Step 3: Create metrics files

Font collections

For every non-standard font you use, a file with font metrics information must be generated. Apache FOP needs this information while performing the XSL-FO -> PDF conversion. You can create the metrics files with the t1Metrics and ttfMetrics targets in our build system. At the command prompt in the root of the firebird-documentation project, type (on one line!):

gradlew ttfMetrics
  --fontFile=D:\Path\To\fontfile.ttf --metricsFileName=filename.xml

to build a TTF metrics file, or

gradlew t1Metrics
  --fontFile=D:\Path\To\fontfile.pfm --metricsFileName=filename.xml

for a Type 1 metrics file.

Please note:

You must provide the full path to the font file, but only a file name for the metrics file. The metrics file will be placed in build/font-metrics. You will need to manually copy it to the appropriate language directory or directories in config.
You are free in your choice of the metrics file's base name, but it's wise to make it indicative of the font.
For the t1Metrics target, you must specify the .pfm file, not the .pfb.
The second character of t1Metrics is the digit 1 (one), not the letter el.
An additional parameter fontName exists to override the font name to use when embedding. For example the MS Mincho font will default to use MS-Mincho as the embedded name, but we override it to MSMincho.

Remember that you must repeat this step for every font you add. If the bold and/or italic variations reside in different files, you must also create a separate metrics file for each variation.

Important

Metrics files created with older version of FOP (which was part of our build tools until March 2020) are not usable with our current FOP version (2.4). If you have such files in your tree, regenerate them with the latest tool set. Notice however that performing a git update may already bring you the current metrics files.

Font collections

Some TrueType fonts are packed together in .ttc files (TrueType collections). The ttfMetrics target allows you to build metrics files for such fonts:

gradlew ttfMetrics --fontFile=D:\Path\To\collection.ttc 
  --ttcName=fontname --metricsFileName=filename.xml

There's an additional ttcName (font name) parameter. If the font name contains a space, make sure to enclose the value in double quotes. To find out which fonts are in a collection, call the ttfMetrics target without the ttcName parameter and with an additional info parameter, like this:

gradlew ttfMetrics --fontFile=D:\Path\To\collection.ttc
  --metricsFileName=filename.xml --info

This will result in a build failure, but just before that you'll find a list of all the fonts contained in the collection.