Font previewer requirements

[Nicolas Mailhot]

Hi,

As several people asked recently both privately and publicly to add font
previews to different static medias (release notes, wiki pages,
packagekit info), and proposed various solutions that didn't cut it,
here are my requirements for a font preview generator. If such a utility
was available adding font previews to all the places people asked of
would probably not be too difficult.

Note that those requirements are different from the ones you want in a
dynamic context (such as a font preview application or a dynamic web
site)

A good static previewer:

1. would take a list of ttf/otf/ttc/pfa/pfc/pcf files as argument

2. would generate one small (size) standalone file from them

3. without needing any further input (even if an option to force a
specific preview text wouldn't hurt)

3. would give a good idea of the unicode coverage of the font files,
probably using pangrams for the most interesting unicode/script blocks
included in them. Wikipedia has a pangram list:

http://en.wikipedia.org/wiki/List_of_pangrams

and fontconfig in fedora-devel has a command to detect the script
coverage of a font:

$ fc-query --format ':lang=
%{lang}\n' /usr/share/fonts/gfs-theokritos/GFSTheokritos.otf 
:lang=eu|fj|gv|ho|ia|id|ie|io|nds|nr|om|so|ss|st|sw|ts|vo|xh|zu

so it's just a matter of hooking one with the other (of course finding
the right heuristic is going to be tricky, and pangrams do not work for
CJK, and listing the full glyph list of a font is out of the question)

4. would generate vector shapes (probably svgz) so the preview does not
degrade on high pixel density displays.

5. would work with complex scripts such as indic, which requires using a
shaper such as pango

6. would not embed the font files themselves, or be a conversion of the
fonts to some other format, as this would result in hairy licensing
problems

7. would be reasonably fast and not have insanely big or exotic sofwtare
dependencies

If someone is interested in working on this it can probably be a fun
little project. If successful it would be used all over the place by all
the entities interested in free/open fonts (font authors, distributions,
oflb, etc)

Best regards,

-- 
Nicolas Mailhot