Chris@76: <?php
Chris@76: 
Chris@76: /**
Chris@76:  * Simple Machines Forum (SMF)
Chris@76:  *
Chris@76:  * @package SMF
Chris@76:  * @author Simple Machines http://www.simplemachines.org
Chris@76:  * @copyright 2011 Simple Machines
Chris@76:  * @license http://www.simplemachines.org/about/smf/license.php BSD
Chris@76:  *
Chris@76:  * @version 2.0
Chris@76:  */
Chris@76: 
Chris@76: /*	Gif Util copyright 2003 by Yamasoft (S/C). All rights reserved.
Chris@76: 	Do not remove this portion of the header, or use these functions except
Chris@76: 	from the original author. To get it, please navigate to:
Chris@76: 	http://www.yamasoft.com/php-gif.zip
Chris@76: */
Chris@76: 
Chris@76: if (!defined('SMF'))
Chris@76: 	die('Hacking attempt...');
Chris@76: 
Chris@76: /*	Classes used for reading gif files (in case PHP's GD doesn't provide the
Chris@76: 	proper gif-functions).
Chris@76: */
Chris@76: 
Chris@76: class gif_lzw_compression
Chris@76: {
Chris@76: 	public $MAX_LZW_BITS;
Chris@76: 	public $Fresh, $CodeSize, $SetCodeSize, $MaxCode, $MaxCodeSize, $FirstCode, $OldCode;
Chris@76: 	public $ClearCode, $EndCode, $Next, $Vals, $Stack, $sp, $Buf, $CurBit, $LastBit, $Done, $LastByte;
Chris@76: 
Chris@76: 	public function __construct()
Chris@76: 	{
Chris@76: 		$this->MAX_LZW_BITS = 12;
Chris@76: 		unset($this->Next, $this->Vals, $this->Stack, $this->Buf);
Chris@76: 
Chris@76: 		$this->Next  = range(0, (1 << $this->MAX_LZW_BITS)       - 1);
Chris@76: 		$this->Vals  = range(0, (1 << $this->MAX_LZW_BITS)       - 1);
Chris@76: 		$this->Stack = range(0, (1 << ($this->MAX_LZW_BITS + 1)) - 1);
Chris@76: 		$this->Buf   = range(0, 279);
Chris@76: 	}
Chris@76: 
Chris@76: 	public function decompress($data, &$datLen)
Chris@76: 	{
Chris@76: 		$stLen  = strlen($data);
Chris@76: 		$datLen = 0;
Chris@76: 		$ret    = '';
Chris@76: 
Chris@76: 		$this->LZWCommand($data, true);
Chris@76: 
Chris@76: 		while (($iIndex = $this->LZWCommand($data, false)) >= 0)
Chris@76: 			$ret .= chr($iIndex);
Chris@76: 
Chris@76: 		$datLen = $stLen - strlen($data);
Chris@76: 
Chris@76: 		if ($iIndex != -2)
Chris@76: 			return false;
Chris@76: 
Chris@76: 		return $ret;
Chris@76: 	}
Chris@76: 
Chris@76: 	public function LZWCommand(&$data, $bInit)
Chris@76: 	{
Chris@76: 		if ($bInit)
Chris@76: 		{
Chris@76: 			$this->SetCodeSize = ord($data[0]);
Chris@76: 			$data = substr($data, 1);
Chris@76: 
Chris@76: 			$this->CodeSize    = $this->SetCodeSize + 1;
Chris@76: 			$this->ClearCode   = 1 << $this->SetCodeSize;
Chris@76: 			$this->EndCode     = $this->ClearCode + 1;
