> > My own focus is on PDF files. The PDF spec says that fonts declared as > OpenType should be OpenType, and the files I'm looking at violate the > spec. (PDF also supports standalone CFF fonts, so it's relatively > little extra work for me to pull the CFF blob out of these bogus > "OpenType" fonts, and handle it as a CFF font.)
Oh yes, you're right there. However, this is a very general problem. Even though OpenType is a Microsoft trademark, Microsoft had done a very poor job in explaining/defining what is and what ISN'T an "OpenType font". Windows had been announcing OpenType fonts with a glyf table but without a DSIG table as "TrueType" for many years, even though TrueType is an Apple trademark. So many end-users for a long time associated CFF-based OpenType with "OpenType". And PDF has its own notion of font format "branding", and then there's a question of how certain apps like Acrobat present these. I lost count of the different variants of fonts that "can exist" in a PDF a log time ago. I guess a Type42 with a variable CFF2 table is also theoretically possible :) Or with just CBDT, without glyf and CFFx. One thing for sure: on "desktop", certain fonts work out they don't, but they need to be kind of "complete". But PDF has this flurry of "partial font resources" which makes it extra-complex. A. >
