<?php
// +----------------------------------------------------------------------
// | TOPThink [ WE CAN DO IT JUST THINK ]
// +----------------------------------------------------------------------
// | Copyright (c) 2010 http://topthink.com All rights reserved.
// +----------------------------------------------------------------------
// | Licensed ( http://www.apache.org/licenses/LICENSE-2.0 )
// +----------------------------------------------------------------------
// | Author: 麦当苗儿 <zuojiazi@vip.qq.com> <http://www.zjzit.cn>
// +----------------------------------------------------------------------
// | GIF.class.php 2013-03-09
// +----------------------------------------------------------------------
namespace CLib\Image;

class GIF{
	/**
	 * GIF帧列表
	 * @var array
	 */
	private $frames = array();

	/**
	 * 每帧等待时间列表
	 * @var array
	 */
	private $delays = array();

	/**
	 * 构造方法，用于解码GIF图片
	 * @param string $src GIF图片数据
	 * @param string $mod 图片数据类型
	 * @throws \Exception
	 */
	public function __construct($src = NULL, $mod = 'url'){
		if(!is_null($src)){
			if('url' == $mod && is_file($src)){
				$src = file_get_contents($src);
			}

			/* 解码GIF图片 */
			try{
				$de = new GIFDecoder($src);
				$this->frames = $de->GIFGetFrames();
				$this->delays = $de->GIFGetDelays();
			} catch(\Exception $e){
				throw new \Exception(_("GIF image decoding error"));
			}
		}
	}

	/**
	 * 设置或获取当前帧的数据
	 * @param  string $stream 二进制数据流
	 * @return boolean        获取到的数据
	 */
	public function image($stream = NULL){
		if(is_null($stream)){
			$current = current($this->frames);
			return false === $current ? reset($this->frames) : $current;
		} else{
			$this->frames[key($this->frames)] = $stream;
		}
	}

	/**
	 * 将当前帧移动到下一帧
	 * @return string 当前帧数据
	 */
	public function nextImage(){
		return next($this->frames);
	}

	/**
	 * 编码并保存当前GIF图片
	 * @param  string $gifname 图片名称
	 */
	public function save($gifname){
		$gif = new GIFEncoder($this->frames, $this->delays, 0, 2, 0, 0, 0, 'bin');
		file_put_contents($gifname, $gif->GetAnimation());
	}

}


/*
:::::::::::::::::::::::::::::::::::::::::::::::::::::::::::
::
::	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/
::
:::::::::::::::::::::::::::::::::::::::::::::::::::::::::::
*/

Class GIFEncoder{
	var $GIF = "GIF89a"; /* GIF header 6 bytes	*/
	var $VER = "GIFEncoder V2.05"; /* Encoder version		*/

	var $BUF = Array();
	var $LOP = 0;
	var $DIS = 2;
	var $COL = -1;
	var $IMG = -1;

	var $ERR = Array(
		'ERR00' => "Does not supported function for only one image!",
		'ERR01' => "Source is not a GIF image!",
		'ERR02' => "Unintelligible flag ",
		'ERR03' => "Does not make animation from animated GIF source",
	);

	/*
	:::::::::::::::::::::::::::::::::::::::::::::::::::
	::
	::	GIFEncoder...
	::
	*/
	function GIFEncoder($GIF_src, $GIF_dly, $GIF_lop, $GIF_dis, $GIF_red, $GIF_grn, $GIF_blu, $GIF_mod){
		if(!is_array($GIF_src) && !is_array($GIF_dly)){
			printf("%s: %s", $this->VER, $this->ERR ['ERR00']);
			exit    (0);
		}
		$this->LOP = ($GIF_lop > -1) ? $GIF_lop : 0;
		$this->DIS = ($GIF_dis > -1) ? (($GIF_dis < 3) ? $GIF_dis : 3) : 2;
		$this->COL = ($GIF_red > -1 && $GIF_grn > -1 && $GIF_blu > -1) ? ($GIF_red | ($GIF_grn << 8) | ($GIF_blu << 16)) : -1;

