "placeId": "ChIJv5r0smlNFmsR5nunau79Fv4", }, { "location": { "latitude": -35.2810979, "longitude": 149.1293176 }, "placeId": "ChIJpYMSrmlNFmsRXkCoIkZxgBg", }, { "location": { "latitude": -35.281152399999996, "longitude": 149.1294256 }, "placeId": "ChIJpYMSrmlNFmsRXkCoIkZxgBg", }, { "location": { "latitude": -35.281152399999996, "longitude": 149.1294256 }, "placeId": "ChIJ601MoWlNFmsR5mvkfPp2ovA", }, { "location": { "latitude": -35.2811784, "longitude": 149.1294706 }, "placeId": "ChIJ601MoWlNFmsR5mvkfPp2ovA", }, { "location": { "latitude": -35.2812258, "longitude": 149.1295413 }, "placeId": "ChIJ601MoWlNFmsR5mvkfPp2ovA", }, { "location": { "latitude": -35.2812771, "longitude": 149.12960759999999 }, "placeId": "ChIJ601MoWlNFmsR5mvkfPp2ovA", }, { "location": { "latitude": -35.281332, "longitude": 149.1296695 }, "placeId": "ChIJ601MoWlNFmsR5mvkfPp2ovA", }, { "location": { "latitude": -35.2813904, "longitude": 149.12972670000002 }, "placeId": "ChIJ601MoWlNFmsR5mvkfPp2ovA", }, { "location": { "latitude": -35.281451700000005, "longitude": 149.1297788 }, "placeId": "ChIJ601MoWlNFmsR5mvkfPp2ovA", }, { "location": { "latitude": -35.28146506991143, "longitude": 149.12978858234607 }, "originalIndex": 3, "placeId": "ChIJ601MoWlNFmsR5mvkfPp2ovA", }, { "location": { "latitude": -35.28151580000001, "longitude": 149.1298257 }, "placeId": "ChIJ601MoWlNFmsR5mvkfPp2ovA", }, { "location": { "latitude": -35.28158259999999, "longitude": 149.129867 }, "placeId": "ChIJ601MoWlNFmsR5mvkfPp2ovA", }, { "location": { "latitude": -35.281666099999995, "longitude": 149.1299091 }, "placeId": "ChIJ601MoWlNFmsR5mvkfPp2ovA", }, { "location": { "latitude": -35.2817377, "longitude": 149.1299379 }, "placeId": "ChIJ601MoWlNFmsR5mvkfPp2ovA", }, { "location": { "latitude": -35.281810899999996, "longitude": 149.1299602 }, "placeId": "ChIJ601MoWlNFmsR5mvkfPp2ovA", }, { "location": { "latitude": -35.281884999999996, "longitude": 149.1299765 }, "placeId": "ChIJ601MoWlNFmsR5mvkfPp2ovA", }, { "location": { "latitude": -35.28194399606459, "longitude": 149.1299842294294 }, "originalIndex": 4, "placeId": "ChIJ601MoWlNFmsR5mvkfPp2ovA", }, { "location": { "latitude": -35.281959799999996, "longitude": 149.12998629999998 }, "placeId": "ChIJ601MoWlNFmsR5mvkfPp2ovA", }, { "location": { "latitude": -35.282035199999996, "longitude": 149.1299895 }, "placeId": "ChIJ601MoWlNFmsR5mvkfPp2ovA", }, { "location": { "latitude": -35.2821254, "longitude": 149.1299851 }, "placeId": "ChIJ601MoWlNFmsR5mvkfPp2ovA", }, { "location": { "latitude": -35.282199999999996, "longitude": 149.1299743 }, "placeId": "ChIJ601MoWlNFmsR5mvkfPp2ovA", }, { "location": { "latitude": -35.2822739, "longitude": 149.1299573 }, "placeId": "ChIJ601MoWlNFmsR5mvkfPp2ovA", }, { "location": { "latitude": -35.2823468, "longitude": 149.129934 }, "placeId": "ChIJ601MoWlNFmsR5mvkfPp2ovA", }, { "location": { "latitude": -35.2824178, "longitude": 149.1299043 }, "placeId": "ChIJ601MoWlNFmsR5mvkfPp2ovA", }, { "location": { "latitude": -35.2824379, "longitude": 