GeoUtils.php

class GeoUtils
{
    /**
     * 判断函数
     * @param $new 放入多边形各个顶点的坐标
     * @param $t 为判断点的位置
     * @param $n 为顶点坐标的个数-1
     * @return int 若点在多边形内则返回1，否则返回0
     * @author zlbao<276363733@QQ.com>
     * @date   : 2018/11/28/028
     */
    static function inpolygon($new , $t , $n)
    {
        for( $i = 0; $i <= $n; $i++ ) {
            $new[$i][0] -= $t[0];
            $new[$i][1] -= $t[1];
        }
        $t1 = $new[0][0] >= 0 ? ($new[0][1] >= 0 ? 0 : 3) : ($new[0][1] >= 0 ? 1 : 2);
        for( $sum = 0 , $i = 1; $i <= $n; $i++ ) {
            if( !$new[$i][0] && !$new[$i][1] ) {
                break;
            }
            $f = $new[$i][1] * $new[$i - 1][0] - $new[$i][0] * $new[$i - 1][1];
            if( !$f && $new[$i - 1][0] * $new[$i][0] <= 0 && $new[$i - 1][1] * $new[$i][1] <= 0 ) {
                break;
            }
            $t2 = $new[$i][0] >= 0 ? ($new[$i][1] >= 0 ? 0 : 3) : ($new[$i][1] >= 0 ? 1 : 2);
            if( $t2 == ($t1 + 1) % 4 ) {
                $sum += 1;
            }
            else if( $t2 == ($t1 + 3) % 4 ) {
                $sum -= 1;
            }
            else if( $t2 == ($t1 + 2) % 4 ) {
                if( $f > 0 ) $sum += 2;
                else $sum -= 2;
            }
            $t1 = $t2;
        }
        if( $i <= $n || $sum ) {
            return 1;
        }
        return 0;
    }

}

调用：

$new = array(
//            [116.408024 , 39.919925] , [116.400479 , 39.915498] , [116.406515 , 39.909521] , [116.408024 , 39.913506] , [116.41363 , 39.912786]
[116.408024,39.919925],[116.407162,39.915443],[116.400479,39.915498],[116.406372,39.913561],[116.406515,39.909521],[116.408024,39.913506],[116.41363,39.912786],[116.409174,39.914889]
        );
        $new2 = array(116.40664,39.910535);
        echo GeoUtils::inpolygon($new , $new2 , count($new) - 1);

不规则区域：

图片.png

图片.png