Chris@76: 			$this->MaxCode     = $this->ClearCode + 2;
Chris@76: 			$this->MaxCodeSize = $this->ClearCode << 1;
Chris@76: 
Chris@76: 			$this->GetCode($data, $bInit);
Chris@76: 
Chris@76: 			$this->Fresh = 1;
Chris@76: 			for ($i = 0; $i < $this->ClearCode; $i++)
Chris@76: 			{
Chris@76: 				$this->Next[$i] = 0;
Chris@76: 				$this->Vals[$i] = $i;
Chris@76: 			}
Chris@76: 
Chris@76: 			for (; $i < (1 << $this->MAX_LZW_BITS); $i++)
Chris@76: 			{
Chris@76: 				$this->Next[$i] = 0;
Chris@76: 				$this->Vals[$i] = 0;
Chris@76: 			}
Chris@76: 
Chris@76: 			$this->sp = 0;
Chris@76: 			return 1;
Chris@76: 		}
Chris@76: 
Chris@76: 		if ($this->Fresh)
Chris@76: 		{
Chris@76: 			$this->Fresh = 0;
Chris@76: 			do
Chris@76: 			{
Chris@76: 				$this->FirstCode = $this->GetCode($data, $bInit);
Chris@76: 				$this->OldCode   = $this->FirstCode;
Chris@76: 			}
Chris@76: 			while ($this->FirstCode == $this->ClearCode);
Chris@76: 
Chris@76: 			return $this->FirstCode;
Chris@76: 		}
Chris@76: 
Chris@76: 		if ($this->sp > 0)
Chris@76: 		{
Chris@76: 			$this->sp--;
Chris@76: 			return $this->Stack[$this->sp];
Chris@76: 		}
Chris@76: 
Chris@76: 		while (($Code = $this->GetCode($data, $bInit)) >= 0)
Chris@76: 		{
Chris@76: 			if ($Code == $this->ClearCode)
Chris@76: 			{
Chris@76: 				for ($i = 0; $i < $this->ClearCode; $i++)
Chris@76: 				{
Chris@76: 					$this->Next[$i] = 0;
Chris@76: 					$this->Vals[$i] = $i;
Chris@76: 				}
Chris@76: 
Chris@76: 				for (; $i < (1 << $this->MAX_LZW_BITS); $i++)
Chris@76: 				{
Chris@76: 					$this->Next[$i] = 0;
Chris@76: 					$this->Vals[$i] = 0;
Chris@76: 				}
Chris@76: 
Chris@76: 				$this->CodeSize    = $this->SetCodeSize + 1;
Chris@76: 				$this->MaxCodeSize = $this->ClearCode << 1;
Chris@76: 				$this->MaxCode     = $this->ClearCode + 2;
Chris@76: 				$this->sp          = 0;
Chris@76: 				$this->FirstCode   = $this->GetCode($data, $bInit);
Chris@76: 				$this->OldCode     = $this->FirstCode;
Chris@76: 
Chris@76: 				return $this->FirstCode;
Chris@76: 			}
Chris@76: 
Chris@76: 			if ($Code == $this->EndCode)
Chris@76: 				return -2;
Chris@76: 
Chris@76: 			$InCode = $Code;
Chris@76: 			if ($Code >= $this->MaxCode)
Chris@76: 			{
Chris@76: 				$this->Stack[$this->sp] = $this->FirstCode;
Chris@76: 				$this->sp++;
Chris@76: 				$Code = $this->OldCode;
Chris@76: 			}
Chris@76: 
Chris@76: 			while ($Code >= $this->ClearCode)
Chris@76: 			{
Chris@76: 				$this->Stack[$this->sp] = $this->Vals[$Code];
Chris@76: 				$this->sp++;
Chris@76: 
Chris@76: 				if ($Code == $this->Next[$Code]) // Circular table entry, big GIF Error!
