dynamic animated gif clock

gif.php

<?php

date_default_timezone_set('America/Halifax');
include 'GIFEncoder.class.php';


$time = $_GET['time'];
$future_date = new DateTime(date('r',strtotime($time)));
$time_now = time();
$now = new DateTime(date('r', $time_now));


$frames = array();
$delays = array();


$image = imagecreatefrompng('countdown.png');
$delay = 100; // milliseconds
$font = array(
	'size'=>40,
	'angle'=>0,
	'x-offset'=>10,
	'y-offset'=>70,
	'file'=>'DIGITALDREAM.ttf',
	'color'=>imagecolorallocate($image, 255, 255, 255),
);
for($i = 0; $i <= 60; $i++){
	$interval = date_diff($future_date, $now);
	if($future_date < $now){
		// Open the first source image and add the text.
		$image = imagecreatefrompng('countdown.png');;
		$text = $interval->format('00:00:00:00');
		imagettftext ($image , $font['size'] , $font['angle'] , $font['x-offset'] , $font['y-offset'] , $font['color'] , $font['file'], $text );
		ob_start();
		imagegif($image);
		$frames[]=ob_get_contents();
		$delays[]=$delay;
                $loops = 1;
		ob_end_clean();
		break;
	} else {
		// Open the first source image and add the text.
		$image = imagecreatefrompng('countdown.png');;
		$text = $interval->format('%a:%H:%I:%S');
		// %a is weird in that it doesn’t give you a two digit number
		// check if it starts with a single digit 0-9
		// and prepend a 0 if it does
		if(preg_match('/^[0-9]\:/', $text)){
			$text = '0'.$text;
		}
		imagettftext ($image , $font['size'] , $font['angle'] , $font['x-offset'] , $font['y-offset'] , $font['color'] , $font['file'], $text );
		ob_start();
		imagegif($image);
		$frames[]=ob_get_contents();
		$delays[]=$delay;
                $loops = 0;
		ob_end_clean();
	}
	$now->modify('+1 second');
}
//expire this image instantly
header( 'Expires: Sat, 26 Jul 1997 05:00:00 GMT' );
header( 'Last-Modified: ' . gmdate( 'D, d M Y H:i:s' ) . ' GMT' );
header( 'Cache-Control: no-store, no-cache, must-revalidate' );
header( 'Cache-Control: post-check=0, pre-check=0', false );
header( 'Pragma: no-cache' ); 
$gif = new AnimatedGif($frames,$delays,$loops);
$gif->display();

GIFEncoder.class.php

<?php

/*
  :::::::::::::::::::::::::::::::::::::::::::::::::::::::::::
  :: Formerly known as:::
  :: GIFEncoder Version 2.0 by László Zsidi, http://gifs.hu
  ::
  :: This class is a rewritten 'GifMerge.class.php' version.
  ::
  :: Modification:
  :: - Simplified and easy code,
  :: - Ultra fast encoding,
  :: - Built-in errors,
  :: - Stable working
  ::
  ::
  :: Updated at 2007. 02. 13. '00.05.AM'
  ::
  ::
  ::
  :: Try on-line GIFBuilder Form demo based on GIFEncoder.
  ::
  :: http://gifs.hu/phpclasses/demos/GifBuilder/
  ::
  :::::::::::::::::::::::::::::::::::::::::::::::::::::::::::
 */

/**
 * Encode animated gifs
 */
class AnimatedGif {

    /**
     * The built gif image
     * @var resource
     */
    private $image = '';

    /**
     * The array of images to stack
     * @var array
     */
    private $buffer = Array();

    /**
     * How many times to loop? 0 = infinite
     * @var int
     */
    private $number_of_loops = 0;

    /**
     * 
     * @var int 
     */
    private $DIS = 2;

    /**
     * Which colour is transparent
     * @var int
     */
    private $transparent_colour = -1;

    /**
     * Is this the first frame
     * @var int
     */
    private $first_frame = TRUE;

    /**
     * Encode an animated gif
     * @param array $source_images An array of binary source images
     * @param array $image_delays The delays associated with the source images
     * @param type $number_of_loops The number of times to loop
     * @param int $transparent_colour_red
     * @param int $transparent_colour_green
     * @param int $transparent_colour_blue 
     */
    function __construct(array $source_images, array $image_delays, $number_of_loops, $transparent_colour_red = -1, $transparent_colour_green = -1, $transparent_colour_blue = -1) {
        /**
         * I have no idea what these even do, they appear to do nothing to the image so far 
         */
        $transparent_colour_red = 0;
        $transparent_colour_green = 0;
        $transparent_colour_blue = 0;

