静态地图API中讨论了路径,但没有提到圆形。这是否可行?
谢谢
由于Google Static Maps不支持绘制圆形,因此可以通过绘制详细的PolyLine
来表示一个圆。
需要算法生成适当的编码多段线。我在PHP中使用了这个实现,但您可以根据所需的编程语言自行找到或开发类似的算法。
以下是我用来生成请求的PHP代码:
<?php
/* set some options */
$mapLat = filter_input(INPUT_POST, 'lat1'); // latitude for map's and circle's center
$mapLng = filter_input(INPUT_POST, 'lon1'); // longitude for map's and circle's center
$mapRadius1 = 0.5; // the radius of the first circle (in Kilometres)
$mapRadius2 = 5; // the radius of the second circle (in Kilometres)
$mapFill_first = '330000'; // fill colour of the first circle
$mapFill_second = 'FF99FF'; // fill colour of the second circle
$map1Border1 = '91A93A'; // border colour of the first circle
$map1Border2 = '0000CC'; // border colour of the second circle
$mapWidth = 450; // map image width (max 640px)
$mapHeight = 450; // map image height (max 640px)
$zoom = 11;
$scale = 2;
/** create our encoded polyline string for the first circle*/
$EncString1 = GMapCircle($mapLat, $mapLng, $mapRadius1);
/** create our encoded polyline string for the second circle*/
$EncString2 = GMapCircle($mapLat, $mapLng, $mapRadius2);
/** put together the static map URL */
$MapAPI = 'http://maps.google.com.au/maps/api/staticmap?';
$MapURL = $MapAPI . 'center=' . $mapLat . ',' . $mapLng . '&zoom=' . $zoom . '&size=' .
$mapWidth . 'x' . $mapHeight . '&scale=' . $scale . '&markers=color:red%7Clabel:S%7C'.$mapLat.','.$mapLng .
'&maptype=roadmap&path=fillcolor:0x' . $mapFill_first .
'33%7Ccolor:0x' . $map1Border1 . '00%7Cenc:' . $EncString1 . '&path=fillcolor:0x' .
$mapFill_second . '33%7Ccolor:0x' . $map1Border2 . '00%7Cenc:' . $EncString2;
/* output an image tag with our map as the source */
//echo '<img src="' . $MapURL . '" />';
echo json_encode($MapURL);
function GMapCircle($Lat, $Lng, $Rad, $Detail = 8)
{
$R = 6371;
$pi = pi();
$Lat = ($Lat * $pi) / 180;
$Lng = ($Lng * $pi) / 180;
$d = $Rad / $R;
$points = array();
for ($i = 0; $i <= 360; $i += $Detail)
{
$brng = $i * $pi / 180;
$pLat = asin(sin($Lat) * cos($d) + cos($Lat) * sin($d) * cos($brng));
$pLng = (($Lng + atan2(sin($brng) * sin($d) * cos($Lat), cos($d) - sin($Lat) * sin($pLat))) * 180) / $pi;
$pLat = ($pLat * 180) / $pi;
$points[] = array($pLat, $pLng);
}
require_once('PolylineEncoder.php');
$PolyEnc = new PolylineEncoder($points);
$EncString = $PolyEnc->dpEncode();
return $EncString['Points'];
}
享受吧!
var pathText = '&path=';
var circumLatLng;
for (var j = 0; j < 361; j = j + 8) {
circumLatLng = google.maps.geometry.spherical.computeOffset(circle.getCenter(), circle.getRadius(), j);
pathText += circumLatLng.lat().toFixed(6) + ',' + circumLatLng.lng().toFixed(6) + '|';
}
这是可能的,但您需要绘制一个有很多边的形状来看起来像一个圆形。
以下是我的示例:
<img src="http://maps.google.com/maps/api/staticmap?size=600x500&path=fillcolor:0x0000FF|weight:3|color:0xFF0000|enc:ue{cI|rrH`@qs@hBis@nDyr@rF_r@tH_q@xJyo@zLgn@vNol@rPsj@lRmh@`Taf@tUqc@dWy`@nX{]vY{ZxZuWx[kTr\_Qh]oMz]}If^iFl^uBn^?n^tBd^hFz]|Ih]nMr\~Px[jTxZtWvYzZnXz]dWx`@tUpc@`T`f@lRlh@rPrj@xNnl@xLfn@xJxo@vH~p@rF~q@lDxr@hBhs@b@ps@c@ps@iBfs@mDxr@sF~q@wH`q@yJvo@yLfn@yNpl@sPpj@mRlh@aTbf@uUnc@eWx`@oX|]wYzZyZtWy[jTs\~Pi]lM{]|Ie^jFo^rBo^?m^sBg^kF{]}Ii]mMs\_Qy[kTyZuWwY{ZoX}]eWy`@uUoc@aTcf@mRmh@sPqj@wNql@{Lgn@yJwo@uHaq@sF_r@oDyr@iBgs@a@qs@&sensor=true" border="0"/>
我使用freemaptools.com生成了这个。
xmlHttp.open("POST","ajax/csv-polyline-encoder.php",true);
)。 - Drew Chapin