Subversion-Projekte lars-tiefland.php_share

<?php

/*******************************************************************************

* Utility to parse TTF font files                                              *

*                                                                              *

* Version: 1.0                                                                 *

* Date:    2011-06-18                                                          *

* Author:  Olivier PLATHEY                                                     *

*******************************************************************************/

class TTFParser

{

	var $f;

	var $tables;

	var $unitsPerEm;

	var $xMin, $yMin, $xMax, $yMax;

	var $numberOfHMetrics;

	var $numGlyphs;

	var $widths;

	var $chars;

	var $postScriptName;

	var $Embeddable;

	var $Bold;

	var $typoAscender;

	var $typoDescender;

	var $capHeight;

	var $italicAngle;

	var $underlinePosition;

	var $underlineThickness;

	var $isFixedPitch;

	function Parse($file)

	{

		$this->f = fopen($file, 'rb');

		if(!$this->f)

			$this->Error('Can\'t open file: '.$file);

		$version = $this->Read(4);

		if($version=='OTTO')

			$this->Error('OpenType fonts based on PostScript outlines are not supported');

		if($version!="\x00\x01\x00\x00")

			$this->Error('Unrecognized file format');

		$numTables = $this->ReadUShort();

		$this->Skip(3*2); // searchRange, entrySelector, rangeShift

		$this->tables = array();

		for($i=0;$i<$numTables;$i++)

		{

			$tag = $this->Read(4);

			$this->Skip(4); // checkSum

			$offset = $this->ReadULong();

			$this->Skip(4); // length

			$this->tables[$tag] = $offset;

		}

		$this->ParseHead();

		$this->ParseHhea();

		$this->ParseMaxp();

		$this->ParseHmtx();

		$this->ParseCmap();

		$this->ParseName();

		$this->ParseOS2();

		$this->ParsePost();

		fclose($this->f);

	}

	function ParseHead()

	{

		$this->Seek('head');

		$this->Skip(3*4); // version, fontRevision, checkSumAdjustment

		$magicNumber = $this->ReadULong();

		if($magicNumber!=0x5F0F3CF5)

			$this->Error('Incorrect magic number');

		$this->Skip(2); // flags

		$this->unitsPerEm = $this->ReadUShort();

		$this->Skip(2*8); // created, modified

		$this->xMin = $this->ReadShort();

		$this->yMin = $this->ReadShort();

		$this->xMax = $this->ReadShort();

		$this->yMax = $this->ReadShort();

	}

	function ParseHhea()

	{

		$this->Seek('hhea');

		$this->Skip(4+15*2);

		$this->numberOfHMetrics = $this->ReadUShort();

	}

	function ParseMaxp()

	{

		$this->Seek('maxp');

		$this->Skip(4);

		$this->numGlyphs = $this->ReadUShort();

	}

	function ParseHmtx()

	{

		$this->Seek('hmtx');

		$this->widths = array();

		for($i=0;$i<$this->numberOfHMetrics;$i++)

		{

			$advanceWidth = $this->ReadUShort();

			$this->Skip(2); // lsb

			$this->widths[$i] = $advanceWidth;

		}

		if($this->numberOfHMetrics<$this->numGlyphs)

		{

			$lastWidth = $this->widths[$this->numberOfHMetrics-1];

			$this->widths = array_pad($this->widths, $this->numGlyphs, $lastWidth);

		}

	}

	function ParseCmap()

	{

		$this->Seek('cmap');

		$this->Skip(2); // version

		$numTables = $this->ReadUShort();

		$offset31 = 0;

		for($i=0;$i<$numTables;$i++)

		{

			$platformID = $this->ReadUShort();

			$encodingID = $this->ReadUShort();

			$offset = $this->ReadULong();

			if($platformID==3 && $encodingID==1)

				$offset31 = $offset;

		}

		if($offset31==0)

			$this->Error('No Unicode encoding found');

		$startCount = array();

		$endCount = array();

		$idDelta = array();

		$idRangeOffset = array();

		$this->chars = array();

		fseek($this->f, $this->tables['cmap']+$offset31, SEEK_SET);

		$format = $this->ReadUShort();

		if($format!=4)

			$this->Error('Unexpected subtable format: '.$format);

		$this->Skip(2*2); // length, language

		$segCount = $this->ReadUShort()/2;