        $this->number_of_loops = ( $number_of_loops > -1 ) ? $number_of_loops : 0;
        $this->set_transparent_colour($transparent_colour_red, $transparent_colour_green, $transparent_colour_blue);
        $this->buffer_images($source_images);

        $this->addHeader();
        for ($i = 0; $i < count($this->buffer); $i++) {
            $this->addFrame($i, $image_delays [$i]);
        }
    }
    
    /**
     * Set the transparent colour
     * @param int $red
     * @param int $green
     * @param int $blue 
     */
    private function set_transparent_colour($red, $green, $blue){
        $this->transparent_colour = ( $red > -1 && $green > -1 && $blue > -1 ) ?
                ( $red | ( $green << 8 ) | ( $blue << 16 ) ) : -1;
    }

    /**
     * Buffer the images and check to make sure they are vaild
     * @param array $source_images the array of source images
     * @throws Exception 
     */
    private function buffer_images($source_images) {
        for ($i = 0; $i < count($source_images); $i++) {
            $this->buffer [] = $source_images [$i];
            if (substr($this->buffer [$i], 0, 6) != "GIF87a" && substr($this->buffer [$i], 0, 6) != "GIF89a") {
                throw new Exception('Image at position ' . $i. ' is not a gif');
            }
            for ($j = ( 13 + 3 * ( 2 << ( ord($this->buffer [$i] { 10 }) & 0x07 ) ) ), $k = TRUE; $k; $j++) {
                switch ($this->buffer [$i] { $j }) {
                    case "!":
                        if (( substr($this->buffer [$i], ( $j + 3), 8) ) == "NETSCAPE") {
                            throw new Exception('You cannot make an animation from an animated gif.');
                        }
                        break;
                    case ";":
                        $k = FALSE;
                        break;
                }
            }
        }
    }

    /**
     * Add the gif header to the image
     */
    private function addHeader() {
        $cmap = 0;
        $this->image = 'GIF89a';
        if (ord($this->buffer [0] { 10 }) & 0x80) {
            $cmap = 3 * ( 2 << ( ord($this->buffer [0] { 10 }) & 0x07 ) );
            $this->image .= substr($this->buffer [0], 6, 7);
            $this->image .= substr($this->buffer [0], 13, $cmap);
            $this->image .= "!\377\13NETSCAPE2.0\3\1" . $this->word($this->number_of_loops) . "\0";
        }
    }

    /**
     * Add a frame to the animation
     * @param int $frame The frame to be added
     * @param int $delay The delay associated with the frame
     */
    private function addFrame($frame, $delay) {
        $Locals_str = 13 + 3 * ( 2 << ( ord($this->buffer [$frame] { 10 }) & 0x07 ) );

        $Locals_end = strlen($this->buffer [$frame]) - $Locals_str - 1;
        $Locals_tmp = substr($this->buffer [$frame], $Locals_str, $Locals_end);

        $Global_len = 2 << ( ord($this->buffer [0] { 10 }) & 0x07 );
        $Locals_len = 2 << ( ord($this->buffer [$frame] { 10 }) & 0x07 );

        $Global_rgb = substr($this->buffer [0], 13, 3 * ( 2 << ( ord($this->buffer [0] { 10 }) & 0x07 ) ));
        $Locals_rgb = substr($this->buffer [$frame], 13, 3 * ( 2 << ( ord($this->buffer [$frame] { 10 }) & 0x07 ) ));

