summaryrefslogtreecommitdiff
path: root/Master/texmf-dist/doc/fonts/ly1/ly1.txt
diff options
context:
space:
mode:
Diffstat (limited to 'Master/texmf-dist/doc/fonts/ly1/ly1.txt')
-rw-r--r--Master/texmf-dist/doc/fonts/ly1/ly1.txt158
1 files changed, 158 insertions, 0 deletions
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
+