Chris@76: 					return -1;
Chris@76: 
Chris@76: 				$Code = $this->Next[$Code];
Chris@76: 			}
Chris@76: 
Chris@76: 			$this->FirstCode = $this->Vals[$Code];
Chris@76: 			$this->Stack[$this->sp] = $this->FirstCode;
Chris@76: 			$this->sp++;
Chris@76: 
Chris@76: 			if (($Code = $this->MaxCode) < (1 << $this->MAX_LZW_BITS))
Chris@76: 			{
Chris@76: 				$this->Next[$Code] = $this->OldCode;
Chris@76: 				$this->Vals[$Code] = $this->FirstCode;
Chris@76: 				$this->MaxCode++;
Chris@76: 
Chris@76: 				if (($this->MaxCode >= $this->MaxCodeSize) && ($this->MaxCodeSize < (1 << $this->MAX_LZW_BITS)))
Chris@76: 				{
Chris@76: 					$this->MaxCodeSize *= 2;
Chris@76: 					$this->CodeSize++;
Chris@76: 				}
Chris@76: 			}
Chris@76: 
Chris@76: 			$this->OldCode = $InCode;
Chris@76: 			if ($this->sp > 0)
Chris@76: 			{
Chris@76: 				$this->sp--;
Chris@76: 				return $this->Stack[$this->sp];
Chris@76: 			}
Chris@76: 		}
Chris@76: 
Chris@76: 		return $Code;
Chris@76: 	}
Chris@76: 
Chris@76: 	public function GetCode(&$data, $bInit)
Chris@76: 	{
Chris@76: 		if ($bInit)
Chris@76: 		{
Chris@76: 			$this->CurBit   = 0;
Chris@76: 			$this->LastBit  = 0;
Chris@76: 			$this->Done     = 0;
Chris@76: 			$this->LastByte = 2;
Chris@76: 
Chris@76: 			return 1;
Chris@76: 		}
Chris@76: 
Chris@76: 		if (($this->CurBit + $this->CodeSize) >= $this->LastBit)
Chris@76: 		{
Chris@76: 			if ($this->Done)
Chris@76: 			{
Chris@76: 				// Ran off the end of my bits...
Chris@76: 				if ($this->CurBit >= $this->LastBit)
Chris@76: 					return 0;
Chris@76: 
Chris@76: 				return -1;
Chris@76: 			}
Chris@76: 
Chris@76: 			$this->Buf[0] = $this->Buf[$this->LastByte - 2];
Chris@76: 			$this->Buf[1] = $this->Buf[$this->LastByte - 1];
Chris@76: 
Chris@76: 			$count = ord($data[0]);
Chris@76: 			$data  = substr($data, 1);
Chris@76: 
Chris@76: 			if ($count)
Chris@76: 			{
Chris@76: 				for ($i = 0; $i < $count; $i++)
Chris@76: 					$this->Buf[2 + $i] = ord($data{$i});
Chris@76: 
Chris@76: 				$data = substr($data, $count);
Chris@76: 			}
Chris@76: 			else
Chris@76: 				$this->Done = 1;
Chris@76: 
Chris@76: 			$this->LastByte = 2 + $count;
Chris@76: 			$this->CurBit = ($this->CurBit - $this->LastBit) + 16;
Chris@76: 			$this->LastBit  = (2 + $count) << 3;
Chris@76: 		}
Chris@76: 
Chris@76: 		$iRet = 0;
Chris@76: 		for ($i = $this->CurBit, $j = 0; $j < $this->CodeSize; $i++, $j++)
Chris@76: 			$iRet |= (($this->Buf[intval($i / 8)] & (1 << ($i % 8))) != 0) << $j;
Chris@76: 
Chris@76: 		$this->CurBit += $this->CodeSize;
Chris@76: 		return $iRet;
Chris@76: 	}
Chris@76: }
Chris@76: 
Chris@76: class gif_color_table
Chris@76: {
Chris@76: 	public $m_nColors;
Chris@76: 	public $m_arColors;
Chris@76: 
Chris@76: 	public function __construct()
Chris@76: 	{
Chris@76: 		unset($this->m_nColors, $this->m_arColors);
Chris@76: 	}
Chris@76: 
Chris@76: 	public function load($lpData, $num)
Chris@76: 	{
Chris@76: 		$this->m_nColors  = 0;
Chris@76: 		$this->m_arColors = array();
