pdfbox/src/main/java/org/apache/pdfbox/pdmodel/font/TrueTypeEmbedder.java - pdfbox - Git at Google

 /*
  * Licensed to the Apache Software Foundation (ASF) under one or more
  * contributor license agreements.  See the NOTICE file distributed with
  * this work for additional information regarding copyright ownership.
  * The ASF licenses this file to You under the Apache License, Version 2.0
  * (the "License"); you may not use this file except in compliance with
  * the License.  You may obtain a copy of the License at
  *
  *      http://www.apache.org/licenses/LICENSE-2.0
  *
  * Unless required by applicable law or agreed to in writing, software
  * distributed under the License is distributed on an "AS IS" BASIS,
  * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
  * See the License for the specific language governing permissions and
  * limitations under the License.
  */

 package org.apache.pdfbox.pdmodel.font;

 import java.io.ByteArrayInputStream;
 import java.io.ByteArrayOutputStream;
 import java.io.IOException;
 import java.io.InputStream;
 import java.util.ArrayList;
 import java.util.HashSet;
 import java.util.List;
 import java.util.Map;
 import java.util.Set;
 import org.apache.fontbox.ttf.CmapSubtable;
 import org.apache.fontbox.ttf.HeaderTable;
 import org.apache.fontbox.ttf.HorizontalHeaderTable;
 import org.apache.fontbox.ttf.OS2WindowsMetricsTable;
 import org.apache.fontbox.ttf.PostScriptTable;
 import org.apache.fontbox.ttf.TTFParser;
 import org.apache.fontbox.ttf.TTFSubsetter;
 import org.apache.fontbox.ttf.TrueTypeFont;
 import org.apache.pdfbox.cos.COSDictionary;
 import org.apache.pdfbox.cos.COSName;
 import org.apache.pdfbox.io.IOUtils;
 import org.apache.pdfbox.pdmodel.PDDocument;
 import org.apache.pdfbox.pdmodel.common.PDRectangle;
 import org.apache.pdfbox.pdmodel.common.PDStream;

 /**
  * Common functionality for embedding TrueType fonts.
  *
  * @author Ben Litchfield
  * @author John Hewson
  */
 abstract class TrueTypeEmbedder implements Subsetter
 {
     private static final int ITALIC = 1;
     private static final int OBLIQUE = 512;
     private static final String BASE25 = "BCDEFGHIJKLMNOPQRSTUVWXYZ";

     private final PDDocument document;
     protected TrueTypeFont ttf;
     protected PDFontDescriptor fontDescriptor;
     protected final CmapSubtable cmap;
     private final Set<Integer> subsetCodePoints = new HashSet<Integer>();
     private final boolean embedSubset;

     /**
      * Creates a new TrueType font for embedding.
      */
     TrueTypeEmbedder(PDDocument document, COSDictionary dict, InputStream ttfStream,
                      boolean embedSubset) throws IOException
     {
         this.document = document;
         this.embedSubset = embedSubset;

         buildFontFile2(ttfStream);
         dict.setName(COSName.BASE_FONT, ttf.getName());

         // choose a Unicode "cmap"
         cmap = ttf.getUnicodeCmap();
     }

     /**
      * Creates a new TrueType font for embedding.
      */
     TrueTypeEmbedder(PDDocument document, COSDictionary dict, TrueTypeFont ttf,
                      boolean embedSubset) throws IOException
     {
         this.document = document;
         this.embedSubset = embedSubset;
         this.ttf = ttf;
         fontDescriptor = createFontDescriptor(ttf);

         PDStream stream = new PDStream(document, ttf.getOriginalData(), COSName.FLATE_DECODE);
         stream.getCOSObject().setInt(COSName.LENGTH1, stream.toByteArray().length);
         fontDescriptor.setFontFile2(stream);

         dict.setName(COSName.BASE_FONT, ttf.getName());

