From: c dot madmax at gmail dot com
Operating system: Ubuntu 12.04
PHP version: Irrelevant
Package: GD related
Bug Type: Bug
Bug description:imageTTFText text shifted right
Description:
------------
Hello PHP Developers,
I want to inform you about a imageTTFText() bug that exists since four
years. The problem is that imageTTFText text is shifted right. The bug
is only visible when using a large fontsize. The bigger the font the
larger the shift.
The bug was introduced with PHP 5.2.10 and reported here:
http://bugs.php.net/bug.php?id=49600 As you can
see in the history of
bug 49600, a fix was made in revision 293268 and the bug was closed. But
then the fix was reverted in revision 296693 and obviously no one has
noticed that.
I strongly urge you to fix this problem. I am using PHP 5.4.0 on Ubuntu
12.04. I am sure the bug still exists in all php versions >=5.2.10 until
this day (except revision 293268-296693).
I have made a test script and uploaded a sample image on two image
hosters to illustrate how massive the shift is:
http://img407.imageshack.us/img407/1888/mbxe.png
(best quality)
http://img223.imagevenue.com/img.php?image=61219_imagettftext_shifted_122_1017lo.jpg
As you can see on the image, the character 'C' is NOT left aligned as it
should because the x position is zero. The character is shifted
approximately 20 pixels instead and overlap the polygon (which is
properly left-aligned). Some characters like 'A' or 'V' are only a
little bit shifted, but also overlap the polygon. It does not matter
what font you use, all are right shifted.
Note:
The array that is returned from imagettfbbox produces values that differ
1 pixel from the values returned from imageTTFText (when using x=0; y=0)
which is also a bug.
Please use my test script and verify the problem. If a php developper
whould use this test script each time he made a change in imageTTFText,
then such bugs would not occour. It seems the developer do not have
enough carefulness. That's a point you should think about.
Test script:
---------------
<?php
$im = imagecreatetruecolor(500, 500);
$bgcolor = imagecolortransparent($im, imagecolorallocate($im, 255, 255,
255));
$fgcolor = imagecolorallocatealpha($im, 0, 0, 255, 64);
imagefill($im, 0, 0, $bgcolor);
$polygon = imagettftext(
$im,
480, // size
0, // angle
0, // x
480, // y
$fgcolor,
'/usr/share/fonts/truetype/msttcorefonts/verdana.ttf',
'C' // text
);
imagesetthickness($im, 2);
imagepolygon(
$im,
$polygon,
sizeof($polygon) / 2,
imagecolorallocatealpha($im, 255, 0, 0, 64)
);
header('Content-Type: image/png');
imagepng($im);
exit;
?>
Expected result:
----------------
The polygon should enclose the character 'C' without overlapping the
character.
Actual result:
--------------
The polygon overlap the character 'C' because every character is shifted
right.
--
Edit bug report at https://bugs.php.net/bug.php?id=65837&edit=1
--
Try a snapshot (PHP 5.4): https://bugs.php.net/fix.php?id=65837&r=trysnapshot54
Try a snapshot (PHP 5.5): https://bugs.php.net/fix.php?id=65837&r=trysnapshot55
Try a snapshot (trunk): https://bugs.php.net/fix.php?id=65837&r=trysnapshottrunk
Fixed in SVN: https://bugs.php.net/fix.php?id=65837&r=fixed
Fixed in release: https://bugs.php.net/fix.php?id=65837&r=alreadyfixed
Need backtrace: https://bugs.php.net/fix.php?id=65837&r=needtrace
Need Reproduce Script: https://bugs.php.net/fix.php?id=65837&r=needscript
Try newer version: https://bugs.php.net/fix.php?id=65837&r=oldversion
Not developer issue: https://bugs.php.net/fix.php?id=65837&r=support
Expected behavior: https://bugs.php.net/fix.php?id=65837&r=notwrong
Not enough info: https://bugs.php.net/fix.php?id=65837&r=notenoughinfo
Submitted twice: https://bugs.php.net/fix.php?id=65837&r=submittedtwice
register_globals: https://bugs.php.net/fix.php?id=65837&r=globals
PHP 4 support discontinued: https://bugs.php.net/fix.php?id=65837&r=php4
Daylight Savings: https://bugs.php.net/fix.php?id=65837&r=dst
IIS Stability: https://bugs.php.net/fix.php?id=65837&r=isapi
Install GNU Sed: https://bugs.php.net/fix.php?id=65837&r=gnused
Floating point limitations: https://bugs.php.net/fix.php?id=65837&r=float
No Zend Extensions: https://bugs.php.net/fix.php?id=65837&r=nozend
MySQL Configuration Error: https://bugs.php.net/fix.php?id=65837&r=mysqlcfg