<?php
/*
:::::::::::::::::::::::::::::::::::::::::::::::::::::::::::
::
::	GIFEncoder Version 3.0 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 V3.00";	/* Encoder version		*/

	var $BUF = Array ( );
	var $OFS = Array ( );
	var $SIG =  0;
	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_ofs,
							$GIF_mod
						) {
		if ( ! is_array ( $GIF_src ) && ! is_array ( $GIF_dly ) ) {
			printf	( "%s: %s", $this->VER, $this->ERR [ 'ERR00' ] );
			exit	( 0 );
		}
		if ( is_array ( $GIF_ofs ) && count ( $GIF_ofs ) > 1 ) {
			$this->SIG = 1;
			$this->OFS = $GIF_ofs;
		}
		$this->LOP = $GIF_lop === false ? false : (( $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, $cmap	);
			if($this->LOP !== false)
			{
				$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 {
					/*
					 *
					 * XY Padding...
					 *
					 */
					if ( $this->SIG == 1 ) {
						$Locals_img { 1 } = chr ( $this->OFS [ $i ] [ 0 ] & 0xFF );
						$Locals_img { 2 } = chr ( ( $$this->OFS [ $i ] [ 0 ] & 0xFF00 ) >> 8 );
						$Locals_img { 3 } = chr ( $this->OFS [ $i ] [ 1 ] & 0xFF );
						$Locals_img { 4 } = chr ( ( $this->OFS [ $i ] [ 1 ] & 0xFF00 ) >> 8 );
					}
					$byte  = ord ( $Locals_img { 9 } );
					$byte |= 0x80;
					$byte &= 0xF8;
					$byte |= ( ord ( $this->BUF [ 0 ] { 10 } ) & 0x07 );
					$Locals_img { 9 } = chr ( $byte );
					$this->GIF .= ( $Locals_ext . $Locals_img . $Locals_rgb . $Locals_tmp );
				}
			}
			else {
				/*
				 *
				 * XY Padding...
				 *
				 */
				if ( $this->SIG == 1 ) {
					$Locals_img { 1 } = chr ( $this->OFS [ $i ] [ 0 ] & 0xFF );
					$Locals_img { 2 } = chr ( ( $$this->OFS [ $i ] [ 0 ] & 0xFF00 ) >> 8 );
					$Locals_img { 3 } = chr ( $this->OFS [ $i ] [ 1 ] & 0xFF );
					$Locals_img { 4 } = chr ( ( $this->OFS [ $i ] [ 1 ] & 0xFF00 ) >> 8 );
				}
				$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 );
	}
}