724 lines
18 KiB
PHP
724 lines
18 KiB
PHP
<?php
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/*******************************************************************************
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* Class to parse and subset TrueType fonts *
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* *
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* Version: 1.1 *
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* Date: 2015-11-29 *
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* Author: Olivier PLATHEY *
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*******************************************************************************/
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class TTFParser
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{
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protected $f;
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protected $tables;
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protected $numberOfHMetrics;
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protected $numGlyphs;
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protected $glyphNames;
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protected $indexToLocFormat;
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protected $subsettedChars;
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protected $subsettedGlyphs;
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public $chars;
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public $glyphs;
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public $unitsPerEm;
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public $xMin, $yMin, $xMax, $yMax;
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public $postScriptName;
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public $embeddable;
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public $bold;
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public $typoAscender;
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public $typoDescender;
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public $capHeight;
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public $italicAngle;
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public $underlinePosition;
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public $underlineThickness;
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public $isFixedPitch;
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function __construct($file)
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{
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$this->f = fopen($file, 'rb');
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if(!$this->f)
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$this->Error('Can\'t open file: '.$file);
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}
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function __destruct()
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{
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if(is_resource($this->f))
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fclose($this->f);
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}
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function Parse()
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{
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$this->ParseOffsetTable();
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$this->ParseHead();
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$this->ParseHhea();
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$this->ParseMaxp();
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$this->ParseHmtx();
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$this->ParseLoca();
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$this->ParseGlyf();
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$this->ParseCmap();
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$this->ParseName();
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$this->ParseOS2();
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$this->ParsePost();
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}
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function ParseOffsetTable()
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{
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$version = $this->Read(4);
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if($version=='OTTO')
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$this->Error('OpenType fonts based on PostScript outlines are not supported');
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if($version!="\x00\x01\x00\x00")
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$this->Error('Unrecognized file format');
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$numTables = $this->ReadUShort();
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$this->Skip(3*2); // searchRange, entrySelector, rangeShift
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$this->tables = array();
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for($i=0;$i<$numTables;$i++)
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{
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$tag = $this->Read(4);
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$checkSum = $this->Read(4);
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$offset = $this->ReadULong();
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$length = $this->ReadULong(4);
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$this->tables[$tag] = array('offset'=>$offset, 'length'=>$length, 'checkSum'=>$checkSum);
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}
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}
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function ParseHead()
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{
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$this->Seek('head');
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$this->Skip(3*4); // version, fontRevision, checkSumAdjustment
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$magicNumber = $this->ReadULong();
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if($magicNumber!=0x5F0F3CF5)
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$this->Error('Incorrect magic number');
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$this->Skip(2); // flags
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$this->unitsPerEm = $this->ReadUShort();
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$this->Skip(2*8); // created, modified
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$this->xMin = $this->ReadShort();
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$this->yMin = $this->ReadShort();
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$this->xMax = $this->ReadShort();
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$this->yMax = $this->ReadShort();
