Rodolphe VAGNER wrote:
Do you mean that it's a problem from Acrobat which can't reconize the
glyphs,
or a FOP problem to convert letters to glyphs that acrobat will reconize ?
Well, neither. Or both depending on your mindset.
Fonts map characters to glyphs. Usually, a certain font
(implementation) maps only a very small subset of the
unicode characters. For example, the generally available
Helvetica fonts usually map only the printable characters
defined also by ISO-Latin-1 (iso-8859-1). If you have
such a Helvetica font, and the text is actually greek
(codepoints somewhere in the range U+0300 to U+03FF),
there are no glyphs to show.
The second problem is that PDF doesn't use Unicode.
Characters are simply indizes into the char-to-glyph
mapping table provided by the font. FOP converts the
Unicode characters from the FO source into such indizes.
Some fonts have a mapping table which is utilized by
FOP, sometimes with manual adjustments. In some other
circumstances FOP apparently resorts to simple calculations.
The PDF renderer happily displays whatever glyph it finds
for the index computed by FOP in the current font, or a "#"
if the position is undefined.
The situation is further complicated by the fact that a lot
of Unicode characters have the same or very similar glyphs,
for example uppercase latin A and uppercase greek alpha are
often indistinguishable. This raises expectations which can't
always be met, if there is no mapping, FOP won't map the
source character to the glyph's index even if you see the
appropriate glyph in the font.


More over I found this in the docs of FOP, and it seams to mean that
the Symbols (so almost one out of the two omegas) should be displayed
properly : " FOP (building PDF files) normally supports only the base 14 font package
defined in the Adobe PDF specification. That includes the following fonts:
Helvetica, Times, Courier, Symbol and ZapfDingbats. "

I don't know what mappings are predefined. It may even depend both on the environment where your FOP binary has been built and the environment where your generated PDF is viewed. Experimentation sometimes helps a bit.

Actually, the Ohm symbol is shown correctly, if you select the
proper font (Symbol).
Does this help?

J.Pietschmann



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