Chris@76: 
Chris@76: 		for ($i = 0; $i < $num; $i++)
Chris@76: 		{
Chris@76: 			$rgb = substr($lpData, $i * 3, 3);
Chris@76: 			if (strlen($rgb) < 3)
Chris@76: 				return false;
Chris@76: 
Chris@76: 			$this->m_arColors[] = (ord($rgb[2]) << 16) + (ord($rgb[1]) << 8) + ord($rgb[0]);
Chris@76: 			$this->m_nColors++;
Chris@76: 		}
Chris@76: 
Chris@76: 		return true;
Chris@76: 	}
Chris@76: 
Chris@76: 	public function toString()
Chris@76: 	{
Chris@76: 		$ret = '';
Chris@76: 
Chris@76: 		for ($i = 0; $i < $this->m_nColors; $i++)
Chris@76: 		{
Chris@76: 			$ret .=
Chris@76: 				chr(($this->m_arColors[$i] & 0x000000FF))       . // R
Chris@76: 				chr(($this->m_arColors[$i] & 0x0000FF00) >>  8) . // G
Chris@76: 				chr(($this->m_arColors[$i] & 0x00FF0000) >> 16);  // B
Chris@76: 		}
Chris@76: 
Chris@76: 		return $ret;
Chris@76: 	}
Chris@76: 
Chris@76: 	public function colorIndex($rgb)
Chris@76: 	{
Chris@76: 		$rgb  = intval($rgb) & 0xFFFFFF;
Chris@76: 		$r1   = ($rgb & 0x0000FF);
Chris@76: 		$g1   = ($rgb & 0x00FF00) >>  8;
Chris@76: 		$b1   = ($rgb & 0xFF0000) >> 16;
Chris@76: 		$idx  = -1;
Chris@76: 
Chris@76: 		for ($i = 0; $i < $this->m_nColors; $i++)
Chris@76: 		{
Chris@76: 			$r2 = ($this->m_arColors[$i] & 0x000000FF);
Chris@76: 			$g2 = ($this->m_arColors[$i] & 0x0000FF00) >>  8;
Chris@76: 			$b2 = ($this->m_arColors[$i] & 0x00FF0000) >> 16;
Chris@76: 			$d  = abs($r2 - $r1) + abs($g2 - $g1) + abs($b2 - $b1);
Chris@76: 
Chris@76: 			if (($idx == -1) || ($d < $dif))
Chris@76: 			{
Chris@76: 				$idx = $i;
Chris@76: 				$dif = $d;
Chris@76: 			}
Chris@76: 		}
Chris@76: 
Chris@76: 		return $idx;
Chris@76: 	}
Chris@76: }
Chris@76: 
Chris@76: class gif_file_header
Chris@76: {
Chris@76: 	public $m_lpVer, $m_nWidth, $m_nHeight, $m_bGlobalClr, $m_nColorRes;
Chris@76: 	public $m_bSorted, $m_nTableSize, $m_nBgColor, $m_nPixelRatio;
Chris@76: 	public $m_colorTable;
Chris@76: 
Chris@76: 	public function __construct()
Chris@76: 	{
Chris@76: 		unset($this->m_lpVer, $this->m_nWidth, $this->m_nHeight, $this->m_bGlobalClr, $this->m_nColorRes);
Chris@76: 		unset($this->m_bSorted, $this->m_nTableSize, $this->m_nBgColor, $this->m_nPixelRatio, $this->m_colorTable);
Chris@76: 	}
Chris@76: 
Chris@76: 	public function load($lpData, &$hdrLen)
Chris@76: 	{
Chris@76: 		$hdrLen = 0;
Chris@76: 
Chris@76: 		$this->m_lpVer = substr($lpData, 0, 6);
Chris@76: 		if (($this->m_lpVer != 'GIF87a') && ($this->m_lpVer != 'GIF89a'))
Chris@76: 			return false;
Chris@76: 
Chris@76: 		list ($this->m_nWidth, $this->m_nHeight) = array_values(unpack('v2', substr($lpData, 6, 4)));
Chris@76: 
Chris@76: 		if (!$this->m_nWidth || !$this->m_nHeight)
Chris@76: 			return false;
Chris@76: 
Chris@76: 		$b = ord(substr($lpData, 10, 1));
Chris@76: 		$this->m_bGlobalClr  = ($b & 0x80) ? true : false;
Chris@76: 		$this->m_nColorRes   = ($b & 0x70) >> 4;
Chris@76: 		$this->m_bSorted     = ($b & 0x08) ? true : false;