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$this->Skip(3*2); // macStyle, lowestRecPPEM, fontDirectionHint
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$this->indexToLocFormat = $this->ReadShort();
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}
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function ParseHhea()
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{
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$this->Seek('hhea');
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$this->Skip(4+15*2);
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$this->numberOfHMetrics = $this->ReadUShort();
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}
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function ParseMaxp()
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{
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$this->Seek('maxp');
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$this->Skip(4);
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$this->numGlyphs = $this->ReadUShort();
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}
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function ParseHmtx()
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{
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$this->Seek('hmtx');
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$this->glyphs = array();
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for($i=0;$i<$this->numberOfHMetrics;$i++)
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{
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$advanceWidth = $this->ReadUShort();
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$lsb = $this->ReadShort();
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$this->glyphs[$i] = array('w'=>$advanceWidth, 'lsb'=>$lsb);
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}
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for($i=$this->numberOfHMetrics;$i<$this->numGlyphs;$i++)
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{
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$lsb = $this->ReadShort();
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$this->glyphs[$i] = array('w'=>$advanceWidth, 'lsb'=>$lsb);
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}
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}
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function ParseLoca()
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{
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$this->Seek('loca');
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$offsets = array();
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if($this->indexToLocFormat==0)
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{
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// Short format
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for($i=0;$i<=$this->numGlyphs;$i++)
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$offsets[] = 2*$this->ReadUShort();
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}
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else
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{
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// Long format
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for($i=0;$i<=$this->numGlyphs;$i++)
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$offsets[] = $this->ReadULong();
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}
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for($i=0;$i<$this->numGlyphs;$i++)
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{
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$this->glyphs[$i]['offset'] = $offsets[$i];
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$this->glyphs[$i]['length'] = $offsets[$i+1] - $offsets[$i];
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}
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}
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function ParseGlyf()
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{
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$tableOffset = $this->tables['glyf']['offset'];
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foreach($this->glyphs as &$glyph)
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{
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if($glyph['length']>0)
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{
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fseek($this->f, $tableOffset+$glyph['offset'], SEEK_SET);
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if($this->ReadShort()<0)
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{
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// Composite glyph
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$this->Skip(4*2); // xMin, yMin, xMax, yMax
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$offset = 5*2;
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$a = array();
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do
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{
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$flags = $this->ReadUShort();
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$index = $this->ReadUShort();
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$a[$offset+2] = $index;
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if($flags & 1) // ARG_1_AND_2_ARE_WORDS
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$skip = 2*2;
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else
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$skip = 2;
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if($flags & 8) // WE_HAVE_A_SCALE
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$skip += 2;
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elseif($flags & 64) // WE_HAVE_AN_X_AND_Y_SCALE
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$skip += 2*2;
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elseif($flags & 128) // WE_HAVE_A_TWO_BY_TWO
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$skip += 4*2;
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$this->Skip($skip);
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$offset += 2*2 + $skip;
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}
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while($flags & 32); // MORE_COMPONENTS
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$glyph['components'] = $a;
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}
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}
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}
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}
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function ParseCmap()
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{
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$this->Seek('cmap');
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$this->Skip(2); // version
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$numTables = $this->ReadUShort();
