Description:
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There is an issue displaying Persian characters in GD generated images.
In persian, characters are arranged right to left (I mean first char is the most right hand arranged one). In addition characters are connected. For example while ی and ک are being written when separated, they should be written یک when connected. So not only they should be arranged right to left but also the shape of characters change during connections.
However displaying text using GD don't arrange persian characters right to left nor connects them correctly.
Some persian developers have made a php function which corrects the problem here: http://persiangd.berlios.de/doku.php
but I think it should be solved globally in the original lib.


Reproduce code:
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header("Content-type: image/png");
//uncomment to correct issue:
//include("fagd.php");

$text="یک";

$im = imagecreate(800, 40);

// Create some colors
$white = imagecolorallocate($im, 255, 255, 255);
$grey = imagecolorallocate($im, 128, 128, 128);
$black = imagecolorallocate($im, 0, 0, 0);

//uncomment to correct issue:
//$text = fagd($string,'fa');

$font = dirname(__FILE__).'/tahoma.ttf';

// Add the text
imagettftext($im, 20, 0, 20, 25, $black, $font,$text);

imagepng($im);
imagedestroy($im);


Expected result:
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this is an image displaying the correct output resulting from passing the text to imagettftext(), after being parsed using the fagd() function (provided by persian developers to correct the issue):
http://khone.ir/test/t2.png

Actual result:
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this is an image displaying the problematic view resulting from direct input of persian text to imagettftext():
http://khone.ir/test/t1.png