gif_file_header::load() - Code Metrics - SimpleMachines/SMF2.1 - Measure and Improve Code Quality continuously with Scrutinizer

gif_file_header::load() B
last analyzed 2022-05-09 18:26 UTC

↳ Parent: gif_file_header

Complexity

Conditions	9
Paths	14

Size

Total Lines	32
Code Lines	21

Duplication

Lines	0
Ratio	0 %

Importance

Changes

Metric	Value
cc	9
eloc	21
c	0
b	0
f	0
nop	2
dl	0
loc	32
rs	8.0555
nc	14

<?php

/**
 * Classes used for reading gif files (in case PHP's GD doesn't provide the
 * proper gif-functions).
 *
 * Gif Util copyright 2003 by Yamasoft (S/C). All rights reserved.
 * Do not remove this portion of the header, or use these functions except
 * from the original author. To get it, please navigate to:
 * http://www.yamasoft.com/php-gif.zip
 *
 * Simple Machines Forum (SMF)
 *
 * @package SMF
 * @author Simple Machines https://www.simplemachines.org
 * @copyright 2022 Simple Machines and individual contributors
 * @license https://www.simplemachines.org/about/smf/license.php BSD
 *
 * @version 2.1.0
 */

if (!defined('SMF'))
	die('No direct access...');

/**
 * Class gif_lzw_compression
 *
 * An implementation of the LZW compression algorithm
 */
class gif_lzw_compression
{
	public $MAX_LZW_BITS;
	public $Fresh, $CodeSize, $SetCodeSize, $MaxCode, $MaxCodeSize, $FirstCode, $OldCode;
	public $ClearCode, $EndCode, $Next, $Vals, $Stack, $sp, $Buf, $CurBit, $LastBit, $Done, $LastByte;

	public function __construct()
	{
		$this->MAX_LZW_BITS = 12;
		unset($this->Next, $this->Vals, $this->Stack, $this->Buf);

		$this->Next = range(0, (1 << $this->MAX_LZW_BITS) - 1);
		$this->Vals = range(0, (1 << $this->MAX_LZW_BITS) - 1);
		$this->Stack = range(0, (1 << ($this->MAX_LZW_BITS + 1)) - 1);
		$this->Buf = range(0, 279);
	}

	public function decompress($data, &$datLen)
	{
		$stLen = strlen($data);
		$datLen = 0;
		$ret = '';

		$this->LZWCommand($data, true);

		while (($iIndex = $this->LZWCommand($data, false)) >= 0)
			$ret .= chr($iIndex);

		$datLen = $stLen - strlen($data);

		if ($iIndex != -2)
			return false;

		return $ret;
	}

	public function LZWCommand(&$data, $bInit)
	{
		if ($bInit)
		{
			$this->SetCodeSize = ord($data[0]);
			$data = substr($data, 1);

			$this->CodeSize = $this->SetCodeSize + 1;
			$this->ClearCode = 1 << $this->SetCodeSize;
			$this->EndCode = $this->ClearCode + 1;
			$this->MaxCode = $this->ClearCode + 2;
			$this->MaxCodeSize = $this->ClearCode << 1;

			$this->GetCode($data, $bInit);

			$this->Fresh = 1;
			for ($i = 0; $i < $this->ClearCode; $i++)
			{
				$this->Next[$i] = 0;
				$this->Vals[$i] = $i;
			}

			for (; $i < (1 << $this->MAX_LZW_BITS); $i++)
			{
				$this->Next[$i] = 0;
				$this->Vals[$i] = 0;
			}

			$this->sp = 0;
			return 1;
		}

		if ($this->Fresh)
		{
			$this->Fresh = 0;
			do
			{
				$this->FirstCode = $this->GetCode($data, $bInit);
				$this->OldCode = $this->FirstCode;
			}
			while ($this->FirstCode == $this->ClearCode);

			return $this->FirstCode;
		}

		if ($this->sp > 0)
		{
			$this->sp--;
			return $this->Stack[$this->sp];
		}

		while (($Code = $this->GetCode($data, $bInit)) >= 0)
		{
			if ($Code == $this->ClearCode)
			{
				for ($i = 0; $i < $this->ClearCode; $i++)
				{
					$this->Next[$i] = 0;
					$this->Vals[$i] = $i;
				}

				for (; $i < (1 << $this->MAX_LZW_BITS); $i++)
				{
					$this->Next[$i] = 0;
					$this->Vals[$i] = 0;
				}

				$this->CodeSize = $this->SetCodeSize + 1;
				$this->MaxCodeSize = $this->ClearCode << 1;
				$this->MaxCode = $this->ClearCode + 2;
				$this->sp = 0;
				$this->FirstCode = $this->GetCode($data, $bInit);
				$this->OldCode = $this->FirstCode;

				return $this->FirstCode;
			}

			if ($Code == $this->EndCode)
				return -2;

			$InCode = $Code;
			if ($Code >= $this->MaxCode)
			{
				$this->Stack[$this->sp] = $this->FirstCode;
				$this->sp++;
				$Code = $this->OldCode;
			}

			while ($Code >= $this->ClearCode)
			{
				$this->Stack[$this->sp] = $this->Vals[$Code];
				$this->sp++;

				if ($Code == $this->Next[$Code]) // Circular table entry, big GIF Error!
					return -1;

