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Request #63814 angles parameters in imagefilledarc are integers, they should be float
Submitted: 2012-12-20 12:32 UTC Modified: 2013-01-02 09:19 UTC
From: webmaster at fxtop dot com Assigned:
Status: Wont fix Package: GD related
PHP Version: 5.4.9 OS: Windows
Private report: No CVE-ID: None
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 [2012-12-20 12:32 UTC] webmaster at fxtop dot com
Description:
------------
see sample result at
http://mon-convertisseur.fr/php/imgangle.php?DEGRE=172.3

angles are truncated to nearest integer, in imagefilledarc function, they shouldn't

you can change parameter if you like

---
From manual page: http://www.php.net/function.imagefilledarc#refsect1-function.imagefilledarc-description
---



Test script:
---------------
header("Content-type: image/jpeg");

if (isset($_GET["DEGRE"])){ $lDegre=$_GET["DEGRE"];}
$lSizeX=916;
$lSizeY=945;
$image  = imagecreatetruecolor($lSizeX, $lSizeY);
$colorGreen = imagecolorallocate($image, 0, 255, 0);
		
// background coming from http://commons.wikimedia.org/wiki/File:Protractor_katomierz.jpg with some little changes
$fond=imagecreatefromjpeg("Protractor_katomierz_tourne05b.jpg");

//HERE I ROUND DEGRE PARAMETER BECAUSE imagefilledarc only accept integers (I prefer it rounded than truncated)
$lNumDegre=round($lDegre);
$lResult|=imagefilledarc ($image , 460 , 474 , 2*430 , 2*430  , -$lNumDegre , 0, $colorGreen , IMG_ARC_PIE );
$lResult|=imagecopymerge($image, $fond, 0, 0, 0 , 0, $lSizeX,$lSizeY,75);
imagejpeg($image, "temp.jpg");
imagedestroy($image);
echo file_get_contents("temp.jpg");

Expected result:
----------------
imagefilledarc should accept float parameters for "start" and "end" parameters.
As you can see on sample at http://mon-convertisseur.fr/php/imgangle.php?DEGRE=172.3 green backgound allways fall on a degre graduation  of the protactor. 



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 [2012-12-20 15:24 UTC] remi@php.net
the gd extension is mostly a wrapper for gd library.

As gd library doesn't accept float values for this comment, I think this is not possible.
 [2012-12-28 10:57 UTC] ab@php.net
-Status: Open +Status: Wont fix
 [2012-12-28 10:57 UTC] ab@php.net
That's right, gd takes only integers for coordinates as they're literally pixels. See here for arcs

http://lxr.php.net/xref/PHP_5_4/ext/gd/libgd/gd.h#546

If you work with float data, you probably will need to do conversion from/to int.
 [2012-12-28 14:12 UTC] webmaster at fxtop dot com
Hello, thanks for your investigation.
I don't blame that coordinates in pixel are integers, that's normal.
The problem is that angles are integers, which is an undue limitation : angles are rounded to nearest degree.  In astronomy, they deal with seconds of arc, which is 1/3600 of a degree. 

If problem is inside an external library, it should be reported to that library.
What is the proper website to report such limitation ?
Regards
 [2013-01-02 09:19 UTC] ab@php.net
Of course you can discuss that on https://bitbucket.org/pierrejoye/gd-libgd , but i don't think it's possible to get around that without using some anti aliasing technics. Also you might want to take a look at the Cairo binding which provides a vector graphics API.
 
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