         // choose a Unicode "cmap"
         cmap = ttf.getUnicodeCmap();
     }

     public void buildFontFile2(InputStream ttfStream) throws IOException
     {
         PDStream stream = new PDStream(document, ttfStream, COSName.FLATE_DECODE);
         stream.getCOSObject().setInt(COSName.LENGTH1, stream.toByteArray().length);

         // as the stream was closed within the PDStream constructor, we have to recreate it
         InputStream input = null;
         try
         {
             input = stream.createInputStream();
             if (ttf != null)
             {
                 // close the replaced true type font
                 ttf.close();
             }
             ttf = new TTFParser().parseEmbedded(input);
             if (!isEmbeddingPermitted(ttf))
             {
                 throw new IOException("This font does not permit embedding");
             }
             if (fontDescriptor == null)
             {
                 fontDescriptor = createFontDescriptor(ttf);
             }
         }
         finally
         {
             IOUtils.closeQuietly(input);
         }

         fontDescriptor.setFontFile2(stream);
     }

     /**
      * Returns true if the fsType in the OS/2 table permits embedding.
      */
     private boolean isEmbeddingPermitted(TrueTypeFont ttf) throws IOException
     {
         if (ttf.getOS2Windows() != null)
         {
             int fsType = ttf.getOS2Windows().getFsType();
             int exclusive = fsType & 0x8; // bits 0-3 are a set of exclusive bits

             if ((exclusive & OS2WindowsMetricsTable.FSTYPE_RESTRICTED) ==
                              OS2WindowsMetricsTable.FSTYPE_RESTRICTED)
             {
                 // restricted License embedding
                 return false;
             }
             else if ((exclusive & OS2WindowsMetricsTable.FSTYPE_BITMAP_ONLY) ==
                                  OS2WindowsMetricsTable.FSTYPE_BITMAP_ONLY)
             {
                 // bitmap embedding only
                 return false;
             }
         }
         return true;
     }

     /**
      * Returns true if the fsType in the OS/2 table permits subsetting.
      */
     private boolean isSubsettingPermitted(TrueTypeFont ttf) throws IOException
     {
         if (ttf.getOS2Windows() != null)
         {
             int fsType = ttf.getOS2Windows().getFsType();
             if ((fsType & OS2WindowsMetricsTable.FSTYPE_NO_SUBSETTING) ==
                           OS2WindowsMetricsTable.FSTYPE_NO_SUBSETTING)
             {
                 return false;
             }
         }
         return true;
     }

     /**
      * Creates a new font descriptor dictionary for the given TTF.
      */
     private PDFontDescriptor createFontDescriptor(TrueTypeFont ttf) throws IOException
     {
         PDFontDescriptor fd = new PDFontDescriptor();
         fd.setFontName(ttf.getName());

         OS2WindowsMetricsTable os2 = ttf.getOS2Windows();
         PostScriptTable post = ttf.getPostScript();

         // Flags
         fd.setFixedPitch(post.getIsFixedPitch() > 0 ||
                          ttf.getHorizontalHeader().getNumberOfHMetrics() == 1);

         int fsSelection = os2.getFsSelection();
         fd.setItalic(((fsSelection & (ITALIC | OBLIQUE)) != 0));

         switch (os2.getFamilyClass())
         {
             case OS2WindowsMetricsTable.FAMILY_CLASS_CLAREDON_SERIFS:
             case OS2WindowsMetricsTable.FAMILY_CLASS_FREEFORM_SERIFS:
             case OS2WindowsMetricsTable.FAMILY_CLASS_MODERN_SERIFS:
             case OS2WindowsMetricsTable.FAMILY_CLASS_OLDSTYLE_SERIFS:
             case OS2WindowsMetricsTable.FAMILY_CLASS_SLAB_SERIFS:
                 fd.setSerif(true);
                 break;
             case OS2WindowsMetricsTable.FAMILY_CLASS_SCRIPTS:
                 fd.setScript(true);
                 break;
         }

         fd.setFontWeight(os2.getWeightClass());

         fd.setSymbolic(true);
         fd.setNonSymbolic(false);

         // ItalicAngle
         fd.setItalicAngle(post.getItalicAngle());