				$Code = $this->Next[$Code];
			}

			$this->FirstCode = $this->Vals[$Code];
			$this->Stack[$this->sp] = $this->FirstCode;
			$this->sp++;

			if (($Code = $this->MaxCode) < (1 << $this->MAX_LZW_BITS))
			{
				$this->Next[$Code] = $this->OldCode;
				$this->Vals[$Code] = $this->FirstCode;
				$this->MaxCode++;

				if (($this->MaxCode >= $this->MaxCodeSize) && ($this->MaxCodeSize < (1 << $this->MAX_LZW_BITS)))
				{
					$this->MaxCodeSize *= 2;
					$this->CodeSize++;
				}
			}

			$this->OldCode = $InCode;
			if ($this->sp > 0)
			{
				$this->sp--;
				return $this->Stack[$this->sp];
			}
		}

		return $Code;
	}

	public function GetCode(&$data, $bInit)
	{
		if ($bInit)
		{
			$this->CurBit = 0;
			$this->LastBit = 0;
			$this->Done = 0;
			$this->LastByte = 2;

			return 1;
		}

		if (($this->CurBit + $this->CodeSize) >= $this->LastBit)
		{
			if ($this->Done)
			{
				// Ran off the end of my bits...
				if ($this->CurBit >= $this->LastBit)
					return 0;

				return -1;
			}

			$this->Buf[0] = $this->Buf[$this->LastByte - 2];
			$this->Buf[1] = $this->Buf[$this->LastByte - 1];

			$count = ord($data[0]);
			$data = substr($data, 1);

			if ($count)
			{
				for ($i = 0; $i < $count; $i++)
					$this->Buf[2 + $i] = ord($data[$i]);

				$data = substr($data, $count);
			}
			else
				$this->Done = 1;

			$this->LastByte = 2 + $count;
			$this->CurBit = ($this->CurBit - $this->LastBit) + 16;
			$this->LastBit = (2 + $count) << 3;
		}

		$iRet = 0;
		for ($i = $this->CurBit, $j = 0; $j < $this->CodeSize; $i++, $j++)
			$iRet |= (($this->Buf[intval($i / 8)] & (1 << ($i % 8))) != 0) << $j;

		$this->CurBit += $this->CodeSize;
		return $iRet;
	}
}

class gif_color_table
{
	public $m_nColors;
	public $m_arColors;

	public function __construct()
	{
		unset($this->m_nColors, $this->m_arColors);
	}

	public function load($lpData, $num)
	{
		$this->m_nColors = 0;
		$this->m_arColors = array();

		for ($i = 0; $i < $num; $i++)
		{
			$rgb = substr($lpData, $i * 3, 3);
			if (strlen($rgb) < 3)
				return false;

			$this->m_arColors[] = (ord($rgb[2]) << 16) + (ord($rgb[1]) << 8) + ord($rgb[0]);
			$this->m_nColors++;
		}

		return true;
	}

	public function toString()
	{
		$ret = '';

		for ($i = 0; $i < $this->m_nColors; $i++)
		{
			$ret .=
				chr(($this->m_arColors[$i] & 0x000000FF)) . // R
				chr(($this->m_arColors[$i] & 0x0000FF00) >> 8) . // G
				chr(($this->m_arColors[$i] & 0x00FF0000) >> 16);  // B
		}

		return $ret;
	}

	public function colorIndex($rgb)
	{
		$dif = 0;
		$rgb = intval($rgb) & 0xFFFFFF;
		$r1 = ($rgb & 0x0000FF);
		$g1 = ($rgb & 0x00FF00) >> 8;
		$b1 = ($rgb & 0xFF0000) >> 16;
		$idx = -1;

		for ($i = 0; $i < $this->m_nColors; $i++)
		{
			$r2 = ($this->m_arColors[$i] & 0x000000FF);
			$g2 = ($this->m_arColors[$i] & 0x0000FF00) >> 8;
			$b2 = ($this->m_arColors[$i] & 0x00FF0000) >> 16;
			$d = abs($r2 - $r1) + abs($g2 - $g1) + abs($b2 - $b1);

			if (($idx == -1) || ($d < $dif))
			{
				$idx = $i;
				$dif = $d;
			}
		}

		return $idx;
	}
}

class gif_file_header
{
	public $m_lpVer, $m_nWidth, $m_nHeight, $m_bGlobalClr, $m_nColorRes;
	public $m_bSorted, $m_nTableSize, $m_nBgColor, $m_nPixelRatio;
	public $m_colorTable;

	public function __construct()
	{
		unset($this->m_lpVer, $this->m_nWidth, $this->m_nHeight, $this->m_bGlobalClr, $this->m_nColorRes);
		unset($this->m_bSorted, $this->m_nTableSize, $this->m_nBgColor, $this->m_nPixelRatio, $this->m_colorTable);
	}

	public function load($lpData, &$hdrLen)
	{
		$hdrLen = 0;

		$this->m_lpVer = substr($lpData, 0, 6);
		if (($this->m_lpVer != 'GIF87a') && ($this->m_lpVer != 'GIF89a'))
			return false;

		list ($this->m_nWidth, $this->m_nHeight) = array_values(unpack('v2', substr($lpData, 6, 4)));

		if (!$this->m_nWidth || !$this->m_nHeight)
			return false;