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$offset31 = 0;
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for($i=0;$i<$numTables;$i++)
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{
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$platformID = $this->ReadUShort();
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$encodingID = $this->ReadUShort();
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$offset = $this->ReadULong();
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if($platformID==3 && $encodingID==1)
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$offset31 = $offset;
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}
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if($offset31==0)
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$this->Error('No Unicode encoding found');
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$startCount = array();
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$endCount = array();
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$idDelta = array();
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$idRangeOffset = array();
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$this->chars = array();
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fseek($this->f, $this->tables['cmap']['offset']+$offset31, SEEK_SET);
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$format = $this->ReadUShort();
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if($format!=4)
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$this->Error('Unexpected subtable format: '.$format);
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$this->Skip(2*2); // length, language
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$segCount = $this->ReadUShort()/2;
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$this->Skip(3*2); // searchRange, entrySelector, rangeShift
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for($i=0;$i<$segCount;$i++)
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$endCount[$i] = $this->ReadUShort();
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$this->Skip(2); // reservedPad
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for($i=0;$i<$segCount;$i++)
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$startCount[$i] = $this->ReadUShort();
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for($i=0;$i<$segCount;$i++)
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$idDelta[$i] = $this->ReadShort();
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$offset = ftell($this->f);
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for($i=0;$i<$segCount;$i++)
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$idRangeOffset[$i] = $this->ReadUShort();
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for($i=0;$i<$segCount;$i++)
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{
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$c1 = $startCount[$i];
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$c2 = $endCount[$i];
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$d = $idDelta[$i];
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$ro = $idRangeOffset[$i];
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if($ro>0)
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fseek($this->f, $offset+2*$i+$ro, SEEK_SET);
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for($c=$c1;$c<=$c2;$c++)
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{
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if($c==0xFFFF)
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break;
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if($ro>0)
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{
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$gid = $this->ReadUShort();
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if($gid>0)
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$gid += $d;
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}
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else
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$gid = $c+$d;
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if($gid>=65536)
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$gid -= 65536;
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if($gid>0)
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$this->chars[$c] = $gid;
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}
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}
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}
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function ParseName()
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{
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$this->Seek('name');
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$tableOffset = $this->tables['name']['offset'];
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$this->postScriptName = '';
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$this->Skip(2); // format
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$count = $this->ReadUShort();
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$stringOffset = $this->ReadUShort();
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for($i=0;$i<$count;$i++)
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{
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$this->Skip(3*2); // platformID, encodingID, languageID
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$nameID = $this->ReadUShort();
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$length = $this->ReadUShort();
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$offset = $this->ReadUShort();
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if($nameID==6)
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{
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// PostScript name
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fseek($this->f, $tableOffset+$stringOffset+$offset, SEEK_SET);
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$s = $this->Read($length);
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$s = str_replace(chr(0), '', $s);
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$s = preg_replace('|[ \[\](){}<>/%]|', '', $s);
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$this->postScriptName = $s;
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break;
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}
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}
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if($this->postScriptName=='')
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$this->Error('PostScript name not found');
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}
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function ParseOS2()
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{
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$this->Seek('OS/2');
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$version = $this->ReadUShort();