		for($i = 0; $i < count($GIF_src); $i++){
			if(strToLower($GIF_mod) == "url"){
				$this->BUF [] = fread(fopen($GIF_src [$i], "rb"), filesize($GIF_src [$i]));
			} else if(strToLower($GIF_mod) == "bin"){
				$this->BUF [] = $GIF_src [$i];
			} else{
				printf("%s: %s ( %s )!", $this->VER, $this->ERR ['ERR02'], $GIF_mod);
				exit    (0);
			}
			if(substr($this->BUF [$i], 0, 6) != "GIF87a" && substr($this->BUF [$i], 0, 6) != "GIF89a"){
				printf("%s: %d %s", $this->VER, $i, $this->ERR ['ERR01']);
				exit    (0);
			}
			for($j = (13 + 3 * (2 << (ord($this->BUF [$i]{10}) & 0x07))), $k = true; $k; $j++){
				switch($this->BUF [$i]{$j}){
					case "!":
						if((substr($this->BUF [$i], ($j + 3), 8)) == "NETSCAPE"){
							printf("%s: %s ( %s source )!", $this->VER, $this->ERR ['ERR03'], ($i + 1));
							exit    (0);
						}
						break;
					case ";":
						$k = false;
						break;
				}
			}
		}
		GIFEncoder::GIFAddHeader();
		for($i = 0; $i < count($this->BUF); $i++){
			GIFEncoder::GIFAddFrames($i, $GIF_dly [$i]);
		}
		GIFEncoder::GIFAddFooter();
	}

	/*
	:::::::::::::::::::::::::::::::::::::::::::::::::::
	::
	::	GIFAddHeader...
	::
	*/
	function GIFAddHeader(){
		$cmap = 0;

		if(ord($this->BUF [0]{10}) & 0x80){
			$cmap = 3 * (2 << (ord($this->BUF [0]{10}) & 0x07));

			$this->GIF .= substr($this->BUF [0], 6, 7);
			$this->GIF .= substr($this->BUF [0], 13, $cmap);
			$this->GIF .= "!\377\13NETSCAPE2.0\3\1" . GIFEncoder::GIFWord($this->LOP) . "\0";
		}
	}

	/*
	:::::::::::::::::::::::::::::::::::::::::::::::::::
	::
	::	GIFAddFrames...
	::
	*/
	function GIFAddFrames($i, $d){

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

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

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

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

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

		if($this->COL > -1 && ord($this->BUF [$i]{10}) & 0x80){
			for($j = 0; $j < (2 << (ord($this->BUF [$i]{10}) & 0x07)); $j++){
				if(ord($Locals_rgb{3 * $j + 0}) == (($this->COL >> 16) & 0xFF) && ord($Locals_rgb{3 * $j + 1}) == (($this->COL >> 8) & 0xFF) && ord($Locals_rgb{3 * $j + 2}) == (($this->COL >> 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->BUF [$i]{10}) & 0x80 && $this->IMG > -1){
			if($Global_len == $Locals_len){
				if(GIFEncoder::GIFBlockCompare($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->BUF [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->BUF [$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->IMG = 1;
	}

	/*
	:::::::::::::::::::::::::::::::::::::::::::::::::::
	::
	::	GIFAddFooter...
	::
	*/
	function GIFAddFooter(){
		$this->GIF .= ";";
	}

	/*
	:::::::::::::::::::::::::::::::::::::::::::::::::::
	::
	::	GIFBlockCompare...
	::
	*/
	function GIFBlockCompare($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);
	}

	/*
	:::::::::::::::::::::::::::::::::::::::::::::::::::
	::
	::	GIFWord...
	::
	*/
	function GIFWord($int){

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

	/*
	:::::::::::::::::::::::::::::::::::::::::::::::::::
	::
	::	GetAnimation...
	::
	*/
	function GetAnimation(){
		return ($this->GIF);
	}
}


