/src/GifCreator/GifCreator.php

<?php



namespace GifCreator;



/**

 * Create an animated GIF from multiple images

 * 

 * @version 1.0

 * @link https://github.com/Sybio/GifCreator

 * @author Sybio (ClĂŠment Guillemain  / @Sybio01)

 * @license http://opensource.org/licenses/gpl-license.php GNU Public License

 * @copyright ClĂŠment Guillemain

 */

class GifCreator

{

    /**

     * @var string The gif string source (old: this->GIF)

     */

    private $gif;

    

    /**

     * @var string Encoder version (old: this->VER)

     */

	private $version;

    

    /**

     * @var boolean Check the image is build or not (old: this->IMG)

     */

    private $imgBuilt;



    /**

     * @var array Frames string sources (old: this->BUF)

     */

	private $frameSources;

    

    /**

     * @var integer Gif loop (old: this->LOP)

     */

	private $loop;

    

    /**

     * @var integer Gif dis (old: this->DIS)

     */

	private $dis;

    

    /**

     * @var integer Gif color (old: this->COL)

     */

	private $colour;

    

    /**

     * @var array (old: this->ERR)

     */

	private $errors;

 

    // Methods

    // ===================================================================================

    

    /**

     * Constructor

     */

    public function __construct()

    {

        $this->reset();

        

        // Static data

        $this->version = 'GifCreator: Under development';

        $this->errors = array(

            'ERR00' => 'Does not supported function for only one image.',

    		'ERR01' => 'Source is not a GIF image.',

    		'ERR02' => 'You have to give resource image variables, image URL or image binary sources in $frames array.',

    		'ERR03' => 'Does not make animation from animated GIF source.',

        );

    }



	/**

     * Create the GIF string (old: GIFEncoder)

     * 

     * @param array $frames An array of frame: can be file paths, resource image variables, binary sources or image URLs

     * @param array $durations An array containing the duration of each frame

     * @param integer $loop Number of GIF loops before stopping animation (Set 0 to get an infinite loop)

     * 

     * @return string The GIF string source

     */

	public function create($frames = array(), $durations = array(), $loop = 0)

    {

		if (!is_array($frames) && !is_array($GIF_tim)) {

            

            throw new \Exception($this->version.': '.$this->errors['ERR00']);

		}

        

		$this->loop = ($loop > -1) ? $loop : 0;

		$this->dis = 2;

        

		for ($i = 0; $i < count($frames); $i++) {

		  

			if (is_resource($frames[$i])) { // Resource var

                

                $resourceImg = $frames[$i];

                

                ob_start();

                imagegif($frames[$i]);

                $this->frameSources[] = ob_get_contents();

                ob_end_clean();

                

            } elseif (is_string($frames[$i])) { // File path or URL or Binary source code

			     

                if (file_exists($frames[$i]) || filter_var($frames[$i], FILTER_VALIDATE_URL)) { // File path

                    

                    $frames[$i] = file_get_contents($frames[$i]);                    

                }

                

                $resourceImg = imagecreatefromstring($frames[$i]);

                

                ob_start();

                imagegif($resourceImg);

                $this->frameSources[] = ob_get_contents();

                ob_end_clean();

                 

			} else { // Fail

                

                throw new \Exception($this->version.': '.$this->errors['ERR02'].' ('.$mode.')');

			}

            

            if ($i == 0) {

                

                $colour = imagecolortransparent($resourceImg);

            }

            

			if (substr($this->frameSources[$i], 0, 6) != 'GIF87a' && substr($this->frameSources[$i], 0, 6) != 'GIF89a') {

			 

                throw new \Exception($this->version.': '.$i.' '.$this->errors['ERR01']);

			}

            

			for ($j = (13 + 3 * (2 << (ord($this->frameSources[$i] { 10 }) & 0x07))), $k = TRUE; $k; $j++) {

			 

				switch ($this->frameSources[$i] { $j }) {

				    

					case '!':

                    

						if ((substr($this->frameSources[$i], ($j + 3), 8)) == 'NETSCAPE') {

                            

                            throw new \Exception($this->version.': '.$this->errors['ERR03'].' ('.($i + 1).' source).');

						}

                        

					break;

                        

					case ';':

                    

						$k = false;

					break;

				}

			}

            

            unset($resourceImg);

		}

		

        if (isset($colour)) {

            

            $this->colour = $colour;

                                    

        } else {

            

            $red = $green = $blue = 0;

            $this->colour = ($red > -1 && $green > -1 && $blue > -1) ? ($red | ($green << 8) | ($blue << 16)) : -1;

        }

        

		$this->gifAddHeader();

        

		for ($i = 0; $i < count($this->frameSources); $i++) {

		  

