Apache FOP: Fonts

The following table summarizes the font capabilities of the various FOP renderers:

The Adobe PDF Specification specifies a set of 14 fonts that must be available to every PDF reader: Helvetica (normal, bold, italic, bold italic), Times (normal, bold, italic, bold italic), Courier (normal, bold, italic, bold italic), Symbol and ZapfDingbats.

The AWT family of renderers (AWT, Print, SVG), use the Java AWT libraries for font metric information. Through operating system registration, the AWT libraries know what fonts are available on the system, and the font metrics for each one.

Support for custom fonts is added by creating font metric files (written in XML) from the actual font files, and registering them with FOP. Currently only Type 1 and TrueType fonts can be added. More information about fonts can be found at:

• Adobe font types
• Adobe Font Technote

Type 1 Font Metrics

FOP includes PFMReader, which reads the PFM file that normally comes with a Type 1 font, and generates an appropriate font metrics file for it. To use it, run the class org.apache.fop.fonts.apps.PFMReader:

Windows (on JDK 1.4 and later):

java -cp build\fop.jar;lib\avalon-framework.jar;lib\commons-logging.jar;lib\commons-io.jar
           org.apache.fop.fonts.apps.PFMReader [options] pfm-file xml-file

Windows (on JDK 1.3.x):

java -cp build\fop.jar;lib\avalon-framework.jar;lib\commons-logging.jar;lib\commons-io.jar;lib\xml-apis.jar;
         lib\xercesImpl.jar;lib\xalan.jar;lib\serializer.jar
           org.apache.fop.fonts.apps.PFMReader [options] pfm-file xml-file

Unix (on JDK 1.4 and later):

java -cp build/fop.jar:lib/avalon-framework.jar:lib/commons-logging.jar:lib/commons-io.jar
           org.apache.fop.fonts.apps.PFMReader [options] pfm-file xml-file

Unix (on JDK 1.3.1):

java -cp build/fop.jar:lib/avalon-framework.jar:lib/commons-logging.jar:lib/commons-io.jar:lib/xml-apis.jar:
         lib/xercesImpl.jar:lib/xalan.jar:lib/serializer.jar
           org.apache.fop.fonts.apps.PFMReader [options] pfm-file xml-file

PFMReader [options]:

• -fn <fontname> By default, FOP uses the fontname from the .pfm file when embedding the font. Use the "-fn" option to override this name with one you have chosen. This may be useful in some cases to ensure that applications using the output document (Acrobat Reader for example) use the embedded font instead of a local font with the same name.

TrueType Font Metrics

FOP includes TTFReader, which reads the TTF file and generates an appropriate font metrics file for it. Use it in a similar manner to PFMReader. For example, to create such a metrics file in Windows from the TrueType font at c:\myfonts\cmr10.ttf:

java -cp build\fop.jar;lib\avalon-framework.jar;lib\commons-logging.jar;lib\commons-io.jar
           org.apache.fop.fonts.apps.TTFReader [options]
             C:\myfonts\cmr10.ttf ttfcm.xml

TTFReader [options]:

• -d <DEBUG | INFO > Sets the debug level (default is INFO).
• -fn <fontname> Same as for PFMReader.
• -ttcname <fontname> If you're reading data from a TrueType Collection (.ttc file) you must specify which font from the collection you will read metrics from. If you read from a .ttc file without this option, the fontnames will be listed for you.
• -enc ansi Creates a WinAnsi-encoded font metrics file. Without this option, a CID-keyed font metrics file is created. The table below summarizes the differences between these two encoding options as currently used within FOP. Please note that this information only applies to TrueType fonts and TrueType collections:

TrueType Collections Font Metrics

TrueType collections (.ttc files) contain more than one font. To create metrics files for these fonts, you must specify which font in the collection should be generated, by using the "-ttcname" option with the TTFReader.

To get a list of the fonts in a collection, just start the TTFReader as if it were a normal TrueType file (without the -ttcname option). It will display all of the font names and exit with an Exception.

