PHP/GD Bug: imageFilledEllipse Centered on Y=0

Paul — Mon, 23 Nov 2009 23:04:43 +0000

I was drawing circles using PHP’s GD function imageFilledEllipse. I noticed that when I went to draw a circle having its center at $y=0,there would be a line missing at $y=1.

Here’s the work-around:

if( -1 <= $py && $py <= 1 ) {
  // Undocumented PHP bug when Y coordinate is zero.
  imageFilledEllipse($img,$px,$py,$X,$X,$color);
  imageFilledRectangle($img,$px-$halfX,$py-1,$px+$halfX,$py+1,$color);
} else {
  imageFilledEllipse($img,$px,$py,$X,$X,$color);
}

PHP Version:

PHP 4.3.9 (cgi) (built: Apr  1 2009 10:41:42)
Copyright (c) 1997-2004 The PHP Group
Zend Engine v1.3.0, Copyright (c) 1998-2004 Zend Technologies

$ yum search php-gd

php-gd.i386                              4.3.9-3.26             installed
Matched from:
php-gd
The php-gd package contains a dynamic shared object that will add
support for using the gd graphics library to PHP.

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PHP/GD Bug: imageFilledEllipse Centered on Y=0