Re: [matplotlib-devel] updated version of the PS backend

[John H. <jdh...@ac...>]

>>>>> "Jochen" == Jochen Voss <vo...@se...> writes:

    Jochen> Hello, I did some clean-up of the matplotlib PostScript
    Jochen> backend.  Main changes:

    Jochen>   - The generated Postscript output is now completely DSC
    Jochen> conformant (I hope).

Great - everyone should take this for a test drive with their favorite
PS viewers before the next release.

    Jochen>   - All PostScript definitions go into a a PostScript
    Jochen> dictionary mpldict instead of the global one.  This will
    Jochen> hopefully prevent problems (name clashes) when including
    Jochen> matplotlib generated eps files into other PostScript files

    Jochen>   - I moved 1.5kb of comments about drawing ellipses from
    Jochen> the generated PostScript into a Python source code
    Jochen> comment.  I think it does not make sense to ship the
    Jochen> comment in each and every genereated picture.

Makes sense to me...

    Jochen> Hopefully I did not cause any new problems.  Comments
    Jochen> about the changes are most welcome.

One other PS quasi-bug you may want to be aware of is the way truetype
fonts are embedded.  The basic problem is that Paul couldn't find a
way to access the individual glyph information so ended up having to
embed the entire font.  For mathtext, with multiple fonts (which is
typical) this makes for large ps files.  It would be nice to just
embed only the required glyphs.  I believe this information is may be
available in face->glyph->outline - see also FT_Outline in the
freetype API abd agg22/font_freetype/agg_font_freetype.cpp which makes
use of this glyph info in decompose_ft_outline.

I haven't looked into this extensively, but I think it should be
possible.  This would help on mathtext for SVG, for which I believe we
require the individual glyph information.

JDH