		$b = ord(substr($lpData, 10, 1));
		$this->m_bGlobalClr = ($b & 0x80) ? true : false;
		$this->m_nColorRes = ($b & 0x70) >> 4;
		$this->m_bSorted = ($b & 0x08) ? true : false;
		$this->m_nTableSize = 2 << ($b & 0x07);
		$this->m_nBgColor = ord(substr($lpData, 11, 1));
		$this->m_nPixelRatio = ord(substr($lpData, 12, 1));
		$hdrLen = 13;

		if ($this->m_bGlobalClr)
		{
			$this->m_colorTable = new gif_color_table();
			if (!$this->m_colorTable->load(substr($lpData, $hdrLen), $this->m_nTableSize))
				return false;

			$hdrLen += 3 * $this->m_nTableSize;
		}

		return true;
	}
}

class gif_image_header
{
	public $m_nLeft, $m_nTop, $m_nWidth, $m_nHeight, $m_bLocalClr;
	public $m_bInterlace, $m_bSorted, $m_nTableSize, $m_colorTable;

	public function __construct()
	{
		unset($this->m_nLeft, $this->m_nTop, $this->m_nWidth, $this->m_nHeight, $this->m_bLocalClr);
		unset($this->m_bInterlace, $this->m_bSorted, $this->m_nTableSize, $this->m_colorTable);
	}

	public function load($lpData, &$hdrLen)
	{
		$hdrLen = 0;

		// Get the width/height/etc. from the header.
		list ($this->m_nLeft, $this->m_nTop, $this->m_nWidth, $this->m_nHeight) = array_values(unpack('v4', substr($lpData, 0, 8)));

		if (!$this->m_nWidth || !$this->m_nHeight)
			return false;

		$b = ord($lpData[8]);
		$this->m_bLocalClr = ($b & 0x80) ? true : false;
		$this->m_bInterlace = ($b & 0x40) ? true : false;
		$this->m_bSorted = ($b & 0x20) ? true : false;
		$this->m_nTableSize = 2 << ($b & 0x07);
		$hdrLen = 9;

		if ($this->m_bLocalClr)
		{
			$this->m_colorTable = new gif_color_table();
			if (!$this->m_colorTable->load(substr($lpData, $hdrLen), $this->m_nTableSize))
				return false;

			$hdrLen += 3 * $this->m_nTableSize;
		}

		return true;
	}
}

class gif_image
{
	public $m_disp, $m_bUser, $m_bTrans, $m_nDelay, $m_nTrans, $m_lpComm;
	public $m_gih, $m_data, $m_lzw;

	public function __construct()
	{
		unset($this->m_disp, $this->m_bUser, $this->m_nDelay, $this->m_nTrans, $this->m_lpComm, $this->m_data);
		$this->m_gih = new gif_image_header();
		$this->m_lzw = new gif_lzw_compression();
	}

	public function load($data, &$datLen)
	{
		$datLen = 0;

		while (true)
		{
			$b = ord($data[0]);
			$data = substr($data, 1);
			$datLen++;

			switch ($b)
			{
				// Extension...
				case 0x21:
					$len = 0;
					if (!$this->skipExt($data, $len))
						return false;

					$datLen += $len;
					break;

				// Image...
				case 0x2C:
					// Load the header and color table.
					$len = 0;
					if (!$this->m_gih->load($data, $len))
						return false;

					$data = substr($data, $len);
					$datLen += $len;

					// Decompress the data, and ride on home ;).
					$len = 0;
					if (!($this->m_data = $this->m_lzw->decompress($data, $len)))
						return false;

					$datLen += $len;

					if ($this->m_gih->m_bInterlace)
						$this->deInterlace();

					return true;

				case 0x3B: // EOF
				default:
					return false;
			}
		}
		return false;
	}

	public function skipExt(&$data, &$extLen)
	{
		$extLen = 0;

		$b = ord($data[0]);
		$data = substr($data, 1);
		$extLen++;

		switch ($b)
		{
			// Graphic Control...
			case 0xF9:
				$b = ord($data[1]);
				$this->m_disp = ($b & 0x1C) >> 2;
				$this->m_bUser = ($b & 0x02) ? true : false;
				$this->m_bTrans = ($b & 0x01) ? true : false;
				list ($this->m_nDelay) = array_values(unpack('v', substr($data, 2, 2)));
				$this->m_nTrans = ord($data[4]);
				break;

			// Comment...
			case 0xFE:
				$this->m_lpComm = substr($data, 1, ord($data[0]));
				break;

			// Plain text...
			case 0x01:
				break;

			// Application...
			case 0xFF:
				break;
		}

		// Skip default as defs may change.
		$b = ord($data[0]);
		$data = substr($data, 1);
		$extLen++;
		while ($b > 0)
		{
			$data = substr($data, $b);
			$extLen += $b;
			$b = ord($data[0]);
			$data = substr($data, 1);
			$extLen++;
		}
		return true;
	}

	public function deInterlace()
	{
		$data = $this->m_data;

		for ($i = 0; $i < 4; $i++)
		{
			switch ($i)
			{
				case 0:
					$s = 8;
					$y = 0;
					break;

				case 1:
					$s = 8;
					$y = 4;
					break;

				case 2:
					$s = 4;
					$y = 2;
					break;

				case 3:
					$s = 2;
					$y = 1;
					break;
			}

			for (; $y < $this->m_gih->m_nHeight; $y += $s)

			{
				$lne = substr($this->m_data, 0, $this->m_gih->m_nWidth);
				$this->m_data = substr($this->m_data, $this->m_gih->m_nWidth);

				$data =
					substr($data, 0, $y * $this->m_gih->m_nWidth) .
					$lne .
					substr($data, ($y + 1) * $this->m_gih->m_nWidth);
			}
		}