149.1298945 }, "placeId": "ChIJ601MoWlNFmsR5mvkfPp2ovA", }, { "location": { "latitude": -35.2824379, "longitude": 149.1298945 }, "placeId": "ChIJe9LPnWlNFmsR7mJw8mYHwG0", }, { "location": { "latitude": -35.282472999999996, "longitude": 149.1298835 }, "placeId": "ChIJe9LPnWlNFmsR7mJw8mYHwG0", }, { "location": { "latitude": -35.2825375, "longitude": 149.1298525 }, "placeId": "ChIJe9LPnWlNFmsR7mJw8mYHwG0", }, { "location": { "latitude": -35.28257309999999, "longitude": 149.1298319 }, "placeId": "ChIJe9LPnWlNFmsR7mJw8mYHwG0", }, { "location": { "latitude": -35.28257309999999, "longitude": 149.1298319 }, "placeId": "ChIJaUpThGlNFmsRMHWxoH7EOsc", }, { "location": { "latitude": -35.282665400000006, "longitude": 149.12974459999998 }, "placeId": "ChIJaUpThGlNFmsRMHWxoH7EOsc", }, { "location": { "latitude": -35.28274030000001, "longitude": 149.1296645 }, "placeId": "ChIJaUpThGlNFmsRMHWxoH7EOsc", }, { "location": { "latitude": -35.282809799999995, "longitude": 149.12957799999998 }, "placeId": "ChIJaUpThGlNFmsRMHWxoH7EOsc", }, { "location": { "latitude": -35.28282136229385, "longitude": 149.12956142620385 }, "originalIndex": 5, "placeId": "ChIJaUpThGlNFmsRMHWxoH7EOsc", }, { "location": { "latitude": -35.2828744, "longitude": 149.1294854 }, "placeId": "ChIJaUpThGlNFmsRMHWxoH7EOsc", }, { "location": { "latitude": -35.282922299999996, "longitude": 149.1294044 }, "placeId": "ChIJaUpThGlNFmsRMHWxoH7EOsc", }, { "location": { "latitude": -35.282931500000004, "longitude": 149.1293876 }, "placeId": "ChIJaUpThGlNFmsRMHWxoH7EOsc", }, { "location": { "latitude": -35.2830263, "longitude": 149.1291788 }, "placeId": "ChIJaUpThGlNFmsRMHWxoH7EOsc", }, { "location": { "latitude": -35.2830263, "longitude": 149.1291788 }, "placeId": "ChIJyd3JiWlNFmsR9RUq2ySTTZQ", }, { "location": { "latitude": -35.283054, "longitude": 149.1290996 }, "placeId": "ChIJyd3JiWlNFmsR9RUq2ySTTZQ", }, { "location": { "latitude": -35.2830794, "longitude": 149.1290094 }, "placeId": "ChIJyd3JiWlNFmsR9RUq2ySTTZQ", }, { "location": { "latitude": -35.2830794, "longitude": 149.1290094 }, "placeId": "ChIJWSb8ImpNFmsRp_4JAxJFE1A", }, { "location": { "latitude": -35.28313383700836, "longitude": 149.12893500604946 }, "originalIndex": 6, "placeId": "ChIJWSb8ImpNFmsRp_4JAxJFE1A", }, { "location": { "latitude": -35.283134499999996, "longitude": 149.12893409999998 }, "placeId": "ChIJWSb8ImpNFmsRp_4JAxJFE1A", }, { "location": { "latitude": -35.283190399999995, "longitude": 149.1288668 }, "placeId": "ChIJWSb8ImpNFmsRp_4JAxJFE1A", }, { "location": { "latitude": -35.2832503, "longitude": 149.1288041 }, "placeId": "ChIJWSb8ImpNFmsRp_4JAxJFE1A", }, { "location": { "latitude": -35.2833133, "longitude": 149.1287463 }, "placeId": "ChIJWSb8ImpNFmsRp_4JAxJFE1A", }, { "location": { "latitude": -35.2833794, "longitude": 149.128694 }, "placeId": "ChIJWSb8ImpNFmsRp_4JAxJFE1A", }, { "location": { "latitude": -35.283448299999996, "longitude": 149.128647 }, "placeId": "ChIJWSb8ImpNFmsRp_4JAxJFE1A", }, { "location": { "latitude": -35.2835199, "longitude": 149.1286054 }, "placeId": "ChIJWSb8ImpNFmsRp_4JAxJFE1A", }, { "location": { "latitude": -35.2835934, "longitude": 149.1285699 }, "placeId": "ChIJWSb8ImpNFmsRp_4JAxJFE1A", }, { "location": { "latitude": -35.283668899999995, "longitude": 149.12854059999998 }, "placeId": "ChIJWSb8ImpNFmsRp_4JAxJFE1A", }, { "location": { "latitude": -35.28372649999999, "longitude": 149.1285237 }, "placeId": "ChIJWSb8ImpNFmsRp_4JAxJFE1A", }, { "location": { "latitude": -35.28386179999999, "longitude": 149.12849319999998 }, "placeId": "ChIJWSb8ImpNFmsRp_4JAxJFE1A", }, { "location": { "latitude": -35.2839978, "longitude": 149.1284682 }, "placeId": "ChIJWSb8ImpNFmsRp_4JAxJFE1A", }, { "location": { "latitude": -35.2840205, "longitude": 149.12846779999998 }, "placeId": "ChIJWSb8ImpNFmsRp_4JAxJFE1A", }, { "location": { "latitude": -35.2840205, "longitude": 149.12846779999998 }, "placeId": "ChIJZe8tFWpNFmsR4brZ1vldk2E", }, { "location": { "latitude": -35.2840524, "longitude": 149.12845969999998 }, "placeId": "ChIJZe8tFWpNFmsR4brZ1vldk2E", }, { "location": { "latitude": -35.284341500000004, "longitude": 149.1284124 }, "placeId": "ChIJZe8tFWpNFmsR4brZ1vldk2E", }, { "location": { "latitude": -35.2843875, "longitude": 149.1284034 }, "placeId": "ChIJZe8tFWpNFmsR4brZ1vldk2E", }, { "location": { "latitude": -35.2843875, "longitude": 149.1284034 }, "placeId": "ChIJVx7Ta2pNFmsRx9OI9CnN5tI", }, { "location": { "latitude": -35.2845916, "longitude": 149.1283726 }, "placeId": "ChIJVx7Ta2pNFmsRx9OI9CnN5tI", }, { "location": { "latitude": -35.2845916, "longitude": 149.1283726 }, "placeId": "ChIJtWxAZmpNFmsRlbUCkc6VtnA", }, { "location": { "latitude": -35.28459730000001, "longitude": 149.1283703 }, "placeId": "ChIJtWxAZmpNFmsRlbUCkc6VtnA", }, { "location": { "latitude": -35.284728747199374, "longitude": 149.12834860726772 }, "originalIndex": 7, "placeId": "ChIJtWxAZmpNFmsRlbUCkc6VtnA", }, ], }
响应使用以下架构。
SnapToRoadsResponse
Field | Required | Type | Description |
---|---|---|---|
| optional | Array<SnappedPoint> | An array of snapped points. See SnappedPoint for more information. |
| optional | string | A string containing a user-visible warning. |
SnappedPoint
Field | Required | Type | Description |
---|---|---|---|
| required | LatitudeLongitudeLiteral | See LatitudeLongitudeLiteral for more information. |
| required | string | A unique identifier for a place. All place IDs returned by the Roads API correspond to road segments. |
| optional | number |
An integer that indicates the corresponding value in the original
request. Each value in the request should map to a snapped value in
the response. However, if you've set interpolate=true or if you're
using nearest roads, then it's possible that the response will
contain more coordinates than the request. Interpolated values will
not have an |
LatitudeLongitudeLiteral
An object describing a specific location with Latitude and Longitude in decimal degrees.