		$this->Skip(3*2); // searchRange, entrySelector, rangeShift

		for($i=0;$i<$segCount;$i++)

			$endCount[$i] = $this->ReadUShort();

		$this->Skip(2); // reservedPad

		for($i=0;$i<$segCount;$i++)

			$startCount[$i] = $this->ReadUShort();

		for($i=0;$i<$segCount;$i++)

			$idDelta[$i] = $this->ReadShort();

		$offset = ftell($this->f);

		for($i=0;$i<$segCount;$i++)

			$idRangeOffset[$i] = $this->ReadUShort();

		for($i=0;$i<$segCount;$i++)

		{

			$c1 = $startCount[$i];

			$c2 = $endCount[$i];

			$d = $idDelta[$i];

			$ro = $idRangeOffset[$i];

			if($ro>0)

				fseek($this->f, $offset+2*$i+$ro, SEEK_SET);

			for($c=$c1;$c<=$c2;$c++)

			{

				if($c==0xFFFF)

					break;

				if($ro>0)

				{

					$gid = $this->ReadUShort();

					if($gid>0)

						$gid += $d;

				}

				else

					$gid = $c+$d;

				if($gid>=65536)

					$gid -= 65536;

				if($gid>0)

					$this->chars[$c] = $gid;

			}

		}

	}

	function ParseName()

	{

		$this->Seek('name');

		$tableOffset = ftell($this->f);

		$this->postScriptName = '';

		$this->Skip(2); // format

		$count = $this->ReadUShort();

		$stringOffset = $this->ReadUShort();

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

		{

			$this->Skip(3*2); // platformID, encodingID, languageID

			$nameID = $this->ReadUShort();

			$length = $this->ReadUShort();

			$offset = $this->ReadUShort();

			if($nameID==6)

			{

				// PostScript name

				fseek($this->f, $tableOffset+$stringOffset+$offset, SEEK_SET);

				$s = $this->Read($length);

				$s = str_replace(chr(0), '', $s);

				$s = preg_replace('|[ \[\](){}<>/%]|', '', $s);

				$this->postScriptName = $s;

				break;

			}

		}

		if($this->postScriptName=='')

			$this->Error('PostScript name not found');

	}

	function ParseOS2()

	{

		$this->Seek('OS/2');

		$version = $this->ReadUShort();

		$this->Skip(3*2); // xAvgCharWidth, usWeightClass, usWidthClass

		$fsType = $this->ReadUShort();

		$this->Embeddable = ($fsType!=2) && ($fsType & 0x200)==0;

		$this->Skip(11*2+10+4*4+4);

		$fsSelection = $this->ReadUShort();

		$this->Bold = ($fsSelection & 32)!=0;

		$this->Skip(2*2); // usFirstCharIndex, usLastCharIndex

		$this->typoAscender = $this->ReadShort();

		$this->typoDescender = $this->ReadShort();

		if($version>=2)

		{

			$this->Skip(3*2+2*4+2);

			$this->capHeight = $this->ReadShort();

		}

		else

			$this->capHeight = 0;

	}

	function ParsePost()

	{

		$this->Seek('post');

		$this->Skip(4); // version

		$this->italicAngle = $this->ReadShort();

		$this->Skip(2); // Skip decimal part

		$this->underlinePosition = $this->ReadShort();

		$this->underlineThickness = $this->ReadShort();

		$this->isFixedPitch = ($this->ReadULong()!=0);

	}

	function Error($msg)

	{

		if(PHP_SAPI=='cli')

			die("Error: $msg\n");

		else

			die("<b>Error</b>: $msg");

	}

	function Seek($tag)

	{

		if(!isset($this->tables[$tag]))

			$this->Error('Table not found: '.$tag);

		fseek($this->f, $this->tables[$tag], SEEK_SET);

	}

	function Skip($n)

	{

		fseek($this->f, $n, SEEK_CUR);

	}

	function Read($n)

	{

		return fread($this->f, $n);

	}

	function ReadUShort()

	{

		$a = unpack('nn', fread($this->f,2));

		return $a['n'];

	}

	function ReadShort()

	{

		$a = unpack('nn', fread($this->f,2));

		$v = $a['n'];

		if($v>=0x8000)

			$v -= 65536;

		return $v;

	}

	function ReadULong()

	{

		$a = unpack('NN', fread($this->f,4));

		return $a['N'];

	}

}

?>