		$this->m_data = $data;
	}
}

class gif_file
{
	public $header, $image, $data, $loaded;

	public function __construct()
	{
		$this->data = '';
		$this->loaded = false;
		$this->header = new gif_file_header();
		$this->image = new gif_image();
	}

	public function loadFile($filename, $iIndex)
	{
		if ($iIndex < 0)
			return false;

		$this->data = @file_get_contents($filename);
		if ($this->data === false)
			return false;

		// Tell the header to load up....
		$len = 0;
		if (!$this->header->load($this->data, $len))
			return false;

		$this->data = substr($this->data, $len);

		// Keep reading (at least once) so we get to the actual image we're looking for.
		for ($j = 0; $j <= $iIndex; $j++)
		{
			$imgLen = 0;
			if (!$this->image->load($this->data, $imgLen))
				return false;

			$this->data = substr($this->data, $imgLen);
		}

		$this->loaded = true;
		return true;
	}

	public function get_png_data($background_color)
	{
		if (!$this->loaded)
			return false;

		// Prepare the color table.
		if ($this->image->m_gih->m_bLocalClr)
		{
			$colors = $this->image->m_gih->m_nTableSize;
			$pal = $this->image->m_gih->m_colorTable->toString();

			if ($background_color != -1)
				$background_color = $this->image->m_gih->m_colorTable->colorIndex($background_color);
		}
		elseif ($this->header->m_bGlobalClr)
		{
			$colors = $this->header->m_nTableSize;
			$pal = $this->header->m_colorTable->toString();

			if ($background_color != -1)
				$background_color = $this->header->m_colorTable->colorIndex($background_color);
		}
		else
		{
			$colors = 0;
			$background_color = -1;
		}

		if ($background_color == -1)
			$background_color = $this->header->m_nBgColor;

		$data = &$this->image->m_data;
		$header = &$this->image->m_gih;

		$i = 0;
		$bmp = '';

		// Prepare the bitmap itself.
		for ($y = 0; $y < $this->header->m_nHeight; $y++)
		{
			$bmp .= "\x00";

			for ($x = 0; $x < $this->header->m_nWidth; $x++, $i++)
			{
				// Is this in the proper range?  If so, get the specific pixel data...
				if ($x >= $header->m_nLeft && $y >= $header->m_nTop && $x < ($header->m_nLeft + $header->m_nWidth) && $y < ($header->m_nTop + $header->m_nHeight))
					$bmp .= $data[$i];
				// Otherwise, this is background...
				else
					$bmp .= chr($background_color);
			}
		}

		$bmp = gzcompress($bmp, 9);

		// Output the basic signature first of all.
		$out = "\x89\x50\x4E\x47\x0D\x0A\x1A\x0A";

		// Now, we want the header...
		$out .= "\x00\x00\x00\x0D";
		$tmp = 'IHDR' . pack('N', (int) $this->header->m_nWidth) . pack('N', (int) $this->header->m_nHeight) . "\x08\x03\x00\x00\x00";
		$out .= $tmp . pack('N', smf_crc32($tmp));

		// The palette, assuming we have one to speak of...
		if ($colors > 0)
		{
			$out .= pack('N', (int) $colors * 3);
			$tmp = 'PLTE' . $pal;

			$out .= $tmp . pack('N', smf_crc32($tmp));
		}

		// Do we have any transparency we want to make available?
		if ($this->image->m_bTrans && $colors > 0)
		{
			$out .= pack('N', (int) $colors);
			$tmp = 'tRNS';

			// Stick each color on - full transparency or none.
			for ($i = 0; $i < $colors; $i++)
				$tmp .= $i == $this->image->m_nTrans ? "\x00" : "\xFF";

			$out .= $tmp . pack('N', smf_crc32($tmp));
		}

		// Here's the data itself!
		$out .= pack('N', strlen($bmp));
		$tmp = 'IDAT' . $bmp;
		$out .= $tmp . pack('N', smf_crc32($tmp));

		// EOF marker...
		$out .= "\x00\x00\x00\x00" . 'IEND' . "\xAE\x42\x60\x82";

		return $out;
	}
}

// 64-bit only functions?
if (!function_exists('smf_crc32'))
{
	require_once $sourcedir . '/Subs-Compat.php';
}