Field | Required | Type | Description |
---|---|---|---|
| required | number | Latitude in decimal degrees |
| required | number | Longitude in decimal degrees |
演示
- 在地图上点击以创建车辆轨迹。请注意,如果点之间的距离过远,可能无法正确贴合。
- 双击可将轨迹贴合到道路上。
以全屏模式查看此示例。
JavaScript
var apiKey = 'YOUR_API_KEY_HERE'; var map; var drawingManager; var placeIdArray = []; var polylines = []; var snappedCoordinates = []; function initialize() { var mapOptions = { zoom: 17, center: {lat: -33.8667, lng: 151.1955,} }; map = new google.maps.Map(document.getElementById('map'), mapOptions); // Adds a Places search box. Searching for a place will center the map on that // location. map.controls[google.maps.ControlPosition.RIGHT_TOP].push( document.getElementById('bar')); var autocomplete = new google.maps.places.Autocomplete( document.getElementById('autoc')); autocomplete.bindTo('bounds', map); autocomplete.addListener('place_changed', function() { var place = autocomplete.getPlace(); if (place.geometry.viewport) { map.fitBounds(place.geometry.viewport); } else { map.setCenter(place.geometry.location); map.setZoom(17); } }); // Enables the polyline drawing control. Click on the map to start drawing a // polyline. Each click will add a new vertice. Double-click to stop drawing. drawingManager = new google.maps.drawing.DrawingManager({ drawingMode: google.maps.drawing.OverlayType.POLYLINE, drawingControl: true, drawingControlOptions: { position: google.maps.ControlPosition.TOP_CENTER, drawingModes: [ google.maps.drawing.OverlayType.POLYLINE ] }, polylineOptions: { strokeColor: '#696969', strokeWeight: 2, strokeOpacity: 0.3, } }); drawingManager.setMap(map); // Snap-to-road when the polyline is completed. drawingManager.addListener('polylinecomplete', function(poly) { var path = poly.getPath(); polylines.push(poly); placeIdArray = []; runSnapToRoad(path); }); // Clear button. Click to remove all polylines. document.getElementById('clear').addEventListener('click', function(event) { event.preventDefault(); for (var i = 0; i < polylines.length; ++i) { polylines[i].setMap(null); } polylines = []; return false; }); } // Snap a user-created polyline to roads and draw the snapped path function runSnapToRoad(path) { var pathValues = []; for (var i = 0; i < path.getLength(); i++) { pathValues.push(path.getAt(i).toUrlValue()); } $.get('https://roads.googleapis.com/v1/snapToRoads', { interpolate: true, key: apiKey, path: pathValues.join('|') }, function(data) { processSnapToRoadResponse(data); drawSnappedPolyline(); }); } // Store snapped polyline returned by the snap-to-road service. function processSnapToRoadResponse(data) { snappedCoordinates = []; placeIdArray = []; for (var i = 0; i < data.snappedPoints.length; i++) { var latlng = new google.maps.LatLng( data.snappedPoints[i].location.latitude, data.snappedPoints[i].location.longitude); snappedCoordinates.push(latlng); placeIdArray.push(data.snappedPoints[i].placeId); } } // Draws the snapped polyline (after processing snap-to-road response). function drawSnappedPolyline() { var snappedPolyline = new google.maps.Polyline({ path: snappedCoordinates, strokeColor: '#add8e6', strokeWeight: 4, strokeOpacity: 0.9, }); snappedPolyline.setMap(map); polylines.push(snappedPolyline); } $(window).load(initialize);
JavaScript + HTML
