滴滴热力图-php版（后面有js版本）

/**
     * 获取边界
     * @return mixed
     * @return false|string
     * @throws Exception
     */
    public function actionBorder()
    {
        $lock_file = "/tmp/process.lock";
        $lock_file_handle = fopen($lock_file, 'w');
        if ($lock_file_handle === false)
            die("Can not create lock file {$lock_file}
");
        if (!flock($lock_file_handle, LOCK_EX + LOCK_NB)) {
            die(date("Y-m-d H:i:s") . " Process already exists.
");
        }

        $cache = Yii::$app->cache;
//        $cache->delete('amap_border');

        $result = $cache->get('amap_border');
        if($result) {
//            return json_encode($result);
        }

        $gaode_url = 'https://restapi.amap.com/v3/config/district?keywords=110100&subdistrict=0&extensions=all&key=****';
        $curl = new HttpCurl();
        $response_json = $curl->get($gaode_url);
        $response_arr = json_decode($response_json, true);
        $left_lng = 0;
        $up_lat = 0;
        $right_lng = 0;
        $down_lat = 0;
        $lng_lat_arr = [];
        $lng_lat_tmp_arr = [];
        $result_arr_list = [];
        if($response_arr['status'] == 1){
            $lng_lat_str = isset($response_arr['districts'][0]['polyline']) ? $response_arr['districts'][0]['polyline'] : '';
            $lng_lat_tmp_list = explode('|', $lng_lat_str);
            $i = 1;
            foreach ($lng_lat_tmp_list as $k=>$lng_lat_tmp){
                $lng_lat_arr_tmp = explode(';', $lng_lat_tmp);
                foreach ($lng_lat_arr_tmp as $lng_lat_arr_v) {
                    // 17152
                    if(!($i % 10)) {
                        $lng_lat_t_arr = explode(',', $lng_lat_arr_v);
                        $result_tmp['lng'] = $lng_lat_t_arr[0];
                        $result_tmp['lat'] = $lng_lat_t_arr[1];
                        $result_arr_list[$k][] = $result_tmp;
                        $lng_lat_arr[$k][] = $lng_lat_t_arr;
                        $lng_lat_tmp_arr[] = $lng_lat_t_arr;
                    }
                    $i++;
                }
            }
//            var_dump(count($lng_lat_tmp_arr));die;

            $tmp_lng_arr = ArrayHelper::getColumn($lng_lat_tmp_arr, '0');
            $tmp_lat_arr = ArrayHelper::getColumn($lng_lat_tmp_arr, '1');
            $left_lng =min($tmp_lng_arr);
            $up_lat =max($tmp_lat_arr);
            $right_lng =max($tmp_lng_arr);
            $down_lat =min($tmp_lat_arr);
        }
        $boundary_arr = [];
        foreach ($result_arr_list as $result_arr) {
            // 获取6个点
            $boundary_arr = $this->draw_other_lng_lat($left_lng, $up_lat, $result_arr, $right_lng, $down_lat);
            $boundary_arr = array_merge($boundary_arr,$boundary_arr);
        }

        $result = [
            'code' => 0,
//            'msg'=>'',
            'data' => $lng_lat_arr,
            'boundary_arr' => $boundary_arr,
            'left_lng'=>$left_lng,
            'up_lat'=>$up_lat,
            'right_lng'=>$right_lng,
            'down_lat'=>$down_lat,
        ];
        $cache->set('amap_border', $result);
        var_dump(count($boundary_arr));die;

    }

    public function draw_other_lng_lat($longitude, $latitude, $result_list, $right_lng, $down_lat) {
        $latDistance = 1.0 / 111322 * cos(45*pi() / 180);//每一米代表多少度
        $lonDistance = 1.0 / 111322;
        $radius = 1000;//1000米
        $boundary_arr = [];
        $count_lenth = 1;
        // for (var i_total=0; i_total<count_lenth; i_total+=10) {
        while(1) {
            $count_lenth++;
            $mLongitude_tmp = $longitude + $count_lenth * 1.5 * $radius * $lonDistance;
            $mLatitude_tmp = $latitude - 2 * $count_lenth * $radius * sin(60 * pi() / 180) * $latDistance;
            if ($mLongitude_tmp > $right_lng && $mLatitude_tmp < $down_lat) { // 到边界了
break;
}
if($count_lenth > 5000) break; // 安全值 防止死循环
}
for ($i = 0; $i <= $count_lenth; $i++) {
$mLongitude = $longitude + $i * 1.5 * $radius * $lonDistance;
            for ($j = 0; $j <= $count_lenth; $j++) {
$mLatitude = $latitude - 2 * $j * $radius * sin(60 * pi() / 180) * $latDistance;
                if ($i % 2 != 0) {
$mLatitude += $radius * sin(60 * pi() / 180) * $latDistance;
}
if($mLongitude > $right_lng && $mLatitude < $down_lat){
echo "运行结束-";
                    break 2;
}else{
if($i == $count_lenth){
$count_lenth = $count_lenth+2;
$i--;
                        echo $count_lenth ." 
";
                        break;
}
                }
$inRing = $this->is_point_in_polygon(['lng'=>$mLongitude,'lat'=>$mLatitude], $result_list); // 是否在多边形内