?>

1			<?php
2
3			/**
4			* Classes used for reading gif files (in case PHP's GD doesn't provide the
5			* proper gif-functions).
6			*
7			* Gif Util copyright 2003 by Yamasoft (S/C). All rights reserved.
8			* Do not remove this portion of the header, or use these functions except
9			* from the original author. To get it, please navigate to:
10			* http://www.yamasoft.com/php-gif.zip
11			*
12			* Simple Machines Forum (SMF)
13			*
14			* @package SMF
15			* @author Simple Machines https://www.simplemachines.org
16			* @copyright 2022 Simple Machines and individual contributors
17			* @license https://www.simplemachines.org/about/smf/license.php BSD
18			*
19			* @version 2.1.0
20			*/
21
22			if (!defined('SMF'))
23			die('No direct access...');
24
25			/**
26			* Class gif_lzw_compression
27			*
28			* An implementation of the LZW compression algorithm
29			*/
30			class gif_lzw_compression
31			{
32			public $MAX_LZW_BITS;
33			public $Fresh, $CodeSize, $SetCodeSize, $MaxCode, $MaxCodeSize, $FirstCode, $OldCode;
34			public $ClearCode, $EndCode, $Next, $Vals, $Stack, $sp, $Buf, $CurBit, $LastBit, $Done, $LastByte;
35
36			public function __construct()
37			{
38			$this->MAX_LZW_BITS = 12;
39			unset($this->Next, $this->Vals, $this->Stack, $this->Buf);
40
41			$this->Next = range(0, (1 << $this->MAX_LZW_BITS) - 1);
42			$this->Vals = range(0, (1 << $this->MAX_LZW_BITS) - 1);
43			$this->Stack = range(0, (1 << ($this->MAX_LZW_BITS + 1)) - 1);
44			$this->Buf = range(0, 279);
45			}
46
47			public function decompress($data, &$datLen)
48			{
49			$stLen = strlen($data);
50			$datLen = 0;
51			$ret = '';
52
53			$this->LZWCommand($data, true);
54
55			while (($iIndex = $this->LZWCommand($data, false)) >= 0)
56			$ret .= chr($iIndex);
57
58			$datLen = $stLen - strlen($data);
59
60			if ($iIndex != -2)
61			return false;
62
63			return $ret;
64			}
65
66			public function LZWCommand(&$data, $bInit)
67			{
68			if ($bInit)
69			{
70			$this->SetCodeSize = ord($data[0]);
71			$data = substr($data, 1);
72
73			$this->CodeSize = $this->SetCodeSize + 1;
74			$this->ClearCode = 1 << $this->SetCodeSize;
75			$this->EndCode = $this->ClearCode + 1;
76			$this->MaxCode = $this->ClearCode + 2;
77			$this->MaxCodeSize = $this->ClearCode << 1;
78
79			$this->GetCode($data, $bInit);
80
81			$this->Fresh = 1;
82			for ($i = 0; $i < $this->ClearCode; $i++)
83			{
84			$this->Next[$i] = 0;
85			$this->Vals[$i] = $i;
86			}
87
88			for (; $i < (1 << $this->MAX_LZW_BITS); $i++)
89			{
90			$this->Next[$i] = 0;
91			$this->Vals[$i] = 0;
92			}
93
94			$this->sp = 0;
95			return 1;
96			}
97
98			if ($this->Fresh)
99			{
100			$this->Fresh = 0;
101			do
102			{
103			$this->FirstCode = $this->GetCode($data, $bInit);
104			$this->OldCode = $this->FirstCode;
105			}
106			while ($this->FirstCode == $this->ClearCode);
107
108			return $this->FirstCode;
109			}
110
111			if ($this->sp > 0)
112			{
113			$this->sp--;
114			return $this->Stack[$this->sp];
115			}
116
117			while (($Code = $this->GetCode($data, $bInit)) >= 0)
118			{
119			if ($Code == $this->ClearCode)
120			{
121			for ($i = 0; $i < $this->ClearCode; $i++)
122			{
123			$this->Next[$i] = 0;
124			$this->Vals[$i] = $i;
125			}
126
127			for (; $i < (1 << $this->MAX_LZW_BITS); $i++)
128			{
129			$this->Next[$i] = 0;
130			$this->Vals[$i] = 0;
131			}
132
133			$this->CodeSize = $this->SetCodeSize + 1;
134			$this->MaxCodeSize = $this->ClearCode << 1;
135			$this->MaxCode = $this->ClearCode + 2;
136			$this->sp = 0;
137			$this->FirstCode = $this->GetCode($data, $bInit);
138			$this->OldCode = $this->FirstCode;
139
140			return $this->FirstCode;
141			}
142
143			if ($Code == $this->EndCode)
144			return -2;
145
146			$InCode = $Code;
147			if ($Code >= $this->MaxCode)
148			{
149			$this->Stack[$this->sp] = $this->FirstCode;
150			$this->sp++;
151			$Code = $this->OldCode;
152			}
153
154			while ($Code >= $this->ClearCode)
155			{
156			$this->Stack[$this->sp] = $this->Vals[$Code];
157			$this->sp++;
158
159			if ($Code == $this->Next[$Code]) // Circular table entry, big GIF Error!
160			return -1;
161
162			$Code = $this->Next[$Code];
163			}
164
165			$this->FirstCode = $this->Vals[$Code];
166			$this->Stack[$this->sp] = $this->FirstCode;
167			$this->sp++;
168
169			if (($Code = $this->MaxCode) < (1 << $this->MAX_LZW_BITS))
170			{
171			$this->Next[$Code] = $this->OldCode;
172			$this->Vals[$Code] = $this->FirstCode;
173			$this->MaxCode++;
174
175			if (($this->MaxCode >= $this->MaxCodeSize) && ($this->MaxCodeSize < (1 << $this->MAX_LZW_BITS)))
176			{
177			$this->MaxCodeSize *= 2;
178			$this->CodeSize++;
179			}
180			}
181
182			$this->OldCode = $InCode;