         // FontBBox
         HeaderTable header = ttf.getHeader();
         PDRectangle rect = new PDRectangle();
         float scaling = 1000f / header.getUnitsPerEm();
         rect.setLowerLeftX(header.getXMin() * scaling);
         rect.setLowerLeftY(header.getYMin() * scaling);
         rect.setUpperRightX(header.getXMax() * scaling);
         rect.setUpperRightY(header.getYMax() * scaling);
         fd.setFontBoundingBox(rect);

         // Ascent, Descent
         HorizontalHeaderTable hHeader = ttf.getHorizontalHeader();
         fd.setAscent(hHeader.getAscender() * scaling);
         fd.setDescent(hHeader.getDescender() * scaling);

         // CapHeight, XHeight
         if (os2.getVersion() >= 1.2)
         {
             fd.setCapHeight(os2.getCapHeight() * scaling);
             fd.setXHeight(os2.getHeight() * scaling);
         }
         else
         {
             // estimate by summing the typographical +ve ascender and -ve descender
             fd.setCapHeight((os2.getTypoAscender() + os2.getTypoDescender()) * scaling);

             // estimate by halving the typographical ascender
             fd.setXHeight(os2.getTypoAscender() / 2.0f * scaling);
         }

         // StemV - there's no true TTF equivalent of this, so we estimate it
         fd.setStemV(fd.getFontBoundingBox().getWidth() * .13f);

         return fd;
     }

     /**
      * Returns the FontBox font.
      */
     public TrueTypeFont getTrueTypeFont()
     {
         return ttf;
     }

     /**
      * Returns the font descriptor.
      */
     public PDFontDescriptor getFontDescriptor()
     {
         return fontDescriptor;
     }

     @Override
     public void addToSubset(int codePoint)
     {
         subsetCodePoints.add(codePoint);
     }

     @Override
     public void subset() throws IOException
     {
         if (!isSubsettingPermitted(ttf))
         {
             throw new IOException("This font does not permit subsetting");
         }

         if (!embedSubset)
         {
             throw new IllegalStateException("Subsetting is disabled");
         }

         // PDF spec required tables (if present), all others will be removed
         List<String> tables = new ArrayList<String>();
         tables.add("head");
         tables.add("hhea");
         tables.add("loca");
         tables.add("maxp");
         tables.add("cvt ");
         tables.add("prep");
         tables.add("glyf");
         tables.add("hmtx");
         tables.add("fpgm");
         // Windows ClearType
         tables.add("gasp");

         // set the GIDs to subset
         TTFSubsetter subsetter = new TTFSubsetter(getTrueTypeFont(), tables);
         subsetter.addAll(subsetCodePoints);

         // calculate deterministic tag based on the chosen subset
         Map<Integer, Integer> gidToCid = subsetter.getGIDMap();
         String tag = getTag(gidToCid);
         subsetter.setPrefix(tag);

         // save the subset font
         ByteArrayOutputStream out = new ByteArrayOutputStream();
         subsetter.writeToStream(out);

         // re-build the embedded font
         buildSubset(new ByteArrayInputStream(out.toByteArray()), tag, gidToCid);
         ttf.close();
     }

     /**
      * Returns true if the font needs to be subset.
      */
     public boolean needsSubset()
     {
         return embedSubset;
     }

     /**
      * Rebuild a font subset.
      */
     protected abstract void buildSubset(InputStream ttfSubset, String tag,
                                      Map<Integer, Integer> gidToCid) throws IOException;

     /**
      * Returns an uppercase 6-character unique tag for the given subset.
      */
     public String getTag(Map<Integer, Integer> gidToCid)
     {
         // deterministic
         long num = gidToCid.hashCode();

         // base25 encode
         StringBuilder sb = new StringBuilder();
         do
         {
             long div = num / 25;
             int mod = (int)(num % 25);
             sb.append(BASE25.charAt(mod));
             num = div;
         } while (num != 0 && sb.length() < 6);

