note 92794 added to function.imagerotate

I wanted to draw a transparent GIF-image and show it on a page, at an angle specified in the URL: <img src="image.php?angle=90" type="image/gif"> I used the native imagerotate() but at angles of 90, 180, etc. the old background colour would become non-transparent. Apparently, there's a bug somewhere in GD, and has been for ages. My solution below: $height = 100; $width = 100; $lsize= $width/2; $angle= $_GET["angle"]; // avoid the bug: if(($angle%90)==0) $angle+= 0.001; $image_p = imagecreatetruecolor($width, $height); $trans = imagecolorallocate($image_p, 254, 0, 0); imagefill($image_p, 0, 0, $trans); imagecolortransparent($image_p, $trans); $black = imagecolorallocate($image_p, 1, 1, 1); $red = imagecolorallocate($image_p, 255, 0, 0); $white = imagecolorallocate($image_p, 255, 255, 255); // draw something here imageline($image_p, 3, $lsize, $lsize/2, $lsize, $black); $image_r= imagerotate($image_p, -$angle, $trans, 0); $w= imagesx($image_r); $h= imagesy($image_r); $image_s = imagecreatetruecolor($width, $height); imagecopyresized($image_s, $image_r, 0, 0, ($w-$width)/2, ($h-$height)/2, $width, $height, $width, $height); $trans = imagecolorallocate($image_s, 254, 0, 0); imagecolortransparent($image_s, $trans); imagegif($image_s); ---- Server IP: 208.69.120.35 Probable Submitter: 83.205.25.185 ---- Manual Page -- http://www.php.net/manual/en/function.imagerotate.php Edit -- https://master.php.net/note/edit/92794 Del: integrated -- https://master.php.net/note/delete/92794/integrated Del: useless -- https://master.php.net/note/delete/92794/useless Del: bad code -- https://master.php.net/note/delete/92794/bad+code Del: spam -- https://master.php.net/note/delete/92794/spam Del: non-english -- https://master.php.net/note/delete/92794/non-english Del: in docs -- https://master.php.net/note/delete/92794/in+docs Del: other reasons-- https://master.php.net/note/delete/92794 Reject -- https://master.php.net/note/reject/92794 Search -- https://master.php.net/manage/user-notes.php