183			if ($this->sp > 0)
184			{
185			$this->sp--;
186			return $this->Stack[$this->sp];
187			}
188			}
189
190			return $Code;
191			}
192
193			public function GetCode(&$data, $bInit)
194			{
195			if ($bInit)
196			{
197			$this->CurBit = 0;
198			$this->LastBit = 0;
199			$this->Done = 0;
200			$this->LastByte = 2;
201
202			return 1;
203			}
204
205			if (($this->CurBit + $this->CodeSize) >= $this->LastBit)
206			{
207			if ($this->Done)
208			{
209			// Ran off the end of my bits...
210			if ($this->CurBit >= $this->LastBit)
211			return 0;
212
213			return -1;
214			}
215
216			$this->Buf[0] = $this->Buf[$this->LastByte - 2];
217			$this->Buf[1] = $this->Buf[$this->LastByte - 1];
218
219			$count = ord($data[0]);
220			$data = substr($data, 1);
221
222			if ($count)
223			{
224			for ($i = 0; $i < $count; $i++)
225			$this->Buf[2 + $i] = ord($data[$i]);
226
227			$data = substr($data, $count);
228			}
229			else
230			$this->Done = 1;
231
232			$this->LastByte = 2 + $count;
233			$this->CurBit = ($this->CurBit - $this->LastBit) + 16;
234			$this->LastBit = (2 + $count) << 3;
235			}
236
237			$iRet = 0;
238			for ($i = $this->CurBit, $j = 0; $j < $this->CodeSize; $i++, $j++)
239			$iRet \|= (($this->Buf[intval($i / 8)] & (1 << ($i % 8))) != 0) << $j;
240
241			$this->CurBit += $this->CodeSize;
242			return $iRet;
243			}
244			}
245
246			class gif_color_table
247			{
248			public $m_nColors;
249			public $m_arColors;
250
251			public function __construct()
252			{
253			unset($this->m_nColors, $this->m_arColors);
254			}
255
256			public function load($lpData, $num)
257			{
258			$this->m_nColors = 0;
259			$this->m_arColors = array();
260
261			for ($i = 0; $i < $num; $i++)
262			{
263			$rgb = substr($lpData, $i * 3, 3);
264			if (strlen($rgb) < 3)
265			return false;
266
267			$this->m_arColors[] = (ord($rgb[2]) << 16) + (ord($rgb[1]) << 8) + ord($rgb[0]);
268			$this->m_nColors++;
269			}
270
271			return true;
272			}
273
274			public function toString()
275			{
276			$ret = '';
277
278			for ($i = 0; $i < $this->m_nColors; $i++)
279			{
280			$ret .=
281			chr(($this->m_arColors[$i] & 0x000000FF)) . // R
282			chr(($this->m_arColors[$i] & 0x0000FF00) >> 8) . // G
283			chr(($this->m_arColors[$i] & 0x00FF0000) >> 16); // B
284			}
285
286			return $ret;
287			}
288
289			public function colorIndex($rgb)
290			{
291			$dif = 0;
292			$rgb = intval($rgb) & 0xFFFFFF;
293			$r1 = ($rgb & 0x0000FF);
294			$g1 = ($rgb & 0x00FF00) >> 8;
295			$b1 = ($rgb & 0xFF0000) >> 16;
296			$idx = -1;
297
298			for ($i = 0; $i < $this->m_nColors; $i++)
299			{
300			$r2 = ($this->m_arColors[$i] & 0x000000FF);
301			$g2 = ($this->m_arColors[$i] & 0x0000FF00) >> 8;
302			$b2 = ($this->m_arColors[$i] & 0x00FF0000) >> 16;
303			$d = abs($r2 - $r1) + abs($g2 - $g1) + abs($b2 - $b1);
304
305			if (($idx == -1) \|\| ($d < $dif))
306			{
307			$idx = $i;
308			$dif = $d;
309			}
310			}
311
312			return $idx;
313			}
314			}
315
316			class gif_file_header
317			{
318			public $m_lpVer, $m_nWidth, $m_nHeight, $m_bGlobalClr, $m_nColorRes;
319			public $m_bSorted, $m_nTableSize, $m_nBgColor, $m_nPixelRatio;
320			public $m_colorTable;
321
322			public function __construct()
323			{
324			unset($this->m_lpVer, $this->m_nWidth, $this->m_nHeight, $this->m_bGlobalClr, $this->m_nColorRes);
325			unset($this->m_bSorted, $this->m_nTableSize, $this->m_nBgColor, $this->m_nPixelRatio, $this->m_colorTable);
326			}
327
328			public function load($lpData, &$hdrLen)
329			{
330			$hdrLen = 0;
331
332			$this->m_lpVer = substr($lpData, 0, 6);
333			if (($this->m_lpVer != 'GIF87a') && ($this->m_lpVer != 'GIF89a'))
334			return false;
335
336			list ($this->m_nWidth, $this->m_nHeight) = array_values(unpack('v2', substr($lpData, 6, 4)));
337
338			if (!$this->m_nWidth \|\| !$this->m_nHeight)
339			return false;
340
341			$b = ord(substr($lpData, 10, 1));
342			$this->m_bGlobalClr = ($b & 0x80) ? true : false;
343			$this->m_nColorRes = ($b & 0x70) >> 4;
344			$this->m_bSorted = ($b & 0x08) ? true : false;
345			$this->m_nTableSize = 2 << ($b & 0x07);
346			$this->m_nBgColor = ord(substr($lpData, 11, 1));
347			$this->m_nPixelRatio = ord(substr($lpData, 12, 1));
348			$hdrLen = 13;
349
350			if ($this->m_bGlobalClr)
351			{
352			$this->m_colorTable = new gif_color_table();
353			if (!$this->m_colorTable->load(substr($lpData, $hdrLen), $this->m_nTableSize))
354			return false;
355
356			$hdrLen += 3 * $this->m_nTableSize;
357			}
358
359			return true;
360			}
361			}
362
363			class gif_image_header
364			{
365			public $m_nLeft, $m_nTop, $m_nWidth, $m_nHeight, $m_bLocalClr;
366			public $m_bInterlace, $m_bSorted, $m_nTableSize, $m_colorTable;