if($inRing == true) {
$height = $radius * sin(60*pi() / 180) * $latDistance;
$lng1 = $mLongitude - $radius / 2 * $lonDistance; $lat1 = $mLatitude + $height;
$lng2 = $mLongitude + $radius / 2 * $lonDistance; $lat2 = $mLatitude + $height;
$lng3 = $mLongitude + $radius * $lonDistance; $lat3 = $mLatitude;
$lng4 = $mLongitude + $radius / 2 * $lonDistance; $lat4 = $mLatitude - $height;
$lng5 = $mLongitude - $radius / 2 * $lonDistance; $lat5 = $mLatitude - $height;
$lng6 = $mLongitude - $radius * $lonDistance; $lat6 = $mLatitude;
$boundary_tmp = [$lng1.','.$lat1,$lng2.','.$lat2,$lng3.','.$lat3,$lng4.','.$lat4,$lng5.','.$lat5,$lng6.','.$lat6];
$boundary_arr[] = $boundary_tmp;
}
            }
//            if($break) break;
}
// }
return $boundary_arr;
}

/**
     *  判断一个坐标是否在一个多边形内（由多个坐标围成的）
     * 基本思想是利用射线法，计算射线与多边形各边的交点，如果是偶数，则点在多边形外，否则
     * 在多边形内。还会考虑一些特殊情况，如点在多边形顶点上，点在多边形边上等特殊情况。
     * @param $point 要查询的点
     * @param $pts 要查询的范围
     * @return bool
     */
public function is_point_in_polygon($point, $pts) {
$N = count($pts);
$boundOrVertex = true; //如果点位于多边形的顶点或边上，也算做点在多边形内，直接返回true
$intersectCount = 0;//穿越点数
$precision = 2e-10; //浮点类型计算时候与0比较时候的容差
$p1 = 0;
$p2 = 0;
$p = $point;

$p1 = $pts[0];
        for ($i = 1; $i <= $N; ++$i) {
if ($p['lng'] == $p1['lng'] && $p['lat'] == $p1['lat']) {
return $boundOrVertex;
}

$p2 = $pts[$i % $N];//right vertex
if ($p['lat'] < min($p1['lat'], $p2['lat']) || $p['lat'] > max($p1['lat'], $p2['lat'])) {//ray is outside of our interests
$p1 = $p2;
                continue;
}

if ($p['lat'] > min($p1['lat'], $p2['lat']) && $p['lat'] < max($p1['lat'], $p2['lat'])) {//ray is crossing over by the algorithm (common part of)
if($p['lng'] <= max($p1['lng'], $p2['lng'])){//x is before of ray
if ($p1['lat'] == $p2['lat'] && $p['lng'] >= min($p1['lng'], $p2['lng'])) {//overlies on a horizontal ray
return $boundOrVertex;
}

if ($p1['lng'] == $p2['lng']) {//ray is vertical
if ($p1['lng'] == $p['lng']) {//overlies on a vertical ray
return $boundOrVertex;
} else {//before ray
++$intersectCount;
}
                    } else {//cross point on the left side
$xinters = ($p['lat'] - $p1['lat']) * ($p2['lng'] - $p1['lng']) / ($p2['lat'] - $p1['lat']) + $p1['lng'];//cross point of lng
if (abs($p['lng'] - $xinters) < $precision) {//overlies on a ray
return $boundOrVertex;
}

if ($p['lng'] < $xinters) {//before ray
++$intersectCount;
}
                    }
                }
            } else {//special case when ray is crossing through the vertex
if ($p['lat'] == $p2['lat'] && $p['lng'] <= $p2['lng']) {//p crossing over p2
$p3 = $pts[($i+1) % $N]; //next vertex
if ($p['lat'] >= min($p1['lat'], $p3['lat']) && $p['lat'] <= max($p1['lat'], $p3['lat'])) { //p.lat lies between p1.lat & p3.lat
++$intersectCount;
} else {
$intersectCount += 2;
}
                }
            }
$p1 = $p2;//next ray left point
}

if ($intersectCount % 2 == 0) {//在多边形外
return false;
} else { //在多边形内
return true;
}
    }