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diff --git a/Master/texmf-dist/doc/fonts/ly1/ly1.txt b/Master/texmf-dist/doc/fonts/ly1/ly1.txt new file mode 100644 index 00000000000..a70d0c12545 --- /dev/null +++ b/Master/texmf-dist/doc/fonts/ly1/ly1.txt @@ -0,0 +1,158 @@ + + + LaTeX support for `texnansi' encoding (LY1) + =========================================== + + ly1enc.def + texnansi.sty + ly1ptm.fd + ly1phv.fd + ly1pcr.fd + ly1.txt + +The files in this directory make known a new encoding `LY1' +to LaTeX that corresponds to the `texnansi' encoding as used +by default in the Y&Y TeX system. There is also an option +to support the `ansinew' encoding that is the default encoding +in Microsoft Windows. + +The main file is ly1enc.def. This contains the declaration of +the encoding. To use `texnansi' encoded fonts within LaTeX, typically +you just need to add the line + +\usepackage[LY1]{fontenc} + +to your document preamble. + +An alternative to the above line is to use the texnansi package + +\usepackage{texnansi} + +This will call the fontenc package, as above, to set up the LY1 +encoding but then make further changes to the uppercase and lowercase +tables. +Note that LaTeX does not need these changes to correctly uppercase +text as its \MakeUppercase and \MakeLowercase commands only require +the uppercase and lower case codes of the letters a-z. + +So for most purposes it is better to use the call to fontenc rather +than use the texnansi package. Then if you pass the file to a site +using T1 (Cork) encoded fonts the line can more easily be changed to + +\usepackage[T1]{fontenc} + +The texnansi package has a package option `ansinew' which modifies +the LY1 encoding to refer to that MS Windows encoding. However you +should only do this if your TeX system can not reencode fonts to +support T1 or texnansi. The `ansinew' treatment of the left quote +` as a grave accent makes it rather unsuitable for TeX use, also it +lacks several useful glyphs. However if you need to you can go: + +\usepackage[ansinew]{texnansi} + +The other possible reason for using the texnansi package relates +to the use of the lowercase table in the hyphenation algorithm. +This is described below, but it is unfortunately of necessity +rather technical, and you may want to stop reading at that point. + +Having declared the LY1 encoding to LaTeX, LaTeX will need to know +the fonts that are available in this encoding. This distribution +includes ly1ptm.fd, ly1plv.fd and ly1pcr.fd which declare the +common Adobe Times/Helvetica/Courier `Standard PostScript' fonts. +If you install other text fonts you can make similar ly1XXX.fd files +based on this model. The LaTeX support packages for MathTime and +Lucida Bright contain suitable LY1 fd files for those fonts. +Note that these LY1 `fd' files assume that you have kept the +original font vendor's file names rather than renaming the fonts +to the Standard TeX `Karl Berry' naming scheme. The choice +of font naming scheme is however not connected to the choice of +encoding. + +For each encoding LaTeX needs to know an `error font' which is its +fall back in the case that the font substitution system can find +nothing better to do. ly1enc.def specifies that the Error Font for +LY1 is Adobe Times Roman. This font is freely available from many +sources (for instance it is included with the Free Adobe Acrobat +reader) and so it seems the best choice as the error font. +If you do not have this, you may wish to edit the lines + +\DeclareErrorFont{LY1}{ptm}{m}{n}{10} +\DeclareFontSubstitution{LY1}{ptm}{m}{n} + +at the top of ly1enc.def to refer to some other font set. +For example if you have Y&Y TeX's `Lucida' distribution +You could change the two occurrences of {ptm} to {hlh} +Which will make LaTeX fall back on Lucida Bright if all else +fails. Note that the copyright is held on ly1enc.def. +This is the only change you should make to that file. + + +A Note on Lowercase Codes and Hyphenation Tables +================================================ + +The lowercase table is used by TeX's hyphenation algorithm, +so in principle one would need to change the lowercase table +to match the encoding used. However, it should not be changed +mid paragraph as all words, whatever font encoding they are +set in, are lowercased using the table current at the *end* +of the paragraph before being checked for hyphenation. +Because of these limitations in TeX's hyphenation algorithm, +LaTeX does not support changing the lowercase table mid document, +so if the texnansi package is used then the texnansi lowercase +table will be used for all fonts (whether or not LY1 encoded) +and conversely if it is not used, the T1 table will be used, even +for LY1 encoded fonts. The reason why this problem is not more +serious is that the majority of letters (as opposed to ligatures, +and symbols) that occur in LY1 occur in the same place in T1. + +The only letters that might possibly appear in a hyphenation table +that are in different positions in T1 and LY1 are: + +\oe (low position OT1 high new) +\ss (low position OT1 high new) +\v{s} +\v{z} +\l +\i OT1 (although *composites* such as \'\i are in T1 position + so this will only affect languages (Turkish?) that use + an unaccented \i) +\"{y} + + +It should be noted that for those symbols that occur twice in LY1, +the `high' copy is used if it coincides with the position used +in T1 (as in the case of \ae, \o) otherwise the `low' copy will +be used which will coincide with the OT1 position (\oe, \ss). +(Unless the setup for ansinew is enabled in which case the high +position is always used.) + + +Fortunately most hyphenation files for Western European languages +(I checked French, German and Danish) duplicate all the hyphenation +patterns using these letters so that the tables work with both T1 and +OT1 (and hence LY1) encoded fonts. However if you are using a language +that makes use of say, \ss, but the hyphenation patterns just refer to +\ss as ^^ff then you will need to copy the hyphenation file and edit +all occurences of ^^ff to refer to the new position; either +^^19 (for texnansi) or ^^df (for ansinew). + +The remaining letters that are in different positions, such as s caron, +may be dealt with similarly, although they are mainly used in Eastern +European languages. The LY1 encoding does not have as many glyphs +for Eastern European languages as T1, so for those languages most likely +this encoding is not suitable. (Of course TeX can produce all the +accented letters required, but the hyphenation algorithm can not work +with such constructed composites it can only work with composite letters +that actually occur in the font.) + +It would be a good thing if hyphenation tables did not refer to any +explicit character positions using the ^^ab notation, but rather always +accessed characters by control sequences such as \ss. This would allow +the remapping to be done via inputting a file such as ly1enc.def +rather than by editing the hyphenation file. However currently most of +the publicly available hyphenation tables unfortunately do `hard wire' +the T1 character codes in this way. + + +Copyright 1997 David Carlisle + |