367
368			public function __construct()
369			{
370			unset($this->m_nLeft, $this->m_nTop, $this->m_nWidth, $this->m_nHeight, $this->m_bLocalClr);
371			unset($this->m_bInterlace, $this->m_bSorted, $this->m_nTableSize, $this->m_colorTable);
372			}
373
374			public function load($lpData, &$hdrLen)
375			{
376			$hdrLen = 0;
377
378			// Get the width/height/etc. from the header.
379			list ($this->m_nLeft, $this->m_nTop, $this->m_nWidth, $this->m_nHeight) = array_values(unpack('v4', substr($lpData, 0, 8)));
380
381			if (!$this->m_nWidth \|\| !$this->m_nHeight)
382			return false;
383
384			$b = ord($lpData[8]);
385			$this->m_bLocalClr = ($b & 0x80) ? true : false;
386			$this->m_bInterlace = ($b & 0x40) ? true : false;
387			$this->m_bSorted = ($b & 0x20) ? true : false;
388			$this->m_nTableSize = 2 << ($b & 0x07);
389			$hdrLen = 9;
390
391			if ($this->m_bLocalClr)
392			{
393			$this->m_colorTable = new gif_color_table();
394			if (!$this->m_colorTable->load(substr($lpData, $hdrLen), $this->m_nTableSize))
395			return false;
396
397			$hdrLen += 3 * $this->m_nTableSize;
398			}
399
400			return true;
401			}
402			}
403
404			class gif_image
405			{
406			public $m_disp, $m_bUser, $m_bTrans, $m_nDelay, $m_nTrans, $m_lpComm;
407			public $m_gih, $m_data, $m_lzw;
408
409			public function __construct()
410			{
411			unset($this->m_disp, $this->m_bUser, $this->m_nDelay, $this->m_nTrans, $this->m_lpComm, $this->m_data);
412			$this->m_gih = new gif_image_header();
413			$this->m_lzw = new gif_lzw_compression();
414			}
415
416			public function load($data, &$datLen)
417			{
418			$datLen = 0;
419
420			while (true)
421			{
422			$b = ord($data[0]);
423			$data = substr($data, 1);
424			$datLen++;
425
426			switch ($b)
427			{
428			// Extension...
429			case 0x21:
430			$len = 0;
431			if (!$this->skipExt($data, $len))
432			return false;
433
434			$datLen += $len;
435			break;
436
437			// Image...
438			case 0x2C:
439			// Load the header and color table.
440			$len = 0;
441			if (!$this->m_gih->load($data, $len))
442			return false;
443
444			$data = substr($data, $len);
445			$datLen += $len;
446
447			// Decompress the data, and ride on home ;).
448			$len = 0;
449			if (!($this->m_data = $this->m_lzw->decompress($data, $len)))
450			return false;
451
452			$datLen += $len;
453
454			if ($this->m_gih->m_bInterlace)
455			$this->deInterlace();
456
457			return true;
458
459			case 0x3B: // EOF
460			default:
461			return false;
462			}
463			}
464			return false;
465			}
466
467			public function skipExt(&$data, &$extLen)
468			{
469			$extLen = 0;
470
471			$b = ord($data[0]);
472			$data = substr($data, 1);
473			$extLen++;
474
475			switch ($b)
476			{
477			// Graphic Control...
478			case 0xF9:
479			$b = ord($data[1]);
480			$this->m_disp = ($b & 0x1C) >> 2;
481			$this->m_bUser = ($b & 0x02) ? true : false;
482			$this->m_bTrans = ($b & 0x01) ? true : false;
483			list ($this->m_nDelay) = array_values(unpack('v', substr($data, 2, 2)));
484			$this->m_nTrans = ord($data[4]);
485			break;
486
487			// Comment...
488			case 0xFE:
489			$this->m_lpComm = substr($data, 1, ord($data[0]));
490			break;
491
492			// Plain text...
493			case 0x01:
494			break;
495
496			// Application...
497			case 0xFF:
498			break;
499			}
500
501			// Skip default as defs may change.
502			$b = ord($data[0]);
503			$data = substr($data, 1);
504			$extLen++;
505			while ($b > 0)
506			{
507			$data = substr($data, $b);
508			$extLen += $b;
509			$b = ord($data[0]);
510			$data = substr($data, 1);
511			$extLen++;
512			}
513			return true;
514			}
515
516			public function deInterlace()
517			{
518			$data = $this->m_data;
519
520			for ($i = 0; $i < 4; $i++)
521			{
522			switch ($i)
523			{
524			case 0:
525			$s = 8;
526			$y = 0;
527			break;
528
529			case 1:
530			$s = 8;
531			$y = 4;
532			break;
533
534			case 2:
535			$s = 4;
536			$y = 2;
537			break;
538
539			case 3:
540			$s = 2;
541			$y = 1;
542			break;
543			}
544
545			for (; $y < $this->m_gih->m_nHeight; $y += $s)
			0 ignored issues – show Comprehensibility Best Practice introduced 2018-10-21 22:13 UTC by Report Bug Copy Issue Report The variable `$y` does not seem to be defined for all execution paths leading up to this point. Loading history... Comprehensibility Best Practice introduced 2018-10-21 22:13 UTC by Report Bug Copy Issue Report The variable `$s` does not seem to be defined for all execution paths leading up to this point. Loading history...
546			{
547			$lne = substr($this->m_data, 0, $this->m_gih->m_nWidth);
548			$this->m_data = substr($this->m_data, $this->m_gih->m_nWidth);
549
550			$data =