         // pad
         while (sb.length() < 6)
         {
             sb.insert(0, 'A');
         }

         sb.append('+');
         return sb.toString();
     }
 }
	/*
	* Licensed to the Apache Software Foundation (ASF) under one or more
	* contributor license agreements. See the NOTICE file distributed with
	* this work for additional information regarding copyright ownership.
	* The ASF licenses this file to You under the Apache License, Version 2.0
	* (the "License"); you may not use this file except in compliance with
	* the License. You may obtain a copy of the License at
	*
	* http://www.apache.org/licenses/LICENSE-2.0
	*
	* Unless required by applicable law or agreed to in writing, software
	* distributed under the License is distributed on an "AS IS" BASIS,
	* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
	* See the License for the specific language governing permissions and
	* limitations under the License.
	*/

	package org.apache.pdfbox.pdmodel.font;

	import java.io.ByteArrayInputStream;
	import java.io.ByteArrayOutputStream;
	import java.io.IOException;
	import java.io.InputStream;
	import java.util.ArrayList;
	import java.util.HashSet;
	import java.util.List;
	import java.util.Map;
	import java.util.Set;
	import org.apache.fontbox.ttf.CmapSubtable;
	import org.apache.fontbox.ttf.HeaderTable;
	import org.apache.fontbox.ttf.HorizontalHeaderTable;
	import org.apache.fontbox.ttf.OS2WindowsMetricsTable;
	import org.apache.fontbox.ttf.PostScriptTable;
	import org.apache.fontbox.ttf.TTFParser;
	import org.apache.fontbox.ttf.TTFSubsetter;
	import org.apache.fontbox.ttf.TrueTypeFont;
	import org.apache.pdfbox.cos.COSDictionary;
	import org.apache.pdfbox.cos.COSName;
	import org.apache.pdfbox.io.IOUtils;
	import org.apache.pdfbox.pdmodel.PDDocument;
	import org.apache.pdfbox.pdmodel.common.PDRectangle;
	import org.apache.pdfbox.pdmodel.common.PDStream;

	/**
	* Common functionality for embedding TrueType fonts.
	*
	* @author Ben Litchfield
	* @author John Hewson
	*/
	abstract class TrueTypeEmbedder implements Subsetter
	{
	private static final int ITALIC = 1;
	private static final int OBLIQUE = 512;
	private static final String BASE25 = "BCDEFGHIJKLMNOPQRSTUVWXYZ";

	private final PDDocument document;
	protected TrueTypeFont ttf;
	protected PDFontDescriptor fontDescriptor;
	protected final CmapSubtable cmap;
	private final Set<Integer> subsetCodePoints = new HashSet<Integer>();
	private final boolean embedSubset;

	/**
	* Creates a new TrueType font for embedding.
	*/
	TrueTypeEmbedder(PDDocument document, COSDictionary dict, InputStream ttfStream,
	boolean embedSubset) throws IOException
	{
	this.document = document;
	this.embedSubset = embedSubset;

	buildFontFile2(ttfStream);
	dict.setName(COSName.BASE_FONT, ttf.getName());

	// choose a Unicode "cmap"
	cmap = ttf.getUnicodeCmap();
	}

	/**
	* Creates a new TrueType font for embedding.
	*/
	TrueTypeEmbedder(PDDocument document, COSDictionary dict, TrueTypeFont ttf,
	boolean embedSubset) throws IOException
	{
	this.document = document;
	this.embedSubset = embedSubset;
	this.ttf = ttf;
	fontDescriptor = createFontDescriptor(ttf);

	PDStream stream = new PDStream(document, ttf.getOriginalData(), COSName.FLATE_DECODE);
	stream.getCOSObject().setInt(COSName.LENGTH1, stream.toByteArray().length);
	fontDescriptor.setFontFile2(stream);

	dict.setName(COSName.BASE_FONT, ttf.getName());

	// choose a Unicode "cmap"
	cmap = ttf.getUnicodeCmap();
	}

	public void buildFontFile2(InputStream ttfStream) throws IOException
	{
	PDStream stream = new PDStream(document, ttfStream, COSName.FLATE_DECODE);
	stream.getCOSObject().setInt(COSName.LENGTH1, stream.toByteArray().length);

