php函数，通过平面内的四个坐标点判断是否是正方形

1，html页提交坐标点

<form action="./a.php" method="post">
   L1:x<input type="text" name="p1[]" />
      y<input type="text" name="p1[]" /><br>
   L2:x<input type="text" name="p2[]" />
      y<input type="text" name="p2[]" /><br>
   L3:x<input type="text" name="p3[]" />
      y<input type="text" name="p3[]" /><br>
   L4:x<input type="text" name="p4[]" />
      y<input type="text" name="p4[]" /><br>
   <button>提交</button>
</form>

2.PHP中对数据进行逻辑处理

function iszf($p){
    $t1 = array_shift($p);
    foreach ($p as $key => $v) {
        if($t1['0'] == $v['0']){
            $h1[] = abs($t1['1']-$v['1']);
        }elseif ($t1['1'] == $v['1']) {
            $h1[] = abs($t1['0']-$v['0']);
        }else{
            $h1['duijue'] = sqrt(pow(abs($t1['0']-$v['0']),2)+pow(abs($t1['1']-$v['1']),2));
        }
    }
    $t2 = array_shift($p);
    foreach ($p as $key => $v) {
        if($t2['0'] == $v['0']){
            $h2[] = abs($t2['1']-$v['1']);
        }elseif ($t2['1'] == $v['1']) {
            $h2[] = abs($t2['0']-$v['0']);
        }else{
            $h2['duijue'] = sqrt(pow(abs($t2['0']-$v['0']),2)+pow(abs($t2['1']-$v['1']),2));
        }
    }
    $t3 = array_shift($p);
    foreach ($p as $key => $v) {
        if($t3['0'] == $v['0']){
            $h3[] = abs($t3['1']-$v['1']);
        }elseif ($t3['1'] == $v['1']) {
            $h3[] = abs($t3['0']-$v['0']);
        }else{
            $h3['duijue'] = sqrt(pow(abs($t3['0']-$v['0']),2)+pow(abs($t3['1']-$v['1']),2));
        }
    }
    $dd = false;
    if(array_key_exists('duijue',$h2)){
        if($h2['duijue'] == $h1['duijue']){
            if($h1['0']== $h1['1'] && $h1['1']==$h3['0'] && $h3['0'] == $h3['1']){
               $dd = true;
            }
        }
    }
    
    if(array_key_exists('duijue',$h3)){
        if($h3['duijue'] == $h1['duijue']){
            if($h1['0']== $h1['1'] && $h1['1']==$h2['0'] && $h2['0'] == $h2['1']){
                $dd = true;
            }
        }
    }
    return $dd;
}

$p[] = $_POST['p1'];
$p[] = $_POST['p2'];
$p[] = $_POST['p3'];
$p[] = $_POST['p4'];


var_dump(iszf($p));