Here is an example of generating a metrics file for a .ttc file:

java -cp build\fop.jar;lib\avalon-framework.jar;lib\commons-logging.jar;lib\commons-io.jar
           org.apache.fop.fonts.apps.TTFReader -ttcname "MS Mincho"
             msmincho.ttc msminch.xml

Register Fonts with FOP

You must tell FOP how to find and use the font metrics files by registering them in the FOP Configuration. Add entries for your custom fonts, regardless of font type, to the configuration file in a manner similar to the following:

<fonts>
  <!-- register a particular font -->
  <font metrics-url="file:///C:/myfonts/FTL_____.xml" kerning="yes"
      embed-url="file:///C:/myfonts/FTL_____.pfb">
     <font-triplet name="FrutigerLight" style="normal" weight="normal"/>
  </font>
  
  <!-- register all the fonts found in a directory -->
  <directory>C:\MyFonts1</directory>
  
  <!-- register all the fonts found in a directory
       and all of its sub directories (use with care) -->
  <directory recursive="true">C:\MyFonts2</directory>

  <!-- automatically detect operating system installed fonts -->
  <auto-detect/>  
</fonts>

• URLs are used to access the font metric and font files. Relative URLs are resolved relative to the font-base property (or base) if available. See FOP: Configuration for more information.
• If relative URLs are specified, they are evaluated relative to the value of the "font-base" setting. If there is no "font-base" setting, the fonts are evaluated relative to the base directory.
• Either an "embed-url" or a "metrics-url" must be specified for font tag configurations.
• The font "kerning" attribute is optional.
• If embedding is off, the output will position the text correctly (from the metrics file), but it will not be displayed or printed correctly unless the viewer has the applicable font available to their local system.
• When setting the "embed-url" attribute for Type 1 fonts, be sure to specify the PFB (actual font data), not PFM (font metrics) file that you used to generate the XML font metrics file.
• The fonts "directory" tag can be used to register fonts contained within a single or list of directory paths. The "recursive" attribute can be specified to recursively add fonts from all sub directories.
• Fonts registered with "font" tag configurations override fonts found by means of "directory" tag definitions.
• Fonts found as a result of a "directory" tag configuration override fonts found as a result of the "auto-detect" tag being specified.
• The fonts "auto-detect" tag can be used to automatically register fonts that are found to be installed on the native operating system.
  • On Unix platforms the autodetect feature looks in java user.home + "/.fonts", "/usr/local/fonts", "/usr/share/fonts" and "/usr/X11R6/lib/X11/fonts" for fonts it is able to use.
  • On Mac platforms the autodetect feature looks in java user.home + "/Library/Fonts/, "/Library/Fonts/", "/System/Library/Fonts/" and "/Network/Library/Fonts/" for fonts it is able to use.
  • On Windows platforms the autodetect feature attempts to determine the Windows fonts directory (usually C:\WINDOWS\FONTS) and also the existence of a PSFONTS directory for fonts it is able to use.

Embedding

Font embedding is enabled in the userconfig.xml file and controlled by the embed-url attribute. If you don't specify the embed-url attribute the font will not be embedded, but will only be referenced.

When FOP embeds a font, it adds a prefix to the fontname to ensure that the name will not match the fontname of an installed font. This is helpful with older versions of Acrobat Reader that preferred installed fonts over embedded fonts.

When embedding PostScript fonts, the entire font is always embedded.

When embedding TrueType fonts (ttf) or TrueType Collections (ttc), a subset of the original font, containing only the glyphs used, is embedded in the output document.

Explicitly embedding the base 14 fonts

There are cases where you might want to force the embedding of one or more of the base 14 fonts that can normally be considered available on the target platform (viewer, printer). One of these cases is PDF/A which mandates the embedding of even the base 14 fonts. Embedding a font such as Helvetica or Courier is straight-forward. The "Symbol" and "ZapfDingbats" fonts, however, currently present a problem because FOP cannot correctly determine the encoding of these two single-byte fonts through the PFM file. FOP now correctly interprets the "encoding" value in the XML font metrics file, but the PFMReader application writes "UnknownEncoding" to the generated XML file. In order to embed "Symbol" and "ZapfDingbats" you have to manually change the XML font metrics file and specify "SymbolEncoding" or "ZapfdingbatsEncoding" encoding respectively as the value for the "encoding" element.

Example:

<?xml version="1.0" encoding="UTF-8"?>
<font-metrics type="TYPE1">
  <font-name>Symbol</font-name>
  <embed/>
  <encoding>SymbolEncoding</encoding>
  <cap-height>673</cap-height>
  <x-height>766</x-height>
  [..]