	// as the stream was closed within the PDStream constructor, we have to recreate it
	InputStream input = null;
	try
	{
	input = stream.createInputStream();
	if (ttf != null)
	{
	// close the replaced true type font
	ttf.close();
	}
	ttf = new TTFParser().parseEmbedded(input);
	if (!isEmbeddingPermitted(ttf))
	{
	throw new IOException("This font does not permit embedding");
	}
	if (fontDescriptor == null)
	{
	fontDescriptor = createFontDescriptor(ttf);
	}
	}
	finally
	{
	IOUtils.closeQuietly(input);
	}

	fontDescriptor.setFontFile2(stream);
	}

	/**
	* Returns true if the fsType in the OS/2 table permits embedding.
	*/
	private boolean isEmbeddingPermitted(TrueTypeFont ttf) throws IOException
	{
	if (ttf.getOS2Windows() != null)
	{
	int fsType = ttf.getOS2Windows().getFsType();
	int exclusive = fsType & 0x8; // bits 0-3 are a set of exclusive bits

	if ((exclusive & OS2WindowsMetricsTable.FSTYPE_RESTRICTED) ==
	OS2WindowsMetricsTable.FSTYPE_RESTRICTED)
	{
	// restricted License embedding
	return false;
	}
	else if ((exclusive & OS2WindowsMetricsTable.FSTYPE_BITMAP_ONLY) ==
	OS2WindowsMetricsTable.FSTYPE_BITMAP_ONLY)
	{
	// bitmap embedding only
	return false;
	}
	}
	return true;
	}

	/**
	* Returns true if the fsType in the OS/2 table permits subsetting.
	*/
	private boolean isSubsettingPermitted(TrueTypeFont ttf) throws IOException
	{
	if (ttf.getOS2Windows() != null)
	{
	int fsType = ttf.getOS2Windows().getFsType();
	if ((fsType & OS2WindowsMetricsTable.FSTYPE_NO_SUBSETTING) ==
	OS2WindowsMetricsTable.FSTYPE_NO_SUBSETTING)
	{
	return false;
	}
	}
	return true;
	}

	/**
	* Creates a new font descriptor dictionary for the given TTF.
	*/
	private PDFontDescriptor createFontDescriptor(TrueTypeFont ttf) throws IOException
	{
	PDFontDescriptor fd = new PDFontDescriptor();
	fd.setFontName(ttf.getName());

	OS2WindowsMetricsTable os2 = ttf.getOS2Windows();
	PostScriptTable post = ttf.getPostScript();

	// Flags
	fd.setFixedPitch(post.getIsFixedPitch() > 0 \|\|
	ttf.getHorizontalHeader().getNumberOfHMetrics() == 1);

	int fsSelection = os2.getFsSelection();
	fd.setItalic(((fsSelection & (ITALIC \| OBLIQUE)) != 0));

	switch (os2.getFamilyClass())
	{
	case OS2WindowsMetricsTable.FAMILY_CLASS_CLAREDON_SERIFS:
	case OS2WindowsMetricsTable.FAMILY_CLASS_FREEFORM_SERIFS:
	case OS2WindowsMetricsTable.FAMILY_CLASS_MODERN_SERIFS:
	case OS2WindowsMetricsTable.FAMILY_CLASS_OLDSTYLE_SERIFS:
	case OS2WindowsMetricsTable.FAMILY_CLASS_SLAB_SERIFS:
	fd.setSerif(true);
	break;
	case OS2WindowsMetricsTable.FAMILY_CLASS_SCRIPTS:
	fd.setScript(true);
	break;
	}

	fd.setFontWeight(os2.getWeightClass());

	fd.setSymbolic(true);
	fd.setNonSymbolic(false);

	// ItalicAngle
	fd.setItalicAngle(post.getItalicAngle());