551			substr($data, 0, $y * $this->m_gih->m_nWidth) .
552			$lne .
553			substr($data, ($y + 1) * $this->m_gih->m_nWidth);
554			}
555			}
556
557			$this->m_data = $data;
558			}
559			}
560
561			class gif_file
562			{
563			public $header, $image, $data, $loaded;
564
565			public function __construct()
566			{
567			$this->data = '';
568			$this->loaded = false;
569			$this->header = new gif_file_header();
570			$this->image = new gif_image();
571			}
572
573			public function loadFile($filename, $iIndex)
574			{
575			if ($iIndex < 0)
576			return false;
577
578			$this->data = @file_get_contents($filename);
579			if ($this->data === false)
580			return false;
581
582			// Tell the header to load up....
583			$len = 0;
584			if (!$this->header->load($this->data, $len))
585			return false;
586
587			$this->data = substr($this->data, $len);
588
589			// Keep reading (at least once) so we get to the actual image we're looking for.
590			for ($j = 0; $j <= $iIndex; $j++)
591			{
592			$imgLen = 0;
593			if (!$this->image->load($this->data, $imgLen))
594			return false;
595
596			$this->data = substr($this->data, $imgLen);
597			}
598
599			$this->loaded = true;
600			return true;
601			}
602
603			public function get_png_data($background_color)
604			{
605			if (!$this->loaded)
606			return false;
607
608			// Prepare the color table.
609			if ($this->image->m_gih->m_bLocalClr)
610			{
611			$colors = $this->image->m_gih->m_nTableSize;
612			$pal = $this->image->m_gih->m_colorTable->toString();
613
614			if ($background_color != -1)
615			$background_color = $this->image->m_gih->m_colorTable->colorIndex($background_color);
616			}
617			elseif ($this->header->m_bGlobalClr)
618			{
619			$colors = $this->header->m_nTableSize;
620			$pal = $this->header->m_colorTable->toString();
621
622			if ($background_color != -1)
623			$background_color = $this->header->m_colorTable->colorIndex($background_color);
624			}
625			else
626			{
627			$colors = 0;
628			$background_color = -1;
629			}
630
631			if ($background_color == -1)
632			$background_color = $this->header->m_nBgColor;
633
634			$data = &$this->image->m_data;
635			$header = &$this->image->m_gih;
636
637			$i = 0;
638			$bmp = '';
639
640			// Prepare the bitmap itself.
641			for ($y = 0; $y < $this->header->m_nHeight; $y++)
642			{
643			$bmp .= "\x00";
644
645			for ($x = 0; $x < $this->header->m_nWidth; $x++, $i++)
646			{
647			// Is this in the proper range? If so, get the specific pixel data...
648			if ($x >= $header->m_nLeft && $y >= $header->m_nTop && $x < ($header->m_nLeft + $header->m_nWidth) && $y < ($header->m_nTop + $header->m_nHeight))
649			$bmp .= $data[$i];
650			// Otherwise, this is background...
651			else
652			$bmp .= chr($background_color);
653			}
654			}
655
656			$bmp = gzcompress($bmp, 9);
657
658			// Output the basic signature first of all.
659			$out = "\x89\x50\x4E\x47\x0D\x0A\x1A\x0A";
660
661			// Now, we want the header...
662			$out .= "\x00\x00\x00\x0D";
663			$tmp = 'IHDR' . pack('N', (int) $this->header->m_nWidth) . pack('N', (int) $this->header->m_nHeight) . "\x08\x03\x00\x00\x00";
664			$out .= $tmp . pack('N', smf_crc32($tmp));
665
666			// The palette, assuming we have one to speak of...
667			if ($colors > 0)
668			{
669			$out .= pack('N', (int) $colors * 3);
670			$tmp = 'PLTE' . $pal;
			0 ignored issues – show Comprehensibility Best Practice introduced 2018-10-21 22:13 UTC by Report Bug Copy Issue Report The variable `$pal` does not seem to be defined for all execution paths leading up to this point. Loading history...
671			$out .= $tmp . pack('N', smf_crc32($tmp));
672			}
673
674			// Do we have any transparency we want to make available?
675			if ($this->image->m_bTrans && $colors > 0)
676			{
677			$out .= pack('N', (int) $colors);
678			$tmp = 'tRNS';
679
680			// Stick each color on - full transparency or none.
681			for ($i = 0; $i < $colors; $i++)
682			$tmp .= $i == $this->image->m_nTrans ? "\x00" : "\xFF";
683
684			$out .= $tmp . pack('N', smf_crc32($tmp));
685			}
686
687			// Here's the data itself!
688			$out .= pack('N', strlen($bmp));
689			$tmp = 'IDAT' . $bmp;
690			$out .= $tmp . pack('N', smf_crc32($tmp));
691
692			// EOF marker...
693			$out .= "\x00\x00\x00\x00" . 'IEND' . "\xAE\x42\x60\x82";
694
695			return $out;
696			}
697			}
698
699			// 64-bit only functions?
700			if (!function_exists('smf_crc32'))
701			{
702			require_once $sourcedir . '/Subs-Compat.php';
703			}
704
705			?>

SimpleMachines / SMF2.1

gif_file_header::load() B last analyzed 2022-05-09 18:26 UTC

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gif_file_header::load() B
last analyzed 2022-05-09 18:26 UTC