<?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'];
}
}
?>
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