[cl-typesetting-devel] Re: [cl-pdf-devel] Character encoding?

[Marc Battyani]

Dmitriy Ivanov wrote:
> Peter Seibel wrote on Mon, 25 Feb 2008 21:48:25 -0800 08:48:
>
> | Actually I now I'm thinking it *is* a cl-pdf issue. Assume for the
> | moment that I'm using a Unicode lisp. (I.e. one whose CHAR-CODE returns
> | Unicode code points.) I should be able to use cl-pdf directly and have
> | it render  properly. That PDF under the covers encodes characters using
> | octets that are really indices into an array that's part of the font
> | should not be an issue I have to deal with.
>
> Relying on an encoding only does not suffice. An additional notion of
> _charset_ is for this
Right but I still think that glyphs substitution is a cl-typesetting issue.

Sure, the simple unicode to non-unicode conversion could be just an
encoding issue but even that can be more complex. For instance you could
gather the unicode glyphs used in a document and dynamically generate a
custom non-unicode encoding that maps them to a font glyphs if you have
less than 256 glyphs and they are all in the font.

Doing more than just the simplest encoding conversions can only be done
at the cl-typesetting level. For instance if a font lacks the euro
glyph, cl-typesetting could substitute a custom cl-pdf box that draws
the euro sign. There are also the ligatures, the ellipsis (... ?) etc.

Marc