Re: [Devel] Advice on Font Subsetting

[Werner LEMBERG]

> Unfortunately, I don't want to use the code from dvipdfmx because
> the code is 1) dependent on kpathsea,

This is a very minor issue.  It just affects file searching.

> and 2) the code relies on the existence of a corresponding tfm
> file---some metrics are read from the tfm file instead of the afm
> file.  This would make my project dependent on an installed TeX
> distribution---which is what I don't want.

Again a minor issue.

> Moreover, FreeType in my opinion is much easier to read than
> dvipdfmx.

Well, you would certainly get support from the dvipdfmx
maintainers...  You might also have a look at pdfTeX and dvips,
another two projects which do Type 1 subsetting.  pdfTeX also handles
TTF, but neither CID nor CFF.

> So I want to use basically the same logic to create a Type1
> subsetted font using FreeType.  I familiarized myself with how FT
> parses Type 1 fonts and would like some advice please. [...]

I still think that FreeType, especially the PS parser, is not the
appropriate tool for your project.  It simply ignores too much of the
data in a font.  Your parser should act as careful as possible to
avoid font problems.

> 7) Would it make sense for me to contribute the code back and try to
> get it into official FreeType distribution?  Is there any interest?

To speak frankly, no.  It doesn't fit into FreeType's scope, being a
rasterizer for various font formats.

On the other hand, it would be great to have a library which accepts
fonts in various formats and a list of glyph indices, and which
outputs a subsetted font covering exactly the glyphs in the list.
Perhaps the dvipdfmx people are interested here also?

If you think that code of FreeType is of use, just use it!


    Werner