Chris@76: 		$this->m_nTableSize  = 2 << ($b & 0x07);
Chris@76: 		$this->m_nBgColor    = ord(substr($lpData, 11, 1));
Chris@76: 		$this->m_nPixelRatio = ord(substr($lpData, 12, 1));
Chris@76: 		$hdrLen = 13;
Chris@76: 
Chris@76: 		if ($this->m_bGlobalClr)
Chris@76: 		{
Chris@76: 			$this->m_colorTable = new gif_color_table();
Chris@76: 			if (!$this->m_colorTable->load(substr($lpData, $hdrLen), $this->m_nTableSize))
Chris@76: 				return false;
Chris@76: 
Chris@76: 			$hdrLen += 3 * $this->m_nTableSize;
Chris@76: 		}
Chris@76: 
Chris@76: 		return true;
Chris@76: 	}
Chris@76: }
Chris@76: 
Chris@76: class gif_image_header
Chris@76: {
Chris@76: 	public $m_nLeft, $m_nTop, $m_nWidth, $m_nHeight, $m_bLocalClr;
Chris@76: 	public $m_bInterlace, $m_bSorted, $m_nTableSize, $m_colorTable;
Chris@76: 
Chris@76: 	public function __construct()
Chris@76: 	{
Chris@76: 		unset($this->m_nLeft, $this->m_nTop, $this->m_nWidth, $this->m_nHeight, $this->m_bLocalClr);
Chris@76: 		unset($this->m_bInterlace, $this->m_bSorted, $this->m_nTableSize, $this->m_colorTable);
Chris@76: 	}
Chris@76: 
Chris@76: 	public function load($lpData, &$hdrLen)
Chris@76: 	{
Chris@76: 		$hdrLen = 0;
Chris@76: 
Chris@76: 		// Get the width/height/etc. from the header.
Chris@76: 		list ($this->m_nLeft, $this->m_nTop, $this->m_nWidth, $this->m_nHeight) = array_values(unpack('v4', substr($lpData, 0, 8)));
Chris@76: 
Chris@76: 		if (!$this->m_nWidth || !$this->m_nHeight)
Chris@76: 			return false;
Chris@76: 
Chris@76: 		$b = ord($lpData[8]);
Chris@76: 		$this->m_bLocalClr  = ($b & 0x80) ? true : false;
Chris@76: 		$this->m_bInterlace = ($b & 0x40) ? true : false;
Chris@76: 		$this->m_bSorted    = ($b & 0x20) ? true : false;
Chris@76: 		$this->m_nTableSize = 2 << ($b & 0x07);
Chris@76: 		$hdrLen = 9;
Chris@76: 
Chris@76: 		if ($this->m_bLocalClr)
Chris@76: 		{
Chris@76: 			$this->m_colorTable = new gif_color_table();
Chris@76: 			if (!$this->m_colorTable->load(substr($lpData, $hdrLen), $this->m_nTableSize))
Chris@76: 				return false;
Chris@76: 
Chris@76: 			$hdrLen += 3 * $this->m_nTableSize;
Chris@76: 		}
Chris@76: 
Chris@76: 		return true;
Chris@76: 	}
Chris@76: }
Chris@76: 
Chris@76: class gif_image
Chris@76: {
Chris@76: 	public $m_disp, $m_bUser, $m_bTrans, $m_nDelay, $m_nTrans, $m_lpComm;
Chris@76: 	public $m_gih, $m_data, $m_lzw;
Chris@76: 
Chris@76: 	public function __construct()
Chris@76: 	{
Chris@76: 		unset($this->m_disp, $this->m_bUser, $this->m_nDelay, $this->m_nTrans, $this->m_lpComm, $this->m_data);
Chris@76: 		$this->m_gih = new gif_image_header();
Chris@76: 		$this->m_lzw = new gif_lzw_compression();
Chris@76: 	}
Chris@76: 
Chris@76: 	public function load($data, &$datLen)
Chris@76: 	{
Chris@76: 		$datLen = 0;
Chris@76: 
Chris@76: 		while (true)
Chris@76: 		{
Chris@76: 			$b = ord($data[0]);
Chris@76: 			$data = substr($data, 1);
Chris@76: 			$datLen++;
Chris@76: 
Chris@76: 			switch ($b)
Chris@76: 			{
Chris@76: 			// Extension...
