NAME

make_volt - Create VOLT code from a TrueType Font

SYNOPSIS

  make_volt [-a file] [-l ligtype] [-i file] [-n] infile outfile
  make_volt -t [-a file] [-l ligtype] [-i file] [-n] infile

Creates a copy of the infile font file adding a VOLT table to it.

OPTIONS

  -a file       Attachment Point database .xml file
  -b            Set un-typed glyphs to type "BASE"
  -c classfile  xml file of class and property information to merge in
  --classprops  specifies whether classes are made for property values in
                the classfile
  --classwarn   issue warnings if classfile contains references to glyphs
                that are not in the font.
  -e file       A file containing names (1 per line) of glyphs that are 
                known to have no outline (thus shouldn't generate warning). 
  -f level      Force value for adding OpenType lookups:
                    0 create lookups only if not already present [default]
                    1 re-create lookups even if same named exist
                    2 don't build any lookups
  -h            print manpage
  -i fontfile   Merge VOLT table from this font or text file
  -l type       How ligatures are built: type =
                    first - class name is first code, contents other codes
                    last  - class name is last code, contents other codes
                    firstcomp - treat extensions as part of elements, as first
                    lastcomp - treat extensons as part of elements, as last
  -m "list"     List of anchors that do not imply a MARK glyph (e.g. "_R")
  -n            Add a normalization ligature lookups
  -o "list"     List of AP names to omit
  -t            output volt code to stdout and don't generate a font file
  -z bitfield   Bitfield of various controls:
                    0 - n/a
                    1 - normalise even if presentation is only references
                    2 - n/a

DESCRIPTION

make_volt aims to make the creation of OpenType fonts much easier. It allows for a font designer to make changes and to feed that changed font forward to merge previously created VOLT code without losing that work. It also creates glyph names, key classes and lookups that can save a lot of work in VOLT.

In addition, make_volt has the capability to merge the volt code it creates with existing volt code either in a font or in a text file.

Glyph naming

Glyphs are named based on the postscript name of the glyph with variants and illegal characters stripped from the name. Name clashes are simply numbered.

Classes

make_volt creates a number of different kind of class. For each attachment point base name (x) a class is created. Class cxDia contains a list of all the glyphs with the attachment point _x. Class cTakesxDia contains all the glyphs with attachment point x. Class cnxDia contains all the glyphs without attachment point _X. And the class cnTakesxDia contains all the glyphs without the x attachment point.

In addition for each glyph name variant (as labelled in a postscript name for a glyh using .var) a class named cvar is created with all the glyphs with that variant in their name. A class named c_novar is also created containing all the corresponding glyphs without the variant, in direct correspondance, so that the non-variant form may be mapped to the variant form using a single rule, for all the glyphs in the class.

Finally a class is created for ligature components. If a glyph is part of a ligature rule it is either the key glyph for the rule or part of the class for the rule. Thus for a rule keyed of a glyph named x there will be two classese: cl_x which is the ligatures involving x and clno_x which contains all the components that correspond to the ligatures found in the other class. This makes a ligature rule a simple 1:1 mapping from clno_x to cl_x.

Ligatures

make_volt has the ability to create ligature mapping lookups. These are controlled by glyph names and follow the approach taken in make_gdl.

SEE ALSO

ttfbuilder, make_gdl

AUTHOR

Martin Hosken http://scripts.sil.org/FontUtils. (see CONTRIBUTORS for other authors).

LICENSING

Copyright (c) 1998-2016, SIL International (http://www.sil.org)

This script is released under the terms of the Artistic License 2.0. For details, see the full text of the license in the file LICENSE.