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$this->Skip(3*2); // xAvgCharWidth, usWeightClass, usWidthClass
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$fsType = $this->ReadUShort();
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$this->embeddable = ($fsType!=2) && ($fsType & 0x200)==0;
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$this->Skip(11*2+10+4*4+4);
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$fsSelection = $this->ReadUShort();
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$this->bold = ($fsSelection & 32)!=0;
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$this->Skip(2*2); // usFirstCharIndex, usLastCharIndex
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$this->typoAscender = $this->ReadShort();
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$this->typoDescender = $this->ReadShort();
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if($version>=2)
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{
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$this->Skip(3*2+2*4+2);
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$this->capHeight = $this->ReadShort();
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}
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else
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$this->capHeight = 0;
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}
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function ParsePost()
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{
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$this->Seek('post');
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$version = $this->ReadULong();
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$this->italicAngle = $this->ReadShort();
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$this->Skip(2); // Skip decimal part
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$this->underlinePosition = $this->ReadShort();
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$this->underlineThickness = $this->ReadShort();
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$this->isFixedPitch = ($this->ReadULong()!=0);
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if($version==0x20000)
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{
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// Extract glyph names
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$this->Skip(4*4); // min/max usage
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$this->Skip(2); // numberOfGlyphs
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$glyphNameIndex = array();
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$names = array();
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$numNames = 0;
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for($i=0;$i<$this->numGlyphs;$i++)
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{
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$index = $this->ReadUShort();
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$glyphNameIndex[] = $index;
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if($index>=258 && $index-257>$numNames)
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$numNames = $index-257;
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}
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for($i=0;$i<$numNames;$i++)
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{
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$len = ord($this->Read(1));
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$names[] = $this->Read($len);
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}
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foreach($glyphNameIndex as $i=>$index)
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{
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if($index>=258)
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$this->glyphs[$i]['name'] = $names[$index-258];
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else
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$this->glyphs[$i]['name'] = $index;
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}
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$this->glyphNames = true;
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}
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else
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$this->glyphNames = false;
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}
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function Subset($chars)
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{
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/* $chars = array_keys($this->chars);
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$this->subsettedChars = $chars;
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$this->subsettedGlyphs = array();
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for($i=0;$i<$this->numGlyphs;$i++)
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{
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$this->subsettedGlyphs[] = $i;
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$this->glyphs[$i]['ssid'] = $i;
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}*/
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$this->AddGlyph(0);
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$this->subsettedChars = array();
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foreach($chars as $char)
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{
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if(isset($this->chars[$char]))
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{
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$this->subsettedChars[] = $char;
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$this->AddGlyph($this->chars[$char]);
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}
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}
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}
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function AddGlyph($id)
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{
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if(!isset($this->glyphs[$id]['ssid']))
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{
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$this->glyphs[$id]['ssid'] = count($this->subsettedGlyphs);
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$this->subsettedGlyphs[] = $id;
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if(isset($this->glyphs[$id]['components']))
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{
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foreach($this->glyphs[$id]['components'] as $cid)
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$this->AddGlyph($cid);
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}
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}
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}