Chris@76: 			case 0x21:
Chris@76: 				$len = 0;
Chris@76: 				if (!$this->skipExt($data, $len))
Chris@76: 					return false;
Chris@76: 
Chris@76: 				$datLen += $len;
Chris@76: 				break;
Chris@76: 
Chris@76: 			// Image...
Chris@76: 			case 0x2C:
Chris@76: 				// Load the header and color table.
Chris@76: 				$len = 0;
Chris@76: 				if (!$this->m_gih->load($data, $len))
Chris@76: 					return false;
Chris@76: 
Chris@76: 				$data = substr($data, $len);
Chris@76: 				$datLen += $len;
Chris@76: 
Chris@76: 				// Decompress the data, and ride on home ;).
Chris@76: 				$len = 0;
Chris@76: 				if (!($this->m_data = $this->m_lzw->decompress($data, $len)))
Chris@76: 					return false;
Chris@76: 
Chris@76: 				$data = substr($data, $len);
Chris@76: 				$datLen += $len;
Chris@76: 
Chris@76: 				if ($this->m_gih->m_bInterlace)
Chris@76: 					$this->deInterlace();
Chris@76: 
Chris@76: 				return true;
Chris@76: 
Chris@76: 			case 0x3B: // EOF
Chris@76: 			default:
Chris@76: 				return false;
Chris@76: 			}
Chris@76: 		}
Chris@76: 		return false;
Chris@76: 	}
Chris@76: 
Chris@76: 	public function skipExt(&$data, &$extLen)
Chris@76: 	{
Chris@76: 		$extLen = 0;
Chris@76: 
Chris@76: 		$b = ord($data[0]);
Chris@76: 		$data = substr($data, 1);
Chris@76: 		$extLen++;
Chris@76: 
Chris@76: 		switch ($b)
Chris@76: 		{
Chris@76: 		// Graphic Control...
Chris@76: 		case 0xF9:
Chris@76: 			$b = ord($data[1]);
Chris@76: 			$this->m_disp   = ($b & 0x1C) >> 2;
Chris@76: 			$this->m_bUser  = ($b & 0x02) ? true : false;
Chris@76: 			$this->m_bTrans = ($b & 0x01) ? true : false;
Chris@76: 			list ($this->m_nDelay) = array_values(unpack('v', substr($data, 2, 2)));
Chris@76: 			$this->m_nTrans = ord($data[4]);
Chris@76: 			break;
Chris@76: 
Chris@76: 		// Comment...
Chris@76: 		case 0xFE:
Chris@76: 			$this->m_lpComm = substr($data, 1, ord($data[0]));
Chris@76: 			break;
Chris@76: 
Chris@76: 		// Plain text...
Chris@76: 		case 0x01:
Chris@76: 			break;
Chris@76: 
Chris@76: 		// Application...
Chris@76: 		case 0xFF:
Chris@76: 			break;
Chris@76: 		}
Chris@76: 
Chris@76: 		// Skip default as defs may change.
Chris@76: 		$b = ord($data[0]);
Chris@76: 		$data = substr($data, 1);
Chris@76: 		$extLen++;
Chris@76: 		while ($b > 0)
Chris@76: 		{
Chris@76: 			$data = substr($data, $b);
Chris@76: 			$extLen += $b;
Chris@76: 			$b    = ord($data[0]);
Chris@76: 			$data = substr($data, 1);
Chris@76: 			$extLen++;
Chris@76: 		}
Chris@76: 		return true;
Chris@76: 	}
Chris@76: 
Chris@76: 	public function deInterlace()
Chris@76: 	{
Chris@76: 		$data = $this->m_data;
Chris@76: 
Chris@76: 		for ($i = 0; $i < 4; $i++)
Chris@76: 		{
Chris@76: 			switch ($i)
Chris@76: 			{
Chris@76: 			case 0:
Chris@76: 				$s = 8;
Chris@76: 				$y = 0;
Chris@76: 				break;
Chris@76: 
Chris@76: 			case 1:
Chris@76: 				$s = 8;
Chris@76: 				$y = 4;
Chris@76: 				break;
Chris@76: 
Chris@76: 			case 2:
Chris@76: 				$s = 4;
Chris@76: 				$y = 2;
Chris@76: 				break;
Chris@76: 
Chris@76: 			case 3:
Chris@76: 				$s = 2;
Chris@76: 				$y = 1;
Chris@76: 				break;
Chris@76: 			}
Chris@76: 
Chris@76: 			for (; $y < $this->m_gih->m_nHeight; $y += $s)
Chris@76: 			{
Chris@76: 				$lne = substr($this->m_data, 0, $this->m_gih->m_nWidth);
Chris@76: 				$this->m_data = substr($this->m_data, $this->m_gih->m_nWidth);
Chris@76: 
Chris@76: 				$data =
Chris@76: 					substr($data, 0, $y * $this->m_gih->m_nWidth) .