/*
:::::::::::::::::::::::::::::::::::::::::::::::::::::::::::
::
::	GIFDecoder Version 2.0 by László Zsidi, http://gifs.hu
::
::	Created at 2007. 02. 01. '07.47.AM'
::
::
::
::
::  Try on-line GIFBuilder Form demo based on GIFDecoder.
::
::  http://gifs.hu/phpclasses/demos/GifBuilder/
::
:::::::::::::::::::::::::::::::::::::::::::::::::::::::::::
*/

Class GIFDecoder{
	var $GIF_buffer = Array();
	var $GIF_arrays = Array();
	var $GIF_delays = Array();
	var $GIF_stream = "";
	var $GIF_string = "";
	var $GIF_bfseek = 0;

	var $GIF_screen = Array();
	var $GIF_global = Array();
	var $GIF_sorted;
	var $GIF_colorS;
	var $GIF_colorC;
	var $GIF_colorF;

	/*
	:::::::::::::::::::::::::::::::::::::::::::::::::::
	::
	::	GIFDecoder ( $GIF_pointer )
	::
	*/
	function GIFDecoder($GIF_pointer){
		$this->GIF_stream = $GIF_pointer;

		GIFDecoder::GIFGetByte(6); // GIF89a
		GIFDecoder::GIFGetByte(7); // Logical Screen Descriptor

		$this->GIF_screen = $this->GIF_buffer;
		$this->GIF_colorF = $this->GIF_buffer [4] & 0x80 ? 1 : 0;
		$this->GIF_sorted = $this->GIF_buffer [4] & 0x08 ? 1 : 0;
		$this->GIF_colorC = $this->GIF_buffer [4] & 0x07;
		$this->GIF_colorS = 2 << $this->GIF_colorC;

		if($this->GIF_colorF == 1){
			GIFDecoder::GIFGetByte(3 * $this->GIF_colorS);
			$this->GIF_global = $this->GIF_buffer;
		}
		/*
		 *
		 *  05.06.2007.
		 *  Made a little modification
		 *
		 *
		 -	for ( $cycle = 1; $cycle; ) {
		 +		if ( GIFDecoder::GIFGetByte ( 1 ) ) {
		 -			switch ( $this->GIF_buffer [ 0 ] ) {
		 -				case 0x21:
		 -					GIFDecoder::GIFReadExtensions ( );
		 -					break;
		 -				case 0x2C:
		 -					GIFDecoder::GIFReadDescriptor ( );
		 -					break;
		 -				case 0x3B:
		 -					$cycle = 0;
		 -					break;
		 -		  	}
		 -		}
		 +		else {
		 +			$cycle = 0;
		 +		}
		 -	}
		*/
		for($cycle = 1; $cycle;){
			if(GIFDecoder::GIFGetByte(1)){
				switch($this->GIF_buffer [0]){
					case 0x21:
						GIFDecoder::GIFReadExtensions();
						break;
					case 0x2C:
						GIFDecoder::GIFReadDescriptor();
						break;
					case 0x3B:
						$cycle = 0;
						break;
				}
			} else{
				$cycle = 0;
			}
		}
	}

	/*
	:::::::::::::::::::::::::::::::::::::::::::::::::::
	::
	::	GIFReadExtension ( )
	::
	*/
	function GIFReadExtensions(){
		GIFDecoder::GIFGetByte(1);
		for(; ;){
			GIFDecoder::GIFGetByte(1);
			if(($u = $this->GIF_buffer [0]) == 0x00){
				break;
			}
			GIFDecoder::GIFGetByte($u);
			/*
			 * 07.05.2007.
			 * Implemented a new line for a new function
			 * to determine the originaly delays between
			 * frames.
			 *
			 */
			if($u == 4){
				$this->GIF_delays [] = ($this->GIF_buffer [1] | $this->GIF_buffer [2] << 8);
			}
		}
	}

	/*
	:::::::::::::::::::::::::::::::::::::::::::::::::::
	::
	::	GIFReadExtension ( )
	::
	*/
	function GIFReadDescriptor(){
		$GIF_screen = array();

