.. -*- rst-mode -*- Greek text with the LGR font encoding *************************************** :Copyright: © 2010 Günter Milde :Licence: This work may be distributed and/or modified under the conditions of the `LaTeX Project Public License`_, either version 1.3 of this license or any later version. :Abstract: The LGR font encoding is the de-facto standard for Greek typesetting with (8-bit) LaTeX. However, the encoding definition file that ships with babel_ misses many of the definitions common since the advent of the NFSS [fntguide]_. The `lgrx` bundle provides packages and definitions for typesetting Greek text with fonts in the LGR encoding. It works for both, monotonic and polytonic Greek, independent of the `babel` package. The bundle is available from CTAN__ and included in TeXLive 2012. Development takes place at the Sourceforge__. __ http://www.ctan.org/tex-archive/macros/latex/contrib/lgrx __ http://milde.users.sourceforge.net/LGR/ .. Note:: The TeXLive 2012 pre-release contains the Unicode definition file ``lgrenc.dfu`` in the documentation instead of the TEXPATH. To enable `Greek Unicode support`_, update via `tlmgr` or place a copy in the TEXPATH «by hand». See http://tug.org/pipermail/tex-live/2012-June/031757.html .. contents:: Manifest ======== The lgrx bundle consists of the following LaTeX files: LaTeX files: :lgrxenc.def: comprehensive LGR encoding definition file :lgrenc.dfu: support for Unicode input :textalpha.sty: ``\text...`` macros for Greek letters in non-Greek text :alphabeta.sty: Greek letters with ``\alpha``, ``\beta``, ... in text and math Literal sources: ``_, ``_, ``_, ``_ Documentation and test documents: .. class:: run-in :``_: user documentation, source ``__ :``_: `Greek script in PDF metadata`, source ``__ :``_: `Greek Unicode with lgrenc.dfu`, source ``__ :``_: source ``__ :``_: source ``__ :``_: source ``__ Motivation ========== Greek font encodings -------------------- Unicode ~~~~~~~ The Unicode standard allows fonts that comprise glyphs from (almost) all known scripts. With the TeX engines XeTeX or LuaTeX, typesetting Greek with LaTeX is as easy as finding a font that contains Greek letters and setting it up with fontspec_. Beware, that you must not use the ``greek`` or ``polutonikogreek`` options of the babel_ package. The `babel` replacement polyglossia_ provides Greek language support for XeLaTeX/LuaLaTeX. If you go this way, you don't need the lgrx bundle. \*T7 ~~~~ The [encguide]_ reserves the name T7 for a Greek `standard font encoding`. However, up to now, there is no agreement on an implementation because the restrictions for general text encodings are too severe for typesetting polytonic Greek. LGR ~~~ The LGR font encoding is the de-facto standard for typesetting Greek with (8-bit) LaTeX. Fonts in this encoding include the `CB fonts`_ (matching CM), grtimes_ (Greek Times), Kerkis_ (matching URW Bookman), and the `GFS font collection`_. Setup of these fonts as Greek variant to matching Latin fonts is facilitated by the substitutefont_ package. The LGR font encoding generates Greek characters via an ASCII transliteration. This enables simple input with a Latin keyboard. Characters with diacritics are selected by ligature definitions in the font (see [greek-usage]_, [teubner-doc]_, [cbfonts]_). \*OT7 ~~~~~ The name LGR does not reflect status of this font encoding due to historical reasons. [encguide]_ classifies encodings starting with `L` as "local". Indeed, LGR started as a local encoding for the `CB fonts`_ by Claudio Beccari. Later, Apostolos Syropoulos advanced it to the default font encoding for the `babel` package's ``greek`` option. A better name would be OT7: * It is an 'old' encoding. * It implements a Latin transcription for a non-Latin script like the OT2 encoding. * It is not confined to 128 bit but OT4 shows that this is no absolute requirement for an `OT` encoding. However, due to the fact that the LGR font encoding has been used under its current name for a long time, the name will not change for compatibility reasons. Problems with the default setup ------------------------------- The `lgrx` budle adresses a set of problems with the LGR font encoding as set up by `babel`: 1. Ligatures with prefix notation prevent kerning (see the example document lgrxenc-test.pdf_ and [teubner-doc]_). 2. Sub-optimal results with the standard accent macros: * no combined accents, * accents above (instead of before) capital letters, * pre-composed characters are not used. 3. The tilde character ``~`` is used for a non-breaking space by default. Therefore the transliteration for the *perispomeni* accent is not available without re-definition of this character. [#tildehack]_ 4. The ``polutonikogreek`` `babel` option redefines both, ``~`` and ``\~`` to produce accents via input ligatures (restricted to the language setting instead of the font encoding). This prevents the placing of a tilde-accent on non-supported characters like in *niño* if the language is set to polytonic Greek, even if ``\textlatin`` is used. [#poluhack]_ 5. There is no Unicode support with `inputenc`_'s ``utf8`` option. The `ucs` package contributed by Dominique Unruh provides Unicode support with the ``utf8x`` option. A babel patch by Werner Lemberg for Greek Unicode support [lemberg2008]_ never got applied.) 