PDFlib Text Extraction Toolkit (TET) Manual

U+0020) for unmappable glyphs with the unknownchar option of TET_open_
document( ).
However, if the keeppua option of TET_open_document( ) is true, unknown characters
will be mapped to increasing values in the Private Use Area (PUA), starting at
U+F200. The same glyph name used in different fonts will end up with the same PUA
value, while TrueType or OpenType glyph ids from different fonts will have different
PUA values assigned.
> If the font or PDF provides Unicode values, these may be contained in the Private Use
Area (PUA). Since PUA characters are generally not very useful, TET will replace them
with unknownchar (by default: U+FFFD). However, if the keeppua option of TET_open_
document( ) is true, PUA values will be returned without any modification. This may
be useful if you can deal with PUA values, e.g. for a specific font, or for all fonts from
a specific font vendor.
Since not all glyphs in a document may have proper Unicode values (e.g. custom symbols),
TET may have to map some glyphs to unknownchar. Your code should be prepared
for this character. If you don’t care about Unicode mapping problems you can simply ignore
it, or use the unknownchar option of TET_open_document( ) to set a different character
as a replacement for unmappable glyphs (e.g. the space character).
In order to check for unmappable glyphs you can use the unknown field returned by
TET_get_char_info( ).
70 Chapter 6: Text Extraction