之前碰到的这样一个需求，要将公司的服务范围在地图中显示出来，并将用户每天的访问坐标进行统计看有多少用户是在所能达到的服务范围半径内。

以下是PHP代码的实现 (仅验证坐标在某片坐标区域内)

<?php
/**
 * 验证坐标点是否在某区域内
 * @author xiaoliang <1058436713@qq.com>
 * Class validationMap
 */
class validationMap{
    private static $coordArray;
    private static $vertx = [];
    private static $verty = [];
    /**
     * 设置坐标区域
     * @param mixed $coordArray
     */
    public static function setCoordArray(array $coordArray)
    {
        self::$coordArray = $coordArray;
    }
    /**
     * 验证区域范围
     * @param array $coordArray
     * @return bool
     */
    public static function isCityCenter(array $coordArray){
        if(!self::vaildatePoint($coordArray)){
            return false;
        }
        return self::pnpoly(count(self::$coordArray), $coordArray['lng'], $coordArray['lat']);
    }
    /**
     * 比较区域坐标
     * @param $nvert
     * @param $testx
     * @param $testy
     * @return bool
     */
    private static function pnpoly($nvert,$testx, $testy)
    {
        $c = false;
        for ($i = 0, $j = $nvert-1; $i < $nvert; $j = $i++) {
            if ( ( (self::$verty[$i]>$testy) != (self::$verty[$j]>$testy) ) && ($testx < (self::$vertx[$j]-self::$vertx[$i]) * ($testy-self::$verty[$i]) / (self::$verty[$j]-self::$verty[$i]) + self::$vertx[$i]) )
                $c = !$c;
        }
        return $c;
    }
    /**
     * 验证坐标
     * @param array $pointArray
     * @return bool
     */
    private static function vaildatePoint(array $pointArray){
        $maxY = $maxX = 0;
        $minY = $minX = 9999;
        foreach (self::$coordArray as $item){
            if($item['lng']>$maxX) $maxX = $item['lng'];
            if($item['lng'] < $minX) $minX = $item['lng'];
            if($item['lat']>$maxY) $maxY = $item['lat'];
            if($item['lat'] < $minY) $minY = $item['lat'];
            self::$vertx[] = $item['lng'];
            self::$verty[] = $item['lat'];
        }
        if ($pointArray['lng'] < $minX || $pointArray['lng'] > $maxX || $pointArray['lat'] < $minY || $pointArray['lat'] > $maxY) {
            return false;
        }
        return true;
    }
}
/**************************** test *************************************/
$map = [  //上海
    ["lng" => 121.488286, "lat" => 31.420147],
    ["lng" => 121.702154, "lat" => 31.294828],
    ["lng" => 121.780918, "lat" => 31.141157],
    ["lng" => 121.782068, "lat" => 30.941157],
    ["lng" => 121.492885, "lat" => 30.909931],
    ["lng" => 121.22325, "lat" => 30.890099],
    ["lng" => 121.161482, "lat" => 31.015526],
    ["lng" => 121.076395, "lat" => 31.226239],
    ["lng" => 121.189873, "lat" => 31.339688],
    ["lng" => 121.459509, "lat" => 31.41368],
];
$array = ["lat"=>31.218681,"lng"=>121.08604];//进行验证的区域
validationMap::setCoordArray($map);
var_dump(validationMap::isCityCenter($array));

在地图中的运用：