Re: [matplotlib-devel] New font manager.

>>>>> "Paul" == Paul Barrett <ba...@st...> writes:

First of all, amazing work.  It's very impressive that you made so
many changes from the frontend to the backend to the config file and
everything still works!

    Paul> I've committed a new font manager to CVS.  It is based on
    Paul> the W3C Cascading Style Sheet, Level 1 (CSS1) design.  It is
    Paul> still rather basic, but does seem to work for most of the
    Paul> backends.  Therefore, FontTools, ttfquery, and
    Paul> ttf_font_manager are no longer needed by matplotlib.

Excellent to hear - that was a maintenance nightmare.  I'll put in an
admin request to finally get those dir trees purged from CVS.

BTW, I added the agg2 tree to CVS so you should be able to build
matplotlib cleanly with a CVS checkout.  No need to copy files and
dirs anymore.  I also remove gtkgd, which was never more than a
proof-of-concept backend.

    Paul> The font manager currently handle only TrueType fonts, but
    Paul> should be generalizable to other font types.

    Paul> The text object now has a fontproperties attribute which
    Paul> describes the basic aspects of the font, such as family,
    Paul> style, weight and size.  This attribute replaces the
    Paul> fontname, fontangle, fontweight, and fontsize attributes.

    Paul> In future, I would suggest using font name sizes, such as
    Paul> small, medium, and large, to specify font sizes, instead of
    Paul> point sizes.  This should make it easier for font sizes to
    Paul> be consistent across backends.  It will also make it easier
    Paul> to change all the fonts just by changing the default font
    Paul> size that is associated with the medium font name.  The
    Paul> default value for this is 12.

    Paul> The other interface issue to be aware of is the font family.
    Paul> This is a list of font names in order of decreasing
    Paul> priority.  This should make it easier to match similar fonts
    Paul> across the various platforms.

I printed out the code so I'll take it home and give it a close
reading tonight.  Here are a few things I noticed while poking around

 * we should cite the ttfquery license since some of font_manager code
   appears to be borrowed from it.  I added license/LICENSE_TTFQUERY
   to CVS so you can just refer to that file in the font_manager
   header

 * the default file .matplotlibrc in the matplotlib root dir needs to
   be updated with the properties you added to rcParams.  With
   comments and commented examples would be most useful.  I noticed
   that in the rc params in matplotlib.__init__.py you specify default
   sizes in points rather than relative sizes - what's the logic here?

 * Could you write some tutorial and/or user documentation?  The two
   most important files are htdocs/fonts.html.template and
   htdocs/backends.html.template.  Also, a blurb for "what's new" for
   the next release would be great.  It might also be nice to have
   something along the lines of a FAQ "Hey my fonts have changed, how
   can I get the old ones back?" in htdocs/faqs.html.template

 * It does not appear you are cacheing the results anywhere.  On my
   modern linux system with not so many fonts, I don't notice any
   performance hit.  I wonder if this might be a problem for a win32
   user with lots of ttf files and a not so speedy computer.

 * I have some concern about the finder algorithm, at least in
   combination with setting a default font in matplotlibrc.  Eg, if I
   untar the following dir on my linux system (which contains a lot of
   ttf fonts) http://nitace.bsd.uchicago.edu:8080/files/share/ttf.tar
   and then point to them with my TTFPATH, and set 
   text.fontname : Vera in matplotlibrc, I don't get Vera.  
   This may be answered by the FAQ above :-)

Many thanks!
John Hunter