	// FontBBox
	HeaderTable header = ttf.getHeader();
	PDRectangle rect = new PDRectangle();
	float scaling = 1000f / header.getUnitsPerEm();
	rect.setLowerLeftX(header.getXMin() * scaling);
	rect.setLowerLeftY(header.getYMin() * scaling);
	rect.setUpperRightX(header.getXMax() * scaling);
	rect.setUpperRightY(header.getYMax() * scaling);
	fd.setFontBoundingBox(rect);

	// Ascent, Descent
	HorizontalHeaderTable hHeader = ttf.getHorizontalHeader();
	fd.setAscent(hHeader.getAscender() * scaling);
	fd.setDescent(hHeader.getDescender() * scaling);

	// CapHeight, XHeight
	if (os2.getVersion() >= 1.2)
	{
	fd.setCapHeight(os2.getCapHeight() * scaling);
	fd.setXHeight(os2.getHeight() * scaling);
	}
	else
	{
	// estimate by summing the typographical +ve ascender and -ve descender
	fd.setCapHeight((os2.getTypoAscender() + os2.getTypoDescender()) * scaling);

	// estimate by halving the typographical ascender
	fd.setXHeight(os2.getTypoAscender() / 2.0f * scaling);
	}

	// StemV - there's no true TTF equivalent of this, so we estimate it
	fd.setStemV(fd.getFontBoundingBox().getWidth() * .13f);

	return fd;
	}

	/**
	* Returns the FontBox font.
	*/
	public TrueTypeFont getTrueTypeFont()
	{
	return ttf;
	}

	/**
	* Returns the font descriptor.
	*/
	public PDFontDescriptor getFontDescriptor()
	{
	return fontDescriptor;
	}

	@Override
	public void addToSubset(int codePoint)
	{
	subsetCodePoints.add(codePoint);
	}

	@Override
	public void subset() throws IOException
	{
	if (!isSubsettingPermitted(ttf))
	{
	throw new IOException("This font does not permit subsetting");
	}

	if (!embedSubset)
	{
	throw new IllegalStateException("Subsetting is disabled");
	}

	// PDF spec required tables (if present), all others will be removed
	List<String> tables = new ArrayList<String>();
	tables.add("head");
	tables.add("hhea");
	tables.add("loca");
	tables.add("maxp");
	tables.add("cvt ");
	tables.add("prep");
	tables.add("glyf");
	tables.add("hmtx");
	tables.add("fpgm");
	// Windows ClearType
	tables.add("gasp");

	// set the GIDs to subset
	TTFSubsetter subsetter = new TTFSubsetter(getTrueTypeFont(), tables);
	subsetter.addAll(subsetCodePoints);

	// calculate deterministic tag based on the chosen subset
	Map<Integer, Integer> gidToCid = subsetter.getGIDMap();
	String tag = getTag(gidToCid);
	subsetter.setPrefix(tag);

	// save the subset font
	ByteArrayOutputStream out = new ByteArrayOutputStream();
	subsetter.writeToStream(out);

	// re-build the embedded font
	buildSubset(new ByteArrayInputStream(out.toByteArray()), tag, gidToCid);
	ttf.close();
	}

	/**
	* Returns true if the font needs to be subset.
	*/
	public boolean needsSubset()
	{
	return embedSubset;
	}

	/**
	* Rebuild a font subset.
	*/
	protected abstract void buildSubset(InputStream ttfSubset, String tag,
	Map<Integer, Integer> gidToCid) throws IOException;

	/**
	* Returns an uppercase 6-character unique tag for the given subset.
	*/
	public String getTag(Map<Integer, Integer> gidToCid)
	{
	// deterministic
	long num = gidToCid.hashCode();

	// base25 encode
	StringBuilder sb = new StringBuilder();
	do
	{
	long div = num / 25;
	int mod = (int)(num % 25);
	sb.append(BASE25.charAt(mod));
	num = div;
	} while (num != 0 && sb.length() < 6);

	// pad
	while (sb.length() < 6)
	{
	sb.insert(0, 'A');
	}

	sb.append('+');
	return sb.toString();
	}
	}