6. The LGR transliteration does not work for PDF metadata. .. [#tildehack] Problem 3 can be solved by the simple one-liner :: \DeclareTextSymbol{\~}{LGR}{126} which results in ``\~`` inserting a plain tilde character if the font encoding is LGR. Drawback: you cannot place a ~-accent on Greek characters except the ones supported by an input ligature. .. [#poluhack] Fortunately, LaTeX saves copies of the accent macros: ``\~`` is an alias of ``\a~`` (which is an alias of ``\@tabacckludge~``), so it can be restored after loading `babel` with:: \addto\extraspolutonikogreek{\renewcommand*{\~}{\a~}} \addto\extrasgreek{\renewcommand*{\~}{\a~}} With this addition, both the comprehensive font encoding definitions and the workaround [#tildehack]_ also work with the ``polutonikogreek`` `babel` option. Components of the `lgrx` bundle =============================== The `lgrx` bundle comprises tools that help typesetting Greek script with (8-bit) LaTeX in Greek as well as multi-lingual documents. Comprehensive font encoding definition file ------------------------------------------- ``lgrxenc.def`` is an alternative to the rudimentary LGR encoding definition file [#fdf]_ ``lgrenc.def`` which comes with babel_'s Greek support. It defines macros for Greek characters the LGR font encoding that select pre-composed glyphs if possible and places the diacritics according to Greek typesetting rules else. Combined accents can be specified as backslash + transliteration (``\~>a``) or iteratively (``\~\>{a}``). For usage and documentation see the literal source lgrxenc.def.html_, the user manual lgrx.pdf_, and the test document lgrxenc-test.pdf_. .. [#fdf] See [fntguide_, section 5] for a definition of `encoding definition files`. Greek Unicode support --------------------- ``lgrenc.dfu`` provides standards-compatible UTF-8 support for Greek based on the comprehensive font encoding definitions. It is compatible with hyperref_ enabling Greek characters in PDF metadata without the need for ``\texorpdfstring``. See the literal source lgrenc.dfu.html_ and the test document greek-unicode.pdf_. Macros for Greek in text ------------------------ ``textalpha.sty`` defines ``\textalpha``, ``\textbeta`` ... macros for Greek letters in text that work in any font encoding and alias macros for compatibility with existing packages. With this package, Unicode input of Greek letters works in any font encoding, too. .. _limitations: However, in any font encoding except LGR: * there is no kerning between Greek characters, * composition of diacritics (like ``\Dasia\Tonos``) fails, * accent macros do not select precomposed characters (pre-composed Unicode literals work fine). See the literal source textalpha.sty.html_ and textalpha-test.pdf_ for details on usage, limitations, and recommended workarounds. Generic macros for Greek letters -------------------------------- ``alphabeta.sty`` allows you to use ``\alpha``, ``\beta``, ... in both, text and math. For this, the math macros are redefined with the help of ``\TextOrMath`` from the standard package fixltx2e_. See the literal source alphabeta.sty.html_ and the test document alphabeta-test.pdf_. References ========== .. [fntguide] LaTeX3 Project Team, `LaTeX 2ε font selection`, 2005. http://mirror.ctan.org/macros/latex/doc/fntguide.pdf .. [encguide] Frank Mittelbach, Robin Fairbairns, Werner Lemberg, LaTeX3 Project Team, `LaTeX font encodings`, 2006. http://mirror.ctan.org/macros/latex/doc/encguide.pdf .. [greek-usage] Apostolos Syropoulos, `Writing Greek with the greek option of the babel package`, 1997. http://www.tug.org/texlive/Contents/live/texmf-dist/doc/generic/babel/greek-usage.pdf .. [cbfonts] Claudio Beccari, `The CB Greek fonts`, Εὔτυπον, τεῦχος № 21, 2008. http://www.eutypon.gr/eutypon/pdf/e2008-21/e21-a01.pdf .. [teubner-doc] Claudio Beccari, ``teubner.sty`` `An extension to the greek option of the babel package`, 2011. http://mirror.ctan.org/macros/latex/contrib/teubner/teubner-doc.pdf .. [lemberg2008] Werner Lemberg, `Unicode support for the Greek LGR encoding`, Εὔτυπον, τεῦχος № 20, 2008. http://www.eutypon.gr/eutypon/pdf/e2008-20/e20-a03.pdf .. _LaTeX Project Public License: http://www.latex-project.org/lppl.txt .. _CB Fonts: http://mirror.ctan.org/help/Catalogue/entries/cbgreek-complete.html .. _grtimes: http://mirror.ctan.org/help/Catalogue/entries/grtimes.html .. _GFS font collection: http://mirror.ctan.org/help/Catalogue/entries/gfs.html .. _Kerkis: http://mirror.ctan.org/help/Catalogue/entries/kerkis.html .. _substitutefont: http://mirror.ctan.org/help/Catalogue/entries/substitutefont.html .. _babel: http://mirror.ctan.org/help/Catalogue/entries/babel.html .. _fontenc: http://mirror.ctan.org/help/Catalogue/entries/fontenc.html .. _inputenc: http://mirror.ctan.org/help/Catalogue/entries/inputenc.html .. _fontspec: http://mirror.ctan.org/help/Catalogue/entries/fontspec.html .. _polyglossia: http://mirror.ctan.org/help/Catalogue/entries/polyglossia.html .. _textgreek: http://mirror.ctan.org/help/Catalogue/entries/textgreek.html .. _fixltx2e: http://mirror.ctan.org/help/Catalogue/entries/fixltx2e.html .. _hyperref: http://mirror.ctan.org/help/Catalogue/entries/hyperref.html .. _bookmark: http://mirror.ctan.org/help/Catalogue/entries/bookmark.html