<!DOCTYPE html> <html> <head> <meta name="viewport" content="initial-scale=1.0, user-scalable=no"> <meta charset="utf-8"> <title>Roads API Demo</title> <style> html, body, #map { height: 100%; margin: 0px; padding: 0px } #panel { position: absolute; top: 5px; left: 50%; margin-left: -180px; z-index: 5; background-color: #fff; padding: 5px; border: 1px solid #999; } #bar { width: 240px; background-color: rgba(255, 255, 255, 0.75); margin: 8px; padding: 4px; border-radius: 4px; } #autoc { width: 100%; box-sizing: border-box; } </style> <script src="https://www.gstatic.com/external_hosted/jquery2.min.js"></script> <script src="https://maps.googleapis.com/maps/api/js?libraries=drawing,places&key=YOUR_API_KEY"></script> <script> var apiKey = 'YOUR_API_KEY_HERE'; var map; var drawingManager; var placeIdArray = []; var polylines = []; var snappedCoordinates = []; function initialize() { var mapOptions = { zoom: 17, center: {lat: -33.8667, lng: 151.1955,} }; map = new google.maps.Map(document.getElementById('map'), mapOptions); // Adds a Places search box. Searching for a place will center the map on that // location. map.controls[google.maps.ControlPosition.RIGHT_TOP].push( document.getElementById('bar')); var autocomplete = new google.maps.places.Autocomplete( document.getElementById('autoc')); autocomplete.bindTo('bounds', map); autocomplete.addListener('place_changed', function() { var place = autocomplete.getPlace(); if (place.geometry.viewport) { map.fitBounds(place.geometry.viewport); } else { map.setCenter(place.geometry.location); map.setZoom(17); } }); // Enables the polyline drawing control. Click on the map to start drawing a // polyline. Each click will add a new vertice. Double-click to stop drawing. drawingManager = new google.maps.drawing.DrawingManager({ drawingMode: google.maps.drawing.OverlayType.POLYLINE, drawingControl: true, drawingControlOptions: { position: google.maps.ControlPosition.TOP_CENTER, drawingModes: [ google.maps.drawing.OverlayType.POLYLINE ] }, polylineOptions: { strokeColor: '#696969', strokeWeight: 2, strokeOpacity: 0.3, } }); drawingManager.setMap(map); // Snap-to-road when the polyline is completed. drawingManager.addListener('polylinecomplete', function(poly) { var path = poly.getPath(); polylines.push(poly); placeIdArray = []; runSnapToRoad(path); }); // Clear button. Click to remove all polylines. document.getElementById('clear').addEventListener('click', function(event) { event.preventDefault(); for (var i = 0; i < polylines.length; ++i) { polylines[i].setMap(null); } polylines = []; return false; }); } // Snap a user-created polyline to roads and draw the snapped path function runSnapToRoad(path) { var pathValues = []; for (var i = 0; i < path.getLength(); i++) { pathValues.push(path.getAt(i).toUrlValue()); } $.get('https://roads.googleapis.com/v1/snapToRoads', { interpolate: true, key: apiKey, path: pathValues.join('|') }, function(data) { processSnapToRoadResponse(data); drawSnappedPolyline(); }); } // Store snapped polyline returned by the snap-to-road service. function processSnapToRoadResponse(data) { snappedCoordinates = []; placeIdArray = []; for (var i = 0; i < data.snappedPoints.length; i++) { var latlng = new google.maps.LatLng( data.snappedPoints[i].location.latitude, data.snappedPoints[i].location.longitude); snappedCoordinates.push(latlng); placeIdArray.push(data.snappedPoints[i].placeId); } } // Draws the snapped polyline (after processing snap-to-road response). function drawSnappedPolyline() { var snappedPolyline = new google.maps.Polyline({ path: snappedCoordinates, strokeColor: '#add8e6', strokeWeight: 4, strokeOpacity: 0.9, }); snappedPolyline.setMap(map); polylines.push(snappedPolyline); } $(window).load(initialize); </script> </head> <body> <div id="map"></div> <div id="bar"> <p class="auto"><input type="text" id="autoc"/></p> <p><a id="clear" href="#">Click here</a> to clear map.</p> </div> </body> </html>