PDF special char in TJ operator, base 14 fonts

Question

Is there any way to use special characters like 'rcaron'(U+0159, ř) in TJ operator in base14 fonts (Helvetica)?

Something like [(\rcaron)] TJ ?

Is it present in the font?

I went through Helvetica.afm and it seems that this character is present in the font. Also when I use this character in an interactive textfield in PDF it seems to be present.

I tried pdfbox to generate a sample file, but it fails - it uses TJ and the character is not correct.

Thanks a lot.

Answer 1

Concerning the character set PDF viewers must support for un-embedded base14 fonts, the PDF specification ISO 32000-1 states in section 9.6.2.2:

The character sets and encodings for these fonts are listed in Annex D.

and in annex D.1:

D.2, "Latin Character Set and Encodings", describes the entire character set for the Adobe standard Latin-text fonts. This character set shall be supported by the Times, Helvetica, and Courier font families, which are among the standard 14 predefined fonts; see 9.6.2.2, "Standard Type 1 Fonts (Standard 14 Fonts)".

If you inspect the tables in D.2, you'll see that rcaron is not explicitly supported, only scaron, zcaron, and a naked caron. The latter indicates that you can construct a rcaron. Unfortunately, though, the table states that the naked caron is not available in WinAnsiEncoding which is the standard encoding assumed in PDFBox.

Thus, to draw the unembedded base14 Helvetica rcaron you essentially will have to use a Helvetica font object with a non-WinAnsiEncoding encoding, e.g. MacRomanEncoding.

Furthermore you have to adapt the encoding of the strings added to your content streams. If you e.g. used to use PDPageContentStream.drawString(String), you'll have to change that because that method uses the COSString(String) constructor which implicitly assumes other encodings ("ISO-8859-1" or "UTF-16BE") not appropriate for the task at hand.