Chris@76: 					$lne .
Chris@76: 					substr($data, ($y + 1) * $this->m_gih->m_nWidth);
Chris@76: 			}
Chris@76: 		}
Chris@76: 
Chris@76: 		$this->m_data = $data;
Chris@76: 	}
Chris@76: }
Chris@76: 
Chris@76: class gif_file
Chris@76: {
Chris@76: 	public $header, $image, $data, $loaded;
Chris@76: 
Chris@76: 	public function __construct()
Chris@76: 	{
Chris@76: 		$this->data = '';
Chris@76: 		$this->loaded = false;
Chris@76: 		$this->header = new gif_file_header();
Chris@76: 		$this->image = new gif_image();
Chris@76: 	}
Chris@76: 
Chris@76: 	public function loadFile($filename, $iIndex)
Chris@76: 	{
Chris@76: 		if ($iIndex < 0)
Chris@76: 			return false;
Chris@76: 
Chris@76: 		$this->data = @file_get_contents($filename);
Chris@76: 		if ($this->data === false)
Chris@76: 			return false;
Chris@76: 
Chris@76: 		// Tell the header to load up....
Chris@76: 		$len = 0;
Chris@76: 		if (!$this->header->load($this->data, $len))
Chris@76: 			return false;
Chris@76: 
Chris@76: 		$this->data = substr($this->data, $len);
Chris@76: 
Chris@76: 		// Keep reading (at least once) so we get to the actual image we're looking for.
Chris@76: 		for ($j = 0; $j <= $iIndex; $j++)
Chris@76: 		{
Chris@76: 			$imgLen = 0;
Chris@76: 			if (!$this->image->load($this->data, $imgLen))
Chris@76: 				return false;
Chris@76: 
Chris@76: 			$this->data = substr($this->data, $imgLen);
Chris@76: 		}
Chris@76: 
Chris@76: 		$this->loaded = true;
Chris@76: 		return true;
Chris@76: 	}
Chris@76: 
Chris@76: 	public function get_png_data($background_color)
Chris@76: 	{
Chris@76: 		if (!$this->loaded)
Chris@76: 			return false;
Chris@76: 
Chris@76: 		// Prepare the color table.
Chris@76: 		if ($this->image->m_gih->m_bLocalClr)
Chris@76: 		{
Chris@76: 			$colors = $this->image->m_gih->m_nTableSize;
Chris@76: 			$pal = $this->image->m_gih->m_colorTable->toString();
Chris@76: 
Chris@76: 			if ($background_color != -1)
Chris@76: 				$background_color = $this->image->m_gih->m_colorTable->colorIndex($background_color);
Chris@76: 		}
Chris@76: 		elseif ($this->header->m_bGlobalClr)
Chris@76: 		{
Chris@76: 			$colors = $this->header->m_nTableSize;
Chris@76: 			$pal = $this->header->m_colorTable->toString();
Chris@76: 
Chris@76: 			if ($background_color != -1)
Chris@76: 				$background_color = $this->header->m_colorTable->colorIndex($background_color);
Chris@76: 		}
Chris@76: 		else
Chris@76: 		{
Chris@76: 			$colors = 0;
Chris@76: 			$background_color = -1;
Chris@76: 		}
Chris@76: 
Chris@76: 		if ($background_color == -1)
Chris@76: 			$background_color = $this->header->m_nBgColor;
Chris@76: 
Chris@76: 		$data = &$this->image->m_data;
Chris@76: 		$header = &$this->image->m_gih;
Chris@76: 
Chris@76: 		$i = 0;
Chris@76: 		$bmp = '';
Chris@76: 
Chris@76: 		// Prepare the bitmap itself.
