create animated gifs with php

I suspect feedburner are doing it with images like this one



However I'm not sure how they're doing it...

 

Wow, this is an old thread that got bumped.

They're actually easy to do... here's one I did, check out the gifmerge class at phpclasses.org

 

you must have just missed me, sorry. It's late but I'll run through a tutorial in the morning

 

Ok, I've pulled up my code and lets see if I can explain it.

I've been around awhile and when you've had to revisit code that's really old the last thing you need is code that's too clever for it's own good and unreadable. Better to be less intense and more readable/maintainable.

So, I start with a simple switch to allow me to quickly turn my code from a gif to a regular script. If debug is false then the headers go out telling the browser to expect an image.

$debug = false;

if ($debug) error_reporting(E_ALL);
else header("Content-type: image/gif");

Code (markup):

next I set up my paths

You will need a cache folder in the MYPATH location

define('MYPATH', '/home/mysite/domains/mysite.com/public_html/');

require('GifMerge.class.php');
require MYPATH .'muck/simplepie/simplepie.inc';

Code (markup):

And now I get the text for my images using SimplePie - bear in mind this is old code so the syntax for simplepie may well have changed.

$feedchoice = 'http://www.mysite.com/feed/'
$bg =   1;

$backgrounds = array(
	'1' => array('img'=>'mysite.gif', 'max'=>35, 'x'=>180), 
	);

//first up, create the single images
$feed = new SimplePie();
$feed->cache_location(MYPATH . 'cache');
$feed->feed_url($feedchoice);
$feed->init();

Code (markup):

These arrays are used to hold information about where to place the images. We don't handle them directly.

$__i = array();  // items
$__d = array();  // delay
$__x = array();  // x location
$__y = array();  // y location

if ($feed->data)
{
	$these = $feed->get_items(); 
	$these = array_splice($these, 0, 10);
	foreach($these as $row)
	{
		if (is_array($row)) $title = $row['title'];
		else $title = $row->get_title();

		//this is clumsy but it's the bare minimum to get rid of dodgy characters in the image
		$title = str_replace('’', "'", $title);
		$title = str_replace('…', "!", $title);
		$title = str_replace('“', '"', $title);
		$title = str_replace('’', "'", $title);
		$title = str_replace('”', '"', $title);
		
		if ($debug) echo "<li>{$title}</li>\n";
		$__i[] = makeSingle($title, $backgrounds[$bg]);
		$__d[] = 200;
		$__x[] = 0;
		$__y[] = 0;
	}
}
if ($debug) exit;


/*
	Params from left to right:
	1 		<== Array of gif frames
	2,3,4	<== Transparent colors (red, green, blue)
	5		<== Frames loop (-10 infinity, 5 : five loop, 9 : nine loop, etc...)
	6		<== Array of delay between frames in millisecond
	7		<== Disposal
	8,9		<== Array of X-Y distances from top & left
	*/
//now put it all together
$gifmerge	= new GifMerge($__i, 1, 1, 1, -10, $__d, 2, $__x, $__y, 'C_FILE');  //black
echo 		$gifmerge -> getAnimation();

exit;
//=================

Code (markup):

makeSingle creates the individual panes in the animated gif

function makeSingle($text, $bg)
{
	$im = imagecreatefromgif ($bg['img']);
	// Create some colors
	$white = imagecolorallocate($im, 255, 255, 255);
	$black = imagecolorallocate($im, 0, 0, 0);

	$loadedfont = 4;
	$bits = explode(' ', $text);
	$lines = array('');
	$ptr = 0;
	$max = $bg['max'];	
	for ($i = 0; $i < count($bits); $i++)
	{
		if (strlen($lines[$ptr].$bits[$i]) < $max) $lines[$ptr] .= $bits[$i].' ';
		else 
		{
			$ptr++;
			$lines[$ptr] = $bits[$i].' ';
		}
	}
	if (count($lines) == 1) imagestring($im, $loadedfont, $bg['x'], 20, $lines[0], $black);
	else
	{
		imagestring($im, $loadedfont, $bg['x'], 10, $lines[0], $black);
		imagestring($im, $loadedfont, $bg['x'], 30, $lines[1], $black);
	}
	// Using imagepng() results in clearer text compared with
	$fname = MYPATH .'cache/'.md5($text).'.gif';
	imagegif($im, $fname);
	imagedestroy($im);
	return $fname;
}//makeSingle
?>

Code (markup):