imageflip() in PHP is undefined - php

Question

Whenever I am trying to use the function imageflip(), it shows me the following message
Fatal error: Call to undefined function imageflip() in D:\xampp\htdocs\temp1\image_flip.php on line 6
Once I have called the imap_open function, even though, I already installed the imap extension and configured all. However, it still shows the same message.

Answer 1

imageflip() is only available after PHP 5.5. However, you can still define it yourself, as explained here (although if you plan to upgrade to PHP 5.5, it is not recommended to implement yours, or at least change the name to avoid duplication problems). For the sake of stackoverflow, I'll paste the code here:
<?php
/**
* Flip (mirror) an image left to right.
*
* #param image resource
* #param x int
* #param y int
* #param width int
* #param height int
* #return bool
* #require PHP 3.0.7 (function_exists), GD1
*/
function imageflip(&$image, $x = 0, $y = 0, $width = null, $height = null)
{
if ($width < 1) $width = imagesx($image);
if ($height < 1) $height = imagesy($image);
// Truecolor provides better results, if possible.
if (function_exists('imageistruecolor') && imageistruecolor($image))
{
$tmp = imagecreatetruecolor(1, $height);
}
else
{
$tmp = imagecreate(1, $height);
}
$x2 = $x + $width - 1;
for ($i = (int) floor(($width - 1) / 2); $i >= 0; $i--)
{
// Backup right stripe.
imagecopy($tmp, $image, 0, 0, $x2 - $i, $y, 1, $height);
// Copy left stripe to the right.
imagecopy($image, $image, $x2 - $i, $y, $x + $i, $y, 1, $height);
// Copy backuped right stripe to the left.
imagecopy($image, $tmp, $x + $i, $y, 0, 0, 1, $height);
}
imagedestroy($tmp);
return true;
}
And to use it:
<?php
$image = imagecreate(190, 60);
$background = imagecolorallocate($image, 100, 0, 0);
$color = imagecolorallocate($image, 200, 100, 0);
imagestring($image, 5, 10, 20, "imageflip() example", $color);
imageflip($image);
header("Content-Type: image/jpeg");
imagejpeg($image);
I haven't tried it, and the code isn't mine at all, but with some tricks you could adapt it to your needs.