			$this->addGifFrames($i, $durations[$i]);

		}

        

		$this->gifAddFooter();

        

        return $this->gif;

	}

    

    // Internals

    // ===================================================================================

    

	/**

     * Add the header gif string in its source (old: GIFAddHeader)

     */

	public function gifAddHeader()

    {

		$cmap = 0;



		if (ord($this->frameSources[0] { 10 }) & 0x80) {

		  

			$cmap = 3 * (2 << (ord($this->frameSources[0] { 10 }) & 0x07));



			$this->gif .= substr($this->frameSources[0], 6, 7);

			$this->gif .= substr($this->frameSources[0], 13, $cmap);

			$this->gif .= "!\377\13NETSCAPE2.0\3\1".$this->encodeAsciiToChar($this->loop)."\0";

		}

	}

    

	/**

     * Add the frame sources to the GIF string (old: GIFAddFrames)

     * 

     * @param integer $i

     * @param integer $d

     */

	public function addGifFrames($i, $d)

    {

		$Locals_str = 13 + 3 * (2 << (ord($this->frameSources[ $i ] { 10 }) & 0x07));



		$Locals_end = strlen($this->frameSources[$i]) - $Locals_str - 1;

		$Locals_tmp = substr($this->frameSources[$i], $Locals_str, $Locals_end);



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

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



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

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



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



		if ($this->colour > -1 && ord($this->frameSources[$i] { 10 }) & 0x80) {

		  

			for ($j = 0; $j < (2 << (ord($this->frameSources[$i] { 10 } ) & 0x07)); $j++) {

			 

				if (ord($Locals_rgb { 3 * $j + 0 }) == (($this->colour >> 16) & 0xFF) &&

					ord($Locals_rgb { 3 * $j + 1 }) == (($this->colour >> 8) & 0xFF) &&

					ord($Locals_rgb { 3 * $j + 2 }) == (($this->colour >> 0) & 0xFF)

				) {

					$Locals_ext = "!\xF9\x04".chr(($this->dis << 2) + 1).chr(($d >> 0) & 0xFF).chr(($d >> 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($this->frameSources[$i] { 10 }) & 0x80 && $this->imgBuilt) {

		  

			if ($Global_len == $Locals_len) {

			 

				if ($this->gifBlockCompare($Global_rgb, $Locals_rgb, $Global_len)) {

				    

					$this->gif .= $Locals_ext.$Locals_img.$Locals_tmp;

                    

				} else {

				    

					$byte = ord($Locals_img { 9 });

					$byte |= 0x80;

					$byte &= 0xF8;

					$byte |= (ord($this->frameSources[0] { 10 }) & 0x07);

					$Locals_img { 9 } = chr($byte);

					$this->gif .= $Locals_ext.$Locals_img.$Locals_rgb.$Locals_tmp;

				}

                

			} else {

			 

				$byte = ord($Locals_img { 9 });

				$byte |= 0x80;

				$byte &= 0xF8;

				$byte |= (ord($this->frameSources[$i] { 10 }) & 0x07);

				$Locals_img { 9 } = chr($byte);

				$this->gif .= $Locals_ext.$Locals_img.$Locals_rgb.$Locals_tmp;

			}

            

		} else {

		  

			$this->gif .= $Locals_ext.$Locals_img.$Locals_tmp;

		}

        

		$this->imgBuilt = true;

	}

    

	/**

     * Add the gif string footer char (old: GIFAddFooter)

     */

	public function gifAddFooter()

    {

		$this->gif .= ';';

	}

    

	/**

     * Compare two block and return the version (old: GIFBlockCompare)

     * 

     * @param string $globalBlock

     * @param string $localBlock

     * @param integer $length

     * 

     * @return integer

	 */

	public function gifBlockCompare($globalBlock, $localBlock, $length)

    {

		for ($i = 0; $i < $length; $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;

	}

    

	/**

     * Encode an ASCII char into a string char (old: GIFWord)

     * 

     * $param integer $char ASCII char

     * 

     * @return string

	 */

	public function encodeAsciiToChar($char)

    {

		return (chr($char & 0xFF).chr(($char >> 8) & 0xFF));

	}

    

    /**

     * Reset and clean the current object

     */

    public function reset()

    {

        $this->frameSources;

        $this->gif = 'GIF89a'; // the GIF header

        $this->imgBuilt = false;

        $this->loop = 0;

        $this->dis = 2;

        $this->colour = -1;

    }

    

    // Getter / Setter

    // ===================================================================================

    

	/**

     * Get the final GIF image string (old: GetAnimation)

     * 

     * @return string

	 */

	public function getGif()

    {

		return $this->gif;

	}

}