Open seehuhn opened 1 week ago
Thinking this through some more: I believe that CFF fonts which use CIDFont operators do not include glyph names, so these cannot possibly work for simple fonts. If this is true, my suggestion would be to just add the following sentence to the existing text in the FontFile3/Type1C
row of the table:
Only CFF font programs without CIDFont operators can be used here.
Maybe this is also what "Type 1-equivalent" is attempting to mean?
Table 124 (Embedded font organisation for various font types) in the PDF-2.0 spec lists the cases when an OpenType font which uses CFF data can be embedded as a font program for a PDF font. The cases listed (in the
FontFile3/OpenType
row) areand
This list includes only three out of the four possible combinations of simple/composite and presence/absence of CIDFont operators. It does not allow fonts with a "CFF " table where a Top DICT that uses CIDFont operators is present in
Type1
font dictionaries.In contrast, the rules for directly embedding the CFF font data without the OpenType wrapper have no such restrictions: The
FontFile3/Type1C
row simply states that the following font type can be embedded:Technical note #5176 includes CID-keyed fonts, so CFF fonts with a Top DICT that uses CIDFont operators seem to be allowed here. (This is, unless additional restrictions hide in the term "type 1-equivalent"; I could not find a definition of this term.)
This seems to be an odd contradiction.
If CFF fonts with a Top DICT that uses CIDFont operators are in fact allowed for
Type1
font dictionaries, my suggestion would be to add a note in the OpenType section, to explain that the restriction there can be worked around by directly embedding the contents of the "CFF " table as described in rowFontFile3/Type1C
.On the other hand, if such fonts are not allowed in a
Type1
font dict, this should be stated in theFontFile3/Type1C
row of the table.