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function Build()
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{
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$this->BuildCmap();
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$this->BuildHhea();
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$this->BuildHmtx();
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$this->BuildLoca();
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$this->BuildGlyf();
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$this->BuildMaxp();
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$this->BuildPost();
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return $this->BuildFont();
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}
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function BuildCmap()
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{
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if(!isset($this->subsettedChars))
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return;
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// Divide charset in contiguous segments
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$chars = $this->subsettedChars;
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sort($chars);
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$segments = array();
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$segment = array($chars[0], $chars[0]);
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for($i=1;$i<count($chars);$i++)
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{
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if($chars[$i]>$segment[1]+1)
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{
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$segments[] = $segment;
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$segment = array($chars[$i], $chars[$i]);
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}
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else
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$segment[1]++;
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}
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$segments[] = $segment;
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$segments[] = array(0xFFFF, 0xFFFF);
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$segCount = count($segments);
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// Build a Format 4 subtable
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$startCount = array();
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$endCount = array();
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$idDelta = array();
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$idRangeOffset = array();
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$glyphIdArray = '';
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for($i=0;$i<$segCount;$i++)
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{
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list($start, $end) = $segments[$i];
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$startCount[] = $start;
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$endCount[] = $end;
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if($start!=$end)
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{
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// Segment with multiple chars
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$idDelta[] = 0;
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$idRangeOffset[] = strlen($glyphIdArray) + ($segCount-$i)*2;
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for($c=$start;$c<=$end;$c++)
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{
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$ssid = $this->glyphs[$this->chars[$c]]['ssid'];
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$glyphIdArray .= pack('n', $ssid);
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}
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}
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else
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{
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// Segment with a single char
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if($start<0xFFFF)
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$ssid = $this->glyphs[$this->chars[$start]]['ssid'];
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else
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$ssid = 0;
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$idDelta[] = $ssid - $start;
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$idRangeOffset[] = 0;
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}
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}
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$entrySelector = 0;
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$n = $segCount;
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while($n!=1)
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{
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$n = $n>>1;
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$entrySelector++;
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}
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$searchRange = (1<<$entrySelector)*2;
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$rangeShift = 2*$segCount - $searchRange;
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$cmap = pack('nnnn', 2*$segCount, $searchRange, $entrySelector, $rangeShift);
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foreach($endCount as $val)
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$cmap .= pack('n', $val);
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$cmap .= pack('n', 0); // reservedPad
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foreach($startCount as $val)
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$cmap .= pack('n', $val);
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foreach($idDelta as $val)
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$cmap .= pack('n', $val);
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foreach($idRangeOffset as $val)
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$cmap .= pack('n', $val);
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$cmap .= $glyphIdArray;
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$data = pack('nn', 0, 1); // version, numTables
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$data .= pack('nnN', 3, 1, 12); // platformID, encodingID, offset
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$data .= pack('nnn', 4, 6+strlen($cmap), 0); // format, length, language
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$data .= $cmap;
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$this->SetTable('cmap', $data);
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}
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|