Chris@76: 		for ($y = 0; $y < $this->header->m_nHeight; $y++)
Chris@76: 		{
Chris@76: 			$bmp .= "\x00";
Chris@76: 
Chris@76: 			for ($x = 0; $x < $this->header->m_nWidth; $x++, $i++)
Chris@76: 			{
Chris@76: 				// Is this in the proper range?  If so, get the specific pixel data...
Chris@76: 				if ($x >= $header->m_nLeft && $y >= $header->m_nTop && $x < ($header->m_nLeft + $header->m_nWidth) && $y < ($header->m_nTop + $header->m_nHeight))
Chris@76: 					$bmp .= $data{$i};
Chris@76: 				// Otherwise, this is background...
Chris@76: 				else
Chris@76: 					$bmp .= chr($background_color);
Chris@76: 			}
Chris@76: 		}
Chris@76: 
Chris@76: 		$bmp = gzcompress($bmp, 9);
Chris@76: 
Chris@76: 		// Output the basic signature first of all.
Chris@76: 		$out = "\x89\x50\x4E\x47\x0D\x0A\x1A\x0A";
Chris@76: 
Chris@76: 		// Now, we want the header...
Chris@76: 		$out .= "\x00\x00\x00\x0D";
Chris@76: 		$tmp = 'IHDR' . pack('N', (int) $this->header->m_nWidth) . pack('N', (int) $this->header->m_nHeight) . "\x08\x03\x00\x00\x00";
Chris@76: 		$out .= $tmp . pack('N', smf_crc32($tmp));
Chris@76: 
Chris@76: 		// The palette, assuming we have one to speak of...
Chris@76: 		if ($colors > 0)
Chris@76: 		{
Chris@76: 			$out .= pack('N', (int) $colors * 3);
Chris@76: 			$tmp = 'PLTE' . $pal;
Chris@76: 			$out .= $tmp . pack('N', smf_crc32($tmp));
Chris@76: 		}
Chris@76: 
Chris@76: 		// Do we have any transparency we want to make available?
Chris@76: 		if ($this->image->m_bTrans && $colors > 0)
Chris@76: 		{
Chris@76: 			$out .= pack('N', (int) $colors);
Chris@76: 			$tmp = 'tRNS';
Chris@76: 
Chris@76: 			// Stick each color on - full transparency or none.
Chris@76: 			for ($i = 0; $i < $colors; $i++)
Chris@76: 				$tmp .= $i == $this->image->m_nTrans ? "\x00" : "\xFF";
Chris@76: 
Chris@76: 			$out .= $tmp . pack('N', smf_crc32($tmp));
Chris@76: 		}
Chris@76: 
Chris@76: 		// Here's the data itself!
Chris@76: 		$out .= pack('N', strlen($bmp));
Chris@76: 		$tmp = 'IDAT' . $bmp;
Chris@76: 		$out .= $tmp . pack('N', smf_crc32($tmp));
Chris@76: 
Chris@76: 		// EOF marker...
Chris@76: 		$out .= "\x00\x00\x00\x00" . 'IEND' . "\xAE\x42\x60\x82";
Chris@76: 
Chris@76: 		return $out;
Chris@76: 	}
Chris@76: }
Chris@76: 
Chris@76: // crc32 doesn't work as expected on 64-bit functions - make our own.
Chris@76: // http://www.php.net/crc32#79567
Chris@76: if (!function_exists('smf_crc32'))
Chris@76: {
Chris@76: 	function smf_crc32($number)
Chris@76: 	{
Chris@76: 		$crc = crc32($number);
Chris@76: 
Chris@76: 		if ($crc & 0x80000000)
Chris@76: 		{
Chris@76: 			$crc ^= 0xffffffff;
Chris@76: 			$crc += 1;
Chris@76: 			$crc = -$crc;
Chris@76: 		}
Chris@76: 
Chris@76: 		return $crc;
Chris@76: 	}
Chris@76: }
Chris@76: 
Chris@76: ?>