Embedded LinuxLibertine OpenType fonts come out totally messed up about pdf-writer HOT 5 CLOSED

Bummer. otf supposed to be rather straightforward passthrough.
Try convertig the font to propper true type (ttf), and see if it solves the problem.

If you want to have an attempt at debugging, I can provide pointers.

Gal.

from pdf-writer.

This is problem at end user side.

So I would like any help I could get to try to debug this issue.

from pdf-writer.

Cool.
The relevant element that writes the glyph data for open types is CharStringType2Flattener::WriteFlattenedGlyphProgram
This method iterates the original glyph drawing commands, for the case of Open Type CFFs and writes them to the source. It pretty much passes through the elements, as PDF uses the same CFF data internally. The only thing it does is to flatten the font program, which is the same thing that everybody does.
What we expect is that there is a bug in one of the passthroughs. probably som mixup with the operators order.

The easiest way to figure out what's wrong is to create a PDF from an application that does it correctly with only one letter. Then do it with hummus.
Then compare the glyph data, and see where the instructions differ. then debug CharStringType2Flattener::WriteFlattenedGlyphProgram and see at what point it started to deviate and try to figure out why.

You'll have to get the font definition from both PDFs. after that you can use ttx or hummus CharStringType2Tracer to get a human readable form of the glyph instructions.

To extract the fotn definition you can use hummus parsing tools. just locate the embedded font program. it will be pointed to by the font descriptor FontFile3 key.

Another option is to just go through CharStringType2Flattener::WriteFlattenedGlyphProgram and try to figure out if it does something out of the ordinary, but without reference that works it may be difficult. but this path also require less preparation. so you can start with this...see if you can figure this out already from there, and possibly get lucky.

Gal.

from pdf-writer.

@stribor good news.
Got some time, and found and corrected the issue. you can see the commit here (the latest):
f178001

Gal.

from pdf-writer.

Perfect, thank you. I started finding some time to look into it :)

from pdf-writer.