		GIFDecoder::GIFGetByte(9);
		$GIF_screen = $this->GIF_buffer;
		$GIF_colorF = $this->GIF_buffer [8] & 0x80 ? 1 : 0;
		if($GIF_colorF){
			$GIF_code = $this->GIF_buffer [8] & 0x07;
			$GIF_sort = $this->GIF_buffer [8] & 0x20 ? 1 : 0;
		} else{
			$GIF_code = $this->GIF_colorC;
			$GIF_sort = $this->GIF_sorted;
		}
		$GIF_size = 2 << $GIF_code;
		$this->GIF_screen [4] &= 0x70;
		$this->GIF_screen [4] |= 0x80;
		$this->GIF_screen [4] |= $GIF_code;
		if($GIF_sort){
			$this->GIF_screen [4] |= 0x08;
		}
		$this->GIF_string = "GIF87a";
		GIFDecoder::GIFPutByte($this->GIF_screen);
		if($GIF_colorF == 1){
			GIFDecoder::GIFGetByte(3 * $GIF_size);
			GIFDecoder::GIFPutByte($this->GIF_buffer);
		} else{
			GIFDecoder::GIFPutByte($this->GIF_global);
		}
		$this->GIF_string .= chr(0x2C);
		$GIF_screen [8] &= 0x40;
		GIFDecoder::GIFPutByte($GIF_screen);
		GIFDecoder::GIFGetByte(1);
		GIFDecoder::GIFPutByte($this->GIF_buffer);
		for(; ;){
			GIFDecoder::GIFGetByte(1);
			GIFDecoder::GIFPutByte($this->GIF_buffer);
			if(($u = $this->GIF_buffer [0]) == 0x00){
				break;
			}
			GIFDecoder::GIFGetByte($u);
			GIFDecoder::GIFPutByte($this->GIF_buffer);
		}
		$this->GIF_string .= chr(0x3B);
		/*
		   Add frames into $GIF_stream array...
		*/
		$this->GIF_arrays [] = $this->GIF_string;
	}
	/*
	:::::::::::::::::::::::::::::::::::::::::::::::::::
	::
	::	GIFGetByte ( $len )
	::
	*/

	/*
	 *
	 *  05.06.2007.
	 *  Made a little modification
	 *
	 *
	 -	function GIFGetByte ( $len ) {
	 -		$this->GIF_buffer = Array ( );
	 -
	 -		for ( $i = 0; $i < $len; $i++ ) {
	 +			if ( $this->GIF_bfseek > strlen ( $this->GIF_stream ) ) {
	 +				return 0;
	 +			}
	 -			$this->GIF_buffer [ ] = ord ( $this->GIF_stream { $this->GIF_bfseek++ } );
	 -		}
	 +		return 1;
	 -	}
	 */
	function GIFGetByte($len){
		$this->GIF_buffer = Array();

		for($i = 0; $i < $len; $i++){
			if($this->GIF_bfseek > strlen($this->GIF_stream)){
				return 0;
			}
			$this->GIF_buffer [] = ord($this->GIF_stream{$this->GIF_bfseek++});
		}
		return 1;
	}

	/*
	:::::::::::::::::::::::::::::::::::::::::::::::::::
	::
	::	GIFPutByte ( $bytes )
	::
	*/
	function GIFPutByte($bytes){
		for($i = 0; $i < count($bytes); $i++){
			$this->GIF_string .= chr($bytes [$i]);
		}
	}

	/*
	:::::::::::::::::::::::::::::::::::::::::::::::::::
	::
	::	PUBLIC FUNCTIONS
	::
	::
	::	GIFGetFrames ( )
	::
	*/
	function GIFGetFrames(){
		return ($this->GIF_arrays);
	}

	/*
	:::::::::::::::::::::::::::::::::::::::::::::::::::
	::
	::	GIFGetDelays ( )
	::
	*/
	function GIFGetDelays(){
		return ($this->GIF_delays);
	}
}