        $Locals_ext = "!\xF9\x04" . chr(( $this->DIS << 2 ) + 0) .
                chr(( $delay >> 0 ) & 0xFF) . chr(( $delay >> 8 ) & 0xFF) . "\x0\x0";

        if ($this->transparent_colour > -1 && ord($this->buffer [$frame] { 10 }) & 0x80) {
            for ($j = 0; $j < ( 2 << ( ord($this->buffer [$frame] { 10 }) & 0x07 ) ); $j++) {
                if (
                        ord($Locals_rgb { 3 * $j + 0 }) == ( ( $this->transparent_colour >> 16 ) & 0xFF ) &&
                        ord($Locals_rgb { 3 * $j + 1 }) == ( ( $this->transparent_colour >> 8 ) & 0xFF ) &&
                        ord($Locals_rgb { 3 * $j + 2 }) == ( ( $this->transparent_colour >> 0 ) & 0xFF )
                ) {
                    $Locals_ext = "!\xF9\x04" . chr(( $this->DIS << 2 ) + 1) .
                            chr(( $delay >> 0 ) & 0xFF) . chr(( $delay >> 8 ) & 0xFF) . chr($j) . "\x0";
                    break;
                }
            }
        }
        switch ($Locals_tmp { 0 }) {
            case "!":
                $Locals_img = substr($Locals_tmp, 8, 10);
                $Locals_tmp = substr($Locals_tmp, 18, strlen($Locals_tmp) - 18);
                break;
            case ",":
                $Locals_img = substr($Locals_tmp, 0, 10);
                $Locals_tmp = substr($Locals_tmp, 10, strlen($Locals_tmp) - 10);
                break;
        }
        if (ord($this->buffer [$frame] { 10 }) & 0x80 && $this->first_frame === FALSE) {
            if ($Global_len == $Locals_len) {
                if ($this->blockCompare($Global_rgb, $Locals_rgb, $Global_len)) {
                    $this->image .= ( $Locals_ext . $Locals_img . $Locals_tmp );
                } else {
                    $byte = ord($Locals_img { 9 });
                    $byte |= 0x80;
                    $byte &= 0xF8;
                    $byte |= ( ord($this->buffer [0] { 10 }) & 0x07 );
                    $Locals_img { 9 } = chr($byte);
                    $this->image .= ( $Locals_ext . $Locals_img . $Locals_rgb . $Locals_tmp );
                }
            } else {
                $byte = ord($Locals_img { 9 });
                $byte |= 0x80;
                $byte &= 0xF8;
                $byte |= ( ord($this->buffer [$frame] { 10 }) & 0x07 );
                $Locals_img { 9 } = chr($byte);
                $this->image .= ( $Locals_ext . $Locals_img . $Locals_rgb . $Locals_tmp );
            }
        } else {
            $this->image .= ( $Locals_ext . $Locals_img . $Locals_tmp );
        }
        $this->first_frame = FALSE;
    }

    /**
     * Add the gif footer 
     */
    private function addFooter() {
        $this->image .= ";";
    }

    /**
     * Compare gif blocks? What is a block?
     * @param type $GlobalBlock
     * @param type $LocalBlock
     * @param type $Len
     * @return type 
     */
    private function blockCompare($GlobalBlock, $LocalBlock, $Len) {
        for ($i = 0; $i < $Len; $i++) {
            if (
                    $GlobalBlock { 3 * $i + 0 } != $LocalBlock { 3 * $i + 0 } ||
                    $GlobalBlock { 3 * $i + 1 } != $LocalBlock { 3 * $i + 1 } ||
                    $GlobalBlock { 3 * $i + 2 } != $LocalBlock { 3 * $i + 2 }
            ) {
                return ( 0 );
            }
        }

        return ( 1 );
    }

    /**
     * No clue
     * @param int $int
     * @return string the char you meant? 
     */
    private function word($int) {
        return ( chr($int & 0xFF) . chr(( $int >> 8 ) & 0xFF) );
    }

    /**
     * Return the animated gif
     * @return type 
     */
    function getAnimation() {
        return $this->image;
    }

    /**
     * Return the animated gif
     * @return type 
     */
    function display() {
        //late footer add
        $this->addFooter();
        header('Content-type:image/gif');
        echo $this->image;
    }

}

Very cool code. Works a treat. Thanks for sharing.

Yeah - thanks indeed! I tweaked gif.php a bit so I could have email authors pass a timezone as a GET variable in the url - a default is still set in the code if none passed. It's here if anyone wants:

Changed:

date_default_timezone_set('America/Halifax');

to

$time_zone = (!empty($_GET['time_zone'])) ? $_GET['time_zone'] : 'America/Halifax';
date_default_timezone_set($time_zone);

I cant seems to get this work, willing to pay to the one who will help me. Wating for pm

How to stop the gif animation after 1st execution?????

Agreed. How do you get this to not loop at the end?

Stupidest solution would be creating global flag and controlling its value.