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VPE accesses, analyzes and evaluates directly the binary data of True-Type / OpenType fonts (in the following called TT fonts), including an internal cache for high performance rendering.

VPE can embed TT fonts into PDF documents. The Enterprise Edition of the PDF Module can also embed subsetted TT fonts, which means that VPE generates and embeds on-the-fly a newly generated TT font, which only contains the used characters. This reduces the size of the embedded fonts and therefore the overall size of generated PDF documents.

Using TT fonts on Windows and Mac OS X platforms is very transparent and easy (for you as a user). Both platforms have a built-in font manager, which is used by VPE. For example, if you instruct VPE to use the Arial font for a portion of text, VPE will call the font managers of either Windows or Max OS X and ask them to provide the font. The font managers themselves care for the list of available fonts on the current machine and which font file at what location needs to be selected and loaded into memory.

On all other platforms (Linux, Unix, Solaris, etc.) VPE uses its own font manager for handling TT fonts. When deploying VPE on a certain machine, you must inform VPE's font manager where to find TT fonts. This is done by setting the environment variable VPE_FONTPATH. It may contain a list of paths separated by semicolons where VPE shall scan for available TT font files (with the suffix .ttf, e.g. arial.ttf).

On each startup, i.e. when VPE is loaded into your application, it will search for a file named „font.catalog“. VPE's font manager stores information about available TT fonts in this file. If the file is not present, VPE will create it by scanning for TT font files in the search path(s) specified by VPE_FONTPATH. If VPE_FONTPATH is not set, VPE will not perform such a scan and therefore no font.catalog file will be generated.

The resulting font.catalog file will be written to the directory location specified by a second environment variable: VPE_CATALOGPATH. If this variable is not set, VPE will use the first directory specified in VPE_FONTPATH as output directory. Make sure that in either case the output directory has write-permissions, so the catalog file can be written.

If you add TT font files later to the system, or if you move files to different locations, you must delete the font.catalog file in order to let VPE rebuild it with the most current information.

 

Advantages of True-Type / OpenType fonts:

•Much greater selection of available fonts than the base 14 fonts

•PDF/A compliant font embedding supported (yet not implemented by VPE)

•Windows version only: no font substitution takes place to substitute post script fonts with TT fonts for the preview and printing

 

Disadvantages of True-Type / OpenType fonts

•You can not assume that receivers of your PDF documents have the TT fonts used in the document installed on their systems, so you need to embed all TT fonts into the generated PDF documents, which makes the PDF documents larger in size. In addition embedding / subsetting requires slightly more CPU time.

•On Linux / Unix / Solaris the font management must be initialized by yourself, by setting the environment variables VPE_FONTPATH and VPE_CATALOGPATH properly. It might also be neccessary to ship and install required TT fonts with your application (take care of the licensing!).