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function BuildHhea()
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{
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$this->LoadTable('hhea');
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$numberOfHMetrics = count($this->subsettedGlyphs);
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$data = substr_replace($this->tables['hhea']['data'], pack('n',$numberOfHMetrics), 4+15*2, 2);
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$this->SetTable('hhea', $data);
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}
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function BuildHmtx()
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{
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$data = '';
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foreach($this->subsettedGlyphs as $id)
|
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{
|
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$glyph = $this->glyphs[$id];
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$data .= pack('nn', $glyph['w'], $glyph['lsb']);
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}
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$this->SetTable('hmtx', $data);
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}
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|
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function BuildLoca()
|
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{
|
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$data = '';
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$offset = 0;
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foreach($this->subsettedGlyphs as $id)
|
|
{
|
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if($this->indexToLocFormat==0)
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$data .= pack('n', $offset/2);
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else
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$data .= pack('N', $offset);
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$offset += $this->glyphs[$id]['length'];
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}
|
|
if($this->indexToLocFormat==0)
|
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$data .= pack('n', $offset/2);
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|
else
|
|
$data .= pack('N', $offset);
|
|
$this->SetTable('loca', $data);
|
|
}
|
|
|
|
function BuildGlyf()
|
|
{
|
|
$tableOffset = $this->tables['glyf']['offset'];
|
|
$data = '';
|
|
foreach($this->subsettedGlyphs as $id)
|
|
{
|
|
$glyph = $this->glyphs[$id];
|
|
fseek($this->f, $tableOffset+$glyph['offset'], SEEK_SET);
|
|
$glyph_data = $this->Read($glyph['length']);
|
|
if(isset($glyph['components']))
|
|
{
|
|
// Composite glyph
|
|
foreach($glyph['components'] as $offset=>$cid)
|
|
{
|
|
$ssid = $this->glyphs[$cid]['ssid'];
|
|
$glyph_data = substr_replace($glyph_data, pack('n',$ssid), $offset, 2);
|
|
}
|
|
}
|
|
$data .= $glyph_data;
|
|
}
|
|
$this->SetTable('glyf', $data);
|
|
}
|
|
|
|
function BuildMaxp()
|
|
{
|
|
$this->LoadTable('maxp');
|
|
$numGlyphs = count($this->subsettedGlyphs);
|
|
$data = substr_replace($this->tables['maxp']['data'], pack('n',$numGlyphs), 4, 2);
|
|
$this->SetTable('maxp', $data);
|
|
}
|
|
|
|
function BuildPost()
|
|
{
|
|
$this->Seek('post');
|
|
if($this->glyphNames)
|
|
{
|
|
// Version 2.0
|
|
$numberOfGlyphs = count($this->subsettedGlyphs);
|
|
$numNames = 0;
|
|
$names = '';
|
|
$data = $this->Read(2*4+2*2+5*4);
|
|
$data .= pack('n', $numberOfGlyphs);
|
|
foreach($this->subsettedGlyphs as $id)
|
|
{
|
|
$name = $this->glyphs[$id]['name'];
|
|
if(is_string($name))
|
|
{
|
|
$data .= pack('n', 258+$numNames);
|
|
$names .= chr(strlen($name)).$name;
|
|
$numNames++;
|
|
}
|
|
else
|
|
$data .= pack('n', $name);
|
|
}
|
|
$data .= $names;
|
|
}
|
|
else
|
|
{
|
|
// Version 3.0
|
|
$this->Skip(4);
|
|
$data = "\x00\x03\x00\x00";
|
|
$data .= $this->Read(4+2*2+5*4);
|
|
}
|
|
$this->SetTable('post', $data);
|
|
}
|
|
|
|
function BuildFont()
|
|
{
|
|
$tags = array();
|
|
foreach(array('cmap', 'cvt ', 'fpgm', 'glyf', 'head', 'hhea', 'hmtx', 'loca', 'maxp', 'name', 'post', 'prep') as $tag)
|
|
{
|
|
if(isset($this->tables[$tag]))
|
|
$tags[] = $tag;
|
|
}
|
|
$numTables = count($tags);
|
|
$offset = 12 + 16*$numTables;
|
|
foreach($tags as $tag)
|
|
{
|
|
if(!isset($this->tables[$tag]['data']))
|
|
$this->LoadTable($tag);
|
|
$this->tables[$tag]['offset'] = $offset;
|
|
$offset += strlen($this->tables[$tag]['data']);
|
|
}
|
|
// $this->tables['head']['data'] = substr_replace($this->tables['head']['data'], "\x00\x00\x00\x00", 8, 4);
|
|
|
|
// Build offset table
|
|
$entrySelector = 0;
|
|
$n = $numTables;
|
|
while($n!=1)
|
|
{
|
|
$n = $n>>1;
|
|
$entrySelector++;
|
|
}
|
|
$searchRange = 16*(1<<$entrySelector);
|
|
$rangeShift = 16*$numTables - $searchRange;
|
|
$offsetTable = pack('nnnnnn', 1, 0, $numTables, $searchRange, $entrySelector, $rangeShift);
|
|
foreach($tags as $tag)
|
|
{
|
|
$table = $this->tables[$tag];
|
|
$offsetTable .= $tag.$table['checkSum'].pack('NN', $table['offset'], $table['length']);
|
|
}
|
|
|
|
// Compute checkSumAdjustment (0xB1B0AFBA - font checkSum)
|
|
$s = $this->CheckSum($offsetTable);
|
|
foreach($tags as $tag)
|
|
$s .= $this->tables[$tag]['checkSum'];
|
|
$a = unpack('n2', $this->CheckSum($s));
|
|
$high = 0xB1B0 + ($a[1]^0xFFFF);
|
|
$low = 0xAFBA + ($a[2]^0xFFFF) + 1;
|
|
$checkSumAdjustment = pack('nn', $high+($low>>16), $low);
|
|
$this->tables['head']['data'] = substr_replace($this->tables['head']['data'], $checkSumAdjustment, 8, 4);
|
|
|
|
$font = $offsetTable;
|
|
foreach($tags as $tag)
|
|
$font .= $this->tables[$tag]['data'];
|
|
|
|
return $font;
|
|
}
|
|
|
|
function LoadTable($tag)
|
|
{
|
|
$this->Seek($tag);
|
|
$length = $this->tables[$tag]['length'];
|
|
$n = $length % 4;
|
|
if($n>0)
|
|
$length += 4 - $n;
|
|
$this->tables[$tag]['data'] = $this->Read($length);
|
|
}
|
|
|
|
function SetTable($tag, $data)
|
|
{
|
|
$length = strlen($data);
|
|
$n = $length % 4;
|
|
if($n>0)
|
|
$data = str_pad($data, $length+4-$n, "\x00");
|
|
$this->tables[$tag]['data'] = $data;
|
|
$this->tables[$tag]['length'] = $length;
|
|
$this->tables[$tag]['checkSum'] = $this->CheckSum($data);
|
|
}
|
|
|
|
function Seek($tag)
|
|
{
|
|
if(!isset($this->tables[$tag]))
|
|
$this->Error('Table not found: '.$tag);
|
|
fseek($this->f, $this->tables[$tag]['offset'], SEEK_SET);
|
|
}
|
|
|
|
function Skip($n)
|
|
{
|
|
fseek($this->f, $n, SEEK_CUR);
|
|
}
|
|
|
|
function Read($n)
|
|
{
|
|
return $n>0 ? fread($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 $a['N'];
|
|
}
|
|
|
|
function CheckSum($s)
|
|
{
|
|
$n = strlen($s);
|
|
$high = 0;
|
|
$low = 0;
|
|
for($i=0;$i<$n;$i+=4)
|
|
{
|
|
$high += (ord($s[$i])<<8) + ord($s[$i+1]);
|
|
$low += (ord($s[$i+2])<<8) + ord($s[$i+3]);
|
|
}
|
|
return pack('nn', $high+($low>>16), $low);
|
|
}
|
|
|
|
function Error($msg)
|
|
{
|
|
throw new Exception($msg);
|
|
}
|
|
}
|
|
?>
|